Mineral Resources and the Rock Cycle

Mineral resources form over a broad range of physical and chemical conditions and are found to occur in all geological environments. The type of mineral formed depends on the temperature and pressure conditions that existed at the time of formation. Apart from this, even hydrothermal fluids penetrating a rock body can give rise to the formation. Hydrothermal fluids are hot fluids that contain some natural chemical components in them. When they interact with a rock body, they lead to the precipitation of chemicals in the rock.

Rocks on the Earth can be divided into three major types: igneous, sedimentary, and metamorphic. Let’s look at them one by one.

• Igneous: Rocks formed directly from lava or magma that has cooled.
• Sedimentary: Rocks formed by the consolidation of sediments derived from weathering.
• Metamorphic: New rocks formed by the physical and chemical alteration of pre-existing rocks.

The formation processes of the three rock types are interdependent on each other. The formation of sedimentary rocks depends on the weathering of igneous and metamorphic rocks. At the same time, the formation of metamorphic rocks depends on the alteration of igneous and sedimentary rocks. The below diagram can aid in understanding the interdependency of these processes.

Types of Mining

There are four main types of mining.

• Underground mining: This type of mining is used to extract mineral resources that exist deep below the Earth’s surface.
• Surface or open-pit mining: These mines are developed on the surface. They are used to obtain minerals that occur on the surface or at a shallow depth beneath the surface.
• Placer mining: This method of mining is used to obtain minerals and gems that are eroded from their original place of origin. They are transported by rivers and streams and are deposited along with other loose sediments at beaches, river channels, continental slopes, etc.
• In-situ mining: This type of mining does not involve the removal of rock bodies. It is used primarily when mining uranium. The mineral resource, in this case, uranium, is dissolved and processed in place at the surface.

Reserve-to-Production Ratio

The reserve-to-production ratio (or R/P) is a method of assessment used to estimate the dimensions of a mineral reserve. The value obtained is used to calculate the amount of time that the reserve will last, provided that its rate of use does not change. The value depends on the size of the reserve and changes with changing size. The R/P is an important method when estimating the size of reserves of fossil fuels and the amount of time before they are completely depleted. As an example, current R/P ratios for coal, natural gas, and oil estimate these resources to last 119, 63, and 46 years, respectively.

Although the R/P method is widely used to estimate the size of reserves, it can be inaccurate at times. This inaccuracy stems from the fact that there may be resources that have not been discovered yet. Economic factors and the rise and fall in demand for a certain mineral/reserve also contribute to the inaccuracy of the method.

Global Consumption Patterns of Mineral Resources

The rate of economic growth in many developing countries has only recently started to increase. With the jump in economic growth comes a jump in the consumption of mineral commodities. Since reserves of mineral resources are not infinite, this could create competition between countries seeking mineral resources to fuel their industrial production. National governments will be looking to secure resources for their domestic industries. Manufacturers in developed countries will face economic pressure as the price of mineral resources, influenced by their developing counterparts, increase. With developing countries reaching the same stage of mineral consumption and industrial production as the developed countries, there will be a significant amount of environmentally unsafe waste produced.

In China, for example, experts have predicted that automobile ownership could increase from 10 to 100 autos per thousand people in the decade. Unless the automobile industry takes a sustainable approach towards production, there will be an increase in environmental pollution.

Ocean Mining for Mineral Resources

Ocean mining or deep-sea mining is the process by which minerals are retrieved from deep-sea environments below a depth of 200 m. With the land sources of minerals being quickly exhausted and the rise in demand for metals, there has been an increase in the number of deep-sea mining expeditions being carried out. However, this has added great pressure on marine ecosystems. The clearing of the ocean floor destroys the natural habitats of marine animals. Apart from that, even processes and instruments employed in ocean mining have the potential to wipe out entire marine species, some of which have not been discovered yet.

The negative impacts of ocean mining on marine ecosystems can be reduced (and in some cases, completely obliterated) by carrying out a regular Environmental Impact Assessment (EIA). Local governments can also develop laws and policies to regulate and monitor the ocean mining activities of companies.

Environmental Effects of Extracting and Using Mineral Resources

Although they are non-renewable, mineral resources play a vital role in the functioning of our construction, energy, and manufacturing industries. However, the techniques and processes used to extract minerals can have a number of negative impacts on the environment. They include:

• Pollution of water due to acids and heavy metals.
• Huge piles of disposed of mineral wastes.
• Erosion and loss of biodiversity due to the boring of wells, holes, and tunnels.

It is critical that the impact of mining on the environment is reduced so that biodiversity and a healthy natural environment can be preserved for future generations.

Apart from extraction methods, even the use of mineral resources has the potential to cause environmental damages, including:

• Noise pollution is caused by the blasting and transport of mineral resources.
• CO2 emissions take place due to the transport of mineral resources from the site of mines to industries where they are utilized.
• Overconsumption of mineral resources diminishes the reserves that are to be preserved for future generations.

These damages to the natural environment can be overcome by recycling resources. Recycling plays an important role in the sustainable use of resources.

Also Read: Green Revolution 2.0: Embracing Artificial Ecosystem