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By Noel N. Moebs

Five LANDSAT lineaments in the coal mining region of southwestern Pennsylvania were investigated by the Bureau of Mines to determine their geologic character, relation to subsurface conditions, and the means of discriminating one from another. The investigation included earth resistivity and very low frequency (VLF) electromagnetic traverses, soil moisture sampling, and a correlation with coal mine roof conditions. The lineaments could not be detected by the methods used, suggesting that they might be a surface phenomenon unrelated to subsurface geologic structures or roof stability in coal mine workings beneath.

Jan 1, 1987

By Khaled M. Mohamed, Michael M. Murphy, Ted M. Klemetti, Heather E. Lawson

"The design of rib support systems in U.S. coal mines is based primarily on local practices and experience. A better understanding of current rib support practices in U.S. coal mines is crucial for developing a sound engineering rib support design tool.The objective of this paper is to analyze the current practices of rib control in US coal mines. Twenty (20) underground coal mines were studied representing various coal basins, coal seams, geology, loading conditions, and rib control strategies.The key findings are: (1) any rib design guideline or tool should take into account external rib support as well as internal bolting; (2) rib bolts on their own cannot contain rib spall, especially in soft ribs subjected to significant load—external rib control devices such as mesh are required in such cases to contain rib sloughing; (3) the majority of the studied mines follow the overburden depth and entry height thresholds recommended by the Program Information Bulletin (PIB) 11-29; (4) potential rib instability occurred when certain geological features prevailed—these include draw slate and/or bone coal near the rib/roof line, claystone partings, and soft coal bench overlain by rock strata; (5) 47% of the studied rib spall was classified as blocky—this could indicate a high potential of rib hazards; and (6) rib injury rates of the studied mines for the last three years emphasize the need for more rib control management for mines operating at overburden depths between 500 ft and 1,000 ft.IntroductionEfforts to improve the stability of underground mine ribs have continued for decades. These efforts by mining professionals around the world persisted throughout the 1990s and 2000s as well, though much of this work focused on rib support methodology and selection of proper support for a specific location. Despite these efforts, it is unfortunate that there has been a continual occurrence of rib-related fatalities in underground coal mines. While overall improvements in rib safety have been achieved, the average fatality rate is still about 1.3 fatalities per year over the last 18 years (Jones, 2014).To manage and control the rib hazard, rib support is used in U.S. coal mines. The current rib support methods for U.S. mines fall into two main categories: rib control based on intrinsic support systems and those based on external support systems. Intrinsic or rib-bolt support requires a roof bolting machine that can install a bolt fixture into the rib. Furthermore, the appropriate level of support needed to control the ribs with an intrinsic-based support system as well as the design parameters for those support systems for various mine conditions have not been established in U.S. coal mines. Furthermore, surface control systems are often an integral part of these support systems and must be considered in the system design."

Jan 1, 2015

By J. A. Harle

Introduction When considering power in Alberta, there automatically come to mind ideas of either hydro or thermal generation, leaving in one's thought an uncertainty as to which one would propose. There is frequently an obvious source of power in some locations on our fastflowing rivers, the major possibilities being described in the report on Surface Water Supply and Water Power of Alberta issued by the Alberta Government in 1948, but it must be realised when reading that report that the sites so described will require extensive geological and other surveys before they can be exploited, and account must be taken also of the transmission distances involved in each instance. From a conservation point of view, where water power can be economically developed and power transmitted to the load centres, this should be done, and our thermal resources should be husbanded for our coming generations, especially if our water resources are falling owing to glacial shrinkage.

Jan 1, 1951

By R. F. Kehrman

Voice Frequency (VF) electromagnetic trapped miner location devices were tested for reliability and effectiveness in 93 coal mines. Tests included uplink pulsed CW, downlink pulsed OW and downlink voice evaluations. Frequencies were 630, 1050, 1950 and 3030 Hertz. Overburden depths varied from 70 feet to 1550 feet. Successful communications were established at 91 of the 93 mines. Data indicate the transmitters and receivers will operate in practically all coal mine environments. Reliability and accuracy as location devices appear to depend on noise, depth and presence of metallic objects which distort the magnetic field. In addition, theoretical models appear to define best case situations in terms of noise and conductivity. Minor hardware problems were encountered, mostly involving battery contacts, switches and antenna cables on the receivers. No hardware problems occurred with the transmitters.

Jan 1, 1978

By Robert J. Evans

Reclamation costs were estimated for 20 coal surface mining operations in the Appalachian and Midwestern Coal Supply Districts (these two districts were divided into three multi-State regions). The cost data were obtained through onsite observations, interviews with mining company personnel, and the authors' cost estimating procedures. The cost data are presented in terms of dollars per acre, dollars per ton of coal produced, and dollars per cubic yard of overburden moved during backfilling. The reclamation process is divided-into three cost categories: Premining planning, backfilling, and revegetation. The average total reclamation costs for the three regions are $2.77 per ton of coal produced and $8,168 per acre. As the result of comparisons of reclamation costs by region, by mining method, by slope, and by size of operation, the most important reclamation cost difference is between area mining methods ($1.73 per ton) and contour mining methods ($3.81 per ton). The Federal Bureau of Mines conducted this study to determine as accurately as possible the actual costs involved with the reclamation of coal surface mined land done in conjunction with active mining operations.

Jan 1, 1975

By Michael Radnor

The purpose of the study was to 1) examine the social and economic impacts of surface mine blasting in relation to variations in conditions of terrain and geology, population density and type, levels of ground motion and air blast; 2) consider technical, legal and government policy issues; and 3) examine the potential, nature and extent of surface mine blasting impacts and its regulations upon both communities and surface mining companies. Phase One designed the empirical research and technical analyses of Phase Two, focused upon surface coal mining and quarrying in the Eastern U.S. Several broad conclusions are evident: 1) blasting is not the major issue for communities or surface mine companies; 2) while the number of instances of severe cracking or annoyance are relatively small, the impact can be severe for individuals immediately involved; 3) blasting/drilling cost curves tend to rise significantly at intervals below 1.0 particle velocity, in/sec, dependent upon the size of a permit area and the size of a mine; and 4) the legal, complaint, cost and density analyses do not suggest the need for a general lowering of present regulations.

Jan 1, 1981

By M. U. Oko

"Monitoring of all the waste streams from Falconbridge's Sudbury Operations to determine whether they meet the required standards, has been performed for many years. By 1969, however, the number of samples being collected had become so large that a complete revision of the existing systemwas necessary. Sites previously designated by name only, were numbered, clearly marked on the ground and on maps which were circulated to all concerned. The types of pollutants analyzed were determined and specified for each sampling location and a chemical analysis report form was designed. The sampling schedule has been computerized to produce a periodic listing of the samples to be taken and the analyses required.An area map showing sampling sites, chemical analysis report form, spill report and a computer print-out example are shown and explained.EVOLUTION OF FALCONBRIDGE'S WASTEWATER. MANAGMENT SYSTEMFalconbridge Nickel Mines employs some 4500 people, operates nine mines, four mills and a smelter in the Sudbury basin. The operations are geographically fragmented into four widely separated locations, the Falconbridge operations east of Sudbury and the Onaping operations in Levack Township being the two largest of the four. The Lockerby area located to the west and the Lindsley Mine just north of Sudbury are now under development. The magnitude, the diversity and nature of the operations are such that constant vigilance is needed to prevent inadvertent damage to the environment. The purpose of this paper is to describe the information system used to monitor and control waste-water disposal on Falconbridge's properties to help ensure the maintenance of effluent standards satisfactory to the Ontario Water Resources Commission (OWRC) and to the Ontario Department of Health."

Jan 1, 1971

By James F. Devine

The radial, vertical, and transverse components of particle velocity were recorded by Bureau of Mines investigators along gage arrays extending in one or two directions for 145 to 3,170 feet at five quarries. Of the 39 quarry blasts, 12 were instantaneous blasts, 5 were of the one hole per delay type, using millisecond delayed caps, and 22 were multiple hole per delay type employing millisecond delay detonating fuse connectors. Charge weight per hole ranged from 8 to 1,500 pounds, and the charge weight per delay interval, including the instantaneous blasts, ranged from 25 to 4,620 pounds.

Jan 1, 1966

By Timothy M. Barton

The U.S. Bureau of Mines is conducting research to assess the effectiveness of different chain pillar designs in maintaining gate entry stability. A particular concern is ground control for deep-cover 1ongwalls located at depths in excess of 1,000 ft. The study described in this report was performed in two experimental sections in one longwall headgate section which contained three different pillar designs. Two of the designs used conventional abutment pillars, while the third was a total-yielding pillar system. Both of the test areas were located under 1,800 ft of cover. The purpose of this study was to evaluate the effectiveness of these three pillar designs for gate road stability. As the longwall mined passed the test areas, Bureau engineers monitored entry convergence, roof sag, and changes in roof quality. The study indicated that the all-yield system performed nearly as well as the better of the two abutment pillar systems; but all of the three designs would have failed to provide acceptable stability for second panel mining without considerable artificial support.

Jan 1, 1989

By F. H. Samuel, A. M. Samuel, H. R. Ammar

Casting imperfections, such as porosity, in cast aluminum components greatly influence their fatigue properties. The effect of porosity on the fatigue life of 319-F and A356-T6 aluminum alloys was studied, where the porosity characteristics on the fracture surfaces of fatigue-tested samples were examined using SEM and image analysis. The results show that porosity has the most detrimental effect on the fatigue life: 92 % of all tested samples fractured due to porosity acting as the main crack initiation site. In the absence of casting imperfections, other microstructural aspects such as slip bands can be responsible ( 4 % ). The porosity was investigated in terms of the pore size at the sample fracture surface and its location i.e. near the edge or close to the interior. It was found that porosity located far from the sample surface (edge) has less influence on the fatigue crack initiation, and the fatigue life decreases as the size of the pore located at the sample surface increases. Aluminium

Jan 1, 2006

By N Bezuidenhout

The performances of ten field-scale experimental final covers were evaluated over an eight-year period. The covers were evaluated as part of the rehabilitation of acid generating coarse coal reject dumps and opencast coalmines in the Northern KwaZulu Natal province in South Africa. The main purpose of the experimental covers was to restrict rainfall infiltration into acid generating coal discard. The mean average rainfall over the monitoring period was 839 mm with 84 per cent occurring between October and April. The average evaporation was 2100 mm. The site is described as a ædry siteÆ since the evaporation exceeds rainfall by a significant margin. Approximately 30 per cent of rainfall infiltrated the uncovered cells. Rainfall infiltration into the fine coal discard was reduced to 20 per cent and 15 per cent for a 300 mm and 500 mm cover respectively. Infiltration was reduced to ten and 12 per cent of rainfall for fine coal discard provided with a 1000 mm double soil cover and a compacted bottom layer. This relatively high infiltration was probably caused by moisture being entrapped in the bottom retentive layer, and not being released by evapotranspiration. The best performing cover comprised 1000 mm single soil with a compacted bottom layer and infiltration was reduced to four per cent of rainfall. Rainfall infiltration into sloped cells varied between seven per cent and 14 per cent of rainfall. The computer software, SoilCover, was used to predict infiltration and moisture content in the cover. Predictions of rainfall infiltration were accurate, but were less accurate for covers where the hydraulic properties of field compacted soils were not adequately characterised. Oxygen ingress was significantly reduced for cells provided with a 1000 mm cover. Oxygen concentrations were generally below one per cent, with the exception during exceptionally dry periods when the cover dried out, resulting in increased oxygen ingress. For other covers, and the uncovered cells, oxygen concentrations were close to atmospheric concentrations. During the eight-year monitoring period, acid breakthrough occurred in five of the cells, including three uncovered cells, one cell with a 300 mm cover and one sloped cell. In contrast, cells covered with 1000 mm, bottom compacted soils shows a marked improvement of leachate quality, indicating that sulfide oxidation processes have been slowed. There was a distinct relationship between oxygen ingress and leachate quality for all of the cells. No cover degradation was evident over the eight-year period, except for some erosion observed on a sloped cell. The results indicate that the onset of acid drainage can be delayed by perhaps hundreds of years and salinity loads can be reduced by more than 90 per cent, if coarse coal reject dumps in the KwaZulu-Natal provinces in South Africa are provided by an adequate cover system. These research outcomes can be extrapolated and applied to other dry site regions where similar materials are being considered.

Jan 1, 2003

By P. A. Manohar

This paper describes an implementation of the Potts model for simulation of grain growth in 2D on a distributed-memory parallel architecture. The simulation scheme utilizes a continuous-time, asynchronous parallel version of the n-fold way algorithm. Each Processing Element (PE) carries a piece of the global simulation domain while the virtual topology of the PEs is in the form of a square grid in 2D and Torus in 3D. Different PEs have different local simulated times. Inter-processor communication is carried by the Message Passing Interface (MPI) routines. Sample results for grain growth simulation in 2D are presented for a 840 x 840 global domain size distributed over 16 PEs. The grain growth kinetics obtained in the simulation of pure, isotropic systems is in good agreement with the theory. Grain size distributions obtained in the parallel simulation are well described by the lognormal distribution, thus validating the simulation procedure. Keywords: Metropolis algorithm. n-fold way algorithm, asynchronous parallelization, grain growth

Jan 1, 2003

By Jay W. Hawkins

Under an approved remining program, mine operators can remine abandoned coal mines without assuming legal responsibility for treatment of the previously degraded water, as long as the discharging waters are not further degraded and other regulatory requirements are satisfied. A U.S. Bureau of Mines review of 105 remining permits in Pennsylvania indicates that remining results in substantial reclamation of abandoned mine lands, utilization of significant quantities of coal, and reduction of contaminant loads (acidity and iron) from degraded mine drainage discharges. Normality tests performed on the water quality and flow data indicate generally nonnormal distributions and extreme right-skewness, tending toward lower values. The water quality of underground coal mines was observed to be more highly degraded in terms of acidity, iron, and sulfate than that of surface coal mines. The optimum baseline sampling scenario is 12 months in duration at a frequency of one sample per month. Analysis of water quality and flow rates before and after remining indicates that a majority of the mines exhibited either no change or a significant decrease in pollution rate because of remining. The discharge flow rate was the dominant controlling factor when the post-remining contaminant load was significantly better or worse than the baseline (pre-remining) load.

Jan 1, 2010

By J Pease, P Cameron, D Drinkwater

"In the 1990s metal prices were trending in a long-term decline and the usual cost-cutting exercises were adopted. Cuts to research and development made innovation difficult and the outlook was grim. But necessity is a strong motivator, and these conditions spurred the Mine to Mill movement that optimised across organisational ‘silos’ and utilised new technology tools, innovative software and increased computing power. Many applications of Mine to Mill exploited the fact that comminution is usually the site processing bottleneck and blasting is more efficient at breaking rock than grinding. This approach sought to: understand and characterise rock breakage from mining to the milldevelop models and simulators for blast design, fragmentation, crusher and mill circuitsdevelop tools to measure in real time the particle size distribution of rocks on run-of-mine (ROM) muck piles, at the primary crusher truck dump pocket and on conveyorsensure effective communication across the silos between geologists, blast design engineers, mining engineers and metallurgists.These methods and the technology tools available in the 1990s were widely adopted at numerous sites around the world with significant benefits. Semi-autogenous grinding (SAG) mill throughput increases of 10–20 per cent were common. This was the advance the industry desperately needed. It was low capital cost; it was obvious. It was here to stay.Except, in too many cases, it didn’t. In the minerals price boom of the 2000s Mine to Mill was no longer necessary to ‘survive’, even though it was still good business. Some operations, including some of the early success stories, slipped back to old habits of optimising within organisation silos instead of across them. Fortunately, other operators still embraced Mine to Mill and developed new techniques. Mine to Mill was still successful, but not as widely adopted as we had expected it to be. Now the boom has ended and operations are again under cost pressure. Since these are the same circumstances that created Mine to Mill, it seems time to achieve the wider adoption. Since the 1990s many new or advanced technology tools are now available for Mine to Mill projects: blasthole sensors, new explosives formulations, new blasting techniques and modelling, ore tracking devices, improved image analysis to determine size, texture and colour of coarse ore, grade sensors, whole-stream simulation tools, and even more powerful computing hardware and data analysis software. If we could achieve so much in the 1990s, how much more can we achieve today when we have the same imperative, the same potential and a larger number of high technology tools?Citation:Cameron, P, Drinkwater, D and Pease, J, 2016. The ABC of Mine to Mill and Metal Price Cycles, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 349–358 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By J. L. Ellenberger

The U.S. Bureau of Mines has cooperated with Cyprus Casa Grande Corporation Cyprus Casa Grande Mine, Cas a Grande, Arizona, since 1988 to assess the hydrology of an in situ leaching test facility. This work has resulted in an in situ design for leaching copper oxide ore that takes advantage of the increased mineral access associated with poor quality rock surrounding mine drifts. Blasting and bulkheads are used to produce readily-leachable rubble and contain and control solution movement, respectively. The design reduces the need for handling solution under high pressures in an injection/recovery system for in situ leaching of underground ore bodies. Early work at the site recognized a stress redistribution zone and increased transmissivity near drifts. Fracture data from a corehole oriented parallel to the dip of the ore body indicated an increase in fracture frequency around drifts a distance of 21 m (70 ft) away from the 5 m (16 ft) diameter drifts.

Jan 1, 1994

By S Gossmann, J Barlow, S Denner

"Unconventional gas resources, including coal seam gas (CSG) reservoirs, can be located above and below aquifers that provide groundwater for agricultural, industrial, urban and other uses. Development of these resources may, therefore, lead to potential impacts on groundwater supply.Management of reservoir/aquifer interconnections necessitates a program of focused data acquisition. For example, groundwater transfer from shallow aquifers to underlying CSG reservoirs may occur where CSG-containing units subcrop beneath shallow aquifers, possibly at significant distances from operating wells.Arrow Energy is undertaking studies of connectivity between aquifers including an investigation in collaboration with the Queensland Office of Groundwater Impact Assessment to evaluate connectivity between the Condamine Alluvium (CA) and CSG-containing Walloon Coal Measures (WCM).The Condamine Valley hosts highly productive agricultural land with groundwater resources heavily utilised for irrigation. Water demand outstrips available supply and groundwater has been subject to restrictions on further development since the early 1970s. Developments that could have an additional impact on groundwater resources in the CA are of major concern to local landholders. This paper describes: planned field investigations at two sites: 1. Stratheden, where pumping from the WCM will be undertaken 2. Daleglade, where pumping from the CA will occur how the data to be collected from field investigations will be used to refine predictions of flux between the CA and the WCM.CITATION:Denner, S, Gossmann, S and Barlow, J, 2013. Planned field investigation of connectivity between the Condamine Alluvium and Walloon Coal Measures, in Proceedings Water in Mining 2013, pp 91-98 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 26, 2013

By C. J. Weiss

"A commercially available Through-the-Earth (TTE) communications system was evaluated at an underground coal mine in eastern Kentucky. This field study was conducted as part of a larger multi-site evaluation of available TTE systems to determine their operational sensitivity. Field testing is being performed along with simulation techniques developed for geophysical surveys. The results of the field test will additionally be used to determine the applicability of these simulation techniques to TTE communications. The mine detailed in this paper was idled at the time of the study, which provided the nearest practical representation of a post-event mine shutdown. For this study, the three following communication modes were tested: surface-to-underground, underground-to-surface and surface-to-surface. Standard deployments of the TTE system using the manufacturer’s recommended procedures were able to achieve clear communications between underground and surface locations. Other arrangements of the units yielded intriguing results, some of which were predicted by computer simulations, others were unexpected. Future experimentation is planned to further evaluate the observed phenomena. INTRODUCTION The ability to establish effective communication between surface and underground personnel after a mine event is essential for both mine evacuation and mine rescue efforts. Current communication technology is reliant on physical infrastructure, such as antennas, cables, and repeaters, located throughout the mine. Such systems are easily disabled during a mine event because of their vulnerability to physical damage. A true emergency communications system would have the ability to function regardless of a mine’s physical state. Through-the-Earth (TTE) wireless communications technology has the potential to provide such a tool. Wireless TTE communications are exceptionally challenging because electromagnetic (EM), or radio, signals are subject to drastic attenuation as they travel through solid strata. In addition to attenuation, EM wave propagation is directly affected by the physical and petrographic characteristics, mineral compositions, metamorphic properties, and the degree of water infiltrations in the strata [1-5]. These strata characteristics are unique to each mine thus making the design of an effective, universally deployable, and reliable TTE communications system very difficult. At present, TTE technology is in the preliminary stages of practical deployment with only a few permissible TTE systems commercially available."

Jan 1, 2015

By S E. Thornett, P L. Kitto, R S. Longley

"The Mbalam Iron Ore Project covers mineralisation in two areas of metamorphosed hematitic banded iron formation (itabirite) in the north-west Congo Craton; namely at Mbarga in south-east Cameroon and at Nabeba in north-west Republic of Congo. The site locations are shown in Figures 1 and 2.The Mbalam Project history is an example of a compressed, yet highly successful, exploration timetable. Due to the thick inaccessible equatorial forest location, the first access was by helicopter in February 2007 at the Mbarga Deposit. Drilling commenced four months later in June 2007. A maiden JORC Code compliant æhigh-grade hematiteÆ inferred mineral resource (190 Mt at 60 per cent Fe) was defined in May 2008, followed by a maiden æitabirite hematiteÆ inferred resource in July 2008 (1.2 Bt at 37 per cent Fe). Subsequently, road access to Nabeba was established in January 2010, with a maiden high-grade hematite inferred mineral resource (200 Mt at 63 per cent Fe) identified only five months later in June 2010. A maiden itabirite hematite inferred resource at Nabeba was announced in June 2012 (1.4 Bt at 34 per cent Fe). The success of the exploration programs has been due to two main factors: Establishment of high-quality camps and facilities at Mbarga and later at Nabeba in Republic of Congo. Exploration support included satellite links for site servers and communications, field logging computers, data acquisition software, an on-site sample preparation laboratory, portable hand-held X-ray fluorescence (XRF) and company-owned drill rigs from 2009. An experienced and dynamic technical support group based in Perth to provide database facilities, data evaluation, internal auditing and software support, resulting in expedited resource estimation and economic evaluation with state-of-the-art mining software. In June 2012, Sundance Resources Ltd announced the current mineral resources for the project of 775.4 Mt at 57.2 per cent Fe of high-grade hematite and 4.047 Bt at 36.3 per cent Fe of itabirite hematite. In December 2012, high-grade hematite ore reserves of 436.3 Mt at 62.6 per cent Fe were announced. These world-class resources and reserves have been delineated and evaluated in a very rapid time frame. This would be considered extraordinary in any environment, let alone in the remote equatorial forest of central Africa.CITATION:Longley, R S, Kitto, P L and Thornett, S E, 2013. Exploration history of the Mbalam Iron Ore Project, in Proceedings Iron Ore 2013 , pp 107-116 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 12, 2013

By Norman Marr

Introduction In Canada, the mining industry and water-power development are intimately associated in that mining, which ranks second among the country's primary industries, depends principally upon hydro-electric energy for its large power requirements. On the whole, the Dominion has been very favourably endowed with water-power resources; generally speaking it is a well-watered country with numerous rivers and lakes located in are as where the topography favours water-power development. Precipitation, the raw material of water power, varies from an annual fall of more than l00 inches on the Pacific coast to about 12 inches in sections of the Prairies and the Northwest Territories; in Ontario and Quebec the annual average is 24 to 40 inches and in Nova Scotia about 45 inches. In its descent to the sea, the resulting run-off, much of it from considerable altitudes, creates sources of potential energy at every rapid and fall along the country's many streams and rivers. Many of the innumerable lakes in the Dominion provide storage basins for the regulation of stream flow, thus enhancing the potential power of available sites. While water-power resources are fairly well distributed across the Dominion, as is shown on the accompanying map of Canada showing power sites (Figure 1), it is particularly fortunate that those areas which are lacking in indigenous fuels have been compensated in large degree for this scarcity by being favoured with a high proportion of the total potential water power. This has an important bearing on the mining industry in that extensive mining operations can be economically carried out in the great Canadian Shield, which is lacking in commercial coal deposits but is rich in water-power resources. This Precambrian formation, which forms a wide belt around Hudson bay and in which many metalliferous ores are found, was 'subject to severe glaciation in a recent geological period, so that its river systems are comparatively young and are characterized by numerous lakes joined by short reaches of fast water, rapids, and falls which offer frequent opportunities for power development. The western Cordilleran region, which also is important in mining, has abundant water power. The accompanying geological map (Figure 2), prepared by the Geological Survey of Canada, shows the great extent of the Precambrian and Cordilleran regions and may be compared with the map of water-power sites to show the high incidence of water-power resources in these potential mining areas in which important mineral discoveries have already been made.

Jan 1, 1949

By J Herrmann, J Richards, B Hutchison

An extensive trial of laser-based survey and monitoring systems at Hillgrove Resources Kanmantoo Copper Mine in the Adelaide Hills, South Australia, has proved the capabilities of the system in monitoring rock movements on open pit walls. Initially, the trial involved deploying a Maptek I-Site 8820 laser scanner and the proof-of-concept Maptek Sentry software in the Nugent Pit to monitor ductile rock movements located up to 260 m away. The system was proven to be capable of monitoring various rock movements from 1.5 tonne rockfalls up to a 40 m high toppling wall failure. Data collected from smaller rockfalls was used to help build a database for Hillgrove’s rockfall management program. As part of the trial, the laser scanner was deployed to monitor a ramp movement event, as well as the toppling failure, adjacent to an IBIS slope stability radar. Both devices monitored the slump and the slowly developing toppling movements, with similar results. Although the radar was used as the successful ‘critical alarm’ device for the toppling failure, post-failure analysis showed the laser-based system to be capable of performing a similar role in the ductile rock regime; albeit over much shorter distances than the radar capability. A second laser scanner was deployed to monitor Kanmantoo’s Emily Pit in early December 2014, where it successfully provided critical alarm warnings for a block topple event. Sentry software, which takes advantage of Maptek I-Site 3D spatial imaging technology, was first released in November 2014 to meet industry demand for a cost effective, flexible system to detect movement. Sentry has now been re-launched as a fully transportable monitoring system. Deployed in a custom trailer, the system offers a power and communications module, cellular and Wi-Fi networking and a stable bollard for the I-Site laser scanner and Sentry software. This paper will present rock wall movement data from the Sentry trial and a subsequent two years of monitoring of the open pit walls at the Kanmantoo Copper Mine, at distances out to 750m. In addition, examples of remote geological mapping and small rockfall detection, using the laser scans, will be described. The Sentry system has proven to be beneficial for the continual improvement of slope monitoring and risk management at hard rock mines. CITATION:Hutchison, B, Richards, J, Richards, J and Herrmann, J, 2018. Mine rockfall and rock wall failures – proven digital laser-based approach for monitoring slopes at the Kanmantoo Copper Mine, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 463–472 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018