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By A. Ignatieff

"THE WORLD'S coal resources represent the largest component of non-renewable energy resources. Coal is now regaining Its position following a temporary decline, particularly in North America during a period of about a quarter of a century. This period provided the opportunity to improve both surface and underground mechanization, thereby increasing the productivity and improving conditions for humans in the mines. Similarly, in preparation, improved cleaning of coal from various impurities including sulphur was achieved, to meet the more demanding requirements for coking coal. Progress was also made in combustion, particularly related to the reduction of pollution. Canada participated in most of these developments, despite the country's strong commitment of the use of hydrocarbons during this period. _Bearing in mind the vastness of this land (3.85 million sq. miles) by comparison with countries like U.S.A., U.S.S.R., and China, Canada's coal resources estimated to date are not large and they are scattered. The original evaluation of 1913 estimated the ""reserves"" from seams over one foot in thickness and a limiting depth of 4,000 ft at 1.2 trillion metric tons. D:. ~.R. MacKay, in his evaluation for the 1946 Royal Commission on the coal industry, known as the Carroll Commission, reduced the ""reserves"" to 99 billion short tons. The increased knowledge now available would indicate that the 1913 estimated was too liberal and the 1946 estimate too conservative but both were closer to a resource than to a reserve designation. Some adjustments of Dr. MacKay's estimates were made in 1970 by B.A. Latour of the Geological Survey of Canada and L.P. Chrismas of Energy, Mines and Resources Canada (EMR). In the last decade the Alberta Energy Resources Conservation Board has developed its own methods of evaluating coal resources and reserves. A methodical approach of exploration and evaluation was carried out by Saskatchewan jointly with the federal government of the lignite resources of Southern Saskatchewan. A similar joint program is in progress in Nova Scotia. Meanwhile, the industry itself carried on an extensive exploration program on the outcrops of promising projects in the Inner Foothills belt of Alberta and British Columbia in preparation for surface mining on a very large scale, with some development of hydraulic mines. All these activities have been reflected in the increase of the country's resources and reserves, which now fortunately are separately defined. In 1979 EMR issued Report E.R. 79/9(1>; the data were developed in 1978 and provided to the World Energy Conference Organization<2>. In 1980 the World Coal Study (Wocol), an international group that included Canada carried out a study which updated the W.E.C. data, indicating some reduction of the 1978 figures; quantities were reported in million metric tons of coal equivalent (C.E.)*(Jl."

Jan 1, 1985

By M. F. Gallerneault, V. Fallah, A. Howells, W. M. T. Gallerneault

"The occurrence of recrystallization in cold-worked aluminum sheet during the brazing process leads to loss of strength, an inhomogeneous grain structure and reduced corrosion resistance. AlMgScZr alloys are known for their extraordinary recrystallization resistance due to the influence of Sc and Zr addition on their microstructure. Here, we investigate the effect of alloy composition (i.e. Mn, Mg, Sc, Zr content), cold-roll reduction and pre-aging treatment on the recrystallization behavior of cold-rolled sheets at brazing temperatures typically used during the manufacture of heat exchanger units. The analysis of recrystallization behavior is carried out through microstructural characterization and the results are compared with the behavior of a commercial, AA3xxx-based heat exchanger alloy.INTRODUCTION Control of recrystallization is of critical importance during brazing, which is a widely-used joining technique for aluminum alloys in aircraft structures (Heinz, 2000) and automotive heat exchangers (Miller, 2000; Marshall, 1993). Due to excessive local heat at brazing temperatures, the cold work texture of aluminum alloys in the cold-rolled sheets may undergo a local recrystallization process (Marshall, 1993). This leads to the formation of an inhomogeneous microstructure and thus anisotropic mechanical properties (Miller, 2000) and low corrosion resistance (Marshall, 1993) across the sheet. X800, a commonly-used Al-Mn alloy series for automotive heat exchangers applications, has been developed specifically for a higher strength as well as an enhanced corrosion resistance as opposed to the traditionally-used AA3003 alloy (Marshall, 1993). X800 alloys, however, exhibit a low recrystallization resistance at normal brazing temperatures, i.e. 590°C. In contrast, Al-Sc-Zr alloys have been shown to exhibit an extraordinary recrystallization resistance at such temperatures (Riddle, 2004) while also being corrosion resistant and possessing a high room-temperature strength (Fuller, 2002). This has been shown to be due to the formation of coherent, nanoscale Al3(ScZr) precipitates that effectively impede grain boundaries while also exhibiting very slow coarsening kinetics at high temperatures (Riddle, 2004; Jones, 2003; Ocenasek, 2001). In this study, we analyze the recrystallization behavior of X800 alloys under brazing conditions through introducing Sc and Zr into the system as well as varying the Mn and Mg content. The effect of processing route is also studied by introducing a pre-aging stabilization treatment as well as varying the cold-roll reduction prior to the final brazing anneal."

Jan 1, 2018

By Agbo Chima

Low-lying sections of open-pit mines accumulate water, especially during the rainy seasons, preventing access to resource-bearing areas. To sustain mining operations, the water must be lifted out of the flooded pits at a high flow rate using pumps. These pumps need to be mobile so that they can be removed during drill-and-blast operations. Most mobile pumps rely on diesel engines with high maintenance requirements. A special pump design was developed to address the unique needs of open-pit mining while making the dewatering process more sustainable. Using the target flow rate and head data, an efficient pump was designed, encased, and deployed in the open pit. A variable speed drive (VSD) was installed in a protective skid so that the pump could be tuned to match the preferred flow rate at any point during its operation. This system was tied to the national electrical grid instead of being powered by diesel pumps, which reduced the carbon intensity per kilowatt-hour. The high availability, low maintenance requirement, and greater reliability reduced the use of spare parts, the fuel consumption, and the logistics associated with operating the pump. This further reduced the carbon footprint of the dewatering process. This paper provides some of the two-year performance metrics for a deployment in West Africa. With a focus on availability, maintenance costs, average cost per volume lifted, and carbon footprint, this encased pump system is compared to the diesel-driven pumps that it aims to replace.

Jan 1, 2023

By D Marshall

The sub-level blasthole benching method of mining has been proved to be economical at Willroy Mines. How-ever due to the nature and attitude of the wall rock, this method is susceptible to serious hanging-wall dilution of the ore. Attempts to solve the dilution problem by various means were not satisfactory until long Stressteel bars were employed as rock bolts. The adoption of this de-vice does not require any special skill, and has become routine in the under-ground operation. Since the inception of this method, the dilution of the ore has been greatly reduced and the ov1!r-all costs of controlling this dilution are much lower. INTRODUCTION T HIS is a report describing the successful use of long Stressteel bars as rock bolts in preventing l1anging-wall failure and consequent dilution in open stopes. Willroy Mines Limited is located (Figure 1) near the town of Manitouwadge, Ontario, approximately l1alf-way between Sault Ste. Marie and Port Arthur.

Jan 1, 1963

By H. H. Wober, P. J. Morgan

"The proposed classification of ore reserves based on geostatistical and economic parameters is designed to be used as a communication tool to identify for investors, bankers, and financial analysts the degree of risk associated with a specific class of ore reserves. The class designation identifies the degree of accuracy of the estimates for tonnage and grade of annual production volumes of ore. It thus enables decision makers to quantify the risks and uncertainties inherent to the ore reserve in achieving over-all economic goals and annual financial objectives.IntroductionDuring the evaluation, in 1980, of the Creede silver deposit in Colorado, U.S.A., as a potential bulk mining project, the authors were faced with the problem of conveying to senior management the risks and uncertainties that are implied by using common or conventional classification systems to categorize ""ore reserves"". The estimated numbers for tonnages and grade of the projected ore reserves represented the only entry for future revenue from the project. It was, therefore, necessary to convey to management the level of risk associated with those numbers when implementing further stages of development, and to convey what impact significant differences would have on the profitability of the project. The desire to quantify these risks led to a revised definition of ""ore"" and to a re-examination of the classification system of ""ore reserves"". Traditional methods for estimating tonnage and grade of reserves do not include a quantification of the errors of these estimates. The advent of geostatistical methods made this quantification possible. The proper application of geostatistical methods, with adequate geological input and a reliable set of sample data, is essential to its validity.Others have proposed a classification of ore reserves based on geostatistical parameters. Diehl and David (1982) recognized ""that concepts of proven, probable and possible have to be linked to the production rate or time horizon"". Royle (1977) had also addressed this problem. Forsyth (1987) pointed out that bankers are concerned with ""the probability that the variability will fall within a certain degree of accuracy"" especially for grade estimates, and would like to see grades expressed together with the error of the estimate at the 950Jo confidence level."

Jan 1, 1993

By Kevin C. Milne

"The solution of problems associated with development of a sour gas reserve will be of increasing importance in tl1e next few years if gas export is approved •by the National Energy Board. The purpose of this paper is to review briefly the history of the Carstairs gas field, and tCI describe in a general manner the reservoir, and the producing and processing facilities.HISTORYThe Carstairs gas field was discovered in April 1958 when the discovery well, Home Carstairs 10-17, was successfully completed as a gas well in the Elkton member of the Turner Valley formation. Geo-graphic location of the field is shown in Figure No. 1. Note that the field is about five miles west of the town of Carstairs, Alberta, which in turn is about 40 miles north of Calgary. Drilling subsequent to the discovery well resulted in three addition-al producing wells and one dry hole during I.958; two producing wells during 1959; and one producing well and one dry hole during 1960. Thus, seven producing wells and two dry holes have been drilled in the Carstairs field to date.In November 1959 a 12-section block in the Carstairs field was unitized on a surface acre basis. Mean-while, in June 1959, operators in the field executed an ""Interim Plant Agreement"" that provided the money needed to start construction of a joint venture processing plant and gathering system. Construction of the plant and gathering system was completed in February 1960."

Jan 1, 1960

By Jae-sang Ahn

As the amount of construction information used in the growing construction field increases, the importance of efficient construction field management has been growing. Therefore, construction industry have been tried to introduce and conjugate various software and IT technology such as PMIS, Web Camera, RFID, GPS, PDA. However, existing IT technology especially PMIS have not been performed systematically because of difficulty of real time information collection and decision-making from the insufficient handy equipment. These problems make construction manager cannot efficiently respond to diverse condition occur in construction sites. In addition, after the completion, individual who use PMIS have to move another site and use another system so than cannot use information from previous sites. On the other hand, development of IT technology transmute PDA phone for text-based work like schedule management, internet research to smart phone for network based multimedia service. In other words, smart phone is not just IT equipment but new way for overall industry and it can satisfy the demand IT technology on construction sites. Therefore, the purpose of this study is introduce mobile based individual unit PMIS system using cloud computing and SNS which is in development progress. It is expected to be possible to collect and record the real-time information that occur at the site and make rapid decisions based on the recorded information, by converting the office works that are managed based on the site PC or Web, if the site management system that is based on the smart phones and Cloud computing that will be constructed through this research are utilized. After this study, it is necessary to research about interwork with project unit PMIS system and test on real construction site.

Aug 1, 2013

By A. J. Russell

"This paper investigates why it is critical for a mine to accurately determine thermal rock properties and virgin rock temperatures. Theoretical simulations of deep mining production zones have demonstrated that thermal conductivity (k), virgin rock temperatures and specific heat (cp) significantly impact rock heat predictions which can be the dominant component of a mine’s heat load. Natural variability in these factors showed that realistic errors can have a significant effect on mine heat loads. This can ultimately affect miner safety and introduces risk to the viability and sustainability of a project. INTRODUCTION Accurate heat load determinations are critical to ensure that underground working conditions are maintained within legislated and mine specific parameters to safeguard the safety and productivity of employees. Underpredicting mine heat loads will result in hot underground conditions, which risk the health and safety of employees, reduce the productivity of employees or stop production if legislated temperatures in working areas are exceeded. Overestimating mine heat loads will result in increased capital and operating costs reducing the viability of the project. Over- or under- predicting the heat load for a project will increase the project risk. Heat sources in a mine can broadly be broken into two categories. These two categories are defined by Hemp and Rawlins (2014) as natural and artificial heat sources. Those sources which depend on the size, location and depth of the mining areas are defined as natural heat sources, whereas those heat sources which are a result of the actual mining activities are defined as artificial heat sources. Autocompression, or the conversion of potential energy, to enthalpy is an important consideration when determining the air temperature in the mine and its interaction with natural and artificial heat sources. It is documented by Jones (1985) and Hemp and Rawlins (2014), that the heat flow from rock in deep mines can dominate other heat sources; information from BBE’s archives show that this is between 40% and 60% of the total heat load. They also point out the importance of accurately measuring both the thermal rock properties and virgin rock temperatures (VRTs) for determining and planning the ventilation and refrigeration requirements for a mine. Both of these texts cite multiple methods for calculating the heat-flux and ultimately the heat load for the different working areas in a mine. All of these methods demonstrate that the heat flux and heat load will increase proportionally with increased thermal conductivity (k), specific heat (cp) of the rock or mineral, and VRT depending the area of the mine or mining method."

Jan 1, 2019

By Yves Pépin, Sylvain Lefebvre, Dimitrios Filippou, Guillaume Hudon

"Titanium dioxide pigment plants using the so-called “chloride process” produce considerable amounts of chloride waste, which contains predominantly iron chloride. In most cases, this waste is dissolved in a weak hydrochloric acid solution and then neutralised. The metal content of the waste is dumped as hydroxide sludge, while its chloride content is lost in an effluent.Rio Tinto Iron & Titanium has developed a new proprietary process whereby pure metallic iron and chlorine gas are recovered from chloride waste by electrolysis. This process uses a two compartment cell separated by an anion exchange membrane to prevent iron cycling between its trivalent and divalent valence. The cathode is made of titanium Grade 7, while the anode is a dimensionally stable one of the type “metal–mixed metal oxide” (MMO) for the evolution of chlorine gas. The catholyte is concentrated and pH-adjusted iron-rich chloride solution originating from chloride waste. The anolyte is recirculating solution containing alkali or alkali earth chlorides such as MgCl2, NaCl, etc. Current efficiencies above 90% can be achieved at temperatures about 80°C using catholyte solutions almost saturated in iron chloride and other chlorides.In this paper, we discuss the details of this process, and how this could be integrated within a chloride pigment plant for the treatment of chloride wastes."

Jan 1, 2016

The effect of long term exposure of full size bolts to corrosive environments is presented. A special test rig was used to test four bolts under different loading conditions. Four, X-grade identical profile bolts, each of 21.7 mm core diameters (23.7 mm full diameter) were subjected to prolonged corrosion testing using acid sulphate water. The pH value of the circulated water varied between 3.4 and 4.3. The corrosion exposure test period lasted three and half years. Two bolts were axially loaded to 10 and 20 tonnes force respectively, the third bolt was subjected to a 360 Nm torsion load and the fourth bolt was left unstressed to act as a reference bolt. After the test period ended, the bolts were stripped of their corroded coatings and weighted for weight loss. The diameter of each bolt was subsequently measured, and the loaded bolt samples were first tested non-destructively for tensile cracks and then tested for tensile failure. No cracks were found on post corrosion bolts tested non-destructively. The failure strength reduction on all four post-corroded bolts was significant, varying between 21% and 39%. The onset of corrosion was not confined to the targeted mid-section length of the bolt, however, the severest corrosion occurred at the anchored ends of the bolts.

Aug 1, 2013

By Pierre Sauvé, Alex Makila

"The Camflo stock of porphyritic quartz syenite is an irregular pipe-like body 200 metres in diameter injected along the axial plane of an E-W trending F2 fold, near the contact between the. Kewagama and Malartic groups. The stock plunges 55° to the NE, almost parallel to the fold axis. The stock, exhibiting pervasive, weak cataclasis with numerous, locally auriferous quartz veinlets, is cut by minor faults striking WNW and dipping about 45°NE.Two types of gold ore are distinguished at Camflo: ""porphyry"" ore and ""fault zone"" ore. ""Porphyry"" ore, accounting for 90% of the gold produced, forms wide zones within the stock. The zones are irregular in shape but tend to be oriented E-W in plan view (on a horizontal plane) and are elongated paraliel to the plunge of the stock. These zones are more abundant in the northern part of the stock. Differences between ore and barren porphyry are not obvious. ""Fault zone"" ore occurs outside the stock along minor faults, particularly in differentiated sills offer rodiorite and felsic granophyre. Gold grade is roughly proportional to the pyrite content which in turns depends in part on the original magnetite content of the host rock. Although both types of ore show some correlation between Au and S, the Au/S ratio is considerably higher in porphyry ore.The bulk of the gold is in quartz syenite and in felsic granophyre, the most brittle lithologies at the mine. Presumably, the vertically continuous, pipe-like stock, made up of shattered rock, provided the main channelway for the ascending mineralizing solutions."

Jan 1, 1990

By H. W. Little

INTRODUCTION MINERAL deposits of Salmo map-area (Figure 1) have aroused the interest of prospectors for more than a half-century. Properties within the map-area have produced lead, zinc, silver, tungsten, and gold. Sheep Creek mining camp ranks fifth in the Province in the total production of gold, but during recent years interest has been concentrated upon base metals, and meticulous prospecting and exploration have resulted in the discovery of many large zinc-lead orebodies. PREVIOUS WORK Geological investigations of the region were begun long ago, and it is interesting to trace the development of ideas with our increasing knowledge of the geology of this complex area. The first geological examination of the rocks of Salmo map-area was made in 1859-60 by H. Bauerman (1), who was employed as geologist accompanying the first international Boundary Survey. Bauerman examined the rocks exposed along Pend d&apos;Oreille river and published a section indicating that the sedimentary rocks are probably of Palaeozoic age, and are intruded by granite of unknown age. McConnell and Brock(2), in 1894 - 1900, carried out the reconnaissance mapping of the West Kootenay Sheet, on which they outlined the Mesozoic rocks of the Rossland Beaver Mountain volcanic groups that they believed rested unconformably upon the sedimentary rocks to the southeast, which they regarded as of Palaeozoic age.

Jan 1, 1951

By D. Mark Richards

Highland Valley Copper is a large open pit copper mine in the southern interior of British Columbia. Machine guidance technology using the Global Positioning System (GPS), was first implemented at the mine in late 1996 for blast hole drill navigation. The purchase of a third BE49R drill in 1998 completed the change to GPS navigation for all the mine?s drilling. The acceptance of this technology was almost immediate at both the operator and management levels. With the purchase of a new P&H 2800 shovel in 1997, the opportunity was taken to extend GPS navigation to a shovel. Due to communication restrictions, this was not as successful as envisaged. In late 1999, following a cost benefit analysis, a three-shovel trial of Caterpillar?s Computer Aided Earthmoving System (CAES), was initiated. The trial was successfully concluded in June 2000 and a further two shovels were equipped. Acceptance of this system has been very good at all levels, which has undoubtedly contributed to its success. In September 2000, CAES was extended to the dozer fleet with the purchase of a new track dozer. The CAES equipped dozer is used for pit production and project work. It is planned to extend CAES to the rest of the shovel fleet in 2001, along with a production front-end loader and one or two more track dozers.

May 1, 2001

By C. Paulo, W. N. Wheeler, M. Kalin, M. P. Sudbury

Many researchers have tested the addition of various phosphatic materials, including Natural Phosphate Rock (NPR), to mining wastes. It was assumed that iron in the waste would form FePO4 precipitates, restricting oxygen access to pyrite surfaces and reducing oxidation. Phosphate additions were based on stoichiometry (phosphate mass to sulphide content of waste). Although some interesting, positive results were obtained with low dosages, these were considered accidental, not having followed the expected stoichiometry. In 1991, we began experimenting on tailings and waste rock with NPR, postulating that if chemo-lithotrophic microbes on the mineral surface accelerate oxidation, then heterotrophic (oxygen-consuming) microbes would reduce oxidation. All wastes with NPR produced effluents with elevated pH and low metal acidity. Later, microscopic investigations of the rocks found an organic layer on the mineral surface, which was confirmed by independent research organizations repeating experiments with very low NPR mass additions to sulphidic wastes. In 2013, heterotrophs were identified and quantified as they grew on German lignite with NPR. These data conclusively showed that the development of heterotrophic biofilms is a consequence of adding waste NPR leading to a reduction of sulphide oxidation and improved effluent from sulphidic mining wastes. We document our gradual understanding of the effects of NPR on the reduction of sulphide oxidation, covering 23 years of research.

Jan 1, 2014

By S. McCarthy, K. E. Waters, A. Jordens

The beneficiation of rare earth (RE) element bearing minerals has become an active area of research as applications for these elements grow while the supply to non-Chinese consumers is restricted by export quotas. One of the most interesting beneficiation techniques for RE minerals is froth flotation as their unique chemistry suggests that collectors with a specific affinity for RE cations should be able to selectively recover these minerals. Existing literature, focusing mainly on bastnäsite flotation, identifies hydroxamic acids as excellent collectors for RE minerals. The high stability of hydroxamate-RE cation complexes is the explanation most often offered for the observed selectivity of these reagents in bastnäsite flotation however some research has also suggested that mineral solubility plays a crucial role in the success of hydroxamic acid flotation of RE minerals. This work investigates the interaction of allanite, a relatively insoluble RE-silicate mineral, with benzohydroxamic acid using zeta potential measurements and microflotation. The effects of Fe(III) and Fe(II) ions as potential activating ions (cations that form stable hydroxamate complexes) on benzohydroxamic adsorption to the allanite surface are investigated as a potential solution to promote hydroxamic acid adsorption. The results indicate that the optimum conditions for separation of allanite from quartz occur at pH 4 using FeCl2 as an activator for benzohydroxamic acid adsorption.

Jan 1, 2014

By Gema Ribeiro Olivo

The hydrothermal Au-Pd deposits are hosted by the jacutinga in the Lake Superior-type iron-formation of the Itabira Group, Minas Supergroup. Jacutinga is a highly sheared, metamorphosed, hydrothermally altered iron-formation composed of hematite, magnetite, quartz, talc and phlogopite (Cauê) or muscovite (Conceição) and minor tourmaline, palladian gold, arsenopalladinite, mertierite II and palladeisite (hydrothermal) and native gold, native palladium Pd-Cu-oxides, and kaolinite (weathering products). The highest concentrations of Pd-Au occur in quartz and hematite veins parallel to the S1 foliation (Corpo Y, CorpoX, Aba Leste and Central orebodies, at Cauê and a single orebody at Conceição) or parallel to the S2 foliation (Aba Norte). The average ore grade is 30-40 g/t Au+Pd. The characteristics of the Au-Pd ore favor an epigenetic model for gold and palladium concentration in the iron-formation. During the D1 deformation and peak metamorphism, the oxiziding, acid and hot hydrothermal fluids transported Au and Pd preferentially as chloride complexes. The reaction of the fluid with the dolomitic carbonate (the probably protolith of the jacutinga) would have dissolved carbonate and K-feldspar to form muscovite or phlogopite and tourmaline, resulting in an increase in solution pH and a decrease of Cl concentration and subsequent deposition of gold and palladium minerals.

May 1, 2003

By Isabelle Demers, Audrey Jalce

L’industrie minière génère chaque année une quantité considérable de rejets miniers, principalement sous forme de stériles ou de résidus de l’usine de traitement. Les stériles sont des roches sans valeur économique, excavées pour atteindre la roche minéralisée. Ils sont usuellement empilés en surface formant des haldes à stériles. Les résidus miniers sont des roches finement broyées, mélangées avec de l’eau, résultant du traitement du minerai. Ils sont généralement pompés et entreposés en surface dans des parcs à résidus. Cependant, leur stockage peut être sujet à des instabilités géotechniques, mais également géochimiques, pouvant entrainer des problèmes environnementaux majeurs, tels que le drainage minier acide (DMA). Le DMA se produit lorsque des minéraux sulfureux, contenus dans ces deux types de rejets, s’oxydent au contact de l’eau et de l’oxygène [1]. Le DMA se caractérise par une solution acide (pH inférieur à 6) riche en métaux, contaminant les eaux souterraines et de surface et représentant alors un danger pour la faune, la flore et la santé humaine [2]. La remise en état et la fermeture des sites miniers doivent donc être pensées dès la phase d’étude du projet d’exploitation, afin de proposer une méthode de gestion des rejets qui permettra de limiter les impacts environnementaux pendant et après l'exploitation.

May 2, 2024

By K. Oishi

We have developed a 76Cu-3Si-21Zn alloy "ECOBRASS®" containing no lead. When 3% Si is added to a 78Cu-22Zn alloy, kappa and gamma phases participate uniformly in the alpha matrix. When being machined, stress concentrates on these hard phases, namely kappa and gamma, and thereby lowering the required cutting force and yielding segmentalized chips without lubricant. Kappa and gamma phases transform into beta phase under high temperature, which makes it easier to extrude and/or forge the alloy. When 0.08% P and 50 ppm Zr are co-added, the grains of ECOBRASS® castings are refined significantly to become as small as several dozens of micrometers. The grain refinement by the co-addition of P and Zr improves castability, tensile strength and elongation of ECOBRASS® castings. Meanwhile, the lead leachate from an ECOBRASS® water meter, field-tested in pH 6.8 drinking water for one year, was less than 5 ppb without correction. No indication of dezincification corrosion was observed, either. ECOBRASS® is equally suitable for rods, forgings and castings, and makes it possible to produce a complete set of plumbing parts (valves, faucets, etc.) by its own. This way, not only improving recyclability, ECOBRASS® also realizes size and weight reduction due to its good corrosion resistance and high strength.

Jan 1, 2007

By Joachim von Scheele

An oxyfuel-based technology - OXYFINES - has been introduced for in-plant recycling. It provides fines, dust, sludge (without any drying-step) and other by-products arising in the steel and metal producing industries to be recycled directly back into existing processes or a separate unit on-site. Results from full-scale installation (20,000 tpy) for dust treatment, full-scale and pilot-scale trials with dry and wet materials in the steel and ferroalloy industries are presented. Processing rates at 3.5 t/h have been demonstrated. The product is agglomerates or lumpy pieces, the latter if the product has passed an all-liquid stage and thereafter been crushed. The technology does not only provide a solution to the problems connected to dust and sludge generated in metal production. It also turns these materials into a low-cost raw material useful for the production in question, thus replacing part of the raw material input in electric arc furnaces, blast furnaces, etc. Elements harmful to re-use of the processed dust or sludge, e.g., zinc and alkaline components in steel production, are removed as secondary dust, and material yield of main components for re-use is very high, about 98%. The paper reviews the concept, the results obtained and its status; its use for sludge recycling is emphasized.

Jan 1, 2004

By H. Nakano

The codeposition behavior of impurities such as Ag, Bi, Fe, Ni, Pb and Sb with Cu was investigated galvanostatically at 5-3000 A/m2 using a Pt cathode at 60 °C in acidic copper (I) chloride (cuprous chloride) solution at pH1-2 containing 1.0 mol/L of Cu+ and 4.9 mol/L of Cl-. The impurities were classified into two groups: Group I (Ag, Bi) which codeposits with Cu as a metal, and Group II (Fe, Ni, Pb, Sb) which is slightly involved in the deposited Cu in nonmetal form from the electrolyte. Silver and Bi in Group I behaved as more noble metals than Cu, and significantly codeposited with Cu, showing typical features of regular-type codeposition. When Cu was deposited dendritically, the Ag and Bi content in the deposit increased with increased duration of electrolysis as a result of decreased net current density caused by increased cathode area. The current efficiency for Cu deposition in impurity-free solution was 95-100% over 100-1000 A/m2, but it abruptly decreased at above 1000 A/m2 when the limiting current density of Cu was attained. Although Fe, Ni, Pb and Sb in Group II were involved to 0.01-0.02 mass% in the deposit, they had no influence on the current efficiency or morphology of Cu.

Jan 1, 2007