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By Alastair J. Sinclair, Asger Bentzen

Abstract - A simple linear model for interpreting duplicate analytical data for a range of values is described. The conceptual model can be quantified using a reduced major axis model rather than the inappropriate traditional least squares approach. The reduced major axis parameters (slope, intercept) and associated errors provide a quantitative basis for: (1) defining bias, and (2) comparing results within laboratories, between laboratories and between sampling/analytical methods. Application of the linear model must be preceded by extraction of obvious outliers or small groups of values that have an inordinately large impact on values of the statistical parameters defining the model. In addition, consideration must be directed to the presence of more than one population of sampling error, as in the case of multiple styles of mineralization being sampled.

Jan 1, 1998

By L. Tang

A seismic monitoring system was installed in 2005 at Dongguashan Copper Mine, the deepest metal mine in China. Based on the seismic events monitored in situ, the possibility of rockburst prediction and prevention is investigated in this paper. The characteristics of space-timeintensity of mining-induced seismicity and the seismic response to mining are studied in detail using the seismic data in Dongguashan Mine. A conceptual model and a criterion of assessment of hazard seismic nucleation are proposed for Dongguashan Mine. In this model, the mine seismic stiffness method is adopted for rockburst prediction within the framework of the unstable failure theory. To analyze rock failure cases in Donggauashan Mine, the rate of the ratio of stiffness of rock in nucleation area to its surrounding area is proposed as a criterion for rockburst prediction.

May 1, 2009

By G. Dodbiba, A. Otsuki, T. Fujita, J. Ponou, A. Shibayama

"The different types of nano to submicron particles, which are well-dispersed nano particles, coagulated nano particles or settled submicron particles, have been measured by the interactive force apparatus (IFA). The information is very useful for mineral processing treatment. The IFA can measure the particle size distribution in low to high concentration of particles in liquids and non-light transparent liquids. Here, mainly the emulsion and bubble size measurements are described.Emulsion (w/o type) is prepared with oil and water mixture. The nano to micro emulsion particle size is usually measured by light scattering method. The particle size distribution of emulsion of light oil measured by IFA agreed well with the one by the dynamic light scattering (DLS) method. The water size distribution in emulsions of gasoline is difficult for the small reflection index and C heavy oil is difficult for the black color by DLS method. The IFA can measure both emulsions.There are many methods to measure fine air bubbles, however, the finer nano size measurement apparatuses are DLS method and IFA. A “ghost” peak appeared in the large particle micron meter size in DLS method. The mean diameter in IFA is similar with DLS for the nano meter size. INTRODUCTIONParticle size distribution measurement of nano to submicron particle, emulsion and bubble size distribution are very useful for ultrafine particle separation and characterization of fine particles by the necessity of recent fine minerals separation (For example, Li et al.2016, Mikhlin et al.2016, Wang et al.2013). As for the size measurement of solid particles in liquids, three different types of nano to submicron particles, that are well-dispersed nano particles, coagulated nano particles or settled submicron particles, have been measured by the interactive force apparatus (IFA). The particle size distributions are compared with the one of dried particles measured by TEM or SEM. The well-dispersed nano particle size distribution by IFA is influenced by the nano size surfactant micelles and becomes smaller, when compared with the TEM result. The size distribution of nano size of magnetite particles in water is influenced by the isoelectric point and the mean diameter of coagulation becomes larger. The particle coagulation in diluted suspension is about 2nm smaller when compared with the higher concentration. The submicron nickel particle size distribution is well agreed the result by SEM. The coagulation effect is small in the submicron size of nickel powder in water (Fujita et al., 2013). In this paper, the emulsion and bubble size measurements are mainly described."

Jan 1, 2016

By Lluís Fontboté, François Lieben, Robert Moritz, Massimo Chiaradia

"Abstract - The Las Cañas stratabound Pb-Zn deposit, in northern Chile, is hosted by the Lower Cretaceous back-arc marine carbonate and subordinate andesitic volcanic and volcaniclastic rocks of the Chañarcillo Group, one hundred meters above a thick pile of magmatic arc-related basaltic to andesitic lavas of the Bandurrias Formation. The deposit is not obviously related to local intrusive rocks, which include an Upper Cretaceous granodiorite batholith and dacite dikes emplaced along normal faults. Stratabound Pb-Zn-Ba mineralization is constrained within several porous stratigraphic units, including a 50 cm thick lapilli-tuff and less well mineralized algal-laminated limestone. Veins that locally carry some Pb-Zn occur along normal faults that displace the stratabound orebodies, and this study shows that they represent a different type of mineralization.Fluid inclusion microthermometric data for ore-stage quartz and barite indicate saline fluids (6 to 30 wt% NaCleq) and a formation temperature in the range of 80°C to 160°C for the stratabound mineralization. Two types of fluid inclusions occur in the veins. The type I vein fluid inclusions indicate less saline (average 7 wt% NaCleq) and slightly higher temperature fluids, in the range of 110°C to 220°C. The type II vein fluid inclusions indicate highly saline fluids (25 to 40 wt% NaCleq) which might be related to minor copper mineralization.206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios for galenas from the stratabound mineralization, with mean values of 18.42, 15.59, and 38.25, respectively, fall within the range of stratabound polymetallic deposits of northern and central Chile, and indicate a Lower Cretaceous magmatic rock source. Galenas from veins have slightly more radiogenic 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios, with mean values of 18.47, 15.61, and 38.34, suggesting two distinct episodes of mineralization.?34S values for galena and barite range from negative values (-31.2‰ to -12.5‰ and -7.7‰ to +12‰, respectively) in the mineralized tuff to higher values in the algal-laminated limestone (-2.5‰ to +1.2‰ and +13.2‰ to +17.4‰, respectively), close to Lower Cretaceous marine sulfate values for barite, and homogeneous values for the galena from veins (-12.0‰ ±1‰). Changing redox conditions can partly account for ?34S variations in the tuff. Sulfur sources include magmatic rock sulfur (-1.5‰ to +9.7‰) as well as sedimentary sulfides and marine sulfate."

Jan 1, 1999

By M. A. Kelly

Pit Optimisation using the Lerchs Grossman algorithm has been successfully applied in many deposits. Pit shells often form the basis for scheduling. Pre-assigned costs may not accurately reflect the costs that strategic scheduling decisions are based on. This can affect all mines, but is particularly true for commodities requiring blending. Adoption of Maximiser technology addresses these cost based scheduling and blending challenges.

May 1, 2007

By Vern Evans

Saskatchewan has historically been recognized for farming, but in 1943 while drilling for oil, potash was discovered. The initial attempt to gain access to the potash beds was unsuccessful, however, subsequent attempts were successful and today there are ten operating potash mines in Saskatchewan. In this paper we will provide a brief overview of the historical and current Potash industry in Saskatchewan.

May 1, 2011

By D. Adiguzel

In this research, providing the sustainability of production quality was aimed for a quarry which is located in Istanbul western part of Turkey and producing concrete aggregates with different types of rock. First, research field was divided in 3 different areas in accordance with the geological differences and parameters that control their product quality, limit values of standards and effect levels were determined. Concrete aggregate conformity tests which are stated in international standards were applied on samples which were taken from these 3 different areas and physical, geometric and chemical properties of each rock type were revealed. The properties of the 3 different types of rock which were produced in the quary were determined and the binary blends were composed. Blending studies were conducted with linear programming technique. In the linear programming model, the cost of aggregate production was aimed to be minimal. The limit values that meet literature and national standards for usability of aggregates in concrete were defined as constraints in the linear programming model and evaluated with objective functions, thus the most suitable aggregate blends were composed. In conclusion, to provide the sustainability of product quality, the most appropriate product blends were composed for the research field and the usability of this model for those quarries were revealed.

Aug 1, 2013

By P. W. Ware

The majority of all refined copper is consumed to produce electrical conductors. Most copper conductors are drawn into wire from 8 mm ETP copper rod produced from high purity copper cathodes. Southwire Company has more than 40 years experience using, designing, fabricating and marketing a process for continuously producing ETP copper wire rod. This process is called the SCR® (Southwire Continuous Rod) process. Today, approximately half the copper wire rod produced in the world, or more than one third of all refined copper consumed, is produced using the SCR process. Southwire has sold 75 SCR copper rod mills to metal producers and wire manufacturers around the world. Southwire is North America's largest electrical wire and cable producer. Southwire operates a 48 metric ton per hour SCR® copper rod system in Carrollton, Georgia. This allows Southwire to provide technical support for existing SCR® system customers based on first-hand knowledge. Rod fabricators and their wire customers are always striving for copper rod that improves productivity. They are looking for improved surface quality, finer wire sizes and fewer wire breaks per ton of rod drawn. This paper will present a brief history of the SCR® process, a description and recent process developments.

Jan 1, 2007

By U. Martin

Advanced copper materials for conducting applications require an optimal combination of high mechanical strength at ambient and moderately elevated temperatures together with superior electrical and thermal conductivity. Mechanical alloying under repeated cooling of the milling vials in liquid nitrogen has been applied to produce ultra-fine grained (UFG) oxide dispersion strengthened (ODS) copper with a high yield strength at ambient temperature. In the present study ODS copper was manufactured by mechanical alloying of copper powder and 3% by volume of incoherent oxide dispersoids. During the high-energy milling a homogeneous distribution of fine dispersoid particles (diameter nearly 100 nm) can be achieved in the powder. Samples with a density of more then 97% of theoretical value were produced by uniaxial hot pressing under 650 MPa at 600°C for 20 minutes. The high yield strength at ambient temperature can be described by a linear superposition of the Orowan stress for particle hardening and of ultra-fine grain strengthening according to the Hall-Petch mechanism. Simultaneously, a best value of 75% IACS could be obtained for the electrical conductivity. The creep behaviour of ODS copper in the temperature range from 500°C to 700°C is described within the frame of diffusional creep deformation.

Jan 1, 2007

By M. Sabau

The Electrowinning Plant at INCO's Copper Cliff Nickel Refinery is a precious metals upgrading plant. The feed to the plant contains copper, nickel, cobalt, iron, significant amounts of precious metals and some impurities. Copper is the most abundant element in the feed. This paper describes the major equipment and process changes over the last twenty years, geared to improve the tankhouse operation, workroom environment and recovery of copper from the acidic solution. Copper is plated on to titanium blanks using explosion-bonded crossrods, animal glue as a levelling agent, and an organic surfactant for mist control. The installation of the stripping machine in 2001 required a number of changes: cathode and anode contacts were redesigned, flat bus bars were replaced with dog-bone type, spacer boards for cathodes and anodes were installed, longer anodes started to be used, and the plating cycle was extended from seven to fourteen days. A number of initiatives for improvement are being carried out. Explosion-bonded crossrods are being replaced with titanium-clad crossrods. The plan for the near future is to increase copper production by increasing current efficiency and current density. The possibility of lowering the iron concentration in electrolyte and changing the acid mist control method is being investigated.

Jan 1, 2007

By G. Viramontes-Gamboa

Approximately 70% of world copper reserves consist of the mineral chalcopyrite, and much international effort has focused on its study. Ultimate objectives include the development of environmentally friendly alternatives to smelting, and technologies to treat low-grade ores, for which concentration and smelting are economically unviable. Unfortunately, chalcopyrite leaching is inefficient in H2S04-Fe2(S04)3-FeS04 solutions, which is considered to be the most desirable oxidizing medium for leaching of copper sulfides, since the chemistry is well known, corrosion of industrial equipment is negligible, subsequent copper recovery by SXlEW is well established, and environmental impact is minimal. The main reason for this inefficiency is the self-passivation of chalcopyrite. We have devoted considerable effort in the understanding of this phenomenon, and have developed a predictive electrochemical methodology capable of establishing a priori the precise range of potentials within which chalcopyrite leaches and where it is passivated. Since potential control is a critical parameter in chalcopyrite leaching, this experimental methodology can be very useful for establishing the best conditions to leach chalcopyrite. In this paper, the scientific foundations of this predictive experimental technique are presented, and its practical application is demonstrated by comparing its predictions with leaching experiments from the literature.

Jan 1, 2007

By Marcel Laflamme

Underground mine workers are continuously exposed to many sources of noise and vibration in carrying out their tasks. Even though the vibration and sound level of some mining equipment is documented, it was found that this information is not readily available for many pieces of equipment and that it is not considered when choosing equipment or planning tasks. As well, health problems related to vibration and noise are among the main causes of work-related compensations in mines. Considering those facts and although no Canadian regulations could force employers to limit the exposure of their workers to vibration, the Société de recherche et développement minier (SOREDEM) decided to address the problem by including vibration among their research priorities. In order to characterize noise and vibration sources of different mining equipment used for underground mining, the authors have performed a study in 8 different mines in Québec on 28 different mining equipments. The paper will present the procedure that was followed to select the list of equipment to be evaluated and the low cost acquisition system developed to perform multichannel time domain acquisition in harsh environments. It will also present the results obtained for the noise level produced by the equipment as well as for the hand-arm and whole-body vibration exposures.

Aug 1, 2013

By M. P. Tibbs

An autonomous spray application system for a structural Thin Spray-on Liner (TSL) is targeting productivity and safety on underground coal continuous miners by potentially replacing steel mesh, and has broader applications as surface support and confinement in metalliferous mines and civil tunnelling. Polymer chemistry, coating formulation, geotechnical assessment and the autonomous application system are being developed as an integrated package as part of a continuous miner automation project. This polymer-based TSL system has significant benefits over conventional steel mesh skin confinement, including being more automatable by spray application, providing complete skin confinement and active skin reinforcement as a fast-curing composite with substrate, and having effective fire retardant properties for the polymer and the underlying coal. This paper presents a preliminary assessment of distance sensing systems that would enable autonomous adaptation of a nominal spray path to spray a consistent thickness of TSL (nominally 5mm) over an irregular topography. Two alternate sensors are assessed; firstly, a 2D LIDAR mounted on a linear axis is used to produce a 3D surface profile for generating an adapted spray path; and secondly, a robot end-effector-mounted ultrasonic sensor is assessed for wall following techniques to dynamically adapt a nominal spray path.

Aug 1, 2013

By Denilson Coutinho, Euler Soares, Paulo de Tarso, Jordana Ferreira, John R. Goode, Andreas Sprecher, Alexandre Rocha

The Serra Verde Project is located in the northern part of Goiás state, Brazil, and comprises 49 mineral claims covering an area of 69,814 ha. The Serra Verde deposit is a rare earth element (REE) enriched weathered granite comparable to the weathered granite, or ionic-clay, deposits found in southeastern China. The Mineral Reserves of the Serra Verde Project total 388 Mt (Measured and Indicated) at an average grade of 1,484 ppm of REE oxide (REO). Several hundred agitated leach and column leach tests have confirmed recovery of about 40 to 55% of the REE, except for Ce, using simple desorption techniques. Present plans call for a heap leach operation followed by precipitation of impurities and precipitation of a pure REE carbonate suitable for refining and separation. The project plan includes initial production of 5,000 t/a of REO, with a high content of heavy and critical REO, rising to 10,000 t/a of REO. This production rate will be obtained by mining of the Mineral Reserves over a 22-year mine life at an initial rate of 6 Mt/a for the first four years with the mining rate thereafter increasing as required by grade and production targets.

Jan 1, 2014

By Chris J. Pritchard

Pumpable, two-component resins for anchoring rock bolts provides significant advantages over traditional cartridge resin and cement grout systems where fast and easily adaptable support is required for difficult ground conditions. Cartridge resin anchoring with rock bolts is often ineffective in oversized, fractured and washed-out holes. Cement grouting of cable bolts is frequently plagued with QA and QC issues related to the grouting process. Installation of cable bolts with resin injection techniques is routinely completed in cycle allowing blasting immediately after cable bolting. Xstrata Nickel has evaluated the Minova Resin Injection System since 2007. The Nickel Rim Mine and partner Minova have tested and validated the Resin Injection process for bolting procedures including Hollow Fiberglass Bolts, Rebar, Modified Cone Bolts and Cable Bolts. The resin injection process is adaptable to most bolting processes and equipment. Currently, Nickel Rim Mine use 2 resin injection products with different set times to grout deep cable bolts and development support in highly variable ground conditions. The product predictability and adaptability in application along with a high crew acceptance continues to make this support process part of an adaptable ground support system. Product consistency and quality significantly reduce the quality control concerns for ground support in highly variable ground conditions.

May 1, 2011

By Nick Vagenas

"Loading and transportation are important activities of the mining process. Automation of these activities in underground hard rock mining has been discussed for a long time. This paper deals with the performance evaluation of a prototype automatic Load-Haul-Dump (LHD) vehicle (a 7-ton GHH LF LHD model) operating in Zinkgruvan mine, Sweden. The purpose of the data analysis is to evaluate the operational and maintenance characteristics of the automatic LHD system in the mine. Graphical and numerical methods have been used for the statistical analysis of the data. IntroductionDuring the past years, the idea of integrated automation and tele-operation on Load-Haul-Dump (LHD) machines (Fig. 1) has attracted considerable interest in the Swedish mining industry. This is mainly due to the demand for improvement in the working environment and due to the rapid development of economic and reliable microprocessors for mining vehicles. Several advantages can be foreseen with the application of a Remote-controlled/Automatic LHD (RAL) system in underground mining. Some of them are (1)':• better utilization of working hours;• less interruption in production at shift changes;• better operational control of a fleet of vehicles;• improved safety; and• one operator may be able to operate more than one vehicle simultaneously."

Jan 1, 1993

By John H. Schloen

"The object of this paper is to review electrolytic copper refining as it was in 1954(1), as it is now in 1984, and to comment on the many improvements which have been made in the last thirty years.In 1954, and even in 1984, the ASTM specification B 115 for cathode copper was 99.90% minimum copper plus silver content and 100% minimum electrical conductivity, IACS standard. However, to meet competition and to satisfy the requirements of the fabricators and the electrical industry, the electrolytic refinery must supply a product of 99.95% to 99.96% minimum copper content, and 101fJlo minimum electrical conductivity.The range of cathode impurities reported by 20 major copper refineries in 1954 are given in Table I.The much more rigid British Specification, DD 78, for high-purity cathode copper, specifies individual elements, as well as groups of elements, as shown in Table 2.The Svenska test has been replaced by a similar procedure which uses 2.r mm diameter wire. The ISO test is the one listed in the DD 78 specification. In Table 3, corresponding values for the Svenska and ISO test s are given for various wire bar coppers."

Jan 1, 1986

By Wataru Inagaki, Kozo Kawano, Tetsuya Ando

Cu–Ni–P alloys are the typical precipitation-hardening material. Thus, Cu–Ni–P alloys is expected to apply alternative materials for heat-exchanger tubes. Therefore, it was investigated that the effect of the heat-treatment simulated brazing on mechanical properties of Cu–Ni–P alloy in this study. The hardness of specimen as heat-treatment simulated brazing after solution heat treated (sht) was shown approximately 105 HV. The peak hardness and tensile strength of the specimen as performed aged at 498 K for 43.2 ks following the heat-treatment simulated brazing achieved at approximately 140 HV and 260 MPa, respectively. From these results, it is expected the application to higher-strength tube for heat-exchanger after brazing in a furnace. INTRODUCTION Copper prices have increased dramatically with high in recent years. At the same time, manufacturing industries are required to reduce the environment load by reducing the wall thickness of the copper tubes used in heat exchangers. High-strength copper alloys are developed for reducing the wall thickness, while achieving high strength, of the copper tubes. Moreover, excellent workability and corrosive durability are also required by these copper tubes. Furthermore, the brazing, which are carried out at about 1050 K during the assembly process of heat exchangers, leads to grain growth and re-solving of additive elements. Nomura et al. achieved a tensile strength and Vickers hardness of approximately 260 MPa and 110 HV, respectively, after aging at 723 K for approximately 36 ks. Tamagawa et al. studied that the strength of Cu–Ni–P alloy rapidly increased at about 125 HV during the cooling process after the heat brazing due to the Ni2P precipitates sized 5–10 nm. Furthermore, Inagaki et al. achieved a Vickers hardness of approximately 130 HV by aging at 498 K for 10.8 ks. In the present study, we focused on the lowest aging temperature of 498 K in the previous study, and investigating the effect of heat-treatment simulated brazing on the mechanical properties of the Cu–0.93 mass%Ni–0.24 mass%P alloy.

Jan 1, 2019

By M. Hashemzadeh

The efficiency of water use is a top priority for the global minerals industry, especially in regions with limited freshwater supplies. In these areas, the freshwater shortage has prompted mining companies to search for alternatives to freshwater sources. Seawater has been proven to be a potential water source for mineral beneficiation and metal extraction processes. This study compares chalcocite leaching behavior with ferric chloride to that with cupric chloride. We carried out leaching tests with a highly pure chalcocite sample in jacketed reactors under fully controlled pH and solution potential. The effect of chloride concentration, oxidant concentration, and temperature on copper extraction was quantified in both cupric and ferric chloride systems. In the ferric chloride system, increasing ferric concentration showed a positive effect on the first stage of chalcocite leaching. In the second stage, increasing temperature markedly enhanced copper extraction. In the cupric chloride system, chloride concentration presented a considerable effect on both the first and second stages of leaching, while temperature had a remarkable effect only on the second stage. The findings of this study would be beneficial to mine operations aiming to replace fresh water with seawater for heap leaching of chalcocite. INTRODUCTION Mineral processing operations/plants are normally operated adjacent to mines which are often located in remote and arid area, such as northern Chile, southern Peru and Australia with limited access to fresh water (Liu, Moran, & Vink, 2011, 2013). Water scarcity in these areas has prompted mining companies to invest in sustainable technologies to reduce the water use and/or increase the water use efficiency. One of the current sustainable approaches in mineral processing operations is to replace fresh water with seawater. Seawater is now being increasingly used for mineral beneficiation and metal extraction processes (Hernández et al., 2015). Another application of seawater could be for heap leaching of copper secondary sulfides, mainly chalcocite. However, the high concentration of chloride ion in seawater may significantly affect leaching kinetics of copper sulfide concentrates and ores (Watling et al., 2014). Therefore, it is essential to develop a fundamental understanding of the leaching of chalcocite in chloride media.

Jan 1, 2019

By Wojciech Naworyta

The development of the Gubin lignite deposit, located in western Poland is the first mining investment of this magnitude in 30 years. Gubin is the second largest prospective lignite deposit in Poland, with over one billion tonnes of indicated reserves, which would be sufficient for a 2700 MW power plant for almost 50 years. The paper presents select problems related to the mining development of Gubin deposit. Attention has been paid to changes in legal and formal requirements for mining investments that were introduced after the change of Polish social and economic system. The significance of spatial, environmental and social conditionings has been emphasized. Typical attributes of the mine planning process have also been presented. Those include the long time horizon of the investment, uncertainty of external conditions and resulting difficulties in the project?s economic evaluation. Focus has been placed on mutual connections between particular elements of the project and time dependence during the process of their development. Iterative characteristics of the design process have been proven, together with resulting necessity of frequent verification of previous assumptions. As a background for presenting selected problems related to future development of Gubin lignite deposit, the methods of design have been discussed ? the variants method, the empirical method and the method of consecutive approximations. The tools and the possibilities of their use for solving specific problems related to mine design of an open pit have been broadly discussed. The chapter in which the authors relate to the specific problems of Gubin deposit development constitutes the main part of the paper. It depicts the assumptions on which the annual production and the total extraction of lignite during life-of-mine period have been based. The process of mine designing has been discussed, taking into consideration environmental, geotechnical, spatial, social and mining conditions. The criteria for choosing the location of the opening cut and the external dump have been mentioned. In the summary, the present state of mine design progress has been presented, together with some problems that will need to be solved during the next stages of the deposit?s development.

Aug 1, 2013