碳化法制备硅钢氧化镁过程中杂质脱除研究

以轻烧氧化镁粉为原料，经消化、碳化制得重镁水，在热解反应前采用络合剂对重镁水中的杂质钙、铁进行络合掩蔽，再经热解得到碱式碳酸镁，碱式碳酸镁经煅烧可制得钙、铁杂质含量较低的氧化镁。在重镁水络合除杂过程中，考察了络合剂三乙醇胺、柠檬酸、草酸单独和复合使用的除铁、除钙效果。以三乙醇胺为络合剂时，在 200 mL重镁水中加10 mL三乙醇胺（1∶1），氧化镁产品中w（氧化镁）=99.3%、w（氧化钙）=0.31%、w（氧化铁）= 0.042%；使用草酸和柠檬酸作为复合络合剂时，在200 mL重镁水中加入1.0 g柠檬酸和2.0 g草酸，氧化镁产品中 w（氧化镁）=98.2%、w（氧化钙）=0.24%、w（氧化铁）=0.030%。

Study on purification and impurity removing in preparing silicon-steel grade magnesium oxide with carbonization method

Light-burned magnesia as a raw material was hydrated and carbonated to obtain magnesium bicarbonate liquor. Before the pyrolyzing of magnesium bicarbonate liquor，complexants were used to cover Fe and Ca impurities.Then the treated liquid was pyrolyzed to obtain basic magnesium carbonate which was calcined to magnesium oxide with low calcium and iron content.During the complexing purification of magnesium bicarbonate liquor，the Fe and Ca removing effects of single or compound complexing agents，such as triethanolamine（TEA），citric acid，and oxalic acid were investigated.By applying triethanolamine as a complexing agent and adding 10 mL triethanolamine（1∶1） in 200 mL magnesium bicarbonate liquid， mass fractions of MgO，CaO，and Fe₂O₃ in the product were 99.3%，0.31%，and 0.042% respectively；meanwhile，using citric acid and oxalic acid as composite complexing agent，mass fractions of MgO，CaO，and Fe₂O₃ in the product were 98.2%，0.24%，and 0.030% respectively in the condition of 200 mL magnesium bicarbonate liquid with adding 1.0 g citric acid and 2.0 g oxalic acid.