Benefication of fluorspar ores

A process for the froth flotation of fluorspar ore containing metallic sulfide accessory minerals to obtain a fluorspar enriched concentrate that is substantially free of sulfide impurities, which comprises the steps of:

• a. preparing an aqueous pulp of said ore suitable for froth flotation;
• b. conditioning the pulp with flotation reagents including oleic acid as a collector for said ore, sodium sulfide as a depressor for metallic sulfides, gangue depressors, and a pH regulator to maintain the pulp in the pH range of about 8.5 to 9.5 while heating the pulp to a temperature in the range of about 85.degree. to 105.degree. F. (29.degree. to 41.degree. C.);
• and
• c. subjecting the conditioned pulp to froth flotation and recovering a fluorspar enriched concentrate having a fluorspar content of at least about 96.5 wt. % and a sulfide sulfur content not greater than about 0.02 wt. %;
• wherein:
• said ore includes about 30 to 60 wt. % fluorspar, up to about 3 wt. % metallic sulfides, and up to about 55 wt. % gangue including silica, calcite, and barite;
• said pulp has a solids content of about 35 to 45 wt. % with a particle size of less than about 48 mesh;
• said gangue depressors are an alkali metal silicate, starch, and quebracho, each added to said pulp at an addition rate of about 1 to 5 pounds per ton of ore (0.5 to 2.5 kg/tonne), and said pH regulator is soda ash;
• said oleic acid is added to said pulp at an addition rate of about 0.5 to 1.5 pounds per ton of ore (0.25 to 0.75 kg/tonne);
• and
• said sodium sulfide is added to said pulp at an addition rate of about 0.05 to 0.4 pound per ton of ore (0.025 to 0.2 kg/tonne).