摘要
用SiO_2作催化剂可大大加快仲钨酸A转变成仲钨酸B,反应后溶液的pH值从6.7升至8.1,在此pH条件下,MoO_4^(2-)不聚合成Mo_7O_(24)^(6-),利用这一差异,在含有杂质钼的仲钨酸B溶液中,加入胍盐后,钨以仲钨酸B胍盐[CN_3H_6]_6W_7O_(24)·4H_2O形式沉淀,钼以MoO_4^(2-)留在溶液中,从而可分离钨和钼。
It is a very slow transformation from paratungs'tate A into Paratungstate B, nevertheless, it can be completed within several hours under the catalysis of silica. When the reaction finished, the pH value of the solution rose up to 8. J from its initial value 6. 7. Under the final pH condition, no polymerization of molybdenum occured. The difference between the abilities of forming polyanions of between tungsten and molybdenum can be used for their separation. Adding guanidine to the solution containing tungsten and molybdenum, tungsten precipitated in the form of guanidine paratungstate B, while molybdenum remained in the solution as normal molybdate.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1990年第8期793-796,共4页
Chemical Journal of Chinese Universities
关键词
仲钨酸A
仲钨酸B
胍
钨钼分离
Paratungstate A, Paratungstate B, Guanidine, Separation of W and Mo
