Device and method for treating waste lithium battery recovery cracking waste gas and wastewater

Abstract

The invention relates to a device and a method for treating waste lithium battery recovery cracking waste gas and wastewater. The device comprises a waste gas treatment unit and a wastewater treatmentunit. The method comprises the following steps: a, the waste gas is burnt, then enters an alkaline solution spraying absorption tower, is sprayed and absorbed by a sodium hydroxide solution, is adsorbed by an active carbon adsorber and then is discharged at a high altitude; b, the pH value of the wastewater is adjusted, and the wastewater is reacted to generate a Na3AlF6 precipitate; c, the obtained defluorinated wastewater undergoes micro-electrolytic treatment, and then enters a Fenton oxidation tower to remove organic matters and reduce the COD of the wastewater; d, the obtained wastewatersequentially enters a sand filtration tank, an active carbon adsorption tank and a cation resin exchange column to remove suspending matters, COD, calcium and magnesium ions; and 4, the obtained wastewater enters a single-effect evaporator and undergoes evaporative concentration. The device and the method realize discharge standard meeting of waste gas treatment and zero discharge of recovered water obtained after the wastewater treatment, and avoids the obstruction phenomenon of nozzles, fillers, pumps and pipelines, caused by water recovery.

Description

technical field [0001] The invention relates to the field of waste gas and waste water, in particular to a waste gas and waste water treatment method for recycling and cracking waste lithium batteries. Background technique [0002] Lithium batteries do not contain harmful heavy metal elements such as mercury, cadmium, and lead. They are called "green batteries", but their positive and negative electrode materials, lithium hexafluorophosphate electrolyte solution and other substances will cause serious pollution to the environment and ecosystem. At the same time, waste lithium batteries Contains a large amount of non-renewable metal resources with high economic value, such as cobalt, lithium, nickel, copper, aluminum, etc. If the waste or unqualified lithium batteries can be effectively recycled, it will not only reduce the pressure of waste batteries on the environment, but also Avoiding the waste of metal resources such as cobalt and nickel has important social and economic...

AI Technical Summary

Problems solved by technology

Use conventional single absorption method, oxidation method, adsorption method, biological method, low temperature plasma method, etc., and a single common process method such as: combustion oxidation method, adsorption method, photocatalytic method, biological method, low temperature plasma method to control VOCs It is difficult to treat organic waste gas and dioxin to meet GB9078-1996 "Emission Standard of Air Pollutants for Industrial Furnaces", GB30484-2013 "Emission Standard of Pollutants for Battery Industry", GB18485-2014 "Emission Standard for Domestic Waste Incinerator Pollution" and GB14554 -1993 "Odor Pollutant Discharge Standard" Class I standard

[0004] The fluorine-containing waste gas seriously corrodes the equipment. For high-temperature and high-corrosion fluorine-containing waste gas treatment equipment, the investment is large and the treatment is difficult. It is difficult to meet the emission limit of the purification treatment of the conventional first-level lye spray treatment tower GB9078-1996 "Industrial Furnace Air Pollution "Emission Standards for Pollutants" and Table 5 Standards of GB30484-2013 "Emission Standards for Pollutants in the Battery Industry"; the concentration at the air inlet (calculated as fluorine) is 180-200g / m 3 ;Calcium hydroxide circulating spray is used for neutralization and absorption, and the liquid storage tank solution is easy to form sludge. When circulating spraying, it is easy to cause blockage of nozzles, fillers, pumps and pipelines, and at the same time, it will cause blockage of ultrafiltration membranes for water reuse treatment , affecting the service life of the ultrafiltration membrane

[0005] The wastewater treatment after exhaust gas treatment adopts conventional wastewater treatment, that is, through physical and chemical treatment to make the heavy metal ions and COD treatment reach the standard, and then reuse the water after ultrafiltration or reverse osmosis treatment, but the water reuse rate is low, generally between 60% and 80%. , the salinity of the reused water becomes more and more concentrated, and it is returned to the waste gas treatment lye spray absorption tower for lye spray water, which will cause the nozzle and packing to be blocked, and the salt in the solution in the pump and pipeline will crystallize and precipitate, causing the pump and pipeline blockage; at the same time, the purification treatment membrane is blocked, the equipment cannot operate normally, and the maintenance cost is high

Organic wastewater and COD in the electrolyte without biochemical treatment, the COD treatment cannot meet the standards in Table 2 of GB30484-2013 "Discharge Standards for Pollutants in the Battery Industry", and the COD of the reused water is getting higher and higher, resulting in purification treatment membranes and Reuse water cannot be used

Images