Sylvinite ores are treated for removing insoluble slimes by froth flotation, which includes flocculating the slimes with a nonionic or polyacrylamide flocculant and using a nonionic or anionic flotation collector, including a mixture of fuel oil or fatty acid and a defoamer of the glycol ester or polyglycol ester type. Thus, 1,000 g of sylvinite containing k2o 12.6, Na 26.5, and water-insoluble compounds 5 pct, was pulped to 27 pct solids at ph 7.6, Scrubbed, and mixed with 0.2 Lb/ton of ore betz 1160 cationic flocculant. After stirring, 0.1 Lb/ton of ore caprylic acid was added, stirred, mixed with 1 drop of frother, and froth floated for 4 min. The process was repeated 4 times with hcl addition to bring the ph down to 2. The slimes contained 72.3 pct water-insoluble materials. Chem. Abstr. 92:218,669W (see also chem. Abstr. 91:143,995T) sylvinite ores are treated for the removal of insoluble slimes by froth flotation, which includes flocculating the slimes with nonionic or polyacrylamide flocculant, then using a nonionic or anionic flotation collector including a mixture of fuel oil or a fatty acid and a defoamer of the glycol ester or polyglycol ester type. Thus sylvinite containing 5 pct insolubles was pulped to 27 pct solids and treated with 0.2 Lb betz 1160/ton of ore as cationic flocculant. After 15 s, 0.1 Lb caprylic acid/ton of ore was added. After 5 min flotation, with hcl additions to give ph 2, the water-insolubles removal was 77.3 pct.
U.S. Pat. 4,192,737, Mar. 11, 1980; Chem. Abstr. 91:143,995T