作者：董礼男, 朱春要, 张良芬, 年季强
作者单位：江苏省沙钢钢铁研究院分析测试中心, 江苏 张家港 215625
关键词：碳化稻壳;氢氧化钾;氟硅酸钾;滴定法;二氧化硅
摘要：
该文基于氢氧化钾熔融法分解,氟硅酸钾滴定检测超低碳稻壳样品中SiO2含量的方法研究。试样在镍或银坩埚中,通过氢氧化钾熔融,二氧化硅转化为硅酸钾,在有过量氯化钾存在的强酸性溶液中加入氟化钾溶液,生成氟硅酸钾沉淀,经抽滤、洗涤后溶于沸水中,以溴麝香草酚蓝与酚红混合物为指示剂,氢氧化钠标准溶液滴定水解后生成氢氟酸,从而间接得出二氧化硅含量。对熔样方式、干扰元素、沉淀时间、温度控制及指示剂的选择等条件进行试验及优化,考察检测方法的准确度和精密度,精密度相对标准偏差(RSD)0.20%(n=6),与经典重量法进行比较,结果一致。
Determination of silicon dioxide in ultra-low carbon carbonised rice husk by potassium fluosilicate precipitation-acid-base titration method
DONG Li'nan, ZHU Chunyao, ZHANG Liangfen, NIAN Jiqiang
Analysis and Characterization Center, Institute of Research of Iron and Steel, Zhangjiagang 215625, China
Abstract: A simple and accurate way was proposed to determine the content of silicon dioxide in ultra-low carbon samples based on potassium fluosilicate titration. The samples were molted in potassium hydroxide in a nickel or silver crucible to generate potassium silicate; the product was placed into a strong acid solution with excess potassium chloride or potassium oxalate and then added with potassium fluoride solution to obtain potassium siliofluoride precipitation. Afterwards, the content of silicon dioxide was acquired by performing the following steps: draw, filter, wash, and then dissolve into boiling water; use bromothymol blue and phenol red as a mixed indicator; and titrate, hydrolyze sodium hydroxide standard solution. Moreover, relevant factors, such as sample-melting method, interference elements, settling time, temperature control, and indicator selection, were optimized. This method showed high accuracy and precision. The relative standard deviation (RSD) of precision was less than 0.20% (n=6) and consistent with those obtained by classic gravimetric method.
Keywords: carbonised rice husk;potassium hydroxide;potassium fluosilicate;titration;silicon dioxide
2015, 41(8): 48-51 收稿日期: 2015-1-11;收到修改稿日期: 2015-2-17
基金项目:
作者简介: 董礼男(1988-),女,辽宁丹东市人,助理工程师,主要从事冶金湿法分析工作。
参考文献
[1] 王孝良,魏玉霞,张淑兰. 碳化稻壳复合覆盖剂[J]. 辽宁工学院学报,1994,14(2):17-20.
[2] 李峰,李大纲,邢鹏飞,等. 碳化稻壳的真空高温除杂研究[J]. 材料冶金学报,2013,12(1):50-53.
[3] 于华财,李淑清.钢包覆盖剂的应用与研究[J].炼钢,2001,
17(4):11-14.
[4] 白小叶,迟爱玲. 镍铁合金中二氧化硅的测定-氟硅酸钾滴定法[J]. 有色矿冶,2013,29(4):51-52.
[5] 李环亭,董艳艳,刘晓毅,等. 氟硅酸钾沉淀-酸碱滴定法测定硅质耐火材料中二氧化硅[J]. 冶金分析,2011,31(2):67-70.
[6] 孙宝莲,张俊芳,李波,等. 氟硅酸钾滴定法测定镍土矿中二氧化硅[J]. 冶金分析,2012,32(4):65-69.
[7] 聂淑兰. 氟硅酸钾容量法测定硅石中二氧化硅含量[J]. 铁合金,2014,235(2):53-56.
[8] 刘珍. 化验员读本:上册[M]. 4版. 北京:化学工业出版社, 2012:412-414.
[9] GB/T 5686.2—2008锰铁、锰硅合金、氮化锰铁和金属锰硅含量的测定[S]. 北京:中国标准出版社,2008.
[10] 王璐,边立槐. 氟硅酸钾容量法测定高炉渣中二氧化硅[J].天津冶金,2011(4):56-58.
[11] 黄仁彬. 氟硅酸钾法测定萤石中二氧化硅[J]. 四川冶金,2003(1):32-33.
[12] 魏恩双,包红霞,张勤,等. 用氟硅酸钾沉淀法快速测定硅铁中的硅[J]. 莱钢科技,2003(5):53.
[13] 戚淑芳,邴一宏,张杰,等. 氟硅酸钾滴定法测定铬铁矿中二氧化硅[J]. 冶金分析,2010,30(9):74-76.
