CRAIC Technologies introduces an advanced vitrinite reflectance measurement system, the 308 Coal that grades coke for steel production.
Coal is a vital component in steel production as a source of carbon and the 308 Coal is designed to ensure that the coal blends used in steel production are optimum and consistent from batch to batch.
Coke is used as a reducing agent when smelting iron ore in the first stage of steel production. Coke is a result of pyrolysis of blends of low-sulphur and low-ash coal. The coking process drives off the volatile components of coal leaving a grey, porous solid.
Blends of bituminous coals are commonly used as the coal must have a certain amount of volatile matter in order to make good quality coke. Generally, levels of 26-29% of volatile materials are considered optimum.
The coals and coal blends must be therefore tested prior to making coke and steel.
Consistency in the coking process is maintained by mixing together different grades of coals while the volatiles are maintained at an optimum level.
Vitrinite reflectance is one of the most important tests conducted in the testing of the coal so that it meets specific criteria for good quality coke.
Vitrinite is a maceral and comprises of various polymers, cellulose and lignin. Measuring the amount of light reflected by vitrinite macerals is a key test for determining the thermal maturity of the coal blend and its suitability for steel production.
The procedure has been standardised by a number of international bodies including ISO and ASTM.
All the standards require the use of a microphotometer, a device designed to measure the intensity of light reflected from a microscopic sampling area at 546 nm.
The microphotometer measures the amount of light reflected from samples from the coal blend at hundreds of points after which a statistical analysis is done by the computer.
The results of the statistical analysis are used to determine the amount of vitrinite in the coal blend, its thermal maturity and therefore its value for coking.
Each sample requires hundreds of measurements to be carried out, resulting in a time-consuming process.
With the introduction of the 308 Coal vitrinite reflectance measurement system and a programmable microscope, this process can be automated to dramatically improve the laboratory’s throughput and accuracy.
Warsash Scientific is the exclusive representative of CRAIC Technologies, Inc.