Treatment method for harmless reclamation of solid waste of heavy metal

Abstract

The invention discloses a treatment method for harmless reclamation of solid waste of heavy metal, comprising the following steps: adding coal-free solid waste mixture with low heat value to a rotary kiln for harmless reclamation of solid waste of heavy metal; combusting the solid waste mixture at a high temperature in the rotary kiln to produce zinc hypoxide and gather other valued metals; producing iron powders from the iron-containing slag that is generated in the rotary kiln as iron screening raw material; using zinc hypoxide as raw material to conduct acid leaching for neutralization to produce zinc sulfate monohydrate, then using the red iron slag that produces zinc sulfate monohydrate as the raw material for zinc hypoxide and leaching the leached slag that produces zinc sulfate monohydrate with high acid to reclaim indium ingot; after reclamation of the indium ingot, smelting the leached slag as raw material of lead to produce lead ingot; and recovering the water-hardening slag that produces lead ingot as the raw material for zinc hypoxide. The treatment method of the invention realizes zero discharge of waste water and slag, which not only saves the energy, but also realizes reclamation and comprehensive utilization of the resources and greatly lowers the production cost of the companies so as to create a core competence of the company.

Description

technical field [0001] The invention relates to a treatment method for harmless and resourceful heavy metal solid waste. Background technique [0002] my country itself is a resource-poor country. It consumes 5 million tons of zinc metal every year, while the mining volume is only 4 million tons. The gap of 1 million tons mainly depends on imports and comprehensive resource recovery. Imports require large amounts of foreign exchange. [0003] At present, various domestic smelting, chemical and iron and steel enterprises produce tens of millions of tons of solid waste containing heavy metals annually. Domestic enterprises in the same industry can only process solid waste with high zinc content and useful value. The mixture generally requires zinc content greater than 10%, calorific value greater than 2000 kcal / kg, a large number of low-grade solid wastes containing heavy metals are dumped and landfilled, which not only wastes resources, but also pollutes the environment. ...

AI Technical Summary

Problems solved by technology

[0014] (2) The industrial solid waste treatment capacity is seriously insufficient:

[0017] (3) The cost of industrial solid waste treatment is high, and there are technical problems:

For example, Hualing Group mainly treats its blast furnace waste by bagging the gas ash, and then mixing the collected waste with iron ore raw materials into the smelting furnace for smelting. Although this method can reduce the impact of solid waste on Environmental pollution, but the mixed smelting of recycled gas ash and iron ore will cause iron ore raw materials to agglomerate and adhere to the inner wall of the smelting furnace, affecting the heating effect and the quality of steel products, and reducing the service life of the smelting furnace

Technical problems have plagued large smelting enterprises like Zhuzhou Smelter for a long time, which is also the main reason why it is difficult to effectively treat solid waste

[0020] (4) Both the government and enterprises lack effective management of industrial solid waste treatment and comprehensive utilization:

[0022] 1. The treatment of solid waste by polluting enterprises is generally handled by subordinate auxiliary units or entrusted to external private enterprises. These enterprises have low barriers to entry and are characterized by miniaturization, diversification, privatization, and labor-intensive. Decentralization of solid waste utilization business operations

Relatively backward treatment technology, it is easy to cause secondary pollution

[0023] 2. The government departments lack systematic tracking and continuous effective supervision of the circulation links of various metallurgical solid wastes generated by enterprises. As long as there is a unit receiving it, no matter whether it adopts the "three modernizations" treatment or not, it will be included in the disposal and utilization, which causes Inadequate end management of solid waste treatment is also the main cause of secondary pollution

[0024] (5) The degree of industrialization and market concentration of industrial solid waste treatment are low:

[0025] 1. Most solid waste utilization enterprises are small in size, low in investment, low in technical equipment capabilities, and their business characteristics are mainly labor-intensive. Solid waste disposal and low-end recycling products converge. The market competition is extremely fierce, but enterprises are content with meager profit production , lack of motivation to invest in technical equipment transformation

[0026] 2. There is a lack of effective coordination between pollution source enterprises and solid waste utilization enterprises. Even if some solid waste utilization enterprises have superior technologies, they cannot play their best role

[0032] At present, the heat consumption of zinc oxide rotary kiln is generally 2200 kcal per ton of waste, which not only causes waste of heat, but also the kiln slag is easy to agglomerate on the kiln wall, resulting in high maintenance costs and short service life of equipment

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