工程科学学报2026，Vol.48Issue(2)：293-302,10.DOI:10.13374/j.issn2095-9389.2025.04.30.003
氢基预还原铬铁矿的还原进程与固结机理研究
Reduction and consolidation mechanisms of hydrogen-based pre-reduced chromite pellets
摘要
Abstract
Ferrochrome alloy is a critical raw material in the production of stainless steel,corrosion-resistant steels,and high-temperature alloys,and its global demand is continuously rising.However,its production is highly energy-intensive,owing to the high-temperature required for reducing Cr2O3(>1600℃)and the elevated melting point of chromium-containing melts(1900-2050 °C).Pre-reduction of chromite ore is an effective approach to lower the energy consumption and carbon emissions in ferrochrome production.Currently,carbon-bearing pellet oxidation roasting remains the mainstream method,which results in high energy use and CO2 emissions.With the advancement of hydrogen metallurgy and the"dual carbon"policy framework,hydrogen-based pre-reduction processes for chromite are gaining strategic significance.In this study,chromite pellets were pre-reduced using a horizontal tube furnace.A custom-developed proton flow meter was employed in combination with a multi-gas mixing system to precisely control the furnace atmosphere.Pellets were first heated to the target temperature under an argon atmosphere,and isothermally reduced in a H2-CO mixed gas a tmosphere;subsequently,argon was reintroduced during cooling of pellets to room temperature for preventing reoxidation.The effects of reduction parameters—H2∶CO ratio,temperature,and time—on iron metallization rate,Fe2+conversion,and compressive strength were systematically investigated.Compressive strength of the reduced pellets was tested using a universal testing machine in accordance with the national standard GB/T 14201-2018.The mineral phase transformation and microstructural evolution mechanisms were analyzed using chemical analysis,X-ray diffraction(XRD),and scanning electron microscopy(SEM),revealing the synergistic mechanism between reduction and consolidation.The results show that the reduction temperature,time,and H2∶CO ratio positively correlated with the iron metallization and deoxygenation rates.Under pure H2 at 1300 °C for 3 h,the Fe metallization rate reached 85.9%.XRD and SEM analyses revealed that the chromite phase exhibits a complex spinel structure of the form(Mg,Fe)(Cr,Fe,Al)2O4.Fe atoms at Fe3+sites were preferentially reduced,whereas Cr reduction was limited,indicating the relatively weak reducing ability of H2 for Cr.Pellet strength initially increased with iron metallization and then declined.The strength enhancement was mainly attributed to the bonding between molten metallic Fe and the bonding phase at high temperatures.When the reduction temperature exceeded 1200 °C,the average compressive strength of the pellets remained above 1000 N,meeting the criteria for furnace charging.However,excessive metallization led to Fe2+depletion in the bonding phase,elevating its melting point,weakening interparticle bonding,and thus decreasing pellet strength.The reduction process of chromite pellets can be divided into four distinct stages:preheating,solid-state reduction,softening and consolidation,and over-reduction-induced weakening.This study is expected to provide theoretical support for the development of hydrogen-based pre-reduction processes for chromite ore.关键词
铬铁矿/氢气/预还原/还原进程/固结机理Key words
chromite/hydrogen/pre-reduction/reduction process/consolidation mechanism分类
矿业与冶金引用本文复制引用
李越,张延玲,武绍文,马立群..氢基预还原铬铁矿的还原进程与固结机理研究[J].工程科学学报,2026,48(2):293-302,10.基金项目
中国宝武低碳冶金创新基金资助项目(BWLCF202204) （BWLCF202204）
