Fuels and Combustion
Beehive coke oven

Facilitates by-products recovery
Produces coke with very poor strength
Takes 2-3 days for coking of coal but requires no external fuel for heating
Gives larger yield of coke (around 85%) as compared to by-product ovens

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Fuels and Combustion
A coal with high ash content is undesirable, as

All of these
It is abrasive to the coal pulveriser (ie.g. ball mill) and the combustion chamber
The ash in molten condition gets absorbed in the pores of the refractory lining of the furnace and causes its spalling due to different co-efficient of expansion/contraction of the refractory and the
The ash retains the sulphur & phosphorus and thus affects the quality of products in metallurgical furnace apart from increasing the slag volume. Besides, it may fuse and stick to the boiler tubes

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