Mining Techniques Based on Nature of Mineral Occurrence

Mining is a tedious undertaking. Many often look at the economic value of minerals but forget how much work mining engineers have to put into extracting them. They must plan for the extraction, install all the necessary equipment and execute the trade to perfection. One missed step and it could all come tumbling down, putting both human and technical wellbeings at risk. Essentially, striking a balance means using the right technique as dictated by the mineral's natural occurrence. Read below to teach you more about that:

Flat-lying Mineral Deposits

Many mineral ores originated in swamp environments, oceans, lakes and other water bodies. Over time, these ores underwent heavy compaction and pressure but often maintained their horizontal orientation. They occur as flat-lying deposits, and mining engineers employ these techniques during extraction:

  • Room-and-pillar mining – room-and-pillar mining is a popular underground mining method where engineers create several parallel drifts on the site. The drifts have connections between them, creating checkered patterns in areas where the length of the connecting drifts equals that of the parallel drifts. Consequently, mineral ore pillars remain to support the surrounding rocks as the extraction continues. The miners will only extract some of the pillars after reaching the mineral ore's boundary.
  • Longwall mining – longwall mining involves dividing flat-lying mineral ore into rectangular blocks or panels. Each block will have several parallel drifts extending into the ground. The drifts are useful for transporting the extracted ore and ventilating the mines. Additionally, the miners drive a cross-cut drift to form the long wall connecting the parallel drifts. They can install hydraulic supports on the long wall to form a protective canopy that allows cutting machines to move back and forth and extract the mineral ore.

Steeply Dipping Mineral Deposits

Some mineral deposits occur in vein-type formations due to the natural distortions in the earth's crust. Shrinkage stopping is the go-to technique for extracting narrow ore deposits with clear boundaries. The miners work upwards from a broken ore, drilling blast holes in slices of intact ore that they will remove from the stope's ceiling. A significant percentage of the fragmented ore is extracted from the bottom as the further blasting weakens the ore that is still sitting in the slice. It falls and replaces what the miners had removed at the bottom. It is worth noting that it is difficult to mechanise the shrinkage stopping technique. Miners must do several manual interventions. It also takes up lots of time as long intervals can elapse between the beginning of ore extraction in the stope and the final extraction of all the blasted ore.

Contact a mining engineering service near you to learn more.