magistrsko delo
Viktorija Musa (Author), Matej Dolenec (Mentor), Uroš Herlec (Co-mentor)

Abstract

Red mud (RM) is a byproduct of the extraction of alumina from bauxite. Red mud contains large amounts of alkali-forming minerals and metal ions that can cause significant environmental damage. Many valuable components such as rare earths, Al, and Fe in RM are difficult to recycle due to their particle size and alkalinity. Therefore, developing an economical and efficient technology to consume a large amount of RM can efficiently solve the problem of disposing of RM. RM samples from the landfill in Podgorica, Montenegro, were analyzed by XRF and XRD to determine the mineral and chemical composition. A test was performed to determine at which slurry densities deposition occurs most rapidly, and SEM/EDS to determine mineral composition and microstructure. Serial tests of HGMS, MGS of representative Podgorica red mud will also be performed. XRF analysis determined major, minor, and trace element levels, with the highest concentration of Fe being 28,6 %. We confirmed this by analyzing other fresh samples, which also had the highest Fe levels. By XRD analysis, hematite was found to occur at an average concentration of 36.5 %. An amorphous phase was also analyzed, which averaged 21.4 %, showing us that in the red mud samples tested, the amorphous phase accounted for 21 %, while the crystalline phase accounted for 79 %. During settling test, it was found that sedimentation is easier when the density of the red mud suspension is lower. The mineral composition and structure of elements were determined by SEM/EDS analysis. The grain range is 50 ? 1 µm, and the analysis also determined the grains, whose obliquity probably hinder favorable separation of these grains. In PCA analysis the core samples are divided into 4 groups. The first group consists of samples extremely rich in Fe, Mn, Zr, Ti, Zn, V and Cr, where these elements bind to Hem, Ant and Ilm. Box and Whiskers showed the same results as PCA analysis, while the Kruskal-Wallis test shown differences between groups for Cal, Ilm, Bhm, S, Ca and Al. PCA analysis was also performed on 10 additional samples. The highest values of Hem are shown by the results done in Leoben - HGMS analysis, on a sample taken from the landfill surfaces, average a bit coarser material compared to one taken for Belgrade HGMS tests, specificly concentrate RM216/218/219.

Keywords

Red mud;valuable elements;iron;hematite;

Data

Language: English
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL NTF - Faculty of Natural Sciences and Engineering
Publisher: [V. Musa]
UDC: 55
COBISS: 115338755 Link will open in a new window
Views: 59
Downloads: 38
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Other data

Secondary language: Slovenian
Secondary title: characterization and examination of possibility of extracting hematite concentrate of Podgorica red mud landfill in Montenegro
Secondary abstract: Rdeči mulj je stranski produkt ekstrakcije glinice iz boksita. Vsebuje velike količine mineralov, ki tvorijo lužine in kovinske ione, kar lahko povzroči znatno škodo okolju. Številne dragocene sestavine v rdečem mulju, kot so redke zemlje, Al in Fe, je težko uporabiti zaradi velikosti delcev in alkalnosti. Razvoj ekonomične in učinkovite tehnologije za ponovno uporabo rdečega mulja bi tako rešil težave s odlaganjem rdečega mulja. Vzorce rdečega mulja z odlagališča v Podgorici v Črni Gori, smo analizirali z metodama XRD, in XRF za določitev mineralne in kemične sestave, s posedalnim testom za določitev gostote suspenzije, pri kateri je posedanje delcev najhitrejše, z SEM/EDS za določanje mineralne sestave in mikrostrukture. Izveden je bil tudi test HGMS in MGS reprezentativnega podgoriškega rdečega mulja. .Z XRF analizo smo ugotovili vsebnost glavnih, stranskih in slednih elementov, med katerimi železo predstavlja najvišjo koncentracijo in sicera 28.6 %, kar je bilo potrjeno z analizo svežih vzorcev, ki so prav tako pokazali visoke vrednosti Fe. Z analizo XRD smo ugotovili, da se hematit pojavlja s povprečno vsebnostjo 36,5 %. Določena je bila tudi amorfna faza, kjer je bilo ugotovljeno, da znaša v povprečju 21,4 %, posledično je kristalne faze 78,6 %. Med posedalnim testom smo ugotovili, da je sedimentacija hitrejša pri manjših gostotah suspenzije rdečega mulja. Mineralno sestavo in strukturo elementov smo določili s SEM/EDS analizo. Razpon velikosti zrn je od 50 ⡤ 1 μm, med analizo smo določili tudi obliko zrn, ki verjetno otežujejo ugodno ločevanje zrn. S pomočjo PCA analize smo vzorce jedra razdelili v štiri skupine. Prvo skupino sestavljajo vzorci, ki so izjemno bogati s Fe, Mn, Zr, Ti, Zn, V i Cr in se, ti elementi vežejo na Hem, Ant i Ilm. Skatlaz-brki diagrami podajo enake rezultate kot analiza PCA, medtem ko smo z neparametrično metodo-Kruskal-Wallisovovim testom pokazali razlike med skupinami za Cal, Ilm, Bhm, S, Ca in Al. Analiza PCA je bila izvedena tudi na dodatnih vzorcih, kjer smo ugotavljali razlike med vhodnim in izhodnim materialov ter njihovo mineralno sestavo vsebnosti. Najvišje vrednosti Hem smo izmerili v površinskih vzorcih odlagališča Leobna (HGMS), na vzorcu, odvetem s površin odlagališća, povprečje nekoliko grobega materiala v primerjavi z Beograjskimi HGMS testi, natančneje koncentrati RM216/218/219.
Secondary keywords: rdeči mulj;redke zemlje;železo;hematit;
Type (COBISS): Master's thesis/paper
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Naravoslovnotehniška fak., Oddelek za geologijo
Pages: XV, 69 str.
ID: 15730061