The average ore handling capacity of Φ12.2 × 11m AG mill shell liner provided by hengin for Sino Iron Mine is 7.5 million tons. Users want to increase the ore handling capacity by more than 15% on this basis, so as to achieve the purpose of synchronous maintenance with the ball mill, which can save downtime, improve the operation efficiency of the mill, and improve the annual ore handling capacity. Therefore, according to the wear condition of the shell liner, we further optimize the design structure, casting process and heat treatment process of the liner, so as to realize the targeted change of the liner parameters in different parts of the shell according to the different wear, reduce the internal casting defects of the Cr-Mo shell liner casting, accurately control the phase transformation temperature range of heat treatment, refine the grain, and obtain the ideal microstructure, so as to realize the optimization The overall service life of the Cr-Mo shell liner is prolonged.The batch is a set of mill shell liners, including 54 feeding shell liners with unit weight of 3447kg and length of 3715mm; 54 middle shell liners with unit weight of 2960kg and length of 3188mm; 54 discharging shell liners with unit weight of 2782kg and length of 3001mm.
According to the different wear conditions of AG shell liner, the height and angle of lifting strip in each part of the shell liner are designed to achieve synchronous wear.
Φ12.2×11m AG Mill Feeding Shell liner Casting ProCAST Simulation
We use Foseco riser with better heat preservation effect to ensure that the internal structure of shell liner casting is more compact and eliminate micro porosity and large inclusions.
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Temperature curve of Cr-Mo phase transformation
A more accurate heat treatment process is worked out by experiment and simulation calculation.For the cross-section of shell liner and 85crmo material characteristics, more accurate control of austenite transformation temperature range and pearlite transformation temperature range and rate, precipitation temperature and control of carbide can achieve the goal of grain refinement and uniform structure.
Metallographic analysis of Cr-Mo after heat treatment
The metallography is very fine pearlite + granular carbide + a small amount of polygonal ferrite. The microstructure shows that the shell liner has a good matching of strength and toughness.
