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By R. Tipman, T. C. Burnett

"A general computer program has been written to calculate material balances using multiple regression techniques. The program can handle metal assays or size distribution data obtained in multiple surveys of the flotation circuit. The ""best fit"" weight split is calculated between the input and product streams by minimizing the sum of squares of the residual errors using all of the available data. The program includes an assay adjustment feature in which each assay is recalculated to fit the ""best fit"" mass balance. Thus assay or sampling errors can be easily identified. Also the assays can be statistically weighted so the most precise measurements are given the most influence on the material balance. The computer output reports the mass balance, the actual and corrected assays, the percent metal recoveries and the significance and confidence levels for the weight splits.The program enables a rapid and accurate evaluation of mass balances from large masses of data obtained in multiple surveys around a flotation circuit. The effects of changing process variables can be quickly evaluated with statistical confidence."

Jan 1, 1978

By J. E. Dreier, R. E. Scheffel, A. Guzman

"This paper outlines a comprehensive, cost-effective testing program for the acid-ferric sulfate heap leaching of oxide, supergene and primary copper ores. It is based on extensive experience in copper heap leaching and uses the many technological advances in the field developed over the past several decades. The approach described requires firstly a detailed resource evaluation, then a hydrodynamic characterization of representative samples and, finally, a focused metallurgical testing program. The principles communicated here can be applied to other acid leachable minerals. The program varies considerably from conventional testing in its disciplined, orderly, step-by-step approach, its application of hydrological and chemical principles to leaching, and its reliance on fewer, more tightly controlled column tests. The purpose of the test program is to optimize the financial, time and other resources devoted to the program, while minimizing the financial risks to the development company or companies and the project funding providers. IntroductionThe major goal of any process development testing program should be the successful implementation of the project. With respect to heap leaching, the metallurgical testing program plays a critical role in the larger objective, as described in Scheffel (2013, 2014). McNulty’s series of papers (1998, 2004, 2014) confirm that the success of any project is directly proportional to the extent and quality of the testing program on which the process is designed.Therefore, a key development objective is to conduct a well-focused metallurgical test program. While the primary focus of this paper is copper, the acid leaching of any substance would benefit from a similar approach.This paper addresses primarily the sulfate system, which is compatible with the bioleaching of sulfide minerals. Nicol et al. (2011) described the advantages of the chloride leaching of copper sulfide minerals. United States patents Nos. US 2009/0173188 A1, US 8,597,933 B2 and US2015/0232963 A1, assigned to BHP Chile Inc. and BHP Billiton S.A. Ltd, describe methods for both the oxidative and nonoxidative leaching of primary and secondary copper sulfides. Reyes (2013) and Ipinza and Flaquer (2014) described commercial applications of chloride-based heap leaching. The testing disciplines discussed in this paper will also apply to the development of an acidic chloride leaching system."

Jan 1, 2016

By Fredy Gutiérrez, Nilton Apaza

En el año 2012, a causa de la situación inestable de la operación y por contar con una visión no muy proyectada al crecimiento organizacional, Raura se encontraba inmersa en una situación económica muy crítica y a punto de declarar su cierre. Por ese motivo, se replantea la visión estratégica de la operación y se alinea a la filosofía de la excelencia operacional por etapas. La principal apuesta de Raura es ser considerada una empresa de clase mundial, para lo cual, bajo un nuevo enfoque de gestión, en los últimos 5 años se implementaron diversas decisiones estratégicas que tuvieron impactos positivos. Así, se logró ser una de las operaciones más rentables de la división minera del grupo Breca.

Sep 20, 2019

By D. H. Yardley

GEOCHEMICAL investigation of trace elements in surface materials was begun near Ely, Minn., in 1953 along the basal contact of Duluth gabbro with Giants Range granite (Fig. 1). This article presents data on the distribution of copper and nickel in till and in stream sediments in the area and proposes an explanation for the types of distribution found. The Duluth gabbro, one of the world's largest basic intrusives, intrudes rocks which range in age from Keewatin to middle Keweenawan. Within the test area the gabbro is in contact with granite except for short sections where it is in contact with remnants of iron formation. Sulfide mineralization occurs within the gabbro, near and parallel to the basal contact for a distance of several miles. Schwartz and Davidson' have described the geologic setting of the mineralization. The sulfides, believed to be syngenetic, include chalcopyrite, cubanite, pentlandite, pyrrhotite, and minor amounts of bornite. They occur disseminated in the silicates and as small interstitial masses. The ratio of copper to nickel is about 3.8:1, based on 66 chemical analyses of rock samples from various outcrops (Ref. 1, p. 702, and Ref. 2). Test Procedures: With specified exceptions, all nickel and copper tests were made by the chromo-graph method,:' which measures the intensity of a colored spot formed by a reaction between the metal being determined and special reagent paper. The intensity is then compared to the intensity of spots prepared from samples of known metal content. Details of the test procedure are outlined in another article (Ref. 4, pp. 77,78). All soil samples tested in this investigation to date have been weighed on an analytical balance. However, a volumetric scoop designed to provide about 0.1 g of soil adds to the speed and ease of testing and has been found to give satisfactory results (Ref. 5, p. 531, and Ref. 19). The size of the samples used for the tests was 0.1 g. Whenever such small samples are used there is some question as to whether they are representative of the several grams in the field sample. Many repeat tests of the samples used in this investigation demonstrated that results can be reproduced within the limits of accuracy of the method without formal mixing beyond that inherent in screening the soil fractions. Furthermore, the 0.1 g is probably as representative of the field sample as the field sample is of its area of influence. Hawkes and Lakin (Ref. 6, p. 291), who considered the general problem, compared ground and quartered bulk samples of 500 g with 5-g grab samples. They concluded that "there is no significant loss in accuracy of data by substituting grab samples for bulk samples." The term soil implies somewhat different things to the geologist, engineer, and soil scientist.' For convenience the term as used in this article refers to unconsolidated material (the mantle) overlying bed rock. Sampling Procedure: Samples were taken at 100-ft intervals along north-south traverse lines across the gabbro-granite contact. The soil (till) samples were taken at an average depth of 1 ft, which was below the high-humus surface layer and into clean till. Samples taken at 1-ft intervals down to ledge showed as high a metal content at 1 ft below the air-surface as at greater depths and in two instances were slightly higher. The till at 1-ft depth did not appear to differ from material at greater depths. Total depth to bedrock has been tested at only a few points and where measured varied from 1 to 10 ft. Aerial Distribution Contours and Profiles: Plotting of copper, nickel, and cobalt content in contour form (Fig. 2) shows that anomalous amounts of these metal ions occur in till over and closely adjacent to mineralized areas of the gabbro. Contouring nickel content alone, or the copper content, outlines the same target area. Contours of the copper content provide a more distinct anomaly than nickel because of the higher copper concentration. The traverses are rather widely spread for interpolation; however, drilling has confirmed the target area essentially as shown.

Jan 1, 1959

A prototype EM Location System was fabricated and tested at the Geneva Mine near Dragerton, Utah. This system consisted of six manpack transmitters and six manpack receivers covering the frequency band from 900 Hz to 2900 Hz as well as a six channel receiver designed for use, in a helicopter. Tests showed that EM signals from lightweight (3/4 lb) transmitters could be detected both on the surface and from a helicopter through as much as 4450 ft of relatively high conductivity (2 X 10- 2 mhos/m) overburden. Furthermore, the resulting field strength profiles could be used to determine source location to within 150 ft of the actual surveyed location in the mine. Modifications were made to a Monitoring, Locating and Communications System being tested at the Bruceton Mine, Pittsburgh, Pennsylvania. These modifications have improved the performance and quality of the paging and voice telephony mode of the system. Subsurface receiver modifications have improved reception of voice downlink signals.

Jan 1, 1973

By J. W. Thompson

This work is a codification and annotation of the Congressional enactments relating to minerals, mineral lands, and mining. It covers every enactment of Congress from the original ordinance of 1785 to the present time, as well as all sections of the Revised Statutes of the United States relating to these subjects. These laws are grouped according to their general subject matter, and are arranged thereunder in numerical or chronological order. Many of the mining statutes include matter not pertinent to the subject, and only those parts of such acts are quoted as will properly show their relation to minerals and mineral lands and indicate how they should be construed. Some mining acts have been repealed or have become obsolete, and others have become incorporated substantially in sections of the Re- vised Statutes; but these are retained in order to show the changes made, and the constructions placed thereon by the courts are given as aids in construing the new or repealing acts. The annotations consist of legal propositions abstracted from the decisions of the various courts and executive officers of the Govern- ment that have interpreted the sections and statutes so codified. These legal propositions are arranged under the different sections and acts with appropriate headings, titles, and subtitles, in logical order, exhibiting the present status of each particular section or act and its application to the subject of mines and mineral lands. The annotations do not purport to be abstracts of decisions on the sub- stantive law of mines and mining generally, but are limited strictly to the interpretation placed on a given section or act definitely re- ferred to by a court or executive officer by the number of the section of the Revised Statutes or the volume and page of the Statutes at Large in which the Congressional enactment is found. It may be observed that the legal propositions stated are not always pertinent to the particular section or act under which they are classed and of which they purport to give a construction. The arrangement, however, is not an arbitrary one, but is so made for the reason that the courts or officers in the construction of a particular section or act definitely referred to by number or volume and page incorporated in the decision matter not strictly pertinent to the par- ticular section or act so designated. This statement applies especially to the interpretations placed on the sections of the Revised Statutes. The decisions abstracted for the purpose of this work are those of the United States Supreme Court, 234 volumes; the various Federal courts, 214 volumes; the decisions of the Department of the Interior

Jan 1, 1915

By F. F. Aplan, E. C. Dowling, R. R. Klimpel

Numerous flotation models have been proposed in the literature. Thirteen of these have been applied to batch flotation data and evaluated with respect to one another using statistical techniques. Flotation tests were carried out on samples of a US porphyry copper ore (Pinto Valley, AZ). The ore was tested using various collector and frother systems to produce different time-recovery profiles. These were used to calculate flotation rate and ultimate recovery parameters for each model. The models were then evaluated statistically to determine the overall fit of the calculated to the observed data and to test the range of significance of the parameters in each model.

Jan 1, 1986

By R. Benito

This paper describes the development of a life of mine schedule (LOM) for one of the world?s largest known sedimentary Copper-Cobalt districts located in the Katanga Province, Democratic Republic of Congo (DRC). A particular feature of the Tenke Fungurume LOM schedule is the considerable number of pits/phases for scheduling, each competing to provide the best ore available to a capacity constrained process facility. This paper discusses the main scheduling objectives and constraints, data pre-processing as a scheduling aid, the mine scheduling approach, and results and conclusions.

Jan 1, 2011

By Robert S. Becker

The results of a laboratory investigation of coal cutting mechanics and noise is presented. These experiments were performed using a linear cutting apparatus that operates over a broad cutting speed range. The influence of several coal cutting parameters on the noise, force, productivity, and specific energy associated with linear cuts is ascertained. Some basic theoretical aspects of coal cutting mechanics and noise generation are discussed, and the results of the laboratory experiments are used to Formulate analytical models of the coal cutting forces and noise. The analytical model For coal cutting noise is then generalized to account for the more important effects of rotary cutting. Based on the generalized model, an estimate of the sound pressure level at an operator's position is made for a typical continuous mining machine. It is concluded that by employing linear rather than rotary cuts, using deeper depths of cut, slower cutting speeds, and more efficient cutting tools, it is possible to reduce the level of coal cutting noise, as well as Provide benefits to other important areas of underground health and safety.

Jan 1, 1980

By Juan Camus

To understand why some companies excel in creating value, Jim Collins (2001) and a group of postgraduate business students engaged in a comprehensive, five-year research project. They examined 1,435 U.S. companies for more than 40 years, seeking those that made significant improvements in their financial performance over time. The distinctive pattern sought was: ?Fifteen-year cumulative stock returns at or below the general stock market, punctuated by a transition point, then cumulative returns at least three times the market over the next 15 years. ?The search identified 11 outperforming companies, all in different industries, that were called the ?good to great? companies. To contrast these companies with similar peers within the same industry, the search also selected a group of comparison companies that failed to make the leap from good to great. Collins then set out to examine the transition point. What distinguishing features did the good-to-great companies have that their industry counterparts did not? At the heart of the findings about these outstanding companies is what Collins refers to as the ?hedgehog concept? ? how to find the one big thing that the company must focus on. According to Collins, those who built the good-to-great companies were, to one degree or another, hedgehogs. Those who led the comparison companies tended to be foxes, never gaining the clarifying advantage of a hedgehog concept, being instead scattered, diffused and inconsistent. This insight is complemented by Peter Drucker (2004), an influential management guru, who asserts that the first question an effective executive should ask is: ?what needs to be done?? Asking this question and taking it seriously, he asserts, is crucial for managerial success; and that the answer almost always has more than one urgent task, but the effective leader only concentrates on one task. In this last respect, Drucker emphasizes: ?If they [executives] are among the sizeable minority who work best with a change of pace in the working day, they pick two tasks. I have never encountered an executive who is effective while tackling more than two tasks at a time.?

Jan 1, 2011

In the spring of 1944 the Congress passed Public Law 290 (58 Stat. 190, 30 U. S. C. Sec. 321) "authorizing the construction and operation of demonstration plants to produce synthetic liquid fuels from coal, oil shales, agricultural and forestry products, and other substances, in order to aid the prosecution of the war, to conserve and increase the oil resources of the Nation, and for other purposes." Section 2 reads: "In order to carry out the :purpose of this act, the Secretary of the Interior is authorized- (a) to conduct laboratory research and development work, and, with pilot plants and semi-works plants, to make careful process engineering studies, along with structural engineering studies, in order to ascertain lowest investment and operating costs necessary to determine the best demonstration plant designs and conditions of operation;

Jan 1, 1948

By David Seymour

Newmont Gold Company (NGC) located in Northeastern Nevada has been processing carbonaceous and sulfide refractory gold ores through a chlorination circuit prior to cyanidation. A "Flash Chlorination" pilot plant was installed in 1987 in an effort to obtain higher chlorine utilization efficiency and increase gold extraction. The Flash Chlorination process oxidizes organic carbon and sulfide sulfur. It also deactivates preg-robbing carbon, making the ore amenable to cyanidation. Significant recovery improvements were observed using this new process. This scheme has also been instrumental in the processing of higher than normal grade ores at economic chlorine levels. The Flash Chlorination pilot plant has been successfully treating carbonaceous ore on a production scale since April 1988. This paper summarizes laboratory and pilot plant optimization test work, using conventional and statistical methods.

Jan 1, 1989

By Pamela Paradis-Sokoloski, Deni Thibodeau, J. Denis, Samantha J. Espley, P. O’Donnell

"During the previous decade, the role of spray-on liners within the mining industry was limited to providing a corrosion resistant coating to screen and bolts; however, increasingly, liners are being used as ground support products. Expanding use and testing of liners have demonstrated their ground support function, yet the definitive support mechanism is still under debate. The most promising theory is the retain/hold/reinforcement concept (Kaiser et al.,1992). This conceptual theory has been the basis for the recent underground trials at INCO where, specifically, shotcrete and MIROC Mineguard were tested in two trials to further define limitations and applications of each liner.In a cursory overview, shotcrete is becoming accepted as a support product, while Mineguard is only slowly gaining acceptance.This discrepancy is the result of the corresponding life-spans within the industry, whereby shotcrete has had wide-spread use for decades, yet Mineguard has only recently been introduced. Currently at INCO, shotcrete is primarily used: to provide support in poor ground conditions, to add stability when developing through backfill, and to provide damage control in seismically active mines. It is also used to protect production headings and secondary-blasting chambers from fly-rock damage during blasting. Despite an obvious support function of the liner, shotcrete has always been used in addition to bolts and screen. Comparatively, Mineguard is still in the testing stage, where the greatest potential is increased productivity for applications in multi-tasking development headings. In this scenario, Mineguard provides instant support to replace screen, and bolts temporarily. When the heading has advanced, the drill and support crews work in tandem, drilling off the next round and installing bolts for long-term radial support, respectively. Other potential applications of Mineguard are within production headings to replace screen in the back, and screen and bolts in walls. The potential for both liners to replace conventional support is clearly war-ranted, such that defining the support role was the primary goal of the two underground trials."

Jan 1, 1996

By Kenneth L. Cook

From March 1944 to July 1945 the Division of Geophysical Exploration of the Federal Bureau of Mines made magnetometer surveys of some of the principal iron ore deposits of the Iron Springs district, Iron County, Utah. The district comprises a belt about 23 miles long and 3 miles wide. Most of the large ore bodies are found as pods of replacement ore within a favorable limestone bed lying at the margins of three separate igneous intrusions in the district The magnetic surveys were confined chiefly to this geologically favorable zone at the margins. The iron ore is a mixture of magnetite and hematite. The magnetite content of the ore ranges from 14 to 58 percent. Magnetic anomalies of 1,250 gammas or more were usually found over the near-surface ore bodies. About 62,000 magnetometer stations were taken over a total traverse distance of about 300 miles. Outcropping ore bodies were surveyed to determine, insofar as was possible from the magnetic data, their probable length, width, depth, extent, strike, dip, and tonnage. Geologically favorable areas where no ore is exposed were explored in an endeavor to find new ore bodies. Favorable locations were determined for exploratory diamond drilling, both in areas of exposed ore bodies and in areas of newly discovered magnetic anomalies. Forty-five separate magnetic anomalies that indicate the possible existence of ore bodies were observed. Of these, 13 anomalies are caused by outcropping ore bodies of proved commercial size. Five are caused by non-outcropping ore bodies of proved commercial size which were discovered, in whole or in part, as a result of the geophysical surveys. Of the remaining anomalies, which lie in virtually un-tested areas where few or no ore bodies are exposed, six probably are caused by large, unexposed replacement ore bodies, nine are possibly caused by large, unexposed replacement ore bodies, and six are probably caused by unexposed magnetite veins of some small commercial importance,

Jan 1, 1949

By F. Turatti

Rio Tinto is one of the world's largest mining companies, involved in every stage of metal and mineral production, producing aluminium, copper, diamonds, coal, iron ore, uranium, gold and industrial minerals. Operations are in more than 50 countries in multiple continents and vary in location between large urban centres, regional industrial complexes and remote regions. A risk-based strategy was developed by Rio Tinto to manage its air quality impacts on a global scale. The strategy consists of three objectives ? improving air quality performance, developing industry leading practices and engaging and influencing in air issues. This paper discusses three major successes achieved this approach. Firstly, how air shed resources are managed in constrained air sheds. Secondly, how financial modelling is used to value air quality constraints, and thirdly, how a rigorous and comprehensive e-learning course is used to improve the overall level of air management knowledge of Rio Tinto?s environment managers.

Feb 27, 2013

By Kadri Dagdelen

New underground coal mines have become increasingly expensive to open. A simple drift mine producing a raw coal product can cost as much as $50 million while a new shaft mine producing a washed coal product can cost up to $200 million. As a result, few if any speculative new mines are constructed. Normally, a long term coal supply agreement is needed to justify new mine projects. Negotiating a supply agreement prior to production start is difficult. Pricing must be based on estimated rather than historic costs and coal quality must be estimated from core hole samples versus actual shipments. Further in todays competitive coal markets, there is little margin for error in either price or quality.

Jan 1, 1983

By Timothy Green

El presente texto explica la historia, características complejas que intervienen en el desarrollo, producción, comercialización del oro. De otro lado, como consecuencia de la abundancia de este metal, se produjeron las "fiebres del oro", originando migraciones de muchedumbres a territorios vírgenes que estimulaban el rápido crecimiento de ciudades y comunicaciones.

Nov 1, 1988

By John Rowson, Caitlin Brown, Kebbi Hughes, Joseph Esslifie-Dughan

The McClean Lake mill in northern Saskatchewan, Canada, is operated by Orano Canada Inc. and has been in production for the last 20 years. The tailings preparation process at the mill has been designed with decommissioning in mind, to produce tailings that are geochemically stable over the long-term within the site’s tailings management facility. Twenty years of study have contributed to a detailed understanding of geochemical and geotechnical properties of the McClean Lake tailings. Validation of the tailings properties has occurred through in-situ sampling campaigns conducted initially every year, and later every five years. Each sampling campaign has applied the same rigorous sampling procedure to provide data with useful correlations year over year. Each campaign result compares elements such as the inherent variability of the tailings, consolidation of the tailings and variations in the tailings placement methods. We will discuss lessons learned from seven sampling campaigns over 20 years and present data to show the reliable tracking of geochemical evolution of the in-situ tailings over time; providing opportunities for continuous improvements.

Jan 1, 2020

Energold Drilling Corp. is a leading specialty drilling company servicing the mineral and energy sectors in the Americas, Africa and Asia. Energold specializes in mineral exploration in remote locations with limited infrastructure. Such locations require the smallest footprint possible going in, leaving as little or no evidence on their way out. Energold?s rigs can be transported by helicopter or manually on footpaths as narrow as 1 m (3.3 ft). They set up quickly and then are struck and packed out, with any sign of their presence quickly disappearing behind them. Energold has teamed up with Atlas Copco and its team of engineers in North Bay, Ontario to design small rigs capable of drilling to a variety of depths, as required for each project.

Jan 1, 2013

By C. W. Owning

"The Bureau of Mines has repeatedly emphasized the necessity of completely ""rock-dusting all coal mines, except anthracite mines, in every part whether in damp or dry condition."" Every open accessible part of, the, mine without exception should be thoroughly rock-dusted, including parallel entries, air courses, trackless entries, crosscuts, and rooms to within at least 40 feet of every coal face. Very few mines have followed this recommendation and warning, with the result that there have been explosions not only in mines which have not used rock dust but also in so-called rock-dusted mines. Following a number of mine explosions it has been reported that the mine was rock-dusted,"" whereas it is probable that only some of the haulage roads had been given a hurried application of rock dust and in most instances not as much as 5 per cent of the mine was really rock-dusted. That is not rock-dusting.Some conscientious, well-meaning mining men have felt that rock-dusting of haulage roads would effectively stop an explosion; however, when shown, through widespread explosions in mines ""well rock-dusted"" according to the above method, that leaving large areas undusted, furnishes paths through which a violent explosion may travel, these mining men have realized the necessity of thorough rock-dusting and have adopted this explosion-prevention method.The Mather Collieries mine, Pickands, Mather and Co., operators, at Mather, Pa., was the first mine in Pennsylvania to receive, full credit for rock-dusting under the new 'stringent ruling of the Pennsylvania Compensation Rating Bureau, the provisions of which require that:"

Feb 1, 1931