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By Richard J. Mainiero, Michael J. Sapko, James H. Rowland III, Marcia L. Harris

All explosive materials produce a cloud of reaction products, the most toxic of which is nitrogen dioxide (NO2). In the study reported here, 4.5-kg (10-lb) charges of blasting agent confined in either thin-wall 10-cm (4-in) diameter galvanized pipe or 10-cm (4-in) schedule 80 seamless steel pipe were detonated in a closed chamber. The detonation gases were analyzed for NO2, nitric oxide (NO), ammonia (NH3), hydrogen (H2), carbon monoxide (CO), carbon dioxide (CO2), nitrogen (N2), oxygen (O2), and methane (CH4). Data were evaluated to determine the kinetics of the oxidation of NO to NO2. Analysis revealed that the only mechanism for NO loss for the conditions existing in the chamber was the reaction 2NO + O2 6 2 NO2. The rate constant was 2.08 @ 10-38 cm6 molecules-2 sec-1 for the rate equation -½d [NO]/dt = K @ [NO]2 @ [O2] for NO concentrations up to 100 ppm. The rate constant is in agreement with that recommended by Baulch, Drysdale, and Horne (1973).

By Uwe König

Traditionally quality control of iron ore sinter, its raw materials and raw mixtures has relied on time-consuming wet chemistry. The mineralogical composition that defines the properties is often not monitored. XRD analysis in combination with Rietveld quantification and statistical data evaluation using Partial Least-Square Regression (PLSR) has been successfully established to determine the mineralogical composition and process parameters such as the FeO (Fe2+) content and basicity of iron sinter within an analysis time of less than 8 minutes per sample. Both methods take the full XRD pattern into account and can be simultaneously applied on the same measurement. In addition the Rietveld method was used to quantify the phase content of raw mixtures to monitor the composition of blending beds.

Aug 16, 2017

By R. G. S. Mussi

An inclined cooling plate is utilized as a modification in the compocasting process of magnesium alloy and the mechanical properties of the composites obtained are studied in this work. Based on crystal separation theory, molten AZ91D is poured onto an inclined plate in order to produce solidification nuclei inside the fluid metal, and is mechanically stirred while reinforcement is added. Particulate SiC was utilized as reinforcement in quantities varying from 0 to 15%vol. Dispersion of the reinforcement was observed by macro and microstructure analysis. SiC was properly mixed into matrix until 15%vol., and Vickers hardness tests were carried out for the composites produced. Results obtained for hardness were shown to increase with reinforcement addition and comparable to those of traditional compocasting. Utilization of Inclined Cooling Plate produced good inclusion and homogenization of SiC through an AZ91D matrix, at lower temperatures and shorter times than traditional compocasting.

Jan 1, 2006

By J. R. Thoenen

During 1928 questionnaires covering the calendar year 1927 were sent to over 1700 quarries: producing stone for purposes other thaw cutting to dimension. These inclined producers of stone for limn burning; cement manufacture, rip rag, and crushed stone. The various rinds of stone represented were limestone, trap rock, sandstone, granite, and marble. Replies received from limestone producers prior to November, 1928, were compiled into tables and published in February, 1925, as a preliminary report (Bureau of Mines Report of Investigation 2911).

Jan 1, 1930

By L. C. IlsLey

The increasing use of Diesel engines for operating equipment on trunk-line railroads and for power-plant units has stimulated interest in the use of Diesel engines for other lines of work, among which is the possibility of substituting Diesel locomotives for trolley locomotives for mines. The possibility of developing Diesel locomotives for duty in American mines is not as remote as it might seem, particularly in view of the fact that locomotives of this type are already used in considerable numbers in European mines. A study of Diesel locomotives in Europe is contained in Report of Investigations 3320, Diesel Mine Locomotives - Development and Use in European Coal Mines, by George S. Rice and F. E. Harris.

Jan 1, 1938

By G. A. Witwicki

"The Thyssen Mining Group of Companies has successfully applied ground freezing technology to numerous projects throughout Europe and North America for over 100 years. Recently, the aspect of data acquisition and data verification has received greater focus.Thyssen Mining has been engaged in several relatively deep shaft sinking projects over the past five (5) years, all of which have required ground freezing to successfully sink through water bearing rock. To safely and economically sink through a quantity of water similar to Saskatchewan’s Potash Mines, it is imperative to understand freeze wall thickness and growth rate.Critical to understanding freeze wall thickness and growth rate, is the collection of accurate data as well as the interpretation of those data. The data can then be utilized to gain a better understanding of the freeze wall growth rate in active projects as well as to provide data to be utilized in modeling for future projects.This paper elaborates on the installation and operation of the data acquisition system utilized at the Newmont Leeville project, Nevada’s first frozen shaft project. In addition, this paper elaborates on the methodology developed by Thyssen Mining to manipulate the freeze wall data derived through the data acquisition system.The successful incorporation of the new system of collection and analysis of freeze wall data for the Leeville Project has given Thyssen Mining a high degree of confidence in the understanding, as well as prediction, of the ground conditions during shaft sinking.This paper will include:•,A brief description of ground freezing and its objective;•,An overview of previous data acquisition methods employed;•,Current data acquisition methods;•,Installation requirements; and,•,Data manipulation and presentation methods."

Jan 1, 2015

By John Watson

New Technologies, New Challenges and New Opportunities For quite some time now, numerous explosive manufacturers have spent untold man-hours and millions of dollars trying to develop a blast initiation technology that would “once and for all” provide users with what was once believed to be only a theoretical possibility...nominal timing. Zero “cap scatter” (the amount of variation of delay timing from the targeted nominal) has been the industry’s goal ever since delays were first introduced into the marketplace. Just as adding delay time between blast-holes improved blast performance since their introduction, having the wrong delay or a poorly timed blast has proven to be very inefficient and in many cases hazardous. The question of how precise a blast initiation system needs to be still remains unanswered, but electronic detonator systems being used today indicate that significant improvements can be achieved over conventional pyrotechnic detonators. These systems can typically provide single digit millisecond ranges of variability, if not sub-millisecond in some cases.

Jan 1, 2003

By B. Prof. Silliman

THE experiments detailed by Dr. Hunt,* having demonstrated the fact that the copper contained in the "clay ore" of Jones's Mine, was rendered completely soluble in the bath of ferrous chloride, used in the Hunt and Douglas process, after heating in contact with carbonaceous matter in a close vessel, I set myself to devise a form of muffle furnace adapted to the treatment of large quantities of these and similar ores by a continuous process. The result is shown in the diagrams on Plate X, reduced from the working drawings, after which this furnace was built early in 1876, at Phoenixville, by the Chemical Copper Company on their works at this place. The peculiar character of this ore determined the form, dimensions, and position, with reference to charging and discharging of these muffles. The ore arrived from the mine with from 20 to 25 per cent. of moisture, and when dried at 212° F., or more slowly at lower temperature, it falls to a light incoherent powder, with occasional lumps of undecomposed rock. In this condition it is readily mingled with coal-dust or any like reducing agent, and requires no other preparation for the muffle than the use of the shovel, to mix it well with the reducing agent. As it is a remarkably good non-conductor of heat, it was obvious that the mass, to be heated through in a reasonable time, must not be too thick, while the weight of the mass must be sustained in a way to avoid undue strain upon the walls of the muffle. These walls must be as thin as practicable, to favor the more rapid transmission of heat, and must, therefore, be so con¬structed as to admit of being stayed on the sides at frequent intervals to resist the lateral thrust of the very mobile mass of pulverulent ore, which, for obvious reasons, must be charged at the top and drawn from the bottom of each chamber. These considerations led to the form adopted, viz., two vertical muffles, standing upon very strong bridge tiles, seen in longitudinal section, on the line E, F, and in plan in Fig. 3, on the same plane. (Plate X.) The vertical section of the muffle is seen in Fig. 4, drawn in the plane G, H, of the longitudinal section, Fig. 6, which is the key to all sections. The walls of the muffles are built of the best firebrick, very care- * See paper by Dr. Hunt, page 325.

Jan 1, 1876

By S H. Marshall, H Hutcheson

Conventional batch cell and FASTFLOT pilot plant studies of reverse flotation of coarse marcasite and pyrite (100 - 400 μm) to reduce the sulphidic sulphur content of a rutile concentrate, were undertaken. The batch cell experiments found no significant improvement in sulphur removal with acid wash and copper activation of marcasite and pyrite. Batch cell trials also identified potential difficulties of conventional mechanical cell plants operated at 40 per cent w/w solids. The FASTFLOT 250 B-2 pilot plant trials indicated that with a 0.6 - 0.7 per cent w/w feed sulphur content, target product grade can be met on a routine basis by a three-stage FASTFLOT plant floating coarse marcasite and pyrite. The trials found that 150 g/t PAX dosage and 15 minutes conditioning time are adequate reagentisation for 40 per cent w/w solids feed to the FASTFLOT plant.

Jan 1, 1998

By W. H. Ode

Because trade increased among various nations after World War II, the Coal Committee of the Economic Commission for Europe established a Classification Working Party in 1949 to develop an International system for classifying coal. Although national classification systems existed, they had been developed in accordance with characteristics of domestic coals without reference to coals of other countries. Terms for describing similar or identical coals differed in each nation. This caused confusion in evaluating coals shipped in international trade and also hampered exchange of technical information on problems of coal utilization. Experts4/ participating in the classification project early in their work agreed that two systems should be formulated, one for the higher rank coals or so-called "hard" coals in European terminology and the other one for the lower rank coals, the latter designated mainly as brown coals and lignites in the various countries. Rank refers to the degree of metamorphism (progressive alteration) in the natural coalification series from lignite and brown coal to anthracite. The system for classification of hard coals was published late in 1956 as a document of the United Nations.5/ Results of a study for applying this system to American coals were published in 1958.6/

Jan 1, 1960

By Michael G. Nelson

Control of the feed provided to mineral processing facilities is a continuing challenge. Much effort is currently being devoted to overcoming these problems. These projects are usually described under the general headings of Mine-to-Mill Integration or Mine-Mill Optimization. It should be possible to combine the knowledge of ore type, mineralogy, and other characteristics (located in the mine modelling system), with the advanced capabilities of state-of-the-art mill control systems, to achieve an improved level of control in mineral processing, allowing optimization of the mill processes on an almost realtime basis. This is not happening because mill feed it is often treated as a uniform material, when in reality it varies in composition and characteristics. The University of Utah is investigating the use of odor sensors for maintaining traceability in ore production and processing. Odor sensors now used in food processing, environmental monitoring, and other applications can detect the presence of very small amounts (0.1 - 500 ppm) of some molecules. An assortment of such molecules could be used to ?tag? blocks of ore as they are mined, according to their respective characteristics. Then, as the ore came into the mill, an array of ?electronic noses? could be used to assess its characteristics in real time.

May 1, 2004

By Thomas Frost

In this time of market globalization, many industrial companies are including detailed arbitration clauses in their international contracts, in order to avoid the potential costs, delays, and uncertainties of litigation in foreign courts. Arbitration is less expensive and more flexible, procedurally, than court proceedings, and arbitral awards enjoy much greater international recognition than judgments of national courts. More than 134 countries have signed the 1958 United Nations Convention on the Recognition and Enforcement of Foreign Arbitral Awards, known as the "New York Convention", which facilitates the enforcement of arbitral awards internationally. There are several other similar arbitration conventions that provide for the enforcement of cross-border arbitral awards. Additionally, arbitral awards are not subject to appeal, whereas judgments of national courts are routinely subjected to a lengthy appeals process, and there are very few viable bases to challenge arbitral awards. This discussion will review key considerations in drafting arbitration clauses, including choice of law and choice of forum considerations; issues surrounding the selection of arbitrators; the discovery process; presentation of evidence; and enforcement of arbitral awards.

Jan 1, 2006

By Miguel Carrera, Martín Bradshaw, Víctor Araya

Teck Resources Limited está implementando desde hace ya algunos años un fuerte programa global de incorporación tecnológica, tanto de desarrollo propio como también de empresas líderes en tecnología minera. Es así como la operación Teck Carmen de Andacollo ha implementado un revolucionario sistema desarrollado por la empresa MineSense Technologies Ltd, que permite mejorar considerablemente la selectividad de los equipos de carguío en las frentes de bancos, reduciendo la cantidad de mineral perdido en botaderos y eliminando el estéril que diluye el mineral destinado al procesamiento.

Sep 30, 2022

By S. I. Anufrieva, N. A. Permyakova, E. G. Likhnikeevich

"Russia’s rare metal reserves are composed of compositionally and structurally complex ores and are characterized by an increased content of natural radionuclides due to their geochemical similarity with rare metals. For instance, concentrates of Zashikhinsky daeposit are characterized by an increased content of uranium (0,06%) and thorium (0,59%); Beloziminsky deposit holds pyrochlore-apatite-magnetite-carbonate ores characterized by increased radioactivity (130 mkR/h) and containing 0,0016-0,0025% of uranium; Etykinsky deposit is characterized by columbite-pyrochlore-microlith mineralization with an average ore grade of 0,013% of uranium and 0,0020% of thorium; eudialyte concentrate of Lovozero deposit (Alluaiv area) belongs to Class II of mineral reserves. Industrial development of these mineral reserves involves the need to comply with environmental standards, public health requirements applicable to finished core and by-products, to take into account the amount and class of the generated radioactive waste, the possibility of disposal or recycling of the radioactive production waste. Concentration processes of radioactive rare metal feeds most often lead to a concentration of natural radionuclides and their accumulation in concentrates. Comprehensive hydrometallurgical processes are currently under development for such concentrates, aimed at producing salable products compliant with the radiation safety standards. The choice of the hydrometallurgical processing method for radioactive rare metal concentrates is based on the mineralogical component of the concentrate, textural and structural features, the distribution of valuable components and impurities, and the content of radionuclides. A systemic approach to the selection of processing methods, in particular integrating several methods, is an effective solution. Methods may not only be combined, but also inextricably linked with each other. Hydrometallurgical processing methods include leaching by acidic and alkaline agents; sulfatization for selectively decomposing the minerals and moving the bulk of U and Th into solution; fluorine extraction process. Methods of precipitation and co-precipitation, extraction (by liquid and solid extractants), sorption, and ion exchange are used to decontaminate the solutions by removing thorium, mezathorium, uranium, and their radioactive decay products. Agents used in hydrometallurgical processing of radioactive rare metal ores include sulfuric, nitric, hydrochloric, hydrofluoric acid, alkali (NaOH, KOH), sorbents (for example, AB-17) for sorption of uranium and extractants (mono- and bidentate organophosphorus compounds, diamides, etc.) for the extraction separation of rare, rare-earth, and radioactive elements."

Jan 1, 2018

By C. Cristoffanini

A real-time transient pipeline simulation was used to model the operational pressure response in the concentrate and tailings pipelines of the Minera Los Pelambres copper mine in Chile. A high-fidelity simulator was needed to train the operators on safe operation of the pipeline for different scenarios. A simulator that solves the transient equations was used to dynamically predict the pressure and flow throughout the pipeline to provide real-time responses to operational changes such as opening or closing a choke valve, or sending a water batch. Slurry rheological properties were incorporated into the model. This paper presents the technical background of the pipeline simulation model and the study of slurry properties. The paper shows the results of the transient simulation for different operating scenarios such as start-up, shutdown and leakage, by presenting the hydraulic gradient curves for each case. Finally, the paper briefly presents how the simulator was connected to an emulated control system and used to train the operator, it demonstrates the most effective tool available to learn to resolve undesirable conditions.

Feb 23, 2014

By P. D. Hanson, H. Colijin

"New procedures and techniques are now available for the design of bulk storage bins. These new methods have essentially eliminated guesswork in the gravity flow of bulk solids, and have provided a sound basis for the quantitative analysis of alternate designs of hoppers and bins. This paper will discuss the practical application of the Solids Flow Theory (Jenike & Johanson) and illustrate the required design procedure with a few examples of actual bin operations."

Jan 1, 1970

By P Breuer, D J. Robinson, A McFarlane, L L. Kuhar

Increasing global demand for commodity metals and capital and the greater operating costs of mining and metal production present significant challenges for the metals mining industry. Current conventional technologies may not be feasible for processing deposits of declining grade, challenging mineralogy or those that occur at increasingly greater depths. To overcome these issues, the development of a step-change technology such as in situ recovery (ISR), which reduces mining and avoids milling costs, may be vital in ensuring future economic metal production. ISR has been used extensively to treat porous soft rock deposits such as the water-soluble salts, sylvite and halite. Although ISR has typically been used for mining conventionally uneconomic uranium ores, it has also been used less frequently for the treatment of other restricted permeability hard rock deposits, such as those containing copper and gold. The reason for the limited uptake of the technology for hard rock mineralisations is primarily due to low natural rock porosity and permeability and hence poor response to available lixiviant. However, additional challenges include solution containment, management of groundwater and regulatory, ecological and societal requirements and expectations. CSIRO has focused on understanding the challenges of hard rock ISR and identifying global capabilities that can contribute to developing the essential enabling technical areas required to realise ISR. Specific focus areas include geochemistry and advanced resource characterisation; drilling and controlled rock-breaking technologies; solution chemistry and environmentally benign lixiviant systems; lixiviant delivery systems and ‘subsurface mixing’; subsurface hydrology and reactive transport mechanisms and models; downstream processing options; legal, social and environmental aspects; and techno-economic modelling. This paper will discuss ISR challenges including industry feedback focused on addressing this issue, gaps preventing ISR from being applied in practice, capabilities to overcome these gaps and the development of a collaborative approach to making hard rock ISR a reality.CITATION:Kuhar, L L, Breuer, P, Robinson, D J and McFarlane, A, 2015. Making hard rock in situ recovery a reality, in Proceedings Third International Future Mining Conference, pp 189–196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By N. Hanief

This research involves the investigation of phase transformations in the platinum-chromium coated system. Single-layer 0.1 µm platinum coatings were deposited via electron beam deposition on 99.98 percent pure chromium substrates. Specimens were subjected to systematic heat treatment in a vacuum furnace at 900°C for up to 20 hours. Phase formation and the changes in surface morphology were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM).Both CrPt and Cr3Pt phases are formed during heat treatment for different times at 900°C. Significant changes in the morphology of this coated system were detected after heat treatment at 900°C for 20 hours.

Jan 1, 2012

By g. Caproni

The main constituent of the feed to the "Sulphide Section" (31 t/h), in the F. Sartori Plant (6000 tid) of the Miniere di Mon)eponi(Sardinia), is the ore of the Campo Pisano -Funtanaperda Mine (1 ? Difficulties have always been experienced in the treatment of this ore, owing to the extramely fine Pyrite-Sphalerite intergrowth and to the high Pyrite and soluble salts contents. The first mentioned difficulty was overcome with a rather complex flowsheet (see fig.1A and lB)(2); the others with a reagent combination that required a pH of 11 in a pulp loaded with soluble salts. This meant high consumption of alkalizer, and also of the other reagents; furthermore the alkalizer had to be mainly NaOH with only minor amounts of lime, because the latter tended to depress not only the pyrite but also the middlings, which were supposed to float. With dialchylditiophosphate alone as a collector, a lower pH could have been used, but a certain amount of amylxanthate was indispensable to promote flotation of the middlings. On the other hand, a bulk-flotation of sphalerite and pyrite at low pH could not be very advantageous on account of the high pyrite content in the feed(3).

Jan 1, 1971

By D L. Head

Critical risk management (CRM) has become one of the latest safety buzz terms in mining. Everyone seems to be doing it, everyone seems to know about it, yet we are still having fatalities in our industry from well understood hazards such as mobile equipment amongst others.

May 5, 2022