TY - THES

T1 - Raw Material Characterization of a Martite Ore: Case Study Kiirunavaara Deposit; Sweden

AU - Wartbichler, Manuel

N1 - embargoed until 17-06-2019

PY - 2014

Y1 - 2014

N2 - Luossavaara Kiirunavaara AB (LKAB) is operating several iron ore mines, benefication plants and pelletizing plants in the northern part of Sweden. The largest and best known of them is the Kiirunavaara deposit with an underground production rate of approximately 27 Mt crude ore annually. The iron ore at Kiirunavaara, consists mainly of magnetite, apatite and silicates. However, several million tons of hematite – magnetite (i.e. martite) ore was recently explored in the northern most part of the deposit. The work aims to provide a systematic ore characterization of the martite ore from Kiirunavaara with regard to processing purposes, to describe the ore properties by physical parameters and to derive a first concept for processing the hematite. For the systematic approach the method taught at the Institute of Mineral Processing of the Montanuniversitaet Leoben was used. It combines defined comminution tests with property analysis and mineralogical investigations. For the mineralogical investigation LKAB offered the opportunity to use the technology available in their laboratories (image analysis and QEMSCAN®). For the stepwise comminution of the ore sample the Optimized Comminution Sequence (OCS) was used, which provides a set of reproducible particle size distributions in the Natural Breakage Characteristic. As comparative material for the OCS, a sample of marite ore from Malmberget was used, which reflects the feed of an already existing plant. Selected particle size classes were subdivided into subsets of defined apparent susceptibility by means of the so called pick-up method. Four methods (Satmagan, chemical analysis, image analysis and QEMSCAN®) were selected for the comparative discrimination of hematite from magnetite. The results of the wet assays served as a standard. Good correlation was found for the physical method consisting of the determination of magnetite by a magnetic balance and calculation of a normative mineral distribution of magnetite, hematite and gangue minerals by the minerals` densities. The image analysis discriminating hematite from magnetite by grey scale revealed hematite contents in good agreement with the wet assays while the magnetite was a little bit underestimated. There was no correlation to be found with chosen settings with QEMSCAN®. The liberation of magnetite from hematite and the intergrowth of the oxide phases with the gangue were evaluated by Henry Reinhardt charts. By the relation between mineral composition and the apparent susceptibility of the minerals the best possible separation result by means of magnetic separation can be predicted.

AB - Luossavaara Kiirunavaara AB (LKAB) is operating several iron ore mines, benefication plants and pelletizing plants in the northern part of Sweden. The largest and best known of them is the Kiirunavaara deposit with an underground production rate of approximately 27 Mt crude ore annually. The iron ore at Kiirunavaara, consists mainly of magnetite, apatite and silicates. However, several million tons of hematite – magnetite (i.e. martite) ore was recently explored in the northern most part of the deposit. The work aims to provide a systematic ore characterization of the martite ore from Kiirunavaara with regard to processing purposes, to describe the ore properties by physical parameters and to derive a first concept for processing the hematite. For the systematic approach the method taught at the Institute of Mineral Processing of the Montanuniversitaet Leoben was used. It combines defined comminution tests with property analysis and mineralogical investigations. For the mineralogical investigation LKAB offered the opportunity to use the technology available in their laboratories (image analysis and QEMSCAN®). For the stepwise comminution of the ore sample the Optimized Comminution Sequence (OCS) was used, which provides a set of reproducible particle size distributions in the Natural Breakage Characteristic. As comparative material for the OCS, a sample of marite ore from Malmberget was used, which reflects the feed of an already existing plant. Selected particle size classes were subdivided into subsets of defined apparent susceptibility by means of the so called pick-up method. Four methods (Satmagan, chemical analysis, image analysis and QEMSCAN®) were selected for the comparative discrimination of hematite from magnetite. The results of the wet assays served as a standard. Good correlation was found for the physical method consisting of the determination of magnetite by a magnetic balance and calculation of a normative mineral distribution of magnetite, hematite and gangue minerals by the minerals` densities. The image analysis discriminating hematite from magnetite by grey scale revealed hematite contents in good agreement with the wet assays while the magnetite was a little bit underestimated. There was no correlation to be found with chosen settings with QEMSCAN®. The liberation of magnetite from hematite and the intergrowth of the oxide phases with the gangue were evaluated by Henry Reinhardt charts. By the relation between mineral composition and the apparent susceptibility of the minerals the best possible separation result by means of magnetic separation can be predicted.

KW - LKAB

KW - Kiruna

KW - Martit

KW - QEMSCAN

KW - Magnetit

KW - Hematit

KW - Anhebemethode

KW - Bildanalyse

KW - Leoben

KW - LKAB

KW - Kiruna

KW - Martite

KW - Magnetite

KW - Hematite

KW - QEMSCAN

KW - pick-up method

KW - Satmagan

KW - image analysis

KW - Leoben

M3 - Master's Thesis

ER -