络合滴定法测定钢渣中游离氧化钙含量

Determination of the Content of Free Calcium Oxide in Steel Slag by Complexometric Titration

目的:利用EDTA络合滴定法对钢渣中游离氧化钙含量进行测定。方法:在装有50mL过滤试液的烧杯(250mL)中,一次加入氯化镁溶液2~3滴、三乙醇胺溶液5mL、氢氧化钠溶液20mL、钙指示剂少许,摇匀后利用EDTA标准滴定溶液将酒红色的溶液滴定至纯蓝色,结束滴定。结果通过实验后得知,粒径为0.15~0.6mm的钢渣中含有约1.65%的f-CaO;粒径为0.6~1mm的钢渣中含有约1.85%的f-CaO;粒径为1~2mm的钢渣中含有约2.63%的f-CaO;粒径≥2mm的钢渣中含有约6.82%的f-CaO;经过热焖工艺处理后的钢渣中含有约0.65%的f-CaO;普通钢渣中含有约6.95%的f-CaO。结论:测定结果相对标准偏差均不超过3%,与测定标准相符合。

Objective： to determine the content of free calcium oxide in steel slag by EDTA complexometric titration. Methods： in a beaker（ 250 ml） containing 50 ml of filtered test solution, add 2-3 drops of magnesium chloride solution, 5 ml of triethanolamine solution, 20 ml of sodium hydroxide solution and a little calcium indicator at a time. After shaking well, titration the wine-red solution to pure blue using EDTA standard titration solution, and end the titration. Results： through the experiment, it was found that about the steel slag with particle size of 0.15-0.6 mm contains about 1.65% f-CaO, steel slag with particle size of 0.6-1 mm contains about 1.85% f-CaO, steel slag with particle size of 1-2 mm contains about 2.63% f-CaO, steel slag with particle size greater than 2 mm contains about 6.82% f-CaO, steel slag treated by the thermal stewing process contains about 0.65% f-CaO, and ordinary steel slag contains about 6.95% f-CaO. Conclusion： the relative standard deviation of the determination results is less than 3 %, which is consistent with the determination standard.