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By V. Labiouse, M. Souley, N. Lafrance, C. Auvray

"Chalk rocks have been used for centuries as a strong building material and for the production of lime. The shallow underground room-and-pillar quarries where the chalk was extracted are now abandoned and endure the effects of time and weathering, increasing their risk of collapse. The risk of instability, involving natural or anthropic underground structures, is an issue for more than 10 000 towns in France.In order to investigate the causes of underground quarry collapse and to aid prevention strategies, we carried out a study of the physico-mechanical behaviour and ageing of chalk in abandoned pillars in two underground quarries, in situ-instrumented by INERIS, in the Parisian Basin, France. Core samples were drilled horizontally from pillars in the Saint-Martin-Le-Noeud dolomitic chalk quarry (Oise, France) and the Estreux glauconitic chalk quarry (Nord, France).Uniaxial tests were performed on dry and saturated cylindrical plug samples extracted perpendicular to the cores at regular distances along their lengths. Physical and mechanical properties were obtained. The dolomitic chalk (Saint-Martin-Le-Noeud) exhibits variation in mechanical and physical properties with horizontal pillar depth. Both density and compressive strength seem to increase outwards from the pillar-core to the pillar-wall. This is the opposite of that would be expected from a purely mechanical point of view. SEM analysis revealed progressive degradation and homogeneity of the grains from the edge to the inside of the pillar. At the pillar wall, the crystal faces are well-defined, almost euhedral, and the grains are of variable size. In contrast, at the inside of the pillar, crystals are finer-grained and are anhedral with highly degraded edges. In the physico-mechanical tests and SEM analyses performed on the Estreux samples, no significant variation was observed between the pillar-walls and pillar-core. However, dissolution marks were observed along the entire length of the half-pillar core."

Jan 1, 2015

By H. Kudelka

Copper electrowinning at Duisburger Kupferhuette was introduced in March 1975. The electrowinning plant has a capacity of 10,000 mT of copper cathodes a year. The cuprous oxide feed material is an intermediate product of the treatment of the leach solutions, originating from chloridizing roasting of pyrite cinders. This material is characterized not only by a wide spectrum of accompanying impurities, but also by an unusually high level of precious metals. As the priority set was the production of high-purity cathodes. there was a need for developing a process which would be suited to treat complex leach liquors . The process adopted consist s of an oxidizing leach in spent electrolyte, followed by two- stage purification, By this means. a low- acid pregnant copper electrolyte is obtained free of elements detrimental to copper quality. Electrowinning is carried out at a current density of 200 A / m2 in the presence of 10 g/l zinc. The electrowon copper has a conductivity of at least 101.4% lACS and a softening temperature not exceeding 200°C, which makes it a suitable product for continuous casting and dip ?forming.

Jan 1, 1977

By I. Nakatsugawa

Chemical conversion coating is a process to create thin oxide/hydroxide film containing several inorganic/organic compounds by way of chemical deposition reaction. In case of the application to Mg mobile electronic housings, the film should possess a good electric conductivity while keeping adequate corrosion resistance and working as a paint base. The use of toxic/hazardous chemicals is strictly prohibited from the environmental aspects. This paper describes the recent trend of conversion coating used for Mg electronic housings and analyzes critically from the point of surface technology. The importance of cleaning process and understanding of surface microstructure are particularly emphasized with several experimental results.

Jan 1, 2006

By A. R. Miller, G. Desrivières, M. C. Bétournay, D. L. Barnes, P. Laliberté

"Over the last four years, an international initiative, championed by Vehicle Projects LLC, the Fuelcell Propulsion Institute and Natural Resources Canada, has been active in carrying out research projects to prove out the concept of applying fuel cell technology to underground mining vehicles. These have been carried out by a consortium consisting of mining companies, equipment manufacturers, technology developers, national laboratories and consultants, with the participation of Canadian and U.S. mine regulatory agencies.This clean technology, which produces only water and electricity, would allow several advantages to be obtained, in the health area (by eliminating diesel emissions and reducing noise generation), in lowering production costs (such as reducing ventilation required) and lowering greenhouse gas emissions.This paper outlines the results obtained in several key areas, such as, the operation of fuel cells in underground conditions, risk issues related to underground and surface operation of hydrogen vehicles and hydrogen production and delivery systems, and the design and mining performance of the world’s first hydrogen mining vehicle, a mine production locomotive. The work to date on the fuel cell loader, designing the power plant and power transmission systems, operational requirements, and operating cost reductions is also presented."

Jan 1, 2003

By G. Griffiths

"P. WitteWitteck DevelopmentThe implications of using a tower mill for fine grainding in the ore processing of tailings are significant. What can those of us who are in a research and development situation do when we recommend this equipment to a client? When this prototype is placed on stream next to a conventional grinding mill as you suggest how do we estimate the power requirements and the grind which will be achieved?ReplyLet me explain the Macassa circuit. The tower mill here was running in parallel with one of the ball mills. The feed entering the tertiary system is scalped in a primary cyclone. The finial cut is made in a secondary cyclone. The actual feed to the tower mill is the underflow from the two cyclones and was split to the ball mill and tower mill. During the testing we were unable to isolate the tower mill to determine its contribution to the overall system. We then started to look at the amount of material produced across the mill. We entered the mill at between 17% and 20% finished material and exiting at between 36% and 40% finished material. We were able to project, with a high efficiency classification system, and arrived at 6 Kwh/ton or better."

Jan 1, 1984

"Accelerated expansion of Western Canada's metallurgical coal industry has again stimulated considerable exploration activity in the Rocky Mountain Foothills Belt and influenced much of the R&D related to transportation, processing and carbonization. Preparation R&D has included further pilot-plant work on desulphurization, spherical agglomeration and modified compound cyclones (which are also proving themselves in other mineral beneficiation studies). Combustion research, aside from increasingly stressing control of combustion source pollution, has directed special attention to lignite PF firing and problems arising from lignite ash. Studies directed toward the non-fuel utilization of coal have centered on such diverse topics as active carbons, carbonaceous filter media, plant nutrients and industrial applications of humic acid derivatives. In addition, a number of long-range research projects related to such matters as coal chemistry and pyrolysis have been actively pursued, and further attention has been given to improved sampling techniques and analytical methods."

Jan 1, 1969

By I. E. Wahn, E. A. Boutin

"The Manibridge Mill is unique in its treatment of relatively high grade nickel-copper ore because in the mill design are included one 10' diam. x 10' Maxwell cell, and three 12' diam. x 12' tank cells. These large cells are used as rougher-scavenger cells. Three 8' diam. x 8' tank cells as well are used for cleaning and recleaning of the tank cell concentrate.Flexibility of flow is the main criterion in the tank cell circuit. Targets from these cells are a high grade nickel-copper product with a minimum of talcose gangue.The operation of the tank cells has been encouraging and they have performed well with both low and high grade heads, yielding a high grade concentrate product.Manibridge Tank CellsDescription:The tank cells at Manibridge consist of one 10' x 10' Maxwell cell, three 12' x 12' tank cells, and three 8' x 8' tank cells. The four large cells are currently being used as rougher scavenger cells. The three small cells are used as cleaner cells.Both sets of tank cells consist of Denver steel tank and Super Agitator Mechanisms with steel beam super-structures. The agitator mechanism has a totally enclosed ball bearing spindle housing with a cold rolled steel shaft, and a stanclard standpipe with adjustable collar.The air rings for the tanks were fabricated by Nelson Machinery. Both large and small cells have injection rings with equally spaced air holes in the bottom centre line of the ring.Air is supplied to the tank cells by a Dresser Clark low pressure air blower.The following is a table of pertinent data on the tank cells:"

Jan 1, 1974

By T. M. Korzekwa, R. L. Cavanagh

Following considerable experience with the beneficiation of Wabana iron ore by standard methods, a study was made of the benefits to be obtained by semi-reduction. The basis of the laboratory program was an extensive mineralogical and liberation investigation which guided subsequent work. Partial reduction and beneficiation on a laboratory scale was carried out on lump ore and fines. The reduced ore was magnetically concentrated and the concentrated fines were briquetted. Data are presented on reducibility, sizing vs reduction rate, magnetic cobbing and separation, and the elimination of phosphorus. Past work is reviewed briefly and comments are made on the relation of laboratory to pilot-scale tests.

Jan 1, 1967

By R. R. Song, Q. Li, H. Xing, X. C. Wei

Geomechanical modelling of fault stability is an important part of CO2 capture and storage (CCS) research program to ensure its viability and long-term safety. Storage of CO2 in deep subsurface reservoirs requires estimates of sustainable fluid pressures that will not induce fracturing or fault reactivation which could cause fault slip. More importantly, fault slip gives rise to seismic waves, which inflict severe damage to the cap rock of the reservoirs and may result in leakage pathways for the buoyant plume and thus compromise the integrity of seal formations. In this study, we generated a numerical model tuned towards conditions usually encountered in the Shenhua CCS demonstration project in Ordos basin. In particular, with the purpose of evaluating the sensitivity of the parameters as well as their relationships with the moment magnitude of the seismicity, a variance-based sensitivity analysis was adopted for importance ranking of the uncertain input parameters of the given model. However, such flow models could involve one or several spatial inputs, for instance, fault dip, distance between fault and the injection well, friction angle of fault, permeability of fault, Young's Modulus of fault, injecting pore pressure and the stress field. Studying the sensitivity to each of these spatial inputs motivated the present work. The results led to the following conclusions: fault depth and fault dip significantly affect the behavior of the fault and the fault slip becomes violent with the fault depth increasing and fault dip decreasing. Furthermore, the results indicate that slip time increases with the fault dip decreasing and decreases with permeability of fault increasing. In addition, the calculation of seismic moment and moment magnitude of an earthquake demonstrates that it rises significantly with the decrease of fault dip and the increase of fault depth, and it decreases with the rising stress field. The results show that variations of the only controllable parameter injection pressure do not show great influence to the fault behavior compared with other geological factors, which imply site selection is extremely important for the CCS projects.

Jan 1, 2015

By C. J. Brown

Since its commercialization thirty years ago, the Recoflo® short bed ion exchange process has been extensively utilized for the recovery of a wide variety of acids and metal salts. In addition to a reduction in resin bed height from 200 cm to 300 cm to 15 cm to 60 cm, the process has a number of features such as utilization of fine mesh resins in a compressed bed which together make it ideal for a number of applications. The process has been extensively exploited, for example, in the metal finishing industry for recovery of valuable chemicals from electroplating, anodizing, etching and pickling wastes. More recently, it has also been applied in the primary metals industry for purification of copper electrolytes and metals recovery from leachates. The paper discusses several of these applications and some of the issues that were found to be key to their success.

Jan 1, 2004

By T. A. Rickard

FROM AN OLD MANUSCRIPT THE text for this contribution to the history of the Patio process is a page taken from a Spanish manuscript of Bartholomé Arzaj Sanches y Uela, now in the possession of the library of Brown University (see Figure 1). I owe the photographic print to the courtesy of the librarian. The date, as will be seen, is 1577. The subject is the treatment of silver ores at Potosi, in old Peru, but in modern Bolivia. The group of drawings (see Figure 1) is entitled "Arrangement of the machines in which the ores of silver are ground on the bank of Potosi, the one of two batteries and the other of one". First, top-left, we have the sketch of a "machine of one battery" operated by a water-wheel. From this mill the water runs in part along an aqueduct supported by pillars to the two-battery mill and in part down the hillside, where men are at work with "tubs, which are called cochas, in which are washed the charges of ore and amalgam". Along the top of the page are shown the "various offices in which are stored the copper, the salt, the ucha [llama dung, used for fuel], the lime, and other materials for the re-duction of the ores". To the right of these are "apartments and warehouses in which is stored the ore brought down from the mountain"?the cerro de Potosi. Through the arched portal come the "sheep [llamas] on which is brought down the ore". To this is added a reference to "the second gate, which closes the whole works". On the level above the aqueduct are seen six men carrying skin-bags that contain water. This is being sprinkled on the ore. On the extreme right are six more of these water-carriers. Next comes the two-battery mill. The mortero, or mortar, is marked on the right. Another description says, "Stone, on which the stamps crush the ore, which is called a mortar". To the left of these are indicated "screens of wire in which the ore is sifted after it has been crushed". Farther to the left, near the ore-washers, is a "shed, in which is placed the metallurgist to test the ore of the boxes". Along the left side of the page are sundry buildings, one of which is labelled a "shed in which are placed the cones of silver". Near it, lower, to the right, is the "furnace, in which are roasted the sulphides to facilitate treatment". Farther to the right is the "place where the Indians mix the charges of sulphide ore, which is called a buitron". Alongside is a "buitron in which the charges are prepared for reduction". Inside is a container, to which are attached the words "measure, called topo" On the extreme right is "another buitron in which the Indians mix the ores with their feet, as well as the heaps for the preparation of the reduction". Near the bottom, on the extreme left, is the "chapel where the holy sacri¬fice of the mass is celebrated". Under the first buitron is the "place where they dry the moist ores, called pãpear".

Jan 1, 1935

By N. C. Clarke, T. Wu, M. le Page, K. J. Henley

In 1994, Gold Mines of Australia acquired the rights to the historic Mt. Lyell copper mine, and commenced a feasibility study into expanding production. The ore was shown in laboratory tests to be amenable to single-stage, fully autogenous grinding (FAG) of underground primary crushed ore, and this route offered the maximum cost savings. Flotation performance was expected to be enhanced. However, batch flotation tests done on pilot-scale autogenously ground ore showed an unexplainable recovery loss of between 1% and 3% Cu. A second pilot plant trial was set up, with the ground product feeding banks of continuous flotation cells. Single-stage FAG, FAG/pebble and FAG/ball circuits were tested. Results confirmed a loss of about 3% recovery with single-stage FAG milling. The FAG/ball circuit eliminated the loss. Analyses showed that autogenous milling probably produced more chalcopyrite/pyrite composites and that recovery of these composites was lower than with ball milling. In size fractions below about 53 microns, where chalcopyrite is well liberated, copper recovery was less affected by milling method and flotation selectivity. It was concluded that for the Mt. Lyell situation, a FAG/ball circuit was preferable to single-stage FAG.

Jan 1, 2002

By Terry Braden

"Meeting probable world mineral demand in the years ahead will almost certainly require an ability to economically treat lower grade and more complex ores. Achieving this will require extensive research and technical development across the full spectrum of mineral processing.For mid-sized or smaller companies the most effective way to participate in such extensive programs - and gain access to the technology required to stay competitive - may be through collaborative research.This paper explores the recent history of collaborative research in mineral processing and in particular its ability to attract world-class multi-institutional research teams with sufficient resources to make step-change advances. It chronicles the advances achieved, but also explores the research architecture and administrative structures required to deliver research outcomes and technology transfer mechanisms to a range of often disparate sponsoring companies.INTRODUCTIONIn medieval times the dream of alchemists was to turn base metals into gold. We modern alchemists, of course, don’t waste our time on that sort of foolishness: we turn base metals into dollars. When I see the profit reports filed by some companies recently, I can only conclude that a lot of those present today must be pretty good at this.But the fact that we are here at this conference reminds us that an alchemist’s work is never done; turning base metals into dollars is not a one-trick wonder but an art that we must extensively refine year after year if we are to survive in a competitive marketplace.It is not that demand for metals is likely to slow; most people seem to think that China, India, Brazil and other emerging economies are still at the lower end of their demand curve. They will need significantly larger volumes of metals in the years ahead. The challenge for us as processors is that to supply increasing tonnages of those metals profitably we will almost certainly need to process more complex or lower grade ores and probably to do so with reduced energy inputs."

Jan 1, 2009

By Ajit K. Sinha

"Abstract - Electromagnetic surveys were conducted over the Yava sandstone-hosted lead deposit in Nova Scotia to evaluate the usefulness of such surveys for detecting and mapping sedimentary­ hosted metallic ore deposits. Both transient and multifrequency systems were used for that purpose. The deposit consists of three zones of disseminated galena which also contain minor amounts of pyrite and sphalerite filling the interstices of the sandstone grains. Each zone overlies a basement depression and is separated from the adjacent zone by an intervening basement high. A conductive shale layer underlies the galena-rich sandstone formation at all three zones.Because the concentration of galena (3% to 4% ) and other sulfides is too low to affect the resistivity of the sandstone formations for detection by ground electromagnetic (EM) methods, the strategy for our survey was to look for areas of basement depressions and the presence of conductive shale in those depressions by EM depth soundings. The presence of the galena-rich sandstone formations could be inferred because of the close association of these two features with the deposits in the Yava area. Both transient and multifrequency EM systems were successful in mapping the basement depressions and detecting conductive shale at the three known mineralized zones. The technique, therefore, seems to offer good prospects for mapping similar stratabound sedimentary-hosted sulfide deposits."

Jan 1, 1993

By J. J. Baz-Dresch

"The Cannon Mine, a joint venture between Asamera Minerals (the operator) and Breakwater Resources, is located in the centre of Washington state at the eastern base of the Cascade Mountains. The mine complex is located three blocks south of the city limits of Wenatchee, part of an urban area with a total population of 47 000. The closest residence is 350 feet from the mine portal.The B-Neath zone is a narrow, high-grade, downward extension of the southern tail of the mine's main ore body, the B-North zone. It also underlies the northernmost portion of the B-West zone (Fig . I) . The ore is usually reasonably competent but completely surrounded by very weak rock consisting of shear zone and unsilicified sandstones and siltstones.The zone has maximum dimensions of 420 ft in thickness, 500 ft in length , and 200 ft in width . The economic reserves extend from the 70-ft elevation (elevation above sea level) to the 630-ft elevation and consist of about 1.3 million tons of geologic reserves (proven and probable) at an average grade of 0.33 ounces per ton.Acquisition and ExplorationInitial DiscoveryThe initial discovery of the B-Neath zone was made by Tenneco Minerals during July through September, 1984. Their 22-hole surface drilling program consisted of 18 200 ft of drilling. Tenneco Minerals had acquired the 91/2 acre lease from United Mining Corporation.Asamera Minerals subsequently purchased Tenneco's lease in July, 1985; Tenneco retained a royalty position which was later purchased by Echo Bay Mining.Follow-up drilling by Asamera Minerals consisted of both surface and underground drilling. Eight surface holes (7200 ft) were drilled commencing in December, 1985. Following evaluation of the geologic data, an access drift was driven on strike along the top of the ore zone on the 500 level. Diamond drilling from this platform consisted of 17 200 ft in 79 holes."

Jan 1, 1990

By W. G. Hatch

Introduction In November, 1927, a paper was presented at the Annual Meeting of the British Columbia Division by H. A. Pearse(l), in which he described the milling practice at Britannia and set forth the metallurgical results which were being obtained at that time. In the intervening four years, various changes and additions have been made in equipment and practice, which have resulted in marked improvements in efficiency and costs. These changes and their effects are discussed in the present paper. During the past few years two major changes have been made in plant equipment. The first of these was the. elimination of an intermediate crushing stage by discarding two gyratory crushers in favour of two Symons cone crushers. The latter installation-now effects in one stage a greater reduction than was formerly accomplished in two, that is, by the gyratories together with a set of rolls. The second important change in equipment took place when the original M.S. flotation machines were replaced by six Forrester pneumatic machines, so that now the flotation department consists entirely of machines of this type. A number of minor changes and some further additions to equipment have also been effective in raising plant capacity and concentrate grade, while making noticeable reductions in tailing losses and costs of ore treatment.

Jan 1, 1932

"8.1. IntroductionThe stoichiometry of most named platinum-group minerals (POM) is known (cf. Cabri, 1981b, in Chapter 7), but, because these minerals are subject to a wide range of element substitutions, representative analyses require treatment in a separate chapter (section 8.2). The analyses, in all cases done by electron microprobe, are grouped in sections according to the principal platinum-group element (POE) for each POM, and then follow sequentially with increasing amounts of the principal POE starting with the ideal composition, when known. In order to facilitate reference to specific POM by name, an alphabetical listing is also given (Table 8.1). A range of compositions, in addition to one or several ""representative"" analyses, is given for some POM when more than one analysis has been reported for a particular locality. The tables of POM analyses (Tables 8.2 to 8. 76) include at least one analysis for every locality for which data have been published, to the best of the authors' knowledge. All analyses are referenced for locality and publication source, and include several unpublished analyses (all but one done at CANMET). Most analyses have been rounded off to one decimal place for amounts more than one per cent and their formulae calculated on the basis of an even number of total atoms. In all tables, ''n.d.'' stands for elements sought for but not detected and a dash signifies elements not sought, or when these haven't been specificed in the publication source.Section 8.3 contains tabulated analyses and, in some cases, also includes a critical assessment of POE-bearing minerals in which the POE occur in trace or minor quantities. The organization of the data in this section is by mineral groups; e.g., sulphides, sulpharsenides, silicates, etc. Some of these data are also discussed in Chapter 4 by Crocket (1981) and are discussed briefly in Chapter 6 by Crocket and Cabri (1981)."

Jan 1, 1979

By M. Morin

"This paper examines the design issues associated with the integration of mineral processing within underground mining using a total systems approach. It demonstrates conceptual integrated system design options appropriate to a range of geological scenarios. Particular reference is then given to a case study of stoping in narrow base metal veins.The performance of such integrated systems in terms of productivity, economical and environmental criteria is demonstrated by means of simulation. Particular attention is given to the potential benefits to mine waste management. Processing technologies appear to offer genuine potential benefits, while underground mining methods may need to evolve further to facilitate full integration. This paper is based on industry supported research aimed at developing selective and clean underground mining systems. IntroductionTotal systems thinking is simple in principle but complex to implement. The premise is that to achieve optimum effectiveness and efficiency from a system, the complete system must be considered. Using this approach will avoid the situation where the optimization of a localized component of any system results in a negative impact on the performance of the complete system. Take for example the parts manager who reduces inventory costs without consideration of the consequences to the plant. If the plant goes down and a part is unavailable, it would then cost significantly more than the cost of having it in inventory (Ackoff, 1994).A tool for applying total systems thinking toward understanding and analyzing different mineral extraction options is the structured analysis and design techniques (SADT). Originally developed by Ross (1977), SADT is a formal systems engineering methodology (FIPS PUB, 1993) for process and enterprise modelling (Marca and McGowan, 1993). Figure 1 presents a highlevel structured analysis of the traditional or conventional metal extraction process. There are three sequential processes with several arrows entering or exiting each process. In SADT, inputs always enter from the left-hand side and exit as outputs of the process on the right-hand side. Constraints affecting the transformation of inputs to outputs enter the process from the top while resources or mechanisms enabling the transformation enter from the bottom. SADT is a hierarchical decomposition technique and further analysis is undertaken by expanding downward into each process."

Jan 1, 2003

By Jolanta Olkowska-Oetzel

Reactions of gold?phosphino complexes [(AuX)(PR3)] (X= Cl, Br, I; R = organic rest) with Se(SiMe3)2 lead to the formation of gold complexes with chalcogenide bridges. The reaction of the complex Ph3PAuCl and tBuSe(SiMe3) gives the cluster [Au5Se2(PPh3)4]Cl 1. The in situ preparation of the complex [(AuCl)2dpph] (dpph = Ph2P(CH2)6PPh2) by reaction of dpph with Me2SAuCl, and subsequent reaction with Se(SiMe3)2 leads to the formation of [(Au3Se)2(dpph)3]Cl2 2. Reactions of the gold(I) complex [(AuCl)2dpppe], (dpppe = Ph2P(CH2)5PPh2) with Se(SiMe3)2 and InCl3 in different molar ratios lead to the formation of [Au10Se4(dpppe)4]InCl5 3 and [Au4(SeInCl3)2(dpppe)2] 4. The reaction of [(AuCl)2dpph] with Te(SiMe3)2 and GaCl3 produces the isostructural cluster compound [Au4(TeGaCl3)2(dpph)2] 5. From the reaction of Se(SiMe3)2 with [(AuCl)2dppe] (dppe = Ph2P(CH2)2PPh2) and InCl3 [Au8Se4In(dppe)4](InCl4)3 6 can be isolated. The structures of 1 - 6 were determined by X?ray diffraction.

Oct 1, 2003

By Gerald Sanders

Presentation Topics ? We?re Going to the Moon Again? ? What is Lunar Mining ? In-Situ Resource Utilization? ? What Are The Challenges to Lunar Mining? ? What is NASA Currently Doing?

May 1, 2009