Method for recycling arsenium and enriching heavy metals in arsenium-containing metallurgical sludge

Abstract

The invention relates to a method for recycling arsenium and enriching heavy metals in arsenium-containing metallurgical sludge by roasting and leaching, which comprises the following steps: (1) mechanical dehydration: drying and dehydrating arsenium-containing metallurgical sludge, and milling after baking or airing for later use; (2) arsenium recycling by calcining: calcining the arsenium-containing metallurgical sludge, which is subjected to mechanical dehydration, at 500-800 DEG C for 2-4 hours, so that arsenium is sublimated along with fume so as to remove arsenium in the arsenium-containing metallurgical sludge, thereby obtaining roasting slag after arsenium removal; (3) heavy metal enriching: while stirring, carrying out acid leaching on the roasting slag after arsenium removal, which is obtained in the step (2), by a two-step process; and (4) safe landfilling of leached slag. The invention can leach out lead and other heavy metals (zinc, copper and cadmium) by multiple steps, lower the difficulty in subsequent separation, and lower the processing cost; the removal rates of arsenium, zinc, copper, cadmium and lead in the sludge with high contents of heavy metals are respectively greater than 90%; and the processed sludge can be landfilled safely.

Description

technical field [0001] The invention belongs to the field of environmental protection of solid waste treatment, and in particular relates to a method of treating arsenic-containing metallurgical sludge to recover arsenic and enrich heavy metals by means of roasting and leaching. Background technique [0002] At present, my country's industrial production is in a period of rapid development, and the demand for non-ferrous metals has greatly increased, which has greatly stimulated the rapid development of the non-ferrous metallurgical industry. The resulting metallurgical heavy metal wastes are also increasing at an alarming rate. If these wastes cannot be Effective disposal not only pollutes the environment but also requires large-scale storage yards. Sometimes, geological disasters and field destruction events are caused by the collapse of the sludge reservoir, causing huge losses to people's property and life safety. Therefore, how to effectively dispose of these heavy metal...

AI Technical Summary

Problems solved by technology

Among them, the replacement electrolysis technology usually has complicated operation procedures, which will involve multiple steps of immersion, filtration, backwashing and replacement, and the change of the composition of heavy metal sludge will affect the applicability of the technology; copper, nickel, zinc) has the advantages of selective leaching, but the slow leaching rate and the odor of ammonia water are the biggest disadvantages of this technology. Therefore, when using this technology to recycle heavy metal sludge, attention must be paid to the impact of ammonia water odor on the surrounding environment. However, the resource recovery of high-concentration heavy metal sludge by microbial technology is rare, and most of them are currently used in the removal of heavy metals from sewage sludge or low-concentration wastewater, but the reaction rate of this technology is slower than other hydrometallurgical technologies , its treatment capacity is only 0.5 tons per day; while the high-temperature melting method for heavy metal sludge treatment has the advantages of recycling metal resources and producing harmless slag, but the high investment cost of equipment is often prohibitive, and if Containing volatile heavy metals, pollution prevention and control equipment must also be monitored to avoid secondary pollution; and heavy metal sludge mineralization technology is currently rare in relevant research and commercial operations, and it is a resource technology in its infancy This technology focuses on the fact that the composition and content of heavy metal sludge is the same as that of minerals. Therefore, if the mineral characteristics can be highlighted, metal resources can be recovered by using mature separation and smelting technology. Since this technology has just started, it is not practical. Strong, there may be considerable room for development in the future