A preparation method and recovery method of an environment-friendly low-mercury catalyst

Abstract

The invention relates to a method for preparing an environment-friendly low-mercury catalyst. Immerse in 35% potassium hydroxide solution for 12 hours, then dry in a converter, the vacuum degree is 0.08MPa, and the temperature is 125°C; the invention also relates to a recovery method, including acidification, subcritical carbon dioxide extraction, extraction and impurity removal, the recovered The activated carbon has a specific surface area of ​​3012㎡ / g, an ash content of 1.8%, a mechanical strength of 99.2%, a mesoporosity of 99.0%, and a hardness of 2H; after soaking in water, it is dried without powdering or shedding debris; the recovered mercury, collected The rate is as high as 99.7%, and the impurity content is low: the total content of phosphorus and sulfur impurities is less than 0.01%; after testing, the mercury content in the waste liquid is extremely low, and it can be discharged directly without polluting the environment. The recovery method is thorough and environmentally friendly.

Description

technical field [0001] The invention relates to the technical field of low-mercury catalysts, and relates to a preparation method of an environment-friendly low-mercury catalyst, in particular to a preparation method of an environment-friendly low-mercury catalyst and a recovery method thereof. Background technique [0002] With the advancement of science and technology, people pay more and more attention to the problem of energy waste, and the requirements for energy recovery and reuse are increasing. China is currently the country with the largest amount of mercury in the world. The annual mercury consumption in the world is about 2,000 tons. 1,300 tons, accounting for about 65%; and the PVC industry has become the industry with the largest mercury consumption and mercury emission due to the excessive expansion of the scale of acetylene-based PVC. In 2007, the mercury consumption was about 650 tons, accounting for 50% of the domestic mercury consumption. Mercury, the molec...

AI Technical Summary

Problems solved by technology

Long-term work in an environment where the mercury vapor content in the air exceeds the allowable range will cause chronic poisoning, memory loss, saliva, fatigue, fatigue, insomnia, dizziness and other mental disorders. The status quo will not only cause serious harm to the environment and human health, but also have to face the fate of stopping production or bankruptcy due to the supply of mercury and the adjustment of national industrial policies

[0003] The existing low-mercury catalysts have shortcomings: fast catalytic activity decay, weak chemical corrosion resistance and salt spray resistance, the carrier is easy to powder after a period of use, the service life is relatively short, and the consumption is often large. To some extent, it limits the application space of low-mercury catalysts

However, the mechanical properties of the activated carbon separated by this method are low, and the problem of high dusting rate and low porosity will occur when it is reused, which directly affects the adhesion of mercury on the activated carbon and the catalytic process of the reaction, and requires a large investment in equipment. , operation difficulty and production cost are also higher

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