Efficiency of stabilization of slag suspensions by polycarboxylate

Moscow State University of Civil Engineering, Yaroslavskoe shosse, 26, Moscow, 129337, Russia

^* Corresponding author: iv.kozlova@mail.ru

Abstract

The paper describes the method of stabilization of slag suspensions prepared on the basis of finely ground slag (FGS) with a predominant particle size of 1-7 μm, a plasticizer based on polycarboxylate (polycarboxylate). In suspension, FGS particles form two types of micelles with negative and positive surface charges. It has been established that stabilization with polycarboxylate, which is an anionic long-chain surfactant, affects slag particles with a positive surface charge. The formation of strong and elastic gel-like films on the surface of FGS leads to an increase in the structural and mechanical factor of aggregative stability of slag suspensions. Thus, the stabilization of slag particles by polycarboxylate is ensured by electrostatic, structural and mechanical factors of aggregative stability. It was established experimentally that the introduction of polycarboxylate into the aqueous dispersion medium increases the aggregative and sedimentation stability of slag suspensions. In the first period of particle sedimentation, on average, stability of slag suspensions is increased by 36 times, in the second period - 19 times, in the third period - 4 times. To ensure stability of slag suspensions, the protective number and the optimal concentration of the polycarboxylate are determined. The protective number of the suspension was 0,016 g/l; the optimal concentration of polycarboxylate - 4 g/l.