Use of Mineral Liberation Analysis (MLA) in the Characterization of Lithium-Bearing Micas

Abstract

The capabilities and opportunities of the application of automated mineralogy for the characterization of lithium-bearing zinnwaldite-micas are critically assessed. Samples of a crushed greisen-type ore comprising mostly of quartz, topaz and zinnwaldite (Li-rich mica) were exposed to further comminution by cone crusher and high voltage pulse power fragmentation. Product properties were analyzed by using a Mineral Liberation Analyser (MLA) and the obtained mineralogical and mineral processing relevant parameters were carefully evaluated with special focus on the characteristics of zinnwaldite. The results illustrate that both samples contain a significant quantity of very fine particles that are products of comminution. The modal mineralogy in the different sieve fractions is characterized by the accumulation of minerals of low hardness in the finest fraction and the enrichment of topaz, having a high hardness, in the somewhat larger fractions. Based on the results of mineral association data for zinnwaldite, a displacement of the muscovite-quartz ratio, in comparison to the results of modal mineralogy, was observed by indicating good quartz-zinnwaldite boundary breakage and weak muscovite-zinnwaldite breakage. Liberation as well as mineral grade recovery curves indicate that fraction -1000 to +500 µm is most suitable for beneficiation. The results of this study demonstrate that SEM-based image analysis, such as MLA, can effectively be used to investigate and evaluate phyllosilicate minerals in a fast and precise way. It is shown that the results of MLA investigations, such as modal mineralogy, are in good agreement with other analytical methods such as quantitative X-ray powder diffraction.

Application of Composite Powders Recycled from Graphite Tailings in Styrene-Butadiene Rubber

“…10,11 As is shown in Table III, the main minerals in the composite powder are graphite, mica (muscovite and biotite), quartz and feldspar, with the content of graphite close to two-thirds of the total. In addition, a small amount of calcite, hornblende, pyrite and kaolinite were also found in the composite powder.…”

MLA-based partition curves for magnetic separation

“…Due to its relatively high content in iron (ca. 12 wt% Fe), zinnwaldite can be enriched by magnetic separation (Botula et al, 2005;Leißner et al, 2012;Sandmann and Gutzmer, 2013). Enrichment of zinnwaldite by magnetic separation is a favorable choice because the greisen ore contains other strongly paramagnetic minerals, namely limonite and columbite (Bleil and Petersen, 1982;Rosenblum and Brownfield, 1999) only in very minor amounts.…”

“…Collected EDX-spectra are then classified using a list of mineral spectra collected by the user. More detailed information about functionality of the MLA system can be found in (Fandrich et al, 2007) and (Gu, 2003), a description of the exact analytical procedure is provided by Sandmann and Gutzmer (2013). MLA measurements were carried out at the Geometallurgy Laboratory at Technische Universität Bergakademie Freiberg.…”

Characterization and Separation Studies of a Fine Sedimentary Phosphate Ore Slime

“…It should be noted that theoretical grade-recovery curves are defined for the value minerals (e.g., apatite) and not based on a final product to be recovered. Furthermore, it is important to advise that the theoretical grade-recovery curve provided by the MLA is generated from 2D liberation measurements and, therefore, overestimate the true liberation by a certain amount [20]. Nevertheless, the theoretical grade-recovery The particle density distribution results ( Figure 3) show that about 45% of the particles have density distributed in a range of 3.1-3.2 g/cm 3 .…”

“…It should be noted that theoretical grade-recovery curves are defined for the value minerals (e.g., apatite) and not based on a final product to be recovered. Furthermore, it is important to advise that the theoretical grade-recovery curve provided by the MLA is generated from 2D liberation measurements and, therefore, overestimate the true liberation by a certain amount [20].…”