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碳化法生产轻质碳酸镁的几个问题 总被引:1,自引:0,他引:1
本文介绍了用白云石生产轻质碳酸镁工业过程中出现的几个问题,并在生产实践中分析原因,提出了解决这些问题的措施,从而保证了生产的正常进行。 相似文献
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利用盐泥制取轻质碳酸镁的研究 总被引:1,自引:0,他引:1
用化学方法从盐泥生产轻质碳酸镁是不少化学工作者感兴趣的课题,一些氯碱生产厂家曾进行过这方面的尝试,本文作者根据对这一课题的研究实践,简要地报道了从盐泥制取轻质碳酸镁基本原理、工艺过程和对一些有关问题的体会,可供继续研究或有兴趣了解本课题的同行参考。 相似文献
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我厂的主要产品轻质碳酸镁是以苦卤和碳化氨水为原料,在反应锅内进行反应,经离心机甩水洗涤蒸汽烘房干燥后得产品。针对原生产系统存在轻质碳酸镁在反应液中粒度细、离心机分离速度慢、滤饼含水量高、原料消耗高蒸汽烘房生产能力低等问题,我 相似文献
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石棉矿渣经氯化焙烧、消化等步骤,再用碳化法和沉淀法分别制备轻质碳酸镁的白炭黑,产品纯度分别达94%和80%,具有良好的经济效益。 相似文献
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以红土镍矿脱硅渣为原料,采用碳化、热解工艺制备出碳酸镁产品,并使NiO在碳化渣中富集到2.96%。研究表明,氧化镁的提取率随着搅拌强度、反应时间及液固比(ml:g)的增加而增加,随着反应温度的升高先增加后减少。在搅拌强度600 r·min-1、反应温度15 ℃、反应时间36 h及液固比(ml:g)40:1的条件下,氧化镁的提取率可达91.57%。经XRD分析,产品为碱式碳酸镁;产品理化性能符合国家化工行业HG/T 2959—2000标准。 相似文献
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采用硬脂酸对轻质碳酸镁进行表面改性,再将改性后的轻质碳酸镁分别加入PP和HDPE中,制备出相应的轻质碳酸镁/PP和轻质碳酸镁/HDPE复合材料。为改善复合材料的力学性能,将POE加入到轻质碳酸镁/PP和轻质碳酸镁/HDPE复合材料中,制备出相应的轻质碳酸镁/PP/POE和轻质碳酸镁/HDPE/POE复合材料。探讨了硬脂酸用量、改性温度、改性时间对改性效果的影响。测定了改性轻质碳酸镁的沉降体积、吸油值和活化度并用红外光谱和热失重进行表征。最终确定了最佳改性条件。硬脂酸用量为2%,改性时间为50 min,改性温度为75℃。 相似文献
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Darryl P. Butt Klaus S. Lackner Christopher H. Wendt Samuel D. Conzone Harriet Kung Yung-Cheng Lu Julie K. Bremser 《Journal of the American Ceramic Society》1996,79(7):1892-1898
The kinetics of simultaneous dehydroxylation and carbonation of precipitated Mg(OH)2 were studied using isothermal and nonisothermal thermogravimetric analyses. Specimens were analyzed using X-ray diffraction, transmission electron microscopy, and through measurements of the volume of carbon dioxide evolved in a subsequent reaction with hydrochloric acid. From 275° to 475°C, the kinetics of isothermal dehydroxylation in helium were best fit to a contracting-sphere model, yielding an activation energy of 146 kJ/mol, which was greater than values reported in the literature for isothermal dehydroxylation under vacuum (53–126 kJ/mol). The carbonation kinetics were complicated by the fact that dehydroxylation occurred simultaneously. The overall kinetics also could be fit to a contracting-sphere model, yielding a net activation energy of 304 kJ/mol. The most rapid carbonation kinetics occurred near 375°C. At this temperature, Mg(OH)2 underwent rapid dehydroxylation and subsequent phase transformation, whereas thermodynamics favored the formation of carbonate. During carbonation, MgCO3 precipitated on the surface of disrupted Mg(OH)2 crystals acting as a kinetic barrier to both the outward diffusion of H2 O and the inward diffusion of CO2 . 相似文献
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The carbonization of magnesium oxide particles by CO2 was investigated using a stirring mill reactor. The effects of the system temperature, stirring rotation speed, influx rate of CO2 and initial diameter of the magnesium oxide particles on the carbonization process were determined, The results show that the system temperature and the stirring rotation speed are the most significant influencing factors on the carbonization rate. The determi-nation of critical decomposition temperature (CDT) gives the maximum carbonization rate with other conditions fixed. A theoretical model involving mass transfer and reaction kinetics was presented for the carbonization process. The apparent activation energy was calculated to be 32.8kJ·mol-1. The carbonization process is co-controlled by diffusive mass transfer and chemical reaction. The model fits well with the experimental results. 相似文献
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碱式碳酸镁纳米花的干燥动力学研究 总被引:1,自引:1,他引:0
以六水氯化镁和尿素为原料,采用均匀沉淀法制备出碱式碳酸镁纳米花。通过干燥动力学实验得到碱式碳酸镁纳米花的干燥曲线和干燥速率曲线。研究结果表明:在一定温度下碱式碳酸镁纳米花干燥速率曲线呈现明显的升速、恒速和降速三个干燥阶段;随着干燥介质温度的升高,干燥速率增大.干燥时间缩短。通过比较得出的干燥方程符合Page模型。 相似文献
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由七水硫酸镁生产碳酸镁和氧化镁 总被引:7,自引:0,他引:7
叙述了以七水硫酸镁和碳酸氢铵为原料,制备碳酸镁和氧化镁的方法,并通过小试对合成碳酸镁的实验温度、时间及反应浓度进行了讨论,找出了正确的工艺条件,并生产出了符合标准的轻质碳酸镁和氧化镁。 相似文献