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一、前言测定锰矿及锰铁中高合量锰,通常都是采用氧化还原法,如铋碳纳法、氧化锌法、过硫酸铵——银盐法、氯酸钾法和氧化铅法等等。近年来由于氨羧络合剂及金属指示剂在分析化学上获得广泛应用。迄至目前为止已有很多文献介绍用 EDTA 法测定锰。如高氏等为了测定锰矿及锰铁中的锰,用氨水或六次甲基四胺将铁、铝等干扰离子与锰分离,取两份溶液,在 pH10时,以镥黑 T 为指示剂,一份测定 Mn、Ca、Mg 总量,另一份除 Mn 后再测定 Ca、Mg 总量,然后 Mn 按差减法求出。此法须时较长,未得到广泛应用。P(?)ibil 先使Mn 与 EDTA 络合,然后加入氰化物,最后用高铁氰酸盐滴定,但此法必须在无氧的存在下,用电位法指示终点,上野景平滴定 Mn 时用兜茶酚紫为指示剂能得到良好终点变化及准确结果,但对干扰离子如何消除
First, the foreword Determination of manganese and manganese in the high manganese content, are usually using redox method, such as bismuth carbon nano method, zinc oxide method, ammonium persulfate - silver salt method, potassium chlorate method and lead oxide method and so on. In recent years, due to the ammonia complexing agent and metal indicator obtained in analytical chemistry widely used. Up to now, there are a lot of documents about the determination of manganese by EDTA method. Such as the high and so in order to determine manganese and manganese in ferromanganese, ammonia or hexamethylenetetramine iron, aluminum and other interfering ions and manganese separation, take two solutions, at pH10, with black T as an indicator , One for the total amount of Mn, Ca and Mg, and the other for the total amount of Ca and Mg after the determination of Mn, and then the Mn is determined by the subtractive method. This method takes a longer time, has not been widely used. P (?) Ibil first Mn and EDTA complexation, and then add cyanide, and finally with high-speed iron cyanide titration, but this method must be in the absence of oxygen, the end point by potentiometric method, Good results can be obtained with patechin violet as an indicator and accurate results, but how to eliminate interfering ions