The Practical Tests on the Shape and Durability of Rod-Mill Liners

In order to extend the durability of a rod-mill liner, it should be necessary to choose its optimum shape, size and material, of which the liner is made, according to the operational conditions of the mill. However, their details are still unknown.<BR>In consideration of this circumstance, the wave-type liner of the optimum material and shape for the rod-mills installed in Doyashiki's and Matsumine's milling plants of Dawa-Hanaoka mine was sought by practical tests, and the following results were obtained.<BR>1) While the conventional liner for a rod-mill had its summit at the middle point of its width, the liner for the tests was designed to have its summit beyond the middle point of its width and to have its summit being moved toward the middle point of the linerwidth by the abrasion of the liner. This design of the liner was useful to prevent the earlier abrasion of the bolt-hole located in the middle point of the liner-width.<BR>2) The summit of the liner for the tests was heightened up to the height corresponding to 50% of the rod-diameter, which was a little higher than that of the conventional liner. This heightening of the summit increased the height of lifting the rod and also increased the degree of hardening the surface of the liner by about 10% compared with the case of the conventional liner.<BR>3) The liner for the tests was made of 13% Mn-steel with the addition of 1.7% Cr, and this liner had the initial hardness which was 8% harder than the conventional one.<BR>4) In the long run, the durability for the tests was increased by 35-50% in terms of the cumulative amount of handled ore as compared with the conventional liner.<BR>5) Although the tests are still being continued, it can be imagined that the durability of the liner will be further increased if the summit of the liner is heightened up to 60-80% of the rod-diameter.