钒钛烧结矿高温冶金性能的研究

试验中研究了钒钛烧结矿的高温冶金性能。试验结果指出,在一定范围内,提高碱度和增加烧结矿中MgO含量来改善钒钛烧结矿高温还原性能及软熔性能是有效的。增加MgO还可抑制硅、钛的还原及碳氮化物的生成,有利于渣铁熔融分离而滴落。钒钛磁铁精矿配入普通富矿粉及适当增加烧结混合料配碳量,可以降低炉渣中TiO_2的活度,增加炉渣的氧化能力,有利渣铁分离。但不利于烧结矿的高温还原性和软熔性能的改善。     

添加剂对钒钛磁铁精矿球团熔融还原冶炼的影响

对钒钛磁铁精矿预还原球团熔融还原冶炼中添加剂的影响进行了研究,并对渣型制度进行了优化。熔融还原渣碱度、添加剂氧化镁和氧化铝对钒钛磁铁精矿的熔融还原作用明显。在添加剂作用下,1 500℃电炉冶炼10min后的熔融还原产物为含96.9%铁、0.52%钒的生铁,以及含66.13%TiO_2的熔融还原渣,实现了钒钛磁铁精矿冶炼中铁钒和钛的有效分离。     

钒钛磁铁精矿低温综合利用新工艺

为了实现钒钛磁铁精矿的低温综合利用,采取碳热钠化工艺降低还原和熔分温度,考察了铁、钒、钛的富集回收情况。结果表明,钠化剂显著改善了钒钛磁铁精矿的还原及熔分效果,当钠化比为1.2时,1 100℃还原60 min即可达到90%以上的金属化率,1 250℃以上的温度下熔分后,铁的收得率达到96%,钒在铁水中的富集率为75%。熔分渣在无酸环境下经湿法处理后TiO_2含量达到77%,经还原熔分去除铁后品位可进一步提升。     

电炉冶炼含TiO_2炉渣的熔化性温度研究及析出相矿物分析

冶炼钒钛磁铁矿新流程中的熔分渣和深还原渣的熔化性温度与(TiO_2+Ti低+Al_2O_3)/(CaO+MSO+FeO)比值呈对数正相关关系。在其它条件近似不变时,随Al_2O_3增加和TiO_2减少,渣熔化性温度由高向低变化;但当Al_2O_3含量较高时,熔化性温度会再升高。随MgO含量的增加,渣熔化性温度降低幅度较大,但当MgO含量大于20％后,渣熔化性温度会急剧升高。 析出相中以黑钛石为主,黑钛石矿物化学式中Al/Mg(原子数比)值高时,熔渣的熔化性温度高。还原渣析出相中∑TiO_2比原渣中含量富集约10个百分点。     

钒钛磁铁矿金属化球团熔分-深还原过程热量损失以及影响钒入铁因素分析

对钒钛磁铁矿金属化球团熔分-深还原过程热量损失进行了计算,讨论了熔分温度、二元碱度、熔分渣中FeO含量、钛走向以及铁水中Si含量对钒进铁影响。结果表明:熔分过程的热量损失为6.34%左右;熔分温度为1 570℃,二元碱度为1.1~1.2,熔分渣中FeO的含量为8%~12%,合理控制配碳比以及适当的提高铁水中的Si含量,有利于熔分过程中钒进铁。     

含钒电熔钛渣的物相组成

用工艺岩石学方法,研究了电熔钛渣的物相组成并认为:含钒电熔钛渣属黑钛石型钛渣,渣中钒钛主要赋存于黑钛石固溶体中;黑钛石性脆,不利选矿富集;添加磷酸,石英有助于黑钛石转变为金红石;FeO对渣中物相组成影响最明显,控制FeO 5～10％范围内,渣的物相组成最简单,对电炉熔分操作和铁与矾钛分离是适宜的。     

化学成分对中钛高炉渣矿物组成影响的热力学分析

采用FACTSage 7.0热力学软件计算了中钛高炉渣结晶过程的平衡物相组成,分析了不同化学成分对中钛渣矿物析出过程和矿物组成的影响规律。结果表明,中钛高炉渣冷却过程中析出的物相主要有黄长石、钙钛矿、尖晶石与透辉石。当碱度较低时(R0.93),渣中不存在单独的钙钛矿相。当碱度超过1.03继续增加时,黄长石含量增加,尖晶石含量降低。碱度越高越有利于钙钛矿的形成。随着TiO_2含量的增加,中钛渣中黄长石含量减少而钙钛矿含量增加;并且随着温度的降低,钛元素逐渐富集,最终转移到钙钛矿中。渣中MgO含量或Al_2O_3含量的增加,使得中钛渣矿物析出过程的变得复杂,且影响了钛元素的析出过程。     

某中低钛型钒钛磁铁矿的烧结特性及产品性能研究

以某中低钛型的钒钛磁铁精矿为对象,研究了其制粒性能、烧结特性以及烧结产品的冶金性能、物相组成和显微结构。研究结果表明,碱度由2.0降低至0.8时,烧结矿产、质量指标呈现先降低后增高的趋势;高碱度烧结矿中主要物相为钛赤铁矿、钛磁铁矿、铁酸钙、钙钛矿和橄榄石,其熔蚀状的复合铁酸钙(SFCA)充填于钛铁矿物相之间,将铁氧化物物相紧密连接;高碱度烧结矿还原度明显高于低碱度,但高碱度烧结矿的低温还原粉化性能较差。     

钒钛磁铁矿碱熔低温冶炼工艺研究

为了实现钒钛磁铁矿的低温冶炼,以NaOH为碱熔剂,采用煤基直接还原技术,研究了钒钛磁铁矿直接还原—熔分工艺。主要考察了Na/Si对钒钛磁铁矿团块金属化率及熔分效果的影响,并通过XRD分析得出了Na/Si对金属化团块及熔渣物相组成的影响。采用Factsage热力学软件对不同Na/Si下Na_2O-SiO_2-TiO_2-Al_2O_3-CaO五元相的渣系熔点进行了计算。结果表明:Na/Si越高,渣系熔点越低。NaOH可有效改善钒钛磁铁矿的直接还原和熔分效果。随着团块Na/Si的升高,团块金属化率随之升高,但升高的幅度逐渐减小。当Na/Si=5.0、直接还原温度为1 150℃、C/O=1.4、直接还原时间为30 min时,团块金属化率就达到了93.17%。随着Na/Si升高,渣铁分离越彻底,当Na/Si4.0时,熔分所得粒铁表面平整度较好,熔分钛渣中无小尺寸粒铁分散。以NaOH处理钒钛磁铁矿金属化团块所得熔分渣中钛、硅、铝大多以钠酸盐形式存在,NaOH可以有效的降低钒钛磁铁矿的还原熔分难度,在1 460℃实现熔分,促进渣铁分离。     

钒钛磁铁精矿预还原球团电炉冶炼研究

对攀西钒钛磁铁精矿球团电炉冶炼进行研究,通过还原剂作用和优化的熔融还原电炉参数,可实现钒钛磁铁精矿球团冶炼过程中铁和钒钛的分离回收,其中钒被还原后富集到生铁中,而钛富集在电炉冶炼渣中。当渣型碱度(CaO/SiO2)为1.1时,还原球团的金属化率为70%,在1 500℃熔融还原10min后,生铁中铁品位为97.96%,铁回收率可达98.81%,生铁中含钒0.36%,钒回收率可达62.42%,试验过程中炉渣流动性好。     

Influences of Technological Parameters on Smelting-separation Process for Metallized Pellets of Vanadium-bearing Titanomagnetite Concentrates

The smelting-separation process for metallized pellets of vanadium-bearing titanomagnetite concentrates was studied.The influences of smelting temperature,smelting time,and the basicity of the metallized pellet on vana-dium and iron recovery were investigated.The characteristics of titanium slag were analyzed using X-ray diffraction, energy dispersive spectroscopy,and mineralographic microscopic analysis.The results demonstrate that appropriate increases in smelting temperature and smelting time can improve the vanadium and iron recovery from metallized pel-lets and are beneficial for the slag-iron separation.Although increasing the basicity of the metallized pellet can consid-erably improve the vanadium and iron recovery,the TiO2 grade of titanium slag was decreased.Under the optimal conditions,90·17% of vanadium and 92·98% of iron in the metallized pellet were recovered,and the TiO2 grade of titanium slag was 55·01%.It was found that anosovite,augite,spinel,glassiness,and metallic iron were the main mineral phases of the titanium slag.     

Phase composition of the vanadium-containing titanium slags forming upon the reduction smelting of the titanomagnetite concentrate from the Kuranakhsk deposit

The phase composition of the vanadium-containing titanium slags that form upon the reduction smelting of the titanomagnetite concentrate from the Kuranakhsk deposit with an added CaCO₃ flux is studied by optical microscopy, X-ray diffraction, and scanning electron microscopy. The laws of formation of the phase composition and the interphase distribution of vanadium and other elements are revealed as a function the CaO and FeO contents in the slags. It is shown that, at low CaO contents (up to 5%), the phase composition of the slags containing 15–30% FeO is mainly represented by spinelides (Al-V-Cr and Al-Ti-V spinels and (Fe,Mg)₂TiO₄ ulvospinel), anosovite, and glass. When the CaO content in slag increases, titanium is fixed into perovskite. At 17–20% CaO and ≤8.3% FeO in slag, a new crystalline phase, i.e., Ca-Al-V titanate of a complex composition, forms along with perovskite, the Al-V-Cr spinel, anosovite, and glass. Vanadium in the slags is mainly distributed between anosovite, the spinelides, and the Ca-Al-V titanate, and vanadium is absent in the glassy phase.     

电炉冶炼高镁酸溶钛渣的热力学及试验研究

电炉冶炼钛铁矿制备酸溶渣时,为降低冶炼温度、保障渣的流动性,高钛渣中通常保留一定数量的氧化亚铁,导致后续钛白粉生产中产生硫酸亚铁,造成酸耗高等不利影响.针对上述问题,通过采用FactSage热力学分析结合电炉冶炼试验,研究了氧化镁对高钛渣物化性质影响规律及其降低炉渣冶炼温度的可行性.结果表明,提高氧化镁含量、降低氧化亚...     

CaO对海滨钛磁铁矿精矿直接还原?磁选工艺中还原气氛的影响

以铁品位为58.58%、TiO₂品位为12.04%的海滨钛磁铁矿精矿为试样,进行煤基直接还原–磁选试验。从反应产生的CO和CO₂气体组成、总反应的气化速率、CO分压值、金属化率、矿物组成等角度进行分析,查明了CaO在海滨钛磁铁矿精矿直接还原?磁选工艺中的作用机理。研究结果表明,CaO可以提高还原剂的气化速率,促进钛磁铁矿的还原,增加CO₂气体的产生量,从而降低CO分压值。同时发现CaO可以参与固固反应,降低含钛矿物中的FeO含量,也有利于钛、铁组分的迁移和富集,促进金属铁颗粒的聚集长大。因此,添加CaO有利于通过磨矿?磁选促进钛铁分离与回收。      

铜渣与镁渣复合改质后磁选提铁的工艺研究

将工业铜渣和工业镁渣按一定比例混合后进行复合改质,对改质后混合渣进行磁选,并通过XRD、SEM分析和热力学计算对改质前后混合渣中的物相变化特征进行研究。结果表明,复合改质能够使铜渣中弱磁性富铁相铁橄榄石向强磁性镁铁尖晶石转变,并可通过磁选进行分离。碱度的降低有利于混合渣中镁铁尖晶石形成,但不利于硅酸盐相生成。本文试验范围内碱度的最佳值为2.05,在该碱度下混合渣的磁选产率和回收率分别为65.32%和79.34%,且磁选后尾渣中硅酸盐相含量相对较多。     

Investigation of Reduction and Smelting Mechanism in the Hi‐QIP Process

A new coal‐based reduction and smelting process for production of high quality iron pebbles in a rotary hearth furnace (Hi‐QIP Process) was developed. The reduction, carburization, smelting, and separating mechanism of the Hi‐QIP process were investigated. The experiments were carried out in a graphite heater furnace under rapidly heating up to 1773 K. A mixture of coal and ore produced molten metal and slag, which were held on the coal and did not come into contact with the refractory located under the coal layer. It is confirmed that the reduction of wettability between the iron and slag promotes the separation of them, when the content of FeO slag decreases. High productivity of the process is expected when using iron ore with small particle diameter and low gangue content. Favourable operating results were obtained in a pilot test using a rotary hearth furnace with a diameter of 7 m and a width of 1.5 m. This test demonstrated the possibility of continuous production of iron pebbles with high productivity (15t‐iron/d).     

铜渣中铁硅分离的研究进展

铜渣是火法炼铜过程中产生的主要固体废弃物,其堆存处置不仅占用大量土地,对周围水和土壤也会造成污染。铜渣中Fe含量高达35%~40%,铁的提取是铜渣资源化利用的主要研究方向之一。铜渣中主要化学组成为Fe和SiO₂,主要物相为铁橄榄石和磁铁矿,因此铁硅分离是实现铁选择性提取的核心。本文回顾了目前铜渣中铁硅分离方法,主要包括磁选法、熔分法、选择性氧化-磁选法、碳热还原-磁选法、氧化焙烧-碱浸法和碳热还原-碱浸法,并对各方法的原理、研究现状及存在问题进行分析和总结。发现铜渣中单一提取铁会产生大量二次尾矿（渣）,铁硅综合提取是实现铜渣清洁、高值化利用的关键。      

Development of Intensified Technologies of Vanadium-Bearing Titanomagnetite Smelting

It was very difficult for the smelting of vanadium-bearing titanomagnetite by blast furnace because the content of TiO2 of blast furnace slag could amount to 20%-25%.After long term development and continuous improvement,special intensified smelting technologies for vanadium-bearing titanomagnetite by blast furnace were obtained and improved gradually.With the improvement of beneficiated material level and equipment level,smelting intensity has been increased gradually and the highest comprehensive smelting...     

Separation of Anosovite from Modified Titanium-Bearing Slag Melt in a Reducing Atmosphere by Supergravity

The anosovite was effectively separated from the modified titanium (Ti)-bearing slag melt in a reducing atmosphere by supergravity. The slag melt went through the filter along the supergravity direction, whereas the high-purity rod-shaped anosovite crystals of size 200 to 4000 μm were intercepted by the filter and separated from the slag melt. Moreover, the effects of slag composition and gravity coefficient on the reduction, precipitation, and separation of anosovite crystals were investigated further.     

Magnetite reduction in copper converter slag using biodiesel produced from waste cooking oil

In copper smelting process, oxygen-enriched smelting leads to the enrichment of magnetite and increase of slag viscosity, which is not conducive to the sedimentation and separation of copper. Therefore, it is necessary to reduce magnetite in order to improve the recovery rate of copper. In this work, biodiesel produced from waste cooking oil was used to replace carbon and diesel, which should be more economical and environment-friendly. Effects of temperature and reaction time on biodiesel pyrolysis, magnetite reduction and slag viscosity were studied. It was found that the main products of biodiesel pyrolysis were carbon monoxide, hydrogen, methane, and carbon. Because methane will decompose to carbon and hydrogen at 823 K, the main reducing agents during magnetite reduction were hydrogen and carbon. With increasing reduction time and temperature, the magnetite phase in the copper slag gradually decreased, while the fayalite phase gradually increased. After injecting biodiesel into molten copper slag at 1523 K for 4 minutes, magnetite was reduced from 31.6% to less than 0.6% and the viscosity decreased from 1.43 poise to 0.68 poise. This low viscosity is beneficial for separation and recovery of copper from the molten slag.