When Coal is heated at 110 o C the loss in weight represents moisture. % of mois

Question

When Coal is heated at 110 oC the loss in weight represents moisture.

% of moisture=( 2.5-2.415)*100/2.5 = 3.4%

Covered crucible is heated at 950oC , loss in weight represents volatile matter.

% of volatile matter = (2.415-1.528)*100/2.5 =35.48%

Residue contain coke , it was again heated loss in weight is fixed carbon. The last residue is incombustible ash.

% of fixed Carbon =(1.528-0.245)*100/2.5 = 51.32%

% of ash =0.245*100/2.5 = 9.8%

This analysis is called proximate analysis .

It examines the chemical composition of coal sample like moisture, volatile matter, fixed Carbon and ash content. It is used to ascertain rank of coals. It is less comprehensive does not give any idea about elements , their quantities. Hence it is so named.

Explanation / Answer

A sample of Gondwana coal of Jharia was analyzed as follows: Exactly 2.5 g was weighed into silica crucible. After heating for 1 hour at 0 110 C, the residue weighed 2.415 g. The crucible was then covered with a vented lid and strongly heated for exactly 7 minutes at 950+20°C. The residue weighed 1.528 g. The crucible was then heated without cover, until a constant weight was obtained. The last residue was found to weigh 0.245 g. (i) Calculate the percentage results of the above analysis. (ii) To which type of analysis does the above description belong? iii) Why is the analysis so- named?

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.