Zero emission circulating system for sealing treatment of regenerated lead smelting tail gas

Abstract

The invention discloses a zero emission circulating system for sealing treatment of regenerated lead smelting tail gas. A smelting furnace, a gravity dust collector, a bag type dust collector, a waterwashing dust collecting tower, an air compressor, a gas-liquid separator, an alkali washing desulfurizing tower and a circulating pipe are successively arranged according to a flowing direction of the smelting tail gas. By adopting multiple processes to collect dust first, carrying out pressurizing and liquefying to recover CO2 by means of a physical method, carrying out desulfurization and denitrification by means of a chemical method and finally, and supplementing O2 to residual gas to return to a smelting furnace, the smelting tail gas circulates in a closed system and is not discharge toair, so that the desulfurization cost is reduced greatly, the carbon recovery benefit is increased, and meanwhile, solid-liquid separation can be carried out to reduce lead dust residues by means of good solubility of a desulfurization product. The desulfurization product is treated harmlessly favorably. The process does not need high precision removal of sulfur and dust, so that the flue gas treatment difficulty is reduced greatly and the process is the most economical, cleanest and environment-friendly process.

Description

technical field [0001] The invention belongs to the technical field of environmental protection for secondary lead smelting, and in particular relates to a zero-emission cycle system for closed treatment of secondary lead smelting tail gas. Background technique [0002] The invention of lead-acid battery has a history of more than one hundred years, and it is the most widely used and oldest battery system in the world today. Although lithium batteries are favored by people in recent years, lithium batteries are expensive and easy to catch fire and explode, while lead-acid batteries are cheap, easy to obtain raw materials, and have sufficient reliability in use. They are suitable for high-current discharge and a wide range of ambient temperatures. Due to the advantages of wide range and mature recycling technology, more than 80% of batteries are still lead-acid batteries at present, so it is difficult to shake the dominance of lead-acid batteries widely used in production and...

AI Technical Summary

Problems solved by technology

During the recycling and smelting of lead-acid batteries, lead dust and SO 2 , SO 3 And the disorderly discharge of nitrogen oxides is serious pollution, especially involving heavy metal lead, so the country has very high environmental protection requirements for smelting pollution control: SO in the tail gas discharged to the atmosphere 2 Content can not exceed 150mg / m 3 , The content of nitrogen oxides should not exceed 200mg / m 3 , lead and its compounds shall not exceed 2mg / m 3 , these standards are extremely high. At present, some domestic enterprises adopt caustic soda desulfurization, and as a result, a huge amount of CO in the tail gas is also removed. 2 , so that the consumption of caustic soda doubles, resulting in pollution control investment higher than economic benefits, making it difficult to run production

However, most smelting enterprises adopt lime water desulfurization process, and the desulfurization effect is not ideal. Many enterprises just want to realize the final micro-treatment, and the cost of pollution control increases a lot, which affects the economic benefits of enterprises. Moreover, the residual lead dust in lime desulfurization paste is easy to exceed the standard. It is difficult to separate, and the cost of harmless treatment is high. In short, the difficulty of desulfurization and dust removal technology is the biggest bottleneck restricting the development of the industry

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