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Mechanism of calcium lignosulfonate in apatite and dolomite flotation system

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International Journal of Minerals,Metallurgy and Materials 2022年第9期29卷 1697-1704页

作者： Bo Feng Liangzhu Zhang Wenpu Zhang Huihui Wang Zhiyong Gao Jiangxi Key Laboratory of Mining Engineering Jiangxi University of Science and TechnologyGanzhou 341000China Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources Central South UniversityChangsha 410083China State Key Laboratory of Rare Metals Separation and Comprehensive Utilization Guangzhou 510600China

Since the physical and chemical properties of apatite and dolomite can be similar,the separation of these two minerals is difficult.Therefore,when performing this separation using the flotation method,it is necessary to search for selective depressants.An experimental research was performed on the separation behavior of apatite and dolomite using calcium lignosulfonate as a depressant,and the mechanism by which this occurs was analyzed.The results show that calcium lignosulfonate has a depressant effect on both apatite and dolomite,but the depressant effect on dolomite is stronger at the same dosage.Mechanism analysis shows that the adsorptive capacity of calcium lignosulfonate on dolomite is higher than that of apatite,which is due to the strong reaction between calcium lignosulfonate and the Ca sites on dolomite.In addition,there is a hydrogen bond between calcium lignosulfonate and dolomite,which further prevents the adsorption of sodium oleate to dolomite,thus greatly inhibiting the flotation of dolomite.

关键词： apatite dolomite calcium lignosulfonate depression mechanism

Production of high-purity Mg metal from dolomite through novel molten salt electrolysis and vacuum distillation

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Journal of Magnesium and Alloys 2023年第4期11卷 1308-1320页

作者： Hyeong-Jun Jeoung Tae-Hyuk Lee Jin-Young Lee Kyung-Woo Yi Jungshin Kang Korea Institute of Geoscience and Mineral Resources 124 Gwahak-ro Yuseong-guDaejeon 34132Republic of Korea Department of Materials Science and Engineering Seoul National University1 Gwanak-roGwanak-guSeoul 08826Republic of Korea Department of Resources Engineering University of Science and Technology217 Gajeong-ro Yuseong-guDaejeon 34113Republic of Korea School of Materials Science and Engineering Pusan National University2 Busandaehak-roGeumjeong-guBusan 46241Republic of Korea

In this study,a novel Mg production process for producing high-purity Mg metal from dolomite was developed.When the electrolysis of calcined dolomite was conducted using Cu cathode and C anode in MgF_(2)–LiF molten salt at 1083–1173 K by applying an average current of 1.42–1.46 A for 9.50–21.0 h,the current efficiency of 66.4–88.6%was obtained.The produced Mg alloys consisted of MgCu_(2)and Cu(Mg)or MgCu_(2)and CuMg_(2)phases,depending on the Mg concentration in the Mg alloy.When the electrolysis of calcined dolomite was conducted in MgF_(2)–LiF–CaF_(2)molten salt at 1083 K,the current efficiency was 40.9–71.4%,owing to undesired reactions such as electroreduction of Ca^(2+)or/and CO_(3)^(2−)ions.Meanwhile,the current efficiency increased from 40.9%to 63.2%by utilizing a Pt anode,because the occurrence of CO_(3)^(2−)ions in the molten salt was prevented.After vacuum distillation of the obtained Mg alloys at 1300 K for 10 h,Mg metal with a purity of 99.9996–99.9998%was produced.Therefore,the feasibility of this novel process for the production of high-purity Mg metal from dolomite was demonstrated.

关键词： High-purity magnesium dolomite Magnesium oxide Electrolytic process Copper metal cathode Vacuum distillation

dolomite genesis and reservoir-cap rock assemblage in carbonate-evaporite paragenesis system

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Petroleum Exploration and Development 2019年第5期46卷 969-982页

作者： HU Anping SHEN Anjiang YANG Hanxuan ZHANG Jie WANG Xin YANG Liu MENG Shaoxing PetroChina Hangzhou Research Institute of Geology(HIPG) Hangzhou 310023China Key Laboratory of Carbonate Reservoirs CNPCHangzhou 310023China

Regarding to the problem on the reservoir-cap rock assemblage evaluation in the carbonate-evaporite paragenesis system,this study examined the dolomite and reservoirs genesis and the characteristics of reservoir-cap rock assemblage.Based on the literature research of the global carbonate reservoirs and the case study on four profiles of carbonate-evaporite succession,together with geological and experimental work,three aspects of understandings are achieved.(1)Lithology of carbonate-evaporite paragenesis system is mainly composed of microbial limestone/bioclastic limestone,microbial dolomite,gypsum dolomite and gypsum salt rock deposited sequentially under the climatic conditions from humid to arid,and vice versa,and an abrupt climate change event would lead to the lack of one or more rock types.(2)There developed two kinds of dolomite(precipitation and metasomatism)and three kinds of reservoirs in the carbonate-evaporite system;and the carbon dioxide and organic acid generated during early microorganism degradation and late microbial dolomite pyrolysis process,and early dolomitization are the main factors affecting the development of microbial dolomite reservoirs with good quality.(3)In theory,there are 14 types of reservoir-cap rock assemblages of six categories in the carbonate-evaporite system,but oil and gas discoveries are mainly in four types of reservoir-cap rock assemblages,namely"microbial limestone/bioclastic limestone–microbial dolomite–gypsum dolomite–gypsum salt rock","microbial limestone/bioclastic limestone–gypsum salt rock","microbial dolomite–gypsum dolomite–gypsum salt rock"and"gypsum dolomite–microbial dolomite–tight carbonate or clastic rock".These four kinds of reservoir-cap rock assemblages should be related with the climate change rules in the geologic history,and have good exploration prospects.

关键词： carbonate-evaporate paragenesis system lithological association sequence microbial dolomite gypsum dolomite reservoir-cap rock assemblage

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Role of tannin pretreatment in flotation separation of magnesite and dolomite

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International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 452-461页

作者： Xiufeng Gong Jin Yao Jun Guo Bin Yang Haoran Sun Wanzhong Yin Yulian Wang Yafeng Fu School of Resources and Civil Engineering Northeastern UniversityShenyang 110819China Key Laboratory of Solid Waste Treatment and Resource Utilization of the Ministry of Education Southwest University of Science and TechnologyMianyang 621010China School of Chemical Engineering China University of Mining and TechnologyXuzhou 221116China School of Materials Science and Engineering Shenyang Ligong UniversityShenyang 110159China Ansteel Beijing Research Institute Co. Ltd.Beijing 102200China

Flotation separation of magnesite and its calcium-containing carbonate minerals is a difficult problem.Recently,new regulat-ors have been proposed for magnesite flotation decalcification,although traditional regulators such as tannin,water glass,sodium carbon-ate,and sodium hexametaphosphate are more widely used in industry.However,they are rarely used as the main regulators in research because they perform poorly in magnesite and dolomite single-mineral flotation tests.Inspired by the limonite presedimentation method and the addition of a regulator to magnesite slurry mixing,we used a tannin pretreatment method for separating magnesite and dolomite.Microflotation experiments confirmed that the tannin pretreatment method selectively and largely reduces the flotation recovery rate of dolomite without affecting the flotation recovery rate of magnesite.Moreover,the contact angles of the tannin-pretreated magnesite and dolomite increased and decreased,respectively,in the presence of NaOl.Zeta potential and Fourier transform infrared analyses showed that the tannin pretreatment method efficiently hinders NaOl adsorption on the dolomite surface but does not affect NaOl adsorption on the magnesite surface.X-ray photoelectron spectroscopy and density functional theory calculations confirmed that tannin interacts more strongly with dolomite than with magnesite.

关键词： tannin pretreatment selective inhibition flotation separation magnesite dolomite

Removal of dolomite and potassium feldspar from apatite using simultaneous flotation with a mixed cationic-anionic collector

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International Journal of Mining Science and Technology 2023年第6期33卷 783-791页

作者： Haoyong Yu Yangge Zhu Liang Lu Xiaoxing Hu Songqing Li State Key Laboratory of Mineral Processing Science and Technology BGRIMM Technology GroupBeijing 102628China

This study aims to investigate the effect of a cationic-anionic mixed collector(dodecyltrimethyl ammonium bromide/sodium oleate(DTAB/NaOL)on the selective separation of apatite,dolomite,and potassium feldspar.Herein,several experimental methods,including flotation experiments,zeta-potential detection,microcalorimetry detection,XPS analysis and FTIR measurements,were used.The flotation tests showed that dolomite and potassium feldspar can be successfully removed from apatite simultaneously when the molar ratio of DTAB to NaOL was 2:1 with pH 4.5.Zeta-potential and microcalorimetry detection suggested that NaOL and DTAB were adsorbed on the surface of dolomite and potassium feldspar respectively,and part of NaOL and DTAB formed co-adsorption on the surface of potassium feldspar to enhance the floatability of potassium feldspar.The XPS and FTIR spectra analysis demonstrated that the cationic collector,DTAB,was first adsorbed on the surface of potassium feldspar through electrostatic attraction in the DTAB/NaOL mixture system.Subsequently,the anionic NaOL collector and cationic DTAB collector form an electron neutralisation complex,thereby resulting in co-adsorption on the surface of potassium feldspar.NaOL was chemically reacted and adsorbed on dolomite surface,but almost no collector was adsorbed on apatite surface.Finally,the adsorption models of different collectors on mineral surface were obtained.

关键词： Flotation Mixed collectors Apatite Potassium feldspar dolomite

Clumped Isotope Analysis of Calcite and dolomite Mixtures Using Selective Acid Extraction

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Journal of Earth Science 2023年第3期34卷 726-734页

作者： Sen Li Andrew Schauer Alexis Licht Jie Liang Kate Huntington Kangning Peng Qingdao Institute of Marine Geology Qingdao 266237China Department of Earth and Space Sciences University of WashingtonSeattle 98195USA Centre Européen de Recherche etd􀆳Enseignement des Géosciences del􀆳Environnement(Cerege) UMR 7330Aix-Marseille UniversitéCNRSIRDINRAEAix-en-Provence 13545France Shandong Provincial Territorial Spatial Ecological Restoration Center Jinan 250014China

Acid extraction methods have been used in the last half century to selectively extract the CO_(2)produced from different carbonate minerals in mixed samples.However,these methods are often time-consuming and labor intensive.Their application to clumped isotope(Δ47)analysis has not been demonstrated.We propose here an acid extraction method with phosphoric acid for bulk stable and clumped isotope analysis that treats mixtures of calcite and dolomite the same regardless of the proportional composition.CO_(2)evolved from calcite is extracted by allowing a reaction with phosphoric acid to proceed for 10 min at 50℃.We then extract CO_(2)evolved from dolomite by rapid ramping the acid temperature from 50 to 90℃and allowing the reaction to complete.The experimental results show that our method yields accurate calcite and dolomiteΔ_(47)values from mixed samples under different proportional compositions.Our method also displays equal or higher accuracy for calciteδ^(13)C and dolomiteδ^(13)C andδ^(18)O values from mixtures when compared to previous studies.Our approach exhibits higher sample throughput than previous methods,is adequate for clumped isotopic analysis and simplifies the reaction progression from over 24 h to less than 2 h,while maintaining relatively high isotopic obtaining accuracy.It yet poorly resolves calciteδ18O values,as found with previous methods.

关键词： mixed carbonate samples selective acid extraction acid fractionation correction clumped isotope bulk isotope calcite dolomite

Early Diagenetic dolomite as a Potential Archive of Paleoredox Fluctuations in an Early Tonian Marine Basin?

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Acta Geologica Sinica(English Edition) 2022年第2期96卷 607-620页

作者： KANG Junyao LI Chenqing DONG Lin XIAO Shuhai Key Laboratory of Orogenic Belts and Crustal Evolution MOEBeijing 100871China School of Earth and Space Sciences Peking UniversityBeijing 100871China Department of Geosciences Virginia TechBlacksburgVA 24060U.S.A.

The Tonian Period witnessed important environmental changes and critical evolutionary innovations. Published iron speciation data suggest a global redox transition of mid-depth seawaters from euxinic to ferruginous in early Tonian, but details of this transition remain unknown. This study explores Tonian stromatolitic carbonates as a possible archive of paleoenvironmental changes, through the investigation of dolomitic limestones and dolostones associated with stromatolites of the Weiji Formation in the Huaibei region of North China. Three types of dolomitization are recognized on the basis of petrographic and geochemical data. Type Ⅰ and Ⅱ dolomitization resulted in dolomitic limestones characterized by LREE depletions, MREE enrichments, positive yttrium anomalies, and a lack of europium anomalies, indicating early diagenetic dolomitization, possibly in the iron reduction zone and under the influence of bottom seawater. The lack of cerium anomalies in these carbonates suggests anoxia in shallow marine environments. The coexistence of ferroan/non-ferroan dolomite crystals and overgrowth bands is interpreted as possible evidence for rapid fluctuations between iron-rich and iron-depleted conditions in pore-waters or seawaters. In contrast, type Ⅲdolomitization resulted in pervasively dolomitized stromatolitic carbonates and likely represents late diagenetic processes. This study highlights the potential of early diagenetic dolomite as an archive for paleoenvironmental investigations.

关键词： redox early diagenesis rare earth elements dolomite Neoproterozoic North China

dolomite fracture modeling using the Johnson-Holmquist concrete material model:Parameter determination and validation

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第2期13卷 335-350页

作者： Michal Kucewicz Pawel Baranowski Jerzy Maachowski Faculty of Mechanical Engineering Institute of Mechanics and Computational EngineeringMilitary University of Technology2 Gen.S.Kaliskiego StreetWarsaw00-908Poland

In this paper,the Johnson-Holmquist concrete(JHC)constitutive model is adopted for modeling and simulating the fracture of dolomite.A detailed step-by-step procedure for determining all required parameters,based on a series of experiments under quasi-static and dynamic regimes,is proposed.Strain rate coefficients,failure surfaces,equations of state and damage/failure constants are acquired based on the experimental data and finite element analyses.The JHC model with the obtained parameters for dolomite is subsequently validated using quasi-static uniaxial and triaxial compression tests as well as dynamic split Hopkinson pressure bar(SHPB)tests.The influence of mesh size is also analyzed.It shows that the simulated fracture behavior and waveform data are in good agreement with the experimental data for all tests under both quasi-static and dynamic loading conditions.Future studies will implement the validated JHC model in small-and large-scale blasting simulations.

关键词： Johnson-Holmquist concrete(JHC)model Rock modeling dolomite Constitutive modeling Split Hopkinson pressure bar(SHPB) Fracture Triaxial compression

Characteristics, formation and evolution of pre-salt dolomite reservoirs in the fifth member of the Ordovician Majiagou Formation, mid-east Ordos Basin, NW China

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Petroleum Exploration and Development 2019年第6期46卷 1153-1164页

作者： FU Siyi ZHANG Chenggong CHEN Hongde CHEN Anqing ZHAO Junxing SU Zhongtang YANG Shuai WANG Guo MI Wentian State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu 610059China Institute of Sedimentary Geology Chengdu University of TechnologyChengdu 610059China School of Mines Inner Mongolia University of TechnologyHohhot 010051China

The characteristics and formation of the pre-salt dolomite reservoirs in the fifth member of Ordovician Majiagou Formation in the mid-east Ordos Basin are investigated through observation of cores and thin sections,and geochemical analysis.(1)The pre-salt dolomites can be divided into dolomicrite,grain dolomite and dolarenite,in which the main reservoir space consists of intercrystalline pores and various dissolved pores.(2)The diagenesis in the study area is complex and mainly includes dolomitization,dissolution,filling,and recrystallization.(3)Multi-stages of dolomitization,including penecontemporaneous capillary concentration dolomitization,seepagereflux dolomitization during penecontemporaneous and shallow burial stage,and burial dolomitization in later stage,are conducive to the preservation of primary pores and development of secondary pores.(4)Multi-stages of dissolution also have strong influence on the development of secondary pores;the secondary transgression and regression cycles during the contemporaneous-penecontemporaneous stage led to exposure and dissolution of soluble minerals and thus the generation of secondary pores.(5)In the burial stage,reservoir pores were further improved due to organic acid dissolution and the dissolution by hydrosulphuric acid from thermochemical sulfate reduction(TSR)and its product H2S.(6)High H2S concentration area in pre-salt reservoirs can thus be considered as targets for future exploration.

关键词： Ordos Basin Ordovician Majiagou Formation dolomite evaporites dolomitization dissolution

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