Removal of iron and titanium minerals from aluminum bearing materials by chlorination and beneficiation

Claim 2

A process for the production of an essentially iron-free alumina product from aluminum mineral bearing materials containing at least iron minerals comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the chlorination stage; (b) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (c) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron materials to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (d) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (e) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; and (f) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent.

Claim 3

A process for the production of an essentially iron-free alumina product from aluminum mineral bearing materials containing at least iron minerals comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the chlorination stage; (b) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (c) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron materials by reaction with a chlorination agent at a temperature in the range of 550° C. to 1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; and said chlorination agent further comprising a member selected from the group consisting of phosgene and chlorine, and when chlorine is used, in combination with carbon, carbon monoxide, or mixtures thereof; (d) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (e) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; and (f) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent.

Claim 4

A process for the production of an essentially iron-free alumina product from aluminum mineral bearing materials containing at least iron minerals comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the chlorination stage; (b) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (c) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron materials by reaction with a chlorination agent at a temperature in the range of 550° C. to 1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; and said chlorination agent further comprising a member selected from the group consisting of phosgene and chlorine, and when chlorine is used, in combination with carbon, carbon monoxide, or mixtures thereof; (d) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (e) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; and (f) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent.

Claim 5

A process for the production of an essentially iron-free alumina product from aluminum mineral bearing materials containing at least iron minerals comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the chlorination stage; (b) subjecting the aluminum mineral bearing material to pelletization, granulation, or both, to obtain a solid form product; (c) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (d) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (e) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (f) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; and (g) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent.

Claim 6

A process for the production of an essentially iron-free alumina product from aluminum mineral bearing materials containing at least iron minerals comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the chlorination stage; (b) subjecting the aluminum mineral bearing material to pelletization, granulation, or both, to obtain a solid form product; (c) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (d) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (e) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (f) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; and (g) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent.

Claim 7

A process for the production of an essentially iron-free alumina product from aluminum mineral bearing materials containing at least iron minerals comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the chlorination stage; (b) subjecting said aluminum mineral bearing material to at least one stage of high intensity magnetic separation using a magnetic field strength of at least 11.0 kilogauss, and removing therefrom a magnetic concentrate comprising chiefly iron and titanium minerals to provide a nonmagnetic portion of the aluminum bearing material for dehydration; (c) subjecting the non-magnetic portion of said aluminum mineral bearing material to pelletization, granulation, or both, to obtain a solid form product; (d) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (e) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (f) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (g) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensating; and (h) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent.

Claim 8

A process for the production of an essentially iron-free alumina product from aluminum mineral bearing materials containing at least iron minerals comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the chlorination stage; (b) subjecting said aluminum mineral bearing material to at least one stage of high intensity magnetic separation using a magnetic field strength of at least 11.0 kilogauss, and removing therefrom a magnetic concentrate comprising chiefly iron and titanium minerals to provide a nonmagnetic portion of the aluminum bearing material for dehydration; (c) subjecting the non-magnetic portion of said aluminum mineral bearing material to pelletization, granulation, or both, to obtain a solid form product; (d) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (e) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (f) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (g) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensating; and (h) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent.

Claim 9

The process of claims 1, 2, 3, or 4 wherein the said aluminum mineral bearing material is selected from the group consisting of bauxite, bauxitic clays and clays.

Claim 10

The process of claims 1, 2, 3, or 4 in which the said gaseous effluent from the chlorinating stage is subjected to condensation and distillation to produce iron chlorides, impure aluminum chloride, and titanium tetrachloride.

Claim 11

The process of claims 1, 2, 3, or 4 wherein the chlorination agent comprises a mixture of aluminum chloride and FeCl 3 , a mixture of aluminum chloride and silicon tetrachloride, aluminum chloride and a catalyst selected from the group consisting of sodium chloride, potassium chloride, sodium aluminum chloride and potassium aluminum chloride, or a mixture of at least aluminum chloride and hydrogen chloride.

Claim 12

The process of claims 1, 2, 3, or 4 wherein the gaseous effluent from the chlorination stage is stage condensed to produce iron chlorides and impure aluminum chloride and titanium tetrachloride with the uncondensed gaseous product consisting essentially of carbon monoxide and carbon dioxide, and wherein uncondensed gaseous carbon monoxide and carbon dioxide are recycled to the said dehydration stage.

Claim 13

The process according to claims 1, 2, 3, or 4 wherein the effluent gases resulting from the chlorination stage comprise at least FeCl 3 , TiCl 4 , SiCl 4 and AlCl 3 , the ferric chloride is removed, the SiCl 4 and residual AlCl 3 are recovered and cycled to the chlorination stage.

Claim 14

The process of claims 1 or 2 wherein the aluminum mineral bearing materials are subjected to pelletization prior to dehydration, are subjected to granulation prior to dehydration, or are granulated and then pelletized prior to dehydration.

Claim 15

A process for the production of an essentially iron-free alumina product from aluminum mineral bearing materials containing at least iron minerals in which said process entails the use of at least two stages of chlorination comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first calculation stage of the said at least two stages of chlorination; (b) dehydrating the said aluminum bearing material in the temperature range of about 625° C. to about 1050° C.; (c) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (d) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (e) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; and (f) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent; (g) subjecting the residual solids from said first chlorination stage to a second chlorination stage by reaction with a chlorination agent comprising starvation amounts of chlorine or phosgene or mixtures thereof and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide and mixtures thereof, at a temperature in the range of 625° C.-1050° C.; (h) cycling at least a major portion of the gases produced by said second chlorination stage to said first chlorination stage as a chlorinating agent; and (i) recovering the residual solids from said second chlorination stage, said solids comprising essentially an iron-free alumina product.

Claim 16

A process for the production of an essentially iron-free alumina product from aluminum mineral bearing materials containing at least iron minerals in which said process entails the use of at least two stages of chlorination comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first calculation stage of the said at least two stages of chlorination; (b) dehydrating the said aluminum bearing material in the temperature range of about 625° C. to about 1050° C.; (c) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (d) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (e) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; and (f) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent; (g) subjecting the residual solids from said first chlorination stage to a second chlorination stage by reaction with a chlorination agent comprising starvation amounts of chlorine or phosgene or mixtures thereof and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide and mixtures thereof, at a temperature in the range of 625° C.-1050° C.; (h) cycling at least a major portion of the gases produced by said second chlorination stage to said first chlorination stage as a chlorinating agent; and (i) recovering the residual solids from said second chlorination stage, said solids comprising essentially an iron-free alumina product.

Claim 17

A process for the production of an essentially iron- and silicon-free aluminum chloride product from aluminum mineral bearing materials containing at least iron minerals and silicate minerals in which said process entails the use of at least two stages of chlorination comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first chlorination stage of the said at least two stages of chlorination; (b) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (c) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C. to 1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycling impure AlCl 3 from the gaseous effluent of said chlorination reaction; (d) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (e) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and chlorides of other metals, and residual aluminum chloride containing residual amounts of other products of condensation; (f) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent; (g) subjecting the solids from said first chlorination stage to a second chlorination stage by reaction with a chlorination agent to convert at least all of the contained Al 2 O 3 to AlCl 3 , said chlorination agent comprising chlorine or phosgene, and when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, and at a temperature in the range of 625° C.-1050° C.; (h) recovering the residual solids from said second chlorination stage, which said solids comprise essentially SiO 2 with minor amounts of Al 2 O 3 product; (i) removing the gaseous products of chlorination comprising major amounts of aluminum chloride and minor amounts of silicon tetrachloride; and (j) subjecting said gaseous products to at least controlled temperature condensation and/or in combination with fractional distillation to produce essentially iron- and silicon-free aluminum chloride.

Claim 18

A process for the production of an essentially iron- and silicon-free aluminum chloride product from aluminum mineral bearing materials containing at least iron minerals and silicate minerals in which said process entails the use of at least two stages of chlorination comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first chlorination stage of the said at least two stages of chlorination; (b) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (c) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C. to 1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycling impure AlCl 3 from the gaseous effluent of said chlorination reaction; (d) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (e) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and chlorides of other metals, and residual aluminum chloride containing residual amounts of other products of condensation; (f) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent; (g) subjecting the solids from said first chlorination stage to a second chlorination stage by reaction with a chlorination agent to convert at least all of the contained Al 2 O 3 to AlCl 3 , said chlorination agent comprising chlorine or phosgene, and when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, and at a temperature in the range of 625° C.-1050° C.; (h) recovering the residual solids from said second chlorination stage, which said solids comprise essentially SiO 2 with minor amounts of Al 2 O 3 product; (i) removing the gaseous products of chlorination comprising major amounts of aluminum chloride and minor amounts of silicon tetrachloride; and (j) subjecting said gaseous products to at least controlled temperature condensation and/or in combination with fractional distillation to produce essentially iron- and silicon-free aluminum chloride.

Claim 19

A process for the production of an essentially iron-free alumina product from aluminum mineral bearing materials containing at least iron minerals in which said process entails the use of at least two stages of chlorination comprising: (a) selecting an aluminum bearing material containing a maximum iron contact calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first chlorination stage of the said at least two stages of chlorination; (b) dehydrating the said aluminum bearing material in the temperature range of about 625° C. to about 1050° C.; (c) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C. to 1050° C.; and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (d) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (e) subjecting the iron-free alumina solids to a carbonizing stage in the presence of a carbon-containing material at a temperature range of 200° C. to 900° C. to remove the volatiles contained in the carbon-containing material; (f) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; (g) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent; (h) subjecting the mixture of residual solids and carbon-containing material from said carbonizing stage to a second chlorination stage by reaction with a chlorination agent comprising starvation amounts of chlorine or phosgene or mixtures thereof and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide and mixtures thereof, at a temperature in the range of 625° C.-1050° C.; (i) cycling at least a major portion of the gases produced by said second chlorination stage to said first chlorination stage as a chlorinating agent; and (j) recovering the residual solids from said second chlorination stage, said solids comprising essentially an iron-free alumina product.

Claim 20

A process for the production of an essentially iron-free alumina product from aluminum mineral bearing materials containing at least iron minerals in which said process entails the use of at least two stages of chlorination comprising: (a) selecting an aluminum bearing material containing a maximum iron contact calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first chlorination stage of the said at least two stages of chlorination; (b) dehydrating the said aluminum bearing material in the temperature range of about 625° C. to about 1050° C.; (c) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C. to 1050° C.; and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (d) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (e) subjecting the iron-free alumina solids to a carbonizing stage in the presence of a carbon-containing material at a temperature range of 200° C. to 900° C. to remove the volatiles contained in the carbon-containing material; (f) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; (g) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent; (h) subjecting the mixture of residual solids and carbon-containing material from said carbonizing stage to a second chlorination stage by reaction with a chlorination agent comprising starvation amounts of chlorine or phosgene or mixtures thereof and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide and mixtures thereof, at a temperature in the range of 625° C.-1050° C.; (i) cycling at least a major portion of the gases produced by said second chlorination stage to said first chlorination stage as a chlorinating agent; and (j) recovering the residual solids from said second chlorination stage, said solids comprising essentially an iron-free alumina product.

Claim 21

A process for the production of an essentially iron-free alumina product from aluminum mineral bearing materials containing at least iron minerals in which said process entails the use of at least two stages of chlorination comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first chlorination stage of the said at least two stages of chlorination: (b) subjecting the aluminum mineral bearing materials to pelletization, granulation, or both, prior to dehydration; (c) dehydrating the said aluminum bearing material in the temperature range of about 625° C. to about 1050° C.; (d) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C. to 1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (e) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (f) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; (g) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent; (h) subjecting the residual solids from said first chlorination stage to a second chlorination stage by reaction with a chlorination agent comprising starvation amounts of chlorine or phosgene or mixtures thereof and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide and mixtures thereof, at a temperature in the range of 625° C.-1050° C.; (i) cycling at least a major portion of the gases produced by said second chlorination stage to said first chlorination stage as a chlorinating agent; and (j) recovering the residual solids from said second chlorination stage, said solids comprising essentially an iron-free alumina product.

Claim 22

A process for the production of an essentially iron-free alumina product from aluminum mineral bearing materials containing at least iron minerals in which said process entails the use of at least two stages of chlorination comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first chlorination stage of the said at least two stages of chlorination: (b) subjecting the aluminum mineral bearing materials to pelletization, granulation, or both, prior to dehydration; (c) dehydrating the said aluminum bearing material in the temperature range of about 625° C. to about 1050° C.; (d) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C. to 1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (e) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (f) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; (g) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent; (h) subjecting the residual solids from said first chlorination stage to a second chlorination stage by reaction with a chlorination agent comprising starvation amounts of chlorine or phosgene or mixtures thereof and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide and mixtures thereof, at a temperature in the range of 625° C.-1050° C.; (i) cycling at least a major portion of the gases produced by said second chlorination stage to said first chlorination stage as a chlorinating agent; and (j) recovering the residual solids from said second chlorination stage, said solids comprising essentially an iron-free alumina product.

Claim 23

A process for the production of an essentially iron-free alumina product from aluminum mineral bearing materials containing at least iron minerals in which said process entails the use of at least two stages of chlorination comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first chlorination stage of the said at least two stages of chlorination; (b) subjecting the aluminum mineral bearing material to at least one stage of high intensity magnetic separation using a magnetic field strength of at least 11.0 kilogauss, and removing therefrom a magnetic concentrate comprising chiefly iron and titanium minerals to provide a nonmagnetic portion of the aluminum bearing material for dehydration; (c) subjecting the non-magnetic portion of said aluminum mineral bearing material to pelletization, granulation, or both, to obtain a solid form product; (d) dehydrating the said aluminum bearing material in the temperature range of about 625° C. to about 1050° C.; (e) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (f) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (g) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; (h) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent; (i) subjecting the residual solids from said first chlorination stage to a second chlorination stage by reaction with a chlorination agent comprising starvation amounts of chlorine or phosgene or mixtures thereof and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide and mixtures thereof, at a temperature in the range of 625° C.-1050° C.; (j) cycling at least a major portion of the gases produced by said second chlorination stage to said first chlorination stage as a chlorinating agent; and (k) recovering the residual solids from said second chlorination stage, said solids comprising essentially an iron-free alumina product.

Claim 24

A process for the production of an essentially iron-free alumina product from aluminum mineral bearing materials containing at least iron minerals in which said process entails the use of at least two stages of chlorination comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first chlorination stage of the said at least two stages of chlorination; (b) subjecting the aluminum mineral bearing material to at least one stage of high intensity magnetic separation using a magnetic field strength of at least 11.0 kilogauss, and removing therefrom a magnetic concentrate comprising chiefly iron and titanium minerals to provide a nonmagnetic portion of the aluminum bearing material for dehydration; (c) subjecting the non-magnetic portion of said aluminum mineral bearing material to pelletization, granulation, or both, to obtain a solid form product; (d) dehydrating the said aluminum bearing material in the temperature range of about 625° C. to about 1050° C.; (e) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (f) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (g) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; (h) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent; (i) subjecting the residual solids from said first chlorination stage to a second chlorination stage by reaction with a chlorination agent comprising starvation amounts of chlorine or phosgene or mixtures thereof and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide and mixtures thereof, at a temperature in the range of 625° C.-1050° C.; (j) cycling at least a major portion of the gases produced by said second chlorination stage to said first chlorination stage as a chlorinating agent; and (k) recovering the residual solids from said second chlorination stage, said solids comprising essentially an iron-free alumina product.

Claim 25

A process for the production of an essentially iron- and silicon-free aluminum chloride product from aluminum mineral bearing materials containing at least iron minerals and silicate materials in which said process entails the use of at least two stages of chlorination comprising: (a) subjecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first chlorination stage of the said at least two stages of chlorination; (b) subjecting the aluminum mineral bearing material to pelletization, granulation, or both, to obtain a solid form product; (c) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (d) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (e) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (f) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; (g) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent; (h) subjecting the solids from said first chlorination stage to a second chlorination stage by reaction with a chlorination agent comprising chlorine or phosgene or mixtures thereof, and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, and at a temperature in the range of 625° C.-1050° C.; using sufficient chlorination agent to convert at least all of the contained Al 2 O 3 to AlCl 3 ; (i) recovering the residual solids from the said second chlorination stage, which said solids comprise essentially SiO 2 with minor amounts of Al 2 O 3 product; (j) removing the gaseous products of chlorination comprising major amounts of aluminum chloride and minor amounts of silicon tetrachloride; and (k) subjecting said gaseous products to at least controlled temperature condensation and/or in combination with fractional distillation to produce essentially iron- and silicon-free aluminum chloride.

Claim 26

A process for the production of an essentially iron- and silicon-free aluminum chloride product from aluminum mineral bearing materials containing at least iron minerals and silicate materials in which said process entails the use of at least two stages of chlorination comprising: (a) subjecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first chlorination stage of the said at least two stages of chlorination; (b) subjecting the aluminum mineral bearing material to pelletization, granulation, or both, to obtain a solid form product; (c) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (d) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (e) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (f) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; (g) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent; (h) subjecting the solids from said first chlorination stage to a second chlorination stage by reaction with a chlorination agent comprising chlorine or phosgene or mixtures thereof, and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, and at a temperature in the range of 625° C.-1050° C.; using sufficient chlorination agent to convert at least all of the contained Al 2 O 3 to AlCl 3 ; (i) recovering the residual solids from the said second chlorination stage, which said solids comprise essentially SiO 2 with minor amounts of Al 2 O 3 product; (j) removing the gaseous products of chlorination comprising major amounts of aluminum chloride and minor amounts of silicon tetrachloride; and (k) subjecting said gaseous products to at least controlled temperature condensation and/or in combination with fractional distillation to produce essentially iron- and silicon-free aluminum chloride.

Claim 27

A process for the production of an essentially iron- and silicon-free aluminum chloride product from aluminum mineral bearing materials containing at least iron minerals and silicate minerals in which said process entails the use of at least two stages of chlorination comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first chlorination stage of the said at least two stages of chlorination; (b) subjecting said aluminum bearing material to at least one stage of high intensity magnetic separation using a magnetic field strength of at least 11.0 kilogauss, and removing therefrom a magnetic concentrate comprising chiefly iron and titanium minerals to provide a nonmagnetic portion of the aluminum bearing material for dehydration; (c) subjecting the non-magnetic portion of said aluminum mineral bearing material to pelletization, granulation, or both, to obtain a solid form product; (d) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (e) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (f) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (g) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; (h) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent; (i) subjecting the solids from said first chlorination stage to a second chlorination stage by reaction with a chlorination agent comprising chlorine or phosgene or mixtures thereof, and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, and at a temperature in the range of 625° C.-1050° C.; using sufficient chlorination agent to covert at least all of the contained Al 2 O 3 to AlCl 3 ; (j) recovering the residual solids from said second chlorination stage, which said solids comprise essentially SiO 2 with minor amounts of Al 2 O 3 product; (k) removing the gaseous products of chlorination comprising major amounts of aluminum chloride and minor amounts of silicon tetrachloride; and (l) subjecting said gaseous products to at least controlled temperature condensation and/or in combination with fractional distillation to produce essentially iron- and silicon-free aluminum chloride and silicon tetrachloride.

Claim 28

A process for the production of an essentially iron- and silicon-free aluminum chloride product from aluminum mineral bearing materials containing at least iron minerals and silicate minerals in which said process entails the use of at least two stages of chlorination comprising: (a) selecting an aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first chlorination stage of the said at least two stages of chlorination; (b) subjecting said aluminum bearing material to at least one stage of high intensity magnetic separation using a magnetic field strength of at least 11.0 kilogauss, and removing therefrom a magnetic concentrate comprising chiefly iron and titanium minerals to provide a nonmagnetic portion of the aluminum bearing material for dehydration; (c) subjecting the non-magnetic portion of said aluminum mineral bearing material to pelletization, granulation, or both, to obtain a solid form product; (d) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (e) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (f) recovering a solids product comprising an essentially iron-free alumina product, and a gaseous effluent; (g) subjecting the gaseous effluent from the said chlorination stage to condensation and/or fractional distillation to recover chlorides of iron and other metals, and residual aluminum chloride containing residual amounts of other products of condensation; (h) recycling to the chlorination stage the said residual aluminum chloride as at least a portion of the said aluminum chloride chlorinating agent; (i) subjecting the solids from said first chlorination stage to a second chlorination stage by reaction with a chlorination agent comprising chlorine or phosgene or mixtures thereof, and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, and at a temperature in the range of 625° C.-1050° C.; using sufficient chlorination agent to covert at least all of the contained Al 2 O 3 to AlCl 3 ; (j) recovering the residual solids from said second chlorination stage, which said solids comprise essentially SiO 2 with minor amounts of Al 2 O 3 product; (k) removing the gaseous products of chlorination comprising major amounts of aluminum chloride and minor amounts of silicon tetrachloride; and (l) subjecting said gaseous products to at least controlled temperature condensation and/or in combination with fractional distillation to produce essentially iron- and silicon-free aluminum chloride and silicon tetrachloride.

Claim 29

The process of claims 11, 12, 13, 14, 15, 16, or 17 wherein the said aluminum mineral bearing material is selected from the group consisting of bauxite, bauxitic clays and clays.

Claim 30

The process of claims 11, 12, 13, 14, 15, 16, or 17 in which the said gaseous effluent from the first chlorinating stage is subjected to condensation and distillation to produce iron chloride, impure aluminum chloride, and titanium tetrachloride.

Claim 31

The process of claims 11, 12, 13, 14, 15, 16, or 17 wherein the first stage chlorination agent comprises a mixture of aluminum chloride and FeCl 3 , a mixture of aluminum chloride and silicon tetrachloride, aluminum chloride and a catalyst selected from the group consisting of sodium chloride, potassium chloride, sodium aluminum chloride and potassium aluminum chloride, or a mixture of at least aluminum chloride and hydrogen chloride.

Claim 32

The process of claims 11, 12, 13, 14, 15, 16, or 17 wherein the gaseous effluent from the first chlorination stage is stage condensed to produce iron chlorides and impure aluminum chloride and titanium tetrachloride with the uncondensed gaseous product consisting essentially of carbon monoxide and carbon dioxide, and wherein uncondensed gaseous carbon monoxide and carbon dioxide are recycled to the said dehydration stage.

Claim 33

The process according to claims 11, 12, 13, 14, 15, 16, or 17 wherein the effluent gases resulting from the first chlorination stage comprise at least FeCl 3 , TiCl 4 , SiCl 4 and AlCl 3 , the ferric chloride is removed, the SiCl 4 and residual AlCl 3 are recovered and cycled to the first chlorination stage.

Claim 34

The process of claims 11, 12, or 13 wherein the aluminum mineral bearing materials are subjected to pelletization prior to dehydration, are subjected to granulation prior to dehydration, or are granulated and then pelletized prior to dehydration.

Claim 35

A process for the production of an essentially iron-, silicon- and titanium-free aluminum chloride product from aluminum mineral bearing materials containing at least iron and titanium minerals and silicate minerals in which said process entails the use of at least three stages of chlorination comprising: (a) selection of said aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first chlorination stage of the said at least three stages of chlorination; (b) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (c) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (d) subjecting the residual solids from said first chlorination stage to a second chlorination stage and contacting with starvation amounts of a chlorination agent selected from the group consisting of chlorine, phosgene or mixtures thereof, and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, at a temperature in the range of 625° C.-1050° C. to produce at least the said chlorination agent aluminum chloride; (e) recycling at least a major portion of the gases produced by said second chlorination stage to said first chlorination stage; (f) recovering the residual solids from said second chlorination stage, which said solids are essentially an iron- and titanium-free alumina product; (g) subjecting said essentially iron- and titanium-free alumina product to a third chlorination stage at a temperature in the range of 550° C.-1050° C. by contacting with a chlorination agent selected from the group consisting of chlorine, phosgene and mixtures thereof as the chlorination agent and when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, to effect said chlorination; (h) removing the solids comprising SiO 2 and minor amounts of Al 2 O 3 ; (i) removing the gaseous products of chlorination comprising major amounts of aluminum chloride and minor amounts of silicon tetrachloride; and (j) subjecting said gaseous products to at least controlled temperature condensation and/or in combination with distillation to produce essentially iron, titanium and silicon-free aluminum chloride.

Claim 36

A process for the production of an essentially iron-, silicon- and titanium-free aluminum chloride product from aluminum mineral bearing materials containing at least iron and titanium minerals and silicate minerals in which said process entails the use of at least three stages of chlorination comprising: (a) selection of said aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration as the feed to the first chlorination stage of the said at least three stages of chlorination; (b) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (c) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (d) subjecting the residual solids from said first chlorination stage to a second chlorination stage and contacting with starvation amounts of a chlorination agent selected from the group consisting of chlorine, phosgene or mixtures thereof, and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, at a temperature in the range of 625° C.-1050° C. to produce at least the said chlorination agent aluminum chloride; (e) recycling at least a major portion of the gases produced by said second chlorination stage to said first chlorination stage; (f) recovering the residual solids from said second chlorination stage, which said solids are essentially an iron- and titanium-free alumina product; (g) subjecting said essentially iron- and titanium-free alumina product to a third chlorination stage at a temperature in the range of 550° C.-1050° C. by contacting with a chlorination agent selected from the group consisting of chlorine, phosgene and mixtures thereof as the chlorination agent and when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, to effect said chlorination; (h) removing the solids comprising SiO 2 and minor amounts of Al 2 O 3 ; (i) removing the gaseous products of chlorination comprising major amounts of aluminum chloride and minor amounts of silicon tetrachloride; and (j) subjecting said gaseous products to at least controlled temperature condensation and/or in combination with distillation to produce essentially iron, titanium and silicon-free aluminum chloride.

Claim 37

A process for the production of an essentially iron-, silicon- and titanium-free aluminum chloride product from aluminum mineral bearing materials containing at least iron and titanium minerals and silicate minerals in which said process entails the use of at least three stages of chlorination comprising: (a) selection of said aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration and as the feed to the first chlorination stage of the said at least three stages of chlorination; (b) subjecting the aluminum mineral bearing material to pelletization, granulation, or both, to obtain a solid form product; (c) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (d) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (e) subjecting the residual solids from said first chlorination stage to a second chlorination stage and contacting with starvation amounts of a chlorination agent selected from the group consisting of chlorine, phosgene or mixtures thereof, and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, at a temperature in the range of 625° C.-1050° C. to produce at least the said chlorination agent aluminum chloride; (f) recycling at least a major portion of the gases produced by said second chlorination stage to said first chlorination stage; (g) recovering the residual solids from said second chlorination stage, which said solids are essentially an iron- and titanium-free alumina product; (h) subjecting said essentially iron- and titanium-free alumina product to a third chlorination stage by contact at a temperature in the range of 550° C.-1050° C. and contacting with a chlorination agent selected from the group consisting of chlorine, phosgene and mixtures thereof as the chlorination agent and when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, to effect said chlorination; (i) removing the solids comprising SiO 2 and minor amounts of Al 2 O 3 ; (j) removing the gaseous products of chlorination comprising major amounts of aluminum chloride and minor amounts of silicon tetrachloride; and (k) subjecting said gaseous products to at least controlled temperature condensation and/or in combination with distillation to produce essentially iron, titanium and silicon-free aluminum chloride.

Claim 38

A process for the production of an essentially iron-, silicon- and titanium-free aluminum chloride product from aluminum mineral bearing materials containing at least iron and titanium minerals and silicate minerals in which said process entails the use of at least three stages of chlorination comprising: (a) selection of said aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration and as the feed to the first chlorination stage of the said at least three stages of chlorination; (b) subjecting the aluminum mineral bearing material to pelletization, granulation, or both, to obtain a solid form product; (c) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (d) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (e) subjecting the residual solids from said first chlorination stage to a second chlorination stage and contacting with starvation amounts of a chlorination agent selected from the group consisting of chlorine, phosgene or mixtures thereof, and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, at a temperature in the range of 625° C.-1050° C. to produce at least the said chlorination agent aluminum chloride; (f) recycling at least a major portion of the gases produced by said second chlorination stage to said first chlorination stage; (g) recovering the residual solids from said second chlorination stage, which said solids are essentially an iron- and titanium-free alumina product; (h) subjecting said essentially iron- and titanium-free alumina product to a third chlorination stage by contact at a temperature in the range of 550° C.-1050° C. and contacting with a chlorination agent selected from the group consisting of chlorine, phosgene and mixtures thereof as the chlorination agent and when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, to effect said chlorination; (i) removing the solids comprising SiO 2 and minor amounts of Al 2 O 3 ; (j) removing the gaseous products of chlorination comprising major amounts of aluminum chloride and minor amounts of silicon tetrachloride; and (k) subjecting said gaseous products to at least controlled temperature condensation and/or in combination with distillation to produce essentially iron, titanium and silicon-free aluminum chloride.

Claim 39

A process for the production of an essentially iron-, silicon- and titanium-free aluminum chloride product from aluminum mineral bearing materials containing at least iron and titanium minerals and silicate minerals in which said process entails the use of at least three stages of chlorination comprising: (a) selection of said aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration and as the feed to the first chlorination stage of the said at least three stages of chlorination; (b) subjecting the said aluminum mineral bearing material to at least one stage of high intensity magnetic separation using a magnetic field strength of at least 11.0 kilogauss, and removing therefrom a magnetic concentrate comprising chiefly iron and titanium minerals to provide a nonmagnetic portion of the aluminum bearing material for dehydration; (c) subjecting the non-magnetic portion of said aluminum mineral bearing material to pelletization, granulation, or both, to obtain a solid form product; (d) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (e) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (f) subjecting the residual solids from said firt chlorination stage to a second chlorination stage and contacting with starvation amounts of a chlorination agent selected from the group consisting of chlorine, phosgene or mixtures thereof, and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, at a temperature in the range of 625° C.-1050° C. to produce at least the said chlorination agent aluminum chloride; (g) recycling at least a major portion of the gases produced by said second chlorination stage to said first chlorination stage; (h) recovering the residual solids from said second chlorination stage, which said solids are essentially an iron- and titanium-free alumina product; (i) subjecting said essentially iron- and titanium-free alumina product to a third chlorination stage at a temperature in the range of 550° C.-1050° C. by contacting with a chlorination agent selected from the group consisting of chlorine, phosgene and mixtures thereof as the chlorination agent and when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, to effect said chlorination; (j) removing the solids comprising SiO 2 and minor amounts of Al 2 O 3 ; (k) removing the gaseous products of chlorination comprising major amounts of aluminum chloride and minor amounts of silicon tetrachloride; and (l) subjecting said gaseous products to at least controlled temperature condensation and/or in combination with distillation to produce essentially iron, titanium and silicon-free aluminum chloride.

Claim 40

A process for the production of an essentially iron-, silicon- and titanium-free aluminum chloride product from aluminum mineral bearing materials containing at least iron and titanium minerals and silicate minerals in which said process entails the use of at least three stages of chlorination comprising: (a) selection of said aluminum bearing material containing a maximum iron content calculated as Fe 2 O 3 of 8.0% following dehydration and as the feed to the first chlorination stage of the said at least three stages of chlorination; (b) subjecting the said aluminum mineral bearing material to at least one stage of high intensity magnetic separation using a magnetic field strength of at least 11.0 kilogauss, and removing therefrom a magnetic concentrate comprising chiefly iron and titanium minerals to provide a nonmagnetic portion of the aluminum bearing material for dehydration; (c) subjecting the non-magnetic portion of said aluminum mineral bearing material to pelletization, granulation, or both, to obtain a solid form product; (d) dehydrating the said aluminum bearing material by heating in the temperature range of about 625° C. to about 1050° C.; (e) subjecting the said dehydrated material to chlorination to differentially chlorinate at least the said contained iron minerals by reaction with at least one chlorination agent at a temperature in the range of 550° C.-1050° C. and in which the chlorination agent comprises at least a 25% stoichiometric excess of aluminum chloride over the amount necessary to convert the iron minerals to their respective chlorides, said aluminum chloride including recycle impure AlCl 3 from the gaseous effluent of said chlorination reaction; (f) subjecting the residual solids from said firt chlorination stage to a second chlorination stage and contacting with starvation amounts of a chlorination agent selected from the group consisting of chlorine, phosgene or mixtures thereof, and, when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, at a temperature in the range of 625° C.-1050° C. to produce at least the said chlorination agent aluminum chloride; (g) recycling at least a major portion of the gases produced by said second chlorination stage to said first chlorination stage; (h) recovering the residual solids from said second chlorination stage, which said solids are essentially an iron- and titanium-free alumina product; (i) subjecting said essentially iron- and titanium-free alumina product to a third chlorination stage at a temperature in the range of 550° C.-1050° C. by contacting with a chlorination agent selected from the group consisting of chlorine, phosgene and mixtures thereof as the chlorination agent and when chlorine is used, in the presence of a reducing agent selected from the group consisting of carbon, carbon monoxide, and mixtures thereof, to effect said chlorination; (j) removing the solids comprising SiO 2 and minor amounts of Al 2 O 3 ; (k) removing the gaseous products of chlorination comprising major amounts of aluminum chloride and minor amounts of silicon tetrachloride; and (l) subjecting said gaseous products to at least controlled temperature condensation and/or in combination with distillation to produce essentially iron, titanium and silicon-free aluminum chloride.

Claim 41

A process according to claims 24, 25, or 26 wherein at least a portion of said silicon tetrachloride produced in the third stage chlorination is recycled to one or more of the three chlorination stages.