EDTA络合滴定法联合测定硅钙钡镁合金中钙钡镁

发布时间：2018-01-23 05:13

  本文关键词： 硅钙钡镁合金 EDTA 络合滴定法 钙 钡 镁　出处：《冶金分析》2015年02期 　论文类型：期刊论文

【摘要】：建立了一种快速测定硅钙钡镁合金中钙、钡和镁含量的分析方法。以盐酸、硝酸和氢氟酸分解试样,高氯酸冒烟除去残余的盐酸、硝酸和氢氟酸,经过氨水沉淀分离铁、铝等干扰元素后,在pH 10的NH3·H2O-NH4Cl缓冲体系中,以邻甲酚酞指示滴定终点,EDTA络合滴定法测定钙镁合量;在pH≥12的氢氧化钾缓冲体系中,分别以钙指示剂和钙黄绿素-茜素混合指示剂指示滴定终点,EDTA滴定法分别测定钙及钙钡合量。根据钙钡合量与钙含量的差值和钙镁合量与钙含量的差值,可分别得到钡和镁含量。经氨水沉淀后试液中残余的铁、铝和其他干扰离子用三乙醇胺掩蔽,钡对滴定钙和钙镁合量以及镁对滴定钙和钙钡合量的干扰分别通过生成硫酸钡和氢氧化镁沉淀的方法消除。建立的方法用于实际硅钙钡镁合金中钙、钡和镁测定,测定值与对照方法测定值相符,钙、钡和镁的相对标准偏差分别为0.38%、1.9%和1.9%。
[Abstract]:A rapid method for the determination of calcium, barium and magnesium in silicocalcium-barium magnesium alloy was established. The samples were decomposed with hydrochloric acid, nitric acid and hydrofluoric acid, and the residual hydrochloric acid, nitric acid and hydrofluoric acid were removed by perchloric acid. After precipitation and separation of iron and aluminum with ammonia solution, o-cresol phthalein was used to indicate the end point of titration in NH3 路H _ 2O -NH _ 4cl buffer system with pH 10. The content of calcium and magnesium was determined by EDTA complexometric titration. In the buffer system of potassium hydroxide with pH 鈮，

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