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By Joerg Hammerschmidt, Marcus Runkel, Steffen Haus

Given the limited number of new plant construction, focus is turning to the optimization of existing metallurgical roasting plants. To meet the goals of high process efficiency with limited capital expenditure, plant owners are looking for new strategies, including digitization and expert support. As a supplier for numerous roasting, gas cleaning and sulfuric acid plants, Outotec has intensified its effort in recent years to develop solutions to accommodate increasing customer need. This article presents a short review on how Outotec is applying advanced control tools for the fluidized bed industry. Focus will be given on how to transfer the existing technology (used in selected Zinc roasting plants for over a year now) to copper roasting. Outotec has developed the Pretium Roaster Optimizer, a system based on heat and mass-balanced simulation models. Direct experience with this technology will be shared and will highlight similarities to the Partial and Sulfate Copper roasting processes. Pretium detects equipment and plant bottlenecks and provides consistency in process development. The Pretium program combines 24/7 advanced online digitalization tools, along with expert personal support when required. INTRODUCTION Fluidized bed reactors have been used for commercial-scale zinc and copper roasting since the 1950s. While the principles of roasting remain unchanged, over time, the technology has advanced to improve process control of roasting plants. In the past, environmental and safety standards were the driving forces for improvement of equipment and plant design. Today, the emphasis is on plant efficiency and optimization. Another change has come in process control philosophy. While plant control and operation have traditionally been the responsibility of owner/operators, they have now shifted to include both integrated digital tools and specific know-how from engineering companies. This can be seen from the earliest design stages through commissioning and into production, as evidenced by zinc roasting plants in Mexico, Brazil and Turkey.

Jan 1, 2019

"The last thirty years have seen enormous changes in all aspects of the gold industry, from the technologies of mining and extracting gold to the role it has played in the fiscal policies of nations. In this time, the market price of gold has increased ten fold and mine production has more than doubled. However, the cost of mining and extracting gold has also increased exponentially, and the industry has struggled with declining ore grades and increasingly refractory ore bodies.With the major economic powers of the world shrugging off the uncertainties of the post cold war era and moving into a period of unprecedented political stability, economic growth and low inflation, gold is also losing its lustre as a hedge against inflation and a backing for national currencies. Consequently, countries that had accumulated and hoarded gold for decades are now disposing of these non-performing assets, resulting in major swings in supply of the metal. Fortunately, this has coincided with the end of communism in many parts of the world and a tentative move to free market economies in most of the developing nations. As a result, people are becoming wealthier, and this is creating more demand for gold, principally in the form of jewelry.On balance, the shift in the role of gold, from one in which a significant portion of new gold production lay dormant in bank vaults as insurance against political or fiscal instability, to one in which most new gold is now freely traded as an industrial commodity, responding to normal market forces of supply and demand, has had a negative impact on the price of gold over the last fifteen years. In that time, the gold price has declined from a peak of $850/oz in 1980 to an average price of about $400 through the rest of the l 980's, to a price of -$320/oz today (1997). In large measure, this has been due to the enormous inventory of gold metal that was held by central government banks in vaults around the world, and which has been dumped on the market as soon as the price has started to trend upwards. Even today, after ten years of fairly steady selling by central banks, about 3 0, 000 tons of gold (or -8 years' supply at the present rate of consumption) is still retained in vaults (Murray et al., 1997).The downward pressure on the price of gold has created exciting opportunities for the development and implementation of new technology. Increasing the efficiency of gold recovery from more and more refractory ore bodies, whilst at the same time lowering production costs, have become critical to survival in this industry. These challenges have been met by the development and implementation of new technologies such as heap leaching, carbon in pulp, resin in pulp and the sulphide ore pre-treatment process of pressure leaching, bacterial leaching and fluid bed roasting. For an industry that saw very little technological change in the first seventy years of the twentieth century, the pace of change over the last thirty years must have seemed bewildering at times."

Jan 1, 1998

By Törbjorn Naarttijärvi, Bengt Ludvig, Agne Rustan

"Falling rock is one of the major causes of serious injuries and deaths in Swedish mines. The research at the Division of Mining and Underground Construction was therefore directed toward controlled blasting in hard intense jointed rock.The project was started with an extensive literature review. Model tests with a new equivalent model material have been initiated to find ways of improving blasting techniques. The result showed that long cracks arise at the perimeter holes when there is a long time delay between adjacent holes. This led to the theoretical development of a new initiation method with ultra short delays (1,5 ms) f or controlled blasting, called ""Cutblasting"".Full-scale tests have been done at LKAB in Malmberget in hard intense jointed magnetite ore. Four different types of perimeter charges have been tested, namely: tube charges, ANFO mixed with plastic beads, detonating cord and linear shaped charges. Three types of initiation of the perimeter holes have been used, conventional (half-second delay detonators), instantaneous and ultra short ""cutblasting initiation"" (1,5 ms delay). The change in rock strength before and after blasting has been studied with bore hole periscope, vibration measurement and ocular observation of the rock surfaces.Thefull-scale tests showed that ""cutblasting"" with detonating cord in the perimeter holes gave the smallest damage to the surrounding rock. A combination of cutblasting initiation and tube charges are anticipated to give an even better result. A new method of controlled blasting using linear-shaped charges has also been tested, however, this charge type needs further development.The full- scale test also showed that the damage which can be seen on the rock surf ace is about the same for different controlled blasting methods but the not-visual-damage zone varies as much as from 0,1 to 0,7 m.A new classification system for controlled blasting regarding the damage to the surrounding rock has been devised."

Jan 1, 1985

By D. V. Krefting, D. R. Bennett

"The Cyprus Anvil Mining Corporation established a lead-zinc mine and concentrating plant at Faro in Yukon Territory in 1969. Following some 12 years of continuous operation from a single pit adjacent to the concentrator, the company decided to expand operations into two additional areas on the Vangorda Plateau. The two new deposits, known as Grum and Vangorda, are located some 15 kilometres from the existing concentrator.Confirmation of mining feasibility was followed by determination of the most practical and economical method of transporting the raw ore from the new mine sites to the existing concentrator. This analysis was carried out in two phases. The first phase reviewed the feasibility of alternative transportation systems on an 'order-of-magnitude' cost basis. This work identified systems worthy of more detailed examination. The second phase examined the preferred alternatives in greater detail.Initially, operating principles and parameters were established and catalogued. Then, based on these criteria, complete systems were developed utilizing alternative modes of transportation . In the overview analysis, some transportation modes were judged impractical and discarded, 'order-o f-magnitude' costs were developed for other systems and the most costly were eliminated . In the detailed study, the favourable systems were examined in depth which required development of accurate capital and operating costs, consideration of environ- mental impacts and an assessment of intangibles associated with the operation of a new development."

Jan 1, 1984

By M. Feinendegen, Ph. Siebert, C. Clauser, K. Willbrand, M. Ziegler

"Three institutes of RWTH Aachen University collaborate on laboratory tests and numerical simulations of hydraulically driven fractures in igneous rocks. The project´s target is to enhance the understanding of hydraulic induced fractures for deep geothermal energy exploration. Based on the idea of creating new discrete fractures in hot dry rock (HDR) reservoirs, the current project stage deals with this process on a laboratory scale. Especially for this purpose, a new testing facility has been developed and laboratory tests are performed to verify a hydraulic fracture propagation code based on the extended finite element method (XFEM). The testing facility enables us to initiate and propagate fractures in large samples of dense rock under triaxial confining pressures and to monitor the fracture propagation by extensive measurements. This contribution gives a short introduction to the project‘s background and mainly focusses on the test facility, the experimental procedure and exemplary results.INTRODUCTIONThe most efficient technique to increase the permeability of subsurface rock is to initiate and open fractures by applying hydraulic pressure from a packed borehole-section and to inject fluid into these fractures to propagate them. Since its first use in petro industries to enhance the production of wells in natural gas and oil reservoirs, the interest in targeted creation of hydraulic fractures has increased exponentially. As the key technology to the extraction of unconventional gas from shale, hydraulic fracturing (HF) became a major topic in a heated public debate. Based on the fact that a fracture tends to propagate in a direction perpendicular to the minimal principal stress, hydraulic fracturing has become an established tool for estimating geological stress states in almost any depth. Enhanced geothermal systems (EGS) in HDR reservoirs use engineered fractures as a heat exchanging system for a cycling fluid driving a power plant."

Jan 1, 2015

By J. R. Bradfield

THOSE familiar with the development of the Horne mine can readily appreciate that more and more accommodation bas been required for underground labour as the mine has grown. A permanent fire-proof change house, 30ft. by 75 ft., was built in 1927 to accommodate 194 men. This was extended ro 30 ft. by 92 ft. in 1928 to accommodate 296 men, and to 30ft. by 110 ft. in 1930 to accommodate 398 men. By 1933 this building was again overcrowded and tentative plans for a new change house were drawn up. However, it was realized that future operations would be centred around No. 4 shaft and a proposed new shaft, and the decision as to the location of the new change house had to be deferred until the area which seemed most suitable for the new shaft had been thoroughly explored underground. In the spring of 1934, the basic idea was accepted of drying the wet clothes in open mesh compartments or baskets located between rows of standard steel street-clothes lockers and built so that the covers or lids would serve as seats or benches.

Jan 1, 1935

By V. Panayotov, M. Panayotova

"Finding a reliable relationship between fundamental properties of minerals of non-ferrous metals and their ability to float is extremely important. The approach presented in this work allows us to draw predictive models for an effective flotation, suitable choice of reagents regime and expected technological results before the minerals enter the flotation process. Attempts to adjust the technological regime in already begun flotation are often unsuccessful because the basic physicochemical processes have already taken place. Mineral processing can be optimized on the basis of objective and basic parameters, decisive for the efficiency of the process - the state of the surface of the mineral; assessment of: minerals flotation ability, the need to apply and the type of needed pretreatment, and expected technological results. The theoretical foundations of such an approach are presented in the work, as well as supporting them experimental results, and information on practical implementation in lead-zinc and copper-pyrite ores selection.INTRODUCTIONIncreasing impoverishment of ores of nonferrous metals incoming to the flotation and rising costs for obtaining the final product lead to the inevitable question - will the mineral processing process be beneficial economically, technologically feasible and environmentally safe and what is the way to improve its efficiency. Some of the possible solutions are already in practice - new more efficient and less energy consuming flotation machines and equipment, new - more efficient and selective reagents, new combinations of flotation regimens, and so on.Finding a reliable relationship between fundamental properties of minerals of non-ferrous metals (sulphides and oxides - most of them with semiconductor properties) and their ability to float is extremely important. This is the subject of research, started in the 60s of the previous century and continuing to the present day. Such dependence would enable a realistic assessment of flotation ability (flotability) of minerals before their flotation processing. The basic dependence, displayed by the researchers as Hoberg (1975), Chanturia and Shafeev (1977), Chanturia and Lunin (1983), etc., represents a relationship between bulk properties of minerals and their flotability, considering especially the concentration of the main charge carriers, namely electrons or holes. The bulk properties are practically constant for minerals from a given field. But the 'main arena' of the flotation process is actually the mineral surface (Carta, 1970; Rao, Labonte, & Finch, 1992; Panayotov, 1999; Rao, 2003; Hu, Sun & Wang, 2010). Therefore, we introduce a methodology for studying the surface of minerals, which methodology gives the degree of semiconductor bands bending on the surface and respectively - the charge of the mineral surface and its ability to interact with reagent-collector. The latter can be used to select the most optimal reagent for the corresponding mineral."

Jan 1, 2016

By Trent Hamilton

Cameco ? McArthur River Operation is a high-grade uranium mine in northern Saskatchewan. Average grades mined are nearly 20%, more than 20 times higher than other operating uranium mines in the world. The significant risks involved with mining this grade has been effectively mitigated using innovative and unique controls, implemented from development and production mining through to ore processing. The types and sources of radiation are presented and protection measures are discussed. McArthur River?s strong radiation culture is evidenced by continually low radiation exposures while transitioning to new mining zones.

Aug 1, 2010

By M. Schwarze

SMS Meer GmbH with its COPPER PLANTS DIVISION produces a full line of systems and machines for the processing of copper. The product range includes: shaft melting furnaces, anode casting lines, horizontal and vertical casting lines, casting and rolling lines for copper wire rod and strip, cold pilger mills, planetary rolling mills as well as tube drawing equipment. The new designed shaft furnaces are the most economic way of copper melting. The CONTILANOD® system with hydraulic shear represents a breakthrough into higher production capacities and improved geometrical accuracy of anodes. The new generation of CONTIROD® lines with individual drives of rolling stands guarantee cost effective production of highest rod quality. A new horizontal continuous casting technology for the production of tube shells as feed stock for the copper tube manufacturing process ? directube® was developed and introduced into production. A first line for continuous vertical strip casting - called VERTICAST® - for higher production rates and improval quality of cold-rollable strips is in the final stage of commissioning. These innovative technologies increase product quality, reduce process costs and help for a wide use of copper in all sectors of life.

Jan 1, 2007

By Malcolm Scoble

Process Technologies Suitable for Application Underground Design Criteria - coarse particle technologies - compact, robust, flexible - waste products suitable for use as backfill Process technologies identified: - Optical/conductivity sorting - Dense media separation - Coarse-particle flotation Process technologies supported by compact & efficient comminution stages Mineralogical evaluation to select process & estimate Performance Further Work U/G Plant Layout & Excavation Modelling Evaluate scenario at increasing depth Establish properties of waste as backfill Model impact of improved backfill quality Evaluate further case studies Evaluate further Environmental Health and Safety Issues Model impact of system development on inventory of national mineral reserves Conclusions Technologies exist for integrated underground mining and processing systems These technologies to be successfully integrated into underground mining system Positive economic and environmental benefits Technical issues to be resolved at depth System Development path identified

May 1, 2004

By Stephan Day

Comments on Robust M3 to Protect Water Quality ?Regulatory and philosophical thinking have tended to evolve at decade scale since 1970s. ?Mines typically last more than a decade. ?Robustness is defined by the ability to adapt to new realities. Managing Water Quality in BC ?1973 ?BC Pollution Control Objectives ?1977 ?Federal Metal Mine Liquid Effluent Regulation (Fisheries Act) ?Late 1980s ?Philosophy of ?Designing for Closure? ?1990s ?Designing for Acid Rock Drainage Management ?2000s ?Awareness of need for water quality management in general, regardless of acidity

May 1, 2010

By Andrew Cormier

"The Early YearsThe Grand Lake coal fields in New Brunswick undoubtedly can claim the distinction of being the first part of North America from which coal was mined and exported. The diaries of the Governor of Massachusetts during the first half of the 17th century clearly establish this fact. There is also a reference in the Massachusetts Colonial Records which indicate that coal exports to New England were carried on as early as 1639.It has generally been believed that Cape Breton mined and exported the first coal; but no account has yet been found to show that this took place earlier than 1676. Both at Grand Lake and Cape Breton the coal was near the surface and removed by hand.When the country passed entirely into British control, Joseph Garrison, a grantee of Maugerville in 1765 moved to Jemseg. While surveying the north side of Grand Lake he discovered outcroppings of coal on the shore of the lake and further inland along the banks of streams. It was he who named Newcastle Creek in reference to Newcastle in England, which was widely known for its coal mines. Joseph Garrison died in 1783, the same year that an influx of United Empire Loyalists increased settlement in Newcastle Creek in the area now known as Minto. Many Loyalists also settled on the shores on both sides of Grand Lake.At a number of points where streams cut channels through the overlying strata, the coal seams were exposed and it was at such outcroppings that the early operations were carried on. A tunnel was driven in the seam from the foot of the bank, affording both an outlet for the coal and natural drainage from the workings. The coal was loaded into boxes and wheeled over wooden tracks to a point on the surface where it could be dumped into wagons and hauled either direct to destination or to where it could be loaded into boats and conveyed via Grand Lake, Jemseg and Saint John river to points of distribution.In the latter part of the 18th century and first years of the 19th century, farmers were undisturbed by mining the coal found on their lands. This was soon to change and resulted in many years of contention between landowners and the Legislative Assembly.New Brunswick became a separate province from Nova Scotia in 1784 and the seat of government moved from Saint John to Fredericton in 1788. The new province had its first priorities; the establishment of counties, the building of roads, and the development of its natural resources. From 1805, records of coal and land development are fairly complete. These records show the increasing interest of the Province in developing the coal fields. This interest resulted in the granting of coal leases to many friends of the government, without any regard for the wishes of the farmers who owned and had occupied the land for many years. The farmers fought back with lawsuits and other forms of dissension but with little success. By the end of the 19th century there were very few farm operators left in the area."

Jan 1, 1992

By Randolph A. Pax, Brian Cornish

The operation of grinding mills in an ore processing circuit is supported by monitoring the input and output variables. These can include the feed ore size distributions, ore feed and water addition rates. The outputs can include the discharge undersize density, oversize tonnage rate and the P80 of the discharge. The grinding mill performance is judged by the power draw, recycle rates and discharge grind size. Conditions inside the mill are inferred from loads cells or bearing pressures and past histories. An overall noise value is sometimes used to evaluate the load as well as the occurrence of excessive impacting of steel balls onto the liners/lifters of the mill. This paper presents results of the internal behaviour of a mill using non-contact stationary microphones located close to the mill outer shell (Pax, 2012). The noise generated by a mill can be attributed to a number of events that occur inside these mills and suitably analysed can provide real-time determinations of in-mill behaviour and can provide powerful insights into the operation of the primary comminution tumbling mills. The acoustically determined signals including a specific 'steel' signal, water hold-up, integrated area together with a classification of impact events. Specific results from case studies will show information of the trajectories inside a mill, steel to rock ratio as well as rheology effects. By incorporating a self-consistent understanding methodology for the in-mill processes from an array of microphones, the information can be used to diagnose the dynamic conditions inside a mill.

Jan 1, 2016

By G. A. Davidson, P. G. Williams

"New developments in centrifugal slurry pump technology are discussed in relation to their importance for improving pump operation and reliability.Experimental data obtained by measuring the velocity of liquid flows in a slurry pump casing using Laser Doppler Velocimetry are presented. This demonstrates the importance of selecting pumps with the proper hydraulic design to provide optimum efficiency, maximum part life and minimum operating cost.The paper also discusses the use of new wear resistant materials, such as ceramic/metal composites, which can significantly improve the life of parts exposed to abrasive media. The results of laboratory attrition tests are presented. IntroductionCentrifugal slurry pumps are of primary importance for the hydro transport of abrasive and corrosive media in the mineral processing industry. As for all process equipment, slurry pumps must be carefully selected and operated to provide optimal performance. To achieve this, it is necessary to select equipment which will provide efficient and reliable operation for the specific service conditions and incorporates the best materials available to obtain maximum parts life.Abrasive wear of liquid end components is the most important aspect that distinguishes the design and application of slurry pumps from other types of pumps. It is therefore necessary to have a fundamental understanding of the mechanical interaction between pump components and the media being handled, as this will impact significantly on hydraulic design, mechanical reliability and selection of wear resistant materials. Recent advances in computational approaches'» have greatly improved the prediction of wear rates in pump casings by facilitating the solution of complex equations which describe the wear mechanisms mathematically. In conjunction with this, new experimental techniques allow researchers to measure flow fields in pump casings using non-invasive devices such as Laser Doppler velocimeters."

Jan 1, 1992

By Mary Kama, Kaul Gena

"Magnetic skarn ore (MSO) is one of the major copper bearing ore extracted by the Ok Tedi Copper Mine in Papua New Guinea. Copper minerals are recovered by flotation while the iron not associated with copper are discarded as tailings. The objective of this investigation was to determine the iron ore reduction kinetics for the Ok Tedi MSO and ascertain if it can be processed to produce sponge iron for a mini steel plant in Papua New Guinea.SEM-EDAX analyses of the Ok Tedi MSO indicated 10.1% C, 30% O, 0.6% Mg, 1.1% Si, 21.1% S, 0.8% Ca and 36.2% Fe. Most of the iron is in sulfide form. Both naturally occurring and roasted sinters of Ok Tedi MSO samples of different particle sizes were reduced by charcoal carbon at three different temperatures and seven different reduction times. Analyses of the reduced products indicated a metallic iron content of more than 65 wt.% on average.Results showed that there was no significant difference in reduction between fluxed and control materials. Only a slight increase in kinetics with reduced particle size, hence the reaction rate constant (K) did not vary much within the temperatures investigated. Reaction kinetics increases with increasing reduction time at 900°C. Therefore, more iron reduction is observed with particles of 106 µm size. In addition, the results also confirmed that the reduction energy used was higher at 800°C and lower at 1,000°C. In summary, iron reduction can be improved but close monitoring of temperature and reduction times are essential to determine the reaction kinetics of the Ok Tedi MSO. INTRODUCTIONMost mines in Papua New Guinea mine large quantities of iron in the form of sulfides, carbonates, oxides and sulfates that are eventually disposed off as tailings. The Ok Tedi magnetic skarn ore (MSO) contains a significant amount of hematite, magnetite, siderite, ilmenite and pyrite that can be a source of iron. The mineralogical compositions of Ok Tedi MSO reveals more iron minerals than copper, yet all iron containing minerals are collected in the tails from the main copper production stream. Therefore, this study is conducted to investigate the possibility of producing direct reduced iron (DRI), or sponge iron, from the MSO. Such sponge iron may serve as the feedstock for electric arc/induction furnace based mini steel plants in Papua New Guinea."

Jan 1, 2016

By Peter Clevenstine

Minnesota Iron Ore Trifecta 1. World Demand 2. Industry Consolidation 3. Competitive Advantages

May 1, 2011

By A. M. Cann, C. I. Godwin

"The Kemess porphyry copper-molybdenum deposit occurs in the Intermontane Belt of north-central British Columbia. The deposit is in andesitic to basaltic flows and tuffs which may be correlated with the Savage Mountain Formation of the Upper Triassic Takla Group. Most known chalcopyrite and molybdenite is associated closely with a 500-m-diameter zone of intense quartz-sericite-pyrite alteration. A zone of supergene enrichment, up to 30 m thick, underlies a leached capping about 20 m thick. The age of mineralization and the surrounding granodiorite and quartz monzonite pluton is Early Jurassic. K-Ar and Rb-Sr analyses indicate that the mineralization and alteration is slightly younger (l82±6 Ma) than the granitic intrusion (KAr: about 205±6 Ma; Rb-Sr: 190±4 Ma). The low 87Sr/J6Sr initial ratio for the granodiorite is typical of plutons in the Intermontane Belt.IntroductionKemess is a medium to small porphyry copper-molybdenum deposit with significant gold and silver values (Pilcher and McDougall, 1976). This paper describes the lithologies and alteration at this property; geochronology by Rb-Sr and K-Ar methods defines the ages of mineralization and surrounding plutons to be Early Jurassic.The property, located in the Thutade Lake area of northcentral British Columbia (NTS Map 94E; lat. 57°04'N; long. 126°44'W), is about 425 km northwest of Prince George (Fig. 1). Closest road access is 35 km southeast of Kemess. Final access must be by float plane or helicopter. The British Columbia Railway right of way passes 70 km to the southwest of theproperty.A prominent gossan zone at Kemess was staked in 1967 by Kennco Explorations (Western) Ltd. following detection of geochemical anomalies during stream sampling the previous year. During 1968, 1969and 1971, Kennco completed 232 m of X-ray diamond drilling, conducted geological mapping and carried out geochemical sampling of silts and soils (Stevenson, 1969; B.C. Ministry of Energy, Mines and Petroleum Resources, G.E .M., 1969 and 1971). Getty Mines Ltd. optioned Kemess in 1975and 1976. They remapped the area and diamond drilled 12 BQ and NQ holes, totalling 2065 m (B.C. Ministry of Energy, Mines and Petroleum Resources, Expl. B.C., 1975)."

Jan 1, 1980

By Jack A. Caldwell

"This paper describes the nature of stage curves and the ways in which they have been used to study the construction sequencing of tailings impoundments. They provide a simple graphical method of representing the main aspects of an impoundment, studying the effects of different impoundment geometries, and predicting and controlling impoundment operations.IntroductionThe designer o f a tailings impoundment must, at all stages of design, examine the relations hip between the volume o r tones of tailings that will be deposited at the impoundment, the height to which the tailings will rise in a given time and that rate at which the various parts of an impoundment will be constructed. The operator, if he is to keep proper control of this impoundment, must be able to examine the effect of different deposit ion rates at the impoundment, and the consequences of placing more or less tailings at different parts of the impoundment. The operator must be able to see at a glance just how much higher an impoundment will be at the end o f the following yea r of deposition, and this he must be able to do in order to formulate his annual construction and operating plans.Stage curves are the best way o f modeling an impoundment. The simple impoundment model represented by the stage curves enables the designer and operator visually to examine the relationships between the various factors, such as impoundment volume, deposition rat e and construction rate, that dictate the essential features o f impoundment design and operation.A design model for a tailings impoundment may be formulated as in Figure 1. This involves the site selection process, the definition o f a geotechnical model, a water balance model and a height-capacity-production model."

Jan 1, 1983

By J. A. Hillier

The staff of the Hudson Bay Mining and Smelting concentrator have developed a new type of reagent feeder. Several factors encouraged the development of such a system: varying heads caused by the mixing of ores from several mines, the increasing number of flotation circuits operated and reagent feeding stations remote from the flotation operator's work area. The reagent feeders also had to be compatible with future plans for reagent control from an on-stream X-ray analyzer and computer system. The new feeder is a positive-displacement pump set to deliver a constant volume per stroke. At a remote panel, the feed rate is altered by changing the time between strokes. The feeders have been found to be reasonably trouble-free and accurate to less than 2 per cent error.

Jan 1, 1973

By A. Gourlie

"This paper describes the performance properties of a new 95 ksi minimum yield strength, oil well casing grade designed specifically to resist hydrogen sulphide stress corrosion cracking, SSCc. The new grade, Soo-95SS, demonstrates NACE Tensile threshold values greater than 90% specified minimum yield strength, SMYS, and NACE Bent Beam values in excess of 12.7 x 1()4 psi. The new Soo-9588 grade also exhibits superior collapse and notch toughness values. IntroductionIn recent years, a trend toward casing grade specialization has resulted in the introduction of numerous proprietary grades designed specifically for particular production environments, In response, Algoma Steel has developed, as part of a "" grade for service"" philosophy, two new 95 ksi minimum yield grades. The two grades are Soo-95, High Collapse (HC), and Sour Service (SS). This paper describes the development of Soo-95 Sour Service.Four main objectives were established:1. Definition of the steelmaking and continuous cast processing practices2. Determination of the acceptable maximum and minimum levels for all chemical elements3. Definition of special processing requirements4. Definition of the physical characteristics and ranges of the product properties.This paper provides a description of the experimental approach, followed by a presentation and discussion of the trial results . Finally, a number of conclusions are given."

Jan 1, 1988