Method for preparing sodium sulfite by sulfur dioxide in tail gas generated by calcining molybdenum concentrate

Abstract

The invention relates to a method for preparing sodium sulfite by sulfur dioxide in the tail gas generated by calcining molybdenum concentrate; when the molybdenum concentrate is calcined by a rotary kiln, the generated tail gas is filter by a bag type dust collector, and larger granular dust is filtered out; after that, the tail gas is sent into a water scrubber by a main fan and an auxiliary fan to further purify the dust and colored substance in the tail gas; then, the tail gas is sent into a multi-stage purification tower, and the sulfur dioxide in the tail gas and alkaline liquor inside the multi-stage purification tower have chemical reaction to generate sodium sulfite solution; after being precipitated and purified, the sodium sulfite solution is treated by evaporative crystallization and centrifuge dripping; and finally, anhydrous sodium sulfite can be obtained after being dried by a drier. After the tail gas is purified, no waste liquid is generated, the water body is avoided being polluted, byproduct can be obtained, and the sulfur dioxide is fully utilized. The method has simple technique and the tail gas purification rate reaching up to 99.8%, is good in purifying effect, and changes waste into valuable, thus leading enterprises to obtain considerable economic benefit.

Description

1. Technical field [0001] The invention relates to a method for effectively treating the tail gas produced in the molybdenum smelting industry and obtaining new products, specifically, using sulfur dioxide in the tail gas produced by roasting molybdenum concentrate to prepare sodium sulfite. 2. Background technology [0002] In the molybdenum smelting industry, when the rotary kiln is used to roast molybdenum concentrate, a large amount of tail gas will be generated to be discharged. The tail gas contains a lot of dust and high concentration of sulfur dioxide. In order to protect the environment from pollution, it is necessary to remove dust from the tail gas Desulfurization treatment. Before the present invention was proposed, the tail gas treatment method was to filter the dust through the bag filter, send the gas containing sulfur dioxide into the absorption purification tower, and discharge the tail gas and the generated waste liquid after liquid reduction and absorption...

AI Technical Summary

Problems solved by technology

The shortcomings of this treatment method are that the air supply volume does not match the wet desulfurization technology, and sulfur dioxide cannot be produced as a by-product; the second is that the tail gas treatment is not thorough, and the waste liquid generated after treatment is directly discharged and pollutes the water body; the third is that The sulfur dioxide in the tail gas cannot be recycled and cannot create economic benefits for the enterprise