难选富银铅锌矿浮选新工艺研究

某难选富银铅锌矿,黄铁矿和毒砂含量高达74%,方铅矿局部氧化,铅锌硫矿物间可浮性差异较小,原工艺添加少量石灰,采用丁基黄药为捕收剂,进行分段粗选和精选,流程结构复杂、分选指标低,铅精矿品位<45%、铅回收率<65%,银在铅精矿中回收率<55%,锌精矿品位<45%、锌回收率<60%,锌精矿含砷>0.5%;新工艺采用增大铅粗选石灰用量、使用GYD作为铅矿物捕收剂、粗精矿集中精选三项措施,简化了流程结构,扩大试验获得良好的浮选指标,铅精矿产率5.36%,铅品位62.23%,含锌3.14%,铅回收率82.40%,含银2214 g/t,银回收率72.02%;锌精矿产率8.04%,锌品位50.45%,含铅1.04%,含砷0.081%,锌回收率88.94%。相比原生产指标：铅精矿品位和回收率提高17%以上,铅精矿中银回收率提高17%以上;锌精矿的品位提高5%以上,锌回收率提高18%以上,锌精矿砷含量下降0.42%以上。当银以包裹体赋存于铅矿物中时,适当增加石灰用量,有利于铅与锌硫分离,改善分选指标。     

云南某高砷铜银矿石工艺矿物学研究

云南境内高砷铜(银)矿众多,为给该类型矿石的选冶研究提供参考,对某高砷铜银矿石开展了工艺矿物学研究。结果表明:(1)矿石构造主要为细脉浸染状、条带状、角砾状等构造;主要结构为他形—半自形—自形粒状、鳞片变晶、碎裂、交代残余等结构。(2)矿石中的金属矿物主要为黄铜矿、砷铁锑黝铜矿、毒砂、黄铁矿,硫铋铜矿、孔雀石少量,偶见蓝辉铜矿等;非金属矿物主要为石英、白(绢)云母、白云石、方解石、斜长石等。主要有用矿物为黄铜矿,其次为砷铁锑黝铜矿及硫铋铜矿;有害矿物主要为毒砂。(3)矿石属于高银硫化铜矿石,硫化铜占总铜的97.25%,94.07%的银分布在硫化铜矿物中,在浮铜过程中,银将随铜矿物的回收而得以综合回收。(4)黄铜矿、砷铁锑黝铜矿的嵌布粒度主要为0.01~0.1 mm,属细粒嵌布,对磨矿细度有一定要求。(5)矿石宜采用抑砷浮铜原则流程进行选矿,对含砷严重超标的铜银精矿宜采用焙烧或焙烧+湿法浸出的工艺进行降砷。     

Improving copper flotation recovery from a refractory copper porphyry ore by using ethoxycarbonyl thiourea as a collector

In this paper, N-propyl-N-ethoxycarbonyl thiourea (PECTU) collector was investigated to concentrate copper minerals from a refractory copper porphyry ore through bench-scale and industrial flotation tests. The flotation results indicated that PECTU had strongly collecting power for copper sulfide minerals and excellent selectivity against iron sulfide minerals under moderately alkaline conditions. Compared with sodium butyl xanthate (SBX), PECTU increased the grades and recoveries of Cu, Au and Mo in the copper concentrates, and performed the flotation separation of Cu/Fe sulfide minerals at cleaner pH ∼10.5 as well as decreased 2/3 lime consumption. The results of UV-visible measurements further demonstrated that PECTU could be used as a high selective collector for copper minerals. The experimentally obtained results have been explained from the structure-reactivity relationship of collector by density functional calculation.     

某高砷锡石硫化铜矿粗粒浮选工艺研究

试验用矿石为铜锡共生多金属硫化矿,矿石中的铜以细粒嵌布为主,且与黄铁矿、毒砂等致密共生。经过粗粒浮选工艺小型试验研究,采用粗磨-混合浮选-粗精矿再磨-铜砷(硫)分离的原则流程,能获得较好的技术指标。该工艺是在一段粗磨(-74μm占40%-45%)的条件下先富集单体及连生体硫化矿物,尾矿再进行选锡作业,这样有效地保护了锡石,减轻了锡石的过粉碎,为重选提供了好的给矿条件。铜粗精矿再磨再选,尾矿进入重选选锡,减少了锡石在硫化矿中的损失,提高了精矿铜品位和回收率,降低了精矿含砷量。该新工艺最终获得产率9.38%、品位23.58%、回收率91.17%的铜精矿,其中含砷仅为0.19%。同时锡在铜精矿中的损失也不到4%。     

Flotation of mixed copper oxide and sulphide minerals with xanthate and hydroxamate collectors

Sherwood Copper’s Minto Mine processes a high grade copper–gold deposit in Yukon, Canada. The ore mined is from a primary copper sulphide deposit with separate additional deposits of copper oxides. In conjunction with Ausmelt Chemicals, Minto is currently investigating options to recover copper oxide and sulphide minerals using flotation by blending their primary sulphide ore with oxide ores. The blend used in this laboratory scale investigation was 70% sulphide ore and 30% oxide ore on a weight basis. The copper sulphides present in the blend were bornite and chalcopyrite, while the oxides were malachite and minor azurite.From previous flotation investigations of mixed copper oxide and sulphide minerals using xanthate and hydroxamate collectors it was hard to distinguish the impact of the alkyl hydroxamate collector on sulphide recovery as the sulphide and oxide minerals occurred naturally together. In the case of the Minto operation the copper oxide and sulphide minerals occur in separate ore deposits and can be treated separately or blended together. This investigation has shown that using n-octyl hydroxamates (AM28 made by Ausmelt Limited) in conjunction with traditional sulphide collectors can successfully simultaneously recover copper sulphides and oxides by flotation from blended ore minerals. The copper sulphide recovery did not decrease when processing the blended ore compared to treating the sulphide ore independently. At a blend of 70% sulphide ore and 30% oxide ore, the rougher scavenger copper recovery was as high as 95.5%. The copper recovery from the blended ore using a mixture of collectors was shown to be superior to the recovery obtained using only xanthate after controlled potential sulphidisation.     

The separation of chalcopyrite and chalcocite from pyrite in cleaner flotation after regrinding

In this study, the differences between the separation of chalcopyrite and chalcocite from pyrite in cleaner flotation after regrinding were investigated. In the rougher flotation prior to regrinding, high chalcopyrite and chalcocite recovery were obtained in conjunction with high pyrite flotation recovery due to the activation of pyrite by copper ions during primary grinding. The rougher flotation concentrate was reground in a rod mill before cleaner flotation. It was found that chalcopyrite and chalcocite exhibited different flotation behavior and also affected pyrite flotation differently in cleaner flotation. The mechanism underpinning these phenomena was investigated by a range of techniques including the polarization of mineral electrodes, X-ray photoelectron spectroscopy (XPS) analyses and ethylene diamine tetraacetic acid (EDTA) extraction. It was found that the flotation behavior of both copper minerals and their effect on pyrite flotation after regrinding were governed by their electrochemical activities and galvanic coupling with pyrite.     

Assessment of the floatability of chalcopyrite,molybdenite and pyrite using biosolids and their main components as collectors for greening the froth flotation of copper sulphide ores

Biosolids and representative compounds of their main components – humic acids, sugars, and proteins – have been tested as possible environment-friendly collectors and frothers for the flotation of copper sulphide ores. The floatability of chalcopyrite and molybdenite – both valuable sulphide minerals present in these ores – as well as non-valuable pyrite was assessed through Hallimond tube flotation tests. Humic acids exhibit similar collector ability for chalcopyrite and molybdenite as that of a commercial collector (Aero 6697 promoter). Biosolids show more affinity for pyrite. The copper recovery (85.9%) and copper grade (6.7%) of a rougher concentrate obtained using humic acids as main collector for the flotation of a copper sulphide ore from Chile, were very similar to those of a copper concentrate produced by froth flotation under the same conditions with a xanthate type commercial collector. This new and feasible end-use of biosolids and humic acids should be new environment-friendly organic froth flotation agents for greening the concentration of copper sulphide ore. Now, further research is needed in order to scale current laboratory assays to operational mining scales to determine efficiencies to industrial scale.     

陕西某复杂含砷铜矿石选矿试验研究*

陕西某铜矿石属于含砷难选铜矿石，铜、砷、硫含量分别为0.74%、0.43%和1.54%，主要有用矿物是黄铜矿、辉铜矿，杂质矿物为毒砂和黄铁矿，矿石中铜砷矿物结合紧密，粒度较细，且矿物种类较多，嵌布关系复杂，普遍相互包裹，有用矿物单体解离较困难。为确定该矿石的选矿工艺进行了选矿试验研究。结果表明，矿石采用抑砷浮铜的优先浮选工艺流程处理，以石灰为含砷矿物抑制剂，获得了铜品位为25.27%、含砷0.085%、含金0.23 g/t、含银40.52 g/t、铜回收率为92.72%的铜精矿，尾矿铜品位为0.053%。铜精矿产品质量达到国家六级品标准，试验指标较理想。     

Current processing technology for antimony-bearing ores a review, part 2

On the basis of knowledge of the beneficiation properties of antimony minerals reported in the previous part of this article, this second half reviews the state of technology for separation of those minerals and summarizes experience from processing plants.The high density of antimony minerals and their tendency to grind to slime (hardness of 2.5 on Mohs' scale) make gravity separation in the mill circuit an interesting possibility for the first step in the process. Gravity concentration is already found in some process layouts, but there are undoubtedly more applications where modern gravity separation equipment could be used.Marketing considerations make separation of arsenopyrite an important part of the process in some cases. Special cleaning processes have been developed for the purpose, but more attention needs to be paid to selectivity in the primary Sb flotation. Because of the rise in gold prices, some antimony ores should really be viewed as gold ores with antimony as a by-product. In this context, cyanide leaching is an obvious step in addition to gravity separation, and the most logical procedure here would be first to separate the antimony at natural pH and then to leach out the gold with cyanide.The design of flotation circuits for beneficiation of stibnite is usually very straightforward: rougher, scavenger and two-stage cleaner flotation are usually enough to produce concentrates grading better than 60% Sb. Recycling circulating returns to the middle of the rougher flotation circuit offers an attractive way of obtaining high-grade concentrates while achieving high capacities.The choice of methods for depressing antimony minerals in complex sulphide ores depends on what kind of mineral is the predominant impurity. It ought to be possible to depress ferrous antimony minerals effectively in pyrite-selective environments.     

石长温都尔高砷多金属硫化矿分离浮选降砷研究

根据石长温都尔铅锌银矿的矿石性质及含铜低、砷高的特点，试验采用了优先浮选分离流程，采取了系列降砷措施，有效地实现了毒砂与铜、铅、锌硫化物之间的分离；产出了铜、铅、锌三种合格精矿。全部满足了冶炼厂对精矿含砷的要求。     

Detailed characterisation of antimony mineralogy in a geometallurgical context at the Rockliden ore deposit,North-Central Sweden

The antimony (Sb) content of the Rockliden complex Zn–Cu massive sulphide ore lowers the quality of the Cu–Pb concentrate. The purpose of this study is to characterise the Sb mineralogy of the deposit. The Sb-bearing minerals include tetrahedrite (Cu,Fe,Ag,Zn)₁₂Sb₄S₁₃, bournonite PbCuSbS₃, gudmundite FeSbS and other sulphosalts. On a microscopic scale these minerals are complexly intergrown with base-metal sulphides in the ore. Based on these observations mineralogical controls on the distribution of Sb-bearing minerals in a standard flotation test are illustrated. Deposit-scale and rock-related variation in the Sb-content and distribution of Sb-bearing minerals were found. This underlines the importance in understanding the geological background as a basis of a 3D geometallurgical model for Rockliden. Such a model is expected to predict the Sb content of the Cu–Pb concentrate, among other process-relevant factors, and helps to forecast when the Cu–Pb concentrate has to be treated by alternative processes, such as alkaline sulphide leaching, before it is sold to the smelter.     

低碱度铜硫分离高效抑制剂的研究

对有机抑制剂DP-1、无机抑制剂DP-2和DP-3浮选分离德兴铜矿一段铜硫混合精矿进行了试验研究。结果表明,DP-1、DP-2和DP-3都是铜硫分离时硫的有效抑制剂,但DP-3的综合性能要优于DP-1和DP-2抑制剂。闭路浮选试验结果表明,当DP-3总用量为500g/t时,可获得铜精矿中铜品位28.43%、铜回收率97.71%和钼品位0.212%、钼回收率80.56%的二段分离指标,与石灰工艺相比,铜、钼、金、银的回收率分别提高了0.75%、31.38%、2.76%和8.31%,表明低碱度浮选工艺对于伴生金属的回收具有十分明显的优势。生产综合样验证试验进一步证明捕收剂Mac-12和抑制剂DP-3可望实现德兴铜矿铜硫低碱度高效浮选分离。     

Selective leaching of penalty elements from copper concentrates: A review

Custom copper smelters impose substantial financial penalties for the presence of deleterious impurity elements in copper concentrates and can outright reject concentrates which contain impurity elements in concentrations that exceed specified values. Hence, there is strong motivation to remove penalised impurity elements from copper concentrates at the mine site before shipping to custom smelters. A number of leach systems have been developed for the selective extraction of penalty elements from copper concentrates, including: alkaline sulphide leaching (ASL); hypochlorite leaching; dilute sulphuric acid leaching with aluminium sulphate; and combined pressure oxidation (POX) leaching with copper precipitation leaching. This paper reviews these four systems with emphasis on the leaching behaviour of penalty elements. ASL has previously been employed in industry for the selective extraction of As and Sb from tetrahedrite-rich copper concentrates. Sodium sulphide solution leaches As, Sb, and Hg from a large range of minerals, however, does not leach arsenopyrite, a mineral which often contains a significant portion of the total As in copper concentrates. Hypochlorite leaching extracts As associated with enargite minerals. This leach system benefits from superior rates of As extraction when compared with ASL, and for this reason, has gained recent interest within the research community. Two major issues have been identified with hypochlorite leaching of copper concentrates. These are poor reagent selectivity towards As-bearing minerals and high levels of hypochlorite consumption. Unless these two issues are resolved it is unlikely that hypochlorite leaching will be employed in commercial processes. Dilute sulphuric acid leaching with aluminium sulphate is used to extract F associated with fluorite. This leach system also extracts F associated with apatite and chlorite. Laboratory-scale experiments and extensive operating experience have indicated that fluorite can be substantially leached from copper concentrates without addition of aluminium sulphate provided that the concentration of sulphuric acid in the leach solution is sufficiently high (at least 40 g L⁻¹). POX/copper precipitation leach systems have potential to extract a large number of penalty elements from copper sulphide concentrates while simultaneously upgrading the concentration of copper in the concentrate. Two patented POX/copper precipitation leach processes have been specifically developed for the deportment of penalty elements. These two processes are reviewed in detail.     

Development and evaluation of an early removal process for the beneficiation of arsenic-bearing copper ores

In conventional flotation flowsheets for treating copper sulphide ores containing small but significant amounts of arsenic, the arsenic is generally concentrated with the copper in final concentrate. Often, a penalty can be imposed by the smelter processing the concentrate, based on the arsenic content. In some cases the arsenic level is such that the smelter will not treat or accept the concentrate.A new approach to address this issue is reported in this paper, which is becoming more significant as the quality of the copper ore bodies currently being mined diminishes. A new flowsheet, based on the early removal of arsenic at the concentrator, has been developed and tested at bench-scale.The proposed flowsheet comprises three key steps: firstly, separation of arsenic and copper minerals using controlled-potential flotation to produce a low-arsenic high-copper concentrate and a high-arsenic low-copper concentrate. The low-arsenic concentrate can be sold without incurring any penalty for arsenic content. In the second stage, the high-arsenic concentrate is subjected to a low temperature roasting, where the arsenic is selectively fumed off into a low-volume stream product. The calcine from the roaster is high in copper and sulphur and can still be smelted directly. In the final stage of the flowsheet, the arsenic in the fume product is immobilised in a low temperature ceramic such that safe disposal back into the ground is possible.The new early removal flowsheet has been sequentially tested in the laboratory at small scale. The technical and economic merits of the flowsheet compared with that of the conventional copper flotation flowsheet show that there is a net benefit.     

Arsenic-rejection flotation circuit design and selection based on a multiple-objective evaluation

This paper describes the application of a shortcut computational method to analyse and compare alternative flotation circuits developed to treat high-arsenic copper ores. The methodology uses a superstructure that considers the many different available elements of the flotation circuits and compares the results. The circuits were evaluated using radial/spider graphs, and were evaluated based on the metric indices of efficiency, capacity, quality, economics and environmental impact.The simulations were performed for a superstructure that considered 27 flotation circuits for an Australian sulphide ore containing chalcopyrite, tennantite, quartz and pyrite. The starting circuit corresponded to the flotation circuit described in previous work on this ore (Haque et al., 2010, Bruckard et al., 2010), and was used as the basis for comparison of the alternative flotation circuits.The key result of the analysis is that the base condition is one of the best circuits with respect to the copper grade in the concentrates, CO₂ emission, and fresh water usage. However, the base condition is one of the most inefficient circuits with respect to the percentage of arsenic in the products, profit, and copper recovery. This study shows that there are more suitable flotation circuits available than the stated base condition for a specific goal and/or multiple goals.     

Flotation of copper sulphides assisted by high intensity conditioning (HIC) and concentrate recirculation

This paper describes the effect of the partial concentrate (rougher floated product) recirculation to rougher flotation feed, here named concentrate recirculation flotation – CRF, at laboratory scale. The main parameters used to evaluate this alternative approach were flotation rate and recovery of fine (“F” 40–13 μm) and ultrafine (“UF” <13 μm) copper sulphide particles. Also, the comparative effect of high intensity conditioning (HIC), as a pre-flotation stage for the rougher flotation, was studied alone or combined with CRF. Results were evaluated through separation parameters, grade-recovery and flotation rates, especially in the fine and ultrafine fractions, a very old problem of processing by flotation. Results showed that the floated concentrate recirculation enhanced the metallurgical recovery, grade and rate flotation of copper sulphides. The best results were obtained with concentrate recirculation flotation combined with high intensity conditioning (CRF–HIC). The kinetics rate values doubled, the Cu recovery increased 17%, the Cu grade increased 3.6% and the flotation rates were 2.4 times faster. These were accompanied by improving 32% the “true” flotation values equivalent to 2.4 times lower the amount of entrained copper particles. These results were explained and proved to proceed by particle aggregation (among others) occurring after HIC, assisted by the recycled floatable particles. This “artificial” increase in valuable mineral grade (by the CR) resulted in higher collision probability between hydrophobic particles acting as “seeds” or “carrier”.     

提高永平铜矿铜精矿品位的探讨

提高铜精矿品位是永平铜矿选矿面临的主要技术问题之一。本文通过试验和实践总结后认为:提高一段磨矿细度能有效提高铜的浮选指标;中矿再磨不仅可以避免铜矿物的过磨,而且能提高铜精矿品位和铜回收率,建议进一步对中矿再磨方案进行深入研究;采用石灰+CTP或石灰+水玻璃强化铜硫分离,比较明显地提高了铜精矿品位;此外,使用新型高效的铜选择性捕收剂是提高铜精矿品位的有效途径。     

Process mineralogy as a predictive tool for flowsheet design to advance the Kamoa project

The Kamoa resource, located in the Democratic Republic of the Congo, contains an array of copper sulphide minerals which are present as small grains, averaging 10–27 μm. An initial flowsheet was developed in 2011/12 for the prefeasibility study that was robust enough to handle flotation of all the copper sulphide minerals. Copper recoveries of the flowsheet were 85.4% for the hypogene ore and 83.4% for the supergene ore. Further work on the flowsheet required reduction of the SiO₂ grade of the concentrate, which at 19.1% negatively affected the downstream smelter processing, and also required improvement to copper grades and recoveries given the high grade of the ore. When new sample material became available as part of the Phase 6 drilling program, a fundamental reassessment of the ore and its flotation behaviour was conducted. Although mineralogical characterisation of the ore and liberation of the sulphides was quantified in previous phases of work, there was little understanding of the kinetics of each of the copper sulphide minerals and how they performed in the flowsheet. Comprehensive flotation kinetic tests at various primary grind sizes were performed. The corresponding timed concentrates of the three best performing grinds were characterised by QEMSCAN on a size-by-size basis to fully understand the flotation kinetics and liberation characteristics of the various copper sulphides. A simple and practical recovery model using minerals, particle size and liberation and association was developed from these data, and various flowsheet configurations were simulated. These simulations led to some robust process implications completely rearranging the flowsheet from the previous iteration into a more simple and economic configuration with better performance. The modelled data was confirmed with practically achieved data, extending the use of process mineralogy as a valid, predictive tool in process design. Additionally, the simulations using mineralogical, reduced empirical flotation testing needed to develop the new flowsheet.     

西藏某含金浸染状次生硫化铜矿石浮选回收铜金试验

西藏某浸染状次生硫化铜矿石铜品位为1.86%，原生硫化铜占总铜的15.05%，次生硫化铜占总铜的76.88%，主要铜矿物为斑铜矿、黄铜矿，其他金属矿物有黄铁矿、磁黄铁矿等；脉石矿物以石榴石、辉石、石英等为主。为了确定该矿石中铜、金的适宜回收工艺，进行了选矿试验。结果表明，矿石在磨矿细度为-0.074 mm占70%的情况下进行1粗2精快速浮选，1粗2扫常规浮选，快速精选1尾矿与常规粗选精矿合并再磨至-0.038 mm占80%的情况下进行1粗2精2扫铜硫分离，获得的快速浮选精矿铜品位为27.05%、金品位为8.28 g/t，铜、金回收率分别为60.79%、50.90%；常规浮选铜精矿铜品位为17.06%、金品位为5.02 g/t，铜、金回收率分别为29.81%、23.99%。快速浮选+常规浮选、快速精选1尾矿与常规浮选粗精矿再磨再选工艺流程既能避免铜矿物的过磨，保证铜的回收率，又可得到较高品位的铜精矿，获得较好的铜、金回收指标。     

Challenges and opportunities in the recovery/rejection of trace elements in copper flotation-a review

In most copper sulphide flotation processes, optimising recovery of trace elements such as gold or maximising the rejection of penalty elements such as uranium, arsenic and fluorine remains a major metallurgical challenge. This review looks at the existing and possible strategies of improving gold recovery in porphyry copper ores and rejection of penalty elements such as uranium, arsenic and fluorine in copper flotation concentrates.