黝铜矿碱性体系制备锑酸钠的试验研究

首先采用碱浸法在硫化钠与氢氧化钠体系中选择性浸出黝铜矿中的锑,然后以碱浸液为原料,采用高温高压氧化沉淀生成锑酸钠。分别研究了碱浸工艺参数对锑浸出率和沉锑工艺参数对锑酸钠沉淀率的影响。结果表明,黝铜矿高温高压下浸出分离锑的最佳条件为:浸出温度150℃、浸出时间6 h、液固比6∶1、硫化钠浓度120 g/L、氢氧化钠浓度80 g/L。在此条件下,锑的浸出率达到80%以上,远高于在低温常压下浸出率仅为45%的指标;黝铜矿浸出液高温高压氧化制备锑酸钠最佳反应条件为:反应时间2 h、氢氧化钠过量系数1.6、氧气压力0.8 MPa、温度150℃,该条件下的沉锑率可高达98%以上。对该方法制备的锑酸钠进行分析的结果显示,所制锑酸钠从产品质量、粒径、形貌上都满足工业需求。

Experimental Study on Preparation of Sodium Antimonate from Tetrahedrite Alkaline System

The alkaline extraction method is adopted to selectively extraction the antimony from the tetrahedrite in the system of sodium sulfide and sodium hydroxide.Then,high temperature and pressure oxidation precipitation was used to generate sodium antimonate from alkaline extraction solution.And the effects of alkaline extraction process parameters on the antimony extraction rate and antimony precipitation process parameters on the precipitation rate of sodium antimonate were studied respectively.The results show that the best conditions of extraction antimony from tetrahedrite at high temperature and high pressure are:extraction temperature is 150℃,extraction time is 6 h,liquid-solid ratio is 6∶1,sodium sulfide concentration is 120 g/L,sodium hydroxide concentration is 80 g/L.Under these conditions,the extraction rate of antimony reaches more than 80%,which is much higher than that of 45%under low temperature and ordinary pressure.The optimum reaction conditions for preparing sodium antimonate by high temperature and high pressure oxidation of tetrahedrite leaching solution are as follows:reaction time 2 h,excess coefficient of sodium hydroxide 1.6,oxygen pressure 0.8 MPa and temperature 150℃.With these conditions,the antimony precipitation rate can reach more than 98%.The results show that the sodium antimonate prepared by this method meets the industrial needs in terms of product quality,particle size and morphology.