Ore

Ore is a special kind of rock.

It has valuable metals inside. These metals are mixed with other rocks.

We must dig the ore out of the earth. Then we clean it to get the metal. This helps us find the good parts.

Some ore is found deep in the ground. Other ore can be found on the ocean floor. This is how we get the metals we need!

Ore is a special kind of rock.

It contains valuable minerals, like metals. These minerals are found in high amounts. We call this amount the ore grade. If the grade is high, it is worth mining.

Most ore is mixed with unwanted rock. This unwanted rock is called gangue. To get the metal, we must separate it from the gangue. We use a way called mineral processing. This helps free the good parts from the bad parts. The leftover waste is called tailings.

Ore forms in many ways. Some ore comes from magma, which is hot melted rock. Kimberlite is a type of rock that brings us diamonds. Other ore forms from fluids in the earth. Banded iron formations are a type of ore.

These formed long ago on the ocean floor. Finding ore takes many steps. First, people use prospecting to find where it is. Then, they use exploration to see how much is there. Finally, they do a study to see if mining is possible.

Ore is a special kind of rock or sediment.

It contains valuable minerals, such as metals. These minerals are found in high amounts compared to the rocks around them. We call this concentration the ore grade. A rock is only called ore if it is worth the cost to mine it.

This means the value of the metal must be higher than the cost to get it out. Some ores are complex because they hold more than one valuable mineral.

Most ore is not pure. It is mixed with unwanted or valueless rocks called gangue.

To get the metal, people use mineral processing. This starts with liberation, which is freeing the ore from the gangue. Then, they use concentration to separate the good minerals. They might use gravity, magnets, or electric methods to do this. The leftover waste is called tailings. These are useless materials that can sometimes harm the environment.

Ore forms through many different geological processes. This way of making ore is called ore genesis.

Some ores come from magma, which is hot, melted rock. For example, kimberlite comes from deep in the mantle to bring us diamonds. Other ores form from fluids. Hydrothermal deposits happen when minerals settle out of hot liquids.

These can form on the seafloor in large mounds.

There are many specific types of ore deposits.

Banded iron formations have the highest concentration of any single metal. They formed on the ocean floor long ago. Another type is the Bushveld Complex in South Africa, which is a source of chromite. Some copper comes from porphyry copper deposits. These are large and round. They usually contain about 0.8% copper by weight. In the ocean, manganese nodules grow very slowly. They grow about one centimeter every several million years.

Finding ore is a careful job that happens in stages.

First, people use prospecting to find where the ore might be. They use maps and special surveys to look for it. Next, they use exploration to see how much ore is there. They might use diamond drilling to check the ore grade and tonnage. Finally, they do a feasibility study. This study helps them decide if the mining project can actually work.

Ore is a specific type of natural rock or sediment. It contains one or more valuable minerals, such as metals. These minerals are concentrated at levels much higher than the surrounding environment. To be called ore, the material must be economically viable. This means the value of the minerals must outweigh the cost of mining and processing them. The level of concentration within the rock is known as the ore grade.

Most ore is not a pure substance. It is mixed with valueless or unwanted rocks called gangue. To get the valuable minerals, humans perform mineral processing, also called ore dressing. This process begins with liberation, which is the act of freeing the ore from the gangue. Next, concentration occurs to separate the desired minerals from the waste. This can be done using gravity, magnets, or electric methods. Once processed, the leftover waste is called tailings. These materials are useless and can sometimes harm ecosystems.

Ore deposits form through geological processes called ore genesis. These deposits are classified by how they are created. Magmatic deposits originate directly from magma, which is molten rock. For example, pegmatites are coarse-grained igneous rocks that crystallize slowly deep underground. They provide industrial minerals like quartz and feldspar. Kimberlites are another magmatic source, originating 150 km deep in the mantle. These rocks often contain diamonds.

Other magmatic deposits are highly specialized. Magmatic sulfide deposits form when mantle melts rise and interact with the Earth's crust. This interaction adds sulfur, causing sulfide minerals to precipitate out. Some of these are Ni-Cu deposits, which include the Sudbury Nickel Basin. Stratiform chromites are also magmatic and form in layered shapes. The Bushveld Complex in South Africa is a famous example.

Metamorphic deposits form through metamorphism, which is the transformation of rocks by heat or pressure. Skarns are a common type of metamorphic silicate. They form when carbonates like limestone undergo recrystallization. Greisens are another type, formed from granitic rock altered by intruding magma. These are important sources of tin and tungsten. Porphyry copper deposits are also significant. These form at convergent boundaries and contain about 0.8% copper by weight.

Hydrothermal deposits are a massive source of various ores. They form when dissolved minerals precipitate out of hot fluids. Volcanogenic massive sulfide (VMS) deposits form on the seafloor from metal-rich solutions. These create large mounds of zinc, copper, lead, silver, and gold. Mississippi Valley-Type (MVT) deposits precipitate from cooler fluids in carbonate rocks. These are sources of lead and zinc. Sediment-hosted stratiform copper deposits also provide 20% of the world's copper.

Sedimentary deposits form through different environmental actions. Banded iron formations (BIFs) hold the highest concentration of any single metal. They formed early in Earth's history when iron-rich water oxidized near photosynthetic plankton. Placer deposits are created by the weathering and transport of minerals by wind or water. These often contain gold or platinum. On the ocean floor, manganese nodules grow incredibly slowly. They grow about one centimeter every several million years.

Extracting ore is a multi-stage scientific and economic process. First, geologists use prospecting to locate potential sites. They use mapping, geochemical sampling, and geophysical surveys to find them. Once a site is found, exploration begins to define the deposit's extent. This involves diamond drilling to determine the ore grade and tonnage. Finally, a feasibility study is conducted. This study determines if the mining operation is actually possible and profitable.