富硅软锰矿强磁选-碱浸脱硅工艺

High-intensity magnetic separation-alkaline leaching process to desiliconize from silicon-rich pyrolusite

对硅锰质量比为3.5:1的富硅软锰矿采用强磁选-碱浸工艺脱硅,通过单因素和正交试验研究强磁选试验中磨矿细度和磁场强度,碱浸试验中反应温度、反应时间、NaOH浓度和液固比对硅脱除率的影响,利用"减缩核模型"研究碱浸过程中反应温度对硅脱除率影响的动力学,并得到相应的动力学方程。研究结果表明:在矿石入选粒度为小于74μm占75%、磁场强度为1273.2kA/m、碱浸反应温度为120℃、反应时间为5.5h、NaOH浓度为16mol/L、液固比(mL/g)为5:1的条件下,得到碱浸渣中硅锰质量比为0.3:1,硅脱除率为81%。碱浸过程受化学反应控制,表观反应活化能为67.77kJ/mol。

By means of high-intensity magnetic separation-alkaline leaching to desiliconize from silicon-rich pyrolusite of silicon-manganese mass ratio of 3.5：1, using single factor and orthogonal experiments to study the grinding fineness and magnetic field strength in magnetic separation test, the effect of temperature and time of reaction, concentration of NaOH and the ratio of liquid-solid to the removal rate of silicon in alkaline leaching test, using the ＂Reduction of nuclear model＂ to study the dynamics of effect of reaction temperature to the removal rate of silicon in alkali leaching process,and get the corresponding dynamic equation. The results show that under the conditions of the selected ore particle size of75% less than 74 μm, the magnetic field intensity of 1 273.2 k A/m, the alkaline leaching reaction temperature of 120 ℃,reaction time of 5.5 h, concentration of NaOH of 16 mol/L and the ratio of liquid-solid（m L/g） of 5：1, the alkali leaching residue is obtained with the silicon-manganese mass ratio of 0.3：1 and removal rate of silicon of 81%. The alkali leaching process is controlled by chemical reaction and the apparent activation energy is 67.77 k J/mol.