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By W. Haibei, Lei. Z., Z. Bangsheng, W. Yufang, J. Kaixi

In 2007 output of zinc was more than 3.71 million tons in China. Some new projects have finished FS and several new zinc plants are building now. In recent ten years it happened great changes in zinc industry. For zinc concentrates one pressure leaching plant was built with capacity 10,000t/a and at least four companies are carrying out FS or engineering design now. Direct atmospheric leaching will put into used in China in 2008 with capacity 100,000t/a. It is estimated that until 2010 the output of direct leaching will be 400,000t/a.

Jan 1, 2008

By W. H. Hodgson, A. R. Preston

"Improved rail production techniques provide new options for the rail user. Steelmaking improvements offer tighter composition control, lower oxide and sulphide counts, greater control of segregates and freedom from hydrogen problem s. New ultrasonic, laser and eddy current equipment gives printout information on surf ace flatness, straightness and internal condition. These have come along at a time when dramatic changes have occurred on the rail heat treatment scene. Rails can now be deep hardened on or offline in ways which should eventually result in a complete rewrite of the world's specifications. Rails of simple composition can be produced in the hardness range 2801400 BHN as required. The rail user can choose the hardness within this range according to requirement without the necessity for any step changes in the process routes.It is suggested that this is the pattern f or the next decade.IntroductionRails have been the subject of very slow improvement over many years but developments gathered momentum in the early seventies. Recent improvements in quality and properties have provided dramatic increases in rail life under the more severe service situations. Rail profile grinding, lubrication and other track improvements have greatly added to expectations of even longer life. All of this, coupled to even newer mill heat treatment developments, tilt both technical and economic advantages away from tradition to the point where specifications will need to be rewritten so that railroads can take full advantage of these new products."

Jan 1, 1988

By T. G. Phillips

"This paper gives an inside look at a bulk terminal and describes the preparations that must be made by a company in developing such a terminal and its position in today's traffic pattern. The following headings cover the subject material: (a) Traffic pressures, their detection and measurement, (b) position in the traffic flow -selection of site, (c) transportation connections -present and possible future routes, (d) engineering studies and costs, (e) contracts, the basic material for insured traffic, (f) financing, (g) budgetary control, (h) development of new techniques, (i) growth into new cargoes or cargo-handling methods and (j) consolidation."

Jan 1, 1968

By D. E. M. Plaumann, B. S. Fee, R. D. Hansen, R. R. Klimpel

"This paper briefly summaries the status of a recent program aimed at identifying new chemistry for use as sulfide mineral frothers and collectors. The background motivation and planning behind this work is given along with the general families of chemical structures synthesied and studied in detail followed by typical flotation application results in various laboratory and plant scale tests. Flotation testing to date has been very encouraging with often improved recoveries of certain minerals and improved pyrite selectivity being observed over commercially available reagents. In addition, in some cases, the dosage and lime requirements of these new collectors are significantly less than that associated with standard sulfide mineral collectors. INTRODUCTIONFroth flotation is one of the most widely used and economic means of concentrating metal sulfide ores. There are numerous reference books that have been published on the chemical aspects of flotation [e.g., ref. 1-7] which are based on studying the influence on selected minerals of chemical structures that have been used commercially for many years. In fact, almost 98% of the volume of flotation collector and frother reagents used at the industrial level today were known and manufactured in some form 25 years ago [8]. There are many reasons for this lack of significant new flotation reagent development [9] including the general utility and relative cheapness of existing collectors such as xanthates and existing frothers such as the alcohols and glycol ethers. Another reason is the inherent complexity of the flotation process itself coupled with highly variable and difficult to standardize feed materials. This environment makes reliable reagent comparisons difficult and seriously limits the use of theoretically based chemical structure studies to predict new or optimal reagents. In addition, the higher cost of specialty flotation reagents demands that their performance attributes be significantly greater than that achieved with existing all-purpose commercial reagents - something often difficult to prove in practice."

Jan 1, 1988

By Y. -B. Kang

New databases are being developed to provide the capability to evaluate the suitability of present and potential new Mg alloys for automotive applications through cost-effective calculations. An extensive and complete thermodynamic database is being prepared for Mg alloys formed from among 25 present and potential alloying elements. The database is being developed by critical evaluation, modeling and optimization of available phase equilibrium and thermodynamic data. It contains model parameters giving the thermodynamic properties as functions of temperature and composition. Using the FactSage thermodynamic software, users can access the database to calculate the amounts and compositions of all phases at equilibrium at any temperature and composition or to calculate any phase diagram section in multicomponent alloys, to follow the course of equilibrium or non-equilibrium cooling, to calculate corresponding heat effects, etc. A database of densities and lattice parameters of Mg alloys and intermetallics (as functions of temperature and composition) is also being developed in order to permit the calculation of volume changes during cooling and phase transformations, c/a ratios of the hcp phase, etc.

Jan 1, 2006

By G. S. Cole

By 2025, the U.S. automotive industry will have to average 54.5 mpg (4.3l/100km) Corporate Average Fuel Economy (CAFÉ). While new/improved powertrain technology (turbocharging, electrification, diesels, transmissions and stop/start) will be critical, it is estimated that 25-40% of the new CAFÉ standards will require significant mass reduction, and lightweight structural materials will be required. This presentation examines vehicle mass reduction based on new developments in manufacturing automotive structures and components using light metals (aluminum and magnesium), conventional heavy metals (iron and steel), polymers, and carbon-fiber reinforced polymer composites. Components that used to be sand cast or pressure die cast provided minimal fatigue strength and ductility. But greater mass reduction uses more light metals in structural applications. They require eliminating porosity and inclusions to improve ductility and fatigue strength. Improved casting processing, with vacuum die casting, counter pressure and squeeze casting, and new forging and extrusion applications are being developed for this purpose. New grades of ultra-high strength steels can be made thinner, and save over 1/3 the mass vs conventional mild steels. But more complex and expensive processing, such as hot stamping and in-mold quenching, is required. Most engine block structures have migrated from grey cast iron to aluminum over the past 40 years. But compacted graphite cast iron has higher strength at high combustion temperatures and pressures so that high powered engines can be smaller and even lighter than aluminum. Assembling a range of lightweight materials into vehicle structures requires specialized assembly techniques, including sophisticated structural adhesives that can mitigate vehicles’ unique corrosion environment. The presentation will conclude with discussing lightweighting strategies of Asian, American and, European marques and the materials, component designs and assembly techniques used to achieve 2025 CAFÉ.

Jan 1, 2016

By J. D. Galloway

The mining industry of British Columbia continues to grow steadily in importance. The gross value of the production in 1925, sixty-two and a half million dollars, was a record, and ali indications point to the 1926 output registering a still higher figure. In an industry such as mining, where production means the depletion of known ore reserves, the discovery and development of new 'ore-deposits is of the utmost importance. To maintain and increase production, steady development is essential. In this respect, the record of the last three years in British Columbia mining is most satisfactory, as in this period more real development has been carried on than in any similar period in the history of mining in the Province. Prospecting, or the search for new ore-bodies, has also been fairly active, but comparatively few important new discoveries have been reported in the past few years. The mineral output of British Columbia consists of Iode minerals, coat and coke, and building materials. In 1925 the value of the output of these three classes of products was, respectively, about 46, 13, and 3 million dollars. The industry as a whole embraces the mining of these materials, and the treatment and manufacturing processes involved in preparing the various products for the market.

Jan 1, 1926

By J. A. Bossert

"In 1957, the Department of Mines and Technical Surveys (now Energy, Mines and Resources Canada) issued their first certificate for a fire-resistant conveyor belt. The testing procedure used was a combination of those used in the U.S.A. and the U.K. Subsequently, certification was granted to fire resistant electric cables (1974), fire-resistant mine duct material (1976) and fire-resistant hydraulic fluids (1978).Until recently, the testing procedures were copied from either the U.S. or the U.K. However, since the founding of the new Canadian Standards Association (CSA) Steering Committee for Electrical/Mechanical Mine Safety in 1981, these requirements have come under the close scrutiny of new CSA technical committees who will attempt to adopt or change the existing procedures to meet Canadian needs. This paper outlines the existing test requirements and attempts to predict how they will appear after ""Canadianization"" by the CSA committees.IntroductionFires in underground mines have always been considered more serious than in other locations because of the confined space and limited atmosphere. A fire can make escape difficult or impossible if it is blocking all of the routes to the surface. Also, the products of combustion from an underground fire can asphyxiate anyone not having self-contained breathing apparatus.In an underground coal mine, the consequences of a fire can be even more serious because of the presence of methane and coal dust in the atmosphere (which can explode) and because the coal itself is combustible.For these reasons, the inspection authorities having jurisdiction over underground mine s in Canada are quite concerned about the flammability of any materials that are used in quantity in the underground environmentAs early as 1957, the Canadian Explosive Atmospheres Laboratory (CEAL) was asked to certify conveyor belting as fire-resistant. This is because many miles of this material are used in underground mines in Canada and, as it generally travels through the mine, it is a perfect vehicle for spreading a fire."

Jan 1, 1982

By Esau Arinaitwe

The most extensively used methods and approaches for characterizing and selecting frothers for plant application are based on measurements in clean water in the absence of solids and without consideration of physicochemical factors that are known to influence the properties and behavior of practical flotation froths, and hence metallurgical performance. These factors include aquatic chemistry, collectors, modifiers, particle shape and size, and pH. Understanding interactions between these factors and the role and relevance that they play in characterizing frothers and froth zone properties will greatly aid in the frother selection and evaluation process. Such an understanding will also greatly enhance the ability to create frother solutions that are sufficiently robust to plant variability (such as mineralogical, comminution, operational, physical and chemical). This paper reports results of a “systems approach” study designed to probe ways in which physicochemical factors a) influence frothing and bubble size in 2- and 3-phase systems, and b) confound correlation of fundamental measurements with flotation outcome. The concepts and insights gleaned from fundamental frother studies, together with empirical laboratory flotation tests and a thorough understanding of plant needs and challenges were used to develop and implement customized frother formulation at a Cu-Mo flotation plant. Plant metallurgical data and qualitative assessment of froth zone properties showed that a frother formulation developed using the approach described here provided marked improvements in froth characteristics (mineralization, mobility, stability, persistence). These improvements resulted in better circuit control and significant performance advantages, such as improved coarse particle recovery, without detrimental downstream effects. INTRODUCTION Successful recovery of value minerals of sufficient grade via the flotation process requires selective manipulation of the value minerals to render them hydrophobic using collectors and modifiers. The hydrophobized minerals then attach to air bubbles and the mineral-bubble aggregates are selectively transported through the froth zone into the launder. Frothers play a critical role in froth formation and more importantly in achieving and maintaining desirable froth characteristics (for example, stability, mobility, persistence) that are essential in facilitating the selective transport and recovery of value minerals. Fundamentally, frothers contribute to the transient stability of thin liquid films and so aid in reducing bubble coalescence rates in the pulp and froth zones, thus maintaining the small bubbles required for efficient bubble-particle attachment. Invariably, the action of frothers at the liquid/gas interface in the pulp and froth zones impacts bubble stability, water and solids transport to the froth, which in turn impacts froth mobility, froth carrying capacity, and the concentrate grade. Consequently, selection and evaluation of frothers for flotation plants requires careful consideration of the frother type, though the choice is limited to only two main classes of compounds in terms of fundamental chemistry (short chain alcohols and polyglycols). Even with the selection of what is thought to be the best frother for a given application, practical knowledge of the froth zone and experience in controlling its properties is essential for maximizing metallurgical performance.

Jan 1, 2019

By R. Liu

As Building Information Modeling (BIM) becomes widely adopted by the construction industry, it holds undeveloped possibilities for supporting Facility Management (FM). Some FM information systems on the market claim to address the needs for FM requirement. However, the question of whether the functionalities provided by the current BIM-based FM software companies are those actually required by the FM Professionals still need to be answered. The data is required by FM professionals in the operation and maintenance phases of facilities and type of maintainability problems that frequently occur, which can be solved early in design phase, have not yet been addressed. The aim of this paper is to clarify the frequently occurring maintainability problems and to investigate the potential areas that can use BIM technology to solve the maintenance problems in early the design phase. A survey was conducted to collect perspectives from the industry practitioners for the maintenance problems and their frequency. The survey results indicated that maintainability considerations should be taken into consideration during the facility design phase. The results also address the perceived areas by practitioners that need maintainability consideration in design phase.

Aug 1, 2013

By Maria Agostina Cinellu

Some aspects of the reactivity of the two different kinds of gold(III) oxo complexes [Au2(N,N)2(?-O)2][X]2 [N,N = 2,2'-bipyridine (bipy) (1), 6-alkyl-2,2'-bipyridine (bipyR) (2), R = Me a, CH2Me b, CHMe2 c, CMe3 d, CH2CMe3 e] and [Au2(C,N,N)2(?-O)][X]2 [HC,N,N = 6-benzyl-2,2'-bipyridine (bipyR') (3), R' = CHMeC6H5 a, CMe2C6H5 b] (X = BF4, PF6) have been studied. Treatment with water converts the unsubstituted bipyridine complex [Au2(bipy)2(?-O)2][PF6]2 (1) and the cyclometallated derivatives [Au2(C,N,N)2(?-O)][PF6]2 (3) into the water soluble monomeric hydroxo species [Au(bipy)(OH)2][PF6] (4) and [Au(C,N,N)(OH)][PF6] (5), respectively. These hydroxo species, likely the intermediates in the formation of the oxo complexes, are quantitatively reverted to the latter ones by reflux in anhydrous solvents. Both kinds of oxo complexes react with PPh3 to give OPPh3, the gold(I) complex [Au(PPh3)2][PF6] and the free bipyridine ligands. The reaction of the dioxo complexes [Au2(bipyR)2(?-O)2][PF6]2 (2a, 2b, 2c, 2e) with different alkenes gives the unprecedented alkene complexes [Au(bipyR)(?2-alkene)][PF6]. The styrene adduct [Au(bipyip)(?2- CH2=CHPh)][PF6] (7) (bipyip = 6-iso-propyl-2,2?-bipyridine c) has been characterized, inter alia, by X-ray diffraction analysis. Organic products arising from olefin oxidation are also found in the reaction mixture.

Oct 1, 2003

By H. W. Fleming

In 1955, the results of a regional, geological interpretation of the northern portion of New Brunswick were used as a basis for selecting, for intensive exploration, three areas in which structural and stratigraphic conditions were believed to be favourable. Airborne electromagnetic work, in one of these areas, provided the justification for acquiring the Murray group. Even though the initial results were discouraging, this geological interpretation, combined with the fortuitous discovery of cop• per-bearing float, was sufficient reason for carrying out further work using geochemical methods. This work finally resulted in the discovery of the Murray massive-sulphide deposit, after about eighteen months of coordinated exploration on the property. While this deposit is a typical New Brunswick-type base-metal occurrence, extensive leaching has produced a fossil gossan that rendered it an elusive target for exploration techniques of limited penetration Full credit for localizing the target area is given to the geochemical techniques, but geophysical surveys were needed to provide the necessary

Jan 1, 1961

By R. H. McCorkell

"Sample drops were evaporated on Lexan disks on which fission tracks were etched and counted after neutron irradiation. [U] = 0.01 ppb could be measured. This method is rapid, cheap, simple and accurate when sufficient control and checking is possible, but several types of error were encountered in its use, the natures and sources of which were investigated but not always determined. The most troublesome were ""annealing"" processes which sometimes altered the fission tracks so that they were not fully revealed, or acquired varying appearances, after etching. Several different annealing processes seemed to exist and seemed to be produced by alteration of the Lexan surface by dissolved components in the solutions and, perhaps, by radiation and local heating during neutron irradiation. The appearances of the etched tracks varied with the natures of the droplet solutions even when annealing appeared to be absent, and for this reason, standards are best prepared by additions of known amounts of U to sample solutions. Contamination of sample droplets by U-containing dust from the air is best avoided by preparing the disks away from areas where other U-analysis is being carried out.IntroductionFission tracks are regions of radiation dam age produced in solids by the fission of atoms such as 235U. They can be enlarged to sizes visible through optical microscopes by etching surfaces through which they pass with solvents in which the solids are slightly soluble. A sample to be analyzed for U may be placed against a film of a solid of negligible uranium concentration (the track detector) and irradiated with thermal neutrons in a nuclear reactor to fission 235U. The track detector is then etched and the number of tracks per unit area, ?, which is proportional to the uranium concentration of the sample, c, and the neutron do se, n, is found by counting through a microscope. Uranium in solutions ha s been measured by evaporating drops on track detectors, irradiating, etching and determining the number of tracks per drop, T(2,3,4,5). Extensive test s of this method are reported here."

Jan 1, 1983

By Robert B. Parsons

"No Canadian or his family is likely to escape the effects of proposals for pension reform tabled on October 9, 1986 by Finance Minster Michael Wilson. New tax rules are proposed for Registered Retirement Savings Plans (RRSPs), company pensions, and other forms of retirement plans. Draft legislation is expected to be released in the first half of 1987.IntroductionOver two years ago on February, 15, 1984, Mark Lalonde, then Finance Minister, tabled two White Papers. The first, Action Plan for Pension Reform, proposed improvements to the public pension system and increases in the minimum pension benefits standards to be mandated by the federal government. Since then changes have been made to the Old Age Security, Guaranteed Income Supplement and Canada Pension Plan programs. Also, benefits provided under pension plans subject to the federal Pension Benefits Standards Act have been improved significantly.The companion paper, Building Better Pensions f or Canadians, proposed to standardize and, in many cases, improve retirement savings through private plans by revising the tax rule s. The tax proposals in the Notice of Ways and Means released by Finance Minister Wilson on October 9. 1986 implement, with modifications, the tax treatment of retirement savings originally proposed in the May 1985 budget in response to that second paper."

Jan 1, 1987

By Janne Karonen, Stephen Hughes, Mikael Jåfs, Jan Stål, Hannu Johto

End-of-life electrical and electronic scrap material attracts attention as a good opportunity for new value creation through efficient metal and energy recovery of such materials. On the other hand, the treatment of such wastes becomes important to avoid problems for society and environment. Treatment of such secondary raw materials faces multiple challenges due to their increasing complexity and evolving nature. Processing of these complex scrap materials together with recovery of a wide range of valuable metals with a combination of pyrometallurgy and hydrometallurgy using Outotec technology is discussed in this paper. One key consideration is environmental performance which needs attention when processing such complex secondary E-waste materials. Outotec has successful experience with commercial projects in the countries at the forefront of environmental and operational standards. INTRODUCTION Increasing attention has been drawn to the responsible processing of end of life Waste Electrical and Electronic Equipment (WEEE) as part of metals recycling, especially copper. It has been estimated that the amount of WEEE globally in 2016 was around the level of 46 Mtpa (Balde et al., 2017), representing a major disposal challenge but at the same time huge opportunity for resource recovery. The potential for increasing the recovery is high, because the official recycling rate of WEEE is in 2016 only 20% (Balde et al., 2017) and at the same time the estimated increase of the WEEE amount is between 3 and 5% per annum in the EU (Eurostat, 2019).

Jan 1, 2019

By A. J. Hyett

Due to the ongoing revolution in electronics and communications more cost-effective geotechnical instruments can be manufactured using digital technology. This new generation of digital instruments have embedded microcontrollers that provide highly accurate and reliable measurement of geotechnical behaviour in real world units that can be immediately interpreted. Digital measurements can be transmitted across existing mine-wide wireless communication networks, interfaced directly with infra-red enabled PDA?s or PC?s, and parsed to memory by low-cost data-loggers.

Apr 1, 2005

By Yongteng Dong, John P. Quinn, Bradford Wesstrom, Guikuan Yue

With increasingly low-grade copper ores being mined, it is difficult to handle growing concentrations of As, Sb, Bi and/or Fe in the whole flowsheet, especially during copper electrorefining. To better elucidate the effects of those impurities on the quality of cathode deposit and/or current efficiency, a detailed speciation study of the electrolyte under industrial conditions is required to quantitatively describe their distribution in the solution, thereby facilitating their effective control and removal. In the present study, a thermodynamic model of complicated iron-arsenic-copper-sulfuric acid electrolyte under industrial conditions was developed. The main species of those elements involved in the electrolyte were first identified, and their thermodynamic data were collected and critically assessed. Those data were then used to estimate the activity coefficients of species, and to calculate the equilibrium constants from 25°C to 70°C. The developed model provides a mathematical tool that is capable of quantifying the concentrations of free ions and complexes in terms of temperature and solution composition. Finally, oxidation-reduction potential measurements were employed to validate the model. INTRODUCTION In copper electrorefining, impurities like arsenic, antimony, bismuth and/or iron can partially dissolve in the electrolyte and accumulate gradually, and eventually cause problems such as bad cathode deposit (co-deposition with copper or mechanical inclusion from the floating slime), lower current efficiency, etc., which eventually increases the operating costs. The presence of impurities may substantially reduce properties of copper products such as conductivity, corrosion resistance, mechanical properties, and leads to more energy consumption (Schlesinger et al., 2011; Jafari et al., 2017). To remove these impurities, various methods have already been proposed and applied in industrial copper production, such as solvent extraction, ion exchange, chemical precipitation, absorption by activated carbon, etc. (Cunningham et al., 1997; Navarro et al., 1999; Toyabe et al., 1987). In addition, adding reducing agents such as sulfur dioxide and trivalent arsenic could also precipitate arsenic, antimony and bismuth from copper electrolyte, by changing the distribution of impurities with various valence (Braun et al., 1976; Xiao et al., 2007). The disadvantages of those methods include high energy consumption, serious contamination, lower selectivity and efficiency, and so on.

Jan 1, 2019

By H. D. S. Miller

"Artificial stope support has become an essential component of many underground mining operations. Because the use of cable bolts in open stopes is a relatively new concept, most support is still designed by trial and error or by rules of thumb. This often results in costly overdesigned support or inadequate support which leads to stope failure.This paper proposes guidelines to determine support requirements using the stability graph method. The stability graph method is an empirical open stope design technique that takes into account the key factors that influence stope stability. The factors for the design of a cable bolt support system include bolt length, bolt intensity and the original rock mass competency and can be estimated using empirically calibrated charts. The empirical charts were developed based on more than 60 case histories of cable bolting success and failure in Canadian open Slope mines.The concept of pre reinforcement and supp ort stiffness will also be discussed.INTRODUCTIONArtificial support, in the form of rock anchors, has become an important component of all underground mining operations because its stabilizing effect contributes to make underground workings safer. There are several types of rock anchors featuring different properties and having a variety of functions. This paper focusses on grouted cable bolt applications in large open stope mining. Such a support system may improve the competency of the disturbed rock mass to a point approaching the undisturbed rock quality by limiting joint movement and dilation. This results in more stable, possibly larger and, thus, more efficient production stopes."

Jan 1, 1989

By Simon Houlding

"The objective of Part J of this paper is to identify the limitations of the traditional modelling methods and to illustrate, by example, the potential for error created by their application to complex deposits and mining situations. Part 2 describes the evolution of new, proven technology which eliminates these deficiencies and provides precise and practical alternatives. These promote the use of realistic geological and mining shapes and eliminate altogether the rectangular approximations of traditional methods.The Case for Precision ModellingIt is not the intent of this paper to promote the benefits of computer modelling per se. It is assumed that these are recognized by the mining industry in general. The concern of Part 1 is to identify, qualify and quantify (where possible) the limitations of the tractitional modelling methods. In many instances these methods continue to be applied to complex geological and mining situations for which they were never intended nor designed. The source and magnitude of the resulting errors, conflicts and inefficiencies are not always obvious, however, they can have far-reaching effects on the efficiency and profitability of mining operations.The conclusions support a rapidly growing demand by industry for practical, precise modelling technology which eliminates the deficiencies and can be applied with confidence to evaluation, design, planning and control of mine production in all situations. Part 2 describes new technology which has evolved in response to these industry pressures and has already been successfully applied to complex mining situations. This new technology can aptly be described as appropriate technology for the 1990s."

Jan 1, 1991

By A. A. Sizikov, V. A. Sizikova

Key parameters to consider for any producer: bring down production cost and lead time; Lean production as a tool to achieve maximum efficiency; How to implement lean principles: discontinuous vs. continuous production (aluminum industry); About RUSAL: global top-three aluminum producer; Lean tools at use at RUSAL's production facilities; Pull system, Standardization of work, Just in time, Continuous improvement, Customer-Supplier relations, etc.

Jan 1, 2006