Liners have become extremely popular in recent times. They offer a ton of benefits. Over time, alloy mill liners are used for carrying out various tasks. They help protect the shell of the mill. With the current rate at which new methods are being researched for reducing milling costs and optimizing the liner design, it is only a matter of time until the ultimate alloy mill liners are developed.
When the tube, rotating ball, and roods mills were first introduced in mineral processing, it led to the realization that operations using abrasive feed ended up eroding the mill shell. The early design of the liners were crude. The individual panels stayed in place because of the metal or timber wedges. Mill liners require replacement and maintenance frequently. The liners were even used in gold mines in New Zealand. Tube mills were later used for the grinding. However, it was the hardness of the ore which eroded the mill liners.
So Why Should You Line?
There is a reason why liners are commonly used. When you install a replaceable liner in the grinding mill, its design and materials help protect the outer shell. The design and materials of the liner influence just how effective it is. They also impact its performance. To ensure that the mill grinds effectively, it is important to use the right material and appropriate lifter design. However, if you make the wrong choice, you would end up having to pay high liner maintenance costs, excess energy usage, and experience poor grinding.
Besides, the liner segments remove the pulp which discharges from the end of the mill. Thus, it acts as a pump rather than just a lifting mechanism. It pumps out grinding media and rock. There are different types of mill liners out there. Each offers different features. You need to understand the difference between a mill that is designed to operate using pulp filters and one that operates in overflow mode. They both affect the duty that is imposed on the liner.
When selecting a mill liner, the physical characteristics of the ore which is being ground need to be considered such as the distribution of the mineral and its abrasiveness. These factors influence the liner material to be used. On the other hand, the rotational speed of the mill itself also influences the relationship between the centrifugal forces and gravity. The charge within the mill runs at around 90 percent when it comes to critical rotational speed. It would behave differently as compared to when it runs at 75 percent.
Austenitic manganese steel and steel alloy are the materials of choice for ball mill and SAG liners. The trend has been heading in the direction of higher carbon chrome steels. It is where the ball mills will be focused.
Alloy mill liners help extend the life of the mill. The manufacturing of lining mills have been optimized to ensure the manufacturing process is smooth. It is based on the lining design.