Fluorite Ore Research Articles

Unlocking the Potential: Atomically Thin 2D Fluoritene from Exfoliated Fluorite Ore and Its Electrochemical Activity.

Fluorite mineral holds significant importance because of its optoelectronic properties and wide range of applications. Here, we report the successful exfoliation of bulk fluorite ore (calcium fluoride, CaF2) crystals into atomically thin two-dimensional fluoritene (2D CaF2) using a highly scalable liquid-phase exfoliation method. The microscopic and spectroscopy characterizations show the formation of (111) plane-oriented 2D CaF2 sheets with exfoliation-induced material strain due to bond breaking, leading to the changes in lattice parameter. Its potential role in electrocatalysis is further explored for deeper insight, and a probable mechanism is also discussed. The 2D CaF2 with long-term stability shows overpotential values of 670 and 770 mV vs RHE for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively, at 10 mA cm-2. Computational simulations demonstrate the unique "direct-indirect" band gap switching with odd and even numbers of layers. Current work offers new avenues for exploring the structural and electrochemical properties of 2D CaF2 and its potential applicability.

A case study of the Yanshanian fluorite mineralization in South China: Fluid inclusion, element and isotope geochemistry and zircon U-Pb geochronology of the Kantian fluorite deposit in southern Jiangxi Province

The Yanshanian events have led to the development of South China as a unique granite province globally. Within South Jiangxi, numerous metallic and non-metallic deposits have a close association with Mesozoic granite formations. The Kantian fluorite deposit, a newly discovered non-metallic deposit in southern Jiangxi Province, is one such deposit that is linked to Mesozoic granites. The orebody at the Kantian fluorite deposit is identified as occurring in veined structures within the silicification fracture zone of Mesozoic granites, with strict control exerted by fault systems. Fluorite ore can be classified into two categories based on the amount of quartz and fluorite. The first category is the fluorite quartz type, which has a higher amount of quartz than fluorite. The second category is quartz fluorite type, which has more fluorite than quartz. Among these two categories, the quartz fluorite type is precipitated during the primary mineralization stage. Through the analysis of fluid inclusions within the fluorite, it was determined that the homogenization temperature is relatively low, ranging from 133 to 236℃. The fluid inclusions also display low salinity (0.18–3.39 wt% NaCl eqv.) and low density (0.75–0.96 g/cm3). Laser Raman spectroscopy revealed that the primary components of the fluid inclusions are H2O, with minor C3H6. Isotope analysis indicated δDVSMOW values of fluorite ranging from −61.9 ‰ to −54.8 ‰ (average −59.8 ‰), while δ18OVSMOW values varied from 1.3 ‰ to 3.1 ‰ (average 2.0 ‰). This study presents chronological, petrological and geochemical data that suggest several processes. The metallogenic age is 135.6 ± 0.7 Ma. The mineralizing fluids were identified to the NaCl-H2O system, with heated meteoric water identified as the primary source; The ore-forming materials originated from the granite, and water–rock interactions are proposed as the primary mechanism for fluorite precipitation. Based on a tectonic setting characterized by stretching, which is closely linked to the subduction of the Pacific plate, we proposed a model for the Kantian fluorite deposit.

Study on synergistic inhibition and mechanism of flotation separation of fluorite and calcite by tannin and sodium humate

At present, the separation technology of fluorite and calcite is still immature, and the research in this paper can promote the improvement of the separation technology of fluorite and calcite. The selective inhibition mechanism of tannin and humate sodium on calcite was studied by means of actual ore flotation test, single mineral flotation test, Zeta potential measurement and FT-IR spectroscopy. The results show that the mixture of tannin and sodium humate inhibitor has a good inhibitory effect on carbonate under weak alkaline condition. The reaction products of sodium humate, tannin and calcium ions in solution interact with organic compounds adsorbed on the surface of calcite, forming multilayer adsorption on the surface of calcite, making calcite more hydrophilic. Based on density functional theory, Materials Studio (MS) was used to calculate the relevant adsorption energy, and the result was as follows: (a) compared with fluorite, tannin and humate sodium molecules are more easily adsorbed on the surface of calcite. (b) Compared with calcite alone adsorption of tannin molecules or sodium humate molecules, the adsorption state will be more stable, and the effect of tannin and sodium humate synergistic inhibition of calcite is better than the effect of inhibition alone. Therefore, using tannin and sodium humate as a combination inhibitor can effectively separate fluorite and calcite, which will promote the development and utilization of fluorite ore in industry.

Ultrasound-enhanced separation characteristics of gas-solid fluidized bed for fine-grained fluorite ore

Due to the increasing mechanization of mining, there is an urgent need to develop dry separation technology for effective pre-enrichment of fine-grained fluorite ore and promote the efficient use of fluorite in arid or water-scarce areas. Therefore, we tried to enhance the separation performance of fine-grained fluorite ore by introducing ultrasound into the gas–solid separation fluidized bed. Fluidization test and high-speed dynamic image analysis were used to reveal the mechanism of density separation of two-component materials enhanced by ultrasound. The effects of gas velocity, static bed height, separation time and amplitude transformer diameter on density segregation of two-component materials were further studied. In addition, a gas–solid fluidized bed separation system under the action of ultrasound was established for the pre-enrichment of fluorite ore with different particle sizes. The study showed that the stability of the bed is improved by the introduction of ultrasound. And the separation efficiency was increased by 15.46% compared with ordinary fluidized bed. The possible deviation (E) values of 1–0.5 mm and 0.5–0.25 mm fluorite ore were 0.22 g/cm3 and 0.175 g/cm3 respectively. This study provides new insights into the separation of fine-grained fluorite ore by gas–solid fluidized bed under the action of ultrasound.

The Influence of Surface Heterogeneity of Fluorite on the Adsorption of Alkyl Sulfonates

Surface heterogeneity of minerals can significantly affect the adsorption of collectors. Petroleum sulfonate is widely used as a fluorite collector, but how the surface heterogeneity of fluorite influences the adsorption of alkyl sulfonates remains unknown. Herein, two kinds of surface heterogeneity situations, i.e., edge and (1 1 1) _vacancy, were modeled, and the adsorption of sodium dodecyl sulfonate on them was simulated. The results show that the stable adsorption configuration of sodium dodecyl sulfonate on the edge was in a bridged mode, and the stable interaction configuration with vacancy was in a tridentate mode. The 2p orbit of fluorine on the surface of the edge and the vacancy could hinder collector adsorption. After adsorption, the 3d orbit of calcium interacted with the collector orbit above Fermi level, and moved towards the lower energy level, benefiting the adsorption process. It was also found that the adsorption intensity/strength of alkyl sulfonate on fluorite was directly proportional to the interaction intensity of the collector with the 3d orbits of calcium ions on the surface and vacancy. Therefore, the rough fluorite surface had a stronger adsorption effect on the collector, and the existence of vacancy could improve the surface adsorption energy, and thus enhance the adsorption of the collector on the fluorite surface. The rough fluorite surface requires high collector concentration to achieve saturated monolayer adsorption, so increasing vacancy was the better choice to improve the adsorption capacity of alkyl sulfonate on the fluorite surface. This study provides novel insights into the flotation mechanism, in the context of surface heterogeneity, and could guide the design of high-performance collectors for fluorite ore flotation.

Potential of low-grade fluorite ore of Landi Kotal, Khyber Pakhtunkhwa Province, Pakistan

This paper describes the results of a beneficiation study conducted on low-grade fluorite ore. The study was aimed at the development of a suitable beneficiation process to produce chemical grade fluorite concentrate. The representative sample of the ore was up-graded by leaching and flotation process. The important parameters of froth flotation process were optimized to obtain highest grade and recovery of fluorite concentrate. A single-factor variation method was applied to get the optimum conditions of the process. The rougher concentrate was reground to liberate fine locked fluorite particles and two cleaning flotation were employed in close circuit to achieve higher grade concentrate. A process flowsheet was designed in the light of these tests. After optimization of process parameters, the fluorite ore containing 62.24% CaF2 could be upgraded to a concentrate assaying 97.55% CaF2 with an overall recovery of 92.73%. The prepared fluorite concentrate meets the specifications of chemical grade and is suitable for production of fluoride based chemicals. Bangladesh J. Sci. Ind. Res. 58(2), 107-118, 2023

Implications for the contribution of Pacific plate subduction to fluorite mineralization in southeast China: Evidence from Nanzhou large fluorite deposit, Fujian province

In SE China, there are numerous Mesozoic igneous rocks and a tectonically active area known as the Wuyi Fluorite Mineralization Belt. The Nanzhou fluorite deposit can effectively represent most hydrothermally filled fluorite deposits strictly controlled by the fault zones. These were mainly trending NE, NNE, followed by NW, and nearly EW. It is the epitome of fluorite mineralization in the Wuyi fluorite metallogenic belt, which can provide clues for the subduction of the Mesozoic Pacific plate to the Eurasian plate. As the surrounding rocks of the Nanzhou fluorite ore bodies, the zircon U-Pb isotopic age of the Anjiang syenogranite is 147±1 Ma, while the biotite plagioclase granulite of the Xiafeng Formation in the Wanquan group is 817±3 Ma and 811±3 Ma. However, fluorite is of hydrothermal origin. It yields an Sm-Nd isochron age of 103.8±5.0 Ma and an Rb-Sr isochron age of 106±15.0 Ma, more than c.a. 40 Ma younger than the Anjiang Syenogranite, indicating fluorite is a product of late hydrothermal mineralization. The right-leaning REE distribution curves of most fluorite samples are similar to those of Yanshanian Anjiang syenogranite and biotite plagioclase granulite of the Xiafeng Formation, which indicates that fluorite is closely related to the surrounding rocks. Most fluid inclusions in fluorite have salinities of 0.5–2.24 wt% NaCl eqv and low homogenization temperatures of 140–200 °C. The inclusions include a NaCl-H2O system with δDV-SMOW between −79.7 to −77.6‰ and δ18OV-SMOW values range from 0.4 to 2.1‰. The (87Sr/86Sr)i ratios of the fluorite, which are between 0.717427 and 0.719482, are characteristic of a crustal contribution. Based on the above description, the mineralized fluid of Nanzhou fluorite deposit belongs to the NaCl-H2O system with medium-low temperature and low salinity, which is obviously different from the magmatic hydrothermal fluid. In addition, the age of fluorite mineralization is younger than that of igneous rocks by ca. 40 Ma, so they are not correlated. It is proposed that the ore-forming fluid may be involved in atmospheric precipitation and circulate within the northeastward fault with increasing geothermal gradient to form Nanzhou-fluorite deposit. The Nanzhou-fluorite deposit was formed in 103.8±5.0 Ma and 106±15.0 Ma, which corresponds to the plate subduction and rollback period of the Late Cretaceous (in ca. 110–70 Ma). The formation of the Nanzhou deposit has important implications for the subduction of the Pacific plate to the Eurasian plate.

Fluid evolution and origin of the Tamazert fluorite deposits, Moroccan High Atlas

This study focuses on the origin of fluorite ore deposits that are associated with the Eocene alkaline igneous suite of the Tamazert complex in the Moroccan High Atlas. Based on field observations and mineralogy, two major ore styles were identified: 1) a disseminated purple fluorite in aegirine-rich nepheline syenites (stage 1) and 2) a banded purple-white fluorite ore in karstic cavities and veins hosted in the Jurassic carbonate (stage 2). Both fluorite mineralization stages are commonly accompanied by calcite. The distribution of fluorite deposits at the peripheries of syenite and the surrounding Jurassic carbonates suggests the development of long-lived hydrologic systems around the shallow intrusion. Based on fluid inclusion, Rare Earth Elements and Yttrium (REY), and C–O isotopic constraints, this study reveals that different fluid systems were responsible for the deposition of fluorite ores in and around the Tamazert alkaline igneous complex. The disseminated interstitial fluorite precipitated from a F-rich magmatic-hydrothermal fluid, which exsolved from the highly evolved alkaline-silicate melt and was subsequently altered by Na–Ca metasomatic brines. Vein-type fluorite deposits hosted in the Jurassic carbonates precipitated from low salinity (1.6–8.5 wt% NaCl equiv.) and heated (Th = 118–157 °C) meteoric fluids, which migrated in response to the heat flow around the shallow intrusion. Fluid cooling, fluid interaction with Jurassic carbonates, and pressure fluctuations were the most important fluorite deposition mechanisms. The evolved melt provided F and REY for the interstitial fluorites, whereas meteoric fluids leached F− from syenites and other F-bearing igneous rocks. Based on the fractionation pattern, the REY inventory of the vein fluorites was acquired by interaction of meteoric fluids with Jurassic carbonates.

3D modeling for mineral resource assessment of fluorite ore and its industrial application in Jbel Tirremi, northeast Morocco

3D modeling for mineral resource assessment of fluorite ore and its industrial application in Jbel Tirremi, northeast Morocco

Spectral Characteristics, Rare Earth Elements, and Ore-Forming Fluid Constrains on the Origin of Fluorite Deposit in Nanlishu, Jilin Province, China

Nanlishu fluorite has had an annual output of nearly 10,000 tons since its discovery and mining in 1987. At present, few studies have been undertaken on the genesis of the Nanlishu fluorite deposit. Microscopy, Fourier transform infrared (FTIR) spectroscopy, Raman microprobe spectroscopy, and ultraviolet–visible (UV–Vis) spectroscopy were used to study the mineral composition, mineral structure, and spectral characteristics, and fluid inclusion and rare earth element (REE) geochemistry studies were conducted to discuss the characteristics and evolution of the ore-forming fluids and the mineralization process. The Nanlishu fluorite ore rock is composed mainly of fluorite, with minor amounts of quartz, pyrite, and apatite, and trace amounts of calcite. The purple in the fluorite is caused by the Ca colloids. The homogenization temperatures of fluid inclusions in Nanlishu fluorite vary from 116 to 179 °C, while the salinity ranges from 0.35 to 4.03 wt% NaCl equiv, and the density varies from 0.90 to 1.00 g/cm3. Ore-forming fluids were derived from heated meteoric water characterized by low temperature, low salinity, and low density. The total rare earth element (∑REE, excluding Y) content of the ore ranged from 8.072 to 27.230 ppm. The light/heavy REE ratio (LREE/HREE) varies from 0.971 to 1.513. The δEu value is 1.010–1.074 and the δCe value is 0.893–1.048. Compared with other deposits, the Nanlishu fluorite has lower ∑REE content, no obvious enrichment of LREEs or HREEs, and no anomalies in δEu and δCe. Water/rock reaction is the main mechanism for Nanlishu fluorite precipitation. The Nanlishu fluorite is a fault-controlled, low-temperature hydrothermal, fracture-filling deposit.

Difficulties and Recent Achievements in Flotation Separation of Fluorite from Calcite—An Overview

As an important strategic non-metallic mineral resource, fluorite has been widely used in various industrial fields, such as metallurgy, optics and semiconductor manufacturing, as well as fluorine-related chemical engineering. Since the major gangue minerals of fluorite ore are silicate and carbonate ones, flotation is the main beneficiation method for the concentration. Compared with the relatively easy operation for silicate-type fluorite ore, fluorite concentration from calcite has always been the most difficult challenge in the field of mineral processing. In this review, analyses of the fundamental reasons for the difficulties of flotation separation of fluorite from calcite are performed, from the similar surface properties of both calcium minerals to the deterioration by the interference of dissolved ions in the pulp during grinding and flotation. Recent achievements in the flotation separation of fluorite from calcite as the main contents are comprehensively summarized, covering all aspects of flotation reagents of collectors, depressants and modifiers. Finally, successful examples of industrial practices for fluorite and calcite flotation separation are introduced. This overview provides a detailed and comprehensive reference source for the current research status of fluorite and calcite flotation separation, and some suggestions for future research are provided.

Investigation on the Beneficiation of Fluorite-ore using a mixture of Oleic acid and Palmitic acid via Froth Flotation

Fluorite (fluorspar), an important industrial mineral ore, is one of the major raw materials for the production of hydrofluoric acid. Naturally occurring fluorite ore contains gangue minerals, primarily silica (SiO2) and calcite (CaCO3). The beneficiation of fluorspar is needed to mitigate the severity of operational issues. Several studies on fluorspar beneficiation using the froth floatation technique have been executed, but the process is restricted by the use of minerals acids to remove calcite. In this study, a novel scheme for fluorspar beneficiation was investigated for the floatation of fluorite and depression of calcite and other gangue minerals simultaneously without the use of mineral acids. Moreover, mixtures of saturated and unsaturated fatty acids (oleic acid and palmitic acid) were used instead of mineral acids. Various parameters were investigated, such as the weight percent of the feed-slurry, feed pH, the effect of reagents on the process selectivity, and the effect of feed boiling and dilution on the up-gradation of fluorspar. The adopted methodology with tested reagents resulted a 67 wt. % reduction of CO32- and 75 wt. % reduction of SiO2 in gangue material at a pH 10 for the feed slurry. Fluorspar purity increased from 65-75 wt. % to 95 wt. % after the boiling and dilution steps, respectively.

Reactive transport modeling of the role of fluorine-rich groundwater in the formation of fluorite ore deposits in the Illinois-Kentucky district, USA

Reactive transport modeling of the role of fluorine-rich groundwater in the formation of fluorite ore deposits in the Illinois-Kentucky district, USA

Study on Flotation Process of a Quartz Fluorite Ore in Western Henan

Study on Flotation Process of a Quartz Fluorite Ore in Western Henan

Combined inhibitors of Fe3+, Cu2+ or Al3+ and sodium silicate on the flotation of fluorite and quartz

Fluorite ore, as an essential raw material in the fluorinated chemical industry, required effective separation and purification. The removal of impurities such as quartz becomes the key point in fluorite flotation. In this work, the fluorite flotation tests via adding the different mass ratios of metal ions (Fe3+, Cu2+, Al3+) and sodium silicate (SS) as a combined inhibitor, were carried out on a laboratory scale. Results indicated that when the mass ratio of SS to Fe3+, Cu2+, and Al3+ was 3:1, 1:1, and 3:1, the fluorite recovery reached 75.01%, 83.56%, and 81.84%, while quartz recovery was only 9.20%, 6.09%, and 4.76%, respectively. In addition, the action mechanisms of the combined inhibitors were investigated and evaluated in-depth. Compared with the single inhibitor of SS, the results of contact angle measurements, Zeta potential measurement, and Fourier transform infrared spectroscopy showed that the combined inhibitor could attenuate the activation of Ca2+ on quartz, and therefore to avoid the quartz mismatching into fluorite concentrates. Therefore, it provides an alternative separation method to realize high-efficient flotation of the fluorite and quartz with the presence of metal ion inhibitors.

The link between Paleo-Tethys subduction and regional metallogeny in the SW Yangtze Block: New evidence from the Zubu carbonate-hosted F-Pb-Zn deposit

The lead–zinc mineralization belt along the southwestern margin of the Yangtze Block is one of the important source for lead, zinc, germanium and silver in China. More than 50% of the deposits in the region occur in carbonate rocks ranging in age from late Ediacaran to early Cambrian. Here we investigate the large Zubu F-Pb-Zn deposit located in the southwestern margin of the Yangtze Block. The ore bodies strike nearly NS in the dolomite fracture zone in the second member of the Cambrian Longwangmiao Formation and discontinuously extend for 0.7 km long. We present Sm-Nd isotopic data on the fluorite ore that yield an isochron age of 211 ± 11 Ma. Fluid inclusions in the fluorite show homogenization temperature between 88 and 247 °C with a peak at 130–180 °C, with salinity ranging between 0.18 and 22.23 wt% NaCl eqv. (average of 9.24 wt% NaCl eqv.), the ore-forming fluid has the characteristics of medium–low temperature and medium–low salinity. The rare earth element (REE) signature of fluorite display positive Eu anomaly and negligible negative to weak positive Ce anomaly. The δ18OV-SMOW values range from 0.6 − 4.7 ‰, δDV-SMOW values range from −41.1–27.6 ‰, fluorite Sr isotopic values range from 0.710668 to 0.711585, and galena Pb isotope ratios with the value of 206Pb/204Pb = 18.551–18.564, 207Pb/204Pb = 15.676–15.693, 208Pb/204Pb = 38.869–38.809. The field, petrologic, geochemical and isotopic data from our study lead to the following salient findings. (1) The ore-forming fluid of the F-Pb-Zn deposit was derived from the mixture of metamorphic water flowing through the basement with basin hot brine and meteoric water. (2) The ore-forming material of the deposit comes from the basement and sedimentary strata. (3) In conjunction with the geochronological data of regional ore deposits, the large-scale mineralization is inferred to have formed during a transitional stage from compression to extension setting related to the Indosinian orogeny after the closure of the late Triassic-early Jurassic (220–190 Ma) Paleo-Tethys Ocean.

Origin and tectonic setting of Pingqiao fluorite-lithium deposit in the Guizhou, southwest Yangtze Block, China

Fluorite and lithium have become extremely important minerals globally. The newly discovered medium-to-large-scale Pingqiao fluorite-lithium deposit in the southwest Yangtze Block contains a rare mineral system with fluorite and lithium associations. This unique deposit provides an excellent example for the study of the origin and formation processes of the fluorite-lithium mineral system. The fluorite ore bodies in the Pingqiao mining area are hosted in the silicified limestone of the late Carboniferous Nandan Formation, and the lithium-bearing ore bodies occur in the claystone and micrite of the early Permian Longyin Formation. Fluorite and lithium clay show different REE patterns, but both have negative Eu and Ce anomalies. The isochron age yielded by the fluorite Sm-Nd isotope data was 152.0 ± 3.7 Ma. The δDV-SMOW values ranged between −63.1‰ and −56.8‰, and the δ18OV-SMOW values ranged from −5.7‰ to −4.9‰. The δ13CV-PDB values were between 1.3 and 2.7‰ for calcite. The 87Sr/86Sr ratios ranged between 0.708489 and 0.708810 for Li-clay and 0.708584 to 0.709180 for fluorite. The field geological, petrological, and geochemical data reported in this study indicate the following salient findings: (1) the ore-forming fluid was formed by mixing basinal water and meteoric water; (2) the ore-forming materials originated from the Cambrian, Ordovician, and Devonian carbonate rocks, and Carboniferous limestone; and (3) the deposit was formed in an extensional setting within the Yangtze Block and is closely associated with the late Jurassic to early Cretaceous polymetallic events and is related to the flat-slab subduction and delamination of the Paleo-Pacific plate. We propose a model of fluorite-lithium mineralisation that explains the fluid composition, transport, and precipitation mechanisms involved in the mineral system.

Application of field-portable geophysical and geochemical methods for tracing the Mesozoic-Cenozoic vein-type fluorite deposits in shallow overburden areas: A case from the Wuliji’Oboo deposit, Inner Mongolia, NE China

Fluorite deposits are widespread throughout eastern China and commonly occur in vein systems. These vein-type fluorite deposits are the primary source of fluorine worldwide and were predominantly formed during the Mesozoic or Cenozoic periods. In the absence of ore outcrops, fluorite exploration is necessarily concentrated within the shallow overburden area. The Wuliji'Oboo fluorite deposit is an example of a medium–low temperature vein-type subsurface orebody in eastern Inner Mongolia. Five portable technology methods have been implemented within the study area, including multispectral remote sensing (RS) technology, very low-frequency electromagnetic measurement (VLF-EM), portable X-ray fluorescence analyses (PXRF), portable gamma-ray spectroscopy, and partial extraction geochemistry. This paper describes the application principles, influencing factors, and technical solutions for each method. By investigating various examples, the applications of portable technology methods and their associated limitations were evaluated. Combining geological research with multi-spectral RS techniques is essential for optimum fluorite ore body prediction, thus narrowing prospecting targets. First, the target area was scanned using VLF-EM to identify the distribution of potential anomalies. Second, PXRF was used to distinguish the mineralised anomaly. Finally, trenching and drilling were performed to verify the effectiveness of the combination of methods. This study establishes a geology-geophysics-geochemistry-remote sensing integrated exploration model that may provide theoretical and technical support for the prediction of fluorite ore bodies in large Quaternary shallow overburden areas.

Genesis of a Ag-Pb-Zn-F system: Insights from in situ sulfur isotope and trace elements of pyrite, and rare earth elements of fluorite in the Baiyine'lebu deposit, Inner Mongolia, China

The recently discovered Baiyine’lebu Ag-Pb-Zn-F deposit in the southern Great Xing’an Range is hosted by NNE-trending transgressional fractures within Late Permian granodiorite. The fluorite ore veins in the periphery of the mining area show close spatial association with the Ag-Pb-Zn ore bodies. A total of four mineralization stages are recognized based on the cross-cutting relationships and mineral assemblages, among which three types of pyrite are identified, including: i) coarse-grained pyrite (Py1) from stage I quartz-pyrite vein, ii) fine-grained cubic pyrite (Py2) from stage II quartz sulfide-rich vein, showing association with metallic sulfide minerals, and iii) anhedral, irregular pyrite (Py3) disseminated in Ag-bearing sulfide ore vein from stage III. The stage IV is quartz-fluorite-calcite vein with very rare distribution of pyrite. Here we investigate the texture, trace element and sulfur isotopic composition of pyrite and rare earth elements (REEs) of fluorite to gain insights into the genesis and mineralization process of the Baiyine’lebu Ag-Pb-Zn-F deposit. Systematic trace element analyses indicate that the compatible and some other elements (Co, Ni, Cr and As) were incorporated in the pyrite structure via isomorphism in all pyrite types, whereas ore metals such as Cu, Pb, Zn, and Sn entered pyrite as structurally bound elements or micro/nanosized mineral inclusions. The Ag concentrations significantly increase from Py1 to Py3 in the form of invisible nanoparticles of sulfides or micro- to nano-sized mineral inclusions during the decrease of temperature. The narrow range of sulfur isotopic compositions from −0.80 to 3.88 ‰ (average in 1.17‰) indicates a relatively homogeneous sulfur source. In combination with REE patterns of fluorite, we propose that the ore-forming fluids originated mainly from post-magmatic hydrothermal fluid mixed with meteoric water in stage IV. The hydrothermal fluorite veins in the periphery of the Baiyine’lebu deposit could be genetically linked to the Ag-Pb-Zn veins. The purple fluorites with enriched REEs and positive Eu anomaly can be used as a proxy for prospecting Ag-Pb-Zn deposits. In addition, the high Sn content of pyrite in hydrothermal Ag-Pb-Zn deposit indicates the potential of Sn mineralization in the surrounding area or deeper level of the ore field in the South Great Xing’an Range.

Resource utilization of waste oil in kitchen waste: preparation of renewable collector for cleaner flotation of high-sulfur fluorite ore

ABSTRACT Waste oils from kitchen waste pose a significant environmental threat. Meanwhile, desulfurization treatment of high-sulfur fluorite ore is also a challenge due to the harmfulness of sulfur. Thus, this study focuses on the preparation of collector from waste oil for the separation of high-sulfur fluorite ore in order to eliminate the environmental threat of the two waste. The flotation kinetic characteristics of pyrite with renewable collectors were studied and the kinetics analysis shows that the rapid flotation of pyrite with different grain sizes could be achieved. Thus, the pre-desulfurization process of high sulfur fluorite ore was proposed. Subsequently, the flotation efficiency of renewable collector on desulfurized fluorite ore was verified. The flotation results illustrate that 83.85% of sulfur can be removed with xanthate dosage of 60 g/t. Further, the sulfur content in the fluorite concentrate can be reduced to 0.02% with 91.52% fluorite recovery by single flotation test with 1.7 kg/t renewable collector dosage. Moreover, the closed-circuit flotation process was designed, fluorite concentrate with CaF2 grade of 97.08% can be obtained, and the sulfur content is only 0.04%. An innovative flotation process of high-sulfur fluorite using renewable collectors prepared from waste oils is proposed, which realized the high-value utilization of waste oils and high-sulfur fluorite.