ХРИЗОТИЛ-АСБЕСТ ӨНДІРІСІНІҢ СЕРПЕНТИНИТТІ ҚАЛДЫҚТАРЫНАН МАГНИЙ ОКСИДІН АЛУҮРДІСТЕРІН ЗЕРТТЕУ

Abstract

Hydromagnesite was used as raw material for the production of magnesian binder. The raw material contains the main substance (98.5-99.1%), as well as a small amount of impurity metals (wt. %): Si – 0.26-0.31; Ca – 0.22-0.38; Mn – 0.18-0.36; Na – 0.16-0.42. The total impurity content does not exceed 1-1.5%. The results of X-ray phase and thermographic studies of the thermal decomposition of hydromagnesite – tetrahydrate magnesium dihydrocarbonate – are presented. Calcination of hydromagnesite at a temperature of 550°C with an isothermal holding time of 60-120 minutes shows that, starting from 60 minutes of isothermal holding, the mass loss does not change significantly and averages 55.6%. Thus, the mass of the decomposition product magnesium oxide is 44.4%. It has been shown that the physicochemical factors determining the degree of conversion of brucite and hydromagnesite into magnesium oxide are the firing temperature and isothermal holding time.