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By R. Roufail

Mineral exploration is in a race to employ drilling technology that can perform the exploration and drilling investigation in a fast and inexpensive manner. After an extensive study of the available drilling technologies in the market, coiled tubing was chosen as a tool to be employed for mineral exploration due to its flexible mobility and ease of operation with a minimum number of personnel. Since coiled tubing technology is primarily used in the oil and gas industry, it was important to re-design the coiled tube rig to drill hard rocks in a fast and feasible manner. The main requirements were to drill the smallest feasible hole diameter and go as deep in the ground as possible, in the shortest reasonable time. The drilled rock particles, cuttings, are to be collected and analysed at the surface for their metal mineral contents. The process also needs to be repeated multiple times at different locations for mapping, without the need to change the tube on the rig due to failure or potential failure. The focus of the new designed coiled tube, for drilling and mineral exploration, is three fold. First is to increase the rate of penetration in drilling by designing a small high speed turbo motor. Second is to determine the controlling parameters of cuttings transport to effectively lift the cuttings to the surface for analysis and third is to minimize the overall weight of the rig for manoeuvring and prolong the life span of the coiled tube string. In this paper, a small downhole turbo motor, 5cm outer diameter, is designed to achieve a rotation speed of up to 10,000 rpm to fit on a small bit, coiled tube drilling assembly. The motor design utilised multiple finite volume and finite element analysis softwares for fluid flow study and fluid structural interaction analysis. The paper is also introducing the concept of a flow slurry loop that is designed to lift the cutting particles to the surface for mineralisation analysis. The controlling parameters of the cuttings transportation are the particle?s physical properties such as size, density, concentration and shape, as well as the rheological properties of the carrying fluid, drilled hole angle, as well as the fluid flow rate and flow dynamics within the annulus gap between the coiled tube and drilled hole. Such parameters are addressed via experimental work as well as numerical analysis. The paper is also presenting the selection and testing procedure of the material type for the coiled tube string. The tube needs to be light in weight for overall rig weight and its transportability. The tube is also required to drill several dozens of investigation holes before failing due to fatigue. A fatigue bending machine is designed to test the endurance limit of candidate materials for coiled tube strings and a performance index methodology is followed for material selection of the optimum material. The coiled tube rig is designed to be light in weight for transportation and relocation. It is also required to speed the drilling operation with the minimum footprint and reclaim the drilled rock particles for mineral composition analysis at the surface.

Aug 1, 2013

By Donald Leroux, Lori Lynn Smith, Robert Hutchison

"The grinding circuit of the Heath Steele concentrator was sampled under five different sets of operating conditions. The balanced results of the sampling campaigns were used to calibrate steady-state rod mill, ball mill and cyclone models using a commercial simulation software package (JKSimMet® ). Thirteen process variables had the potential to affect significantly the performance of the grinding circuit. Statistical-Design-of- Experiments techniques were applied to plan the suite of simulations in order to improve the quality of and minimize the time to find the optimal solution. The effect of each factor on three performance indices (the cyclone overflow size distribution, the circulating load and the cyclone underflow density) was modeled with empirical polynomial relationships using another software package (Design-Expert@)T. he conditions under which the cyclone overflow size distribution was maximized while respecting circulating load and cyclone density constraints were identified using these relationships. Among the most interesting results is the prediction of a set of conditions where the circuit target size distribution is achieved with only three ball mills instead of four.IntroductionProduction at the Heath Steele concentrator (near Miramichi, New Brunswick) started some 43 years ago at a rate of 750 t/d. The plant capacity was increased to 4000 t/d through successive expansion phases in the seventies (Sapiro, 1977; Johnston, 1978). However, as a result of depleting ore reserves, the plant throughput had to be gradually reduced to the current production rate of 2700 t/d. Heath Steele Mines currently have proven and probable reserves which would see it producing until the end of 1999 (Noranda Inc., 1997).An analysis of the grinding circuit of the Heath Steele concentrator was recently commissioned to identify opportunities for reducing operating costs while maintaining budgeted mill throughput and metallurgical performance. Since the plant will likely be operated below nominal capacity for the rest of its lifetime, the possibility of improving grinding efficiency by operating with fewer ball mills and/or crushers was contemplated."

Jan 1, 1999

The uphole bench extraction strategy at EKJV Management Pty Ltd?s Raleigh Mine, requires simultaneous horizontal and vertical exposure of paste filled stopes. In order to prevent excessive ore dilution, the paste fill must be of sufficient strength to prevent failure during exposure. A numerical modelling methodology has been developed to accurately simulate the initial stress distribution within paste filled stopes, together with the strain-softening loading response of paste fill material. Due to the narrow orebody width and high deformation behaviour of the host rock mass, high closure strains are likely to cause a stiff, brittle fill material to undergo crushing failure upon exposure. The stability of paste fill exposures at the Raleigh Mine was determined by conducting a series of three-dimensional numerical models that incorporate the extraction, filling and exposure sequence of paste filled stopes. Stability charts for 2.5 m and 3.5 m wide simultaneous horizontal and vertical exposures have been derived based upon the numerical modelling results. Implementation of the stability charts has proved successful in limiting the amount of ore dilution from paste fill and provides a basis to optimize paste fill cementation and stability throughout the life of the mine.

May 1, 2007

By M. E. Rossi, J. E. Camacho

"Geostatistical conditional simulations are becoming increasingly popular as tools that provide models of uncertainty at different stages of a mining project. They have been used as grade control tools in daily operations to assess the uncertainty of mineable reserves at the project’s feasibility stage, and to assess mineralization potential in certain settings. Other applications include assessment of recoverable reserves, resource and reserve classification, and drill hole spacing optimization studies. All large-scale applications of conditional simulations intend to benefit from the correct (or accurate) characterization of uncertainty, adequately describing the variability observed from the data and its effect on the final objective.The objective of this paper is to compare the ad-hoc uncertainty model provided by a traditional classification scheme with the probability intervals resulting from a conditional simulation model. It is argued that the uncertainty model derived from the use of classification schemes is of little practical use to the mining company or operation. The paper emphasizes differences in uncertainty based on the size of the mining unit considered, the extraction method, and local geological differences. Most importantly, it discusses confidence intervals for these mining units, as compared to the relative precision envisioned by a typical classification scheme.The application described in this paper is taken from a medium-sized Cu open pit and underground mine in northern Chile, and demonstrates the impact of several variables on the resulting conditional simulation models. It also compares a more traditional resource classification scheme applied, and the wide difference in local confidence intervals for each mining unit."

Jan 1, 2004

By Peter Wells, Laxman M. Amaratuga, Todd M. Kanhai

"Certain mining methods (eg. Cut-and-fill) result in the contamination of run-of-mine ore with shotcrete. This shotcrete remains mixed with the ore throughout processing. Experimentation performed by Falconbridge Limited revealed that underground contamination of ore by shotcrete (eg. as little as 1% by weight) has led to ill-effects on the nickel recoveries from the flotation process in the mill. The nickel recoveries of contaminated samples were lower than tests without the shotcrete Contamination.To optimize flotation circuits it is important to know why the contamination has created these effects and also to find a method to abate or remove them. Laboratory testing showed that the age of the shotcrete was a factor in it’s effect on nickel recoveries. Younger aged shotcrete gave nickel recoveries lower than baseline nickel recoveries with no contamination. Older shotcrete gave nickel recoveries similar to the baseline.Literature on other cementitious material contaminations on ore revealed that a possible means of remediating this problem is the use of acid in the flotation. The initial pH in the flotation pulp was designed to be pH 9.2, but with the young shotcrete contamination the pH was in the neighbourhood of 10.5. Acid addition may act as a means of lowering the pH to the optimal operational value. Laboratory test work showed that acid addition brought nickel recoveries closer to the baseline."

Jan 1, 2000

By Michael Stuart Parsons

The haulage cycle is the sequence which a haulage vehicle must first arrive at the loading area, then turn around and reverse into position. Once it is loaded, the vehicle leaves and travels to the unloading area, where again it must turn around and back up to unload. The cycle is repeated over and over again. The Vector Neutral truck is a rubbertired, self-propelled hauling vehicle designed such that it eliminates the requirement to turn around and back-up to either load or unload. Vector Neutral Truck Cycle: 1.) Travel from the load station to the dump station. 2.) Stop and dump load. 3.) Travel from the dump station to the load station. 4.) Stop and load. The Advantage is in the Difference: 1.) Shorter distance traveled. 2.) Fewer brake and steering actuations. 3.) Easier to automate. 4.) Easier to adapt for remote control operation.

May 1, 2003

By V. D. del Valle, T. G. Joseph, J. J. Berezan

Aggressive driving patterns, rough and poorly maintained roads and pit floors, along with the occasional bump and poorly placed load from a shovel can create intense and sometimes serious vibration levels on a heavy hauler. The effects of high vibration have been shown to be of concern for the health of the operator as well as the reliability of the equipment. It is proposed that an onboard vibration warning system based on the ISO 2631-1 standard could be used to help operators reduce the vibration levels experienced in a heavy hauler. The onboard system would consist of a screen that displays the instantaneous vibration in the form of three lights: green (safe zone), yellow (cautious zone), and red (danger zone), as well as an overall vibration exposure or dose for the entire shift. With the utilization of the warning system, it is anticipated that the overall vibration levels will be decreased resulting in improved operator health, a reduction of vibration-induced maintenance, and improved haul roads through reduced impact loading and repair for localized trouble areas.

Jan 1, 2004

By T. A. Rickard

FROM AN OLD MANUSCRIPT THE text for this contribution to the history of the Patio process is a page taken from a Spanish manuscript of Bartholomé Arzaj Sanches y Uela, now in the possession of the library of Brown University (see Figure 1). I owe the photographic print to the courtesy of the librarian. The date, as will be seen, is 1577. The subject is the treatment of silver ores at Potosi, in old Peru, but in modern Bolivia. The group of drawings (see Figure 1) is entitled "Arrangement of the machines in which the ores of silver are ground on the bank of Potosi, the one of two batteries and the other of one". First, top-left, we have the sketch of a "machine of one battery" operated by a water-wheel. From this mill the water runs in part along an aqueduct supported by pillars to the two-battery mill and in part down the hillside, where men are at work with "tubs, which are called cochas, in which are washed the charges of ore and amalgam". Along the top of the page are shown the "various offices in which are stored the copper, the salt, the ucha [llama dung, used for fuel], the lime, and other materials for the re-duction of the ores". To the right of these are "apartments and warehouses in which is stored the ore brought down from the mountain"?the cerro de Potosi. Through the arched portal come the "sheep [llamas] on which is brought down the ore". To this is added a reference to "the second gate, which closes the whole works". On the level above the aqueduct are seen six men carrying skin-bags that contain water. This is being sprinkled on the ore. On the extreme right are six more of these water-carriers. Next comes the two-battery mill. The mortero, or mortar, is marked on the right. Another description says, "Stone, on which the stamps crush the ore, which is called a mortar". To the left of these are indicated "screens of wire in which the ore is sifted after it has been crushed". Farther to the left, near the ore-washers, is a "shed, in which is placed the metallurgist to test the ore of the boxes". Along the left side of the page are sundry buildings, one of which is labelled a "shed in which are placed the cones of silver". Near it, lower, to the right, is the "furnace, in which are roasted the sulphides to facilitate treatment". Farther to the right is the "place where the Indians mix the charges of sulphide ore, which is called a buitron". Alongside is a "buitron in which the charges are prepared for reduction". Inside is a container, to which are attached the words "measure, called topo" On the extreme right is "another buitron in which the Indians mix the ores with their feet, as well as the heaps for the preparation of the reduction". Near the bottom, on the extreme left, is the "chapel where the holy sacri¬fice of the mass is celebrated". Under the first buitron is the "place where they dry the moist ores, called pãpear".

Jan 1, 1935

By Andrew Bamber

Between the early 20th Century and the present, the production of mined copper ore has increased from tens of millions of tonnes per annum to several billion tonnes per annum, an unprecedented increase. Contemporaneously, the average grade of mined copper ore has declined from over 2% to approximately 0.5%. Again, in parallel, the price of copper has increased dramatically to reflect the increasing cost of extracting and beneficiating such large amounts of low-grade ore. Within the period the copper price however exhibited several periods of intense volatility, driven by interrelationships between demand and supply, themselves strongly driven by periodic industry developments in the fields of exploration, ore extraction, mineral processing and extractive metallurgy. It is notable that these periods of intense innovation exhibit a strong correlation to preceding periods of price, demand or production volatility. This paper examines key trends in each theme between 1900 and 2018 and draws strong conclusions as to the interrelationship between them. INTRODUCTION The production of copper metal has increased from around half a million tonnes per annum to over fifteen million tonnes per annum over the course of the 20th Century. Contemporaneously, the average grade of copper ore mined has declined from over 2% to approximately 0.5% copper by weight. As a result, the volume of Run-of-Mine (ROM) copper ore required has increased from around ten million tonnes per annum to over a five billion tonnes per annum over the period, an unprecedented increase. The adage is that demand drives supply, that prices rise in times of high demand and/or short supply, and that prices fall when supply catches up with demand. The market sellers in biblical times knew this well; mediaeval market sellers equally. Dutch tulip sellers in the 1600’s experienced both in extremis — much to their dismay — and the great industrialists and early capitalists of the industrial revolution knew this also. Mining recently went through a cycle where investors and producers both believed that the “old” rules did not apply any more and that the industry was in a “supercycle” where prices would continue to rise on the back of increasing demand. However, as the GFC of 2008–2011 showed, this was not to be. Another adage says that we constantly innovate to lower costs of production. Is this true? Do we only innovate to lower cost? Has the true cost of producing copper actually gone down over the century? Or are there other balancing forces at play? Herb Kellogg, in his Centenary address to the American Institute of Mining Engineers (now SME), categorized two types of innovation: ‘Bigger and Better’, and ‘New Process’ (Kellogg, 1970). ‘Bigger and Better’ allows increased production at presumably lower cost; ‘New Process’ supports the same result at presumably the same scale, but at significantly enhanced efficiencies and (therefore) lower cost. It is suggested that both types of innovation are constantly and interchangeably required to achieve the kind of scale-up, at achievable operating and capital cost that the industry has achieved over the period. What can be shown, over this last Century and a bit, is that supply and demand are indeed inextricably linked, price and demand are linked, but so are price and cost of production. And the innovation required to sustain that weaves in between them all, cost-effectively increasing production capacity or lowering the cost of production at the same throughput, and sometimes both.

Jan 1, 2019

By T. G. Joseph

"The Oil sands-Equipment Interactions Program (OsEIP) is a collaborative research venture between Syncrude Canada Ltd., James Progithin International Ltd. (JPi), the University of Alberta, P&H MinePro, and Caterpillar Inc. The objective is to better understand the behaviour of oil sands as it interacts with mining equipment, in particular, large trucks and shovels. With a move to ever larger equipment, mining oil sands of highly variable bitumen content, ground stability comes into question. This paper outlines this aspect of OsEIP and provides some insight into how some of the findings enable an improved understanding of oil sands behaviour that may impact large equipment design, operational and maintenance strategies. IntroductionThe mechanical behaviour of oil sands in the underfoot and in the face yields some of the harshest stability and digging conditions of any mining environment. High maintenance costs from truck and shovel fatigue failures predominate as a result of ground stability issues. Wear rates of shovel and dozer ground engaging tools (GET), rollers, roller paths and crusher screens result in costly and frequent replacement, or even more frequent and costly sacrificial wear zone building. From the shovel face to the crushers and screens, dry oil sands mechanics affects the degree of fragmentation and, ultimately, bitumen production.An increased knowledge of the behaviour of oil sands with respect to stability, fragmentation and abrasion, etc. would enhance the long-term equipment design process at the vendor level, and provide the end user with improved short-term operational guidelines and long-term strategies for future purchases and operation. Truck vendors recognize that the interaction between operator, seat, frame, suspension, tires and oil sands is unclear, and must be better understood before proceeding to next generation designs. Similarly for shovel manufacturers, the relationship between bucket/dipper motion, carbody, side frame, rollers, track and oil sands follow in the same vein."

Jan 1, 2002

By K. U. Kainer

Magnesium and its alloys as the lightest available construction metal offer a wide range of opportunities for the usage in transportation industries, especially Magnesium wrought alloys with their improved mechanical properties show a high potential for structural applications, While magnesium cast components have found their application the interest is now spreading to wrought alloys due to the possibility to get even more homogeneous and better properties compared to cast parts, Therefore alloy and process development especially for extruded and sheet material is a main concern to enhance the application of Magnesium wrought alloys, Castings are still form the majority of applications of magnesium alloys, although efforts to develop adequate wrought alloys have increased, In the presentation, the alloy requirements for processing of cast and wrought alloys will be discussed, The various processing routes and alloy compositions result in specific microstructures and properties which determine the potential use of these alloys, Today, the spectrum of available alloys covers standard alloys as well as alloys for use at elevated temperatures, The trend will be to further diversify the alloy compositions and to improve the alloy properties, Areas of concern still remain the wrought processing and the high temperature (creep) and corrosion properties of magnesium alloys, Examples of recent developments in these sectors will be given, The presentation will also provide an overview of the historical and current use of magnesium and an outlook on future applications.

Jan 1, 2006

By M. Schmidt, P. Nord, M. Larinkari

Cathode stripping machine technology has been developed significantly both in electrorefining (ER) and electrowinning (EW) applications in the last ten years. The main driver has been robotic cathode handling, which has enabled increased flexibility to meet different layout and material handling requirements for both ER and EW processes. Additionally, cathode stripping stations have been continuously developed to optimize speed and to reduce mechanical stress of permanent cathodes. 'taco' type cathodes have been proven as beneficial approach for high capacity operations (particularly in Cu ER), where over 600 cathodes per hour continuous throughput has been achieved. However, the latest developments also apply to split type cathode stripping. Besides material handling, the modern cathode stripping machine has also an important role to provide information for production and quality monitoring. This paper describes the latest developments from the field of copper cathode stripping based on several different projects implemented in the recent years. INTRODUCTION After introduction of the permanent cathode technology in the late 1970s, it became the prevailing technology in copper refineries over the traditional starting sheet process by the end of 1980s. The main driver was less labour-intensive production due to fewer processing steps required along with more automated electrode handling equipment (cathode stripping machine, anode preparation machine, anode scrap washing machine and tankhouse cranes). Since then the design of the cathode stripping machine has followed the development of permanent cathode technology. The main development steps so far can be summarized as follows: Full Deposit Stripping Machine (FDSM) based on waxed permanent cathodes or cathodes with bottom edge strips resulting in split cathodes (copper sheets separated, see Figure 1) Wax less cathode stripping based on V-groove on bottom of the edge strip resulting in either ‘taco’ cathodes (enveloped copper sheets, see Figure 1) or split cathodes Full Deposit Robotic Stripping Machines (FDRSM) using 1–5 robots for permanent cathode handling and cathode stacking.

Jan 1, 2019

By Grant Goddard

Cameco?s ?Double U? Strategy ? Double existing production ? To 40 million lbs U3O8 annually ? By 2018 ? Existing operations ? Saskatchewan ? United States ? Kazakhstan ? Projects under evaluation ? McArthur River expansion ? Kintyre (Australia) ? Inkai Block 3 (Kazakhstan) ? Development properties ? Cigar Lake project Measures of Success ? Safe, healthy and rewarding workplace ? Supportive communities ? Clean environment ? Outstanding financial performance

Nov 1, 2011

By H. J. McQueen

Mineral and energy resource consumption were continuously reduced by process improvements as chemical understanding was developed and applied. During the past two centuries, technological improvements increased human productivity that was accompanied by social advances and labour saving products; however, these sometimes proliferated to endanger sustainability, e.g., automobiles. In the steel industry, precisely controlled rolling of HSLA steels required little extra mineral consumption but reduced weight and heat-treating energy. Continuous casting of slabs reduced scrap compared to ingots and energy for the homogenizing soaking pit. Al alloy extrusions were improved by retaining the strengthening in the near-surface substructure, of high strength textures and of press quenching that is suitable for direct age hardening. Continuous bar casting of Al-0.65Fe, coupled with rod rolling and followed by wire drawing with only a final recovery anneal, yielded electrical wiring for households to replace less plentiful Cu and later for light-weighting use in autos and aircraft Looking backwards, the 1970 decade saw the first oil crisis and inspired Ottawa to undertake a campaign to develop an energy strategy that would decrease dependence on imported fuels. One significant undertaking under Energy Mines and Resources was the organization of industrial energy conservation, managed by each industry association,that collected detailed current statistics and set the goals for a 2-year campaign. The metal producing industries, as compared by E.C.N. Perryman to about 7.2 exajoules (EJ) for the nation, consumed about 0.8 EJ, being about one third of all heavy industries. While manufacturing consumed 30.2% of total energy, it created 87.3% of total national dollar value. Within the industrial envelope, smelting and refining utilized 28% (0.67 EJ, mining beneficiation 6.7%, 0.16 EJ); there was a significant contribution to exports: 80% of iron ore and 70% of aluminium in 1973. A general concern was that decreases in ore grade would lead to a rise in energy expenditures countering benefits from processing efficiency.

Jan 1, 2012

By P. Rosario

"Industry practice for high-pressure grinding roll (HPGR) assessment and sizing relies on tests using pilot-scale machines with 0.7–1.0 m roll diameters. Typically 1–10 t of sample are required, depending on the level of study and resource complexity. This is challenging during early-stage development, which hinders incorporating HPGR into designs. With support from the Canadian Mining Industry Research Organization, researchers at the Norman B. Keevil Institute of Mining Engineering at The University of British Columbia developed bench-scale piston–die press tests (PPTs) that correlate to pilot- and full-scale HPGRs. This paper describes a new regression model to estimate the HPGR-specific throughput rate using both PPT results and an HPGR database. A case study is presented to show how the current PPT method is used for engineering studies. ¦ KEYWORDS Empirical modelling, High-pressure grinding roll (HPGR), Piston–die press test (PPT), Sizing and scale upRÉSUMÉ La pratique en vigueur dans l’industrie concernant l’évaluation et le calibrage d’un cylindre de broyage à haute pression (HPGR, de l’anglais high-pressure grinding roll) dépend d’essais menés à l’aide de machines à l’échelle pilote dont les diamètres de bobine sont de 0,7 à 0,10 mètre. On a généralement besoin de 1 à 10 tonnes d’échantillons en fonction du niveau de complexité de l’étude et des ressources. C’est une pratique difficile durant les premières phases de développement, qui empêche l’intégration du HPGR dans les plans. Bénéficiant du soutien de la Canadian Mining Industry Research Organization (CAMIRO, l’organisation de recherche de l’industrie minière canadienne), des chercheurs du Norman B. Keevil Institute of Mining Engineering (l’institut Norman B. Keevil de génie minier) de l’université de la Colombie-Britannique (UBC) ont mis au point des essais en laboratoire sur des presses à matricer à pis¬ton (PPT, de l’anglais piston–die press tests), qui mettent en corrélation les HPGR aux échelles pilote et réelle. Cet article décrit un nouveau modèle de régression qui évalue le taux de production spécifique aux HPGR à l’aide des résultats tirés des PPT et d’une base de données dédiée aux HPGR. Une étude de cas est présentée afin de décrire l’utilisation de la méthode actuelle des PPT dans les études techniques. ¦ MOTS CLÉS calibrage et mise à l’échelle, cylindre de broyage à haute pression (HPGR), essai sur presses à matricer à piston (PPT), modélisation empiriqueINTRODUCTION It is widely accepted that high-pressure grinding rolls (HPGRs) are a viable, energy-efficient solution for modern comminution flowsheet design. Table 1 summarizes select examples of HPGR applications in the mining industry. The main benefits of HPGRs are energy savings, which leads to lower operating costs, and stable operating characteristics that can better cope with variations in ore hardness compared to the conventional autogenous (AG) or semi-autogenous (SAG) mill-based comminution circuits."

Jan 1, 2019

By Mary A. Wells, Amir Hadadzadeh, Mark A. Whitney, Stephen F. Corbin

In an effort to produce less expensive titanium sheet via roll compaction, the room temperature compaction behavior of titanium sponge granules (99.9% pure, Alfa Aesar) was studied under uniaxial die compaction. The titanium sponge granules were irregularly shaped, with a high degree of porosity, having a maximum particle size of 3mm. Manual die compaction was conducted using a Carver hand press, in a hardened tool steel die with 12.61 mm inner diameter. Uniaxial die compaction in a hardened tool steel die with 9.50 mm inner diameter was also performed using a Gleeble® 3500 thermal-mechanical simulation testing system which allowed for controlled deformation rates. Compaction behavior of the titanium sponge was studied using well-established compaction equations (Heckel, Panelli-Filho and Ge), and it was observed that compaction rate influences the room temperature compaction behavior of this material. The Heckel analysis of the titanium sponge showed that the behavior of the material could be analyzed in two compaction pressure regimes. In the low pressure regime (<100 MPa) the granules exhibited high compressibility, while; in the high pressure regime (>100 MPa) lower compressibility of the titanium sponge was observed.

Jan 1, 2015

By Carol J. Odell

As a mining social practitioner, social indicators are within the purview of required competencies. A situation, where the ER manager requested assistance in quickly deriving a few social indicators for the strategic plan motivates this paper: despite ample technical knowledge about indicators, a clear understanding of stakeholder aspirations and concerns, as well as familiarity with management priorities such a request required reflection to produce a satisfactory approach, which combined pragmatism with enough academic rigour to provide reliable measures, while being justifiable to management who are unfamiliar with many of the pertinent debates. Importance: Social indicators enable the identification of more and less effective mine-community engagement strategies as well as providing primary data to better understand how the mine-community social system responds to different interventions, thus guiding future engagement plans. In addition social indicators: ? Assist communication about social strategies with Engineering and Operations management, using a quantitative language that is familiar to them. ? Provides concrete data to engage stakeholders to discuss progress and challenges arising, to move discussions towards technically robust strategies and away from politically interested proposals. ? Finally, social measurement is required more and more in due diligence, covenants and ongoing monitoring in Independent Engineering assessments of projects for financing. This paper begins by considering some technical considerations that are useful to guide indicator development. It then introduces the field research informing this paper and discusses some useful results in the light of further applicable concepts from the literature. The paper ends by considering corporate aims in applying corporate social responsibility (CSR) programs and discusses the application of the research for practitioners at mining operations, in the light of these aims.

May 1, 2010

By Jeff R. Reinson

The Diavik Diamond Mine is producing diamonds from two orebodies, the A154 South and A154 North kimberlite pipes, discovered beneath the waters of Lac de Gras. Innovative dike technology with appropriate water collection and treatment systems allowed Diavik to start open pit mining of the ore bodies in 2002. To allow planning, engineering, and implementation of sufficient water handling infrastructure, reasonably accurate estimates of groundwater inflow quality and quantity over the life of mine are required. Prior to mining, a numerical model using the continuum approach was developed for regional and site wide water management. After approximately two years of mining, groundwater inflows to the pit were found to exceed those predicted by the base case hydrogeologic model. The most likely explanation was flow through Dewey?s Fault zone. As this fault was not explicitly accounted for in the model, a detailed hydrogeologic investigation was conducted to evaluate its geometry and hydraulic properties. A multi-disciplined approach was used and involved core logging, fluid logging, geophysical logging, packer testing, a pumping test, and water quality sample collection. The results of the field investigation were used to update the conceptual and numerical models and to develop a Discrete Fracture Network (DFN) model to address small scale problems such as flow into future underground drifts. The updated numerical hydrogeologic models predict that up to 70 per cent of the groundwater inflow to the A154 N/S open pit is through the relatively narrow fractured rock zone associated with Dewey?s Fault. Consistent with the continuum model, the DFN model predicts that inflow to a drift excavated in Dewey?s Fault will be approximately 10 times the inflow to a drift excavated in competent rock. The DFN model provides a better understanding of the distribution of these inflows on a local scale over the length of the drift.

May 1, 2006

By Hamid Butt

Information Technology ??Advanced Information Technology is dramatically changing information flow within organizations. This enables employees to have information at their fingertips to make informed and prompt decisions. ??Real-time information allows timely analysis, which dramatically reduces cycle times, making organizations faster and more flexible. Business Challenges ??Continual growth of mining and Mine mobile fleet.??Increasing maintenance costs. ??Difficult to identify and troubleshoot equipment problems while equipment is operating. ??New equipment is increasing in complexity and cost. Therefore, each failure results in a greater impact to production and cost. ??Troubleshooting practice is reactive. ??Protect and optimize the use of mining assets to realize maximum business value. ??Maintenance and Operating information is not easily accessible ?no near real-time system that provides complete information.

May 1, 2006

By Jose R. Hernandez-Aguilar

"Three models to predict the effect of bubble size (Db) on metallurgical response were tested in a pilot-scale flotation column at Teck Highland Valley Copper mine. The column was fed with slurry collected from the Cu/Mo separation circuit. The first model was the one developed by Gorain et al. (1997), which assumes that the collection zone rate constant (kc) is inversely proportional to Db. The second model was the one proposed by Hernandez-Aguilar et al. (2010), which considers kc as an inverse square function of Db. The third model was the one developed by Yoon and Luttrell (1989) which provides expressions to describe the efficiency of particle collection (E) based on first principles. The results showed a significant bias between experimental and predicted data using the model of Gorain et al. (1997), possibly reflecting the model’s inability to explain the impact of bubble size, bubble rise velocity and flow regime on E. The model of Hernandez-Aguilar et al. (2010) well described the experimental evidence. The model of Yoon and Luttrell gave accurate and unbiased predictions. However, Yoon and Luttrell’s approach calls for a criterion to determine whether the flow regime is potential or intermediate, a subject that requires more fundamental research.INTRODUCTIONParticle collection, i.e., bubble-particle collision followed by attachment, is the basis of flotation. In a quiescent environment (such as the one observed in a column, or away from the impeller in a mechanical cell), a collision event can take place as long as the “degree of turbulence” caused by the rising bubble does not prevent particle and bubble to flow in close proximity. Upon collision, the particle slides on the bubble surface for a period of time. If the particle is hydrophobic, attachment occurs when the “sliding time” is longer than the “induction time”, which is the time required to thin and rupture the intervening liquid (usually water) film forming a three-phase contact angle. While the induction time is largely influenced by the degree of hydrophobicity of the particle, the degree of turbulence is governed by the bubble size. Generally, direct control of bubble size is not exercised by most mineral processing practitioners, in spite of its obvious importance. Studies to model the effect of bubble size on particle collection using fundamental approaches have been conducted (e.g., Anfruns and Kitchener, 1977; Webber and Paddock, 1983; Yoon and Luttrell, 1989; Dai et al., 1999). However, these models have been validated under highly idealized laboratory conditions (micro-scale experiments using single minerals and uni-sized bubbles), far from resembling those existing in practical industrial applications. Fundamental studies to interpret the effect of bubble size on particle collection in industrial environments are largely absent in the literature. Partly because of this lack of practical knowledge, many mineral processing practitioners perceive laboratory “bubble size” studies to be valuable academic exercises, but not something that can be directly applied to daily production issues."

Jan 1, 2011