This artificial uranium mine is contained in the slag material from power station coal combustion and deposited in landfills.
The road is unusually constructed of compacted iron slag .
The stats and history of this limestone slag heap are impressive in their own right.
The concentrates are refined by smelting - they are melted, and the impurities are removed as a slag .
Some people had even died in slag slides, picking loose bits of coal in order to keep their homes heated.
In particular, tuyeres in the furnace became blocked with slag .
Blast furnaces are used to recycle slag , dross, and residues from other processes.
There were areas of bare rock and slag , which were around old gold mines, according to the naturalist.
"Oh, it used to be a slag heap, " John said.
It is usually caused by the scouring action of sand, gravel, slag , earth, and other gritty material.