X射线CT技术在工艺矿物学中的应用

工艺矿物学主要通过研究各类矿石性质为制定合理的选冶工艺流程提供理论依据,在矿床综合评价以及矿产资源合理高效利用过程中均发挥着重要作用。在工艺矿物学的研究过程中,利用传统分析手段往往只能获取矿石的二维平面信息,而缺乏对矿石三维矿物学和结构的了解。近年来,X射线CT技术因其独特的对样品三维结构特征的无损提取能力,在国际上已逐步应用于工艺矿物学研究领域。本文介绍了X射线CT的结构、成像原理,以及利用X射线CT对矿物粒度、解离特征、矿物量等重要工艺矿物学参数进行量化表征的典型应用实例。随着X射线CT硬件设备的性能提升和数字图像处理技术的不断发展,X射线CT技术将可能成为工艺矿物学研究中的重要分析测试手段。     

某复杂低品位铜锌硫化矿工艺矿物学研究

针对某复杂低品位铜锌硫化矿,为降低选矿成本及为生产提供指导依据,进行了工艺矿物学研究。采用化学多元素分析、矿物自动分析仪(MLA)、光学显微镜等分析手段,查明了矿石的元素组成及矿物组成、主要矿物的嵌布特征、共生关系、粒度分布及解离度特征。结果表明,矿石中Cu品位为0.60%,锌品位为0.25%;含铜矿物主要为黄铜矿,含锌矿物主要为闪锌矿;铜锌硫矿物嵌布关系复杂,嵌布粒径大小悬殊,主要矿物单体含量低,黄铜矿及闪锌矿的单体解离度分别为37.92%、32.43%、单体解离度不高;矿石中存在极细粒黄铜矿且细粒级黄铜矿包裹于黄铁矿、磁铁矿、闪锌矿、脉石中导致铜回收困难,部分闪锌矿粒度极细且铜锌硫矿物共生关系紧密,相互包裹,共同赋存于脉石中导致铜锌分离困难。     

Investigation of particles with high crack density produced by HPGR and its effect on the redistribution of the particle size fraction in heaps

The application of comminution technology such as the high-pressure grinding rolls (HPGRs), which is able to generate a high density of cracks in the ore particles, is favourable for leaching processes. Extraction of metallic values by the heap leach process, can take place on the particles with partial exposure of mineral grains, if it can provide sufficient surface front for chemical attack by leaching solution. The aim of this study was to assess the benefits of high crack density in the ore particles produced using the HPGR and how it could diminish due to inadequate percolation of the leaching agent.A zinc ore was comminuted using HPGR at three different pressure settings and with a cone crusher for the control experiment. Subsamples from the (+23/−25, +14/−16, +5.25/−6.75 mm) size fractions were characterized and packed into leach reactors. The reactors were stopped from time to time to investigate the progress of crack and micro-crack growth and its effect on metal extraction using the X-ray computed tomography (CT). The results are validated with those obtained using traditional techniques such as SEM and QEMSCAN. Investigation of the leach reactors residue indicated significant changes in the particle size distribution (PSD) of initial feed toward the fine size fraction. The residues from the reactors leaching the material prepared using the HPGR product contained more fine particles than the reactors, which were fed by cone crusher product. These differences were up to 10.3%.     

某高硫铅锌矿选矿生产工艺流程考查及改进措施研究

为挖掘某高硫铅锌矿选矿生产技术指标提升的方向及潜力,对入选原矿进行了化学成分、矿物组成、嵌布特征等矿石性质研究,测定了精矿产品及尾矿中主要目的矿物的单体解离度和粒度分布等。结果表明,矿石中目的矿物方铅矿、闪锌矿及黄铁矿的嵌布粒度粗细不均匀,且共生关系密切、包裹关系复杂,属于难解离矿石;精矿互含高是导致精矿质量不高及金属回收率低的主要因素,方铅矿损失的主要原因是单体解离不充分,闪锌矿损失的主要原因除单体解离不充分外,还受到浮选分离工艺的严重影响。并在此基础上,针对性地提出了降低选矿处理量、强化细磨分级、优化药剂制度、合理调整矿浆浓度等改进措施及建议,为提升选矿技术指标提供了技术参考。      

Investigation of the effect of mineralogy as rate-limiting factors in large particle leaching

Although heap leaching is by now well established in the mining industry, the process remains limited by low recoveries with different rate-limiting factors that are not clearly understood. In this study, three large particle size classes (+19/−25, +9.5/−16, +4.75/−5 mm) were prepared from a sphalerite ore by two different methods of comminution (HPGR and cone crusher). The particles were then packed into leach reactors that were operated continuously for 11 months with well-mixed internal circulation of the leach solution. Characterization of the residue of the leach reactors indicated that there are areas within the ore particles where although sphalerite grains are accessible to the solution, they remain unreacted. X-ray tomography and QEMSCAN® analysis of the selected samples before, during and after leaching, showed increased leaching of sphalerite grains associated with pyrite due to galvanic interactions. Mineral chemistry (Fe, Mn content of sphalerite) and jarosite precipitation were also investigated as factors influencing sphalerite leaching.     

微波场中矿物颗粒裂纹分布及演化研究

以方铅矿和方解石组成的岩石颗粒为研究对象,采用离散单元法研究了在微波照射下矿物颗粒内部裂纹扩展演化过程及其分布特征,并分析了照射时间、功率密度、能耗、矿物尺寸等的影响。结果表明,矿物裂纹主要表现为拉伸裂纹,根据分布特征及所在位置可以将其分为三类:在方解石内的扩散型裂纹、在方解石和方铅矿交界处的环形裂纹和方铅矿内裂纹,前两者的形成是微波能辅助碎矿磨矿的根本原因。其中方解石内的扩散型裂纹和交界面处的环形裂纹的形成是微波辅助碎矿和磨矿的根本原因。矿物裂纹数目随微波照射时间及能量消耗增长的曲线可以分为两类:功率密度低的为三阶段增长形式,功率密度高的为两阶段增长形式。矿物形成裂纹数目相同的情况下,随着功率密度提高,能耗降低,但高于一定值后,能耗变化不大。微波辅助方法和其他碎矿磨矿的方式类似,矿物越小越难破碎。     

影响某深海多金属硫化物选冶的矿物学因素

某深海多金属硫化物中锌、铜、金、银的品位分别为20.44％、0.41％、6.89 g/t和141 g/t,有价元素含量高,综合利用价值大.通过矿物组成、重要矿物的嵌布特征、嵌布粒度及磨矿产品中解离特征的研究,对影响选冶回收的矿物学因素进行了系统的分析.研究表明:闪锌矿是含量最多的矿物,具有含铁量变化较大、铁含量普遍较低...     

硫化铅锌矿物浮选分离药剂研究进展

铅锌分离一直以来都是矿物加工领域的难题,浮选是分离方铅矿和闪锌矿最有效的方法之一。铅锌多金属硫化矿分离铅锌困难,是由于方铅矿和闪锌矿具有相近的可浮性、二者致密共生且嵌布关系复杂,而解决铅锌分离困难的关键在于高效浮选药剂的应用。本文系统概述了硫化铅锌矿捕收剂、抑制剂、活化剂和pH调整剂的主要研究进展,分析了各种浮选药剂的适用范围以及优缺点。在此基础上,展望了硫化铅锌矿浮选药剂未来的研究重点和发展方向。     

Characterisation of coarse composite sphalerite particles with respect to flotation

The flotation response of a typical zinc-lead (Zn/Pb) ore, with respect to coarse composite (sulphide/non-sulphide) particles is reported. The flotation tests were carried out on a selected feed particle size range (−600 + 75 μm, at P₈₀ of 390 μm) and the recovery of Zn composite particles analysed on a size by size basis. The best results were achieved with the use of 75 g/t sodium isopropyl xanthate (SIPX), obtaining a Zn recovery of 77%, with a significant improvement at the coarse end of the particle size distribution. Computerised scanning electron microscope (QEMSCAN) was used to characterise value mineral grain size and degree of liberation, as well as gangue and sphalerite association in particles reporting to both concentrate and tailings. A new characterisation function (Locking ratio, LR) was developed based on the data from the automated mineralogical analysis to characterise particles into two-phase composites with different degree of locking texture (simple and complex). The function, which is based on the mode of occurrence of sphalerite, grain size, proportion and composition of the constituent minerals in each particle, was used to study the flotation response of the particles with different degrees of locking. The results highlight the difference in recoverability of the sphalerite bearing particles with different degrees of locking, with simple locking texture giving higher recovery than complex locking texture, for the same overall liberation.     

新疆昆仑山某铜锌矿工艺矿物学研究

对新疆昆仑山某铜锌多金属矿进行了工艺矿物学研究,查明了矿石中铜、锌元素的赋存状态,矿石组成及主要有用矿物的嵌布特性,为选矿试验提供了重要依据。研究结果表明,矿石中的铜、锌主要以黄铜矿、闪锌矿的形式存在,这两种硫化矿物嵌布关系密切,且粒度偏细,将给铜、锌的分选带来不利影响。     

Prediction of mineral liberation characteristics of comminuted particles of high grade ores

In mineral processing, the liberation of valuable mineral is of key importance in achieving high recoveries from downstream separation processes such as froth flotation and gravity concentration. To quantify mineral liberation, information on ore texture of the parent rock as well as properties of comminuted particles is essential. These properties have been quantified by statistical measures such as the proximity function and covariance function, which were extracted from SEM images of parent rock and particle polished sections, using convenient and efficient image analysis techniques based on Labview™ software. To quantify fully liberated particles, a phase specific line segment function has been introduced and evaluated by placing random line segments on the image. It was also found that the ore texture assumptions made by Barbery are not valid for the high grade sulphide ore tested and the general applicability of these assumptions is therefore questionable. Using the measured information above, predictive liberation models to quantify volumetric grade distribution of particles in 1D and 3D have been developed based on Barbery’s work. Results show that the grade distributions of composite particles predicted from the proposed 1D model is closest to measured data than those of Barbery’s 1D model. The predictions using the proposed 3D model are similar to those predicted from Barbery’s model and are considered more realistic as the model does not rely on assumed ore texture but on measurements made on the parent rock and particle sections.     

江西某铅锌矿石工艺矿物学研究

江西某铅锌矿在现采矿境界下部发现较大新矿体,为确定新探明资源的合理开发利用工艺,对新探明资源进行了工艺矿物学研究。结果表明：该矿石中矿物种类复杂,有用元素主要有铅、锌、银、金等,主要铅、锌、银矿物有方铅矿、闪锌矿、硫锑铅银矿、硫锑铜银矿。铅锌矿物嵌布特征复杂,共生关系密切,受构造应力作用破坏,闪锌矿碎裂成碎粒,被黄铁矿、方解石等胶结;银矿物在方铅矿中呈蠕虫状、微脉状分布。方铅矿、闪锌矿均为极不等粒嵌布,矿石属难解离、难分选铅锌矿石。最后指出了选矿试验研究过程中应重视的几个问题。     

谦比希铜矿中铜矿物的解离特性及其可浮性研究

矿物的单体解离是浮选分离的前提，查明矿石细度、目的矿物单体解离度和矿石可浮性三者之间的内在联系，可为浮选前物料的准备提供指导。为此，以赞比亚谦比希西矿体矿石为例，借助矿物解离分析系统（MLA），初步探讨了不同细度下有用矿物的解离特性与可浮性的关系。研究结果表明：谦比希铜矿中的主要铜矿物为黄铜矿，含量为5.32%，脉石矿物主要有正长石、石英和云母；原矿中黄铜矿属于以微细粒为主的不等粒嵌布，黄铜矿颗粒介于10~500 μm，且多数与长石和石英毗邻，部分细颗粒被包裹在粗颗粒的长石和云母中，仅有少量单体解离颗粒存在；将原矿磨至-74 μm占70%，黄铜矿的自由表面由60.88%升高至78.14%，单体解离颗粒含量由28.90%增加至54.24%，但连生体中铜矿物的分布规律没有改变；试验矿石浮选过程最有效的选别粒度为18~100 μm，粗颗粒中铜的损失是由于铜矿物单体解离度低，过细物料的损失则是因为物料可选性差。     

Utilization of optical image analysis and automatic texture classification for iron ore particle characterisation

Optical image analysis is a very convenient tool for obtaining comprehensive information about fine iron ore size fractions. Data can be obtained on mineral abundances, porosity, particle shape and ore textures with a high level of accuracy. A range of techniques has been used to characterise iron ore samples on a particle-by-particle basis. Automatic textural classification of iron ore particles was used to establish classes containing particles with very similar mineral composition and texture. Image analysis coupled with probe analysis and mineral density measurements provided information about the chemical composition and density of each particle class. The combination of these results enabled a “virtual feed” to be created, which can be a key input into a beneficiation unit model for predicting its performance. Identification and classification of the textural type of each particle was performed according to the CSIRO-Hamersley Iron Ore Group Classification Scheme. If more detailed classification is needed, further classification can be performed based on dimensional, chemical or mineral criteria, such as the presence of certain minerals in particles or total iron content. Some deficiencies of the current image analysis procedures and their further improvement and automation are also discussed.     

广东大尖山某铅锌多金属矿石工艺矿物学研究

广东大尖山某铅锌多金属矿石铅品位为1.10%,锌品位为4.95%,银品位为23.4 g/t,铁品位仅10.79%,硫品位为7.30%,其中铅、锌、银具有较高的利用价值。为给该矿石选别工艺流程的制定提供依据,对该地区代表性矿石进行了工艺矿物学研究。结果表明:(1)矿石金属矿物主要有方铅矿、铁闪锌矿、闪锌矿、黄铁矿、磁黄铁矿、黄铜矿、白铁矿,银分散在方铅矿、闪锌矿等硫化矿物中,未形成独立银矿物。(2)矿石闪锌矿、方铅矿、黄铁矿呈致密块状分布;黄铁矿、闪锌矿呈浸染状分布;磁黄铁矿、黄铁矿、闪锌矿、方铅矿组成不规则团块与脉石构成不规则斑染状分布;由方铅矿、闪锌矿及脉石组成的矿脉穿切黄铁矿、石英、绢云母;黄铁矿呈自形晶产出,浸染状分布,被闪锌矿、方铅矿脉穿切交代。(3)方铅矿和铁闪锌矿、闪锌矿的嵌布粒度均属极不等粒嵌布,方铅矿嵌布粒度较铁闪锌矿、闪锌矿更为分散。(4)方铅矿单体解离较差,-0.076 mm粒级仅有90.38%单体解离,-0.045 mm粒级也未达到完全解离;铁闪锌矿、闪锌矿单体解离度较方铅矿高,-0.076 mm粒级92.91%已单体解离。     

某复杂多金属铅锌铁矿石工艺矿物学研究

为更好地开展矿石的选矿工艺研究，对某复杂多金属磁铁矿石进行了工艺矿物学研究。结果表明：矿石铁、锌品位分别为59.94%和2.93%。矿石中的主要矿物为磁铁矿，少量其他铁矿物赤铁矿、褐铁矿（包括针铁矿）为成矿后期的次生氧化物；金属硫化物主要有闪锌矿、黄铁矿、磁黄铁矿，黄铜矿、方铅矿较少；脉石矿物主要为普通角闪石，透闪石少量，此外还有少量绿帘石、绿泥石、云母类矿物等。矿石中的铁主要以磁铁矿的形式存在，占总铁的87.82%，锌、铅氧化程度均较高，硫化锌、氧化锌分别占总锌的55.29%和42.32%，硫化铅、氧化铅分别占总铅的39.39%和43.94%。矿石构造为黑色致密块状构造，多呈自形-半自形粒状连晶结构，各种矿物间形成交代结构、交代残余结构等。矿石中的有用矿物磁铁矿、闪锌矿的嵌布粒度与闪石类矿物相差不大，磁铁矿、闪锌矿及其与其他矿物间的嵌布关系较复杂，单体解离较困难。为了确保铁精矿含硫不超标，在弱磁选回收磁铁矿前需采用浮选工艺尽可能脱除硫化矿物。     

矿物浮选分离硫化铜、硫化锌的研究进展

随着我国对金属铜、锌资源需求的不断增加,有效的处理铜、锌矿石及对两者的高效利用对我国的经济建设有着极大的意义。硫化铜矿以黄铜矿为主,通常与硫化锌矿中的闪锌矿伴生,因此对两者进行分离是选矿研究中的一个热点。由于磨矿过程中黄铜矿溶解出的铜离子会对闪锌矿造成明显的活化效果,使得两者可浮性相近,这是导致铜、锌矿物分离困难的主要原因。对于铜锌硫化矿浮选分离当前的研究热点主要为抑锌浮铜,但在闪锌矿抑制剂研究方面深度不够,必须进一步研究不同抑制剂的抑制机理,从而更加清楚地调控矿浆环境及合理改变矿物的表面性质,以此增强抑制剂对闪锌矿的选择性。而发展新型氧化型药剂、外界物理化学方法改性以及研究抑铜浮锌的新方法是今后铜锌浮选分离的研究方向。     

巫山桃花鲕状赤铁矿工艺矿物学研究

对巫山桃花鲕状赤铁矿矿石的结构和构造、矿物组成、嵌布特征、主要元素的赋存状态和分布规律等进行研究。研究结果表明,矿石中有含铁金属矿物、硫化物、磷酸盐、非金属脉石矿物4类共12种矿物,矿石中对铁回收率影响最大的矿物是赤铁矿和赤褐铁矿。矿石中的赤铁矿虽含量低,但矿物较纯,是提高铁精矿品位的积极因素,需重视其回收。赤褐铁矿与脉石矿物紧密嵌布难以解离,是影响铁回收率的主要因素。如在选矿中以赤褐铁矿为主体的鲕粒为选铁对象,可降低磨矿细度,减少泥级产率和铁的流失,是一个有益的探索方向。     

攀西地区某用于制造纤维的玄武岩工艺矿物学

用于制造玄武岩纤维的玄武岩原料性质是影响其产品性能的关键因素。本文通过X射线荧光光谱仪、X射线衍射仪、岩矿鉴定分析等手段,对攀西地区某用于制造纤维的玄武岩的化学成分组成、矿物组成及嵌布特征等进行了详细研究。结果表明该玄武岩中主要矿物为斜长石、辉石、绿泥石和石英,还有少里的磁铁矿等金属矿物,其中二氧化硅和三氧化二铝总量达到64.28%, TFe品位为13.65%,玄武岩中主要矿物的嵌布关系与当前工业化生产用的玄武岩原料基本一致。由于铁质组分对玄武岩纤维制备工艺和产品性能的影响较大,还对该玄武岩进行初步的磁选除铁试验,并成功获得了高铁玄武岩和低铁玄武岩,为玄武岩纤维的制备提供了多种可能的原料。     

基于X射线分选矿石图像的轮廓提取算法综述

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