Abstract：After the sample was dissolved in hydrochloric acid and nitric acid, the solution was heated with sulfric acid added until thick white smoke appeared. In diluted sulfuric acid medium, lead was converted to lead sulfate precipitate.After the precipitate was dissolved in HAc-NaAc buffer solution, the content of lead was determined by EDTA complexometric titration using xylenol orange as indicator.Then, excessive sodium hydroxide solution was added into filtrate,so that the iron, manganese and nickel ions were converted to precipitate in strong alkaline medium (pH>12), while aluminum and zinc existed in solution in the form of aluminate and zincate, realizing the separation of aluminum and zinc from iron, manganese and nickel ions. Two portions of filtrate were sampled. The solution was adjusted to slightly acid, and HAc-NaAc buffer solution at pH5.5-6.0 was added. In one portion of solution, the corresponding masking reagent was added, and zinc was determined by complexometric titration using xylenol orange as indicator. In the other portion of solution, excessive EDTA standard solution was added to complex aluminum and zinc, 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 potassium 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, lead and zinc in certified reference materials of iron ore. The relative standard deviations of determination results were in the range of 1.2 %-2.5 %. The found results were consistent with the certified values.
赵树宝. EDTA络合滴定法连续测定铁矿石中铝铅锌[J]. 冶金分析, 2011, 31(11): 66-69.
ZHAO Shu-bao. Continuous determination of aluminum, lead and zinc in iron ore by EDTA complexometric titration. , 2011, 31(11): 66-69.
