Eastman-kodak Company

Cominco, Ltd.

Michael Palmer

Ted L Douglas

Samuel L Gott

Ambrose J Clonce, Jr

Richard J Lobban

James T Furey

Certain water dissipatable polyester materials containing ether groups and metal sulfonate groups are useful as depressants for siliceous gangue in the froth flotation separation of zinc sulfide concentrates from complex ores containing, minerals of other metals such as lead and iron, as well as various silicon compounds. The polyester materials ae effective in amounts ranging from about 0.03 to about 1.5 kg/tonne of ore feed. Zinc rougher concentrates when conditioned with the depressant yields zinc cleaner concentrates containing less than about 1.5% silica without the need for extensive regrinding of the rougher concentrate. Particularly useful polyester material is prepared from an acid component of from about 80 to 85 mole % isophthalic acid with the remainder comprising mainy 5-sodiosulfoisopthalic acid, and a diol component of from about 50 to 60 mole % diethylene glycol with the remainder comprising mainly 1.4-cyclohexanedimethanol.

Silica depressant in froth flotation of sulfide ores

The present invention provides an improvement in methods for preparing and processing readily polymerizable acrylate monomers. The improvement comprises employing phenyl-para-benzoquinone, 2,5-di-phenyl-para-benzoquinone, and mixtures thereof as process inhibitors. The process inhibitors are present in a concentration of about 50 to 3000 ppm, preferably about 250 to 2000 ppm, and most preferably about 500 ppm.

Process inhibitor for readily polymerizable acrylate monomer

Stabilization of wet p-benzoquinone with metal chelating agents

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Kingsport, TN, United States of America

Michael Palmer