Abstract: An environmentally safe composition of matter for use as a promoter chemical in flotation separation of carbonates from industrial sand is disclosed. The promoter chemical replaces the standard petroleum sulfonate, glycol ether and nonphenol used in promoter chemicals with biodegradable substitutes permitting the waste from flotation separation to be disposed without fear of contamination of ground water. The biodegradable promoter is technically sound and causes little change to the flotation process.

Abstract: A process for treating effluents, such as precious metal tailings, having a pH of at least 9 and containing cyanide is described in which Caro's acid is added to the effluent having a pH of at least 9 and commencing the reaction of the cyanide with Caro's acid at 0.degree. C. to 80.degree. C. in the absence of an added alkali; adding sufficient Caro's acid within a mole ratio of Caro's acid to cyanide of 0.3/1 to 3/1 to reduce the pH of the effluent to below 9, continuing the reaction between Caro's acid and the cyanide to reduce the amount of cyanide remaining in the effluent and to recover an environmentally compatible effluent reduced in amounts of cyanide.