What is the raw material of cola?

Under the condition of air isolation, the bituminous coal is heated to 950- 1050℃, dried, pyrolyzed, melted, bonded, solidified and shrunk, and finally coke is made. This process is called high temperature coking (high temperature dry distillation). Coke obtained by high temperature coking is used for blast furnace smelting, casting and gasification. The recovered and purified coke oven gas produced in coking process is not only a high calorific value fuel, but also an important raw material for organic synthesis industry.

Physical properties of coke

Physical properties of coke include coke screening composition, coke bulk density, coke true relative density, coke apparent relative density, coke porosity, coke specific heat capacity, coke thermal conductivity, coke thermal stress, coke ignition temperature, coke thermal expansion coefficient, coke shrinkage, coke resistivity and coke permeability.

The physical properties of coke are closely related to its mechanical strength, thermal strength and chemical properties at room temperature. The main physical properties of coke are as follows:

The average specific heat capacity is 0.808kj/(kgk)( 100℃),1.465kJ/(kgk) (1000℃).

The thermal conductivity is 2.64kj/(mhk) (room temperature) and 6.91kj/(mhk) (900℃);

Ignition temperature (in air) is 450-650℃;

Low calorific value of dry ash-free base is 30-32kJ/g;

Chemical composition of coke

The reactivity of coke and its ability to react chemically with carbon dioxide, oxygen and steam, CRI = (G0- g1)/G0×100% (Note: G0-weight of test coke sample, g; G 1- weight of coke sample after reaction, g; )。 The strength of coke after reaction refers to the ability of coke after reaction to resist crushing and wear under the action of mechanical force and thermal stress. In the process of blast furnace ironmaking, cast iron smelting and fixed bed gasification, coke will react with carbon dioxide, oxygen and water vapor. Because the reaction of coke with oxygen and water vapor is similar to that of carbon dioxide, most countries use the reaction characteristics of coke with carbon dioxide to evaluate the reactivity of coke.

The repeatability r of coke reactivity CRI and post-reaction strength CSR shall not exceed the following values:

CRIr≤2.4%

Corporate social responsibility: ≤3.2%

The test results of coke reactivity and post-reaction strength are the arithmetic average of parallel test results.