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By G. Riveros

A new, continuous fire refining process for copper has been developed and tested at the 5 tph pilot scale. During oxidation, the blister copper flows through a packed bed of crushed refractory bricks counter-current to a hot oxygen containing gas. The resulting desulphurized copper flows then directly into a packed bed of charcoal for deoxidation. By controlling the air to natural gas ratio, both temperature and reducing conditions can be controlled. Based on extensive laboratory scale measurements of the rate of copper oxidation and reduction, the process concept was developed aided by process modeling and simulation. The industrial-pilot scale installation built at the ENAMI Paipote smelter in Chile, consists of two cylindrical, compact reactors, operating in line, with a designed capacity of 5 t/h of blister copper. The results of the industrial-pilot tests confirmed the feasibility of the new process. The blister copper processing capacity was increased to 10 t/h with satisfactory sulphur removal. The degree of oxidation as well the copper temperature was controlled with relative ease. The specially designed siphon block allowed for smooth tapping of the oxidized copper and separation of refining slag. The reduction of oxidized copper in the packed bed of charcoal appeared to be very effective while control of the degree of reduction according to the height of the bed ensured control of the oxygen content in the refined copper at the required level.

Jan 1, 2007

By N. Schreithofer, M. Aspiala, R. Serna

The novel attachment timer apparatus presented in this paper serves as a diagnostic tool that allows the detection of changes in bubble-particle attachment probability and therefore floatability caused by alterations in the chemical environment and particle properties. The apparatus consists of six identical capillaries where bubbles with defined size are produced simultaneously in a measurement chamber. The bubbles at the capillary tips are placed in contact with the submerged particle bed for specific time periods, controlled with the help of automatic actuators. The advantage of the instrument is that hundreds of bubble-particle contacts can be measured automatically within a short time period. Microscopic pictures of each measured bubble are taken while recording the movement of the bubble before, during and after contact with the solid particles. The recorded pictures can be used to determine the actual bubble size and its corresponding deviation, and to detect the attachment of particles. The attached particles are collected in a detachable chamber for subsequent characterization. Furthermore, the device is portable and can be taken to the mineral processing plants for quick evaluation of particle-bubble attachment efficiency with particles and process water sampled directly from real processes.

Jan 1, 2017

By P. K. Kaiser, S. Maloney, S. Yazici

"This paper focusses on the strength or capacity of cable bolts and introduces a new perspective for cable bolt design by demonstrating that mining-induced stress changes may affect cables in a detrimental manner. The concept underlying a novel cable bolt pull-out resistanceor bond capacity model is described and its practical significance is demonstrated by application to a simple two dimensional scenario of a fall-of-ground.A number of practical implications emerging from the application of this model are discussed to provide guidance to ground control personnel jar improving cable bolt support systems in mining applications. These include cable layout optimization, use of cable pre-reinforcements, assessment of embedment length requirements, need for plated cables (or straps), use of bird-caged cables (or buttons), and grout quality issues.IntroductionDuring the last decade, cable bolting has become a standard support technique in mining for handling wide spans, reinforcing are passes, preventing or reducing dilution of ore in marginally stable stopes, and for many other rock support need s.In its infancy, many deficiencies in cable bolt supports resulted from improper installation techniques and, in particular, grout quality control problems and the use of empty breather tubes (Goris, 1990). The development of special grout pumps and fail proof placement procedures (Oliver, 1992; Bourchier and O'Flaherty, 1992) have eliminated many of these early problems. Nevertheless, there are still situations where cables seem to lose their capacity during mining, and in these cases the cables do not provide the expected and needed ground support. In some instances, cables perform extremely well, whereas in others the same support layout and quality of support installation seem to be insufficient, allowing falls-of-ground or progressive cavings to occur."

Jan 1, 1992

By V. Concha, M. Hashemzadeh

"The objective of this study was to gain a better insight into the kinetics of chalcocite leaching in an acidic ferric sulfate media. Chalcocite leaching in acidic media is known to occur in two sequential stages, with the first stage being much faster than the second. The leaching residue from the first stage is typically assumed to be a covellite type of material. This study hypothesized that the mineralogy after the first-stage leaching varies in response to different leaching conditions. We investigated the dependency of the mineralogy of the first-stage leaching residue on temperature and initial ferric concentration. The experimental results showed that chalcocite leaching behavior altered upon temperature and initial ferric concentration. A proposed combined reaction model was found to be able to describe the experimental data. The first stage was described very well by the shrinking core diffusion model while the second stage was described very well by the shrinking core chemical reaction model. This finding has important implications for mine operations to manipulate leaching conditions to create the desirable leaching kinetics.INTRODUCTION The kinetics of chalcocite leaching in sulfate media has been extensively studied (Cheng & Lawson, 1991; Fisher, 1994; Fisher, Flores, & Henderson, 1992; Niu, Ruan, Tan, Jia, & Sun, 2015). Sullivan (John D. Sullivan, 1930) proposed a two-stage process for chalcocite leaching in an acidified ferric sulphate solution. The two-stage leaching of chalcocite is presented as the following reactions:"

Jan 1, 2017

Bahuerachi Project Characteristics Why it?s nicer at Bahuerachi Mexico is a mining country Low political, regulatory and trade risk Low social/permitting risk Proximity to infrastructure Road Power grid (8 km) Rail line (25 km) High grade zones (skarns), CRD and near surface oxide component are sweet spots to the overall system. Size of low grade system points to potential long mine life?and numerous new targets developing. Timelines-2006? 90 to 100 combined RC and core holes to go! MAIN ZONE Drilling ? Goat ?Finish Mid April ? Main Zone, going North, depth of testing dependent, estimated for May ? North Lobe-May ? Commission independent resource estimate by May 06 for results of first pass drilling to date ?tonnesand grades ?Main Zone Milestone. ? Continue infill or expanded drilling to July (minimum) ? 1stpass RC scheduled until September OTHER Targets ? Begin drill testing North Skarn target Mid-April, minimum 5 drill holes, 1,000 meters. Ongoing expansion of target with surface work (mapping) ? Road to Colome(Skarnin north of Main Zone) as part of porphyry program ? Tule(southern) porphyry and skarn system-soils and mapping OUTSTANDING events Metallurgical report on floating and leaching tests (Sulphide/oxides).

May 1, 2006

By W. J. González

"With the increasing demand for minerals, technologies to maximize mineral recovery are paramount to a mine’s economic success. Many mining process waters have the potential to form calcium-based inorganic scales, which inhibit effective mineral recovery. Often, the solution to inhibit these deposits is the implementation of a chemical antiscalant program. This paper examines the application of a fouling analyzer to continuously monitor the formation of inorganic scale in mining process streams. The fouling data can be used to compare antiscalant programs and to optimize antiscalant feedrates. Case studies validate the ability of this technology to help optimize mineral recovery processes.INTRODUCTION The mining industry uses significant quantities of water. From quarrying, to crushing, to flotation, leaching, and refining, water is often the integral motive force to move slurries, separate or agglomerate fines, and extract and purify minerals. As well, water is used in a number of ancillary applications at mines, including dust suppression, gas scrubbing, and utility processes such as boiler, cooling, and waste water operations. For many processes, the quality of water being used is inconsequential. However, for certain processes, such as flotation, leaching, and desorption / stripping, water quality plays a key role in the ability of the operation to economically recover the target minerals. Dissolved solids such as calcium and magnesium salts can concentrate in process waters, exceed their solubility limits, and precipitate as scale on metal surfaces such as feed and transfer pumps, piping, and equipment. Some of the more common scales that form in mining operations include calcium carbonate (CaCO3, or calcite) and calcium sulfate (CaSO4, or gypsum), and to a lesser extent, calcium and magnesium silicate compounds. Any scale that deposits in a process stream will negatively impact mineral recovery, and increase the operational costs of the mine site. Whether it is acid washing a scaled heat exchanger in a carbon strip at a gold operation, replacing plugged emitter tubes in a leaching operation, or hydroblasting process lines in a scrubber unit, there are costs associated with labor, cleaning chemicals, repairs, and replacement parts. These costs pale in comparison to the potential costs of downtime and lost production, should the scale deposits occur in a process that is critical to the recovery of the target mineral."

Jan 1, 2014

By A. C. Ter-Oganesyants, N. N. Anisimova, G. P. Kotukhova, G. N. Dylko

The process utilized at Norilsk Nickel Polar Circle Division for treating slimes from the electrorefining of copper and nickel was developed in the late nineteen fifties and has survived without any fundamental changes. This technology is a combination of pyro and hydrometallurgical operations to produce PGM concentrates that are sent away for refining. The characteristic feature of the current technology is multiple-stage, extended cycle treatment with significant incomplete production, low labour and automation efficiency and poor hygiene and sanitary conditions. To eliminate all negative aspects mentioned above, specialists of Norilsk Nickel Polar Circle Division have developed a new hydrometallurgical process for treating electrolytic slimes. The main steps of the flow sheet developed are autoclave leaching of the slimes and electrochemical opening-up of a cake from autoclave leaching. The implementation of the new process will allow Norilsk Nickel Polar Circle Division to shorten the process cycle 4-5-fold thus reducing the volume of incomplete production, considerably increase labour efficiency, simultaneously improving working conditions, upgrade the final concentrate, reducing costs and increasing PGM recovery during refining and, ensure higher security of precious metals by employing automated processes and vacuum sealed units.

Jan 1, 2004

By Fathi Habashi, Ernesto Bourricaudy, Fouad Kamaleddine

Ilmenite occurs in black sand at the mouth of great rivers as in India, or as massive deposits like in Quebec Province in Canada. It is unsuitable for processing into pigment or for metal production because of its high iron content and its low grade. Pyrometallurgical and hydrometallurgical methods have been developed to cope with this problem which resulted in the production of two commercial products that became known as synthetic rutile and Sorelslag. Attempts are also underway to produce TiO2 pigment directly from ilmenite. This report presents a newly developed process called the Magpie process, which enables the production of high-grade synthetic rutile (over 95% TiO2) from low grade ilmenite (10-12% TiO2). Naturally, if such process is applied for low-grade ore it can be applied with advantage to high grade material as well.

Jan 1, 2014

By J-L. Tang

A new rhcoforming processing of Al alloys with component shaping systems apart from slurry preparation systems is experimentally exploited, using the reversible multilevel-speed electromagnetic stirrer, the slurry transfer tool and its coating, the thin plate sample with five steps and rheocasting mould, all of which are independently developed. The results show that semi-solid A356 alloy slurry with shape factor of about 0.85 and particle size of 70~80 µm (under air-cooling condition) could be prepared in 20~25 s, fully meeting the production rate of high pressure die casting. The slurry could be smoothly transferred from the slurry preparation equipment to the rheocasting shot chamber while the slurry temperature of slurry decreases by no more than 3 . The tensile strength and elongation of the semi-solid rheocasting samples could be respectively increased by 11.6~18.2 % and 42.5~50 % compared with the traditional liquid die casting ones, and the rheoforming processing has close affinity with the traditional hot working processes.

Jan 1, 2007

By H. Abdollahi

Cold rolling is one of the most important techniques in metal forming since the cold rolling products are almost finished product, The product quality of this process is widely influenced by friction in the roll gap; therefore, controlling the friction and other parameters affecting the cold rolling is very important in order to have a product with high quality, Among the cold rolling parameters, the pressure distribution or friction hill within the roll gap is known as the most significant one, In this study, a new software (Matroll), is introduced which can determine the coefficient of friction (COF) and plot the friction hills for an industrial mill, Besides, based on rolling equations, it offers about 25 rolling parameters as outputs. To verify the software operation, the real industrial rolling data was used as inputs, The results (outputs) are in good agreements with the findings of other researchers, The COF values are very reasonable, The friction hill shows that COF is not constant over the whole arc of contact.

Jan 1, 2005

By L. Yaun

In underground coal mining operations, gas content in a coal seam is used to assess the risk of coal and gas outbursts. To estimate the gas content, a number of systems have been developed, however issues remain about the rapidness and accuracy of these systems. To address these issues, a new and improved system has been developed that includes a sampling-while-drilling unit for coal sampling, a coal canister, an underground-based portable measurement unit, a surface-based measurement apparatus, and gas content calculation software. The system has been successfully applied in underground coal mines at Huainan, China. This new, rapid and accurate system, its main components and field trials are described in this paper.

Aug 1, 2013

By B. E. Shaw

This paper describes the use of the Free Piston Valve, and a simple hoist brake control system, which has been developed over the last two years, greatly improving the performance of low-pressure brake engines. The basic control system is outlined, with sections devoted to emergency trips and differential braking, and the application of the system to deep shaft hoisting is discussed.

Jan 1, 1966

By D. F. VanDine, H. George

"The possibility of spoil pile failure at the Kara Kara bauxite strip mine, Guyana, South America, is of major concern to the mine operators. The current mining technique requires the continuous operation of an 11 ms bucket capacity walking dragline on top of 18 metres of freshly spoiled uncompacted overburden material consisting of varying mixtures of kaolinitic clay and quartzitic sand. A field biased geotechnical study of undisturbed overburden and corresponding spoiled material has identified site-specific, non-linear correlations between vane shear strength, standard penetration resistance and spoil pile composition. Readily available geological exploration borehole logs has enabled a composite clay isopach map of the entire mining property to be drawn and critical areas to be zoned according to expected slope stability. Stability has been assessed using simple hand calculation techniques. Use of the resulting stability map provides the mine operators with a means of forecasting the need for appropriate preventative measures at varying stages of mine development, throughout the life of the mine.A similar investigation procedure could be employed at many presently operating and future strip mines.IntroductionThe Kara Kara bauxite stripe mine is located at Linden within the bauxite belt of Guyana in South America. The mining property covers a total area of 88 hectares of flat to gently sloping ground of which some forty per cent is being actively mined or being preparatorily stripped of overburden, prior to eventual mining (George and Gordon, 1979). The regional climate is tropic and humid. Temperatures vary from 16°C to 38°C and yearly rainfall averages 2600 mm, with at least 55 per cent of this precipitation occurring during the 'wet season' months of May to July and December to January."

Jan 1, 1983

By Luino Jr. Dell'osso, Richard L. Every

The enormity of the methane-in-coal problem is discussed, with a brief summary of the state-of-the-art. Laboratory techniques and data on the desorption of methane from Pittsburgh seam coal are presented and discussed and include the effect of time, temperature and vacuum. Under laboratory conditions, it was possible to displace 90 per cent of the residual methane by flooding the coal samples with carbon dioxide. Carbon dioxide was found to be three times more effective than air and almost five times more effective than helium.

Jan 1, 1972

By B. Dubreuil

Arsenical bearing deposits are posing an increasing challenge for the mining industry. In particular, mineral processing of arsenical sulfidic ores for base and precious metals recovery tend to produce problematic arsenical tailings. This arsenic being present as sulphide or oxide, tends to dissolve, contaminating surface and underground waters. To meet the environmental regulations, it is often required to stabilize the arsenic in a more insoluble form. Nichromet has developed a new patented technology using vitrification of the arsenic oxide in an economical way, giving a stable solid, well below the environmental regulations upon leaching. This technology involves oxidation of As (III) to As (V), by using a low cost natural oxidizer and transformation of the produced arsenic oxide into calcium arsenate, which is not volatile at the melting temperature of the glass. This technology would be advantageously applied on most cases around the world where sulphide concentrates are oxidized in a fluidized bed or smelted.

Aug 1, 2013

By B. Dubreuil, J. -M. Lalancette, D. Lemieux

Arsenical bearing deposits are posing an increasing challenge for the mining industry. In particular, mineral processing of arsenical sulfidic ores for base and precious metals recovery tend to produce problematic arsenical tailings. This arsenic being present as sulphide or oxide, tends to dissolve, contaminating surface and underground waters. To meet the environmental regulations, it is often required to stabilize the arsenic in a more insoluble form. Dundee Sustainable Technologies has developed a new patented technology using vitrification of the arsenic oxide in an economical way, giving a stable solid, well below the environmental regulations upon leaching. This technology involves oxidation of As (III) to As (V), by using a low cost natural oxidizer and transformation of the produced arsenic oxide into calcium arsenate, which is not volatile at the melting temperature of the glass. This technology would be advantageously applied on most cases around the world where sulphide concentrates are oxidized in a fluidized bed or smelted.

Jan 1, 2014

By Glenn Kosick, John Starkey, Glenn Dobby

"A practical new test has been developed for SAG hardness determination. Using two kilogram samples of minus one inch diamond drill core or crushed muck samples, the Starkey SAG Test has been shown to give accurate predictive information which directly relates to on-stream SAG mill performance. Typical results and test criteria are discussed in the paperAchievements to date include:• Identification of hardness profiles and the location of hard and soft zones in a large ore body.• Accurate prediction of the hardness of a bulk sample by using an adjacent diamond drill hole.• Derivation of a plotted curve relating pilot plant power to laboratory relative hardness.• Demonstration that for every test done to date, the Starkey SAG Test produced a product size distribution identical to that produced in a pilot plant or full scale plant SAG operation.This test can now be used for blast hardness monitoring and short term control of mine production in existing plants and for identifying the proper locations for bulk samples in new projects. In addition, new SAG mill design can now be rationalized in a low cost way to eliminate unforeseen production shortfalls.IntroductionThis paper is presented to introduce the Starkey SAG Test, a practical new laboratory tool for measuring the relative hardness of small ore samples in a semi-autogenous grinding (SAG) environment. The test was first designed for use on diamond drill core samples during the prefeasibility stage of new mining projects, to provide new information about the ore body at reasonable cost. It is a new tool and does not replace existing pilot plant test requirements.The test will also be useful for throughput prediction in existing SAG plants by assisting in short and long term mine planning, where forecasting of metal grades and milled tonnage is used to control mine profitability. Because in-plant hardness testing has previously been unavailable on small samples, this test offers exciting possibilities for SAG mill operations where hardness variation is or could be a problem.The Starkey SAG Test provides the following benefits to the mining industry"

Jan 1, 1994

By D. Milne

Laser profilometers exist for obtaining very accurate two and three dimensional profiles of joint surfaces. The application of this technology is not commonly applied to the collection of field data on discontinuity surface roughness. Rugged and portable field devices are not commonly used and the value of the possible field data that can be collected has not been well recognised. This paper reviews commonly used field techniques for assessing discontinuity roughness, discusses the value of this data and presents a new laser profilometer design for field application.

May 1, 2009

By Jean-Luc Collins

"This new tool can be used as a quick guide f or the assessment of the potential economic wealth of any risky capital project. It does provide an unambiguous recommendation of the type ""go or no go"" to the decision-maker simply by comparing two different ratios profit/investment. One ratio determines the minimum value required to at least break even while the other measures a probable value based on the asymptotic theory of statistical extremes.Its application is briefly illustrated by means of an underground gold mine extension project, an oil sands mine project and a polymetallic open pit project.Once a favourable recommendation has been obtained then a detailed ""cash flow after taxes"" analysis can be carried out for the project.IntroductionMany tools are used in financial decision-making such as the payback period, the discounted cash flow, the internal rate of return and the wealth growth rate (Berry , 1971).These tools are useful and meaningful in evaluating normal projects closely related to regular business where the number of assumptions made is usually very small and where the cost of capita! is usually selected as a discount rate or a hurdle value. In situations where a significant number of assumptions have to be made,two problems can emerge, namely:I. the risk involved is underestimated leading to a potential financial disaster; or2. a good opportunity is lost because the approach used in evaluating the project is too conservative.Each assumption has its own degree of uncertainty and it is well known that combining uncertainties together can lead to a total uncertainty of critical proportion. The easiest way to account for risk is to increase the discount rate or the hurdle value, but this approach alone is quite subjective and can easily lead to the problems described above."

Jan 1, 1993

By I. C. Brown

Introduction Many tables of nomenclature for igneous rocks have been introduced from time to time, and each has its strong proponents. As a result, any discussion of igneous? rocks is apt to prove confusing unless the names used for these rocks are defined. This ?became so obvious to a discussion group, formed by the members of the Geological Survey of Canada in 1948, that an attempt was made to establish a scheme of nomenclature that could be used by any member mapping anywhere in Canada. The writer was asked to co-ordinate the ideas presented by individuals in the discussion group, to arrange them in tabular form, and, later, to distribute copies of the resultant table to Canadian universities, provincial geological surveys, and some other geological discussion groups. Many useful suggestions and criticisms were received, were studied ?by members? of the original group, and, so far as practicable, were incorporated in the scheme of nomenclature. The result is the table presented here. This nomenclature of igneous rocks is at present being used by most members of the Geological Survey of Canada who are working with igneous rocks, and by some Canadian universities. We hope it will be found useful and be more widely accepted. With this idea in mind, certain principles were adopted in drawing up the nomenclature.

Jan 1, 1952