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By Jaime Fernández Concha

El presente texto refiere el origen del comité potencial minero y la determinación de sus funciones como la estimación de reservas de las diversas minas del país, a fin de evaluar sus posibilidades de mineral potencial. En este sentido, el comité debe determinar primero el concepto de reservas para valorizar el potencial minero de una zona. La reserva es la suma de mineral probado más mineral probable de una zona determinada. Sin embargo, su definición se limita principalmente al contexto económico que varía de acuerdo a una serie de factores condicionantes. Los factores condicionantes son el volumen, la ley, precio de metal, método de explotación minera y maquinaria de explotación disponible, método metalúrgico aplicable, medio de transporte, impurezas, impuestos, así como las resevas de la nación.

Nov 20, 1969

By Masakazu Niinae, Kenji Aoki

"Electrokinetic soil remediation by electroosmosis and ionic migration is restricted to soluble substances. At a higher pH, the soil particles sorb more heavy metals than at a lower pH and the precipitation of heavy metals are promoted. Both mechanisms make heavy metals immobile, rendering cleanup more difficult and electrokinetic extraction inefficient.In this study, the effectiveness of introducing a complexing agent to enhance the removal of cadmium from kaolinite in the region of neutral pH by ionic migration is examined. The complexing agent selected was ethylenediaminetetraacetic acid (EDTA). The investigation was carried out in a laboratory-scale column containing kaolinite contaminated with cadmium. As the results of the study, cadmium migrates toward the anode without accumulation of cadmium and is successfully removed at the anode reservoir."

Jan 1, 2003

By Jhonny Torre, Mario Carpio, Elmer Boulangger, Jesús Fuentes

El INGEMMET, a raíz de la importancia del avance energético y de las innovaciones tecnológicas, propone entre los años 2015 a 2017, realizar estudios en ambientes primarios pegmatiticos-intrusivos y metamórficos tanto en las unidades morfoestructurales de la Cordillera Oriental y Cordillera de la Costa, para definir ocurrencias y futuros depósitos que albergan litio en el Perú. Entre los años 2018 a 2019, INGEMMET, por intermedio del programa de Rocas y Minerales Industriales, de la Dirección de Recursos Minerales y Energéticos (DRME), realizó dos proyectos denominados GE34 A-5: “Prospección regional de Litio en el Sur Peruano” y GE34 A-6:“Prospección regional de Litio en el Centro y Norte del Perú”, para determinar ambientes geológicos favorables en relación a valores anómalos de litio en el Perú

Sep 30, 2022

By Rick T. Richins

Despite what may be overwhelming evidence that natural degradation of cyanide and cyanide attenuation in hydrogeochemical processes are capable of reducing or eliminating potential water quality problems associated with heap leach facilities, the recent sharp increase in the price of gold and wide interest in the cyanidation process has focused all regulatory eyes on cyanide leaching. Regulations continue to increase, design criteria are more strict, and detoxification requirements approach or exceed the level of detectability. Current governmental regulation of mining and milling operations using cyanide varies considerably from state to state. The lack of regulatory consistency at this level is largely attributable to the current Bevill Amendment exclusion of mine wastes as potentially hazardous wastes, the undefined status of the Environmental Protection Agency's ongoing mine wast study effort, and the mining industry's reluctance to develop a consistent policy regarding state versus federal mine waste regulation.

Jan 1, 1998

By Joseph J. Feiler

Historical mining operations in Colorado and other western states have resulted in thousands of remnant mine openings. Many are sources of metals loading and acid water generation in surface and ground waters. It is estimated that more than 965 km (600 miles) of streams in Colorado have been impacted by past mining activities. The Animas River watershed in southwestern Colorado is one of the most heavily affected areas in the state. Abandoned mine features pose significant safety hazards to those who enter them. These hazards can include bad air, unstable rock or falls into open shafts, stopes and winzes. Backcountry skiers and snowmobile enthusiasts are particularly vulnerable to falls into snow covered mine openings.

Jan 1, 2006

By B. C. Vargas

The Toulon tunnel project is a key component of the Highway corridor on the French Riviera between Marseille and Nice and is a fundamental transportation infrastructure for the region. The first design studies started in the 1960?s. The tunnel project is made of 2 separate tunnels: South and North tunnel. The North tunnel was built between 1992 and 2002 after 10 years of difficult construction (for example, on March 15th, 1996, a collapse of the tunnel in the ?Marchand Area? generated a sink hole in the city Center, causing 20 months delay). The South tunnel alignment runs parallel to the North tunnel at the same depth below Toulon historical downtown (20 to 40m depth with some areas with less than 10m of cover). The Risk management program was studied to be a State of the Art program in urban tunneling construction. The Hydro Geological Context The whole project area is covered with backfills and colluviums of 1 to 4m thick. The Schist, marls and sandstones, randomly distributed along the alignment below the first layer have different characteristics. While the Schist are pretty compact, the marls are fractured. The other layers have very different characteristics, and many faults are located along the alignment, especially in the limestones. The Breccia are heavily decompressed and deformable, as well as the other soils located in the Marchand Area. This 80m long area is where the settlements need to be controlled with an extensive monitoring program. The complete Geological profile is presented in Figure 1. [ ]

Jan 1, 2012

By V. P. Mehrotra

The effect of dissolved ions present in plant water on the flotation of phosphate ore from central Florida was investigated. Of the three most abundant ions, namely Ca++, Mg++ and SO4--, calcium ions were the most detrimental in the flotation of phosphate with sodium oleate collector. In one feed, a 10 ppm concentration of Ca++ ions reduced the BPL recovery from 86% to 46% whereas in the other a 40 ppm concentration lowered the recovery from 90% to 52%. The effect of Na2C03, NaHC03, Zeolite and EDTA to remove ca++ ions from water and hence improve apatite flotation was also studied.

Jan 1, 1986

By Edward Jr Walter

This paper discusses the problems that arise in the process of developing adequate explosives noise legislation. Case histories are used to illustrate how and where these problems arise and the course of action followed in overcoming them. It is imperative that those concerned keep informed as to possible legislation and be prepared to present solid facts that will insure fair and reasonable controls.

Jan 1, 1975

By Yuri Yemelianov, Stanislav Balikov, Alexander Epiforov, Andrey Boldyrev, Andrey Bogorodsky

"Test work was carried out using copper gold-bearing flotation concentrate with 6.85%Cu, 14.30%Fe, 20.70%S and 2.34%As. Gold and silver grade in the concentrate is 54.6 g/t and 92 g/t, respectively. Gold and copper are valuable components in the concentrate. Gold is partially associated with pyrite and fahlores. Copper in the concentrate can be found as tennantite (Cu12As4S13). The 71% of gold from the flotation concentrate is recoverable by cyanidation with simultaneous cyanide consumption in the amount of 96 kg/t. The major reason of refractoriness is that gold is fine encapsulated into sulfides and the presence of cyanicide-copper. The concentrate ground as much as 95% minus 10 µm was treated using low-temperature POX at the temperature of 100±5°C, L:S ratio of 5:1 and the process time of 1-5 hours. Residual sulfide sulfur in the cake is 2.28% which is 89% sulfide oxidation. The highest copper recovery to POX solution is 91%. It was found that gold recovery to cyanide solution is 85-94% during alkaline pre-treatment of POX cakes followed by cyanidation. In this case, cyanide and lime consumption is 75-90 kg/t and 120 kg/t, respectively. In order to recover precious metals from POX cakes leaching using sodium sulfite was carried out. Test work was conducted at varied reagent concentration, L:S ratio and leaching time. Gold and silver recovery achieved was 85-95% and 59-63%, respectively."

Jan 1, 2014

By E L. Kotova

Completeness of extraction of a mineral from ore depends on many reasons. First of all it is a function of quality of disintegration of ore. It is supposed that two basic factors: character of structure and texture of the ore aggregate and a disintegration technique influence the quality of the mineral aggregate destruction, æopeningÆ of its internal boundaries. In this paper, the problem of technological mineralogy from the point of view of genesis of the mineral aggregate, its typomorphical features and methods of their quantitative description are discussed. The purpose of this research is to provide information for technologists. It should enable the development of a rational flexible scheme of disintegration of ore with full extraction of a useful component, without its losses and without unnecessary expenses of energy. For achievement of this purpose the mineralogical information should have ½number and a measure+. By the authors, the technique of the quantitative analysis of fabric of the mineral aggregate based on several models û thermodynamic, crystallographic and geometrical is offered and discussed. The leading role in the quantitative analysis of a fabric of ore belongs to internal bounders. But internal bounders of the mineral aggregate by bounders or faces of the mineral individuals or mineral grains are formed. Their geometry, orientation concerning own (mineral grain) crystallographic lattices, orientation and distribution in space of the ore aggregate are proportional to the energy accumulated at origin and the further growth. These characteristics of mineral individuals are consequences of conditions of their formation. That is why the named triad of models is used. From crystallography it is known that faces of different stability and mobility form borders of crystals. They also contain different quantity of energy. Mineral grains also are faceted by different energy borders. They form intergrowths with each other according to a principle of balance or unbalance. That is why in addition to traditional parameters of the description of a fabric of the mineral aggregate (mode and grainmetrical composition) it is necessary to add new. For example, length and the square of intergrowthing bounders of mineral individuals differentiated (in couples), crystallographic symbols of borders, their roughness and so forth. Consequently, solving a problem of the geometrical characteristic of borders, we define also its power characteristic. In this paper experience of application of our technology in studying ores of one of deposits of Urals Mountains is presented. For realisation of these types of the analysis technologies of measurement, the program of calculation and the devices, which are carrying out the analysis in a semi-automatic mode, are possessed. Structure and texture of rock or ore aggregate reflect its formation and transformation conditions. It is important to understand that disintegration energy cannot be more than aggregation energy, the energy of intergrowths formation. The square and orientation of mineral individuals borders vary at pressures or stresses of mineral aggregate evolution. These phenomena often cause selective increase in the square of borders at constant average grain size, ie the granulation. Granulation presents the increase in quantity of mineral individuals while their modal share remains constant. At the same time their average mineral grains size. Some mineral individuals increase in size at increased pressure. When lithostatic or lateral pressure drops the majority of mineral grains increases in volume at the cost of intersticial or film solutions or fine grains. These are only special examples of the ontogenesis of the mineral aggregate. They illustrate our statement that all changes in fabric of the mineral aggregate are a reaction on varying external (ie geological) conditions. It is possible to consider that structurisation of totality of mineral individuals as a whole is a process of adaptation of the mineral aggregate, which forms and exists in varying force and energy fields. Differential and integrated geometry of total internal boundaries of the mineral aggregate serves as adaptation mechanism of the mineral grains system. Boundaries form intergrowths of the mineral aggregate. Thus, it is possible to consider that the most informative parameters of the stereometric analysis for restoration of the ontogenesis of the mineral aggregate are the following. First of all, it is a quantitative estimation of the volumetric shape of the ore mineral in crystallographic coordinates, a total area of borders of all mineral grains in the aggregate, the specific square of their boundaries, the specific square of intergrowth boundaries of the ore mineral separately with grains of each minerals of the matrix of the mineral aggregate as well as traditional grainsmetric and modal composition. For realisation of these types of the analysis technologies of measurement, the program of calculation and the devices that are carrying out the analysis in a semi-automatic mode are possessed.

Jan 1, 2008

By Charles Camsell

At the last annual meeting of this Institute the programme very properly was drawn up and carried out with the special object of calling attention to the Dominion's position and problems with regard to fuel supplies. That subject, always one of serious concern, was a source of considerable anxiety twelve months ago. It is still so, but in a decidedly less degree than at that time. So far as the immediate fuel situation is concerned our anxieties have been relieved. And I think we can safely say that such a consciousness of our difficulties and determination to overcome them, has been developed in the minds of our people that there will be no slackening of the offensive until a final solution is reached. In selecting a subject of major importance for the present occasion I have felt free to digress from the pressing problems of last year and to go back, for a starting point, to the presidential address of two years ago .. I do not, however, wish to enter the controversy that has developed as a result of that address, though in spite of my own failure to amass a fortune from participation in certain mining ventures, I am decidedly inclined to the optimistic view that Dr. Corless presented of the future of our mining industry. You will perhaps have observed that in its general wording the title of my paper bears a marked resemblance to that of that address. This simila1ity of titles is not accidental. It is intentional on my part.

Jan 1, 1924

By S. Mehrdad Heidari

The concentrator plant is located near a very high (105m), large (- 500m) and steep (a, > 45' ) wall. Geologically, the wall was composed of very complicated formations and broad range of soils and rocks type in which a variety of local typical failures models have been occurred on different soil and rocks formations. The construction of concentrator plant structure and other activities have been overshadowed by these local failures. Safety and risk of huge failures were serious concern. For distinguishing the wall conditions a broad campaign of slope stability investigation with detailed geotechnical drilling on berms of wall have been done and the structure of slope was fully identified and further Lab tests and slope simulation models done. Slope stability of the wall was analyzed and the effects of instability factors were described in short term (for construction phase) and long term (for production phase).The results indicated, if a well-appointed drainage system is implemented, the overall stability of the wall in short term will not cause any particular problem but about long term stability, the wall must be supported by rock bolting, consolidation grouting, shotcrete reinforced with fibers. The results have been confirmed by passing one year after this investigation.

Jan 1, 2005

By E. J. Ripling, M. W. Toaz

Tensile tests were conducted on pure magnesium and on four commercial alloys over a variety of temperatures and strain rates. The high positive slope of the ductility vs testing temperature curves that is found over a short range of testing temperatures for these materaturerials was shown to result from the fact that the microstructure was not stable at these testing temperatures. Pure magnesium did not display a transition temperature, although its sub-room temperature ductility was low. This poor ductility resulted from a grain boundary weakness. The aluminum-bearing commercial magnesium alloys had a higher ductility than the pure magnesium. ness.Thealuminum-bearingcommercialThese alloys did exhibit a transition temperature and grain boundaries that were stronger than the grain material. Both pure magnesium and the commercial alloys began initiating cracks at strains equal to one half of their fracture strain. MAGNESIUM base alloys' enormous potential as structural materials lies in their high strength to weight ratios. At present, the high strength magnesium base alloys such as AZ-80, which will be discussed later, have about as high a tensile strength to specific gravity ratio as the highest strength wrought aluminum alloy, 75s-T6, and, of course, a much higher strength to weight ratio than structural steel. Further, since the magnesium base alloys develop their high strength to weight ratios with moderate strengths and extremely light weights, the ratio of load carrying capacity to the weight of many structures is relatively higher for the magnesium base alloys than their strength to weight ratios would indicate. This results because judicious increases in section size, such as increasing the depth of bending members or adding reinforcing ribs, can frequently increase the weight of a structure linearly while the strength and stiffness increase as the second or third power of the added weight. Strength and rigidity must be designed into lightweight structures by those techniques which establish multiaxial stress states. Consequently, strong, lightweight structures frequently also possess a greater propensity toward brittle failures. In order to insure against these catastrophic failures, an extra premium must be placed on ductility and toughness in light alloys. Current knowledge of the ductility and toughness behaviors—notched behaviors—of magnesium base alloys is limited.* Most of the magnesium base alloys * The state of present knowledge regarding the effect of testing temperature on mechanical properties has recently been summar-ized by Pritchard.' crystallize in the hexagonal system, so that they are expected to exhibit a tough and ductile to brittle transition temperature. Actually, a transition temperature behavior has been reported for commercially pure magnesium in the literature, but the characteristics of this transition temperatureh uggest that it may not be a transition in the usual meaning, but simply the onset of some thermal softening, a performance much like that which face-centered-cubic lead might exhibit slightly below room temperature. If transition temperatures do exist, such important questions as the manner in which they are affected by internal variables such as chemical composition and grain size, or the effect of external variables such as rate of straining or notch severity have never been investigated. The investigation reported upon herein was undertaken in order to define some of the mechanical behaviors of the magnesium base alloys better, to gain a better understanding of the influence of some of the above listed variables, and particularly to understand their effect on ductility and toughness better. Material and Procedure Material-—Pure magnesium and four commercial alloys were used in this investigation. The alloys were selected so that chemically they made up a series with approximately the same minor alloying

Jan 1, 1957

By R. D. Saltsman

Under contract with the Federal Bureau of Mines, Bituminous Coal Research, Inc., performed a statistical study to find less expensive and time-consuming methods of monitoring the noncombustible content of coal mine dust. Calculations based on thermodynamic considerations verified the reasonableness of Federal rock-dusting requirements. The results of extensive sampling in southwestern Pennsylvania mines indicated that, at the 95-percent confidence level, the present system of sampling at 200-foot intervals may be replaced by sampling at 500-foot intervals, and that a 1-inch scoop floor sampler may replace the standard 6-inch scoop for floor sampling. Further field testing is recommended.

Jan 1, 1975

By Gene Asai

Properties obtained for columbium carbide-carbon castings ranging in car-bon content from 12 to 17 weight-percent were compared with those of hot-pressed composites of similar composition. The properties were oxidation resistance in static air between 500° and 700° C, linear thermal expansion between 20° and 2,400° C, electrical resistivity between 20° and 1,500° C; microhardness between 20° and 1,500° C, and modulus of rupture between 1,300° and 1,800° C. CbC-C castings differed markedly from hot-pressed material with respect to microstructure, electrical resistivity, and modulus of rupture, but behaved quite similarly with respect to oxidation resistance, thermal expansion, and hot hardness. In oxidation resistance, thermal expansion, and hot hardness both materials were independent of carbon content. Both castings and hot-pressed composites oxidize rapidly in air above 600° C, have thermal expansion coefficients very similar to columbium metal, and the logarithm of the hardness decreases linearly with increasing temperature. The microstructures of hot-pressed composites contained varying amounts of graphite in a CbC matrix but did not contain significant amounts of a eutectic structure present in all castings, nor did they contain graphite needles which were present in the hypereutectic castings. The higher electrical resistivity of hypereutectic castings over hypereutectic hot pressings was attributed to the presence of highly oriented graphite needles in the castings. The modulus of rupture of castings was 1-1/2 to 2 times that of hot-pressed composites. Both materials displayed bend ductility above 1,800° C.

Jan 1, 1971

By Charles H. White

Discussion of the paper of A. L. Sweetser, Tress., xxxviii., 236. CHARLES H. WHITE, Harvard University, Cambridge, Mass. (communication to the Secretary*) :-Those interested in leaching-processes gladly welcome contributions on either laboratory-tests, such as are reported by Mr. Sweetser, or mill-tests made on larger quantities of ore; and especially valuable are such reports, even with negative results, if the methods adopted are the outgrowth of an intimate knowledge of the conditions to be met. It seems very desirable, therefore, that as complete details as possible be given in reporting on such tests, particularly with respect to the character of the ore under examination. The questions of prime importance in the sampling of ore and in the making up of charges for laboratory-tests are those respecting its grade and uniformity. In Mr. Sweetser's paper the first of these questions is answered definitely, but the answer to the second, although apparent on inspection of the results, might be more strongly emphasized with advantage, since it is only on account of the extreme uniformity of the ore that the satisfactory results obtained could have been expected. It seems advisable to call attention to the fact that for average ores, and more particularly for uneven, or 11 spotted ores, the quantities used by Mr. Sweetser are not usually regarded as sufficient to insure satisfactory results. Let us examine the method somewhat in detail. The ore was crushed to pass a 5-mesh screen, and a sample of 45 lb. was taken out for assay and tests. The diameter of the largest grain of this ore, according to Richards,1 was 2.67 mm.-assuming here, as in the following cases, that the wire of the screen was of the largest size used for the purpose, thereby giving any possible advantage in this respect in favor of the method. The table in Richards's book, p. 852, shows that 45 lb. is a sufficient quantity for a fair sample with uniform ores, but not sufficient

Jan 7, 1908

By Kelvin K. Wu

A coal waste disposal dam failed on Buffalo Creek near Saunders, West Virginia, on February 26, 1972. This accident resulted in the loss of 125 lives, left over 4000 people homeless, and resulted in millions of dollars in damage to several downstream communities. As a result of this tragic event, major changes occurred in the mine waste disposal practices used by the U.S. coal industry. This paper summarizes changes in U.S. coal-waste disposal practices in the nearly 35 years since the Buffalo Creek dam failure and identifies safety issues that need to be addressed for continued improvement. While many organizations and individuals have played roles in the improvements that have occurred, this paper focuses on the role played by MSHA and its predecessor agencies.

Jan 1, 2006

By E. G. De Coriolis

The development of huge production facilities and of new or improved processes for manufacturing magnesium from its raw sources has been an outstanding achievement of this war. Furthermore, at least one new method has reached a stage of pilot production that offers promise. Its potentialities seem to indicate that a reduction in cost and simplification or elimination of problems incident to the use of at least one of the present processes are quite within the realm of possibility. Although magnesium of very high purity (99.9 per cent and higher) is obtained, and the rate of recovery reasonable (60 to 70 per cent). the ferrosilicon reduction process is open to a serious objection, which at the time its use was proposed was thought to be sufficient to raise some doubts as to its success, at least on a high production basis. The temperature range at which the reaction is carried out—namely, 2100" to 2150°F.—is very close to the failure temperature of the material of which the retort is made. It is so close that for a time it was assumed it might make commercial use of the process an impossibility. However, at the time under discussion, the demand for magnesium was so great that it was felt by those who had to go ahead and produce this essential metal that the emergency warranted their taking a chance on this process. Subsequent developments have fully justified the soundness of their decision. Fortunately for the war effort, when the plants were put into operation it was discovered that although the retorts did collapse in rather short periods of time, as predicted, they could be blown back into operable shape by application of high-pressure air. This practical method of operation so relieved the situation that the problem disappeared. Nevertheless, if the process had not been successful, or the production of magnesium by the electrolytic process had not been able to keep pace with demands, our war program would have been seriously impaired. Fireless Cooker'' Process For this reason a program was set up and assigned for the development of a new method that had been suggested to the War Production Board in 1941. It is believed justifiable in terming the method "new" for several reasons: (I) while utilizing the same (ferrosilicon) process as the Pidgeon, hence involving similar reactions, the type of retort or furnace is essentially different, (2) the method of operation, reaction temperatures, etc., differ materially, and, most important of all, (3) the problems to be overcome in making the process successful were not and could not have been anticipated by anything previously known about the Pidgcon process. As will be shown later, the briquetting process, the condenser, the furnace lining

Jan 1, 1949

By Dale Preece, C. Mick Lownds

Detonation delay timing has been an important aspect of quality rock blasting for decades. Detonators that enable delay timing have improved over the years especially with the recent advent of precision electronic detonators. The positive effects of precision delay timing have been observed repeatedly in the field with improved fragmentation, heave and overall blast control.

Jan 1, 2008

By R. L. Urie, L. Burdzinski

Non-operational mine facilities are subject to placement on the EPA's National Priority List (Superfund). Once a mine site is undergoing investigation and/or remediation, MSHA regulations for health and safety may no longer be applicable. This paper addresses the changes in the applicable and relevant standards that apply to health and safety and public health related to site contaminants. The implementation of health and safety plans, and the development of public health risk assessments are described. Examples are presented from Superfund activities at the Eagle Mine, near Minturn, Colorado; the Anaconda Smelter near Mill Creek, Montana; California Gulch near Leadville, Colorado; and Bunker Hill, Idaho.

Jan 1, 1991