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一、前言测定铝的关键是分离,尤其是铝与铁、钛的分离。汞阴极电解、溶剂萃取、离子交换等分离法,操作繁复,有的尚有:Mn、Ti等仍不能除去,分离能力差,成本高等缺点。在沉淀分离法中,磷酸铝法只能分离铁,而Al、Ti仍一同沉淀;苯甲酸盐法也有此缺陷。由于铝的两性,故人们广泛采用强碱分离,单独用氢氧化钠分离时,由于氩氧化铁之胶状沉淀共沉淀等现象严重,为此,人们用NaOH+H_3BO_3,NaOH+H_2O_2,NaOH
First, the foreword Determination of aluminum is the key to separation, especially aluminum and iron, titanium separation. Mercury cathodic electrolysis, solvent extraction, ion exchange and other separation methods, complex operation, and some are still: Mn, Ti and so can not be removed, poor separation, high cost shortcomings. In the precipitation separation method, the aluminum phosphate method can only separate iron, while Al, Ti still precipitate together; benzoate method also has this defect. Due to the amphoteric nature of aluminum, people widely use strong alkali separation, when separated by sodium hydroxide alone, due to the phenomenon of co-precipitation of colloidal iron hydroxide precipitated, so people use NaOH + H_3BO_3, NaOH + H_2O_2, NaOH