Search Documents

By Gabriel Böde Jimenez Leon, Michael Karmis, Christopher Newman, Zach Agioutantis

"When utilizing high recovery underground mining methods, such as longwall or high-extraction room-and-pillar mining, the movement and deformation of the overburden propagate toward the surface and may affect the integrity of overlying surface streams (Peng et al, 1996). Published studies cite three major mechanisms of subsidence as most likely to impact streams: displacement, slope and strain. While subsidence-induced vertical displacement cause little structural damage to the stream bed, it may create adverse drainage and stream flow issues as the subsidence trough allows for ponding (Dawkins, 2003). Subsidenceinduced changes to the slope, or tilt, of a stream may have adverse effects on water flow. As the stream enters the subsidence trough, the gradient increases providing potential erosion control problems. When exiting the subsidence trough, a reduction of the gradient may inhibit stream flow, causing localized ponding (Peng, 2008). While vertical displacement and tilt both may have detrimental effects to surface streams, the resulting strains have been documented as being the most damaging to surface streams and structures causing distortion, fractures, or failure (Singh, 1992). When stream beds are subjected to high tensile strain, tensile cracks may form at the surface level allowing for the direct loss of stream flow through fissures. When stream beds are located in areas of high compressive strain, rock layers forming the stream bed can fail as the stream bed ruptures, upward, blocking stream flow or having the stream diverted into the fracture zone at the base (Iannacchione, et. al., 2010).Recent investigations on the effects of underground mining on surface bodies of water suggest that to determine the degree of stream impact one must also consider the geologic structure and thicknesses, surface topography, watershed drainage areas, width of river bed and rate of mining. Due to the complex nature and number of parameters affecting surface streams, subsidence modeling tools and software packages should be implemented throughout all stages of subsidence planning, prediction and control. The Surface Deformation Prediction System (SDPS) utilizes the influence function for the calculation of final subsidence deformations with respect to the angle of influence, supercritical subsidence factor as a function of the percent hard rock, edge effect offset distance, and surface topography. Developed more than 25 years ago, SDPS has been continually updated with new analysis and prediction features, providing a reliable and versatile program for subsidence management methodologies. Most recently, the program has been updated to evaluate the effect of varying surface topography in the prediction of horizontal displacements, referred to as ground strain, allowing for the accurate three-dimensional representation of surface deformations in mountainous terrain (Agioutantis and Karmis, 2014). Ground strain has become one of the predominant deformation indices used in the evaluation of potential damage to surface structures (Karmis et al., 1995). Ongoing work with SDPS software seeks to investigate the calculation of ground strain in SDPS and its ability to accurately and realistically predict damage to surface streams due to underground mining operations."

Jan 1, 2015

By C L Humphrey

Biological monitoring programs for environmental protection require techniques that will provide both early detection of possible adverse effects, and assessment of the ecological significance of these effects. Monitoring techniques must include responses sensitive to the impact, that can be subjected to rigorous statistical analysis and for which statistical power is high. Such issues in baseline research of 'what and how to measure?' and 'for how long?' have been the focus of a program being developed to monitor and assess effects of mining operations on the effectively pristine, freshwater ecosystems of the Alligator Rivers Region (ARR) in tropical northern Australia. Application of the BACIP design, utilising a form of temporal replication, to univariate data (single species) and multivariate (community) data is described. For new ventures in Australia (such as mining), monitoring programs should be designed to establish with high probability that an impact on the ecosystem no greater than a prescribed amount has gone undetected - as opposed to simply allowing development to continue as long as 'proof' of impact is not available. Such a precautionary approach represents a shifting of the 'burden of proof' and would require with the BACIP design, a minimum number of baseline years in order to achieve some desired level of statistical power in a test for impact. Power analyses conducted on two to five years (depending upon the technique) of baseline data from streams of the ARR indicate that the BACIP design would not impose developmental constraints on mining and that a policy of reversal of the burden of proof would provide the cornerstone required for managing such development in an ecologically sustainable manner.

Jan 1, 1994

By J. Parreira

This paper presents a deterministic/stochastic model that was created to compare an autonomous haulage truck system to a manual one by calculating and estimating benchmarked Key Performance Indicators (KPIs) such as productivity, safety, breakdown frequencies, maintenance costs, labour costs, fuel consumption, tire wear, and haulage cycle times.

Aug 1, 2013

By John C. Gagliardi

The size and complexity of modern surface haulage trucks has resulted in an increased reliance upon sensors and electronic-based instrumentation for safe and efficient operation. Design engineers need accurate information about the equipment vibration environment to efficiently and effectively build components for installation on mobile mining equipment capable of withstanding the mine environment. Examples of such components include backup alarms, communication equipment, microprocessor-based controllers, and a wide variety of sensors. Unfortunately, this information is not available to the majority of both original equipment and aftermarket equipment manufacturers. To address this problem, the U.S. Bureau of Mines performed field vibration measurements on a variety of surface mining haulage trucks. The vibration measurements were then analyzed and test specifications were developed in the form of envelopes. In conjunction with test specifications, recommendations to aid manufacturers in implementing a vibration environment test program have been included with an illustrative example.

Jan 1, 2010

By A. Lane

The socio economic risks of mining in South Africa have been emerging for some time now, and have been brought into sharp relief by recent events in the platinum sector. The slow pace of social upliftment in the country has lead to widespread social unrest with consequent calls for different forms of resource nationalism. Fundamentally, the key stakeholders are not fully aligned, and are not engaging productively. This poses significant above-the-ground risk to mining companies. Measuring social impact, deploying inclusive solutions and engaging effectively with stakeholders are three ways in which mining companies can mitigate this risk.

Jan 1, 2012

By Philip C. Tully

This bibliography contains 2,072 citations to technical and scientific literature about helium and alpha-particles abstracted by 12 abstract service publications during 1962. Citations are listed by 16 major subject classifications with several subclassifications to minimize areas of literature search. Automatic data processing was used to reduce the time and labor required to compile the bibliography.

Jan 1, 1969

By J. L. Hoover, P. W. Conrad, J. Downey, S. Parrow, S. Rosenthal

The goal of the drill bit consumption study was to develop an equation(s) based on various components that affect drill bit wear and use that equation(s) to estimate the consumption of bits during production drilling. Drill bit data from various geographic locations were compiled and used to develop linear regression equations using the Microsoft Excel software package. Multiple drill bit consumption equations were developed and statistical analysis was used to verify the accuracy of those equations. The equations will allow mining companies to more accurately forecast drill bit consumption when evaluating new mine properties. This capability becomes increasingly beneficial to forecasting as the cost of consumables increases.

Jan 1, 2012

By V. A. Ettel

Current practices in electrolytic winning and refining of copper , nickel and zinc are reviewed from the point of view of their respective energy requirements. The electrical energy requirements of these processes are broken down in to the individual components, which belong to two basic categories: (a) thermodynamic energy requirements (G of the desired reaction) : (b) energy losses (anode and cathode polarizations, ohmic drops in the electrolyte and in the cell hardware, energy losses due to unwanted side reactions and electrical shorts). The individual energy components are separately examined for each electrolytic process and the potential for energy saving in these processes is discussed. It is shown that many potential energy-saving measures are uneconomical at the present time, as they increase over-all operating costs. The discussion is focused on those approaches which hold most promise for the future.

Jan 1, 1977

By G. Stecklein

This report summarizes the results of research into the areas of the fragmentation and entrainment of Airborne Respirable Dust (ARD). The objectives of this program were four-fold: first, to review the present state of knowledge regarding ARD; second, to expand this state of knowledge through the identification of hypothetical microscopic mechanisms by which the coal is fragmented and the dust becomes entrained; third, to specify the informational requirements to verify or nullify these hypotheses; and fourth, to relate experimental techniques that will produce that required information. Additionally, insights are provided regarding potential methods of extraction and/or treatment which may reduce the concentration of ARD.

Jan 1, 1982

By Jonisha P. Pollard, F. Nasarwanji, Lydia M. Kocher

This study identifies nonfatal injury incidence rates, nature of injury, work activities, glove usage, and sources of hand and finger injuries in the U.S. mining industry, as reported to the Mine Safety and Health Administration (MSHA) from 2011 to 2017. Hand and finger injuries occur at a rate of 6.53 per 1000 full-time employees, which is nearly double the rate of the next highest affected body part, the back.

Feb 24, 2022

By R. Matusewicz

The key drivers for the copper smelting industry are a complex mix of economic and "human" factors which combine to drive technology in new directions and can provide a strong indication of future industry trends. Recent examples have been the drive to achieve increased scale of production and resultant cost efficiencies by using a single furnace high intensity smelting vessel, and the broad acceptance of Top Submerged Lancing (TSL) technology for this duty. The development and adoption of continuous converting processes to counter the increased pressures faced by the Peirce Smith converting process is another example of the need for innovation. This paper discusses the merits of the continuous converting process, describes how the Ausmelt TSL batch converting process has been adapted to the new Ausmelt Continuous Copper Converting (C3) process in response to these industry trends and examines the Ausmelt continuous converting flowsheet options available to the end user.

Jan 1, 2007

By Alfred Petrick

This report analyzes the byproducts systems of lead, zinc, uranium, rare earths, iron, aluminum, titanium, and lithium. Specific byproduct metals covered are cadmium, germanium, indium, and thallium from the zinc system; antimony and bismuth from the lead system; vanadium, radium, and scandium from the uranium system; rare-earth oxides from the rare-earth system; and cobalt, gallium hafnium, and rubidium from other systems. The report discusses various metallurgical systems, marginal and incremental production costs of byproduct subsystems, industry structure and organization, and historical data on price, consumption, and supply.

Jan 1, 1973

In a ætypicalÆ gold deposit each tonne of ore will contain tens of millions of very fine gold particles, whereas; at Bendigo the majority of gold in each tonne of ore is present in just five to 15 very coarse gold particles, a distribution more akin to diamond deposits. At Bendigo the minimum sample size required for good assay repeatability is estimated at 4.5 t for each assay. Drill core samples are several orders of magnitude too small to generate representative assays.The drilling data are characterised by a nugget effect approaching 90 per cent, a very skewed distribution and, on average, under-report in situ grade by 50 per cent to 75 per cent. Since 2002 Bendigo Mining NL has completed 47 000 m of diamond drilling, 1200 m of on reef development, collected and processed 100 bulk samples (150 t each), 800 mini bulk samples (50 kg each) and processed in excess of 25 000 t of ore through a pilot plant. The results of this work have provided the information required to develop and verify a robust grade estimation procedure. No standard geostatistical manipulation of the drilling assay data can generate an accurate grade estimate as the samples and associated assays are not representative of the ore being sampled. The recognition of this fact was critical as a radical transformation of the raw drill assay data was required to develop a workable methodology for grade estimation in such a high nugget environment. The aim of the transformation was to reduce the nugget effect and high variance and so approach a lognormal assay distribution. Ideally the average drill grade would approximate actual in situ grade and the assay distribution would reflect actual grade distribution within the reefs. Following the data transformation simple block modeling within the defined resources allows grade estimates to be made that can be used in the estimation of Indicated Resources and hence Probable Reserves. The grade estimates have been checked by extensive bulk sampling and processing of 25 000 t of ore (three per cent of total resource) through a pilot plant with planned full scale mining to provide the ultimate verification.

Jan 1, 2004

By K. C. McMahon

This report is the result of the engineering efforts performed by the Mining Equipment Operations of FMC to develop methods of automating a continuous miner. This work was done as part of modification number three of the contract for the development of a miner/bolter system. As the demand for energy places an ever-increasing pressure on the coal mining industry to produce more coal, methods for underground mining which will increase productivity with a con-current increase in safety are being actively sought. Removing the machine operator from his station on the continuous miner and placing him at a safer location behind the machine while retaining his control functions via an umbilical cable or a radio link was an important first step. However, the problems of poor visibility, no control "feel", and the judgmental problems of controlling the sump distance and the shear limits have not been conducive to the productivity increase that is desired.

Jan 1, 1975

By P de Caritat, A Davidson, A Mann

Top outlet sediments from the National Geochemical Survey of Australia have been extracted by a partial extraction method for over 50 elements including gold. The partial extraction results from this low-density survey show discrete coherent anomalies for Au in the vicinity of many of AustraliaÆs known goldfields, and in the vicinity of some minor gold occurrences. In several instances catchment outlet anomalies for Au have been recorded from areas not known to contain significant economic gold. Several large economic goldfields are shown to not produce anomalies in catchment outlet samples. A survey of overbank samples in the Swan Avon catchment of Western Australia at double the sampling density shows that low level anomalies (>1 ppb) can be traced back to source using overbank sediments. Follow-up of one of the Au anomalies at Kent River in previously regarded non-auriferous terrain (western Albany-Fraser Belt) indicates a non-economic, but perhaps geochemically significant, Au anomaly with associated pathfinders including palladium. This may indicate that further exploration of the western part of Albany Fraser Belt for Au is warranted. The combination of catchment overbank samples and partial analysis technique has been shown to be effective at locating the source of gold anomalies from initial low-density continental and regional surveys.CITATION:Mann, A, Davidson, A and de Caritat, P, 2013. High resolution soil geochemistry for gold exploration at the continental, regional and prospect scale, in Proceedings World Gold 2013 , pp 167-174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By L. C. IlsLey

Explosives have been fired electrically for several decades. Mountains have been tunneled, deep shafts sunk, extensive coal and metal mine workings excavated and, in times of war, railroads, buildings, bridges, and fortifications have been destroyed by means of electrically fired explosives. Modern engineering depends so much on explosives that their safe and efficient handling and especially their detonation are of prime importance to all those connected with the use of explosive agents. Electric shot-firing is only one method of igniting explosives, but it is rapidly spreading and because of certain inherent safety features should be encouraged. Data collected by the Bureau of Mines indicate that in the United States a large percentage of the blasting in quarries, shafts, and tunnels, and from 15 to 25 per cent of the blasts in mining operations, are set off electrically. The Bureau of Mines is interested in electric shot-firing because of its use in mining, and especially because electric methods, when properly applied, are undoubtedly safer than other methods commonly used.

Jan 1, 1926

By H. W. Smith, N. Ichiyen

A convenient method for the calculation of metallurgical balances, based on statistical treatment of all available data, is presented. An error analysis is included. Examples show the advantages of the method, and also that such balances are less precise than might be supposed.

Jan 1, 1973

By Oliver Bowles

PRICES of quartz sold in the United States in 1938 ranged from $1.15 to $36,000 a ton. This startling variation was due simply to the differences between glass sand and rock - crystal, materials that are virtually the same in composition. It illustrates the complexities in qualities, uses, and values of industrial minerals. It is generally stated that mineral deposits are exhaustible resources which can never be replaced when depleted. This statement is no longer true with respect to certain industrial minerals now recovered in increasing quantities from that most inexhaustible of all sources of supply, the ocean. Salt has long been obtained from sea water, particularly on the Pacific Coast, and reference was made a year ago to the large bromine recovery plant at Wilmington, N. C. Now the Westvaco Chlorine Products Corp. is operating a large plant at Newark, Calif., having a capacity sufficient to recover daily from the ocean raw materials that will produce 60 tons of various magnesium products. Lime is used to precipitate the magnesia from salt-water bittern. The products are chiefly magnesium carbonate for chemical uses, periclase and other refractories, and oxychloride cement for flooring.

Jan 1, 1939

By George E. Aikens

Prolonged subzero climatic conditions impose some unique engineering problems for the developer and operator of open-pit mines in the Far North. The remoteness of the job site and the extremely cold, long, dark winters severely tax both man and machine in the quest for the Arctic's rich mineral wealth. Undoubtedly the singular most troublesome problem for the engineer is Permafrost which underlies about 201o of the land area of the world and about 85% of the state of Alaska. Permafrost has its impact on building construction and mine excavation, while posing a more pervasive threat to the-delicate ecologic balance within the Arctic wilderness. Yet the difficulties associated with mining up North may not be as overwhelming as has been previously supposed. For example, the lowest temperature recorded at Point Barrow is -560F, whereas Montana has recorded -69.7° F.. There are no specially designed machines for mining and construction in the Arctic, and efficient equipment utilization is maintained through proper operation and servicing techniques. However, neither equipment or people can be assumed to function normally at -40°F. Special techniques in drilling, blasting, and ripping are being used to yield economically competitive ores. Overall, a fundamental understanding of the nature of Permafrost will allow the engineer to deal expeditiously with an Arctic mining venture and at the same time to deal fairly with Arctic environment.

Jan 1, 1972

By J Harris, M Shi, S Vink, P A. Kirsch

Across the life-of-mine, water is both an essential commodity to mining, and one of the most significant hazards. In Australia, a land of drought and floods, availability of water is a critical strategic risk for mine sites and neighbouring stakeholders, with both insufficient water leading to curtailed operations and contested space, and extreme water closing operations through flooding of mine sites, transportation infrastructure and unplanned regulatory restrictions. In addition to these major strategic risks, water must be addressed in operational risk management activities in many different ways.This paper develops a set of categories for classification of water risks based on academic papers from the water in mining literature. These categories are applied to media content analysis of articles in International Longwall News (ILN) (an online coal industry news site) obtained with the search terms ‘water’, ‘rain’ and ‘flood’. Identified risks are discussed within the context of the life-of-mine. The paper uses these same categories to analyse the treatment of water risks in a new coal industry risk management body of knowledge called RISKGATE (http://www.riskgate.org, Minerals Industry Safety and Health Centre, The University of Queensland). The discussion of water risks in both INL and RISKGATE is compared and contrasted to pinpoint opportunities (and a roadmap) for further development of a specific RISKGATE water module for site-based operations. The media review also identifies areas for development of RISKGATE expansion topic(s) that would address other strategic water risks, eg severe weather events.CITATION:Shi, M, Kirsch, P A, Vink, S and Harris, J, ?2014. Water as risk in mining – media analysis and the RISKGATE body of knowledge, in Proceedings Life-of-Mine 2014 , pp 205–218 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014