Method of reducing scale in the bayer process

A method for reducing aluminosilicate containing scale in a Bayer process, comprising:

• identifying a Bayer process equipment surface that is subject to scale formation during the Bayer process;
• contacting the identified Bayer process equipment surface with an amount of a scale inhibiting composition effective to form a treated surface that is more resistant to scale formation upon subsequent contact with a Bayer process stream than an otherwise comparable untreated surface;
• wherein the scale inhibiting composition comprises a liquor comprising an aqueous solution of one or more water-soluble salts having at least about 0.004 wt/wt % or more of total dissolved salts or a liquor having a pH of about 11.0 or greater, the scale inhibiting composition further comprising a silicon-containing compound;
• and
• contacting the treated surface with the Bayer process stream,
• wherein the silicon-containing compound is a reaction product of at least a polyamine, a first nitrogen-reactive compound, and a second nitrogen-reactive compound,
• wherein:
• the first nitrogen-reactive compound comprises a —Si(OR1b)3 group and a nitrogen-reactive group, where R1b is H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, optionally substituted C2-C20 alkenyl, Group I metal ion, Group II metal ion, or NR2b4, each R3b being independently selected from H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, and optionally substituted C2-C20 alkenyl;
• the second nitrogen-reactive compound comprises a nitrogen-reactive group and does not contain a Si(OR1b)3 group.

A method for reducing aluminosilicate containing scale in a Bayer process, comprising:

• identifying a Bayer process equipment surface that is subject to scale formation during the Bayer process;
• contacting the identified Bayer process equipment surface with an amount of a scale inhibiting composition effective to form a treated surface that is more resistant to scale formation upon subsequent contact with a Bayer process stream than an otherwise comparable untreated surface;
• wherein the scale inhibiting composition comprises a liquor comprising an aqueous solution of one or more water-soluble salts having at least about 0.004 wt/wt % or more of total dissolved salts or a liquor having a pH of about 11.0 or greater, the scale inhibiting composition further comprising a silicon-containing compound;
• and
• contacting the treated surface with the Bayer process stream,
• wherein the silicon-containing compound comprises:
• a first component having a general formula X or XI—
• wherein R1g is independently CH2, or CH2—CH2;
• and X3 is NH, NH—R1g—NH, or NH—R1g—NH—R1g—NH;
• 3-glycidoxypropyltrimethyloxysilane as a second component;
• and
• 2-ethylhexylglycidyl ether as a third component;
• wherein synthesis of the compound proceeds by combining the first component with the 3-glycidoxypropyltrimethyloxysilane at a reactive hydrogen of the first component to form an intermediate, and the intermediate then reacted with the 2-ethylhexylglycidyl ether to form the silicon-containing compound.

A method for reducing aluminosilicate containing scale in a Bayer process, comprising:

• identifying a Bayer process equipment surface that is subject to scale formation during the Bayer process;
• contacting the identified Bayer process equipment surface with an amount of a scale inhibiting composition effective to form a treated surface that is more resistant to scale formation upon subsequent contact with a Bayer process stream than an otherwise comparable untreated surface;
• wherein the scale inhibiting composition comprises a liquor comprising an aqueous solution of one or more water-soluble salts having at least about 0.004 wt/wt % or more of total dissolved salts or a liquor having a pH of about 11.0 or greater, the scale inhibiting composition further comprising a silicon-containing compound;
• and
• contacting the treated surface with the Bayer process stream,
• wherein the silicon-containing compound is a polymer having pendant thereto a group or end group according to Formula XII:
• wherein v is an integer of either 1 or 2;
• v+w=3;
• R1b is chosen from H, C1-C12 alkyl, aryl, Na, K, Li, and NH4;
• and J is chosen from H and a hydrocarbon group having a number of carbons within the range of 1 to 20 carbons.

A method for reducing aluminosilicate containing scale in a Bayer process, comprising:

• identifying a Bayer process equipment surface that is subject to scale formation during the Bayer process;
• contacting the identified Bayer process equipment surface with an amount of a scale inhibiting composition effective to form a treated surface that is more resistant to scale formation upon subsequent contact with a Bayer process stream than an otherwise comparable untreated surface;
• wherein the scale inhibiting composition comprises a liquor comprising an aqueous solution of one or more water-soluble salts having at least about 0.004 wt/wt % or more of total dissolved salts or a liquor having a pH of about 11.0 or greater, the scale inhibiting composition further comprising a silicon-containing compound having one or more —Si(OR)n groups;
• wherein:
• n is an integer from 1 to 3;
• and
• R is H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, optionally substituted C2-C20 alkenyl, Group I metal ion, Group II metal ion, or NR14;
• where each R1 is independently chosen from H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, and optionally substituted C2-C20 alkenyl;
• and
• contacting the treated surface with the Bayer process stream,
• wherein the Bayer process stream comprises an amount of suspended solids in a range of about 0.01% to about 60% by weight, based on total weight of the Bayer process stream,
• wherein the solids are iron oxides.

A method for reducing aluminosilicate containing scale in a Bayer process, comprising:

• identifying a Bayer process equipment surface that is subject to scale formation during the Bayer process;
• contacting the identified Bayer process equipment surface with an amount of a scale inhibiting composition effective to form a treated surface that is more resistant to scale formation upon subsequent contact with a Bayer process stream than an otherwise comparable untreated surface;
• wherein the scale inhibiting composition comprises a liquor comprising an aqueous solution of one or more water-soluble salts having at least about 0.004 wt/wt % or more of total dissolved salts or a liquor having a pH of about 11.0 or greater, the scale inhibiting composition further comprising a silicon-containing compound;
• and
• contacting the treated surface with the Bayer process stream,
• wherein the Bayer process stream comprises an amount of suspended solids in a range of about 0.01% to about 60% by weight, based on total weight of the Bayer process stream,
• wherein the silicon-containing compound is a polymer or polymeric reaction product comprising a unit of formula (I) and a unit of formula (II)—
• wherein
• T1 and E1 are each independently a first optionally substituted hydrocarbyl radical comprising from about 2 to about 40 carbons;
• Q1 is a second optionally substituted hydrocarbyl radical comprising from about 1 to about 20 carbons;
• A1a and A2a are each independently a direct bond or an organic connecting group comprising from about 1 to about 20 carbons;
• R1a is H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, optionally substituted C2-C20 alkenyl, Group I metal ion, Group II metal ion, or NR2a4, where each R2a is independently chosen from H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, and optionally substituted C2-C20 alkenyl;
• and
• the polymer has a weight average molecular weight of at least about 500,
• wherein the organic connecting groups A1a and A2a are each independently represented by -A3a-A4a-A5a-A6a-, wherein:
• A3a is a direct bond, NR3a or O, where R3a is H or C1-3 alkyl;
• A4a is a direct bond, C═O, optionally substituted C1-C10 alkylene, or optionally substituted C6-C12 aryl;
• A5a is a direct bond, O, NR4a, amide, urethane or urea, where R4a is H or C1-3 alkyl;
• and
• A6a is a direct bond, O, optionally substituted C1-C20 alkyl, optionally substituted C2-C20 alkenyl or optionally substituted C7-C20 aralkyl;
• wherein at least one of the organic connecting groups A1a and A2a is —CH2—CH(OH)—CH2—O— and optionally substituted C1-C10 alkylene, or optionally substituted C6-C12 aryl,
• wherein Q1 is chosen from butyl, 2-ethylhexyl, C8-10 alkyl, phenyl, cresyl, nonylphenyl, cetyl, octenyl, and octadecyl.

A method for reducing aluminosilicate containing scale in a Bayer process, comprising:

• identifying a Bayer process equipment surface that is subject to scale formation during the Bayer process;
• contacting the identified Bayer process equipment surface with an amount of a scale inhibiting composition effective to form a treated surface that is more resistant to scale formation upon subsequent contact with a Bayer process stream than an otherwise comparable untreated surface;
• wherein the scale inhibiting composition comprises a liquor comprising an aqueous solution of one or more water-soluble salts having at least about 0.004 wt/wt % or more of total dissolved salts or a liquor having a pH of about 11.0 or greater, the scale inhibiting composition further comprising a silicon-containing compound;
• and
• contacting the treated surface with the Bayer process stream, wherein the Bayer process stream comprises an amount of suspended solids in a range of about 0.01% to about 60% by weight, based on total weight of the Bayer process stream,
• wherein the silicon-containing compound is a reaction product of at least a polyamine, a first nitrogen-reactive compound, and a second nitrogen-reactive compound, the reaction product having a weight average molecular weight of at least about 500,
• wherein:
• the first nitrogen-reactive compound comprises a —Si(OR1b)3 group and a nitrogen-reactive group, where R1b is H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, optionally substituted C2-C20 alkenyl, Group I metal ion, Group II metal ion, or NR2b4, each R3b being independently chosen from H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, and optionally substituted C2-C20 alkenyl;
• and
• the second nitrogen-reactive compound comprises a nitrogen-reactive group and does not contain a Si(OR1b)3 group.

A method for reducing aluminosilicate containing scale in a Bayer process, comprising:

• identifying a Bayer process equipment surface that is subject to scale formation during the Bayer process;
• contacting the identified Bayer process equipment surface with an amount of a scale inhibiting composition effective to form a treated surface that is more resistant to scale formation upon subsequent contact with a Bayer process stream than an otherwise comparable untreated surface;
• wherein the scale inhibiting composition comprises a liquor comprising an aqueous solution of one or more water-soluble salts having at least about 0.004 wt/wt % or more of total dissolved salts or a liquor having a pH of about 11.0 or greater, the scale inhibiting composition further comprising a silicon-containing compound having one or more —Si(OR)n groups;
• wherein:
• n is an integer from 1 to 3;
• and
• R is H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, optionally substituted C2-C20 alkenyl, Group I metal ion, Group II metal ion, or NR14;
• where each R1 is independently chosen from H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, and optionally substituted C2-C20 alkenyl;
• and
• contacting the treated surface with the Bayer process stream,
• wherein the Bayer process stream comprises an amount of suspended solids in a range of about 0.01% to about 60% by weight, based on total weight of the Bayer process stream,
• wherein the silicon-containing compound comprises at least one compound having at least three components, one being a R1f component, one being a R2f component and one being a R3f component, the components within the compound arranged according to general Formula VII—
• wherein the compound is at least one of carbonates, bicarbonates, carbamates, ureas, amides and salts thereof;
• and
• wherein R1f is chosen from H, alkyl, amine, alkylamine, structure (VIII) and Formula (IX)—
• wherein R2f and R4f are independently chosen from H, alkyl, amine, alkylamine, GG and EE,
• wherein GG is chosen from 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltrialkoxysilane, 3-glycidoxypropylalkyldialkoxysilane, 3-glycidoxypropyldialkylmonoalkoxysilane, 3-isocyanatopropyltrialkoxysilane, 3-isocyanatopropylalkyldialkoxysilane, 3-isocyanatopropyldialkylmonoalkoxysilane, 3-chloropropyltrialkoxysilane, 3-chloropropylalkyldialkoxysilane, and 3-chloropropyldialkylmonoalkoxysilane;
• wherein EE is chosen from 2-ethylhexyl glycidyl ether, n-butyl glycidyl ether, t-butyl glycidyl ether, C3-C22 glycidyl ether, C3-C22 isocyanate, C3-C22 chloride, C3-C22 bromide, C3-C22 iodide, C3-C22 sulfate ester, C3-C22 phenolglycidyl ether, and any combination thereof;
• R3f and R5f are independently chosen from H, alkyl, aminealkylamine, GG and EE;
• and
• n1 is an integer from 2 to 6.

A method for reducing aluminosilicate containing scale in a Bayer process, comprising:

• identifying a Bayer process equipment surface that is subject to scale formation during the Bayer process;
• contacting the identified Bayer process equipment surface with an amount of a scale inhibiting composition effective to form a treated surface that is more resistant to scale formation upon subsequent contact with a Bayer process stream than an otherwise comparable untreated surface;
• wherein the scale inhibiting composition comprises a liquor comprising an aqueous solution of one or more water-soluble salts having at least about 0.004 wt/wt % or more of total dissolved salts or a liquor having a pH of about 11.0 or greater, the scale inhibiting composition further comprising a silicon-containing compound having one or more —Si(OR)n groups;
• wherein:
• n is an integer from 1 to 3;
• and
• R is H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, optionally substituted C2-C20 alkenyl, Group I metal ion, Group II metal ion, or NR14;
• where each R1 is independently chosen from H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, and optionally substituted C2-C20 alkenyl;
• and
• contacting the treated surface with the Bayer process stream,
• wherein the Bayer process stream comprises an amount of suspended solids in a range of about 0.01% to about 60% by weight, based on total weight of the Bayer process stream,
• wherein the silicon-containing compound comprises at least three components, wherein a first component of the at least three components is according to general Formula X or XI—
• wherein R1g is independently CH2, or, CH2—CH2;
• and X3 is NH, NH—R1g—NH, or NH—R1g—NH—R1g—NH,
• a second component of the at least three components is 3-glycidoxypropyltrimethyloxysilane;
• and
• a third component of the at least three components is 2-ethylhexylglycidyl ether;
• wherein synthesis of the compound proceeds by combining the first component with the second component at a reactive hydrogen of the first component to form an intermediate, and then reacting the intermediate with the third component to form the compound.

A method for reducing aluminosilicate containing scale in a Bayer process, comprising:

• identifying a Bayer process equipment surface that is subject to scale formation during the Bayer process;
• contacting the identified Bayer process equipment surface with an amount of a scale inhibiting composition effective to form a treated surface that is more resistant to scale formation upon subsequent contact with a Bayer process stream than an otherwise comparable untreated surface;
• wherein the scale inhibiting composition comprises a liquor comprising an aqueous solution of one or more water-soluble salts having at least about 0.004 wt/wt % or more of total dissolved salts or a liquor having a pH of about 11.0 or greater, the scale inhibiting composition further comprising a silicon-containing compound having one or more —Si(OR)n groups;
• wherein:
• n is an integer from 1 to 3;
• and
• R is H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, optionally substituted C2-C20 alkenyl, Group I metal ion, Group II metal ion, or NR14;
• where each R1 is independently chosen from H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, and optionally substituted C2-C20 alkenyl;
• and
• contacting the treated surface with the Bayer process stream,
• wherein the Bayer process stream comprises an amount of suspended solids in a range of about 0.01% to about 60% by weight, based on total weight of the Bayer process stream,
• wherein the silicon-containing compound is a polymer having pendant thereto a group or end group according to Formula XII—
• wherein v is an integer of either 1 or 2;
• v+w=3;
• R1b is chosen from H, C1-C12 alkyl, aryl, Na, K, Li, and NH4;
• and J is chosen from H and a hydrocarbon group having a number of carbons from 1 to 20.

A method for reducing aluminosilicate containing scale in a Bayer process, comprising:

• identifying a Bayer process equipment surface that is subject to scale formation during the Bayer process;
• contacting the identified Bayer process equipment surface with an amount of a scale inhibiting composition effective to form a treated surface that is more resistant to scale formation upon subsequent contact with a Bayer process stream than an otherwise comparable untreated surface;
• wherein the scale inhibiting composition comprises a liquor comprising an aqueous solution of one or more water-soluble salts having at least about 0.004 wt/wt % or more of total dissolved salts or a liquor having a pH of about 11.0 or greater, the scale inhibiting composition further comprising a silicon-containing compound having one or more —Si(OR)n groups;
• wherein:
• n is an integer from 1 to 3;
• and
• R is H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, optionally substituted C2-C20 alkenyl, Group I metal ion, Group II metal ion, or NR14;
• where each R1 is independently chosen from H, optionally substituted C1-C20 alkyl, optionally substituted C6-C12 aryl, optionally substituted C7-C20 aralkyl, and optionally substituted C2-C20 alkenyl;
• and
• contacting the treated surface with the Bayer process stream,
• wherein the Bayer process stream comprises an amount of suspended solids in a range of about 0.01% to about 60% by weight, based on total weight of the Bayer process stream,
• wherein the silicon-containing compound is a polymer that comprises a unit of Formula XIII and a unit of Formula XIV—
• wherein:
• A1b and A2b are each independently a hydrocarbon group having from 1 to 20 carbons or A1b and A2b are each independently a direct bond between the nitrogen atom and the adjoining group;
• T2 and E2 are each independently hydrocarbon group having from 2 to 40 carbons;
• and
• Q2 is chosen from H and a hydrocarbon group having from 1 to 20 carbons, wherein the molecular weight of the polymer is at least 500, and Q2 does not contain a silane group.