What are the negative and positive aspects on coal?

Answer 1

Many people hear "coal" and think it is a single homogeneous product. In reality it is a commodity ranging from lignite to bituminous and anthracite. Uses range from metallurgical coal, to thermal coal to aggregate for filtration beds. While primarily carbon, the coal can have various contaminants from heavy metals to radioactive materials. The points raised below are therefore general, covering each stage of the mining, processing, use and disposal of coal.

POSITIVE ASPECTS Use In many countries coal is th primary source of a readily available and relatively low cost fuel that can be easily processes and used in homes, industry and for power generation.

Coal reserves are asource of fossil fuel that is generally safe from international embargos.

Coal uses production, transportation, and combustion technology that is easily understood and easily implementable. Extended coal use technology can provide a wide range of other hydrocarbon products generally obtained from oil

NEGATIVE ASPECTS

Mining

Coal mines can be open pit, strip mining or deep mines similar to hard rock mineral mines. In all cases the mines remove tonnes of coal and rock to remove the desirable coal. The waste rock is disposed of on site. Both mining and waste rock can impact ecological systems (streams and forests). The mines can cover extensive areas.

Removal of mine drainage can impact area streams.

Processing

Once mined the coal is processed to make it into an appropriate size for sale. The fines can escape into the environment. Smaller sizes of coal can be transported in open gondola cars with acoating of dust controlling latex. Use

The main consumption of coal involves its combustion. This releases carbon dioxide, SOX and other air pollutants. Air pollutin tratment s requires. Water used for cooling is released to increase thermal burden on streams. Disposal

Wastes from coal use include fly ash, bottom ash, fines, water treatment sludge, air treatment sludge, contaminated water. The solid wastes must be disosaed of in secure landfill sites. Waste waters must be treated to mee discharge criteria.