(a) Draw a sketch map of Nigeria. On the map, show and name one area each where the following minerals are mined: (i) coal: (ii) crude oil; limestone. (b) D...

(a) Sketch map of Nigeria showing one mining area for each mineral

The map below is an outline of Nigeria on which one producing area is marked and named for each of the three minerals: coal at Enugu (south-east), crude oil in the Niger Delta / Port Harcourt (south-south) and limestone at Ewekoro-Sagamu (south-west).

(b) Process of mining coal in Nigeria

Coal in Nigeria (notably at Enugu) is worked mainly by the underground (adit / drift) method, and where seams lie near the surface by the open-cast method.

Underground (adit) method:

1. The overlying soil and rock (overburden) covering the seam are first removed or a tunnel is driven in.
2. A horizontal or gently sloping tunnel (adit) is cut into the hillside to reach the coal seam.
3. Timber props made from strong tree trunks are built to support the roof of the mine and prevent collapse.
4. Fresh air is pumped into the mine by machines to ventilate it, and water is drained out.
5. Explosives may be used to loosen and aid the excavation of the coal seam.
6. Pick-axes, drills and cutting machines are used to break the coal from the seam.
7. Shovels are used to load the broken coal onto tubs or a conveyor belt.
8. The coal is conveyed out of the mine to the surface, then sorted and graded.
9. It is finally transported by rail or truck to the point of consumption or to the ports for export.

Open-cast method (where the seam is shallow): the overburden is stripped off; explosives are used to break the exposed seam; pick-axes and shovels loosen and load the coal; it is conveyed by rail or truck to the processing plant and then to the point of use or export.

(c) Four problems affecting the mining industry in Nigeria

1. Shortage of capital and investment for exploration, machinery and expansion.
2. Inadequate skilled labour and technical expertise, together with the high cost and scarcity of spare parts.
3. Poor transport, infrastructure and erratic power supply to the mining areas.
4. Insecurity, illegal mining and price fluctuation of minerals on the world market, which discourage steady production.