Coal used for this process is called steaming coal. In 2008 77% of the electricity generated in Australia was produced by coal fired power stations (includes black and brown coals). Some types of black coal are suitable for coke-making.
These symptoms may occur in the back, leg and down to the foot. The most common nerve irritation originating from the lumbar spine is Sciatica. This is an irritation of the sciatic nerve, which can produce pain, numbness, and weakness down the leg along the areas innervated by the sciatic nerve.
Many of these injuries are stretch injuries. The nerve sheath is intact and some degree of recovery can be seen. What was injured was the frontal branch of the right facial nerve. Where your nerve was injured the nerve fibers are actually very fine. It is probably amazing that we do not see more of these injuries. I would say that after about 6 months it is unlikely that recovery will take place.