The Experts below are selected from a list of 3180 Experts worldwide ranked by ideXlab platform
Haifeng Wang - One of the best experts on this subject based on the ideXlab platform.
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Liberation characteristics of coal middlings comminuted by jaw crusher and ball mill
International journal of mining science and technology, 2013Co-Authors: Yaqun He, Linhan Ge, Yajun Huang, Haifeng WangAbstract:Abstract The associated Minerals make coal middlings possess a relatively high ash content. Subsequent Liberation through size reduction can cause recovery increase. However, effect of comminution facilities on Mineral Liberation of middlings was ignored. This paper studied the Liberation characteristics of middlings crushed with different kinds of fragmentation forces. Middlings of −3 mm + 0.5 mm sampled from a dense medium cyclone were comminuted by a jaw crusher and a ball mill to −0.5 mm with similar size distribution respectively. The generating mechanism of fines was also analyzed. Full densimetric analyses indicate that Mineral Liberation of the product crushed by the jaw crusher is better than that by the ball mill at each fraction. For sizes of −0.125 mm + 0.074 mm and −0.074 mm, yields of the product with ash content 11% comminuted by jaw crusher are nearly 20% higher than that by the ball mill. Sectional micrographs observed by the scanning electron microscopy (SEM) also show the same law for these two fractions and some intergrowth particles still exist in the fraction of −0.5 mm + 0.25 mm.
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Liberation characteristics of coal middlings comminuted by jaw crusher and ball mill
International journal of mining science and technology, 2013Co-Authors: Yaqun He, Linhan Ge, Yajun Huang, Haifeng WangAbstract:Abstract The associated Minerals make coal middlings possess a relatively high ash content. Subsequent Liberation through size reduction can cause recovery increase. However, effect of comminution facilities on Mineral Liberation of middlings was ignored. This paper studied the Liberation characteristics of middlings crushed with different kinds of fragmentation forces. Middlings of −3 mm + 0.5 mm sampled from a dense medium cyclone were comminuted by a jaw crusher and a ball mill to −0.5 mm with similar size distribution respectively. The generating mechanism of fines was also analyzed. Full densimetric analyses indicate that Mineral Liberation of the product crushed by the jaw crusher is better than that by the ball mill at each fraction. For sizes of −0.125 mm + 0.074 mm and −0.074 mm, yields of the product with ash content 11% comminuted by jaw crusher are nearly 20% higher than that by the ball mill. Sectional micrographs observed by the scanning electron microscopy (SEM) also show the same law for these two fractions and some intergrowth particles still exist in the fraction of −0.5 mm + 0.25 mm.
Yaqun He - One of the best experts on this subject based on the ideXlab platform.
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Liberation characteristics of coal middlings comminuted by jaw crusher and ball mill
International journal of mining science and technology, 2013Co-Authors: Yaqun He, Linhan Ge, Yajun Huang, Haifeng WangAbstract:Abstract The associated Minerals make coal middlings possess a relatively high ash content. Subsequent Liberation through size reduction can cause recovery increase. However, effect of comminution facilities on Mineral Liberation of middlings was ignored. This paper studied the Liberation characteristics of middlings crushed with different kinds of fragmentation forces. Middlings of −3 mm + 0.5 mm sampled from a dense medium cyclone were comminuted by a jaw crusher and a ball mill to −0.5 mm with similar size distribution respectively. The generating mechanism of fines was also analyzed. Full densimetric analyses indicate that Mineral Liberation of the product crushed by the jaw crusher is better than that by the ball mill at each fraction. For sizes of −0.125 mm + 0.074 mm and −0.074 mm, yields of the product with ash content 11% comminuted by jaw crusher are nearly 20% higher than that by the ball mill. Sectional micrographs observed by the scanning electron microscopy (SEM) also show the same law for these two fractions and some intergrowth particles still exist in the fraction of −0.5 mm + 0.25 mm.
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Liberation characteristics of coal middlings comminuted by jaw crusher and ball mill
International journal of mining science and technology, 2013Co-Authors: Yaqun He, Linhan Ge, Yajun Huang, Haifeng WangAbstract:Abstract The associated Minerals make coal middlings possess a relatively high ash content. Subsequent Liberation through size reduction can cause recovery increase. However, effect of comminution facilities on Mineral Liberation of middlings was ignored. This paper studied the Liberation characteristics of middlings crushed with different kinds of fragmentation forces. Middlings of −3 mm + 0.5 mm sampled from a dense medium cyclone were comminuted by a jaw crusher and a ball mill to −0.5 mm with similar size distribution respectively. The generating mechanism of fines was also analyzed. Full densimetric analyses indicate that Mineral Liberation of the product crushed by the jaw crusher is better than that by the ball mill at each fraction. For sizes of −0.125 mm + 0.074 mm and −0.074 mm, yields of the product with ash content 11% comminuted by jaw crusher are nearly 20% higher than that by the ball mill. Sectional micrographs observed by the scanning electron microscopy (SEM) also show the same law for these two fractions and some intergrowth particles still exist in the fraction of −0.5 mm + 0.25 mm.
Jens Gutzmer - One of the best experts on this subject based on the ideXlab platform.
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automated sem Mineral Liberation analysis mla with generically labelled edx spectra in the Mineral processing of rare earth element ores
Minerals, 2019Co-Authors: Bernhard Schulz, Gerhard Merker, Jens GutzmerAbstract:Many rare earth element (REE) deposits have experienced multistage geological enrichment processes resulting in REE bearing Mineral assemblages of considerable complexity and variability. Automated scanning electron microscopy (SEM) Mineral Liberation analysis of such REE ores is confronted by the difficult assignment of energy-dispersive X-ray (EDX) spectra to REE Mineral names. To overcome and bypass this problem, a generic and reliable labelling of EDX reference spectra obtained from REE-bearing Minerals based on their contents of Si, Ca, F and P in a bulk normalised analysis is proposed. The labelled spectra are then combined into groups of REE-P (~monazite), REE-Ca-Si-P (~britholite), REE-Ca-F (~synchysite) and REE-F (~bastnaesite, parisite, fluocerite). Mixed spectra with low counts for REE from minute REE Mineral grains are combined into a separate group. This classification scheme is applied to automated SEM Mineral Liberation analysis (MLA) data from beneficiation products by comminution and multistage flotation of REE carbonatite ores. Mineral modes, Mineral grain size distribution, Mineral Liberation, Mineral locking and Mineral grade versus recovery curves based on the analysis of >200,000 particles in a sample can be recognised and interpreted in virtual grain size fractions. The approach as proposed here will allow future process Mineralogical studies of REE deposits to be robust and comparable.
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a Mineral Liberation study of grain boundary fracture based on measurements of the surface exposure after milling
International Journal of Mineral Processing, 2016Co-Authors: Thomas Leisner, Kai Bachmann, Jens Gutzmer, Duong Huu Hoang, Martin Rudolph, Thomas Heinig, Heinrich SchubertAbstract:Abstract Minerals can be liberated by random fracture of particles into smaller fragments or by detachment along phase boundaries. These two mechanisms represent borderline cases. When ores get comminuted the Liberation of Minerals is achieved to some extent by both mechanisms. This article describes a method to determine the extent of transgranular and intergranular fracture based on 2-dimensional analysis of surface exposure of Minerals. The approach uses the unbiased surface information of phase specific surface area ( PSSA ), phase specific free surface ( PSFS ) and phase specific interfacial area ( PSIA ) of Minerals and their change with comminution. The parameters are discussed related to the normalized grain size, which is the ratio of Mineral grain size in the product to Mineral grain size in the unbroken material. Finally, the amount of transgranular and intergranular fracture on surface exposure can be calculated using the phase specific surface parameters. A sedimentary rock (apatite ore), an igneous rock (nepheline-syenite) and an artificial material (copper slags) were ground to different fineness. Based on the Mineral Liberation analysis (MLA) of feed and products, the extent of phase boundary fracture on the surface exposure of the Minerals is studied.
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efficient and accurate identification of platinum group Minerals by a combination of Mineral Liberation and electron probe microanalysis with a new approach to the offline overlap correction of platinum group element concentrations
Microscopy and Microanalysis, 2015Co-Authors: Inga Osbahr, Joachim Krause, Kai Bachmann, Jens GutzmerAbstract:Identification and accurate characterization of platinum-group Minerals (PGMs) is usually a very cumbersome procedure due to their small grain size (typically below 10 µm) and inconspicuous appearance under reflected light. A novel strategy for finding PGMs and quantifying their composition was developed. It combines a Mineral Liberation analyzer (MLA), a point logging system, and electron probe microanalysis (EPMA). As a first step, the PGMs are identified using the MLA. Grains identified as PGMs are then marked and coordinates recorded and transferred to the EPMA. Case studies illustrate that the combination of MLA, point logging, and EPMA results in the identification of a significantly higher number of PGM grains than reflected light microscopy. Analysis of PGMs by EPMA requires considerable effort due to the often significant overlaps between the X-ray spectra of almost all platinum-group and associated elements. X-ray lines suitable for quantitative analysis need to be carefully selected. As peak overlaps cannot be avoided completely, an offline overlap correction based on weight proportions has been developed. Results obtained with the procedure proposed in this study attain acceptable totals and atomic proportions, indicating that the applied corrections are appropriate.
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characterisation of graphite by automated Mineral Liberation analysis
Mineral Processing and Extractive Metallurgy, 2014Co-Authors: Dirk Sandmann, Sabine Haser, Jens GutzmerAbstract:AbstractThe beneficiation of graphite is very costly and energy intensive and can necessitate multiple processing steps, often including flotation. Products have to satisfy very stringent quality criteria. To decrease beneficiation costs, a careful characterisation of feed and concentrate materials is needed. This study elucidates the additional benefit of methods of automated SEM-based image analysis, such as Mineral Liberation analysis (MLA), in addition to ‘traditional’ methods [optical microscopy and X-ray powder diffraction (XRD)] for the analyses of graphite raw materials and processing products. Owing to the physical and chemical properties of the Mineral graphite, samples require delicate sample preparation as well as particular backscattered electron (BSE) imaging calibration for automated image analysis. These are illustrated in this study. The results illustrate that SEM-based image analysis of graphite feeds and concentrates can provide accurate and reliable information for the graphite benefi...
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use of Mineral Liberation analysis mla in the characterization of lithium bearing micas
Journal of Minerals and Materials Characterization and Engineering, 2013Co-Authors: Dirk Sandmann, Jens GutzmerAbstract: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.
Linhan Ge - One of the best experts on this subject based on the ideXlab platform.
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Liberation characteristics of coal middlings comminuted by jaw crusher and ball mill
International journal of mining science and technology, 2013Co-Authors: Yaqun He, Linhan Ge, Yajun Huang, Haifeng WangAbstract:Abstract The associated Minerals make coal middlings possess a relatively high ash content. Subsequent Liberation through size reduction can cause recovery increase. However, effect of comminution facilities on Mineral Liberation of middlings was ignored. This paper studied the Liberation characteristics of middlings crushed with different kinds of fragmentation forces. Middlings of −3 mm + 0.5 mm sampled from a dense medium cyclone were comminuted by a jaw crusher and a ball mill to −0.5 mm with similar size distribution respectively. The generating mechanism of fines was also analyzed. Full densimetric analyses indicate that Mineral Liberation of the product crushed by the jaw crusher is better than that by the ball mill at each fraction. For sizes of −0.125 mm + 0.074 mm and −0.074 mm, yields of the product with ash content 11% comminuted by jaw crusher are nearly 20% higher than that by the ball mill. Sectional micrographs observed by the scanning electron microscopy (SEM) also show the same law for these two fractions and some intergrowth particles still exist in the fraction of −0.5 mm + 0.25 mm.
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Liberation characteristics of coal middlings comminuted by jaw crusher and ball mill
International journal of mining science and technology, 2013Co-Authors: Yaqun He, Linhan Ge, Yajun Huang, Haifeng WangAbstract:Abstract The associated Minerals make coal middlings possess a relatively high ash content. Subsequent Liberation through size reduction can cause recovery increase. However, effect of comminution facilities on Mineral Liberation of middlings was ignored. This paper studied the Liberation characteristics of middlings crushed with different kinds of fragmentation forces. Middlings of −3 mm + 0.5 mm sampled from a dense medium cyclone were comminuted by a jaw crusher and a ball mill to −0.5 mm with similar size distribution respectively. The generating mechanism of fines was also analyzed. Full densimetric analyses indicate that Mineral Liberation of the product crushed by the jaw crusher is better than that by the ball mill at each fraction. For sizes of −0.125 mm + 0.074 mm and −0.074 mm, yields of the product with ash content 11% comminuted by jaw crusher are nearly 20% higher than that by the ball mill. Sectional micrographs observed by the scanning electron microscopy (SEM) also show the same law for these two fractions and some intergrowth particles still exist in the fraction of −0.5 mm + 0.25 mm.
Yajun Huang - One of the best experts on this subject based on the ideXlab platform.
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Liberation characteristics of coal middlings comminuted by jaw crusher and ball mill
International journal of mining science and technology, 2013Co-Authors: Yaqun He, Linhan Ge, Yajun Huang, Haifeng WangAbstract:Abstract The associated Minerals make coal middlings possess a relatively high ash content. Subsequent Liberation through size reduction can cause recovery increase. However, effect of comminution facilities on Mineral Liberation of middlings was ignored. This paper studied the Liberation characteristics of middlings crushed with different kinds of fragmentation forces. Middlings of −3 mm + 0.5 mm sampled from a dense medium cyclone were comminuted by a jaw crusher and a ball mill to −0.5 mm with similar size distribution respectively. The generating mechanism of fines was also analyzed. Full densimetric analyses indicate that Mineral Liberation of the product crushed by the jaw crusher is better than that by the ball mill at each fraction. For sizes of −0.125 mm + 0.074 mm and −0.074 mm, yields of the product with ash content 11% comminuted by jaw crusher are nearly 20% higher than that by the ball mill. Sectional micrographs observed by the scanning electron microscopy (SEM) also show the same law for these two fractions and some intergrowth particles still exist in the fraction of −0.5 mm + 0.25 mm.
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Liberation characteristics of coal middlings comminuted by jaw crusher and ball mill
International journal of mining science and technology, 2013Co-Authors: Yaqun He, Linhan Ge, Yajun Huang, Haifeng WangAbstract:Abstract The associated Minerals make coal middlings possess a relatively high ash content. Subsequent Liberation through size reduction can cause recovery increase. However, effect of comminution facilities on Mineral Liberation of middlings was ignored. This paper studied the Liberation characteristics of middlings crushed with different kinds of fragmentation forces. Middlings of −3 mm + 0.5 mm sampled from a dense medium cyclone were comminuted by a jaw crusher and a ball mill to −0.5 mm with similar size distribution respectively. The generating mechanism of fines was also analyzed. Full densimetric analyses indicate that Mineral Liberation of the product crushed by the jaw crusher is better than that by the ball mill at each fraction. For sizes of −0.125 mm + 0.074 mm and −0.074 mm, yields of the product with ash content 11% comminuted by jaw crusher are nearly 20% higher than that by the ball mill. Sectional micrographs observed by the scanning electron microscopy (SEM) also show the same law for these two fractions and some intergrowth particles still exist in the fraction of −0.5 mm + 0.25 mm.