Study On The Flotation Process Of Low Grade Phosphorite

With the fast development of national economy, the demand for phosphorus resource is expanding constantly, and resource reduce constantly, especially there are fewer and fewer rich ores that can be utilized directly, the price of the phosphorus ore is going up constantly too. Because quarrying a ton of rich ores each time should lose 6- tons of lean ore, which causes enormous waste of phosphorus resources. With the constant deficient issue and government's relevant regulation, the trend of rich and poor ores mining simultaneously and the mining process of lean ore are imperative, the constant rise of the price of phosphorus ore makes the mining process of lean ore feasible economically too.According to the diffculty of dolomite desertion from phosphorite, three kinds of technological process that referred to straight floatation, straight-reverse floatation and double reverse floatation were studied, which had shown that both of the straight-reverse floatation and double reverse floatation could reach a good index that the content of P₂O₅ was more than 30% and the content of MgO was lower than 1%. Grinding experiment indicated that the best mesh-of-grind was 92% to 93% under the order of 200. The best dosage of collector, depressing agent and conditioning agent were decided with single factor and orthogonal experiments. Experiments of agitation level and aeration amount pointed out that better results could be gained when the level of agitation was high and the amount of aeration was low. Experiments of surfactant pointed out that SDS had a better effect in improving the grade and recovery rate of the concentrate, when the dosage of SDS was 4% to G-4, the grade and recovery rate of the concentrate had an increasing level of 2.64% and 26.52% separately. Due to the use of amine collector, the double reverse floatation flow had overcome the shortage of heating in the routine floatation of phosphorus, and its drug cost was relatively low.The function mechanism among the minerals and floatation drugs had been studied with the way of IR and academic calculation, which pointed out that absorption of G-4 on the surface of phosphorite belonged to physical and chemical types, but the chemical one was in the highest flight. Absorption of amine collector named GE-609 on the surface of quartz belonged to electrostatic and physical type. Distilled water could hardly wash the GE-609 down from the surface of quartz. Leading component of S-721 was the concentrated compound of naphthol sulfonic acid and formaldehyde. The compound had a stronger affinity to the Mg²⁺ on surfaceof dolomite than the Ca2+ on surface of phosphorite, which is the essential reason in the separation of phosphorite and dolomite. The leading components of soluble glass in function were HSiO3 hydronium and F^SiC^ colloid granule. Besides the restraining effect to quartz, soluble glass had a certain effect in dispersal of the pulp.According to the research, the text had basically clarified the new process flow in the separation between phosphorite and dolomite, calcite and quartz.