Abstract: Coal chemical industry is one of the economic pillars of China. Coal gasification slag and gasification wastewater are the wastes produced in the process of coal gasification, and the current treatment is too simple and causes great pollution to the environment. In this paper, microemulsion was used as the capture agent for flotation of coal gasification fine slag, and the physicochemical properties of residual charcoal were analysed by means of industrial analyser, FTIR, BET, SEM, XRD, Raman, XPS and other means of characterization, and the electrochemical properties of the residual charcoal were analysed by means of CV, EIS test, and the electrochemical properties and stability of the residual charcoal as a particle electrode in the three-dimensional electrochemical system were examined, and the feasibility of using it as a The feasibility of the residual carbon as a particle electrode was investigated, and the mechanism of ammonia nitrogen removal by the residual carbon particle electrode was proposed to be analysed. The results show that the flotation residual carbon has a high specific surface area, and the pore structure is dominated by mesopores. In addition, some of the carbon in the residual carbon exhibits a certain degree of electrical conductivity due to graphitization, which provides a basis for its electrochemical applications. In addition, the residual carbon particles electrocatalytic system had lower electrical resistance, which was conducive to accelerating the charge transfer rate. The three-dimensional electrocatalytic system of residual carbon particles had 19.82% higher ammonia nitrogen removal rate than the two-dimensional electrocatalytic system under the same conditions of ammonia nitrogen wastewater degradation, and it has certain catalytic ability.In the residual charcoal particle electrode cycling test, the residual charcoal particles were reused for five times, and the removal rate of ammonia nitrogen only decreased by 5.3%, and this result shows that the residual charcoal particle electrode has good stability. In this paper, a novel particle electrode material in a three-dimensional electrocatalytic system is developed, and through systematic characterisation and performance evaluation, it is demonstrated that the residual charcoal particle electrode of gasification slag has great potential in improving the efficiency of wastewater treatment. The development of residual charcoal particle electrode provides a new idea for the resourceful utilisation of gasification slag, and also provides a new method for wastewater degradation treatment technology.