FIELD: methods of conversion of paper mill slimes or similar materials. SUBSTANCE: slime with ash content on dry basis of 20-50% is introduced into cyclone furnace together with the second fuel source for combustion of slime to utilize slime calorific value and to convert ash content of slime into slag. Slime provides for 10-40% and more of heat produced in furnace. Slime is dried to prepare it for operation before its introduction into cyclone furnace. Slime may be granulated before its combustion. If organic matter is contained in slime in considerable amounts and ash content on dry basis is within 20-50%, method includes combustion of slime in cyclone furnace to form solid, strong and durable glassy slag, and removal of molten slag from furnace. Molten slag may be molded into glassy product or fiber. EFFECT: higher economic efficiency of slime conversion with production of useful product. 9 cl, 2 dwg, 4 tbl
