钢铁厂烧结机头电除尘灰综合利用-化学工程专业论文.docxVIP

II Abstract Iron ore sintering is used as an important preparation process of blast furnace burden in HYPERLINK /dict_result.aspx?searchword=%e9%92%a2%e9%93%81%e7%94%9f%e4%ba%a7amp;tjType=sentenceamp;styleamp;t=iron%2Band%2Bsteel%2Bproduction  iron and steel production.The process can produce a lot of flue gas, which is dedusted by the ESP and form sintering head ESP dust. The ESP dust is referred sintered ash, which contains high levels of potassium and lead. Because these two elements are harmful to steel production, the sinter dust is not suitable for direct return to the sintering ingredients, therefore, It is imperative to develop new processing to treat the dust. In this paper, basic research of sintering ash was carried out, such as chemical composition, mineralogical properties and dispersion in water. Based on the research, a new process for comprehensive utilization of sintering ash was developed, which contained water washing, magnetic separation and chloride leaching. Basic research on comprehensive utilization of sintering ash showed that, in the secondary electric field sintering ash, the content of potassium and lead is high( 6%). Iron in the dust exist mainly in the form of magnetite and hematite, and magnetic iron content is high. Potassium and lead in the dust exist mainly in the form of KCl and PbOHCl respectively. Adding a small amount of inorganic acid and surface active agent could significantly improve the sintered ash dispersion in water.The dust suspension could well disperse aqueous solution by the addition of 2 % sulphuric acid and 2 ‰ LAS. In the removal of potassium by water washing, at leaching temperature 30℃, solid-liquid ratio 1:4 and stirring speed 100 rpm, 97.57 percent of the potassium could be removed within 30 min. After purified by carbon dioxide gas, decolorized by active carbon and added ammonium sulfate into the leachate to carry out double decomposition reaction, and then by condensation and crystallization, a