王水分金渣氨水浸出回收金银试验研究

黄金提纯过程使用王水分金产生的分金渣中会有少量未被溶解且被氯化银包覆的金,为更好地回收有价金属,提高资源利用率,进行了氨水浸出氯化银、葡萄糖还原银、王水溶金等试验研究。其结果表明:每100 g烘干王水分金渣,在加入450 mL氨水、反应时间45 min、固液比为6的条件下,Ag浸出率可达72.5%;氨水浸出渣再采用王水溶金,金浸出率约77.29%;银总回收率71.05%,指标较好。

机械活化对氧化锌矿碱法浸出及其物化性质的影响

研究了不同活化时间、活化方式对云南兰坪低品位氧化锌矿碱法浸出的影响.结果表明,当浸出液NH4Cl浓度2.0mol/L、NH3·H2O浓度1mol/L、温度30℃、浸出液与浸出矿样液固比为10L/g时,未活化矿样浸出90min浸出率仅为60.08%,而活化90min矿样浸出90min的浸出率为69.36%,为可浸出含锌物相的103.97%;先磨后浸的强化效果优于边磨边浸.不同活化时间、活化方式不仅造成矿物的形貌、粒度分布不同,而且使矿样在球磨过程中的物相转化存在差异:活化与浸出步骤分离时,球磨过程发生了机械化学反应,矿样中ZnS被氧化成利于浸出的物相,从而比两步骤合并的浸出效果好.

云南某硫化铜银精矿火湿配合冶炼工艺研究

云南某铜银精矿铜、银、硫含量分别为5.63%、2 419 g/t和4.28%,-0.077 mm含量为79.50%。为了提高产品附加值,减少运输成本,为企业创造更好的业绩,对该精矿进行了火湿冶金工艺条件研究。结果表明,在工业食盐与试样质量比为1∶20,焙烧温度为850℃,焙烧时间为1.5 h情况下进行氯化焙烧,焙烧产物用浓度为2%的稀硫酸预处理后,再添加浓度为25%、体积为稀硫酸体积10%的氨水处理60 min,可获得96.60%和96.40%的铜、银浸出率。该方法是从铜银硫化矿精矿中高效回收铜、银的方法,具有工艺简单、回收率高、易操作等特点。

Dissolution kinetics of malachite in ammonia/ammonium sulphate solution

The dissolution kinetics of malachite was investigated in ammonia/ammonium sulphate solution. The effects of ammonia and ammonium sulphate concentration, pH, leaching time, reaction temperature, and particle size were determined. The results show that the optimum leaching conditions for malachite ore with a copper extraction more than 96.8% are ammonia/ammonium concentration 3.0 mol/L NHaOH ＋ 1.5 mol/L （NH4）2SO4, liquid-to-solid ratio 25：1 mL/g, leaching time 120 min, stirring speed 500 r/rain, reaction temperature 25 ℃ and particle size finer than 0.045 mm. The dissolution process of malachite with an activation energy of 26.75 k J/tool is controlled by the interface transfer and diffusion across the product layer. A semi-empirical rate equation is obtained to describe the leaching process and the reaction orders with respect to concentration of ammonia and ammonium sulphate are 2.983 0 and 0.941 1, respectively.