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By M. O. Magnuson

This publication describes abandoned-mine fire-control work administered by the Bureau of Mines under cooperative agreements with State and local governments. The work was done by private contractors under the supervision of Bureau engineers. The work is authorized by Public Law 738, approved August 31, 1954, and Public Law 89-4, approved March 9, 1965. Earlier work was authorized by Interior Department Appropriations Acts for fiscal years 1949-55. A total of 70 fires have been controlled under this program in the eastern bituminous region. The nature and extent of the abandoned-mine fire problem in the bituminous region is discussed, and the methods used for controlling these fires are described. The methods that have been used, either singly or in combination, include loading out and cooling the burning material, installing fire barriers, surface sealing, and water and pneumatic flushing.

Jan 1, 1974

By Chang-Young Choi

Korea Zinc commenced zinc production in 1978 with a capacity of 50,000 tpa. Since then, continuous investments have been made and resulted in Korea Zinc now being the biggest zinc and lead producer in the world. In the course of increasing zinc production capacity, the company management realized that the company needed a lead smelter to prevent the solid waste disposal problems by treating the lead containing solid waste. This paper begins by briefly stating the objectives and the roles of the lead smelter at Onsan. It describes the QSL process and the TSL process, and further extends the description of the TSL process, through which harmless inert solid waste could be produced for secure final disposal. It is also mentioned that the TSL process plays an important role in the integration of zinc and lead production. Throughout the paper, a positive attitude in handling the environmental issues in the non-ferrous smelting industry is emphasized. Finally, a solution for the solid waste disposal problem in the zinc and lead industry is proposed, with which the environmental issues can be an opportunity rather than a crisis. The current operation at Ousan suggests the future direction of the non-ferrous smelting technology that all of the zinc and lead producers should pursue.

Jan 1, 2003

By V 9. 0 / 300 dpi

ATHOUGH turquoise mining was, so far as we know, the first large, well-organized mining operation,' gem mining, from the Roman con-quest of Egypt until the opening of the South African pipe diamond mines some 50 years ago, was largely carried on' by individuals 01' small companies in a relatively primitive way. Now" however" gem mining does not yield in efficiency or in scale of operations to the mining of other mineral products. In 1926 the diamond mines of the world milled some 9,000,000 cu. yd. and produced 0,43 cu. yd. diamonds, a remarkable example of concentration. The Premier Diamond Mining Co. up to Oct. 31, 1927, had milled 116,455,550 loads (each of 16 cu. ft.) from which 26,-217,144 carats of diamonds" worth £29,897,971 2s, 9d., were recovered. The Burma Ruby Mines, Ltd., operating sever-al alluvial mines in Burma in 1911-12, mined and milled 1,479,845 truckloads of gemmiferous earth for 15c. per load. We of the industry can there-fore, with good grace, disclose some of the myths and also describe some of the primitive mining methods of the, dark ages of our industry. The methods, so far as I know, were not patented, and if they were, the patents have expired, so that engineers in other branches of the art are free to use them if they see fit.

Jan 1, 1928

By Robert Alfred

This paper is one of a aeries being published by the Federal Bureau of Mines on methods and practices used in mining and preparing crushed stone for market. Performance, in terms of units of work or tons produced per machine and per operator man-hour, is given whenever that information can be obtained. Direct operating costs are useful for comparing different methods and are included if available. In addition to descriptions of equipment and methods used the Bureau considered it desirable to discuss the engineering reasons for the choices that have been made, This paper is particularly concerned with the operation of the Liberty quarry and plant of the Campbell Limestone Co, The plant is in Pickens County, adjacent to the main line of the Southern Railway, and is about 18 miles west of Greenville, S, C. Access also is available by United States Highway No, 123, The company's main offices are at Knoxville, Tenn.

Jan 1, 1958

By F. Keith Shelton

"INTRODUCTION Cobalt is an essential metal in the normal industrial ac¬tivity of the United States. Being an important constituent of high-speed steels and other cutting-tool materials, it becomes of critically essential importance during periods of national emergency. 3/ The Presidential order of December 20, 1940, included cobalt among other essential commodities that could be exported only under license. The Executive order 4/ listed cobalt metal, cobalt oxide, and alloys containing more than 5 per¬cent cobalt as being within the licensing requirements.There was no domestic marketed production of, cobalt products from 1931 until 1940 when the Pyrites Co. 5/ produced some cobalt oxide. The major portion of the domestic cobalt requirements has been obtained from Northern Rhodesia, the Belgian Congo, and French Morocco. 6/ The uncertainty of sea transportation from those sources of supply demanded that steps be taken to obtain from domestic raw materials an adequate supply of cobalt for use in the materials required for production of indispensable machined war metal products. In connection with the national policy for attaining self-sufficiency of strategic and critical materials, the Bureau of Mines, Boulder City, Nev., Experiment Station initiated studies to recover cobalt from the low-grade oxidized cobalt deposits in the Goodsprings district, Nevada. Hewett 7/ reported occurrence of cobalt specifically in the Blue Jay, Columbia, Copper Chief, and Highline mines and generally over a widespread area in the district."

Jan 1, 1946

By A. W. Bryson, S. P. Fox, S. A. Godorr

"This work is an extension of a previous investigation on the development of surface roughness during electrodeposition of copper. A comprehensive model based on diffusion and migration in a force field together with surface diffusion and sticking probabilities is used to generate profiles which are compared to those produced experimentally. The roughness is characterized by using the technique of fractal geometry which is shown to describe both qualitatively and 9uantitatively the development of surface morphology during electrodeposition.The work is extended to the deposition of copper in the presence of various concentrations of thiourea. The development of roughness is observed experimentally on the edge of a thin copper disc mounted between two glass plates. This enables photographs to be taken at various stages during growth. The surface outline is digitized using an image analyzer which enables the fractal dimension to be determined as growth proceeds. As expected, the presence of thiourea at low concentrations produces a fractal dimension which is closer to unity (i.e. the surface becomes smoother).IntroductionThe development of surface morphology during electrodeposition has far-reaching implications for copper plating in the electrowinning and electrorefining processes. Short circuits as the cathode surface grows unevenly require operator intervention in a dangerous environment and imply processing delays, and the inclusion of electrolyte in small gaps in the plated cathode have implications in downstream processing of the cathode. Higher current densities are obviously desirable, as they result in greater production rates, but as shown by Ettel et. al.(l), Harvey et. al.(2), Cook (3), and Harvey et. al.(4), it is not possible to operate near the projected economically optimum conditions because the electrodeposition of copper from sulphate and acid solutions is a mass transfer controlled process. It has been shown (Ettel et. al.(l), Harvey et. al.(2)) that the closer a system operates to mass transfer limiting conditions, the poorer the resulting cathode quality. One solution is to use agitation techniques to increase the limiting current density. Another is to add surface active additives to the electrolyte which has been shown by Ettel et. al.(l), Harveyet. al.(2) and Afifi et. a1.(5) to allow higher rates of production without decreasing cathode quality. The second proposed solution is of interest in this work, since there is very little knowledge of the conditions under which these additives operate effectively, and little fundamental understanding of the mechanism by which they operate. The current work seeks to contribute to this field by correlating a simulation model with experimental results to describe the development of surface morphology in the electrodeposition process."

Jan 1, 1997

By P. Couceiro, J. Navarro

A new methodology to perform selective blast designs by adapting the explosive energy, hole by hole (or in the hole), to the rock properties as a combination of their strength properties through the X-Rock model has been developed based on drill-monitoring data from both autonomous and manual rotary drilling modes. For that, a thorough normalization process has been developed to minimize external influences in the data induced by the different rig system and the operator interventions during manual drilling operation. Principal component analysis has been used to combine drill monitoring information. Data from 48,385 blastholes, comprised in 102 production blasts at 7 different levels in one expansion of the mine have been used for the analysis. The methodology, called X-Energy, combines the X-Rock model outputs with actual blast design parameters (drill pattern, stemming and borehole length, explosive mass/density and others) and a constant variable obtained from a machine learning algorithm, to estimate size distribution and percentage of fines and coarse material, hole by hole, by combining and recalibrating the Kuznetsov (Cunningham, 1987) based equation. From it, a new shovel-independent diggability model has been developed as combination of the P80 size, the rock properties (from the X-Rock) and a constant variable obtained from a machine learning algorithm. The X-Energy application presented in this study have been implemented in Minera Escondida Limitada (MEL), to design and operate production blasts with the goal of varying the explosive density to the rock properties to obtain a more uniform size distribution and digging rates, hole by hole, based on a target size and rate, and improving slope care, preventing active faults to fail. The methodology has been applied and validated in 17 production blast (8,277 blasthole), unlocking an average of 12.8% reduction in explosives costs (explosive consumption), by combining a pattern expansion strategy and a better distribution of the explosive density within the blast. The results demonstrate how a better distribution of the explosive energy by varying its density in the hole according to the rock and blast geometry variables can reduce powder factor (explosive consumption) while improving or maintaining blasting and digging results.

Jan 1, 2024

By J Zhao, Q B. Zhang

The shock behaviour of a material represents its response to very high strain rate loading at pressures associated with those generated by explosive and blasting loadings. Three sets of shock wave experiments have been conducted to determine shock Hugoniot behaviour, spall tensile strength and shear strength using a plate impact facility. Embedded manganin stress gauges (ie longitudinal and lateral gauges) and high-speed velocimetry using heterodyne techniques were used for the measurements of stresses, shock velocity and free surface velocity. The gabbro exhibited classic linear Hugoniot equations of state in the US-up (ie shock velocity-particle velocity) plane; while for marble a polymer-like non-linear response was observed. The detailed experimental procedures used to make these measurements are to a great extent standard methods when determining mechanical properties and deformation fields at high strain rate.CITATION:Zhang, Q B and Zhao, J, 2015. The response of rock materials to one-dimensional shock loading, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 665–672 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Fred Morelko, Michael Connelly, Brad L. Ricks

INTRODUCTION The $1.1 billion Bajo la Alumbrera Project, started up in 1997 by Minera Alumbrera Limited in the Catamarca Province of Northwestern Argentina, is the first large scale modern mining project to be developed in Argentina. Like many modern Andean mining projects, existing infrastructure was not available to economically transport the 875,000 tonnes of product per year. A variety of alternatives were investigated, including upgrading of existing roads and railroads, slurry pipelines, and combinations of these systems. The final system selected was to combine a 312 km slurry pipeline with an 820 km rail haul to a ship loading facility near Rosario. The concentrate pipeline crosses divergent terrain between the minesite at 2400 m elevation and the filter plant at 400 m elevation. The system selected represented the lowest net present cost alternative by a significant margin. BACKGROUND The Bajo Alumbrera deposit was discovered in 1947 by Professor Cetioni from the University of Tucuman. It is a large (>750 million tonnes) medium-grade (0.6%) copper deposit with high gold values (0.5 g/t*). The deposit outcrops, making it very suitable to modern, large scale, open pit mining techniques using 218 t trucks and 43 m3 shovels. Advances in gravity concentration of the gold helped to demonstrate the feasibility of the project in a study prepared by Fluor Daniel for Minera Alumbrera in 1994. The initial concentrator is the largest green-field concentrator ever constructed, rated at 85,000 t/d. Production will peak at 190,000 tonnes of copper metal and 710,000 troy ounces of gold per year, one of the top 10 copper and top 15 gold producers in the world. * Throughout this paper, the word tonne and abbreviation refer to the metric ton of 1000 kg.

Jan 1, 1998

By Travis A. Davidson, Ralph E. Burnham, Cathy Aimone-Martin, J. Kelly Ratliff

Blasters face a long list of tasks to execute daily—from vehicle inspections to blast design and layout, hole loading and tie-in, securing the site, and finally, safely executing the blast. Good practices and, in most cases, regulations and requirements necessitate documenting their work, specifically their blast report. While some blasters use paper forms, others use electronic means to streamline the process. The authors have served as attorneys and expert witnesses in representing companies and individual blasters in numerous administrative and legal matters in which documentation of the blaster’s work was both critical and detrimental to the effectiveness of defending their work. This paper discusses in a case-study manner the authors' observations concerning good blast report format, specific observations around electronic and paper report completion, record-keeping, seismograph setup and recordkeeping, video and photo documentation, internal auditing, and other topics related to documenting the blast. The paper aims to serve as a discussion guide for blasters to improve their blast record-keeping process, develop better practices that effectively document their work, and allow them to defend their work should a claim arise concerning their operations.

Jan 21, 2025

By M Spiteri, S Woth, J Caratti, K Henley

Blasting is an essentially violent process aimed to disrupt and loosen rock for productive excavation and downstream processing. Dilution of the orebody to some extent is the inevitable result, particularly in narrow vein gold mines. A small change in gold recovery is usually a strong lever on revenue generation. As a result blast designs are carefully engineered to both minimise and control the direction of rock movement. Traditionally blast designs in gold mines have used the minimum powder factor that will still permit rock excavation. This now conflicts with the recent industry trend to optimise the total process flowsheet from the mine to the mill. Numerous mines have achieved success in reducing total mining cost by increasing powder factors. Not only is explosive energy cheaper than mechanical comminution energy requirements, the increased blasting effect may deliver benefits across all downstream processes of digging, hauling, crushing and milling. Kalgoorlie Consolidated Gold Mines (KCGM) Fimiston operation is the largest gold mine in Australia, located in the heart of the Kalgoorlie Goldfields. Blast dilution has been reduced at KCGM by managing location of blast boundaries and by firing along strike to choked faces. Significant economies of scale have resulted from application of a bulk mining methods. The bench height of 10 m is the largest in the Western Australian Goldfields, and is typically mined in a single pass with large face shovels. Recent increases in production rates in both the mine and mill has been partly attributed to a 30 per cent increase in powder factor. KCGM then examined the benefit of a further 18 per cent increase in powder factor to 1.0 kg/BCM. A concern though was the impact of very high powder factors resulting in excessive blast movement and subsequently ore dilution. This was the subject of a project conducted with Orica Explosives. OricaÆsDMC(Distinct Motion Code) blast model was applied to understand the effect of not just further increases in powder factor but also blast geometry and explosive type. The modeling work demonstrated that high powder factors may be applied with minimal increase in ore dilution provided the combination of blast geometry and explosive type is optimised. These results are currently being implemented to achieve further reductions in total mining costs without a significant impact on recovery.

Jan 1, 2001

By W. L. Cooley

Electrical accidents occurring in coal mines from 1975 through 1979 were categorized and analyzed. The data was searched for common electrical hazards, common activities on the part of those injured, and common negligent or careless behavior. The most common electrical hazard was abnormal arcs or sparks, the most common injured activity was handling energized trailing cables, and the most common careless behavior was failure to de-energize circuits before working on them. The accident data was combined with mine production statistics to form a normalized electrical accident rate. It was found that some mines have consistently more lost workdays per man-hour worked than do other mines. Bureau of Mines electrical safety research contract expenditures were reviewed to judge whether the research effort was directed to those areas which are related to the most accidents. In some cases it was not. A method was devised and utilized to estimate the relative cost to the mining industry to implement certain safety measures developed through Bureau research, and also to estimate the potential safety benefits. Some safety changes are recommended, others are not. MSHA regulations were reviewed for effectiveness in preventing electrical accidents, and suggestions were made for discontinuing, clarifying, or otherwise modifying the regulations.

Jan 1, 1981

By F. F. Aplan

Mineral processing engineers have recorded an- other year of active research and development work. Most gratifying was the broadly based attendance at the Mineral Processing Fundamental (formerly Basic Science) Committee sessions at the 1968 Annual Meeting of the AIME. Because of the availability of good papers, the active discussion and the growing attendance, sessions have grown from one to three at the annual meeting. Prof. M. C. Fuerstenau of the University of Utah will chair the Mineral Processing Fundamentals Committee for the next two years and we may thus be assured of continued active leadership. The name change from "Basic Science Committee" to the more descriptive "Mineral Processing Fundamentals Committee" approved by the MBD executive council is a welcome improvement. Our profession continues to attract the interest and cooperation of those in other professional groups. The 1968 Engineering Foundation Particulate Matter Conference, under the chairmanship of John Karpinski of Bethlehem Steel, was devoted exclusively to comminution this year. It attracted conferees from five continents and served as a particularly stimulating source of interchange of knowledge from many technical fields. Next year's conference will be under the chairmanship of Professor L,. G. Austin of The Pennsylvania State University. This conference plus the Symposium on Wettability and Flotation to be held at the annual American Chemical Society meeting in Minneapolis in April indicates the success achieved in the inter-disciplinary approach to problems. Other evidence of this spirit of professional cooperation is the forth- coming book on Size Reduction edited by D. W. Fuerstenau. This is the outgrowth of an AIChE symposium on size reduction held in 1965.

Jan 2, 1969

By Grano S. R, Ralston J

It is the perennial problem most metallurgists face when examining data collected from laboratory float tests and plant surveys - there are more numbers than we know what to do with! The objective of this paper is to analyse and interpret a set

Jan 1, 1994

By Paul M. Tyler, Carle R. Hayward

DOES it pay to do really good work? Quite likely the practical millman will answer that it does not. The preparation of ores for market is primarily a business enterprise, and by and large the individual operator does not bother his head about squandering our national resources or making easier the job of the smelterman. Having accepted such ore as he may get fro111 the mine, his job is to make the best possible showing with his mill fro111 the standpoint of financial return. His success is measured in dollars and cents, and he has no rightful reason to expect more than scant acknowledgment of any other achievements from the stock- holders of his company who in the last analysis are his employers.

Jan 1, 1936

By Charles Winter

The Ohio Department of Transpor- tation's (ODOT's) $228 million 1-480 Valley View Bridge project was needed to keep traffic flowing on one of the state's busiest freeway segments. Deterioration from age and steady high- traffic volumes necessitated the replacement of the existing decks of the I-480 east- and west-bound bridges over the Cuyahoga River Valley in suburban Cleveland. To facilitate this work without creating tremendous backups and traffic delays due to long-term lane closures, the project included design and construction of a new four-lane bridge in the median gap between the existing 1-480 bridges. Now complete, the new center bridge allows for all four lanes of I-480 to be maintained in each direction while deck replacement and other repairs are made to the existing bridges, while also providing increased capacity after project completion. ODOT awarded the project to the Walsh Design-Build Team (DBT) in late 2017. This article describes how the Walsh DBT, with Jacobs Engineering as the DBT lead design firm, incor- porated an innovative approach to the design and construction of the driven pile foundations for the new I-480 center bridge. I-480 crosses approximately 200 ft (60.9 m) above the Cuyahoga River Valley. With an overall length of 4,150 ft (1,265 m) and spans ranging from 180 to 300 ft (54.8 to 91.4 m), the design and construction of the foundations for the new center bridge were critical to the success of the project. Due to their overall height and span lengths, the foundation loads for a typical pier consisted of a factored vertical load of 22,000 kips, (100 MN) plus significant overturning forces due to horizontal loads and thermal effects.

May 1, 2022

By H. Y. Sohn

The considerable progress made in the sulfide smelting technology since the first International Sulfide Symposium of 1983 is discussed. The new developments and innovations have largely been driven by the recognition of environmental concern as well as the need for increased productivity. The smelting technologies for various nonferrous metals are reviewed, with an emphasis on the industry trend towards larger plants and continuous processes. The tremendous advances made in process modeling and computer simulation to describe the complex smelting processes are also reviewed. The goal of these mathematical models is the quantitative description of the processes and the reactors that will provide a means for the control and optimization of smelting operations as well as the optimal design of the operating conditions and the reactors. Environmental issues remain a key consideration in the smelting industry. One of the most remarkable improvements made in the last fifteen years since the 1983 Sulfide Smelting Symposium is the rapid increase in the sulfur capture by nonferrous smelters. This and other related issues are briefly discussed. Finally, the challenges that the smelting industry faces as the new millenium approaches are discussed. The industry continues to face technical challenges to improve productivity and efficiency, while being responsive to ever-increasing public pressure for environmental protection. It also faces external challenges from factors that may cause the reduction of metal uses as a result of substitutions by other materials. Another serious challenge and dire consequence that the primary metals industry is expected to face is the serious diminution of university-educated manpower as well as basic-research output. To remain competitive and healthy, the industry should take up the void left by the complete disappearance, at least in the U.S., and the reduction in other nations, of the governmental support of higher education and basic research in the field of primary metals production.

Jan 1, 1998

By A. A. Sobek

Controlled release systems delivering the required concentration of an effective bactericide over an extended time period have been developed by The BFGoodrich Company's ProMac® Systems group. The ProMac system is site-specific and includes a four-step approach to controlling acid mine drainage (AMD): (1) Diagnosing the problem, (2) Prescribing the treatment, (3) Supervising the application of controlled release bactericides, and (4) Honitoring the success of applied treatment. The success of the ProMac system is evidenced by improved water quality, healthy vegetation, a reduction in levels of acidophilic thiobacillus, and a corresponding increase in population of beneficial microorganisms.

Jan 1, 1986

By Erika Moonin, Jim Nickerson, Claudio Cimiotti, Roberto Bono

"In response to the severe drought on the Colorado River basin and in order to preserve existing water capacity to the Las Vegas Valley, the Southern Nevada Water Authority contracted a new deep-water intake (Intake No. 3) located in Lake Mead. The current project (Contract No. 070F-01-C1) includes 5 km (3 miles) of tunnel with very difficult geological conditions and a 200- m (650-ft) deep shaft and marine works. This paper will present the current status of the design-build contract being constructed by Vegas Tunnel Constructors and the challenges and problems faced and the innovative solutions developed to handle the difficult conditions encountered during tunneling with up to 15 bars of pressure.ProjectbackgroundThe Las Vegas Valley receives the majority of its water from Lake Mead, which is located approximately 30 km (20 miles) east of the Las Vegas, NV metropolitan area. Due to the severe drought that has hit the southwest region of the United States, the water level in Lake Mead has receded from its high water level of 372 m (1,221 ft) above mean sea level (amsl) to a low of 330 m (1,076 ft) amsl in June 2015. Should the lake level continue to fall, at elevation 320 m (1,050 ft) amsl, the current water intakes will not be able to draw enough water to meet the needs of the local area. The risk of losing water capacity has prompted the construction of a new deeper intake. Not only is the new Intake No. 3 situated at a lower elevation in the lake at 262 m (860 ft) amsl, the new Intake No. 3 is also located to draw better quality (Fig. 1).Project challengesThe project has had several difficult challenges to overcome:• The work consisted of a 1.2 kt (1,300 st) structure constructed on a barge and lowered 100 m (330 ft) into Lake Mead anchored with 9,200 m3 (12,200 cu yd) of tremie concrete.• The drill-and-blast starter tunnel was impacted by three inflow events, resulting in a one-year project delay.• One of the main challenges was selecting the tunnel boring machine (TBM) and excavating the tunnel with expected hydraulic head pressure of as much as 17 bar (16 bar was the highest pressure recorded during the drive), crossing faulted areas, low rock cover and the risk of tunnel instability due to direct connection with the lake.• Extensive pre-excavation grouting with a constant head pressure ranging from 12 bar to 15 bar.• Structural repair of the cutterhead in difficult hydrogeological conditions [water inflow of approx. 800 m3/hr (4,000 gpm)].• Complete repair of the cascade sealing system for the main bearing and two replacements of the pinion bearings.• The TBM approach to the intake structure."

Jan 1, 2015

By Gustavo Huerta Valer, Jorge Cárdenas Miranda, Johan Salas Flores

One of the challenges of mining is the optimization of the blasting process, which has an important impact downstream in the processing of crushed ore in the plant, that is why mining companies ensure the results of granulometry obtained from the blasting process through a joint work with companies specialized in the process of loading with explosives.

Feb 6, 2023