The durability of the dry briquettes was determined with the aid of a durability tester, i.e., a dust tight 300 mm x 300mm x 475 mm enclosed box using the ASAE standard method, S269.3. Test sample of three briquettes (approximately 100g) was tumbled for 10 minutes at 50rev/min. The weight of the solid briquettes remaining was then determined. The durability rating for each type of briquette was expressed as a percentage of the initial mass of the material remaining in the box.