TY - THES

T1 - Testing of magnetic processability of mixed hematite-magnetite ores from Gruvberget, Northern Sweden

AU - Reisinger, Stefan

N1 - no embargo

PY - 2023

Y1 - 2023

N2 - LKAB intends to reopen Gruvberget mine in Svappavaara. As the deposit contains a significant amount of hematite and hematite-magnetite mixed ore, the processability of the ore by a sequence of Low Intensity Magnetic Separation and High Gradient Magnetic Separation was systematically tested. The raw materials analysis comprised a comparative study of 5 differing samples originating from drill cores representing the variation in Fe content and the ratio between magnetite and hematite in the deposit. Energy controlled grinding test work following a LKAB routine and subsequent Davis Tube testing at the Chair of Mineral processing showed no significant differences in the grindability between the ore types and sufficient liberation of the ferromagnetic iron oxides from the P and SiO2 carrying gangue minerals at a p80 of 45 µm. Lab scale Low Intensity Separation in two stages on 3 samples of medium iron content and varied hematite - magnetite ratio by means of a drum separator operated in con current mode prepared the subsequent HGMS stage on a matrix separator test rig installed at the Chair of Mineral Processing. After removing ferromagnetic residuals at 0.06 T background field with the ball matrix, the hematite recovery increased at stepwise increased intensity of background field (from 0.180 T to 0.579 T). The interpretation of results of mass balancing for iron oxides as well as phosphorous and silica was supported by microscopic investigation on polished sections of the magnetic fractions and SEM analysis.

AB - LKAB intends to reopen Gruvberget mine in Svappavaara. As the deposit contains a significant amount of hematite and hematite-magnetite mixed ore, the processability of the ore by a sequence of Low Intensity Magnetic Separation and High Gradient Magnetic Separation was systematically tested. The raw materials analysis comprised a comparative study of 5 differing samples originating from drill cores representing the variation in Fe content and the ratio between magnetite and hematite in the deposit. Energy controlled grinding test work following a LKAB routine and subsequent Davis Tube testing at the Chair of Mineral processing showed no significant differences in the grindability between the ore types and sufficient liberation of the ferromagnetic iron oxides from the P and SiO2 carrying gangue minerals at a p80 of 45 µm. Lab scale Low Intensity Separation in two stages on 3 samples of medium iron content and varied hematite - magnetite ratio by means of a drum separator operated in con current mode prepared the subsequent HGMS stage on a matrix separator test rig installed at the Chair of Mineral Processing. After removing ferromagnetic residuals at 0.06 T background field with the ball matrix, the hematite recovery increased at stepwise increased intensity of background field (from 0.180 T to 0.579 T). The interpretation of results of mass balancing for iron oxides as well as phosphorous and silica was supported by microscopic investigation on polished sections of the magnetic fractions and SEM analysis.

KW - martite ore

KW - Low intensity magnetic separation

KW - high gradient magnetic separation

KW - raw material analysis and processability

KW - Martit Erz

KW - Schwachfeldmagnetscheidung

KW - Hochgradientmagnetscheidung

KW - Rohgutcharakterisierung

U2 - 10.34901/mul.pub.2023.141

DO - 10.34901/mul.pub.2023.141

M3 - Master's Thesis

ER -