A method of 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; and contacting the treated surface with the Bayer process stream; without adding a silicon-containing compound having one or more -Si n groups to the Bayer process stream; wherein the scale inhibiting composition comprises a liquor comprising an aqueous solution of one or more water-soluble salts having at least 0.004% by weight of total dissolved salts and a silicon-containing compound, wherein the silicon-containing compound is resistant to degradation in alumina recovery process streams at process temperatures from 100°C to 265°C, 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(OR 1b) 3 group and a nitrogen-reactive group, where R 1b is H, optionally substituted C 1 -C 20 alkyl, optionally substituted C 6 -C 12 aryl, optionally substituted C 7 -C 20 aralkyl, optionally substituted C 2 -C 20 alkenyl, Group I metal ion, Group II metal ion, or NR 2b 4, each R 2b being independently selected from H, optionally substituted C 1 -C 20 alkyl, optionally substituted C 6 -C 12 aryl, optionally substituted C 7 -C 20 aralkyl, and optionally substituted C 2 -C 20 alkenyl; the second nitrogen-reactive compound comprises a nitrogen-reactive group and does not contain a Si(OR 1b) 3 group, wherein the silicon-containing compound is free of β-hydroxy ether groups, 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; and contacting the treated surface with the Bayer process stream; without adding a silicon-containing compound having one or more -Si n groups to the Bayer process stream; wherein the scale inhibiting composition comprises a liquor comprising an aqueous solution of one or more water-soluble salts having at least 0.004% by weight of total dissolved salts and a silicon-containing compound, wherein the silicon-containing compound is resistant to degradation in alumina recovery process streams at process temperatures from 100°C to 265°C, 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(OR 1b) 3 group and a nitrogen-reactive group, where R 1b is H, optionally substituted C 1 -C 20 alkyl, optionally substituted C 6 -C 12 aryl, optionally substituted C 7 -C 20 aralkyl, optionally substituted C 2 -C 20 alkenyl, Group I metal ion, Group II metal ion, or NR 2b 4, each R 2b being independently selected from H, optionally substituted C 1 -C 20 alkyl, optionally substituted C 6 -C 12 aryl, optionally substituted C 7 -C 20 aralkyl, and optionally substituted C 2 -C 20 alkenyl; the second nitrogen-reactive compound comprises a nitrogen-reactive group and does not contain a Si(OR 1b) 3 group, wherein the silicon-containing compound is free of β-hydroxy ether groups, the first nitrogen-reactive compound comprises a -Si(OR 1b) 3 group and a nitrogen-reactive group, where R 1b is H, optionally substituted C 1 -C 20 alkyl, optionally substituted C 6 -C 12 aryl, optionally substituted C 7 -C 20 aralkyl, optionally substituted C 2 -C 20 alkenyl, Group I metal ion, Group II metal ion, or NR 2b 4, each R 2b being independently selected from H, optionally substituted C 1 -C 20 alkyl, optionally substituted C 6 -C 12 aryl, optionally substituted C 7 -C 20 aralkyl, and optionally substituted C 2 -C 20 alkenyl; the second nitrogen-reactive compound comprises a nitrogen-reactive group and does not contain a Si(OR 1b) 3 group, wherein the silicon-containing compound is free of β-hydroxy ether groups,