Form Of Isomorphism Research Articles

Trace element signatures of sphalerite in the Sichuan Daliangzi Ge-rich Pb-Zn deposit and its implications for deep ore prospecting

The Daliangzi Pb-Zn deposit is one of the typical Ge-rich Pb-Zn deposits in the Sichuan-Yunnan-Guizhou Pb-Zn polymetallic metallogenic triangle area (SYGT), with its Pb, Zn, and Cd reserves reaching the scale of a large-sized deposit and its Ge reserve reaching that of a medium-sized deposit. Based on LA-ICP-MS in-situ analysis in combination with element mapping, this study reveals the occurrence state of trace elements and ore-forming temperature of sphalerite in ores. The study shows that the sphalerite in the deposit is characterized by rich Cd, Ge, and Ga, relatively rich Fe, very variable Cu and Pb contents, and poor Mn, In, and Sn. This data indicates that Cd, Mn, Fe, and Pb occur in sphalerite in the form of isomorphism or locally in the form of microinclusions in galena. Good correlation between Cu(Ag) and Ge and that between (Cu+Ag) and (Ga+As+Sb) suggest that the substitution relationship with Zn is nCu2++Ge2+↔(n+1)Zn2+ or n(Cu, Ag)2++Ge2+↔(n+1)Zn2+ and (Cu+Ag)1++(Ga+As+Sb)3+↔2Zn2+, and chalcopyrite and Ge, Gu, and Ga-rich microinclusions exist locally; the contents of Ge, Cd, Cu, Pb, Fe, Mn, and other elements in brown yellow sphalerite are higher than those in light yellow sphalerite while Ga and In are relatively more enriched in the latter. The estimation by GGIMFis geothermometer and the trace element signature of the sphalerite indicates that the temperature of the deposit is low-moderate: the formation temperature of the sphalerite in stage II is 86–213°C (134°C on average) ∼ 106–238°C (170°C on average) and that in stage III is 88–105°C (96°C on average) ∼ 134–147°C (140°C on average), demonstrating that the precipitation mechanism of ore-forming elements is the drop in fluid temperature. Based on this, an ore-forming model of the deposit has been established, and it is believed that the ore district has potential for deep prospecting of Cu, Pb, Zn, and other metal resources.

Mediated by the giants: Tracing practices, discourses, and mediators of platform isomorphism in a media organization

News media are increasingly interwoven with social media platforms. Building on institutional theory, we trace the repercussions of the platform infrastructure inside a media organization by focusing on organizational discourses and practices in connection with the journalistic use of social media. The empirical material includes interviews, field notes, chat logs, and documents collected from a public service media organization during a 6-month on-site and virtual ethnography. The findings show how platform pressures intertwine with content production, audience representation, journalistic values, and organizational development, thus manifesting the infrastructuralization and institutionalization of platforms in the media industry. While the interviewees articulated tensions related to adopting social media, the fieldwork data revealed forms of mimetic and normative isomorphism, mediated by platform data and professional roles in the organization. Moreover, the platform infrastructure seems to cultivate both critical and aspirational talk in the organization, which implies a more complex relationship beyond coercive platform power.

Occurrence of yttrium in the Zhijin phosphorus deposit in Guizhou Province, China

Abstract The Zhijin phosphorite (P)-bearing rare earth element (REE) deposit in Guizhou Province (China) hosts vast ore resources (P: 1.348 billion tonnes; REE: 1.44 Mt). Up to date, the Zhijin phosphorite resource has not been exploited because of the uncertain occurrence of the associated REEs, which hampers mineral processing and extraction. In this study, the structure, the valence state, and the coordination position of Y in the REE-yttrium-rich bioclastic samples from Zhijin were revealed by means of synchrotron radiation X-ray absorption fine structure analysis. The results show that the Y occurs as Y(iii) in the samples, and that the form of Y is different from the Y2O3 form in standard xenotime samples. Yttrium in the samples was in a complex coordination position without Y–O–Y bonding, and the Y–O bond lengths range widely without clear patterns. We suggest that Y in the samples is surrounded by organic or macro-molecular compounds, rather than in inorganic ones. Thus, Y in collophanite is unlikely to be in the form of isomorphism.

Ore Genesis of the Dongping Gold Deposit in the Northern Margin of North China Craton: Constraints from In-Situ Major, Trace Elemental Analysis of Magnetite and Pyrite

The Zhangxuan district in North China, also known as Northwestern Hebei “Golden Triangle,” develops many intrusion-hosted lode-gold deposits. The Dongping gold deposit in the Zhangxuan district is well known for its unique hosting of rocks and ore mineral assemblages. Magnetite and pyrite are common minerals that widely exist in ores of the Dongping deposit. To get a better understanding of the evolution of the ore-forming fluids responsible for mineralization, we report on an integrated study on the electron microprobe analysis (EMPA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analysis of magnetite and pyrite from the deposit. The major results are as follows: The magnetite grains from the Dongping deposit show a variable content of major and trace elements such as Ti, Al, Si, Fe, Mn, Cr, Na, V, and Co, and the majority of the magnetite contain low Ti contents, revealing potential properties of hydrothermal magnetite. The flat time-resolved signals of LA-ICP-MS imply that the majority of trace elements in magnetite exist in the form of isomorphism, except for some incompatible trace elements. Magnetites from the Dongping deposit have compositional characteristics of hydrothermal origins, and the genetic discriminant diagrams of Ti–V, Ti–Ni/Cr or (Ca + Al + Mn)–(Ti + V) show that they may be originated from magma differentiated hydrothermal solutions. Co, Ni in pyrite from Dongping mainly enter the lattice via isomorphism, and Cu, Zn, Ag, W, Sn, Au, Pb, and Bi are partitioned into pyrite as micro/nano- mineral inclusions. The Co, Ni content, and the Ni/Co ratios, indicated that the temperature of the ore-forming fluids has decreased from Py-1 to Py-2, and the enrichment of Au in Py-2 may be related to the cooling and boiling of the fluids.

Why We Should Reject the Restrictive Isomorphic Matching Definition of Empathy

A growing cadre of influential scholars has converged on a circumscribed definition of empathy as restricted only to feeling the same emotion that one perceives another is feeling. We argue that this restrictive isomorphic matching (RIM) definition is deeply problematic because (1) it deviates dramatically from traditional conceptualizations of empathy and unmoors the construct from generations of scientific research and clinical practice; (2) insistence on an isomorphic form undercuts much of the functional value of empathy from multiple perspectives of analysis; and (3) combining the opposing concepts of isomorphic matching and self-other awareness implicitly requires motivational content, causing the RIM definition to implicitly require the kind of non-matching emotional content that it explicitly seeks to exclude.

Games and Scott sentences for positive distances between metric structures

We develop various Ehrenfeucht–Fraïssé games for distances between metric structures. We study two forms of distances: pseudometrics stemming from mapping spaces onto each other with some form of approximate isomorphism, and metrics stemming from measuring the distances between two spaces isometrically embedded into a third space. Using an infinitary version of Henson's positive bounded logic with approximations, we form Scott sentences capturing fixed distances to a given space. The Scott sentences of separable spaces are in Lω1ω for 0-distances and in Lω2ω for positive distances.

Intuitive master device for endoscopic robots withvisual-motor correspondence.

Master devices exclusively used for endoscopes with position control are being developed as an isomorphic form of endoscopes. These master devices are difficult to intuitively operate because the movement direction of the endoscopic image and control handle do not match. To solve this problem, a master device was developed. Its movement direction is compatible with that of the endoscopic image. It analyzes image movements according to flexible endoscopic ureteroscope movements for each degree of freedom. A driving testbed experiment was conducted that modelled the internal structure of a kidney. The time taken in the experiment was shorter when using the proposed master device than the existing isomorphic master device. The proposed device yielded fewer mistakes. It was confirmed the proposed device is effective in exclusive use for endoscopes because of its feasibility of position control and movement direction's coinciding with that of the endoscopic image.

Beliefs and (in)stability in normal-form games

In this paper, we use experimental data to study players’ stability in normal-form games where subjects have to report beliefs and choose actions. Subjects saw each of 12 games four times in a regular or isomorphic form spread over two days without feedback. We document a high degree of stability within the same (strategically equivalent) game, although time and changes in the presentation of the game do lead to less stability. To look at stability across different games, we adopt the level-k theory, and show that stability of both beliefs and actions is significantly lower. Finally, we estimate a structural model in which players either apply a consistent level of reasoning across strategically different games, or reasoning levels change from game to game. Our results show that approximately 23% of subjects apply a consistent level of reasoning across the 12 games, but that they assign a low level of sophistication to their opponent. The remaining 77% apply different levels of reasoning to different games. We show that this may be due to subjects being attracted to the action with the highest possible payoff.

Insights into neo-institutional theory in accounting and auditing regulation research

PurposeNeo-institutional theory (NIT) has strengthened its position as one of the theories and frameworks used to investigate accounting as organizational, legislative, social and policymaking phenomena. This study aims to review how aspects of NIT are used and understood by accounting researchers. As a growing body of accounting and auditing articles in recent years has used NIT as a theoretical framework, this paper reviews and analyzes articles using NIT.Design/methodology/approachThis study develops a comprehensive synthesis of current academic knowledge about NIT in accounting and auditing regulation literature. Further, it reveals areas requiring further examination.FindingsThe findings of this study indicate that prior studies have found evidence that accounting and auditing regulation is associated with all forms of isomorphism (coercive, mimetic and normative). For instance, institutional pressures influence the accounting and auditing standards adoption in different environments. Therefore, the synthesis of the literature suggests that coercive, mimetic and normative pressures have played a significant role in the harmonization of accounting and auditing practices worldwide. To conclude, NIT has become one of the relevant alternative approaches used to explore accounting and auditing regulation as a complex phenomenon.Research limitations/implicationsAccounting has often been referred to as a “narrow” and “technical” topic. In a way, NIT broadens the research field by extending, for instance, the approach of which external and internal pressures are associated with accounting standards adoption and why different accounting practices are adopted.Originality/valueThis study informs accounting scholars as to how NIT has been applied, and can be applied, in the accounting and auditing regulation literature. This benefits accounting researchers if they are considering whether to use NIT in their research. This study evaluates the contribution of NIT within this research field. It can be suggested that accounting researchers need to become more aware of the debates within the NIT literature, particularly as the theory is seen as conceptually ambiguous. To conclude, the synthesis highlights that NIT has offered a range of important contributions and has drawn attention to the link between accounting and auditing regulation research and the institutional environment.

A preliminary study of reserve estimate and resource potential assessment of critical elements in the Jiaodong gold deposits, China

通过对大尹格庄和夏甸两个超大型金矿床的精金矿与尾矿砂中关键元素含量的分析，发现相对于华北克拉通地壳元素丰度，本次分析的稀贵元素Co、Rh、Ir和Ru，稀散元素Cd、Te和Se，稀有元素W和In均发生了不同程度的富集；特别是Te、Co和Cd超常富集达到伴生组分综合评价品位。根据伴生有用组分综合评价规范和金矿选矿报告相关参数，分别估算了金矿石和精金矿中可利用的关键金属矿产储量，其中夏甸金矿床内Te储量为69吨（精金矿中52吨）、Co储量为604吨（精金矿中413吨），大尹格庄金矿床内Cd储量为224吨（精金矿中206吨），这些均可直接回收利用。矿物学和矿物化学综合研究表明：Te主体以碲金矿、碲银矿、碲铋矿、碲铅矿和陈国达矿等独立矿物存在，与可见金密切共生；Co常以微量元素形式分布在金成矿早阶段的粗粒黄铁矿和磁黄铁矿中；Cd主要以类质同象的形式赋存于金成矿晚阶段的闪锌矿、黄铁矿和黄铜矿中。进一步通过对典型金矿床中黄铁矿原位和/或单矿物的Te与Co含量对比、并结合矿石中Co与Cd元素组成及其区域地球化学空间分布特征，综合约束了其超常富集特征与资源潜力，揭示新城、玲珑和寺庄金矿床及栖霞异常区分别有约2329吨、1035吨、1553吨和22790吨Co资源量，乳山、新城和焦家金矿床有约1529吨、126吨、216吨Te资源量，仓上、新立、三山岛、寺庄和新城金矿床、以及栖霞和招平北段异常区分别有约47.6吨、78吨、63.7吨、69吨、3564吨、7120吨和696吨Cd资源量；即胶东金矿集区具备近期被综合利用或作为未来潜在接替资源的Co、Te和Cd资源条件，且其展布区域广泛、资源潜力巨大。初步研究已显示胶东具有形成大型-超大型Cd、Te和Co矿床的资源条件，但关键金属资源的空间分布极不均一、其超常富集机理与规律尚不清楚，亟需深入研究。;Through analysis of critical element content in fine gold mine and tailing sands of the two super-large gold deposits of Dayingezhuang and Xiadian, it is found that relative to abundance of elements in crust of the North China Craton, rare and precious elements Co, Rh, Ir and Ru, scattered elements Cd, Te and Se, and rare elements W and In have all been enriched to different degrees; Especially, extreme enrichment of Te, Co and Cd has reached the comprehensive evaluation grade of associated components. According to comprehensive evaluation specifications of associated useful components and relevant parameters of gold beneficiation report, the available critical metal reserves in gold ores and fine gold mines were estimated respectively. The Te reserves in the Xiadian gold deposit are 69 tons (52 tons in fine gold mine), Co reserves are 604 tons (413 tons in the fine gold mine), and the Cd reserves in the Dayingezhuang gold deposit are 224 tons (206 tons in the fine gold mine), all of which can be directly recycled. Mineralogy and geochemistry studies show that Te mainly exists as independent minerals such as gold telluride, silver telluride, bismuth telluride, lead telluride and Chenguoda mineral, and they are closely associated with visible gold; Co is often distributed in the form of trace elements in the coarse-grained pyrite in the early stage of the gold mineralization; Cd mainly occurs in the sphalerite, pyrite and chalcopyrite in the late stage of gold mineralization in the form of isomorphism. Furthermore, by comparing the Te and Co content of pyrite in situ and/or single minerals in typical gold deposits, combined with the elemental composition of Co and Cd in the ore and its regional geochemical spatial distribution characteristics, the extreme enrichment characteristics are comprehensively restricted. The Xincheng, Linglong and Sizhuang gold deposits and the Qixia anomaly area have about 2329 tons, 1035 tons, 1553 tons, and 22790 tons of Co potential resources, respectively, and the Rushan, Xincheng and Jiaojia gold deposits have about 1529, 126, and 216 tons of Te resources, the Cangshang, Xinli, Sanshandao, Sizhuang and Xincheng gold deposits, and the Qixia and northern Zhaoping anomaly areas are about 47.6 tons, 78 tons, 63.7 tons, 69 tons, 3564 tons, 7120 tons and 696 tons of Cd resources, respectively; that is, the Jiaodong gold mining area has the Co, Te, and Cd resource conditions that are comprehensively utilized in the near future or as potential replacement resources in the future, and its spread area is wide and the resource potential is huge. Preliminary studies have shown that Jiaodong has the resource conditions for the formation of super-large Cd deposits, large-scale Te and Co deposits, but the spatial distribution of critical metal resources is extremely uneven, and its extreme enrichment mechanism and law are still unclear, and in-depth research is urgently needed.

Enhancing transparency through the new Directive 2014/95/EU transposition – An institutional isomorphism perspective

ABSTRACT This study explores the non-financial perspective of reporting settled by the Directive 2014/95/EU. The analyses conducted assess transposition both quantitatively and qualitatively. This enriches the existing literature by shedding light on how institutional isomorphism (mimetic, coercive, and normative) influenced the adoption process across all EU Member States. The findings provide evidence of all forms of isomorphism, with significant influences from the mimetic and normative pressures. Thus, countries with a higher ability to embrace new rules based on resemblance with existing practice, and relying on greater openness towards change sustained by their professionalism in auditing and reporting, were more likely to transpose the new Directive. Moreover, the institutional isomorphism positively influenced comparability, consistency, accessibility and timeliness of non-financial disclosure. Finally, the study brings forth a mapping visualisation of the three patterns expressing how this legislative reform achieved its desired outcome – enhanced transparency.

Enrichment of rare earth elements in the early Cambrian Zhijin phosphorite deposit, SW China: Evidence from francolite micro-petrography and geochemistry

The Zhijin phosphorite deposit is a giant early Cambrian rare earth element (REE) deposit, with particular enrichment in heavy REEs, and is of high economic significance. The REEs of the deposit occur almost entirely in apatite, which, on the basis of petrographic characteristics, can be divided into francolite grains (90%), amorphous apatite, and phosphate fossils. In this paper, we report an investigation into francolite grains in different types of phosphorite from ore sections of the Zhijin deposit. Detailed petrographic and transmission electron microscopy observations reveal that the francolite grains are composed of nano-apatite crystals measuring 120–160 nm long. Trace-element contents of pyrite and whole-rock geochemical indicators (such as Cr/Zr and V/Ni ratios and Th/U–Co/Ni plots) suggest that the Zhijin phosphorite formed in an anoxic hydrothermal sedimentary environment. However, the negative Ce/Ce* and Eu/Eu* anomalies indicate that the diagenetic environment of the francolite grains was oxidic. Different diagenetic redox environments and the presence of transportation fractures in francolite grains identified under back-scattered electron imaging reveal that the francolite grains underwent prolonged abrasion and transportation in seawater before sedimentation. Petrographic observations and laser ablation–mass spectrometry element surface scanning analyses indicate that the REEs are uniformly distributed in nano-apatite in isomorphic form, and no nano-inclusions or REE minerals were found, implying that late mineralization was not the cause of REE enrichment. The higher (La/Yb)N ratios of francolite grains relative to seawater indicate that the francolite grains captured abundant REEs during the early diagenetic stage. We infer that prolonged exposure to seawater and the high specific surface area of francolite grains are the key factors that led to the enrichment in REEs. Combining the timing of the metallogenic epoch (543 Ma), Sr–Nd isotopic data, and the Y/Ho ratio, which is close to those of modern seawater, indicates that the REEs were sourced from paleo-seawater. Paleogeographic information suggests that during the early Cambrian, extensive continental collisions caused great amounts of continental weathering products to enter the paleo-ocean, leading to the production of abundant amounts of hydrothermal–sedimentary phosphorus and REEs in shallow seas, thus forming an ideal sedimentary environment for generating the REE resources of the Zhijin phosphorite deposit.

Spinel ferrite transformation for enhanced upgrading nickel grade in laterite ore of various types

Upgrading nickel grade in low-grade nickeliferous laterite ores before metallurgical extraction process is of utmost importance. However, most of nickel exists mainly in the form of isomorphism in serpentine or goethite, resulting in difficulty in upgrading of nickel by physical separation methods. In this paper, spinel ferrite transformation for enhanced upgrading nickel grade in laterite ore of various types was proposed. The mineral phase transformation and migration of valuable metals for various laterite ores during calcination process was investigated, as well the influences of mineral phases and chemical compositions on magnetic properties, separation efficiency, and nickel contents in separated laterite ore. The results show that spinel nickel ferrite mainly composed of nickel oxide and iron oxide could be completely formed after calcined at 800, 1000 and 900 °C for limonite, saprolite and transition laterite ore, respectively. With the increase of calcination temperature, the crystallinity and saturation magnetization Ms value of as-calcined samples become improved, leading to increased nickel recovery, while the nickel content in magnetic fraction is first increased and then slightly decreased. Under the optimum calcination conditions, the nickel recovery for limonite, saprolite and transition laterite ore could reach 68.5%, 68.9% and 67.3%, respectively, while the nickel contents in magnetic fraction are 3.01%, 3.23% and 3.15% with increasing by 1.82, 2.27 and 2.11 times, respectively. This paper could provide theoretical basis and technology support for enhanced upgrading of valuable metals from complex associated mineral resources.

LA-ICPMS trace elements of pyrite from the super-large Dulong Sn-Zn polymetallic deposit, southeastern Yunnan, China

滇东南马关都龙是一个以锡锌为主，共-伴生铟、铜、铅、钨、铁、银等多种元素的锡锌多金属超大型矿床。虽然前人从矿物学、矿床地球化学、年代学等不同角度开展了较多的研究，该矿床锡锌多金属矿化为燕山晚期岩浆热液活动的产物已是不争的事实，但关于该矿床是否存在热水沉积作用及其与锡锌多金属成矿作用的关系依然存在较大争议。本文选取都龙矿区广泛存在的黄铁矿作为主要研究对象，在矿相学基础上利用LA-ICPMS对不同阶段黄铁矿的微量元素组成开展了系统的研究。野外及显微鉴定结果表明，矿区存在四种类型（期次）的黄铁矿，即：鲕状黄铁矿Py1；穿切或交代Py1的细脉状黄铁矿Py2；与闪锌矿等硫化物共生的自形黄铁矿Py3；包裹早期黄铁矿或闪锌矿等硫化物的他形黄铁矿Py4。LA-ICPMS分析结果表明，该矿床黄铁矿中富集多种微量元素，其中Co、Ni、As、Ge等元素以类质同象的形式存在黄铁矿晶格中，而其余元素多以显微矿物包体形式赋存于黄铁矿中。上述四期黄铁矿微量元素组成存在较大差别，Py1相对富集Zn和As，而其余微量元素含量较低，Co与Ni含量较低，Co/Ni比值远低于1.00，其微量元素组成与典型沉积作用形成黄铁矿基本一致；Py2与Py1具有相似的微量元素组成特征，其Co/Ni比值接近Py1变化范围；Py3和Py4除富集Zn、As外，Mn、Co、Ni、Cu、Sb、Pb、Bi元素含量也相对较高，其Co/Ni比值相对较高，多大于1，与典型岩浆热液型黄铁矿微量元素组成相似，而与沉积型黄铁矿差异明显。结合各阶段黄铁矿产出地质特征，对比不同类型黄铁矿微量元素组成，本研究认为：Py1鲕状黄铁矿为热水沉积作用形成；Py2为Py1变质改造形成的细脉状黄铁矿，其微量元素继承了Py1；Py3为岩浆热液活动形成的自形黄铁矿；Py4为岩浆热液活动晚期形成的他形黄铁矿，Ag和Bi组成作为区分不同成因类型黄铁矿的化学指标的潜力。矿区早期沉积作用形成鲕状黄铁矿过程可能为后期成矿作用提供了部分硫源及少量Zn等成矿物质，海西-印支期区域变质改造作用对矿区成矿作用影响不大，而燕山晚期岩浆热液活动才是矿区锡多金属大规模成矿作用的主导因素。;The Dulong Sn-Zn polymetallic deposit, located in the southeastern Yunnan Province, is a super-large Sn-Zn polymetallic deposit with by-products of In, Cu, Pb, W, Fe, Ag, etc. Many studies on mineralogy, ore deposit geochemistry and chronology have been carried out on this deposit, confirming a genetical relationship of its Sn-Zn mineralization to the Late Yanshanian magmatic activity. However, whether the deposit underwent exhalative sedimentary Sn-Zn mineralization is still controversial. Based on detailed petrographic observation, the LA-ICPMS trace element compositions of pyrite that widely occur in the Dulong deposit are investigated systematically in this paper. Field and microscopic observations show that four types of pyrite have been identified in Dulong, including the oolitic pyrite (Py1), fine vein pyrite (Py2) crosscutting and/or replacing Py1, euhedral pyrite (Py3) coexisting with sphalerite and other sulfides, anhedral pyrite (Py4) enclosing early generated pyrite and sphalerite. LA-ICPMS analysis results suggest that pyrite is enriched in Co, Ni, As and Ge, which are mainly incorporated into the pyrite lattice in the form of isomorphism. Other elements occur mostly as mineral micro-inclusions in pyrite. The trace element compositions of the four types' pyrite exhibit significant difference from each other: Py1 is enriched in Zn and As but depleted in Co, Ni and Cu with low Co/Ni ratios (<1.0), which share similar features with typical sedimentary pyrite; Py2 is similar in its trace element compositions and Co/Ni ratios to those in Py1; while Py3 and Py4 have elevated Zn, As, Mn, Co, Ni, Cu, Sb, Pb and Bi contents with high Co/Ni ratios (mostly >1.0), which is consistent with that of euhedral pyrite formed by magmatic-hydrothermal activity rather than sedimentary pyrite. Comparing with the trace element compositions of pyrite in different types, we consider that Py1 is of sedimentary origin, Py2 that inherits the trace element features of Py1 is formed by metamorphic reworking of Py1, while Py3 and Py4 are formed by late magmatic-hydrothermal activity. Ag and Bi in pyrite display potential probobilities as a geochemical indicator to distinguish pyrite of different genetic types. Oolitic pyrite formed in the depositional diagenesis stage may provide some sulfur and a small amount of Zn for the later Sn-Zn mineralization. The regional metamorphic reworking in the Hercynian to Indosinian displays a limited effect on the Sn-Zn mineralization, while Late Yanshanian magmatic-hydrothermal activity is the controlling factor for the formation of the super-large scale Dulong Sn-Zn polymetallic deposit.

The occurrence and spatial distribution of cobalt in Longqiao iron deposit in Luzong Basin, Anhui Province

中国东部的长江中下游、莱芜、邯邢和临汾等矿集区中发育大量的矽卡岩型铁矿床，其中普遍伴生钴，部分矿床估算伴生钴资源量大于1万t，达到中型钴矿床的规模。已有研究表明，中国东部富钴矽卡岩型铁矿床的成矿时代相同，成矿特征相似，均为中国东部130Ma大规模成矿作用的产物，反映较大规模的铁钴成矿作用受统一的动力学背景控制。钴与其他伴生组分一样，其工业价值主要不取决于矿石中钴的含量，而取决于钴的赋存状态，因此开展矽卡岩型铁矿床中钴的赋存状态和分布规律研究具有重要的理论和实践意义。龙桥矽卡岩型铁矿床位于长江中下游成矿带，是目前发现的成矿带内伴生钴含量最高的矿床。矿床主矿体长1000m，成矿岩体位于矿体中部，黄铁矿分布范围广，距离岩体中心不同距离均有分布，是研究矽卡岩型铁矿床中钴赋存状态和空间分布规律的理想对象。本次研究在龙桥铁矿床勘探巷道-370m平面自西向东采集了9件含黄铁矿样品，黄铁矿主要呈浸染状-细脉状交代磁铁矿。研究表明，龙桥铁矿床中钴主要赋存在黄铁矿和磁铁矿中，其次为独立钴矿物（主要为辉砷钴矿）。黄铁矿的LA-ICP-MS微区微量元素分析结果表明，龙桥黄铁矿中Co（0.019×10^-6~5639×10^-6）、Ni（0.025×10^-6~5798×10^-6）和As（0.46×10^-6~14526×10^-6）的含量均具有较大的变化范围，黄铁矿总体上具有边缘富钴、核部贫钴的特征，黄铁矿边部的钴含量是核部的100~1000倍。通过对LA-ICP-MS测试数据以及时间分辨率剖面的逐一对比，推测Co主要以类质同象形式替代Fe进入黄铁矿晶格。由于钴在黄铁矿中分布极不均匀，不同空间位置采集的黄铁矿样品中Co含量平均值和变化范围没有明显规律。本文通过类比，提出中国东部矽卡岩型铁矿床中钴矿物可能是普遍存在的，但以前受限于分析测试手段未能发现；如何在选矿过程中分离富集钴矿物和富钴黄铁矿，是矽卡岩型铁矿床硫精粉中钴回收利用的关键。;A large number of skarn-type iron deposits are developed in the Middle-Lower Yangtze River, Laiwu, Hanxing and Linfen areas in eastern China. The average grades of cobalt in those iron deposits are 0.01%~0.03%, and some iron deposits are estimated to contain more than 10,000 tons associated cobalt resources (medium-sized cobalt deposit). Previous studies have shown that those Co-rich skarn iron deposits in eastern China have the same metallogenic age and similar metallogenic characteristics, which are the products of large-scale mineralization event at 130Ma in eastern China, indicating that the large-scale Fe-Co mineralization is controlled by same mineralization process. According to previous studies, independent cobalt minerals are very rare in skarn iron deposits, and pyrite is the main Co-bearing mineral, but the occurrence and spatial distribution of cobalt in skarn iron deposit is still unknown. The Longqiao skarn iron deposit with average 0.01% of cobalt is located in the Middle-Lower Yangtze River metallogenic belt. The main ore body of the deposit is 1000m long, and the ore-forming intrusion is located in the middle of the ore body. Pyrite is widely distributed in different distances from the intrusion to distal. Therefore, it is an ideal object to study the occurrence and spatial distribution of cobalt in the skarn iron deposit. In this study, 9 pyrite-bearing samples were collected from west to east in the -370m level of Longqiao iron deposit. Pyrite is mainly disseminated-veined in magnetite ore. LA-ICP-MS analysis results show that the contents of Co (0.019×10^-6~5639×10^-6), Ni (0.025×10^-6~5798×10^-6) and As (0.46×10^-6~14526×10^-6) in pyrite varied widely. The highest and lowest Co contents differ by several magnitudes. Through comparison of LA-ICP-MS analysis data and time-resolution profile, it is inferred that there are no Co-rich mineral inclusions in pyrite, and Fe²⁺ in pyrite is mainly replaced by Co²⁺ in the form of isomorphism. The Co content in the same pyrite grain often changes by 2~3 orders of magnitude, and cobalt can be abnormally enriched in a single pyrite grain. Independent cobalt minerals such as pyroarsenite are also developed in the deposit, indicating that independent cobalt minerals maybe widely exist in skarn iron deposits in eastern China. Due to the limitations of analysis and testing methods, those cobalt minerals has not been reported before. The mean and variation range of Co content in pyrite samples at different spatial locations have no obvious regularity, and there is no particularly Co-rich ore body in the deposit. According to the distribution characteristics of cobalt in pyrite, how to separate Co-rich and Co-poor pyrite in the process of beneficiation is the key to the recovery and utilization of cobalt in skarn iron deposit.

Establishment of a research workflow for occurrence state of critical metal in ore concentrate powder: A case study of the cobalt-rich sulfur ore concentrate powder from the Middle-Lower Yangtze River Valley Metallogenic Belt, China

长江中下游成矿带作为我国矿床学研究程度和矿产利用技术水平最高的成矿带之一，大部分矿床中除了主要成矿元素铜、金、铁和硫等，还伴生潜在可利用的关键金属资源镉、钴、硒、碲和铼等。由于目前矿山主要选矿回收铜、铁、硫、铅、锌、金和银等主要矿种，在不改变选矿工艺的条件下，矿山产品矿精粉中关键金属的分布特征和可利用性是当前关键金属资源利用的核心问题之一。本文对成矿带内玢岩型铁矿床、矽卡岩型铁矿床、矽卡岩型铁铜矿床、矽卡岩型铜金矿床、斑岩型铜金矿床和角砾岩筒型铜金矿床等六类矿床的矿山产品（铜金粉、硫精粉、铁精粉和金精粉）进行了系统化学成分分析，发现目前的矿山产品中关键金属元素含量普遍不高，但矽卡岩型铁矿床中的龙桥铁矿床硫精粉中富集钴，具有综合回收利用钴资源的潜力。在此基础上，本次工作利用综合矿物分析技术（TIMA），扫描电镜（SEM）和激光剥蚀-等离子体质谱仪（LA-ICP-MS）三种测试方法，系统开展了富钴硫精粉中钴的赋存状态研究。结果表明，龙桥硫精粉中钴矿物为辉砷钴矿、铁硫砷钴矿和硫铜钴矿，分别占硫精粉中总钴含量的9.93%、0.64%和0.01%。黄铁矿晶格中类质同象形式产出的钴占总量的81.97%，此外还有7.46%的钴赋存在其他矿物中。通过对比研究，初步建立了矿精粉中关键金属元素赋存状态的研究方法流程，为矿精粉中钴的回收利用提供了依据。;The Middle-Lower Yangtze River Valley Metallogenic Belt is one of the metallogenic belts with well-studied economic geology research and comprehensive mineral utilization technology in China. In addition of the main ore-forming elements Cu, Au, Fe and S, most deposits are associated with potentially available critical element resources, such as Cd, Co, Se, Te and Re. At present, the mines processed and recovered Cu, Fe, S, Pb, Zn, Au, Ag and other major products. Without changing the mineral process, the key problems in the utilization of critical element resources are the understanding of the occurrence of critical metals in ore concentrations. We have conducted a systematic chemical composition analysis of the mine products (i.e., copper concentrate powder, sulfur concentrate powder, iron concentrate powder and gold concentrate powder) of six types of deposits in the metallogenic belt, including apatite-magnetite Fe deposit, skarn Fe deposit, skarn Fe-Cu deposit, skarn Cu-Au deposit, porphyry Cu-Au deposit and breccia-hosted Au deposit. It is found that the contents of critical elements (Cd, Co, Se, Te and Re) in those mine products are generally low, except Co enriched in sulfur concentrate powder of Longqiao skarn iron deposit, which has the possibility of recovery and utilization of cobalt resources. In this study, the occurrence of cobalt in Co-rich sulfur concentrate powder was analyzed by Tescan Integrated Mineral Analyzer (TIMA), Scanning Electron Microscope (SEM) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). The analyses results show that the cobalt independent minerals in Longqiao sulfur concentrate powder are cobaltite, glaueodot and carrollite, which account for 9.93%, 0.64% and 0.01% of the total cobalt in sulfur concentrate powder, respectively. The amount of cobalt occurs as isomorphic form in pyrite lattice accounts for 81.97% of the total. In addition, 7.46% of cobalt exists in other unknown minerals. Research workflow of critical elements deportments in ore concentrate powder is established initially, which provides a theoretical basis for the recovery and utilization of cobalt in ore concentrate powder.

Mercury Thermoforms and Their Distribution in the Sedimentary Sequence of the Juan De Fuca Ridge

This paper addresses the vertical distribution of total mercury and its thermoforms in the Holocene–Upper Pleistocene sedimentary rocks from the Dead Dog active hydrothermal field in the Middle Valley, Juan de Fuca Ridge, Pacific Ocean. Sediment samples were taken from the core of Hole 858B drilled during ODP leg on the top of a sulfide hill, in a zone of ascending hydrothermal fluid, in the vicinity of high-temperature vent with temperature of 276°С. The contents of mercury and its thermoforms were measured by atomic absorption spectrometry (AAS) with thermal atomization. The highest mercury concentrations in the sediments reach 10.3 μg/g. Mercury is present in sediments in the following thermoforms: free mercury (FR), chloride (ChL), physically sorbed (PhS), chemically sorbed (ChS), sulfide (SF), and isomorphic (IS) forms. In the sedimentary section, contrasting concentrations of mercury alternate like a “layer cake” due to its accumulation at geochemical barriers.

LA-ICP-MS trace element analysis of magnetite and pyrite from the Hetaoping Fe-Zn-Pb skarn deposit in Baoshan block, SW China: Implications for ore-forming processes

The Hetaoping deposit is one of the largest Fe-Zn-Pb skarn deposit in SW China, which is characterized by Zn-Pb mineralization in the upper part and the Fe mineralization in the deeper part. The Fe mineralization is dominated by magnetite and pyrite. Magnetite can be subdivided into four types: primary banded magnetite samples in clinopyroxene-actinolite skarn (Mt-1), primary disseminated magnetite in garnet skarn (Mt-2), primary disseminated magnetite in clinopyroxene-actinolite skarn (Mt-3), and altered magnetite in clinopyroxene-actinolite skarn (Mt-4). Pyrite can be subdivided into three types: pyrite in oxide-ore stage (Py-1), pyrite in early sulfide-ore stage (Py-2), and pyrite in late sulfide-ore stage (Py-3). The flat time-resolved signals of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) imply that trace elements exist mainly in the form of isomorphism in magnetite and pyrite with the exception some incompatible trace elements (e.g., Ca, K and Na in magnetite and Pb, Bi and Ag in pyrite). Trace element concentrations in magnetite and pyrite demonstrate that the ore-forming fluid in Hetaoping is of magmatic origin. Furthermore, compared to porphyry, IOCG, Kinuna and BIF type magnetite, the magnetite from Hetaoping has relatively low Ti, V and Ni concentrations but high Al, Mn and Ca concentrations, implying a typical skarn genesis. The variation of Ti concentrations in magnetite is an indication of the formation temperature and shows that banded magnetite (Mt-1) precipitated in a relatively high-temperature environment compared with disseminated magnetite (Mt-2 and Mt-3). Compared to Mt-1 and Mt-3, Mt-2 has a higher Si, Al, and W contents and a lower Mg and Mn contents. The Mn content increases from Py-1 to Py-2, and decreases from Py-2 to Py-3, suggesting that the fluid-rock interaction increased from the oxide-ore stage to the sulfide-ore stage, and decreased from sulfide-ore stage to post-ore stage. The variation of the V concentration in magnetite grains indicates a relatively higher oxygen fugacity of Mt-2 compared to Mt-1 and Mt-3, implying that the oxygen fugacity of the ore-forming fluid in the garnet skarn zone is higher than that in clinopyroxene-actinolite skarn zone. The variable oxygen fugacity probably caused spatial zoning of mineralization in Hetaoping Fe-Zn-Pb skarn deposit. The temperature and oxygen fugacity of the ore-forming fluid, and the extent of fluid-rock interaction, controlled the temporal order and spatial zonation of magnetite and sulfide precipitation, which led to the formation of the Hetaoping Fe-Zn-Pb skarn deposit.

Isomorphism From Quaternion To Matrix Ring Over Field ℤp

The quaternion ring and matrixs ring 2 by 2 over ℤp are non-commutative rings. It seams, the two rings are not identical. However, the result of the study show that the two rings area identical or isomorphic. This paper, presents several forms of isomorphism between the two rings.

Recovering Cobalt and Sulfur in Low Grade Cobalt-Bearing V–Ti Magnetite Tailings Using Flotation Process

There is 0.032% cobalt and 0.56% sulfur in the cobalt-bearing V–Ti tailings in the Panxi Region, with the metal sulfide minerals mainly including FeS2, Fe1−xS, Co3S4, and (Fe,Co)S2, and the gangue minerals mainly including aluminosilicate minerals. The flotation process was used to recover cobalt and sulfur in the cobalt-bearing V–Ti tailings. The results showed that an optimized cobalt–sulfur concentrate with a cobalt grade of 2.08%, sulfur content of 36.12%, sulfur recovery of 85.79%, and cobalt recovery and 84.77% were obtained by flotation process of one roughing, three sweeping, and three cleaning under roughing conditions, which employed pulp pH of 8, grinding fineness of &lt;0.074 mm occupying 80%, flotation concentration of 30%, and dosages of butyl xanthate, copper sulfate, and pine oil of 100 g/t, 30 g/t, and 20 g/t, respectively. Optimized one sweeping, two sweeping, and three sweeping conditions used a pulp pH of 9, and dosages of butyl xanthate, copper sulfate, and pine oil of 50 g/t, 15 g/t, 10 g/t; 25 g/t, 7.5 g/t, 5 g/t; 20 g/t, 5 g/t, 5 g/t, respectively. Optimized one cleaning, two cleaning, and three cleaning condition dosages of sodium silicate of 200 g/t, 100 g/t, 50 g/t, respectively. Study of analysis and characterization of cobalt–sulfur concentrate by X-ray diffraction (XRD), automatic mineral analyzer (MLA), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) showed that the main minerals in cobalt–sulfur concentrate are FeS2, Co3S4 and (Fe,Co)S2, of which FeS2 and (Fe,Co)S2 accounted for 65.64% and Co3S4 for 22.64%. Gangue minerals accounted for 11.72%. The element Co in (Fe,Co)S2 is closely related to pyrite in the form of isomorphism, and the flotability difference between cobalt and pyrite is very small, which makes it difficult to separate cobalt and sulfur. Cobalt–sulfur concentrate can be used as raw material for further separation of cobalt and sulfur in smelting by pyrometallurgical or hydrometallurgical methods.