Selective separation and recycling method for industrial solid waste slag

Abstract

Disclosed is a selective separation and recycling method for industrial solid waste slag. The selective separation and recycling method is suitable for recycling the solid waste slag generated in steel, metallurgy and chemical industries. The selective separation and recycling method is based on the systematic study of the microstructure of the industrial solid waste slag, high-selectivity chemical agents are adopted, through soaking, milling, magnetic separation, multistage sedimentation and other process steps, bonding materials between crystalline particles are dissolved or softened, and thus spatial dissociation of the crystalline particles with different components is achieved with a chemical method. Meanwhile, the surface characteristics of certain crystalline particles are changed selectively through the high-selectivity chemical agents, the differences of the sedimentation performance of different components are enhanced, separation of multistage sedimentation is completed conveniently, thus the separation efficiency is improved, energy consumption can be reduced by a large margin, and the treatment process is simplified. The selective separation and recycling method is suitable for recycling steel slag, stainless steel slag, metallurgy waste slag and the like and can also be used for recycling useful components or enrichment of certain trace elements from chemical solid waste slag.

Description

technical field [0001] The invention belongs to the technical field of recycling industrial solid waste residues, and is suitable for recycling useful metals and compounds thereof from solid waste residues produced in iron and steel, metallurgy and chemical industries. Background technique [0002] In the production process of iron and steel, metallurgy, and chemical industry, a large amount of solid waste slag containing metals and their oxides is often discharged, such as iron slag from the ironmaking industry, steel slag from the steel industry, steel slag from the stainless steel industry, metallurgical slag from the non-ferrous metallurgy industry, etc. On the one hand, these solid waste residues mostly contain elements such as iron, nickel, chromium, manganese and trace amounts of precious metals silver, beryllium and their compounds. The open-air stacking not only takes up a lot of land, but also seriously pollutes the surrounding soil and water bodies; on the other ha...

AI Technical Summary

Problems solved by technology

On the whole, these technologies have achieved certain results in energy saving, magnetic material recovery, and comprehensive utilization of tailings, but there are still significant deficiencies.

First of all, because steel slag and metallurgical slag are calcined at high temperature, they have the characteristics of high hardness and large particle size, which are very difficult to crush and grind, and cause serious wear and tear on equipment; secondly, these solid wastes are mixtures with very fine crystallization. Separation efficiency and recovery rate, the particle size requirement is very fine (generally above 300 mesh), it needs to be pulverized and ground many times, and the energy consumption is very high

Have again, in similar CN1282635A method dry processing process, there is dust secondary pollution problem

Again, the recovery of useful components in solid waste residues in the prior art only relies on limited means such as "magnetic separation" and "gravity separation (or flotation)", but many metals and their oxides are not magnetic, and the fine crystal particles are bonded to each other. It is difficult to completely dissociate, so the recovery effect of non-magnetic metals and their oxides is not ideal

[0004] A large number of studies have shown that most industrial solid wastes contain a large amount of silicates, and some of them are in an amorphous state microscopically, and become the main bridge for the bonding of crystalline particles or metal particles in solid wastes; secondly, only iron , chromium and other metals and some of their oxides are more or less magnetic, while most of the other components are not magnetic, and it is difficult to achieve the required effect by pure magnetic separation recovery; in addition, these solid waste residues are not only metal or alloy particles, other large The crystalline particles of some substances are very fine, and the general particle size is mostly between a few microns and tens of microns

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