How to get the accurate and reliable analysis result for ash determination?
1. Adopting Slow Ash Method, make the sulfides in coal sample fully oxidated and discharge before the carbonate decomposition to avoid the calcium sulfate formation. 2. Keep a good ventilation condition in the ashing process to make sure the sulfur oxides can discharge in time. Therefore , the muffle furnace is required to be equipped with chimney. The vent in the furnace door or a slit kept while closing the furnace door are used to ensure a natural air circulation in the furnace.