赤铁矿磁化焙烧过程中增磁剂量的确定

本文论述赤铁矿在磁化焙烧过程中的增磁措施，它是在竖炉还原段内设置增磁段且通入适量增磁剂来实现的。增磁剂则由焙烧矿在冷却过程中产生的水蒸气和外加的焦炉煤气组成的。因此，确定水蒸气发生量和焦炉煤气添加量．乃是本文所要解决的技术课题。     

SLon型磁选机在齐大山选矿厂的应用

SLon立环脉动高梯度磁选机是新一代高效强磁选设备，具有富集比大，选矿效率高，磁介质不易堵塞，设备工作稳定的优点，2001年鞍钢齐大山选矿厂在重选-强磁-反浮选技改中采用该机控制细粒赤铁矿尾矿品位获得成功，全流程的选矿指标为：给矿品位30.15%，铁精矿品位67.00%，尾矿品位11.05%，铁回收率75.86%，选矿指标创厂历史新高。     

南芬选矿尾矿回收铁金属的初步研究

本文通过对南芬选矿厂尾矿进行的工艺矿物学研究，表明尾矿中的铁金属主要以磁铁矿和赤铁为主，并且在-200目级别中单体解离度较高，具有回收价值。用强磁选进行初步富集和用摇床进行精选的试验表明，每年可获得初级铁精矿40多万t。     

滇东北黑树地区硫磺渣工艺矿物学特征

通过化学元素分析、物相分析、XRD试验、镜下鉴定和电子探针等手段对云南省镇雄县黑树地区硫磺渣开展了工艺矿物学研究。结果表明:试样中含铁主要有用矿物为赤铁矿(18.04%)和磁铁矿(3.90%),脉石矿物包括莫来石(23.70%)、透长石(18.26%)、石英(14.18%)、方石英(6.86%)、石膏(5.52%)、脱硫不完全矿物磁黄铁矿及残留黄铁矿(2.44%)。有用矿物赤铁矿粒度细小,疏松多孔,与脉石矿物共生关系复杂,电子探针数据表明赤铁矿含有Al、Ti、Si和Mg等杂质元素。在-0.043 mm80%条件下,赤铁矿单体解离度为68.52%,在选矿过程中需提高研磨细度使其与脉石矿物充分解离。大部分脉石矿物可通过磁-重法抛除,残留黄铁矿需要通过浮选法去除。含钛有用矿物主要为锐钛矿和钛铁矿,其中锐钛矿主要存在于细粒的渣土中,选钛工作还需进一步研究。     

磁选-阴离子反浮选工艺应用现状及展望

通过我国铁矿石资源与国外主要铁矿生产国铁矿石资源情况的对比,阐述我国铁矿石因具有储量大、品质差的特点必须加强选矿研究工作的重要性。介绍了国内一些选矿厂实施以“磁选-阴离子反浮选”选别工艺为核心的工艺流程的研究过程及效果,分析了“磁选-阴离子反浮选”选别工艺的特点,提出今后如何更加优化以“磁选-阴离子反浮选”选别工艺为核心的相关工艺流程和更好地在全国范围内推广这一工艺的建议。     

钙 镁离子对石英 赤铁矿凝聚与絮凝的作用

本文对钙、镁离子影响石英、赤铁矿凝聚与絮凝的作用进行了较为详细的考察研究。试验表明:钙、镁离子能大幅度地提高石英的凝聚与絮凝作用,它们对赤铁矿的凝聚与絮凝作用影响较小,从而大大缩小了絮凝剂5~#对它们絮凝能力和絮凝选择性的差异,不利于石英、赤铁矿的絮凝分选。     

TGA kinetic study on the hydrogen reduction of an iron nickel oxide

Reduction of a mixed iron nickel oxide by hydrogen to produce ferronickel alloy was investigated by thermo-gravimetric analysis (TGA). The iron nickel oxide, which contains 50 wt% Fe and 10 wt% Ni mainly in the form of hematite (Fe₂O₃) and nickel ferrite (NiFe₂O₄), is a residue produced from the water leaching of a selectively sulfation roasted nickel calcine. Continuous heating tests with a fixed heating rate as well as isothermal tests were performed. Results indicate that the reduction of the mixed oxide began above 350 °C. The reduction reactions occurred in a non-topochemical mode at low temperatures between 350 °C and 600 °C with its rate controlled by the solid–gas chemical reactions. The reduction rate increased with the increase in temperature from 350 °C up to 1100 °C. Between 600 °C and 1200 °C, the rate controlling step was the diffusion of reducing gas through the pores of the sample bed with an apparent activation energy of 34.1 kJ/mol. Due to the melting of the silicate material at 1200 °C which substantially reduced the sample porosity, the reduction rate decreased. Above 1200 °C, the reduction rate increased again due to the increased diffusion of the reducing gas through the molten sample at higher temperatures.     

Plasma-chemical reduction of iron oxide photoanodes for efficient solar hydrogen production

We demonstrate the effect of hydrogen plasma treatment on hematite films as a simple and effective strategy for modifying the existing substrate to improve significantly the band edge positions and photoelectrochemical (PEC) performance. Plasma treated hematite films were consist of mixed phases (Fe₃O₄:α-Fe₂O₃) which was confirmed by XPS and Raman analysis, treated films also showed higher absorption cross-section and were found to be a promising photoelectrode material. The treated samples showed enhance photocurrent densities with maximum of 3.5 mA/cm² at 1.8 V/RHE and the photocurrent onset potentials were shifted from 1.68 V_RHE (untreated) to 1.28 V_RHE (treated). Hydrogen plasma treatment under non-equilibrium conditions induced a valence dynamics among Fe centers in the sub-surface region that was sustained by the incorporation of hydrogen in the hematite lattice as supported by the density functional theory calculations.     

Ultrathin hematite films deposited layer-by-layer on a TiO2 underlayer for efficient water splitting under visible light

Ultrathin hematite (α-Fe₂O₃) film deposited on a TiO₂ underlayer as a photoanode for photoelectrochemical water splitting was described. The TiO₂ underlayer was coated on conductive fluorine-doped tin oxide (FTO) glass by spin coating. The hematite films were formed layer-by-layer by repeating the separated two-phase hydrolysis-solvothermal reaction of iron(III) acetylacetonate and aqueous ammonia. A photocurrent density of 0.683 mA cm⁻² at +1.5 V vs. RHE (reversible hydrogen electrode) was obtained under visible light (>420 nm, 100 mW cm⁻²) illumination. The TiO₂ underlayer plays an important role in the formation of hematite film, acting as an intermediary to alleviate the dead layer effect and as a support of large surface areas to coat greater amounts of Fe₂O₃. The as-prepared photoanodes are notably stable and highly efficient for photoelectrochemical water splitting under visible light. This study provides a facile synthesis process for the controlled production of highly active ultrathin hematite film and a simple route for photocurrent enhancement using several photoanodes in tandem.     

东鞍山含菱铁矿赤铁矿石分级浮选试验研究

东鞍山烧结厂矿石铁品位为32.45%,具有贫铁、高硅的特点,主要铁矿物为赤铁矿,主要脉石矿物为石英,同时含有少量的菱铁矿和磁铁矿,是一种含菱铁矿赤铁矿石。对磨矿细度为-0.074 mm占70%的产品筛分分析表明,随着粒度的增加,各粒级铁品位逐渐增大,铁矿物单体解离度逐渐减小。在该磨矿细度下进行分级浮选闭路试验,-0.074 mm粒级以柠檬酸为分散剂、氧化钙为活化剂、淀粉为抑制剂、KS-Ⅲ为捕收剂,+0.074 mm粒级以淀粉为抑制剂、十二胺为捕收剂,可获得精矿铁品位63.30%和铁回收率71.32%的浮选指标。与全粒级浮选相比,分级浮选可减弱微细粒矿物的黏附罩盖,提高浮选指标。