The precious metal roasting furnace is designed for recovering precious metals from solid waste. The furnace utilizes pyrolysis gasification principles, where the waste undergoes anaerobic pyrolysis and gasification within the static roasting furnace, resulting in flue gas rich in combustible components like CO and CH4. After the combustible flue gas enters the secondary combustion chamber tangentially, it undergoes a vigorous mixing and combustion with the secondary combustion air, which is injected at high speed after preheating. The temperature at the outlet of the secondary combustion chamber can reach 1100°C, ensuring complete combustion of the flue gas. The roasting treatment and flue gas treatment are designed as a system to ensure safe and compliant emissions of exhaust gases.
The calcining furnace has the following advantages:
(1) Wide adaptability to the shape and size of waste; the material generally does not require crushing or other pretreatment.
(2) Waste undergoes static gasification and incineration within the furnace, resulting in minimal dust generation. This not only significantly reduces the loss of precious metals trapped in the dust but also alleviates the workload of the subsequent exhaust purification equipment.
(3) The technology of one-time loading and continuous operation for waste treatment significantly reduces contact between waste and operators, ensuring employee safety and greatly alleviating the labor intensity of operation.
(4) High level of automation; automatically adjusts fuel consumption; automatically regulates the burner's combustion state based on the flue gas temperature inside the furnace and at the outlet of the secondary combustion chamber.
(5) The equipment has a low cost, short construction period, easy operation, small footprint, and low requirements for civil engineering.
(6) When the calorific value of the waste is above 3,000 kcal, no additional fuel is needed for combustion, and the central temperature at the outlet of the secondary chamber can reach 1,150°C.
This system is an advanced calcination treatment system that integrates high-temperature stable roasting of precious metal waste, efficient thermal utilization (considering the recovery of hot water or steam), safe and compliant exhaust emissions, and automated operation. This calcination technology has been widely applied domestically.