Operating a mine, whether underground or open pit, is a large-scale project. So it’s not surprising that mining projects can take 10 to 15 years to launch, and may be subject to a number of major decisions. In fact, operating a mine involves a series of steps, from the discovery of the deposit to the closing of the mine. The cycle comprises the following steps:
- Exploration and feasibility
- Development and construction
- Mining operations
- Closing and restoration
1. Exploration and feasibility
Mineral exploration consists of identifying sites where minerals can be mined. Drilling programs are used to extract and analyze samples to determine the deposit’s volume and grade. This first step in the mining cycle is over once the technical, financial, and environmental feasibility analyses are complete.
2. Development and construction
The second step in the mining cycle, the development and construction of the mine, is undertaken only if the deposit is sufficiently large to ensure the project’s economic profitability.
Mine development stages:
- Characterize the mineral resource
- Design the mine layout
- Conduct public consultations on the project
- Assess the financial and environmental impacts
- Obtain the necessary permits
- Conduct a final evaluation of the mine’s operations
Once the development step is complete, construction of the mine and its ore processing facilities can proceed. The development and construction of a mine may take from five to ten years, of which two to four years are required for the actual construction.
3. Mining operations
The operation of the mine is the third step. It involves extracting ore from the deposit and processing it to obtain mineral products of value to society, such as metals.
The ore is then sent to a processing plant where it is crushed and ground into fine powder. At this point, various processes are undertaken to separate the useful minerals from waste rock. The ore left after processing is termed the “concentrate”. This concentrate is then refined to further increase its purity. Some mines have no on-site processing facilities and must send ore elsewhere for processing.
Of the ore mined, only a portion contains the target minerals. The tailings (or waste rock) are used to fill mined or excavated areas. They may also be used to build roads at the site.
A mine can operate for just a few years or for decades, as was the case with the Sigma and Lamaque mines located in Val-d'Or, Abitibi-Témiscamingue.
4. Closing and restoration
Mines have limited lifespans. These are two reasons for closing a mine:
- The ore is depleted
- Low metal prices make operations unprofitable
Although closing the mine is the final step in the mining cycle, site restoration activities will have been planned long before the mine opened and the first ore was extracted. Environmental choices are not left to chance and mine closures raise plenty of questions that must be addressed.
The closing process is orderly and proceeds in an environmentally friendly manner. Areas transformed by mining must once again become ecosystems. The whole excavation site is filled, piles are levelled, and the entire area is reforested. Thus, the ecosystem is restored.
It can take up to 10 years to close a mine.
Want to know more?
The mining cycle is a blueprint for quickly and easily understanding the various steps in a mine’s operation, from its inception to the depletion of its resources. If you want to know more about the mining industry, see this overview of the mineral development process. The diagram identifies the steps companies must go through to extract minerals from Québec’s subsoil.
The lower boxes indicate the trades and jobs companies need to fill at every step of the process. A good many jobs are only indirectly related to the mining industry but nevertheless are required for a company to function properly, such as electricians, caretakers, and nurses.
This tool serves as a guide to help you identify the steps in the mineral development process that best match your job hunt goals. That way you can target companies and mining projects offering the best job prospects in your area of expertise. You will be better positioned to submit your application at the right time and to the right employer.