本文選題：紅土鎳礦 + 固態(tài)還原��； 參考：《西安建筑科技大學》2015年碩士論文

【摘要】：近年來,中國不銹鋼產(chǎn)業(yè)的快速發(fā)展導致了金屬鎳的供不應求,世界上金屬鎳冶煉原料中硫化鎳礦占60%,但其資源總量只占鎳礦資源的28%左右。因此,隨著硫化鎳礦資源減少,紅土鎳礦已經(jīng)成為生產(chǎn)鎳鐵產(chǎn)品的重要原料。由于國內(nèi)紅土鎳礦資源儲量少、品位低,促使紅土鎳礦的合理開發(fā)利用變得迫在眉睫。因此,從長遠來看需要開發(fā)新的和更經(jīng)濟的處理技術,以達到紅土鎳礦資源的高效化利用是非常必要的。本文提出了一種以紅土鎳礦為原料,同時生產(chǎn)直接還原鐵和膠凝性材料的高資源利用和環(huán)境友好的新工藝。通過合理配料與溫度控制,實現(xiàn)金屬氧化物還原和水泥中膠凝組元的生成反應的耦合,磨碎選分后可得到金屬和膠凝材料。實現(xiàn)還原同時對脈石成分的有效利用。通過基礎熱力學分析(Factsage軟件模擬)、物相檢測與分析(X-射線衍射、掃描電鏡等)、實驗室還原試驗(一段升溫法和分段升溫法),考察了還原溫度、還原時間、添加劑加入量、還原劑加入量、反應氣氛等因素對試驗結果的影響。得到以下結論:(1)熱力學研究表明:原料中金屬氧化物的還原順序由易到難依次為Fe2O3、NiO、CoO、Fe3O4、FeO和Cr2O3;2CaO·Fe2O3被C還原溫度最低為910.6℃,其還原為逐級還原(2CaO·Fe2O3→CaO、Fe3O4→CaO、FeO→Fe);在溫度低于1300℃時,硅酸二鈣優(yōu)于硅酸三鈣形成,隨著系統(tǒng)溫度的進一步提高,溫度在1300℃以上,先期形成的硅酸二鈣開始與CaO反應形成硅酸三鈣,其反應所適用的溫度范圍為1300℃~1800℃,并且溫度在1450℃左右時,硅酸三鈣的生成最快。(2)實驗研究結果表明:在一段法升溫實驗中,在焙燒溫度1450℃、焙燒時間90分鐘、堿度2.9、還原劑配比10%的條件下,硅酸二鈣生成量最大75.21%,由于氧化鈣和還原劑加入量差距過大導致鐵氧化物還原反應的動力學條件變差以及氣氛原因沒有出現(xiàn)單質Fe。在兩段法升溫實驗中,反應產(chǎn)物中出現(xiàn)了硅酸三鈣(其含量大概在30%~50%),隨著配碳量的增加,硅酸三鈣呈先增后減、硅酸二鈣呈先減后增的趨勢;還原時間對硅酸三鈣的生成有很大的影響,在含碳量14%,還原溫度1450℃條件下,還原時間由0.5h→1h→2h,其含量由27%→33%→52%。(3)改善還原反應的動力學條件,反應中保證反應氣氛,如30%碳粉、1000℃保溫15min、1450℃保溫60min,可使鎳鐵合金和以硅酸三鈣、硅酸二鈣為主的膠凝性材料共存(8%Fe Ni、34%C3S、38%C2S)。通過分析金屬鐵、鎳的還原率是72.7%和80%。
[Abstract]:In recent years, the rapid development of stainless steel industry in China has led to the shortage of nickel metal supply. In the world, nickel sulphide ores account for 60% of the raw materials for nickel smelting, but their total resources only account for about 28% of nickel ore resources. Therefore, with the decrease of nickel sulfide resources, laterite nickel ore has become an important raw material for the production of nickel iron products. Due to the low reserves and low grade of laterite nickel ore in China, the rational exploitation and utilization of laterite nickel ore becomes urgent. Therefore, in the long run, it is necessary to develop new and more economical treatment technology in order to achieve high efficiency utilization of laterite nickel resources. In this paper, a new process of producing direct reduction iron and cementitious material with laterite nickel ore as raw material and high resource utilization and environmental friendliness is proposed. The coupling of metal oxide reduction and the formation of cementitious components in cement can be realized by reasonable proportioning and temperature control. After grinding and sorting, metals and cementitious materials can be obtained. The effective utilization of gangue components can be realized simultaneously. By means of basic thermodynamic analysis and factsage software simulation, phase detection and analysis, X-ray diffraction, scanning electron microscope and laboratory reduction test (one-stage heating method and piecewise heating method), the reduction temperature, reduction time and additive content were investigated. The effect of the amount of reducing agent and reaction atmosphere on the test results. The results show that the reduction order of metal oxides in raw materials is Fe _ 2O _ 3H _ 3O _ 4 Feo _ 4 and Cr _ 2O _ 3N _ 2CaO _ 2 Fe2O3 at the lowest reduction temperature of 910.6 鈩，

本文編號：1943399