Tectonic stress release:
occurs as a result of energy releases in the mass of rock from the creation of empty underground spaces. The rock is stressed by the extraction of ore, pressure is created in it and energy is accumulated, which can be released in an instant by a rockfall. Bumps and slides occur mainly in saddle seams, where there is solid overlying rock.
coal used in combustion processes by power producers and industrial users to produce steam for power and heat. Also called ‘steam coal’.
a metric tonne, a measure of mass equal to one thousand (1,000) kilogrammes or approximately two thousand, two hundred and five (2,205) pounds.
Total coal production:
the total production volumes of thermal and coking coal.
Total coal production per employee:
total coal production per mining employee including mining contractors.