Today (4 May 2016), The Linde Group, a world-leading gases and engineering company, its African subsidiary African Oxygen Limited (Afrox) and alternative energy company Renergen Limited, through its subsidiary TETRA 4 (Pty) Limited, signed an historic agreement for the commercialisation of the Free State Helium and Natural Gas (NG) field. The 187,000 hectare Helium/NG field….