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Jan 1, 1996

This paper summarises the development t,) date for the Hidden Valley Gold (HVG) Project. It starts with the original exploration work, covers the detailed feasibility study activities and concludes with the current phase of extra exploration drilling. A brief technical summary has been made from the various mining, process and environmental studies that were undertaken as part of the project approval process. A discussion of the influential non-technical factors is included, as well as a view of the future prospects for an operating mine. The project was always seen as marginal, given the low grades, small resource and short mine life. However the capital and operating costs were lowered with aggressive design and it was regarded an acceptable development by CRA. The opportunity was taken to review the project when delays in start-up were encountered. An updated financial evaluation showed a subeconomic resource in 1990 terms and this resulted in a new exploration phase to identify a larger deposit.

Jan 1, 1991

The National Mining Hall of Fame and Museum (NMHF&M) will induct its the 2014 National Mining Hall of Fame Class on Sept. 13, 2014 during its 27th Annual Induction Banquet and Ceremony at the Westin Hotel in Denver, CO. Representing the domestic and worldwide metal production, education, and health and safety sectors of the industry, this year?s four inductees cover a diverse cross-section of the mining industry. Harry M. Conger III, Günther Franz (Frank) Joklik, Ellen Swallow Richards and Dr. Alfred Weiss will join 223 other mining industry pioneers when they are formally inducted into the National Mining Hall of Fame. They were selected for being visionaries, leaders and ambassadors, both within their own sectors and across the industry at large. Conger was a great role model and strong advocate within Homestake Mining Co. and among his industry peers on behalf of environmentally responsible, safe, profitable and high-performance operations. As chairman and chief executive officer, Conger was instrumental in revitalizing and rebuilding Homestake into an industry leader in technological advances and environmental protection. Through his contributions in exploration, project development and operations management as Kennecott president and chief executive, Joklik did much to strengthen Kennecott as a company and assisted in restoring the competitiveness of the U.S. mining industry. Richards is generally recognized as the founder of ecology. She was the very definition of a pioneer in such diverse fields as chemistry, geology and mineralogy, mining and metallurgy, environmental science, public health, home economics and education. Weiss was a true visionary in using quantitative methods and digital computers to aid mineral exploration, plan and design mines, operate mineral production facilities and integrate the disparate information resources throughout a mining company into a modern management information system. NMHF&M Board of Directors Chairman, Paul C. Jones, said, ?Again this year we are honored to be able to induct an outstanding group of deserving individuals who have made exceptional contributions to the mining industry in the United States. Included are two living inductees who have made significant contributions to management in the industry. One inductee was the first female graduate from the Massachusetts Institute of Technology, its first female faculty member and the first female member of AIME who had an outstanding career as a mineral investigator in the United States. Another inductee was a lifetime innovator in bringing digital technology into common use in our industry. Each of our 2014 inductees made significant and lasting contributions to our industry and are well deserving of becoming a member of the National Mining Hall of Fame.? The Hall of Fame Induction Banquet and Ceremony is a marquee event for the National Mining Hall of Fame and Museum each year. The 27th Annual Induction Ceremony and Banquet will be held at the Westin Hotel in Denver, CO on Saturday, Sept. 13, 2014. For banquet reservations, contact the NMHF&M office at 719-486-1229. More information is available on the NMHF&M website at www.mininghalloffame.org.

Safety is the No. 1 concern of any drill contractor or mine operator. Everyone in the industry knows a safe site helps stabilize operational costs and enables higher productivity. When it comes to exploration drilling, research has proven a majority of injuries are caused by the mishandling of coring rods. A driller helper will typically handle up to 50 rods per shift or up to 15,000 rods per year. With an annual 340 t (750,000 lb) in rods managed by hand, the risk of serious injury is extremely high. Because of this, the top request from the exploration industry is diamond rod handling. The Boart Longyear 4200 surface exploration drill, slated for release in 2009, will give the industry a hand-free, operationally safe rig.. Developed through the collaboration of its global drilling services and products divisions and targeted at the 1,200-m (3,900-ft) NQ market, the upcoming Boart Longyear 4200 surface exploration drill features the safest and most flexible rod management sys-tem in its class. The rig includes the industry?s first, truly hands-free rod handling system. This increases operator safety on the jobsite. In addition to the rod handler, the rig also features many new innovations that boost productivity and rig efficiency while minimizing the risk of downtime due to component failure or operator error. Boart Longyear has also included an intelligent PC-based operating system designed to allow complete drilling control as well as diagnostics reporting for the rig.

Jan 1, 2009

By P. L. Ngwenyama, I. Maubane

Soundless chemical demolition agents (SCDAs) are proving to be the future of sustainable and environmental-friendly mining. These expansive chemicals become critical when there is a need to break rock close to communities, environmentally sensitive areas, and critical structures and infrastructure. Unlike explosives, the SCDAs do not generate air-blast, ground vibrations, flyrock, noise, dust, and noxious fumes, which can negatively affect the environment, surrounding communities, sensitive areas, and critical structures and infrastructure. Over the years, several types of SCDA products have been used successfully in the civil and construction industries for the demolition of old and dilapidated buildings near vibrations and environmentally sensitive areas. They have also been used to fragment boulders in the mining and construction industries. However, to date, no study has investigated the applications of soundless chemical demolition on a large-scale in opencast mines. Therefore, this study evaluated whether soundless chemical demolition can break large volumes of in situ rock. This was done by conducting five trials using Nex-Pand soundless chemical demolition agents in four different surface mining sites. Trial 1 was unsuccessful as it was unable to break the rock due to the large confinement between the drilled holes and the use of a hole diameter that was 182% larger than recommended. Trial 2 was a success as it was able to fracture the rock with a crack width that reached 110 mm after 72 hours. Trial 3 generated cracks at the biggest hole diameter of 102 mm. The cracks developed and ceased to increase after 96 hours at a crack width of 100 mm. Trial 4 achieved the smallest crack width due to a very competent rock compared to the other sites. Trial 5 generated cracks at a slower rate than other trials because of the use of Nex-Pand powder at lower ambient temperatures than recommended. These trials proved that soundless chemical demolition agents can replace explosives in areas closer to sensitive infrastructure and communities. This will ultimately enable mines to unlock value and access deposits in these areas.

Jul 23, 2025

By R. S. Dean

[Methods s of preparing the manganese metal that has been used in chemical and metallurgical investigations have passed through a cycle. Most of the investigations made before the turn of the century, used Moissen's pyrophoric manganese.3/ This material was made by electrolysis into a mercury cathode and distillation in vacuo. The material was essentially pure, and investigations in which it was employed (with proper precautions against oxidation) led to accurate results on tie intrinsic behavior of metallic manganese.]

Jan 1, 1941

By J Belke

Murrin Murrin Operations have not had a successful beginning. Numerous reliability and operability issues, many of which are the result of design decisions, have been addressed through mechanical and operational changes and the CCD circuit is no exception. Four design aspects of the CCD circuit that have caused and continue to cause operational problems are: the inclusion of solution neutralisation gypsum in the CCD circuit feed which was designed solely for HPAL residue without proper investigation of its impact on the achievable underflow density and resulting wash efficiency; the decision to construct the thickener base from thickened solids; the lack of redundancy in the overflow, underflow and tailings pipe work; and the lack of thickener operational flexibility in the central rake-lift and feedwell dilution system. In November 2002, the lack of operational flexibility in the rake-lift and the feedwell dilution system was improved through mechanical modification as follows:CCD1 rake mechanism was modified to allow central vertical lift of 600 mm; and CCD1 changed to forced dilution using the Outokumpu TurbodilRântechnology by replacing the E-DucânRtechnology of Eimco. The installation and the results of the CCD1 rake-lift mechanism and feedwell dilution system changes are discussed in this paper.

Jan 1, 2004

By D. X. Tang, G. Wilson, S. S. Peng

Design and implementation of a roof bolting plan requires reliable geotechnical information of strata, such as rock strength, and locations of interfaces and voids/fractures. The drilling parameters obtained during normal roof bolt installation cycle provide a fast and economic way to gather information on the geological structure within the bolted horizon. The purpose of this research project is to develop a method for identifying the geological features in the mine roof strata based on drilling parameters of roof bolter. The criterion for void/fracture prediction has been developed and proven valid. This paper focuses on the estimation of the strength of roof strata by using drilling parameters. Based on the results of a series of underground and laboratory tests, feed pressure is found to be the most sensitive parameter when the strength of roof strata changes. Moreover, it was also found that both penetration rate and rotation rate have obvious impact on the magnitude of feed pressure. Based on these findings, the criterion for the estimation of roof strata strength has been developed using the relationship among feed pressure, penetration rate and rotation rate and implemented in MRGIS.

Jan 1, 2006

Jan 1, 1998

By Arndt C. R

The Ispat Mexicana SA de CV (IMEXSA) pelletising plant is located at Lazaro Cardenas on the west coast of Mexico. It is the primary source of feed stock for the adjacent direct reduction (DR) plants and steelmaking facilities. The initial design of the pellet plant began in 1981 for 3 Mtpa of DR grade pellets using local concentrate received by pipeline.' Several construction delays, an ownership change, and a decision to use imported concentrates delivered in 60 000 to 90 000 tonnes ship cargoes required flowsheet modifications and additions. The design concepts are described for the plant which includes concentrate regrind to final pelletising particle size.

Jan 1, 1999

By W. van Antwerpen, J. Guzek, A. Lane

Strategy is about making choices. Mining companies choose to do certain things and not to do other things. Mining is a long-term business, and the choices made typically have large investments attached to them, long payback periods, and significant socio-economic consequences. In today’s uncertain world, it is important to make the right choices. The mining industry in South Africa finds itself in a difficult situation. Operating conditions are tough, the socio-political environment is complex, and financial performance is under pressure. The choices made by all the stakeholders in this industry in the short term will shape the future of the industry. This paper characterizes some of the big, difficult decisions faced by the mining industry in the South African context, and discusses how these decisions could be approached in a fact-based and robust way.

Jan 1, 2015

By D. A. Trotter, G. J. Goddard

"This paper describes a method of deciding on various design parameters for a sublevel caving layout. Layout design curves are obtained from the output of a computer optimization program. The program uses mathematical relationships derived from the theory of gravity flow of material to optimize the large number of interdependent design variables which are involved.IntroductionIn the design of an efficient sublevel caving mining system, a large number of interrelated variables need to be considered. Although many papers discuss individual variables, very little exists in the literature to show how these variables interact to achieve optimum results. This can lead to trial and error in sublevel caving design, which can prove costly, particularly because sublevel caving is a mining method which requires integration with sublevels above and below. With no pillars being left, experimental stopes cannot be isolated for study. Unfortunately, the complexity of layout design and the costs associated with trial and error have caused many planning engineers to choose more tried and tested mining methods.Sublevel caving works best to extract low-value ore surrounded by incompetent rock. All phases of the mining method can be highly mechanized, allowing low operating costs and high production rates. Good safety records are achieved, as workers are always in 'good' ground and the method is regular, making it comparable to an industrial process."

Jan 1, 1981

By H. Warren Newcomen

Assessments of the stability performance of open pit highwalls have traditionally been based on consideration of surface movement rates. Although generally accepted in industry, this approach presents challenges for establishing appropriate threshold values to allow for safe mining operations and does not address the issue of total strain. Surface movement monitoring data from a limited number of open pit mining operations in North and South America has been evaluated in terms of highwall strain, rock mass quality and inferred mechanism of instability. Threshold strain levels for key stages of highwall stability proposed from previous work have been reviewed and are generally endorsed based on evaluation of additional data. An empirical highwall strain criteria for the assessment of highwall stability performance is postulated based on the observed trends in highwall strain data from the case histories presented.

May 1, 2004

By Janet Torma-Krajewski

Research has shown that an ergonomics process that identifies risk factors, devises solutions to reduce musculoskeletal disorders (MSDs), and evaluates the effectiveness of the solutions can lower worker exposure to risk factors and MSDs and improve productivity. A review of the Mine Safety and Health Administration (MSHA) injury/illness database indicated that 46% of illnesses in 2004 were associated with repetitive trauma and 35% of nonfatal lost days involved material handling during 2001? 2004. Even though these statistics show that MSDs significantly contribute to occupational illnesses and injuries in the U.S. mining industry, few mining companies have implemented an ergonomics process. Despite the many unique challenges in the mining environment, three mining companies partnered with the MSD Prevention Team at the National Institute for Occupational Safety and Health?s Pittsburgh Research Laboratory to demonstrate that an ergonomics process could be systematically implemented and effectively integrated with existing safety and health programs. Because these three mining companies were very different in organization, culture, and size, the ergonomics processes had to be modified to meet the needs of each company. A description of how these three companies applied ergonomics and the tools and training used to implement their processes is given. Prior to discussing the case studies, general information on the elements of an ergonomics process is provided.

Feb 1, 2009

By Harold M. Smith

[Important discoveries of new oil fields were made in 1937 in the State of Illinois. Oil production, which was virtually constant during 1934, 1935, and 1936 at about 4,400,000 barrels a year, a increased to 7,499,000, barrels during 1937, and in 1938 this production was trebled. In 1939, 94,302,0003/ barrels were produced (almost foot times the 1938 quantity), making Illinois one of the cost important oil-producing areas in the United States. The Bureau of Mines has analyzed 35 samples of petroleum from these new Illinois fields and presents the analyses herein. Included with them in this report are analyses of seven samples from fields developed before 1936.]

Jan 1, 1940

By Harold M. Smith

Important discoveries of new oil fields were made in 1937 in the State of Illinois. Oil production, which was virtually constant during 1934, 1935, and 1936 at about 4,400,000 barrels a year, a increased to 7,499,000, barrels during 1937, and in 1938 this production was trebled. In 1939, 94,302,0003/ barrels were produced (almost four times the 1938 quantity), making Illinois one of the cost important oil-producing areas in the United States. The Bureau of Mines has analyzed 35 samples of petroleum from these new Illinois fields and presents the analyses herein. Included with them in this report are analyses of seven samples from fields developed before 1936.

Jan 1, 1940

By Robert A. Cortese, Henry E. Perlee

Coal dust and float coal dust, produced during normal mining operations, in underground coal mines, are carried from the point of origin downstream by the ventilating air, where it deposits on the surfaces of the mine entry. In an explosion, this dust is lifted from the surfaces by the aerodynamic disturbances and, if of sufficient quantity, can continue to propagate the explosion. To prevent the surface coal dust from contributing, it must be inerted, typically by spreading pulverized limestone, i.e., rock dust, over the coal dust surface. To facilitate the dusting operation, the National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory(PRL), developed an automated system that continuously monitors the accumulation of coal dust. This system could activate a rock-dusting machine that disperses rock dust into the ventilation air when dangerous deposits accumulate and deactivate the machine when sufficient inert has been deposited on top of the coal dust. The system consists of a microprocessor-controlled optical float dust deposition meter. This device measures the light intensity reflected from a deposited layer of dust. A standard cap lamp is used as a fixed-position light source. From the reflected light signal, the microprocessor determines the hazard level of the deposited layer and performs the appropriate action. Full-scale studies conducted in the Experimental Mine at PRL's Lake Lynn Laboratory, using alternating thin layers of rock dust and coal dust, successfully demonstrated the operation of the device. Based on the statistical data from these studies, a mathematical model was developed to predict long-term error in total rock dust content using this inerting procedure. Downwind dust dispersion was also examined to provide optimum placement of the dust sensors and to determine the need for better rock dust dispersion techniques.

Jan 5, 1998

IN all wet concentration processes it is of primary importance to determine to what degree the crushing must be carried in order to obtain the maximum profit per ton of ore milled.To effect a clean separation, either by gravity or flotation treatment, between either one valuable sulphide from another, or a sUlphide from the gangue, the ore must have been subjected to grinding to such an extent that the particles to be separated are completely liberated from each other.Insufficient crushing will result in either an incomplete separation of the sulphides from each other, and thus a loss of the one sulphide in the other, or else a loss of the valuable sulphide in the gangue.This being so, the question arises whether the added cost of extra crushing would be economically warranted by the increased recovery consequent on such a step.

Jan 1, 1927

By R G. Richards

The Australian glass sand industry produces some 2.8 million tonnes per annum of silica sand, of which about 2.0 million tonnes are exported and the rest is for the domestic market. Approximate production rates for each Australian state are listed. The variety of processing methods used in the currently exploited deposits reflects the size, location, and characteristics of the various deposits and the requirement of the end market/s. The industry uses to a large extent equipment developed for the separation of mineral sands, particularly as it applies to low grade heavy mineral deposits, where low cost, high capacity and metallurgically efficient equipment has proved eminently suitable for the production of the low value glass sands. The requirements of the domestic market, as well as those of the present and potential export markets are discussed covering quality requirements, distribution channels and other factors critical to success.

Jan 1, 1990

By Bhaskar B. Thapa

The proposed Caldecott fourth bore will consist of a two lane highway tunnel along California State Route 24 near the City of Oakland. The proposed design and construction sequence for the 15-m-diameter tunnel are based on the New Austrian Tunneling Method (NATM). The initial support system incorporates combinations of shotcrete, rock dowels, lattice girders, spiles, and grouted steel pipe canopies. The final lining is cast-in-place reinforced concrete. A waterproofing membrane and drainage system are placed between the initial and final linings. State Route 24 is a lifeline route, required to be open to emergency vehicles within 72 hours after a major earthquake, defined as having a return period of 1,500 years and a peak ground acceleration of 1.2 g. Although the seismic design criteria are stringent, the design of the tunnel lining system is ultimately controlled by static ground loads in the weak rock along the alignment.

Jan 1, 2008