Gypsum additive to control mercury
AssigneeEcolab USA Inc.
InventorsBruce A. Keiser, Wayne M. Carlson, Nicholas R. Denny, Jianwei Yuan, Tommy Hung-Ting Chen
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Abstract
Additives including sulfur-containing compounds are used in methods of treating synthetic gypsum. The additives can thermally stabilize heavy metals, such as mercury. This thermal stabilization reduces mercury release from the synthetic gypsum. Illustrative, non-limiting examples of sulfur-containing compounds include inorganic sulfides, organic sulfides, organic compounds containing nitrogen and sulfur, organic compounds containing oxygen and sulfur, and polymers containing sulfur.
Claims10
A method of treating synthetic gypsum, comprising:
- transporting the synthetic gypsum from a wet flue gas desulfurizer;
- and
- contacting the synthetic gypsum with an additive, the additive comprising a sulfur-containing compound and water, wherein the sulfur-containing compound is a polymer comprising sulfur that is modified to contain at least one of a sulfide and a dithiocarbamate salt group.
A method of treating synthetic gypsum, comprising:
- transporting the synthetic gypsum from a wet flue gas desulfurizer;
- and
- contacting the synthetic gypsum with an additive, the additive comprising a sulfur-containing compound, wherein the sulfur-containing compound is a polymer comprising sulfur that comprises a weight average molecular weight of about 500 g/mol to about 200,000 g/mol.
A composition comprising synthetic gypsum, mercury, and an additive, the additive comprising a sulfur-containing compound, wherein the sulfur-containing compound comprises a polymer including at least an acrylic-x monomer and an alkylamine, wherein the acrylic-x monomer comprises the following generic structure:
- wherein X may be OR, OH, salts of OR, salts of OH, or NHR2;
- R1 and R2 are independently selected from H, an alkyl group, or an aryl group;
- and R is an alkyl group or an aryl group.
Dependencies are inferred from the claim text.