US3904397A — Method for reducing metal ores

Claim 1

Independent Claim 141 words

IN A METHOD FOR THE BATCHWISE GASEOUS REDUCTION OF METAL OXIDES TO METALS IN A MULTIPLE UNIT RACTOR SYSTEM OF THE TYPE IN WHICH SEPARATE BODIES OF METAL-BEARING MATERIAL ARE SIMULTANEOUSLY TREATED IN A PLURALITY OF REACTORS AND A REDUCING GAS IS PASSED SUCESSIVELY THROUGH REACTORS OF SAID SYSTEM, THE IMPROVEMENT WHICH COMPRISES FEEDING A PREFORMED HOT REDUCING GAS LARGELY COMPOSED TO CARBON MONOXIDE AND HYDROGEN AND AT A TEMPERATURE OF 900* TO 1100*C. THROUGH A BODY OF METAL OXIDE IN A REDUCTION REACTOR OF SAID SYSTEM TO REDUCE SAID METAL OXIDE AT LEAST PARTICALLY TO SPONGE METAL, COOLING THE EFFLUENT GAS FROM SAID REDUCTION REACTOR, REHEATING A PORTION OF SAID COOLED EFFLUENT GAS TO A TEMPERATURE OF 900* TO 1100*C. AND RECIRCULATING IT THROUGH SAID REDUCTION REACTOR TO FROM A REDUCTION GAS CIRCUIT, AND PASSING THE REMINDER OF SAID COOLED

Claim 2

Dependent Claim 141 words

IN A METHOD FOR THE BATCHWISE GASEOUS REDUCTION OF METAL OXIDES TO METALS IN A MULTIPLE UNIT RACTOR SYSTEM OF THE TYPE IN WHICH SEPARATE BODIES OF METAL-BEARING MATERIAL ARE SIMULTANEOUSLY TREATED IN A PLURALITY OF REACTORS AND A REDUCING GAS IS PASSED SUCESSIVELY THROUGH REACTORS OF SAID SYSTEM, THE IMPROVEMENT WHICH COMPRISES FEEDING A PREFORMED HOT REDUCING GAS LARGELY COMPOSED TO CARBON MONOXIDE AND HYDROGEN AND AT A TEMPERATURE OF 900* TO 1100*C. THROUGH A BODY OF METAL OXIDE IN A REDUCTION REACTOR OF SAID SYSTEM TO REDUCE SAID METAL OXIDE AT LEAST PARTICALLY TO SPONGE METAL, COOLING THE EFFLUENT GAS FROM SAID REDUCTION REACTOR, REHEATING A PORTION OF SAID COOLED EFFLUENT GAS TO A TEMPERATURE OF 900* TO 1100*C. AND RECIRCULATING IT THROUGH SAID REDUCTION REACTOR TO FROM A REDUCTION GAS CIRCUIT, AND PASSING THE REMINDER OF SAID COOLED

Claim 3

Dependent Claim 27 words

A method according to claim 1 wherein at least a portion of the effluent gas from said cooling reactor is cooled and recycled to said cooling reactor.

Claim 4

Dependent Claim 44 words

A method according to claim 1 wherein a portion of the effluent gas from said cooling reactor is cooled and recycled to said cooling reactor and the remainder of said cooled effluent gas is removed from said system for use as a fuel gas.

Claim 5

Dependent Claim 31 words

A method according to claim 1 wherein the volumetric ratio of gas recycled to said reduction reactor to the gas fed to said reduction gas circuit is from 1:1 to 10:1.

Claim 6

Dependent Claim 35 words

A method according to claim 2 wherein the volumetric ratio of gas recycled through said cooling reactor to effluent gas from said reduction reactor passing to said cooling reactor is from 1: 1 to 10:1.

Claim 7

Dependent Claim 57 words

A method according to claim 1 in which said system comprises three reactors, the first of which is said reduction reactor, the second of which is said cooling reactor and the third of which is disconnected from said first and second reactors for discharge of reduced ore from said third reactor and recharging thereof with fresh ore.

Claim 8

Dependent Claim 78 words

A method according to claim 1 in which said system comprises two reactors, the first of which is said reduction reactor and the second of which is said cooling reactor, and the flow of gas through said cooling reactor is interrupted while continuing the flow of reducing gas through said reduction reactor for a predetermined time interval, said time interval being sufficient to permit discharge of reduced ore from said cooling reactor and recharging thereof with fresh ore.

Claim 9

Dependent Claim 203 words

In a method for the batchwise gaseous reduction of metal oxides to metals in a multiple unit reactor system of the type in which separate bodies of metal-bearing material are simultaneously treated in a plurality of reactors and a reducing gas is passed successively through reactors of said system, the improvement which comprises feeding a preformed hot reducing gas largely composed of carbon monoxide and hydrogen and at a temperature of 900* to 1100*C. through a body of metal oxide in a reduction reactor of said system to reduce said metal oxide at least partially to sponge metal, cooling the effluent gas from said reduction reactor, reheating a portion of said cooled effluent gas to a temperature of 900* to 1100*C. and recirculating it through said reduction reactor, passing the remainder of said cooled effluent gas through a body of largely reduced metal oxide in a cooling reactor of said system to cool the body of reduced metal oxide therein, and continuing the flow of cooled gas through said cooling reactor for a predetermined time interval, said time interval being sufficient to permit discharge of reduced ore from a third reactor of said system and recharging of said third reactor with fresh ore.

Claim 10

Dependent Claim 203 words

In a method for the batchwise gaseous reduction of metal oxides to metals in a multiple unit reactor system of the type in which separate bodies of metal-bearing material are simultaneously treated in a plurality of reactors and a reducing gas is passed successively through reactors of said system, the improvement which comprises feeding a preformed hot reducing gas largely composed of carbon monoxide and hydrogen and at a temperature of 900* to 1100*C. through a body of metal oxide in a reduction reactor of said system to reduce said metal oxide at least partially to sponge metal, cooling the effluent gas from said reduction reactor, reheating a portion of said cooled effluent gas to a temperature of 900* to 1100*C. and recirculating it through said reduction reactor, passing the remainder of said cooled effluent gas through a body of largely reduced metal oxide in a cooling reactor of said system to cool the body of reduced metal oxide therein, and continuing the flow of cooled gas through said cooling reactor for a predetermined time interval, said time interval being sufficient to permit discharge of reduced ore from a third reactor of said system and recharging of said third reactor with fresh ore.

Claim 11

Dependent Claim 32 words

A method according to claim 8 wherein at least a portion of cooled effluent gas flowing from said reduction reactor through said cooling reactor is cooled and recirculated through said cooling reactor.

Claim 12

Dependent Claim 229 words

In a method for the batchwise gaseous reduction of metal oxides to metals in a multiple unit reactor system of the type in which separate bodies of metal-bearing material are simultaneously treated in a pluralIty of reactors, a reducing gas composed largely of carbon monoxide and hydrogen is generated by the catalytic conversion of a mixture of methane and steam in a reformer, and said reducing gas is passed successively through reactors of said system, the improvement which comprises heating said reducing gas to a temperature of 900* to 1100*C., passing the heated gas through a body of metal oxide in a reduction reactor of said system to reduce said metal oxide at least partially to sponge metal, cooling the effluent gas from said reduction reactor, reheating a portion of said cooled effluent gas to a temperature of 900* to 1100*C. and recirculating it through said reduction reactor, passing the remainder of said cooled effluent gas through a body of largely reduced metal oxide in a cooling reactor of said system to cool the body of reduced metal oxide therein, cooling a first portion of the effluent gas from said cooling reactor and recycling it to said cooling reactor, adding methane to the gas recycled to said cooling reactor, and using a second portion of the effluent gas from said cooling reactor as the methane fed to said reformer.

Claim 13

Dependent Claim 229 words

In a method for the batchwise gaseous reduction of metal oxides to metals in a multiple unit reactor system of the type in which separate bodies of metal-bearing material are simultaneously treated in a pluralIty of reactors, a reducing gas composed largely of carbon monoxide and hydrogen is generated by the catalytic conversion of a mixture of methane and steam in a reformer, and said reducing gas is passed successively through reactors of said system, the improvement which comprises heating said reducing gas to a temperature of 900* to 1100*C., passing the heated gas through a body of metal oxide in a reduction reactor of said system to reduce said metal oxide at least partially to sponge metal, cooling the effluent gas from said reduction reactor, reheating a portion of said cooled effluent gas to a temperature of 900* to 1100*C. and recirculating it through said reduction reactor, passing the remainder of said cooled effluent gas through a body of largely reduced metal oxide in a cooling reactor of said system to cool the body of reduced metal oxide therein, cooling a first portion of the effluent gas from said cooling reactor and recycling it to said cooling reactor, adding methane to the gas recycled to said cooling reactor, and using a second portion of the effluent gas from said cooling reactor as the methane fed to said reformer.

Claim 14

Dependent Claim 29 words

A method according to claim 10 wherein a third portion of the effluent gas from said cooling reactor is used as fuel gas to supply heat to said reformer.

Claim 15

Dependent Claim 33 words

A method according to claim 11 wherein a third portion of the effluent gas from said cooling reactor is used as fuel gas to heat the reducing gas supplied to said reduction reactor.

Claim 16

Dependent Claim 57 words

A method according to claim 10 wherein the effluent gas from said cooling reactor other than said recycled first portion is used (a) as the methane feed to said reformer, (b) as a fuel gas to supply heat to said reformer and (c) as a fuel gas to heat the reducing gas supplied to said reduction reactor.

Claim 17

Dependent Claim 55 words

A method according to claim 10 wherein the flow of cooling gas through said cooling reactor is interrupted while continuing the flow of reducing gas through said reduction reactor for a predetermined time interval, said time interval being sufficient to permit discharge of reduced ore from said cooling reactor and recharging thereof with fresh ore.

Claim 18

Dependent Claim 46 words

A method according to claim 14 wherein during said time interval said remainder of said cooled effluent gas from said reduction reactor is mixed with said added methane and at least a portion of the resulting mixture is used as the methane feed to said reformer.

Claim 19

Dependent Claim 48 words

A method according to claim 15 and wherein said resulting mixture is used (a) as the methane feed to said reformer, (b) as a fuel gas to supply heat to said reformer and (c) as a fuel gas to heat the reducing gas supplied to said reduction reactor.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-09-08	1979-03-10	1979-09-09	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-09-08	1983-03-10	1983-09-09	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-09-08	1987-03-10	1987-09-09	$7700.00	Window Closed / Lapsed

Method for reducing metal ores

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag