Evaluation of the Properties of Coal Gasification Residue and Its Compatibility with Cement

Coal gasification slag is the waste of coal gasification process, at present, gasification slag has not been effectively utilized. In order to solve the problems of resource waste and environmental pollution, the nature of gasification slag is analyzed, and its main composition is similar to silicate cement, which can be used as an additive to replace part of the aggregate and cement. This paper analyzes the nature of fine slag and evaluates the compatibility of fine slag in cement paste with different dosage. The main research includes the following aspects. The properties of coal gasification slag were analyzed by characterization methods such as chemical element analysis, thermogravimetric analysis, XRD, stretching, SEM, etc. The results showed that the fine residue is flocculent and the surface is honeycomb-shaped. The chemical composition of slag is mainly carbon, SiO2, silica-aluminate, and Fe2O3. The mass loss of fine slag is 4.3 mg, the weight loss of coal gasification fine slag is high, the decomposition and oxidation reaction ability at high temperature is strong, and the stability is poor. Different dosages of coal gasification coarse slag and fine slag were added into cement slurry, respectively, and the results showed that the performance of coal gasification coarse slag cement slurry was better than that of fine slag cement slurry by evaluating the performance of cement slurry in terms of expansion and contraction, degree of hydration, density, and fluidity, etc., and it reached the requirement of road construction material at 20% dosage.