By : Akhmad Khusyairi, M. Eng
Coal is one of the strategic mineral resources as well as a huge energy. Indonesia in 2006 capable of producing coal at 162 million tons and 120 million tonnes of which is exported. Meanwhile, about 29 million tonnes is exported to Japan.
Indonesia has coal reserves are spread across the island of Borneo and Sumatra, while small amounts of coal in West Java, Central Java, Papua and Sulawesi. While the empirical formula for this type of bituminous coal is C137H97O9NS, whereas for anthracite is C240H90O4NS.
Coal Types
The type and quality of coal depends on the pressure, heat and time of formation of coal. Based on this, the coal can be grouped into 5 types of coal, such as anthracite, bituminous, sub bituminous, lignite and peat.
1. Anthracite is a type of coal quality, coal type has a characteristic metallic black color, contain the element carbon between 86% -98% and has a water content of less than 8%.
2. Bituminous coal with a quality second, this type of coal has a carbon content of 68% -86% and water content of between 8% -10%. Coal types are often found in Australia.
3. Sub-bituminous coal with a kind of third quality, this coal has a carbon content less characteristic and contain lots of water.
4. Merupupakan lignite coal with a quality fourth, coal has the cirri have this type of young brown color, very soft and has a water content of 35% -75%.
5. Peat is a kind of lowest-quality coal, coal has the cirri porous and moisture content above 75%.
While based on burning calories produced, coal grouped into three;
1. Very High Calorie Coal is coal that has a very high calorie burning results with the number of calories more than 7100 cal / g
2. High Calorie Coal is coal that has a calorie burning results between 6100-7100 cal / gr.
3. Low Calorie Coal is coal combustion products that have less calories than 5100 cal / gr.
Impact of Coal Mining
To meet domestic demand and exports, Indonesia has some coal mines scattered on the island of Sumatra and Borneo, both of which are operated by State-owned and private companies.
In 2006, Indonesia ranked second after Australia in the order of the State of export coal. Approximately 74% of Indonesian coal mining is the result of private enterprise, while it was the only state-owned coal mining PT Tambang Bukit Asam. Based on information Technology Research and Development Center for Mineral and Coal, 2006, most of the coal used for energy generation.
Coal mining caused some adverse impacts surrounding residents and the environment. If the surface of the coal-containing pyrite (iron sulfide, also called stupid gold) interacts with water and air it will form sulfuric acid. If there is rain in the mining area, the sulfuric acid will be moving along the waterways, and throughout the occurrence of rain in the area of the mine tailings the sulfuric acid production continues to occur, either during the mining operation or not. If the coal in open pit mine, which is open all layers interact with water and produce sulfuric acid, it will damage soil fertility and pecemaran river began to occur due to the high content of sulfuric acid, this might impact on the killing of fish in rivers, plants, and biota water is sensitive to pH changes drastically.
In addition, penambagan coal also produces methane gas, this gas has potential as a greenhouse gas. Contribution of methane gas caused by human activities, contributed by 10.5% in greenhouse gas emissions.
From the results of the panel between the State Government members of the UN on Climate Change, methane has a global warming potential 21 times greater than carbon dioxide over the last 100 years. If the coal power plant produces emissions of danger on the fuel, the coal mining process may generate hazardous gases. These harmful gases can pose a threat to mine workers and a source of air pollution. Besides coal mining damaging the existing vegetation, destroys the genetic soil profile, replacing the genetic profile of the soil, destroying wildlife and habitat, air quality degradation, changing land use and to some extent be altering the general topography of the mining area permanently.
source : nu.or.id
Indonesia has coal reserves are spread across the island of Borneo and Sumatra, while small amounts of coal in West Java, Central Java, Papua and Sulawesi. While the empirical formula for this type of bituminous coal is C137H97O9NS, whereas for anthracite is C240H90O4NS.
Coal Types
The type and quality of coal depends on the pressure, heat and time of formation of coal. Based on this, the coal can be grouped into 5 types of coal, such as anthracite, bituminous, sub bituminous, lignite and peat.
1. Anthracite is a type of coal quality, coal type has a characteristic metallic black color, contain the element carbon between 86% -98% and has a water content of less than 8%.
2. Bituminous coal with a quality second, this type of coal has a carbon content of 68% -86% and water content of between 8% -10%. Coal types are often found in Australia.
3. Sub-bituminous coal with a kind of third quality, this coal has a carbon content less characteristic and contain lots of water.
4. Merupupakan lignite coal with a quality fourth, coal has the cirri have this type of young brown color, very soft and has a water content of 35% -75%.
5. Peat is a kind of lowest-quality coal, coal has the cirri porous and moisture content above 75%.
While based on burning calories produced, coal grouped into three;
1. Very High Calorie Coal is coal that has a very high calorie burning results with the number of calories more than 7100 cal / g
2. High Calorie Coal is coal that has a calorie burning results between 6100-7100 cal / gr.
3. Low Calorie Coal is coal combustion products that have less calories than 5100 cal / gr.
Impact of Coal Mining
To meet domestic demand and exports, Indonesia has some coal mines scattered on the island of Sumatra and Borneo, both of which are operated by State-owned and private companies.
In 2006, Indonesia ranked second after Australia in the order of the State of export coal. Approximately 74% of Indonesian coal mining is the result of private enterprise, while it was the only state-owned coal mining PT Tambang Bukit Asam. Based on information Technology Research and Development Center for Mineral and Coal, 2006, most of the coal used for energy generation.
Coal mining caused some adverse impacts surrounding residents and the environment. If the surface of the coal-containing pyrite (iron sulfide, also called stupid gold) interacts with water and air it will form sulfuric acid. If there is rain in the mining area, the sulfuric acid will be moving along the waterways, and throughout the occurrence of rain in the area of the mine tailings the sulfuric acid production continues to occur, either during the mining operation or not. If the coal in open pit mine, which is open all layers interact with water and produce sulfuric acid, it will damage soil fertility and pecemaran river began to occur due to the high content of sulfuric acid, this might impact on the killing of fish in rivers, plants, and biota water is sensitive to pH changes drastically.
In addition, penambagan coal also produces methane gas, this gas has potential as a greenhouse gas. Contribution of methane gas caused by human activities, contributed by 10.5% in greenhouse gas emissions.
From the results of the panel between the State Government members of the UN on Climate Change, methane has a global warming potential 21 times greater than carbon dioxide over the last 100 years. If the coal power plant produces emissions of danger on the fuel, the coal mining process may generate hazardous gases. These harmful gases can pose a threat to mine workers and a source of air pollution. Besides coal mining damaging the existing vegetation, destroys the genetic soil profile, replacing the genetic profile of the soil, destroying wildlife and habitat, air quality degradation, changing land use and to some extent be altering the general topography of the mining area permanently.
source : nu.or.id