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By Par G. Jönsson, Joachim von Scheele, D. S. Sarma, Mukul Goyal

Dust from flue gas cleaning systems at iron and steel production is frequently considered as a waste problem, but it is actually a potential raw material source. By using a technology like the oxyfuel based OXYFINES technique, it can be melted into a suitable form. The product from this processing, however, needs to meet the requirements of a recyclable raw material, here particularly a top-charged blast furnace feed. The present work has been focused on characterization of the product produced from these dusts by OXYFINES technology. The investigation has been carried out on samples of processed dusts from a European integrated steel mill. It was done by means of chemical analysis, density measurement, light optical microscopy, X-ray diffraction, scanning electron microscopy combined with energy dispersive spectroscopy, and micro indention hardness measurement. Special attention was paid to the presence of zinc, an element that might be harmful while recycling the material (e.g., in a blast furnace). The results show that the product contains four different regions with different morphologies and properties in the material, which are discussed in detail. The overall conclusion is that by processing the dusts in this way, a raw material suitable for recycling in a blast furnace can be obtained.

Jan 1, 2004

By S. M. J. Mirazimi, F. Rashchi

Recovery of vanadium from LD (Linz-Donawits) converter slag was evaluated by means of microbial leaching. Vanadium leaching was performed in two stages. In the first stage, the bacteria were grown in a culture medium and in the second stage; vanadium containing slag was added to the metabolites produced by bacteria. Bioleaching was performed using heterotrophic bacteria Pseudomonas Putída. Control tests without bacteria inoculation were also performed and the results were compared with bioleaching outcomes. Optimal conditions for the bioleaching of vanadium containing slag were determined.

Jan 1, 2011

By A. S. MacNeil

In the operation of any colliery, a factor of prime importance is power, of which there are three sources available--man, horse, and mechanical. It is obvious that man-power is by far the most expensive, .and that animal-power, also, is more costly than mechanical. In recognition of this fact, mine owners must, for economical ?reasons, reduce the use of man-and horse-power to the minimum by the increased use of machinery. In other words, they must aim at as complete mechanization as conditions will permit, taking advantage of existing physical factors that are favourable and making the necessary adjustments and modifications to meet the less favourable conditions. Intensive coal-mining, or the concentrated production of coal, has two distinct objectives: First, the maximum production from a limited area, in a given time, thereby reducing the pit-room to be maintained; and second, reduction in cost. To this end the coal should be mined, loaded and delivered to the surface by mechanical means wherever possible. To do this, however, requires the solution of many problems arising out of the varying conditions that obtain underground. The system of longwall mining lends itself to a more efficient scheme of mechanization than does pillar-and-room, as, in the former, the first step has already been taken by the removal of all the coal in one operation, and the opening-out of one face, the equivalent in mining area of fifteen or more rooms. Much has been clone of late towards mechanization in the longwall mines of the Sydney coal-field, and with gratifying results, but not without great difficulties and frequent disappointments. In 1923, an attempt was made with shaker conveyors. The introduction of conveying was a step to bridge the gap between the face, where the coal is produced, and the main transportation arteries leading to the slope or shaft. The receiving of the coal at the faces and its delivery to main loading points on main haulage-ways was the part allotted to the conveyors.

Jan 1, 1932

By Stanley Davidson

Introduction The ore deposit mined by Falconbridge Nickel Mines, Limited, is one of the numerous nickel-copper sulphide bodies marginal to the large oyster-shaped mass of differentiated norite in the Sudbury district, famous as the world's most important nickel producing field. The unique character of the ore deposits of the district has resulted in its intensive geological study over a period of more than fifty years. The results of these studies have given rise to a voluminous geological literature and to a great deal of controversy as to the genesis of the ores. This description of the structural geology at the Falconbridge mine is presented in the hope that it may form a small part of the chain of evidence leading to a reasonably satisfactory explanation of the ore genesis. The mine, named after Falconbridge township in which the deposit occurs, lies along the southeast margin of the norite mass which, however, is here concealed beneath a deep mantle of glacial sands and gravels averaging over 100 feet in thickness. As a consequence, the deposit was not discovered by the early prospectors, and it was not until 1916-17 that E. J. Longyear, of Minneapolis, located the ore by drilling. The discovery was foreshadowed in 1899 by the work of Thomas A. Edison, who found indications of the deposit by what is believed to have been a combination of magnetic and electrical geophysical surveys. He sank a prospect shaft over what has to date proven to be the largest and richest ore section in the mine. A wet quicksand layer at the rock surface proved impenetrable, however, and the "Edison' shaft never reached bed-rock.

Jan 1, 1946

By C J. Coveney

This paper, after a brief introduction to the mineralization and structure in the mine area, outlines the methods now being employed for grade control at Bethlehem Copper Corporation. Sampling, subgrade drilling, blasting and the actual outlining of the ore are among the topics covered. The paper concludes with a summary of the results obtained, showing a reduction in dilution and an improvement in the grade of the copper ore going to the mill. Introduction T HE Bethlehem property is located in southern British Columbia in the Highland Valley about 30 miles southeast of the town of Ashcroft. The property is located within the Guichon batholith. The rock comprising the batholith is a massive, coarse-textured diorite, which, at Bethlehem, has been intruded by a younger quartz diorite, porphyries and breccia, referred to as the "Younger Complex." Mineralization, consisting of chalcopyrite and bornite with minor pyrite and molybdenite, occurs as disseminations, fracture fillings and coarse blebs. The ore zone lies close to the Guichon -Younger Complex contact where, prior to the development of the breccia, the rocks were shattered and jointed. Subsequent mineral

Jan 1, 1965

By F. R. Deluca

"ClassificationClassification is a combination of mechanical and hydraulic operation which separates a pulp into two portions according to their respective settling rate. The finished product, the overflow, is removed from the other product, sand, which requires further grinding.Pulp is the uniform suspension of solids in a liquid. Overflow is the fines and therefore the more slowly settling portion of the pulp which is carried over the top of the classifier by the flow of water; sand is the coarser and more rapidly settling portion of the original pulp which is discharged from the classifier by the mechanical action of the rakes or conveyed out by a ""screw"" .Selective classification is classification that has for its object the concentration of the heavy constituents of the original pulp in the sand product so that it may be ground finer than the lighter constituent.Classification is used as follows:I. To make a size separation, for example, a sand-fines separation so that each product may be given a different treatment.2. For closed circuit grinding so that the maximum size of particles entering the circuit is limited, and so that the useful work is increased by enabling the mill to operate mainly on the particles that require the reduction.3. For differential grinding of the heavy mineral constituent and the gangue. In this case, the heavy mineral is concentrated in the sand product and is reduced further, while the lighter gangue material overflows the classifier.The selection of the proper size and type of classifier is determined by the function required, the character of the ore, and the tonnage to be handled, the initial cost and the operating cost."

Jan 1, 1989

By S. Shairp

Copper is an impurity as well as a necessary reagent in the processing of zinc sulfide concentrate at Hudson Bay Mining & Smelting Co., Limited's (HBMS) zinc pressure leach plant. Copper is present in the zinc concentrate as chalcopyrite, which consumes reagents necessary for zinc leaching. A small percentage of copper precipitates in the autoclaves, discharge lines, and flash tanks, requiring maintenance of the equipment and disposal of the solids. Copper also precipitates in the neutralization stages and is removed to low levels in a specific copper removal stage of purification. Yet some copper, as copper sulfate, is required, along with potassium antimony tartrate, in the final purification stage to improve cobalt removal from the zinc sulfate solution prior to electrowinning. The behaviour of copper experienced at HBMS's zinc pressure leach plant is discussed.

Jan 1, 2008

By J. H. Baek, S. Alexandrovskii, D. W. Lee, B. K. Kim

Nano-phase titanium carbide was synthesized by Mg-thermal reduction process using a novel route of Mg-thermal reduction. The processes are based on I) feeding of TiC14+CxC14 x = 1, 2 ) solution into liquid magnesium, 2) Mg-reduction of metal chlorides, 3) TiC formation by the reaction of released Ti and C atoms, and 4) vacuum separation of residual liquid phases of Mg and MgCl2. In this study, the process for titanium carbide production with composition close to stoichiometry and the minimum content of impurities was optimized with the various process parameters such as concentration of initial solution, its feeding rate and reaction temperature, as well as a kinetic study.

Jan 1, 2004

By G. Brooks, M. Hamed, S. Nightingale, K. Coley

The Marangoni effect plays a significant role in slag line corrosion of refractories. Previous experimental studies for various refractory /slag systems and mathematical models are reviewed and show that Marangoni flow is important in slag line corrosion under static conditions. Recent work by the authors is presented which also shows significant slag-line corrosion of MgO refractory in SiO2-CaO-FeOx-MgO slag. The rate of attack of the MgO was marginally slower in the case of slags containing alumina. A semi-empirical model developed by Hrma based on mass transfer control described reasonably well the observed progression of corrosion with time. Further work is proposed to evaluate this model.

Jan 1, 2004

By Sandra L. Mesa-Espitia, Gretchen T. Lapidus

Gold present in arsenopyrite matrices is refractory and requires highly oxidative pretreatments in order to obtain acceptable degrees of extraction. However, these release many byproducts that are harmful to the environment. In the present work, a high-grade arsenopyritic ore was pretreated with different solutions, containing hydroxide ion, EDTA, oxalic, tartaric, or citric acids, to improve gold extractions in a posterior leaching step. The pretreatments were carried out at room temperature for 24 hours with a respective ligand concentration of 0.25 M. Once completed, the residue was leached in a thiosulfate solution to quantify the effect of the pretreatment on gold extraction. Only 29% of the gold content was leached, with very slow kinetics, in the untreated mineral. However, after pretreatment with tartaric or citric acid, the kinetics improved, although the percentage of gold extraction only reached 42-45%. The highest gold recovery, with very rapid kinetics, was found with the oxalic acid or the hydroxyl ion pretreatment (70 and 62%), respectively, but also corresponded to the most arsenic co-dissolution.

Jan 1, 2014

By W. D. Fogwill, P. J. Clarke

"The Dawn Lake uranium deposits are located 340 km north of La Ronge, Saskatchewan, in the Athabasca Basin between the Midwest Lake and Rabbit Lake deposits. Four zones of uranium mineralization, called the ""11, 14, 11A and 11B Zones,"" lie within the Athabasca Sandstone, at the sub-Athabasca unconformity and in the basement.At Dawn Lake, approximately 100 metres of Helikian Athabasca Group clastic sediments overlie Aphebian Wollaston Group pelitic and calcareous metasediments and pegmatites. Uranium with some nickel, cobalt and copper, occurs near the sheared stratigraphic contact between calc-silicate gneiss and graphitic, pyritic pelite. The mineralization lies in an area of low magnetic susceptibility which is thought to represent a rock sequence lying stratigraphically high within the Wollaston Group. There is no obvious vertical displacement of the unconformity by faulting, despite considerable brecciation, shearing and slickensides seen in the basement rocks. This suggests horizontal displacement on steeply dipping wrench faults as the main tectonic control along the 11, 11A and 11B trend.Below the Athabasca unconformity, the Wollaston Group rocks are altered to fine-grained mixtures of clays, chlorite and silica commonly called regolith. Along the mineralized trend post-Athabasca fracturing and (or) compaction have occurred through this clay-rich alteration zone, causing the steeply-dipping primary foliation to become contorted. This ""crenulated"" horizon can reach depths of 35 metres below the unconformity and is thickest along fault zones in the calc-silicate rocks. The ""crenulite"" is a distinctive unit which at Dawn Lake is commonly found above pods of ore located deep below the unconformity.Much of the mineralization in the 11A and 11B Zones occurs above, beside and below the thickest part of the crenulated zone, although the crenulated rock itself contains negligible amounts of carbonate, pyrite and uranium. Intense vuggy alteration and collapse breccias are found in calc-silicate rocks deeper and to the west of the 11A and 11B mineralization. There are at least two ages of uranium deposition in the basement zones, shown by small bright cubes of ""pitchblende /"" overgrown and replaced by duller botryoidal ""pitchblende II. ""Sooty pitchblende and yellow secondary minerals are the result of still younger reworking.The geological setting of mineralization, along the contact between carbonate-rich calc-silicate rock and pyritic pelite, suggests that the uranium was concentrated at a pH/Eh boundary located between deeply weathered, carbonate-rich and sulphide-rich basement rocks."

Jan 1, 1986

By Junto Nishiwaki, Shinji Kumai

"Mechanical and physical properties of the impact welded dissimilar metal joints are controlled by joint interface morphology. An intermediate layer (IML) is often formed at the joint interface and this deteriorates the interface quality in some metal combinations. Numerical and experimental studies were performed in order to examine the formation mechanism of the wavy interface and intermediate layer for explosive welded Al/Cu dissimilar metal joints. The impact welding process consists of (1) high-speed oblique collision of metal plates, (2) metal jet emission and large deformation and temperature increase at collision point and (3) rapid cooling at the joint interface. Euler-Lagrange coupling method, smooth particle hydrodynamic (SPH) method and modified laplacianFoam (LF) method were linked together to simulate a series of processes from (1) to (3), and the final interface morphology including the formation of IML was reproduced. The wavy morphology (wave-height, wavelength) and the position and composition of IML formed at the joint interface of Al/Cu joints were quantitatively in good agreement with those reproduced by numerical analysis. Our simulation results are useful for the control of the interface morphology, reduction of the amount of IML, and improvement of the mechanical properties of the impact welded dissimilar metal joints.INTRODUCTIONImpact welding is a kind of solid state joining method providing extremely high joint strength for both similar-and dissimilar metal combinations. Explosive welding and magnetic pulse welding are representative methods to achieve the impact welding. By a high-speed oblique collision between two metal plates, a metal jet is emitted from the collision point. The metal jet can remove any oxide films and contaminations on the plates and produce an active refreshed surface. Consequently, good metallurgical bonding can be achieved even for dissimilar metals (Crossland, 1982). Solid metals deform like fluids under the high pressure condition at the collision point and characteristic wavy interface is formed. In addition to the wavy interface, an intermediate layer (IML) is often formed at the joint interface in some metal combinations. Elimination or reduction of the amount of IML at the joint interface is desired since the excessive IML formation along the joint interface causes a large reduction in physical and mechanical properties. Formation of IML is considered to result from characteristic thermal history at the joint interface including partial melting due to the local temperature increase and successive rapid cooling behavior at the joint interface. In order to control the IML formation at the joint interface, it is necessary to reveal both heating and cooling processes at the joint interface. However, it is impossible to observe the phenomenon occurring at the joint interface and also difficult to investigate the temperature change at the joint interface directly during the impact welding. Therefore, simulation or numerical analysis is indispensable to overcome this problem. In the present study, the explosive welded Al/Cu joint, which is prone to form IML at the joint interface, was selected for the research. By using a newly developed numerical analysis method, not only the formation process of wavy interface, but also the local temperature increase and successive temperature decrease at the joint interface were reproduced. The formation process of IML was investigated by using both numerical analytic and experimental results."

Jan 1, 2018

By László Guczi1

Nanosize model gold particles with varying size were fabricated by deposition of a 10 nm thick gold film onto SiO2/Si(100) substrate by electron beam evaporation followed by modification using low energy Ar+ ion bombardment. The change in particle size were monitored by the Au 5d valence band states determined by ultraviolet photoelectron spectroscopy (UPS). The gold/iron oxide interface was studied by iron oxide deposition on gold. It was found that the energy profile of Au 5d valence band states are strongly redistributed with decreasing the gold particle size mostly affecting at the lowest and at the highest binding energies. The size effect in the UPS spectra can be interpreted by the energy redistribution rather, than by narrowing the 5d states. The iron oxide deposition increases the catalytic activity in CO oxidation whether it is on gold nanoparticles or on a continuous 80 nm thick gold film. The activity enhancement is significantly larger in case of gold nanoparticles. The interface interaction is operative in enlargement of the catalytic activity even if gold particles are not exposed to the surface, but they are located below the iron oxide layer.

Oct 1, 2003

By K. G. Markkola

Since 2005, Compafifa Contractual Minera Candelaria (CCMC) has defined various strategies which aim to optimize the usage of the available energy in each of the SAG grinding circuit modules (SABC-A configuration). For this purpose, the use of larger size balls along with operating with an optimum balls/load ratio has been implemented. Additionally, in the ball mills, the amount of balls in relation to the equipment's usable diameter has been optimized. In the pebble crushing circuit, the percentage of material passing 12 mm (112 in) product has been increased by 15% by: (1) modifying the crusher mantle profile, (2) implementing a strategy for maximizing the power in each crusher, (3) using continuous improvement tools (Lean - Six Sigma), (4) redesigning SAG mills discharge grates, and (5) changing discharge grates in order to control the crusher feed size distribution profile. All these activities have improved plant throughput by 1,000 t/d with no significant capital investment. As part of the energy consumption optimization study, we have considered determining the optimum operational rate of each SAG mill, in relation to the mill liner life and also the improving the control strategy in conventional grinding.

Jan 1, 2007

By B. Hewitt

Murrin Murrin Operations has not had a successful beginning. Numerous reliability and operability issues many of which are the result of design decisions have been addressed through mechanical and operational changes and the CCD circuit is no exception. The decision to install, the installation and the results of the CCD1 rake-lift mechanism and feedw ell dilution system are discussed in this paper. The installation was justified on improved operational robustness and an increase in the in the underflow density of 1% (per cent w/w). At approximately the same time process modifications in the solution neutralisation circuit were implemented and these changes altered the rheology of the slurry reporting to CCD1. Since the modifications to CCD1 and the solution neutralisation circuit, the CCD circuit has averaged a 2% improvement in the circuit underflow density. The CCD1 modification was completed on time and mechanically has performed well. From a risk point of view, the central rake-lift and Turbodil® dilution system add a degree of freedom and robustness to CCD1 operation that has extended the range of operational confidence. In this respect, the modification has been a success and is complementary to solution neutralisation improvements.

Jan 1, 2004

By B. Tougas

Recycling of titanium represents an important economic activity due to high cost of the material and the amount of returns of machined parts which represent the bulk of finished titanium products (typical "buy to fly" of 10 in the aeronautic industry). In the present work, the metallurgical quality of 76 mm in diameter and 20 cm ingots poured in coated graphite mold will be assessed against the nature and condition of application of 4 coatings namely aluminum oxide, yttrium oxide, zirconium oxide and zirconium oxide with 4% aluminum oxide. The metallurgical quality has been evaluated in terms of alpha case thickness, microstructure and composition. Microhardness from surface will be assessed against casting conditions. Least square regression analysis have been use to optimize casting conditions.

Jan 1, 2011

By H. Clare Horwood

"Three types of structures, the main shear zone, the north shear zone, and a series of hanging-wall fractures, contain all the orebodies so far discovered at the McKenzie Red Lake mine. Lenses and veins of quartz in these zones and fractures are the sources of the ore. The ore-bearing structures are unusual in that they are in a complex intrusive mass known as the McKenzie-Gold Eagle stock. They are believed to have been produced by compressive stresses from the south andsouthwest.The mine is on the northeast side of McKenzie island, in Dome township in the central part of the Red Lake area. The original discovery, the main shear zone, was made in 1928, about 3 years after the property was staked, by M. L. Bouzan who was in charge of prospecting and development work on the property. Subsequent diamond drilling and underground exploration led to the installation of a mill, which came into production early in 1935. The hanging-wall fractures were found branching out from the main shear zone during development work on the 350-foot level. The north shear zone was discovered in 1940.From 1935 when the mill began operation until the end of 1946 total production from the mine was approximately 269,349 oz. gold and 69,317 oz. silver, having a value of $9,679,739, recovered from 823,527 tons of ore.GENERAL GEOLOGYThe McKenzie-Gold Eagle stock has a total length of approximately 1 ½ miles and a width of about ½ mile. It was intruded into a complex synclinal fold in Timiskaming sediments. The sediments, which have been cut in only one place in the underground workings, are principally wellbedded greywackes. The stock is composed of large masses of diorite and granodiorite, a small mass of hornblende pyroxenite, and basic dykes of two ages. The diorite occurs as irregular masses in large measure surrounded by the granodiorite that it intrudes. It contains tabular crystals of andesine, having a maximum length of3/4 inch. The hornblende pyroxenite is an elongated lens or dyke in the diorite. The granodiorite masses occupy about two-thirds of the stock. Along its eastern side the main mass tends to become darker and more dioritic toward the diorite contact.Basic dykes of pre-vein and post-vein age are the youngest intrusive rocks at the mine."

Jan 1, 1954

By W. H. Mathews

"The Hardie group of cinnabar claims is in the interior of British Columbia; 25 miles northwest of the city of Kamloops. It is one of a number of mercury; properties scattered along a north trending belt 20 miles long and up to 5; miles wide. In all but one of these properties cinnabar is associated with; dolomite veinlets in zones of carbonate alteration in bedded rocks of Triassic; and Cretaceous (?) age; or in intrusives cutting these bedded rocks. No dolomite alteration or cinnabar mineralization is known in the undoubted Tertiary rocks adjacent to the mercury belt.The mercury showings of the Hardie group lie for the most part in a granitic stock cutting Cretaceous (?) volcanics. The rock in this intrusive shows marked variations in texture and has been described in earlier reports as granite and granodiorice, granite porphyry, and trachyte or dacite porphyry. At Hardie mountain the cinnabar mineralization, unlike that of the other properties, is associated with a fine-grained, almost chalcedoni c, quartz; carbonates, though present, are of minor importance. Some of the most interesting showings are found in an adit in the southeastern part of the property where cinnabar mineralization shows a very distinct structural but not a genetic relationship to a brown porphyry dyke 2 to 8 feet wide cutting a phase of the stock that may best be described as aplitic"

Jan 1, 1954

By Juergen Antrekowitsch, Stefan Steinlechner

"Waelz oxide from steel mill dust recycling is usually sold to the primary zinc industry, where it is first charged to the roasters to eliminate the remaining fluorides and chlorides. This limits the overall amount of secondary materials which can be used because of different operating problems in the roasters. Another option, in the case where the halides are low, would be direct leaching with low or medium concentrated sulphuric acid. Unfortunately, because of the carryover of some steel mill dust, iron is also present in the Waelz oxide, reaching contents up to 5 wt.%. Since the objective is to treat the solution more or less directly by electrowinning, with only a few simple preliminary purification steps, iron in the solution is a very important factor. Various trials have been done to investigate the dissolution behavior of the iron contained in the Waelz oxide. Although the zinc extraction should reach a maximum, all other elements, especially iron, should be low. This paper describes the results of our research in this area and offers possible options for Waelz oxide utilization. There is also a focus on how other elements, present in the material, influence the dissolution behaviour of zinc and iron, and whether a loss of zinc is unavoidable, if low iron dissolution is required.INTRODUCTION One of the most important secondary zinc resources is the zinc oxide originating from steel mill dust recycling. For the treatment of high zinc containing steel mill dusts, the Waelz kiln process is the so called “best available technology” and it dominates the industry, with roughly a 90% market share. The product Waelz oxide contains mostly zinc oxide, but it also contains lead compounds and halides due to evaporation with the zinc. In addition, it contains iron and some slag compounds due to mechanical carry-over. The presence of halides limits the use of the material as an alternative concentrate for primary zinc electrowinning. Such halides can be reduced to a certain extent by washing and/or solvent extraction (see following chapter). Although lead is not troublesome and theoretically represents a second recoverable valuable metal, iron is unwanted and causes additional problems during leaching. Even though Waelz oxide is generally a highly welcome input material in primary zinc metallurgy, due to its high zinc content, it still contains halides, and in the majority of cases, the oxide must first be treated in a roasting process. Different circumstances, like accretion formation because of the lead and halogen compounds as well as unwanted cooling effects in the roaster, limit the amount of Waelz oxide which can be substituted for the primary concentrate. Another, even more limiting factor, is the allowable concentrations of chlorides and fluorides in zinc electrowinning, the last step in the primary zinc processing route (Ruetten, 2011)."

Jan 1, 2016

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