Tungsten Trioxide and Carbon Monoxide Reaction
Carbon monoxide(CO) is colorless, ordourless, nonirritant gas, it is one of the products of incomplete combustion. Mixing with air will cause explosion, the exposure limitation is 12.5%～74.2%. CO is easily to combine with hemoglobin to form carbonyl hemoglobin, then hemoglobin will lose ability and function of carrying oxygen which will results in apnea of tissue and lead to death.
Tungsten trioxide can easily be reduced to tungsten metal powder by hydrogen and carbon monoxide. CO used as reducing agent can re
duce many metal oxides into pure metal under high temperature. So it is often used to metallurgy of metal. Heat tungsten trioxide and CO under high temperature(750℃), the chemical equation is:
WO3 + 3CO = W + 3CO2
It is also one of the producing methods of tungsten powder. The early preparation method of tungsten powder mainly use carbon reducing tungsten trioxide, the temperature is higher than hydrogen reduction method which will reach 1050℃.