Recycling method for mold release waste liquor of aluminum profile factory

Abstract

The invention relates to an alkaline waste liquor recycling method capable of being used for recycling mold release waste liquor in the aluminum profile production process and belongs to the technical field of environmental protection. The method comprises the steps that after the mold release waste liquor is filtered in a pressed mode, refined lime slurry is used for reacting with sodium aluminate in the mold release waste liquor, then aluminum in the mold release waste liquor is removed by means of solid-liquid separation, obtained alkali liquor is added into solid caustic soda to improve concentration, then the alkali liquor can return to be used in the mold release process, and generated calcium aluminate precipitate can serve as high-quality coagulant to be used for treating acid waste water. The method has the advantages of being low in cost and achieving total recovery and zero emission, working procedures and adopted equipment are simple, and the method is an ideal recycling method for the mold release waste liquor of the aluminum profile factory.

Description

technical field [0001] The invention relates to a method for recycling alkaline waste liquid, which can be used for recycling waste liquid from demoulding in the production process of aluminum profiles, and belongs to the technology in the field of environmental protection. Background technique [0002] In the production process of aluminum profile production, aluminum profiles are formed through an extrusion process. Molds are needed for extrusion, and after the extrusion of these molds, the remaining aluminum shaft heads on the mold need to be removed. When removing them, they must be soaked in caustic soda (NaOH) and the lye with a high concentration must be heated at the same time. The demoulding process can only be completed after the aluminum shaft head attached to the mold comes out. These high-concentration sodium hydroxide solutions will dissolve the metal aluminum in the mold, making the mold clean and easy to reuse. The lye used in this mold treatment process wi...

AI Technical Summary

Problems solved by technology

The mold release waste liquid is a waste liquid with a high alkali content. If it is not treated, it will cause greater environmental pollution.

[0003] At present, the commonly used wastewater treatment methods at home and abroad mainly include acid-base neutralization method, chemical precipitation method, coagulation method, adsorption method, microbial method, membrane separation method and constructed wetland method, etc., but these methods are only suitable for The waste water with low volume is treated, and the demoulding waste liquid is a kind of waste liquid with high alkali content. It will cost a lot to process it with these methods, and the alkali cannot be recovered, and it will also produce waste water discharge, impact on the environment

And the notification numbers are respectively the methods described in patents such as CN101786746A, CN102642945A, CN203781897U, CN103451436B are also all a kind of acid-base neutralization method in essence, all are to utilize waste acid to neutralize the alkali in the demoulding waste liquid, can only The aluminum in it is recovered, but the alkali in it cannot be recovered, and there is waste water discharge

Cannot achieve the effect of zero emission and full recovery