The isolation, purification and characterisation of pure lignin, extracted from black liquor obtained from a large pulp and paper mill, are reported. The ultimate analysis of the purified lignin, resulting in 0.3% ash content, confirms its quality as being comparable to any high-grade imported lignin. Thermal analysis resulted in an activation energy of 29.87 kJ mol(-1) for the thermal decomposition of pure lignin; this is discussed. Detailed IR spectroscopic, XRD and DTA/DTG analyses of the lignin sample are also presented.