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By C. B. Strachan

The Mascot concentrator treats 1,900 tons of zinc ore per day by gravity concentration and flotation. During the year 1929 the heads averaged 2.90 per cent zinc, and the recovery was 90.15 per cent; the concentrates produced contained 60.19 per cent zinc. ACKNOWLEDGMENT Acknowledgment is made to M. H. Newman, geologist, Robert Ammon, chief metallurgist, D. B. Grove, mill superintendent, and W. A. Calhoun, metallurgical clerk for assistance in the preparation of this paper.

Jan 1, 1930

By L. J. E. Hofer

This Bureau of Mines study, part of a broad program of research in air pollution related to minerals, was conducted to determine the nature and extent of the poisoning of catalysts when used to remove certain air pollutants from exhaust gases. The poisoning examined in this investigation occurs when leaded gasoline is used as a fuel for automotive engines. This research was conducted in cooperation with the Public Health Service. The smog in the Los Angeles area is attributed to the effect of radiant energy on the mixture of hydrocarbons and nitrogen oxides found in the atmosphere there. A large portion of the hydrocarbons is believed to originate in the exhaust gases of automobiles. To prevent the escape of these hydrocarbons into the atmosphere catalytic mufflers have been proposed. In principle, these are simple and nonmechanical, consisting of a vessel charged with a catalyst capable of destroying the exhaust hydrocarbons by catalyzing their oxidation. However, these catalysts are severely affected by the particulate matter, mainly in the form of lead sulfate (PbS04), lead oxysulfate (PbS04.Pb0), and Lead chlorobromide (Pb(Cl,Br)2), contained in the exhaust gas. Deposition of lead on the catalyst as PbS04, PbS04, PbS0, and Pb(Cl,Br)2 restricts catalytic activity. As a result,after 20,000 miles of operation the temperature necessary to achieve 50-percent conversion of isopentane in a mixture of 0.2 percent isopentane, 2 percent carbon monoxide and 4 percent oxygen, and the balance nitrogen at 10,000 hourly space velocity has risen from 400° C. to 500° C. even with a catalyst taken from the exit portion of the catalyst bed. The rest of the catalyst was more severely affected. Therefore, it would appear that operation for 20,000 miles is near the limit for a catalyst.

Jan 1, 1963

By B. T. Lu

The corrosion and wear properties of a series of chrome white iron (CWI) castings were study using electrochemical and low-stress sliding abrasion tests. The results confirm that the corrosion resistance of these materials is largely dependant on the quantity of chromium in the matrix, while the wear resistance is mainly controlled by the volume fraction of chromium carbides. A pseudo-wear/corrosion map is developed to identify alloy compositions that may be suited for erosion/corrosion conditions.

Jan 1, 2005

"The Australasian Joint Ore Reserves Committee (JORC), which is sponsored by the Australian mining industry and its professional organisations, developed the JORC Code to provide minimum standards for public reporting. JORC was first published in 1989 and later incorporated into the Listing Rules of the Australian and New Zealand Stock Exchanges making compliance mandatory for listing public companies in Australia and New Zealand."

Jan 1, 2003

SME-AIME Fall Meeting and Exhibit

Jan 9, 1979

By D. Tao

Froth flotation is widely used in the coal industry to clean -28 mesh or -100 mesh fine coal. A successful recovery of particles by flotation depends on efficient particle-bubble collision and attachment with minimal subsequent particle detachment from bubble. Flotation is effective in a narrow size range outside which the flotation efficiency drops sharply. A fundamental analysis has shown that use of picobubbles can significantly improve the flotation recovery of particles by increasing the probability of collision and attachment and reducing the probability of detachment. A specially designed column with a picobubble generator has been developed for enhanced recovery of fine coal particles. Picobubbles were produced based on the hydrodynamic cavitation principle. Experimental results with one metallurgical coal and one steam coal have shown that the use of picobubbles in a 2" column flotation increased fine coal recovery by 10-30%, depending on the feed rate, collector dosage, and other flotation conditions. Picobubbles also acted as a secondary collector and reduced the collector dosage by one third to one half.

Jan 1, 2006

By S Hanke, J Burden, P Spies

The Waterview Connection will complete Auckland’s long-planned Western Ring Route, a 48 km north-south motorway alternative to State Highway 1 that bypasses the central city to the west. The project involves construction of 5 km of new motorway – half of it underground in tunnels – to connect the Southwestern (State Highway 20) and Northwestern (State Highway 16) motorways.The Western Ring Route will link the major population and industrial centres of Manukau, Auckland and North Shore to give the region the connected and resilient strategic road transport system it needs to underpin economic growth and sustainable development. It will also provide a direct motorway link between Auckland’s central business district (CBD) and international airport.The project involves construction of twin 2.4 km driven tunnels with an outside diameter of 14.41 m beneath residential suburbs, a major arterial road and a rail corridor. Enabling works began in January 2012 while tunnel construction using an earth pressure balance (EPB) tunnel boring machine (TBM) began in November 2013.This presentation introduces the Waterview Connection project, its role in the development of the Auckland motorway network, its procurement process, the alliance delivery model and an overview of the project’s design features and construction progress to date.Design and construction highlights of the presentation include the TBM start-up, turnaround and breakthrough arrangements as well as the experience gained during the first tunnelling drive. The presentation also covers an innovative process developed for invert construction behind the TBM that is independent of tunnel excavation.CITATION:Spies, P, Burden, J and Hanke, S, 2014. The Waterview Connection Project – progress to date, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 519–540 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

As a bubble travels through the pulp region of a flotation cell, it will collect the most hydrophobic particles of an intermediate particle size range, this being the primary source of true flotation selectivity. Despite its role on bubble-particle attachment, however, particle hydrophobicity is still missing a mathematical definition that can be used for plant simulation. In this paper, particle hydrophobicity is defined in terms of the induction time necessary for attachment and then linked to the mass of collector adsorbed per particle. This allows particle hydrophobicity to be written as a function of density of collector adsorption as well as particle size and mineralogy. The model is calibrated from the experimental measurement of the flotation rate constant. Liberation data from an industrial flotation rougher is used for model validation. It is demonstrated that the model can describe a broad experimental dataset by means of a minimal number of parameters. Main industrial application is in simulating the effect of the chemical environment upon plant metallurgical performance.

Jan 1, 2006

By G. Ferrara

During several years of operation in Europe, South Africa and other countries, the Tri-Flo has demonstrated to represent a substantial improvement of the dense medium dynamic separation systems. The reasons are: (1) high sharpness separation due to the multistage system and the application of new concepts in designing the regeneration circuit and controlling the medium rheology; (2) the possibility of performing two cuts at different densities using a since separation device and a single regeneration circuit. The paper discusses in detail the above mentioned points, with particular reference to the multistage technology, based on the circuit analysis theory, and to the control of the medium rheology based on recent work in the modelling, and simulation of the rheological behavior of dense suspensions.

Jan 1, 1993

By H Arvidson, V Chamberlain, J Joughin, N Pollock, F Cessford, T Flitton, T Rowl

Environmental, social and governance issues (ESG) have become a defining feature in the marketplace to differentiate preferred investments. With the sustainability commitment and reporting landscape anticipated to evolve exponentially, it is now imperative to rapidly develop the approach taken by mineral companies to adequately identify and address ESG risks and opportunities in the reporting of Mineral Resource and Mineral Reserve (MRMR). MRMR cannot be effectively reported as technically and financially assured and realistically executable, if ESG is not integrated into the strategy, business model, input assumptions and process that defines and drives robust MRMR public reporting. Regulatory reporting codes across the globe are presently in various stages of being updated and modified to ensure ESG factors are appropriately covered as a key part of diligent and transparent disclosure. Security exchanges are making it clear that companies must not omit ESG risks from reports to investors. This paper discusses associated challenges for MRMR reporting and suggests avenues for improvement. Key themes include: the importance of procedure rather than prescription and checklists; how ESG criteria impact Modifying Factors and determination of Reasonable Prospects for Economic Extraction (RPEE); the need for financial models to account for material ESG commitments; the uniqueness of each mineral asset; the need for education, upskilling and accreditation of both ESG experts about MRMR reporting and equally Competent Persons in ESG matters; and the need for clear and balanced reports that meet the needs of end users. (RPEE is adopted here for simplicity and consistency, recognising that some reporting codes still include ‘Eventual’ in the term (ie RPEEE). Whilst RPEE and RPEEE are subtly different the intent is to point to the process of assessing ESG factors in determining reasonable prospects.) The principles of transparency, materiality and competence remain paramount when considering the impact of ESG matters on MRMR reporting, and this necessitates an inclusive, cohesive, and integrated approach to assessing ESG issues to ensure the necessary expertise and diligence is applied.

May 24, 2023

By Rongjie Kong, Shiwei Wang, Guomin Wei

Owing to the selective oxidation and uneven combustion that occur on the surface of carbon anode, some carbon particles detach and form carbon residue, which is defined as spent anode slag (SAS). The highly graphitized and toxic impurities such as fluorite ( CaF2), corundum (α-Al2O3), and cryolite ( NaAl11O17) are crucial components of SAS resource but are difficult to separate from graphite. This study developed a method of using water-soluble (emulsified) kerosene to separate the carbon particles from the toxic impurities in the SAS resource. The flotation purification approach of utilizing conventional kerosene was experimentally investigated and compared with that of using water-soluble kerosene. The results showed that with the use of emulsified kerosene, the maximum combustible matter recovery of the carbon particles was 89.86% while that of using traditional kerosene was 80.30%. The emulsified kerosene was comprehensively examined by various instruments to clarify its adsorption mechanism on the carbon particle surfaces. Because of the superior dispersibility of emulsified kerosene, it effectively envelops carbon particles with a smooth surface, oxygen-containing functional groups, and hydrophilic C–F bonds, thereby increasing the surface hydrophobicity and flotation responses of targeted carbon particles.

Feb 6, 2024

"The zinc concentrator of the Butte & Superior Copper company, shown on the opposite page, represents an industry which is coming into importance in Butte. The existence of large bodies of zinc ore in some of the silver veins of Butte has been realized for years, but it is only recently that some of them have proved amenable to successful concentration. Most of the zinc ores thus far found in the camp are mixed with considerable pyrite, but those found in the Black Rock and Elm Orlu mines contain very little pyrite, so that a concentrate low in iron is possible.The Butte & Superior mill is rated at 1,200 tons daily capacity. The ore is sphalerite, most of which is finely disseminated through a hard quartz gangue, with small quantities of galena, pyrite, chalcopyrite, rhodocrosite and rhodonite. In mining, the included granite and the low grade vein matter are sorted out and used for waste filling so that the ore as it goes to the concentrator will carry about 20 per cent of zinc, 1 per cent lead, .25 per cent copper, 8 to 10 ozs. silver and a little gold. The ore bodies ranging from 5 to 103 feet in width, are mined by the square set method and filling of stopes with waste rock.The ore is hard and tough requiring extensive crushing and grinding equipment, consisting of Blake and gyratory crushers, 54-inch and 42-inch high speed rolls, Chili mills, Tube, and Conical mills. All of the lead con¬centrate and part of the zinc concentrate are recovered in the upper part of the mill by jigs and tables. The classifier overflow and the re-ground jig and table tailings go to settling tanks and from there to the Hyde Flotation process, where the balance of the zinc concentrate is recovered, and the tailing go to waste."

Jan 1, 1913

By Joseph A. Hrabik

The Bureau of Mines compared the feasibility of mining deep phosphate deposits by a borehole mining system with mining by proven conventional techniques. An economic comparison of the borehole mining system with conventional dragline and bucket wheel excavator mining systems was completed at various mining depths and production rates. Hypothetical phosphate deposits, with various overburden thicknesses and reserve tonnages, were defined. Geologic conditions necessary for the application of the borehole system were identified. Discounted cash flow analyses based on derived capital and operating costs were used to generate rates of return and product prices. Borehole mining was found to be more economical where overburden thickness was 150 ft or greater; however, at 50- and 100-ft thicknesses, conventional surface mining was more economical. Overburden thickness has a great effect on the economic feasiblity of the conventional mining systems but less effect on the economics of borehole mining. Economies of scale are only realized in conventional mining, since larger equipment is employed to achieve greater production, whereas increased production from borehole mining is achieved using additional equipment units. A comparison of the environmental effects of borehole and conventional surface mining systems showed that borehole mining is environmentally more desirable.

Jan 1, 1983

"11.1. IntroductionThe recovery of platinum-group elements (POE) from ores is a subject which has received almost no mention in the literature. Edwards (1975) refers to the process used for refining of the POE, throughout the Western World, as a so-called ""conventional"" process .... ""not because of the simplicity or convenience of the operations, but more probably because of the inertia of established processes and the aura of secrecy with which the major platinum refiners have surrounded this process."" There is no doubt in this writer's mind that the latter is also applicable to the dearth of knowledge of the mineralogy, geochemistry and ore deposits of PGE and that the poor recoveries, mainly attributed to the mineral beneficiation stages of concentration, are also affected by this traditional secrecy. Fortunately, this attitude is changing, due no doubt to the advantages that accrue from more open research which may be critically assessed in the literature in the traditional manner. Examples of this more open approach to recoveries and recovery problems are represented by Newman (1973), who gave some typical recovery percentages for Merensky Reef ores, and the recent encouragement and cooperation on mill samples from the Sudbury area by lnco Metals Company (cf. Cabri, 1981a).In general, platinum-group elements are recovered from an ore by the use of a physical concentration method, such as gravity separation or flotation, followed by further upgrading using further physical, wet chemical or pyrometallurgical techniques. The final process of refining in which the individual platinum-group elements are produced in pure form is outside the scope of this chapter.Platinum-group element deposits naturally fall into different categories according to the recovery process best suited for them, viz. those amenable to gravity separation, those amenable to flotation, and those where platinum-group elements are by-products of base metal sulphide, chromite and miscellaneous other deposits."

Jan 1, 1979

By Tim O’Neil

Nearly 4,800 mining professionals and exhibitors occupying 580 booths attended the 2000 SME Annual Meeting and Exhibit, Feb. 28-March 1, in Salt Lake City, UT. The technical program included80 sessions and four specialty symposia: bulk material handling, control 2000, minor elements 2000 and plant operaters. Meeting highlights included the keynote session. Executive shared their perspectives on pivotal issues and approaches to address the challenges of the new millennium. SME has begun planning for its 2001 Annual Meeting, Feb. 26-28, in Denver, CO. The meeting carries the theme “2001 — A Mining Odyssey.” A call for papers has been issued and exhibit space is 80% reserved. For information, visit SME’s website, www.sme-net.org. Or write Box 625002, Littleton, CO 80162-5002,ph 800 763 3132 or 303 973 9550, fax 303 979 3461, or email meetings@smenet.org.

Jan 1, 2000

By A Parbhakar-Fox, B G. Lottermoser, N Fox

"Determining the deportment of economic and environmentally significant elements in sulfidic mine materials (eg ore, gangue and waste) requires the use of advanced microanalytical techniques, including electron microprobe analysis (EMPA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). Sulfidic boulders were sampled from an acid rock drainage impacted ephemeral stream adjacent to historical copper-silver workings at Baal Gammon, northern Queensland. The abundance and deportment of a range of trace elements and precious metals were analysed in these samples. Whilst many of these elements represent a potential environmental risk if leached from sulfidic rocks into streams in the surficial environment, significantly some of these elements (eg In, Sb and Co) represent specialised metals that are currently considered to be in critical supply.Sulfidic waste rock material at Baal Gammon is dominated by chalcopyrite, arsenopyrite, pyrrhotite and pyrite. Microanalytical investigations revealed that chalcopyrite contains significant quantities of In, Sn, Ag and Zn either substituted directly into the crystal lattice or occurring as discrete sphalerite and stannite inclusions. Arsenopyrite, which may comprise more than 50 per cent of some boulders, is notably enriched in Sb, Co and Ni but also contains inclusions of sphalerite, chalcopyrite and stannite. In contrast, pyrrhotite contains no trace elements of economic significance, but instead represents a likely contributor to acid generation during oxidation in the surficial environment. Trace metals (eg In, Sb, Co, Ni, Zn) are liberated during sulfide oxidation of these boulders in the surficial environment, generating a metal-rich, low-pH leachate.Fe-oxides precipitated as rinds on the surface of these boulders under low pH conditions also contain abundant As, Bi, Sn, Cu and Zn. Abandoned or historical mines represent potential sources of metalliferous drainage that poses potential environmental risks to water and habitats. However, sulfide-rich historical waste rock, stockpiles and processed waste (eg tailings) at abandoned mines may also represent significant sources of critical (eg indium) or other significant metals (eg Sn) that if liberated economically could improve environmental conditions in and around abandoned and historical mines.CITATION:Fox, N, Parbhakar-Fox, A and Lottermoser, B G, 2016. Critical and Deleterious Metal Deportment in Sulfidic Waste Rocks, Baal Gammon, North Queensland, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 173–182 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By Knud Sinding

Mining firms are widely criticised for their adverse impacts on the environment. At the same time many firms in the industry devote extensive resources, both financial and managerial, to the reduction or elimination such impacts. Very considerable improvements have been made, although these are sometimes overshadowed by a few high-profile accidents, such as the occasional collapse of a cyanide-containing tailings dam. In parallel, much effort is also directed at projecting a positive environmental image, as witnessed by extensive environmental reporting, both on paper and increasingly through web-platforms. Mining projects today almost invariably involve some form of environmental protection. In industrial countries regulations in this area are extremely stringent, as is enforcement. In less well developed countries, regulation and enforcement may be weaker, but firms are in many cases and for a number of reasons committing themselves to high levels of environmental protection, even if they might get away without doing so. Research in the area of environmental performance of mining firms has so far paid much attention to concepts such as sustainability indicators and the sustainability of individual firms. Given the still raging debates about the appropriate way to determine the degree to which any given firm is sustainable (Welford 1995) as well as the usefulness of what will in the final analysis be a value judgement, anyone on the sidelines of the debate will come back to the fundamental issue, how is knowledge that a particular firm has been judged ?sustainable? going to be made use of. This issue remains unresolved, which may explain the lack of progress in formulating a useful definition of a sustainable firm The question addressed in this paper is not so much about what firms are doing on the ground or in any particular case of environmental protection, but more in the subsequent use of these efforts - and by extension - on the overall direction of corporate environmental strategy. The fundamental problem facing all mining firms is that they cannot easily benefit from unilaterally reducing their environmental impact. The firm can of course avoid liability and keep a variety of stakeholders happy and hence experience lower costs of obtaining the [input] resources they need (in a broad sense, not just minerals), but this represents only part of the opportunities available form pursuing an environmental strategy (Reinhardt 2000). The other part, which may have an enormous potential, involves the concepts of competitor management and product differentiation. The logic of keeping stakeholders happy has been most forcefully argued by Pfeffer and Salanchick (1978) who link the behaviour of firms in all domains to their ability to obtain the resources they need, at a cost that is lower than it would otherwise be (Pfeffer & Salanccik 1978). Several varieties of strategy can be included under this heading, including cost reduction and risk management. The alternative logic is to convince customers that they want to pay more for minerals supplied by mining firm X or directly attributable to mine Y, or by making all mineral users pay more. These two strategies, which may be referred to as product differentiation and competitor management, respectively (Reinhardt 2000) are related to the demand side of mineral supply, whereas cost reduction and risk management are related to the supply side. Mining firms have not pursued the demand side very much, if at all. This is probably due to the extreme difficulty of moving mineral products, bulky and unglamorous as they are, away from their

May 1, 2003

The Sao Chico gold project is located on the Tocantinzinho trend which is the most mineralised zone in the Tapajos Mineral Field of Brazil (see Figure 1). The Tapajos goldfi eld was the site of the biggest gold rush in Brazilian history in the late 1970s and 1980s when approximately 500 000 garimpeiros (artisanal miners) rushed to the area to exploit extensive areas of newly discovered alluvial gold. Approximately 20 - 30 million ounces of gold were produced from these operations before the easily won alluvial gold deposits were largely depleted. The Tapajos region has had little exploration by modern exploration methods compared to any other equivalent gold fields in the world. The gold occurs in sulfide veins developed in shear zones within Proterozoic granites. Gold grades vary from approximately 15 g/t in the hard rock veins, to up to several ounces per tonne in the supergene weathered upper portions of the veins. Goldbearing vein zones in the weathered profile are free digging. In addition, tailings dumps from previous mining operations contain gold grades of approximately 1 g/t. Metallurgical test work conducted to date indicates that gold recoveries of at least 70 per cent can be achieved via gravity concentration. Gold Anomaly, via its 100 per cent owned Brazilian subsidiary, Gold Aura Do Brasil Mineracao Ltda (GOAB), plans to mine the tailings and weathered vein material by open cut methods to generate a quick cash fl ow and to provide a better understanding of the mineralisation as part of a feasibility study for mining the underlying sulfide zone mineralisation (see Figure 2). Mining will utilise locally hired excavators and trucks and ramp up to a rate of 100 tonnes per day. To treat the gold-bearing material, GOAB has purchased an integrated 'state of the art' gravity concentration processing plant from Gekko Systems of Australia. The processing plant includes a scrubber for clay and oversize removal, coarse gold gravity separation via an inline pressure jig and an inline spinner; and fine gold gravity separation via a Falcon Concentrator. The plant is expected to be operational by late 2010. This is an ABSTRACT ONLY. No paper was prepared for this presentation. 

Aug 1, 2010

By Zhen Hu, Chenghang Wang, Jianjian Zou, Xiujuan Li, Hanwen Li, Tai Wang, Baoxu Song

A rare earth deposit in Sichuan, China is rich in wulfenite in addition to bastnaesite and barite, and the deposit has already adopted high intensity magnetic separation technique to pre-enrich the rare earth minerals, during which the wulfenite and barite have been left in the non-magnetic product. Because the chemical composition of wulfenite is only 24.17% Mo and 42.15% Pb, it is very hard to obtain qualified lead or molybdenum concentrates by physical separation process. To pre-concentrate the wulfenite, flotation has been first introduced, and by using 100g/t GY-7 as dispersant, 1500g/t CP-1 as depressant and 160g/t GY-4 as collector, a floatation concentrate assaying 15.52% Mo with a recovery of 86.12% was obtained. Then a leaching process was conducted by using 1.2mol/L Na2S as leaching agent, and molybdenum can be translated into sodium molybdate in the solution with a leaching recovery of 99%. To recover rare earth oxides (REO) and lead from the leaching residue, a magnetic separation process has been conducted. Above all, by the whole process, the molybdenum recovery reaches 86.16% in the sodium molybdate solution, and a lead concentrate assaying 54.59% Pb with recovery of 27.99% could be obtained.

Jan 1, 2014

By A. F. Sirianni

The Peace River iron ore deposit represents the sole source of raw material for an integrated steel industry in Alberta. The ore has proved refractory to beneficiation by a number of techniques. A selective oil-phase agglomeration technique is described. Medium-grade concentrates, analyzing 48-53% Fe and 10-14% SiO2 were obtained with recoveries of about 75% of the total iron. These results appear to represent the optimum possible for this ore body.

Jan 1, 1977