What are minerals and mineral resources?
A mineral is a solid that nature makes inside the earth. It is not made by plants or animals in a factory. Most minerals are found mixed inside rock.
When a mineral is useful to people and we can dig it out at a fair cost, it becomes a mineral resource. A tiny speck of gold in a huge rock is not a resource. A thick layer of iron ore is.
Minerals are non-renewable: they take millions of years to form, so once dug out they are not replaced in our lifetime.
Main minerals: metals, fuels and building minerals
There are three big families.
- Metals: iron (steel for bridges and machines), copper (wires), aluminium (light vehicles, foil), also gold and silver. Metals come from ore.
- Fuels (energy minerals): coal, oil and natural gas. We burn them to get heat and power.
- Building and other minerals: sand, gravel, limestone (for cement), clay, salt, mica.
Some regions are rich in one family and poor in others. That is why countries trade minerals.
How we get minerals: mining
Open-pit mining: when the mineral is near the surface, we remove the top soil and rock and dig a wide pit in steps. It is cheaper and safer.
Shaft (underground) mining: when the mineral is deep, we sink a vertical shaft and dig tunnels sideways. It costs more and is riskier for workers.
Mining also has costs: dust, noise, land damage and water pollution. Good mines restore the land afterwards.
From ore to product
Ore is rock that holds enough metal to be worth digging. The path is: dig the ore, crush it, separate the metal-rich part, heat it in a furnace (smelting) to get the metal, then shape it into sheets, wires or parts. Each step uses energy and creates waste.
Rational use: reduce, reuse, recycle
Rational use means using minerals in a sensible way so they last and cause less harm.
- Reduce: use only what you need; design lighter things.
- Reuse: repair and use again.
- Recycle: melt old metal and make new things. Recycling aluminium needs far less energy than making it from ore.
- Also: waste less during mining, find substitutes, and look for new deposits carefully.
In the 3D free play, a stock of 100 units with 10 dug each year lasts 10 years. If 50% is recycled, new digging is only 5 a year, so it lasts 20 years.
Try it
Look around your room and list five things. For each, say its mineral family (metal, fuel or building) and whether it could be recycled. Then in the 3D, slide recycling from 0% to 80% and predict the years before you read them.
Key formulas and definitions
- Mineral = natural solid formed in the earth, usually inside rock
- Ore = rock with enough metal to be worth mining
- Years a stock lasts = stock / (use per year)
- With recycling share r: new digging per year = use x (1 - r)
- Non-renewable = takes millions of years to form
Worked examples
1. Put these in families: copper, coal, limestone, aluminium ore, natural gas, sand.
Metals: copper, aluminium ore. Fuels: coal, natural gas. Building minerals: limestone, sand.
2. A mineral lies 20 m below the surface in a wide, flat layer. Which mining method is likely, and why?
Open-pit mining. The layer is shallow and wide, so removing the top rock is cheaper and safer than tunnels.
3. A country has 600 units of a metal and digs 20 units a year. How many years will it last? What if it recycles 50% of its use?
600 / 20 = 30 years. With 50% recycled, new digging is 20 x 0.5 = 10 a year, so 600 / 10 = 60 years.
4. Why is a small gold speck in a big rock not called a mineral resource, while a layer of iron ore is?
A resource must be useful and affordable to extract. A tiny speck costs more to separate than it is worth. A thick iron layer can be dug at a fair cost.
5. Arrange in order: smelt, mine ore, make a product, crush ore.
Mine ore, crush ore, smelt, make a product.
Common mistakes
- Thinking ore and metal are the same. Ore is the rock; metal is what we get after crushing and smelting.
- Saying minerals are renewable because there is a lot of rock. They take millions of years to form, so they are non-renewable.
- Forgetting that coal, oil and gas are minerals too (fuel minerals).
- Believing recycling means mining is no longer needed. It only reduces how much new mining we need.