Consuming vast quantities of the atmospheric gases nitrogen, oxygen and argon, the blast furnaces in the Chinese Xiangtan steel works in the province of Hunan are now to be served by a fifth air-separation unit. This latest addition will ensure sufficiently high availability of industrial gases to enable Xiangtan to boost its annual steel production from its current 6.5 million tonnes. Oxygen promotes combustion and is blasted into the furnaces in order to attain the high temperatures required for melting steel.