Process mineralogy of Weishan rare earth ore by MLA

Process mineralogy of Dalucao rare earth ore and design of beneficiation process based on AMICS

The Bear Lodge REE deposit is located in northeastern Wyoming. The Eocene carbonatite dyke and stockwork system intrudes trachytic-phonolitic rocks that contain multiple diatremes. The original magmatic characteristics of the REE-enriched carbonatite complex are strongly overprinted by carbo-hydrothermal and later supergene fluids. These fluids redistributed the REEs and created high variability in the ore mineral assemblage, as well as compositional variability within individual REE mineral species. The REE ore minerals at Bear Lodge can be classified into four types: 1. fluorocarbonates (bastnaesite, parisite, synchysite), 2. phosphates (monazite, xenotime, florencite, rhabdophane, churchite), 3. cerianite, and 4. ancylite. These minerals vary greatly in abundance, grain size, and morphology. REE distribution is heterogeneous throughout the deposit. Variations within a given REE mineral in terms of Ce depletion, Th content, degree of heavier REE enrichment, etc., create difficulties in the initial definition of discrete mineral species (i.e., by X-ray spectra) and their resultant species identification protocols for use in automated mineralogy (QEMSCANⓇ in this study). Prevalent submicron-scale supergene mineralization result in hybrid spectra from multiple phases. Iterative work in reconciling QEMSCANⓇ data interpretation with bulk assay, XRD, SEM, and optical petrography data allows for refinement of the protocols to quantify for both ore and gangue minerals. Use of automated mineralogy in the development of complex deposits requires rigorous review of these identification criteria in order to achieve results that can be applied with confidence to resolve mineral processing issues.

Use of QEMSCAN® to characterize oxidized REE ore from the Bear Lodge carbonatite, Wyoming, USA

There is a close spatial relationship between the ore body of Aktas gold deposit and the contact zone of the rock body of different periods. This paper by conducting a detailed study of geological and geochemical characteristics with 15 samples of andesitic porphyrite, diorite, slanted granite and medium fine-grained granite, analyzes the relationship between the geochemical features and formation mechanism of magmatic rocks and its mineralization process. It is found that the average content of SiO2 in volcanic rock of Aktas is 49.69wt%, which suggests that those volcanic rocks are alkaline or calc-alkaline rocks and has no direct influence on mineralization. Besides, the average content of SiO2 in intrusive rock is 63.17wt%, which means that this kind of rock belongs to medium acid rock, the main source of metallogenic material. The paper also found that the light rare earth is relatively rich while heavy rare earth few, and the LREE/HREE ration of volcanic rock is lower than that of intrusive rock, showing that some crustal substances may be involved in the ascending process of deep magmatic rocks and mixed with mantle material. The source substance of intrusive rock mainly comes from the earth's mantle, therefore the intrusive rock, especially the plagiogranite in this area, may be closely related to the formation of Aktas gold deposit. Combining with the evolution mechanism theory of regional tectonism, this paper concludes that the metallogenic material of Aktas gold deposit originates from the combined action of the ore-bearing fluid from deep mantle and the fluid from shallow crust.

Geochemical features of magmatic rocks and mineral deposit genesis of xinjiang aktas gold deposit

Magnetic field simulation of helicon plasma thruster

The process mineralogy characteristics, such as the chemical composition of the ores, the chemical phase of the rare earth, the mineral components and contents, the occurrence states of the main minerals, the disseminated grain size of the rare earth minerals, and the liberation analysis of the rare earth minerals, were studied in detail with the methods of lens-below identification, mineral liberation analyzer (MLA), scanning electron microscope, X-ray diffraction, chemical elements analyses, and the chemical phase analyses. The results show that the main rare earth mineral of the ores was bastnaesite (including parisite), which took up 87% of the total. Bastnaesite (parisite) was mainly disseminated in sparse and scattered forms along the edge or within the intergranular spaces of dolomite, celesite, apatite and quartz. The statistical results of the disseminate grain size indicate that the grain size smaller than 0.038 mm took up 40.47%. The rare-earth miners were featured with tiny grain size, high degree of dispersion, and complicated intergrowth relationship with the disseminated minerals. According for these characteristics, fine milling procedure would be applied to obtain high grade rare earth ore concentrate.

Liu Yang

Papers

Chemical and Mineralogical Study on Bastnaesite Dominated Rare Earth Ores