摘要
样品经盐酸-硝酸溶解,硫酸加热至白烟冒尽,然后控制溶液的酸度,在pH 3.0～4.0的条件下,以多聚磷酸钠掩蔽溶液中的Fe3+等金属离子,用淀粉作指示剂,在有硫氰酸盐介质中,加入过量硫代硫酸钠标准溶液,使溶液中的Cu2+作还原生成硫氰化亚铜沉淀,然后再用碘标准溶液回滴过量的硫代硫酸钠标准溶液,建立了用碘滴定法快速测定铜矿石中铜含量的方法。方法用于铜矿石标准样品中铜含量的测定,其相对标准偏差在0.39%～1.0%之间,结果与认定值相符。方法既保持经典方法准确性,又没有使用碘化钾和氟盐,这可以消除了在滴定过程中碘的挥发及碘化亚铜沉淀对碘滴定的影响和氟盐对环境的污染。
The sample was dissolved in hydrochloric acid-nitric acid. After heating in sulfuric acid me- dium until white fume disappeared, the metal ions such as Fea＋ were masked with sodium polyphos- phate at pH3. 0 - 4. 0. The starch was used as indicator. In thiocyanate medium, excessive sodium thiosulfate standard solution was added to reduce Cu2＋ to cuprous thiocyanate precipitation. Then, the excessive sodium thiosulfate standard solution was back titrated with iodine standard solution. The rapid determination method of copper content in copper ore by iodimetry was established. This method was applied to the determination of copper content in cupper ore standard sample with relative standard deviation （RSD） of 0.39 %-1.0%. The determination results were consistent with the cer- tified values. This method could remain the accuracy of classical method and did not use the potassium iodide and fluoride, which could eliminate the influences of iodine volatilizing and cuprous iodine pre- cipitate on the titration of iodine and the pollution of fluoride to environment.
出处
《冶金分析》
CAS
CSCD
北大核心
2013年第8期76-80,共5页
Metallurgical Analysis
关键词
硫酸冒烟
多聚磷酸钠
碘滴定法
铜
铜矿石
sulfuric smoke
sodium polyphosphate
iodimetry
copper
copper ore
