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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 F. Habashi

The pioneer work on pressure hydrometallurgy was conducted in Russia at the end of the nineteenth, and the beginning of the twentieth centuries, by Karl Josef Bayer (1847-1904) and Vladimir Nikolyevitch Ipatieff (1867-1952), both working independently in Saint Petersburg. Bayer was studying pressure leaching while Ipatieff was studying the precipitation of metals and their compounds by hydrogen under pressure. Gradually, industrial applications took place first in the aluminium and later in the nickel industry. Today, the technology is well established in a large number of industries, such as uranium, gold, zinc, titanium, tungsten, and more recently copper.

Jan 1, 2004

A series of field and laboratory evaluations were conducted in order to characterize the effects of a Mann+Hummel SMF-AR® diesel particulate filter (DPF) system on the aerosols and criteria gases emitted by diesel engines. This system, with a durable sintered metal filter media and available active regeneration via an on-board electrical heater, has been considered for retrofitting diesel engines used in light- and medium-duty underground mining applications. Two DPF systems were installed on a forklift and locomotive from the underground mining fleet of the Vale?s Creighton Mine and evaluated over a 1,500-hour trial. This evaluation was complemented with field and laboratory emissions tests. The field tests were performed on the vehicles while at the Creighton Mine surface shop. During those tests, the emissions were assessed for the engines operated at hydraulic stall, high idle, and low idle conditions. The laboratory tests were executed at the diesel engine emissions laboratory at the National Institute for Occupational Safety and Health (NIOSH), here the DPF removed from the forklift was further evaluated at four steady-state engine operating conditions as well as at transient conditions using a custom-designed duty cycle. Very similar methodologies were used during field and laboratory tests to measure concentrations of aerosols and criteria gases in the diesel exhaust, both upstream and downstream of the DPF system. The concentrations and size distributions of aerosols were measured using a fast mobility particle sizer spectrometer, in exhaust diluted by a partial flow dilution system. The concentrations of CO2, CO, NO, and NO2 were measured in the raw exhaust using a Fourier transform infra-red spectrometer. Both field and laboratory emissions tests showed that the evaluated DPF systems were very effective in reducing aerosol emissions from all tested engines, and for all test conditions. The systems were found to have minor effects on gaseous emissions from those engines. The findings from this study should help the mining industry to better understand the benefits and challenges of using DPF systems to control the exposure of underground miners to diesel aerosols.

Aug 1, 2013

By C. Liu

Corrosion behavior of the stir zone in a friction stir weld of dissimilar A12024/AZ31 alloys was investigated in the immersion test in distilled water (pH=6) for different times. Microstructures and the distribution of chemical elements were analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Due to the difference in the corrosion potentials between A12024 and AZ31, the AZ31 alloy constituent in the stir zone was susceptible to the corrosion attack in the distilled water. The corrosion attack was found to occur in the narrow region of the AZ31 alloy adjoining the A12024 region, where there was a low ratio of anode-to-cathode surface area. The corrosion attack became more severe in the AZ31 alloy regions with increasing immersion time. The A12024 alloy region in the stir zone of the weld was protected by cathodic reactivity due to sacrificial anode AZ31 alloy.

Jan 1, 2007

By Z. Huda

The effect of various percentages of cold-working and recrystallization on the microstructure and hardness of commercially-pure aluminum plate, has been studied. The 'A critical deformation for the aluminum, has been determined. Experimentation involved cold rolling and recrystallization processes followed by quantitative metallographic practice and the hardness measurements. The raw material chosen was a plate of commercial aluminum which was cold rolled to different percentage of cold-work and then recrystallized by heat treatment at 150°C. The critical deformation percentage of aluminum was computed to be around 30% of cold-worked.

Jan 1, 2007

By M. El Tokhi, H. Arman, B. M. Amin

"This paper aims to overview some mechanical and physical features of the gabbroic rocks. The study has two phases: filed study/in-situ measurements and laboratory work. During the field studies, rock block samples were collected from different locations of the study area to represent the different types of the gabbroic rocks. Either core or rock samples for various tests were prepared from rock samples taken to the laboratory. The unconfined compressive strength (UCS), indirect tensile strength (ITS), point load index (PLI), Schmidth hammer rebound value (SHV), slake durability index (SDI), sonic velocity (SV) and unit weight (UW) test were carried out either on the selected rock block samples or core samples.INTRODUCTIONThe geology of the United Arab Emirates (UAE) has been divided into three major rock units (Lippard et al., 1986); an autochthonous succession, allochthonous units composed mainly of Mesozoic rocks and include the Sumeini Group (concomittent slope sediments), Hawasina Complex (basinal sediments) and the Semail ophiolite nappe (massive slice of former oceanic crust), that were emplaced as a series of thrust nappe in the Late Cretaceous and Neo-autochthonous sequence of Maastrichtian and Lower Tertiary sediments.The Semail Ophiolite (600 km long and up to 150 km wide) is thought by some authors (Glennie et al., 1990) to have been generated along a subduction related back-arc spreading axis during the Cenomanian-Turonian and was obducted onto the Arabian continental margin during the Campanian. Others, however, consider it to represent a primitive arc-spreading center related to oblique subduction Lippard et al., 1986). The Ophiolitic rocks in the study area comprise mantle and crustal sequences. The mantle peridotite and crustal gabbros are the dominant rock types of the exposed Semail Ophiolite north of the Hatta zone. This paper is only concentrated on the gabbroic rocks."

Jan 1, 2015

By E. Ghali

"Corrosion of support system components (e.g., bolts, mesh, plates) is a safety and economic concern in underground mines. This paper reports the results of a five-year study wherein corrosion coupons were installed at select locations in participating mines, recovered at regular intervals, analyzed for signs of corrosion, and tested to quantify loss in capacity. Complementary tests were conducted on recovered mesh and friction bolt specimens. The data provide insights into contributing factors for support systems corrosion, which aid in the selection of appropriate support strategies and reliable assessment of the useful life and need for rehabilitation of a support system.RÉSUMÉ La corrosion des composantes des systèmes de soutien (p. ex. boulons, grillages et plaques) est une préoccupation économique et de sécurité dans les mines souterraines. Cet article présente les résultats d’une étude de cinq ans pendant laquelle des coupons de corrosion ont été installés à des endroits spécifiques dans les mines participantes; ces coupons ont été retirés à des intervalles réguliers, analysés pour des signes de corrosion et mis à l’épreuve pour quantifier la perte de capacité. Des essais complémentaires ont été effectués sur les grillages récupérés et sur les échantillons de boulons d’ancrage. Les données aident à comprendre les facteurs qui contribuent à la corrosion des systèmes de soutien, ce qui est utile dans le choix de stratégies appropriées de soutien et pour une évaluation fiable de la durée de vie utile et du besoin de remise en état d’un système de soutien."

Jan 1, 2015

By L. Juteau

"""The north coast of the St. Lawrence River will be the scene of an industrial development during the coming decades"". The facts which underlie this statement are the occurrences of iron and titanium ore, the abundance of hydro-power and the availability of deep-water ports in this region. Havre St-Pierre, Sept-Iles, Port Cartier and Baie Corneau already exist as major ports and urban centers. The huge quartz deposit at Baie Comeau will be a decisive contributing factor in the development of a metallurgical plant in this area. Due to its purity, it lends itself, first of all, to the manufacture of glass of different kinds, being comparable to the quartz sands now used by the plate glass and glass container industries in the Montreal area, Moncton, N.B., Trois-Rivieres and - in the future - at Bécancour, Quebec. However, its high quality will also make it possible to use it as one of the main basic materials for the production of silicon carbide and ferrosilicon, and as a flux in metallurgical processes. It is intended, in this report, to offer conclusive proof of the economical importance of this large quartz deposit by presenting the results of the studies made to date."

Jan 1, 1971

By M. E. D. Raymont

"During the history of the sulphur industry there have been three distinct phases of production. Factors controlling supplies during these periods have shifted from demand for sulphur to demand for energy and a cleaner environment. The pattern of brimstone production is t raced through these phases and includes estimates of future supply; these indicate an involuntary excess production of some 20 million plus tons per year by 1980 unless some large-scale new uses are found. Traditional uses for sulphur, including fertilizer, chemicals, fibers, etc., are generally expanding slowly; how• ever, supply in ""by-product"" form alone will soon outstrip demand. The predicted oversupply situation can be corrected by the development of novel potential markets. Promising areas include construction materials, insulation and plastics, among others."

Jan 1, 1972

By H. Wilton Clark

"IntroductionTHE CANADIAN use of short-period delay-action detonators in coal shooting has been carried on for about two years, mostly in British Columbia, and this is a preliminary report on progress to date. Entire coal faces are being shot successfully with one application of electric current.The electric blasting cap came into use about the beginning of the century. The low-tension electric cap, the type most commonly used, consists essentially of a metal tube containing an initiating explosive. Two wires lead into the end of the cap and are connected inside the cap with a short 'bridge wire .of very high resistance. This •bridge wire is buried in a match-head of a readily ignitable powder composition. When current goes through the lead wires, the bridge wire becomes extremely hot and sets• off the match-head which, in turn, ignites the powder just below it in the tube. This explosion sets off the main charge of explosive. Thus, by connecting a group of caps to a source of electric .current, a number of charges could be exploded simultaneously. This immediately became of great value to mine and quarry operators. Explosives could now be used to break up large masses of material at one time, as against the older, slow method .of blasting small amounts with single charges.The next step was to develop a delay detonator which would allow charges of explosive to fire one after the other, one or two seconds apart. Such detonators allowed first blasts to relieve some rock burden before the next charge fired, giving the second charge an easier task in forcing out more rock, and so on for the rest of the series of charges."

Jan 1, 1953

By R. M. T. Raja Ismail

Shipping and stevedoring industry is going to witness a massive increase in the amount of containers to be handled while land constraints become more critical. Offshore transfer operations hence offer a preferable solution to deal with the surge in cargos rather than to expand the port outwards. Recently, there has been increasing research interests on offshore crane automation. Suspended cargos in a ship-mounted crane system are caused to swing due to the vibratory motion of the ship induced by ocean waves, which can lead to collision between cargos and deck. Therefore, it is vital for offshore crane systems to satisfy rigorous requirements in terms of safety and efficiency. This paper presents the modelling and control development for offshore boom crane systems. A second-order sliding mode control law is proposed for trajectory tracking and sway suppression control, making use of its capability of actuator chattering alleviation while achieving high tracking performance and preserving strong robustness. The asymptotic stability of the closed-loop system is guaranteed in the Lyapunov sense. Simulation results indicate that the proposed controller can significantly reduce the effect of disturbances coming from gusty waves and other dynamic loadings.

Aug 1, 2013

By D. R. Murray

"In 2017, Nutrien Allan Potash remediated a portion of the concrete liner in the production shaft. A set of underslung work platforms and collection boxes were used in conjunction with hydraulic splitters, jackleg drills and hand chippers to excavate and remove the broken concrete. New concrete was placed with the original pressure relief design, using a shaft slip form. Shortly after excavating, it was found that the estimated breaking rate and amount of original concrete in-situ was under estimated. Fifteen feet of excavated concrete (2719cu.ft) and ten feet (of replaced concrete was completed on April 28, 2017, and operation of the production shaft was returned to mine operations. During February 2019, Nutrien Allan Potash began remediation of a portion of the concrete liner in the service shaft. The project is different than the 2017 project, as the remediation has occurred during normal running operations and occurred only on night shift. Rather than hydraulic splitters and hand chippers, the new method includes a concrete saw and mechanical excavator from a working platform. The selected method is based on the lessons learned from the 2017 project in the production shaft. The service shaft project was scheduled to be completed in July, 2019. INTRODUCTION Nutrien Allan Potash is located approximated 75 km east of the city of Saskatoon, Saskatchewan, Canada. There are currently two shafts at Nutrien Allan Potash: the Production Shaft and the Service Shaft, transporting people and material from surface to a depth of 3,335 ft. The Production Shaft was completed in 1967, with one section of grey cast iron tubbing installed in the Blairmore formation between the 1605 and 2037 ft Levels. A second set of cast iron tubbing was installed in the Duperow formation between 2203 and 2463 ft Levels in 1999. The remainder of the concrete as of todays standards is designed as a pressure relief liner. The Service Shaft was completed in 1968, with one section of grey cast iron tubbing installed in the Blairmore formation between the 1600 and 2048 ft Levels. A second set of cast iron tubbing was installed in 1981, with 169 ft installed through the Duperow formation. The remainder of the concrete as of todays standards is designed as a pressure relief liner. PRODUCTION SHAFT REMEDIATION During the second quarter of 2015, the Mine Engineering team were notified of an area of concern in the production shaft. The shaft specialists of Golder Associates Ltd (Golder, formerly Alan Auld Canada) were contacted to complete an inspection of the production shaft liner with emphasis on the area of concern. Based on the inspection and documentation review, it was determined that the concrete at the 2804 foot elevation had been broken out for some time and was retained with #8 rebar bolts with resin encapsulation. The broken concrete was encroaching on the clearance to the conveyance."

Jan 1, 2019

By Jaime Meléndez Martínez

Recent interest in unconventional reservoirs motivates our work in laboratory measurements of seismic anisotropy. Seismic anisotropy is the variation in speed of a wave as a function of its direction of propagation. Analyzing anisotropy in unconventional reservoirs is important since anisotropy leads, for example, to differential stresses upon loading and could affect hydraulic stimulation (Reinicke et al., 2010, Zimmermann and Reinicke, 2009); in this sense, laboratory measurements are an important tool to study seismic anisotropy at small scales which can aid in the characterization of larger formations. The purpose of this work is to describe the laboratory methodology used to simultaneously measure ultrasonic P and S-waves in three different directions from a single core sample. Elastic anisotropy of a Proterozoic sedimentary rock from south-west Alberta is investigated. In metamorphic rocks seismic anisotropy is caused by preferred mineralogical alignment or foliation. Assuming a transversally isotropic medium, arrays of compressional and shear piezoelectric ceramic transducers were mounted on a sample trimmed from a core to measure travel times of ultrasonic P-waves and S-waves as a function of confining pressure at directions perpendicular, parallel, and oblique to the plane of foliation (bedding). Results show strong anisotropy agreeing with the assumption of a transversely isotropic medium. Dependence of travel times and hysteresis effects can be observed when pressurizing and depressurizing.

Jun 1, 2012

By S. K. Shaha, W. Kasprzak, D. L. Chen, J. Friedman, F. Czerwinski

The role of solutionizing conditions within the T6 heat treatment of the cast Al-Si-Cu-Mg alloy with micro-additions of Zr-Ti-V was assessed in terms of their influence on microstructure and mechanical properties. As a solution treatment, a single step process at 485 and 510oC and a two-step process at 510 and 525oC for varying time intervals from 0.5 to 9 h, were examined. In all cases, solution treatment was followed by isothermal aging at 150oC for 100 h. The microstructural analysis showed that the solution treatment changed the eutectic silicon morphology from needle-like, present after casting, to spherical shape in the T6 state and that the extent of changes was strongly influenced by temperature and time. The Cu- and Mg-rich phases completely dissolved during solution treatment while the Fe-containing phase, Al8Si6Mg3Fe, remained partially in the microstructure. The Ti, V and Zr containing phases, Al13Si2Ti3Zr and Al3Si26FeTiV10, present in as-cast state, were partially dissolved during solution treatment, reducing their size by 10 - 48%. The studied alloy reached the maximum ultimate tensile strength of 335 MPa and yield stress of 303 MPa for two-step solutionizing with a total time of 4.5 h. It is concluded that the two-step solution treatment resulted in higher tensile properties than the single-step process.

Jan 1, 2015

By J. A. Finch

Individual mineral cyclone performance curves were determined for the four major minerals at two lead-zinc concentrators. Sizing was by screen and cyclosizer down to approximately 10 um, with lead , zinc and iron as saying of each size fraction. The performance curves were similar in shape and located according to the mineral specific gravity, Pm. The curves displayed a discontinuity at the fine end and a magnitude of short-circuiting of fines to the underflow which increased with Pm. Mass fraction of water to the underflow was only a guide to this short-circuiting. Sharpness of separation seemed in dependent of Pm. An inflection in the over-all performance curve was shown to be a consequence of the individual component mineral performance. A general relationship was observed showing that the flow regime of classification changed from laminar/ intermediate to turbulent with increasing cyclone feed size. Individual mineral size reduction for the four major minerals at one of the concentrators was also determined. Size reduction of the silica was greater than that of the galena, in contradiction to their accepted relative grind-ability. The observation did correlate with silica being much coarser than the galena in the feed to the ball mill. It is suggested that the silica acted as a buffer to the galena.

Jan 1, 1977

By Claude Bazin, François Robichaud

"The control of the operation of semi autogeneous grinding (SAG) mills is mainly achieved through adjustments of feed rate, water addition and speed of rotation. With the introduction of image based sensors it is possible to have on-line measurements of the size distribution of the ore feeding a SAG mill. This information could be used for the development of a control strategy to regulate a SAG mill feed size distribution to a set-point. The control of the size distribution is carried out by adjustment of the speed of the ore extractors underneath the ore stockpile. The potential and difficulty associated with the implementation of such control are assessed using a multivariable statistical analysis of data collected from the operation of the grinding circuit of the Agnico-Eagle Goldex mine in Val d’Or, QC. A control strategy for the ore feed size distribution is assessed using a simulator of the ore stockpile operation.INTRODUCTIONThe popularity of autogeneous (FAG) and semi autogeneous (SAG) grinding mills has been increasing over the last 20 years (Napier Munn et al., 1996). These mills use the ore or a combination of ore and steel balls as the grinding media. Since the ore is used as a media for the size reduction the mill ore feed size distribution impacts the performance of the mill. Several papers were recently published on this subject (Dance et al.,2011; Wennen & Murr, 2011; Dance & Valery, 2011; Allaire et al., 2011) showing the advantages of preparing the feed size distribution to maximize the circuit throughput or mill efficiency (Wennen & Murr, 2011; Dance & Valery, 2011; Allaire et al., 2011). With the availability of particle size sensor based on image analysis of the ore on a conveyor (Partanen et al., 2001; Bobo et al. 2004; Edwards et al., 2002; Wei & Craig, 2009) it is possible to control the size distribution of the ore feeding autogeneous or semi autogeneous mills (Partanen et al., 2001).This paper describes a method to control a size distribution index to a set point via the manipulation of the speed of the extractors that withdraw the ore from the stockpile feeding the grinding circuit. The paper consists of 4 sections. The first section describes the considered grinding circuit. A statistical analysis of the collected data on the grinding circuit is presented in the second section. This analysis demonstrates the necessity of using real-time adaptation mechanisms to develop a control strategy for the size distribution of a grinding circuit. The third section describes the method used to simulate the ore stockpile operation and the last section describes the preliminary development and assessment of a control strategy of size distribution of the ore feeding a SAG mill."

Jan 1, 2013

By X. Cao, J. J. Jonas, Wanjara. P., J. Gholipour, E. Dalgaard

The linear friction welding (LFW) behaviour of near-ß titanium alloy Ti-5Al-5V-5Mo-3Cr (Ti- 5553) was investigated. Microhardness measurements were performed in order to evaluate the mechanical properties of the welded material. The linear friction welded (LFWed) Ti-5553 was examined with optical microscopy and scanning electron microscopy (SEM) to evaluate the microstructure’s response to the thermomechanical conditions. Characterization of the welds included analysis of the microstructural features of the weld region and thermomechanically affected zone (TMAZ) in relation to the parent material.

Jan 1, 2010

By Wignall. T. K., J. De Geoffroy

Statistical models are fitted to the observed distributions of eighteen characteristics of the population of commercial porphyry deposits of North and South America. The statistical base required for the formulation of the statistical models includes 58 commercial porphyry-copper-molybdenum deposits of the Cordilleran Belt from which geological, geometric and economic data were collected. Predictive and composite models are derived from the statistical study to assist explorat10n. planning, engineering studies and fmanc1al analyses as required for the development of new porphyry deposits in the Cordilleran Belt.

Jan 1, 1973

By S. Borle

The microstructural features produced in friction stir welded AZ31, AZ80 and AZ91 alloys are examined when different welding parameters are applied. The microstructures primarily consist of a-Mg grains with a-Mg + Mg17A112 colonies, however melted films of Mg17A112 are produced in AZ91 alloy when high rotation speeds are applied. When the rotation speeds are slow, or the travel speeds are fast the Mg17A112 were incorporated into the stir zone, however they do not exhibit an elongated lamellar morphology associated with melted films. In the case of AZ80, the extruded base material contains a smaller fraction of Mg17A112 and few of these phases are observed in the stir zones. The results are explained based on the dissolution rate and melting temperatures of Mg17A112 controlling the overall morophology and fraction of phases in the stir zone.

Jan 1, 2011

By Mosquera. J.

Tailings Storage Facilities (TSFs) are vast structures that respond to site-specific characteristics, rate of production, placement techniques, and the physical and mechanical properties of tailings. As a common denominator, TSFs are in some degree vulnerable to failure due to liquefaction, poor management, slope instability and/or unusual climatic events. In practice, stability of TSFS is determined by calculating a minimum Factor of Safety (FOS) using the Limit Equilibrium Method (LEM). However, it has been proven that relying exclusively on the limit equilibrium approach is not accurate because it is basically a static method that does not take into account the stress-strain distribution and displacement experienced by the constitutive materials of a TSF. In order to overcome these limitations of the LEM, the finite element method - Shear Reduction Technique (SRT) has been used as a more reliable tool for TSFs stability assessment. This paper presents a comparative stability analysis between an upstream tailings storage facility (UTSF), and a water retention tailings dam (WRTD) under static and pseudo-static states using simplified and rigorous LEMs and the SRT. Additionally, and taking into consideration the intrinsic uncertainty of tailings properties, sensitivity and probabilistic analyses in the form of Monte Carlo Simulation (MCS) and the Point Estimate Method (PEM) are applied to determine the Probability of Failure (Pf) and Reliability Index (ß) of each TSF. It is shown that the friction angle of UTSF?s foundation and the core?s cohesion of the WRTD are the main variables that govern stability. Further analysis shows that the WRTD has a higher reliability index and a lower probability of failure than the UTSF.

Aug 1, 2013