Sublevel stoping mining method - Epiroc

Summary

Sublevel stoking is an efficient and versatile large-scale mining method used for mining steep and regular ore bodies with defined boundaries. The process involves blasting large stokes, which are backfilled for maximum ore recovery. The ore body is divided into primary and secondary stokes, with the primary mined first and the secondary left as pillars for support. The method allows for high productivity as multiple production points can operate simultaneously, and the backfilling process uses waste materials such as tailings. Support systems, like cable bolts, are installed to stabilize the rock mass, ensuring safety and enhancing productivity.

Takeaways

• 😀 Sublevels stoping is a widely used method in large-scale mining, especially for ore bodies with steep dips and well-defined boundaries.
• 😀 The method is based on blasting large stopes, which are backfilled to maximize ore recovery.
• 😀 Drifts are created through the ore body to enable mining of stopes between sublevels.
• 😀 Ore bodies are divided into primary and secondary stopes, with primary stopes mined first.
• 😀 Secondary stopes act as pillars until primary stopes are mined and backfilled, stabilizing the structure.
• 😀 Backfilling helps prevent sidewall cave-ins when secondary stopes are mined.
• 😀 It is common to drill the entire stope before charging and blasting, especially when conditions allow for it.
• 😀 Once the first section is blasted and mucked out, more room is made to blast larger sections of the stope.
• 😀 Waste materials such as tailings or sand from processing plants can be reused as backfill material.
• 😀 Cable bolts are often installed above the stopes to provide additional support to the rock mass, preventing larger rock blocks from falling into the stope.
• 😀 Sublevels stoping offers high productivity by enabling mining at different levels and stopes simultaneously, maintaining low ore dilution.

Q & A

What is sublevels stoking, and how is it used in mining?

Sublevels stoking is a mining method used primarily for large ore bodies with steep dips, regular shapes, and defined boundaries. It involves creating drifts through the ore body and blasting out large stokes, which are typically backfilled to maximize ore recovery.

What are the key advantages of sublevels stoking in large-scale mining?

Sublevels stoking offers high productivity as it allows mining of ore on different levels and stokes simultaneously, reduces dilution, and ensures efficient ore recovery. It also utilizes waste materials for backfilling, which helps optimize costs and resources.

What are the different variations of sublevels stoking?

There are variations of sublevels stoking based on the shape of the ore body. However, the core principle remains the same: blasting out large stokes between sublevels and backfilling them to enhance ore recovery.

What is the role of primary and secondary stokes in the sublevels stoking method?

Primary stokes are mined first, and secondary stokes are left as pillars to support the structure until the adjacent primary stokes have been mined and backfilled. This ensures the stability of the excavation process.

How are secondary stokes supported during mining?

Secondary stokes are supported using cable bolts installed above them. These bolts provide additional reinforcement to the rock mass and help prevent large rock blocks from falling into the excavated area.

Why is backfilling important in the sublevels stoking method?

Backfilling helps stabilize the mine by preventing the sidewalls from caving in when secondary stokes are excavated. It also maximizes ore recovery by filling void spaces with waste materials like tailings and sand.

How does the blasting process work in sublevels stoking?

The process often involves drilling the entire stoke before charging and blasting. After blasting the first section and mucking it out, enough space is made to continue blasting larger sections of the stoke. This iterative process ensures continuous mining.

What types of materials can be used for backfilling in sublevels stoking?

Materials like waste tailings and sand from the processing plant can be used for backfilling in sublevels stoking. This helps reduce costs and make use of available waste materials.

How does sublevels stoking maintain high productivity?

Productivity is maintained at a high rate because sublevels stoking allows for mining at multiple levels and stokes simultaneously, enabling a constant and steady flow of material extraction.

What are the safety precautions taken during sublevels stoking?

Safety precautions include the installation of cable bolts to provide support to the rock mass, ensuring stability. Additionally, the use of backfilling minimizes the risk of cave-ins during secondary stoke mining.