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By Kiran B. Chaudhuri, Michael Koch, Jorg Lema Patino

"Stricter pollution regulations together with other factors have stimulated interest in the modernization of the traditional sinter - blast-furnace lead operation. In this context, direct smelting methods have again come into prominence. Consequently, the Kivcet Lead Smelting Process, which belongs to this group, has attracted the attention of the lead producers of the world. The Kivcet Process offers the advantage that lead and zinc can be simultaneously recovered in a single furnace unit. KHD Humboldt Wedag A G, Koln, Federal Republic of Germany, has signed a contract with the Sociedad Complejo Metalurgico de Karachipampa of Bolivia for the delivery of a turn-key Kivcet plant, which is expected to be the first plant of its kind in commercial operation. This paper describes the design and expected operating data of the plant."

Jan 1, 1980

By G. R. Peeling

The Mining Association of Canada launched the Towards Sustainable Mining initiative in 2004. TSM's goal is to improve the mining industry's performance by aligning its actions with the priorities and values of Canadians. The initiative currently includes performance indicators for four areas: tailings management, energy use and greenhouse gas management, external outreach and corporate crisis management planning. Over the past year, the association has been designing a performance assessment and verification system for these performance areas, as its members prepare to move external verification of their performance in 2007. The initiative and its evolution, as well as the challenges faced in developing a verification system applicable to an entire sector will be examined.

Jan 1, 2007

By Tony Lipiec, Ian Orford

"A key part of plant design is the selection of the design tonnage which is the hourly tonnage target that the equipment selection is based on. Its selection is critical for ensuring that the nominal tonnage which is critical to the financial performance of the project will be met. With deposits being developed at lower grades, higher tonnages and a higher degree of hardness variability, it is essential to ensure that the design process selects the comminution equipment which will be able to deal with the impact of this ore quality variation.Ore hardness and its variance are key factors to be taken into consideration for the selection of the design tonnage. It is well accepted that for the nominal or name plate tonnage to be consistently achieved, it is necessary to base the design tonnage on a hardness value greater than the average ore hardness of the deposit to be mined. The question is how much greater should this design value be to ensure that the nominal tonnage is met to the satisfaction of the project financial model. Standard industry practice is to set the design tonnage by:1. Select an ore hardness percentile that is greater than the average ore hardness to be the basis of the nominal tonnage. Typically either the 75th or 80th percentile value from the data set will be selected.2. Selection of a design factor to multiply by for determining the design tonnage, i.e. the design tonnage = tonnage (based on the average ore hardness) multiplied by design factor.This paper discusses the selection of the design ore hardness through the use of modelling or the use of a design factor. It further shows the impact of ore hardness variance on the capacity of the process and its ability to meet the nominal tonnage. Insight is provided as to what ore hardness percentile value should be selected balancing the shortfalls of tonnage for ores harder than the design value versus the above target production achieved for ores softer than the design ore hardness."

Jan 1, 2016

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 Jie Zhu

Coal bumps are a special form of release of geologic strain energy that has already been one of the most dangerous hazards to underground mining safety in China. A number of coal-bump models have been developed to quantify coal failure under assumption that a bump is a kind of non-gas induced outburst. However, some technical experts in charge of micro-seismic and gas monitoring have found unusual gas emissions before and after bump, which suggests that it is possible for gas to trigger coal bumps. Considering the coal reservoir as geological body composed of the coal matrix and gas, a new model based on Lippmann?s bump model is proposed to understand the initiation of coal bumps. The redistribution zone from excavation of a roadway has been calculated and analyzed regarding its relation with mining depth. It is shown that high gas pressure may push the coal seam to overstep the critical state due to extension of the plastic disturbed zone, and this is harmful to the stability of coal seam. This model successfully explains the bump phenomena of the Xinzhouyao mine at shallow depth.

Aug 1, 2013

By J-F. Magnan, M-A. Thibault, R. Boulianne, C. Gauthier, J-P. Gagné, G. Dufour

During the production of aluminium in smelters, the anodes used in electrolysis cells have to be replaced frequently. Anode butts are usually placed on anode trays for transportation and cooling, a practice during which Hydrogen Fluoride (HF) is emitted in large quantities. Covers developed in 2000 by Alcoa Deschambault to fit on the anodes trays were implemented, resulting in significant reductions of HF emissions. However, the covers are expensive to maintain and use short-life consumable parts. In January 2004, STAS and Alcoa decided to develop a more efficient design of cover, with lower maintenance costs and no need for consumable materials (like soft cushions). This paper presents a summary of the work performed to develop the new design as well as a summary of the test results.

Jan 1, 2006

By Oscar F. Tangel

This paper outlines Canada's current status in world iron ore markets, and evaluates the prospects for the future. Estimates for the production, export and consumption of iron ore are given. Canada's major market will continue to be the United States, with the European Common Market countries, Japan and the United Kingdom also forming important outlets. The advantages held by Canada's major competitors in these latter three market areas are briefly discussed.

Jan 1, 1966

By Oscar F. Tangel

This paper outlines Canada's current status in world iron ore markets, and evaluates t he prospects for the future. Estimates for the production, export and consumption of iron ore are given. Canada's major market will continue to be the United States, with the European Common Market countries, Japan and the United Kingdom also forming important outlets. The advantages held by Canada's major competitors in these latter three market areas are briefly discussed

Feb 1, 1966

By M. Sakamoto

Copper foil is an indispensable material for Printed Circuit Boards (PCBs). PCBs in turn are essential elements of all electronic equipment today and thus important for our living in the new age of IT. The requirements from the copper foil market have lately been increasingly strict and diversified due to the rapid technical advancements in miniaturized high-density electronic equipment and highly integrated semiconductors. Tight control of thickness, metallurgical properties, surface morphology and characteristics is needed. In this paper, both electrodeposited copper foil for PCB and rolled copper foil for the flexible printed circuit board are discussed, and the recent technical developments in these copper foil products are reviewed.

Jan 1, 2007

By B. Burke

Magnesium and its alloys are attractive materials for use in automotive and aerospace applications because of the low density and good mechanical properties. However, difficulty in forming magnesium and the limited number of available commercial alloys limit their use. The present paper reviews the efforts to improve the attractiveness of magnesium through non-traditional processing, and presents preliminary results of current work on producing magnesium alloys via powder metallurgy P/M. P/M can be used to alleviate the formability problem through near-net-shape processing, and also allows unique chemical compositions that can lead to new alloys with novel properties. The feasibility of producing magnesium powder metallurgy products utilizing the industrially dominant process of mixed powder blending, uniaxial die compaction and controlled atmosphere sintering was investigated. An alloy composition based on the commercial Mg alloy AZ31 (3% Al, 1% Zn) was used to facilitate comparison to similar wrought products. The optimal processing conditions (compaction pressure, sintering time and temperature, and quenching temperature) were found to maximize sintered density and mechanical properties.

Jan 1, 2007

By Arnold R. Miller

Overview ? Vehicle Projects LLC (prime contractor) and the Fuelcell Propulsion Institute have developed the world?s first fuelcell locomotive. ? Principal applications are underground mining and tunneling. ? Because fuelcell vehicles solve the problem of underground emissions, mining is expected to be their first commercially viable market. ? The first year of a three-year project to develop a fuelcell mine loader is funded and underway.

May 1, 2002

By P. Radziszewski

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

Jan 1, 2007

By R. J. McLeod

"Grinding at Giant Yellowknife is done in two stages. The first stage consists of two ball mills in closed circuit will: mechanical classifiers, the classifier overflow goes to flotation. The tailings from this flotation circuit are separated into slime and sand portions, the slimes go to an additional flotation circuit while the sand portion goes to the secondary grinding mills.Milltronic automatic sound control units were installed on each of the two primary ball mills and put into operation September 3, 1966. After about two months adjustments to the control units the operators were taken off the grinding circuit on November 1, 1966. The operators duties were taken over by the automatic control units while miscellaneous work was taken over by the helpers in the mill. The labour saving by the installation is approximately $2250.00 per month.After a short period of operation it was apparent there was a slight change in grind. The screen analysis of the primary classifier overflows for the period May to August 1966 averaged 62.23% minus 200 mesh while for the period September to December 1966 averaged 62.0% minus 200 mesh. This is a slight coarsening of the grind. The change in the primary grind has manifested itself also in the screen analysis of the final grind. Before automation the final grind was 80% minus 200 mesh, while after automation it was 7 5% minus 200 mesh. A change of grind was also noted in the flotation concentrates. Before automation the screen analysis of the concentrates was 35% plus 200 mesh and 50% minus 3 25 mesh. A ft er automation it was 35% plus 200 mesh and 47 .5% minus 325 mesh. In other words the grind got coarser or perhaps we should say there was less overgrinding. Another significant change took place in the assays of the slime and sand portion of the primary flotation tailings. It was usual under manual control for the slime portion to assay higher in gold than the sand portion. The reverse is now true."

Jan 1, 1967

By W. G. Jeffery

"The mining and mineral industries have been, and remain, a major component of the Canadian economy. There are approximately 560 producing mining establishments of which there are some 130 metal mines and an equal number of non-metal mines, the balance being quarries for stone, sand and gravel. For 17 metals and minerals, Canada ranks within the top five as a world producer. There are 29 metallurgical plants. Employment in mining, smelting and refining was about 150000 in 1990. Mineral production, including coal, is about $20 billion. Exports up to the metal stage amount to $15 billion providing a positive trade balance of some $10 billion.The producing industry has a wide diversity of products. The companies range from small single mining operations to large multinationals. In terms of technology the industry has always been in the forefront of cost-effective practice, either using home-grown innovation or freely importing technology from around the world,The Mining Industry Technology Council (MITEC) makes an annual survey of the exploration and R&D expenditures of the senior mining industry that is the mining companies that are involved in mineral production from their existing mines. It does not include those companies solely involved in exploration using funds raised through equity sales.Table 1 shows the actual R&D and exploration expenditures as a per cent of sales. R&D shows a rising trend since 1988although the drop in value of output due to lower prices must be recognized as contributing to the increase. The point about this compilation is that the mining industry re-invests some 4070 of its sales in both exploration and R&D in order to sustain itself. Exploration for the renewal of metal inventories for future mining is a process unique to mining. It is not classified as R&D, and the necessity for this investment goes unrecognized by those who state that the industry does not do enough R&D."

Jan 1, 1993

By R. A. L. Drew, C. A. Rodríguez González, Caleym W. F.

This work addresses the need of new refractories for copper converters. Technological improvements and environmental regulations for chromium containing refractories have generated this need. Chemical interactions, mechanism of penetration and the effect of oxygen potential and temperature in the system Cu2S-FeS-SiO2-O2 are presented for two refractories: a burned magnesite chrome brick (typically used by the copper industry) and a chrome-free spinel direct bonded brick. The main difference determined in the refractory performance was the blister copper penetration resistance; burned magnesite chrome brick is penetrated while direct bonded brick is not. These results are very promising since blister copper penetration has been reported as the major cause of refractory wear. The results are explained in terms of refractory porosity and wetting characteristics.

Jan 1, 2004

By Changyoon Kim

Technological advances in mobile systems, such as smartphones and tablet computers, provide engineers with new opportunities to enhance the current facility management processes. Equipped with powerful system processors, touch screens, and wireless communication capabilities, mobile systems enable the experience of omnipresence of facility information. Building information modeling (BIM) also enables improvements in facility management. With an advanced data structure and visualization capacity, BIM can be used in numerous applications for facility management. This study aims to incorporate the strength of mobile systems and BIM in facility management. The proposed system, which utilizes smartphone technology, allows engineers to conduct facility management functions, such as maintenance planning, inspection, and assessment, irrespective of a user?s location. The integration of building information modeling in a system provides detailed visual information of the building components. A case study was conducted to verify the applicability of the mobile system in terms of the hardware functions, system design, and user interface. This proposed system, with its study results, provides a guideline as to how mobile systems can be effectively integrated with BIM for improved management of facility information.

Aug 1, 2013

By Hong Zhong, Shuai Wang, Gang Zhao, Lanqing Deng, Guangyi Liu

In this paper, three novel surfactants containing double reactive centers(-CONHOH and –CONH-), double hydrophobic groups were designed and synthesized as collector for separation of diaspore and aluminosilicate minerals, such as N-(4-(hydroxyamino)-4-oxobutyl)octanamide (HA-8), N-(4-(hydroxyamino)-4-oxobutyl)decanamide (HA-10) and N-(4-(hydroxyamino)- 4-oxobutyl) -dodecanamide (HA-12). The adsorption mechanism of N-(4-(hydroxyamino) -4-oxobutyl)alkylamides (HA) onto diaspore was also investigated by FTIR spectra, zeta potential measurement and DFT. The flotation results demonstrated that three collectors all exhibited superior collecting power to diaspore and selectivity against kaolinite and illite, and could effectively realize flotation recovery of diaspore from bauxite ores contained aluminosilicate minerals under neutral conditions. Moreover, HA-12 was a superior collector than other two collectors for bauxite separation. The results of XPS, FTIR spectra and zeta potential illustrated that at around pH 6.0, HA might chemisorb on diaspore surfaces through Al-O coordination bonds formed by binding its –C(=O)NHOH or –C(=O)NH– chelate groups with aluminum atoms on diaspore surfaces. HA’s unique properties, such as characteristic bond patterns onto diaspore surfaces, double hydrophobic groups, and intermolecular hydrogen bonds between neighboring HA molecules coated on diaspore surfaces, rendered it to be a superior flotation collector for diaspore.

Jan 1, 2016

By T Salman

The construction and use of the B.E.T. (gas adsorption) apparatus is described. Examples are given for the determination of large and small surface areas using nitrogen and krypton. Introduction A NY study of the milling of ores from crushing to grinding, classification, and concentration and finally dewatering of the products involves solid particles which are either in contact with a gas or a liquid phase. The surface area of the solid and its characteristics constitute important parameters in all mineral dressing operations. The success of any particular operation is dependent on the interaction of the surface of the solid particles with the gas or the liquid phase. Particle size and specific surface (surface area per unit weight) continue to be important parameters in the flotation research associated with the adsorption of collector molecules or ions on mineral particles, as in the early years of mineral dressing research (1). In order to understand the mechanism of the flotation process, it is essential that the surface properties of the adsorbent be known.

Jan 1, 1965

By A. J. Hyett, R. D. Reichert

"A laboratory and field research program was conducted to investigate the major factors influencing bond capacity of grouted cable bolts. The results indicate that cable bolt capacity most critically depends on the grout uniaxial compressive strength (UCS), the radial confinement, and the embedment length.In the laboratory &apos;split-pipe&apos; tests were conducted using P VC, aluminum and steel pipes to provide radial confinement, and field test sites were chosen in granite, limestone and shale rock masses. For both datasets higher capacities were obtained under conditions of higher radial confinement. A correlation between the two was obtained through a comparison of the radial wall stiffness of the laboratory pipes with that of the field boreholes as measured using a high pressure dilatometer. Cable bolt capacity was found to increase with embedment length though not in direct proportionality.The use of low water cement ratio grouts (<0.40) can increase cable bolt capacities by 50% to 75%. This effect is maximized under conditions of high radial confinement. However, the use of super thick grout paste (0.30 and less) may be both impractical and undesirable, first because of their limited pumpability and second because of their inconsistency in strength. Grouts with a water cement ratio of between 0.35 and 0.40 are recommended for practical cable bolt applications."

Jan 1, 1992

By Jin Li

The tensile properties and microstructure of AZ91 Mg alloy before and after equal channel angular extrusion (ECAE), and the fracture behavior during tensile testing for as-extrusion and ECAE AZ91 were investigated. The alloy was performed ECAE from one to eight passes at 498K. The elongation decreased with the pass number increasing after ECAE. Grains were refined, partial coarse ß-Mg17Al12 phase fell to pieces, fine ß-Mg17Al12 precipitated in the AZ91 Mg alloy after ECAE. During tensile test the a-Mg/ ß-Mg17Al12, a-Mg/Al8Mn5 interface and the grain boundaries in a-Mg matrix acted as the crack initiation sources. The frequency of micro-cracks at the a-Mg/ß-Mg17Al12 interfaces and grain boundaries increased after ECAE, which accelerated the growth and coalescence of the micro-cracks during tensile test and resulted in the decrease of elongation of AZ91 Mg alloy by ECAE.

Jan 1, 2006