Golden Bay Cement is reducing a significant waste problem, reusing a valuable resource and reducing emissions by burning waste tyres for energy.
Producing cement requires high temperatures, typically achieved using coal. The business has used waste wood for more than 17 years to help reduce its coal use and emissions. In March 2021 it opened its upgraded cement plant in Whangārei which burns waste tyres.
Tyres are an attractive fuel alternative because the natural rubber content has a high calorific value and results in lower fossil fuel emissions. The high temperatures in the cement kiln means that the tyres burn cleanly, with any ash and steel content becoming part of the finished cement. Waste tyres have lowered coal use by up to 20 percent and reduced emissions by about 13,0000 tonnes per year.
Recycling the steel from waste tyres also prevents the mining of 5,000 tonnes of iron sand for use in cement.
Golden Bay Cement plans to use up to 3.1 million waste tyres per year – half of the nation’s output.