Abstract:Based on the physical and chemical properties of coal gangue with different sulfur content, the law of coal gangue oxidation to produce acid and alkali was analyzed by static simulation test. Coal gangue oxidation acid production is a coexisting process of acid and alkali production. The acid production process is mainly controlled by the chemical oxidation of sulfide minerals, and the alkali production process is the acidity neutralization caused by dissolution of alkaline minerals and proton exchange that occurs on the surface of some silicate minerals due to ion dissolution. The acid production stage of coal gangue can be divided into rapid acid production period and stable acid production period, and its alkali production stage can be divided into fast alkali production period and slow alkali production period. Sample No.1 coal gangue system is a rapid acid production period from 0 to 48 hours, and its acid production rate reaches 1.889 mmol/(kg?h), and then enters a stable acid production period with acid production rate of 0.012 mmol/(kg?h); 0 to 24 hours is the period of rapid alkali production, the alkali production rate is 1.594 mmol/(kg?h), and then the alkali production rate drops to 0.013 mmol/(kg?h). The acid production and alkali production process of sample No.2 coal gangue system takes 48 hours as the transition point, the rapid acid production rate is 0.243 mmol/(kg?h), and the stable acid production rate is 0.008 mmol/(kg?h); The rate of rapid and slow alkali production is 1.008 mmol/(kg?h) and 0.033 mmol/(kg?h) respective.