Selective flocculation process for the recovery of phosphate
AssigneeResource Technology Associates
InventorDouglas R. Shaw
Life of this patent
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Abstract
A process for separating and recovering non-metallic minerals, particularly phosphate, from an ore containing non-uniform sized particles, including colloidal particles. The ore is slurried in an alkaline, aqueous solution with a dispersing agent. A flotation collector is added, and the mixture is contacted with a hydrophobic, high molecular weight, nonionic polymer to flocculate the fine particles and make them amenable to subsequent flotation. A second embodiment provides a process for the recovery of an upgraded non-metallic ore from ore slimes, such as phosphate slimes, utilizing a high molecular weight, polyacrylamide, anionic flocculating agent.
Claims6
A process for separating an upgraded phosphorus ore from an aqueous slurry containing said phosphorus ore comprising particles from about minus 20 to about minus 150 mesh, comprising:
- (a) contacting the slurry at a pH of at least about 10 with a dispersing agent selected from the group consisting of sodium silicate, sodium hydroxide and polyacrylate in an amount sufficient to achieve dispersion in the slurry of substantially all the ore particles;
- (b) contacting the dispersed mixture of step (a) with a flotation collector in an amount sufficient to coat and render hydrophobic substantially all the ore particles capable of being coated therewith;
- (c) vigorously agitating the mixture of step (b) to achieve said coating;
- (d) contacting the mixture of step (c) with a hydrophobic nonionic polyethylene oxide in an amount sufficient to cause the agglomeration of substantial portions of the fine particles of about minus 150 mesh;
- (e) gently mixing the mixture of step (b) to provide dispersion of the polyethylene oxide of step (d) and form said agglomerates without significantly breaking up said agglomerates;
- (f) subjecting the mixture of step (e) to froth flotation by the addition of gas bubbles thereto;
- (g) separating the phosphorus-rich froth concentrate from the mixture of step (f).
A process for recovering a phosphorus ore upgraded by at least about 5% phosphate content from a phosphate slime containing clays and said phosphorus ore comprising particles of about minus 150 mesh in an aqueous slurry of a ratio of solids to liquids of between about 10% and about 30%, comprising:
- (a) adjusting the pH of said aqueous slurry to a pH of at least about 10;
- (b) contacting said slurry with a dispersing agent selected from the group consisting of sodium silicate, sodium hydroxide and polyacrylate in an amount sufficient to disperse the fine particles in the slurry;
- (c) contacting said slurry with an anionic polyacrylamide in an amount sufficient to agglomerate a substantial portion of the fine ore particles to the exclusion of the clay particles;
- (d) allowing the mixture of step (c) to separate into an upper slime phase and a lower flocculate concentrate phase;
- (e) contacting the concentrate phase with a flotation collector in an amount sufficient to coat and render hydrophobic substantially all of the ore particles capable of being coated therewith;
- (f) subjecting said concentrate phase to froth flotation by the addition of gas bubbles thereto;
- and
- (g) separating the phosphorus-rich froth concentrate from said concentrate phase.
Dependencies are inferred from the claim text.