研究低品位红土镍矿预焙烧过程矿相的转化和碱浸过程硅的提取.结果表明,红土镍矿经650℃预焙烧2 h,由于利蛇纹石转化为镁橄榄石和原顽辉石使得矿物的活性显著提高,当磨细矿样(44~61μm)经预焙烧后,与氢氧化钠溶液(60 g/L)按照1:5的固液比混合在140℃浸出120 min,硅的提取率可达到89.89%,镁、铁、镍等有价元素在固体渣中得到富集.红土镍矿的浸出动力学可由扩散通过产物层控制模型来描述,计算得到过程的活化能为11.63 kJ/mol,动力学方程为1?3(1?x)2/3+2(1?x)=13.53×10?2exp[?11.63/(RT)]t.%The mineralogical phase transformation of a low-grade nickel laterite ore during pre-roasting process and the extraction of silicon during alkaline leaching process were investigated. The results indicate that the reaction activity of nickel ores is effectively improved by pre-roasting at 650 ℃ for 2 h, because of the transformation of lizardite into magnesium olivine and protoenstatite. When finely ground ore samples (44?61μm)pre-roasted firstly react with sodium hydroxide solution (60 g/L) with a solid/liquid ratio of 1:5 at 140 ℃ for 120 min, the extraction of silicon can reach 89.89%, and the other valuable elements of magnesium, iron and nickel are accumulated in the solid residues. The leaching kinetics of nickel laterite ore can be described successfully by the diffusion through the product layer control model. The activation energy is calculated to be 11.63 kJ/mol and the kinetics equation can be expressed as 1?3(1?x)2/3+2(1?x)=13.53×10?2exp[?11.63/(RT)]t.
展开▼
