摘要
菱苦土中活性氧化镁的含量是决定菱苦土制品性能的最主要因素。本文应用差热分析、光学显微镜、XRD和电子显微镜对菱苦土中氧化镁的特性进行了分析,用水化法测量了氧化镁的活性。结果表明:在空气中久置的菱苦土因与空气中的水份发生反应生成氢氧化镁而使其活性降低,必须在650℃煅烧两个小时,才能最大程度恢复其活性。菱苦土中含有一定量的结晶完整的氧化镁,这部分氧化镁没有参与化学反应,而是以骨架状存在于制品结构中。用水化法测得的氧化镁的活性不能准确代表菱苦土实际的反应能力,实际反应能力往往比测得的活性值低,所以,计算制品配方时,应适当增大菱苦土的用量以得到更多的5·1·8相,建议MgO/MgCl_2的摩尔比至少不能低于6。
The contents of active magnesia in magnesia powder is the most important factor influencing the product performances. The characteristics of magnesia is analyzed by thermal analysis , polarization microscope,XRD and SEM, and the activity is calculated. The magnesia saved in the air for a long time can generate a little magnesium hydrate on its surface, thus its reaction activity was decreased. However, it can be restored by calcinating at 650℃ for 2 hours. There is a fairly amount of well-crystallized magnesia in magnesia powder, this part of well-crystallized magnesia doesn＇ t take part in chemical reaction but exists in the form of framework. The activity degree of the magnesia calculated by the method of hydrating doesn＇ t represent accurately the actual reaction ability which is usually lower than the measured value. When a batch formula is calculated in order to get more 5Mg（OH）2 MgCl28H2O phase, more magnesia than the calculated should be used and the mol ratio of MgO/MgCl2 must be no less than 6.
出处
《金刚石与磨料磨具工程》
CAS
北大核心
2008年第4期74-76,39,共4页
Diamond & Abrasives Engineering
基金
河南工业大学科研基金项目(06XJC028)
关键词
菱苦土
活性氧化镁
氢氧化镁
magnesia powder
active magnesia
magnesium hydrate
