两种白钨矿碱分解溶液的蒸发与结晶过程研究  

STUDY ON THE EVAPORATION- CRYSTALIZATION OF LEACHING SOLUTION FOR TWO KINDS OF SCHEELITE BY KAUSTIC SODA

作　　者：徐志昌[1] 张萍[1] 

机构地区：[1]清华大学核能与新能源研究院,北京102201

出　　处：《中国钼业》2016年第2期32-39,共8页China Molybdenum Industry

摘　　要：本文采用旋转薄膜、玻璃真空蒸发器,对两种组成不同的白钨矿的苛性钠浸出溶液,选择了两种蒸发温度（90℃和80℃）下的蒸发-结晶试验。蒸发-结晶过程是按照流程设计的要求,所进行的承上启下的中间过程。目的是取得含有与不含有钼酸钠的钨酸钠结晶,以方便萃取分离钨/钼过程使用,并节省调整酸度过程的耗酸量;同时,取得高浓度氢氧化钠溶液,以便循环使用苛性钠试剂,并节省浸出试剂的消耗量。试验结果表明,对于含钼的钨酸钠-苛性碱浸出溶液而言,蒸发-结晶温度为90℃时（-0.098 MPa,56 r/min）,尽管,氢氧化钠的回收率达到了尽善尽美,ηNa OH=100%,但是,美中不足的结晶率分别是：ηW=84.39%和ηM o=69.60%。即钨酸钠和钼酸钠的循环率分别为：ρw=16.17%和ρMo=31.29%。对于不含钼的钨酸钠-苛性碱溶液而言,蒸发-结晶温度为80℃,（-0.098 MPa,56 r/min）,尽管,氢氧化钠的回收率接近完美,ηNa OH=100.0%,但是,美中不足是钨酸钠的循环率达到了,ηW=17.00%。两种结果表明,蒸发-结晶温度范围为80~90℃下,氢氧化钠的回收率,尽如人意,美中不足的是钨酸钠的循环率达到了16.1%~17.0%,钼酸钠的循环率达到31.29%。钨酸钠和钼酸钠之间的分离系数范围是1.21~1.56。Evaporation and crystallization of two kinds of leaching solution of scheelite were tested by glass evapora- tor of film rotary so as to recover caustic soda in the leaching process and to get the sodium tungstate in the liquid- liquid extraction process. The results have shown that there are two kinds of status. One is the solution bearing mo- lybdenum and another is the solution free molybdenum. Although the former（90℃, -0. 098 MPa,56 r/min） is to get complete recovery of caustic soda （ ηNaon = 100% ） , bring a few and a larger recycle rate of 16. 17% and 31.29%. The latter（80℃, -0.098 MPa,56 r/min） is to get recovery rate of sodium hydroxide （ηNaOH, = 100. 0% ） ,bring a certain recycle rate of the sodium tungstate , 17.00%, In the both of evaporation-crystallization process, the recycle rate of sodium tungstate is about 16. 17% - 17.00% and the recycle rate of sodium molybdate is 31.29%. The separation coefficient between tungsten and molybdenum is about 1.21 - 1.56.

关 键 词：旋转薄膜蒸发-结晶过程 含钼的与不含钼的白钨矿浸出溶液 钨酸钠和钼酸钠的结晶率 氢氧化钠回收率 钨酸钠和钼酸钠的循环率 分离系数 

分 类 号：TF803.23[冶金工程—有色金属冶金]