Leaner and Meaner SAG Mills

October 30, 2018

Among the new innovations that are improving the milling process is a condition monitoring technology that tracks SAG mill liners and grinding mill liners to extend liner life.

As mines get increasingly larger and commodity prices fluctuate with global trends, mill operators have to stay efficient and competitive. Luckily, several original equipment manufacturers and software providers are creating new solutions to help operators improve mill performance. And here at Unicast, we work hard to make our wear parts for SAG mills and grinding mills tougher and longer lasting so operators can keep doing what they do best, without worrying about replacements and unplanned maintenance.

In February FLSmidth announced its new SAGwise system, which uses acoustic sensors and the company’s proprietary process control software to analyze impacts on the mill and other variables like power usage, mill weight and bearing pressure. It then adjusts the mill’s load, which helps decrease steel-on-steel impact. The result, the company says, is a more stable SAG mill, reduced energy consumption and higher productivity.

“Where an operator might make adjustments every few minutes, this solution can make less drastic adjustments more frequently, down to every 20 seconds or less,” King Becerra, FLSmidth’s global product line manager for automation process optimization, said in a press release.

Made from alloy, rubber or hybrid material, Unicast head liners and shell liners optimize mill performance.

Outotec’s MillMapper, the world’s first mill condition monitoring technology, tracks the condition of SAG mill liners and grinding mill liners to allow operators to extend liner life cycles, optimize liner design, prevent against liner failure, and detect any problems before they become critical. Mine personnel use Outotec’s specially calibrated terrestrial laser scanner during a planned inspection shutdown to record the mill’s entire visible internal surface, which then generates liner thickness measurements that are used to create a 3D model and wear tracking curves. The software will note high wear zones and any uneven wear patterns.

Metso has seen increased interest in its Vertimil stirred milling technology as plants need to up their milling capacity or achieve a finer grind without adding a second ball mill. The Vertimil has higher energy efficiency, longer wear life — limiting the need to spend money and time replacing Metso parts — and a smaller environmental footprint than ball mills. The company has also worked hard to make its wear parts more accessible so that when maintenance time does come around, it isn’t so time consuming.

On the software side, both Agnico Eagle and Goldcorp have begun using Honeywell’s multivariable predictive control (MPC) technology, which operates a milling process closer to its limits, to help maximize the mill’s capacity. At Agnico’s Goldex mine in Val d’Or, where MPC was implemented in 2015, the technology controls the SAG mill, ball mill and ore blending, among other outputs. The system uses historical data to create a model that correlates several control variables and outputs in a grinding or milling circuit to predict the effects of ore and set-point changes.

Unicast’s SAG mill parts, grinding mill parts and ball mill parts include shell and head liners; drives, gears, pinions and bearings; and grates and screens. Our SAG and ball mill liners are cast in chrome-moly steels and high chrome white iron processed to have the optimal combination of high hardness and toughness ensuring longer wear life than our competitors.

For other parts of the comminution process, we also offer mining wear parts including roll crusher parts; gyratory crusher parts; cone crusher wear parts and jaw crusher wear parts.

Stop losing time and money on unplanned downtime caused by insufficient wear parts. Unicast’s industrial wear parts can withstand extreme temperatures and tough working conditions longer than other products. Contact us at 1-866-728-3557 or visit our website to learn more.