STUDY ON PHASE CONSTITUTION OF DOLOMITE-ALUMINIUM HYDROXID SYSTEMS AT ELEVATED TEMPERATURES

Abstract

      In this paper, thermal behavior of Thanh Hoa dolomite and Tan Binh aluminium hydroxide system at various temperatures was studied by differential thermal analysis (DTA) and powder X-ray diffraction (XRD) techniques. The DTA curve shows two endothermic peaks at 772.1 and 832.7 ºC. The first peak is associated with the formation of magnesia (MgO), calcite (CaCO3) and CO2. The second peak represents the decomposition of calcite with formation of CaO. The raw mixes were prepared from 1000 oC to 1450 oC using the sintering method. Calcium monoaluminate (CA), spinel (MA) and calcium dialuminate (CA2) are the main phases when heating raw mixes at 1450 oC.

Keywords: differential thermal analysis, X-ray diffraction, dolomite, aluminium hydroxide, refractory cement, spinel.