(昆明理工大學(xué) 冶金與能源工程學(xué)院，昆明 650093)
摘 要: 赤鐵礦渣由于鐵含量高，存在極大潛力作為副產(chǎn)品銷售給鋼鐵、水泥制造以及涂料行業(yè)，從而實(shí)現(xiàn)鐵資源化利用，硫含量是影響赤鐵礦品質(zhì)并實(shí)現(xiàn)其資源化利用的重要因素之一。赤鐵礦渣中硫主要以亞穩(wěn)態(tài)的鐵礬、SO42-的不可逆吸附以及堿式硫酸鐵等形式存在，其中鐵礬是硫的主要存在形態(tài)。FeSO4-H2O體系中Fe(II)氧化水熱水解赤鐵礦沉鐵及過程亞穩(wěn)態(tài)鐵物相轉(zhuǎn)化研究表明：溫度是影響亞穩(wěn)態(tài)鐵礬物相形成和轉(zhuǎn)化的關(guān)鍵因素，升高溫度亞穩(wěn)態(tài)鐵礬的熱力學(xué)穩(wěn)定性變差，有利于其向赤鐵礦轉(zhuǎn)變。降低初始硫酸濃度、延長反應(yīng)時間、添加晶種均會促進(jìn)Fe(II)氧化水解，也有利于亞穩(wěn)態(tài)鐵礬物相向赤鐵礦轉(zhuǎn)變，從而獲得鐵含量高、硫含量低的高品質(zhì)沉鐵渣。在初始Fe2+濃度30 g/L、Na2SO4濃度0.15 mol/L、初始酸濃度1.6×10-4 mol/L、溫度200 ℃、氧分壓 400 kPa、反應(yīng)時間180 min、攪拌轉(zhuǎn)速500 r/min的優(yōu)化技術(shù)參數(shù)下，F(xiàn)e(II)氧化水熱水解赤鐵礦沉鐵過程中沉鐵率為95%，獲得不含亞穩(wěn)態(tài)鐵礬的赤鐵礦沉鐵渣，其中鐵、硫和鈉硫含量分別為66.6%、0.92%和0.033%(質(zhì)量分?jǐn)?shù))。
關(guān)鍵字: 沉鐵；Fe(II)氧化水解；亞穩(wěn)態(tài)鐵礬轉(zhuǎn)變；赤鐵礦；硫含量；水熱冶金
（Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China）
Abstract:Because of high iron content, hematite precipitate is a potential marketable byproduct as a material in the steel making, cement and pigment industries. While, sulfur content is a key factor which affects the hematite quality and its utilization as a resource. The residual sulfur in hematite precipitate is attributed to the part existing as metastable jarosite, irreversible absorption of SO42- ions and basic ferric sulfate, and jarosite appears to be the main sulfate-contaminating phase. The results shows that temperature is the key factor which affects the formation and conversion of metastable jarosite. Therefore, jarosite becomes thermodynamically unstable and to converses into hematite with increasing temperature. It is advantage for metastable jarosite conversion and obtaining high quality hematite precipitate with higher iron content and lower sulfur content by decreasing initial sulfuric acid concentration, prolonging retention time and addition of seed. High quality hematite precipitate with Fe, S and Na content of 66.6%, 0.92% and 0.033%, respectively, and with iron precipitation ratio of 95% are obtained under the condition as follows: initial solution containing 30 g/L ferrous ion, 0.15 mol/L sodium sulphate and 1.6×10-4 mol/L initial acid, temperature of 200 ℃, oxygen partial pressure of 400 kPa, reaction time of 180 min and agitation speed of 500 r/min.
Key words: hematite precipitation; ferrous ion oxydrolysis; metastable conversion; hematitie; sulfur content; hydrothermal metallurgy
