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By Józef Czemecki

Polish copper concentrates are characterized by high levels of impurities, particularly Pb and As. Two technologies are being used for copper concentrate smelting at KGHM Polska Meidz S.A., namely the shaft furnace process (Legnica Copper Smelter, Glogów I Copper Smelter) and a single-stage process for direct to blister concentrate smelting in a flash furnace (Glogów II Copper Smelter). Both technologies are used at different physical and chemical conditions which results, in different impurities behavior. The paper presents flow sheets for copper production in a plant using the shaft furnace process and in another in which a single stage flash process is used. The metals distribution in particular semi-products is given as well as a method for elimination of impurities from the copper production cycle. Methods are also discussed for alloy and matte converting and copper refining to obtain low Pb and As concentrations in anode copper (0.3% Pb and 1500 ppm As maximum) that are being used in the KGHM Polska Meidz plants. Useful co-operation between the plants using different technologies, aimed at the limiting the effect of undesired impurities on the quality of blister copper produced, is also described.

Jan 1, 1998

By A. B. Hooker

The flame safety lamp with metal-gauze enclosure was invented by Sir Humphrey Davy more than a century ago, primarily for its safe light; however, it soon became the standard device for detecting the presence of methane in mine atmospheres. It still is the most widely used device for this purpose and is also the most practicable means of detecting deficiency of oxygen in coal mines. A permissible flame safety lamp is similar in all respects to one that, after a series of tests, has been approved by the Bureau of Mines as safe for use in gassy mines. However, safety depends largely upon the way lamps are maintained and used.

Jan 1, 1944

By Forest Mintz

Many oil and gas producers find it advantageous to borrow against the value of their hydrocarbon re- serves. This paper considers the requirements for a reserve based loan and the calculations that a bank would perform to arrive at a loan amount. Three of the most common loan structures, i.e. a term loan, a production payment, and a revolving credit/term loan will be discussed. A typical outline for each type of loan is presented. Finally, a comparison of major considerations in the three financing techniques is shown.

Jan 1, 1982

THE annual meeting of the Institute was held at the Office of the Secretary on Tuesday, May 23d. President Holley appointed Messrs. J. C. Kent and Frank Firmstone scrutineers to examine the ballots of the Institute. The following were declared elected: President-ABRAM S. HEWITT. Vice-Presidents-W. P. BLAKE, E. B. (AXE, R. W. RAYMOND. Managers-R. W. HUNT, J. S. NEWBERRY, T. F. WITHERBEE. Treasurer-T. D. RAND. Secretary-T. M. DROWN. The meeting was then adjourned to June 20th. The adjourned meeting to be held in Philadelphia.

Jan 1, 1877

By W. H. (Bill) Jay

The destruction of cyanide creates a significant impost on the financial returns of gold mines. These losses increase substantially when ores containing cyanide-soluble copper are treated. Failure to remove or destroy free or WAD cyanide before it is discharged into tailings dams has, on a number of occasions, led to significant fish, bird and animal deaths. Thus, the retention of cyanide within the leach circuit and the recovery or removal of stable metal cyanide complexes needs to become standard practice for all gold mining operations. Furthermore, reducing cyanide purchases will minimise the quantity of cyanide transported to the mine site thereby reducing the opportunity for spillage of this chemical. Many different physical and chemical methods have been investigated for the removal of cyanide from process solutions. All cyanide destruction methods create a financial impost on the economic viability of the gold mine. To reduce these costs, the recycle of cyanide and the economic recovery of the metals solubilised by cyanide is of prime importance. The alternative methods currently in use, or under consideration for the treatment of copper cyanide, entail high reagent costs, produce the recovered metal in a contaminated form and require the safe handling of hydrogen cyanide. These processes will be briefly discussed within this report Environmental and financial benefits are enhanced by recent laboratory and pilot plant studies conducted by Oretek Limited. The Oretek CPC process for the recovery of copper and the recycle of cyanide from copper cyanide-containing solutions does not require pH adjustment to the alkaline cyanide leach conditions. Copper ions are coordinated to a water-soluble and/or an organic soluble polychelating agent under alkaline conditions and the cyanide ions are displaced Membrane separation, or phase separation of the polychelated copper from the cyanide ions enables the cyanide ions to be recycled and the copper to be directly electrowon from the polychelating polymer. The polychelating polymer is then recycled. Ion exchange resins and solvent extraction systems which may be incorporated into the above process will also be discussed in detail.

Jan 1, 1998

By John Gittins

Lots 11 and 12, Range IX, Calumet island, are underlain by a Grenville metamorphic complex into which sills of tourmaline granite pegmatite have been injected. The pegmatite has an average mode-potash feldspar 65 per cent, sodic plagicdase 10 to 20 per cent, quartz 5 to 20 per cent, tourmaline 10 to 15 per cent, accessory minerals < 5 per cent; it is unzoned except for a narrow border zone. Some of the feldspar has been replaced by calcite. Microcline has been ?partially replaced by sodic plagioclase. Three varieties of tourmaline are present (black, blue, and green) and spectrographic analysis suggests progressive compositional changes during its crystallization. The presence of U- and Th-bearing minerals in the pegmatite prompted the Quebec Nickel Cor,porat10n, Ltd., to explore the possibility of developing the pegmatite but it does not appear that this is economically possible at the ? present time. Tt\e Grenville metamorphic complex consists of recrystallized limestones and calcsilicate rocks of the albite-epidoteamphibolite facies and the amphibolite facies, which were derived from sedimentary rocks. Several of these are dis-equilibrium assemblages, and retrograde metamorphism has probably formed biotite and epidote from hornblende. The schistosity of the gneisses dips steeply eastward. Numerous strike faults are roughly parallel to the schistosity and one of the pegmatite sills is bounded by such a fault, dipping at 60 ° with about one foot of fault breccia. The general structure of the map-area seems to be an asymmetrical syncline ?overturned to the west. The emplacement of the pegmatite is associated with a period of folding, metamorphism, and igneous intrusion.

Jan 1, 1956

By Lyman File

This paper discusses the overall challenges to construct a two-lane highway tunnel located in southwestern Colorado on U.S. Highway 160 for the Colorado Department of Transportation by the Kiewit Western Company. The purpose of this project is to provide the excavation and temporary support for a highway tunnel 280 m (916 feet) long. The tunnel cross section is 14.3 m (47 feet) wide by 8.5 m (28 feet) high, 105 m2 (1,130 SF).Construction methods include conventional drill and blast excavation with rockbolt and shotcrete ground support. This unique tunnel is being constructed under alpine tunnelling conditions and in the immediate vicinity of active highway traffic.

Jan 1, 2003

By Richard Murphy

"The general geology of the Great Bear Lake area has been described by; D. F. Kidd in the Summary Report of the Geological Survey for 1932. A brief description of the Eldorado mine was prepared by C. S. Lord for Memoir 230; Mineral Industry of the Northwest Territories; published by the Geological Survey in 1941. Recently; a detailed geological examination of the mine area has been initiated by the Geological Survey and; under A. W. Jolliffe's leadershif; J. D. Bateman; H. B. Thurber; and M. Feniak have prepared a number of maps and reports; as yet unpublished. Detailed mapping of the mine has been carried out since August; 1943; by A. W. Esty.Kidd has shown that, in the largely granitic country along the east side of Great Bear lake, the Echo Bay district is one of several underlain by older rocks . These he has divided into the Echo Bay and Cameron Bay groups. The former are strongly altered sediments, .porphyries, and lavas; the latter and younger group is predominantly sedimentary and far less altered. Associated with the granite, which everywhere intrudes the sediments and volcanics, are earlier differentiates. Later than all these rocks are various basic intrusives, collectively termed diabase. All the rocks are of Precambrian age."

Jan 1, 1954

By Montaser S. El‑Salmawy, AHMED A. S. SEIFELNASSR, Ahmed Al‑Abady, Abdeaziem M. Abdelaal, Amr F. M. Ibrahim

Iron is a key detrimental impurity in silica sands that determines their contribution to high-technology industries. Herein, a simple ecologically sound approach is investigated for iron removal from a silica sand sample obtained from the El-Zaafarana area-Egypt. The sample was subjected to a detailed microscopic mineralogical study supported by XRD and XRF characterization. The sample was beneficiated using distilled water attrition scrubbing and screening over a 25 μm sieve followed by leaching using a mixture of equal amounts of phosphoric and oxalic acids. Leaching experiments were designed and analyzed using the Box-Behnken design (BBD) methodology. A model was developed and evaluated using the analysis of variance technique to map the relationship between the residual iron oxide in the produced concentrate and selected variables such as leaching temperature, oxalic acid, and phosphoric acid concentrations. XRD and mineralogical analysis reveal that quartz is the most dominant constituent of the studied sand and other minerals such as kaolinite, iron oxide, rutile, and zircon exist in trace amounts. The head sample shows a silica and iron oxide content of 95.69% and 2379 ppm, respectively. Attrition and separation over a 25 μm sieve increase the silica content to 97.05% and decreases the residual iron oxide to 455 ppm. The final product after leaching under optimized conditions shows 99.82% silica and 55 ppm iron oxide.

Aug 30, 2022

By Y. Guglielmi, C. Gout, P. Henry, P. Dick, C. Nussbaum

For a decade, observations and experiments conducted in underground environments worldwide (mines, underground research laboratories - URL) made it possible to bridge the scale gap between laboratory scale and large scale faults. Indeed, underground rock laboratories allow developing decameter scale relatively well constrained experiments at the smallest distance from the hypocenters. URL’s experiments allowed developing new monitoring technologies coupling pressure-strain-seismic measurements and reproducing complete earthquakes sequences analogous to natural ones. They also allowed exploring past movements of faults and sometimes also paleofluids in three dimensions and characterizing different fault architectures and hydromechanical properties in unaltered conditions. This is particularly important in the study of faults affecting clay formations which could not be observed at the Earth’s surface because of the high alteration. Here we show how examples from the Mont Terri (Switzerland) and Tournemire (France) The URLs may help in (i) defining the concepts of fault architecture in shales, (ii) estimating fault hydromechanical properties from field decameter scale experiments. Some key results are that faults which are critically stressed or at the rupture limit can reactivate for stresses variations within the range of those produced by shallow underground excavations, and that slight micrometer-to-millimeter scale reactivations may lead to large factor-of-10-to-1000 permeability increases. Such promising results show that URL’s experiments may bring new insights on some key processes that control the relations between fault stability and permeability evolutions in very permeable layers.

Jan 1, 2015

By W. A. Gow, G. M. Ritcey, M. C. Campbell

"Uranium is a unique commodity. It is both a metal and a fuel, It has both commercial and military uses. It yields ""clean energy "" but presents environmental concerns. All of these factors have an impact on the commerce of uranium.Being a metal, uranium is extracted from ore like many other metallic minerals. As a fuel, it is subject to the vagaries of energy commodity market forces. The history of uranium in the first nuclear weapons has led to nation al governments carefully controlling production and sale of uranium. The spectre of radioactive contamination of the environment adds further to the public concern over the disposal of low-level radioactive wastes from uranium processing and use.There have been a number of excellent reviews on the commercial aspects of the uranium industry. In this discussion, these aspects will be briefly summarized to provide a general picture of the strengths of the Canadian uranium industry and the pressures to which it is being subjected currently. The principal thrust of this paper will be to outline Canada&apos;s resource strength and to identify some factors which will affect Canada&apos;s ability to continue holding a sizeable share of the world uranium market."

Jan 1, 1985

By S G. Li

Mine intelligent ventilation is an important guarantee to realise intelligent mining. It is the integration of the Internet of Things, big data, artificial intelligence, internet, cloud computing with ventilation technology, forming a complete ventilation system with intelligent perception, intelligent decisionmaking, intelligent emergency response and airflow control. In order to fully grasp the progress and trends of mine intelligent ventilation research in western China. The paper based on literature analysis and field application research, comprehensively expounds the main research and practical results of mine intelligent ventilation in western China, mainly analyses the development status of key technologies such as accurate and rapid determination of mine ventilation parameters, intelligent analysis and decision-making of ventilation and intelligent regulation of ventilation equipment, and introduces the field test or application of mine intelligent ventilation technology in western China. It lays the foundation reference for related research and improving the intelligent level of mine ventilation.

Oct 12, 2022

By R. T. Sorensen

Research and testing in a small scale equivalent of a commercial flota-tion plant was completed on four low-grade, iron-bearing materials from the western Mesabi range. Closed circuit-flotation of calcium-activated silica with fatty acid collector developed data for comparison with the batch process and highlighted problems not evident from previous bench testing. The four ore samples contained from 27 to 39 percent Fe and were equally represented by nonmagnetic taconite and semitaconite type materials. Iron concentrates containing 6.0 percent, or less, SiO2 were made 5, all four samples. Of the two material types, the semitaconite was the ore amenable to treatment, yielding iron recoveries of about 90 percent as cc pared with 70 to 80 percent for the other. Pilot plant tests showed that concentrate grade made in batch tests could be duplicated in the closed circuit and demonstrated that the amount of recoverable middling iron varied considerably between ore samples. The continuous tests also showed that water temperature strongly influenced results in the treatment of one ore but apparently was of indifferent consequence in another. Progress in thickening and filtration of flotation concentrates was made through introduction of tapioca flour to serve the dual role of iron mineral depressant and flocculant.

Jan 1, 1966

By J. P. Dick

THIS paper is a description of the milling practice and metallurgy at the Moneta Porcupine mine, Timmins, Ontario. The results obtained with an all-cyanide circuit and later with flotation followed by cyanidation are described. The ?investigation which prompted the various changes in milling practice have also been dealt with. Moneta ore is possibly the most refractory now being milled in the Porcupine district. This is due to the ultra fine state in which the gold occurs and to its intimate association with pyrite. No doubt there is ore of similar characteristics on the neighbouring properties but it probably forms only a small portion of the tonnage being mined, whereas at Moneta the bulk of the ore requires an extremely fine grind to liberate the gold. The fineness to which an ore can be ground economically has gone far beyond what was thought to be the limit only a few years ago. Formerly, a set of standard screens was all that was required to measure the fineness to which an ore was ground. At present, the Haultain infrasizer is practically indispensable, and the nominal micron has become a familiar unit of measurement to all those dealing with the problems of fine grinding.

Jan 1, 1941

By R. Minnitt, C. Morgan, D. Fourie

The problems associated with outliers and their adverse effects on resource estimation in deep level South African gold mines are presented, and solutions suggested in available literature are reviewed. Traditional Witwatersrand type outlier capping uses the 99th percentile grade as the upper limit, a somewhat blunt approach. The occurrence of high and low grade areas in mining operations and the estimation of resources using geostatistical techniques require that the assumption of stationarity be upheld. Honouring the stationarity of data requires that mining areas be subdivided into appropriately sized and spaced domains. In order to overcome high-grade conditionally biased block estimates, the overly strong influence of extreme grades is mitigated by using naturally occurring grade sub-domains, by identifying outliers within the grade sub-domains, allocating relevant capping limits, and weighting them in a post-estimation process to. Rather than applying a capping value across a domain it applies a maximum cap based on the extreme value and its range of influence; the method also ensures that relevant capping occurs even in lower grade sub-domains. The proposed method for capping outliers recognises that metal contained in high grade chip samples should not be over-capped, and based on the grade of surrounding samples. The post-processing method of capping outliers does not interfere with the kriging equations. The method is simple, elegant, and can be easily applied. An advantage is that the output from the kriging process is not overwritten, allowing for comparison between original kriging results and post-processing results.

Sep 1, 2021

The continuous casting of zinc alloys has been of fundamental importance for many years in the production of a number of products, including sheet for architectural applications, battery cans for dry cells and wire for metallising. The intrinsic benefits of continuous casting, including efficiency and high tonnage capability, uniformity of metallurgical structure and properties, and absence of voids and other defects, have contributed to the success of these products. Less well known, but of growing importance, is the more recent application of continuous casting technology to the production of zinc alloy bar stock products, including bearing stock, machining bar stock, forging stock and cathodic protection anodes. A wide range of zinc alloys are now continuously cast in a variety of cross sectional shapes and sizes to suit the diverse characteristics of these products. Of particular significance are the introduction of hollow zinc-aluminum bearing stock, and the availability of zinc alloy machining bar stock for hydraulic applications and for producing prototypes of zinc alloy pressure die castings. In addition to the traditional benefits, continuous casting provides special properties which are important in the application of these bar stock products. The list of successful applications of continuously cast zinc alloy bar stock is growing rapidly, and the market potential for resultant new zinc applications appears to be significant.

Jan 1, 1993

By W. R. Hardwick

This paper describes mining methods and practices of the Chino Mines Division, Kennecott Copper Corp., Grant County, N. Mex. It is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. A similar program was conducted from 1928 to 1939, which helped to improve the efficiency of mining operations. The primary purpose of the program is to promote development and conservation of our mineral resources by disseminating technologic information on methods, practices, and related features in mining mineral deposits. It is expected that the program will: (1) Promote efficiency in operating mines; (2) assist operators and engineers in evaluating and developing new mineral deposits; (3) provide data for engineering curriculums in mining schools; and (4) furnish performance and cost data for revising engineering handbooks and for inclusion in engineering textbooks.

Jan 1, 1958

By B. R. Mohal, S. Chander

"The adsorption and wetting behavior of freshly ground and aged coals has been determined in the presence of a nonionic surfactant. The amount of surfactant adsorption changes with the concentration and ""age"" of the coal. The freshly ground coal has smaller amounts of adsorption at lower surfactant concentrations than the ""aged"" coal whereas at large surfactant concentrations, the order is reversed . In the latter case, more surfactant is adsorbed on fresh coal than on the ""aged"" coal . . It is proposed that at low concentrations, the surfactant adsorbs through both hydrophobic and hydrophilic interactions with the molecule lying parallel to the· surface, whereas at higher concentrations surface micelles form at the hydrophobic sites. The wetting behavior correlates well with the adsorption behavior.INTRODUCTIONNonionic surfactants have many applications in the coal and mineral processing industry. They can be used as dispersing agents to modulate flotation, flocculation and filtration of particulates (1). They can also be used to increase the wettability of hydrophobic solids such as coal and can hence be used as dust suppressants (2,3). Although the adsorption of representative nonionic surfactants such as Triton N-101 (an ethoxylated nonylphenol with 9.5 moles of ~thylene oxide and HLB equal to 13.4) have been studied extensively on substrates such as calcium carbonate (4), silica (5) carbon black (6) and graphite (7), very few studies are available for coals. Coals differ from other substrates with respect to two important characteristics: 1) coal are porous and 2) coals consist of a patchwork of hydrophobic and hydrophilic sites (8). Since the adsorption characteristics of a surfactant are influenced significantly by the nature of the substrate the characteristics of the coals must be taken into consideration."

Jan 1, 1989

By C M. Standen

The SAG mill at Rasp Mine has undergone a number of liner design modifications since commissioning in 2012, making liner wear and failure difficult to predict from historical data. During 2017, several instances of liner failure or near failure were experienced resulting in unplanned downtime for emergency relines or to patch liners in the lead up to a planned shutdown. The strategy for relining mills is often to minimise the frequency of relines (and subsequent shutdown costs) by extending liner life, achieved through design modifications. However, it was observed that as the Rasp SAG mill liners wear, mill performance declined with power draw increasing and throughput declining. Opportunity and inefficiency costs start to erode the revenue per additional tonne milled for a given set of liners, and in turn the benefit of delaying relines. As such, optimising the frequency of relines becomes a trade-off between reline costs and opportunity/inefficiency costs in delaying relines. The aim of this paper is to demonstrate a frame work for analysing costs using a marginal economic analysis with the assumption that the Law of Diminishing Returns can be applied to the life of mill liners. The SAG mill operating variables can be modelled to determine their impact on costs and an optimal reline point can be defined where the total costs are minimised. This prevents unexpected failures due to accelerated wear by providing justification to reline earlier and thereby allowing efforts to be focused on sustaining milling performance.CITATION:Standen, C M, 2018. An economic approach to optimising mill reline frequency – a case study of SAG mill relines at Rasp mine, in Proceedings 14th AusIMM Mill Operators&#39; Conference 2018, pp 197–206 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By R. Merkl

Since the 1940s, decanter centrifuges have become more important for increasingly complex solid-liquid or solid-liquid-liquid separation processes. Sometimes processed industrial or metalliferous minerals are abrasive or are treated with corrosive chemical agents. Traditional mining applications include the processing of coal, gravel and other products, where low-speed decanters, as well as screen bowl decanters and filters, dominate. These have been increasingly replaced by high-speed decanters during the last decade. Decanter centrifuges also started to play a key role in applications such as drilling muds, processing carbonates and separating SX crud in copper platinum ore concentrations of nickel and gold. Communication between machine producers and mineral processing engineers is vital for the right choice of materials and the design of the right decanter centrifuge for the individual process.

Feb 1, 2012