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By D. W. Ginsberg, D. Cieplinski

"The lifetime cost of a material handling system, or any mine system, can be reduced through the application of quality engineering. Dynamic simulation is a powerful tool that can be used to enhance the experience and ingenuity of the design team. It cannot only de-bottleneck the system to improve system productivity, but also define critical design criteria to eliminate over-design and reduce capital cost. Eliminating over-design also reduces operating costs by lowering component replacement costs and by ensuring all parts of the system operate at a higher utilization and efficiency. IntroductionA mine owner’s profitability is improved when a mine is developed at the lowest lifetime cost. This cost relates not only to capital and operating costs, but also, to a great extent, on the efficiency and reliability of the operation. These factors are tied directly to the quality of the engineering which depends on the experience of the engineers involved, and their ability to apply known system information in a rational and constructive manner.It is becoming apparent that it is increasingly more difficult to deliver the quality of engineering expected and needed to provide attractive lifetime costs using traditional design methods. Historically, system information has been evaluated based on a limited amount of information to which global rules-of-thumb and the engineer’s personal experience were applied to develop design criteria. However, market forces are dictating that more system parameters be defined and that they be defined more accurately so that the most economical system can be developed. This increase in the volume of information and the need for more accurate predictions is straining, if not already exceeding, the ability of engineers to apply simple global rules of- thumb and to combine all the information in a rational, comprehensive and representative set of design criteria. Furthermore, as proposed system production rates increase beyond established industry practice, the extrapolation of the engineer’s experience becomes more difficult and increases the risk in the proposed design."

Jan 1, 1998

By J. B. Kwon

For improvement in the productivity of tall building projects, table formwork is one of the main methods that have been adopted for slab formwork. Because the table formwork method is an equipment-oriented construction method, the type of lifting equipment and method of operation considerably affects the productivity and cost of the table formwork. It is also important to make an equipment input plan for completing the table formwork within the time given, according to the structural construction cycle. For performing the table formwork, a tower crane or an independent lifting system, and shifting trolleys, are required. However, if an inefficient equipment input plan is made, exorbitant cost may be incurred. Therefore, the purpose of this study is to analyze the productivity of a table formwork, considering the type and number of lifting equipment and the number of trolleys inputted, and to suggest quantitative data for making a cost-efficient equipment input plan within the construction duration given. It is expected that the results of this research will be utilized as a basis for cost-efficient equipment input planning.

Aug 1, 2013

By G. Wang, L. R. Moore, Y. Xiong, A. Gorken

"Mining is a very water intensive industry. As such, the industry has become dependent on applying alternate sources in efforts to minimize the impact on the locally available fresh water. Sources such as recycled water, sea water, and even acid mine drainage have been applied at some limited applications, while other mines may not even have the option of fresh water available in their region. However, the different sources of water will have varying concentrations and types of soluble salts and suspended solids, which can lead to dramatic differences in mineral processing when comparing these types of waters. Water quality is known to affect bubble generation and strength, mineral surface charge, and even reagent coordination properties. This paper focuses on the exploration of how water quality and soluble salts affect the flotation of iron and titanium containing minerals from feldspar, and the design of flotation collectors for optimal performance in this water.INTRODUCTIONFeldspar is defined as a tectosilicate mineral with the generic structure of MAlxSixO8, where M represents the cation (Celik, 2001). Feldspar is most often found naturally occurring with quartz, iron containing minerals (i.e mica), and titanium containing minerals (i.e. rutile). The alumina component of feldspar is of interest to glass making, while the alkali metal component is of interest to ceramics (Vidyadhar, 2002). In glass making, the alumina is known to improve product hardness, durability, and resistance to chemical corrosion. In ceramics, the alkalis act as a flux; a flux lowers the melting temperature of the mineral mixture, and assists in connecting the other components present in ceramics. Quartz is stated as having a negative effect on the melting point of the feldspar. Although quartz is typically not removed during the feldspar applications in the glass industry, it needs to be reduced for the ceramics industry. Iron and titanium based minerals are known to have negative effects on color and quality of the products in both glass and ceramics. Thus, these “contaminants” must be reduced to a certain product specification via feldspar beneficiation (Table 1)."

Jan 1, 2016

By Mauro Chiesa

An Overview on the Presentation A.The Markets ?Mining Industry ?Capital Markets ?A Six-Cell Matrix of Strategic Options B.De-Risking The Mining Assets ?The Value-Added ?The Assets: Current and in Development ?The Feasibility Study C.(Questions, and answers) Post-Crunch: Some Maxims ?Three Metal Market Models No Longer Prevail ?New models are uncharted: ?be prepared?(ref: Lord B-Powell). ?Capital markets are pricey & uncertain: be your own financier first ?focus on value and on cash-flow (not oz, lbs, tonnes, LOMs, etc) ?Know your banker/financier(and it should know mining) ?In the past, it was ?know your borrower? ?It?s a buyer?s market that wants the ?right deal?: so cast a big net: ?Data must be current, concise and consistent ?3rdparty validation of feasibility work is now a ?passport? ?The risk matrix, with de-risking, is as important as the ?math?

May 1, 2011

By Jean-Luc Collins

"This paper shows how simple reliability concepts such as mean time between failures and mean repair time can be used efficiently to help increase equipment availability and so reduce the economic losses associated with unreliability.More specifically, the paper shows how these simple concepts can be used in maintaining an appropriate balance between fleet failure and repair rates and how they can be used for setting up priority repair rules f or queuing equipment.IntroductionA profitable mining operation must handle large quantities of ore and waste at the lowest possible cost. To achieve this objective, the operation must optimize the productivity of its fleets of equipment by efficient management of the time element. Figure I shows some basic equipment activities in an open pit operation while Figure 2 shows a tree diagram describing some time elements of these activities.It should be noted that the only time a piece of equipment can generate a profit is when it can be found in the operating status. In order to maximize this time element, the sum of the other time elements must be minimized because the total time is always fixed.This paper shows the application of simple techniques capable of reducing the waiting time for repair (maintenance delay) by using simple reliability concepts."

Jan 1, 1988

By Jose A. Jimenez

"Mining operations generate an enormous amount of data that is difficult to organize, analyze and act on. These data require an extremely broad range of experts to investigate and manage the cross-disciplinary information. The data collects in paper files, diverse databases, historians, stand-alone applications, and excel files. This collection of sources represents everything from monthly, weekly, or daily inputs to real-time feeds or sporadic unscheduled entries. With the operational complexities ever increasing and fewer engineers per mine, an efficient operation is becoming more and more challenging. Engineers are typically burdened with data collection, clean up, and administrative efforts leaving very limited time for engineering assessment and/or optimization analysis. Often optimization becomes limited to the analysis of equipment uptime through existing field automation systems. A great portion of the field data is tucked away in historians seldom reaching those engineers who might leverage the data. Few mine operators have the time or budget to re-architect their operations data collection or management practice, so solutions must enable improvements without requiring expensive or time-consuming implementation. This presentation highlights examples where the aforementioned challenges are addressed using a solution framework designed to enable: 1) data integration and connectivity, 2) monitoring and opportunity recognition, and 3) engineering workflow automation. The initiative extends the concepts and success proven in the automation market segment to all disciplines across the mine operations. INTRODUCTIONThe mining industry by its very nature spends a great deal of its capital on equipment maintenance and replacement. In addition, periodic shutdowns due to equipment failure are typically very costly in terms of interrupted operations. Keeping mining equipment running at peak performance and avoiding costly shutdowns can make a huge difference in the overall return from mining operations. Today, information can be make available that can go a long way towards spotting equipment issues and permitting timely intervention to avoid costly unplanned shutdowns. That said, gathering all of the information from numerous points on many different pieces of equipment necessary to enhance overall equipment effectiveness presents its own daunting issues."

Jan 1, 2016

By G. Binks

In 1997, the Zinifex Hobart Smelter ceased ocean disposal of jarosite and the flowsheet was converted to reject iron as paragoethite. This paper describes the evolution of the flowsheet since the changeover and considers future flowsheet developments. The major change to the flowsheet has been an increase in the silica content of the calcine resulting from treating increasing levels of Century concentrate. The high silica levels impacted on the paragoethite precipitation stage, causing a deterioration in the settling and filtration characteristics of the paragoethite and an increase in the contained zinc level. The implementation of a two stage neutral leach step has enabled the flowsheet to cope with the higher input silica levels. Future developments include an understanding of the form of the zinc in the paragoethite and options to lower the zinc level to improve the overall zinc recovery.

Jan 1, 2006

By R. Frank Chiappetta, E. B. Wilson

"The maintenance records for AL-60 airlegs at Falconbridge Ltd. are used to demonstrate some of the procedures for the analysis of such data.The data are not representative of pure failure s of one type or another. In fact, the records are for the undefined pseudo-failures which are usually found in industrial operations. However, because the machines are brought to the shop only when inoperative, the individual recorded components are treated as failures. Manual calculations are conducted to show the analysis of variance (ANO VA) approach to determine whether certain data can be combined; only a limited number of the 206 machines being considered. The manual procedures continue with the weighting of the suspensions; i.e. terminations f or reasons other than the failure of the given component. After the data are sequenced in the proper order, the nature or pattern of the data is determined using the Kolmogorov-Smirnov (KS) test.It is recognized that these manual examples must be replaced by compute r methods 10 process voluminous data of this nature. Such programs are developed and available. However, a program called RELCODE is used in this case to correspond to the manual examples and to take into account the suspensions. These analytical procedures form the basis for those studies required for good maintenance management."

Jan 1, 1985

By J. Keith Haddock

"Introduction The Boundary Dam Mine is located 5 km south of the City of Estevan, Saskatchewan and is operated by Manitoba and Saskatchewan Coal Company Ltd., one of the Luscar companies. The entire production of 1.7 million tonnes per year is delivered to the Boundary Dam Generating Station of Saskatchewan Power Corporation. Geology There are basically two seams mined on the property, the main Estevan seam ranging in thickness from 3.0 m to 4.5 m with partings and the upper Roche Percee seam (roughly 15 m to 23 m above the Estevan) which ranges from 0.6 m to 2.0 m in thickness. Most of the reserves are concentrated in the Estevan seam, the Roche Percee only being mined whenever its thickness makes it economic to recover. The coal measures belong to the Ravenscrag Formation of Tertiary (Paleocene) Age. This formation is widespread in North Dakota and Montana and contains the lignite fields of North Dakota and subbituminous coals of Montana. The formation is gently tilted to the southeast at Boundary (0.5 degrees) and consists of weak sandstones, siltstones and silty mudstones. Reserves and Coal Quality The present minesite encompasses a coal reserve of approximately 50 million tonnes calculated to a maximum stripping depth of 37 metres or 20:1 mining ratio. The reserves form only a part of the total reserves in the Estevan area which are owned by the Saskatchewan Power Corporation. The coal being mined is classed as Lignite ""A"" and has the following specifications:"

Jan 1, 1985

Concentrator Improvements -1990-1995Back to Basics ?pilot plant versus plant opportunities identified ?understand process fundamentals & baseline -1996-2000Point ?C?Projects ?strategy to improve global competitiveness ?structure implemented to generate & drive ideas ?capital investment for life of mine asset renewal - 2001-200?Six Sigma Methodologies ?emphasis on data, measurements & analyses ?dedicated, highly trained personnel on projects 1990-1995 Improvement Phase??Philosophy??back to basics?approach?understand what each piece equipment needed to do?understand reagents, control variables?confirm operating strategies ??probe, stabilize, institutionalize??test theories, confirm with lab and plant trials?process stability (equipment reliability, controls)?enhanced operator guidelines, operator training?focus on continuous improvement?optimize existing equipment capability?stop looking for ?magic?solutions 1990-1995 Improvement Phase??Technical?finer grind, same equipment?optimize media size/shape to grinding application?balanced available ball mill power to applications?lowered cyclone feed densities where possible?improved selectivity, same equipment?balanced available cells to applications?streamlined process (eliminate process steps)?added cleaning stages where required?understanding pulp/mineral surface chemistry?lowered flotation pulp densities 1990-1995 Improvement Phase??Effort?numerous studies to understand process?liberation and mineralogical characterization?pulp and mineral surface chemistry?flotation kinetics and entrainment?extensive internal and external manpower?Brunswick, Noranda Technology Centre?CanMet, AMTEL, MinnovEx, Lakefield Research, McGill University?small capital expenditure

May 1, 2002

By S. C. Tadolini

"Roof bolts are the primary means of roof support in underground mines in the United States. Presently, post installation loads are measured on about 10% of the expansion anchor and combination bolts by using standard torque wrenches that Unit the accuracy of the measurements to about ±30%. No system has been available for measuring the loads generated on full-column resin grouted bolts. Mine roof bolts are long, slender, non-uniformly sized, roughly forged, and placed in a corrosive environment, creating obstacles for researchers trying to utilize ultrasonic reflection techniques to measure strain. A complete measurement system has now been developed by the U.S. Bureau of Mines, Denver Research Center. This system is being used successfully in determining loads measured on expansion anchor and combination bolting systems, examining the transfer mechanics of full-column, resin-grouted bolts, and measuring loads generated on bolts in an underground roadway support system.IntroductionMillions of roof bolts are used each year to provide structural support in underground U.S. metal, non-metal, and coal mines. Approximately 45% of the bolts used are expansion anchor, 45% are resin-assisted combination or full-column resin-grouted, and 10% are friction anchored. The effectiveness of these bolting types is dependent on a number of factors including rock density, bolt length, in situ stresses, rock properties, bolt pattern, installation tension, etc. When implementing expansion anchor and resin assisted combination bolts , installation and post-installation tension, or load, is a major determinant of support quality and subsequent behaviour of the reinforced roof. The method by which these systems carry roof loads is well understood and documented(1,2).The importance of these installation and long-term bolt tension measurements is well recognized and are required in the federal government regulations(3). A statistical sample of the bolts, lout of 4 during installation and lout of 10 inby the last open crosscut, is required to be measured using current torque wrench technology. The disadvantages of this system are the disturbance and weakening of the anchorage and limitations of accuracy to approximately ± 30%. The method by which resin-grouted bolting systems carry roof loads is much less understood, mainly because testing procedures used to evaluate point-anchor systems are not effective on resin-grouted bolts.Due to these problems, the U.S. Bureau of Mines designed a measurement technique that provided a highly accurate, low cost-per- bolt system that led to the development of ultrasonic pulse echo instrumentation. The original system was designed to measure the tension only on expansion anchor bolts. Recent developments and system modifications have permitted measurements on resin-assisted and full-column resin-grouted bolts. The use of these types of support systems has been increasing steadily in underground coal mines.The development of this instrumentation has provided laboratory and field results that help to explain the mechanics and relationships between the applied loads and the interaction between the grouted bolt system consisting of the bolt tendon, grout, and rock."

Jan 1, 1990

By G. K. Rutherford, G. W. Van Loon

"Tailings in the mining and smelting industry are reject products of the refining process which are deemed too deficient in native are to warrant smelting. They are essentially finely ground rock materials which have been moved by alluvial suspension from the site of crushing to a deposit site. It is realized that components of flotation chemicals used in specific gravity separation may become part of the tailings and also that sewage sludge or other materials may be added at some stage to the tailing deposits.It would seem, then, that as tailings have a similar parent material to soils, namely rocks, and that they have also been comminuted to similar size fractions, they would react in similar ways to soils. There is an increasing body of evidence and experience which both supports and negates this supposition. It is the object of this paper to point out similarities and contrasts between these two materials which may influence the vegetation and rehabilitation of tailings.Soil-Formlnq FactorsThere are considered to be six soil-forming factors which impart the particular and unique properties harboured by a soil at any site. It is .relevant to consider each of these in turn, as each provides an historically based parameter with which to judge tailing properties.Parent MaterialsAlthough all mineral soils have originally come from rocks, for most soils the route has been rather circuitous. Soils may be formed directly from underlying rocks, as in some parts of tropical and semitropical regions today; these are sedentary soils. However, most soils of the world have been formed by materials which were transported to their present site by ice, water or wind, or as volcanic ash. Virtually all soils in Canada have been transported by ice or water and deposited on an extraneous rock surface during the last glacial retreat. Ice-deposited materials are extraordinarily heterogeneous in their size components and may range from very bouldery and gravelly to predominantly clay-sized materials. Water deposited sediments are usually homogeneous, but nevertheless these also show considerable level variations. In many parts of Canada, clay-sized materials deposited in ephemeral post-glacial lakes form the parent material for soils."

Jan 1, 1982

By Cy Jordan, Ben Burdett, Adrian Dance, Jack Rainey

"In 1997, EIMCO Minerals installed a knowledge-based control system on one of the five primary grinding lines at Highland Valley Copper. The objective of the system is to maximise throughput without affecting circuit product size or flotation recovery. The system was commissioned in October 1997 on a SAG mill/ball mill circuit following a plant audit and upgrade of the control instrumentation.The system monitors and controls the SAG mill power, bearing pressure and recycle load by manipulating the solids feedrate, water addition and mill speed. The two ball mill and cyclone circuits are controlled through water addition at various points in the circuit as well as the number of operating cyclones.An on-line particle size analyser is used to measure the cyclone overflow quality. Models of the SAG mill charge level and overflow product size are also incorporated. A method of predicting the SAG mill power response to feedrate changes is used to lessen the effect of dead time for improved mill power control. In the future, inferred measurements of SAG feed particle size and hardness will allow changes in ore behaviour to be predicted and compensated for by the system.This paper describes the development of the project -from installation and commissioning to modifications and refinement -along with prospects for the future.BackgroundIn early 1997, EIMCO Minerals was contracted by Highland Valley Copper to install a knowledge-based or expert system control strategy on one of the five grinding lines in the mill. This was to become the start of the Advanced Control Project at Highland Valley Copper (HVC). This paper will review the progress of the Project as well as discuss the prospects for the future.Following a preliminary engineering study (or plant audit) by EIMCO in 1996, it was decided to implement an advanced control system in order to improve plant operations and increase productivity. The study suggested that such a system had a pay-back period of a few months through increased throughput without loss in flotation recovery. Highland Valley already had successfully applied higher level control through their Elsag Bailey distributed control system (DCS) and this was the next stage in process optimisation."

Jan 1, 1998

By D. T. A. Symons, M. M. Kapnistos

"Gravity profiles were established over five known Middle Silurian pinnacle reef s in Lambton County, southwestern Ontario. The profiles were approximately 3 km long, with stations every 60 m. Four fairly recent technological developments were used which now make the gravity method relatively efficient and inexpensive compared to the techniques available two decades ago. These are: (1) a La Coste-Romberg model G gravimeter to measure the gravitational attraction with a sensitivity of 0.01 mgal; (2) a Sokkisha model B-2 semiautomatic engineers level to measure the station elevations with an accuracy of 0.5 cm; (3) a Huntec FS-3 hammer reflection seismograph to determine the overburden thickness to an accuracy of ± 7%; and (4) a modern microcomputer to process the data sets and mathematically filter the gravity values. Thus, two men can measure and analyze approximately 1 km of profile per day and obtain the residual gravity profile to an accuracy of ± 0. 05 mgal. Positive gravity anomalies of 0.17 to 0.72 mgal were observed along all five profiles that approximately delineate the dimensions of the known pinnacle reefs, which have an average height of 120 m, diameter of 1500 m and depth to top of 575 m. The relative ease of the gravity survey method makes it a cost-effective technique for hydrocarbon exploration in southwestern Ontario. IntroductionPinnacle reefs are important sources of oil and gas. Although the pinnacle reefs in southwestern Ontario are small, they may contain commercial pools of oil and gas because of their proximity to refineries. They are also useful for subsurface storage of gas to meet the winter surge in gas demand.At present, geophysical exploration for new pinnacle reefs is done primarily by relatively expensive seismic methods, which are also limited in southwestern Ontario by prohibitions on blasting. Gravity methods of exploration were attempted more than two decades ago in this region. (Pohly, 1954); however, the level of technology at that time made the method marginal in sensitivity and quite expensive. Several subsequent developments- gravimeters with greater sensitivity and operating ease, ""self-levelling"" levels for elevation control, hammer seismic reflection units for determining overburden thickness and portable microcomputers for efficient data analysis-have significantly improved the precision and cost effectiveness of the gravity method. Five known pinnacle reefs were selected in Lambton County, southwestern Ontario (Fig. 1), to test the effectiveness of integrating these developments to locate and define additional reefs. Isolated reefs were chosen to avoid the problem of the gravity effect s of one reef interfering with those of a neighbouring reef. The surveys were facilitated by choosing reefs with a concession road passing directly over them ."

Jan 1, 1980

By G. E. Agar, J. J. Barrett

"Traditionally, batch bench-scale flotation tests have been used for evaluating flotation reagents by comparing the results of tests done with various additions of the reagent in question. Usually, comparisons are made of the concentrate grade and recovery or some figure of merit involving an empirical combination of both. In some cases, statistical methods have been used to make the comparison and even to identify optimal combinations of reagents.None of the preceding technology utilizes the fact that flotation separations can be described by relatively simple kinetic equations that will serve not only to quantitatively describe the influence of a reagent, but will also aid in designing an optimal separation procedure. Examples of the use of a first-order rate equation for evaluating the impact of a reagent addition and for optimizing the reagent addition are given.IntroductionThe classical method of evaluating flotation reagents is to conduct batch bench-scale tests while varying one factor at a time. Some of the shortcomings of this technique have been pointed out and statistical design and evaluation of experiments has been advocated. Although the statistical approach is superior to the one-at-a-time method, it still is dependent on the results of a batch test conducted for a specific duration.That flotation is primarily a rate process than can be described by a first-order rate equation has been recognized for a long time, but the application of this knowledge to the evaluation of reagents has received little attention. In this work, it is demonstrated how the parameters of the first-order rate equation can be utilized to evaluate the influence of reagents on flotation."

Jan 1, 1983

By R. F. Engler

"IntroductionThe Coal Branch region of west-central Alberta has been the focal point for unprecedented exploration and development activities over the past ten years prompted by the renewed markets for high-quality thermal coal. Although mines were developed and operated extensively throughout the region from 1910 until 1960, information relating to the detailed stratigraphy of the coal measures and their areal distribution tended to be localized to individual mine sites. Continuity along trend was impaired by a paucity of outcrop restricting geologic mapping to stream bank and roadside exposures. Recent studies and subsequent publications by Jerzykiewicz and McLean of the Geological Survey of Canada (1978, 1980) have established a detailed sedimentological model and defined the stratigraphic nomenclature for the region . The term Coalspur Beds has been adopted to describe the coal-bearing sequence between the overlying Paskapoo Formation and underlying Brazeau Formation. Complete sections of the Coalspur Beds have been compiled from sub-surface borehole data and published by Manalta Coal Ltd ., Dentherm Resources Ltd. and Luscar Stereo Ltd. This paper is an attempt to correlate this information on a regional basis to illustrate trends within the Coalspur Beds."

Jan 1, 1986

By N. Bartie

Realising the circular economy (CE) is faced with some significant challenges. Process metallurgy and its infrastructure play key roles at the heart of making the CE work. Therefore, the enabling role of process metallurgy within the CE will be central to the discussion in this paper, touching among others on product and system design as well as the key metallurgical and other process fundamentals that need to be investigated and understood to make the CE a reality. The central role of materials and its processing will be discussed in an integrated circular cities perspective. A key focus will be a discussion on designing a resilient “Smart Materials Grid” using and innovating metallurgical process engineering tools, which will manage the flows through Sustainable Circular Cities. The discussion will be using copper as leitmotiv of the discussion i.e. from copper ore, to metal, to complex products, recycling, product design and simulation and its impact. INTRODUCTION The transformation of our economies from linear to circular models in which waste materials become resources is the focus of the Circular Economy (CE) paradigm. Its important intentions: to take control of the damage we have been doing to the planet to ensure its livability and the welfare of future generations. This can only be achieved through careful utilisation of human, natural and economic resources. The concept is derived from several others (Beaulieu et al., 2015), of which Cradle-to-Cradle, Extended Producer Responsibility (EPR), Industrial Ecology, and Life Cycle Thinking are just a few. Other relevant concepts include resource efficiency (RE), design-for-recycling (DfR), and various others discussed by Blomsma and Brennan (2017) and Homrich et al. (2018), as well as various R-hierarchies e.g. Reduce, Reuse, Recycle (3R). However, does society comprehend these concepts, the actors and actions that influence them and how they interact? Do we know the limits of CE? Does society understand the key role of Copper and other metals to rendering the CE operable? True life cycle and systems thinking, focussed on simulation-based, process and metallurgical design are required to answer these questions. Lieder and Rashid (2016) identify nine widely-varying fields that study the concept ranging from sustainability sciences and engineering to economics, business, law, and social sciences. Overlap between questions addressed highlights the need for interdisciplinary collaboration (Nanz et al., 2017) in the assessment of the current status, and further steps needed to transform to CE. This doesn’t apply just in academia, but also in industry where concrete implementation of CE needs to occur at multiple levels, thus necessitating cooperation between government, civil society and other stakeholders (Beaulieu et al., 2015).

Jan 1, 2019

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 F. Barriga-Ordonez, J. A. Finch, L. Calzado, S. R. (Ram) Rao

Sludge, formed by lime treatment of acidic drainage and stored in tailing ponds of the Sudbury region, contains 5-7% Ni, mostly in a mix of hydroxides with Fe (~ 10%), Mg (~ 10%) and Cu (-0.5%), and Ca (-3.5%) as sulphate. Investigations were conducted to recover nickel by a 2-stage process. In the first stage, the sludge was leached with sulphuric acid at pH 3.2. About 90% of the nickel was extracted, producing a solution, which contained mainly nickel (2 g/L) and magnesium (3.7 g/L). In the second stage, nickel was separated by treating with ozone which recovered 99% of the nickel in the Ni(III) oxidation state as -85% pure nickel oxide-hydroxide (NiOOH) precipitate. The oxide settled and filtered readily. A potential use of the product in battery making is suggested. The leach residue contained 0.5% Ni making it less toxic for disposal. Some physical properties of nickel oxy-hydroxide and process parameters including ozone consumption will be discussed.

Jan 1, 2005

By F. Liu, S. Rezaei, M. Muinonen, M. Barati, V. L. Lakshmanan, S. Marcuson

Canadian nickel-copper ore deposits have been a major source of nickel, copper, cobalt and precious metals for more than 100 years. The two main minerals of interest, pentlandite (Pn, (Ni,Fe)9S8) and chalcopyrite (Cp, CuFeS2), are usually accompanied by large quantities of pyrrhotite (Po, Fe1-xS). Until the 1950s, Po containing small amounts of nickel was routinely smelted as part of the valuable Ni concentrate. The rapid growth in Ni demand following the Second World War created impetus to treat the Po separately. This action would liberate a valuable smelting capacity for higher value Pn, allow for recovery of Ni locked in Po, convert the Fe to iron oxide or metallic iron pellets, and recover S as sulphuric acid or elemental sulphur. The roasting process also has the potential to produce energy due to the highly exothermic oxidation of Po. The Ni industry would then have a “waste-free” process. Both Inco (now Vale) and Falconbridge (now Glencore) developed processes and built large industrial plants for this purpose that operated with some success. But technical issues and tenuous economics were continual challenges. By the early 1980s these industrial operations were closed. Sophisticated froth flotation methods of rejecting Po were developed, and Po containing up to 1% Ni became a waste material reporting to the tailings stream. As part of a major study on possible processing methods of Po for both value recovery and waste remediation, this paper presents a historical perspective on Canadian Po tailings with regards to their generation, inventory, value, and attempts to process them.

Jan 1, 2017