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By D. M. Xue, T. B. Li

"With the increase of human engineering activities, global climate change and active plate tectonics movement, the giant landslide frequently occurred in southwest China, which caused huge property and human losses. Besides, the potential landslides pose severely threaten to the construction and operation of airports, railways, highways and power stations etc. In order to provide accurate guidance for the landslide investigation, stability analysis and mitigation, the giant landslide is redefined according to landslide volume, depth of slip surface, complexity of landslide mechanisms, and degree of landslide mitigation difficulty, and classified with the typological classification approach based on the twofold attributes of landslide behavior including formation mechanisms and reactivation features. Finally, the threefold particularity of the giant landslide is also summarized, which enables a more effective landslide mitigation design.INTRODUCTIONWith the increase of anthropogenic activities, global climate change and active plate tectonics movement such as continual uplifting of Qinghai-Tibet plateau and strong earthquakes, the occurrence of giant landslides was in ascending trend in southwest China (Huang, 2009), which caused serious destruction, and greatly endangers such engineering construction from safety, time and economic aspects as airports, railways, highways, power stations, etc. Giant landslides have huge scale, complex formation/reactivation mechanisms and mechanical behavior. They may not be identified during the hazard investigation, but may be firstly initiated or reactivated due to the following engineering activities, heavy rainfall or strong earthquakes. Consequently, the landslide mitigation is inevitable and costly. However, it is difficult to control the deformation of giant landslide with lack of a correct understanding of genetic mechanisms (Marui, 2012; Zhang, 2000) and the excessive large sliding forces of the slide blocks calculated by the conventional limit equilibrium method. For instance, the failure of anchored pile wall for the No.102 giant ancient landslide (Zhu et al., 2012) and stabilization measures for the Sidi Rached viaduct landslide(Guemache et al., 2011); four rows of piles had not prevented the occurrence of the No.12 landslide in a high fill slope in the Panzhihua airport (Li et al., 2012)."

Jan 1, 2015

By Guocheng Pan

"Although many factors play roles in the estimation of recoverable reserves, smoothing effect and conditional bias are considered major geostatistical issues in the estimation. This paper introduces measures for smoothing effect and conditional bias, and provides insights into their relation to the estimation of recoverable reserves. Both smoothing effect and conditional bias are intrinsic to the information effect and kriging estimators. For a given level of drilling information, however, it is possible to identify the optimal search radius that minimizes conditional bias. Furthermore, it is also feasible to define variance correction factor for reduction of the smoothing effect from exploration block models. Both of these components are key to the accurate estimation of recoverable reserves. IntroductionThe accurate estimation of recoverable reserves is critical to decision making in different phases of feasibility study and mine planning. Much attention for improving the methodology of estimation has been focussed on the effect of the change-of-support (Parker, 1980; Dagdelen, 1996). For example, it is essential to make a volume- variance correction to the estimate of multiple indicator kriging (Hoerger, 1992). When the size of block, b, in the geostatistical model differs from that of selective mining unit (SMU), v, a volume-variance correction is warranted for the prediction of recoverable reserves.Most mining plans and decisions are made prior to the availability of high density blast-hole samples. In most mining operations, the true SMU grade Zv is unknown at the time of selection. Instead, the selection is based on the estimate Z v**derived from high density blast-hole samples within the deposit G. Nevertheless, the estimate Z v * of recoverable reserves in the stage of mine planning is derived from exploration data. At the end, the production result must be reconciled to the estimate Z v * . In other words, the selection is based on Z v** from blast-hole samples, while the final production figures are reconciled to Z v * from exploration drilling. For a given preselected cutoff grade z0, the actual mining panels will consist of the units having the estimated grade Z v** =z0 rather than the true grade Zv =z0. The difference between Z v** and Zv is usually of less concern."

Jan 1, 1998

By W. E. Cockfield

"The Stump Lake mining camp is in Nicola mining division of southern British Columbia. It lies about halfway between the cities of Kamloops and Merritt.The deposits at Stump Lake are among the earliest lode discoveries of British Columbia, many of the claims having been staked between 1882 and 1885. A considerable amount of work was done prior to 189Cl, after which very little was done until 1916. Since that time mining has been carried on at intervals, much of it on the same deposits, by a number of companies, including the Donahue Mines Corporation, the Planet Mines and Reduction Company, the Nicola Mines and Metals Company, the Consolidated Nicola Goldfields, Limited, and others. According to the British Columbia Department of Mines, total production from the area has been: gold, 8,520 oz.; silver, 259,413 oz.; copper, 40,822 lb.; lead, 2,208,859 lb.; and zinc, 367,869 lb. Most of the production has come from the Enterprise vein and a branch of the Enterprrsethe King William vein."

Jan 1, 1954

By R. M. Giegerich

"This paper begins with a brief history of Madawaska Mines, a brief description of the geology, mining methods and equipment, and the historical development of 7/8-in. tapered drilling equipment. It then outlines the performance characteristics and inherent problems of the traditional 12-degree, tapered connection, blade-type insert bits. Service-free (Unipass) button-type insert bits are presented as a possible solution to these problems. The paper concludes with an analysis of button bit performance to date.Brief History of Madawaska MinesMadawaska Mines Limited, near Bancroft, Ontario, is in Faraday Township, Hastings County, approximately 100 miles northeast of Toronto and 100 miles west of Ottawa.The mine re-opened in 1976committed to 1,500 tons per day to provide approximately 600,000 pounds of yellowcake (U3O8) per year to A.G.I.P. (an Italian government agency) under the joint ownership of Federal Resources Corporation, Salt Lake City (51%), and Consolidated Canadian Faraday Limited (49%). At present, the mine is producing approximately 2 pounds per ton (.1% U3O8) at the rate of 60,000 pounds per month. The mine employs about 400 employees.Brief Description of Geology, Mining Methods and EquipmentGeologyThe Grenville metasediments of the mine area are chiefly paragneiss, amphobolite and some carbonate (marble) rocks, which were intruded by a basic rock, altered to a metagabbrometadiorite. These formations are generally concordant, striking east to northeast and dipping 45 to 60 degrees to the south. Locally, the metagabbro is often discordant. The above group of rocks (mixed hybrid gneisses) forms the hanging wall of the south-dipping Faraday granite sheet and was intruded by nepheline syenite, syenite and granite. The ore occurs in the granite-syenite-pegmatite dykes that are probably genetically related to the Faraday granite. The ore shoots are erratically distributed within the pegmatite bodies, mainly on the hanging or footwalls but also medially. Their size varies from 50 to 350 feet in length, 5 to 40 feet in width and 50 to 200 feet in height. The ore occurs most frequently in a medium-grained granite or syenite, well hematized with 10 to 30% mafic crystals of pyroxene, amphibole and/or relics of the host rock."

Jan 1, 1982

By T. Patching

"COAL MINING at Canmore, Alberta, began in 1886 and continued there until July 1979. A comprehensive review of the Canmore operations is not available, but the following notes have been prepared to accompany references where more complete information about the operations and problems encountered may be found. The coal measures at Canmore occur in the Kootenay formation of Lower Cretaceous age, and at least twelve seams of varying thickness and horizontal extent have been recognized. The coal, of high quality, ranges from semi-anthracite in the lower seams to low-volatile bituminous in the upper seams. The strata of the Canmore area form an asymmetric syncline, the western limb being overturned to vertical by the Palaeozoic strata of the Mount Rundle Range. The eastern limb is more gently sloping, its dip ranging from IO to about 40 degrees. Tectonic movements have created a troubled and complex coal field. The seams were initially not regularly or uniformly deposited, and mountain-building activity folded and faulted the strata and in many places sheared and crushed the original structures of the coal(l,2,3,4,5). The lack of continuity of the seams, and changes in thickness and inclination, made longrange mine planning difficult and necessitated flexible methods of work, and the local disturbances sometimes created problems in roof support and contributed to the occurrence of sudden outbursts of coal and gas. Almost all of the coal was produced from underground operations but a few relatively small V-cut mines were worked along surface outcrops. These have all been filled in and revegetated. The basic method of underground work was by room-and-pillar, but many variations in layout and sequences were employed. Gangways were driven along the strike and pillars were formed by raises or slopes and crosscuts. Pillars were recovered to the extent that ground conditions permitted by splitting or taking 'skips' from the sides of the raises or splits or crosscuts. Because of the variety of conditions that existed in the field a considerable range of cutting, loading and support methods were employed, including hand-loading, slushers and scrapers, duckbills and shaker conveyors, mobile loaders and continuous miners. Except for the coal obtained by continuous miners most of the coal was broken out by blasting when driving narrow working places or by air picks when cutting from a face. In the early years hand loading onto cars or conveyors predominated. A continuous miner was introduced into Canmore in 1959 on a trial basis, and another was subsequently acquired, in order to minimize blasting and hand loading, but problems in operating these machines in inclining seams and difficulties in providing safe roof support for the machines and workers restricted their efficient use. Another major difficulty with the use of continuous miners was the problem of ventilating development headings in the very gassy conditions. In the early 1970s they were replaced by electric and compressed air slushers and scrapers, resulting in a general increase in productivity, roof control, safety, and flexibility of operations(1.6,7,8.9)."

Jan 1, 1985

By N. Molaei, E. R. Bobicki

The continued demand for mineral products, coupled with the depletion of high-grade ore resources, has led to the mining of lower grade ores, which often require fine grinding to achieve mineral liberation. Regrinding of low-grade ores results in the production of fine gangue mineral solids and produces vast quantities of fluid fine tailings which are difficult to separate from water, particularly if they are composed of clay minerals. Organic synthetic polymers and inorganic salts have been widely applied in flocculation of colloidal suspensions in the treatment of mining tailings. However, there are growing concerns regarding their impact on the environment and human health. Recently, extracellular biopolymer flocculants or bioflocculants have attracted much attention as alternative reagents. In this study, much effort has been devoted to considering the effectiveness of protein and polysaccharide-based biopolymers for the dewatering of clay slurries. The interaction between kaolinite and illite clays and biopolymers was investigated via settling tests at pH 7 and 10. Zeta potential measurements were also conducted as a complementary technique. Results showed that protamine and lysozyme protein- based biopolymers were generally the more effective bioflocculants. Pectin, a polysaccharide-based biopolymer, showed a dispersing effect and has the potential to be used as a dispersant and/or depressant for clay minerals in froth flotation. INTRODUCTION With the depletion of high-grade ore resources, the need for mining of low-grade ores has increased over the past few decades (Bourgès-Gastaud, Stoltz, Dolez, Blond, & Touze-Foltz, 2014; Chen, Walshe, Fru, Ciborowski, & Weisener, 2013; C. Wang, Harbottle, Liu, & Xu, 2014). Low-grade ores often require fine grinding and contain clay minerals, leading to the generation of fluid fine tailings (FFT). It is a challenging process to separate suspended clay particles from water (Craciun, Manaila, & Stelescu, 2013; Dompierre, Lindsay, Cruz-Hernández, & Halferdahl, 2016; Kasperski & Mikula, 2011; Mercier et al., 2012). Clay minerals form stable dispersions in water due to their anisotropic nature, non-spherical morphology and colloidal size (Lagaly & Ziesmer, 2003; Olphen, 1977). The difficulty in separating clay minerals from water has led to the accumulation of vast quantities of FFT in oil sands, phosphate, copper and nickel operations, representing a huge liability for mining companies (Chen et al., 2013; Mercier et al., 2012)

Jan 1, 2019

By A. de Ville d’Avray, G. Guezennec, P. Wavrer, E. Braak

The aim of the European CEReS project was to develop an innovative copper recycling route based on the coprocessing of coal production waste by bioleaching and printed circuit boards (PCBs) from Wastes of Electrical and Electronic Equipment (WEEE). Coal waste is processed by bioleaching in stirred tank reactors, and the resulting bio-lixiviant solution is used to extract copper from PCBs pre-treated by catalytic cracking. Copper is then extracted using solvent extraction, stripping and electrowinning. The whole process flowsheet combines thermal, biotechnological, physical and hydrometallurgical operations. Once the process concept has been validated at laboratory scale, a simulator of the whole process has been built in the USIM PAC software platform. The tool enables to improve the analysis of the results of the lab-scale experiments and to design industrial-scale scenarios by simulation. The results of such simulations allow to estimate the economical interest and to perform environmental impact assessment. After presentation of the CEReS project objectives and main results, the paper describes the methodology used to build the simulator and define the scenarios corresponding to feasible process routes. The main results of the simulations are then presented with technical, economic and environmental point of views. INTRODUCTION Because of rapid technological innovations in the electronics industry, electronic waste represents the fastest growing waste stream in the world, especially in developing countries (Işildar et al., 2018). Meanwhile, the global copper demand is expected to go on rising in the future. As significant amounts of copper are present in end-of-life printed circuit boards (PCBs), it becomes a necessity to develop efficient copper recycling routes. Metal refining from e-waste is traditionally performed by pyrometallurgical processes. However, the hydrometallurgical processing of PCBs, which has been shown to be technically feasible at laboratory scale with a wide range of leaching reagents, could be a less energy intensive and more flexible alternative (Tuncuk et al., 2012). However, a large amount of leaching reagent is required to leach the metals from PCBs.

Jan 1, 2019

By W. V. McKnight

The paper discusses the equipment and methods used to establish some of the characteristics of a braking system. Some typical tests are described and an explanation of the approach used to derive information from the recorder charts is given.

Jan 1, 1966

By Oberlando Gonzalez, Claudia Serna, Andrea Alzate, Esperanza López, Maria Holuszko

This paper presents a systematic approach on gold recovery from electronic waste (e-waste) using ammonium persulfate. This process was developed as a response to the lack of hydrometallurgical systems capable of separating gold from its metallic substrate without material grinding, with minimum formation of pollutants, and achieving a lower reaction time. Computer memory boards, electronic processors and electronic pins and contacts were analyzed to determinate base metals (Ni, Fe, Cu) and gold (Au) using microwave plasma atomic emission spectroscopy (MP-AES). An aqueous commercial grade ammonium persulfate with oxygen and pressure was used to produce the persulfate anion (S2O82-) and the oxidative sulfate ion (SO42-), which partially oxidized and leached the base metals breaking the Au-Ni-Fe-Cu bonds and allowing gold to be recovered in its original non-leaching state. The influence of the oxidative parameters was evaluated using full factorial (FF) and central composite designs (CCD) with response surface methodology (RSM) and first and second order models were developed. Using RSM allowed to obtain a faster recovery of gold, minimizing the agent consumption. The findings presented suggest that optimized quantities of ammonium persulfate, oxygen, pressure, temperature and liquid solid ratio could be used for selective oxidization of the base metals and to extract more than 96% of gold from e-waste.

Jan 1, 2017

By Rita Awwad

Building Information Modeling (BIM) has been gaining a significant edge in the construction industry over the last decade. BIM allows gathering all building information in one shared database that can help all construction entities better understand, integrate and visualize all work progress from inception to operation of the building. The main purpose behind BIM is to bring all project participants together (Client, Architect, Contractor, Consultant) since the initial stages of a project allowing them to cooperate and work as a team in the promise of an increased productivity, reduced cost, enhanced quality and faster delivery. However, a full-fledged implementation of BIM tools and benefits is not yet achieved in the construction industry and remains a debatable issue for researchers and practitioners in the construction field. This paper aims at assessing BIM awareness and usage in the Lebanese construction industry through conducting interviews with contractors, architects and consultants that are key players in the Lebanese market. A comprehensive literature review about BIM adoption in some developed countries and in the surrounding region is also provided in order to better evaluate the Lebanese industry status in comparison with foreign industries. This research sheds the light on BIM awareness of the different construction parties in the Lebanese market, assesses the extent of its current use, identifies the pertaining implementation challenges, and provides recommendations to enhance BIM role in the Lebanese construction industry.

Aug 1, 2013

By K. Ihara, T. Yamaguchi, K. Matsumoto

"Al-Fe alloy sheets having layers with different strain components were produced by unlubricated hot rolling and the recrystallization texture formation during annealing was investigated in each layer. In this study, the strain component introduced by rolling was quantitatively evaluated by measuring degree of bending of an aluminum pin embedded in the sheet. The textures before and after annealing were investigated by the SEM-EBSD technique. It was clarified that, in the middle layer, where comparatively small shear strain was introduced, ß-fiber subgrains and cube {001}<100> oriented subgrains were formed before annealing, and cube oriented recrystallized grains grew after annealing. On the other hand, in the surface layer, where large additional shear strain was introduced, shear texture components and cube oriented subgrains were formed before annealing, and shear texture was retained even after annealing, while cube oriented subgrains did not grow and were encroached. It was suggested that introduced strain components influenced the recrystallization texture formation by inducing different distribution of the subgrain size, stored strain energy and orientation relationship with surroundings before annealing.INTRODUCTION The microstructure developed during the hot-rolling process of aluminum and aluminum alloys affect the mechanical properties of the final product sheets. Especially, the crystallographic orientation in the final product sheets affects the r- value and ears during deep drawing (Humphreys & Hatherly, 2004), then the texture control in the hot-rolling process is important. When the friction between the rolling roll and rolled sheet in the hot-rolling is large, both the rolling texture and recrystallization texture tend to be heterogeneous in the thickness direction. It is known in many rolled aluminum alloy sheets that the texture in the surface layer was different from that in the middle layer because of additional shear strain. It was reported that in the vicinity of the surface layer, where large additional shear strain was introduced, the shear texture <1 1 1>//ND and < 1 1 0> // RD which contain components of {1 1 1} <1 1 0> and {0 0 1} <1 1 0> developed during rolling, and the shear texture developed even after recrystallization annealing (Sakai et al., 2002). Particularly, it is thought that the <1 1 1> // ND texture contributes to improve the r-value and press formability (Inoue & Takasugi, 2007). Therefore, asymmetrical rolling and high friction rolling have been applied to improve formability of aluminum alloys by adding shear strain in the rolled sheets as deep as possible (Kamijo et al., 1972; Inoue et al., 2005). However, few researches have been focused on the microstructures and texture before annealing and thus, the detailed mechanism is still unclear how the texture after annealing is affected by the texture before annealing. In this study, the Al-Fe alloy of commercially pure aluminum was chosen as the first material to be studied in order to clarify the fundamental process of the recrystallization texture formation. The main purpose of this study is to clarify the effect of additional shear strain on the rolling and recrystallization textures in the hot-rolled sheets by analyzing the transition of microstructure and orientation distribution through recrystallization annealing."

Jan 1, 2018

By M. J. Collins

The Advocate Mines Limited asbestos property is 6 km north of Baie Ve rte on the northeast coast of Newfoundland. Mining began in the early 1960s and was concluded in 1981. The chrysotile asbestos deposit lies at the north end of the Baie Verte Lineament, the interface between a closing ocean floor and continental margin. Asbestos occurs within ultramafic rocks of abducted ophiolite massifs that were thrust westward against Fleur-de-Lys Supergroup metasediments (continental rise sediments) in the Lower to Middle Ordovician. The asbestos-bearing ultramafics belong to the Central Ultrabasic Sequence of the Advocate Complex. Serpentinized peridotite of this sequence has a 'waste cap' core that grades outward to increasingly sheared rock. Asbestos is found mainly in a northtrending, basin-shaped zone surrounding the core, specifically within fractured serpentinized peridotite that abuts the sheared rock. Asbestos appears as stockworks of chrysotile cross fibre veins and is concentrated between brown, narrow brucitic dunite dykes and sills. Shear contacts commonly surround the ultrabasic body. Cross faults and complex Jointing also exist. The Advocate Mines Limited mill produced 65,000 tonnes of Group IV fibres and 1 l , 000 tonnes of Group VJ fibres annually. The bagged product enjoyed markets worldwide.

Jan 1, 1984

By A. E. Wraith, J. Protheroe Jones, P. J. Mackey

INTRODUCTION When Victoria became queen in 1837, that technical wonder of the 19th century—electricity— had progressed from being an exciting physical curiosity and was now a field of intense scientific investigation, invention and application. Its role in electrochemistry had been brilliantly quantified by Faraday in 1833–1834, and his earlier discoveries in electro-magnetism were to lay the foundations of electricity generation and the electric motor. In this age of electrical experiment, silver electro-plating emerged as a popular decorative art, at first using batteries to provide the deposition current, superseded by dynamos in the early 1840s. The decorative chemical and electroplating of precious metals was largely pioneered in England by the firm of G.R. Elkington and Co., founded in Birmingham by George Richards Elkington (1801–1865) in 1832, and protected by a series of patents which helped the company establish a leading position in the new field of ‘electrometallurgy’. In the same decade, the technique of electrotyping emerged, the first application of electro- forming by electrolytic deposition. Simultaneously invented by Spenser in England and Jakobi in Russia, but generally claimed for Jakobi, electrotyping involved plating a thick copper layer on to an electrically conducting mould wall embossed or incised with a pattern or profile which would consequently be replicated on the copper deposit—essentially a method of casting by electro-deposition with the mould wall as cathode. Woolrich’s invention of the low voltage magneto-dynamo in 1842 eliminated the need for batteries as a continuous source of deposition power, opening up the possibility of making more massive electroplated deposits, and by the mid-point of Victoria’s reign in 1869, the work of Wilde, Wheatstone and Siemens had produced the self-excited electro-dynamo, capable of higher voltages and yet greater deposition power. In this early Victorian period copper was extracted and refined by methods which had developed step-by-step over many decades. Only relatively rich copper ores containing more than, say, 6% Cu were economically useful, and the final copper product was far from pure. Copper production in Britain was located principally in the Swansea area of South Wales, based upon the ‘Welsh process’ of reverberatory batch smelting and refining, using locally mined coal and ore imported from Cornwall and elsewhere. Silver was an important by-product. Much of the output was exported and South Wales remained a principal supplier to the world copper market until the 1890s. It was here at Pembrey, a few miles west of Llanelli, that a new primary copper smelter was stablished in 1849 under the name Mason and Elkington, arguably to supply the Elkington company’s market for electrotype products.

Jan 1, 2019

Mirador - Overview ? Located in Andean foothills of SE Ecuador ? Copper-gold porphyry hosted by calc-alkaline Late Jurassic granitic and porphyritic rocks ? 438 MT of 0.61% Cu and 0.19 g/t Au measured and indicated resources (at 0.4% Cu cut-off) ? Additional inferred resources of 235 MT of 0.52% Cu and 0.17 g/t Au ? Initial 25,000 tonnes/day production, expanding to 50,000 in year 6 320 MT of 0.62% Cu, 0.2 g/t Au ore mined at an average 1.4:1 strip ratio over a 21 year mine-life

May 1, 2006

By J. Kang

There is increasing demand to utilize aluminium alloy sheets and their spot welds by the automotive industry. While traditional uniaxial tensile tests only determine mechanical properties to small strain, direct measurement of the constitutive behaviour of aluminium alloy spot welds at large strain remains a challenge. A technique was successfully developed using digital image correlation coupled with shear tests to directly measure the constitutive behaviour of an AA6022-T4 spot weld to large strains. The results show that the spot welding process not only decreases the yield strength but also lowers the work hardening rate of the nugget versus the base material. Details of sample preparation, experimental approach and results will be discussed.

Jan 1, 2011

By Z. Farhat

In spite of advances in cutting tool technology, the understanding of the basic wear behavior and failure mechanisms needs further study. Tool wear is the main factor contributing to geometrical error and thermal damage in machined components. Manifested as a reduction in tool life, it also affects the workpiece surface finish, increases cutting forces and induces residual stresses. Furthermore, the emergence of high and ultra-high speed machining processes necessitates the investigation of tool wear under these severe working conditions. Tungsten carbide-cobalt composite material has been used traditionally as wear resistant materials for many years. One main application of this material is in cutting tools. WC-Co tools consist of hard WC particles imbedded in a tough Co matrix, which functions as a binder phase. More recently, Cubic boron nitride (CBN) tool material have attracted special attention due to its high hardness and excellent wear resistance. Boron nitride in its cubic form is known to be the hardest material next only to diamond. In this paper microstructural and tribological properties of commercial grade WC-Co and CBN cutting tool materials are investigated under high speed cutting conditions. The CBN cutting tools were found to be superior to tungsten carbide (WC) tools. Four-fold increase in productivity and significant reduction in chipping and cratering was achieved for CBN as compared to WC. Wear mechanisms are proposed and are related to the observed wear characteristics in the cutting zone.

Jan 1, 2006

By G. I. Mathieu

"An experimental study was carried out to evaluate the performance of column flotation versus conventional flotation for the recovery of molybdenite from a Newfoundland ore. The objective was to verify the claims made by the inventors of the flotation column, Messrs. Pierre Boutin and Remi Tremblay, that their apparatus reduces the entrainment of fine gangue and other mineral impurities in the froth product. The research included a factorially designed series of tests to determine satisfactory operating conditions of the column. These provided a basis for comparative flotation tests with column and Denver cells. In the course of the work, the action of a few depressants was studied. Results indicated greater selectivity in the column and reduced reagent consumption."

Jan 1, 1972

By P. Shibley, P. R. Clarke

Since this was an interim report of the initial operation of a long term project it is not available for publication. It is expected when the project is completed a full report of the work will be published.

Jan 1, 1968

By Melvin S. Taylor

The environmental control program at Cassiar Mine is an active one involving government, unions and company personnel all working together to achieve a goal- "A clean and safe working environment". This can only be achieved by utilizing three of Cassiar&apos;s most important resources; i.e., people, time and money. Past environmental programs have more than proved that the goal can be reached and. with the future programs now in progress. Cassiar Asbestos will achieve its environmental goals.

Jan 1, 1978

By M. Somppi, D. Weirmeir, Z. Yamak

"Milling operations commonly employ activated carbon to capture complexed gold from lixiviants in leaching processes. As the carbon moves through pipes, pumps, vessels, kilns and other processes in the gold leaching circuit, this consumable may experience losses by various mechanisms like attrition, breakage, and rupturing. Whenever possible, capturing the fine gold-bearing carbon portion of this stream could provide value to milling operations at low capital cost and manageable financial risk. Identifying, testing, and validating the successful payback of a low-tech flocculant system is described. However, the work more closely explores a Monte Carlo risk-based methodology for understanding the potential payback of this project at various confidence levels – an approach that many improvement projects can follow where some level of uncertainty exists.INTRODUCTION Gold milling operations commonly employ activated carbon to adsorb gold from solutions. Normal handling causes the carbon particles from this material to abrade, break, rupture to a size that becomes too small for further use in the process. Operations often concentrate on capturing the fine particles because gold is associated with the carbon and this metal content can be a valuable revenue stream for toll processing. However, the small particle sizes become difficult to separate from the process and can ultimately leave the facility in the waste stream. Hence, operations often place a great deal of care in capturing as much fine carbon as possible by a variety of methods including using screens, settling tanks, and chemical methods. Retrofitting a circuit to capture more carbon fines is common but can expose the operation to financial risk. Approaching this potential improvement by leveraging a Monte Carlo methodology can be effective in understanding the risk and the associated payback of a project at various confidence levels. This method provides a strong framework for capital go-no-go decisions and the structure to validate the potential project success before implementation."

Jan 1, 2019