Full-cycle comprehensive utilization integrated complete production line for ardealite and by-products of ardealite

Abstract

The invention provides a phosphogypsum and by-product full-cycle comprehensive utilization integrated set production line, which comprises purification tanks, calcining cylinders and a heat exchange cylinder, the calcining cylinders are connected in series end to end, a solid-liquid separator is further arranged between two adjacent purification tanks, a thickener is further arranged between the first purification tank and the first solid-liquid separator, and the other solid-liquid separator is arranged between the second purification tank and the second solid-liquid separator. A slurry pump is arranged in the purification tank, the slurry pump respectively extends into the thickener and the next solid-liquid separator through feeding pipes and is connected with the head end of the first calcining cylinder, the upper part of the thickener extends into the synthesis tower through a purification liquid pipe, a reflux pump is arranged in the synthesis tower and is connected with a reflux water pipe, the first heat exchange cylinder is further connected with a steam condensing pipe, and the steam condensing pipe is connected with the condensing pipe. And the tail end of the backflow water pipe and the tail end of the steam condensing pipe extend into the first purification tank. By adopting the technical scheme provided by the invention, by-products such as purified liquid, steam condensate and the like generated in the treatment process of the industrial gypsum raw slag are reasonably and effectively recycled, so that the effective utilization rate of resources is improved, and the pollution to the environment is avoided.

Description

technical field [0001] The invention relates to the technical field of industrial gypsum treatment technology, in particular to an integrated complete production line for full cycle comprehensive utilization of phosphogypsum and its by-products. Background technique [0002] Phosphogypsum is a chemical by-product with calcium sulfate as the main component produced in the process of preparing phosphoric acid from phosphate rock by wet method. Nearly five tons of phosphogypsum are produced for every ton of phosphoric acid produced. Phosphogypsum also contains undecomposed phosphate rock, SiO 2 , alumina, iron oxide, magnesium oxide, fluorine-containing substances, acidic insoluble organic substances and other impurities that are harmful to human health and biological growth, and affect the quality of phosphogypsum products; phosphogypsum is different from natural gypsum, although its CaSO 4 2H 2 The content of O is relatively high, but it contains 0.3% to 2.0% of P 2 o 5 ...

AI Technical Summary

Problems solved by technology

At present, the amount of phosphogypsum stacked in China is more than 600 million tons, and it is still growing at a rate of more than 70 million tons every year, but its effective utilization rate is less than 20%. A large amount of phosphogypsum is still stored in the form of direct stacking, which not only occupies land resources , bring a heavy burden to the production enterprises, and also cause safety hazards and environmental pollution

[0004] In the prior art, the technical means for treating phosphogypsum mainly include purification, calcination, etc. These technical means can avoid environmental pollution caused by direct discharge of industrial phosphogypsum, However, in the process of processing phosphogypsum, a large amount of energy will still be consumed, and many by-products will be produced. If these by-products are directly discharged, they will still pollute the environment, and the gain outweighs the gain. For example, the publication number is: "CN104211103A" The patent literature discloses a method for closed recycling of leachate from a phosphogypsum storage yard. The leachate from a phosphogypsum storage yard treated with anti-seepage treatment is sent to a ball mill (21) together with sewage from the production system through a leachate collection tank for wet The ore is ground by the method to make a slurry, which is then reacted in the extraction tank and enters the filtration system, and the filtered phosphogypsum is transported to the phosphogypsum storage yard, so that the filtrate of the phosphogypsum storage yard is closed and recycled

This patent document makes reasonable and effective use of the treated phosphogypsum. However, a large amount of filtrate produced during the treatment of phosphogypsum is not a neutral liquid substance, and the pH has not yet reached the national discharge standard, and direct discharge will still pollute the environment. Therefore, whether it is to ensure the sustainable development of phosphorus chemical industry or to protect the ecology of the Yangtze River and the recycling of resources, and to reduce carbon emissions, it is urgent to develop a new complete equipment production line to solve the full recycling of phosphogypsum.

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