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By C E. Vidal

Geological exploration and mining development increased their intensity and rate of success during the last five years in Peru. Particularly relevant are the mining projects of Yanacocha and Pierina for epithermal Au and Ag. Also relevant are the new mining operations at Iscaycruz and Uchucchacua for limestone replacement Zn- or Ag-rich base metal skarn deposits. Miocene continental volcanics host the low-grade but near-surface orebodies of the Yanacocha mining district in Cajamarca. Several deposits have been mined since 1994 with open-pit and heap-leach gold production increasing from 300 000 ounces to 1 300 000 ounces in 1998. In a similar geological setting, but with three times the grade of Yanacocha, the Pierina valley-leach operation in Ancash is set to produce 800 000 ounces Au during 1999. At Iscaycruz in Lima, Cretaceous limestones host massive pyrite and sphalerite skarn deposits with 10 to 20 per cent Zn. Mining and milling were started in 1996 with last yearÆs production rising to 180 000 tonnes of Zn concentrates. At Uchucchacua, selective underground mining of fracture-controlled Ag skarns, with 400 to 420 g/t, has been recently increased from 1200 to 2000 tonnes per day to produce 5.5 million ounces Ag during 1998. Advanced exploration projects are located in the framework of nine Phanerozoic metallogenic provinces. Mineral deposits of preferred attention are precious metal disseminations and veins, base metal replacements and skarns, porphyry Cu (Mo-Au), Mississippi-Valley-type Zn and base metal volcanogenic massive sulphide deposits. Geological discovery of new orebodies enables a sustainable development of the mining industry in the country.

Jan 1, 1999

By R. S. Dean, John Gross

"In a preliminary report made a year ago it was shown that certain minerals when subjected to heating with water under high pressure and temperature were shattered upon the sudden release of that pressure. The main feature in which the results of this method differ from those of conventional grinding is in the differential effect obtained. The more metallic minerals, and hence the valuable minerals, are shattered more readily than are the gangue minerals. In other words, explosive shattering is unique among possible methods for comminuting an ore in that it wastes the least energy on the useless part of the ore. Explosive shattering, therefore, offers possibilities as a means for reducing grinding costs, arid it is this potential advantage of the process that makes it worthy of further experimental study. The first part of this paper is devoted to a study of the mechanism of the process; the, second part reports results obtained in toots on a selected list of ores to exhibit some of the advantages of explosive shattering."

Feb 1, 1933

By Edward P. Barrett

The production of sponge iron is one of the earliest arts in the metal¬lurgy of iron and steel. The idea of producing iron direct from ore at temperatures lower than the melting point of, the iron has persisted throughout the centuries. The purpose of this paper is to present a general picture of the methods, proposed or tried within the past 100 years, for producing sponge iron by treating hot ore with heated reducing gases. The abundant literature has been abstracted, and quoted freely. Publications concerning more detailed information on the various methods are referred to in the footnotes and in the bibliography.

Jan 1, 1949

By Jack Zhang, Yunguo Tang, Baodong Zhao

"Rare earth elements (REEs) have numerous key applications in both traditional and advanced technologies. A shortage of some critical REEs is expected due to the discrepancy between the REE abundance in REE deposits and the REE demand from the market. For example, Neodymium, Europium, Terbium, Dysprosium, Erbium and Yttrium are expected to be in short supply. REE recovery and separation from secondary resources such as uranium wastes, heavy mineral sands, and recycled materials can balance the shortfall in a cost effective way.The Saskatchewan Research Council (SRC) is engaged in the development and commercialization of complete REE recovery and separation technologies in Canada. One of SRC’s newest developments is the design and commissioning of a heavy rare earth (HREE) separation pilot plant. The pilot plant uses hundreds of stages of solvent extraction (SX) to produce high purity individual HREEs from both primary and secondary resources.This paper presents the design of an HREE recovery process for the particular case of uranium processing wastes. The separation results of a group separation are reported and discussed, as well as the issues and the challenges of the development, commissioning and operation of the continuous SX pilot plant.IntroductionSignificant amounts of strategic specialty heavy rare earth elements (HREEs) are found in uranium wastes in Saskatchewan. It estimated that about 47 tonne/a of heavy rare earth element oxides (HREO) including 27 tonne/a of Y2O3, plus 6 tonne/a of Sc2O3 are in the raffinate of every uranium mill for potential recovery. Since the HREEs are already in the raffinate, cost effective HREE production is promising in Saskatchewan.Selective precipitation including nutraulization, oxalate and double-salts precipitation, as well as sulfide precipitation, ion exchange (IX) and SX are commonly used technologies for the recovery and purification of REE solution. REE oxalate precipitation is an effective technology to remove Fe, Al, Ca, Si and other impurities by taking the advantages of the solubility difference between oxalates of REEs and impurities in acidic solution (Xu, 2005)."

Jan 1, 2017

By W. M. Dressel

The Federal Bureau of Mines has obtained data by differential thermal analysis of the various minerals that represent the nation's resources in manganese. These data are supported by X-ray diffraction analysis, chemical analysis, mineralography, and optical mineralogy, and provide fundamental information on the response of each mineral to thermal treatment in oxidizing, reducing, and neutral atmospheres. The information can be applied advantage¬ously in the identification of manganese minerals. Its greatest potential value, however, lies in the application of the quantitative data on the reaction temperatures, rates, and products to the more efficient extraction of manganese from U.S. ores. Thermal analysis curves are presented for certain manganese minerals, namely hausmannite, bixbyite, braunite, pyrolusite, lithiophorite, cryptomelane, hollandite, manganite, rhodochrosite, and rhodonite. The original minerals and the products of their thermal decomposition were identified by X-ray diffraction analysis, supplemented by chemical analysis and mineralogical identification.

Jan 1, 1961

By Y. C. Kim

An alternate development drilling strategy to the one currently in use at the nine was investigated using geostatistics for a portion of the pit. The study area consisted of 4,000' x 5,000' in plan and 1,080' in elevation. The massive orebody, the three-dimensional nature of the problem, and the location of ultimate pit limit in the study area all created some unique problems in devising the development drilling strategy, as compared to the two-dimensional tabular deposits such as coal deposits. Rather than using the confidence interval of the global reserve estimate as the main criterion for development drilling, the confidence interval of short and medium range mine planning blocks was used as the objective. Based on somewhat arbitrarily selected level of confidence, the results from this study showed that a total of 50 DDHs rather than the planned 62 DDHs is sufficient in the study area, if the selected confidence levels are acceptable to the management. This paper also emphasizes the importance of the particular objectives being used in development drilling and how they influence the "optimai" place- ment of the development drill holes.

Jan 1, 1981

The long-term production schedule of open pit mines that maximises the net present value (NPV) of a given project relies on the proper design of phases (pushbacks) within the ultimate pit limits. There is not a phase design algorithm applied in the mining industry today that gives yearly production schedules that are optimum.The majority of phase design algorithms currently in use by the mining industry aims at grouping the blocks that fall within the ultimate pit limits into phases such that the average value of the blocks within each phase decrease as the size of the phases increase. Current phase design methods are typically based on a pit limit optimisation algorithm, originally introduced by Lerchs and Grossmann (LG) in 1965. To obtain multiple pit shells to be used for the phase design, the LG pit limit algorithm successively applied to economic block models by changing the price of the commodity or some other factor that properly parameterises the size of the pit. These modified economic block models are developed by predetermining the destination for each block in the model based on a breakeven analysis and highest economic outcome between alternative destinations. Phase designs determined by these existing algorithms may be suboptimal if a given project utilises multiple processing facilities for metal recovery and particularly if these facilities have restrictions (constraints) that require blending of attributes in the feed. To overcome these problems in obtaining phases that optimise overall production schedules, a new algorithm is developed at the Colorado School of Mines. The algorithm determines the phases of an open pit mine by taking into account multiple process options for the blocks and period by period blending requirements. This algorithm has been implemented within a software program (the software) and is being prototyped successfully in the design of improved pushbacks at a copper mine in South America and on a gold mine in Nevada. This presentation will demonstrate the shortcomings of the traditional phase design methodologies based on comparison of results coming from the new approach versus the traditional.

Dec 6, 2010

By B. P. Bellport

This paper summarizes the Bureau of Reclamation's experience in the use of boring machines to excavate six major tunnels on the Bureau's water resources development projects in the western United States. The summary of experience is presented as a compilation of brief case studies for each of the six tunnels. Each compilation presents data on the tunnel dimensions, geological characteristics of the excavated rock, the tunneling machine used, machine operation, muck handling, method of tunnel support, ventilation system, and related information. The listing of the six tunnels in Table 1 reflects a diversity of tunnel lengths and diameters. However, despite this diversity of dimensions as well as the variety of rock encountered during excavation, the six tunnels have one major characteristic in common: their excavation was significantly expedited by the use of boring machines. Beginning with the 10,079-foot-long Tunnel No. 1 on the Navajo Indian Irrigation Project in New Mexico - the Bureau's first tunnel to be excavated by a boring machine - the boring machines, or "moles," have demonstrated their effectiveness in rapid and economical tunnel excavation. Tunnel No. 1, virtually 2 miles long, was bored through in 9 months, an unprecedented achievement in Bureau engineering experience, as compared with tunnels previously excavated by conventional means. Boring of the 45,630-foot-long Blanco Tunnel and the 26,610-foot-long Oso Tunnel, both on the San Juan-Chama Project in Colorado, set world records in rates of excavation,l/* Two days of exceptional progress highlighted the

Jan 1, 1970

By M. J. Papo, A. Muwila

Hercules? is a low nickel austenitic stainless steel developed at Mintek that has a typical composition of 9 wt% Mn, 0.05 wt% C, 2 wt% Ni, 0.25 wt% N and 16.5 wt% Cr. A more corrosion resistant version of Hercules? (Hercules? B) with 0.5 wt% Mo has also been developed. Potentiodynamic tests performed on Hercules? B in a 5 wt% sulphuric acid solution showed it to have improved corrosion resistance comparable to that of AISI 304. The effect of a varying Mn content on the corrosion resistance of Hercules? B has also been investigated and the results discussed in this paper. From the corrosion test results, it is clear that decreasing the Mn content of Hercules? B increased the corrosion rate while increasing it decreased the corrosion rate. KEYWORDS Austenitic stainless steel, %ferrite, molybdenum, manganese, nitrogen, electrochemical corrosion tests, potentiodynamic scans, microstructure, chemical analysis.

Jan 1, 2006

These proceedings consist of an overview of the in situ mining research currently being carried out by the Bureau of Mines. The following papers emphasize two general aspects of the in situ mining method: the environment and productivity. Both areas are extremely important, particularly because in situ leach mining is a relatively new mining method from a commercial point of view. Topics covered include the restoration of ground water, the selection of lixiviants, in situ mining of commodities other than uranium, in situ mining costs, the application of resistance measurements to in situ mining, an acid leach mining case history, and the use of branched boreholes for in situ mining. A bibliography of Bureau of Mines publications on in situ mining is appended.

Jan 1, 1981

By Patrick Cloutier

Presentation objectives ? Introduce discrete-event 3D computer simulation as a tool to design, improve and optimize construction projects: ? Describe a real typical construction project planning issue. ? Present an applied use of simulation to solve this issue. ? Detail benefits of using simulation versus traditional planning methods.

Aug 1, 2013

By R. A. Cattell

With the surrender of the Japanese Imperial Government as a climax to the capitulation of the German High Command , the main objective of the Petroleum and Natural Gas Division pivoted from war assignments to its main normal functions . One of these functions is to give wide public distribution to valuable technical facts which the Division has obtained through research on petroleum , natural gas , helium , and related subjects . During the war years many engineering data and scientific facts could be released only on a restricted basis as reports to war agencies and others immediately concerned . Moreover , many of the wartime reports contained masses of detailed data that were prepared under stress to meet emergency schedules . For peacetime publication and application , these data must be reviewed , correlated , and rearranged so as to present the essentials in proper form . To illustrate , a wartime report of 50 pages might be resolved into one curve in a composite graph for a peacetime publication . Another factor affecting the orientation of the work of the Division is the broader horizon of research revealed by its war activities . Fundamental research and careful engineering analyses are just as important in time of peace as in time of war; in fact , they should be more important to the forward view , because under peace conditions disrupting influences that distract from the orderly acquisition of knowledge are minimized . Therefore , the concerted effort has been not to " salvage " the results of the war activities , but to evaluate them on the basis of their relative importance in the future economy of the country . Where wartime investigations have pointed to peacetime accomplishments , the effort has been to give the corresponding type of work additional emphasis . This adjustment can not be made hurriedly , but many of the necessary preliminary steps on the new course have been taken ..

Jun 1, 1949

By Max Roesler

I. INTRODUCTION THE following article concerns the geological occurrence of the iron-ore deposits on the south coast of Cuba. The article is based on a detailed field study, made in the hope that some information would I gained which might be of value in the search for further orebodies, Or in the economic development of the ore already found. LOCATION The iron-ore deposits of the Firmeza district lie near the coast, in the southeastern part of Cuba, in the Province of Oriente. The orebodies of this district form part of a belt of deposits that extends from Sigua, 25 miles east of Santiago, to Sevilla, 5 miles east of Santiago, and lies on the seaward slope of the Sierra Maestra range of mountains.

Jan 10, 1916

By Teele Tuuna, Voglers Eesti OÜ

Blasting operations are a strong and important part in any kind of building and mining industry, a shot-firer profession is one of the oldest professions in the civilized world. It still serves an important and ongoing purpose in the modern economy all over the world. Europe, nowadays, values strongly the mobility of workers, the movement of know-how and labor force between different countries inside Europe. There are no borders for most of the everyday professions.

Jan 1, 2018

By Jr. Sillers

This is the third report of investigations dealing with the application of electrolytic manganese to steel-foundry practice and the seventh in a series of reports dealing with tests to establish the technological acceptability of electrolytic manganese in the iron and steel industries. The work was carried out by Metallurgical Division of the Bureau of Mines as part of an extensive program for the development and utilization of domestic ores. The electrolytic manganese used in the tests was produced by the Bureau at its Boulder, City, Nev., pilot plant by the process developed by the Bureau of Mines.

Jan 1, 1949

By Mary Ann Bennett, Val Nichols, Colleen Proctor

"In 1997 when Royal Oak Mines Inc. went into receivership, the mineral processing technicians (mill operators) who had been working at Giant Mine in Yellowknife, Northwest Territories for most of their career walked out with no credentials to serve as testimony of their knowledge and skills.As a result of new diamond mining activity and the establishment of socio-economic agreements, mining industry representatives approached the Department of Education, Culture and Employment (ECE), Government of the Northwest Territories, in 1999. They requested support and direction to promote training and recognition for mineral processing technicians at BHP’s (BHP Diamonds Inc.) Ekati mine. ECE recommended the development of occupational standards and certification.This paper describes the development process and end products that resulted from this collaborative project between industry, government and education. In addition, industry representatives involved in the project share their views on the development process and the benefits of standards and certification.The conclusion invites industry members to support national occupational standards and certification with their associated benefits: standardized training in the workplace and institutions, proof of competence for hiring, recognition of prior learning, and a nationally and internationally recognized credential.INTRODUCTIONSwiftly changing labour market demands are nothing new in the North. The fur trade and mineral discoveries have brought employment to workers in a feast and famine cycle for decades. In the late 1990s, the Giant, Con, Lupin, Polaris and Nanasivik mines were nearing the end of productive runs. Many experienced workers found that without credentials, they had no proof of their abilities to offer prospective employers."

Jan 1, 2005

By Y X. Xue, J Pan, D Q. Zhu

In order to reveal the correlation between the fundamental sintering characteristics of iron ores and their real sintering behaviours, a comprehensive evaluation index is proposed based on the measurement of four high temperature indexes, ie assimilation temperature, liquid phase bonding strength, liquid fluidity and calcium ferrite formation percentage, and the sintering pot tests of single ore fines and their blends. The results show that both the lowest assimilation temperature and liquid fluidity of ore blends appear to be the linear superposition of those of single iron ores except for the liquid phase bonding strength and calcium ferrite formation percentage. Furthermore, the tumble index of the sinter product obtained from blended iron ores also corresponds to a linear superposition of that of single ores, but not for the solid fuel rate and productivity. The comprehensive strength index YT exhibits a credible linear positive correlation with the four high temperature reactivity indexes, whereas the comprehensive productivity index YP possesses a lower correlation with the four high temperature reactivity indexes. The comprehensive strength index YT developed can predict the tumble index of the sinter product quite well, but the comprehensive productivity index YP cannot be used to evaluate the productivity effectively.CITATION:Zhu, D Q, Xue, Y X, Pan, J and Shi, B J, 2017. Correlation between high temperature sintering characteristics and sintering behaviours of iron ore fines, in Proceedings Iron Ore 2017, pp 123–132 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Vincent Roy

Numerous on going activities at the Daniel-Johnson Dam : ? Surveillance / monitoring ; ? Structural investigations & evaluation ; ? Injection work ; ? Crack mapping ; ? Instrumentation management (drawings & inventory) ; ? Drainage system state ; ? Foundation evaluation

Aug 1, 2013

By Seth C. Schaefer

The Bureau of mines investigated thermodynamic properties of MnSO4 and 2CdO CdSO4 to obtain basic thermodynamic data applicable to the treatment of mineral concentrates during roasting and sintering processes. Standard Gibbs energies of formation were determined with high-temperature galvanic cells using stabilized Zr02 as the electrolyte. Potential measurements were obtained from the cells?

Jan 1, 1983

Economic Sustainable Power for Mineral Processing

Sep 13, 2010