Method for stabilizing cadmium in industrial waste through mullite

Abstract

The invention provides a method for stabilizing cadmium in industrial waste. The method comprises the following steps that firstly, after cadmium containing industrial waste and the mullite and quartzmixture are mixed, uniform scattering is conducted, and mixed raw materials are obtained through drying; secondly, the raw materials obtained in the first step are pressed and formed, and formed materials are obtained; and thirdly, the formed materials obtained in the second step are sintered at 600 DEG C-950 DEG C. The method technology is simple, only the mullite and quartz mixture which is wide, easy to obtain and low in cost needs to be used as the main raw material, through the simple sintering method, the cadmium can be effectively doped into a cadmium-aluminum-silicon oxide crystallinephase compound, and the danger that the metal cadmium is released into the environment is obviously reduced. The cadmium-aluminum-silicon oxide crystalline phase compound obtained through the methodhas very high acid leaching resistance, and the method is an effective method for low-cost treatment of electronic waste and treatment of the common heavy metal cadmium in residues.

Description

technical field [0001] The application belongs to the field of treatment of heavy metal pollutants in waste, and in particular relates to a method for stabilizing cadmium in industrial waste by using mullite. Background technique [0002] With the continuous growth of industrial activities, wastes containing heavy metals (eg, Ni, Cu, Zn, Cd, and Pb) are also increasing. These toxic metals are released into the environment from mining drainage, smelters and metal refineries, paint operations, automobile manufacturing, electronics manufacturing, industrial and domestic sewage, and incineration residues such as fly ash. A large amount of heavy metals released from solid waste is harmful to the environment, especially human body. They are not biodegradable, so they can exist stably in nature for a long time. Some heavy metals are highly toxic and can even cause cancer. Heavy metals will bioaccumulate in animals through the food chain, so that the accumulation of heavy metals ...

AI Technical Summary

Problems solved by technology

Although the use of cement or other binders in the S / S process does not generate high prices, if the S / S method is used to treat a small amount of raw waste, there will be a larger volume of treated waste dumped in landfill because Binder materials add bulk to the final product

Moreover, cadmium is weakly bound in acidic environments and it may be leached from immobilized products at high levels

[0006] The patent No. CN105439507A discloses a solidification of cadmium-containing waste residue and its preparation method. However, the operation steps of this method are too cumbersome and require the preparation of curing agent, cadmium residue treatment agent, aggregate and stabilizer. Although the raw materials are cheap and not It will produce secondary pollution, but there are certain requirements for the pH value of cadmium-containing waste residue, the curing time is long, and it needs 20-30 days of curing, and the addition of cement and loess will result in a large volume, which may be leached under high acidic conditions. risk

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