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By Edward Martinez

Due to its unique properties, chrysotile asbestos is used in many diversified applications. In recent years, a better understanding of the structure and properties of chrysotile has evolved due to the research efforts of many investigators. A summary of the results of some of these investigations is given. An attempt is made to show the relationships between the properties of chrysotile and its crystal structure. Examples taken from the literature are cited in which methods have been developed for modifying the properties to improve the performance of asbestos in some applications. These include the effect of pH on the positive zeta potential and the addition of sodium silicate to improve filtration characteristics. The dehydroxylation and formation of forsterite when chrysotile is heated are also discussed.

Jan 1, 1966

By Xun An

Slag from an electric slag cleaning furnace was injected with methane and air mixtures to facilitate the recovery of copper and cobalt. The effects of methane-to-air ratio, gas flow rate and temperature on the reduction and metal separation were investigated. The results showed that over 90 percent copper and up to 60 percent cobalt could be recovered from the slag with a gas utilisation of around 70 percent, as calculated by thermodynamic simulation. Methane-to- air ratio was a major factor affecting the rate of reduction under the present experimental conditions. Further, injection of gaseous reductants greatly enhanced the coalescence and settling of entrained metal droplets. A reduction mechanism is proposed and the factors influencing the coalescence of copper droplets are discussed.

Jan 1, 1998

By E. W. Williams

THE Ontario Research Foundation has developed a process for producing low-density steel shapes by direct reduction of iron oxide powders. The process is a combination of reduction, sintering (without compaction), and carburizing, and has been described by Cavanagh (1). Iron oxide powder, in the form of mill scale or highly concentrated iron ore, carefully sized, is poured into a porous mould. A reducing agent, generally coke breeze, is placed around this mould in a heat resistant sagger which is sealed off and heated to 2,000°F. for a number of hours. The coke/ ore ratio, the particle size distribution, the temperature and time of soaking, and the size and shape of the reduced product, determine the densities and carbon contents attained. The Defence Research Board sponsored a programme of research into some of the mechanical properties of the material (which was named Controlled Density Steel) and this paper is an account of various factors which govern the tensile strength of the steel. The ?practically attainable range of density is from 1.5 to 5.5 gm./ cc. but higher densities are obtained on hot working. This paper, however, is restricted to discussion of results for moulded products.

Jan 1, 1957

By P Cesare, S Munro, D Wandel, R A. Bearman

Consideration of the processing plant operational envelope is a key factor in production scheduling,and therefore mine planning, for any mining operation. In many cases hard-wired or regressionbased tonnage-grade-recovery relationships are used as mine planning constraints and as a means of valuing the system output. In extensions of this type of approach, various regressions can be used to describe throughput limits, based on a number of global metallurgical parameters.The ultimate position for the optimisation of a mine plan and production schedule is to have a full process plant model running as an integrated part of the mine planning exercise. A plant model suitable for this needs to have all the required sensitivities to input parameters such asfragmentation, grade, mineralogy, strength and hardness. The model then needs to convert these to performance measures for the plant, which include recovery, throughput, product size distributions, energy consumption, water use and operating cost.In this paper an approach is outlined that takes this view and then goes beyond it to provide a full, time-based bottleneck identifi cation and valuation tool.Using such an approach it becomes possible to run mine plans and production schedules in windows of days, weeks, months and over the life-of-mine with a time-enabled process model acting as the active constraint. In this way virtual bottlenecks can be identifi ed for various mine plans and schedules well ahead of time. The value of de-bottlenecking can be defi ned, not just at a plant scale, but in terms of the overall mining operation, and the data can be used as the basis for capital investment decisions.CITATION:Bearman, R A, Cesare, P, Munro, S and Wandel, D, 2014. Incorporation of a full process plant model as an active constraint for mine planning and production scheduling, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 121–128 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By R. Venugopal, V. K. Saxena, Veerendra Singh

"Ore morphology plays a vital role during the milling and liberation of minerals. This study was carried out to understand the role of mineral crystallography and mineral interfaces on the milling and liberation processes. Data related to mineral crystallography, Vickers Hardness Number and beneficiation processes were collected from literature, and detailed statistical analysis was conducted to relate these parameters. Review of the crystallographic information of minerals present in ores indicates that molecular weight and cell parameters significantly affect milling and liberation characteristics. Mineral interfaces were classified into the three categories of coherent crystals, semi-coherent and incoherent crystals, and breakage behaviors were studied. The studied cases revealed that these material interfaces control the micropore properties that play a vital role in the initiation of intergranular and intercrystalline fractures which occur in siliceous manganese ores and dolomite as a result of thermal treatment. In contrast, banded hematite jasper and coal exhibited a much more complex fracture pattern due to their coherent interfaces and finer physical associations. This study explains the effect of the various types of interfaces on milling, and the approach can be helpful in developing a methodology to enhance mineral liberation with minimum energy consumption.IntroductionComminution is a vital unit operation in the mineralprocessing, cement-making, power-generation and pharmaceutical industries. Its importance in mineral beneficiation operations is increasing every year as a result of the growing need to exploit lower-grade ore bodies and process reject materials (Blazy et al., 1994; DOE, 2005). Low-grade ores require significant energy during grinding to liberate the valuable minerals, which are further separated from the gangues by various beneficiation methods. Various attempts have been made to enhance mineral liberation during grinding to minimize energy consumption. Most of these studies focused on the analyses of the compression mechanism, chemical additives, thermal treatment, microwave treatment and electric disintegration (Klimpel and Austin, 1982; Norgate and Weller, 1994; Bearman et al., 1997; Kumar et al., 2010; Wang et al., 2011; Singh et al., 2012). However, many of these efforts had limited success, and there is a need to see the problem from a fresh perspective."

Jan 1, 2015

By Michael Clar

Total suspended solids (TSS), generally referred to simply as sediment, is one of the four major parameters of water pollution associated with surface mining activities. The other three para¬meters are iron, manganese and pH. Currently the Environmental Protection Agency (EPA) is in the process of developing and implement¬ing effluent limitations for these pollutants pursuant to section 301 of the Federal Water Pollution Control Act Amendments of 1972, 33 USC 1811.1 To date, effluent guidelines for existing point sources have been published, and guidelines for new sources are forthcoming. The effluent limits which have already been developed for TSS have been subjected to some controversy.1 Some industry spokesmen have indicated that they may be unable to meet these effluent limitation guidelines for TSS. The industry claims that in certain areas the suggested limit is unattainable since high suspended solid loads already exist in streams due to numerous and various sources of nonpoint pollution which include agriculture, silviculture and urban construction for which no TSS effluent limits have been set. An opposite viewpoint asserts that the TSS limitations are too lenient since permit data from the Regions (U.S. EPA Regions) indicates present compliance for several companies under more stringent TSS limits. The experience at the Centralia mine in Washington is one example.2

Jan 1, 1977

By Brian T. Hamilton, Richard Piliounis, Cian Murphy

"The Eglinton-Crosstown Light Rail Transit line is a 19-kilometre corridor with a 10-kilometre underground portion currently being constructed by Metrolinx in Toronto through a densely populated urban environment. Tunneling works are being completed through two separate design-bid-build contracts that include consideration for a phased handover to a follow on contractor who will take ownership of the tunnels, including warranties, and will complete the stations and remainder of the system through a PPP delivery model including maintenance of the system for 30 years. Warranty provisions, settlement apportionment, tunnel leakage, potential delays and conflicts between contractors are just some of the risks the team managing tunnel contract integration had to consider when developing the PPP contract. This paper will present an overview of how these risks were assessed and allocated through the contracts and the strategies adopted to minimize risks to Metrolinx while ensuring successful procurement was maintained. INTRODUCTION The Big Move is a 25 year, $50 billion ($-CAD) plan for coordinated and integrated transportation in the Greater Toronto and Hamilton Area (GTHA) in Ontario, Canada. This plan has been initiated by Metrolinx, a division of the provincial government of Ontario, and its vision, goals and objectives are rooted in creating a high quality of life; a thriving, sustainable and protected environment; and a strong, prosperous and competitive economy for the GTHA. The Big Move will triple the length of rapid transit service in the GTHA to 1,725km, significantly increase the percentage of the GTHA population living within two kilometers of rapid transit, reduce commute times to an average of 77 minutes per person per day and decrease greenhouse gas emissions from passenger transportation per person by 29%. Work is currently underway on several projects and more than $16 billion ($-CAD) of the planned investment has already been committed. A key project that forms part of this commitment is the Eglinton Crosstown Light Rail Transit (LRT) Project which is being delivered in the City of Toronto under Metrolinx’s Rapid Transit (RT) Program. This complex and sizeable undertaking has been broken into a number of separate contracts comprising: LRT Vehicles contract; Eglinton West Tunnels Project; Eglinton East Tunnels Project; and a Public-Private-Partnership (PPP) contract to complete the underground stations, at-grade stops, all rail infrastructure and systems and to maintain the entire system for 30 years. The PPP contract, which includes an initial capital portion of approx. $5.1 billion ($-CAD), has recently been awarded to Crosslinx Transit Solutions, a Special Purpose Vehicle (SPV) consortium comprised of SNC Lavalin, Aecon, Dragados and EllisDon."

Jan 1, 2016

By Errol L. Montgomery

The region of metalic ore deposits in northern Chile, southern Peru, western Bolivia, and northwestern Argentina occurs in arid zones at altitudes as high as 4,600 meters. Because surface water supplies are meager, new mines require unexploited sources of water. Prolific groundwater aquifers occur in salar basins in this region of the Andean Highlands. Exploration water wells have been constructed and aquifer characteristics have been tested in eight salar basins. Results indicate groundwater quality is good. Aquifer transmissivity and storage computed from results of pumping tests indicate maximum production water well capacities in excess of 170 liters per second.

Jan 1, 1982

By A. C. Mollison

In November of 1983 a fire inside the autoclave caused the curtailment of operation of the Kidd Creek pressure leaching facility. Subsequent repairs and recommissioning of the autoclave in 1984 allowed Kidd Creek to increase its production of zinc as originally planned. This paper describes the operation of this process from 1984 to 1988 and details major mechanical work carried out on the vessel in 1.988:

Jan 1, 1990

By J W. Glatthaar, M Mavotoi

The occurrence of fluorine in the copper/gold concentrates produced by Ok Tedi Mining Limited has provided a series of challenges to metallurgists since 1988. Although fluorine is distributed throughout the gangue minerals contained within Ok Tedi ores, itsÆ presence in talc and phlogopite (naturally floating fluorosilicates) has proven to be the predominate sources of fluorine in the final concentrate. Initial treatment for the fluorosilicates consisted of the use of a carboxy-methyl cellulose depressant added to the flotation cleaners. This was superceded in 1998 with the installation of a fluorine reverse flotation process for the removal of naturally floating fluorosilicates from the final concentrate when the fluorine content of the final concentrate exceeds smelter-defined trigger points. The fluorine reverse process is similar to by-product molybdenite concentrate production in that sodium hydrosulfide is used to depress copper/gold flotation whilst allowing the fluorosilicates to float. The process was installed in two parallel modules (to match the existing grinding/flotation modules at Ok Tedi), each consisting of a closed rougher/cleaner circuit configuration. Both rougher and cleaner cells are Jameson Cells from MIM Process Technologies, with the selection based on both processing characteristics and available construction space. This paper discusses both the nature of fluorine in-, and its removal from-, Ok Tedi copper/gold concentrates.

Jan 1, 2003

By Raja V. Ramani, Sachin Shankar

"Re-entrainment refers to dislodgement of particles deposited by both atmospheric and nonatmospheric processes and their subsequent insertion into a flowing field. Formation of sand dunes, snow drifts, soil erosion and fugitive dust emissions are a few examples of the natural occurrence of re-entrainment. Re-entrainment studies have been done for the estimation of potential hazards from nuclear fallouts. The phenomenon of re-entrainment has been utilized for the cleaning of wafers and filters. Re-entrainment is associated with both surface and underground mining activities. However, studies on dust re-entrainment in mine atmospheres are limited. Understanding the re-entrainment phenomenon is important because dust particles lying seemingly harmless on the ground and adhering to numerous surfaces can get re-entrained and become a health and safety hazard.There are significant differences in the kind of re-entrainment encountered in underground mines and those in other fields of interest. These major differences are air velocity, direction of air flow, particle size, amount of particles, and time of exposure. While numerous studies have been done in other fields to identify the role of interacting variables and their contribution to the mechanisms of re-entrainment, no similar reported work is available for dust in mine atmospheres.In this paper, recent research efforts on re-entrainment are reviewed. The most suitable form of representing re-entrainment in underground coal mine atmosphere is presented. Various approaches to studying re-entrainment phenomenon in mines are also outlined.In the mineral industries, formation of dust particles of widely varying sizes is a natural outcome of the fragmentation required in mining the solid resources. Fine particles in mine atmospheres, particularly in the respirable size range, are a threat to the health and safety of the miners when present in high concentrations. In 1980 the National Academy of Sciences (NAS) Committee on the Measurement and Control of Respirable Dust in Mines recommended that the spatial and temporal characteristics (of fragments produced in coal mining) need to be understood so that the exposure of workers to the dust can be controlled. Recently several studies have been performed to understand the fundamental behavior of the airborne respirable dust in mine airways (Bhaskar, 1987; Qin, 1988; Polat, 1989; Bode, 1990)."

Mar 1, 1992

A viable flow sheet of the sorption-flotation technology for gold recovery from low-grade ores and concentrates using powdered activated carbon modified by organic compounds as the sorbent-bearer has been developed. The powdered activated carbon, with high kinetic ability and sufficient specific area, was selected as the all-purpose gold cyanide complex-bearing sorbent which is active during flotation. To improve carbon adsorption capacity and to provide the required floatability its porous structure was filled with a quaternary ammonium compound which can extract gold cyanide complexes and render additional flotation properties to the carbon. To optimise the process and to simplify the layout, adsorption and flotation processes were carried out simultaneously in a mechanical flotation cell. The proposed technology was used for extended and pilot-plant tests of sorption-flotation gold recovery from 0.6 g/t Au final tailings and 2.0 g/t Au gravity tailings. The extended tests were carried out on Taseevskaya (Chita Region) flotation tailings, whereas pilot-plant tests were conducted on Kommunarovskaya (Krasnoyarsk Region) gravity tailings passing to cyanidation, followed by processing with filtration technology. Additional gold recovery from Taseevskaya final flotation tailings was 50.8 per cent. Gold recovery from Kommunarovskaya final gravity tailings was 92.5 per cent. Compared to the complete sludge process conventionally used at the plant, gold recovery was increased by 7.5 per cent due to lower gold losses in the liquid phase and conversion of the refractory non-cyanided metal into a carbon concentrate. This paper presents the experimental results of gold adsorption onto powdered activated carbon modified with quaternary ammonium compounds (sorbent-bearer) as well as sorbent-bearer flotation with various collectors from cyanide solutions and pulps.

Jan 1, 2005

By Nick Rose, Mathieu Veillette, Matthew King

"The Teck Highland Valley copper (THVC) mine is located approximately 55 km (34 miles) southwest of Kamloops and approximately 20 km (12 miles) west of Logan Lake, BC, Canada (Fig. 1). Mining at THVC is conducted at three openpit operations comprised of Valley, Lornex and Highmont with a total annual output on the order of 300 kt (330,000 st) copper concentrate and 5 kt (5,500 st) of molybdenum concentrate. The Phase 8 pushback in the Valley Pit (Fig. 2) was mined from 2011 to 2016. Successful slope steepening occurred in the later stage of the pushback with the implementation of presplit blasting in 2015 and 2016.This article summarizes the investigation and design approach including: structural analysis, kinematic assessments of bench breakback potential, development of discrete fracture networks (DFNs) to characterize discontinuity fabric, rockfall modelling, 2D anisotropic limit equilibrium and 2D distinct element modelling, assessment of potential kinematic failure modes affecting double benches with 3D distinct element modelling and improved blasting techniques using e-dets. THVC is currently undertaking a mine life expansion involving the pushback of the west wall of the Valley Pit above Phase 8 to extend the mine life to 2029. Engineering geologyThe east wall slope in the Valley Pit is comprised of a 350-m (1,148-ft) thick sequence of glacial valley sediments that occur along the Highland Valley (Fig. 2), exposing an overburden slope up to about 225-m (740-ft) high below the crest of the ultimate east wall. The glacial overburden units consist of pro-glacial outwash and glaciofluvial deposits, glacial outwash sands and gravels interbedded with till and alluvial fans consisting of cross-bedded sands and sandy-gravels. Lacustrine sediments occur within the mid to lower portion of the glacial sequence and contain intervals of low-shear-strength clays and silts. Two large (1.3 and 7 Mt or 1.4 and 7.7 million st) waste rock buttresses were required to maintain slope stability using slot-cut and fill mining methods, as described in Fortin et al. (2011).The Valley porphyry deposit occurs in the central portion of the late Upper Triassic Guichon Creek Batholith, which intrudes assemblages of the Permian Cache Creek and Upper Triassic Nicola groups. The Valley deposit occurs in an area of intense fracturing near the intersection of the northerly trending Lornex Fault and the northwest to westerly trending Highland Valley Fault."

Apr 1, 2019

By G. B. Harris, C. W. White

A study to investigate the recovery of base metals, notably copper, nickel, cobalt, zinc and manganese from iron-free concentrated chloride solutions using ion exchange was undertaken. In such solutions, apart from nickel and, to a lesser extent manganese, these metals are present predominantly as complex anions, and therefore conventional separation techniques based on cationic resins are not applicable. The results demonstrated that zinc, copper and cobalt can all be separately recovered leaving nickel and manganese behind. Specifically, zinc is a major nuisance element in nickel and cobalt processing, and the testwork showed that it can be preferentially removed prior to copper and cobalt. Selective resins for both copper and cobalt were identified, and it was demonstrated that the strength of the chloride background matrix has a significant effect on the efficiency of separation. An additional major advantage in such systems is that stripping can mostly be effected with water. Finally, some observations are made on the hurdles that must be overcome when attempting to introduce and commercialise new technologies.

Jan 1, 2015

By R. Cavanagh

Studies relating to the fixation of sulfur by reaction of 4 to 8 mm diameter cylinders of calcined limestone or dolomite with high strength sulfur dioxide in the temperature range 880°C to 1020°C were undertaken. Dolomites are far superior in sulfate capacity and reactivity than dense limestones even at high strength SO2. The sulfation reaction was first order with respect to SO2 concentration below 100 percent. Zero reaction rate at 100 percent SO2 concentration indicates that sulfate was the exclusive reaction product and that sulfite had no role in the reaction. At relatively low SO2 concentrations gaseous diffusion through the reaction product layer has a marked effect on the rate. As SO2 concentrations were increased up to 100 percent more complex rate controlling mechanisms unfold. By sectioning partially reacted dolomitic limestone pellets a moving interface was observed. Reaction ceased because of pore plugging for dense non-porous limestones at 30% conversion. With dolomitic material virtually complete sulfation of the calcium was observed. S.E.M. analysis showed that the average atom ratio Ca:S was 1.01, thus supporting the argument that little if any of the magnesium was sulfated.

Jan 1, 1996

By K Faure

At Sams Creek a peralkaline granite porphyry dyke hosts gold-bearing sulfide-quartz-siderite veins. The granite dyke intrudes Ordovician-Silurian metapelite and quartzite, and has thin lamprophyre dykes along its contacts. The mineralised veins and the granite and lamprophyre dykes have been deformed during several phases of folding, the youngest of which is Early Cretaceous. The granite has been hydrothermally altered, with early magnetite-siderite¦biotite alteration overprinted by sulfide and quartz-siderite veins and quartz-perthite-albitesiderite-pyrite-rutile¦sericite alteration assemblages. The sulfide veins are composed of arsenopyrite + pyrite ¦ gold ¦ galena ¦ sphalerite ¦ chalcopyrite ¦ pyrrhotite ¦ graphite, with minor quartz and siderite. The gold contains significant silver (up to 30.8 wt per cent) and ranges in fineness from 692 to 844. Immiscible liquid-rich fluid inclusions, in quartz protected from recrystallisation by enclosing arsenopyrite, contain carbonic liquid that homogenised at temperatures of 320 - 355¦C. The Sams Creek gold deposit is distinguished from the orogenic gold deposit type by its stockwork veining, magnetite-siderite¦biotite alteration, high sulfide content, ore mineralogy and the absence of mineralisation in the metapelite country rocks. Features of the Sams Creek gold deposit do not fit neatly into existing classifications of granite-related gold-bearing deposits. The peralkaline composition of the Sams Creek granite and the absence of molybdenite and paucity of chalcopyrite, are major points of difference with gold-rich porphyry copper deposits. The presence of a lowsulf idation-state ore mineral assemblage, carbonate alteration and carbonic fluid inclusions at Sams Creek are typical of many of the reduced granitic intrusion-related type of gold deposit. However, notable differences are: the reduced type granites are metaluminous and calc-alkaline; and Sams Creek only has high As in contrast to elevated Bi, W, As, Mo, Te, and Sb in the reduced type. The Sams Creek deposit also shows affinities with gold deposits associated with alkaline magmatism, and it appears to be a new variant of this type as an As-Au deposit associated with a peralkaline granite and lamprophyre.

Jan 1, 2004

By J. Kolacz

"A new sensor based sorting system has been developed, providing a possibility for laboratory scale testing and further scale-up of the separation results to the industrial operation. The new system contains different sensors as: X-ray detectors, visible light cameras, NIR cameras, ultraviolet cameras and magnetic sensors, in the same sorting unit. The sorting unit allows advanced calibration options and fine-tuning of the installed sensors to achieve the best separation effect under controlled conditions. Finally, the processed material can be analysed and separated by the rejection mechanism, similarly to the industrial scale operation. At the same time, the process is carried out with limited amount of material allowing detailed statistical calculations for processed particles and all sensor types. The optimal settings and sensor types are specified for the industrial application.The paper describes the scale up of the results achieved for iron ore and coal, where the test work was first carried out using the new laboratory sorting system and where the industrial scale sorting system has been built, in the final stage. The industrial scale sorting results showed a very good correlation between the laboratory and full scale operation. Thanks to the detailed study carried out in the laboratory equipment, the settings of the sensors in the full scale operation provided much better separation efficiency. It was especially important to provide proper setting for the X-ray sensor data calculations, which can be very critical for achieving the best results. During the industrial scale sorting of coal, the input material had 40-55% rock particles as the direct source of ash in the coal stream. The optimal laboratory unit settings and transferring these settings to the industrial sorter, provided 98.8% efficiency for removing rock particles with only few % losses of coal."

Jan 1, 2016

By W. K. Gummer

"THE LOCATION of Canada's present aluminum industry is determined by availability of hydroelectric power, and ready access to ocean transport facilities. The chief raw material for the production of the metal is imported by ship over several thousand miles of water. In times of freedom of shipping and uncontested movement this provides the industry with its cheapest method of operation. However, during the early part of the last decade the general conditions of ocean and rail transportation were such that interest in the treatment of materials other than bauxite was greatly stimulated. This was the case not only in Canada, of course, but in most other countries.Canada has no deposits of bauxite and much research was carried out on other aluminous materials, chiefly silicates, in an effort to develop more or less economic and feasible methods of treatment. In the United States, this research was considerably more extensive. Some projects were early shown to be of little or no value, whereas others, including the widely publicized lime-sinter and soda-lime-sinter methods, became important. In North America, however, apart from the application of the sinter method to the hitherto waste-product (red mud) of the normal Bayer plant operation, none of these processes contributed appreciably to the production of aluminum during the war. In certain European countries, on the other hand, largely because of their situation with regard to bauxite deposits, they had a more general application, and Germany, for example, produced alumina from clay, ashes, and slag by at least four methods."

Jan 1, 1952

By M Araos, I Onederra

A novel explosive formulation that substitutes the use of ammonium nitrate (AN) with hydrogen peroxide (HP) as the main oxidising agent has been developed and tested as part of an Australian Coal Industry Research Program (ACARP) project. The main objective was to provide a step-change solution that has the potential to completely eliminate NOx fumes in blasting. The development of this HP/fuel-based explosive started with a comprehensive detonation characterisation program, consisting of unconfined velocity of detonation (VOD) measurements of samples at different diameters, densities and void sensitisation techniques. VOD results showed that the HP/fuel-based explosive mixtures behaved similarly to non-ideal commercial explosives; in that way mixtures could be tailored to achieve specific detonation performance targets. The next stage of testing in this development involved preliminary confined tests to evaluate the rock breakage potential of the HP/fuel-based explosive mixtures. Fully instrumented single-hole tests were conducted in a limestone quarry. Results from these preliminary trials confirmed the rock breakage performance of HP/fuel-based explosive mixtures. The confined VOD measured in one of the tests was 5100 m/s in a 102 mm diameter blasthole at a density of 0.96 g/ml. The corresponding borehole pressure measurement of this HP charge was 2.61 GPa with a detonation temperature of 2921°C. Based on near-field accelerations, both HP and ANFO charges displayed similar attenuation characteristics in the test conditions. Post-blast observations indicated that the breakage performance of the HP mixtures clearly reflected the in-hole detonation performance measurements obtained, confirming the ability of these explosive mixtures to both fragment and effectively displace the rock mass under evaluation. Further research work continues with the future commissioning of a prototype mixing and delivery unit, the successful completion and analysis of data from multiple-hole trials, and further characterisation work associated with product stability, reliability and performance under different geotechnical conditions.CITATION:Onederra, I and Araos, M, 2015. Detonation and breakage performance of a hydrogen peroxide-based explosive formulation, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 565–574 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By J. Fogarty, J. Sofra

The mobile telecommunications sector is one of the fastest growing industries worldwide. However, increasingly stringent environmental regulations are placing pressure on manufacturers to accept responsibility for end of life products. The companies are therefore exploring avenues to recover the valuable components contained within the mobile telecommunications devices thus reducing the quantities of toxic components going to landfill. Batteries used to power the devices, are typically based on either nickel-cadmium, nickel metal hydride, or lithium ion cells. They contain toxic metals including nickel, cadmium, lithium, potassium, lead, and cobalt in a complicated arrangement of battery cells surrounded by a metals then plastic casing. The Ausmelt Catalytic Waste Converter (CWC) for waste treatment and recycling is well suited to processing all three mobile phone battery types for the recovery of valuable metals in marketable products that can be recycled to industry without turning out harmful levels of toxic emissions. Ausmelt recently demonstrated the capabilities of its CWC by continuously processing 4.5 tonnes of nickel-cadmium batteries. Using Ausmelt's pilot plant facility in Australia, the nickel-cadmium batteries were processed to produce a nickel iron sulphide (matte), a cadmium fume and a final slag which satisfied CS toxicity leach test criteria and was safe f<~r disposal to landfill. This paper explores the commercial development of the Ausmelt CWC for treating each of the three battery types in light of (a) the outcomes of the recent demonstration, and (b) the current and expected future availability of batteries for processing.

Jan 1, 2000