The Peculiarities of Combustion and Phase Formation during SHS of Mechanically Activated Mixtures Quartz – Calcite

S.Kh Aknazarov,B.S Sadykov,N.N Mofa

doi:10.18321/ectj83

Abstract

The work with the influence of mechanochemical treatment (MCT) of minerals (quartz-SiO2, calcite-CaCO3) on the process of their combustion under the conditions of SHS with aluminium. It is shown that activation of the charge mixture in the mill increases the power state of the material and contributes to the change of kinetic characteristics of combustion process: the decrease in the induction period of ignition and the increase in combustion rate. The change in combustion temperature is of a complex character due to activation of both exothermal reactions related to formation of such compounds as anothite, helenite, wollastonite. The use of deferent organic modifiers of the charge mixture results in formation of nitride and carbide compounds in the process of SHS. It is shown that changing the conditions of MCT, modifiers and ratios between the charge components it is possible on the basis of activated and modified systems to synthesize composition SHS-materials different in their phase compositions.

Highlights

SH-synthesis is a unique technological process of creating composition materials for different purposes, in particular, refractories and thermal insulators
After preliminary mechanochemical treatment (MCT) the induction period reduces and the longer the treatment of mixture, the quicker the sample ignites, but the temperature of combustion considerably decreases in the course of the whole process of synthesis (Fig. 4)
The results of the carried out of investigations have shown that mechanochemical treatment of minerals used as components of the charge mixture for SH- synthesis of composition systems contributes, first of all, to the change of kinetic characteristics of the combustion process: the decrease in the induction period of ignition and the increase of combustion rate

Summary

Introduction

SH-synthesis (technological combustion) is a unique technological process of creating composition materials for different purposes, in particular, refractories and thermal insulators. After preliminary MCT the induction period reduces and the longer the treatment of mixture, the quicker the sample ignites, but the temperature of combustion considerably decreases in the course of the whole process of synthesis (Fig. 4).

Results

Conclusion