硫酸浸提对磷矿石物性变化影响

Effects of Sulfuric Acid Leaching on Physical Properties of Phosphate Ore

以硫酸浸提磷矿石的反应过程为研究对象,在反应温度80℃,搅拌速率300 r×min^(-1),反应时间180 min的反应条件下,对硫酸浸提体系进行研究。通过原子吸收、扫描电镜、X射线电子衍射、比表面积与粒径分布等测量及表征。结果表明:磷矿浸提反应120 min内大部分磷矿石转变为CaSO_4·2H_2O晶体,反应过程中,CaSO_4·2H_2O晶体首先在磷矿表面产生,在磷矿表面堆叠。随着反应进行,晶体长大后脱落,矿石结构坍塌。由此导致矿物平均粒径先增大后减小,孔性能的N_2等温吸附曲线滞回环由H3型转变为H4型。

Sulfuric acid leaching of phosphoric ore was investigated under conditions of reaction temperature 80℃, stirring speed 300 r·min^-1 and reaction time 180 min. SEM, XRD, EDS, BET and particle size analysis were used to characterize the resultant crystals. Atomic absorption spectrophotometer （AAS） was employed to determine ion concentrations. The results show that phosphate ore is almost decomposed and changed to CaSO4·2H2O grain after 120 min. The crystals of CaSO4·H2O grow on the surface of phosphate ore at the beginning, which peel off from the surface after reaching to certain limit with ore structure collapsed. The average particle size increases first and then decreases. The hysteresis loop of nitrogen adsorption isotherms changes from H3 into H4.