Trace and Rare Earth Element Geochemistry of Micrite Mound Carbonates and Other Related REE Mineralized Carbonates from Bayan Obo Area in Inner Mongolia

Whatismicritemound?Itisthegeological body,whichismadefrommicro carbonate,micro andothersubstancesformedataspecificenviron ment,whoseshapeislikesmallhill[1,2].However, itcannotbefoundinthepre Cambriansedimentary rocksduetotheverystrongalterationduringthe…     

Trace Elements and Rare Earth Elements of Sulfide Minerals in the Tianqiao Pb-Zn Ore Deposit, Guizhou Province, China

Trace elements and rare earth elements(REE)of the sulfide minerals were determined by inductively-coupled plasma mass spectrometry.The results indicate that V,Cu,Sn,Ga,Cd,In,and Se are concentrated in sphalerite,Sb,As,Ge,and Ti are concentrated in galena,and almost all trace elements in pyrite are low.The Ga and Cd contents in the light-yellow sphalerites are higher than that in the brown and the black sphalerites.The contents of Ge,Ti,In,and Se in brown sphalerites are higher than that in light-yellow sphalerites and black sphalerites.It shows that REE concentrations are higher in pyrite than in sphalerite,and galena.In sphalerites,the REE concentration decreases from light-yellow sphalerites,brown sphalerites,to black sphalerites.The ratios of Ga/In are more than 10,and Co/Ni are less than 1 in the studied sphalerites and pyrites,respectively,indicating that the genesis of the Tianqiao Pb-Zn ore deposit might belong to sedimentary-reformed genesis associated with hydrothermal genesis.The relationship between LnGa and Lnln in sphalerite,and between LnBi and LnSb in galena,indicates that the Tianqiao Pb-Zn ore deposit might belong to sedimentary-reformed genesis.Based on the chondrite-normalized REE patterns,δEu is a negative anomaly(0.13-0.88),andδCe does not show obvious anomaly(0.88-1.31); all the samples have low total REE concentrations(<3ppm)and a wide range of light rare earth element/high rare earth element ratios(1.12-12.35).These results indicate that the ore-forming fluids occur under a reducing environment.Comparison REE compositions and parameters of sphalerites,galenas,pyrites,ores,altered dolostone rocks,strata carbonates,and the pyrite from Lower Carboniferous Datang Formation showed that the ore-forming fluids might come from polycomponent systems,that is,different chronostratigraphic units could make an important contribution to the ore-forming fluids.Combined with the tectonic setting and previous isotopic geochemistry evidence,we conclude that the ore-deposit genesis is hydrothermal,sedimentary reformed,with multisources characteristics of ore-forming fluids.     

湖南东山下锰矿地质特征及找矿前景分析

东山下锰矿是舂陵水两岸风化淋滤型氧化锰矿的典型矿床之一,二叠系孤峰组硅质岩是锰矿的赋存层位,南北向挤压破碎带是矿区的导矿和容矿构造,矿区的地层、岩性、含锰建造、地质构造、气候和地貌等条件均对成矿十分有利,分析研究此类矿床成因进而寻找类似锰矿床对缺锰地区具重要意义。     

辽宁白云金矿床地球化学异常分带模型与找矿预测标志

白云金矿是辽东青城子矿田的一处大型金矿床,矿体赋存于辽河群盖县组碎屑岩中,受白云EW向断裂控制。构建矿床地球化学异常分带模型,总结找矿预测标志,有助于开展深部及矿区外围的找矿预测。通过对白云金矿床不同中段微量元素与烃类组分的含量变化及其在矿体周围的异常展布特征和富集规律进行分析总结,得出该矿床原生晕分带序列为：Hg、烃类（前缘晕）→As、Sb（矿头晕）→Au、Ag、Cu、Pb、Zn（近矿晕）→Co、Ni、Mo、Bi、Mn（尾晕）。研究表明,白云金矿床向深部仍有一定的找矿空间,矿床地球化学异常分带模型对区域上寻找同类型矿床具有一定的参考价值。     

重庆市秀山县老田庄锰矿地质特征及矿床成因分析

南华系下统大塘坡组第一段为本区的含锰岩系,其厚度及岩性组合与锰矿有着直接的关系。本区锰矿属沉积菱锰矿矿床类型,具有多层含矿性。古地理、古构造对锰矿沉积的控制作用,在还原环境的条件下,沉积了一套以含炭质水云母页岩为主的黑色含锰岩系地层,锰矿即产于含锰岩系地层之底部。     

Rare Earth Elements Geochemistry of Laowan Gold Deposit in Henan Province： Trace to Source of Ore-Forming Materials

The compositions of REE in quartz and pyrite from the main stage of the Laowan gold deposit in Henan Province and that in quartz from Laowan granite were determined by inductively coupled plasma-mass-spectrometry (ICP-MS) to trace the source of ore-forming materials. Meanwhile, the REE compositions of the deposit ore, granite and metamorphic wall rock were also considered for comparative studies in detail. The range of ∑REE of quartz and pyrite from the deposit ores is 4.18×10-6～30.91×10-6, the average of ∑REE is 13.39×10-6, and the average of ∑REE of quartz in the Laowan granite is 6.68×10-6. There is no distinct difference of REE parameters between the deposit ore quartz and granite quartz. The quartz in gold deposit has the same REE particular parameters as quartzes from Laowan granite, such as δEu, δCe, (La/Yb)N and (La/Sm)N, partition degree of LREE to HREE, especially, the chondrite-normalized REE patterns, but no similarity to those from metamorphic wall rock, which shows that ore-forming hydrothermal fluid is mainly the fluid coming from the Laowan granite magma, rather than metamorphic fluid. Meanwhile, comparison studies on REE features between minerals from the deposit ores and related geological bodies in the deposit show that REE characteristics of minerals can serve as an indicator of ore-forming fluid properties and sources, while the REE characteristics of the bulk samples (such as deposit ores, granites and wall rocks) can not trace the source of the ore-forming materials exactly.     

华力西—印支期海相沉积盆地演化与广西下雷锰矿床成矿关系探讨

主要研究华力西—印支期海相沉积盆地演化,从古地理、沉积相和地层时代几个关键因素出发,结合广西下雷锰矿床的地质特征,分析了盆地演化的几个重要因素与下雷锰矿床的成矿关系。认为华力西—印支期为锰矿床沉积的重要时期,而晚泥盆世为下雷锰矿床的地层年代控矿因素,硅质岩—碳酸盐沉积相为矿层层控特征,下雷浅海盆地的差异性沉降和断裂作用,是形成下雷锰矿巨型矿床的关键原因。     

湖南奥陶纪天马山组中沉积型氧化锰矿成矿地质条件

在湖南常宁市茶潦村的天马山组下段地层中,首次发现有沉积型氧化锰矿存在。矿区位于南岭纬向成矿构造带的中段北缘,属于塔山隆起构造变形区,矿区天马山组主要由浅变质砂岩和板岩组成,矿床产于天马山组下段,矿区内褶皱、断裂构造与成矿关系密切。矿区内锰矿带断续延展3 km,有3个锰矿层,深度目前未探明,找矿前景良好。     

Improved manganese extraction in the production of manganese ferroalloys

In the production of manganese ferroalloys from ore, about 50% of the manganese in the ore is lost. The manganese lost with the enrichment-slag tailings may be returned to the production of manganese ferroalloys by dithionate method of enrichment of the slurries. A technology is developed for the production of high-carbon ferromanganese from concentrate obtained by the chemical enrichment of tailings slurries. Low-phosphorus Mn slag is used in the production of ferrosilicomanganese and refined manganese ferroalloys. A method is described for alloying hot metal with manganese from slag during the production of lowand medium-carbon ferromanganese. Processes are developed for the production of medium-carbon ferromanganese by mixing ore–limestone melt with high-carbon ferromanganese and removing the phosphorus from Mn-bearing melts by bubbling with CO. The degree of phosphorus removal (70–90%) depends on the bubbling time. By means of improved production of manganese ferroalloys and extraction of manganese from slag and slurries, the manganese extraction may be significantly increased.     

Sulfuric acid leaching of polymetallic Abu Zeneima gibbsite-shale

The gibbsite shales belonging to the Paleozoic sequence of sedimentary rocks occurring at the Abu Zeneima area in SW Sinai Egypt has been found to host several economic metal values. These include Al, Cu, Zn, Co, Ni, REE, and U beside several Mn minerals. In this work, the ore was subjected to sulfuric acid leaching to maximize extraction of these metal values. The optimum leaching conditions were 800 g/L acid with a Solid/Liquid ratio of 1/2 at 100 °C for 4 h and using an ore size of − 60 mesh. Under these conditions, it was possible to achieve high leaching efficiencies with complete leaching of Al together with 93.0% Cu, 58.6% Zn, 69.0% Co, 92.6% Ni and 84.4% U. Extension of the leaching time to 8 and 12 h significantly improved the leaching efficiencies of Co and Zn to 91.0% and 84.0% respectively.     

内蒙古自治区阿鲁科尔沁旗阿根他拉铜矿床地质特征及成因分析

阿根他拉矿床的控矿层位为二叠系黄岗梁组,矿床由侵入的花岗斑岩、沉积的碳酸盐岩及层间断裂构造破碎带共同控制,围岩蚀变有明显的分带现象,矽卡岩化近岩体处蚀变最强,赋矿岩石为矽卡岩、矽卡岩化大理岩。通过分析研究矿床的地质特征、成矿规律及控矿因素,提高对矿床的控制程度,确定了矿床成因,并指出了找矿标志。     

Contrasting REE Signatures on Manganese Ores of Iron Ore Group in North Orissa, India

The distribution pattern of Rare Earth Elements （REE） in three categories of manganese ores viz. stratiform, stratabound-replacement, and detrital of Precambrian Iron Ore Group from north Orissa, India was reported. These categories of Mn-ore differed in their major and trace chemistry and exhibited contrasting REE signature. The stratiform ores were relatively enriched in ∑REE content （697 μg·g^-1） and their normalized pattern showed both positive Ce and Eu anomalies, whereas the stratabound-replacement types were comparatively depleted in ∑REE content （211 μg·g^-1） and showed negative Ce and flat Eu signatures. The detrital categories showed mixed REE pattern. The data plotted in different discrimination diagrams revealed a mixed volcaniclastic and chemogenic source of material for stratiform categories, and LREE （Light Rare Earth Elements） and HREE （Heavy Rare Earth Elements） are contributed by such sources, respectively. In contrast, the stratabound ore bodies were developed during the remobilization of stratiform ores, and associated Mncontaining rocks under supergene condition followed by the redeposition of circulating mineralized colloidal solutions in structurally favorable zones. During this process, some of the constituents were found only in very low concentration within stratabound ores, and this is attributed to their poor leachability/mobility. The detrital ores did not exhibit any significant characteristic in respect of REE as their development was via a complex combination of processes involving weathering, fragmentation, recementation, and burial under soil cover.     

新疆哈密市大水锰矿矿床成因及找矿模型探讨

红柳河-大水锰矿带是东天山成矿带的主要组成部分,其成矿带内的大水锰矿规模最大,锰矿石品位较高,有重要的工业价值。本文以大水锰矿为例,从矿床地质特征,矿体矿石特征入手,结合控矿因素分析其矿床成因,明确找矿标志,建立综合信息找矿模型,为该区的接下来的锰矿勘察工作指明方向。     

辽宁省岫岩县中沟铜铁矿床地质特征及其找矿意义

中沟铁铜矿床是20世纪90年代在辽宁省岫岩县大营子镇境内发现的,属于沉积变质热液再造型铁铜矿床。本文从矿床地质特征、矿区物化探异常、成矿地质条件等方面,分析其对该成矿区带的找矿意义,以扩大找矿前景。     

Effect of surface manganese oxide species on soot catalytic combustion of Ce–Mn–O catalyst

Constructing cerium and manganese bimetallic catalysts with excellent catalytic performance for soot combustion is the research frontier at present. In order to find out the key factors for catalytic soot combustion of Ce–Mn–O catalysts, a series of Ce–Mn–O catalysts with different Ce/Mn proportions were prepared by co-precipitation method. The activity test results show that it increases first and then decreases with the increase of Mn content. The best catalytic activity is obtained for Ce_0.64Mn_0.36 catalyst, which shows a maximum rate temperature (T_m) at 306 °C for CO₂ production in TPO curve. Compared with non-catalytic soot combustion, the T_m decreases by more than 270 °C. Systematical characterization results suggest that when the adsorbed surface oxygen, lattice oxygen, specific surface area and total reduction amount of the catalysts reach a certain value, the key factors leading to the difference of catalytic activity become the readily reducible and highly dispersed surface manganese oxide species and contact performance of the external surface. The surface manganese oxide species is beneficial to improving the low-temperature reducibility of catalysts and the porous surface is conducive to the contact between catalyst and soot. Furthermore, for the soot combustion reaction containing only O₂, the promoting effect of Mn⁴⁺ is not obvious.     

贵州赫章铜厂沟铜矿稀土元素地球化学特征及成矿物源示踪

通过对赫章铜矿化带的野外地质调查、采样、室内显微镜下分析、化学分析、扫描电镜、X衍射成分分析,研究了铜矿的矿物组成、矿石类型特征(初步划分为砂岩型铜矿石和蚀变构造角砾岩型铜矿石),矿石铜品位为3.26%～3.88%。采用ICP-MS方法测定了赫章铜矿两类型矿石、赋矿围岩及峨眉山玄武岩的稀土元素及微量元素组成,并进行了稀土特征值等的对比研究;LREE/HREE比值为9.43～11.12,La/Yb比值为11.86～14.6,显示出各样品轻稀土明显富集;δCe值为0.75～0.84,显示出负异常。除HTC-3的δEu=1.11、显示出很弱正异常外,其余样品的δEu=0.94～1.06,Eu仅显示非常微弱的异常。铜厂沟铜矿岩矿样品微量元素分布模式图表明其分布特征具有同源性。通过研究各样品的稀土元素、微量元素地球化学特征、铜矿化蚀变过程中稀土元素的迁移规律及呈现继承性的特点,结合飞仙关组砂岩的形成环境,得出峨眉山玄武岩为铜矿成矿(矿化)的物质来源结论。     

Dissolution behaviour of manganese ore in basic oxygen furnace type slag

In order to improve manganese yield during the reduction process of manganese ore in blowing practices employing less slag at BOF, the dissolution behaviour of manganese ore in slag has been studied in an experimental scale. The effect of temperature, slag composition, addition of CaF₂, and pre-treatment of manganese ore was examined for the dissolution behaviour of manganese ore into BOF type slags. The precipitation of (Fe,Mn)O phase in slag was observed during the addition of manganese ore. The dissolution rate of manganese ore into molten slag increased with temperature, and also increased with the initial contents of FeO, MgO and MnO. However, the effect of slag basicity was not evident on the dissolution rate of manganese ore into slag. The addition of CaF₂ and pre-treatment of Mn ore were very effective to promote the dissolution of manganese ore into slag.     

New Varieties of Na-Ca-Ba-RE Fluorocarbonate Series Minerals

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Study on Red Long-Time Luminescent Material Y2O2S:Eu,M (M = Mg,Ca, Sr,Ba)

The red long-time luminescent material Y₂O₂S:Eu³⁺, M (M = Mg, Ca, Sr, Ba) was prepared by high temperature solid-state method. The XRD result of the sample showed that the crystal phase was Y₂O₂S, which belong to hexagonal system, and no new crystal phase were by doping different amount of Mg, Ca, Sr, Ba. The excitation spectrum was a broad band within 200 × 400 nm region, the characteristic peaks of emission spectrum were located at 583, 595, 597, 617, 627, 707 nm. There was no marked change in excitation spectra, emission spectra and maximum of their wavelengths of the luminescent materials by doping with different ions. The luminescent intensity of the phosphors were stronger when the concentration of doping ions was Mg/Y = 6%, Ca/Y = 4%, Sr/Y = 8%, Ba/Y = 2.5%, respectively. Its sequence of luminescent intensity from high to low is Sr > Ba > Mg > Ca.