White coal is a form of fuel produced by drying chopped wood over a fire. It differs from charcoal which is carbonised wood. White coal was used in England to melt lead ore from the mid-sixteenth to the late seventeenth centuries. It produces more heat than green wood but less than charcoal and thus prevents the lead evaporating. [1] [ dubious – discuss ] White coal could be used mixed with charcoal for other industrial uses than lead smelting. [2] White coal was produced in distinctive circular pits with a channel, known as Q-pits. They are frequently found in the woods of South Yorkshire.
Although traditionally made by drying chopped wood, white coal can be made from numerous waste products, most of which are formed into briquettes. Raw materials which can be used include: [3]
India is fast becoming a major manufacturer and consumer of white coal. A large number of companies have switched their boiler fuels to use white coal instead of fossil fuels. White coal manufacturing capacity is increasing in the state of Gujarat, Maharashtra, Tamil Nadu and Rajasthan. The production of white coal (briquettes made of biomass) using agricultural and forest waste is more common in North India. [4] [5]
Producers of white coal proclaim the following benefits from using the fuel: [6] [7] [8]