What is the difference between coal and coke fuel? Coal is a shiny, black fossil fuel that contains impurities, emits smoke when burned, and produces less heat than coke. Coke is a dull, black byproduct of coal that burns hotter and cleaner.
A non-caking coal is that coal which on heating in absence of air doesn't from a coherent mass of residue. A coking coal is that coal which on heating in absence of air leaves a solid residue. A non-coking coal also leaves a solid coherent residue which may not possess the physical & chemical properties of the coke.
Coking coal is usually bituminous-rank coal with special qualities that are needed in the blast furnace. While an increasing amount of steel is being recycled, there is currently no technology to make steel at scale without using coal.
Non Coking Coal does not have any caking properties and it is mainly used as thermal coal for power generation. It has a higher ash content and also used in industries like cement, fertilizer, glass, ceramic, paper, chemical and brick manufacturing.
The free-swelling index (FSI) is a measure of the increase in volume of coal when heated under specified conditions (ASTM D720; ISO 335). The FSI method is a small-scale test for obtaining information regarding the free-swelling properties of a coal.
Fluidity is a test which measures the rheological properties of coal. In industrial scale, testing of fluidity of individual coal samples and the blends made using these coals is important in predicting coke quality.
Coal rank is the measure of the degree of organic metamorphism (coalification) of a coal, ranging from low-rank peat to high-rank meta-anthracite.
By distilling bituminous coal in retorts to obtain gas for illumination, or by burning it in kilns or pits, the residue left behind is called coke, which is simply coal charcoal, and is nearly pure carbon.
What are the types of coal?
- Anthracite: The highest rank of coal.
- Bituminous: Bituminous coal is a middle rank coal between subbituminous and anthracite.
- Subbituminous: Subbituminous coal is black in color and dull (not shiny), and has a higher heating value than lignite.
Washery Grade -VI. Exceeding 42% but not exceeding 49% Grades of Semi-coking and Weakly Coking Coal. Grade. Ash+Moisture.
Steam coal (sometimes called thermal coal) is a grade of coal used in electric power plants to generate steam to create electricity.
Coal is mostly carbon with variable amounts of other elements; chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years.
Coking coal - also known as metallurgical coal - is mainly used in steel production.
Without oxygen, the coal does not burn. Instead, it begins to melt. The high temperatures volatilize unwanted impurities, such as hydrogen, oxygen, nitrogen, and sulfur. These off-gasses can either be collected and recovered as by-products or burned off as a source of heat.
Since smoke-producing constituents are driven off during the coking of coal, coke forms a desirable fuel for stoves and furnaces in which conditions are not suitable for the complete burning of bituminous coal itself. Coke may be combusted producing little or no smoke, while bituminous coal would produce much smoke.
This one is obvious – renewables! Blast furnaces need coal, but there is an alternative technology called an Electric Arc Furnace (EAF). This is responsible for approximately 30% of the world's steel production and does not require coal.
Around 0.6 tonnes (600 kg) of coke produces 1 tonne (1000 kg) of steel, which means that around 770 kg of coal are used to produce 1 tonne of steel through this production route. Basic Oxygen Furnaces currently produce about 74% of the world's steel. A further 25% of steel is produced in Electric Arc Furnaces.
Brown coal (lignite) is classed as a low-rank coal because it has a high ash and moisture content, and less carbon, which means that it produces less energy when it is heated. Black coals are ranked higher because they are harder, have more carbon, less ash and less moisture and thus a higher energy content.
Greenpeace said of the event “A decade ago, a day without coal would have been unimaginable, and in 10 years' time our energy system will have radically transformed again.” But there have been claims that using wood pellets is actually speeding up not slowing climate change.
As of 2017, the iron and steel industry produces seven to nine percent of the total global GHG emissions. When hydrogen used in this process is derived from renewable or decarbonized sources itself, the steel making process can become completely emission-free, creating 'green steel.
Two different methods are used to switch coal-fired plants to natural gas. The first method is to retire the coal-fired plant and replace it with a new natural gas-fired combined-cycle (NGCC) plant. The second method is to convert the boiler of a coal-fired steam plant to burn other types of fuel, such as natural gas.
But steel production would not be possible without the use of coal and coke. What is coke? Coke is used as a fuel and a reducing agent in melting iron ore. It is produced by baking coal until it becomes carbon by burning off impurities without burning up the coal itself.
Coal is classified into four main types, or ranks: anthracite, bituminous, subbituminous, and lignite.
What is soft coal used for?
Smithing coal
Coking coal
Power generation
Coal is primarily used as fuel to generate electric power in the United States. The coal is burned and the heat given off is used to convert water into steam, which drives a turbine.
Because coal is less dense than most rocks and minerals (such as pyrite), it floats in liquids of equal or greater density than the coal; rock and pyrite sink. The single float-sink test defines the relative amount of float-product and sink-reject that should result from the coal being washed in that preparation plant.
Coal is a combustible sedimentary rock formed from ancient vegetation which has been consolidated between other rock strata and transformed by the combined effects of microbial action, pressure and heat over a considerable time period. This process is commonly called 'coalification'.
