Description: Coal is a combustible black or brownish-black sedimentary rock normally occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure. Coal is composed primarily of carbon along with variable quantities of other elements, chiefly hydrogen, with smaller quantities of sulfur, oxygen and nitrogen
Occurrence: Coal begins as layers of plant matter accumulating at the bottom of a body of water. For the process to continue, the plant matter must be protected from biodegradation and oxidization, usually by mud or acidic water. This traps their carbon in immense peat bogs that are eventually covered over and deeply buried by sediments. Under this compression the plant material is metamorphosed into coal: over time, the chemical and physical properties of the plant remains are changed by geological action to create a solid material.
The wide shallow seas of the Carboniferous period provided ideal conditions for coal formation, although coal is known from most geological periods. The exception is the coal gap in the Lower Triassic, where coal is rare: presumably a result of the mass extinction which prefaced this era. Coal is even known from Precambrian strata, which predate land plants: this coal is presumed to have originated from algal residues.
Coal, a fossil fuel, is the largest source of energy for the generation of electricity worldwide, as well as one of the largest worldwide anthropogenic sources of carbon dioxide releases. Gross carbon dioxide emissions from coal usage are slightly more than those from petroleum and about double the amount from natural gas. Coal is extracted from the ground by mining, either underground by shaft mining through the seams or in open pits.
Locations: Coal exploration in Nigeria started as far back as 1916. Available data show that Coal (mainly sub-bituminous steam Coals except for the Lafia-Obi bituminous Coking Coal) occurrences in Nigeria have been indicated in more than 22 Coalfields spread over 13 States of the Federation.
The proven Coal reserves so far in Nigeria total about 639 million metric tones whilethe inferred reserves sum up to 2.75 billion metric tones. Presently, the Nigeria Coal Industry has 4 existing mines, Okpara and Onyeama Underground Mines in Enugu state, Aba surface mine in Kogi State and Owukpa Underground Mine in Benue State In addition, there are more than 13 undeveloped Coal fields.
The undeveloped Coal fields in Nigeria are of two categories, viz: the Virgin Coal fields where further detailed exploration work and/or access roadways are required and the developing Coalfields where reserves have been proven and Mine access road ways developed. The developing coal fields in Nigeria are stated in the table below.
Locations | State |
Azagba Lignite field | Delta |
Ogboyoga Coal field | Kogi |
Ezimo Coal field | Enugu |
Lafia-Obi Coal field | Nassarawa |
lnyi Coal field | Enugu |
Amansiodo | Enugu |
Ute | Ondo |
Lamla area | Adamawa |
Gindi-Akunti | Plateau |
Afuze | Bauchi |
Janata-Koji | Kwara |
Okpara Mine | Enugu |
Specifications: The coal specification varies depending on the requirement of the buyer and this could vary base ranges stated in table below.
Features | Percentage |
Fixed Carbon | 40-70% |
Moisture | 8-12% |
Volatile Matter | 20-30% |
Ash Content | 5-10% |
Sulphur | 0.2-0.8% |
Size | 30-100mm |
Uses: Coal has many important uses worldwide. The most significant uses are in electricity generation, steel production, cement manufacturing and as a liquid fuel. Around 6.1 billion tonnes of hard coal were used worldwide in 2010 and 1 billion tonnes of brown coal. Since 2000, global coal consumption has grown faster than any other fuel.
Different types of coal have different uses. Steam coal - also known as thermal coal - is mainly used in power generation. Coking coal - also known as metallurgical coal - is mainly used in steel production.
The biggest market for coal is Asia, which currently accounts for over 65% of global coal consumption; although China is responsible for a significant proportion of this. Many countries do not have natural energy resources sufficient to cover their energy needs, and therefore need to import energy to help meet their requirements.
Other important users of coal include alumina refineries, paper manufacturers, and the chemical and pharmaceutical industries. Several chemical products can be produced from the by-products of coal. Refined coal tar is used in the manufacture of chemicals, such as creosote oil, naphthalene, phenol, and benzene. Ammonia gas recovered from coke ovens is used to manufacture ammonia salts, nitric acid and agricultural fertilizers. Thousands of different products have coal or coal by-products as components: soap, aspirins, solvents, dyes, plastics and fibers, such as rayon and nylon. Coal is also an essential ingredient in the production of specialist products:
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· Activated carbon - used in filters for water and air purification and in kidney dialysis machines.
· Carbon fiber - an extremely strong but light weight reinforcement material used in construction, mountain bikes and tennis rackets.
· Silicon metal - used to produce silicones and silanes, which are in turn used to make lubricants, water repellents, resins, cosmetics, hair shampoos and toothpastes.
Export market: The five largest coal users - China, USA, India, Russia and Japan - account for 77% of total global coal use. Japan, Chinese Taipei and Korea, for example, import significant quantities of steam coal for electricity generation and coking coal for steel production
Export Price: Depending on the carbon content of the Coal the FOB price could vary from USD100-250/MT.
Local price: The local market price of Coal at the loading point could vary from NGN5,000-NGN7,000/MT or more.
