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By C. M. Campbell

THE dire effects of rapidly vanishing natural resources, widespread unemployment, and increased debt and taxation in recent years have challenged Canadians to produce a practical solution to these national economic problems. In more recent months, wars and rumours of war have indicated, among other things, the need for better control of our mineral wealth. The erection of a smelter on the lower mainland coast of British Columbia, treating all Western ores, and such ores as it will be found advisable to import, will make an important contribution toward a solution of these problems. It is believed that the ores tributary justify a smelter of major proportions. A stock-taking to confirm this can be made with reason-able accuracy in a short time, and this should be undertaken without delay. Enough general information is, however, available .in this paper to justify the technicians of the Department of Mines at Ottawa and of interested smelting companies making a preliminary study of the matter. THE DEFENCE ARGUMENT As a factor in rearmament, metals play a vital part. That rearmament is to continue on an increasing scale is indicated in Premier Chamberlain's address of October 3rd last, when he said: ?'For a long period now we have been engaged in this country in a great programme of rearmament which is daily increasing in pace and volume. let no one think because we have signed 'this agreement between the four powers at Munich we can afford to relax our efforts or call a halt in our armaments at this moment'. As matters stand, the facilities in British Columbia are entirely out of line with the strategic importance of this Province as the Western Front of Canada and the Empire. All our copper ores, and an appreciable part of our lead and zinc ores, are sent for treatment to Japan, United States, and Europe, while we import our iron and alloys. A treatment plant on this Coast would not only give us control of war metals and chemicals but it would provide an increased industrial and research population, badly needed in this area and of the greatest value in the case of war. This is where the mining industry can do its bit.

Jan 1, 1939

By F. Baerhold

Recycling of hydrochloric acid from the pickling of mild steel using pyrohydrolysis is a state-of-the-art technology. Recent developments have focused on the production of a high value iron oxide by-product, where the chemical purity and physical properties are the main issues. New processing routes, especially for TiO2 and Ni production, use leaching operations with hydrochloric acid. The feasibility of those processes depends on the availability of an economic and reliable process for the recovery of the acid. Depending on the level and type of impurities and the required specification of the by-product, pyrohydrolysis in a fluid bed or in a spray roast reactor can be the ideal solution. In stainless steel annealing and pickling lines, a mixture of nitric and hydrofluoric acids is used to remove the scale from the surface after heat treatment. Nitrate emissions from the pickling and the rinsing processes have to be avoided because of more stringent environmental regulations. An annealing and pickling line that is totally wastewater-free was developed, where not only the nitric/hydrofluoric acid but also the rinse water, is completely recycled. New developments to increase the HNO3-recovery rate and to obtain a metal oxide by-product that is easier to recycle are presented.

Jan 1, 2006

By J. A. du Plessis, C. Dorfling

Selenium, tellurium and other precious metals (OPMs, namely Rh, Ru and Ir) dissolve in the final leaching stage of base metal refineries. Se and Te are typically removed from the copper sulphate leach solution by precipitation with sulphurous acid. Recovery of dissolved OPMs is desirable because it will reduce OPM inventory and losses. Thiourea is an effective OPM precipitation reagent, but yields insufficient Te removal. Copper is known to enhance Te precipitation when using sulphurous acid as precipitation reagent. The primary objective of this project was to evaluate whether simultaneous precipitation of Se, Te and OPMs using thiourea with metallic copper as precipitation reagents is possible. Batch precipitation tests were performed to evaluate the effect of temperature (50 – 70°C), thiourea addition (160 – 430% excess) and copper addition (2 – 8 g/L) on Se, Te and OPM precipitation. Increasing the temperature from 50°C to 70°C resulted in an average increase of 55.6 percentage points for Se precipitation and 13.5 – 23.5 percentage points for OPM precipitation. The copper addition did not have a significant impact on the precipitation behaviour. Increasing the thiourea addition increased the precipitation of Se and Te, especially when the copper addition was low; Rh and Ru precipitation also increased with up to 10 and 12 percentage points, respectively. Despite these observations, the precipitation of Se was significantly faster when no thiourea was added. It is not currently clear why thiourea appears to inhibit the Se precipitation by reaction with metallic copper. In general, Te precipitation was low (less than 30%) at the conditions investigated. Simultaneous precipitation of Se, Te and OPMs at temperatures below 80°C does not appear to be a viable option; a multiple stage operation for sequential removal of Se and Te with copper followed by OPM precipitation with thiourea would be required.

Jan 1, 2016

By K. C. Corin, Z. G. Song, J. Y. Liu, M. W. Zhang, State Key Laboratory of Mineral Processing-BGRIMM, J. G. Wiese

"In the present study effect of grinding media on flotation of two mineral systems have been investigated, viz. sulphide minerals (including a pure chalcopyrite and pyrite mineral, and two different base metal sulphide ores), and oxide minerals (quartz, hematite and cassiterite). It was shown that mild steel media milling produced lower recoveries in the case of chalcopyrite and pyrite, as compared to the case of milling using ceramic media. For oxide minerals, the effects of using mild steel media as opposed to ceramic media were not as significant as was for the sulphides, although, after mild steel milling, at acidic pHs their recoveries were significantly reduced. For two base metal sulphide ores, viz. Nkomati and Dexing ores, the differences resulting from different milling media , although marginal, were opposite for each of these ores.For oxide minerals XPS showed that oxides and hydroxides of iron (e.g. FeOOH) adsorbed on the surfaces of the minerals. In the case of the Nkomati ore, adding Fe2+ or F3+ ions after milling with chrome steel media resulted in reduced talc (gangue) recovery, but increased water recovery and reduced concentrate grades. Further investigations are currently in progress to examine the Fe ions effect on the talc surfaces and froth properties.INTRODUCTIONGrinding of ores is necessary to liberate the valuable minerals from its gangues to allow for their selective recovery during mineral processing such as flotation. The grinding process inevitably involves contact of the ores with the surface of the grinding device and the grinding media. Accompanied by grinding, several phenomena can occur including the grinding medium wear, formation of precipitated species on the ore surfaces, chemical reaction, galvanic effects, changes in the Eh of solution, etc. There is a considerable body of literature on the differences observed in the flotation of various ores after milling using various grinding media. Laboratory studies have used balls or rods made from mild steel, ceramic, stainless steel or chrome steel to investigate the effects of different grinding media on mineral flotation. It is found that the interactions between the ore and the grinding environment can affect flotation separation of sulphide (Wei and Sandenbergh, 2007; Bruckard, 2011), oxide (He et al., 2014) and carbonate minerals (Song, 2009 and 2010). For example, mild steel milling produces relatively high concentrations of Fe ions in the pulp, affecting the recoveries of minerals compared to the case of ceramic media. On the other hand, the stainless steel media or chrome media are reported to be beneficial to the recovery of sulphides, when compared to the cases of using mild or carbon steel media (Rey and Formanek, 1960; Peng et al., 2003a,b; Huang and Grano, 2006; Bruckard, 2011). It is not clear, however, whether these Fe ions may affect the surface properties of the minerals involved or the general pulp/froth behaviour and hence their floatability. In addition, in the study of an low-S PGE ore carried out by Miettunen et al. (2012), forged media grinding in the CO2 atmosphere led to the highest Pt and Pd grades and recoveries, but the high chrome grinding media gave lower flotation recoveries than those using the forged media."

Jan 1, 2016

By Jr. Carmichael

"THE MAYO AREA was prospected as early as 1887. The first major activity started in 1898, when the Stewart River and its tributaries were examined for placer deposits, and in succeeding years the district became a small producer of placer gold. The first discovery of the lead-zinc-silver mineralization which has become the main interest of the district occurred in 1906, when a vein was found in the canyon of Galena Creek on the northwest slope of Galena Hill. This deposit was later known as the Silver King mine. In 1919 further discoveries were made on Keno Hill, approximately 15 miles east of the Silver King, the most important being the No.9 vein. Directly or indirectly, these finds are attributable to the search for placer gold, as galena was frequently found in the stream gravels.The 1919 Keno Hill discoveries were acquired by Yukon Gold Co. and operated through a subsidiary, Keno Hill Ltd., from 1920 to 1923. Most of the production came from No.9 vein. In 1921 Treadwell Yukon Corporation entered the field and acquired the Ladue mine. This company continued to operate for 21 years. It acquired in succession the Ladue, Sadie, Friendship, Lucky Queen, Elsa, Silver King, and Calumet mines. Its record of successful operations is very largely the achievement of the late Livingston Wernecke. Under his direction, the Treadwell Yukon Corp. produced metals with a gross value in excess of $21,000,000, in the face of greater transportation problems than exist today and with considerably lower metal prices.Treadwell Yukon ceased operations in 1942. Its entire assets were acquired in 1946 by United Keno Hill Mines Ltd., which has substantially increased the original holdings. It has drawn the bulk of its production from the Hector mine, adjacent to the Calumet. The Hector was not developed by Treadwell Yukon because of legal disputes among the vendors. It has proven to be the largest deposit yet discovered in the district."

Jan 1, 1949

By H. Huang, R. N. Gow

Acidic treatment of enargite (Cu3AsS4) dissolves both arsenic and copper from the mineral and then attempts to separate them in the leach solution. The reactivity of enargite was examined in acidic to neutral solutions, over the pH range 1-7, to determine a potential range for co-dissolution. Enargite mineral samples from Butte, MT and Quirivilca, Peru were used as working electrodes in a cyclic voltammetry corrosion cell setup, which were then cycled multiple times over -1000 to 1000 mV. Surface reactions and transitions were characterized using in-situ Raman spectroscopy, which were then compared to updated EH-pH diagrams for the copper-arsenic-sulfur-water system from a previous study done under alkaline conditions. The region of co-dissolution is limited to > 600 mV vs. SHE and pH < 1 under the proposed diagram.

Jan 1, 2014

By Alireza Golabchi

The AEC (Architecture, Engineering, Construction) industry is an information intensive industry and all related processes employed during different phases of a project, including planning, designing, building, manufacturing, occupying, and maintenance, involve vast amounts of data that is used for a wide variety of purposes. Building Information Modeling (BIM) is a powerful shared knowledge resource which stores this data to support decision making about a facility through all these different phases in its life cycle. Nowadays, BIM is mostly used in the design and construction phases while it can also be highly beneficial beyond those stages. For example, in the Operation and Maintenance (O&M) phase, BIM could be used for automated facilities management or robotic inspection to provide semantic knowledge for navigation. For any implementation not related to the original intent of the BIM (design), organizations need to be able to represent their project data in a common interpretable form, which provides the possibility of an accurate exchange of data among different software products and platforms, known as interoperability. This study has investigated the current state of interoperability between software products used as Building Information Modeling tools. The main focus has been on a popularly used format for BIM models, Industry Foundation Classes (IFC), since it has been specifically developed to enable standardized data exchange. The research methodology involved a comprehensive literature review and the gathering of all fragmented prior research related to the field in order to develop a consistent understanding of the current state of knowledge. This was accompanied with a detailed case study that evaluated and compared two dominant pieces of BIM software, Revit and Bentley, and examined their interoperability strengths and weaknesses while using the IFC format.

Aug 1, 2013

By Douglas Brand

"The data that many mineral processing plants make use of, is provided by samples taken from sampling systems which are inadequately designed or improperly maintained, and therefore cause detrimental effects to plant operations, production planning and metallurgical accounting! Poorly designed or maintained sampling systems will likely produce low probability samples which give the operator a false sense of security of the product and the process. If data is the basis for action (Flintoff, 1992, p.2), then using the resulting suspect or bad assays by operators, control systems, or metallurgist and administration personnel will act and make decisions which may adversely affect the profitability of a processing plant. Here we will discuss some of the fundamental sampling problems, propagation of errors and a method to estimate what impact this has on an operations Net Smelter Return.INTRODUCTIONIn order to control a mineral processing plant at its best potential, it is necessary to obtain the best possible measurement results of the metal or mineral in question. The sample which is delivered to a measuring instrument, or lab, needs to be of the highest probability to be able to achieve this. This paper will discuss the effects of sampling errors on grade / recovery and grade / Net Smelter Return (NSR) and provide a method to estimate the monetary advantages of using probabilistic sampling in a processing plant.REVIEW OF SAMPLINGSampling, by definition, is the removal of a small representative portion from a total consignment, or flow, for the purpose of accounting or process control.• A sample can only be considered representative, if each and every increment collected, in each of the sampling stages, is representative.• Each particle of the sampling lot must have the same probability of being included in the final sample.• If both of the above conditions are met, then the final sample will be representative of the complete sampling lot.It is commonly known that in order to take truly representative and probabilistic sample, best practices indicate that:• The total stream should be sampled.• The sample cutter should intersect the sample at right angles to the flow.• The sample cutter should travel through the stream at a linear and constant speed and the speed deviations should be less than 5%."

Jan 1, 2016

"A numerical procedure based on Smoothed Particle Hydrodynamics (SPH) is developed for rock blasting phenomena involving multiple intersecting joints. In this procedure, an elasto-plastic damage constitutive model has been applied in the framework of SPH to simulate yielding response of the surrounding rock medium. In this paper, a square shape rock medium with centrally located emulsion explosive in a borehole is numerically blasted with and without the presence of two diagonal rock joints. The model is simulated by assuming all four sides of the rock medium as free surfaces. The paper elaborates the propagation of stress wave, expansion dynamics of gaseous products, and development of fracture, fragmentation of the medium and dissipation of energy due to damage.INTRODUCTIONDamage prediction of rock mass and its mean fragmentation size are of important to design blast parameters for a given explosive. Current blasting practice solely depends on empirical relationships between fragmentation sizes to those blast design parameters while mathematical descriptions of the physical laws governing the process of rock blasting are limited. A constitutive relationship based on properties of explosives and rock mass is of special interest because of its capabilities in describing the key features of rock fracture and fragmentation, resulting in understanding of the physical process involved in rock blasting. It is well known that blast-induced damage and fragmentation of rock mass occur due to detonation induced stress wave and product gas driven fracture propagation. Nevertheless, the fundamental mechanism of the failure process and the behavior of rock characteristics under these two different loading are not well understood in many cases, which are closely related to growth of fractures and interaction of cracks under different loading conditions.Continuum damage mechanics is considered to be appropriate to describe the failure process under such high-amplitude stress wave. Based on this approach, several theoretical models have been developed to analyze the dynamic damage of brittle material such as rock and concrete with microstructure (Chen, 1999; Taylor et al., 1986; Wu et al., 2004; Yazdchi et al., 1996). These models are mostly based on the theory of damage mechanics or fracture mechanics with some statistical treatment to incorporate random distribution of microcracks. In the application of fracture mechanics theory, sometimes it is difficult to estimate the micromechanical parameters such as crack density and fracture toughness in different modes. In this study, damage in rock material is evaluated according to the earlier model developed by Grady and Kipp (1980), which is a fracture model coupled with a material description for stress wave propagation to predict quantitatively fracture and fragmentation under explosive loading conditions."

Jan 1, 2015

By J. Mcdvcka

Sustainable development has become a driving imperative for the resource industry as it is for the rest of the global business world. Being unsustainable is a risk no business can afford. Yet implementation of sustainable development practices beyond satisfaction of compulsory reporting is still sporadic. The current standard approaches to problem analysis and decision making are too narrow to capture the complexity of the issues at stake. Hence it is necessary to develop innovation in thinking and in doing. Those who search for ways to implement sustainable development use concepts such as Whole Systems Thinking and Eco-efficiency as well as tools like Life Cycle Analysis. Others develop their own instruments. In their effort to innovate they face both resistance and support within their organisation as well as within the industry or the wider context. This paper explores the factors that support, hinder and shape the sustainable development drive of the industry and proposes a comprehensive decision-making framework that links the goal of sustainability with the tools of sustainable development. This exploration is illustrated by a case study used in a doctoral research conducted on an engineering firm providing services to our industry.

Jan 1, 2007

By Yi Yang, Mark Zoback

"We report laboratory studies of the time-dependent deformation of core samples from four different formations in the Williston Basin - the Lodgepole formation, the Middle and Lower Bakken formations and Three Forks formation. The laboratory tests reveal varying amounts of viscoplastic deformation in response to applied differential stress. The time-dependent deformation is generally greater in rocks with higher clay and organic content, and can be described by a power-law function. Because the magnitude of the creep strain is linearly proportional to the applied differential stress, we can utilize viscoelastic theory and geophysical logs to estimate the degree to which tectonic stress is affected by viscoplastic stress relaxation. We suggest that viscoplastic stress relaxation results in the Upper and Lower Bakken Formations act as frac barriers during hydraulic fracture stimulation in the Middle Bakken, but the Lodgepole and the Three Forks Formations are not frac barriers.INTRODUCTIONHorizontal drilling and multi-stage hydraulic fracturing in shale reservoirs are critical for successful exploitation of ultra-low permeability shale gas, tight gas and shale oil reservoirs. Characterization of the mechanical properties of the reservoir rocks is essential to understanding the behavior of rocks during drilling and completion. Previous laboratory studies have shown that the timedependent deformation in clay-rich shales can be characterized as linear/viscoelastic deformation (Chang et al., 1997; Hagin and Zoback, 2004a, b; Sone and Zoback, 2013b, 2013c). Sone and Zoback (2013c) showed that laboratory measurements of time-dependent deformation in various gas shale reservoir rocks, and demonstrated that the viscoplastic deformation of these rocks can be characterized by a power-law function. They interpreted the results in the framework of linear viscoelastic theory to quantitatively assess the geomechanical effect of viscous time-dependent deformation over engineering and geological time scales. (Sone and Zoback, 2014) further extended the theory and proposed a viscous relaxation model that can be applied to predict the continuous differential stress magnitude using the geophysical logs. They tested the validity of their model by comparing the stress prediction with the occurrence of drilling induced tensile fractures (DITFs) and the vertical hydraulic fracture penetration observed from microseismicity."

Jan 1, 2015

By Maciej Wrobel, Joerg Hammerschmidt, Dana Nurgaliyeva, Alexandros Charitos, Jochen Guentner

"Smelting of copper concentrates in the flash smelter generates a flue dust stream that contains a substantial amount of copper and accumulates more than half of the arsenic input to the smelter. In view of its high copper content flue dust recirculation to the flash smelter is common practice. Globally traded copper concentrates are affected by ever increasing arsenic contents and cause an increasing circulating arsenic load in flash smelter operation. Control of the arsenic level in the smelter slag becomes a challenge. This interaction of arsenic loaded copper feedstock, need for flue dust recirculation and slag quality control call for possibilities to reduce the arsenic load of the recirculated flue dust stream.The technology of partial roasting is known from pre-treatment of copper concentrates before smelting, and gold concentrates before cyanide leaching, to remove the harmful element arsenic. The partial roasting technology can be adapted for use in the purification of the flue dust. A major challenge for flue dust treatment is its extremely fine particle size compared to usual concentrates. For this reason Outotec developed a new process, which allows handling of such fine flue dust. This process solution provides an efficient possibility to reduce the arsenic burden in copper smelter operations.The suggested process aims at reducing the arsenic load to the smelter by treating the flue dust prior to recirculation to the smelter. The presented results are based on test work in the Outotec R&D-centre in Frankfurt. It is possible to remove 80-85% of the contained arsenic and to collect it in an arsenic trioxide residue with a concentration above 90%. The final off gas contains SO2 from decomposition of sulphates that are contained in the flue dust. The off gas stream is relatively small. We assume that it is possible to combine the off gas stream with other smelter process gas streams and to treat it in an existing sulphuric acid plant. Coal is used as fuel and as reductant to reduce pentavalent arsenate to trivalent arsenite. Arsenite can be kept in gas form at temperatures above 450°C. This permits separation of a calcine stream with arsenic levels of 0.2 – 0.3%, which is recirculated to the furnace.Outotec has a wide range of roasting testing facilities from lab-scale to pilot-scale. Outotec has both capability to modify and adapt technology to specific ore or concentrate requirements, but also the necessary infrastructure in its research centers in Frankfurt and Pori to do appropriate validation tests in lab and pilot scale size plants."

Jan 1, 2016

By M. Leahy

"Very little is known about the large scale fluid dynamics and associated distribution of copper in an operating electrowinning cell, yet they will have a major influence on mass transfer and plating quality. The CFD model in this work is used to simulate an entire EW cell with 60 cathodes and 61 anodes, or 121 anode–cathode pairs, elucidating for the first time the three-dimensional (3D) flow and copper distribution in an industrial cell. Two methods for the distribution of electrolyte are modelled:1. Downcomer method: electrolyte is fed by a downcomer at one end of the cell, overflowing at the opposite end.2. Manifold method: a horizontal manifold pipe runs the whole length of the cell and feeds electrolyte via small holes in the top of the manifold pipe.The recirculation that develops within each anode-cathode pair, driven by oxygen bubble generation on the anode, is similar to that seen previously in two-dimensional models of single anode–cathode gaps. However a more complex 3D flow recirculation is established, which involves flow of electrolyte down the side gaps (being a path of low resistance for return flow) as well as the usual return flow down the cathode side of each pair gap. The bubble-driven flow is not influenced by the mode of electrolyte distribution.The electrolyte flow due to the manifold and downcomer is somewhat secondary to the bubble driven flow. In the case of the downcomer distribution mode, the high injection velocity causes a very turbulent flow in the first 1–2 m down the cell from the downcomer, with several large vortices developing. This may lead to some sludge particles being entrained into the bulk of the cell.In the manifold pipe case, the jet from each hole is dissipated very quickly, within the first 10–20 cm. The jets are directed into the downward flowing zone of the bubble-driven recirculation, which leads to unstable and periodic behaviour on a large spatial scale.In both the manifold and downcomer cases, there is a marked two-zone vertical stratification in copper concentration."

Jan 1, 2016

By R J. Tremblay, R. R. Hoffman

This paper deals with materials of construction and problems encountered and overcome in leaching and filtration of oxidized sulphuric acid slurry in the Port Radium mill after eight years of operation. The slurry is characterized by a high calcium sulphate content as well as a high chloride level under oxidized conditions, both of which affected initial design and subsequent changes. Leach agitation tanks are of wood with a mild steel superstructure and stainless steel agitator and moving parts below solution level. Electro-polished 316 stainless steel cooling coils are used for temperature control of the slurry. The string filters are of the Oliver type with wood decking. Extensive use is made of wood, Linatex lined mild steel and stainless steel for the slurry handling. A typical analysis of the slurry solution follows:(pH-1.30) ClOa Fe+++ Free Acid UaOs c1-so.--0.10 gms/litre 10.2 gms/litre 6. 7 gms/litre 3.5 gms/litre 2.0 gms/litre 155 gms/litre

Jan 1, 1961

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 H. C. Cooke

Geological examination of the underground workings of the Horne and Aldermac mines during the summer of 1927 has brought out the following facts: (1) That the ores tend to replace bodies of breccia or tuff rather than massive lava or dyke material; (2) That the faulting and folding at the Horne has had a pronounced effect in localizing the ore-bodies; (3) That there is a tendency in cert?-in cases for ore-bodies to be localized beneath gently dipping dykes, which acted as impervious roofs; (4) That there is a great difference in age between the chalcopyrite part of the ore-bodies and the pyrite-pyrrhotite portion. A statement of the development to date at the Aldermac mine is also included in the paper. ALDERMAC MINE The Aldermac property is made up of eight claims in the western half of Boischatel township, Quebec, including 747 acres in all. The mine itself is approximately three miles, 25 chains from the west boundary, and four miles, 55 chains from the north boundary, of the township.

Jan 1, 1928

"The content of production reports has its origins in raw measurements taken in harsh production environments. The ensuing measurement/estimation errors always affect reproducibility such that, regardless of the fact that they are balanced through statistical data reconciliation, reported numbers are simply the most probable values of inferred probability distributions. This has important implications for how metal recoveries should be monitored and reported. Indeed, in a context where many process optimisation activities are based on small improvements in recovery, there should be no doubt that inadequate handling of measurement/estimation errors can easily exaggerate or mask actual changes in process performance. However, estimates of the reproducibility of reported metal recoveries are rarely reported to plant management. This situation persists despite the fact that a code compliant metal accounting system must inform management about business risks related to metal accounting. To this extent, this paper focuses on the continuous management of reproducibility level of metal recoveries in compliance with the best practices. Sensitivity analysis of primary and secondary metal accounting models is performed to show the resulting probability distributions for metal recoveries. Some guidelines are given for designing and managing metal accounting systems capable of achieving and sustaining predefined levels for the reproducibility of metal recoveries.INTRODUCTIONEach and every mineral processing plant produces daily, weekly and monthly production reports in which metal balances for payable and penalty elements are presented. While such production reports are usually consulted in offices, underlying raw measurements are taken in harsh production environments where mechanical vibrations, humidity, corrosion and dust, to name a few, disturb measurement procedures. It is thus no surprise that several authors (Francois-Bongarcon & Gy, 2002; Gaylard, Randolph, & Wortley, 2014; Holmes, 2010; Spangenberg & Minnitt, 2014) have reported pervasive issues related to mass/sampling measurements in the context of mineral processing."

Jan 1, 2016

By D. A. Sloan

THE Young Davidson mine is of particular interest because of the extremely low costs and also because of the novel method devised for pillar recovery. The outstanding feature of the mining system is its simplicity and regularity. The successful operation of this property was de-finitely assured by the rise in price of gold in 1934. The mine is situated in the southeastern part of Powell township, about forty-five miles southeast of Timmins, Ontario. The local town, two miles distant, in Matachewan, which is twenty-five miles northwest of Elk Lake, the terminus of a branch line of the Temiskaming and Northern Ontario railway. Mining is confined to one of a group of five claims. The ore occurs in a body of syen.ite porphyry which is intruded along a contact of Timiskaming conglomerates with Keewatin altered ruffs and greenstones. This intrusion extends in a north-easterly direction from Davidson creek for 3,300 feet, of which length 700 feet lies within the Matachewan Consolidated property. The maximum width of the mass is 700 feet; it tapers off as it extends east-ward. The Orebody.-The syenite porphyry is of three types, probably all differentiates of the same magma, but only one of them is gold bearing. This is a cherry-red, coarsely crystalline type which forms the central part of the mass. It is more brittle and more fractured than the others, and consequently has allowed easier access to the gold-bearing solutions. The gold has been brought in by a branching system of quartz veins and along minute fractures. It is mainly in the form of very fine &apos;free&apos; gold, but also occurs in pyrite, which is the chief metallic mineral.

Jan 1, 1942

By T. R. Kostecki, J. Hirschi

"Analytical engineering design is based upon a trial-and-error iterative and deterministic process. Within this process, the engineer obtains some estimated values, plugs them into de facto closed-form equations, and receives output, which is expected to be a single number that serves as the basis for the design. This number is typically a factor of safety, or some other equivalent strength-stress ratio. This provides the engineer with a quick and relatively quantitative design methodology. This can create problems however, because in mining applications, the actual in situ system is highly variable, complex and often chaotic, which can lead to potentially incorrect conclusions that result in unsafe designs. A more appropriate and reliable approach is a probabilistic analysis for engineering design. This process is used widely in civil and other engineering disciplines, but is often overlooked for applications in coal mine design. Additionally, it seems the amount of past studies using this approach, especially in coal mine design, are rather limited. Considering how the probabilistic approach can account for uncertainty in parametric values and how unpredictable a mining design can be, the authors believe that this approach has potential in mining. This paper will focus on a summary of past studies related to probabilistic analysis in coal mine pillar design and provide recommendations for future work that could improve design reliability. INTRODUCTIONFeasibility and fundamental design procedures for excavations often start with an assessment of mine openings, pillar design, and the surrounding structure by using a deterministic approach with closedform solutions (ex. Bienawski, Obert-Duvall). These are reliable methods, but designers know that the inputs in these closed-form solutions are estimates at best and do not incorporate any degree of uncertainty. This is therefore not an optimal design procedure.A more appropriate design should incorporate some uncertainty because of the chaotic and variable nature of geology and mining conditions in general. In an attempt to account for uncertainty, a probabilistic approach can be adopted, which accounts for deviations in variables and provides a more optimum design solution. By applying a probabilistic approach, a designer can look at multiple failure scenarios at the same time instead of using the same deterministic design over and over."

Jan 1, 2015

By A. Hayatdavoudi, D. Chitila, F. Boukadi

"Shale oil and gas have provided a tremendous boost to energy production in the United States even though the characteristics and behavior of shale are yet to be fully understood. Hydraulic fracturing is often applied to horizontal shale wells to stimulate production. This experiment seeks to determine effects of cyclic variable temperature, water vapor and exposure time on shale micro fracture propagation. We used 22 small Pierre shale specimens and subjected them to aforementioned conditions. Fractures developed in 19 specimens. Combination of high temperature and high water vapor generated the largest number of micro fractures on the specimen surfaces.INTRODUCTIONShale oil and gas have contributed immensely to energy independence in the United States. Most if not all shales depending on their total organic content (TOC) and their clay content bear the promise of being a source rock. For example, the Eagle Ford shale play, located in south Texas, is one of the key contributors to the recent rise in oil and gas production in the United States. Data from the U.S. Energy Information Administration (EIA), published in 2014, states that monthly oil production from Eagle Ford wells increased from 340 barrels per day (bbl/d) in January 2009 to nearly 1 million bbl/d in June 2013. Natural gas production has also increased at a similar rate over the same period, from 5.8 million cubic feet per day (MMcf/d) to nearly 4,000 MMcf/d (EIA, 2014).According to the railroad commission of Texas (RRC) 2014 published information, the Eagle Ford shale play is an important play because it produces gas and more oil than other shale plays in the United States. It is an organic-rich play with carbonate shale percentage in the 70% range in south Texas and the shale content increases moving to the northwest. High carbonate proportion renders this play brittle and suitable for hydraulic fracturing treatments."

Jan 1, 2015