Standards for pollution control in hazardous waste landfills
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In accordance with requirement 6.3 of Note 1 in the \"Standards for Controlling Pollution from Hazardous Waste Landfills (18598-2019)\\", hazardous waste materials with a total content of water-soluble salts exceeding 10% and an arsenic content exceeding 5% must be landfilled in rigid hazardous waste landfills.
Therefore, it is necessary to enhance research and development as well as engineering applications in areas such as the separation and treatment of mixed salts and the washing of fly ash to significantly reduce the amount of industrial hazardous waste that needs to be processed.
Many people are also exploring the recycling of by-product salts. If the salt component is single and present in high concentrations, the yield and success rate are higher, but it is not yet stable enough
The main principle of the Fixed Waste Incineration Fly Ash Washing for Salt Extraction (FWD) technique is to take advantage of the fact that chlorides in fly ash are soluble in water, as well as the similarity between the components of fly ash and those of cement raw materials. First, the chlorides in the fly ash are separated to produce salt through washing, and then the chloride-free fly ash is used in cement kilns for high-temperature calcination to produce cement clinker. This technology consists of five systems, namely the fly ash elution system, water quality purification system, evaporation salt production system, drying system, and kiln feeding system.
After the \"zero discharge\" treatment of coal chemical wastewater, what remains are mostly mixed salts, which include various inorganic salts as well as a large amount of organic matter. However, from the perspective of strengthening environmental protection, the miscellaneous salts generated in coal chemical industry evaporation and crystallization processes are still classified as hazardous waste and are subject to strict control; as a result, companies not only cannot profit from recycling these miscellaneous salts but also have to bear high costs for their treatment.
The stabilization, detoxification, and resource utilization of crystalline salts are research directions for further processing of crystalline salts in coal chemical industry, and they are also key to \"zero emission\" technologies.
Waste treatment designers, welcome to discuss together
Single salts are manageable, but mixed salts are difficult to handle. Currently, many new disposal facilities are being built, and the disposal costs continue to decline. The salts that are separated are generally accepted by downstream users; however, there is still a long way to go