摘要
利用双氧水易与钨形成可溶性过氧钨酸的特性,提出了双氧水(H2O2)协同盐酸分解人造白钨(CaWO4)的新工艺,使CaWO4以氯化钙(Ca Cl2)和过氧钨酸(H4[WO3(O2)2])的形式溶解到浸出体系中,大幅提高了人造白钨的分解率。研究盐酸和双氧水浓度、反应温度、液固比及反应时间等因素对人造白钨分解效果的影响。结果表明:在H2O2存在的情况下,盐酸用量可大幅降低,所用的盐酸初始浓度很低故挥发损失很少;H2O2浓度的增加有利于反应的进行;当温度低于30℃时,升高温度对人造白钨的分解浸出有明显的促进作用,超过40℃后H2O2会逐渐分解且产物过氧钨酸变得不稳定反而不利于浸出。得到的较优条件如下:H2O2浓度2.4mol/L,盐酸浓度1.5mol/L,温度30℃,液固比10:1(mL/g),反应时间40min。在此条件下,人造白钨实现了完全分解。
A new process was proposed for the digestion of synthetic scheelite （CaWO 4 ） in hydrochloric acid solution using hydrogen peroxide （H2O2） as complexing agent. H2O2 as a chelating agent, can readily react with H2WO4 to form water-soluble peroxotungstic acid H 4 [WO 3 （O 2 ） 2 ], and the conversion rate of WO 3 was raised substantially. The effects of relevant parameters, such as the concentrations of HCl and H 2 O 2 , reaction temperature, liquid-to-solid ratio and reaction time, were studied. The results show that increasing the concentration of H 2 O 2 benefits the process and both the concentrate and consumption of HCl drastically drop and the volatility loss of HCl reduces noticeably. Elevating the temperature promotes the decomposition of CaWO 4 below 30℃while becomes unfavorable above 40℃because the stability of H 2 O 2 and peroxotungstic acid gradually decreases. The optimum process conditions are as follows： the concentrations of H 2 O 2 and HCl are 2.4 and 1.5 mol/L, respectively, the temperature is 30℃, the liquid-to-solid ratio is 10：1 （mL/g）, and the reaction time is 40 min. Under these conditions the synthetic scheelite can be completely decomposed.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2014年第12期3142-3146,共5页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金重点项目(51334008)
关键词
人造白钨
盐酸
双氧水
过氧钨酸
synthetic scheelite
hydrochloric acid
hydrogen peroxide
peroxotungstic acid
