细粒磁铁精矿球团孔隙结构的优化研究

针对-10 μm粒级含量32.63%、比表面积2 980 cm²/g的细粒磁铁精矿,通过有机粘结剂取代部分膨润土优化细粒磁铁精矿球团的孔隙结构,从而改善了生球及成品球质量。相比单独添加1.75%的膨润土球团,配加0.05%的有机粘结剂使膨润土用量降低至0.8%,由于有机粘结剂使小颗粒团聚成较大的颗粒,使得生球的孔隙率从16.68%提高到23.15%,球团爆裂温度从370 ℃提高到500 ℃;且预热过程球团的氧化率从67.48%提高到79.08%,球团均匀氧化避免了球团焙烧时形成双层结构;同时焙烧球孔隙率从12.33%提高到16.83%,使得球团还原度从56.8%提高到69.7%。有机粘结剂部分取代膨润土成功解决了细粒磁铁精矿球团孔隙率低导致的爆裂温度低、氧化速度慢、还原性能差等问题。     

某选矿厂处理粗粒磁铁矿精矿经济分析

肃北县酒钢某磁铁矿选矿厂长期处于停产状态,为充分利用其现有资产,对途经该厂的酒钢外购粗粒磁铁精矿进行再磨再选,并进行了技术经济分析。通过分析表明,利用该选厂对粗精矿进行精选加工,精选后精矿中SiO₂含量降低约5个百分点,粒度更有利于后续的烧结作业,技术上可行,经济上有利。     

攀西地区白马辉长岩型超低品位钒钛磁铁矿选铁试验研究

论文以攀西地区白马辉长岩型超低品位钒钛磁铁矿为研究对象,查明了该矿石中化学组分、矿物组成、铁和TiO₂的相态。在此基础上进行了多粒级多磁场梯度干式磁选抛尾试验,通过铁和TiO₂的相态分析阐述了干式磁选抛尾的合理性；进行了干式磁选精矿阶段磨矿阶段选别试验,二段磁选在-200目占80%细度下获得了TFe 57.78%、TiO₂ 7.72%、V₂O₅ 0.69%的铁精矿,铁精矿产率为12.93%、铁回收率51.56%,相对磁性铁回收率为98.70%,V₂O₅回收率78.26%。结果表明该矿石虽然铁品位低,仍具综合回收利用价值。      

高压辊磨+搅拌磨在某复杂难选铁矿石选别工艺中的优越性研究

为了验证在某复杂难选铁矿石的选矿工艺中，应用高压辊磨机和立式搅拌磨的优越性，进行了一系列对比试验。结果表明，与颚式破碎机相比，高压辊磨机产品的粉矿率更高，产品的可磨性更好；与球磨机相比，立式搅拌磨机细磨效率更高、效果更好，相同磨矿细度下，立式搅拌磨机磨矿产品的解离度更高，磁选铁精矿品位也更高；高压辊磨+立式搅拌磨在处理复杂难选铁矿石方面具有显著的优势。     

某铁矿尾矿资源化利用试验研究

针对某铁矿山尾矿开展了矿石性质研究,并探索采用磁选方法从该尾矿中回收含铁矿物的可行性。物相分析结果表明,该尾矿中磁铁矿含量约为40%,且磁铁矿解离度约97%。在铁尾矿中铁品位为19.87%的情况下,无需磨矿,经过一次粗选即可获得铁品位68.96%、回收率39.40%的选别指标。     

Synthetic fayalite Fe2SiO4 by kinetically controlled reaction between hematite and silicon carbide

The present work explores the preparation of fayalite α-Fe₂SiO₄, the iron-rich end-member of the olivine solid-solution series, as a tar removal catalyst for biomass gasification. The synthetic procedure was developed starting from the stoichiometric mixture of hematite and micrometer size silicon carbide and employing thermal treatments in controlled atmospheres at 1000-1100°C supported by thermodynamic modeling to assess the required redox conditions. The treatments in dry and humidified inert gas yielded phase mixtures containing metallic Fe as one of the main phases, thus emphasizing a shortage of oxygen supply. XRD and TGA studies of precursor mixtures on heating in dry CO₂ demonstrated a multistep mechanism of the overall reaction including (a) fast reactivity between silicon carbide and hematite at ~920°C with formation of metallic Fe and amorphous silica followed by (b) formation of fayalite involving oxygen supplied in the form of CO₂ and competing with (c) over-oxidation to thermodynamically favorable Fe₃O₄+SiO₂ mixture. Comparative studies of reactivity in powdered and pelletized samples emphasized the importance of the kinetic factor in the formation of Fe₂SiO₄ while preventing further oxidation. The preferential formation of fayalite in the CO₂ atmosphere is shown to be favored by shorter treatments of compacted samples at higher temperatures. The procedure was designed (2-step heating to 1100°C in CO₂ followed by fast cooling) for the preparation of pelletized fayalite α-Fe₂SiO₄ catalyst with only minor traces of surface over-oxidation which can be suppressed by adding 10 vol.% of forming gas to CO₂ flow.     

The isothermal reduction kinetics of chromium-bearing vanadium–titanium magnetite sinter

The reduction of chromium-bearing vanadium–titanium magnetite sinter (CVTMS) by CO was investigated at 1123–1223?K. The reduction degree increased with increasing temperature. The isothermal reduction kinetics of CVTMS was analysed, according to Sharp analysis and ln–ln analysis, the kinetic mechanism of reduction process for all samples in different basicity can be represented as f(α)?=?1.61(1?α)[?ln(1?α)]^1–1/1.61. The reaction activation energy of all samples (R?=?1.9, 2.1, 2.3, obtained according to the components of the materials burdening used in sintering process) at different reaction degrees were calculated by the model-free method. And the pre-exponential factors of reaction also were calculated by the mathematical method. The rate controlling step for the reduction process under the present reduction condition was chemical reaction.     

战略性稀有金属资源绿色高值利用技术进展

从资源紧缺、环境污染、产品低端等方面，总结了我国钒、钛、镍、钴、锂稀有金属资源在战略性新兴产业迅猛发展时代所面临的国家重大需求，回顾了领域近年来通过升级和变革传统稀有金属资源利用技术取得的主要进展和成就。其中煤基钠化冶炼、高温碳化?低温氯化、亚熔盐氧化等非常规介质强化手段是实现钒钛磁铁矿中钒、钛绿色高值高效利用的核心；盐酸常压浸出?低温选择性水解?共沉淀新技术是一种低成本、短流程高效高值利用红土镍矿全组分的先进技术代表；双功能协同复合萃取原理是实现高镁盐湖卤水的锂资源绿色利用的关键基础。基于固废资源化和源头减废两个思路，现阶段战略性金属资源的利用技术初步解决了环境污染和资源利用率低的问题，但仍存在资源绿色利用基础原理匮乏、产品科技含量低等普遍问题。以战略性产业关键材料为导向的绿色高值利用技术的应用基础研究是稀有金属相关绿色产业战略性发展的重要科技保障，是未来重要的前沿研究方向。     

基于DEA的钒钛磁铁矿开发效率评价—以攀西地区为例

矿产资源是社会重要的自然资源。矿产资源开发效率评价对助推矿业升级改造、提高资源利用水平具有重要的意义。本文从投入产出的角度,对钒钛磁铁矿资源开发效率影响因素进行了分析,构建了以注册资金、技术人员比、使用土地面积为投入指标,以工业总产值、年利税总额、治理土地面积为产出指标的指标体系,以矿山为评价单元,采用数据包络分析(DEA)来确定各级效率前沿面,对各个钒钛磁铁矿矿山开发效率进行划分。最后以攀西地区为例,验证了指标体系与评价方法的有效性,得出矿山的有效状态和优化方向,为有针对性的矿产开发提供一定的参考性建议。     

电感耦合等离子体原子发射光谱法测定钒钛磁铁矿中锌

钒钛磁铁矿中含有一定量的锌,在高炉冶炼过程中,锌被还原成金属锌,而金属锌会侵蚀炉体的耐火材料,因此在钒钛磁铁矿冶炼中锌是一种有害元素,需要对进入炉体中锌的含量进行严格控制。试样采用盐酸-硝酸-氢氟酸-高氯酸体系溶解,选择Zn 206.200nm作为分析谱线,采用基体匹配法绘制校准曲线消除基体效应的影响,使用电感耦合等离子体原子发射光谱法(ICP-AES)测定钒钛磁铁矿中锌。锌含量为0.01%~0.05%(质量分数)时与其发射强度呈线性,相关系数为0.9999;方法检出限为0.0030μg/mL。按照实验方法测定两个钒钛磁铁矿样品中锌,结果的相对标准偏差(RSD,n=10)小于1%;加标回收率为98%~102%。