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By C. S. Parsons

Custom milling-plants have been operated successfully for a great many years on this continent. One of the outstanding examples in the United States is the Golden Cycle mill at Colorado Springs, which mills the gold-telluride ores from the Cripple Creek district. In eastern Canada, the Northern Custom Concentrators, Limited, at Cobalt, successfully treated the cobalt-silver ores of that area for a number of years. Flotation plants have entered the custom field in the past few years. The building of flotation concentrators to treat ores on a custom basis indicates the advance which has been made in flotation. In fact, three years ago it was considered almost impossible to treat successfully a mixture of miscellaneous ores by flotation. The methods used at that time were considered so delicate that any change, even in a single ore, would usually result in decreasing the effectiveness of the separation. Today we find four large custom flotation plants in the United States and one in Canada for treating complex lead-zinc ores from many different localities. The advent of these mills was brought about by the serious problem confronting the lead-smelting plants due to increasing amounts of zinc in the ores presented for treatment. It was necessary to penalize the mines shipping high-zinc ores. The penalty is justified, because high zinc in the lead blast-furnace charge not only decreases the tonnage of the furnace but increases the amount of flux necessary, as well as increasing the metal loss in the slag. It has been estimated that in the Salt Lake valley alone, 75,000,000 pounds of zinc was lost in the slag-dumps from the operations of three large lead blast-furnace plants. It has also been estimated that $150,000 worth of additional flux was required to slag this zinc. It was to avoid at least a part of this wste and to help maintain an ore supply that custom flotation concentrators were built by the smelters.

Jan 1, 1928

By C. R. Whittemore

Introduction The technical library in the service of industry is gradually becoming a well recognized and important part of all progressive industrial organizations. The larger mining, metallurgical, and chemical firms of Canada are establishing extensive reference libraries in connection with their research and operating departments in order that the members of the organization may keep abreast of the rapidly developing fields of engineering in which they are interested. It is the purpose of this paper to point out the usefulness of such a department in any industrial organization, to give a general outline of a system for filing and dispensing information, and to outline briefly the literature to be consulted and the procedure to be adopted in instigating a literature search. The technical library falls under the classification known as 'Special Libraries', and is quite different from the general library in that it is a storehouse of facts and owes its value to the ready presentation of information required for each specific case, and in a form most ready for use. The library brings all the available information relative to the interests of the corporation from without the plant to the organization within, and also keep in touch with each department of the organization.

Jan 1, 1930

By Luke Meers

Roadway development rates in Australian underground coal mines are failing to keep pace with modern longwall systems and are unlikely to sustain further improvements in longwall productivity into the future unless step change improvements to roadway development equipment and practices are made. Bottlenecks which limit and constrain improved production and impact the safety of operators have been identified through a series of industry surveys, with the manual installation of strata support materials, consumables delivery, coal haulage and monorail installation being highlighted as major areas to improve development performance. This paper looks at research being carried out at the University of Wollongong in designing an integrated system approach for the fully automated handling and installing of development consumables, and the systems required to support these activities. A series of hard automation manipulation devices have been demonstrated in surface trials and the results indicate that rapid roadway development can be achieved.

Aug 1, 2013

By C. E. Dowker

"IntroductionMechanization underground at the Buffalo Ankerite mine in Deloro township, Porcupine district, had reached a high level by 1944, both in equipment available, and in the use of this equipment, for all stoping operations. Power feed leyners and the latest type of stopers for drilling, slushers for moving ore and fill, and tugger hoists for all servicing, did much to halt rising stope costs, and in some cases decreased them. On the other hand, little beyond the use of mucking machines and power feed leyners had been adopted in the effort to reduce level development costs, or to increase the advance per man-shift.Faced with ever increasing level development costs, caused by rising prices of equipment and supplies, coupled with increasing wage demands for less physical effort, it was realized that more mechanization of development work was essential. The objectives of such further mechanization were:(1) Decreased development costs(2) Increased footage per man-shift(3) Less physical effort by development crews, with greater take-home pay (4) A more satisfied and stable labour force"

Jan 1, 1950

By John T. Ling

"This paper describes the operation of a rope haulage used as the main system of transportation in an underground coal mine. Prince Colliery, which is operated by the Cape Breton Development Corporation, has been in operation for 23 years and produces 1.2 million tonnes of coal annually. The mine extends a distance of 8000 metres under the Atlantic Ocean. All personnel and supplies are transported by means of an endless rope haulage system consisting of a train of rail cars that are operated by an electric engine on surface. The wire rope is 15 km long and weighs 63 tonnes. The system is believed to be the longest of its type used in an underground coal mine. The design of the system, safety features of the haulage, and problems encountered during the design and construction are described. IntroductionCoal has been mined commercially in Cape Breton, Nova Scotia since the 1800s. Several coal seams that are part of the Sydney coal fields, dip toward the north and northeast out under the Atlantic Ocean at angles between -4 and -15 degrees. Coal has been economically mined at depth in excess of 1200 m and more than 11 km from the coastline.Traditionally, single and double drum hoists have been used to haul the coal to the surface and also for transporting the workers and the materials required for mining up to 8 km. With the introduction of mechanized mining methods in the late 1960s, conveyor belts began to replace rope hoists for coal transportation. Improvements in hoisting system design also allowed for drums that could wind up to 6100 m of 32 mm wire rope in 15 layers.These hoists are commonly referred to as “drop hoists” because they take advantage of the gradient of the slope to assist in allowing the mine car train to reach the end of travel. The cars travel on steel rails and the rope is guided by rollers to reduce friction in the system."

Jan 1, 1999

By S. E. Wolfe

The presence of helical ribs in smooth-bore round pipe results in the transport of granular solid particles m water at a much lower velocity than required to transport the same solids in a smooth pipe. The helical motion imparted to the flowing mixture effectively returns settled solid particles to the main stream. The flow may be stopped and restarted without difficulty. Due to the lower velocity required for satisfactory transport large power savings are realized. Also: due to lower velocity, the wear on the pipe walls is much reduced. For satisfactory performance, the ribs should have a high angle relative to the long axis of the pipe and the lineal spacing between adjacent ribs should be modest.

Jan 1, 1967

By Mory Ghomshei

Pebble Creek Geothermal Power project is associated with a massive recent volcanic eruption in Southwestern British Columbia Canada. Slim holes drilled to depths 1100 m in the prospect area, show very high temperature gradients around 80?100?C/km. The temperature and chemistry of the Pebble Creek hot springs indicate the possibility of a steam reservoir in the prospect area. In addition to high temperature gradients, presence of host rocks with high permeability, along with abundance of recharge waters (from the Lillooet River) provides clear signature of a high-grade geothermal power reservoir at depth 2000 to 3000 m. Data show that over five hundred Megawatt of green power can be generated from the prospect area in a commercially viable manner. The generated power will be base-load, which in comparison with large hydro has the advantage of lower capital costs and a significantly smaller footprint. The final hurdle to overcome, before starting the development phase, is deep exploratory drilling for resource confirmation. This paper is a summary of the data available on the Pebble Creek geothermal power prospect, presented in the context of viability of the resource for large-scale commercial power generation.

Aug 1, 2013

By R. J. Chase, C. Davies

"The Merelani graphite-tanzanite deposit is located in northeast Tanzania, 14 kilometers south of Kilimajaro International Airport and in close proximity to the towns of Moshi and Arusha. The graphite mineralization is hosted by relatively undeformed linear Proterozoic metasedimentary gneisses, several of which have been subjected to hydrothermal alteration resulting in tanzanite mineralization. Exploration work comprised detailed geological mapping coupled with pit and trench channel sampling and a subsequent 1500 meters of diamond drilling. In addition, metallurgical tests have shown the graphite to be of unusually coarse flake size, crystallinity and high purity.Feasability studies have shown the economic viability of a major coarse flake graphite deposit with the measured resource to 50 meters in excess of 9 million tonnes assaying over 85 graphitic carbon. Production is due to start by the end of the first quarter of 1994 with the processing plant design capacity initially set at 15 000 tonnes per annum.In addition to graphite production, tanzanite will be produced through selective mining within the graphite open pit in the upper horizon and from underground workings within the lower horizon.The Merelani graphite-tanzanite deposit will be the first major orebody to be exploited through means of private funding since Tanzania gained independence"

Jan 1, 1994

By H. E. T. Haultain

I HAVE considerable hesitation in preparing and presenting this paper. These machines have been such an intimate part of my own experiences and predilections for such a long time that J would find it difficult to tell the story in an impersonal way. They have had several attractions for me. They were needed for the study of the fundamental features of modern milling, size analysis and accurate batch concentration of the very fine particles. I had been a millman once, a real operating millman, and, when I became academic". I always had the craving to link the academic laboratory with the field, as Rittinger and Richards had done. My first milling experience was with a small concentrator at a tin mine in Bohemia, forty-seven years ago. There was no assay office and the testing of our tailings was by means of a "Vanning Shovel", introduced from Cornwall by Captain Josiah Thomas, the great Josiah of Dolcoath, some fifteen years previously. This was a most effective instrument and it has always been a puzzle to me that it has not been more universally used by millmen. Later, at Freiberg, on the other side of the Erz Gebirge from the tin mine, I was introduced to the "Sichertrog", made out of wood shaped something like a very shallow boat or an elongated saucer, a most effective piece of apparatus when. the difficult technique of handling it was once achieved. Later, in the Slocan in British Columbia, my partner, the late Maurice Bucke, used a short length of flat trough or launder suspended by four wires, with which he got very satisfactory results as a small batch concentrator. In the University laboratory we had frequent need for something of this kind, and many efforts were made to solve the problem. With W. E. Johnston, we were working on the problem of gold-bearing telluride ores, which called insistently for a separation of the very fine telluride particles which existed only in minute quantities in the Kirkland Lake ores. Under this spur there finally developed the Superpanner, which is a mechanized combination of the Vanning Shovel, the Sichertrog, and the Maurice Bucke suspended launder.

Jan 1, 1937

By H. C. Cooke

Those who have followed the geological developments in connection with the copper deposits of Quebec will recall that on many properties the sulphide bodies occur as replacements of fault breccias or tuff breccias, and exhibit a pronounced distaste for the more massive lavas. At the same time the rocks around the ore-bodies are profundly altered, first by addition of silica and sericite, later by conversion of these minerals into chlorite. It has been known for some years that at the Amulet and Waite-Ackerman Montgomery mines these conditions do not prevail. At both mines the ore-bodies are replacements of massive lavas, and at the Amulet they are associated with a very peculiar rock christened ?spotted dog', or 'dalmatianite'. Accordingly, when in 1929 the writer had the opportunity to make a further examination of these properties, two problems presented themselves for solution. The first was to determine, if possible, the conditions under which massive lava, rather than breccia, is replaced by the sulphide masses; the second, to find out the exact nature of dalmatianite and its relations to the sulphide bodies. The first of these problems is believed to have been solved; the second has been found very complex, and will require further work before it is satisfactorily settled.

Jan 1, 1930

By R. Clarkson

"Free gold particles occur in many base metal and precious metal mines throughout the world. Due to the high density and malleability of gold, large circulating loads of free gold particles can build up over time in grinding circuits. This gold is often deposited in unintended traps throughout the mineral processing system.These unidentified free gold deposits represent a serious security risk as well as an inaccessible inventory of gold. Deposits of free gold particles often remain undetected by mine management until they are accidentally discovered while repairing mill equipment.Nuclear tracers have been used to determine the free gold recovery efficiency of gravity recovery equipment, drills, and sampling equipment (Clarkson, 1994, 1995; Walsh and Rao, 1986; Walsh and Kelly, 1992). In November, 1993, the author inspected the grinding circuit at La Mine Doyon in Rouyn-Noranda, Quebec and made recommendations to recover coarse gold and to eliminate gold traps from the circuit. In 1995, the author salted mineral processing circuits with radioactive gold particles. The gamma and X-ray radiation from gold’s nuclear isotope (Au198) were detected through steel, in pipes, and in moving equipment using scintillometers. The radiotracers proved to be a safe, rapid and accurate method of identifying gold traps and improving security.Nuclear TracersWhen particles of gold are placed in a nuclear reactor, some of the gold atoms (Au197) absorb another neutron in their nucleus to form gold’s radioactive isotope (Au198). In the process of radioactive decay, this isotope emits high energy gamma rays and X-rays which are easily detected (even through steel) with scintillometers.Radioactive gold (Au198) has a very short halflife of 2.7 days. At the relatively low activity levels used for tracing, the particles remain detectable with a small hand-held scintillometer for about 10 to 14 days. After 14 days the irradiated gold is close to background levels and within two months it is essentially non-radioactive. The radiation has no effect on the recovery characteristics of the gold particles. The gold radiotracers are very safe due to their very low level of radiation, short half-life, and their inherent physical and chemical stability. However, the use and possession of even mildly irradiated gold is strictly licensed and regulated."

Jan 1, 1997

By K. Swedburg, M. Samuels

"The expansion of the concentrator at New Gold’s New Afton copper-gold mine in British Columbia, Canada, completed in 2015, included an increase in the required retention time of the cleaning circuit. On site pilot testing of a Woodgrove Staged Flotation Reactor (SFR) had shown that a high grade copper concentrate would be produced with excellent recovery. The SFR was selected rather than conventional tank cell technology based on the much smaller footprint (which rendered a separate and expensive building extension unnecessary), high concentrate grades demonstrated in testing, and the lower energy requirement. Three SFRs, each capable of taking a nominal feed of 700 cubic meters per hour were installed and commissioned 10 months after the receipt of order. The SFRs operate in series and all of the cells produce a final concentrate typically grading 32% Cu, while the overall SFR stage recovery averages 55%. The tailings from the SFRs are treated in the original conventional three-stage cleaner circuit where the remaining values are recovered in a concentrate grading 28% Cu. Design production was achieved within days of the initial start-up of the SFR circuit.INTRODUCTIONThe New Afton concentrator, located near Kamloops, British Columbia, Canada processes a copper-gold ore with a designed head grade of 0.96% Cu, 0.72 g/tonne Au, and 2.22 g/t Ag.The New Afton Mine is a block cave mining operation. Ore is undercut from the bottom up and removed at the extraction level from a grid of draw points. Ore is trammed to the ore passes by underground loader and dropped to a haulage level for transport by trucks to the gyratory crusher. From the crusher, the ore is conveyed to the mill via a 4.5 kilometre long conveyor system. Block caving was chosen for the New Afton deposit because the underground infrastructure could be built below the historical open pit of the Afton Mine (a previous operation of Teck Resources) and this method is favorable to large-scale low-cost mining.The New Afton deposit is a copper-gold, alkalic porphyry system. Hypogene mineralization is characterized by discontinuous copper sulphide veinlets and disseminations, principally chalcopyrite and minor bornite, along with pyrite as the second most dominant sulphide. Gold particles vary in size from 5 µm to 40 µm and occur as native gold and electrum, associated mostly with the chalcopyrite grains and never with the pyrite. In some instances, a second alteration phase has resulted in the copper sulphides being replaced by tennantite-tetrahedrite locally and along faults that transect the mineralized body. The design head grade of arsenic is 244 PPM, although the presence of tennantite is inconsistent and can vary from trace levels to 15% of the total copper. No arsenopyrite is present in the hypogene ores. Supergene mineralization, consisting of native copper with accessory chalcocite occurs in minor amounts along faults and highly oxidized near-surface portions of the deposit."

Jan 1, 2016

By R. D. Brown

For the first time in years, the spring budgets of federal and provincial governments have not brought down major new proposals affecting the tax burdens of the mining industry in Canada. It seems appropriate to use this unaccustomed period of tranquility to set out an extremely abbreviated summary of the principal features of the federal and provincial income and mining tax rules affecting the mining industry.

Jan 1, 1977

By Grant Arnold

Le Camp Minier de Matagami est situé dans la ceinture volcano-sédimentaire Harricana- Turgeon appartenant à la Province du Supérieur, sous-province de l?Abitibi, au Québec. Les gisements de métaux de base polymétalliques sont retrouvés exclusivement dans les deux domaines lithotectoniques comprenant l?association basalte-rhyolite (Matagami-Brouillan et Joutel-Raymond). Tous ces dépôts, à l?exception de ceux de Selbaie, sont de type exhalatif et représentent des dépôts volcanogènes à Zn-Cu, typiques de l?Archéen. Le complexe volcanique de Matagami est constitué principalement de deux phases de volcanisme tholéïtique. Les dacites et les rhyolites du Groupe de Watson, représentent la phase la plus précoce et celles-cis sont recouvertes par la seconde phase qui est constituée majoritairement de roches intermédiares à mafiques intercalées d?horizons felsiques, formant le Groupe de Wabassee. Un sédiment chimique sulfuré, la Tuffite Clef, marque le contact et l?hiatus entre ces deux groupes. Cette tuffite est reconnue à la grandeur du flanc sud du camp minier et représente l?horizon favorable à explorer puisque sa déposition a correwspond à une période d?intense activité hydrothermale. Le complexe volcanique de Matagami est limité au nord et au sud par des bandes sédimentaires orientées est-ouest, connues respectivement sous les noms de Groupe de Matagami et Groupe de Taïbi. Le Complexe intrusif de la Rivière Bell, qui occupe la base du Groupe de Watson, est un complexe lité consistant en une séquence stratifiée gabbroïque avec localement des niveaux stratiformes à concentrations d?oxydes magmatiques, la bordure de ce complexe est marquée par la présence d?un horizon granophyrique. Cette intrusion synvolcanique prétectonique, représente probablement la source de chaleur étant à l?origine de l?activité hydrothermale observée dans les roches volcaniques sus-jacentes. Suite à un levé aéroporté, le camp minier de Matagami a vu le jour en 1956 lors de la découverte du dépôt de Mattagami Lake, un gisement volcanogène de 25.6 millions de tonnes. Depuis ce temps, un total de neuf gisements ont été exploités et un dixième, Bell Allard, est présentement en production. En date du 31 décembre 1999, la production historique du camp s?élevait à plus de 41 millions de tonnes. Cette présentation mettra l?accent sur la géologie des récentes découvertes dans le prolifique camp minier de Matagami. Les ressources publiées pour le dépôt Persévérance sont de 947,000 tonnes titrant 19.12% Zn, 1.37% Cu, 32 g/t Ag et 0.40 g/t Au. Deux autres découvertes, Équinoxe et Persévérance Ouest contibueront à la ressource globale. Les trois dépôts sont situés au niveau de la Tuffite Clef même si les roches sus-jacentes ne sont pas celles typiquement observées dans les autres dépôts du flanc sud. Ces découvertes sont le résultat d?un programme d?exploration ciblé et soutenu, démontrant ainsi la possibilité de découvrir de nouvelles ressources même dans les camps miniers comme Matagami qui ont été explorés intensivement depuis plus d?un demi-siècle.

May 1, 2001

By R. Simon, A. Khosravi

"Tensile strength of rock samples is measured by direct and indirect tensile tests in accordance with standard guidelines. Due to the difficulties in performing direct tensile test, the indirect tensile (Brazilian) test is conventionally carried out to obtain the ultimate tensile strength. A limited number of studies have been conducted to investigate the role of sample size (length to diameter ratio = L/D) in the stress distribution of the Brazilian test using numerical and analytical methods. These investigations showed that the tensile stress distribution along the loading diameter is not uniform. They also indicated that the difference between the tensile stress at the middle part and at the sides of the sample with higher L/D ratio is greater than that in the other samples.The objective of this study is to show the effect of tensile stress distribution on the fracture surface created by the Brazilian test from a morphological point of view on the samples with different L/D ratio. Hence, a series of fracture surfaces created using the Brazilian tests on the rock samples with L/D of 0.5, 0.75, 1, 1.25 and 1.5 were investigated.In this study, all fracture surfaces were scanned by a 3D laser profilommeter. A number of roughness profiles parallel and perpendicular to loading axis have been selected from the samples with different L/D ratio and spacing of 1 mm. The results show that the roughness of the profiles perpendicular to the loading axis increases with an increase of L/D ratio, while the roughness of the profiles parallel to the loading axis decreases. Furthermore, some roughness profiles parallel to the loading axis were chosen and divided into three segments. The results revealed that the segment in adjacent to the upper loading platen possesses higher roughness than the other segments."

Jan 1, 2015

Over five decades ago Kitchener et al. in England and La Mer and Healy in the US were advancing our understanding and application of flocculants, primarily related to water treatment and filtration of sludge. This paper identifies the beneficial uses of flocculants in the mining industry and revisits some less common applications. Flocculants are used in unique ways in the mining industry: (a) to increase the effectiveness of sediment ponds to achieve discharge compliance; (b) to eliminate air emissions and costs associated with concentrate drying; (c) to reduce soil loss by applying a flocculant to erodible soils, and reducing wind and water erosion; (d) to remove/thicken metal precipitates in acid rock drainage treatment; and (e) to enhance clarification and thickening in mineral processing. The mechanism of how flocculants, coagulations and potentially-determining ions function is described and how their use can be controlled and optimized. The potential toxic effects of flocculants and coagulants when used to achieve effluent permit discharge compliance for suspended solids is discussed. A review of numerous best management practice (BMP) guidelines for the design and operation of sediment ponds treating mine site runoff to remove total suspended solids (TSS) and turbidity revealed an absence of a predictive methodology to address regulatory discharge compliance for TSS concentration, turbidity and flocculant-induced toxicity. An essential component of pond design is the need to determine whether flocculants and/or other settling aids are required based on the site-specific soil particle size distributions upslope of the pond. Procedures are provided to predict the need for settling aids and estimate pond discharge quality and downstream impact for TSS, turbidity, toxicity and sub-lethal toxicity. The need to develop BMP guidelines are discussed for (a) the application of flocculant to surface soils to reduce erosion, (b) the application of flocblocks to increase the ?sediment control? aspects of erosion and sediment control, as part of the mine site erosion control plan strategy and (c) the application of flocculant to silt socks to treat mine site runoff.

Aug 1, 2013

By G. W. Harris, P. Mousset-Jones, J. Daemen

"To minimize ore dilution induced by blast movement in surface mines, it is necessary to quantify such movement. This will enable more accurate location of the grade boundaries beneath the surface of a blasted rock pile before excavation. A method has been developed and tested to accurately measure the direction and magnitude of subsurface blast movement. This technique uses a cesium vapour gradiometer and a real-time, differentially corrected GPS system to locate pre- and post-blast position of magnetically enhanced target objects placed within blastholes inside a bench. The procedure developed does not require the blasted rock to be disturbed, and the movement information is available within a sufficient time to allow for modification of the selective mining boundaries for each surveyed blast. It was found that the maximum depth of target detection was 18 m, with the overall accuracy being measured as ±1 m (horizontally) and ± 1.2 m (vertically). IntroductionOre dilution is a critical concern for many mining operations. In some instances, it may be the cause of considerable mineral loss. Where the mineralization is finely grained, sedimentary and disseminated in nature, and exhibits no clearly defined visual ore/waste boundary, there is a heightened possibility for ore grade dilution. In most modern open pit gold mines, it is economically desirable to minimize dilution in the production process through the practice of selective mining by defining pre-blast ore digging boundaries, called digging polygons, on the preblast bench area. The polygons’ positions are defined by sampling the production drill holes, with the resultant assay and survey data being used to estimate the areas of specified grade content within the bench. Once the ore is blasted in the bench, the pre-blast locations of these digging polygons are flagged as designated areas on the broken ore pile. The purpose is for the loader operator to be able to recognize which areas of blasted rock are to be sent to the appropriate processing facility or to the waste dump."

Jan 1, 2001

By L. Mercier, A. El-Hsaeri, L. Amaratunga

Laboratory scale studies of the development and application of high capacity heavy metal ion adsorbents with uniform nanoscale porosity (denoted MP-HMS, mercaptopropyl - hexagonal mesoporous structure) to extract gold from solutions is described. The adsorbents are selective towards gold ions. The adsorption capacities of these materials are also among the highest reported. MP-HMS has shown the capability to adsorb 330-mg gold per gram adsorbent (up to 30% of their weight). Gold uptake by the adsorbent was found to increase dramatically with solution agitation. The adsorbent was found to be extremely effective in adsorbing gold ions from ultra- low concentrations, like those found in mine effluents. Experimental studies indicated that MP-HMS maximum adsorption of gold (99.9%) occurred under all solution concentrations. Another promising attribute of these materials is their favorable adsorption kinetics. The contact time required for 80% adsorption of gold was found to be less than 60 seconds. The efficiency of these nanoporous materials for the recovery of gold from mining effluent is evaluated and their prospect for application in the mining industry discussed. The process thus has the prospect of becoming an efficient and environmental friendly method to recover gold from aqueous solutions, such as gold mill effluents.

Jan 1, 2004

By J. Borlee, F. Sorrentino, A. Fleischanderl, M. Gimenez, W. Gebert, U. Gennari

Large quantities of solid by-products are generated by the steel industry and other important activity sectors in Europe (power plants, car dismantling companies, urban incinerators) with no or very limited potential for direct recovery. In the frame of a multi¬national project supported by the European Union, a consortium has been created to develop a treatment process able to turn these by-products into valuable metallic and mineral products. VAI has been responsible for the design, erection and start-up of the pilot plant for the new metallurgical process and for the execution of the test campaigns, with the targets defined together with the partners. Up to now, 9 campaigns comprising 60 heats have been performed successfully. By-products from C-Steel and stainless steel plants, as well as fly ash and auto shredder residues, have been used and defined products such as hydraulic binders for cement, metallurgical powders for De-S practice and recycled metal phase have been produced. The mineral products were positively assessed under industrial conditions. Results from cement tests and secondary metallurgy are reported, as well as a detailed characterization. The economic value of the products, credits from avoiding dumping and significant savings on CO2 emissions make the new process economically very attractive.

Jan 1, 2004

By Xu Wang, Yizhe Zhang, Yangge Zhu, Xiao’ou Xia, Fangming Liu

"The progress of lean magnetite preconcentration in China was introduced in this paper, such as using coarse crushing to reject tailings, and multistage grinding, multistage magnetic separation. The applications of “more crushing and less grinding” process and equipment in lean magnetite preconcentration could reduce production costs effectively. The related analysis and study on concrete cases were carried out in this paper.INTRODUCTIONIn the case of the slowdown and weak recovery in the global economy, bulk commodity prices fell sharply in 2015. Take iron ore's prices for example, about 60% grade iron ore's import prices in China from about $65 per ton at the beginning of 2015 fell to about $42 per ton in the end of the year, down by about 35%. But iron ore resources are non-renewable resources, with the continuous development and utilization of mineral resources, high grade iron ore resources will be exhausted gradually. Accompanying with the economic recovery iron ore prices after this fall is bound to return to its value to maintain a high level.The development and utilization of resources is gradually turning to the low grade iron ore. Restricted by technical development level and disadvantages of lean iron ore resources, the cost of utilization lean iron ore resources is relatively high. Making full use of their rich lean ore resources has become many countries' important strategy to get rid of dependence on foreign countries' ore. Over the years with the development and progress of lean magnetite mineral processing technology in China, the production number of concentrator has been greatly improved.As the world's largest steel producer and consumer countries, ensuring a stable and continuous supply of iron ore is particularly important for the healthy development of China's iron and steel industry. Chinese iron ore production and import data in recent years are showed in Table 1.With the expansion of iron and steel production, iron ore demand has also been a phenomenal growth. Taking 2013 for example, China's crude steel production is about 780 million tons in 2013, accounting for about half of the world's total output of crude steel. At the same time, China is also the first major iron ore import countries whose iron ore imports in 2013 was about 820 million tons, an increase of about 10%. The degree of external dependence is very high. In some years, the cost of China's iron ore imports was even more than $100 billion, and second only to oil’s import cost in all bulk commodities."

Jan 1, 2016