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By Ekin Güngor, Berkant Ozdemir, Erkan Bayrak, Serdar Ergün, Sedat Esen

"This paper presents the final wall blasting practices at Eldorado Kisladag Gold Mine in Turkey. Benchmark and improved wall control designs were explained in detail. Kisladag Mine has been implementing a high quality slope stability program on-site. The quality of pit walls is generally considered excellent, with very few wall failures being evident and with presplit hole barrels prominent in most areas of the pit. However, a minor scale slope failure occurred recently at the north-east section the pit. A project was initiated to diagnose the cause of the crest loss and evaluate ways to limit its effect on final walls. Final wall blasting practices and geotechnical designs were evaluated. The work presented in this paper showed that changes to the blasting and geotechnical parameters are required atthe north-east section of the pit. Geotechnical design changes were 10 m bench heights with 70 ° slope face angle at that specific area. Having implemented several geotechnical and blast design changes (elimination of the subdrill for the catch bench, appropriate primer location, more favorable blast tie-up and delays), the crest loss was minimized significantly (<1.5 m) (<5 ft)."

Jan 1, 2017

By J. Peterson, D. D. Tannant, J. Todd

"A review of blast designs and improved blasting practices at the EkatiTM diamond mine is presented along with the results of three blast-monitoring experiments. Blast monitoring was undertaken to investigate blast damage mechanisms in the mine’s well jointed rock mass. Rock mass damage caused by production, pre-shear and wall control blasts was measured. EkatiTM uses 270 mm holes for production blasting, and 165 mm holes loaded with a decoupled charge for pre-shearing. The production blasts are loaded with bulk emulsion/ANFO blends. The mine plan involves using 30 m double benches. A 30 m high pre-shear is drilled and blasted prior to the production blasting that is done with sequential 15 m benches. This paper summarizes the monitoring equipment and data gathered to date. IntroductionThe EkatiTM diamond mine is located about 300 km northeast of Yellowknife, Northwest Territories, Canada. The mine is a joint venture of BHP Diamonds Inc. (80%) and geologists Charles Fipke and Stewart Blusson (10% each). The EkatiTM mine is Canada’s first diamond mine and BHP is the operator. The mine is accessed by air and by a winter ice road.The first kimberlite pipe mined at EkatiTM is known as the Panda pipe. The Panda open pit mine will have a total depth of 315 m (Fig. 1), a width of about 600 m, and a 50° overall slope. Initial ore production is 9000 tonnes per day.This paper summarizes the pre-strip blasting and the evolution of the production and wall control blast designs from 1997 to 2000. The initial blast designs and the rationale behind subsequent changes that took place are presented along with the techniques currently in use.The paper also briefly presents an experiment done to measure the rock mass response to blasting. Three blasts were instrumented with geophones, gas pressure sensors and time domain reflectometry cables. A brief summary of the instrumentation and data gathered is included."

Jan 1, 2001

By T N. Little

This paper is concerned with the influence of engineering geology on design of Wall Control Blasts. In the Introduction, the Blast Management Framework and the Blast Design Requirements classification system (previously developed by the author) is drawn upon to set the context. Blasting objective for all wall control blasts involves both profile and damage control. Four classes of approaches for blast design are outlined and briefly discussed. Five distinct wall control blasting techniques are summarised. The general relationship between geology and blast design is explored in the paper. Influence of geology on pre-split and post-split design and blasting direction is highlighted. Wall damage modelling from the closest row of blastholes is also introduced using the Analytical Damage Model (ADM). The relationship of rock properties and explosive selection and in particular the Mach wave generation is introduced to assist blast designer in this regard. Finally a Conceptual Model that relates vibration, damage and rock mass condition has been presented along with some applications that have been undertaken by the developer. Eight conclusions have been formulated based on extensive work in this area and the current study.

Jun 22, 2022

By J. Janeson

Wall control at the Pipe Open Pit is of primary importance in ensuring the long-term stability of the operation, while keeping costs to a minimum. Blasting techniques have been adapted to the variations in competence and structure of the wall rocks. A portion of the perimeter wall is being developed in incompetent peridotite . A recent change in pit slope design provides a wide safety berm on alternate benches. A support program which consists of pinning the crests of wide berms with vertical reinforced concrete dowels and horizontal bolting of walls shows evidence of increasing the stability of the pit walls. This paper describes the blasting and support techniques which are contributing to successful wall control in the Pipe operation.

Jan 1, 1979

Barrick Gold Granny Smith Mine is currently undergoing conversion from an open cut operation to an underground mine at the Wallaby deposit. The underground project commenced in 2005 with the development of the reserves immediately below the pit and is now currently entering a production ramp-up phase for mining of these two initial surfaces below the pit. With increasing gold prices the owner has been forced to re-evaluate the underground project and has decided to investigate the potential of a deep level mine. This deep level underground mine presents a collection of challenges with the most notable being exploitation of a series of well separated near horizontal lodes ranging in thickness from less than 1 to 20 m. A variety of room and pillar mining methods are employed for extraction with careful consideration to resource recovery and pillar design for long-term stability. Compounding these deep level challenges is a need to accelerate mine level development to maintain the production profile of the mine. This paper describes the challenges, key learnings and outcomes of the studies undertaken to date associated with this project.

Jan 1, 2008

By Ben Roderds

The Waneta Expansion Project (WAX) is located near the existing Waneta Dam site at the confluence of the Pend d?Oreille and Columbia rivers, approximately 10 km (6.2 miles) south of Trail, BC, Canada. The WAX owners consist of a partnership between Fortis Inc., Columbia Basin Trust and the Columbia Power Corp. This design-build project was awarded to SNC-Lavalin in late 2010 and is expected to be operational in mid-2015. The WAX consists of a new 335-MW powerhouse, including two new Francis turbine units, each generating approximately 167 MW. The powerhouse is located downstream of the existing Waneta Dam, and will make use of excess water that would otherwise be spilled during the runoff season. Water will be funneled to the turbines through an intake structure and two 10.5- m (34.5-ft) diameter, concrete-lined Penstock Tunnels. A 10-km (6.2-mile) transmission line will connect the powerhouse to existing electrical grids. Redpath/FKCI Waneta Tunnelers (RFK) was subcontracted by the heavy civil contractor, the Aecon/SNC Lavalin (ASL) joint venture, to excavate the two penstock tunnels and install the cast-in-place concrete liner. RFK is a joint venture partnership between J.S. Redpath Ltd., an underground mine contractor located in North Bay, Ontario, and Frontier-Kemper Constructors ULC, a heavy civil tunneling contractor based in Nova Scotia, Canada. Since penstock tunnel excavation was planned using drill-and-blast methods with a significant grade of more than 17 percent, the combined experience of these two contractors was a perfect match.

Mar 1, 2014

By D Craw, C E. Martin, C Smith, C Rufaut

Wangaloa Coal Mine opened in 1945, and by the time of its closure in 1989, had produced 750 000 tonnes of coal and disturbed an area of 75 ha. The original mining licence required land rehabilitation to exotic forestry, however the current owner, Solid Energy, has worked with Crown Minerals and local councils to write a new rehabilitation objective. The site is now being stabilised and replanted with native species, and may be available for public use before the coal mining licence expires in 2007. Site discharge permits expire in 2017, and by that time, it is anticipated that discharge water chemistry will be similar to background levels. MWH are currently contracted for management of the mine rehabilitation project. The Kaitangata coal unit mined at Wangaloa is sulfurous lignite with associated pyrite. Kaitangata coal contains 3.2 wt per cent sulfur, which is higher than most New Zealand coals. Initial analyses at Wangaloa indicate low pH (2.56.2) values in soil, groundwater and surface waters as a result of acid rock drainage (ARD) processes, leading to increased metal mobility and challenging conditions for vegetation. Pilot studies indicate pinus radiata needles contain up to 67 mg/kg boron, and elevated As, Cu and Zn concentrations in surface waters. The main lake at the site has a pH of approximately 4.9, despite lime dosage in 2002. There is a real need for a complete geochemical model of the Wangaloa coal mine. Such a model could be applied to similar restoration projects, and would assist by pinpointing geochemical processes and toxic metal relationships most harmful to the receiving environments. Using this model, rehabilitation in the future will be targeted and more efficient. This project is part of a larger scheme to characterise and model the Wangaloa mine site restoration, including waters, soil, vegetation, geology and invertebrates.

Jan 1, 2003

By AIME AIME

THOUGH the Annual Meeting of the Institute-officially numbered 158 on the records was delayed a bit at the start by low steam pressure on the locomotives bringing members to New York, the crowd that finally arrived more than lived up to expectations, and the technical program had few difficulties because of absent authors or lack of competent discussers. The transportation difficulties were occasioned by the fact that Monday, Feb. 15, was the third coldest day in the 72 year history of the New York Weather Bureau, the official temperature being 8 below zero. The New York Central&apos;s premier train, the 20th Century, due at 9:30 a.m., arrived about 6:30 p.m., and the Commodore, another crack train from Chicago, was about equally late.

Jan 1, 1943

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

"It’s been 80 years since Charles Warman invented the iconic Warman slurry pump, a pump that revolutionized the mining industry and continues to push the boundaries of pump performance to this day.In honor of this legendary brand, Weir Minerals hosted an event at the end of May in Kalgoorlie, Western Australia. Throughout the evening, attendees relived Warman pumps’ history and gained an insight into some of the future innovations planned.“It was a privilege to share this special night with some of our key customers, past and present employees, and members of the Western Australian School of Mines,” said Ricardo Garib, divisional president of Weir Minerals. “Warman is one of our leading brands. It has truly shaped the mining industry over the past 80 years and is a product we are all very proud of. The Warman pump, invented to solve high wear issues in slurry pumping, created a thriving industrial business that is now the cornerstone of Weir Minerals with more than 8,000 people, and more than 150 manufacturing and service centers across the globe.”Always inventingCharles Warman invented the Warman slurry pump in Kalgoorlie in 1938. It was a hardwearing slurry pump that used replaceable liners and a replaceable impeller, something that had never been done before.“Charles Warman was a visionary and an innovator. The use of rubber lining in the pump was groundbreaking as it reduced total ownership costs, was safer to handle and offered extended wear life in many abrasive slurry applications. It is a great example of solving customer problems with material science, and is still taught in universities today,” said Marcus Lane, global product manager for centrifugal pumps at Weir Minerals.It was quickly adopted throughout the goldfields in Western Australia and by the 1950s, as customer demand rose, Warman expanded his business by opening offices in Sydney and Perth.During the 1960s the rapid growth of the business continued with manufacturing and sales outlets established around the world. The Warman Series ‘A’ pump was accepted and became a world leader in its field. Further work on the Warman AH pump resulted in the development of interchangeable metal and rubber wearing components."

Jan 9, 2018

By Mike Ounpuu

"Locked cycle testing has become more common practice in the last 10 years. Reasons vary from a desire to avoid pilot plant testing, demand for more variability testing within deposits, and perhaps most importantly, a request from the financial institutions who invariably finance many of the projects. Surprisingly, many people don’t understand locked cycle testing, analysis and balancing. This paper provides a brief overview of locked cycle testing, and then progresses into a more detailed discussion on the analysis and balancing of locked cycle test data. The paper endeavors to educate CMP personnel on how to determine if the test was good and if a reasonable metallurgical projection was made. The paper uses case studies to illustrate the key points.INTRODUCTIONA locked cycle test is a repetitive batch used to simulate a continuous circuit. The basic procedure has a complete batch test performed in the first cycle which is then followed by similar batch tests which have “intermediate” material from the previous cycle added to the appropriate location in the current cycle. These batch tests, or cycles, are continued in this iterative manner for an arbitrary number of cycles. The final products from each cycle, i.e. final concentrate and final tailings, are filtered and thus removed from further processing. At the end of the test, all the products, final and intermediate, are dried, weighed and subjected to chemical analysis. The test is balanced and a metallurgical projection is made.This description can be found in many of our classical textbooks for the mineral engineer 1, 2, 3,4. Unfortunately, none of these textbooks provide any discussion beyond the basic procedure. Often, they provide comments such as in Taggart’ where he states; “It is questionable whether in any case it approximates mill results any more closely than the standard batch test”. It is truly surprising that our classic textbooks promote that locked cycle tests are more art than science, and suggest that they can be of dubious value. None of the textbooks provide meaningful insight or discussion in how to assess:"

Jan 1, 2001

By P J. Handley

"Predicting how coal seams will be beneficiated through the coal handling processing plant (CHPP) has long been challenging within BHP Coal. Various coal seams from different areas are mined and stockpiled separately, often depending upon a deleterious coal quality parameter; high/low trace elements for example. These stockpiles are then fed in different ratios into the CHPP to produce the desired product/s. In understanding the washability characteristics of the feed source, mine geologists and process engineers work together to improve the beneficiation of different coal materials through the CHPP.For the majority of the BHP Coal deposits, the washability data is available for the coal seams across the deposits. However, no previous standardised modelling and prediction technique existed that could ensure the correct information was available for forecasting and refining CHPP processes. This paper will discuss the steps undertaken to implement a geometallurgical prediction tool that simplified and streamlined the washability modelling and yield estimation process. The value realised to the BHP Coal assets resulting from this process was: improved compliance to plan increased throughput increased CHPP recovery through improved efficiencies and increased revenues.CITATION:Handley, P J, 2017. Washability modelling and estimation techniques used to improve coal handling preparation plant beneficiation, in Proceedings Tenth International Mining Geology Conference 2017, pp 327–336 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 20, 2017

By Andrew R. Klaetsch, Peter W. Deming

"The Washington Avenue tunnel in Kingston, NY was completed in 1912 to convey combined storm water and sanitary sewage. Over a mile in length, the tunnel was driven almost entirely in bedrock, with the exception of an approximately 170 foot long brick arch segment constructed in soil. About 90 years after the tunnel was put into service, persistent subsidence problems and sinkholes were observed in Washington Avenue above the shield-driven soil tunnel segment, eventually causing the important traffic thoroughfare to be closed. Subsequent tunnel inspections revealed a breach in the brick arch and a significant volume of fine soil within the tunnel. A two-phase remediation program was implemented to control seepage, reduce soil migration, and remedy sinkhole problems. The first phase included in-situ soil densification by vibratory pile probe driving to improve density in shallow sandy soil loosened by ground loss. The second phase included installation of a continuous soilcrete arch structure over and alongside the tunnel, extending to rock or compact glacial till and spanning the length of the soil tunnel segment. Overlapping vertical soilcrete columns were installed through interlayered sandy and clayey silt by jet grouting to form a continuous arch structure, using grout parameters verified by full scale field testing.PROJECT BACKGROUNDThe Washington Avenue tunnel in Kingston, NY (Figure 1) was completed in 1912 to convey combined storm water and sanitary sewage to Rondout Creek by the Board of Water Supply of the City of New York. The tunnel is over a mile in length and constructed primarily in rock. Contract documents indicate the tunnel was designed with a horseshoe shape at least 3 ft wide and 5.5 ft high."

Jan 1, 2016

Jan 1, 1882

By Thomas R. Kuesel

Just south of the L&apos;Enfant Station in Seventh Street, the WMATA system splits into two branches, each comprising twin single-track soft ground tunnels. Immediately at the beginning of the section, Interstate Route 95 crosses transversely over the alignment in open cut, removing most of the cover over the tunnels. Seventh Street spans I-95 on a bridge whose abutments and pier also cross transversely over the four tunnels, with their footings as little as 7 feet above the tunnel crown (Figure 1). Soil investigations revealed that the tunnels would have to be driven through mixed face, with a clay invert and a waterlogged sand crown. Thus, there was a good chance that the roof would fall in, leaving 1-95 and the Seventh Street Bridge in a crater. Since there was no roof that could be counted on, these were figuratively (and potentially truly) Washington Metro&apos;s Topless Tunnels (Figures 2 and 3). DESIGN ALTERNATIVES Faced with this situation, the designers considered several options, including temporary detours that would permit demolition of the bridge and building tunnels under the 1-95 Freeway by cut-and-cover methods. They also investigated structural underpinning of the bridge and freeway pavement, and strengthening the bridge abutments and center pier by post-tensioning to enable them to span over any subsidence trough.

Jan 1, 1976

By William S. Alldredge

The Washington Metropolitan Area Transit Authority(WMATA) officially came into existence in February 1967 after the District of Columbia, Maryland, and Virginia joined in a com¬pact pursuant to Federal creative legislation signed the previous November to build a regional rapid rail transit system called METRO (1). The parent organization was the National Capital Transportation Agency (NCTA), a Federal agency, subject to Federal statutes and regulations. Soon after the completion of the transition from NCTA to the new "non-Federal" status of the Authority, the Board of Directors of the Authority formally adopted procurement policies and procedures (2). These are specific statements concerning competition by formal advertising for bids or by solicitation of proposals for negotiation, contracting authority, approval of awards, awards of contract modifications, and processing of claims and disputes. These policies and procedures are silent as to Federal procurement statutes and regulations. But because of the Authority&apos;s origin, the sensitive nature of the compact among the several sovereign jurisdictions, Federal financing of two-thirds of the costs, and the resultant surveillance by the General Accounting Office over staff operations, the Authority&apos;s procurement practices follow closely Federal regulations adapted to WMATA&apos;s needs. This is an important point and is the foundation of contractual relations between the Authority as the owner and its construction contractors. Various constraints and flexibilities of this arrangement with respect to excavation and tunneling contracts will be pointed out in the ensuing discussions.

Jan 1, 1974

By T. F. Witherbee

It is proposed to give, first, a description of the works; second, a report of the first six months of the present blast; and third, such improvements as have been suggested by the practical working. The site selected for this furnace was, at the time of commencing work, October, 1872, entirely covered by the navigable waters of Lake Champlain. A coffer-dam was first built of cribs of round timber filled with stone, forming three sides, while the shore answered for the fourth. Considerable excavating was done with a steam-dredge, a hole being left for it to pass out. The opening was then built up, and the cribbing banked up with blue clay from the bottom of the lake, to render it water-tight and the dam pumped out; the remainder of the excavating being done by hand. All of the foundations, with the exception of the elevator-tower, and fifteen feet of the east side of hot blast, rest on the Potsdam sandstone, which forms the shore line, dipping into the lake at an angle of fifteen degrees. Owing to jogs in the formation, a much greater depth was found necessary than was at first anticipated, the foundation under the stack

By Charles D. Walcott

Jan 1, 1901

"The Washoe Smelter is situated about two miles east of the City of Anaconda. The smelter site includes about 240 acres and peculiarly adapts itself in topography to the efficient handling of material. By reason of its being on a hill side it is possible to make the level of delivery of the product of one building the level of the charge floor of the next succeeding one.THE ORES: The ore treated comes principally from the Butte district and is hauled by the Butte, Anaconda & Pacific railway, a distance of twenty-eight miles, in trains of fifty 50-ton bottom-dump cars to the railroad yards at East Anaconda. At this point these trains are• split up according to their destination,—that is, as to whether they go to the concentrator and sampling mill ore bins, or to the storage bins. In each case they are made up into trains of eight or sixteen cars, according to the size of engine to be used, and are carefully weighed before delivery to their respective bills.Some idea of the magnitude of the works may be obtained from the following figures:Amount of ore that can be treated in 24 hours…12,000 tonsLime rock from adjacent quarries…2,300 tonsCoke used…500 tonsCoal for reverberatory use…500 tonsCoal for power use…50 tonsWater, per minute, 35,000 gallons.Men employed in and around Anaconda, 3,000. Monthly payroll for above, $300,000.00."

Jan 1, 1913

By Evan O. Jones

Processes involving distillation under reduced pressure were developed at the Pacific Northwest Laboratory several years ago to recover spent acid solutions generated during the manufacture of nuclear fuel for the N-Reactor at the Hanford site. Following construction and testing of a pilot-plant, the technology was licensed to Viatec Recovery Systems, Inc. for commercialization. The technology developed included specialized distillation and rectification of volatile acids, removal of water and/or volatile acid from sulfuric acid, and precipitation of salts. A key feature of the Waste Acid Detoxification and Reclamation (WADR) technology is the development and use of advanced thermoplastic and fluoropolymer materials of construction in all critical process equipment. The technology was then expanded to include crystallization to recover metal salts for possible reuse. Economic and environmental advantages of the procedures include recovery of acids for reuse, simplification or elimination of the disposal of waste solutions, and possible recovery of metals. Industries expected to benefit from such applications include galvanizing, electroplating, sand leaching and any where metals are cleaned in acid solutions. Currently a modular system has been assembled for recovery of several different spent acid solutions.

Jan 1, 1995