Underground v.s. Surface Coal Mines: Is Deep Drilling Worth the Cost?
Although both methods have their benefits and drawbacks, underground drilling may just be the cost worthy selection for you
Mining for coal depends on many variables. The geology and environmental aspects play a vital role, but depth and quality of the seam is what brings home the bacon. Depending on where the seam (profitable bed of coal) is located, extracting this black gold can require a smorgasbord of options.
Coal mining typically requires two methods of operations: underground and surface mining. The method is differentiated by whether the seam is relatively close to the surface area or buried deep below. An array of underground and surface mining techniques exist, however, technical and economic feasibility studies are required to determine which process is best. These studies are based on the regional geologic conditions, including characteristics of the site; coal seams continuity; thickness; structure; quality; and depth and strength.
There are many advantages as well as disadvantages to both methods, including financial and environmental reasoning. You decide which is best for you.
Underground or “deep” mining consist mostly of two methods - room-and-pillar and longwall mining. In room-and-pillar, coal deposits are mined by cutting a network of “rooms” into the coal seam and leaving behind “pillars” of coal to support the roof of the mine. The coal is extracted in two phases, first with the pillars of untouched material left to support the roof as the open areas “rooms” are recovered.
The second technique, longwall, is the preferred choice in underground mining. The technique utilizes a longwall shearer, a large machine with a rotating drum that moves back and forth across a coal seam. The longwall equipment moves forward during production permitting it to bypass overlying rock, making high levels of production and safety enhanced.
Although there are opponents and proponents of underground mining, the disadvantages include destruction of land, surface subsidence, abandoned shafts, extensive surface spoil heaps, mine explosions, collapses and flooding. That doesn’t incorporate the costly price tag that comes with underground mining. The process requires mechanized operations with sophisticated equipment. Along with vehicles, rail haulage and multiple drill units, copious amounts of precaution is needed to maintain miner safety, including mine ventilation.
Opencast mining, otherwise known as surface mining consist of three different techniques: strip mining, open-pit mining, and mountain top blasting. In general, the three processes include breaking up soil and rocks via explosives and then removing debris until coal seams are exposed. Trucks and shovels are used to remove excess fragments as a drill systematically bores into the mine, stripping it of coal, typically recovering a higher proportion of the coal deposits than underground mining.
Strip mining is sensible when the ore body is near the surface. The practice includes some of the largest machines on earth, removing long strips of overlying soil and rock and then removing coal deposits. Open-pit mining utilizes blasting and mineral removing, digger deeper into the earth causing a crater-like result. Mountaintop removal requires explosives to blast debris off mountain tops in order to reach coal seams deep inside the earth, sometimes 400 feet below the surface.
The major drawback of surface mining is the method destroys large areas of land, demolishing landscape and natural habitat to recover coal.
Is deep drilling worth the cost?
While underground mining requires an array of resources, equipment and financial backing, the method is best suited if the environment and coal potential harmonize. Longwall mining accounts for 50 percent of coal mines in the world and is much safer than other methods of coal mining. If done right, the process is much more profitable as resource recovery is dramatically improved (about 80 percent compared with about 60 percent for room-and-pillar). Despite the fact coal mining has the potential to cause harm to the environment and its habitat, deep drilling is worth every penny as productivity, profitability, and safety are all greatly increased.
Net zero benefits the mining industry and the environment
How do we get the world to net-zero faster?
Emitwise’s founders, Mauro Cozzi, Eduardo Gómez and Ben Peddie, approached a network of more than 100 of the world's largest enterprises and asked their CEOs, CFOs, and sustainability managers the big question: How do we get the world to net-zero faster? The challenge many shared was the lack of timely and accurate emissions data to enable strategic decisions. Companies often relied on annual audits of their carbon footprint for carbon accounting purposes. However, static yearly results were outdated upon publishing.
Emitwise saves companies an average of 260 working days a year by automating their scope 1, 2 and 3 emissions data. With the added benefits of clean audit trails and auto-populated accounting reports in line with GHG Protocol, all at the click of a button. Their easy to use solution enables businesses to quickly identify the carbon hotspots to target, and the precise real-time data empowers teams to remain agile and respond effectively, making achieving those goals possible.
Unique AI Technology
Emitwise’s unique AI technology empowers businesses to automatically measure, report and reduce their carbon footprint across their operations and supply chain, future-proofing companies for a zero-carbon world. It is the only solution that enables companies to fully automate their carbon accounting across all business units and suppliers, therefore liberating them from the drudgery of collecting and processing emissions data.
By using artificial intelligence to precisely measure emissions in real-time, businesses can identify and tackle carbon hotspots swiftly, enabling them to devise a trackable roadmap to net-zero carbon. At the same time, accurate audit trails and auto-populated annual reports ensure that companies comply with international reporting requirements, and align businesses with global climate targets to mitigate risk across their operations and supply chain.
The Oren Marketplace
Environmental management, social license to operate, safety, renewable energy to lower emissions and operational efficiency for mining can be supported by a range of digital solutions enabling dynamic operations. To address these issues, Shell and IBM joined forces to create the Oren Marketplace – the first B2B solutions platform for the mining sector.
With the adoption of many of the digital solutions offered through Oren, mining companies can adapt in real-time to risks or adjust plans ahead of a problem occurring. The goal is a shift towards proactive management as the optimal outcome for all stakeholders – community, shareholders, and employees.
Emitwise was founded with the goal of helping industries across all sectors reduce their carbon footprint. Similarly, Shell aims to become a net-zero emissions energy business by 2050, or sooner, in step with society and its customers. And Oren is focused on offering innovative products and services that can help mining companies track and reduce their emissions.
“Oren is the starting point for how we help our mining customers to de-carbonise,” explains Carol Chen, Global Lubricants Marketing, Vice President, Shell. “It’s our ambition to work with sectors like mining to help them find their own pathway to net-zero emissions through collaboration. The Oren marketplace offers a great opportunity for collaboration between the miners and technology companies that are joining this digital marketplace.”
Emitwise will be showcasing its vision for a net-zero future live from Lisbon at this year’s Web Summit. Bringing together the people and companies redefining the global tech industry, the online event welcomes 100,000+ attendees from around the world to hear from more than 800 speakers and view offerings from 2,500 startups covering a vast range of topics from Data Science and Climate Change to AI and Machine Learning. To find out more and book your ticket visit
Emitwise is one of many solutions providers on the Oren platform seeking to address the pain points and environmental concerns of heavy industries like mining. To discover a range of solutions that can further support your operation’s digital transformation and commitment to sustainability, visit the