充气量对低品位铝土矿旋流-反浮选分离的影响

Effect of Aeration Quantity on Separation of Low-Grade Bauxite by Cyclone-Reverse Flotation

依据我国铝土矿的特点和旋流分选规律，对w（Al2O3）／w（SiO2）为4．39，磨矿细度为粒度小于0．074mm占61．90％（质量分数）的铝土矿进行了旋流-反浮选试验．考察了充气量对分离过程和分离指标的影响．结果表明：在0～4．0m^3／h范围内增大充气量，轴向零速包络面向轴心收缩，分选指标变差；在同样的充气量条件下，增大入料压力有利于旋流-反浮选过程的进行，分选指标得以改善；在0-0．8m^3／h范围内增大充气量，轴向零速包络面向轴心轻微收缩，削弱矿物颗粒间基于粒度差异的分级作用，但却能在一定程度上强化它们之间基于密度和表面性质差异的分选作用，分选指标优于不充气时．

Based on the characteristics of China＇ s bauxite and cyclone separation, the cyclonereverse flotation technique was experimentally carried out for the separation of low-grade bauxite, of which the w（Al2O3）/w（SiO2）, abrasive size and mass fraction are 4.39, less than 0.074 rnm and 61.90%, respectively. The effect of aeration quantity on separation process/indexes was investigated. The results showed that when the aeration quantity increases in the range from 0 to 4.0 m^3/h, the envelope of zero vertical velocity will shrink around the axis, and make the separation indexes poorer. But with the same aeration quantity, the increasing feed pressure will be advantageous to the process of cyclone-reverse flotation and make the separation indexes better. When the aeration quantity increases in the range from 0 to 0.8 m^3/h, the envelope of zero vertical velocity shrinks slightly around the axis to weaken the classification effect on mineral particles due to size difference, but strengthen the separation effect on those particles due to the differences of density and surface properties, and at that time, the separation indexes are better than no aeration.