本文關(guān)鍵詞： 硫鐵礦燒渣 SEM形貌分析 硫酸浸出 除砷 動力學(xué)　出處：《昆明理工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：硫鐵礦燒渣是在使用硫鐵礦為主要原料煅燒硫酸時(shí)產(chǎn)生的固體廢渣,目前對硫鐵礦燒渣的處理主要是堆放或者簡單的填埋處置,既占用大量土地,還會對大氣、水體、土壤等造成嚴(yán)重的污染。硫鐵礦燒渣中主要成分為鐵的氧化物,含量一般為30%～60%,部分硫鐵礦燒渣還含有少量的Cu等有價(jià)值的元素,是一種寶貴的二次資源,但由于硫鐵礦燒渣中的雜質(zhì)含量普遍偏高,特別是燒渣中有砷的存在,直接影響其作為鐵精礦的回收利用,鐵精礦含有砷將導(dǎo)致鑄鐵熱力學(xué)性能降低,還會造成一系列的工藝和環(huán)境問題,脫除硫鐵礦燒渣中的有害雜質(zhì)是十分有必要的。對于含有有價(jià)金屬的硫鐵礦燒渣能在回收鐵資源的同時(shí)回收其他有價(jià)金屬,既能消除其對環(huán)境的影響,還可獲得一定的經(jīng)濟(jì)價(jià)值。本論文在充分查閱和參考硫鐵礦燒渣綜合利用、含砷物料的脫砷研究等相關(guān)文獻(xiàn)資料的基礎(chǔ)上,對高砷含銅硫鐵礦燒渣進(jìn)行了研究。該燒渣含鐵51.15%、As含量為3.35%,Cu含量為1.02%；硫鐵礦中的鐵主要以赤鐵礦(Fe2O3)和磁鐵礦(Fe3O4)形式存在,As主要以砷化物(As2O3)存在,Cu主要以CuFe2O4存在；高砷含銅硫鐵礦燒渣呈浸染狀、蜂窩狀等結(jié)構(gòu),表面結(jié)構(gòu)疏松；部分脈石礦物與鐵礦物相互包裹,或者附著在鐵礦物表面,雜質(zhì)元素在燒渣表面均勻分布,這種復(fù)雜連生結(jié)構(gòu)導(dǎo)致其物理或機(jī)械處理方法分離變得困難。實(shí)驗(yàn)的研究是根據(jù)燒渣的礦物學(xué)性質(zhì),采用硫酸溶液浸出硫鐵礦燒渣,可達(dá)到脫砷和銅等其他雜質(zhì)的目的,同時(shí)提高鐵的品位。實(shí)驗(yàn)進(jìn)行了硫酸濃度、固液比、溫度、反應(yīng)時(shí)間和清水洗滌的影響實(shí)驗(yàn),最后確定最佳實(shí)驗(yàn)條件：初始硫酸濃度(質(zhì)量濃度)為15%,固液比1：3,浸出溫度60℃,在機(jī)械攪拌下浸出3.0h,攪拌洗滌兩次。高砷含銅硫鐵礦燒渣在最佳實(shí)驗(yàn)條件下浸出,可使高砷含銅硫鐵礦燒渣中As的含量降至0.20%、Cu含量降至0.39%、Fe的品位提高到57.66%,達(dá)到鐵礦燒結(jié)廠對鐵礦中Fe的品位和對As、Cu雜質(zhì)含量的要求。由于浸出液中含有大量的鐵、砷和銅,因此實(shí)驗(yàn)采用中和沉淀去除砷和鐵的方法,使銅存留于濾液,便于后序的回收利用。鑒于濾液中主要是三價(jià)砷,而三價(jià)砷比五價(jià)砷毒性大,且五價(jià)砷更易于與三價(jià)鐵形成砷酸鐵鹽,所以在中和沉淀前采用雙氧水氧化三價(jià)砷,實(shí)驗(yàn)得出在常溫下中和沉淀除砷和鐵的最佳工藝條件為：中和沉淀終點(diǎn)pH值為3,反應(yīng)時(shí)間為10min,最大除砷率為99.89%,除鐵率為99.77%,而銅的損失率僅為3.35%,溶液中的銅的含量達(dá)到了1.4g/L,具有萃取回收利用的價(jià)值。采用熱力學(xué)對中和沉淀鐵和砷進(jìn)行理論分析,論證中和沉淀終點(diǎn)pH值的正確性。通過對高砷含銅硫鐵礦燒渣中砷的浸出動力學(xué)機(jī)理研究,為硫酸浸出高砷硫鐵礦燒渣提供理論依據(jù),對硫酸法處理高砷含銅硫鐵礦燒渣具有重要的指導(dǎo)意義,并可以為其他高砷物料的無害化處理提供理論參考。
[Abstract]:Pyrite cinder is a solid waste produced when pyrite is used as the main raw material to calcinate sulfuric acid. At present, pyrite cinder is treated mainly by stacking or simple landfill disposal, which not only takes up a large amount of land, but also affects the atmosphere and water body. The main component of pyrite cinder is iron oxide, the content of which is generally 300.Some pyrite cinders also contain a small amount of valuable elements, such as Cu, which is a valuable secondary resource. However, the content of impurities in pyrite cinder is generally high, especially the presence of arsenic in slag, which directly affects the recovery and utilization of iron concentrate, which will lead to the reduction of thermodynamic properties of cast iron. It can also cause a series of technological and environmental problems, and it is necessary to remove harmful impurities from pyrite cinders. For pyrite cinders containing valuable metals, pyrite cinders can recover other valuable metals while recovering iron resources. It can not only eliminate its influence on the environment, but also obtain certain economic value. This paper makes full reference to the comprehensive utilization of pyrite cinder and the study of arsenic removal from arsenic-bearing materials. The iron content of pyrite cinder with high arsenic and copper content is 51.15% and 3.35% and Cu content is 1.02.The iron in pyrite is mainly in the form of hematite Fe2O3) and magnetite Fe3O4). The pyrite cinder with high arsenic and copper content is impregnated, honeycomb structure and loose surface structure. Some gangue minerals and iron minerals are wrapped in each other, or attached to iron mineral surface, and impurity elements distribute uniformly on the surface of slag. This complex conjunctive structure makes it difficult to separate its physical or mechanical treatment methods. According to the mineralogical properties of cinder, pyrite cinder can be leached by sulfuric acid solution, so as to remove arsenic and other impurities such as copper. The effects of sulfuric acid concentration, solid-liquid ratio, temperature, reaction time and clean water washing were studied. The optimum experimental conditions were as follows: the initial sulfuric acid concentration (mass concentration) was 15, the solid-liquid ratio was 1: 3, and the leaching temperature was 60 鈩，

本文編號：1526402