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By Stephen G. Rieben

Almost everyone has at least heard of the two one-call systems which serve New England. They are "Call Before You Dig", which covers Connecticut, and "Dig Safe", which covers the remaining five New England states. Those of you who are more familiar with these programs know that it is our job to help guard against the accidental dig-ups of buried plant and to prevent facility service disruptions. We cover all types of buried facilities, from cable television to high pressure gas transmissions lines, telephone cables, electric facilities, fiber optics and everything in between

Jan 1, 1990

By V. Aitken

Line-of-sight radio control has received widespread acceptance for use in many mining methods because today’s technology offers improved economics and personnel safety. Significant advances in higher autonomy for mining machines are not currently seeing widespread use even though they offer great future potential. With autonomous capabilities being a longer-term goal, a logical sequence of advances based on TeleRemote control is proposed. Under Tele - Remote control, the operator is in direct control of the machine at all times. Three levels of Tele - Remote control systems are presented including line-of-sight, extended line-of-sight, and full load-haul-dump applications. Distributed control and sensing subsystems arranged in a vehicle control area network support incremental system expansion through the three levels of TeleRemote control and prepare the machine for integration of higher levels of automation as mature technology becomes available. This approach allows full exploitation of today’s mining automation technology with a flexible future growth path.

Jan 1, 1998

By M. Pearson, J. Irvine, L. Mercer, P. Lauzon

Severe service ball valve performance has a direct impact on the mechanical availability of high pressure oxidation and leach plants. The primary function of these valves is to isolate the autoclave for maintenance. Valve failure has historically contributed significantly to the maintenance downtime of these process plants. An understanding of the root causes of valve failures is the first step in increasing the reliability of the severe service ball valves. A rigorous failure analysis practice has been developed by Hatch for investigating refractory failures in furnaces and kilns based on Kepner-Tregoe methodology. The method has also been modified for valve failure analysis. From a root-cause failure tree analysis of each of the valve components, a list of all potential valve failure mechanisms was developed for ranking and evaluation, along with recommendations for further valve development. The purpose of this paper is to present the reader with the modified Kepner-Tregoe method and examples of this analysis.

Jan 1, 2004

By M C. Evans

"Mine decommissioning is the final phase in a mining project. Planning for decommissioning must commence for a proposed mine even before the government approves it. Queensland mining approvals require proponents to commit to completion (or closure) criteria defining successful rehabilitation. Queensland mining project statutory environmental authorities must also specify how progressive rehabilitation is to occur throughout the mining project. Final landforms with graded banks together with creek and run-off diversions are often required and constructed early in the life of a mining project. At closure, mining projects must demonstrate that future medium-term risks are not significant, or failing this, a residual risk financial payment must be made to the state. CSIRO climate change projections indicate that Queensland is likely to become warmer this century with less rainfall in parts and with extreme rainfall events likely to occur more frequently. This project was undertaken to?determine: if current rehabilitation planning tools assist in determining the environmental risks from mining closure not adequately addressing climate change if these risks are addressed by current rehabilitation outcomes.The north-west Queensland mining region and the central Queensland coalfields were represented in this project by five study sites. Local data sets for temperature, rainfall and rainfall intensity were produced using conservative greenhouse gas emission scenarios representing likely future atmospheres, and using the SimCLIM climate model, Evaporation data sets were also derived from available climate parameters. These projected climate variables supported equations and models used in Queensland to determine mining project rehabilitation completion criteria. Storm intensities and return intervals were directly applied to assess the likelihood of failure of engineered structures such as stormwater diversions and banks. Plant cover change determined by an existing growth model together with rainfall intensity and changes in the R and C factors of the universal soil loss equation (USLE) erosion model enabled estimates of long-term erosion rates. Flood estimates were undertaken using regional rated catchments.The study found that stormwater diversions and banks on recontoured rehabilitated landforms, if constructed to currently accepted completion criteria, would likely fail within 30 years and with the likelihood of failure steadily increasing thereafter. The change in likelihood of failure was able to be estimated and could be applied to the determination of residual environmental risk for approval of a surrender application involving rehabilitation. The USLE model showed that long-term erosion rates increased as a consequence of climate change from north to south across the Queensland mining precincts. Because the growth model did not consider carbon dioxide fertilisation affects, results would likely be worse-case.Likely climate change outcomes have consequential residual environmental risks of mining project rehabilitation failure. This increased risk may result in increased payments to the state from mining projects where high consequences exist. The liability to the state and risk to the environment can be avoided if today’s completion criteria address tomorrow’s climate change impacts.CITATION:Evans, M C, 2014. Queensland mines should consider climate change impacts for decommissioning, in Proceedings Life-of-Mine 2014, pp 535–562 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 16, 2014

By M. S. Cetiner

This report describes the prototype development If a medium to high voltage coupler, suitable for underground coal mining operations. The coupler has such unique features as automatic dust covers and continuous phase pin shielding. The coupler is rated at 7500V and 250A continuous operation.

Jan 1, 1982

By C. W. Owings

The number of major coal-mine explosions occurring annually in the United States is decreasing, due mainly to fuller recognition of explosion hazards in coal mines and knowledge of methods to prevent them, which can be attributed largely to the dissemination of information by the United States Bureau of Mines, State departments of mines, and other coal-mining agencies. Conditions vary considerably from one coal field to another; consequently, outstanding causes of and methods of combatting explosions vary, also. The Safety Division of the United States Bureau of Mines is making a critical study of coal-mine explosions in the various coal-mining States, and an analysis of the results is published as each study is finished. It is believed that, with completion of the series enough information will be at hand which, if applied, will prevent all coal-mine explosions. ACKNOWLEDGMENTS The data in this circular are based on records of the United States Bureau of Mines and the Industrial Commission of Ohio. The cooperation and assistance of T. P. Kearns, superintendent of the Division of Safety and Hygiene of the Industrial Commission of Ohio, and of James Berry, chief inspector of the Division of Mines of Ohio, is acknowledged.

Jan 1, 1937

By William L. Rice

This Bureau of Mines Open Pile Report on cobalt is one of a series of minerals availability commodity deposit abstracts. Nonconfidential information from the Minerals Availability Program data base covering domestic and foreign cobalt properties and deposits has been abstracted for use in his report. Abstracts include applicable data on location, published reserves and resources, geology, mine and beneficiation systems, and operation information.

Jan 1, 2011

By L. A. Mills

After three years of experience in operating the pilot plant for the Noranda Continuous Smelting Process, the decision was made, in March 1971, to build an 800 ton per day commercial plant at Noranda, Quebec. The de- sign and layout of the plant is discussed and the installed equipment described. Experience previously gained in the pilot plant is mentioned when it has been used in the choice of equipment or plant layout. The full- scale reactor was started up in March 1973 and the operational datacollected and the experience acquired during the first 30 months of operation are described. This includes operation to produce both high grade matte and copper. Areas discussed include refractory wear, fuel consumption and throughput of copper concentrates. Changes made to original equipment and methods of operation are discussed, together with the reasons. The ad- vantages of using solid fuels to handle inert materials and to maximize converting air flowrates and concentrate throughputs are described. Relative efficiencies of oil and natural gas are compared. The addition of oxygen from a 94 ton per day oxygen plant to the reactor converting air was started in August 1975 and the initial operating results are included.

Jan 1, 1976

By Scott W. Hazen

COMPREHENSIVE summary is presented of results of several years of research at the Bureau of Mines Mining Research Center at Denver on adapting and applying techniques of statistical analysis in mine and mineral-deposit sampling and in computing grade and tonnage of ore for a mineral deposit. In addition to elementary statistical theory the material presented in the bulletin includes: (1) Certain special statistical techniques that have been found useful in mining applications; (2) problems, implications, and limitations that may be encountered in applying these techniques in mine sampling and evaluation; and (3) numerous examples to demonstrate application of the theory and techniques.

Jan 1, 1967

By Michael J. Brnich

During the past 15 years the number of reportable mine fires has declined. A decline in the number of reportable fires is a gross indicator that allows experts to say something about the underground coal industry generally: There has been some improvement in overall mine fire preparedness. However, such an indicator is less reliable as a predictor of readiness at any particular operation. An indication of fire fighting preparedness would have to be assessed from evidence gathered at the mine site. In other words, there are two levels from which to view the problem. On a general level, there has been significant improvement in the industry's fire response capabilities over the past two decades. Specifically, however, little data has been gathered on a site-by-site basis to determine what improvements might be made on a local level. These improvements would move beyond regulatory compliance. It is expected that this manuscript, based on work conducted at an underground coal mine in the western United States, will help to focus attention on some central concerns involving this critical issue.

Jan 1, 2006

By Robert J. Timko

In early June 1986, an underground fire of unknown origin erupted in one of several entries of a coal mine located in southwestern Colorado. For a time, mine personnel aggressively fought the fire. However, control of the fire was later lost. To prevent further damage and reduce the possibility of an explosion, all portals and shafts to the mine were sealed. The mine operator requested the U.S. Bureau of Mines' assistance in obtaining and analyzing mine fire gases taken from sampling ports placed through the mine seals, as well as down boreholes drilled after the fire. This report recounts activities within the first 2 years of the mine being sealed. It includes a description of gases analyzed and mine atmosphere status equations generated from the analyzed gases. The gases were analyzed by chromatography and included standard atmospheric gases as well as higher hydrocarbons that are found in postfire atmospheres. Nine equations were used to evaluate what was occurring within the sealed mine. Following a description of the rationale behind each equation, the 2-year trend is briefly analyzed.

Jan 1, 2010

By L. Sandbak

The TRJV Mine is located approximately 43 miles northeast of Winnemucca, along the east flank of the Osgood Mountains in the Potosi Mining District, Humboldt County, Northwest Nevada (see Figure 1). The Turquoise Ridge Mine is an underground mine, and is a 25% joint venture partner with Newmont Mining. The TRJV mine utilizes the underhand cut-and-fill mining method due to the relatively low rock quality in the ore zones and the relatively shallow dipping 25-45 degree ore body geometries. This paper defines a rehabilitation risk rating system (RRRS) for prioritizing rehabilitation of drifts damaged in the mining processes including long term development drifts providing access to the mining areas. The ultimate use is as a mine planning tool for the organized scheduling of rehab in a timely manner. A few case studies of the most needy rehab areas identified by the RRRS mapping system is presented, and the type of rehab completed design for these areas. Suggestions on improving the rehab risk mapping system include the use of support history and rock mass strength rating factors.

Feb 23, 2014

By G. Chahal, L. C. So, S. Faucher, S. Mostaghel, S. -Y. Oh, S. K. Lee

Slag dumping and water granulation are the most commonly used slag treatment methods in the metallurgical industries. In both processes, water is present (by desire for cooling and dispersion or as a result of rain accumulation) and thus equipment and operations are designed to minimize and mitigate the risk of steam explosions resulting from the inappropriate contact of slag with water. Slag handling practices have, therefore, never been inherently safe; even good design, operation, and maintenance are not sufficient to prevent explosions or other related injuries from occurring. For slag handling to become inherently safe, our industry must eliminate the potential contact of water with molten slag. This is today feasible with the advent of dry granulation technologies, a review of which is presented, and it thus falls to us, in the metallurgical sector, to lead the way in their final stages of development and adoption. Furthermore, while slag dumping and water granulation offer some metallurgists the means of valorizing their slag as a by-product, for most, this is not the case. The energy in slag is lost through dumping and water granulation processes, and where slag is sold as a by-product, it is for its chemical content only. Here, dry granulation processes also offer advantages including the production of by-products which hold value in both their chemical content and physical properties and heat recovery. Dry granulation, therefore, augments the methods by which slag may be valorized over traditional processing methods.

Jan 1, 2015

By Philip J. Bangerter, Chris Twigge-Molecey

Design for safety is critical to metallurgical plants, due to the inherently dangerous nature of their processes. Two significant areas of concern are: 1. preventing catastrophic process failures that cause damage or injury; and 2. operational safety that directly affects those working in or living near the plant. Process safety involves human behaviour, but the designer can eliminate or control hazards by engineering approaches, and control impacts through the design of the operating procedures. The tools available to guide safe facility design include bowtie analysis, hazard analysis, and hazard and operability studies. Clean plant design principles can guide the design process to address in-plant occupational health and safety issues. Auditing and review is a key part of the overall design process.

Jan 1, 2015

By E. A. Ziemba

The modified in-situ process is one of the methods being considered for extracting oil from oil shale. One of the questions to be answered for this approach is the environmental consequence of underground retort abandonment. This report outlines a study which addresses the question in terms of a grouting solution. It covers the development of a spent shale ash based grout which will fulfill the environmental requirements in terms of strength, stability, and impermeability. In addition, it will allow the reinjection of up to 50 percent of material mined and surface retorted as part of this process.

Jan 1, 1982

"EAF dust is categorized as a hazardous solid waste. EPA approves only two treatment methods: either sending the dust to zinc recycling facility, or stabilizing it first and then disposing it to a specially-lined landfill. Both treatment methods are costly to EAF steelmakers. In order to reduce the cost and even better to make profit from the dust, EAF steelmakers need to find a costeffective technology to separate zinc from EAF dust. This paper is dedicated to discussion of a novel recycling strategy: in-process separation of zinc from EAF dust. The concept of in-process separation of zinc from EAF dust is first defined, and then a simple Zn concentration model is developed. From this model, two approaches of in-process separation of zinc from EAF dust are derived: (1) prematurely capturing dust at very high temperature when zinc is still in vapor status, (2) prematurely collecting dust immediately after quickly cooling EAF off-gas from high temperature to low temperature. Next, thermodynamic analysis is conducted to understand zinc behavior in EAF off-gas. It is demonstrated in theory that zinc is in vapor status while it exits from electric arc furnaces. At last, recycling routes and economics of in-process separation of zinc from EAF dust are discussed.IntroductionElectric arc furnace (EAF) plays an increasingly important role in steel production. According to USGS, steel production from electric arc furnaces has long exceeded that from basic oxygen furnaces [JJ. In 2009, electric arc furnaces produced 64% of total steel in the United States.Along with the fast growth of EAF steel production, generation of EAF dust is also rapidly increasing. A survey by AIM Market Research showed that 10 - 20 kg EAF dust was generated for every ton of EAF steel produced [2] In 1999, the United States alone produced 770,000 metric tons of EAF dust [3] In Europe, annual generation rate of EAF dust is more than one million tons [4-5]. In Japan, about 450,000 tons of EAF dust is produced each year [6] Globally, total generation of EAF dust was estimated to be more than 5 million tons per year [5] EAF dust is categorized as a hazardous solid waste since it often contains heavy metals, such as lead, chromium and cadmium. US Environmental Protection Agency (EPA) approves only two methods for treating EAF dust: (1) recycling the dust by EAF-dust recyclers, and (2) specially landfilling the dust for disposal after it is chemically stabilized. These two methods of treating EAF dust are both very costly to EAF steelmakers. It was estimated that a fee of $150 to $200 per ton of EAF dust was paid for various treatment options, which added approximately $2 - 3 cost for every ton of liquid steel produced by electric arc furnaces [?J."

Jan 1, 2011

By W. P. Lass

(San Francisco Meeting, October, 1911.) TEE purpose of this article is not only to describe the plant and method of cyaniding the Treadwell concentrates, but to present some of the results of the experimental work obtained in the past three years for the Alaska-Treadwell Gold Mining Co., at Douglas Island, Alaska., under the direction of F. W. Bradley, Consulting Engineer, and Robert A. Kinzie, General Superintendent, of the affiliated companies. At the time the experimental work was undertaken the concentrates were being shipped to the smeltery at Tacoma, Wash., and the cost for treatment of 3-oz. (gold) concentrates was $11.95 per ton, divided as follows: Smelting-charges, . $4.00 Loading, freight, insurance, etc., 2.89 Interest due to time lost in transit and in settlement, . 0.05 Loss due to settlement for 95 per cent. of the gold at $20 per ounce, 5.01 Total, . . $11.95 From the experimental work described later, it was estimated that 96 per cent. extraction could be made by treatment on the ground, and that the cost, when treating 80 tons per day, would be $3.25 per ton, divided as follows; Per Day. Per Ton. Labor, . $66.16 $0.827 Chemicals, . 76.60 0.960 Power and steam-heat, 67.60 0.845 Marketing-, refining- and other charges, 49.36 0.617 Totals, . . $259.72 $3.250 Adding to this total the 4 per cent treatment-loss, which on 3-oz. concentrates amounts to $2.48, gives a total cost of $5.73 per ton. Comparing this with $11.95, the cost when shipping to the smelter, leaves a net gain of $6.22 per ton by the local

Feb 1, 1912

By Steve Kral

"Liebherr, as most anyone involved with the global mining industry knows, is one of the world’s largest makers of mining and construction heavy equipment. The familyowned company has been around since the 1940s and, according to Stefan Heissler, by the end of next year, will employ about 44,500 people worldwide. Heissler is a member of the board of directors of Liebherr International AG.It all started for the Switzerland-based company when Hans Liebherr first recognized a need for heavy equipment in the construction industry, Heissler said. His first product, introduced in 1949, was the TK10, a mobile crane that, at the time, was a groundbreaking innovation to the heavy construction industry. From there, the company began its growth into a world-leading heavy equipment manufacturer that always relied on innovation.In October, Liebherr gathered a group of mining and construction magazine editors in Leoben, Austria to take a look at the company’s latest addition to the global mining and construction markets. On the mining side, Liebherr provided a demonstration of its T-236 100-t (110-st) haul truck and the PR- 766 50-st (55-st) crawler tractor. The one-day demonstration took place at the Erzberg iron mine near Leoben, where both machines are being proven.The Erzberg Mine, operated by VA Ersberg, has been in operation for about 1,300 years and is said to be Europe’s largest surface mine. It employs about 230 people and mines about 12 Mt/a (13,200 million stpy) of ore, producing about 3 Mt/a (3.3 million stpy) of fine-grained iron ore.T-236 rigid-frame truckThe new T-236 rigid-frame dump truck, with a diesel electric drive system, is Liebherr’s entry into the 100-t (110-st) class and is the first in this class with a four-corner, oilimmersed braking system. The haul truck was first introduced during the 2016 MinExpo in Las Vegas, NV. The unit has since successfully completed its testing phase and is currently in its first field operation trials at the Erzberg iron mine in Austria."

Jan 12, 2017

By C. Roos

Traditionally within the mining industry, the main functional process flow for resource and reserve evaluation proceeds from geologists who build the geological model, to resource estimation geologists (modelers) who estimate the grades, to mining engineers who develop the mine design and schedule. The interface between these three disciplines is not always seamless. Assumptions made during one stage of the process are not always communicated down the line, even though most mining companies have procedures in place to encourage communication across the various disciplines. These procedures do not always achieve their aim due to a variety of reasons including time constraints, appropriate people not being available, or a lack of understanding of what other disciplines require, and the handover process can degenerate into one of sending computer files on to the next discipline in the process flow. This paper focuses on the interface between the resource estimation and mine engineering disciplines, and outlines some of the common assumptions made when generating a resource model and the risks that engineers may be taking when elevating cutoff grades, optimizing schedules or generating forecasts. The case studies presented focus on openpit gold deposits, but the concepts should be applicable throughout the industry. A summary of key questions and recommendations is provided.

Jan 1, 2014

By Jordaan Koos

This report looks at the application of Shaft Boring (SB) as an alternative methodology to conventional mechanized Drill and Blast (D&B), Shaft Sinking. Various Continuous Mechanized Shaft Sinking concepts, equipment and projects are also reviewed in this report. Their significance relates to designs and systems related to Shaft Boring. Shaft Boring is increasingly a method considered for the excavation of deep and increasingly large diameter shafts for mines in hard rock. Many methods have been used as an alternative for D&B Shaft Sinking.

Sep 1, 2017