System and method for low-temperature treatment of heavy metals and dioxins in fly ash

A system for low-temperature treatment of heavy metals and dioxins in fly ash, comprising:

• a water washing tank configured to receive fly ash and water, and wash the fly ash;
• a plate and frame filter press connected to the water washing tank, and configured to conduct solid-liquid separation on an obtained water-washed fly ash, and then transport an obtained fly ash slurry to the water washing tank using a diaphragm pump to repeat three times of water washing;
• a buffer tank connected to the plate and frame filter press and the water washing tank, and configured to store an obtained fly ash water washing solution after pressure filtration, and pump the fly ash water washing solution to the water washing tank for secondary use;
• a single-cylinder dryer connected to the plate and frame filter press, and configured to dry an obtained tertiary fly ash slurry after tertiary water washing and pressure filtration;
• a stirring reactor connected to the single-cylinder dryer, and configured to conduct a heat treatment at 300° C. to 350° C. and a low-temperature heat treatment at 200° C. to 250° C. on the fly ash;
• a metering feeder connected to the stirring reactor, and configured to separately deliver a calcium-based additive for a reaction at 300° C. to 350° C. and a low-temperature section-targeted pyrolysis additive for a reaction at 200° C. to 250° C. to the stirring reactor;
• and
• a nitrogen generator connected to the stirring reactor, and configured to supply nitrogen to the stirring reactor.