摘要
以机械活化碱分解黑白钨混合中矿及常压碱煮钨渣所得高杂粗钨酸钠溶液 (m(As) /m(WO3) =(0 .32～ 2 .94)× 10 -3,m(Si) /m(WO3) =(1.2 6～ 5 .84)× 10 -3)为原料进行钨酸钠结晶过程除砷、硅等杂质的研究 ,分析了结晶率及氧化铝的添加量对除杂效果的影响 .试验结果表明 :除杂效果与结晶率有关 ,当结晶率为 80 %～ 90 %时 ,除砷率和除硅率均可达 90 %以上 ,对m(As) /m(WO3)和m(Si) /m(WO3)分别为 3 .2 1× 10 -4 和 2 .41× 10 -3 的料液而言 ,除杂后的精液中m(As) /m(WO3)和m(Si) /m(WO3)可分别降至 3 .5 0× 10 -5和 3 .5 6× 10 -4 以下 .添加Al2 O3 可明显改善结晶过程中的除杂效果 ,且Al2 O3 经化学改性处理后 ,活性增强 ,除杂效果更好 ;在相同条件下 ,与不加铝盐相比 ,添加活性Al2 O3 可使精液中的杂质含量明显降低 ,除砷率由 88.48%增加到 94.6 5 % ,除硅率由 89.77%提高至97.74% .
The removal of arsenic and silicon from impure Na 2WO 4 solution was investigated by crystallization using the liquors ( m (As)/ m (WO 3)=0.32×10 -3 ～2.94×10 -3 , m (Si)/ m (WO 3)=1.26×10 -3 ～5.84×10 -3 ) from middle grade mixed wolframite and scheelite concentrate decomposed with NaOH by mechanical activation and tungsten residue leached by traditional digestion. The influences of the crystallization ratio and the addition of Al 2O 3 on removing impurities of As and Si were investigated. It was concluded that the results of removing impurities are related with the crystallization ratio of sodium tungstate and higher than 90% of removal ratio of arsenic and silicon can be obtained under the conditions of 80%～90% of Na 2WO 4 crystallizing ratio. High quality Na 2WO 4 solution can be reached and the values less than 3.50×10 -5 for m (As)/ m (WO 3) and 3.56×10 -4 for m (Si)/ m (WO 3) in the pure Na 2WO 4 solution can be obtained for the impure Na 2WO 4 solution containing 3.21×10 -4 of m (As)/ m (WO 3) and 2.41×10 -3 of m (Si)/ m (WO 3). It was also found that the addition of aluminum oxide can improve the process and better results can be obtained when Al 2O 3 was activated by chemical method. Under the same conditions the removal ratio of arsenic and silicon can be increased from 88.48% to 94.65% and from 89.77 % to 97.74 respectively compared with no Al 2O 3 addition.
出处
《中南工业大学学报》
CSCD
北大核心
2001年第3期251-254,共4页
Journal of Central South University of Technology(Natural Science)
基金
国家"九.五"科技攻关计划基金资助项目 (96 118 0 3 0 1)
关键词
钨酸钠
除砷
除硅
结晶率
除杂效果
sodium tungstate
crystallization
removing impurities
