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By Y. G. Seredkin, A. A. Vasiliev, A. Y. Senchenko, A. V. Aksenov

"Autoclave oxidation, bacterial and chemical liberation, roasting, acid oxygen processes, atmospheric oxidation prior to cyanidation are applied to process refractory sulphide concentrates. It is obvious that the processes with the maximum effect regarding gold recovery are those in which complete destruction of sulphides takes place and gold becomes accessible for further cyanidation through liberation from sulphide “capsula”. But the significant recovery increase is often accompanied by a process complexity, high expenses for equipment purchase and maintenance. It makes material processing costinefficient. Process optimization has led to progress in ultrafine grinding, bacterial and autoclave oxidation processes. In our opinion sulphide atmospheric oxidation processes are the most interesting as oxidation there runs without high temperature (up to 100°?) and excess pressure (open units), and with acid environment close to neutral. The process of sulphide concentrates treatment named “Albion” (Albion Process™) represents a combination of ultrafine grinding and oxygen oxidation without pressure and external heating. The process has a number of advantages: sodium cyanide consumption decrease during gold leaching and high ecological compatibility. TOMS institute in collaboration with Glencore Technology Pty ltd (Australia) tested Albion technology aiming at liberation of finely disseminated gold from flotation concentrate produced from refractory ore of one Russian deposit. The testing has shown that Albion technology makes it possible to process refractory products with quite small capital investments. It enables involving medium and small refractory gold deposits into processing.INTRODUCTIONThe considerable part of the world Au-bearing reserves is present by refractory ores with finely disseminated gold. Gold in such ores is often associated with sulphide minerals and locked in so called “sulphide capsula” since it is closed inside dense sulphide grains and inaccessible to recovery by cyanidation. To treat refractory sulphide concentrates containing gold a number of processes were developed and they can be divided into three groups (Figure 1)."

Jan 1, 2016

By Y. Zedan

Cutting fluids play important roles during machining, including the reduction of friction and temperature. Using a cutting fluid, however, degrades the quality of the environment and increases machining costs. The aim of the present research work is to study the effect of cutting fluids and their interactions with cutting parameters on the quality of holes during the drilling of 6061-T6 aluminum alloys. The lubrication types and modes investigated are dry machining, flood lubricant machining and minimum quantity lubrication machining (MQL), while the part quality criteria include the surface finish, the dimensional accuracy, and burr forms and sizes. A scanning electron microscope (SEM) was used to investigate the formation of built-up edges (BUE) in the drill flutes as well as the surface texture of drilled holes. It was found that dry machining and MQL machining can produce parts having quality levels comparable to those obtained in wet machining, when using the optimal cutting conditions.

Jan 1, 2011

By C. Van Den Heuvel, C. B. Van Buuren

BIOX® has been successfully demonstrated over the past 2 decades for the recovery of gold from refractory sulphide concentrates. To date 12 successful BIOX® plants have been installed in 8 countries spanning 4 continents with the 13th installation currently nearing completion in the Philippines. In 2010 BIOMIN introduced the ASTER™ process for improved water balances in commercial BIOX® applications by supporting tightening environmental legislation on water usage and availability in both arid and tropical regions. Previously, a common challenge for BIOX® plants was the inability to recycle thiocyanate containing water due to the low tolerance of the organisms. ASTER™, a biological thiocyanate and cyanide destruction process, renders a non-toxic solution for re-use in BIOX®. Two commercial ASTER™ plants are in operation with the 3rd ASTER™ plant under construction in the Philippines. A 3rd BIOMIN technology, specifically developed for double refractory ores is available for implementation. The HiTeCC process has shown considerable success on ores where competition from disseminated carbon has rendered ineffective gold recoveries. Through HiTeCC, gold is desorbed from the carbonaceous matter by manipulating the ionic strength and temperature of conventionally treated CIL product. One Australian commercial plant utilises HiTeCC while a 2nd installation is set for commissioning 4th Quarter 2014. BIOMIN’s premier solutions for refractory gold processing are described herein.

Jan 1, 2014

By G. Bonin, A. Jamal, G. Preciado, S. Gillis

"Accurate, easy to obtain, and reliable methods of measurement are the cornerstone of shaft and tunnel developments - during their sinking, operation and maintenance, or in some cases, remediation. This paper presents a new methodology to capture existing shaft conditions in such a manner that they can be transferred from the field to a digital copy, where they can be stored and used for engineering design purposes in a space not directly affected by the costs associated with schedule and equipment performance. The methodology utilizes basic principles of excavation alignment (plumb lines and survey instruments) while adding modern LiDAR, geolocation and survey control tools that can more completely capture the surrounding environment. The complete cycle of collection, processing, and delivery of pertinent information underground can take under an hour. During sinking, capturing data as a live stream measurement and being able to assess the alignment of the shaft liner can be critical to meeting rigid design tolerances. As sinking progresses, small changes in alignment or liner deviations can be captured and immediately corrected. Likewise, post-construction as-built conditions can be recorded and digitized, which will allow the mine personnel to compare the proper working condition to the actual condition years later. Observed changes can be identified and planned as future shaft repair works. This methodology has been developed and successfully deployed during the on-going sinking works of the two shafts at the Jansen Potash Project in south-central Saskatchewan and is described in greater detail in this paper.INTRODUCTION Light Detection and Ranging (or LiDAR) scans of the BHP Jansen Production and Service shafts during construction identified sections of both shafts where the internal radius of the temporary primary liner was insufficient to accommodate the tolerances of the permanent liner that was to be installed inside the temporary liner. These locations are referred to as “tights”. The “Tights Removal Program” was designed to collect high resolution point clouds of the shaft, using stringent survey control, that could be compared to the design profile to generate a heat map of locations for removal of up to 75 mm of steel-fiber-reinforced, 70 MPa concrete liner. This work was all on critical path, which made it valuable to save time on the schedule. Because concrete removal was a time-intensive task, it was essential to locate and remove only the concrete that would encroach on the planned permanent liner, while attempting to maximize the amount of cutting time. Removal was carried by a road header attached to a Brokk(R) 160, a small multi-attachment demolition machine."

Jan 1, 2019

By R. A. Ford

The paper outlines: methods used for the determination of wear metals in motor and transmission oils; contaminents in motor, transmission and crusher lubricating oils; and viscosity determinations. Case histories and costs are presented to illustrate the value of an oil analysis program. Introduction NORANDA MINES LIMITED (BELL COPPER DIVISION) is located on the shores of Babine Lake, approximately 450 miles north of Vancouver, British Columbia. Access to the mine is by road from Topley, B.C., about 40 miles away. When a preventive maintenance analysis program was first considered, it was obvious that if samples were to be sent out for analysis, results would not be available for at least a week, due to the distance from any commercial laboratory. The assay laboratory was asked to investigate the possibility of determining wear metals on site. A limited program was started soon after production commenced, and this has now grown to include all large mobile equipment as well as crushers and grinding mills. The laboratory also now determines viscosity, fuel dilution, dirt and abrasives, glycol and water. All these results are ready within two days. This paper will outline the methods used, data interpretation, several case histories and the benefits from such a program.

Jan 1, 1977

By A. D. Akerman, D. D. Young, G. R. Baiden

The development and maintenance of underground roadways are increasingly important aspects of the modern mining process. With the trend toward automation and track-less mining, roadbeds capable of with standing increased wheel loading have proven necessary to maintain high vehicle speed and reduced maintenance costs. Concrete has been used successfully on some roadways in order to obtain the required characteristics. However, this solution usually involves unacceptable expense. The objective of the Road Router project was to create a drift floor profiling machine capable of cutting a smooth surface out of the existing rock floor of development drifts and ramps. This surface would provide a durable, high strength, low rolling resistance roadbed that would allow for reduced operating cycle times and lower maintenance costs of scoops and haulage trucks. The Road Router has the potential to offer an alternative to concrete with substantial cost savings.

Jan 1, 1997

By H. Lee

Recently, the effects of global climate changes have become top concerns for governments? decision making regarding infrastructure investments. Extreme weather events that exceed the capacity of existing systems have considerably increased in frequency, and the potential effects of changing trends in temperature and rainfall on infrastructure are difficult to ignore. It is essential for governments to estimate the costs and benefits of adaptation to climate change to properly assess the financial feasibility of infrastructure adaptation strategies. This paper proposes a framework for estimating the economic aspects of infrastructure adaptation to climate change. The framework is composed of three steps of implementation: establishment of alternatives for infrastructure adaptation, performance prediction of infrastructure using future climate scenarios, and asset valuation based on costs and benefits. The first step specifies target assets, their adaptability to climate change, and applicable adaptation technologies. The second step evaluates the effects of climate change on the performance of infrastructure. The last step determines the optimal adaptation strategies among various alternatives based on their net benefits. The framework reasonably incorporates future climate scenarios into the estimation processes for climate change effects and provides a basis for budget allocation for governmental infrastructure investments. The framework is expected to assist government decision makers in establishing adaptation strategies in a rational manner under uncertain future climate change.

Aug 1, 2013

By J. G. Speight

Laboratory studies indicate that autogenous heating of low-rank coal can be prevented by a prior treatment which involves immersing the coal for short (5-15 min.) periods in an inert liquid at temperatures between ~ 350° and 400°C. Such "carbonization" effectively reduces the accessible pore volume of the coal to levels at which heat generation through subsequent sorption of moisture and oxygen is too slow to cause significant temperature rises in a stockpile. In addition, this treatment also irreversibly removes most of the moisture held in the raw coal and raises its calorific value by as much as 10-12%.

Jan 1, 1973

By DALE MacGREGOR, VERA TUREK

The Blue Mountain nepheline syenite deposit has been the subject of several detailed studies. It has been variously referred to as an intrusive stock, a metasomatic deposit, an intrusive sill and a metamorphic-metasomatic body. The body is divided into six mineralogical zones, the first five being based on the characterizing accessory mineral; muscovite, muscovitemagnetite, biotite-muscovite, biotite, hornblende and pink syenite. Mining currently takes place only in the biotite zone. Foliation is particularly prominent in the central (hornblende) zone and near the margins of the nepheline syenite. Majic bodies within the nepheline syenite may represent basic rocks that have been less altered by metasomatism, metamorphosed basic dykes or sloped blocks of metasediments. The most prominent structural features are the northeast-trending folds that have been modified by later north west-trending folds.

Jan 1, 1984

By J. -M. Bosgiraud, G. Armand, S. Dewonck, L. Richard-Panot

"The Meuse/Haute-Marne Underground Research Laboratory (URL) is located on the eastern boundary of the Paris Basin. The URL started to be built in 2000 (shaft sinking operations) in the framework of ANDRA’s (French national radioactive waste management agency) research program aimed at determining the feasibility of a reversible deep geological disposal of high-level and intermediate-level long-lived radioactive waste (HLW, IL-LLW). Its underground drifts are used to study the Callovo- Oxfordian claystone layer between 420 m and 550 m in depth.The ongoing research program (started in 2006) following the “Technology Readiness Level” (TRL) Scale is more dedicated to technologies improvement and demonstration issue of the different disposal components, even if characterization and monitoring studies are still ongoing.In rock mechanics, at the main level of the URL (located at 490 m), construction and evolution of disposal cells of different size are studied for HLW and IL-LLW packages. A step by step approach, started in 2006, is carried out based on comparison of HM behavior of parallel drifts excavated/supported by different construction methods. These various configurations give insight of the influence of construction method on the EDZ extent and evolution and on the progressive loading of the support, which are key issues to design the Cigéo disposal drifts and excavations.The concept of disposal cells studied for HLW consists in horizontal steel lined micro-tunnels 80 m long and 70 cm in diameter. Several campaigns of tests have been carried out since 2009 in order to demonstrate the feasibility of excavating such micro-tunnels and study their behavior under different conditions (with and without back filling the annular gap between the rock and the casing, watertight or not casing). A full scale demonstrator representative of the benchmark concept has also been excavated, to study its behaviour under thermal loading with heat produced by electrical heaters."

Jan 1, 2015

By V. Thangadurai

The critical problems in commercialization of the present solid oxide fuel cells (SOFCs) and useful electrical and physical properties of IT-SOFCs electrolytes are discussed briefly. The conductivity behavior of the perovskite-type and perovskite-related structure metal oxides are summarized. Perovskite-type La0.9Sr0.10ao.8Mgo.203_8 (LSGM) exhibits high ionic conductivity of 0.1 S/cm at 800 °C. In order to improve the electrical conductivity of LSGM and the In analogue of LSGM, substitutions have been made at the A-and B-sites. Substitution of trivalent La3+ by isovalent Pr3+ in LSGM and La09Sro ilno.sMgo.202.85 (LSIM), yield new mixed conductors. Among the investigated compounds in the present study, La0APro.4Sro.21no sMgo.2028 exhibits the highest total electrical conductivity of 3.2 x 10-5 S/cm at 200 °C in air with the lowest activation energy of 0.44 eV (200-700 °C). LSIM and Pr-substituted LSGM and LSIM perovskites show p-type electronic conductivity in the oxygen partial pressure range 10-5 ? 0.21 atm at 750 °C. The perovskite-type solid solution SrSn1-xFex03 exhibits compositionally driven phase transitions. For example, compound of the composition x = 0 to 0.3 crystallizes in an orthorhombic GdFeO3-like perovskite structure, where as that of x = 0.4-0.9 crystallizes in simple cubic SrTiO3-like, and that of x = 1 in orthorhombic structure. The electrical conductivity of SrSn1_xFex03 increases with the increasing Fe content and reaches a value of about 10-1 S/cm at 25 °C in air for x = 1. Compounds with low Fe content exhibit both ionic and electronic conductivity, while the higher Fe content 0.5) perovskites are electronic conductors over a wide range of oxygen partial pressure of 10-22? 0.21 atm at 750 °C.

Jan 1, 2005

By R. O. Loutfy, J. C. Withers

"Titanium powder is produced from a small fraction of sieved sponge, HDH of sponge or gas blown from a melt produced billet. Ore from foreign sources is chlorinated in a very high temperature fluid bed to make TiCl4, then vacuum distilled purified and then reduced to sponge by Kroll processing. Domestic ores of ilmenite or perovskite can be carbothermically reduced to Ti2OC which can be chlorinated at low temperatures of 250–400°C to produce TiCl4 which can be electrolyzed in a fused salt to Ti powder, or the Ti2OC used as an anode in electrolysis to produce Ti powder. The electrolysis process can be operated continuously to produce Ti powder at a lower cost than Kroll processed sponge including produce control size powder. Electrolysis processing was scaled up and operated at the commercial demonstration stage on a continued basis that verifies the potential of a low cost process to produce Ti powder.INTRODUCTIONTitanium and alloys of titanium powder have been elevated to strategic status resulting from a focus of producing meltless titanium components as well as a feed for additive manufacturing processing. However, the high cost of titanium powder has limited wide scale implementation of using titanium powder as a feed to any process to produce titanium components. Titanium powder free of alloying is available as sponge fines from the Kroll process as illustrated in Figure 1. Titanium alloy powder is much more expensive, also illustrated in Figure 1 produced from an alloy ingot or mil product as the feed and then transformed into powder by one of several melt form processes which accounts for the high cost of titanium alloy powder at approximately $60–150/lb. Ton lots of titanium alloy powder (i.e. Ti-6Al-4V) from one source is quoted at $120/lb. in the U.S. It appears that alloy powder production cost by current processing is not sensitive to volume."

Jan 1, 2016

By Joël P. T. Kapusta

Back in 1995, Air Liquide and Union Minière presented a joint paper at the Copper 95 – Cobre 95 Conference in Santiago, Chile, describing the first full scale plant trials of shrouded sonic injection in a Hoboken converter at the Hoboken smelter in Belgium. Almost a quarter of a century later, the technology known as ALSI, or Air Liquide Shrouded Injection, has been tested or commercially implemented in several copper and nickel smelters. Despite these successes, the copper industry did not adopt it widely in the same manner the steel industry adopted the Savard-Lee tuyere in the 1970s and beyond, not even in the way the lead industry adopted it with the Queneau-Schuhmann-Lurgi, or QSL, process. The development and implementation of bottom-blowing smelting and converting technologies in China in the last ten years, however, changed the industry’s perception that high- and ultra-high oxygen injection in copper smelting and converting was indeed possible under specific process conditions. In this paper, I retrace the key learnings of my journey with sonic injection over the twenty five years from my humble beginnings in my early years with Air Liquide, through plant trials and technology implementation in the late 1990s and into the first decade of the new millennium, and ultimately, to the most conclusive proof that the sonic injection design methodology I established is valid, and the calculation tools I developed are accurate. I conclude by sharing my thoughts about whether the deployment of the Savard and Lee legacy within the nonferrous industry was just a pipe dream or whether it will become a reality. INTRODUCTION In the context of lower quality ores and changing economic markets, copper smelters need to continuously innovate and improve to remain competitive and respect their corporate social responsibility engagements. One avenue towards this business, social, and environmental goal is to increase process intensity while lowering fossil fuel consumption to lower greenhouse gas emissions and reducing process off-gas volumes to better capture As and SO2–laden emissions. I believe high oxygen sonic injection for submerged tuyere copper bath smelting and converting is one technology that can help smelters achieve that goal of higher business, social, and environmental performance. Twenty five years ago, when I discovered that the Savard-Lee tuyere had revolutionized the steel industry (Savard & Lee, 1966; Knuppel, Brotzmann, Fassbieder, Savard, & Lee, 1972), I had a dream — or was it a vision? — that within the first decade of the new millennium, modern copper smelters operating submerged tuyere bath smelting and converting vessels will have implemented high oxygen sonic injection and will be reaping the financial and environmental benefits that the steel industry enjoyed in the 1970s. As we approach the end of the second decade of the new millennium, I have to admit that my dream has been all but shattered as the majority of copper bath smelting and converting vessels today continue to operate under bubbling regime conditions. This mode of operation is archaic, still requires tuyere punching and blows at inherently low enrichment levels, particularly in converting, producing large volumes of process off-gases. Under such operating conditions, regulations and emission quotas for As, SO2, and particulate matter oblige smelters to use not just primary or secondary hoods, but sometimes even tertiary hoods. I vividly recall being told, fifteen or twenty years ago when visiting smelters to promote the application of the Savard-Lee tuyere in nonferrous processes, that implementing sonic injection was not economically viable due to the high cost of compressing air and oxygen. Some of the smelters I visited back then have since mandated their engineering partners to design and build secondary or even tertiary hoods. I cannot fathom how secondary and particularly tertiary hoods, with all of their auxiliary equipment and added ducting, could be more economically viable than purchasing and installing a few compressors, expanding the pipeline network for compressed air and oxygen, and installing a new control valve train to feed sonic tuyeres. Besides, adding hoods does not address the problem of As and SO2-laden fugitive emissions at its source but merely provides a costly mitigation for it by capturing larger volumes of process off-gases rather than reducing these large volumes in the first place. Moreover, hooding does not reduce energy consumption nor does it increase process intensity, two aspects that I believe are critical for smelters to remain competitive and sustainable in a deeply changing market environment.

Jan 1, 2019

By Bevan. P. A.

The general location, topography and climate are discussed briefly, together with an historical record of the deposit. General geology, grade control and ore reserves are covered at some length, and reasons are given for the operation being placed on a salvage basis.

Jan 1, 1973

By Hani S. Mitri

Strainbursts in brittle rock are common to deep underground mines. The state of stress at the boundary of mine openings is dictated by a biaxial stress/loading condition. This paper reports the results of a series of biaxial compression tests carried out on 100 mm cubic samples of norite rock, under different horizontal-to-vertical stress ratios. The results indicate that the biaxial compressive strength is considerably higher than the uniaxial one. It is found that the norite sample behaviour under biaxial loading mirrors field behaviour where shearing and progressive spalling of the opening boundary are observed prior to strainbursting. Sample failure is initiated by rock spalling at the sample free faces, i.e. in the plane of biaxial loading. Finally, it?s the out-of-plane shear failure mechanism that causes the sample to collapse. Shear failure takes place violently and abruptly and is accompanied with considerable audible noise.

Apr 1, 2005

By C. Lapointe

"IntroductionTen years ago, when nuclear fission became practical, the element uranium, until then a not very desirable by-.product of the radium industry, became overnight the strategic material par excellence. One of the several important problems that had to be solved at that time was the rapid and precise determination of uranium in ores and concentrates.GeneralThe chemical analysis of uranium ores is a long and difficult business and is complicated by the presence in most ores of a large number of interfering elements. True, much progress has been made, during the past few years, toward simplification of the analytical methods, but the chemical determination still remains the job of a skilled operator. For this reason, the chemical method has been replaced, whenever possible, by a physical determination based on the measurement of the radiations emitted by the elements of the uranium family. There are several types of instruments suitable for these measurements, but of all the radiation detectors known to the physicist, such as ionization chambers, crystal detectors, scintillation, proportional counters, and the like, the Geiger-Mueller counters have proved to be the most satisfactory for routine determinations, because of their simplicity.The Geiger-Mueller counter is a very versatile instrument; it can be constructed to detect any type of radiation, corpuscular -0r electromagnetic. Here, however, we are interested in these counters because of their ability to detect the beta and the gamma radiations, both emitted by some members of the uranium family. The beta radiation is corpuscular, and is composed of fast electrons, while the gamma radiation is electromagnetic."

Jan 1, 1950

By J. S. Stewart

THIS paper was prompted by a persistent demand for what information we have that will throw light on the oil and gas possibilities of the Maritime Provinces. The problems involved were made familiar to the writer during three seasons of field work in New Brunswick and Nova Scotia. The reasons for renewed interest are: (1) In many parts of that region, the surface is underlain by a thick series of unaltered sedimentary rocks. (2) Oil seepages occur, and oil in commercial quantity has been exploited' near Moncton, New Brunswick, for many years. (3) In recent years, a new method of attack has been developed toward the finding of stratigraphic traps. This method is based on a detailed study of the geological history of the region, as revealed in surface outcrops and samples from deep wells. The well samples show the lateral variation of strata, far from any possible surface outcrop of the same beds. Sufficient work has now been done in the Maritime Provinces to reveal the broad features of the geological history and the character and distribution of the various rock formations. Comparatively little deep drilling has been done in this region, but the holes are widely scattered and the samples from them have added much to the information obtained from the numerous outcrops of bed-rock. The following discussion gives a summary of available information that has a bearing on the subject.

Jan 1, 1943

By P. Radziszewski

Industrial practice in mineral processing shows that an important problem in understanding and monitoring in-mill parameters is due to the lack of fundamental knowledge and appropriate sensors. With the development and growing use of DEM charge motion simulators for mill optimisation and design, it is possible to describe the fundamentals of grinding mill behaviour, in improving the understanding of internal grinding mill dynamics and in developing solutions to industrial practice. The main challenge to bringing this DEM technology to the mill operator however was the need for substantial computing power and time. However, what about a simplified DEM charge motion model running in real-time? What about the use of sensor technologies to correct any possible drift in simulator prediction? Could such a technological system be used to predict mill performance and eventually be used for mill control and optimisation? Some of these questions are answered with the development of an "on-line" DEM charge motion simulator package (SAGTools?) along with that of a number of sensor technologies (liner wear, acoustic, instrumented ball) that can contribute to simulator precision. With the objective of bringing this modelling and sensor technology into the concentrator control room to assist operators, this paper aims to describe the main elements of this emerging and developing technology and discuss how it can lead to online mill performance prediction and eventual control.

Jan 1, 2007

By R. Bonifaz

The Chagres Smelter, part of the Anglo American plc group situated 80 Km north of Santiago in Chile, completed a series of operational improvement in 2005 resulting in an optimum capacity in its operational units. At present the Chagres Smelter has developed an operational strategy which seeks to reduce bottle-necks in the production process. In this way we have managed to lower operational cost, decrease energy consumption and maximize the capacity of the Acid, Oxygen, and Smelting, Converting, Refining and Casting units. A constant application of international benchmarks together with continuous staff improvement and the latest smelter technology have combined to place Chagres among the finest smelting works in the world. In response to environmental challenges, we have studying various options for investment suitable for a profitable business of benefits to both Anglo American and Chile as a whole. The most relevant technical indicators are the figures : Energy consumption less than 6,3 GJ/ton fine copper, Intensity of smelting rate in Flash Smelting unit of 6900 ton of copper concentrate/m2 settler of furnace area and be one of the top five smelter in direct cash cost .

Jan 1, 2007

By Craig Haase

A. Introduction

Jan 1, 2003