Company Announcement - Optimising the grinding circuit requires a specialist skill set that has at its foundation an in-depth understanding of the application of available products to facilitate optimum throughput, minimum unscheduled downtime and eliminate unnecessary wear. Multotec is in a position to offer its customers the necessary expertise and experience in optimising comminution circuits. The company employs two dedicated comminution engineers, with in excess of 50 years’ experience between them, and according to Javier Kirigin, comminution product manager at Multotec Rubber, it is this strategy of maintaining long term, interactive relationships with its customers that has allowed Multotec to provide fit-for-purpose solutions.

Multotec’s success can be attributed to its methodology that begins with undertaking a grinding circuit survey which provides a snap shot or overview of the current status of the plant. “This information allows us to accurately assess the plant and to then infuse a change into the circuit that is designed to optimise its performance, with a positive influence on the customer’s bottom line,” Kirigin says.

One of the main objectives of a circuit survey is to determine the Work Index Efficiency of a circuit both before and after optimisation steps have been implemented. This is then compared to the Bond Standard Circuit Efficiency of 100%, with no correction factors.

“The primary objective is to improve grinding efficiency and reduce grinding costs in terms of energy usage, grinding media and liners, across the full spectrum of commodities. For this reason we consider plant throughput, power and granulometry or particle size distribution. Typically information is gathered from sampling points that include the mill feed, mill discharge, cyclone feed, cyclone overflow and cyclone underflow in a closed circuit configuration,” Kirigin adds.

This information, together with liner design software, enables the engineering of appropriate lining solutions for each particular application. “Following the implementation of the initial changes, a second survey is conducted to quantify these changes in terms of the initial stated goals,” says Kirigin. In addition to circuit surveys, Multotec also undertakes mill inspections that assess the condition of the ball load, the mill liner and the grinding media.

The company has a widespread footprint and is focused on providing support to customers even in the remotest areas in Africa. “We adopt a philosophy of manning our operations with people that understand both the language and culture of the region in which the customer operates. We can reference a number of successful projects where our solutions have resulted in major cost savings and drastically reduced downtime and maintenance,” Kirigin points out.