Beneficiation of fluorspar ore

Claim 2

In a method for beneficiating a fluorspar concentrate, containing apatite as a gangue mineral, which includes further concentrating the fluorspar by a froth flotation process utilizing an acid flotation circuit, the improvement, which comprises adding an apatite-collecting cationic reagent to the flotation circuit to collect and float substantially all of the apatite; adding a source of fluoride ions to the flotation circuit to depress the fluorspar; removing the floated apatite; and recovering the fluorspar from the underflow.

Claim 3

The method of claim 1 wherein the cationic reagent is selected from the group consisting of higher aliphatic amines and their salts with water-soluble acids; esters of amino alcohols with high molecular weight fatty acids and their salts with water-soluble acids; higher alkyl-O-substituted isoureas and their salts with water-soluble acids; higher aliphatic quaternary ammonium bases and their salts with water-soluble acids; reaction products of polyalkylene polyamines with fatty acids or fatty acid triglycerides; higher alkyl pyridinium water-soluble acids; and higher quinolinium salts of water-soluble acids; and the cationic reagent is employed in an amount sufficient to collect and float substantially all of the apatite; and the source of fluoride ions is employed in an amount sufficient to depress substantially all of the fluorspar, and the pH is controlled in a range of from about 2 to about 5.

Claim 4

The method of claim 2 wherein the source of fluoride ions is hydrofluoric acid.

Claim 5

The method of claim 2 wherein the source of fluoride ions is a water-soluble fluoride salt.

Claim 6

The method of claim 4 wherein the water-soluble fluoride salt is selected from the group consisting of sodium fluoride, potassium fluoride, ammonium fluoride, and ammonium bifluoride.

Claim 7

The method of claim 4 wherein the pH is controlled with a mineral acid selected from the group consisting of sulfuric acid, hydrochloric acid, and nitric acid.

Claim 8

The method of claim 2 wherein the cationic reagent is an aliphatic amine of from about 6 to about 20 carbon atoms, and is employed at a concentration of from about 0.05 lb. to about 1.0 lb. per ton of concentrate, the source of fluoride ions is employed in an amount sufficient to provide from about 1 lb. to about 7 lb. of fluorine per ton of concentrate, and the pH is controlled in a range of from about 3 to about 4.

Claim 9

The method of claim 2 wherein the cationic reagent is an aliphatic amine of from about 8 to about 18 carbon atoms, and is employed at a concentration of from about 0.1 lb. to about 0.5 lb. per ton of ore, the source of fluoride ions is employed in an amount sufficient to provide from about 3.5 lb. to about 5 lb. of fluorine per ton of concentrate, and the pH is controlled in a range of from about 3 to about 4.