Method for resource utilization of graphene waste acid

Abstract

The invention belongs to the technical field of graphene waste acid treatment, and particularly relates to a method for resource utilization of graphene waste acid. The method comprises the followingsteps: a) pre-treatment: adjusting the content of sulfuric acid in waste acid and removing suspended particles and macromolecular impurities in the waste acid; b) membrane filtration: treating the pre-treated waste acid by an aromatic polyamine nanofiltration membrane to obtain a concentrated liquor and a permeable liquid; c) precipitating treatment: adding silicofluoric acid into the permeable liquid and filtering the mixture to obtain a filter cake and a filtrate; and d) vacuum concentration: concentrating the filtrate in a vacuum condition to obtain sulfuric acid, of which the mass fraction is greater than 95%. Sulfuric acid is recycled and metal ions are recovered in a graphene production process, so that the industrial value is improved, and the industrial production cost of grapheneis lowered. The method has an obvious economical benefit. In addition, the environmental pollution is also eliminated, the environmental quality is improved favorably and the method has a good socialbenefit.

Description

technical field [0001] The invention belongs to the technical field of graphene waste acid treatment, in particular to a method for resource utilization of graphene waste acid. Background technique [0002] At present, domestic and foreign methods for treating waste acid mainly include waste acid cracking, concentration, solvent extraction, ion exchange, membrane separation and chemical conversion. These methods have their own advantages and disadvantages in practical application, and a single process is very difficult It is difficult to meet the target requirements. [0003] The preparation of graphene by the Hummer redox method usually treats the raw graphite with an inorganic strong protonic acid (such as concentrated sulfuric acid, concentrated nitric acid, or a mixture thereof), inserts small molecules of the strong acid between the graphite layers, and then uses a strong oxidant (such as potassium permanganate , potassium perchlorate, etc.) to oxidize it. During the ...

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Problems solved by technology

If it is not treated effectively, it will not only cause serious environmental pollution, but also cause a great waste of resources.

[0004] Chinese patent CN104085861B discloses a device for recovering sulfuric acid from graphene acid-containing wastewater and its corresponding process, purifying sulfuric acid from graphene wastewater to achieve the purpose of resource recycling, using its device and process to account for the recovery rate of acid liquid Reach 92%-95%, but require corrosion-resistant equipment and higher energy consumption

[0005] Chinese patent CN103696015A discloses a treatment method for waste sulfuric acid in the production process of graphene, which is characterized in that the waste sulfuric acid is collected, filtered and settled to obtain transparent waste sulfuric acid, and then the dilute sulfuric acid solution prepared by diluting the waste sulfuric acid with water is used Calcium sulfate whiskers are synthesized with dilute sulfuric acid. The beneficial effect of this invention is that waste sulfuric acid is used to produce calcium sulfate whiskers in the graphene production process, which eliminates pollution and improves environmental quality. However, sulfuric acid cannot be recycled to graphite due to the introduction of calcium precipitants. In the production of alkene, the production cost cannot be effectively reduced, and it does not involve the resource utilization of metal ions in waste acid

Concentrate the waste water, combine multi-effect evaporation to obtain potassium sulfate by-products and deionized water. This invention only recycles manganese and potassium, and mainly uses chemical conversion to process graphene waste acid, resulting in waste of sulfuric acid resources.

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