Zinc producer Nyrstar has started to recover 156 GWh of annual waste heat from its Balen smelter in Belgium, cutting its natural gas consumption by half.

Nyrstar’s smelter now generates enough hot water to replace 233,000 tonnes of low-pressure steam. Its improved self-sufficiency saves 52,000 MWh of natural gas, previously supplied by steam boilers.

The smelter also generates higher amounts of electricity from steam using an extraction turbine. In total, Nyrstar produces on-site electricity equivalent to 8,000 households.

Overall, Nyrstar has saved 30,000 tonnes of CO2 emissions from its heat recovery project.