Research On Regeneration And Stabilization Technology Of Aluminum Alloy Milling Fluid

After the chemical milling fluid is discarded,it will cause a lot of waste of chemical raw materials,high end treatment costs,high environmental pressure and other problems.A certain aerospace research institute in Shanghai solves the chemical milling fluid scrap problem by using a chemical milling fluid with water to dilute the crystal.During the process debugging process,it was found that the treatment effect could not reach the expected design effect,it could only prolong the service life of the chemical milling liquid,and it could not solve the problem of scrapping the chemical milling liquid well.In this paper,according to the problems found in the process of debugging and the production situation of the chemical milling workshop,through the experimental research on the key factors such as SS,dilution ratio,stirring speed,seed quantity and type in the chemical milling fluid,find the best parameters that can achieve the best treatment effect,and optimize the trial operation process according to the best parameters.Finally,through field experiments,a set of optimized processes that can actually solve the problem of chemical milling fluid scrapping is obtained.The conclusions of the study are as follows:（1）According to the pilot test results of each key factor,the optimal parameter combination is:the filtered chemical milling liquid is mixed with the same volume of water in a 1:1 dilution,add 200 mesh aluminum hydroxide seeds whose Al³⁺mass is equivalent to 20%of the Al³⁺mass in the diluted milling liquid,and stir at 20 rpm and100 rpm,the Al³⁺removal rate reached 24.87%in 3 days,and the Al³⁺removal rate reached 47.41%in 7 days,which could achieve a theoretical treatment effect of about48%,but the treatment time Too long.（2）Adding sodium bicarbonate can reduce Al³⁺concentration in chemical milling fluid very quickly.Under the optimal conditions of each factor for 3 days,the mass m1of the required sodium bicarbonate is calculated from the Al³⁺concentration in the chemical milling fluid.When the theoretical dosage of sodium carbonate is 2.5 times,the Al³⁺removal rate in the chemical milling fluid can meet the current daily production requirements of the chemical milling workshop,reaching a theoretical treatment effect of about 48%.（3）According to the best parameter data of the small test experiment and the data of the experiment of adding sodium bicarbonate.In view of the problems found in the process debugging,an optimization scheme is proposed,and further debugging and improvement are carried out through field experiments,and an improved process capable of stably adjusting the concentration of the chemical milling fluid Al³⁺is obtained.During the field experiment,the concentration of Al³⁺in the chemical milling tank stock solution gradually increased from 50 g/L to 65 g/L within 3 to 5 days.After 3 to 5 days,the Al³⁺removal rate of the crystallization tank is about 22%,which is not much different from the 24.87%of the beaker experiment.By adding a sufficient amount of sodium bicarbonate to further reduce the concentration of Al³⁺in the crystallization bath,the concentration of the original solution Al³⁺can be adjusted from 65g/L to an initial value of 50g/L,and finally the purpose of stable regeneration of the aluminum alloy milling liquid is achieved.During the field experiment,the chemical milling speed of the chemical milling fluid can be maintained at a good level of 3um/min,and the workload of grinding the workpiece after chemical milling is greatly reduced.