以轻烧白云石为原料二次碳化法制备高纯碱式碳酸镁  

Preparation of High Purity Basic Magnesium Carbonate with Light-burned Dolomite by Twice-Carbonation Method

作　　者：王志强[1] 刘家祥[1] 饶发明[2] 

机构地区：[1]北京化工大学材料科学与工程学院,北京100029 [2]武汉钢铁集团矿业有限责任公司乌龙泉矿,武汉430213

出　　处：《硅酸盐学报》2013年第10期1437-1441,共5页Journal of The Chinese Ceramic Society

摘　　要：以轻烧白云石粉料为原料,采用二次碳化法,通过控制碳化终止pH值、热解温度和碳化时间等条件制备高纯碱式碳酸镁。研究了碳化时Ca2+、Mg2+浓度与pH值的关系,建立了它们之间的数学关系模型,计算出一次碳化的最佳碳化终止pH值为7.27,实验得出的一次碳化的最佳碳化终止pH值为7.20,相对误差为0.27%,实验结果与计算结果吻合;二次碳化以Mg2+浓度不变为终止条件,此时溶液pH值在7.0左右。运用X射线衍射仪对碱式碳酸镁样品进行物相表征,结果表明其分子式为4MgCO3 Mg(OH)2 4H2O。通过化学分析得到的碱式碳酸镁中MgO含量为42.25%,CaO含量为0.03%,Fe含量为0.001%,明显优于中国化工行业标准(HG/T 2959—2010)的优等品指标。A high purity basic magnesium carbonate was prepared by a twice-carbonation method with a light-burned dolomite powder as a raw material. The carbonation terminates pH, pyrogenation temperature, carbonization time and other conditions were controlled in the process. A model for the relationship between the ion （i.e., Ca^2＋, Mg^2＋） concentration and the pH during the carboniza- tion was proposed. The theoretical carbonation terminates pH value obtained by the model is 7.20, which is similar to the experimen- tal result. The termination condition of twice-carbonation is defined as Mg2＋ concentration does not change, and the solution pH is thus 7.0. The result of basic magnesium carbonate sample characterized by X-ray diffiaction（XRD） indicates that the formula is 4MgCOyMg（OH）2.4H2O, which contains MgO of 42.25%, CaO of 0.03% and Fe of 0.001%.

关 键 词：轻烧白云石 二次碳化法 碱式碳酸镁 

分 类 号：TB321[一般工业技术—材料科学与工程]