Coal is one of the primary sources of electricity in India and abroad, offering ease of combustion and high calorific/heat value. A substantial quantity of coal has to be imported from other countries, in order to fulfill the ever-increasing energy demands in India, as well as for use in manufacturing steel, cement, fertilisers, paper, ceramics, and other industrial items. Coke is generally formed through the destructive distillation of coal, and is mainly used in steel manufacturing in blast furnaces.

Coal occurs in four main types, or "ranks": lignite or brown coal, bituminous or black coal, anthracite and graphite. These ranks have different physical and chemical properties which can be verified by proper testing techniques.

Importance of coal testing

Coal testing results are important for characterisation, commercial grading and assigning ranks, and for deciding what purpose the coal is best suited to.

There are two main types of analysis that can be conducted on coal, each determining different parameters: proximate analysis and ultimate analysis. The results of proximate analysis determine the coal rank and several important indicators related to the commercial value, such as heating/calorific value and application in boilers.

Eurofins Environment Testing India conducts testing of coal, coke and other fuels as per various national and international standards with the utmost diligence, ensuring flawless accuracy in the test results.

Some of the common tests conducted on coal include:

• Calorific value (gross/net)
• Proximate analysis - moisture, volatile matter, ash and fixed carbon
• Ultimate analysis - C,H, O, N, S and Ash
• Ash analysis - Al2O3, SiO2, CaO, MgO,TiO2, Na2O, K2O, S etc.
• Ash fusion temperature
• Coke reactivity
• Hard-grove grindability index
• Porosity
• Density
• Angle of repose
• Reflectivity
• Crucible swelling index/free swelling index

Major equipment we use

• Bomb calorimeter
• Carbon and hydrogen determination apparatus
• Proximate analyser
• Ash fusion temperature apparatus/ash fusion tester