Study Of Dolomite’s Hot-pressing Decomposition Methods And Sintering Products

This paper was based on the existing theory of thermal decomposition of dolomite, by using medium frequency furnace exploration under the condition of the hot pressing process of thermal decomposition of dolomite, and industrial computed tomography (CT), X-ray powder diffraction and other large-scale instrument were used to research sintering products under the different conditions of dolomite fines hot-pressing process. We concluded some understandings as follows:Thyristor medium frequency furnace is a high degree of automatic equipment generally used to do hot-pressing sintering for metal materials. But dolomite is non-metallic materials, tested by this equipment was a new attempt. The intermediate frequency furnace in dolomite hot pressing sintering process can set different technological parameters effectively, to make the experiments successfully completed.In the research of sintering products, industrial CT can to do nondestructive testing of dolomite sintering products to look the products’internal characteristics; And X-ray powder diffraction, can detect the sintering product phase. In this article, using the large-scale instrument can detect the dolomite of sintering products’ internal structure characteristics and phase composition.According to the existing theory of the thermal decomposition of dolomite, we designed the hot pressing sintering(the thermal decomposition) temperature of the dolomite, at room temperature to900℃(equivalent to the initial stage of thermal decomposition of dolomite),900℃-1000℃(equivalent to the thermal decomposition of dolomite of end), and more than1000℃(equivalent to the thermal decomposition product of dolomite in sintering).When temperature was below900℃, dolomite is not decomposed, showing the sintering products’s color similar to the original dolomite powder, the sintering products were still dolomite.During hot pressing sintering temperature between900℃and1000℃, sintering products appeared obvious physical differences from internal to external, internal was gray and external white. With greater pressure, the volume of gray matter was larger, and the stronger the density, the higher the degree of crystallization. XRD test results indicated that under the condition of low pressure, phase of the internal gray material was CaO, MgO and CaCO3, while MgO and CaCO3with high pressure. External phase is only CaO and MgO.During hot pressing sintering temperature higher than1000℃, dolomite sintering products’differences were stronger between internal and external material. Internal is colored deep gray and external white, the greater the pressure was, the smaller volume of the deep gray matter. XRD test result indicated that the internal phase of sintering products was CaO, MgO and CaCO3, while the external phase was CaO and MgO.