Activation of Sintering Processes in Magnesium Oxide and Certain Technical Products on Its Base

摘要

The process of sintering low-temperature magnesium obtained from the carbonate or hydrate was investigated and technical products on its basis were studied. With a high degree of dispersion of the magnesium oxide hydrate, intensive sintering is achieved without thermal activation. During isothermal sintering the low-temperature magnesium oxide obtained from the crystalline natural carbonate is intensively sintered in the primary period, characterized by a short time interval. Thermal activation or dispersion will increase the sintering rate. Particular features of the sintering of low-temperature magnesium oxide are caused by the defective structure of the crystalline lattice of periclase, which has increased parameter values. The kinetics of periclase recrystallization and of the process of pore formation as a function of sintering temperature were clarified. It was established that healing of pores during sintering procedes their coalescence; these factors determine the increase in average pore diameter. Intensive sintering of the magnesium oxide hydrate with a high degree of dispersion causes not only fragmenting of brucite crystals but also the formation of a colloidal hydrate which contains the positive ion H(+). (Author)