Effect of the firing medium and other technological parameters on the properties and phase composition of dinas articles on dry mineralizers

The effect of the gaseous firing medium and other technological factors (grain composition of the charge, pressing pressure, temperature and time of the hold at the final firing temperature) on the properties of dinas and the degree of transformation of silica in it is investigated. On the basis of results of a comparative analysis of the phase compositions and properties of specimens the following parameters are recommended as optimum technological parameters for fabricating dinas on dry mineralizers that provide high operating characteristics for the articles: the maximum grain size of quartzite is 2 mm, the pressing pressure is at least 50 MPa, the firing temperature is 1420°C, the duration of the hold is 44 h. Petrographic and x-ray analyses are used to show the preferableness of firing dinas in a reducing medium, which promotes a fuller transformation of quartz in the dinas and provides high operating properties for the articles.Translated from Ogneupory i Tekhnicheskaya Keramika, No. 6, pp. 14–17, June, 1996.The work has been done in collaboration with L. M. Khvostishkova. The physicochemical properties of the specimens were investigated in specialized laboratories of the Ukrainian Research Institute of Refractories.