Lingwa Agħżel:
Il-mineral tal-ħadid huwa r-raba ' element l-aktar komuni fil-qoxra tad-dinja. Il-ħadid huwa essenzjali għall-manifattura tal-azzar u għalhekk materjal essenzjali għall-iżvilupp ekonomiku globali. Il-ħadid jintuża wkoll ħafna fil-kostruzzjoni u l-manifattura tal-vetturi. Il-bi ċċa l-kbira ta ' riżorsi ta ' minerali tal-ħadid huma magħmulin minn formazzjonijiet ta ' ħadid banded (BIF) li fih il-ħadid jinstab komunement fil-forma ta ' ossidi, idrossidi u sa ċertu punt il-karbonati.
Il-kompo żizzjoni kimika tal-minerali tal-ħadid għandha firxa wiesgħa apparenti fil-kompo żizzjoni kimika speċjalment għall-kontenut ta ' FE u l-minerali tal-gangue assoċjati. Minerali kbar tal-ħadid assoċjati mal-bi ċċa l-kbira tal-minerali tal-ħadid huma hematite, goethite, limonite u manjetite. Il-kontaminanti ewlenin fil-minerali tal-ħadid huma SiO2 u Al2O3. Is-silika tipika u l-alumina li jġorru l-minerali preżenti fil-minerali tal-ħadid huma l-kwarz, kaolinite, gibbsite, il-pori tad-dijaspora u l-korundun. Minn dawn ta ' spiss jiġi osservat li l-kwarz huwa l-mineral prinċipali li jkollu l-silica u l-kaolinite u l-gibbsite huma l-minerali taż-żewġ l-alumina prinċipali li jġorru.
L-estrazzjoni tal-minerali tal-ħadid titwettaq prinċipalment permezz ta ' operazzjonijiet ta ' tħaffir fil-minjieri miftuħa, li jirriżultaw f ' ġenerazzjoni sinifikanti ta ' truf. Is-sistema ta ' produzzjoni ta ' minerali tal-ħadid normalment tinvolvi tliet stadji: Minjieri, proċessar u attivitajiet ta ' petizzanti. Ta ' dawn il-, l-ippro ċessar jiżgura li jinkiseb grad adegwat ta ' ħadid u kimika qabel l-istadju ta ' petizzanti. L-ippro ċessar jinkludi tgħaffiġ, Klassifikazzjoni, Tħin, and concentration aiming at increasing the iron content while reducing the amount of gangue minerals. Kull depożitu minerali għandu l-karatteristi ċi uniċi tiegħu rigward il-minerali li jġorru l-ħadid u l-gangue, u għalhekk teħtieġ teknika ta ' konċentrazzjoni differenti.
Magnetic separation is typically used in high-grade iron ore beneficiation where the dominant iron minerals are ferro and paramagnetic. Separazzjoni manjetika b ' intensità baxxa mxarrba u niexfa (LIMS) tekniki huma użati għall-proċess ta ' minerali bi proprjetajiet manjetiċi qawwija bħal manjetite filwaqt li s-separazzjoni manjetika ta ' intensità għolja mxarrba hija użata biex tissepara l-minerali li jġorru l-FE bi proprjetajiet manjetiċi dgħajfa bħal hematite mill-minerali tal-gangue. Minerali tal-ħadid tali goethite u limonite huma komunement misjuba fil-trufijiet u ma jisseparax tajjeb ħafna minn kwalunkwe teknika.
Il-flotazzjoni tintuża biex tnaqqas il-kontenut tal-impuritajiet fil-minerali tal-ħadid ta' grad baxx. Iron ores can be concentrated either by direct anionic flotation of iron oxides or reverse cationic flotation of silica, however reverse cationic flotation remains the most popular flotation route used in the iron industry. The use of flotation its limited by the cost of reagents, the presence of silica and alumina-rich slimes and the presence of carbonate minerals. Madanakollu, flotation requires waste water treatment and the use of downstream dewatering for dry final applications.
The use of flotation for the concentration of iron also involves desliming as floating in the presence of fines results in decreased efficiency and high reagent costs. Desliming is particularly critical for the removal of alumina as the separation of gibbsite from hematite or goethite by any surface-active agents is quite difficult. Most of alumina bearing minerals occurs in the finer size range (<20um) allowing for its removal through desliming. Overall, a high concentration of fines (<20um) and alumina increases the required cationic collector dose and decreases selectivity dramatically. Therefore desliming increases flotation efficiency, but results in a large volume of tailings and in loss of iron to the tailings stream.
Dry processing of iron ore presents an opportunity to eliminate costs and wet tailings generation associated with flotation and wet magnetic separation circuits. STET has evaluated several iron ore tailings and run of mine ore samples at bench scale (pre-feasibility scale). Significant movement of iron and silicates was observed, with examples highlighted in the table below.
The results of this study demonstrated that low-grade iron ore fines can be upgraded by means of STET tribo-electrostatic belt separator. Based on STET experience, the product recovery and/or grade will significantly improve at pilot scale processing, as compared to the bench-scale test device utilized during these iron ore trials.
The STET dry electrostatic fine iron ore separation process offers many advantages over traditional wet processing methods, such as magnetics or flotation, including:
Contact us to learn more about dry processing of iron ore.
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