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By José Luis Calderón

En los tres anexos (Pueblo Nuevo, Zarumilla y Chuquitambo) del área de influencia directa (AID) de Compañía Minera Poderosa se ha institucionalizado y formalizado una nueva gestión del agua de consumo poblacional, lo que ha permitido prevenir conflictos socioambientales y mantener la estabilidad social que posibilita el normal desarrollo de las operaciones mineras en el distrito de Pataz, región La Libertad.

Jul 30, 2019

By A. W. Jacob

THE shatter cut, or burn cut as it is often called, is one in which the centre of the round is almost reamed out by drilling holes so close together that the blasting of a few holes shatters the rock embraced by all of them. The idea of shattering the centre of a face by shooting holes drilled parallel to one another is not new. Some miners have used this method for years past, when drilling quartz or a face near timber. But, they followed the age-old practice of first blasting the cut, then the square-up. It was not thought possible to shoot both together. In the case of machine men, the two largest contributors to silicosis are dust from drilling and dust from blasting. It follows, then, that material reduction of exposure to either constitutes an important step in lessening the incidence o silicosis. It was? the hope of being able to do away with the necessity of the men having to return early to a face, through dust concentrations of 60,000 to 80,000 particles per cubic centimeter, that aroused interest "in the shatter cut at McIntyre. Efforts to this end were successful. Now, with this kind of cut, all holes of a round are shot simultaneously.

Jan 1, 1942

By R. Letsaole, H. Mabowa, J. Sehat, J. Tshilongo, T. Rampfumedzi, N. Ntsasa, A. Mkhohlakal1

This study explores the use of co-collectors to enhance the recovery and determination of rhodium during fire assay with lead collection, followed by acid dissolution using conventional hot plate methods. Rhodium, a critical platinum group metal, poses analytical challenges due to its low natural abundance and complex chemistry. Among the co-collectors tested, palladium and tellurium demonstrated significantly improved rhodium recoveries, ranging between 100% and 120%, whereas silver resulted in poor recovery and higher error margins. These findings highlight that co-collectors can enhance the efficiency and sensitivity of platinum group metal analysis, although their effectiveness is dependent on the chemical interaction with the target element. Acid dissolution was essential to ensure complete digestion of prills prior to analysis, enabling accurate quantification of rhodium. Overall, the findings suggest that palladium and tellurium are effective co-collectors for rhodium determination in fire assay, while silver and lead flux alone are unsuitable. This work provides important insight into optimising fire assay procedures for reliable rhodium analysis, with potential benefits for platinum group metals recovery and economic evaluation.

Mar 6, 2026

By Dennis R. Dolinar

The National Institute for Occupational Safety and Health?s Pittsburgh Research Laboratory conducted a full-scale test of a composite polyurethane-aggregate seal in a hydrostatic chamber at the Lake Lynn Experimental Mine. This composite seal consisted of a polyurethane and limestone aggregate core that was formed between two concrete block walls. In the hydro-static chamber test, water is used to pressurize the seal. During the test, the maximum average water pressure the seal was able to withstand was 18.9 psi. Further, the seal began to yield at an average water pressure of only 17 psi. At the time of the test, the minimum seal design requirement was 20 psi under 30 CFR4 75.335 (2005). Therefore, based on this test, the seal did not meet the regulatory minimum design requirement. Uniaxial compressive tests conducted on samples from the polyurethane-aggregate core revealed that both the compressive strength and the elastic modulus of the material were much less than that for polyurethane only with a density of 10.0?12.0 lb/ft3. The significant reduction in the strength and stiffness of the polyurethane-aggregate mixture results from the formation of a soft polyurethane foam around each piece of aggregate. The formation of the soft foam seems to be caused by residual moisture from the aggregate. The moisture also caused the density of the polyurethane in the polyurethane-aggregate mixture to be less than the design requirements. The lower density of the polyurethane in the mixture, along with the formation of zones of pure polyurethane only, resulted in the overall seal density being less than the design requirements. During seal construction, steps were taken to control the moisture, but were not successful. An analysis of the seal failure showed that the calculated shear stresses at failure and the estimated shear strength of the polyurethane-aggregate mixture are fairly close. This suggests that the strength properties of the polyurethane-aggregate mixture along with a weak zone of poorly bonded aggregate controlled the maximum pressure the seal could withstand. At the time of the seal testing, the minimum design requirement was 20 psi, as specified at 30 CFR 75.335 (2005). New emergency temporary standards for seal designs were promulgated on May 22, 2007, with a minimum requirement of 50 psi under specified conditions. However, it will be shown that the evaluation of the polyurethane seal performance as designed to meet the older 20-psi criterion can be relevant to the design requirements under the new standards.

Jan 1, 2008

After nine years of negotiations, the U.N. Conference on the Law of the Sea approved a Law of the Sea Treaty text in April. Israel, Turkey, the United States and Venezuela voted against the text and 17 other nations including Belgium, the Netherlands, Italy, the Soviet Union, the United Kingdom and West Germany abstained. These nations still have the option of joining the treaty when it is opened for signing in December. However, the Reagan Administration has stated that several provisions of the deep seabed mining portion of the text are unacceptable and it seems unlikely that the United States, at least, will change its position. ALUMINUM Reynolds Metals Co. has criticized an Oregon state plan to relax air pollution standards for aluminum plants. The company feels that relaxation of the rules does not go far enough. Reynolds officials say that they have spent about $31 million at their Troutdale plant for state-of-the-art pollution control equipment, and if they are required to make the pollution reductions called for in the 1986 rules, Reynolds would be forced to close the 40-year-old plant.

Jan 1, 1982

How Mining Engineers Will Fare in 1977 Mining Education- The State of the Discipline Coal Mining Technologists are a New Force in the Labor Pool Trained Manpower Provided by Mining Technology Programs Putting New Engineers to Work-A Management Perspective

Jan 1, 1977

By G. E. Walker

"El Manto Ombla en Morococha, ha producido cobre durante más de 30 años. Cuando esta producción llega a su etapa final, se decidió hacer una investigación y descartar evidencia de otro mineral existente. Por ello, el texto señala los resultados de este estudio, como los conceptos nuevos sobre la geología. La mineralización de este manto no constituye un reemplazarriento selectivo, sino más bien fue controlado por una falla de compresión, cuyo producto estriba en la compresión lateral, plegamiento asimétrico y décollement. El fallamiento de compresión se extendió oblicuamente a través de los horizontes incompetentes formando una traza característica en ""S"", paralela al plano axial origina del pliegue asimétrico, y eventualmente se unió al plano basal de desprendimiento en el contacto volcánico. Dicha mineralización se inició con una etapa con una fase pirítica que formó reemplazamiento masivo a lo largo del contacto volcánico y penetró también los horizontes de anhidrita a lo largo de ciertas fracturas. Así, la anhidrita no parece haber causado la disminución de la mineralización en profundidadexcepto en el sentido de haber restringido la migración de las soluciones mineralizantes. "

Aug 20, 1963

By James Paone

The Bureau of Mines made drillability studies with impregnated diamond bits in the laboratory on 7 rock types and in the field on 21 different rock types. Results indicate that drill parameters of rotational speed, thrust, and torque must produce sufficient applied forces to induce stress levels that cause continuous failure in rock to achieve efficient penetration rates. Higher rotational speeds appear to be more effective in drilling relatively harder rocks, although the increased speed causes more bit wear; increases in thrust result in higher drilling rates but not linearly; and up to a critical value a linear relation exists between torque and penetration rate for a specific rock type. Penetration rates with impregnated bits show a trend similar to that obtained with surface-set bits for rock under 25,000 psi compressive strength.

Jan 1, 1966

By Clayton A. Signor

Abstract: Expansive soils cause more damage to structures annually than a combination of other major natural disasters. Because of the cost to our society, all means and methods need to be fully explored to mitigate the problems associated with expansive soils. This study will present a foundation design approach that is underutilized in this application, driven piles. The main objective of the study is to present pile test results and analysis from four driven pile project sites in three types of expansive soils found in central Texas: Del Rio formation, Taylor/Navarro formation, and expansive alluvium. High strain dynamic pile tests were conducted on each of the four studies with rigorous signal matching analysis from the CAse Pile Wave Analysis Program (CAPWAP). Ultimate pile capacities ranged from 73 to 311 kips with an average of 61% of the total capacity coming from the pile shaft and were two to six times the structural capacity needed. Allowable loads calculated from Modified Gates dynamic formula best modeled allowable test results. Average unit skin frictions ranged from 0.50 to 4.71 ksf. Restrike pile tests of 1 to 17 days after initial driving reported 30 to 100% shaft capacity gain. All open-ended pipe piles driven produced soil plugs ranging from 4 to 14 feet thick. Small diameter, thick-walled, open-ended pipe piles reached penetration of twice the depth of designated zone of seasonal moisture change without problem. The observed production rate of the driven piles was on average 8 minutes, which implied daily production of 15 to 40 piles. Predrills or augered holes should be specified for underground obstructions found in soil investigation.

By Zhao Guangwen, Wu Tan, Qiuzhan Tian, Duan Shuzhen

"A thorough study of lost currents in bipolar cells has been made for the development of the great potential of bipolar cells in energy saving. A proper equivalent circuit for bipolar cells has been found, and mathematic methods for computing lost currents at all kinds of polarization have been developed.At linear polarization, the lost currents can be computed by solving either a tridiagonal matrix or an ordinary differential equation of second order. This kind of values can be used to evaluate the minimal lost currents at given conditions. At other kinds of polarization, the lost currents can be computed by the same methods as above if the necessary experiments of measuring the cell voltages of every electrolytic compartment have been made. This kind of values can be used to design bipolar cells at practical conditions.Extensive experiments have been made to evaluate the effects of electrode polarization, emf of galvanic cell for the formation of electrolyzed substance, gaseous products, geometric dimensions of electrolytic cells, special resistance of electrolyte used, and the total and ordinal number of electrolytic compartments on lost currents. It is the first time to make such a systematic research by experiments in the world. Experiments showed that theoretic models were in good agreement with measured data. Experiments also showed that D.C. energy consumption of 0.45 kwh/kg of Pb for lead electrolysis from molten chlorides could be achieved in a cell with 7 bipolar electrodes.IntroductionIt is very promising to apply bipolar electrolytic cells to electrolysis of aluminum, magnesium, lead, zinc and perchlorinates for their great potential of energy saving for example, bipolar cells had been used in the production of magnesium and saved more than 30% of energy, being one of the three main techniques of energy saving in the production of titanium sponge (1)."

Jan 1, 1988

By Peter Riccio

Oxiana Sepon?s mineral processing facility in south central Laos produces copper cathode using leach-autoclave-SX/EW flotation technology. Pyrite recovery in the flotation circuit is critical to the operation, as it is used to generate acid for the leach circuit. However, low pyrite recovery has been an ongoing challenge in the flotation circuit. Tailings characterization work done by Ian Wark Research Institute showed that the pyrite losses to the tail are made up of a combination of coarse liberated particles and finer particles that have been coated by clay fines. In December of 2005, a joint Cytec-Oxiana technical program was initiated to address the pyrite recovery issue. A series of diagnostic tests were performed in the Cytec Stamford Research Facility using synthetic plant water showing that the collector was precipitating as a metal salt, and was un-available for mineral attachment. The tests also identified several collector chemistries that would likely be robust in the Sepon low pH, high dissolved metal ion environment, and will not complex with ferric, ferrous, or copper in solution. With the support of the Sepon on-site engineers, an extensive, successful laboratory program was completed, which then was followed by on plant testing that showed a step wise improvement in pyrite recovery.

Jan 1, 2014

By J. M. Wempen, R. D. WEYHER, M. K. McCarter

Beam theory is a proxy for the behavior of intact, deforming roof strata above underground openings. Strong, stiff, intact strata have the ability to store significant strain energy when underground openings have large spans, as is typical of longwall operations. When strata fail, they may release some or all of this strain energy. Released energy is partitioned between fracture, thermal, and seismic energy. The tensile failure surface in simply supported beams is predicted to be free of shear stress. This prediction and the kinematic inability of crack slip during fracture make significant dissipation of energy by friction unlikely. In this study, the failure energy partitioning of Nugget Sandstone specimens is examined. Tensile fractures in specimens were induced using three-point loading tests. Elastic waves emanating from fracture events were recorded using an array of accelerometers. Accelerometers were placed within two crack lengths of the fracture surface, and the acceleration records are similar to strong motion seismic records. Spectral analysis was performed and used to develop synthetic, well-behaved, acceleration signals. Synthetic velocity signals were used to estimate radiated seismic energy generated by fracture. These estimates of radiated seismic energy demonstrate a potential means to constrain the minimum seismic partition. Fracture testing was performed on additional samples to estimate the fracture toughness of the sandstone. Synthesis of this data demonstrate a potential means to constrain a maximum seismic partition. Bounding the seismic partition for this type of fracture event could aid the detection and evaluation of seismicity emanating from longwall operations. Having better information about the location and magnitude of mining-induced seismicity within longwall overburdens could lead to better understanding of extraction sequencing and rock behavior in general. These energy estimates also support the hypothesis that dissipation of thermal energy by friction is small in bending tensile failure.

Jul 1, 2020

By Kelly D, Moore C

The Golden Mile, which has been mined continuously for the past 100 years by both underground and more recently open pit methods, occupies an area of 1.2 km by 4 km adjacent to the city of Kalgoorlie Boulder in Western Australia (Figure 1). Large-scale open pit mining at the Kalgoorlie Consolidated Gold Mines (KCGM) Fimiston operations is currently extracting 7.8 million tonnes of oxide and sulphide ore for a total production of 522 000 oz per annum. The effectiveness of grade estimation techniques at KCGM has been examined with reference to existing 10 m bench sample data from all operating areas within the Eastern Lode System of the Main and North pits. The aim of the study was to recommend practical parameters for grade control estimation. The review included comprehensive variography and comparison of nonparametric estimation methods (Joumel, 1983) such as indicator kriging and probability kriging with ordinary kriging, leading to the development of improved grade control parameters and procedures for both daily quality control and short term mine planning. This paper reviews the geological, statistical, geostatistical, mining and modelling features studied in order to present KCGM's Mining Department with recommendations for improving grade control.

Jan 1, 1994

By Stephen H. Stow

Economically important heavy minerals have been studied in the sediments of offshore Alabama and Mississippi. Sandy samples have been collected from a 200 square mile area from Dauphin to Horn Islands. The minerals concentrate in sediments under 10-35 feet of water and may reach 2.4% by weight. The distribution of total heavies is related to the hydrodynamics of offshore Alabama-Mississippi; the greatest concentrations are in the Gulf where the longshore current is diverted from its westerly flow. Preliminary observations indicate that the distribution of individual minerals can be correlated with wave energy, particle size, specific gravity, and morphology of the mineral grains. The coarser, lighter minerals--kyanite, sillimanite and staurolite--are concentrated in relatively low energy areas in the Mississippi Sound and at the end of Dauphin Island in the Gulf; maximum concentration for each is 34.5%, 6.0% and 43.2%, respectively, of the heavy minerals. The smaller, more denseminerals--ilmenite, rutile, leucoxene, zircon and monazite--are concentrated in high energy areas in the Gulf; maximum concentration for each, respectively, is 42.0%, 5.9%, 9.652, 10.7% and 1.3% of the heavy minerals. On the basis of a minimum concentration of 1% heavy minerals, two areas have been identified and the total amounts of different minerals have been calculated to a depth of 25 feet of sediment. The data are preliminary and in no way indicate recoverable reserves, but they do show that on the order of 20 million tons of heavies exist. These deposits should be termed "indicated resources".

Jan 1, 1975

By Alan Bauer

In recent years there has been increasing interest in employing the technique of explosive casting in strip mines. Explosive casting, applied to dragline mining, describes the procedure whereby the overburden is horizontally displaced by blasting causing a portion of the material to be thrown into the previously mined cut. Therefore, it is not necessary to subsequently excavate this waste with the stripping equipment. In addition, allowing the overburden unrestricted movement during the blast most often results in improved fragmentation and enhanced machine productivity. The method is receiving attention because the capital and maintenance costs of stripping equipment has risen rapidly in relation to explosives costs. Improved productivity is necessary to maintain unit costs at an acceptable level.

Jan 1, 1983

By John T. Bartlett

During the last decade, the increasing price of gold has renewed interest in the various metallurgical techniques for recovering precious metals. Much of the recent technology advance has been aimed at low grade deposits resulting in more complex processes and the necessity of tighter economic control. These factors along with more stringent environmental constraints have made it necessary to optimize each process to minimize energy and raw material consumption and reduce waste discharge. In most cases, detailed process analysis is required to detect inefficiencies and provide alternative solutions for process improvement. Also during this same period, the computer has become widely accepted and computerized mathematical modeling has been applied to an increasingly broader range of problems. Microcomputer based process modeling and simulation systems are routinely used to analyze and improve communition, hydrometallurgical, and pyrometallurgical processes for the recovery of precious metals.

Jan 1, 1987

By M. S. Prasad

This paper presents the process methods of beneficiating various copper-cobalt and copper-zinc ores mined by Gecamines in Zaire. Geology and mineralization of both sedimentary and vein type deposits are described with special emphasis on the production of oxide, dolomitic and sulfide concentrates. Description of different types of concentrators and their treatment methods are discussed for the production of sulfide, oxide and dolomitic concentrates. Production of concentrates, their consumption and stocks are briefly reviewed. Modernization of the concentrators with substantial investments on grinding, classification, flotation methods and tailings treatments are also discussed to improve the metallurgical efficiency of the concentrators with a view to improve the production of concentrates both qualitatively and quantitatively.

Jan 1, 1990

By W. R. Reed, G. W. Luxbacher

As directed by the MINER act of 2006, the NIOSH Office of Mine Health & Safety Research (OMSHR) has annually awarded contracts to enhance mine safety and health. OMSHR has a history of research that focuses on both respirable coal mine dust and respirable crystalline silica (or quartz) dust, and contracts have been awarded since 2010 in support of our intramural research efforts. In 2018, a National Academies of Science consensus study report recommended expansion of respirable dust research. As a result, beginning in 2018 through 2021, eighteen contracts were awarded focusing on this area. These contracts can be grouped in three topic areas: characterization of coal/dust, development of real time monitors, and improvement of respirable dust controls. This paper summarizes the outcomes of completed contracts and the progress of current contracts.

Mar 2, 2022

By S. Tandanand

The Bureau of Mines, U.S. Department of the Interior, assessed the geological effects on the ratio of maximum subsidence and extraction thickness, hown as the subsidence factor, to develop a simple method for predicting the maximum subsidence. The study is restricted to the Northern Appalachian Coal basin where data were collected from 13 coal mines. A model previously developed to relate the subsidence factor with the lithology and with the width and depth of working panels was used in the assessment. The result shows the possibility of determining maximum subsidence without resorting to a rigorous method.

Jan 1, 1982

By M. Z. Emad, M. U. Khan, A. ur Rehman

The use of stemming plugs in surface blasting is gaining popularity because of the environmental, technical, and economic advantages. Although previous studies have established the operational effectiveness of different types of stemming plugs, evaluations of the economic and ergonomic impacts are lacking, thereby hindering their application in many mining operations. Consequently, a significant proportion of mining operations end up performing less efficient blasts. We evaluated the effectiveness of three types of stemming plugs by conducting multiple full-scale production blasts. The results show that stemming plugs reduce the need for secondary blasting and increase blast performance. An economicanalysis showed that the incorporation of stemming plugs can reduce blasting costs significantly.

Jul 1, 2021