Research On Depression Of Microorganisms To Dolomite In Flotation Of Phosphate Rock

The phosphate rock resources in Guizhou are abundant. However, it is large reserves of siliceous and calcareous phosphate with middle-low grade, the content of calcium minerals,silica minerals and sesquioxid are high. Magnesium oxide and sesquioxide can cause adverse effect on wet process for producing phosphoric acid.Therefore, strengthening the study on mineral processing of middle-low grade phosphate and reducing the content of magnesium oxide and sesquioxide of phosphate concentration is particularly important to improve the utilization rate of phosphate rock resources in Guizhou. Double-reverse flotation process is more methods for phosphate rock that contains silica and calcia. But the reverse flotation has poor effect on sesquioxid, amine collectors which price is high, and it is not easy to control the process and large amount production of flotation foam. Direct flotation has good effect on sesquioxid and it can overcome the problems of amine collectors for using fatty acid collector.Hereby, the removal effect of dolomite is poor. Organic Inhibitor of dolomite is not friendly to the environment. The biological inhibitor has the advantages of good sorting effect and no polluting the environment, study on biological flotation inhibitor to dolomite and its mechanism is of great significance.Focusing on the siliceous and calcareous phosphate with high content of sesquioxide and dolomite in Guizhou, the direct flotation technology is used to study on actual ore flotation,and on the basis study on flotation of the microorganism is used as dolomite inhibitors and the inhibitory mechanism of microorganism is used as dolomite inhibitors.Actual ore flotation research shows that under the condition of pH equals 10,using sodium silicate, tannin inhibition of silicate minerals and calcium carbonate mineral, GYF collecting phosphate mineral, via coarse separation, fine separation and scavenging, with the grade of phosphate concentrate P2O5 is 30.02%, the recovery rate of P2O5 was 74.67%, the content of Fe2O3 is 1.11%, the content of Al2O3 is 1.81%, the content of MgO is 2.67%, the effect on silicon removal and stripping is better, but concentrate in the high content of magnesium oxide. Escherichia coli and bacillus subtilis was used as the dolomite inhibitors, depression effect of escherichia coli ondolomite is better. Closed circuit of one-stage roughing separation and one-stage scavenging was adopted, the grade of phosphorus concentrate for P2O5 is 30.75%, the recovery rate is 75.32%, content of MgO is 1.15%, the effect of mechanism depress magnesium is better.Adsorption experiments showed that the absorption quantity of escherichia coli and bacillus subtilis on the surface of the dolomite were greater than that on the surface of the collophanite. The adsorption in escherichia coli has good selective adsorption to dolomite, the Inhibitory effect of escherichia coli depression on dolomite is better than bacillus subtilis.Mechanism study on microbial flotation depression by infrared spectrum and dynamic potential method shows that escherichia coli and bacillus subtilis chemical adsorption occurred on the mineral surface under alkaline conditions.After the action of the two kinds of bacteria on the mineral surface, the negative potential value of the mineral increases.But the negative potential of the dolomite increases significantly than that of the compound phosphate rock.