... self lubrication have doubled, and can be used in metallurgy oil, coal mine, mining, power, chemical industry, etc. Because of ... nonferrous metal and non-metallic mining etc, concentrator is used in great quantities in the pulp conveying pipeline, such ... coal, mining pulp, conveying, coal-water slurry, conveying, thermal power plant, the fly ash conveying, rivers and lakes dredging, municipal sewage ...