Study On The Regeneration Of Pickling Waste And The Synthesis Of Iron Oxide Red By Electrochemistry

The steel industry is the foundation of a national heavy industry,the development of steel industry has also promoted the development of steel processing industry,pickling has become essential of the steel industry.When the iron ions in the pickling reach a certain concentration or the pH of the pickling is higher than a certain level,the effect of pickling becomes worse,the pickling becomes unused.Pickling waste contains a large amount of iron and free acid.It will cause serious environmental pollution and waste a lot of resources,if pickling waste directly discharged into the environment.Research status on treatment technology of pickling waste:neutralization precipitation is a common method to deal with pickling waste by domestic enterprises.This method can't solve the problem of waste of resources and easily cause secondary pollution.Scholars at home and abroad are studying more environmental treatment technology and able to recycle resources,including direct roasting,evaporation,membrane separation,etc.However,most of these methods are difficult to be widely applied in the domestic market due to cost and some technical problems.In this paper,based on difference of quality between pickling waste and pickling washing waste in pickling process,propound the direct separation of iron resources from the pickling waste by electrochemical technology,and improves the hydrogen ion concentration,so as to achieve the recycling.A homemade concentric structure electrochemical device with a porous titanium electrode,a stainless steel electrode is used to treat simulated pickling waste,and the separated iron are synthesized to be iron oxide red.The influence of the technological parameters such as voltage,initial Fe2+ concentration,initial pH and electrode split-flow on treatment effect of pickling waste were investigated.The performance parameters of synthetic iron oxide red were characterized,and the reusing effect of regenerated acid was verified by the rust removal experiment.The results display,when the voltage is 12V,the separation effect of iron is the best.The higher initial pH is more beneficial to the transformation and separation of iron and the reduction of pH.The maximum reduction rate is 40%.The initial Fe2+ concentration has no obvious influence on the treatment effect.The mechanism of electrochemical treatment of pickling waste was explored by electrode split-flow.The rust removal test of iron nails shows that the regeneration acid has certain pickling effect.The synthetic iron oxide red materials are characterized by SEM,XRD,EDS and TG.The patterns and crystal of the iron oxide products can be designed by different reaction conditions.It is feasible to treat pickling waste by electrochemistry,propounding a direct treatment method to regenerate and reuse pickling.It has a certain reference value for the treatment of pickling waste and the recycling of resources.