US 4,364,824 A · Flotation of phosphate ores containing dolomite

Abstract

A reverse flotation process for removing alkaline earth metal carbonate impurities particularly dolomite and calcite as the cell overflow from a flotation feed reagentized with water, a carbonate collector, a phosphate depressant and a pH regulator to about 20-30% solids and a pH of about 5.5-6.0. The phosphate concentrate is collected as the cell underflow. The carbonate collectors comprise stable salts of sulfonated linear fatty acids having a straight carbon chain of about eight to twenty-two carbon atoms and a direct sulfur to carbon bond. The sodium salt of sulfonated oleic acid is the preferred carbonate collector. Phosphate depressants include sodium tripolyphosphate. The flotation feed particle size is preferably such that 90% by weight of the particles pass through a 42 Mesh (Tyler) screen. The effectiveness of the separation improves as the particle size of the flotation feed is decreased.

Claims23

Dependent claims

A flotation method for separating alkaline earth metal carbonate impurities from a deslimed sized phosphorite ore the steps comprising

(a) slurrying with water to about 20-25% solids a phosphorite ore fraction containing phosphate values and an excessive level of alkaline earth metal carbonate impurities, said phosphorite ore fraction having a particle size less than about 0.45 mm;
(b) reagentizing said phosphorite ore fraction by adding thereto a pH regulator to adjust the pH of said slurried phosphorite ore fraction to about 5.5-6.0, a carbonate collector comprising a water soluble salt of a sulfonated linear fatty acid having a straight carbon chain of 12 to 22 carbon atoms, said carbonate collector having a direct carbon to sulfur bond, and a phosphate depressant to depress the phosphate;
(c) subjecting said reagentized, slurried phosphorite ore fraction to flotation;
(d) separating the cell overflow which contains the major amount of said alkaline earth metal carbonate impurities;
and
(e) collecting the cell underflow phosphate concentrate from said flotation cell which contains the major portion of said phosphate values and a substantially reduced level of alkaline earth metal carbonate impurities.

3 more elements

A process for beneficiating a phosphate ore flotation feed by a reverse flotation process, said feed being obtained from a phosphorite ore having a particle size range in which at least 90% by weight of the particles are less than about 0.45 mm said phosphorite ore including discrete particles of francolite containing a major portion of the phosphate values in said phosphorite ore, said ore also including discrete particles of an alkaline earth metal carbonate mineral impurity, the steps of said process comprising:

(a) first preparing a reagentized phosphate ore flotation feed by adjusting the solids level of the phosphorite ore with water to a solids level of 20-30%;
adding a pH regulator as necessary to adjust the pH to a range from about 4.5-7.0;
adding a francolite depressant to said phosphorite ore at the rate of about 0.2 to 5 lbs/ton of solids, said depressant being selected from the group consisting of sodium tripolyphosphate, sodium hexametaphosphate, sodium pyrophosphate, fluosilicic acid and orthophosphoric acid;
adding a carbonate collector anionic reagent to said phosphorite ore in an amount from about 0.2 to about 5.0 lb/ton of phosphorite ore solids, said carbonate collector being selected from the group consisting of the alkali metal salts of sulfonated linear fatty acids having a straight carbon chain from about eight to twenty-two carbons, and a direct carbon to sulfur bond, thereby forming a reagentized phosphate ore flotation feed;
(b) subjecting the reagentized phosphate ore flotation feed to a reverse flotation wherein a major portion of the alkaline earth metal carbonate impurities are floated away as the flotation cell overflow and a major portion of the francolite from the phosphate ore flotation feed is recovered as the flotation cell underflow.

2 more elements

Dependencies are inferred from the claim text.

Flotation of phosphate ores containing dolomite

Life of this patent

Flotation of phosphate ores containing dolomite

Life of this patent

Abstract

Claims23