含钼滤渣以及滤液中铝的测定

采用NaOH熔融分解滤渣,热水浸取熔融物,将溶液调至微酸性后加入pH值为5.5～6.0的乙酸-乙酸钠缓冲溶液,加入盐酸羟胺使六价钼还原成五价钼,然后在溶液中加入过量EDTA标准溶液,使之与溶液中的铝、钼、镍等金属离子络合,以二甲酚橙为指示剂,用氯化锌标准溶液滴定过量的EDTA标准溶液,然后用氟化钠破坏EDTA-Al络合物,再用氯化锌标准溶液回滴释放出来的EDTA,从而间接测定铝.用本方法对废钼镍催化剂回收实验中滤渣及滤液中的铝进行测定,测定值与认定值相符.

Determination of Aluminum in Residue and Filtrate Containing Molybdenum

After the residue was decomposed by NaOH fusion,the fusant was leached with hot water.The Solution was adjusted to slightly acid,and HAC-NaAC buffer solution at pH 5.5~6.0 was added,then the Hydroxylamine Hydrochloride was added to make hexavalent molybdenum reductive into pentavalent molybdenum.In the solution,excessive EDTA standard solution was added to complex aluminum and molybdenum,nickel,and the excessive EDTA standard solution was titrated with Zinc chloride standard solution using xylenol orange as indicator,then,the EDTA-Al complex was destroyed with sodium fluoride,and the released EDTA was back titrated with Zinc chloride standard solution,so that the content of aluminum could be indirectly determined.The proposed method was applied to the determination of aluminum in the experiment of recovery from waste molybdenum and nickel catalyst,which is indicated the results were consistent with the certified values.