1. Analysis & Characterization Center, Institute of Research of Iron & Steel, Jiangsu Province/Sha-Steel, Zhangjiagang 215625, China; 2. Department of Production, Jiangsu Shagang Group, Zhangjiagang 215625, China
Abstract：A method was introduced for the determination of calcium oxide and calcium fluoride in steel slag powder deoxidizer by EDTA complexometric titration. After the sample was melted by mixed flux of sodium carbonate and boric acid and leached by diluted hydrochloric acid, hexamethylenetetramine was used to separate the ions of iron and aluminum, and triethanolamine was used to mask the remaining interference ions. In strong alkali medium, the content of total calcium oxide in samples was titrated by EDTA standard titration solution with calcein as indicator. By leaching separation method with acetic acid, calcium carbonate and calcium oxide were leached, and calcium fluoride was filtered and separated. Fluoride in leaching solution was determined by fading spectrophotometry with zirconium-xylenol orange, which was changed into the amount of calcium fluoride. Simultaneously, calcium fluoride in the precipitation was determined by EDTA complexometric titration after decomposed with mixed acid. Then, the content of calcium fluoride in the sample was the sum of them divided by the sample mass.Subsequently, the content of total calcium oxide minus the content of calcium oxide, converted from the content of calcium oxide, to obtain the content of calcium oxide in the sample.This method was used for six parallel determinations of steel slag powder deoxidizer samples. The relative standard deviations (RSD) were less than 1.5%. The samples A1, A2, A3 of steel slag powder deoxidizer were synthesized by high purity aluminum powder, aluminium oxide and calcium fluoride of primary reagent, and fluorite certified reference materials, and the samples A4 of steel slag powder deoxidizer was synthesized by adding calcium oxide of primary reagent and fluorite certified reference material into refining slag certified reference material. This method was applied to determination of these samples, and the results were in accordance with the theoretical value. The recovery test was conducted by adding calcium oxide of primary reagent and fluorite certified reference materials into the steel slag powder deoxidizer samples with recoveries of 94%-102%.
陆钢, 牛四通, 黄钢汉, 等.多功能调渣剂的开发与应用[J].包头钢铁学院学报(Journal of Baotou University of Iron and Steel Technology), 2001, 20(4):316-318.
[2]
E Kh Shakhpazov, A I Zaitse, N G Shaposhnikov, et al. Physicochemical prediction of the types of nonmetallic inclusions: Complex deoxidation of steel with aluminum and calcium[J].Russian Metallurgy (Metally), 2006(2):3-13.
[3]
周云, 李君彦, 马兴云.济钢KR复合脱硫剂的开发与应用[J] .安徽工业大学学报(Journal of Anhui University of Technology), 2007, 24(4):366-368.
