Development And Application Of Reverse Flotation Collector For Magnesium Removal From Collophane

Phosphate rock is a vital nonrenewable resource which is neither substitutable nor recyclable in agricultural applications. The increased need for world food production assures the long-term growth in world phosphate rock demand.Phosphate rock resources abound in our country. With the utilization of phosphate rock resources, rich ore resources become less and less, making it urgent to make use of cellophane which is poor, fine and complex.The separation of dolomite from apatite has been recognized as one of the most difficult subjects in mineral processing due to the similarities in their physiochemical properties.In an attempt to develop a selective collector to separate dolomite from phosphate, a series of surfactants were used to mix with oleate. Then, the compound collector was applied to flotation tests of Fang Ma Shan phosphate and flotation tests of flotation column.In the flotation tests developing collector, Shen Long Jia phosphate were used as sample. Mixtures of surfactants and sodium oleate(major components) were used as reverse flotation collector. The components and proportion of each component constituting the collector MG-1 obtaining the optimum flotation index were found out by comparing reverse flotation index of different collectors. In addition, factors influencing flotation index were investigated, including dosage of sulfuric acid,pulping time and temperature. The experimental investigation shows that:MG-1 turns out to be a more effective collector when the temperature is comparatively low; under conditions that the dosage of sulfuric acid is 10kg/t, the dosage of MG-1 is 0.8kg/t and the grade of raw ore is 23.60%,through one roughing, favorable flotation index,concentrate grade of 32.26% and recovery of 84.41%, was achieved.The performance of MG-1 was tested using Fang Ma Shan phosphate as sample.In the flotation of Fang Ma shan phosphate, direct flotation process of one roughing,one cleaning and one scavenging and reverse flotation process of one roughing and one scavenging were used. In direct flotation, Conditions of roughing were that the dosage of Na2CO3 was 3kg/t, the dosage of Na2 Si O3 was 4kg/t and the dosage of FMS collector was 0.6kg/t; no reagent was used during cleaning; 0.2kg/t FMS wasused during scavenging. In reverse flotation, 12kg/t sulfuric and 0.2kg/t MG-1 were used during roughing;2kg/t sulfuric was used during scavenging. the grade of raw ore is 23.60%. Favorable flotation index, concentrate grade of 28.69% and recovery of80.73%, was achieved.In the flotation tests applying MG-1 to a newly developed flotation column,under conditions that the dosage of MG-1 was 0.8kg/t, the dosage of sulfuric was8kg/t, flotation index, concentrate grade of 32.74% and recovery of 81.72% was achieved by only one roughing at room temperature.Possible functions of compositions were explained by calculating HLB value of each surfactant. Result shows that mixture of A and B plays the role of oxidized ore collector; C plays the role of foaming and dispersion; D plays the role of dispersion and solubilizing. Synergistic effect between anionic surfactant A and B was calculated and confirmed. By comparing CMC value, conclusions can be draw that a small amount of C can lower CMC value of mixture of A and B and therefore achieving good flotation index;a small amount of C and D can lower CMC value of mixture of A and B and therefore achieving better flotation index.