Relatively few people will have ever heard of Taconite, but without it steel production around the world would be devastated. Taconite is one of the main ores of iron. Taconite is a low grade ore when compared to Magnetite and Hematite, and is silica rich.
Historically speaking Taconite was always believed to be just a waste product of iron ore mining but after the end of the Second World War, it soon became obvious that all of the sources of high grade iron ore had been exhausted. Thus the waste materials were examined once again, and with new processing capabilities Taconite pellets were created, these pallets are 65% concentrated iron. To get the pallets though it is necessary mine the Taconite.
Primarily mined in China, Canada and the United States, the process of Taconite mining is essentially the same. Today two thirds of all Taconite is mined in Minnesota, with the Mesabi Iron Range being one of the primary mines. The majority of mined sources of Taconite are found near to the surface of the earth, in large formations, and as such open pit mining for Taconite is used in preference to shaft mining.
The topsoil is removed as part of the overburden removal process. When the Taconite ore is exposed, rotary drills are used to create sixteen inch holes in it, drilled to a depth of about fifty feet. A blasting mixture is then placed in the whole. When the explosion is detonated, Taconite is broken off, this break off could weigh anything up to 1.5million tons. The Taconite is then scooped up by giant shovels and moved into giant dump trucks.
The trucks then transport the taconite to the processing plants. The blocks of Taconite are then crushed into fine powder as the rock is mixed with water. The actual iron ore is then removed from the powder through the use of powerful magnets. The iron ore is then mixed with limestone and bentonite clay until pellets are formed.
The actual mining and processing of Taconite is more costly than Hematite, but the finished product is actually more efficient.
Open cast mining of Taconite is considered an eyesore, and certainly the landscape is devastated when compared to shaft mining. In most cases though open cast mines are put to other uses after the end of their usefulness, either filled in and turned into parkland, or made into pools.