The molten material mixture is added to the furnace for high temperature melting, and the temperature in the furnace depends on different products, which are generally around 1200-1600 degrees, and the fuel is heavy oil. Electricity, etc. The furnace generally has two kinds of crucible and pool kiln, the general crucible has only one mouth, feeding and discharge are in this mouth, the pool kiln may feed and discharge mouth separate, this only one mouth of the furnace often have to be charged at night, and then closed, generally the newly added material to melt 8 hours before use, so adding material is not available at any time, often wait until the material has been used up and then add, so generally a cylinder of material available for a day, about 600-900 liters.