Mining Methods: Supported & Caved:

Supported and caved stoping methods are mining techniques used for underground mining operations. These methods involve the extraction of ore from a vertical or steeply inclined deposit. Here are the explanations of both methods:

1. Supported Stoping:

Supported stoping is a mining method where the surrounding rock or backfill material is used to support the walls and roof of the stope, which is the underground excavation where ore is extracted. The key features of supported stoping include:

a. Cut-and-fill stoping: This method involves extracting the ore in horizontal slices or lifts. After each lift is extracted, the void is backfilled with waste rock, tailings, or other fill material to provide support. This process is repeated until the entire orebody is mined.

b. Square-set stoping: In this method, the stope is divided into a grid pattern using square-set timbering. The ore is then extracted from each square-set panel, and the void is backfilled with waste material or fill material like cemented rock fill (CRF) or hydraulic fill.

c. Sublevel stoping: This method involves the extraction of ore from multiple horizontal levels or sublevels within the orebody. The sublevels are accessed by ramps or vertical raises. The ore is blasted and then loaded using equipment such as trucks or loaders.

2. Caved Stoping:

Caved stoping, also known as sublevel caving, is a mining method where the ore is allowed to naturally cave or collapse under its weight. It relies on the inherent structural instability of the orebody to extract the ore. The key features of caved stoping include:

a. Sublevel caving: This method involves the creation of a series of horizontal sublevels within the orebody. The ore is extracted from the lowermost sublevel, and as it is removed, the rock above collapses or caves into the void, creating a funnel-shaped cavity. The broken ore is then collected at the bottom of the cave and transported to the surface.

b. Block caving: Block caving is similar to sublevel caving, but it is typically used for larger, more massive orebodies. The ore is undercut at the bottom of the orebody, and as it is removed, the overlying rock fractures and caves, forming a large funnel-shaped cavity. Gravity allows the broken ore to collect at the bottom and is then extracted through drawpoints.

Both supported and caved stoping methods have their advantages and disadvantages, and the choice of method depends on various factors such as the geology of the deposit, orebody size and shape, depth, and economic considerations. Safety precautions and monitoring systems are crucial for the successful implementation of these mining methods.