叶蜡石的矿物成分对合成金刚石的影响

Influence of Mineral Formation of Pyrophyllite on Diamond Synthesis

通过对闽东矿区五种不同类型叶蜡石所做的化学分析及DTA、TG分析,计算出了其相应的矿物成分。将这几种叶蜡石分别制成传压介质进行了合成金刚石的实验并与北京门头沟叶蜡石作了比较,结果表明:(1)含有一定量石英(20%左右)的叶蜡石做传压介质有利于降低金刚石合成压力,提高金刚石质量;(2)结晶水含量较低的叶蜡石合成出的金刚石质量更好。作者对实验结果进行了分析并指出:在选择作为传压介质的叶蜡石时,不能只要求其硬度低、叶蜡石成分高,而应全面考虑其中所含矿物成分及其在高温高压下可能发生的变化。

Based on the data of chemical analysis and the DTA&TG testing diagram of different kinds of pyrophyllite collected in east China, the mineral formations of these pyrophyllite are calculated respectively. Using these pyrophyllite in our experiment synthesis of diamond as pressure - transmitting - medium, it is find out that ( 1) by using the pyrophyllile which contains about 20% quartz, the synthesis pressure can be decreased; (2) by using the pyrophyllite which contains less crystal water, belter quality diamond can be obtained. The author discussed the experimental results and pointed out that when we choose pyrophyllite as pressure - transmitting - medium, we should not care about its hardness and purity only, instead we should pay more attention to its mineral formation and its possible transformation under HT/HP.