What areas do most of the coal mining and iron working symbols appear?

Miners remove the coal in the pillars, thereby recovering as much coal from the coal seam as possible.

Coal mining is the process of extracting coal from the ground. Coal is valued for its energy content and since the 1880s, has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron from iron ore and for cement production. In the United Kingdom and South Africa, a coal mine and its structures are a colliery, a coal mine – a pit, and the above-ground structures – a pit head. In Australia, "colliery" generally refers to an underground coal mine. In the United States, "colliery" has been used[when?] to describe a coal mine operation, but this usage is less common today.

Coal mining has had many developments over the recent years, from the early days of men tunneling, digging, and manually extracting the coal on carts to large open cut and long wall mines. Mining at this scale requires the use of draglines, trucks, conveyors, hydraulic jacks and shearers.

plz mark me as brainliest :)

are these the benchmarks questions?

yes i think there would be volunteers