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By A Murphy, I Samsonova, N Eastwood, D Whittle

Part XI of the United Nations Convention on the Law of the Sea (UNCLOS or the Convention) (United Nations (UN) Division for Ocean Affairs and the Law of the Sea, 1982) establishes a comprehensive regulatory framework for the conduct of deep seabed mining (DSM) activities of mineral resources in the Area (defined in Article 1(1) of UNCLOS as ‘the seabed and ocean floor and subsoil thereof, beyond the limits of national jurisdiction’). Under that framework, DSM activities can only take place in the Area pursuant to an approved Plan of Work in the form of a contract with the International Seabed Authority (ISA) (the Authority), a 168-member international body created under UNCLOS to administer the Area. Private contractors can undertake DSM activities if they are sponsored by Member States of UNCLOS, providing a dual system of international and domestic regulatory control and oversight for activities in the Area.

Sep 1, 2024

By John Thella, Edward McNew, Christina Thella, Mends Emmanuel, Pengbo Chu

Ore sorting is an emerging technology in mineral processing that can produce a significant impact on the total mining and processing economics. The technology is capable of preconcentrating an ore based on differences in the mineralogical characteristics, which can include color, brightness, transparency, size, shape, density or near-infrared response. The current practice of conducting an ore sorting test typically requires large amounts of materials to be sent to a commercial testing facility, which is expensive and time-consuming. Here, we present a novel method to simulate commercial ore sorting on a laboratory scale using a rare earth ore.

Jan 1, 2025

By W. A. Hockings

This report describes a computer program for the solution of material balances in complex mineral processing flowsheets. The program, which is entitled MBS Metallurgical Balance System), evolved as the culmination of a series of material balance programs whose development began in 1967 at the Institute of Mineral Research, Michigan Technological University. The need for such a program became evident when the Institute became heavily involved in a large number of short-term pilot plant projects. Calculating material flows from analytical data by means of the standard two-product formulas grew increasingly difficult and time-consuming as the complexity of the flowsheets increased and as choices between conflicting analytical values had to be made. It was recognized that what was needed was a program that would assimilate all of the available data and calculate mass flow rates so that steady-state inputs and outputs would balance at each point in the flowsheet. Such a program should be capable of handling underdetermined, overdetermined and mixed systems, and when the given data are inconsistent, the program should adjust the data in such a manner that the adjustments are minimized. Missing analyses should also be calculated whenever possible. In addition to solving material balances, the program should be convenient to use and print out the results in a useful form. Thus, the inputting of data should be simple enough to be handled by relatively untrained personnel with diagnostic messages being printed out to identify errors and anamolous data when they occur. Most importantly, the program should produce well-formatted output which can be directly included into a report without the necessity of retyping. The proper spacing of table titles, column headings and the ability to control the columns being printed are important features in this respect.

Jan 1, 1977

By V. Avzian Belozersky reg 453524, Vasily V. Lodeischikov, Adolf F. Panchenko, Til E. Vidusov, Olga D. Khmelnitskaya, Vladimir E. Dementyev

"Presently, there is a number of gold deposits which cannot be developed using the conventional technologies with acceptable economic indices due to low gold content, high depth of ore occurence and other conditions. For such ores, an innovation technology of underground gold leaching in the place of their occurrence is of special interest. The technology excludes ore mining and hoisting to the surface. This enables the production cost of 1 g of gold to be considerably reduced in comparison with conventional methods of gold recovery.The Maminskoye deposit oxidized ores were chosen as the subject of underground leaching because they are ideally suited for this purpose due to their composition and hydrological parameters. The ore reserves within the underground leaching block are 90, 000 t with 0.7 g/t average gold grade.An experimental system for underground leaching with a throughput of 15 cubic m solutions per hour was developed. A combined filtration-and-infiltration system of the ore massif development by holedrillingwhere pregnant solutions are air-lifted was worked out.The underground leaching flowsheet includes Au dissolution by chlorine-containing solutions, Au adsorption from solution onto active carbon, carbon concentrate ashing and calcine melting to produce Dore metal."

Jan 1, 2003

By Boghani. A. B.

A computer program has been developed to simulate evacuation of a mine in various configurations. The simulation input variables include characteristics of the mine, expressed, in the form of a network of passages, properties of hoists and hoisting strategies, initial miner positions, ventilation and compressed air velocities, stench warning system and self rescuer capabilities. The simulation can be carried out for cases in which there is no fire, i. e. , fire drill simulation, or for cases in which there is a fire at any arbitrary location. The fire is assumed to generate gases which impede movement of miners in the gaseous region. However, the thermal effects of the fire are not considered. The simulation output include the evacuation time for each miner, movement of the hoists, propagation of smoke through the mine passages and smoke exposure of the miners. Several illustrative simulations have been carried out to verify validity of the program and to demonstrate its capabilities. The computer program has been able to predict evacuation time, within 5 percent, for an actual fire drill. It is believed that this program can be used to evaluate evacuation performance of a mine, identify problem areas and demonstrate improvements due to the recommended corrective actions.

Jan 1, 1977

By Fulvio V. Fonseca

The Trombetas bauxite deposits were discovered by ALLAN, as from the original work of the geologists Drs. E. E. GREIG and 3.A. STAARGAARD on the axis of the Amazon river, between Manaus and Santarem - (see fig. 1). With research licences obtained in 1965 by the SANTA RITA BAUXITA - a subsidiary of ALAN a group of Brazilian geologists, under the supervision of IGOR MOUSASTICOUSHVILLY, begins researches on the areas of Parintins, Juruti and Mathias with unsatisfactory results. In 1966, photographs obtained from the US Air Force and the Brazilian Oil Company PETROBRAS -, covering an Amazon region between Parintins, Santarem and north of Trombetas river, permitted the identification of a great number of plateaux between the Nhamunda and the Trombetas rivers. Based on this information, a research group has worked intensively from 1966 to 1967 allowing the discovery of the trihydrated bauxite in a quite large area. After five years of intense work and analysis of approximately 56.000 samples, near 500 million of tonnes of bauxite are evaluated on the several plateaux of the, area, thus insuring the commercial exploration of these deposits. Such discovery places Brazil among the detainers of the main bauxite stocks of the world and as a potential exporter.

Jan 1, 1980

By H. Polat, Q. Hu, S. Chander

"The collection efficiency of dust particles was determined in a laboratory dust chamber equipped with a water spray. Measurements were made in the presence of selected nonionic, cationic and anionic surfactants. For the nonionic and the anionic reagents, efficiency was maximum in a narrow range of concentration. The surfactant concentration corresponding to high collection efficiency was usually much below the commonly used concentration of l "", however. In comparison, much higher collection efficiency was observed for a cationic surfactant at extremely low concentrations. For delineating the mechanism of capture of dust particles, surface tension and contact angle results were used to obtain a correlation between the work of adhesion and the efficiency of collection. Such a correlation was reasonable for the nonionic surfactants but not for charged surfactants. In the latter case, electrostatic interactions between charged droplets and particles were more important, especially for the cationic reagent. INTRODUCTIONSeveral methods are used to control dust in mines. These include: ventilation, foam, scrubbers and sprays. This article is concerned with improving the effectiveness of water sprays, which are widely used to remove dust particles during continuous mining, by adding small quantities of surfactants. Water sprays produce small droplets which act as collectors of dust particles suspended in air. Sprays directed at the actual source of dust have the additional property of wetting the coal before the ·particles become airborne (Hamilton, 1974). Wetting agents, also called surfactants, arc known to play an important role in many applications where dust is a problem. However, conflicting reports exist in the literature with regard to the effectiveness of surfactants in water sprays (for a review, see Chander et al., 1988). In spite of the conflicting reports, the use of surfactants for dust control has increased over the years. In a recent study by the Bureau of Mines, a 27'6 reduction in respirable dust levels was observed in a mine test when surfactants were added to sprays (Foley, 1991)."

Mar 1, 1992

By Robin J. Batterham

The Bologna Process started in 1999 with a declaration signed by ministers from most European countries. As of 2012, the Bologna Process now has 47 participating countries (EHEA 2012). Overall, the Bologna process has demonstrably changed higher education in many countries to allow for considerably more flexibility in course offerings. Keywords: bologna model, education

Sep 1, 2012

By John Place

El presente texto describe la relación de la crisis de metales con la calidad de vida en Estados Unidos. En ese sentido, la crisis de energía es un ejemplo de que el "status" sin recursos clama por una dirección pública. Asimismo, la presión mundial por el suministro de metales y la demanda por los metales básicos no ferrosos, genera un desequilibrio entre la extracción en el precio de los metales y gas. Por ello, se debe analizar nuevas tecnologías que reduzcan el costo de exploración, o que aumenten su costo-efectividad.

May 1, 1973

By L. Xinguang

Shandong MinMetals Corporation, a state-owned import and export organization located in the city of Qingdao, Shandong Province, China, was opened in 1954, with the mission of marketing metal products and industrial raw material in oversea areas for hard currency to support the modernization project of the country as well as the province. The management officers are appointed by the provincial government, and report to the Foreign Trade Department of Shandong Province. Meanwhile, the company also receives guidance from MinMetals head office in Beijing, the capital city of China. The head office does not own and control any provincial MinMetals organizations, but merely coordinate business among provinces.

Jan 1, 1990

By David J. Dunn

Of many physical parameters critical to design of grinding processes, impact of grinding media is among the most difficult to measure or predict. Yet impact of falling grinding balls, pebbles, or rods accomplishes the fine grinding essential to metallurgical recovery of most important minerals. Unfortunately, the same impacts that break ore fragments deform or crack grinding mill liners. A project was undertaken at Climax Molybdenum Company to measure impact forces in operating ball mills so that they might be used to calculate stresses in liner materials and be correlated with service performance of mill liner alloys. Towards that end, a method of measuring impact forces on ball mill liners using an instrumented grinding ball has been developed. Preliminary tests show that impact forces and contact stresses imposed on bare mill liners are quite high but are greatly reduced by cushioning when coarse ore particles are crushed between balls and liners. Compressive and shear stresses induced in liners not protected by coarse ore are so severe that deformation or minute subsurface cracking are inevitable in all but the small production grinding mills, regardless of mill liner alloy strength or hardness.

Jan 1, 1977

By AIME AIME

REGISTRATION and licensing of engineers is now being given consideration by a special committee of the Institute, authorized at the March meeting of the Board of Directors. The subject is one that has recently been or is now actively before engineering organizations in many of the States of the Union. In Washington, D. C., the Washington Society of Engineers and the local sections of ten national engineering societies, including the A.I.M.E., recently had a joint committee investigate the subject: this committee formulating a proposed law that has been presented to Washington engineers for their consideration. At the same time, the committee has summarized the reasons for and against registration of engineers in Washington, D. C. As many of these reasons are of more than local application, they are here reprinted so that all members of the A.I.M.E. may be informed on the subject. It is expected that some report of the Institute's Committee on Registration, State Councils and Professional Development will he made at some forthcoming meeting of the Board of Directors.

Jan 1, 1932

By S. J. Cohen

Changes in our energy, national security, and commerce needs have necessitated identification of new sources of minerals, such as rare earths, lithium, copper, silver, aluminum, titanium, and the minerals on the U.S. Geological Survey’s (USGS) list of critical minerals (USGS, 2022). With the need to domestically produce these minerals, more mining will be required within the U.S. Some of these critical minerals deposit with naturally occurring radioactive materials (NORM), therefore, mining these minerals may concentrate NORM to the point that some states may require licensing and radiation protection programs. NORM is not regulated by the Federal government; it is regulated by the individual states. Consequently, overall national state of NORM regulation is chaotic with each individual state either choosing to regulate or not regulate NORM, and, if a state chooses to regulate NORM, then that state develops its own unique regulations. Further complicating the regulatory environment, states utilize a wide variety of strategies for regulating NORM, which sometimes results in inappropriate regulations, inconsistencies with specific radionuclides that are regulated, and inconsistencies with specific NORM types that are regulated. This paper will review the nature of NORM regulations, identify regulatory traps, and provide general guidance for identifying NORM and potentially avoiding regulatory jeopardy. Because of the chaotic nature of NORM regulations nationally, seeking guidance from qualified professionals with relevant expertise is recommended. Also, contacting the appropriate regulatory agency to gain a complete understanding of the NORM regulatory environment is useful for maintaining compliance.

Feb 1, 2023

By K. Hawboldt, J. E. Halfyard, C. Bottaro, I. A. Harrison

"The removal of elemental sulfur from leach residues derived from massive sulfide concentrates via hydrometallurgical routes has been demonstrated in a laboratory setting by converting water-insoluble sulfur to water-soluble polysulfides. The approach was applied to leach residue from Vale's nickel hydromet demonstration plant in Argentia, Newfoundland, which contained significant amounts of elemental sulfur. This technique offers an alternative treatment protocol for residues with a sulfur component not amenable to standard flotation/hot filtration processes. The practical considerations of a proposed flow sheet will be discussed including the impact of other sulfur species (e.g. thiosulfate and sulfides) and key process variables. INTRODUCTIONPresently, large scale elemental sulfur extraction from hydrometallurgical leach residue is performed by Teck Resources using a process of sulfur flotation followed by hot filtration (Chalkley et al., 1993). As mentioned, the technique proves viable for residues derived from specific concentrations - in this case zinc - whose residues constituency is primarily elemental sulfur itself. However, problems arise when this constituency is altered as happens when, for example, a mine containing one particular concentrate is mixed or replaced with a differing concentrate from a second mine. Such cases can often strain the effectiveness of current sulfur removal processes (D'Odorico, 2004). If hydrometallurgical residue containing elemental sulfur cannot be effectively treatment by flotation, the residue is stored subaqueously as is the case in some 'grass roots' hydrometallurgical plants (those not coupled with smelting operations). Hydrometallurgical processing of concentrates involving pressure leaching is becoming increasingly common throughout the mining world, the genesis of which can be found in research performed by Sherritt in Fort Saskatchewan since the 1950’s (Ozberk et al., 1995).The investigation of elemental sulfur removal by means other than flotation includes the uses of sulfide salts (NH3S or Na2S) effecting the conversion of hydrophobic elemental sulfur to hydrophilic polysulfides. The work of Kunda et al. (1974) and Olper et al. (2007) shows that elemental sulfur can be quantitatively removed from hydrometallurgical leach residue via the formation of a mixture of polysulfides."

Jan 1, 2012

By A. Jordens, Y. Zhiyong

"IMBSRE, one of the largest rare earth element (REE) producers in China, produces a rare earth oxide (REO) concentrate as a by-product by floating the middlings stream from a low intensity magnetic separation step in the main iron ore processing stage. As the mine depth has increased, flowsheet changes in the main iron ore circuit have reduced the REO grade and increased the magnetite to REO ratio in the middling product used as flotation feed for the REO circuit. Extensive laboratory work was carried out and identified a new modified hydroxamic acid product, Florrea 8920, that could provide better metallurgical results over the standard hydroxamic acid used as the main collector. This paper briefly reviews the use of hydroxamates in the flotation of oxide minerals, provides detailed information on the different hydroxamates available from Florrea and then provides a case study of the successful implementation of the Florrea 8920 product in a commercial Chinese REE flotation plant. The case study consists of a one year program of pilot plant testing and industrial trials to confirm the results of laboratory tests. The implementation of the new collector resulted in an improvement in grade and recovery to 61% and 64% respectively. The new collector also provided significant economic and environmental benefits.INTRODUCTIONThe flotation of rare earth element (REE) bearing minerals is a topic which has been dominated in the English language literature by the work conducted on the Mountain Pass bastnäsite deposit (Pradip, 1981; Fuerstenau, Pradip, Khan, & Raghavan, 1982; Pradip & Fuerstenau, 1983, 1985, 2013; Fuerstenau & Pradip, 1991; Fuerstenau, Pradip, & Herrera-Urbina, 1992; Herrera-Urbina, Pradip, & Fuerstenau, 2013). By far the most important collector type used for the flotation of rare earth minerals (REM) is hydroxamates. These reagents were initially extensively described as REM collectors in the English literature by Pradip (1981) however they have been successfully applied to numerous other minerals such as: cassiterite (Sreenivas & Padmanabhan, 2002); pyrochlore (Gibson, Kelebek, Aghamirian, & Yu, 2015); hematite, chrysocolla, rhodonite, hubnerite and pyrolusite (Fuerstenau, 2005); and malachite (Lenormand, Salman, & Yoon, 1979) amongst others."

Jan 1, 2016

By Luis Bergh, Francisco Díaz, Isabel Panire, Juan Yianatos, Luis Vinnett

"In this paper, industrial data of residence time distribution (RTD) in mechanical flotation cells is presented, which were measured in several plants using the radioactive tracer technique. Results include mechanical flotation cells of 100 - 300 m3, which were operated with effective residence times from 2 to 7 min. Tests were developed in forced air and self-aerated cells for liquid and solids (non-floatable) per size classes. Different RTD model structures including perfect mixer, Large and Small Tanks in Series (LSTS) and by-pass flow plus perfect mixer were evaluated and compared for single cells. The actual mixing regime was related to the effective residence times and cell designs based on the model fitting. By-pass flow percentages were typically lower than 10%, therefore the perfect mixer model plus a dead time was a suitable model structure in most cases. On the other hand, the arrangement of cells in series was effective in reducing the bypass flow observed in single cells (by-pass flow percentage greater than 5%). In addition, the N perfectly mixed reactor in series model was used to represent the mixing regime along flotation banks, which were operated with mean residence times in the range of 18 - 53 min. Results showed that N tanks in series plus dead time were closer to the actual values in most cases."

Jan 1, 2014

By Hernán Chavez, Sandro Ludeña

La minería es un industria muy retadora para lograr su desarrollo, desde la etapa exploratoria, pre factibilidad, factibilidad, construcción y finalmente llegar a operar, en todas estas etapas se presenta el gran reto de generar gran volumen de información, en medio ambiente desde la línea base, ha sido el cuello de botella el homologar y/o organizar una sola base de datos integral, para que estos sean usados para sustentar distintas estudios, la situación social también conlleva a tener un mejor control y aseguramiento de la información, mientras más transparente sea, serás mejor visto ante las comunidades.

Sep 29, 2023

By R. S. Mateer

Linear programming on desktop computers is commonly used to optimize coal blending proportions. The objective function is usually the cost of the blend. The constraints consist of materials and heat balances as expressed as linear functions of the blend. This is illustrated in Example 1. Inclusion of a sulfur compliance constraint in more complex because the maximum permitted sulfur percentage is not a pre-specified constant. Rather, it is a function of the calorific power of the blend itself. The current limit of 1.2 pounds of sulfur dioxide per million Btu may be expressed as: [Sulfur Max%= 0.6 . Hl10,OOO with H in Btu/lb.] A proper constraint equation may be formed by defining for each coal a function that is the difference between the actual sulfur percentage and the maximum sulfur percentage. This may be regarded us an excess sulfur percentage. For Coal A of Example 1. this would be: [ Sulfur Excess%=0.5-0.6 13,000/10,000=-0.28] This value would be used as the coefficient of the weight proportions of this coal in the blend. The complete constraint equation would then be the sum of such terms for each coal set less than or equal to zero. This is illustrated in Example II. [ ]

Jan 1, 1995

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

D.2 Principal Types of Coating A Sodium Silicate Sodium silicate is a good fire retarder when freshly applied, but it loses its effectiveness if the relative humidity is at all high, thus exposure to a relative humidity exceeding 65 percent causes a serious decrease in the effectiveness after only one month. In fire, sodium silicate swells to a frothy mass (intumescence) which hardens and insulates the wood against heat. This property is destroyed by exposure to moisture. Manufacturers of many of the proprietary paints containing silicates state that their products have overcome this difficulty The reagent may be applied alone, or, better, in a mixture with lime-water and common salt, or with inert fillers such as kaolin or asbestos. B Ammonium Phosphate Strong solutions (25 to 35 percent) of monammonium phosphate or diammonium phosphate give good protection. Two or three coats of hot solution should be applied either with a large flat brush or an ordinary paint spray gun The solution should be applied as hot as possible, as this improved penetration, and it should be the aim of the operator to apply 4 lbs of reagent, i e , one gallon of 33 percent solution to every 100 square feet of surface

Jan 1, 1976

By J. C. Edwards, C. C. Hwang

A Computational Fluid Dynamics (CFD) program was used to model buoyancy induced Product-Of-Combustion (POC) spread from experimental fires in the National Institute For Occupational Safety And Health (NOSH), Pittsburgh Research Laboratory (PRL), safety research coal mine. In one application, the CFD program was used to predict spread from fires in an entry under zero airflow conditions. At a location, 0.41 m below the entry's roof at a distance of 30 m from the fire, the measured smoke spread rates were 0.093 and 0.23 m/s for a 30 and a 296 kw fire, respectively. The CFD program predicted spread rates of 0.15 and 0.26 m/s based upon the measured fire heat production rates. Based upon a computation with [c3h3] as the hydrocarbon fuel, a predicted 5 PPM co alert time of 70 s at a distance of 30 m from the fire is to be compared with the measured alert time of 148 s. In a second application, the CFD program was used to analyze smoke flow reversal conditions, and the results were compared with visual observations of smoke reversal for 12 diesel fuel fires. The CFD predictions were in qualitative agreement with visual observations of smoke reversal.