Quick Guide to Soft Rock Mining | An Underground Miner

Soft rock mining refers to the process of extracting soft underground minerals such as oil, coal, shale, and potash from soft rock mineral resources.

Since mineral deposits of soft or sedimentary rocks are evenly layered and relatively soft, methods for mining such materials are much more different from those used to extract hard rock minerals.

Similarly, underground mining, whether for sedimentary or hard rocks, also differs from surface mining.

Here is a beginner's guide into the basics of soft rock underground mining.

CC Image by Helen Simonsson via Flickr

Several techniques are used in underground soft rock mining. These include:

• Longwall mining
• Short wall mining
• Room and pillar mining
• Drill and Blast mining

This is by far the most common modern method of underground soft rock mining. As the name suggests, it involves mines longer in size, usually about 100-300 meters high.

Coal and similar materials can be extracted along the entire length of the longwall, depending on the techniques and terrain involved.

With longwall mining, it is possible to cut the coal into different pieces of a specific width and move them into designated locations.

They can then be transported to processing plants to produce the final product.

Modern longwall face equipment uses hydraulic-powered energy to effectively extract blocks of coal of different sizes.

Longwall mining's main advantages are that permanent support is only required in the mining process's early stages.

This is especially true when installing equipment as well as during the recovery operations.

The minerals extracted using the longwall method are stable and not susceptible to leakage or spillage.

Once extracted, the raw materials are covered and transported to nearby central location or processing plants using sophisticated transport technology.

The main disadvantages of longwall mining are the economics involved. The equipment for underground longwall mining is typically expensive.

The system for extraction can be complex and require significant expertise. The nature of the long walls can also be a safety risk.

Therefore, working with the right training can help ease the process. This is also dependent on the site location and the nature of operations.

At the same time, it is vital to take the necessary precautions and follow safety guidelines when employing human resources to transfer the raw materials from the mines.

The technology behind underground longwall mining also invented the shortwall approach of extracting materials from underground mines.

This technique was first invented in the 1960s and grew in popularity due to its many advantages.

The primary advantage was that the method did not require costly equipment such as those used in the longwall mining process; hence it was more cost-effective.

As a substitute for longwall devices, more flexible and shortfall mining was conducted to achieve the same results and benefits as longwall mining.

Unfortunately, this strategy proved to be ineffective in the long run. It turned out that it was only applicable in sites with fewer mineral extracts.

However, when it comes to extracting minerals in smaller spaces, shortwall mining proved to be more effective and less costly.

Coal skimming was another technique that was used to mine coal more efficiently and with less complicated equipment.

It was less time consuming and also much easier when compared to the other methods.

Otherwise referred to as continuous mining, room and Pillar Mining is safer, more old-fashioned, and the most eco-friendly of all mining methods.

As the name suggests, room and pillar mining entail leaving large solid pillars of coal standing to support the room inside the mine.

Portions of large coal are left intact to act as pillars that maintain the land surface's stability above.

Using this method, the minerals extracted from a horizontal display or room are ideal for extracting coal and iron.

For the room and pillar method to be successful, pillars must be both specific and precise.

Both the size of the pillars and the room must be determined correctly; otherwise, valuable materials might go to waste, affecting the overall profits of the entire project.

Furthermore, if the pillars are smaller in size in relation to the room, the mine might collapse.

The room and pillar method is one of the oldest mining techniques that have not evolved much in terms of technology.

It requires a delicate balancing act to ensure the pillars are firmly fixed; otherwise, one disproportionate pillar can bring the whole mine tumbling down.

To mitigate such a potential tragedy supporting pillars must be erected to act as barriers.

Finally, the last stage in the room and pillar mining method is the retreat method. This method makes the process of removing or adjusting the pillars more flexible.

Once the mining is complete, the mine walls are left to collapse at the far end of the mining location.

Coal pillars can then be removed in a calculated, systematic manner. Removing the pillars require utmost precision and expertise with regards to safety precautions.

Drill and Blast mining is a fundamental and essential mining process. When it comes to underground soft rock mining, blasting and drilling go hand in hand.

It is the process that involves breaking the mineral extracts into small pieces using blasting technology.

This is yet another method that requires significant expertise and precision. For instance, if this method is not professionally executed, the economic factors of the mining project can be adversely affected. Blast mining is also applicable in pit mining techniques.

The blast mining process entails using blasting technology to blast and break off large quantities of mineral blocks.

Disintegrate them for transport to a dumpsite or processing plant with the aid of technology or relevant equipment.

Bolter Miners: Bolter miners are powered by either electricity or hydraulic energy and are heavy-duty, high capacity machines that provide safe and efficient excavation.

They are also used for the installation of rock bolts used for ground support. Bolter miners are typically ideal for mining coal, potash, and similar sedimentary mineral rocks.

Stationery Hybrid Crusher: Ideal for crushing applications on its three stages, namely primary, secondary and tertiary. The stationary hybrid crushes have the following components:

• Special teeth
• Hydraulic gap adjuster
• Overload protection
• Scraper system to remove sticky substances

The stationary hybrid also has the capacity of nearly 12,000 metric tons per hour, which boosts productivity.

Feeder Breakers: Ideal for heavy-duty underground coal and potash mining operations.

Road Headers for Mining: Designed with robust cutter heads and are ideal for excavating tunnels, underground caverns, and roadways.

Top Hammer rock drills: Ideal for drilling applications underground and on surface such as dimensional quarrying, rock bolting, stone quarrying, and tunnel drilling.

Hydraulic rock drill: Applicable in road cutting, bolting, trenching, foundation drilling, and dimensional stone quarrying.

Compact core drill rigs: For core drilling and underground explorations.

Cutting attachments: For demolition, trenching, roadway levelling, scaling and tunnel rehabilitation.

Other equipment for soft rock underground mining include:

• Continuous miners
• Mobile bolters
• Stationary screens and feeders
• Stationary impact crushers
• Longwall face bolters
• Borer miners
• Exploration tools
• Diesel and electric locomotives
• Down the hole drilling tools

As lucrative as underground mining is, it also has potential health and safety risks. This is a challenge experienced the world over, even in developed countries.

Valuable and precious metals are extracted deep underground. However, the deeper the mine, the higher the risks.

But with the right safety equipment and precautions such as the ones listed below, the risks can be significantly reduced.

Illumination: Underground mines must be adequately illuminated with high-quality lighting to ensure miners can see various mine and machinery-related hazards. This can be done through machine mounted or area lighting.

Hazard signage: Should be clearly visible in specific places.

Communication: Signals for both telephone and radio must be strong enough to ease communication and prompt emergency response.

Refuge Chambers and Medical resources: For quick emergency intervention.

Personal Protection Equipment (PPE)

These include but are not limited to the following:

• Work gloves
• Footwear
• Hearing protection
• Ventilation and alarm system
• Equipment maintenance
• Fall protection

So now you know the technical aspects of underground soft rock mining.

If you would like to learn more about underground soft rock mining or general information about underground mining.

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This article was written by An Underground Miner