Sublevel caving mining method - Epiroc

Summary

Sublevel caving is a highly efficient mining method ideal for large ore bodies with steep dips, where controlled rock mass fracturing ensures safe extraction. The process involves blasting, drilling, and managing ore dilution through precise extraction techniques. Key activities include maintaining roads, using bucket weighing for dilution control, and transporting ore efficiently to crushers. Though sublevel caving has challenges such as ore loss and surface subsidence, it offers significant benefits in terms of productivity and automation potential, making it a safe and scalable solution for large-scale mining operations.

Takeaways

• 😀 Sublevel caving is a large-scale mining method suitable for steeply dipping ore bodies.
• 😀 This method works by fracturing the host rock in the hanging wall under controlled conditions.
• 😀 Mining starts at the top of the ore body and progresses downwards in a safe, systematic sequence.
• 😀 All ore is fragmented by blasting, and the hanging wall rock mass caves once production drifts are excavated.
• 😀 Drilling in ring patterns with minimized hole deviation is crucial for effective blasting and ore fragmentation.
• 😀 Loading from the cave front is done to control dilution of waste rock and ensure proper ore extraction.
• 😀 In cases where ore and waste rock have significant density differences, bucket weighing can be used for dilution control.
• 😀 Maintaining good road conditions in the mine is essential for productivity and efficient transportation.
• 😀 Ore is transported efficiently via passes connected to the haulage level, moving material from production points to crushers.
• 😀 Sublevel caving features a systematic drift layout, allowing parallel production activities to be carried out simultaneously.
• 😀 While effective, sublevel caving inevitably causes some ore loss and waste rock dilution, and eventually leads to surface subsidence.

Q & A

What is sublevel caving, and in what type of mining conditions is it most suitable?

Sublevel caving is a large-scale mining method best suited for steeply dipping ore bodies where the host rock in the hanging wall fractures under controlled conditions. It is particularly effective in these types of rock masses.

How is infrastructure typically placed in sublevel caving mining operations?

In sublevel caving, the infrastructure is always placed on the footwall side to ensure safety, as the ore body and surrounding rock mass cave under controlled conditions.

What is the sequence of mining in sublevel caving?

Mining starts at the top of the ore body and progresses downward in a safe sequence. The process is highly structured to maintain safety and efficiency.

How does blasting work in sublevel caving mining?

Blasting is used to fragment the ore, and once production drifts are excavated and reinforced, the rock mass in the hanging wall caves in. This fragmented ore is then loaded from the cave front.

Why is drilling important in sublevel caving, and what should be minimized during drilling?

Drilling is crucial for creating blast holes in a ring pattern, which helps to fragment the ore effectively. It is essential to minimize hole deviation during drilling, as it can affect the fragmentation and flow of the caving rock mass.

What is the role of dilution control in sublevel caving?

Dilution control involves managing the amount of waste rock mixed with ore. This is achieved by controlling the extraction percentage and, if necessary, using bucket weighing to separate ore from waste rock, ensuring the ore quality is maintained.

How does the mining process ensure efficient transportation of ore?

Ore is transported efficiently through passes connected to the haulage level, which leads directly to the crusher. Proper road maintenance is crucial for maintaining the productivity of this transportation system.

What is the significance of the parallel drift layout in sublevel caving?

The parallel drift layout allows activities in different production drifts to occur simultaneously, improving the overall mining process and operational efficiency.

What are the main challenges associated with sublevel caving?

The main challenges include ore loss, waste rock dilution, and surface subsidence caused by the caving process. These issues arise as the ore body caves and the surrounding rock mass fractures.

How does sublevel caving allow for automation in mining operations?

With proper planning, sublevel caving mining enables the safe and efficient use of mining equipment, opening up opportunities for automation to improve productivity and safety in the mining process.