Manufacture of a Soderberg electrode incorporating a high carbon-contributing phenolic sacrificial binder

Claim 2

A feedstock composition for the production of a Soderberg continuous carbon electrode wherein said composition has sufficient mobility to travel through the Soderberg temperature gradient as a moving viscous bed and wherein said moving viscous bed of heated composition enters a use zone of said Soderberg electrode as a paste, hardens, and attains electrode integrity, comprising a mixture of particulate carbonaceous aggregate, phenolic resin binder, plasticizer, and hexamethylenetetramine wherein said plasticizer has a boiling point above 200° C., wherein the amount of said plasticizer is greater than 0%-50% by weight based on the combined weight of resin solids and plasticizer; and wherein the amount of said hexamethylenetetramine is from 0% to no more than 5% by weight based on phenolic resin solids, said mixture retaining a plasticity at 200° C., said phenolic resin binder comprising a phenolic novalac resin characterized by a minimum melt point of 100° C. and a free phenol content of not more than 4% by weight as measured by gas chromatography analysis.

Claim 3

The composition of claim 1 wherein said feedstock composition comprises pitch wherein the weight amount of said pitch is equal to and less than the weight amount of said phenolic novolac resin.

Claim 4

The feedstock composition of claim 1 wherein the plasticizer has a boiling point of at least 250° C.

Claim 5

The feedstock composition of claim 1, wherein said plasticizer is selected from the group consisting of a glycol, ester, aromatic alcohol, anthracene oil, pyrol and mixtures thereof.

Claim 6

The composition of claim 4 wherein said glycol is diethylene glycol or triethylene glycol.

Claim 7

The composition of claim 4 wherein said glycol is a polyethylene glycol.

Claim 8

The composition of claim 4 wherein said plasticizer is a dibasic ester selected from the group consisting of adipic dimethyl ester, glutaric dimethyl ester, succinic dimethyl ester and mixtures thereof.

Claim 9

The composition of claim 4 wherein said plasticizer is an aromatic alcohol.

Claim 10

The composition of claim 4 wherein said plasticizer is a heterocyclic compound.

Claim 11

The composition of claim 4 wherein said plasticizer is an anthracene oil or a naphthalenic compound.

Claim 12

The feedstock composition of claim 4, wherein said ester comprises a glycol ester.

Claim 13

The feedstock composition of claim 1 wherein said free phenol content is not more than 2% by weight as measured by gas chromatography analysis.

Claim 14

A feedstock composition for the production of a Soderberg continuous carbon electrode wherein said composition has sufficient mobility to travel through the Soderberg temperature gradient as a moving viscous bed and wherein said viscous bed enters a use zone of said Soderberg electrode, retains plasticity at about 500° C., hardens and attains electrode integrity comprising free flowing particulate resin coated, carbonaceous aggregate, plasticizer having a boiling point above 200° C. wherein the amount of said plasticizer is of 0-50% based on the total weight of resin solids and plasticizer, and hexamethylene-tetramine wherein the amount of said hexamethylenetetramine is from 0% to no more than 5% based on phenolic resin solids, said resin coated carbonaceous aggregate being formed from a mixture comprising phenolic novolac resin and particulate carbonaceous aggregate.

Claim 15

A feedstock composition for the production of a Soderberg continuous carbon electrode wherein said composition has sufficient mobility to travel through the Soderberg temperature gradient as a moving viscous bed and wherein said viscous bed enters a use zone of said Soderberg electrode, retains plasticity at about 500° C., hardens and attains electrode integrity comprising free flowing particulate resin coated, carbonaceous aggregate, plasticizer having a boiling point above 200° C. wherein the amount of said plasticizer is of 0-50% based on the total weight of resin solids and plasticizer, and hexamethylene-tetramine wherein the amount of said hexamethylenetetramine is from 0% to no more than 5% based on phenolic resin solids, said resin coated carbonaceous aggregate being formed from a mixture comprising phenolic novolac resin and particulate carbonaceous aggregate.

Claim 16

The feedstock composition of claim 13 wherein said phenolic novolac resin used for coating said particulate carbonaceous aggregate was in flake form or in hot melt form.

Claim 17

The composition of claim 13 wherein said phenolic novolac resin used to coat said particulate carbonaceous aggregate was a solution wherein the solvent of said solution had a boiling point greater than 150° C.

Claim 18

The composition of claim 13 wherein said phenolic novolac resin used to coat said particulate carbonaceous aggregate was a solution wherein the solvent of said solution had a boiling point low enough so that the solvent is removed by evaporation during the mixing of said mixture.

Claim 19

The feedstock of claim 13 wherein said phenolic novolac resin used to coat said particulate carbonaceous aggregate was in a water-borne dispersion/emulsion form.

Claim 20

A process for making a feedstock composition for a Soderberg continuous carbon electrode prepared from a particulate carbonaceous aggregate, a resin binder comprising a phenol formaldehyde novolac resin in particulate or hot melt form, and hexamethylenetetramine, said novolac having a melting point of at least 100° C., a total volatiles content at 135° C. and not more than 5% by weight of said resin solids including a free phenol content of not more than 4% by weight of said resin solids as measured by gas chromatography analysis, comprising: mixing said particulate aggregate with sufficient resin binder so that the solids of said resin comprise 6%-15% by weight of said aggregate and with 0%-5% by weight of hexamethylenetetramine based on the weight of said phenol formaldehyde novolac to coat said aggregate to produce a free flowing resin-coated aggregate material.

Claim 21

A process for making a feedstock composition for a Soderberg continuous carbon electrode prepared from a particulate carbonaceous aggregate, a resin binder comprising a phenol formaldehyde novolac resin in particulate or hot melt form, and hexamethylenetetramine, said novolac having a melting point of at least 100° C., a total volatiles content at 135° C. and not more than 5% by weight of said resin solids including a free phenol content of not more than 4% by weight of said resin solids as measured by gas chromatography analysis, comprising: mixing said particulate aggregate with sufficient resin binder so that the solids of said resin comprise 6%-15% by weight of said aggregate and with 0%-5% by weight of hexamethylenetetramine based on the weight of said phenol formaldehyde novolac to coat said aggregate to produce a free flowing resin-coated aggregate material.

Claim 22

The free flowing resin-coated aggregate material formed by the process of claim 18.

Claim 23

The free flowing resin-coated aggregate material formed by the process of claim 18 wherein said material is shaped and packaged.

Claim 24

The free flowing resin-coated aggregate material formed by the process of claim 18 wherein said material comprises a plasticizer.

Claim 25

A process for making a feedstock composition for the production of a Soderberg continuous carbon electrode wherein said feedstock has sufficient mobility to travel through the Soderberg temperature gradient as a moving viscous bed of heated paste that retains plasticity at about 500° C. and to enter a use zone of said Soderberg electrode wherein said heated moving bed of viscous paste hardens and attains electrode integrity comprising mixing particulate carbonaceous aggregate, curable resin binder, plasticizer having a boiling point above 200° C. wherein the amount of said plasticizer is greater than 0-50% based on the combined weight of resin solids and plasticizer, and hexamethylenetetramine wherein the amount of said hexamethylenetetramine is from 0% to no more than 5% based on resin solids, until a free flowing resin-coated aggregate material is formed, wherein said curable resin binder comprises a novolac resin in an amount of from about 5% to about 20% by weight of resin solids based on the weight of said carbonaceous aggregate, said plasticizer and said curing agent if used being present in amounts sufficient to impart sufficient mobility and flowability to said paste as it travels toward said use zone.

Claim 26

A process for making a feedstock composition for the production of a Soderberg continuous carbon electrode wherein said feedstock has sufficient mobility to travel through the Soderberg temperature gradient as a moving viscous bed of heated paste that retains plasticity at about 500° C. and to enter a use zone of said Soderberg electrode wherein said heated moving bed of viscous paste hardens and attains electrode integrity comprising mixing particulate carbonaceous aggregate, curable resin binder, plasticizer having a boiling point above 200° C. wherein the amount of said plasticizer is greater than 0-50% based on the combined weight of resin solids and plasticizer, and hexamethylenetetramine wherein the amount of said hexamethylenetetramine is from 0% to no more than 5% based on resin solids, until a free flowing resin-coated aggregate material is formed, wherein said curable resin binder comprises a novolac resin in an amount of from about 5% to about 20% by weight of resin solids based on the weight of said carbonaceous aggregate, said plasticizer and said curing agent if used being present in amounts sufficient to impart sufficient mobility and flowability to said paste as it travels toward said use zone.

Claim 27

The process of claim 22, wherein said plasticizer is selected from the group consisting of a glycol, ester, aromatic alcohol, anthracene oil, pyrol, and mixtures thereof.

Claim 28

The process of claim 23 wherein said glycol is diethylene glycol or triethylene glycol.

Claim 29

The process of claim 23 wherein said glycol is polyethylene glycol.

Claim 30

The process of claim 23, wherein said ester comprises a glycol ester.

Claim 31

The process of claim 22 wherein said plasticizer is a dibasic ester selected from a group consisting of adipic dimethyl ester, glutaric dimethyl ester, succinic dimethyl ester and mixtures thereof.

Claim 32

The process of claim 22 wherein said plasticizer is an aromatic alcohol.

Claim 33

The process of claim 22, wherein said plasticizer is a heterocyclic compound.

Claim 34

The process of claim 29, wherein said heterocyclic compound is 2-pyrrolidone.

Claim 35

The process of claim 22, wherein said plasticizer is an anthracenic compound or a naphthalenic compound.

Claim 36

The process of claim 31, wherein said anthracenic compound is anthracene oil.

Claim 37

The process of claim 22 wherein said curable resin binder is a phenolic novolac resin with a free phenolic content of less than 3% as measured by gas chromatography analysis.

Claim 38

The process of claim 22 for making a Soderberg continuous carbon electrode, wherein the feedstock composition comprises a mixture of particulate carbonaceous aggregate, phenolic resin binder, plasticizer and hexamethylenetetramine, wherein said plasticizer has a boiling point of above 200° C., wherein the weight amount of said plasticizer is greater than 0%-50% based on the combined weight of resin solids and plasticizer, and wherein the weight amount of said hexamethylenetetramine is 0% to no more than 5% based on phenolic resin solids, said phenolic resin binder comprising phenolic novolac resin characterized by a minimum melt point of 100° C. and a free phenol content of not more than 4% by weight as measured by gas chromatography analysis.

Claim 39

A Soderberg electrode made by the process of claim 34.

Claim 40

A Soderberg electrode of claim 35, wherein said electrode is useful for the electrolytic production of aluminum.

Claim 41

A Soderberg electrode of claim 35, wherein said electrode is useful in the production of calcium carbide.

Claim 42

A Soderberg electrode of claim 35, wherein said electrode is useful in an electric furnace.

Claim 43

A process for making a Soderberg electrode comprising the steps of (1) passing a feedstock that retains plasticity above 200° C. of resin-coated carbonaceous particles through the three Soderberg electrode forming zones wherein in a first zone said feedstock moves downwardly toward a baking zone in the form of discrete, free-flowing particles; (2) in said baking zone passing said feedstock through a temperature gradient and converting said feedstock from discrete free-flowing particles to a bed of a viscous paste that moves downwardly toward an electrode-forming and use zone; and (3) in said electrode-forming and use zone hardening said paste into a continuous electrode shape and then using said shape as a continuously-formed Soderberg electrode; wherein said feedstock comprises an admixture of resin coated carbonaceous aggregate, plasticizer having a boiling point of at least 200° C. wherein the amount of said plasticizer is greater than 0%-50% based on the total weight of resin solids and plasticizer, and hexamethylenetetramine wherein the amount of said hexamethylenetetramine is from 0% to no more than 5% based on resin solids, said resin coated carbonaceous aggregate comprising a phenolic novolac resin coated on particles of a particulate carbonaceous aggregate.

Claim 44

A process for making a Soderberg electrode comprising the steps of (1) passing a feedstock that retains plasticity above 200° C. of resin-coated carbonaceous particles through the three Soderberg electrode forming zones wherein in a first zone said feedstock moves downwardly toward a baking zone in the form of discrete, free-flowing particles; (2) in said baking zone passing said feedstock through a temperature gradient and converting said feedstock from discrete free-flowing particles to a bed of a viscous paste that moves downwardly toward an electrode-forming and use zone; and (3) in said electrode-forming and use zone hardening said paste into a continuous electrode shape and then using said shape as a continuously-formed Soderberg electrode; wherein said feedstock comprises an admixture of resin coated carbonaceous aggregate, plasticizer having a boiling point of at least 200° C. wherein the amount of said plasticizer is greater than 0%-50% based on the total weight of resin solids and plasticizer, and hexamethylenetetramine wherein the amount of said hexamethylenetetramine is from 0% to no more than 5% based on resin solids, said resin coated carbonaceous aggregate comprising a phenolic novolac resin coated on particles of a particulate carbonaceous aggregate.

Claim 45

The process of claim 39 wherein said feedstock composition comprises pitch in a weight amount equal to or less than the weight amount of said phenolic novolac resin.

Claim 46

The process of claim 39 wherein said plasticizer has a boiling point of at least 250° C.

Claim 47

The process of claim 39, wherein said plasticizer has a boiling point above 200° C. and is selected from the group consisting of a glycol, ester, aromatic alcohol, anthracene oil, pyrol, and mixtures thereof.

Claim 48

The process of claim 42 wherein said glycol is diethylene glycol or triethylene glycol.

Claim 49

The process of claim 42 wherein said glycol is a polyethylene glycol.

Claim 50

The process of claim 42, wherein said ester is glycol ester.

Claim 51

The process of claim 39 wherein said plasticizer is a dibasic ester selected from the group consisting of adipic dimethyl ester, glutaric dimethyl ester, succinic dimethyl ester, and mixtures thereof.

Claim 52

The process of claim 39 wherein said plasticizer is an aromatic alcohol.

Claim 53

The process of claim 39, wherein said plasticizer is a heterocyclic compound.

Claim 54

The process of claim 48, wherein said heterocyclic compound is 2-pyrrolidone.

Claim 55

The process of claim 39, wherein said plasticizer is an anthracenic compound or a naphthalenic compound.

Claim 56

The process of claim 50, wherein said anthracenic compound is anthracene oil.

Claim 57

The process of claim 39 wherein said resin has a free phenol content of not more than 4% by weight as measured by gas chromatography analysis, and said resin is characterized by a minimum melt point of 100° C.

Claim 58

The process of claim 52 wherein said resin has a total volatiles content of not more than 5% by weight of solids content.