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By Biplop Das, E. Herrera, A. Burrows, P. J. Mackey, G. R. F. Alvear Flores

Since the first commercial plant was built at Mount Isa, another twenty ISASMELT™ furnaces have come into commercial operation, and construction of new plants continues. The primary copper ISASMELT™ top submerged lance (TSL) technology continues to attract interest from potential users who seek to smelt productively. In addition to the known benefits of productivity and flexibility, ISASMELT™ operators have also achieved improvements to energy efficiency when switching from their previous technologies. The recent production statistics for operation at Tuticorin, India show that ISASMELT™ has taken the first steps into territory beyond 400,000 t/y (copper cathode basis) and this will likely be the scale chosen by future new copper smelters operating purely on a toll smelting basis. Highly energy-efficient technologies will be expected at these smelters

Jan 1, 2015

By M. Dupuis, V. Bojarevics

It is well known that horizontal current density in the metal pad contributes greatly to the generation of MHD driven bath-metal interface wave. It is possible to compute very accurately the metal pad current density using a very detailed finite element model [1], but a MHD model must be compatible to this level of mesh refinement and to recalculate the current distribution at each time step, including the full busbar supply system. The accuracy of the instability prediction of the cell depends on the accuracy of the metal pad current density calculation. This study presents the comparison of the metal pad current density calculation of the detailed finite element model and the MHD-Valdis model for different metal pad heights and ledge thickness. It also presents the corresponding cell MHD stability predictions.

Jan 1, 2006

By D. W. Li

Due to the ultrasonic testing and mechanical wind speed sensor have high requirement for the environmental of the coal mine, the charge induction wind speed detection method based on wavelet analysis is proposed. The same wavelet disturbance detection method is used at a fixed distance to obtain an induction signal to obtain a pass time, and then calculate the magnitude and speed of the wind. Simulation and verification experiments show that the method has application across a wide range of test speeds (up to 60 m/s). The metal probe causes little pipeline flow field interference. The method is particularly well-suited to dusty environment, and does not cause dust deposition through long-term operation. It can be widely used in coal mines for point wind speed continuous online testing.

Aug 1, 2013

By S. Malkin, Z. Shi, H. Attia, D. Chellan

An experimental investigation is reported on creep-feed grinding of a nickelbased alloy (IN718) using conventional aluminum oxide grinding wheels. Straight surface grinding expe.riments were conducted on nickel-based alloy blocks over a wide range of grinding conditions with straight oil as- grinding fluid applied at high pressure. Grinding power, forces, workpiece surface roughness, and radial wheel wear were measured. Specific material removal rate as high as 64 mm2/s was Used without burning the workpiece, which can be attributed to the extremely low specific energy of 12.6 J/mm3. It was found that the grinding wheel under the present test conditions had a strong capability of self-sharpening as indicated by the stabilized power, forces, and surface roughness after an initial short transient.

Jan 1, 2006

By Hasan Ozturk

Laboratory testing examined the effect of a variety of intrinsic rock properties and environment conditions that influence the adhesive bond between rock and thin spray-on liners. The liner materials used for these tests were Tekflex, provided by Fosroc, Castonite, provided by Rohms and Haas Co., Rockweb provided by Spray-on Plastics, and CS 1251 2K, provided by Master Builders. Some of the variables examined include: rock strength (tensile/compressive strength) rock mineralogy, rock surface roughness (grain size, fracture/joint roughness), and surface contamination (oil, water or dust). Under optimal conditions, adhesive strengths reaching at least 3 MPa can be achieved. Where the rock surface is contaminated with dust or the rock is weak in tension, it may be difficult to reach adhesion strengths of 1 to 1.5 MPa.

May 1, 2004

By Fraser Rowe

This paper discusses the philosophies, strategies, goals and pitfalls in automating a mine schedule. The intention of the paper is to give an open and honest view of who could benefit from moving to an automated system, what you can expect from such a system, and what you should be aware of. Many companies feel that moving to an automated mine planning solution will allow the mine scheduling engineer to push a button and walk away, but the reality is that is hardly ever the case. Part of that awareness comes from understanding what is meant by ?automated mine scheduling?, and this paper address that. By contrasting what is meant by ?manual scheduling? and ?automated scheduling? it is hoped that the reader can gain an appreciation of the entire process.

Oct 1, 2009

By S. Tuttle, R. Sisson

"Suncor Energy Inc. has proposed a 2.2 billion dollar expansion to the current oil sands operation, which will more than double the productive capability of the facility. As part of the application for this expansion, a comprehensive closure plan had to be developed and filed.Closure planning includes a systematic evaluation of the area to be developed, the development activities planned, the goals and objectives of the corporation in re-establishing landforms and ecosystems at the same time as running an effective operation. As early as is practical during the mine development, surface contouring is completed, soil is reconstructed, and vegetation, surface drainage and wetlands are re-established. Once active reclamation is complete and vegetation has been re-established, Suncor monitors maturation of landscapes and ecosystems to provide the submission basis for reclamation certification"

Jan 1, 1999

By A. Fischersworring-Bunk

The new inline six spark-ignition engine is the realization of BMW's concept of efficient dynamics at high technological level to achieve the attributes of low weight and high efficiency, The paper presents different aspects of the development and manufacturing of BMW's inline six-cylinder engine magnesium-aluminium composite crankcase, Reference will be made on the AJ magnesium alloy optimization approach to balance between mechanical properties and the high pressure die cast ability requirements, Next to this aspect some mechanical design issues will be covered, with CAE methods playing an instrumental role in the early project stage for the assessment of the compound concept, Due to the compound design chosen, the interface posed challenges to both design and productions, A set of novel techniques has been used to cope with these tasks.

Jan 1, 2006

By A. Chaisantikulwat

Most solid-oxide fuel cell (SOFC) modeling emphasizes steady state cell operation. However, understanding the dynamic behavior is essential to predict the performance and limitations of SOFC power systems. In this work, we demonstrate a dynamic model of a SOFC, and we simulate a feedback control scheme that can maintain output voltage despite load changes. Dynamic response is determined as the solution of coupled partial differential equations derived from conservation laws for energy, mass and electric charge. From such a model, the step responses to system input variables can be determined. Low order dynamic models that are sufficient for feedback control design can be derived from the step responses. The development of the partial differential equation model is outlined, and the limitations of the control system are discussed.

Jan 1, 2005

By J. Gao

We present results from our investigation of the concept and practice of using surface-charged latex nanoparticles as building blocks for conductive membranes. Nanoparticles were synthesized by free-radical co-polymerization of two hydrophobic monomers, butyl acrylate (BA) and methyl methacrylate (MMA), a crosslinker, N, N'- methylenebisacrylamide (BIS), and a charged monomer, sulfonate styrene sodium salt (NaSS), in water. The resultant nanospheres were characterized with static and dynamic laser light scattering. Thin films were cast from concentrated particle dispersions, followed by incubation at ?110 °C. Conductivity, water uptake and final charge content were measured. The membranes have higher conductivities than both amorphous films cast from sulfonated BA-MMA-Styrene copolymer chains and BA-BIS-MMA-NaSS gel films. TEM images and neutron scattering spectra confirm the particulate structure of the membranes.

Jan 1, 2005

By Margaret Armstrong, Chris Roth

Abstract -Estimating ore reserves for vein type deposits is a two-stage procedure: first, calculate the geometry of the vein system, and second, estimate the grades within this system. The grade estimation can only be consistently performed if the vein geometry - its size, shape and orientation - has been correctly characterized. Getting the size and shape of the different veins right means that the ore tonnages will not be artificially inflated, e.g., by falsely classifying host rock as veins. Similarly, correctly estimating their orientation and location helps mine management decide on the appropriate mining technique, selective or not. When applying geostatistics to estimate the vein geometry all available information needs to be used and not just the standard lithologic indicator of being or not being in a vein.

Jan 1, 1998

The following briefing is intended to provide an overview of the present and future challenges associated with our access to a secure and adequate supply of electrical energy necessary to support safe, productive and sustainable mining initiatives at Musselwhite. Contents ??Site power demand vs. current available supply ??Supply technical deficiencies ?adequacy and security of present supply ??Present internal generation ??Anticipated future internal generation requirements ??Increased requirements necessary for planned expansion ?demand/security ??Goldcorp?s strategy to achieve required supply ?transmission line initiative ??Subsequent benefits to others from the Goldcorp initiative. ??Economic impact of MusselwhiteMine on the northwest region ??Anticipated economic impact of planned expansion ??Expected life cycle of MusselwhiteMine ??Comparative energy costs for similar operations in other jurisdictions ??Conclusions ??Anticipated action plan ??Energy Management Initiatives ??Site Orientation

May 1, 2009

By Bian Xue, Wu Wenyuan

High quality, mono-dispersed, hollow CeO2 microspheres with high surface area were produced by a spray pyrolysis method at 700oC. CeCl3 was used as the raw material of the process rather than Ce(NO3)3 because the latter is relatively difficult to obtain in industrial quantities. X-ray diffraction and electron microscopy results confirm the high quality synthesis of hollow CeO2 microspheres with narrow size distribution, good mono-disperse, and good reproducibility. The process of the formation of mono-dispersive CeO2 microspheres was investigated by chemical dynamics and a possible mechanism is proposed. This simple method for synthesis of CeO2 microspheres is easily scaled up to fabricate other metal oxide nanostructured materials at industrial scale.

Jan 1, 2014

By Nicolas Gatelier, Sophie Laurent, Thierry You

Hard-rock caverns for hydrocarbon storage are a very particular type of underground facility controlled not only by local administrative and regulatory constraints that can be very specific, but also by the possible risks of geotechnical or geomechanical failure. Each such facility throughout the world is a prototype that needs to be adapted to very different site conditions. The straight forward application of design methodologies from relatively similar fields (mines, tunnels) can be very useful, but risks holding back the scientific and technical improvements needed by an engineering industry in full development. Here we look at various case histories and at problems that have been raised where recent attempts at standardization would appear to have been ill adapted, and where storage designers, through experience and judgment, may still provide innovative engineering solutions.

Jan 1, 2015

By Abhinav Karanam, Lukas Bichler

Yttria Stabilized Zirconia (YSZ) is a promising thermal insulator for high temperature environments due to its thermal stability and chemical inertness. As was demonstrated with other technical ceramics (e.g., Alumina), addition of Single-Wall Carbon Nanotubes (CNTs) to a ceramic matrix may significantly enhance the mechanical properties of the composite ceramic. In this work, 8 mol% YSZ with 0.2, 0.5 and 1wt% CNTs composites were prepared via Spark Plasma Sintering process. The densification, Vicker’s microhardness, specific gravity and microstructure evolution of the composites were investigated. The results suggest that the addition of up to 1wt% CNTs to YSZ yielded optimal combination of the studied properties. At higher addition levels, the specific gravity decreased and clustering of CNTs occurred, leading to poor densification and a relative loss of performance.

Jan 1, 2014

By E. L. Horner

"Srnoky River Coal is capable ofprocessing 3 million tonnes per year ofrun-of-mine coal at the Smoky River Coal preparation facilities to produce 2.1 million tonnes of high quality, low volatile coking coal for export markets. Multi-seam surface and underground mining operations are scheduled to maintain raw coal feed to the plant. Two beneficiating circuits wash the coal. A heavy medium cyclone circuit cleans the plus 0.5 mm coal and a froth flotation circuit cleans the minus 0.5 mm coal. Clean coal is thermally dried, loaded into unit trains, treated for dust suppression, and transported to west coast port facilitiesf or export. Plant by-products are used as thermal fuel Jn an adjacent power station. Quality control procedures ensure efficient resource recovery for a yield of uniform specification product, at a 7% ash level. Introduction Smoky River Coal operates surface and underground mines in the Smoky River coalfield. Approximately 3 million tonnes per year (mt/ a) of run-of-mine (ROM) coal can be processed at the coal preparation plant to provide 2.1 mt/ a of clean, high quality, low volatile bituminous coking coal. Coal is processed by heavy media and froth flotation cleaning circuits and is thermally dried.Raw Coal Characteristics The characteristics of the ROM coal, both in terms of quality and size consistency, vary with intrinsic seam qualities and mining methods employed. The two seams mined (No. 4 and No. 10) show distinctly different washability characteristics. Seam No. 4 contains relatively few middlings and can be readily cleaned by dense-medium cyclones and froth flotation to give a clean coal at specification ash content. Seam No. JO is more difficult to wash, and the ash content of the clean coal is higher than No. 4 seam at the same operating conditions. However, when the upper I m is excluded from the plant feed, the remaining lower section has washability characteristics similar to No. 4 seam. Coal mined by underground means sometimes contains caprock and consequently tends to be dirtier than similar coal mined by surface means."

Jan 1, 1985

By Song (Bruce) Li

This paper presents a three-tier web-based GIS application that uses Java Server Page (JSP), Java Servlet and relational database to manage performance monitoring and reporting in the oil sands mining industry. It is a real-time Earth Structure Performance Monitoring System (ESPMS), which allows the user to record and store instrumentation monitoring readings as well as technical observations and instrumentation installation documentations into a complete relational database. The ESPMS introduces the advantages of precise field record keeping, due diligence, security, consistency and completeness while at the same time simplifying the task of reporting. ESPMS combines web-based Geographic Information System (GIS) mapping and data management to facilitate the collection, organization, retrieval, reporting and communication of the vast amounts of monitoring data related to mining and tailings engineering associated with site investigation and construction information. ESPMS utilizes web-based GIS technology to incorporate referenced aerial photographs, Energy, Mines and Resources (EMR) maps or AutoCAD drawings as a base map for the monitoring site. It dynamically creates and administers all instrumentation monitoring locations and reading frequencies. It enables the user to collect and manage the data associated with an unlimited number of reading events. It provides the designer with real-time monitoring data (what, why, when, how), thereby allowing them to make early adjustments to design protocols or procedures, or to take remedial action(s) regarding the subject earth structure under construction or after completion. It provides more cost-effective reporting and data sharing through the Internet. It improves security on data entry and eliminates unauthorized data changes. It allows better integration of graphics and illustrations with numerical data files. It is capable of managing the continually expanding workload resulting from new and larger structures in the oil sands or other mineral mining industries. The ESPMS facilitates easier data gathering for preparation of as-built and after-built or regulatory reports, etc. It enables quick location of the interested instruments and summarization of the performance of the instruments. It enables one to visualize performance data and QA/QC construction test results spatially on any given cross-section. Data can be exported to MS Excel for detailed analysis and to evaluate the stability of the earth structures.

May 1, 2004

By L. A. Melis, A. R. Marchbank, S. A. Webster

"Certain northern Saskatchewan uranium ores have a high content of nickel and cobalt which offer the potential for recovery as a by-product to uranium. A nickel/cobalt recovery process has been developed as a viable method of recovering a marketable concentrate from typical uranium raffinate solution.Impurities are first removed from the raffinate and the pure solution is then treated with sodium carbonate to recover a bulk nickel/cobalt carbonate precipitate for sale to a primary nickel producer. All contaminants of concern are removed to very low levels and the product is free of radioactive contamination with gamma emissions significantly below natural background. Cost estimates have shown that installation of a nickel/cobalt recovery circuit within a uranium process plant is economically feasible.The testwork that led up to the selected process is described along with recommendations for further investigations such as additional testing of hydroxide precipitation as a possible viable alternative to carbonate. The selected process is described and project economics are briefly reviewed.PROCESS TEST PROGRAMBackgroundExtensive metallurgical research has been performed over the years to develop a process for recovering uranium from the Midwest deposit in northern Saskatchewan. During the course of this research, a certain amount of information became available which suggested that recovery of nickel and cobalt from uranium raffinate could be economically feasible. It was decided to undertake a test program which would investigate methods of separating nickel and cobalt from radioactive and other metal contamination to permit production of a saleable product.Available technology suggested that three general approaches could be taken to recover nickel and cobalt. The first and simplest approach would be to selectively precipitate the impurities of concern, primarily arsenic, iron and radium, and then recover a bulk concentrate from the purified raffinate. The second approach would be to purify the raffinate and then remove cobalt from solution by solvent extraction producing pure nickel and cobalt solutions for further treatment. The third approach would be to precipitate all metals from solution and then selectively re-dissolve nickel and cobalt in ammoniac solution which would be further treated by solvent extraction for nickel recovery, leaving cobalt for further treatment."

Jan 1, 1993

By A. L. Mular

"IntroductionSince the mid -1960s, automatic control of grinding circuits has become the rule, to avoid losses attributable to frequent circuit upsets associated with uncontrolled disturbances such as ore hardness variations. Higher capital costs of grinding equipment and corresponding operating costs-especially with respect to energy consumption-are major factors that continue to stimulate interest in grinding control.Grinding circuit control strategies depend upon the control objectives defined by the processing plant and are subject to constraints such as: maintain final per cent solids within some range, do not transport steel ball s out of the discharge trunnion, or do not overflow or empty the pump box and so on. Constraints depend on the nature of equipment employed within the grinding circuit and may actually determine the characteristics of the control scheme. Typical control objectives are:1. Maintain final particle size at set point by ,a. manipulation of fresh feed rate with circulating load maintained by manipulation of pump box water addition rate, orb. manipulation of pump box water addition rate with circulating load maintained by manipulation of fresh feed rate, where the methodology utilized to accomplish either (a) or (b) is dependent upon equipment/circuit constraints such as the availability of a variable speed pump.2. Maintain circuit throughput at a maximum by,a. manipulation of fresh feed rate subject to constraints on final particle size and variables such as power draw, circulating load and mill overload.3. Maintain mill load at set point by a. manipulation of fresh feed rate subject to constraints such as on power draw.4. Maintain mill power draw at set point bya . manipulation of fresh feed rate subject to mill load constraints. Often, a grinding control objective is dictated by the recovery vs fineness-of-grind characteristic that exists for downstream separation circuits. When recovery is relatively insensitive to size, maximum throughput in the grinding circuit is advantageous.The purpose of this paper is to review control strategies for primary ball mill grinding circuits, rod mill/ball mill grinding circuits and semi-autogenous grinding mill circuits. Primary sensors employed are highlighted and modern trends are documented briefly."

Jan 1, 1989

The Discrete Element Method (DEM) is a powerful tool for analysing the flow of charge, the energy consumption and the pattern of energy utilisation of a SAG mill. With the development of laser scanning measurement, the detailed internal working surfaces of a SAG mill can now be included in DEM models. Using scanned results for new and worn shell liners for a 32? (9.75 m) SAG mill, it is shown that the feed and discharge lifters have significant effect on the flow of the charge introducing significant threedimensionality. The effects of the resolution accuracy of liner geometry and the lower cut-off of the rock size distribution are explored. Finally, using a matched new and end of life worn liner and operating conditions taken from site surveys, the effect of wear on charge motion, distribution and energy utilisation are evaluated.

Jan 1, 2012