How are materials transported vertically to the surface from underground mines?

Getting ore and waste from deep underground to the surface is a monumental logistical challenge, often relying on powerful vertical transport systems. While underground mines use track or trackless systems for horizontal and inclined movement, bringing materials to daylight requires specialized methods.

Here are the primary ways materials are transported vertically to the surface from underground mines:

1. Hoisting Systems (Shaft Hoisting): This is the most common method for deep mines. Materials are loaded into large containers called skips (for bulk ore/waste) or cages (for equipment and personnel) within a vertical shaft. These conveyances are then raised and lowered by powerful electric motors and winding ropes connected to a mine hoist (winder) located in a headframe above the shaft. There are two types of hoists: Drum Hoists in which the rope winds onto a large drum. Common in North America, South Africa, and South America. Friction Hoists (Koepe Hoists): the rope passes over a friction wheel (no winding onto the drum). More common in Europe, Asia, and Australia. Often use multiple ropes for larger payloads and balanced systems.
2. Vertical/Steeply Inclined Conveyor Systems: * Mechanism: While traditional conveyors are horizontal or moderately inclined, specialized vertical conveying belts or steeply inclined conveyors can transport bulk materials at very high angles, sometimes even completely vertically. These often use corrugated sidewalls or cleats to hold the material on the belt. It offers continuous material flow, potentially lower operating costs than hoisting for certain applications, and can eliminate the need for large, expensive skip loading stations underground. Some systems can lift materials over 500m vertically in a single flight. (Vertical conveying belt – Monster belting, KJ Kuchling Consulting Ltd, n.d).
3. Hydraulic Hoisting (Slurry Pumping): An innovative and less common method for some materials (like evaporite ores). Mined ore is crushed and ground underground into a slurry (a mixture of solids and water). This slurry is then pumped directly to the surface through pipelines. Can reduce the need for large, expensive vertical shafts and traditional hoisting equipment. Allows for continuous flow and can be more cost-effective for specific ore types. Can also utilize mine drainage water for slurring. Being explored and used for fine particle streams or specific types of ore (Hydraulic Hoisting – Stantec, n.d).

Each of these vertical transport systems has specific advantages and is chosen based on factors like mine depth, production volume, material characteristics, capital investment, and operational efficiency goals.

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Reference:

Hydraulic Hoisting – Stantec, Google Patents

Vertical conveying belt – Monster belting