论文部分内容阅读
为改进钼精矿中铼的回收，美国矿务局开发了一套由压力浸出、溶剂革取和离子交换组成的完整工艺。工业上，铼是从硫化钼焙烧成氧化钼过程中所排放的气体中进行回收的。因该工艺效率低，所以30％－40％的铼损失掉，而且需要大面积洗气设备才能回收气体SO2。美国矿务局研究人员指出，当硫化钼转变成氧化钼的反应在温度为200－215℃；氧过压为200－300lb／in2，反应时间为3－4h条件下，铼的可溶率达99．9％以上，并且可直接把硫转变成硫酸。处理洗气液的工序是把浸出液的pH值从0．7调到10以回收铼。准备取而代之的新工艺采用溶剂萃取法把铼和所有可溶性钼富集转变成碱性溶液。采用McCabe-Thiele分析法所预示的条件进行溶剂萃取，连续溶剂革取系统由三级革取、一级洗涤、一级或两级反革组成。在稳定态条件下，铼的浓度提高了5倍，回收率达99％以上。碱性反萃液流过氯化季铵，进一步得到净化并提高铼的浓度。全部铼和少于0．5％的钼得到吸附。为了选择性地除去钼，用0．1mol氢氧化钠溶液洗涤吸附了钼的树脂，然后用0．5molNH4SCN溶液来解吸铼。载有铼的洗提液可进行蒸发使其饱和析出高铼酸铵。
To improve the recovery of rhenium in molybdenum concentrates, the U.S. Bureau of Mines has developed a complete process consisting of pressure leaching, solvent extraction and ion exchange. Industrially, rhenium is recovered from the gas discharged during the molybdenum sulfide molybdenum sulfide process. Due to the low efficiency of the process, 30% -40% of the rhenium is lost, and a large area scrubber is needed to recover the gaseous SO2. US Bureau of Mines researchers pointed out that when the reaction of molybdenum sulfide into molybdenum oxide at a temperature of 200-215 ℃; oxygen overvoltage of 200-300lb / in2, the reaction time is 3-4h, rhenium soluble rate of up to 99.9%, and can be directly converted into sulfuric acid sulfur. The process of treating the scrubbing liquid is to adjust the leachate pH from 0.7 to 10 to recover the rhenium. The new process, to be replaced, uses solvent extraction to convert rhenium and all soluble molybdenum into an alkaline solution. Solvent extraction was performed using the conditions indicated by the McCabe-Thiele analysis. The continuous solvent extraction system consisted of three stages of extraction, one stage of washing, one stage or two stages of counter-revolution. Under steady-state conditions, rhenium concentration increased 5-fold, the recovery rate of 99% or more. The basic stripping solution flows through the quaternary ammonium chloride to further purify and increase the rhenium concentration. All rhenium and less than 0.5% molybdenum get adsorption. In order to selectively remove the molybdenum, the molybdenum-adsorbed resin is washed with 0.1 mol sodium hydroxide solution and then the rhenium is desorbed with 0.5 mol NH4SCN solution. The rhenium-containing eluent may be evaporated to saturate ammonium perrhenate.