Features of the Structure Formation of Silicate Bricks Obtained with the Use of Solid Waste Produced by JSC "Berezniki Soda Plant"

Abstract

The results of studying the structure formation features of silicate bricks obtained with the use of solid waste produced by JSC "Berezniki soda plant" are presented in this article. Various samples, such as sludge from the "closed" sump with a moisture content of 5 %, sludge from the open sump surface with a moisture content of 35 %, moistened sludge from the open sump with a moisture content of 70 %, were taken from the sludge collectors for the research. It was established the building lime meeting the requirements of GOST 9179 can be received by means of heat treatment at 950 °C of the dehydrated slime selected from the closed settler. By results of silicate brick samples forming parameters and their structure optimization it was found that the use of lime from soda production solid waste as part of lime-silica autoclave hardening binder allows to obtain silicate bricks samples, characterized by the strength grade M200. Samples microstructure studies obtained using the methods of electron microscopic and x-ray phase analysis showed that silicate samples produced with the use of soda production waste are characterized by a cementing substance heterogeneous structure and an insufficient number of tobermorite group low-basic calcium hydrosilicates formed during autoclaving. This is due to the waste material composition, namely the presence of reactive-passive components and impurities. Increasing the structural strength of samples made with the use of soda production wastes is possible due to raising the lime-silica binder specific surface area and the binder modification with fine mineral additives.