煅烧白云石制造硫酸镁水泥及其机理研究  

作　　者：唐鑫科 严建华[1] 郝挺宇[2] 杜加俊 王鹏[1] 

机构地区：[1]北京工业大学,北京100124 [2]中冶建筑研究总院有限公司,北京100088

出　　处：《中国水泥》2023年第6期57-64,共8页China Cement

摘　　要：对利用白云石为原料制备硫氧镁水泥(MOS)进行研究。首先研究氯化钙煅烧助剂对煅烧白云石烧失量、活性氧化镁(α-MgO)、游离氧化钙(f-CaO)及比表面积(BET)的影响,优选白云石煅烧条件。然后对煅烧白云石中α-MgO、f-CaO的含量以及硫酸镁浓度对硫氧镁水泥性能的影响进行研究,并采用XRD、SEM和DTA/TG对各过程机理进行分析。试验结果表明,在700℃下对掺入5%氯化钙的白云石煅烧3h,所得煅烧白云石活性氧化镁含量可达到21%,且f-CaO可控制在2%以下。将所得煅烧白云石与硫酸镁溶液混合制成MOS水泥,在硫酸镁浓度为50%时其强度最优。在上述硫酸镁溶液中添加1%的柠檬酸制备MOS,MOS的强度较空白样提高91.6%。微观分析结果表明,硫酸镁溶液中柠檬酸的添加促进了MOS微观结构中针状交叉分布517相的形成,提高了MOS的强度。The preparation of magnesium oxysulfide cement(MOS)by using calcined dolomite as raw material was investigated.The effect of calcium chloride on the calcination of dolomite was studied in the respect of the production ofα-MgO.free calcium oxide(f-CaO)and specific surface area(BET).The effects of a-MgO and f-CaO in calcined dolomite and magnesium sulfate concentration on the properties of magnesium oxysulfide cement were examined.The mechanisms were decided with XRD,SEM,and DTA/TG.The results showed that the content ofα-MgO in dolomite reached 21%,while f-CaO was controlled below 2%.when dolomite mixed with 5%calcium chloride was calcined at 700'C for 3h.MOS cement was prepared by mixing the calcined dolomite and magnesium sulfate solution,and the strength reached its maximum when the concentration of magnesium sulfate solution was 50%.MOS prepared with Magnesium sulfate solution containing 1%citric acid was determined to raise the strength of MOS by 91.6%,compared with that prepared with just magnesium sulfate solution.A large amount of 517 phase with needle shape was discovered in the sample prepared with citric acid added magnesium sulfate solution,while 318 phase and Mg(OH)2 in large amount was in that with just magnesium sulfate solution,indicating the promotion of strength of MOS by the modification of its microstructure.

关 键 词：氯化钙 煅烧白云石 活性氧化镁 硫氧镁水泥 柠檬酸 

分 类 号：TQ172.45[化学工程—水泥工业]