Cut and fill mining method - Epiroc

Summary

Cut and fill mining is a versatile method for extracting steeply dipping and irregular ore bodies, offering selective mining and adaptability. It involves mining in horizontal slices, with backfilling using waste materials like tailings or waste rock. This method allows for high selectivity and ore recovery with minimal dilution, though it is considered low productivity. The process includes drilling, blasting, mucking out ore, and reinforcing the rock as needed, with mining continuing until the entire ore body is extracted.

Takeaways

• ⛏️ Cut and fill mining is a preferred method for steeply dipping and irregular ore bodies.
• 🔄 It offers adaptability to variations in the rock mass and selective mining capabilities.
• 🏗️ This method is considered small-scale and is carried out in horizontal slices along the ore body.
• 🔄 The bottom slice is mined first, followed by backfilling and then mining upwards.
• 🚧 Backfill material can be reused waste such as tailings, sand, or waste rock.
• 🔩 Backslashing is used for access to upper slices within the stope.
• 🚧 After a stope is completed, a new access drift is created to continue mining in the upper stope.
• 💥 The mining process involves drilling, blasting, ventilation, mucking out, and rock reinforcement.
• 🔄 Cut and fill mining allows for the mining to be tailored to the shape of the ore body, reducing dilution.
• 🔄 It is a low productivity method but offers high selectivity, good ore recovery, and low dilution.

Q & A

What is cut and fill mining?

Cut and fill mining is a small-scale mining method favored for steeply dipping and irregular ore bodies. It is preferred by mines that require selective mining and adaptability to variations in the rock mass.

How is mining carried out in cut and fill mining?

Mining is carried out in horizontal slices along the ore body, starting with the bottom slice. The excavated area is backfilled, and production continues upwards, with each level being mined by drifting until the entire slice is mined.

What is the purpose of backfilling in cut and fill mining?

Backfilling serves to provide a working platform for mining the next level and also allows for the reuse of waste materials such as tailings sand or waste rock from development.

How does access to upper slices within the stope occur in cut and fill mining?

Access to upper slices is provided by back slashing, which is done for providing access to the upper slices within the stope. Once a stope is completed, a new access drift from the ramp is created to continue production.

What are the advantages of using cut and fill mining?

Cut and fill mining offers the advantage of reusing waste for backfill material, high selectivity with good ore recovery, and low dilution, allowing for the minimization of waste rock dilution.

What are the steps involved in mining one of the slices?

The steps include drilling blast holes, charging and blasting the ore, ventilating toxic blast fumes, mucking out the ore into an ore pass or onto a truck, and then continuing with the next round.

How is the rock reinforced in cut and fill mining?

The method of rock reinforcement is decided by the mine for each individual situation, ensuring stability and safety as the mining progresses.

Why is cut and fill mining considered a low productivity method?

Cut and fill mining is considered low productivity due to the sequential nature of mining and backfilling, which can be time-consuming and labor-intensive compared to other methods.

How does the shape of the ore body influence cut and fill mining?

The shape of the ore body allows cut and fill mining to be tailored to suit its contours, which can help minimize dilution and maximize ore recovery.

What equipment is typically used for cut and fill mining?

The equipment used for mining the ore is usually the same as what is used for development, indicating a versatility in the tools needed for this method.

How does the increase in rock stresses affect cut and fill mining?

As the ore body is mined, the rock stresses increase in the pillars above the mined area, which may require additional support or changes in mining strategy to ensure safety and stability.