The basic principle for coal preparation is to first liberate the coal particles from the gangue (quartz) and then, by applying different water based techniques, separate the coal particles and gangue particles.
Acetaminophen in the Treatment of Acute Low Back Pain. For low back pain, acetaminophen can be effectively used as an analgesic (or pain killer). Doctor-written article on acetaminophen as a pain reliever for lower back pain.
By the way, there's also an Aspirin for Back Pain Quiz, and a Tylenol for Back Pain Quiz, Try them all and you will likely go into the drugstore armed with the information you need to make the best possible choice for you. Sources: Hersh, EV, Pinto, A, Moore, PA.