Search Documents

By R. Switalski, M. Schafer, R. Pintabona, M. Kritzer, B. Lukajic, S. Janosko

Methane gas caused an eight-month shutdown of mining operations at the Mill Creek, Phase 3, Tunnel. The gas-related shutdown occurred as the tunnel was advanced to an approximate distance of 2,700 feet, which constitutes approximately18% of the total tunnel length. The construction of an emergency ventilation shaft, a comprehensive program of de-gassing wells and an expanded gas monitoring system were used to mitigate the gas condition. When complete, this tunnel will be utilized to convey and store combined storm and sanitary sewage collected from a portion of Cleveland, Ohio and ten suburbs. This paper will provide an overview of gas related remedial measures and explain how these measures were integrated into the project to ensure safe tunneling conditions.

Jan 1, 2007

By Lucien Weber

In the Shanghai area, the soil conditions are such that bearing piles have become an essential foundation part of the new highrise buildings. In order to reduce the settlements under the high working loads of about 2300 kN/pile, the Chinese building authorities require the pile tip to penetrate into the compact sand layer, situated at approx. 60-70 m depth. No H-piles have yet been tested under these conditions in Shanghai. This paper describes the driving of 8 H-bearing piles with 4 different shapes and with lengths varying from 45 to 75 m. Dynamic measurements are performed during driving and after a wait time of approx. 40 hours in order to assess the change in bearing capacity in function of time and in order to get an idea about the resistance distribution along the piles by using a stress wave analysis program (CAPWAP). One pile is equipped with channels between the flanges for executing verticality measurements with an inclinometer. However, this test has not yet been performed. One month after driving, two piles of 75 m length are statically loaded both in vertical and in horizontal directions.

Jan 1, 1987

By W. F. Visser

The growing availability of information and data analysis capabilities of recent years provides new opportunities for improving the performance of mining operations. By using real-time measurements and artificial intelligence, it is possible to respond faster to changing conditions, while accurate and timely information permits rapid evaluation of changes and fast business improvement decisions. This article presents a blueprint for alignment of systems, organizational design, and management practices to leverage these developments in performance-driven operations management in mining and mineral processing. The first component of the blueprint is a performance framework with a system of key performance indicators for production control that can be used across organizational levels. This system places improvement at the core of management activities, giving greater importance to improvement skills at lower organizational levels, so companies can leverage available information for improving operational control. Secondly, the blueprint defines an organizational structure that strengthens performance improvement with technological and change management capabilities. Finally, the blueprint proposes alignment of management practices, covering the optimization of short-interval controls, the application of an improvement project portfolio management system that determines the ownership of improvement projects, and the coordination of controls across the organization. This combination of systems, organizational design, and management alignment supports rapid decision-making at the right organizational level. Introduction of the presented blueprint for operations management enables mines to leverage the developments in information and analysis capabilities to improve the performance of operations.

By G. J. Joy

Although rates of pneumoconiosis in coal miners have declined substantially in the United States since the passage of the Federal Coal Mine Health and Safety Act of 1969, new cases continue to occur, including cases of rapidly progressive disease. In contrast, Australia's underground coal mining industry has reported few new cases of pneumoconiosis for more than 20 years. Mortality from coal workers' pneumoconiosis in official health statistics and the prevalence of pneumoconiosis among miners screened in X-ray surveillance programs are also lower in Australia. The U.S. National Institute for Occupational Safety and Health (NIOSH) was requested by both industry and labor stakeholders to examine this issue, with the ultimate aim of reducing the rate of pneumoconiosis among U.S. coal miners. A number of factors, including coal dust exposure, silica exposure and coal rank were examined as potential contributors to the above noted differences. Comparison of coal rank data from each country did not illuminate the issue. Air sample data from the coal mining industries in both countries show that coal dust levels in Australian mines are somewhat higher than those reported in similar U.S. mines; however, quartz exposure for Australian miners is lower than for many U.S. miners. If quartz is contributing to the greater number of cases of pneumoconiosis in the United States, more effective dust control measures, as well as an independent exposure standard for respirable quartz in coal mining, should be implemented to reduce this potentially disabling condition.

Jan 1, 2012

By Kim Wiwchar, Elizabeth Mbaja, Lynne Dang, Jim Furey, Anita Marks

"Suncor Energy Inc., located north of Fort McMurray, Alberta, commenced pilot scale operation using a CPT 4’ diameter flotation column in March 2003. This larger scale trial follows two previously successful flotation column bench scale tests. They included an April 2002 trial with a 2.4” inner diameter column from the University of Alberta and a 20” diameter CPT column in August 2002. The column receives middlings stream feed from one of Suncor’s deep cone separation cells and is operated in parallel with a set of WEMCO flotation cells. The recovery, tails losses, and concentrate quality are being compared between the two systems. The column, to date, has been tested with all types of run of mine ore grades. Variables such as wash water flow and temperature, sparger nozzle size and location, sparger air/water flow rates, and column residence time has been adjusted to achieve better recovery and final product quality.Used in many mineral processing applications, column flotation is primarily used for the final stage of sulphide cleaning and flotation of phosphate or iron ore. As well, mechanical cells are often used in combination with a column to retrofit an operation and to produce a cleaner product.Initial results prove that this is the first successful application of a flotation column in an oilsand application. If viable, it will be an inexpensive process for recovery of bitumen from a middlings stream and able to produce a final product suitable for froth treatment.INTRODUCTIONSuncor’s oilsand is surface mined from the Athabasca Oilsand deposit north of Fort McMurray, Alberta. The oilsand is then mixed with hot process water (HPW) and the bitumen is slurried in a pipeline. Large separation cells as shown in Figure 1 float off the bitumen product, which is then steam or static deaerated and sent to Secondary Extraction for further cleaning. The tails stream from the cell is sent to the Final Tails Pumphouse (FTPH) for processing. The tailings flotation froth product gets recycled to the separation cell oilsand feed. The tailings are pumped from the FTPH to tailings ponds. The middlings stream is drawn off the separation cell approximately 9’ from the froth overflow level. It runs down, by gravity, to the scavenger banks for bitumen recovery. It was from this stream off of the Line 6 Separation Cell that the feed to the Canadian Process Technologies Inc (CPT) flotation column was taken."

Jan 1, 2004

By S. Z. Pethö, H. Yilmaz

South Deep Mine is currently undertaking numerous voidfilling projects using low strength aerated cement products. Representative samples from one such site, were taken and tested for the load deformation behaviour under uniaxial loading conditions. The process of sample collection, laboratory preparation and testing are explained in detail. The results of testing were analyzed and the critical aspects pointed out as a design consideration to be implemented as part of the quality control and assurance program. Design aspects and underground application of the aerated cement product are discussed for the particular site on 58 level SV1. A simple instrumentation has been designed and installed to enable monitoring of any future movements in this area. A quality control and assurance process has been formulated enabling all aspects of the support installation in this excavation to be signed off.

Jan 1, 2003

By Dan Brown

Two drilled shaft foundations were subjected to axial load tests in order to measure the influence of drilling fluid on performance. Other than the differing drilling fluids, the shafts were constructed with great care to ensure identical conditions. The results indicate superior performance in both side shear and base resistance of the shaft constructed using a polymer over that of the shaft constructed using bentonite drilling slurry.

Jan 1, 2002

By I. Campbell, P. C. Jones, E. G. Potter, R. P. Taylor

"The Cobalt embayment is a large domain of Paleoproterozoic clastic sedimentary rocks that unconformably overlies the Archean Abitibi greenstone belt. Regionally extensive sills and dikes of Nipissing diabase, emplaced circa 2219 Ma, occur throughout the embayment and are the preferential host to gold-bearing polymetallic vein systems on the Merico-Ethel property, near the northeastern margin of the Cobalt embayment. These gold-bearing, polymetallic veins are predominantly east-west-trending, steeply dipping, discordant calcite- quartz vein systems that formed close to the time of crystallization (within ~15 m.y., based on Pb-Pb ages) of the Nipissing diabase. The ore mineralogy is complex in character, typically comprising sulfides, arsenides, native metals (gold and silver), and specular hematite, preferentially concentrated along the interface between silicate and calcite gangue. A simplified sequence of mineral deposition in the veins is: (1) "Early-stage" pyrite ± chalcopyrite hosted in quartz ± chlorite gangue; (2) "Main-stage" polymetallic (Cu + Co + As + Ag + Au + Bi ± Pb ± Ni ± U) sulfides, arsenides, and native metals hosted in calcite gangue; and (3) "Late-stage" calcite flooding ± galena. Wall-rock alteration in Nipissing diabase is restricted to narrow (<5 cm) haloes of calcite-chloriteepidote- bearing assemblages, whereas a weak alteration halo of specular hematite, calcite, and allanite-epidote has been observed in the surrounding sedimentary rocks. In terms of their age, geology, mineralogy, paragenesis, and morphology, the gold-bearing vein systems at Merico-Ethel closely resemble the silver-sulfarsenide vein deposits of the historic Cobalt and Gowganda mining camps. These observations indicate that the Au-bearing veins are variants of the Ag-vein systems and as such, have a common genesis belt. L’Échancrure de Cobalt est un large domaine de roches sédimentaires clastiques d’âge Paléoprotérozoïque qui reposent en discordance sur la ceinture de roches vertes d’Abitibi d’âge Archéen. La Diabase de Nipissing, mise en place vers 2219 Ma et qui constitue un réseau de sills et de dykes d’importance régionale, est présente dans l’ensemble de l’échancrure et constitue la roche-hôte principale des systèmes de veines aurifères-polymétalliques de la propriété Merico-Ethel, près de la bordure nord-est de l’Échancrure de Cobalt. Ces veines à minéralisation aurifère et polymétallique constituent un système de veines de calcite-quartz sécantes d’orientation principalement est-ouest et à pendage fort qui se sont formées peu de temps après la cristallisation de la Diabase de Nipissing (à ~15 Ma près, d’après les âges Pb-Pb). La minéralogie de la minéralisation est complexe; elle consiste typiquement en sulfures, en arséniures, en métaux natifs (or et argent) et en hématite spéculaire, préférentiellement concentrés à l’interface entre les silicates et la gangue de calcite. La séquence de déposition simplifiée des minéraux dans les veines est : (1) «Stade précoce» pyrite ± chalcopyrite encaissés dans une gangue de quartz ± chlorite; (2) "Stade principal" sulfures polymétalliques (Cu + Co + As + Ag + Au + Bi ± Pb ± Ni ± U), arséniures, et métaux natifs dans une gangue de calcite; et (3) "Stade tardif" calcite massive ± galène. L’altération pénétrative de la Diabase de Nipissing est confinée à des halos étroits (<5 cm) présentant des assemblages marquées par la présence de calcite-chlorite-épidote, tandis qu’un faible halo d’altération en hématite spéculaire, calcite et en allanite-épidote est noté dans les roches sédimentaires environnantes. De par leur âge, leur géologie, leur minéralogie leur paragenèse et leur morphologie, les systèmes de veines aurifères de Merico-Ethel ressemblent beaucoup aux gîtes filoniens d’argent-sulfoarséniures des camps miniers historiques de Cobalt et de Gowganda. Ces observations indiquent que ces veines aurifères constituent une variante des systèmes des veines argentifères et qu’elles partagent"

Jan 1, 2009

Perhaps one of the most important conferences or symposia which our Institute has conducted, was the joint Aus. LM.M./AJ.M.E. meeting held in Canberra in May 1978, with the theme International Resource Management (Woodcock, 1978).We were privileged to witness active participation in the meeting by outstanding personalities from the mining and metallurgical industries of Australia and New Zealand, the United States of America, Canada and the United Kingdom and to hear addresses on subjects of international significance to the mining and metallurgical industries.Our Institute is one concerned with professionalism.The principal objects of The Institute as described by our founders include, &quot;promoting the arts and sciences connected with the economical production of the useful minerals and metals, and the welfare of those in the industries, by meetings for social intercourse, and the reading and discussion of professional papers, and to circulate by means of publications amongst its members and associates, the information thus obtained&quot;.Sir Maurice Mawby (1968) said in his Presidential Address to the Institite, &quot;the most important aspect of these objects was the promotion of the arts and sciences of the mining industry&quot;.Why is it then, that a large proportion of the papers given at the meeting in Canberra dealt with world wide social aspects of the mining and metallurgical industries, rather than the technology, the arts and sciences of mining and metallurgy as principal factors in international resource management?The answer is quite simple of course, and that is that the social and political factors are the principal factors which create the demand for basic raw materials and in the long term determine the costs and prices of the commodities which our professional abilities are drawn upon to produce.

Jan 1, 1979

By Antonio Rivera

On Nov. 13, 1985, Colombia&apos;s Ruiz volcano erupted, killing an estimated 25,000 people and burying several villages. Damages were estimated to be about $US300 million. The following is an account by SME member Antonio Rivera of the volcanic activity that led to the eruption. His account also includes a description of the geography and some geology of the affected area. Mining operations in the area were mostly unaffected, although some operations were forced to close until the roads leading to them could be repaired. Introduction The Ruiz volcano is located on the Central Cordillera of Colombia about 28 km (17 miles) southeast of Manizales, the capital of the state of Caldas. Ruiz is one of nine volcanoes that form a complex volcanic chain within the middle portion of the Central Cordillera. The Cordillera has 30 other volcanoes in the southern part of Colombia. Ruiz volcano Ruiz&apos;s elevation is 5200 m (17,060 ft). It is covered by an ice cap estimated to be 20 m (66 ft) thick at its summit, an area that covers 17 km2 (6.5 sq miles). Drainage is composed of several rivers that flow into the Magdalena River on the east and Cauca River on the west. The rivers flowing to the east are Guali, Azufrado, Lagunillas, and Recio. The rivers that flow to the west are Claro, Molinos, and Chinchina. There is a road from Manizales to El Refugio, a ski area located on the northeast flank of the volcano at 4800 m (15,750 ft) in elevation. The Ruiz volcanic complex was built in two stages. The first is a shield type of volcano (mainly lavas) formed about a million years ago. The second is a younger stratovolcano overlaying the ancient one. It consists of lavas and pyroclastics and was built over the past 500,000 years. Twenty-four eruptions of Ruiz are known to have occurred during the last 14,000 years. Its products mainly consist of lava flows, pyroclastic flows, mudflows (lahars), and directed lateral explosions. Historic eruptive record 1595 - Debris avalanche, blast, pyroclastic flows, mudflows, ash flows, and ash fall. 1828-1829 - Ashes (phreatic). 1831-1833 - Gas emissions and ashes. 1845 - Mudflows and pyroclastic flows. 1985 - Sept. 11- Fumarolic activity, phreatic eruption, ash fall, and small mudflows. 1985 - Nov. 13 - Ash and pyroclastic fall, major destructive mudflows (magmato-phreatic eruption). From 1845 through 1984, Ruiz volcano always had a slight fumarolic activity. It was restricted to the crater area. In November and December 1984, the fumarolic activity increased and the first ash emission and vapor-sulfur formation started. Small local earthquakes accompanied these volcanic activities. The volcano had a small erup¬tion on Sept. 11, 1985. It was manifested by phreatic explosions that ejected fragments of the vent and formed ash deposits 25 mm (1 in.) thick around an area 2.5 km (1.5 miles) from the crater. Fine material was blown by the wind and reached Manizales and neighboring areas, producing a small layer of ash up to 10 mm (0.4 in.) thick.

Jan 2, 1986

After the Loma Prieta Earthquake, which caused major damage to viaducts in the Bay Area, the California Department of Transportation set up a test programme for foundation piles. Funderingstechnieken Verstraeten B.V., beter known as Fundex, was approached, since one of the piling systems of Fundex, named Tubex, is extremely suitable in areas sensitive to earthquakes and we were very much interested to prove the capabilities of this piling system. Equipment For the installation of Tubex and Tubex grout-injection piles special piling equipment is required. Since our company is not only a contractor, but also a designer and manufacturer of piling equipment, all special equipment for our range of foundation techniques is designed and built by our own piling equipment department. For the installation of both Tubex piles and Tubex grout-injection piles for the Caltrans test programme, the following pieces of equipment were selected: a) Fundex F12 piling rig b) Drill table c) Hydraulic powerpack d) Grout mixing unit and high pressure pump

Jan 1, 1993

The Mining Foundation of the Southwest (MFSW)promotes public understanding and education related to the mining industry. Towards this goal, the Foundation has funded several projects from donations and fundraising activities. The MFSW was incorporated in 1993 by combining the Mining Club of the Southwest and the Mining Club of the Southwest Foundation. The Mining Club began in 1971 as a social organization. It provided members of the mining community an opportunity to meet. The club also provided a means for public education about mining. In the early 1990s, the club’s efforts were directed mainly toward educational activities. And in 1992, discussions began concerning incorporation into a non-profit foundation to further the public understanding of mining. In 1983, the American Mining Hall of Fame was inaugurated to honor significant contributors to the industry and profession. The Hall of Fame serves to educate people about prominent persons associated with the mining industry, present and past. The honorees number 75. Plaques commemorate their induction and are on display at the Arizona Historical Society’s Museum in Tucson, AZ. The combined honors ceremony and banquet have remained one of the fund raising activities.

Jan 1, 1999

By David E. Albus, Ahmadreza Mortezaie, Bidjan Ghahreman

The structural evaluation of seismic performance of an existing hospital in Long Beach, California, required spring constants of foundation elements. The structure included support by deep foundation elements comprised of belled (underreamed) caissons. The available relationships in the governing building code (ASCE41-13) to compute axial stiffness is not applicable due to the belled configuration of the caissons. The large diameter of the bells required consideration of the foundation medium to the axial stiffness; a detail not clearly described in ASCE 41-13. Furthermore, prescriptive equations in ASCE 41- 13 used to estimate lateral stiffness only consider pile groups with the assumption that the only source of lateral stiffness is the axial reaction of individual piles. These assumptions were invalid for the project at hand where all caissons are configured as single foundation elements, not a pile group. In the present work, the approach taken to estimate seismic stiffness of single-belled caissons is described which accounts for the elastic behavior of the foundation medium below the bell base and lateral behavior of single-pile shafts. Results of the work provide a more satisfactory derivation of the spring constants consistent with current modeling methods. INTRODUCTION Seismic evaluation of an existing hospital in Long Beach, California, required geotechnical investigation followed by site-specific ground motion analysis. This evaluation was required by the Office of Statewide Health Planning and Development (OSHPD) in order to meet the requirements of the Structural Performance Category 4D (SPC-4D) published as a part of the 2016 California Building Code, CBC (Section 3412A). SPC-4D utilizes ASCE41-13, as modified by OSHPD, and involves two seismic performance objectives: BSE-1E (20% probability of exceedance in 50 years) and BSE-2E (5% probability of exceedance in 50 years). Spring constants and capacities of foundation elements were needed for evaluation of the structural performance of the building subjected to these two performance objectives. Our review of the as-built foundation plans indicated that both shallow footings and caissons were used for support of the structure. The plans demonstrated that all caissons are belled (under-reamed) and are individual, i.e. not part of pile groups. In this paper, the subject site condition and foundation elements are described first. This is followed by details of assessing spring constants and vertical capacities for belled caissons. The new requirements of the 2016 CBC concerning the evaluation of critical facilities will likely entail evaluation of other structures with belled caissons due to the more extensive use of these foundations in the past. This paper proposes a method to address the conditions of individual belled caissons not explicitly considered in the current code provisions.

Jan 1, 2018

Probably no other country or coutinent has so many rich deposits of various different minerals as Australia. Long ago in the days of my boyhood in the old land the marvellous discoveries of high percentage copper at Burra Burra, Peak Downs, Yudanamutana, and other mines, was one of the principal themes of conversation in mining circles whilst the specimens of malachite, azurite, etc, brought home by returning miners were the admiration of my boyish eyes.Later on the WalIaroo and Moonta mines still further helped to heighten the reputation of Australia as a copper-producing country. During the 21 years that the writer has been resident in the Australian colonies, other mineral deposits have sprung into prominence, and with a Mount Bischoff for tin, a Broken Hill for silver and lead, and a Mount Morgan for gold, Australia can now boast that it has had within its borders the leading mines of the world, in four different minerals, and still at least maintains that pre-eminence in gold, silver and tin. To the miner from the old land, Australian mining is at first a revelation and a wonder. In very many instances he looks in vain for the regular strike and dip of the veins he has been accustomed to&apos;Smooth hanging and foot alls are often wanting. &apos;Huge irregular deposits, like those mentioned above, viz., Burra Burra, Mount Bischoff, Broken Hill, and Mount Morgan, are mysteries that will take time to fathom-if, indeed, they are ever thoroughly understood and in many a smaller deposit there is much to interest alike the professor in the college and the miner in the mine.

By R. C. Earlougher

Jan 1, 1970

By W. K. Connor, O&apos

Thermal Treatment Technology Division Albany Research Center, U.S. Dept. of Energy Oregon. This evaluation included a characterization study and direct smelting tests conducted in a bench-scale electric arc furnace (EAF). In contrast to other thermal treatment technologies considered for these wastes (i.e., fluidized bed combustion), direct smelting in the EAF can process 100% of the wastes without prior beneficiation, and utilizes solid oxidant additions (in this case iron ore) rather than air to oxidize the carbon. This solid oxidant addition is advantageous because it results in the production of several value-added furnace products. These products include cast iron resulting from the reduction of the iron oxides, baghouse dust containing virtually all of the zinc from the residues, and a clean (nonhazardous) slag product suitable for recycle as concrete aggregate or construction fill. Offgas from the smelting furnace also holds potential as fuel gas for cogeneration. The direct smelting tests conducted thus far were successful at producing the desired furnace products, exhibiting the potential for complete recycle of the waste pile. A cast iron product of comparable quality to conventional cast irons was produced, at nearly 80% iron recovery to the metal. The slag product was determined to be nonhazardous, based on the EPA TCLP. Lead and zinc partitioning to the dust product was greater than 99%. The material balance over the furnace indicates that for every ton of feed processed, 540 lb. of cast iron, 600 lb. of slag, and 150 lb. of dust would be produced. Energy consumption was roughly 1.10 kWxh/lb of feed material. Prior experience suggests that these figures measured in the bench-scale furnace would translate to 0040 to 0.50 kWxh/lb at the industrial-scale.

Jan 1, 2000

By Claude Bazin, Jalna Lamontagne

"The operators of mineral processing plants collect daily samples from strategic process streams with a view to prepare production balances to assess plant performances. The rules to minimize the risk of systematic sampling errors are known and applied in many mineral processing plants. The mass of the sample to be collected is calculated to yield a target measurement reproducibility considering the fundamental error associated to the sampling of heterogeneous material. This paper demonstrates that this practice is partly valid if one does not account for the time variation of the ore composition during the day. The concept is demonstrated using samples collected on a 30 minute basis from different streams of a gold ore concentrator. Results show that depending of the natural variability of the stream characteristics the mass of the daily samples may not be the critical variable to obtain reproducible measurements. On the other hand the number of cuts taken during the day could impact on the variance of the measurements obtained from daily samples.IntroductionMineral processing plants may treat several thousand tons of ore every day to produce concentrate or impure gold ingots. The operation and performances of these plants are monitored on a daily basis through the collection of ore samples from various streams of the processing circuit. The samples are prepared and assayed to obtain the concentrations of target elements that are subsequently used to calculate the mass flowrates in the streams of the circuit and ultimately the distribution of the target metals for the estimation of the plant performances (Morrison, 2009; Lachance and Leroux, 2016).The acquisition of representative and reproducible samples is therefore the first step in the characterization of plant performances. The term representative sample is used here to indicate an unbiased sample, i.e. a sampling procedure that does not introduce a systematic error. Rules for the collection of unbiased samples are reviewed in the literature by different authors (e.g. Morrison, 2009) and are not discussed in this paper. The term reproducible indicates the dispersion of the measurements around the average value of a characteristic of a stream meets an acceptable level of variance. The reproducibility of a measurement process (sampling and analysis) is assessed by the relative standard deviation or coefficient of variation of the measurement that is a function of the sampling and assaying errors (Morrison. 2009; Gy, 1979). Usually the focus is put on the fundamental error of sampling whose variance can be controlled by the choice of the primary sample mass or adequate particle size reduction during the preparation of secondary or tertiary samples extracted for the chemical analysis. When a sample is taken from a stream that exhibits a time varying characteristic, the obtained measurement exhibits a variability that is not only a function of the sample mass but also of the natural variability of the ore in the sampled stream. This paper examines this aspect of the sampling of a time varying process on the reproducibility of composite samples for a day of production."

Jan 1, 2017

By Brian Maroney

In this paper an overview of the California Department of Transportation&apos;s (CALTRANS) bridge design criteria is presented. Special emphasis is focused upon seismic design and retrofit criteria. Topics include earthquake load definitions, foundation and structure type selection, structural earthquake analysis, and structure behavioral requirements.

Jan 1, 1993

By D. van Rensburg

Jointed rock slopes are generally stable, as there is no freedom of movement for blocks of rock. In an open- pit mining environment, blasting opens up space into which blocks of rock can fail, resulting in the common occurrence of slope failure. Prior to the blasting of a trim pattern, the immediate highwall is scaled, where loose rock material is removed by means of a mechanical scaler. As mining of the pit progresses, the height of the scaled highwall from the pit floor progressively increases. These highwalls are never scaled again for the remainder of the pit life, and time-dependant deterioration contributes to these highwalls becoming subject to rockfall and, sometimes, slope failure. This paper documents the development of a South African innovation, a remote-controlled mechanical highwall scaler, a world first for the mining industry. The scaler will enable open-pit highwalls to be scaled from crest to toe whenever the need arises. It will reduce the risk associated with highwalls and deliver on the Anglo American promise of producing safe, profitable platinum.

Jan 1, 2012

By M. Salimov, J. Sattarvand

The conventional visualisation method of remote equipment is through the installation of one or more cameras on the machine, and sending a live feed to the operator’s flat display. However, the performance of the teleoperation can be enhanced using better visualisation through virtual reality (VR). This paper presents the process of the design and manufacturing of a robotic platform that will be used in the next phase of the project for a VR-assisted teleoperated excavator. The robot consists of a loading boom and arm arrangement installed on the undercarriage of a CAT300-9D. All hydraulic cylinders are replaced with electric actuators, and crawling motors are substituted by electric motors. The pieces of the boom and the arm, as well as the bucket were designed in Autodesk Inventor, and manufactured from aluminium sheets using a desktop and CNC machine. Parts are joined by pins and welding as needed. An Arduino-based control system is developed for the robot, and motor controllers are used to convert the power commands from the microcontroller to the high-amperage actuators. The control system is capable of communicating with a wireless Play Station controller to operate remotely. The manufactured robotic excavator is planned to be utilised in multiple autonomy research projects.

Sep 1, 2021