Gold, copper, silver, coal – when we think of these precious items that we use in almost every aspect of our everyday lives, we hardly think of the process that helps us access these minerals – underground mining. When we eventually think of mining, we often picture dirt-covered miners, dark underground tunnels, shafts, and other common concepts associated with mining, but there is more to mining than all of these.
Mining, especially underground mining, is often overlooked even though its products are all around us every day. From the cutlery we use to eat, the jewelry we adorn ourselves with to the salt we consume. According to the U.S. Geological Survey, the average American uses over 664 tons of minerals in a lifetime. These minerals include lead, aluminum, zinc, clay, salt, iron, gravel, stone, sand, and cement – all of which are used in staggering quantities.
The bottom line is that although we may not realize or acknowledge it, we are very dependent on mining. There are so many interesting things about mining that you probably don’t know. So, in this article, I’ll tell you six interesting facts you didn’t know about mining. Let’s dig in.
Fact #1: There Are Two Types of Underground Mines
Yes – you read that right. This is probably one of the most surprising things for people who know very little or nothing about mining. There are two types of underground mines, these are:
● Hard rock underground mines
● Soft rock underground mines
I bet you are wondering “what’s the difference between both types of underground mines?”
Well, in hard rock underground mines, hard minerals containing lead, nickel, zinc, copper, silver, and gold are excavated. The type of extraction methods used in hard rock underground mines often depends on the kind of deposits found. As such, there is no one-method-fits-all approach to excavating in hard rock mines.
On the other hand, soft rock underground mines are underground mines where minerals such as oil shale, coal, potash, and other soft rocks are excavated. Just like in hard rock underground mines, the mining methods used in excavating minerals from soft-rock underground mines differ based on the type of rock being excavated.
Fact #2: Underground Mining Is Crazy-Expensive
You probably know mining is expensive, but you might not know that underground mining is even more expensive. Underground mining requires a more extensive range of tools and equipment than surface mining.
This is why, when compared to surface mining, underground mining is more expensive. Also, the risk associated with underground mining is much higher than that of surface mining. These two factors are the main reasons why underground mining is crazy expensive.
Fact #3: Underground Mines Are Really Really Deep
Generally, mines are deep, but underground mines go way deeper than surface mines. While surface mines can’t really go down past 200 feet into the Earth, underground mines can reach much deeper than that. A typical Underground mine can go down more than 2,500 feet. Awesome, right?
But, before you get blown away, you’ll probably be shocked out of your boots to learn that some underground uranium mines can go as deep as 6,500 feet into the Earth! I know mines are deep but it’s hard to beat the depth of underground mines.
Fact #4: Underground Mining Technology Keeps Changing
Technology has led to significant changes in almost every aspect of our lives, underground mining included. Before advanced technological solutions emerged, miners used only shovels to excavate materials. Also, they used canaries as a warning system. However, with new technologies emerging almost daily, the underground mining industry is continuously experiencing significant changes.
Many mining companies are adopting novel methods, as well as advanced tools and equipment. In terms of the best underground mining technology, it’s the case of Epiroc vs Sandvik but the most important thing to keep in mind is that the more underground mining technology solutions advance, the safer and less stressful underground mining becomes, especially for underground miners.
As I mentioned earlier, the risks and the costs associated with underground mining are much more than they are for surface mining. However, this does not mean that underground mining is not a lucrative investment choice. The truth is that, when well managed, underground mining can be a worthy investment that can generate a lot of money for you.
Fact #5: Copper And Gold Were The First Metals Discovered
Copper and gold were the first metals discovered by humans. Studies suggest that copper was already being mined as far back as 9000 BC. Archaeological evidence also indicates that around 4000 BC, humans already had the technology to fashion gold into jewelry. While gold was mostly used for ornamental purposes, copper was, instead, used to make tools and weapons.
While it is unclear how far back copper smelting was invented, archaeological findings suggest that copper smelting was discovered in Central America around 600 AD, in China around 2700 – 2800 AD, and in some parts of West Africa around the 10th century AD.
Fact #6: Zinc Is Recyclable
Yes, you might not know this but zinc is 100% recyclable as it does not lose any of its chemical or physical properties during the recycling process. This is why, in many countries, approximately 90% of all zinc-containing products are recycled.
So, how is zinc recycled? Well, one of the most common zinc recycling procedures is known as Electric Arc Furnace (EAF) heating. This method is typically used on collected scrap galvanized steel. Here’s how a typical EAF heating procedure goes:
● Step 1: The scrap is heated until the zinc evaporates, thus separating the zinc from the steel as a gas.
● Step 2: Next, the separated gas is collected and cooled in nitrogen. This causes the zinc vapor to morph into what is known as zinc dust.
● Step 3: Lastly, the zinc dust is treated in a rotary kiln. This transforms the zinc into zinc oxide. Zinc oxide is then used to produce zinc metal.
And, that’s pretty much how the whole thing works. Cool, right?
So, which of these six cool facts about underground mining did you find the most interesting?
Featured image credit: Unsplash (Vladimir Patkachakov).