The new ball-rolling mill of EVRAZ NTMK – new possibilities for customers

Abstract

In view of increase of ferrous and nonferrous ores mining, the need for grinding balls, used for the ores grinding in the process of concentration, is also increasing. Description of technical solutions, realized at accomplishment of an investment project at JSC EVRAZ NTMK, presented. The investment project on the technical modification of the rail and beam shop included construction of the new ball-rolling mil further to production of steel grinding balls. The new ball-rolling mill, which was put into operation in 2018, has a possibility to produce ball of diameter from 60 up to 120 mm with hardness up to 5th group. The mill is equipped by an automation system of the process and balls stocking control. The ball production section comprises a walking beams heating furnace with automated heating modes to ensure energy-efficient operation; automated hot rolling mill for production grinding balls of 60 ‒ 120 mm diameter; balls thermal treatment line, including temperature leveling facility, quenching machine and tempering furnace. The system of the process automation enables to trace on-line all the technological parameters for production quality products, parameters of the environment to increase the energy efficiency of the section, and control system to create safety working area at the section. Within a year after the ball-rolling mill commissioning, the whole nomenclature series of balls was mastered and the passport productivity at each profile was reached. The maximum mill productivity obtained was 22 t/h. The JSC EVRAZ NTMK mill of grinding balls of 60 ‒ 120 mm diameter production meets all the modern market requirements.