Effect of Carbon-Containing Solid Waste from Calcium Carbide Production on Combustion and Slagging Characteristics of Zhundong Coal Blend

Abstract

ABSTRACT Co-combustion in pulverized coal boilers is one of the best methods to achieve harmlessness, reduction and resource disposal for carbon-containing solid wastes. This work aims to study the effect of dried dust (DD) generated from CaC2 production on the combustion and slagging characteristics of Zhundong (ZD) coal blend. The combustion of ZD coal blend with different ratios (0%, 2.5%, 5.0%, 7.5%) of DD was conducted in a thermal gravimetric analyzer under air atmosphere. The ash fusion temperature tests and slagging experiments were carried out to understand the effect of the addition of DD on the slagging behavior of ZD coal blend. The results showed that the ignition and burnout temperatures of ZD coal showed different varying tendency with the blending ratio of DD increasing. Increasing the adding ratio of DD could raise the ash fusion temperatures of ZD coal blend. The addition of 5% DD promotes the formation of gypsum in deposited slags, and it also alters the chemical components of fine particles adhered onto the surface of molten particles. Meanwhile, in comparison with raw ZD coal blend, more Ca would combine into silicates in sampled slags. After the overall evaluation, a low blending proportion of DD (<5%) is suggested for pulverized boilers.