Coal is generally obtained through open pit mining. Major coal reserves are found in China, the United States, India, Australia, Russia, Poland, Indonesia and Japan. Coal is mainly used for the production of electricity and heat. When used in a power plant, coal emits sulphur gas (containing sulphur dioxide, sulphur trioxide and sulphuric acid mist). This sulphur gas contributes to the formation of acid rain.
4 June 2009, 7.55pm EDT