Method for recovering cobalt manganese catalyst from terephthalic acid reaction mother solution

Abstract

A disclosed method for recovering a cobalt manganese catalyst from a terephthalic acid reaction mother solution comprises the following steps: recovering acetic acid form the reaction mother solution by evaporation; adding water to concentrated mother solution, and cooling to precipitate organic compound precipitation from the reaction mother solution; separating and recovering the organic compound precipitation; heating the solution and adding alkali and an oxidant, so as to enable metal ions such as iron, chromium and the like in the solution to form acid-corroding metal precipitation and precipitate; removing the acid-corroding metal precipitation, and continuing to add alkali into the solution, so as to enable metal ions such as cobalt, manganese and the like to precipitate and form a cobalt manganese catalyst precipitation; and performing filtering and water washing on the cobalt manganese catalyst precipitation, adding into hydrobromic acid or acetic acid, so as to dissolve the cobalt manganese catalyst precipitation and recover the precipitation as the cobalt manganese catalyst. Therefore, the purpose of recovering the cobalt manganese catalyst efficiently for reutilization is realized.

Description

technical field [0001] The invention relates to a method for recovering and reusing a cobalt-manganese catalyst, in particular to a method for recovering a cobalt-manganese catalyst from a terephthalic acid reaction mother liquor and reusing it as an oxidation catalyst. Background technique [0002] Purified terephthalic acid (PTA, purified terephthalic acid) and purified isophthalic acid (PIA, purified isophthalic acid) are mainly used to synthesize polyethylene terephthalate (PET, polyethyleneterephthalate), which is generally made of p-xylene ( PX, para-xylene) or m-xylene (MX, meta-xylene) is obtained by air oxidation. Cobalt acetate (Co(CH 3 COO) 2 ) and manganese acetate (Mn(CH 3 COO) 2 )) as an oxidation catalyst, and adding hydrobromic acid (HBr) as an oxidation accelerator, while using acetic acid as a reaction solvent. [0003] In the process of generating terephthalic acid from the oxidation of p-xylene, since the product of the reaction - terephthalic acid i...

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Problems solved by technology

[0009] However, although the above-mentioned multiple cobalt-manganese catalyst recovery methods have been proposed, in practical application, there is still no method that can directly recover cobalt and manganese catalysts from the discharged reaction mother liquor at the terephthalic acid production plant site.

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