MILL SCATS
RECYCLING
re-use | reduce waste | save money
Mill Scats Recycling - Turning Waste into value
How Recycling Mill Scats Improves Efficiency and Reduces Costs
​After the initial crushing stage, raw material is often further processed by grinding in Ball or SAG mills to make it easier to extract the desired minerals downstream. These mills use grinding media, typically steel balls of varying sizes, which are lifted and tumbled to reduce raw material through impact and grinding as it passes through — a process known as comminution.
Grinding media such as steel balls can start as large as 100mm or more in diameter. Over time, these steel balls wear down, becoming smaller and lighter. Once they reach a size where they no longer contribute to efficient grinding, they are screened and discharged as waste—commonly referred to as ‘mill scats'.
If not removed, mill scats can damage downstream equipment such as pumps or unnecessarily consume power within the mill without contributing to grinding efficiency. Consequently, mill scats must be separated and removed from the process, with many tonnes being discarded as scrap each month. However, since different ball mills require different ball sizes, scats from larger mills can sometimes be repurposed in smaller mills, reducing waste and saving costs.
BHT Facilitated Mill Scats Recycling for an Australian Gold Miner
BHT has successfully designed and commissioned a scats reclaim hopper and kibble loading system for an Australian gold mining operation. This system enables safe loading of mill scats via a Front-End Loader (FEL), which are then fed into a loading kibble through a pneumatically actuated chute. The kibble is lifted by an overhead crane and discharged into the feed chute of a smaller mill, enabling the reuse of the scats.
Given the irregular size and solid steel nature of the scats, careful attention was given to ensuring controlled feeding into the kibbles when loading. The belt runs on a polymer sliding bed, and the pneumatically operated chute is manually controlled by the operator via a push-button mechanism located behind an interlocked safety guard.
Developed based on extensive experience in belt feeder and hopper design, the BHT Scats Reclaim Feeder and Kibble Loading System is scalable to accommodate different FEL sizes and throughput requirements. A rubber-lined chute minimizes noise, and the loading of kibbles is a simple process manually controlled via on-board controls. The interlocked safety screen allows operators to monitor the filling of the loading kibble while ensuring safe disconnection and reconnection to the overhead crane at the start and completion of the kibble filling process.
When integrated with BHT's grinding media Steep Angled Conveyors, the system provides a complete solution for reclaiming mill scats, combining them with new grinding media, and delivering the full charge to a ball mill feed chute.
