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By Stephan Buys, Dan Curry, Chris Rule

"The use of fine grinding (FG) in mineral processing is well established. The application of FG in the South African platinum industry is more recent and it’s use in the recovery of PGM’s from dormant tailings dams is unique. Anglo Platinum uses IsaMill FG technology at their Western Limb Tailings Retreatment project (WLTR) near Rustenburg in the North West Province of South Africa.In December 2003, Anglo Platinum commissioned the first purpose built tailings re-treatment facility for PGM recovery in South Africa. The concentrator re-treats Merensky ore tailings from concentrators that operated early last century. The WLTR facility takes advantage of modern technology, such as FG, to economically recover PGM’s from material historically considered as waste. The WLTR concentrator has a capacity of 4.8 Mtpa, and has been designed to easily expand to 10.8 Mtpa. The flow sheet includes recovery of tailings by high pressure water monitoring, ball milling, rougher flotation, rougher concentrate regrinding and cleaner /recleaner flotation.The rougher concentrate is reground in an IsaMill, which is a stirred mill that operates with inert silica sand grinding media. For this project, Anglo Platinum required a stirred mill of a unit size not previously available. Xstrata Technology and Anglo Platinum collaboratively developed the largest wet, fine grinding mill available; the M10,000, 2.6 MW IsaMill.The use of IsaMill technology was enabling for the WLTR project, as it allowed smeltable concentrate grades to be produced from the oxidised, slow floating tailings. The economics and practicality of fine grinding has fundamentally changed with the M10,000 IsaMill. Flotation is transformed by high intensity attritioning in the inert media environment, and the narrow size distribution of product in open circuit configuration. The use of conventional steel media grinding to improve fine particle flotation is limited due to the oxidation of liberated mineral surfaces inherent in these environments."

Jan 1, 2005

By R. A. Hill, J. D. Pitts

"Long distance slurry pipeline systems have been successfully trans-porting steam coal, iron concentrates, copper concentrates and limestone for an aggregate of nearly 60 years and nearly three billion ton-miles annually. A phosphate concentrate pipeline is nearing start-up and systems for coking coal, lead/zinc concentrates and fly ash are planned. The solids pipeline concept, first patented in the early 1900's and commercialized in the 1950's, is now a proven technology providing an economic, environmentally pleasing and safe method for long distance bulk transport.The challenge for larger tonnage and longer distance movements of solids, for traversing increasingly rugged terrain in grass roots mineral developments, for transporting untried materials and for shipping more economic forms of proven materials still remains. This has necessitated continued refinements and optimization of the technology. The economic and environmental incentives for slurry pipelines when compared to other transport alternatives has justified substantial activity in this area. The scope of planned systems in coal, iron and other minerals is indicative of the firm place slurry pipelines will have in worldwide mineral development.In this presentation, the state-of-the-art in long distance slurry pipelines is reviewed with a focus on major systems of interest to the mineral processing industry. An overview of new developments in the application of this concept is presented, and finally, a projection of the future of pipelines in mineral development both worldwide and in Canada is discussed."

Jan 1, 1978

By B. K. Gorain

"Mining of low grade deposits along with the necessity to design and operate flotation plants with high throughput presents unique metallurgical and environmental challenges that need to be addressed to reduce project risks, improve project economics and to sustain the profitability of operations over the life of a mine.Some of the key challenges include poor recovery of valuables and concentrate quality issues due to complex mineralogy, the need to use poor quality water such as brackish or sea water, reduce environmental impact from the process, integrate flotation with hydrometallurgy to maximize precious metals recovery, escalation of capital and operating costs, use of unproven technology and constant use of larger equipment, high ore variability, worldwide constraints on resource availability and an ever increasing need for reliable metallurgical input to financial models to evaluate economic viability of projects.The need to develop effective solutions to these problems in a short time frame is becoming a key to the success of any new project and for sustaining the profitability of a mining operation. An integrated multi-disciplinary approach to problem solving is crucial with the need for a more lateral thinking along with strategic partnerships and collaboration involving the right players. This paper presents some of the key findings based on experiences from a large number of challenging projects and operations focused on solving complex flotation problems.INTRODUCTIONThere are various challenges to successful development of mineral resources. Most of the ore bodies being developed worldwide are of lower grades requiring high throughput to be economical. Many of these lower grade ore bodies have significant occurrences of deleterious and penalty elements that could render a deposit unworthy of development unless there are technological solutions to process them economically in a sustainable manner with minimal environment impact. Even in a high metal price scenario, the economics for some of these low grade ore deposits is marginal. From a metallurgical perspective, these ore bodies have complex mineralogy and use of any off-the-shelf technology is not always effective. Development of innovative processes are often required, which is expensive, time consuming and sometimes risky.This paper will provide a broader perspective on the steps involved in solving flotation problems for operating plants and for greenfield development projects. In addition, some of the key challenges in flotation of complex low grade ore bodies along with the economic benefits in developing solutions to these problems will be presented."

Jan 1, 2013

By Bennett McLaughlin

AGNICO-EAGLE started sinking the Penna Shaft in 1995 with a hoisting plant capable of hoisting 1,800 tonnes per day from a 2,240 metre deep shaft. Exploration success lead to the installation of a hoisting plant capable of extracting 4,500 tonnes of ore and 1,800 tonnes of waste per day from a depth of 2,210 metres. The introduction of a new rope selection factor, permitting a safety factor of 4.0, represented the breakthrough required for a cost-effective project. This paper describes the process taken to introduce the new rope selection factor and its impact on the original plant.

May 1, 2001

By Paul Hosford, Tim Haldane

"The paper describes the fast-track development of the project from feasibility study through to detailed design and construction, highlighting the process adaptations for handling sticky ore and water management in a tropical environment, and subsequent commissioning and operating experience of the mine. The paper discusses the geological setting, the environmental and socioeconomic considerations in developing and operating a mining operation in an underdeveloped country and the logistical challenges involved in bringing a large capital investment into Central America.INTRODUCTIONGlamis Gold Ltd. acquired the San Martin project in Honduras as a result of its merger with Mar-West Resources in late 1998. Despite the prevailing low gold price environment at the time of acquisition, Glamis anticipated rapid development of the San Martin project due to the quality of the deposit and other positive factors.Following favorable exploration and permitting activities in the first half of 1999, Glamis prepared a Feasibility study. In October 1999, Glamis decided to proceed with the development of the project and selected Hatch to provide the engineering, procurement and construction management services for the project. The San Martin project was in full-scale commercial operation approximately 14 months after the receipt of Board approval, and by July 2001 the San Martin project was operating at approximately 150% of its feasibility design capacity."

Jan 1, 2002

By U. Dillon, G. Blackwell

"Geographic information systems (GIS) provide an efficient means for the recording, manipulation, revision, display and analysis of spatially referenced data. GIS are widely used at the exploration stage of mine development, and are increasingly used for reclamation planning. The ability of a GIS to perform spatial searches and query spatially referenced data make it a powerful tool for use at all stages of mine development. As the amount of data available for analysis increases, so does the power and flexibility of GIS as a planning tool.Starting from the exploration database, this paper describes how a GIS can be used for the development of mining plans based on topography, geology and mineralization information stored in a relational database. Planning decisions approaching the optimal can then be made for a wide range of parameters, including stockpile and waste dump locations, the location of potentially acid generating and neutralizing material for dump design, profitable and risk-controlled mine extraction sequencing, and haul road locations. This is made possible by the overlay and buffer analysis capabilities of a GIS which are explored and exploited to produce a continuous mine production planning program, as well as site remediation and reclamation using a successful case study. IntroductionGeographic information systems (GIS) are a relatively new tool in the mining industry. Although they have existed for a number of years, the potential of GIS for mine management and planning is only beginning to be investigated and exploited. The unique spatial capabilities of GIS make them particularly wellsuited for use in mining, where spatial information is fundamental to the processes of mineral exploration, mine development, and environmental reclamation. A number of potential applications for GIS in the mining industry have been identified, and they are widely used for exploration and reclamation. The use of a GIS as a platform for the development of mine planning routines and software remains an interesting, but as of yet unexplored, application of this technology."

Jan 1, 2003

By F. McGravie, S. T. Solinski, W. W. Robertson

During this, the Centennial year of the discovery of the Hall-Heroult process, it seems appropriate to review some of the developments which have taken place in Canada and to explain why it has become an important world centre for the production of primary aluminum. For many years after it was recognized that the element aluminum existed, scientists were frustrated in their efforts to isolate it. In the early 1800s H. C. Oersted and Frederick Woehler prepared small quantities sufficient to measure some of the physical properties. A quasi-commercial process involving reduction with metallic sodium was developed by the French scientist H. St. Claire Deville in 1855 but the cost was very high ($30. 00 per kg). It was not until 1886 that Charles Martin Hall in the United States and P.L.T. Heroult in France, more or less simultaneously but completely independently, discovered the process which is essentially that in use today. Some of the early pioneers in the industry quickly recognized the potential of the hydro-electric resources in Canada as economic energy suppliers for aluminum production. The first commercial production in Canada was in Shawinigan, Quebec in 1901, only 15 years after the process was discovered. Subsequently operating plants were established at nine different locations in Canada (Quebec and British Columbia) (Table 1). Operations continue today in all locations except one (La Tuque). The table shows present plant capacity which for the older plants was reached in an evolutionary manner including replacement of obsolete capacity or upgrading and modernization of existing designs.

Jan 1, 1999

By E. R. Weltevreden, C. Klauber, C. Vernon

"In this paper a review of the current status in recycling technologies for cathode ray tubes is given for both the glass and phosphors. Particular emphasis is placed on the opportunities for the recovery of the rare earth elements (REE) from the phosphor coatings. This is placed in the market context of alternative virgin sources and some of the advantages and disadvantages for REE waste recovery. Future opportunities are explored and also some experimental detail on a low cost leach system is presented. INTRODUCTIONThe disposal of cathode ray tube (CRT) based colour televisions has accelerated world-wide with the development of high definition flat screen panels. The total number of colour CRT televisions that have been sold in the United States in the mid-20th century is estimated to have been over 2 billion (U.S. Environmental Protection Agency, 2007), with high current rates of disposal. It is estimated that of the 20 million televisions annually discarded, 78% are send to landfill (Nnorom, Osibanjo & Ogwuegbu, 2011). However, this easily accessible item of electronics cannot only be turned into a valuable resource using the right recovery procedures, it can also prevent the substantial environmental contamination arising from improper disposal. In this review we focus on previous and current work performed on the recycling of CRT based televisions. Due to the increasing demand for rare earth metals, the main focus will be on the possibilities and challenges of recycling the fluorescent phosphor powders on the CRT’s panel glass.CATHODE RAY TUBE’S GLASS RECYCLINGConventional cathode ray tubes consist of three main parts, the panel, the funnel and the neck (Figure 1). To produce the different colours on the screen, the inside of the panel is coated with a matrix of hundreds of thousands of small phosphor dots. Each dot is one of three types of coloured phosphors, emitting either red, green or blue light. These emit light when excited by a beam of electrons generated by electron guns located in the neck of the CRT. These beams pass through holes in the shadow mask and excite the phosphor coating on the inside of the panel, to give light of variable RGB composition, see Figure 1."

Jan 1, 2012

By A. Zorkovská, S. Castro, P. Baláž, Z. Bujnáková

Enargite (Cu3AsS4) belongs among refractory copper minerals with very low hydrometallurgical extractability of copper. An application of enargite leaching in acid solutions leads to simultaneous dissolution of copper and arsenic and the final leach solutions have to be treated for the separation of both elements. However, the alkaline leaching of enargite is selective. Arsenic passes into leach while produced copper sulphide represents the raw material suitable for pyrometallurgy. The hydrometallurgical processing of mineral can be influenced positively by mechanochemical route. We have shown that more than 80 % of arsenic can be extracted from enargite concentrate by atmospheric alkaline leaching at 95 °C when mechanical activation in an attritor is applied. The produced Cu2S can be further treated with elemental iron where mechanochemical intervention is applied in the second stage of enargite processing. The final product forms Cu/FeS nanocomposite from which copper nanoparticles can be easily separated. The illustrated concept of copper obtaining from copper sulphide is an example of so-called “dry” processing, as reactions in gas and liquid phases are excluded. This concept of environmentally friendly metallurgical processing can be classified as an impetus for novel technology to produce copper from enargite concentrates.

Jan 1, 2012

By C. A. Ingram

The Cigar Lake ore body is a high-grade uranium deposit situated within water-saturated sandstone. In order to extract the uranium ore remotely, ensuring minimal radiation dose to workers, and also to access the ore from stable ground, the Jet Boring System (JBS) was developed. This method of mining involves drilling a pilot hole up through a frozen ore body and utilizing a high-powered water jet to mine out cavities. During the mining process an ultrasonic sensor will be used to provide feedback to the operator, who is located beneath the ore body, as to the dimensions of the cavity. However, more precise data is required to determine final shape, volume, and location of the cavity for mine planning purposes. Selecting a device that will provide sufficient range data in the challenging environment will be vital to optimizing the mining process. Major issues include fog build up and flying debris during mining, and an environment that is wet, dark, and cold A test cavity has been designed and constructed at the Saskatchewan Research Council (SRC) so that a study comparing three different technologies, as prospective candidates for the survey system, can be conducted. The devices being evaluated include a Senix ultrasonic sensor, an MDL Cavity Auto-Scanning Laser System (C-ALS), and a MESA Time of Flight (ToF) camera. The ultrasonic sensor is known to provide range data in foggy conditions but has low accuracy. The C-ALS has been developed for surveying remote cavities but is expensive and does not provide reliable data in fog. The ToF camera provides a high volume of data in a short time period, with potential to provide accurate information in extreme conditions, but has not been tested in a mine cavity application. Iterative closest point (ICP) registration is applied in an attempt to create a 3D point cloud from the scan data and to also compute rotation and translation of the ToF camera. This paper presents an overview of the challenges involved in conducting a survey within a JBS mined cavity, the analysis used to determine the suitability of each device, and the data collected from the test cavity.

Aug 1, 2013

By Ifeanyichukwu Nweke

"Aluminium rolling processing from ingots to cold rolled coils comes with a lot of challenges especially in controlling defective products in casting, hot mill and cold mill operations. Hence this study focused on reducing defects at mills and cast-house using six sigma approaches. The use of six sigma approach will help the production experts to determine the gap between its operation and world class process. Practical data from First Aluminium Rolling mills were presented and analysed and mini improvement projects were proposed based on organisation need to achieve excellence. This study encourages aluminium alloy industries to pursue process improvement projects on the basis of analysis on data obtained from their shop floor, hence ensuring that through this, recovery is improved and cost of poor quality is reduced.INTRODUCTION Engineer Bill Smith while working at Motorola in 1986 introduced a new concept in which a set of techniques and tools are used for process improvement by controlling variations (defects). These tools and techniques are explained by an acronym DMAIC. D DEFINE the problem M MEASURE the variables in the problem A ANALYSE the variables of the problem I IMPLEMENT and verify the solution to the problem C CONTROL the solution to sustain it Most times in six-sigma approach, variations in the process that results in defects and customers’ dissatisfaction are targeted at 3.4 defects per million opportunities. There are numerous methods six sigma application use to achieve quality results and innovative strategies. Improving the quality of process through these methods helps identify and reduce variations which paves way for organisational excellence. In this study, it is encouraged to use six sigma techniques to improve aluminium rolling operations and other aluminium processing activities, the benefits of such improvement concept include: • Satisfy the voice of the customer (VOC) • Minimise costs • Maximise Profits • Build Good Team • Implement Profitable Project"

Jan 1, 2018

By Ross G. Bertinshaw

"The Line Creek Mine of Crows Nest Resources started mining coal in the fall of 1981. There are seven mineable seams with thicknesses ranging from 1.5 to 13 metres and with dips varying from 0 degrees to 60 degrees. This, together with internal partings and the very friable nature of the coal, creates a number of mining problems.The coal is divided into zones depending on the dip of the seam. Each zone requires a different mining technique to ensure optimum recovery and low dilution while still keeping fines to a minimum.Line Creek employs a combination of hydraulic front shovels and backhoes to mine its coal without blasting or use of dozers. This has been very successful in reducing the proportion of fine coal hauled to the plant, thus improving quality control and reducing costs in coal processing.There have been a number of other benefits from the use of excavators instead of more conventional methods. These include better selectivity, good cleanup, reduction in traffic at the face and lower cost.IntroductionThe Line Creek Mine is situated approximately 25 km north of Sparwood in southeastern British Columbia (Fig. I). Preproduction stripping began in J98J with the first coal shipments made in 1982. In 1983 the mine produced 2.1 million tonnes of raw coal.Similar to other East Kootenay coals, the seams at Line Creek are characterized by their friability, producing a large proportion of fine coal during mining. In an attempt to reduce these fines Crows Nest Resources has instituted the use of hydraulic excavators to mine and load the coal.Hydraulic excavators offer other substantial advantages over front-end loaders and dozers, which has been the conventional system in other mines in the area."

Jan 1, 1985

By J. J. Benitez

MIBC (methyl-isobuthyl carbinol) was previously shown to enhance significantly sylvite flotation when used at the stage of preparation of amine dispersions. In this paper Atomic Force Microscopy (AFM) is used to study the effect of MIBC on deposition of octadecylamine (ODA) on the surface of mica. The AFM images indicate that amino terminated, and therefore hydrophilic, deposits of ODA are observed on the mica surface in the ODA dispersions free of MIBC. In the presence of MIBC a methyl terminated (hydrophobic) monolayer is obtained on the mica surface. The transition between the monolayer and bilayer phases is due to the presence of MIBC. Experiments carried out in distilled water reproduced the results obtained from the brine. Working in pure water instead of brine simplifies the preparation conditions and the analysis by AFM.

Jan 1, 2006

By S. J. Cook

The system of mining statistics for Canada, as it exists today, represents the result of long years of progress, first by the Geological Survey, later and more comprehensively by the Mines Branch of the Department of Mines, and now by the Mining Branch of the Dominion Bureau of Statistics-all supplemented by the very comprehensive reports published by the several provincial departments of mines. It is the purpose of this paper briefly to state the development and present status of Canada's statistical service, more particularly in regard to information on mineral production, and to show that in its evolution continuous progress has been made in the elimination of factors tending to duplication and overlaping, with the result that the construction of an adequate statistical service has been carried out with the least possible expenditure of .public funds. For the purpose of this discussion, the subject of mineral statistics may conveniently be considered from two points of view. The technical difficulties in obtaining satisfactory and complete data from the variety of industries represented in the mining fields of Canada must be apparent to all. Methods of record-keeping are almost as numerous as mines and even the larger concerns which maintain elaborate records for their own information, often find it difficult to compile the statistical reports required of them, because the specific form of inquiry differs from the method in use in their offices.

Jan 1, 1924

By B. Roy

The Somita plant processes low sulphide gold ore in Burkina Faso with a CIL process. After experiencing recurrent low gold recoveries, Somita undertook an investigation on the source of the problem. COREM conducted a mineralogical study on different pit samples. A series of tests was also conducted on a composite sample from the plant which shows a content of 3.4 g/t in gold and 0.48 % in graphite. A reference test in laboratory resulted in a recovery of gold of 75%, similar to plant recoveries for the evaluated ore. In these tests, even if cyanide is not deficient, it was diverted mainly into iron cyanide complex, copper cyanide complexes and by graphite adsorption. Causes of low recovery were also identified and quantified. Solutions to increase gold recovery were suggested such as increasing gold dissolution kinetics by O2 or by lead nitrate addition, change in activated carbon addition point location to the 1st cyanidation tank and finer grinding to increase liberation. Increase in the pH could also contribute to reduce cyanidation consumption. Following these recommendations, Somita changed carbon addition from tank 2 to tank 1 in the CIL circuit. This change led to an increase of more than 5% in gold recovery. A system for the addition of lead nitrate is also under implementation at the plant and benefit will be evaluated in 2013. Finally, pit management for cyanidation will be done based on mineralogy instead of gold content in the future.

Jan 1, 2014

By H. S. Price, F. N. Kissell, R. C. McCulloch, J. C. Edwards

"The methane em1ss10n from deep coalbeds which are actively mined is a serious problem facing the mining industry today. Pinpointing the source of methane and predicting the emission of this gas from these coalbeds is necessary if preventive techniques are to be effectively used to control methane emission. In general, because most coalbeds have water associated with them, the system to be studied may be either single-phase (methane gas) or two-phase (methane and water). Because coal mine geometry is complex and the fluids have variable properties as functions of pressure and methane concentration, the differential equations describing the flow of methane and water are not amenable to analytic solution, but must be solved numerically using high-speed computers. This paper presents the development of such a complex mathematical model along with some preliminary applications of the model to methane emission from one- and two-dimensional coalbeds with and without water present."

Jan 1, 1973

By F. Sorenson, P. A. Castellarini, F. Garbarino, M. N. Garcia

"Recently, significant efforts to improve productivity from the tight intervals of the Mulichinco Formation within the Sierra Chata Field in the Neuquén Basin have been ongoing. Because conventional high quality reservoirs were being developed in this field, a proper reservoir understanding and completion approach was applied. After developing these high permeability reservoirs, the operator began evaluating the tight intervals and new areas within the field, but a completely different approach was necessary to achieve motivating production improvement.An extensive study to help enhance reservoir understanding and identify key factors controlling productivity of these tight intervals (which tend to be in the range of 5 µD) has been ongoing. Some of the issues discussed in this study are 1) petrophysical review, 2) rock properties calibration, 3) geomechanics understanding, 4) faulting and micro faulting/lineaments description, 5) stimulation and completions review and, 6) understanding key production drivers.As in many other tight reservoir projects, a considerable area of the reservoir must be effectively stimulated during the hydraulic fracturing process to achieve economic productivity. Two critical issues hinder these objectives. First, the low permeability in addition to a pore pressure close to or even lower than hydrostatic are critical characteristics when attempting to flow back the well and clean up fractures. Second, very high horizontal stress anisotropy resulting from a strike slip stress regime promotes the generation of simple planar bi-wing fractures. It is well-known that this fracture geometry will contact much less reservoir area compared to more complex fractures, as the operator would normally intend to create at very low permeability reservoirs.This paper discusses these issues and how they were addressed. A pilot drilling and completion program was initiated during 2012 to validate this study. Key factors include well location relative to formation unconformities, their orientation relative to the far field principal stresses, hydraulic fractures generated, and overall completion design."

Jan 1, 2015

By John A. Herbst, Xiangjun Qiu

"Prediction of wear on a microscale level in mineral processing equipment turns out to be a challenging undertaking. This is particularly true for cases in which the objective is to use such predictions for wear parts design. The key to obtaining such predictions has turned out to be the use of physics based models along with phenomenological constitutive equations. In this paper, two components of the HFS tool set, one for particles (DEM) and one for slurry (MPF), are used for modeling. These tools are applied to the simulation of wear of SAG/AG shell lifters/plates and wear in slurry pumps. In each case wear predictions are validated with plant measurements.INTRODUCTIONHigh Fidelity Simulation (HFS) has emerged as an important tool set for mineral processing plant equipment design and optimization (Herbst and Potapov, 2003; Herbst and Nordell, 2002; Herbst and Lichter, 2006). This tool set consists of Discrete Element Modeling (DEM) of particle motion, Multi-Phase Flow (MPF) for liquid motion, discrete grain breakage (DGB) for particle fragmentation and discrete grain liberation (DGL) for mineral liberation (Campbell, Potapov and Tsuji, 1997; Ferzinger and Peric, 1997; Potapov and Campbell, 1996; Herbst and Potapov, 2005).Three sample snapshots of basic HFS illustrating the use of each of the various types of mineral processing equipment are shown below.Figure 1 shows a snapshot of a DEM simulation of ball charge motion in a commercial scale Vertimill. DEM simulation involves simultaneous solution of Newton’s Laws of Motion for 400,000 balls."

Jan 1, 2007

By D. J. MacKinnon

Zinc metal was first produced in India around 1100 A.O. and a zinc industry based on retorting gradually developed in both India and China(1) . The vertical retort method for smelting zinc ores was developed in England in the 1730s; this was followed by the more fuel efficient horizontal retort process developed by the Belgians in the 19th century(2) . The horizontal retort process was the standard method of zinc manufacture until the 1950s when it became obvious that it could not compete with electrolytic zinc technology(2). The present day extractive metallurgy of zinc is dominated by the electrolytic process which now accounts for almost 80% of the world's primary zinc production. In recent years the electrolytic zinc process has seen significant improvements: the fluid-bed roasting of zinc concentrates, improved leaching and residue treatment techniques such as the jarosite and goethite processes, improved solution purification procedures, mechanization of the zinc electrolysis step and of the zinc melting and casting operation. In addition, new leaching processes have been implemented for the treatment of oxidized ores, particularly silicates, and the pressure leaching of zinc sulphide concentrates is now a commercial reality. Although the electrolytic zinc process was first used on a commercial scale in 1916, its history can be traced back to the 1860s. The purpose of the present paper is to outline the early history of the electrolytic zinc process and to trace the significant developments which led to the first successful commercial electrolytic zinc plants.

Jan 1, 1999

By Martin Stoklossa

Surface mining operations typically require run-of-mine material to be sized for further processing. In-pit crushing facilities serve this need, as stationary, semi-mobile or fully mobile units. Although in particular fully mobile crushing facilities have been in use for over half of a century, other surface mining techniques have typically been implemented. However, with increasing operating costs in truck and shovel operations, and other economic considerations, mobile crushing plants are increasingly a viable option. The operational and economical parameters in relation to the optimal surface mining equipment selection will be reviewed. The role of the mobile crushing technology within the continuous vs. noncontinuous surface mining operation and basis for mine planning are also discussed. Current applications and respective case studies will be reviewed. Key performance indicators will be presented. These performance parameters can be viewed as a tool to aid in the equipment selection process. The future direction for further research and development in mobile crushing facilities will also be presented.

May 1, 2008