In the production process of coal preparation equipment, the pH of the slurry depends on the pH of the industrial water, the nature of the chemical, and the nature of the slime. It is more and more the nature of the mineral impurities in the slime. They have a greater impact on the pH of the slurry; this is due to some of the impurities. The dissolution of these components in the pulp simply changes the concentration of hydrogen ions and hydroxide ions in the liquid phase. According to some materials, when the pH value of the slurry is 6.9-7.0, the ash content of the flotation clean coal is low. There are still materials that show that the appropriate pH of the pulp is beneficial to reduce the sulfur content in the clean coal.

Someone used alcohols for flotation tests, and the results showed that when the pH value of the slurry was equal to 9.0, the desulfurization effect of clean coal was good. In short, flotation in neutral and slightly alkaline (pH=7.0-7.5) slurry is beneficial to increase the yield and quality of clean coal; while flotation in weak alkaline (pH=8-8.5) slurry, The desulfurization effect of clean coal is better.