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含钛高炉渣中富钛相因其分散在炉渣的多种矿相中且晶粒细小,常规选矿分离技术难以将富钛相从含钛高炉渣中有效地分离出来。将超重力场引入到CaO-TiO2-SiO2-Al2O3-MgO熔体,为了在冷却过程中钙钛矿相定向富集,重点探讨了熔体中钙钛矿相在不同重力系数及冷却速率下富集规律。研究结果表明当CaO-TiO2-SiO2-Al2O3-MgO熔体以v=5 K·min-1冷却速率在重力系数G≥750进行富集后,试样沿着超重力方向出现明显分层且试样中钙钛矿相沿着超重力方向呈现粒度梯度分布。对分层的试样纵剖后进行光学显微镜观察,熔体中的钙钛矿相在超重力作用下全部富集到试样的中下部区域,而在试样上部区域没有发现钙钛矿晶粒。对本实验条件下熔体中钙钛矿相运动机制进行分析,熔体中钙钛矿晶粒的运动速度与晶粒直径的平方成正比,熔体中大粒径的钙钛矿晶粒比小颗粒晶体在相同的重力系数下具有更大的运动速度,最终富集到试样的底部,而细小的钙钛矿晶粒则富集到式样的中部。假设熔体中的钛以TiO2形式存在,当CaO-TiO2-SiO2-Al2O3-MgO熔体以v=5 K·min-1冷却速率在重力系数G=750时进行富集后,富集到试样中下部精矿中的TiO2质量分数可达34.8%,而尾矿中TiO2质量分数仅为11.28%。考虑到常重力试样中TiO2质量分数为22.34%,通过离心富集后,精矿中钛的回收率高达77.13%。
The titanium-rich phase in titanium-bearing blast furnace slag is dispersed in various mineral phases of slag and the grains are small. It is difficult to separate the titanium-rich phase from the titanium-containing blast furnace slag by conventional separation and separation techniques. In order to enrich the perovskite phase during the cooling process, the supergravity force field was introduced into the CaO-TiO2-SiO2-Al2O3-MgO melt. The perovskite phase in the melt under different gravities and cooling rates Set rules. The results show that when the CaO-TiO2-SiO2-Al2O3-MgO melt is enriched with the gravitational coefficient G≥750 at v = 5 K · min-1 cooling rate, In the sample, the perovskite phase presents a gradient distribution of particle size along the direction of supergravity. The layered samples were observed by optical microscope after longitudinal section, the perovskite phase in the melt was all enriched to the middle and lower regions of the sample under the action of super-gravity, and no perovskite crystals were found in the upper region of the sample grain. The mechanism of perovskite phase movement in melt is analyzed under this experimental condition. The velocity of perovskite grains in melt is proportional to the square of grain diameter. The grain size of large-diameter perovskite in melt is small Particle crystals have a greater velocity of motion at the same gravitational coefficient, eventually enriching to the bottom of the sample, while fine perovskite grains are concentrated in the middle of the pattern. Assuming that the titanium in the melt exists in the form of TiO2, when the CaO-TiO2-SiO2-Al2O3-MgO melt is enriched at a cooling rate of v = 5 K · min-1 at a gravitation factor of G = 750, The content of TiO2 in the middle and lower concentrates can reach 34.8%, while the TiO2 content in the tailings is only 11.28%. Taking into account the normal gravity of TiO2 sample mass fraction of 22.34%, after enrichment by centrifugation, the recovery of titanium concentrate 77.13%.