【摘要】 测定钨精砂中的钨和辉钼矿中的钼可用氯化亚铬的电位滴定法来代替经典的重量法。测定钨的实验条件是盐酸浓度保持10N 左右,每160毫升钨的含量不低于1毫克当量。测定钼的条件是盐酸浓度为6N,加入硫氰酸钾约为1克/80毫升。在上述实验条件下,钨、钼都可以用不补偿法在室温下滴定。分析结果基本上与重量法符合,而时间缩减为3小时。更多还原

【Abstract】 Modifications of the method of potentiometric titration with chromous chloride in thedetermination of tungsten and molybdenum have been described.The optimum experimentalconditions are:(a) for tungsten,the concentration of HCl should not be less than 10 N and thetungsten concentration,not less than one milli-equivalent in 160 ml; (b) for molybdenum,the solution to be titrated should ,be 6 N in HCl and contain about one gram of KCNS in 80 ml.The addition of KCNS gives a sharp potential jump at the end-point.Under such conditions thetitration may be carried out with non-compensation method at room temperature.Themethod has been applied to the determination of tungsten in wolframite and scheelite,and ofmolybdenum in molybdenite with results agreeing with those obtained by gravimetric methods.Such a determination may be accomplished within three hours.更多还原