Method for the alteration of siliceous materials from Bayer process liquids
AssigneeNalco Chemical Company
InventorPeter A. Dimas
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Abstract
Siliceous materials produced by thermally treating Bayer process liquors are obtained in modified form when produced in the presence of ammonium, aromatic amine, and amine compounds, or compounds bearing ammonium, aromatic amine or amine moieties, such as N-propylamine, pyridine and tetramethylammonium hydroxide. These modified siliceous materials possess morphologies which confer upon them a reduced tendency to deposit on surfaces throughout the process.
Claims15
A method for modifying the morphological characteristics of sodium aluminosilicate crystals in a Bayer Process liquor to reduce their tendency to adhere to equipment surfaces, the method including the step of adding to the liquor from about 50 to about 10,000 parts per million of at least one compound selected from the group consisting of ammonium compounds, aromatic amine compounds and amine compounds, said ammonium compounds having the formula:
- ##STR7## wherein:
- R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are, individually, a straight or branched chain C.sub.1 -C.sub.6 aliphatic group, a straight or branched chain C.sub.1 -C.sub.6 carboxyl group, a straight or branched chain C.sub.1 -C.sub.6 hydroxyalkyl group, an aromatic group, an alkylaryl group or a hydrogen atom;
- and M is an anion;
- said amine compound having the formula:
- ##STR8## wherein R.sub.5, R.sub.6, and R.sub.7 are, individually, a straight or branched chain C.sub.1 -C.sub.6 aliphatic group, a straight or branched chain C.sub.1 -C.sub.6 carboxyl group, a straight or branched chain C.sub.1 -C.sub.6 hydroxyalkyl group, an aromatic group, an alkylaryl group, or a hydrogen atom;
- and said aromatic amine compound having the following formula:
- ##STR9## wherein R.sub.8, R.sub.9, R.sub.10, R.sub.11 and R.sub.12 are, individually, a straight or branched chain C.sub.1 -C.sub.6 aliphatic group, a straight or branched chain C.sub.1 -C.sub.6 carboxyl group, a straight or branched chain C.sub.1 -C.sub.6 hydroxyalkyl group, a hydroxyl group, or a hydrogen atom.
A method of reducing the formation of insoluble sodium aluminosilicate deposits upon Bayer Process equipment during a thermal treatment of the Bayer Process liquor, the method comprising the step of adding to the liquor prior to or during the thermal treatment from about 50 to about 10,000 parts per million of at least one compound selected from the group consisting of ammonium compounds, aromatic amine compounds and amine compounds having the respective formulas:
- ##STR10## wherein:
- R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are, individually, a straight or branched chain C.sub.1 -C.sub.6 aliphatic group, a straight or branched chain C.sub.1 -C.sub.6 carboxyl group, a straight or branched chain C.sub.1 -C.sub.6 hydroxyalkyl group, an aromatic group, an alkylaryl group or a hydrogen atom;
- and M is an anion;
- and ##STR11## wherein R.sub.5, R.sub.6, and R.sub.7 are, individually, a straight or branched chain C.sub.1 -C.sub.6 aliphatic group, a straight or branched chain C.sub.1 -C.sub.6 carboxyl group, a straight or branched chain C.sub.1 -C.sub.6 hydroxyalkyl group, an aromatic group, an alkylaryl group, or a hydrogen atom;
- and said aromatic amine compound having the following formula;
- ##STR12## wherein R.sub.8, R.sub.9, R.sub.10, R.sub.11 and R.sub.12 are, individually, a straight or branched chain C.sub.1 -C.sub.6 aliphatic group, a straight or branched chain C.sub.1 -C.sub.6 carboxyl group, a straight or branched chain C.sub.1 -C.sub.6 hydroxyalkyl group, a hydroxyl group, or a hydrogen atom.
Dependencies are inferred from the claim text.