Process and chemistry for reducing dolomite concentrations in phosphate processing
A magnesium suppressant/flocculant for use in separating dolomite from calcium phosphate. The magnesium suppressant/flocculant may be applied at a mine site prior to subjecting ore fractions to phosphate flotation or at a chemical plant after grinding.
1. A method of reducing dolomite concentrations in phosphate processing, the method comprising:
adding magnesium flocculant to phosphate rock during processing at a chemical plant; and wherein the magnesium flocculant is a polymer comprising:
a base monomer comprising acrylic acid, acrylamide, or a combination of acrylic acid and acrylamide: and
a functional monomer comprising hydroxyl ethyl methacrylate, 2-acrylamido-2-propane sulfonic acid, 3-allyl-1, 2-propanediol, and/or a derivative thereof.
2. The method of claim 1 , further comprising:
transferring the phosphate rock to a clarifier or thickener, where the magnesium flocculant selectively flocculates dolomite in the phosphate rock such that the dolomite settles to the bottom of the clarifier or thickener; and
removing the dolomite from the bottom of the clarifier or thickener.
3. The method of claim 1 , further comprising rinsing the phosphate rock with pond water to extract soluble magnesium prior to adding the magnesium flocculant.
4. The method of claim 3 , further comprising adding coagulant with the magnesium flocculant.
5. The method of claim 1 , further comprising grinding the fractions prior to adding the magnesium flocculant.
6. The method of claim 5 where the grinding results in a particle size of less than 100 microns.