Question

Burning of substance in absence of air ​

Answer 1

Fire resulting from the combustion of a fuel. ... Another idea ascribed the high temperature of flame to the fast motion of active air particles, and it was learned that sulfur mixed with nitre can burn in the absence of air (nitre is a compound of oxygen which releases oxygen to the sulfur).

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Answer 2

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In calcination the carbonate ores in absence of air decompose to form metallic oxides and carbondioxide

Combustion requires oxygen gas either from the air or that which is released from chemicals used in a reaction. When a chemical reaction takes place without oxygen but still shows burning, it is because the reaction is excessively exothermic i.e., it generates excessive heat, which carries the reaction forward and completes it, without the need for oxygen