Coke

Coke is a high-carbon solid formed by the slow distillation of coal. It is used as a fuel and is widely used as an alternative to coal. Coke is a grey, hard, and porous fuel with a high carbon content and few impurities, made by heating coal or oil in the absence of air—a destructive distillation process. It is an important industrial product, used mainly in iron ore smelting, but also as a fuel in stoves and forges when air pollution is a concern. The unqualified term “coke” usually refers to the product derived from low-ash and low-sulphur bituminous coal by a process called coking. A similar product called petroleum coke, or pet coke, is obtained from crude oil in oil refineries. Coke may also be formed naturally by geologic processes

COKING COAL:

Coking coal, also known as metallurgical coal, is used to create coke, one of the key irreplaceable inputs for the production of steel. There are many varieties of coal in the world, ranging from brown coal or lignite to anthracite. The property that really sets coking coals apart from other coals is its caking ability, which is the specific property required in order to make coke suitable for steel making.
Coke is produced by heating coking coals in a coke oven in a reducing atmosphere. As the temperature of the coal increases, it becomes plastic, fusing together before solidifying into coke particles. This is known as the caking process. The quality of the resultant coke is determined by the qualities of the coking coals used, as well as the coke plant operating conditions. Coke quality is largely influenced by coal rank, composition, mineral content and the ability to soften when heated, become plastic, and solidify into a coherent mass. Bituminous class coals of high, medium, and low volatile rank that possess these properties are called “coking” coals.
High quality coking coals are in great demand by steel producers, who need these coals to make high quality coke to maximize the productivity of their blast furnace operations.

Thermal Coal :

Thermal coal, also called steaming coal, has a lower energy content and higher moisture and is used to generate electricity. Metallurgical or coking coal has a higher energy content and lower moisture and is used to make iron, steel and other metals. The affordable price of thermal coal as well as its high resistance have made this product applicable in many different industries.Most coal mined is thermal coal (also called steam coal as it is used to make steam to generate electricity) but metallurgical coal (also called “metcoal” or “coking coal” as it is used to make coke to make iron) accounts for 10% to 15% of global coal use.