Mining gold isn’t as simple as spotting a shiny yellow vein in some rock and setting up a mine or casually panning for gold while camping by the river. It can take 10 to 20 years to establish a mine because of the required research, planning, and construction. There are also different types of mines, techniques, and methods. After that, it goes to the refinery. This long, complicated process of how gold is mined is fascinating from beginning to end, so buckle up and prepare to impress your fellow precious metals enthusiasts with fun facts about gold mining by the time you finish reading. 

How Gold is Mined Step by Step 

While there are many different types of mining techniques and even various types of gold deposits, where it all goes once it’s mined is all the same. Let’s look at the process from beginning to end in simpler terms before we dive into the nitty-gritty details of the long, complicated operation of mining gold and turning it into jewelry and bullion. 

1. Prospectors search for gold deposits. 

2. Once a deposit is found, a geologist investigates it and takes samples to determine its quality and quantity. They also map out the locations of all the deposits in the surrounding area. 

3. If the deposit and samples prove a potential resource, engineers assess the area, determine where to establish the mining operation, and calculate the economic viability of the resource. 

4. A mine is established, and extraction begins. 

5. Once extracted, the rock is taken to a crusher at a processing plant to break down the chunks further and locate the ore. 

6. Next, it goes into a flotation unit, separating as much solid ore from the rock as possible. 

7. The last step in the processing plant is for the gold to go through a carbon leach circuit and become a doré bar. 

8. The bars are sent to refineries for further processing into 99% purity.  

9. Finally, the gold is sent to mints or jewelers and turned into coins, bars, rounds, and jewelry.  

Mining Techniques 

There are three different methods of mining gold: hard rock mining, placer mining, and byproduct mining. Within these main methods are multiple mining techniques, which are used in specific circumstances, such as above-surface, underground, and the type of ground the deposit is found in. 

Hard Rock Mining 

As the name implies, this mining method is done in solid rock. Most mining operations are done using this method, but there are two different techniques of doing hard rock mining because the mine’s location above or below the surface of the Earth requires different equipment, personnel, and processes.  

Open-Pit 

Also called open-cut mining, this process involves mining minerals from an open area on the Earth’s surface.  

First, they drill a pattern of holes and then fill the holes with explosives. Next, they detonate the explosives and load the rock into trucks to take to a refinery for further processing in a crusher to fully extract the gold. Any rock leftover that does not appear to contain gold, or waste rock, is usually blasted into smaller sizes and taken to a waste dump. Examples of this type of mine are the Fort Knox mine in Alaska or the Goldstrike mine in Nevada.  

Underground 

Mining underground is a much longer, more dangerous, and costlier process than surface mining. First, a shaft (also called an adit) is drilled into the ground to access the lode deposit. Then, long, vertical tunnels called stopes are dug from the top of the ore to the bottom. Next, explosives are inserted along the length of the ore. Once detonated, the broken-up ore falls to the bottom of the stope, which is then collected for refinement. The largest underground mine in the world is in South Africa, which goes down 12,800 feet below the surface.  

Placer Mining 

This method is used only above ground and in areas where the deposit is in loose ground, such as sand, gravel, or sediment. These areas are often found along bodies of water. 

Panning 

A manual process of sifting the loose ground material to separate the gold. Done by a professional or an amateur, a shallow pan is filled with loose ground and submerged in water. The pan is gently shaken, allowing the gold to settle first to the bottom of the pan because it is denser than the loose ground.  

Sluicing 

Ideal for small-scale mining operations, sluicing uses a contraption called a sluice box. This is a man-made channel with riffles designed to create slower areas in the current, allowing the gold to drop out and fall to the bottom of the box. The remaining material flows out of the box. 

Dredging 

An older method some small-scale miners use today, dredging is a technique that uses small machines operated by one to two people floating on the water. The machines contain sluice boxes attached to pontoons and connected to a hose controlled by a miner under the water. 

Rocker Box 

Much like a sluice box, the rocker box is a high-walled man-made box that uses a rocking motion to facilitate the movement of water rather than a natural current to sift the gold out of the loose ground. This uses less water and is primarily operated in areas with low or still bodies of water.  

Byproduct Mining 

Sometimes, gold is found in mines that produce different precious metals, such as copper. The largest gold mine in the world, located in Papua, Indonesia, is primarily a copper mine. Gold produced in mines where it is not the primary resource is called byproduct mining.  

Types of Gold Deposits 

The extraction of gold depends on the type of deposit the ore is found in: lode or placer.  

Lode Deposit 

A lode deposit is a concentration of gold within solid rock. It can be above or below the surface of the Earth, and the technique used to mine the gold depends on its location. 

Unsurprisingly, mining gold above the surface is much easier, faster, and cheaper than when it’s below the surface. When a lode deposit is above the surface, miners use open-pit techniques. When it is below the surface, underground mining techniques are necessary.  

Placer Deposit 

This is one you can find yourself if you’re lucky. Loose gold in a stream or along the beach is called a placer deposit. These common, usually smaller sources of gold can be mined with any of the above placer mining techniques.   

The Lifecycle of a Gold Mine 

Finding, establishing, and running a mine is a lengthy process that takes several decades. The mine goes through multiple stages in its lifecycle, from deposit discovery to closure.  

Exploring the Gold Mines 

The first step in creating a gold mine is finding a significant source of gold ore, which can take 1 to 10 years. Searching for new, undiscovered gold deposits requires vast amounts of time, money, and the expertise of geologists, geographers, engineers, and chemists. Geologists estimate that about 10% of gold deposit discoveries worldwide contain enough gold to mine profitably. Of course, a potential gold deposit’s geology and ore body must be studied extensively to determine its feasibility as a profitable mine. 

Mine Development 

Next is developing the mine, which takes approximately 1-5 years. Complex planning and construction are necessary to begin a gold mining operation. Every nation in the world requires gold mining companies to apply for permits and local licenses before they break ground. The development process can take many years depending on several factors, such as location, local regulations, and ore body processing needs. Construction is not limited to the gold mine site, either. Frequently, mine owners need to construct local infrastructure and services to facilitate the gold mine’s logistical and operational needs. 

Mining Operation 

Now, it’s time to actually mine the gold. This stage refers to the physical extraction of gold ore from the newly developed gold mine. The hope is that the ore will be rich in gold. Unrefined rock extracted from the gold mine requires rough processing at the site and specialized processing at a refinery to fully recover the gold within the deposit and other valuable minerals such as silver or copper. Gold mining companies adhere to exacting health and safety standards, including those designed to minimize the environmental impact of the mine’s overall operation. Mines are only operable for as long as there is gold to extract, and depending on the supply, it can take 10-30 years before the ore is completely exhausted.  

Mine Closure

Once the ore supply cannot yield enough gold to mine (either physically or economically), operations halt, and the mine is decommissioned. Closing a gold mine is a complicated affair. Responsible gold mining companies generally monitor and upkeep the non-productive mine site to ensure that the rehabilitation of the land is successful. This process is lengthy and costly, much like every other stage of the mine.