The Preparation Of Iron Oxide Red From Iron And Steel Pickling Waste Liquor And Its Industrialization

For a long time,the process of the development of the steel industry has produced a large amount of pickling waste liquors.These waste liquors have a complex composition and a large amount of emission,which is difficult to deal with and have an adverse impact on our ecological environment.All these problems seriously limit the development of the local economy.Therefore,it is imperative to strengthen the treatment of the pickling waste liquors.Solving these problems not only need the enforcement of relevantly environmental policies and laws of our nation but also the support of new technology.To solve the problem confronted by the steel industry,we developed a green method that can solve the pollution caused by the steel pickling waste liquors and bring considerable economic benefits.In this process,the iron oxide red with high value-added was prepared from the steel pickling waste liquors.The indicators of the iron oxide red conform to that of national prime standard.The specific work of this topic includes the following several parts:?1?The purification of the steel pickling waste liquors:We apply precipitation separation method,using ammonia as precipitant,to remove the heavy metal ions and non-metallic harmful impurities in the steel pickling waste liquors.We analyze the change of the impurity content before and after the purification of the steel pickling waste liquors by ICP-AES.?2?The preparation of crystal seed:In the seed preparation,we mainly investigate the influence of process parameters,such as initial concentration of Fe²⁺,the air flow rate,oxidation time and so on,on the preparation of crystal seed.?3?The preparation of iron oxide yellow:In the preparation stage of iron oxide yellow,we mainly investigate the influence of process parameters,such as the seed dilution ratio,the initial concentration of Fe²⁺,the air flow rate,oxidation time and so on,on the preparation of iron oxide yellow.By analyzing the characterization of XRD?SEM?particle size distribution about the products,we find the best conditions for the preparation of iron oxide yellow.?4?The preparation of iron oxide red:In the preparation stage of iron oxide red,we mainly investigate the influence of oxidation time and oxidation temperature on the preparation of iron oxide red.By analyzing the characterization of color?XRD?SEM?particle size distribution about the products,we find the best conditions for the preparation of iron oxide red.?5?On the basis of laboratory research,we gradually enlarge the amount of the steel pickling waste liquors and carry on the extended experiment and the pilot projects respectively.We analysis the phase?morphology?particle size distribution of the iron oxide yellow and iron oxide red prepared by the two experiments through the characterization of XRD?SEM?particle size distribution.Meanwhile,the test results of the pigment properties of the iron oxide red show that these products have excellent properties and wide usesThrough the intensive study on the preparation of iron oxide red from the steel pickling waste liquors,this research topic demonstrates the concept of transforming the waste into useful substances and achieve the comprehensive utilization of the steel pickling waste liquors and make the waste profitable.In addition,the success of the extended experiment and the pilot project provide a theoretical basis and practical guidance for the industrialization of this method and bring hope for the resource utilization of the steel pickling waste liquors.