A method of co-producing high-purity Schaeffer's salt and g-salt

Abstract

A method of combined production of high-purity Schaffer's salt and G salt comprises the following steps: 1) performing a reaction with 2-naphthol as a raw material and sulfuric acid as a sulfonating agent at 20-90 DEG C for 1-10 h to prepare a sulfonated solution; 2) adding water to the sulfonated solution for hydrolysis at 70-150 DEG C for 1-2 h to obtain a hydrolyzed solution; 3) adding ammoniato the hydrolyzed solution, maintaining temperature at 70-130 DEG C for 1-5 h to perform salting-out; 4) cooling the mixture to 40-50 DEG C and filtering the mixture, water-washing and drying a filtercake to obtain a Schaffer's salt product, mixing the filtrate and washing waste water, adding ammonia or ammonium sulfate and maintaining temperature at 70-130 DEG C for 1-5 h to perform salting-out,and cooling the mixture to 40-50 DEG C and filtering and separating the mixture, and drying a filter cake to obtain a G salt product. The method can achieve combined production of the Schaffer's saltand G salt at high purity; meanwhile, total utilization rate of raw materials and equipment utilization rate are increased. The method has simple processes, is environment-friendly and is economical.

Description

[0001] (1) Technical field [0002] The invention relates to the technical field of chemical industry, in particular to a method for co-producing Schaeffer's salt and G salt. [0003] (2) Background technology [0004] Both Schaeffer's salt (2-naphthol-6-sulfonate) and G salt (2-naphthol-6,8-disulfonate) are important chemical intermediates, and Schaeffer's salt is used to make acid Dye and food dye; G salt is used to produce dyes such as acid scarlet 3R, acid complex violet 5RW and weak acid scarlet G, and can also be used to prepare 2-amino-8-naphthol-6-sulfonic acid and 2-amino-6 , 8-Naphthalene disulfonic acid and other intermediates. [0005] The traditional production of Schaeffer's salt is to use 2-naphthol as raw material, sulfonate concentrated sulfuric acid at 100-120°C for 3-10 hours, and then salt out and filter to obtain the crude product after cooling down, add lye to dissolve, then acidify and salt out to produce have to. There are certain drawbacks in this me...

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Problems solved by technology

But even so, the resulting G salt yield is still low (about 70%), and the filter cake still contains more by-products such as Scherrer's salt and R salt, resulting in a purity≤80%. If the G salt of higher purity is to be obtained , it is bound to further affect the yield

However, there is a large amount of R salt in the G salt wastewater, which needs to be extracted by extraction / back extraction, but only poor quality R salt can be obtained.

[0007] In summary, the synthesis of Schaeffer's salt / G salt has disadvantages such as difficult purification of finished products, low yield, low utilization rate of raw materials, and complicated procedures.

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