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By I. D. Lindley

The Wild Dog vein gold deposit in East New Britain Province, Papua New Guinea, forms part of a recently discovered 26 km zone of auriferous quartz vein mineralisation. The deposit, which was discovered in July 1983, has no silt anomaly, and a panned concentrate anomaly and float train restricted to within 500 m and 800 m respectively, of the discovery outcrop. Discovery of the Wild Dog deposit was a result of the methodical followup of regional panning which, as followup progressed, was replaced in importance by float sampling. Of the sampling methods used during the exploration leading to discovery, panning and float followup provided immediate indications of the presence of mineralisation. This high degree of spontaneity of followup is not provided by geochemical techniques, and has obvious advantages in high cost exploration for precious metal deposits in remote locations.

Jan 1, 1988

By Jeff Poe

When a takeup weight is offset to the side of a conveyor, a wire rope is commonly routed from the takeup weight through a series of sheaves to the takeup carriage. The friction developed from a series of wire rope sheaves can effect the actual belt tension at the make up carriage. Through real-mime testing the actual tension on a makeup carriage was recorded with data acquisition using an internally strain-gauged turnbuckle. The wire rope used to transfer the makeup weight to the makeup carriage was routed through a series of lubricated bronzed bushed sheaves. The tension on the makeup carriage was found to be as much as 26% higher than the weight of the makeup due to the friction in the sheaves. A detailed discussion of the testing and results will be made.

Jan 1, 2000

By G. A. Doyle

The quality of water in mine pit lakes depends in part on the physical limnology, including such factors as thermal and chemical stratification, turnover and the development of anoxic conditions with depth. Limnologic data collected from four existing pit lakes in Montana and Saskatchewan indicate that pit lakes develop a thermocline (temperature stratification) in the upper 10 to 30 m (33 to 100 ft) of the water column. Two o f the pit lakes, 26- and 55-m (85 and 180 ft) deep, undergo seasonal turnover of the entire water column, whereas two deeper, pit lakes, 110 and 240-m (360- to 790 ft) deep, undergo seasonal turnover of only the upper portion of the water column. In the deeper lakes, seasonal mixing does not extend through the entire water column, and a distinct chemocline develops with depth.

Jan 1, 1997

By D. D. Runnells, G. A. Doyle

The quality of water in mine pit lakes depends in part on the physical limnology, including such factors as thermal and chemical stratification, turnover and the development of anoxic conditions with depth. Limnologic data collected from four existing pit lakes in Montana and Saskatchewan indicate that pit lakes develop a thermocline (temperature stratification) in the upper 10 to 30 m (33 to 100 ft) of the water column. Two of the pit lakes, 26- and 55-m (85and 180 ft) deep, undergo seasonal turnover of the entire water column, whereas two deeper pit lakes, 110- and 240-m (360- to 790 ft) deep, undergo seasonal turnover of only the upper portion of the water column. In the deeper lakes, seasonal mixing does not extend through the entire water column, and a distinct chemocline develops with depth.

Jan 1, 1998

By Z. T. Bieniawski, E. H. Skinner, R. A. Cummings, F. S. Kendorski

INTRODUCTION Caving Mine Drift Support Design The support of production drifts remains a high-cost item facing the developer or operator of an underground caving mine. Support costs are incurred well in advance of ore production, and there is a strong need to minimize these pre-production commitments of capital. Due to the extensive rock loads that normally develop during the caving process, the support used in caving mines is typically quite heavy and therefore costly. The process of designing this support increasingly makes use of basic tunneling principles, but is hindered by the still-incomplete state of knowledge of rock behavior in caving mines, and high variability of geological conditions in caving orebodies. Caving mines differ from tunnels in that the deformations and rock loads induced are transient and dynamic in occurrence, and are normally large in magnitude, often well in excess of rock mass strength. As opposed to tunnels, caving mine layouts are more intricate, and the methods and effects of construction ordinarily are not as closely monitored. Safety factors in mining tend to be lower and rock masses tend to he weaker. These aspects prevent strict application of tunnel design technology to caving mine drift support, with the result that mine drift supports are commonly designed chiefly on the basis of experience at other mines. Mining procedures at caving mines are evolved in response to site-specific requirements, to the extent that there are really as many caving methods as there are caving mines.

Jan 1, 1983

By M. J. Farrell

Mining is a significant emitter of greenhouse gases and is the focus of increasing attention from green groups and regulators. Miners need to know their own carbon emissions and how they compare with the rest of the industry. Miners and mining companies need to know where they fit in the emissions curve. Who is in the bottom quartile? This article updates data from minecost.com which detail the specific carbon dioxide emissions for over 200 mines producing 90% or more of western world copper, zinc, lead and nickel in 2009. This data shows the potential impact on mine economics of proposed carbon taxation regimes and emissions trading schemes proposed at COP 15 in Copenhagen during December.

Jan 1, 2010

By R. M. Owens, J. F. Lupo

The Shirley Basin Uranium mine, located in southeastern Wyoming, USA, was an open pit mining operation consisting of a series of several open pit mines excavated into poorly consolidated sandstones, siltstones, and claystones. Since the initial open pits were developed in 1969, slope failures have plagued the mine and mining operations. These slope failures have persisted into the current mine reclamation period. When the mine was first developed, the open pit slopes were designed to range between 45 to 55 degrees. Numerous slope failures during mine development required the pit slopes to be redesigned with slopes as shallow as 26 degrees. At present, movements are occurring within the open pits on reclaimed slopes that are shallow as 12 degrees. Several detailed slope studies were conducted at the mine in the early 1970s. These studies, combined with more recent geotechnical investigations, provide a unique detailed history of pit slope failures on shallow slopes. This paper presents an evaluation of the slope failures at the Shirley Basin mine, highlighting important mechanisms causing slope failures on very shallow slopes. The evaluation demonstrates important key parameters for shallow slope design.

Jan 1, 2001

By R. K. Sinha, B. S. Choudhary, Desh Deepak, A. K. Mishra, Hemant Agrawal, Shankar Kumar

There are several methods (empirical, statistical, and machine learning tools) to calculate blast-induced ground vibration. Still, due to complications in the blasting procedure, under varying blasting loads and strata conditions, it is not easy to predict and simulate blast vibration precisely. Therefore, a study was conducted to simulate the field blast data in Ansys software using explicit dynamics. For this study, monitoring of ground vibration for 20 single hole blasts was carried out. The density of emulsion explosives was in the range of 0.9 to 1.15 g/cc. In the laboratory, rock properties were determined from the rock sample collected from the mine site before blasting. The in-hole velocity of detonation (VoD) and the density of the emulsion explosive were also determined. These parameters were used for numerical analysis to know the ground vibrations at specified points. The results of ground vibration predicted by the model are validated using field data.

By Muhammad I. Kabir

The streamline method of recovery prediction reduces a two-dimensional problem to a bundle of one-dimensional ones. This paper presents the development and application of a novel scaling technique which, when used with a streamline model, causes s bundle of one-dimensional problems to further reduce to a single one-dimensional calculation. The one-dimensional calculation accounts for chemical-rock interactions and the streamline model for areal sweep. The scaling technique significantly reduces computation time, is readily modified to desk-top calculations, and can be applied to both absorbing and reacting species. The work was sponsored by the Interior Department's Bureau of Mines.

Jan 1, 1984

By Arif Emre Dursun

The aim of this study is to present hazard classifications of location, type, and causes of accidents in Turkish coal-extracting industries using Analytic Hierarchy Process (AHP). In this study, fatal mine accidents were analyzed by pairwise comparison and weighting, and the most important hazards were identified by determining the effective main and sub-criteria among location, type, and causes of accidents. For this purpose, 1st, 2nd, and 3rd level hazards consisting of location, type, and causes of accident were determined by using the data of fatal mine accidents in underground and open-pit coal mining in Turkey between the years of 2010 and 2020. And then the data were categorized, and each category was prioritized using the AHP technique. According to the weights calculated by AHP, the most dangerous main criteria at 1st level hazards in underground coal mining is ventilation operations (0.363), while the most dangerous sub-criterion at 2nd level hazards is firedamp explosions and other gas accidents (0.409). On the other hand, in open-pit coal mining, the most dangerous main criteria at 1st level hazards are slopes and benches (0.575), while the most dangerous sub-criterion at 2nd level hazards are landslides (0.429).

Dec 30, 2023

By H. Wagner

Recently a detailed study ?Minerals Planning Policies and Supply Practices in Europe? has been completed. The study, conducted on behalf of DG Enterprise, demonstrated that there are very few written down national minerals policies within European Union. Mineral policy elements are dispersed in many different documents and acts. The paper discusses the essential elements of minerals policies; particularly importance is placed in issues related to planning (land use planning, mineral development, etc.). A number of examples of successful and less successful mineral planning policy approaches are presented in other to support the idea of importance of comprehensive mineral policy. The main sources of information were the country reports of 26 European countries that are appendix of the study. We conclude that comprehensive written mineral policy that incorporates essential elements is crucial in order to achieve secure minerals supply.

Jan 1, 2007

By B. McNulty

The Niblack polymetallic volcanogenic massive sulfide deposits are located on Prince of Wales Island in southeast Alaska, approximately 50 km southwest of Ketchikan. The property hosts a number of polymetallic volcanogenic sulfide occurrences within the folded Lookout rhyolite volcanic succession. The Lookout deposit is the primary focus of current resource delineation and contains an indicated resource of 4,136,000 tonnes at 1.13% Cu, 2.32 g/t Au, 2.27% Zn, 38.70 g/t Ag and an inferred resource of 1,736,000 tonnes at 1.09% Cu, 1.77 g/t Au, 2.02% Zn, and 25.52 g/t Ag as of March 2011. Sulfide mineralization is interpreted to have formed sub-seafloor, within permeable felsic fragmental volcanic rocks. Sulfide minerals of economic interest include chalcopyrite and Fe-poor, Zn-rich sphalerite. Of considerable importance, the Lookout deposit contains elevated gold that occurs as inclusions within the base metal sulfides.

Jan 1, 2012

By F. Calizaya

This paper describes the basic requirements for the utilization of belt air to ventilate working sections at remote locations in relation to the main fans. It highlights the risks involved, potential problems, and the provisions that must be followed by mine operators for the safe use of belt air. The paper also presents a brief review of the current regulations, conveyor belting tests, atmospheric monitoring system requirements, and the experience gained by mine operators to utilize the belt entries to ventilate remote working sections or areas where mechanized equipment is being installed or removed. The paper concludes with a set of recommendations with respect to the utilization of belt air and the composition of belt material in under-ground coal mines.

Jan 1, 2008

By Aram Grigoryan

This paper addresses historical aspects and construction sequencing of the subway complex under Columbus Circle in Manhattan; the structural elements of the rehabilitation and new construction; and the challenges associated with design and construction. PB is providing engineering services to New York City Transit (NYCT) for the rehabilitation of the 59th Street/Columbus Circle Station Complex that services over 150,000 customers daily. The project involves structural repairs, modifications and new construction requiring underpinning and temporary supports, custom framing details, and construction staging procedures to meet stringent limitations within the operating transit station and around the Columbus Circle street intersections.

Jan 1, 2008

By Liangguo Kang

Coal, as one of the vital sources of energy in China, has raised widespread concerns regarding its safety issues amidst the country’s economic growth driven by coal. To address this concern, this study employed the Kuznets curve, multiple linear regression, and data envelopment analysis models to investigate the impact of Chinese coal economic development on coal mine deaths from 1992 to 2021. The findings revealed a clear correlation between the Chinese coal economy and coal mine deaths. Specifically, per capita coal output, the death rate per million coal tons, and the death rate per hundred thousand persons exhibited positive, negative, and negative correlations, respectively, with the growth of coal income over the past three decades. Moreover, when the coal workers and coal output factors remained unchanged, the income of coal demonstrated a negative correlation with future changes in coal mine deaths. Notably, with three decades of coal economy development, substantial improvements in coal mine safety have been observed in China. Consequently, this research provides valuable insights for formulating safety measures and policies in coal mines across different economic levels, as well as a useful framework for assessing safety development in the coal industry.

Jan 20, 2024

By A. M. Anthony, A. Y. Atta, S. S. Magaji, U. Abubakar-Zaria

There are two major gold recovery methods: the hydrometallurgical technique, which employs cyanide solutions, and amalgamation method, which involves mercury (Hg). These methods present considerable health, safety, and environmental concerns. Past applications of alpha-cyclodextrin (α-CD) on gold scraps show that α-CD is not only inexpensive, but is also environmentally friendly. This research work used α-CD to recover gold from gold ores instead of gold scraps. The gold ore was sourced from Shanono gold deposit site Kano State,Nigeria. The gold ore was characterized by fire assay (FA) for the precious metal. The concentrate was digested with aqua regia (AR) for 24 h. Modified AR, where hydrochloric acid was replaced with hydrobromic acid, was used for the gold digestion due to the good match in molecular recognition between gold bromide ion (AuBr)− and α- CD in a second sphere coordination complex. The digestate was characterized using atomic absorption spectroscopy (AAS). Gold recovery using this technique is pH sensitive, and five pH values (2.0, 3.6, 4.0, 5.4, and 6.0) were investigated. FA analysis showed the Shanono gold ore deposit contains an average of 4.71 ppm of gold, AAS analysis showed highest gold recovery of 69% at pH 4.0, which is lower than recoveries from the metal scraps. This could be due to the presence of other gangue minerals closely associated with the ore. However, gold recovery using α-CD on Shanono gold ore has shown to have a higher yield of 69% compared to 35.5% yield obtainable by Artisan Small Scale Miners using mercury.

May 5, 2020

By M. Dayne Aldridge

A discussion of the definition of automation in mine ventilation applications is presented. The results of theoretical studies, experiments and practical experience from work in the United Kingdom, Belgium, Poland, the Soviet Union and the United States are summarized. Conclusions are drawn from these efforts and the prospects for the future development of automatic mine ventilation systems are explored.

Jan 1, 1978

By Florence Ntsiful, Eric Stemn

Exposure to whole-body vibration has been recognised as an occupational hazard in the mining industry, especially in the operations of earthmoving equipment. Managing whole-body vibration exposures requires periodic measurement of exposure levels to identify priority areas for implementing controls. However, due to different approaches to collecting exposure values, significant variabilities lie in the results. This systematic review is the first attempt to analyse whole-body assessment methods in the mining industry. The aim was to identify how whole-body vibration has been assessed, including the sources of variabilities to improve future research. The PRISMA methodology was adopted for the review and a total of 152 peer-reviewed journal articles were identified. However, only 24 were included in the review, following the application of some inclusion criteria. Descriptive and thematic analyses were performed on the 24 selected articles. Results indicate that whole-body vibration has been assessed as a function of either equipment characteristics, activity undertaken, operator characteristics, measurement approach or the assessment standards. Due to the multifactorial and dynamic nature of wholebody vibration exposures, the variabilities in results are due to the interrelationships between the risk factors of whole-body vibration and the differences in the sample sizes. To identify the sources of variabilities, a comprehensive assessment of all the risk factors, including equipment characteristics, road conditions, operator characteristics, and activity undertaken, is highly warranted. Finally, research gaps and directions for future research have also been discussed.

Dec 21, 2022

By J. Torma-Krajewski, M. Lehman

In 2005, NIOSH and Badger Mining Corporation entered a partnership to implement ergonomic interventions, including a systematic process, to address exposures to risk factors that may result in musculoskeletal disorders or other types of injuries/illnesses. As a result of this partnership, an ergonomics process was integrated with the existing safety and health program to promote an on-going application of ergonomic principles, and over 40 task-specific interventions were implemented during the first year of the process. This paper presents details of the process integration, and several examples of task-specific interventions that reduced exposures to risk factors.

Jan 1, 2007

By Harry E. Hughes

A section of the largest Superfund site in the country has become a success story for engineering innovation and for cooperative problem solving. “Superfund site” and “success story” are phrases that are not commonly found in the same sentence. Yet, their use seems justified. The project’s certification of construction completion from the US Environmental Protection Agency (EPA) includes a commendation. It reads, “for completing the project nearly a year ahead of schedule, at a cost substantially less than estimated originally and without com-promising the requirements for protection of human health and safety or the environment.” The EPA director who issued that certification also referred to the project as “a positive example of cooperation among all who have a stake in the outcome.”

Jan 1, 1996