MLA技术在某铜钼矿选矿工艺研究中的应用

MLA是目前世界上最先进的工艺矿物学参数自动定量分析测试系统之一。目前国内MLA技术主要用于指导选矿工艺研究,以要进行选矿加工的矿石为研究对象,为选矿流程提供矿物组成、含量、目标矿物嵌布粒度、磨矿产品解离度、伴生元素赋存状态等信息,指导确定选矿工艺,提高选矿试验研究效率。本研究采用MLA技术指导某铜钼矿选矿工艺研究。根据MLA工艺矿物学研究结果确定选矿工艺和药剂制度,通过条件试验确定详细的工艺参数和各药剂用量,最终在原矿铜品位0.63%、钼品位0.022%的条件下,得到铜品位24.82%,铜回收率91.90%,钼品位35.15%,钼回收率57.56%的选别指标。与现场生产指标相比,铜回收率接近,钼回收率提高12%。     

The value of automated mineralogy

Automated mineralogy methods and tools, such as the Mineral Liberation Analyser (MLA) and the QEMSCAN, are now widely used for ore characterization, process design and process optimization. Several case studies published recently demonstrate that large gains can be obtained through grinding and flotation optimization guided by automated mineralogy data. However, since automated mineralogy can only provide the information pointing to where the process gains can be made, it does not directly impact the production gain. Thus the question is often asked: how to value the contribution of automated mineralogy to process improvement at a particular plant. This appears to be a difficult question to answer. On close examination however, it is found that this is essentially a question of the value of information and this is reasonably well documented in various other industries. Hubbard, 2010, in chapter 7 “Measuring the Value of Information”, dealt with exactly this type of problem. The value of information is the reduced risk of an investment and opportunity loss. The methods Hubbard developed can be applied to estimate the value of automated mineralogy, as well as metallurgical test work, both producing information that reduces the risk of investment.This paper first introduces Hubbard’s theory on the value of information and how to measure it. It then applies his methods to estimate the value of automated mineralogy, using Anglo Platinum’s fine grinding project as an example. In the end, a general model is developed to allow the simulation of the value of automated mineralogy in different mining operations constrained by different parameters.     

工艺矿物学研究的新技术与新理念

近年来,基于扫描电镜的矿物自动分析仪如QEMSCAN（Quantitative Evaluation of Minerals by Scanning Electronic Microscopy）、MLA（Mineral Liberation Analyser）和AMICS（Advanced Mineral Identification and Characterization System）已经广泛应用于矿物的自动识别与测量;激光剥蚀等离子质谱仪（LA-ICP-MS）由于其在痕量上的检测优势,使元素赋存状态的研究更加准确与深入;飞行时间二次离子质谱仪（TOF-SIMS）的应用为研究矿物表面特性及其变化提供了便利和可靠的方法。部分大型矿山企业在地质勘查阶段就对不同区段的样品进行工艺矿物学研究,关注矿石性质的空间变化给选矿工艺及指标带来的影响,为及时优化改进工艺流程提供依据和指导。就目前研究成果而言,矿物自动测量与分析技术的不断完善,建立数学模型预测选矿指标以及矿物三维数据表征技术在工艺矿物学研究中的应用是其持续发展的新趋势和方向。      

白云鄂博尾矿库中铁的赋存状态研究

白云鄂博尾矿库是选铁和稀土后堆存的尾矿,尾矿中含铁16.71%。为查清尾矿中铁的赋存状态,采用光学显微镜、化学物相并结合MLA(自动矿物分析仪)对其展开了详细研究。结果表明,尾矿中的铁矿物主要为赤铁矿,另有少量磁铁矿和微量褐铁矿,铁在这三种矿物中的占有率达到66.83%;赤铁矿与磁铁矿的粒度主要分布于细粒级别中,其单体解离度分别为65.53%和49.34%,其连生体主要与脉石连生,且以富连生体居多。基于上述工艺矿物学特征,建议采用强磁选预先抛尾,粗精矿再磨的原则流程。     

自动矿物分析系统的统计误差分析

通过简化假设,提出了工艺矿物学中矿物体积百分含量p、统计量n与相对误差E的数学模型。对给定目标矿物的体积百分含量、统计颗粒数和置信度,可以估算出目标矿物的测量误差。采用四种矿物调配成已知含量的样品,用于验证自动矿物分析系统的测量精度。验证试验表明,当统计量越大时,不同含量的矿物的测量值均向理论值收缩,反之统计量变少时其测量值越偏离理论值,造成统计误差增大。通过对统计量的选择,可以实现对不同品位矿石的工艺矿物学参数的准确测量。     

内蒙古某多金属硫化矿工艺矿物学研究

内蒙古某硫化矿中含铜1. 29%、锌1. 27%、锡0. 267%、铁13. 46%、砷0. 878%、银74. 60μg/g。通过采用化学物相分析以及MLA、XRD、EDS、光学显微镜等分析方法和手段,查明了铜主要载体矿物为黄铜矿,锌为铁闪锌矿,闪锌矿次之,锡为锡石,砷为毒砂,铁为绢云母以及黄铁矿,银以类质同象形式分布于方铅矿、黄铜矿以及独立矿物银黝铜矿中,为选矿提高矿石综合利用率提供了矿物学依据。     

Understanding the performance of a pilot vermiculite exfoliation system through process mineralogy

This paper reports on the application of process mineralogy to understand the experimental performance of a microwave based system for the exfoliation of vermiculite type minerals. When montmorillonite type clay structures are exposed to high intensity electric fields they expand very rapidly with the degree of expansion being directly related to the applied electric field strength. This basic understanding of the interaction of microwave fields with such materials has been used to develop a pilot scale microwave based process for the exfoliation of vermiculite. During commissioning of the system it was noted that vermiculites from different geographical sources behaved very differently in terms of the achieved expansion ratio. A systematic mineralogical evaluation of these different materials was carried out using Mineral Liberation Analysis (SEM/MLA), Thermo-gravimetric analysis and X-ray Diffraction (XRD) in order to determine the reasons for the variation in performance. Samples from vermiculite mines in Australia, Brazil, China and South Africa were studied. The mineralogy and mineral characteristics such as liberation, size and texture of the samples were quantified for each ore sample. The South African and Australian samples were found to be predominantly hydrated forms of mica. The Brazilian sample was predominantly composed of vermiculite while the Chinese sample was composed almost totally of hydrobiotite. The relationships between the form of hydration and degree of expansion were derived and it is shown that pure vermiculite exfoliates at lower field intensities than the other forms of hydrated mineral. The paper concludes with deductions obtained from the mineralogical assessments of the vermiculites, thereby elucidating the reasons for the performance observed for each feed material in the microwave exfoliation system.     

内蒙古某铜浮选尾渣工艺矿物学研究

以内蒙古赤峰某铜冶炼企业的铜浮选尾渣为研究对象,利用X射线衍射分析、光学显微镜、MLA矿物自动测量系统对尾渣进行较为系统的工艺矿物学分析,系统研究了冶炼渣中主要矿物物相的嵌布特征和嵌布粒度,并分析了该铜浮选尾渣的综合回收方案。结果表明,铜浮选尾渣中铁和锌的含量分别为39.75%和2.45%,渣的主要矿相为磁铁矿、铁橄榄石及玻璃相,粒度较细,单体解离度仅为32.15%。单独磁选富集磁铁矿获得高品位铁精矿的难度较大,建议采用直接还原磁选工艺进行选铁,磁选尾矿可作为水泥的原料。     

铁精矿理论品位预测新方法——攀枝花铁精矿工艺矿物学研究

对攀枝花LYM原矿和铁精矿做了详细工艺矿物学研究,发现在原矿性质和工艺流程都近似的前提下,加大磨细度、大幅减少磁选机作业,铁精矿品位高于原单矿物法測定的理论精矿品位。通过MLA等先进方法分析,认为是钛磁铁矿矿物内部结构特征决定了精矿品位的变化,从而确定了铁精矿理论品位预测的新方法。     

Research of iron ore grinding in a vertical-roller-mill

The total energy consumption for ore comminution will further increase within the next decades. One contribution to minimise the increase is to use more efficient comminution equipment. Vertical-roller-mills (VRM) are an energy-efficient alternative to conventional grinding technology. One reason is the dry in-bed grinding principle. Results of extensive test works with two types of magnetite iron ores in a Loesche VRM are presented here. Within these test works, mill parameters like grinding pressure, separator speed and dam ring height were varied, following a factorial design of the experiments. The effects of the grinding parameters on the liberation of valuable minerals are characterised using mineral liberation analysis (MLA). It is shown how the different mill parameters influence important performance values like energy consumption, production rate and mineral liberation. Via multiple regression analysis, an optimal parameter range can be modelled for both ore types. The parameter predictions have been successfully verified in practical test works.     

The effect of using different comminution procedures on the flotation of Platinum-Group Minerals

The use of High Pressure Grinding Rollers (HPGR) has been widely reported to have major benefits in the treatment of minerals such as iron ore and diamonds. To date there have been few investigations into its use in the treatment of ores containing Platinum-Group Minerals (PGMs). HPGRs are known to reduce energy consumption and wear costs and improve the throughput in the circuit. In the present investigation the effect of the comparative use of HPGR and conventional crushing in combination with either dry or wet rod milling on the flotation of PGMs was studied using batch flotation. Previous studies of a base metal sulphide had shown that either HPGR or conventional crushing followed by dry milling produced the highest grades and recoveries (Palm et al., 2010). However in the present study it was observed that a similar treatment of Platinum-Group Minerals produced the poorest results and the highest grades and recoveries were obtained for the case of conventional crushing in combination with wet milling. The HPGR showed no advantages in terms of flotation performance and dry milling produced particularly poor flotation results.The results were investigated further using various surface characterization techniques in order to determine the reason for the decrease in grades and recoveries of platinum when using dry milling and HPGR as opposed to the case for base metal sulphides. The feed and product samples were analysed using ToF-SIMS, XPS and MLA. The paper will propose reasons to explain the different flotation behaviour of the two ore types following the various comminution processes focusing on the surface characteristics of the ores, the particle size distribution and the pulp chemistry.     

利用MLA对某铜矿石中伴生微细粒金、银的工艺矿物学研究

为了有效回收某铜矿石中伴生的低品位金和银,利用矿物自动分析仪MLA对其进行了系统的工艺矿物学研究,结果表明,该矿石中的金、银都以独立矿物存在,其中金矿物主要为自然金、银金矿和碲金银矿,银矿物主要为碲银矿和硒银矿,粒度均呈微细粒产出,金的载体矿物主要为硫化铜矿物,银的载体矿物主要为脉石,因此,金易回收于铜精矿中,银易损失于尾矿中。     

焙烧时间对钒转浸率影响的机理分析

对四种不同焙烧时间下的焙烧渣和酸浸后的残渣进行浸出前后EDS形貌分析、MLA物相含量分布和钒元素赋存形式和走向对比分析研究。结果表明,钒渣焙烧前后钒尖晶石由致密光滑的表面变成表面凹凸不平且形成多孔的结构;MLA物相分析数据显示,焙烧渣和残渣中物相的种类变化不大,但是由于钒酸钙的大量减少导致物相含量在浸出前后变化很大;钒元素分布测试结果表明,焙烧前期影响钒转浸率的因素是氧化铁固溶体相因固溶大量的钒和其他杂质元素难以被酸浸出;当焙烧时间达到360 min后影响钒转浸率的主要因素为烧结形成的辉石—硅酸钙过渡相阻碍了氧的扩散导致部分钒元素包裹其中而难以被酸浸出。     

加拿大某钒钛磁铁矿工艺矿物学研究

针对加拿大某钒钛磁铁矿的矿石特点,利用MLA(矿物参数自动分析系统)、光学显微镜、XRD、XRF等多种分析手段对矿石进行了详细的工艺矿物学研究,查明了矿石的化学成分、矿物组成、含钛矿物的嵌布粒度及解离度特征,有益元素的赋存状态,为该矿的选冶工艺、流程制定及提高回收率提供了理论依据。     

Understanding Gamsberg – A geometallurgical study of a large stratiform zinc deposit

The Gamsberg zinc deposit in the Northern Cape in South Africa has been the subject of a number of studies by Anglo American over the years. Two distinct ore types have been identified, namely pelitic and garnet-magnetite ore. The ore is characterised by relatively high manganese levels. Manganese reporting to the flotation concentrate is problematic for downstream refining.Anglo Research was asked by the exploration division of Anglo Base to study the relationship between the mineralogy and the floatability of the ore from reef intersections obtained from the eastern ore body. The two ore types were found to have different mineralogical characteristics resulting in different flotation responses both in terms of zinc and manganese recoveries and concentrate grades.The presence of the manganese sulphide, alabandite, was also established, and was found to be extremely detrimental to sphalerite flotation. The reasons for this were explained using the surface analysis facility at Anglo Research.     

贵州织金某含稀土磷矿工艺矿物学研究

运用MLA、EDS、SEM、ICP-MS等测试手段，对贵州织金某含稀土磷矿进行了工艺矿物学研究，重点考查矿石性质、主要矿物嵌布特征和稀土元素赋存特征等。研究结果表明，矿石属于中低品位钙硅质胶磷矿，P2O5品位为20.18%；磷灰石是主要有用矿物，含量为40.86%，与白云石、石英、黄铁矿等脉石矿物紧密共生伴生；La、Ce、Nd、Y是主要的稀土元素，其中，Y元素主要检出于磷灰石中，La、Ce、Nd元素主要检出于白云石，未发现稀土独立矿物。      

Mineralogy and mill performance optimization- a case study of south crofty tin mine

Mineralogy applied to the optimization of mill performance is an often negelected branch of mineral processing once a mill circuit has been established. This paper sets out the results of a case study carried out at South Crofty tin mine during a period of mine development, outlining the application of mineralogy in determining the possible long term effects of ore body development on mill performance. Three lines of investigation have been followed and these investigations have shown that certain mineral assemblages exist that are detrimental to mill performance and that specific ore bodies contain these mineral assemblages. Bu using this information it has been possible to predict how the mill should respond to future development, and to investigate alterations to the mill circuit to accomodate for the predicted changes in the ore mineralogy.     

梅山铁矿硫浮选原矿和硫精矿的工艺矿物学研究

针对梅山铁矿硫浮选所得硫精矿品位不高和硫回收率较低的问题,运用矿物解离分析仪（MLA）测试与化学分析、XRD分析等相结合的手段,详细研究了浮选原矿和硫精矿中硫矿物的工艺矿物学特征,重点分析了浮选回收主要矿物黄铁矿的嵌布特征、粒度及解离特性等,查明了浮选原矿粒度较粗、黄铁矿单体解离不充分是其浮选选别指标较差及浮选铁尾矿中硫含量较高的主要原因,提出了浮选粗精矿再磨再选的建议,为梅山铁矿浮硫工艺流程优化提供了理论依据。      

The formulation and use of mixed collectors in sulphide flotation

Mixtures of collectors have been widely used for many years in sulphide flotation, and a range of performance benefits have been reported for many different systems. The combinations of collector types have varied, as have the ratios that have been used. Synergistic effects have been obtained (greater than the sum of the parts) and in some cases the mechanisms of this improved behaviour have been identified. These benefits have been attributed to increased carrying capacity of the froth phase, faster kinetics, and more successful recovery of middling or coarse particles. It is the interaction between the various components of the mixed collector system, rather than the individual main effects, that dominate the performance benefits. The process benefits include increased paymetal recoveries and grades – as well as increased rates of recovery whilst using lower dosages of reagents. Various mechanisms have been reported and are discussed. These have been shown to affect different composition/liberation classes and sizes of mineral particles. In recent years, automated quantitative mineralogy and surface analysis technology such as ToF-SIMS have enabled the development of better information, to establish what aspect of the process has been affected. This has been successful mostly for use in a diagnostic capacity. Candidate selection for the mixed collector suite is presently based on experience and contextual knowledge. Predictive properties from these systems are a desirable future goal. Currently optimum combinations are preferably identified experimentally at laboratory scale prior to any plant trial. It is recommended that such laboratory work be performed using a factorial design with replicates and quality controls, such as may be delivered from High-Confidence Flotation Testing. The purpose of this paper is to summarise and review current theory and practice in the usage of mixtures of collectors in sulphide flotation – both in the application and in research in order to develop insights and guidelines to develop a methodology for use in a predictive capacity. A case study demonstrating this approach will be published at a later date.     

褐铁矿烧结成矿过程工艺矿相学研究

本文针对大宝山褐铁矿原料烧结,利用矿相显微镜查明了不同烧结时间,烧结温度和烧结碱度下各焙烧小团块的矿物组成与显微结构,揭示了褐铁矿烧结矿成矿的机理,找到了生成以针状铁酸钙为主粘结相的褐铁矿烧结矿的适合碱度、烧结温度及烧结时间,为褐铁矿低温烧结新工艺研究提供了理论依据。