Goderich - The Worlds Largest Underground Salt Mine

Welcome to the largest underground salt mine in the entire world, located in Goderich, Ontario. Miners travel over 1800 feet below the ground to start their workday. This is the same distance as the height of the CN tower in Toronto, Canada. Well, in this case, by accident. In 1866, local mill owner Samuel Platt teamed up with Chief Driller Peter McEwen in hopes of drilling into the ground and discovering oil.
Instead, after 102 days of drilling, the two discovered 40 feet of salt rock. A new industry in the town of Goderich was born. So how exactly does salt go from here to here? Salt begins its life underground in the form of rocks that cover the walls, ceilings and floors of the mine tunnels. Mine engineers start by utilizing the latest technologies to provide plans for the safe extraction of salt on a seemingly endless network of roadways.
After all, the priority of the salt mine is everyone's safety while meeting production demand, maintaining all active openings and supporting the equipment. The ground control team oversees all scaling activities to mitigate any dangers. Areas requiring scaling will use large scaling machines, hand tools and even explosives to alleviate any risks. Then, following the engineered plans, the miners begin the cutting process of the walls and ceilings.
This is done by a machine called the continuous miner, a remote controlled 50-foot-long machine that uses metal teeth attached to the cutting drum to cut through layers of rock and salt. The width and height of the walls depends on where the mining is happening. But typically, these walls are cut at a height of just over 14 feet in increments of four passes.
That means the complete height of an underground pathway is over 55 feet tall, enabling the miners to move and use all sorts of giant, heavy machinery as the metal teeth cut the salt rock.
The gathering head underneath the cutter drum carries the salt chunks onto the continuous miner’s conveyor chain, where it is dumped into a large haulage truck or a flexible conveyor train.
When the haulage truck is full, this vehicle hauls 40 tons of rock salt to a separate location called the stock-out. Loaders at the stock out will scoop the salt rock and place it onto the east or west conveyor belts. Remember, this is the largest underground salt mine in the world. Its expansion under the lake is farther than the length of its hometown.
Once on the conveyors, the salt rock is crushed up into small pieces and travels towards the underground milling operation. The underground mill is a screening process near the front of the mine. It uses mechanical and optical sorting tables to separate the pieces of high-grade salt to produce two products. Chemical and highway salt. They are deposited along two different belt lines and into their own stockpiles.
These stockpiles are then pushed into trench shoots in the ground, placed on to a conveyor and travel up to the surface inside of 30-ton skips. The skips dump onto conveyor cars that carry the salt to separate storage domes above the ground. Where finally the salt is loaded onto transport trucks, trains or boats and delivered around the Great Lakes to highway salt storage piles and some evaporator plants for salt bagging, testing and packaging.
In Goderich, this evaporator plant processes evaporated salt by boiling saturated brine. This brine is mined from salt deposits in three active brine wells which are down in the river flats by the Maitland River. At a staggering 400 gallons a minute saturated brine is sent back from those wells and into the evaporation process. There are five phases of mechanical evaporation, boiling, vapor, steam, drying, and finally the salt crystals that you see on your dinner table.
Once the salt crystals are made, chemical testing and product research are conducted on site at the evaporator laboratory. One example of a test that they do every single day is called the purity test. It's a big responsibility to know that the salt crystals are meeting their purity standards. That way, the food and products that people eat, and use are being produced at the best and safest quality that they can be.
Being able to test the salt crystals on site enables the staff to have rapid results and respond quickly to the outcome. Some examples of these SALT products include agricultural products, food grade products, pool salt and even cosmetics. So, the next time that you see the salt truck on the road or refill your water softener tank at home, or grab your groceries at the store, remember where that tiny mineral came from?