This article addresses the problem of reducing costs in the operation of crushing and milling equipment associated with high consumption of lubricant, as the volume of lubrication systems of crushing and milling equipment can be up to 60 m3. The reasons of rejection of the lubricant in the lubrication system of crushing and milling equipment, as well as to define the criteria of a limiting condition of the lubricant. The possibility of use in the lubrication system of crushing and milling equipment purified used motor oils. The study found that the replacement of the lubricant on the actual condition will reduce costs in the operation of crushing and milling equipment.