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易熔合金系由两种低熔点金属组成,即锡和铋。它的杂质一般有铅、锌、铜、铁等。锡和铋的络合滴定法介绍较多,П.Г.Шахова提出以酒石酸掩蔽锡,在 pH2～3滴定铋,然后用回滴法滴定锡、铋及其它元素之合量,并从中减去铋和其它元素以求得锡。韦尔切推荐之 Fritz 法,提出用硫脲作指示剂在 pH1.5～2滴定铋,这样可消除较多
Fusible alloys consist of two low-melting-point metals, tin and bismuth. Its impurities are generally lead, zinc, copper, iron and so on. The complexometric titration of tin and bismuth is described in more detail. П.Г. Шахова proposes masking tin with tartaric acid, titrating bismuth at pH 2-3, and titrating the amounts of tin, bismuth and other elements by the back-drop method and subtracting Bismuth and other elements in order to obtain tin. Vercert recommended Fritz method, proposed thiourea as an indicator of titration bismuth at pH 1.5 ~ 2, so you can eliminate more