Ore-forming mechanism of Huxu Au-dominated polymetallic deposit in the Dongxiang Basin,South China:Constraints from in-situ trace elements and S-Pb isotopes of pyrite

The Huxu Au-dominated polymetallic deposit is a hydrothermal deposit located in the Dongxiang volcanic basin in the middle section of the Gan-Hang tectonic belt in South China.The orebodies primarily occur within the Jurassic-Cretaceous quartz diorite porphyry,while the genesis of this deposit is unclear.This study focused on geological and mineralogical characteristics,in-situ trace elements and S-Pb isotopes of three generations of pyrite of the Huxu deposit to clarify the distribution of trace elements in pyrite,ore-forming fluid and material sources,and genetic types of the deposit.The mineralization stage of the deposit can be divided into quartz-pyrite stage(S1),quartz-pyrite-hematite stage(S2),quartz-polymetallic sulfide stage(S3)and quartz-hematite stage(S4),with the corresponding pyrite being divided into three generations(Py1-Py3).in-situ trace element data of pyrite show that Au in pyrite mainly exists in the form of solid solution(Au^(+)),and the content is relatively low at all stages(0.18 ppm for Py1,0.32 ppm for Py2,0.68 ppm for Py3),while Pb and Zn mainly exist as sulfide inclusions in the pyrite.S-Pb isotopes show that the sulfur and ore-forming material of this deposit are mainly sourced from magma.The mineral association,mineral textures and trace elements in different stages of pyrite indicate that fluid boiling and fluid mixing are the key factors of native gold precipitation in S2 and S4,respectively,while water-rock interaction controlled the precipitation of Pb-Zn sulfides.These integrating with geological characteristics suggests that the deposit should be an intermediate sulfidation epithermal deposit.

Quantitative prediction process and evaluation method for seafloor polymetallic sulfide resources

Seafloor polymetallic sulfide resources exhibit significant development potential. In 2011, China received the exploration rights for 10,000 km2 of a polymetallic sulfides area in the Southwest Indian Ocean; China will be permitted to retain only 25% of the area in 2021. However, an exploration of seafioor hydrothermal sulfide deposits in China remains in the initial stage. According to the quantitative prediction theory and the exploration status of seafloor sulfides, this paper systematically proposes a quantitative prediction evaluation process of oceanic polymetallic sulfide resources and divides it into three stages： prediction in a large area, prediction in the prospecting region, and the verification and evaluation of targets. The first two stages of the prediction process have been employed in seafloor sulfides prospecting of the Chinese contract area. The results of stage one suggest that the Chinese contract area is located in the high posterior probability area, which indicates good prospecting potential area in the Indian Ocean. In stage two, the Chinese contract area of 48^-52~E has the highest posterior probability value, which can be selected as the reserved region for additional exploration. In stage three, the method of numerical simulation is employed to reproduce the ore-forming process of sulfides to verify the accuracy of the reserved targets obtained from the three-stage prediction. By narrowing the exploration area and gradually improving the exploration accuracy, the prediction will provide a basis for the exploration and exploitation of seafloor polymetallic sulfide resources.

Bioleaching of complex polymetallic sulfide ores by mixed culture

Bacterial leaching of single sulfide minerals and polymetallic sulfide ores was operated in shake flasks and small-scaled columns.The results show that bioleaching of jamesonite is not accessible,the iron extraction rate of pyrrhotite bioleaching reaches 98.2% after 26 d,and the zinc extraction rate of marmatite bioleaching reaches 92.3%,while the corresponding iron extraction reaches only 13.6% after 29 d.Pulp density has a significant effect on metal extraction of pyrrhotite and marmatite bioleaching.The corresponding metal extraction rate decreases with the increase of pulp density.For the polymetallic sulfide ores,zinc extraction of 97.1% is achieved after bioleaching in shake flasks for 10 d,while only 7.8% is obtained after bioleaching in small-scaled column.Analytical results of scanning electron microscopy(SEM) and energy dispersive X-ray analysis(EDX) reveal that large amount of calcium sulfate is formed on the mineral surface.

Mineralogical characteristics of polymetallic sulfides from the Deyin-1 hydrothermal field near 15°S, southern Mid-Atlantic Ridge

A seafloor hydrothermal field, named Deyin-1 later, near 15°S southern Mid-Atlantic Ridge（SMAR） was newly found during the 22 nd cruise carried out by the China Ocean Mineral Resources Research ＆ Development Association（COMRA）. Sulfide samples were collected at three stations from the hydrothermal field during the26 th cruise in 2012. In this paper, mineralogical characteristics of the sulfides were analyzed with optical microscope, X-ray diffractometer, scanning electron microscope and electron microprobe to study the crystallization sequence of minerals and the process of hydrothermal mineralization. According to the difference of the ore-forming metal elements, the sulfide samples can be divided into three types：（1） the Ferich sulfide, which contains mainly pyrite and chalcopyrite;（2） the Fe-Cu-rich sulfide consisting predominantly of pyrite, chalcopyrite and isocubanite, with lesser amount of sphalerite, marmatite and pyrrhotine; and（3） the Fe-Zn-rich sulfide dominated by pyrite, sphalerite and marmatite, with variable amounts of chalcopyrite, isocubanite, pyrrhotine, marcasite, galena and gratonite. Mineral precipitations in these sulfides are in the sequence of chalcopyrite（isocubanite and possible coarse pyrite）, fine pyrite,sphalerite（marmatite）, galena, gratonite and then the minerals out of the dissolution. Two morphologically distinct generations（Py-I and Py-II） of pyrite are identified in each of the samples; inclusions of marmatite tend to exist in the coarse pyrite crystals（Py-I）. Sphalerite in the Fe-Zn-rich sulfide is characterized by a＂chalcopyrite disease＂ phenomenon. Mineral paragenetic relationships and a wide range of chemical compositions suggest that the environment of hydrothermal mineralization was largely changing. By comparison, the Fe-rich sulfide was formed in a relatively stable environment with a high temperature, but the conditions for the formation of the Fe-Cu-rich sulfide were variable. The Fe-Zn-rich sulfide was precipitated during the hydrothermal venting at relatively low temperature.

Mineralogical Characterization of a Polymetallic Sulfide Ore to Improve Silver Recovery

Based on the mineralogical characterization for the polymetallic sulfide ore, the way to improve silver recovery was studied. The results showed that silver was the most valuable metal whose grade was 448.82 g/t Ag, while 0.118% Cu, 1.65% Pb and 1.06% Zn may be comprehensively utilizated. The main silver-bearing minerals were argent and aregentite which accounted for 87.18% of total silver. Argentite and other metal minerals were distributed in the gangue minerals in complex forms. Argentite grains of 33.76% minus 50 μm indicated that a fine grinding scheme was necessary to enhance the degree of dissociation, and meanwhile selective grinding must be considered to prevent a complete grinding of coarse grains. The optimum regrinding fineness in the Cu flotation was determined as 73% minus 37 μm, while grains of 68.5% minus 74 μm in one-stage grinding remained unchanged as much as possible. Consequently, silver recovery increased to 2.68%, as well as the content of Pb simultaneously decreased from 7.26% to 2.68% in the Cu concentrate. From the lead pyrometallurgical point of view, recovering larger amounts of silver and lead at the expense of decreasing the grade of lead to a suitable level is not only economically viable for the plant, but also convenient for subsequent processing. Silver and lead recovery increased to 13.18% and 12.58%, respectively, while the Pb grade decreased from 53.1% to 46.12% for the Pb concentrate.

Ore-controlling Characteristics of Synchronous Faults of Dongshengmiao Polymetallic Sulfide Deposits in Inner Mongolia

1 Introduction The Dongshengmiao deposit is a super-large Zn-Pb polymetallic sulfide deposit which occurring in the Langshan-Zhaertaaishan metallogenic belt,and located in the western margin of the North China Platform.The ore-bodies of Dongshengmiao deposits are mainly hosted in the second Formation of Langshan Group.There are some studies on the geological characteristics(Peng et al.,2004),geological and

Experimental investigation of the inhibition of deep-sea mining sediment plumes by polyaluminum chloride

Deep-sea sediment disturbance may occur when collecting polymetallic nodules,resulting in the creation of plumes that could have a negative impact on the ecological environment.This study aims to investigate the potential solution of using polyaluminum chloride(PAC)in the water jet.The effects of PAC are examined through a self-designed simulation system for deep-sea polymetallic nodule collection and sediment samples from a potential deep-sea mining area.The experimental results showed that the optimal PAC dose was found to be 0.75 g/L.Compared with the test conditions without the addition of PAC,the presence of PAC leads to a reduction in volume,lower characteristic turbidity,smaller diffusion velocity,and shorter settling time of the plume.This indicates that PAC inhibits the entire development process of the plume.The addition of PAC leads to the flocculation of mm-sized particles,resulting in the formation of cm-sized flocs.The flocculation of particles decreases the rate of erosion on the seabed by around 30%.This reduction in erosion helps to decrease the formation of plumes.Additionally,when the size of suspended particles increases,it reduces the scale at which they diffuse.Furthermore,the settling velocity of flocs(around 10^(-2) m/s)is much higher that of compared to sediment particles(around 10^(-5) m/s),which effectively reduces the amount of time the plume remains in suspension.

Petrophysical characteristics of rocks and sulfides from the SWIR hydrothermal field

Study of petrophysical properties of rocks in seafioor hydrothermal fields has great significance for inves- tigation of seafloor hydrothermal activities, especially for polymetallic sulfides prospecting. In the present study, based on the current experimental conditions, we conducted systematic experiments to measure the magnetic susceptibility, electrical resistivity, porosity, density, as well as acoustic wave velocity of seafloor rocks and sulfides. Subsequently, we measured the physical characteristics of hydrothermal sulfides, basalts and peridotites which were collected from newly discovered seafloor hydrothermal fields at 49.6°E, 50.5°E, 5 1°E, 63.5°E, and 63.9°E of the Southwest Indian Ridge （SWIR）. Previously available and newly collected data were combined to characterize the physical differences between polymetallic sulfides and rocks. We also discussed the impact of hydrothermal alteration on the bedrock and demonstrated how these petrophysical properties of rocks can help in geophysical prospecting of seafloor hydrothermal fields as indicators.

Multi-scale impact crushing characteristics of polymetallic sulphide ores

The effects of crushing energy, ore hardness and particle size of cassiterite polymetallic sulphide ore and lead-zinc polymetallic sulphide ore on the crushing characteristics during impact crushing were investigated by mineral liberation analyzer(MLA) and drop weight test. The results show that both ores contain pyrrhotite, sphalerite, jamesonite, gangue mica and quartz except cassiterite. Cassiterite is closely associated with sulphide and quartz to form aggregates, which are mixed with each other in the form of intergrowth or symbiotic disseminated fine grains. Cassiterite has a significant impact on ore crushing characteristics. Ore hardness is negatively correlated with the product of crushing parameters of A and b, i.e. A×b, the effect of crushing energy on crushing fineness is related to crushing parameters A and b, and the influence degree increases with the increase of A. The influence degree increases with the increase of b when crushing energy ECS is less than 1 kW·h/t, and the influence degree decreases with the increase of b when crushing energy ECS is greater than 1 kW·h/t. The impact of crushing energy on crushing fineness is greater than that of ore particle size when the crushing energy is lower;on the contrary, the impact of ore particle size on crushing fineness is greater than that of crushing energy when crushing energy is higher.

东乡盆地虎圩金多金属矿床金属沉淀机制:来自矿物组合和微量元素的限制

钦杭结合带中部的虎圩金多金属矿床为东乡火山岩盆地内典型热液矿床,基础地质研究表明该矿床赋矿围岩为侏罗纪-白垩纪石英闪长玢岩和流纹质火山碎屑岩,矿体受断裂构造控制,呈NW向脉状展布,然而有关该矿床的成因类型、金属沉淀机制和成矿过程研究尚欠缺。本文针对该矿床开展详细矿相学和黄铁矿微量元素研究。结果显示,从早到晚,该矿床矿化过程可分为四个阶段:石英-黄铁矿阶段(S1)、石英-黄铁矿-赤铁矿阶段(S2)、石英-多金属硫化物阶段(S3)和石英-赤铁矿阶段(S4)。金主要以自然金的形式存在于S2和S4阶段中;S2阶段黄铁矿(Py2)明显富集Pb、Sb、Bi、W、V、Sc、U、Al和Ti等元素,不同阶段黄铁矿中不可见金含量均较低(均值0.8~1.7μg/g),As(均值517~931μg/g)与Au整体上正相关,局部存在解耦,微量元素变化主要受控于黄铁矿中不同类型矿物包裹体。综合地质特征、矿物组合、矿物结构、微量元素和热力学计算分析显示,该矿床为中硫型浅成低温热液矿床,流体沸腾和流体混合导致的氧逸度快速上升分别是S2和S3阶段自然金沉淀的关键因素,而黄铁矿中的不可见金主要受控于As对黄铁矿晶格的改变,局部受控于动力学过程控制的黄铁矿晶格缺陷。

某低品位铅锌铜多金属硫化矿富集与分离试验研究

云南某低品位铅锌铜多金属硫化矿铅品位0.61%、锌品位3.28%、铜品位0.25%,伴生Au、Ag品位分别为0.09、18.04 g/t。矿石嵌布粒度较细,共生关系复杂。为高效开发利用该低品位矿石,进行了系统的浮选试验。结果表明:矿石采用铜铅混合浮选—铜铅分离—锌浮选工艺处理,获得了铜品位21.97%、铜回收率80.85%、金品位1.60 g/t、银品位189.00 g/t、铅品位1.80%的铜精矿,铅品位76.22%、铅回收率88.72%、金品位0.75 g/t、银品位1433.00 g/t、铜品位1.87%的铅精矿,锌品位52.18%、锌回收率93.03%的锌精矿,主要有价成分铅、锌、铜的分离与富集效果较好,金、银一定程度富集在铜精矿、铅精矿中;铜精矿锌含量偏高与黄铜矿、闪锌矿间的嵌布关系异常密切有关;原矿Au、Ag品位低,且在矿石中分散程度高是造成金银综合回收指标偏低的原因。

一种复杂多金属硫化矿中硫精矿再选优化工艺

由于某多金属铅锌矿选厂脱硫一步扫尾(硫精矿)金属损失严重,脱硫二步作业流程产出的铅锌精矿2品位较低,与分离产出的铅锌精矿1混合拉低了总铅锌精矿品位。为解决这一问题,提高混合铅锌品位,脱硫一步扫尾再浮选,实验室以脱硫粗一扫尾为原矿,脱硫二步开展氧化钙、硫酸铜药剂用量试验,进一步优化脱硫二步粗、扫选工艺。铅锌2改造为活流程的方案(高原矿时铅锌2直接进入铅锌精矿,低原矿时返回脱硫一步精选作业),降低硫精矿中Cu、Pb、Zn的品位,减少金属损失,提高回收率。

锡石多金属硫化矿矿石磨矿特性研究

针对过磨与欠磨的问题以及磨矿方式和入料粒级对矿石磨矿效果的影响。以锡石多金属硫化矿为研究对象,基于批次磨矿试验,通过改变磨矿方式、入料粒级、磨矿时间等磨矿影响因素,探索磨矿产物粒度分布规律和磨矿行为特性。结果表明,研磨磨矿是一个低能磨矿过程,矿石所受作用力小,易发生欠磨现象。抛落磨矿和冲击磨矿是一个高能磨矿过程,矿石所受作用力大,破碎更加充分,易发生过磨现象。在研磨磨矿下,磨矿技术效率E和磨矿产物t_(10)随磨矿时间变化幅度稳定,产物粒度分布比较均匀;在抛落磨矿和冲击磨矿下,磨矿技术效率E和磨矿产物t_(10)随磨矿时间变化明显,且变化幅度大,总体上两种磨矿指标均大于研磨磨矿。从入料粒级看,矿石的磨矿行为与入料粒级的关系较为复杂,没有明显的规律。研究结果将为后续研究抛落状态下研磨和冲击两种作用力的强弱及其相互影响提供理论依据。

多金属硫化矿矿石表征与选矿工艺研究

本文旨在研究探索多金属硫化矿矿石的表征与选矿工艺,以解决资源开发和矿石加工领域的重要问题,以便于更好地理解矿石的性质和特征,为矿石加工和资源评估提供科学依据。并有助于优化矿石开采和处理流程,实现矿石资源的高效利用和可持续发展。

多金属硫化矿选矿过程中的矿石预处理技术优化

随着全球经济的快速发展和人们对资源的需求不断增长,多金属硫化矿的选矿预处理技术优化成为了矿业领域的重要研究方向之一。本文旨在探讨多金属硫化矿选矿预处理方案的优化,并结合不同的预处理技术,以提高选矿效果和经济效益。

安徽某难选铜铅锌多金属硫化矿选矿工艺试验研究

安徽某铜铅锌多金属硫化矿属复杂难选多金属硫化矿,铜铅锌矿物嵌布关系复杂,各矿物之间致密共生,粒度极为不均,综合回收难度大。为提高资源整体综合利用率,针对该矿石性质以Z-200为铜捕收剂,25^(#)黑药为铅捕收剂,丁基黄药为锌硫捕收剂,采用铜铅锌硫依次优先浮选工艺流程,在原矿含铜0.58%、铅0.57%、锌2.50%、硫5.39%的条件下,获得了铜精矿Cu品位18.83%、回收率76.33%,铅精矿Pb品位45.83%、回收率68.58%,锌精矿Zn品位50.25%、回收率87.44%,硫精矿S含量40.89%、回收率44.64%的实验室指标。研究结果为下一步工业化生产提供了指导依据。

Seafloor hydrothermal activity and polymetallic sulfide exploration on the southwest Indian ridge

Polymetallic sulfides have attracted more attentions,which are regarded as one of the potential seabed mineral resources for their high grade of precious metal elements such as Cu,Zn,Pb,Au,and Ag.Since2007,there are four China dayang cruises(CDCs)with eight legs totally,which have been carried out to investigate polymetallic sulfides on the southwest Indian ridge(SWIR),and eight hydrothermal vents have been found.In2011,the China Ocean Mineral Resources Research and Development Association(COMRA)and International Seabed Authority(ISA)signed a 15-year contract for exploration for polymetallic sulfides located on the SWIR between 46°S and 53°S.The area allocated to the COMRA is approximately 10,000 km2.In this paper,we review the recent research advances about hydrothermal activity of the SWIR by the CDCs.As for the sulfides exploration in the future,some aspects should be emphasized,such as the controlling factors of sulfide mineralization on the SWIR,prospecting methods of inactive and buried sulfide deposits,sulfides resources assessment method,and the nearbottom sulfides exploration technology systems.

Review of Nodule Mineral Image Segmentation Algorithms for Deep-Sea Mineral Resource Assessment

A large number of nodule minerals exist in the deep sea.Based on the factors of difficulty in shooting,high economic cost and high accuracy of resource assessment,large-scale planned commercial mining has not yet been conducted.Only experimental mining has been carried out in areas with high mineral density and obvious benefits after mineral resource assessment.As an efficient method for deep-sea mineral resource assessment,the deep towing system is equipped with a visual system for mineral resource analysis using collected images and videos,which has become a key component of resource assessment.Therefore,high accuracy in deep-sea mineral image segmentation is the primary goal of the segmentation algorithm.In this paper,the existing deep-sea nodule mineral image segmentation algorithms are studied in depth and divided into traditional and deep learning-based segmentation methods,and the advantages and disadvantages of each are compared and summarized.The deep learning methods show great advantages in deep-sea mineral image segmentation,and there is a great improvement in segmentation accuracy and efficiency compared with the traditional methods.Then,the mineral image dataset and segmentation evaluation metrics are listed.Finally,possible future research topics and improvement measures are discussed for the reference of other researchers.

海洋有色金属矿产地球物理勘探进展

随着对海洋矿物资源的勘探研究,人们意识到多金属结核、富钴结壳和多金属硫化物等是具有战略意义的海洋有色金属矿产。近年来,随着地球物理勘探技术的发展,勘探深度逐渐从浅海过渡到深海,加深了人们对深部有色金属资源的认识,深海有色金属资源逐步成为世界各国关注的热点。近十年来,我国在深海矿产资源领域的研究取得了一系列的重要进展。首先,本文主要介绍国内外海洋有色金属矿产的勘探现状,并且在原理基础、正反演技术方法等方面回顾了适用于深海环境的地球物理勘探方法的发展。然后,结合我国在太平洋的多金属结核勘探区、富钴结壳勘探区和在西南印度洋中脊的多金属硫化物矿勘探区的研究进展,归纳了海洋有色金属矿产的地球物理勘探方法及实例分析。

海底多金属硫化物采掘机构滚筒切削特性研究

为提高采掘机构滚筒的工作性能,采用离散单元法对不同工况下滚筒的切削过程进行了数值模拟。采用单因素分析法和正交试验法分析了切削厚度、转速、牵引速度对切削阻力、产能及比能耗的影响,以滚筒的切削阻力和比能耗为评价指标,利用矩阵分析法获得了最佳的滚筒工作参数。结果表明,随着切削厚度增加,切削阻力和产能均增大,比能耗减小;随着转速增加,切削阻力和产能均减小,比能耗增大;随着牵引速度增加,切削阻力、产能均增大,比能耗减小。滚筒最佳工作参数为:切削厚度50 mm、转速100 r/min、牵引速度0.06 m/s。