The Environment Agency increased its permit to use tyres in its kiln from 12% to 25%. The company will use tyres as part-replacement for coal at the plant.
 
The Environment Agency's decision comes after research showed burning tyres reduced emissions of oxides of nitrogen by up to a 30%.
 
Cemex's Rugby plant was last month granted permission to trial another waste-derived fuel, Climafuel, to replace up to 30% of the fossil fuels used at the plant. Climafuel contains waste such as screened paper, cardboard, wood and carpet.
 
The company said tyres and Climafuel could substitute up to 55% of the fuel used to heat the kiln.