为了优化菱镁矿尾矿酸浸提镁工艺,提高酸浸效率,对某菱镁矿尾矿中的镁进行了酸浸行为研究,考察了不同反应因素对菱镁矿尾矿中镁浸出率的影响,从动力学角度分析了菱镁矿尾矿中镁的浸出行为。研究结果表明:提高菱镁矿尾矿的细度、硫酸的浓度和浸出温度均有利于镁浸出率的提高,液固比变化对镁浸出率的影响不大。当试样的粒度为0.074~0 mm,硫酸的浓度为1.5 mol/L,浸出液固比为3 m L/g,浸出温度为80℃,浸出时间为2 h时,镁浸出率可达84%。镁的硫酸浸出过程符合液-固相非催化反应的缩芯模型,浸出过程受扩散和化学反应共同控制,浸出反应的表观活化能为21.02 k J/mol。
Bacillus mucilaginosus was used in pretreatment ofpyrolusite to facilitate the flotation removal of quartz from pyrolusite minerals. Quartz was activated by B. mucilaginosus, whereas pyrolusite was unaffected at pH 7 with laurylamine as collector. Flotation recovery of pyrolusite with B. mucilaginosus pretreatment is 73.62%, slightly lower than that of the process without biopretreament, namely 74.70%. The grade of concentrate of recovered pyrolusite is 19.44%, 2.18% higher than that of the recovered pyrolusite without B. mucilaginosus pretreatment （17.26%）. The results of FTIR and SEM showed that no bacteria were adsorbed on the surface of quartz or pyrolusite, indicating that the better selectivity and collectability of flotation resulted from bacterial byproducts. And interaction of bacterial byproducts such as extracellular bacterial polysaccharide, extracellular bacterial protein and acetic acid, on minerals were studied by FTIR and adsorption.
