Pennzoil Company

Duval Corporation

Ben E Adams

John B Sardisco

Erhart K Drechsel

Edward J Gidak, Jr

Langbeinite and kieserite are beneficiated in a flotation process in which separation of ore particles is conducted in a froth flotation process with a magnesium chloride brine containing at least 20 moles MgCl.sub.2 per 1000 mols H.sub.2 O. Said brine is maintained at a pH below about 3.5. The preferred flotation agent is a combination of a fatty acid amine (preferably tallow amine) and an organic acid, either oleic or sebacic acid, in an approximate ratio of 2 to 4 parts amine to 1 part oleic or sebacic acid, and preferably in an amine-oleic or amine-sebacic acid ratio of about 3:1. Flotation is preferably conducted in two stages wherein the sink product from the rougher flotation contains langbeinite above about 95% concentration which is relatively free of kieserite and the froth from the rougher flotation is passed to a second 'cleaner' flotation step where the kieserite is further concentrated to above about 75% kieserite. The sink product from the cleaner flotation is recycled to the rougher flotation step for further processing with the pulp containing the incoming ore particles.

Beneficiation of kieserite and langbeinite from a langbeinite ore

Potassium sulfate (K.sub.2 SO.sub.4) is prepared by contacting potassium chloride with an aqueous solution containing potassium bisulfate at a temperature of about 65.degree.-110.degree. C., cooling the solution and permitting the potassium sulfate to crystallize from solution.

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Hanford, CA, United States of America

Ben E Adams