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By J. Y. Hascoet, M. Marya, S. Marya

Additive manufacturing (AM) brings disruptive changes over the ways parts and products are designed, tested, qualified, assembled, inspected and marketed. With these changes come real technical challenges, therefore, concerns that mainly stem from the maturity and diversity of today’s AM processes, the feedstock materials, and the interactions between the numerous process parameters. Additive manufacturing is somewhat similar to laser and electron-beam conduction-mode welding and involves a multitude of dynamic physical events between projected feedstock and moving heat source that influence process robustness, thus deposit properties. For this paper, a simple air vent, selected for its size, thin-wall, hollow geometry and materials (specifically 316L) was made using a laser-based powder blown technology (Construction Laser Additive Direct or CLAD) and systematically inspected by optical microscopy, microhardness indentations, and electron-back-scattering diffraction (EBSD). This exemplary part is first analyzed to broadly discuss metallurgical phenomena in additive manufacturing, particularly solidification and texture development. The paper then expands to other alloys and continues correlating metallurgical observations to process parameters and part properties, also borrowing from past experience with the same 3D printing CLAD system.

Jan 1, 2014

By James Ransford Dankwah

This work investigates the effect of waste plastics addition on the reduction of iron oxide by sawdust. Composite pellets of iron oxide containing sawdust (SD), high density polyethylene (HDPE) and blends of SD/HDPE were fired under argon in a horizontal tube furnace at temperatures between 1300 and 1500 °C. Reduced samples were weighed after 10 minutes of reduction and the extent of reduction was calculated from the measured oxygen contents of the compact. The results showed improved extent of reduction when SD was blended with HDPE. The highest extent of reduction was achieved at SD:HDPE ratio of 2:3.

Jan 1, 2014

By R. H. O. Wagner

"This paper describes the bench testing, pilot plant studies of alternative flowsheets, to determine the feasibility of gold recovery, by carbon in pulp extraction, in the Schumacher Mill gold flotation tailings. The economics were calculated based on pilot plant recoveries and actual industry operating costs.The economics of the carbon in pulp treatment of the gold flotation tailings were not justifiable. The economics of desliming the gold flotation tailings followed by carbon in pulp treatment were marginal, but favourable. INTRODUCTIONPamour Porcupine Mines, Limited is a gold, silver and copper producer located in Timmins, Ontario. In 1983 the head grade of Pamour's gold ores averaged nine one hundredths of a troy ounce of gold per short ton.Pamour operates two area mills to concentrate the gold ores. Free milling gold ores are processed at the Pamour One Mine mill, whereas the refractory carbonaceous gold ores, and complex gold, silver, and copper sulphide ores, are processed through the Schumacher Mine mill.The complex Schumacher mill feed ores do not all react favourably to flotation methods, consequently this study was commissioned to investigate the feasibility of the carbon in pulp cyanidation of the Schumacher mill gold flotation tailings. These tailings contain ten to fifteen percent of the gold in the mill feed. During the study period, the average grade of the Schumacher mill flotation tailings was nine one thousandths of a troy ounce of gold per ton, or one quarter of a gram of gold per metric tonne."

Jan 1, 1984

By Rudy Tenbergen, Dick Farmery, Jim Naylor

"Paste backfill has replaced cemented rock fill as one of the components to improve ground · control and mine safety at the Macassa Operation of Kinross Gold Corporation in Kirkland Lake, Ontario. It is the first operation to utilize "" flash thickening ""of very fine gold tailings to a paste consistency in the ""Paste Production and Storage Mechanism"", a joint technical development of Inco and GL&V. The tailings paste is mixed with alluvial sand to produce an engineered quality paste backfill. The development leading up to the decision to proceed with this novel technology is discussed, as well as commissioning of the backfill operation.IntroductionThe occurrence of a major rockburst on November 23, 1993 prompted a review of mining and backfill procedures at the Macassa No 3 shaft . This shaft is some 7238 ft deep and lies in a mining belt that is prone to seismic events. The recommendations were to change the mining from underhand cut and fill to mechanized long hole stopping and to look at alternatives to the rockfill backfill system in place. The Macassa cemented rock backfill operation, while producing the desired fill stiffness had drawbacks as compared to paste fill. With paste fill, placement rates are faster, more openings can be filled, it is less expensive and less prone to the occurrences of compensable incidents.Macassa mining personnel visited the Sudbury operations of Inco in 1993, where development on paste backfill was in progress. As some of the R&D was taking place with funding from the Premier's Council Technology Fund of the Ministry of Trade and Technology of the Province of Ontario , Inco personnel at that time did some feasibility and conceptual consulting on the use of paste fill for the industry. Inco had developed the use of alluvial sand paste fill, an engineered blend of alluvial sand and tailings fines and was doing development work to eliminate the ""conventional"" way of producing paste from mill tailing by thickening and filtration. This latter development work was taking place with GL&V Ontario. That work led to the filing of a joint Inca/ GL&V patent application for the PPSM, the Paste Production and Storage Mechanism with all marketing rights being held by GL&V."

Jan 1, 1997

By Roger Payne, John R. Goode, Feng Gao, James Brown

The Eco Ridge deposit is located in the Elliot Lake mining camp in Northern Ontario, Canada. Between 1955 and 1996, the area produced more than 138,000 t (300 million pounds) of U3O8 and very significant amounts of thorium and heavy rare earths. Based on the NI 43-101 Preliminary Economic Assessment by Roscoe Postle Associates (RPA) dated June 2012, and the economic review by RPA as announced in Pele Mountains’ Press release dated September 12, 2013, the Eco Ridge Mine Project would extract and process 46 Mt of material to produce about 19,000 t (42 million pounds) of U3O8 and about 65,000 t of rare earth oxide (REO) over a 14-year life. This paper discusses process optimization studies including beneficiation and hydrometallurgical testwork. The proposed modified flowsheet includes the flotation and processing of 1) a pyrite concentrate, 2) a dominantly light rare earth elements (LREE) concentrate, 3) a concentrate containing most of the balance of the uranium and heavy rare earths (HREE), and 4) a relatively inert tailings.

Jan 1, 2014

By K. Lundholm, A. E. Mäkinen

"Ore grades are declining and getting more complex around the world which not only complicate the ore processing but also produce new type of requirements to manage the produce waste streams. One specifically problematic and increasingly identified element in waste streams produced in mining and metallurgy is arsenic.Arsenic is a compound that has no significant market value, but that needs to be removed from ores, concentrates and other process streams because of environmental or process technical reasons. One example of a removal process is partial roasting of high-As sulfide concentrates, originally developed by Outotec. In this process the arsenic is volatilized in the gas phase and thus separated from the solid material, i.e. the calcine. If the arsenic is recovered by wet methods the process gas is quenched and all arsenic needs to be stabilized in the effluent treatment plant.Outotec has developed ferric arsenate precipitation as a method to produce stabile arsenic residues from wet gas cleaning effluents. Iron based precipitates, when correctly produced, can meet typical landfill criteria measured with different types of leaching methods meant for characterizing the arsenic dissolution behavior from the precipitates.In this paper partial roasting of sulfide concentrates with arsenic volatilization in combination with ferric arsenate precipitation is discussed from the perspective of producing wastes that can meet the stability requirements set by common leaching tests methods, TCLP and CEN. These leaching test methods set the normative landfill requirements for most operations generating arsenic containing wastes. A typical flow sheet of Outotec® Ferric arsenate process is discussed with results showing the importance of correct process control and sequence on producing arsenic containing waste that can meet the landfill disposal requirements."

Jan 1, 2014

By M. W. Lewis, J. Werner

Fluctuating metal prices, declining head grade, and increased operational costs are forcing many open pit mining companies to look to their balance sheets for significant cost reductions in order to remain competitive. Maintenance continues to represent a significant proportion of the total operating costs in the mining industry. Compared with the other major cost components of the mining process, very little effort has gone into maintenance optimization. The potential payoff from maintenance optimization on the cash cost of the commodity is enormous. A large percentage of these costs are incurred in unscheduled maintenance events, which typically cause serious disruptions to the production process. These maintenance-induced production losses can be a significant contributor to the overall operating costs. A structured proactive maintenance approach using the latest advances in technology can achieve dramatic cost reductions and productivity improvements. Remote condition monitoring systems are becoming increasingly commonplace and have the potential to identify problems prior to failure. Detection of equipment degradation prior to failure will enable repairs to be scheduled thereby reducing costs and interruptions to production. Remote condition monitoring technology has evolved rapidly in recent years, with a host of new tools becoming available to assist mine operators in improving their maintenance operations. These tools have capabilities such as remote real-time vital signs and performance monitoring, alarm/event handling, trend analysis, and maintenance workflow management. When these monitoring tools are used in conjunction with a mine management system, the vital signs data can be integrated and associated with maintenance history, predictive maintenance data, operational information, and geographical information. This integrated approach to the management of vital maintenance data will help shift the mobile equipment maintenance paradigm from reactive to proactive. This paper will introduce a proactive approach to the management of the maintenance process and the tools required to facilitate this process.

Jan 1, 2005

By A. J. Stapleton

"The Copper Mountain mine of Gaspe Copper Mines, Limited was brought into production in January, 1968.This paper describes the organization, scheduling and control of maintenance of large open-pit equipment, including 8-cu.yd shovels and 85-ton electric-wheel haulage units. The facilities for repair as well as maintenance are also described, including repair shops and field repair equipment. Maintenance costs are discussed and particular reference is made to tire inspection, records and costs."

Jan 1, 1969

By F. P. Hassani, H. B. Poorooshasb

"A kinematically admissible velocity field is applied to study the arching phenomenon in a cohesionless granular backfill placed between two rough vertical inflexible walls. The study is different from the previous works which are almost entirely based on statically admissible stress fields. It is shown that the development of arches is strongly influenced by the previous loading history of the backfill which controls the nature of the constitutive laws that govern the mode of stress deformation of the backfill. This preliminary study employs simple models in order to show the potential use of such an approach in evaluating and understanding mine backfill behaviour in the underground excavation. The pressure exerted on the floor supporting the backfill is also studied in some detail.INTRODUCTIONAlthough the importance of the design of mine backfill has been discussed extensively by a number of authors, i.e. Hassani et al. (1985), such theories have not as yet been incorporated in design criteria for underground mine backfilling operation . One factor that such theories must incorporate is the so-called arching action .The phenomenon of arching has been the subject of study by many researchers in the field of civil engineering and mining engineering. Among these scholars the works of Terzaghi (1943), Krynine (1945), Lusher and Hoeg (1964) and Handy (1985) are noteworthy. All these authors use a statically admissible stress field as a starting point to develop their theories. The approach taken by the authors of the present paper is completely different because they employ a kinematicallyadmissible velocity field. It is their belief that the arching phenomenon is closely linked to the interlocking of grains as manifested by the degree of dilatation of the granular mass when subjected to a shearing process.This paper is written in the following sequence. To define the interlocking quantitatively it is necessary to state the constitutive law governing the stress deformation characateristics of the granular mass. This is done in the next section as the law proposed by Poorooshasb and Pietruszazck (1985, 1986) is stated and simplified to suit the present analysis. Next the mode of formation of an arch in a simple system consisting of a mass of backfill sandwiched between two vertical rough walls of infinite extent is examined. The velocity field obtained from the above example is used to obtain solutions to two more complicated situations. The first situation assumes that the backfill is supported, in addition to the vertical rough walls, by a Winkler foundation at its base. The second situation assumes that the Winkler foundation has been replaced by a horizontal beam of uniform section and simply supported at its extremities. The findings of the study are summarized and their practical implications discussed in the concluding remarks."

Jan 1, 1989

By S. K. Mitterecker, T. Hofbauer, F. Baerhold

"Acid regeneration is a very important process step in each acid leach circuit. It is required to recover dissolved metals and HCl from spent leaching acid. Andritz Metals presents its recently commissioned spray roast pilot plant. The facility is now available for testing and demonstrating acid recovery or metal oxide production which is a requirement in several flow sheets under development for the mining and specialized oxides industries. Results from pilot test campaigns are reported here. We are currently focusing on a nickel ore leaching process, which requires both a feasible iron control and acid regeneration step. In addition, we disclose the results of a magnesium ore and aluminium recycling test campaign conducted in our pilot plant facility.INTRODUCTION Hydrochloric acid regeneration is widely used in the steel industry to regenerate spent pickle liquors into hydrochloric acid at a typical concentration of 18 wt.%. Andritz Metals (formerly known as Ruthner) has built more than 200 acid regeneration plants worldwide (Andritz Metals brochure). As technology leaders Andritz also has vast experience with specialty metal oxide plants, producing metal oxides such as aluminium oxide (Al2O3), magnesium oxide (MgO), nickel oxide (NiO), cobalt oxide (Co3O4) and mixed oxides from metal chloride solutions (Baerhold F., Lebl A., Starcevic J., 2006), (Jedlicka, H., n.d.), (Ruthner M.J., Krischner H., 1973), (Ruthner Ind. Planungs AG, 1967). Hydrochloric acid leach circuits have been developed and proven in the industry for many years. Examples of industrial applications are: synthetic rutile production (TiO2) (Walpole E.A., Winter J.D., 2002), Quebec Iron and Titanium’s UGS process (Patoine M.-C., De Mori A., Borowiec K., Coscia C., 2002), magnesium and potassium production (Priemer H., 1973) and Goro Nickel (Vahed A., Colton D.F., Duterque J.P., Karner W., Baerhold F., 2004), (Taylor A., 2013). One of the critical process steps in developing a hydrometallurgical process is acid regeneration, as it is an economic requirement to recover both the dissolved metals and acid (commonly HCl) from the spent leaching solution."

Jan 1, 2016

By H. M. Lewis

The current status of the international zinc market is summarized, and a supply /demand outlook is presented for the next five years. A number of technical problems facing the industry are outlined. Introduction ZINC has sometimes been called the unknown metal. Considering that on a world basis it ranks third among non-ferrous metals in production and consumption, zinc retains a certain modesty. It has no distinctive colour like copper, lacks the low density of aluminum or magnesium and is not always easy to identify as a product. The 'spangle' of galvanized steel is probably zinc's most distinguishing feature. The purpose of this article is to develop an over-all review of zinc. Starting with the current position of the metal, the major factors that will shape its future will be described so that an assessment of the outlook for zinc can be made.

Jan 1, 1978

By J. A. Meech, R. J. Tucker

"Since the establishment of froth flotation as an effective method of mineral beneficiation there has been both academic and industrial interest in the levels of the various reagents required to perform the desired separations. Academic interest was spurred by a desire to understand the mechanisms involved - industrial interest by a need to improve the efficiency of the process. These efficiency improvements can take two forms: cost reductions due to reduced reagent consumption and/or improved separation efficiencies. The latter are indicated by either improved grade-recovery relationships for removal of a valuable mineral from gangue, or improved separation of two similar valuable minerals.The processing of lower grade ore bodies at higher tonnage rates has necessitated increased interest in both reagent consumption and metal recovery. Furthermore, the development of accurate and functional on-stream analysis equipment in the 1960's and 1970's has allowed for a better understanding of the dynamic processes involved in a flotation circuit and has required a more concrete statement of the relationships and reactions between the minerals and chemicals in the flotation pulp. Development of these relationships is necessary in order to make use of on-stream analysis to control the process at, or near its more efficient level."

Jan 1, 1984

By Kosuke Hosoda, Shuji Owada, Hiroyuki Tokuichi, Hirobumi Ohta, Chiharu Tokoro, Moto-o Sato, Katsushi Okumura, Hiroto Ogawa, Hideaki Umezawa

The Japanese government enforced the "Small Domestic Appliances (SDAs) Recycling Law" in 2013. The law targets metals such as Ta, Nd, Dy, Co, and W to be recycled. Considerable amounts of these minor rare metals are mounted on printed circuit boards (PCBs) of the SDAs and/or e-scrap (electric and electronic scraps). Although precious metals and copper can be recovered from the e-scrap in non-ferrous metals smelters, most of the minor rare metals report to the slag in these smelters in non-recoverable forms. These metals are often used in particular types of devices, and therefore it is possible to concentrate them by separating such devices before feeding to the smelters. In previous work we developed technology for "Device Separation" to concentrate several minor rare metals, but some problems remained, such as how to remove the PCBs from e-scrap bodies, and how to detach devices from PCBs after their removal from escrap bodies. This paper proposes a two-stage crushing process in which, firstly, PCBs are removed from the e-scrap body with various crushers, and secondly, devices are detached from the PCBs involving the application of elevated temperatures. It was found that in the first stage, crushers with physically flexible rotating media such as chains, which provide high collision probability with the sample and consume relatively low energy, can quite effectively separate the PCBs from the e-scrap bodies non-destructively. In the second stage, heating was found to be remarkably effective in helping to detach mounted devices from PCBs, also non-destructively. This paper will also discuss the detailed mechanism of the heating effect on the detachment of devices from PCBs.

Jan 1, 2014

By W. P. Campbell

Introduction OWING to the necessity of curtailing the length of this paper, nothing like an exhaustive treatment of the subject will be attempted. Instead, merely a few aspects will be considered, viz., water trouble in wells, sampling of waters, analysis, methods of reporting analysis, and the comparison of a few typical waters. The waters discussed will not be confined to those occurring in areas where oil or gas has already been found, but will include samples from areas in which drilling is being carried on in the hope that oil or gas may be found, i.e., from unproved fields. The Water Problem The problem of dealing with water encountered in oil and gas producing areas has engaged the attention of petroleum engineers from the early days of the industry. Water was not always considered a menace to oil sands; indeed, a certain amount of it was considered beneficial in some areas, but if such exist today they are very exceptional. In some fields, the problem is more acute than in others, and at times has baffled all attempts to solve it satisfactorily. Wells have been brought-in with promise of good production, but after a brief period have 'gone to water'. Whether ?it has always been a case of poor engineering in the form of unsuccessful water shut-off of 'top' or 'bottom' water, or because 'edge' water was present and water and oil were in such close contact it was impossible to remove the one without the other, is hard to say.

Jan 1, 1929

By Karla Kaboth, Brad Garraway

"The surface of many concentrate thickeners has traditionally looked like that of a flotation cell. Over the last three years Normandy Golden Grove Concentrator, in partnership with Outokumpu Technology have developed and implemented an innovative breakthrough deaeration technology to address this problem.When installed in the thickener feedline, the system successfully detached air bubbles adhering to the solid particles and removed air bubbles from the feed stream, subsequently presenting a fully deaerated feed to the thickener feedwell.Tests to date have shown an 80% reduction in overflow solids. As a result, costs associated with concentrate loss and measures to recover concentrate that settles in process tanks and ponds have been minimized.MOTIVATIONIt is recognised in mineral processing operations that the entrainment of finely divided air in thickener feeds can cause significant problems in the operation of a thickener. This is particularly the case with thickening of flotation concentrates, in which air bubbles are strongly attached to the mineral particles and are difficult to remove. Such particles attached to fine air bubbles rise to the thickener surface, and hence over the weir and into the thickener overflow. High solids carryover can lead to a direct loss of mineral product, and if the product settles in process water tanks and ponds, the recovery of this product by means of intermittent dredging operations is usually expensive and inconvenient.Many concentrate thickeners are fitted with devices which attempt to alleviate this problem. Froth rings or baffles, skimmers and froth sprays, all play a part in reducing the amount of solids carried over into the overflow. However, many froths are very stable and persist despite these measures. In the worst cases, a thick froth layer forms which builds up to a depth greater than the froth ring, and hence may overflow or pass beneath the ring . Any concentrate that finds its way past the froth ring can also cause blockage of the overflow weir and launder, and has the potential to upset clarification performance by cutting off sections of the overflow handling system. The formation of a froth layer on the thickener also makes it more difficult for the operator to monitor the clarification performance."

Jan 1, 2001

By Brian A. Ferguson, Raynald O. Vezina, Marielle Gaudet, Raoul R. Boissonneault

"Kiena has been committed to developing a fresh management and employee relations approach since the commencement of production in 1981. The functional organizational structure encourages joint participation and commitment on the part of all employees to common goals in safety and production. The results over the last four years have been extraordinary. Kiena won the John T. Ryan Canada Trophy for 1983 for its safety record and has experienced a steadily increasing productivity through the application of new mining equipment and technology in the hands of a well-trained and motivated team of employees.This paper serves to highlight the fact that productivity, safetyand technical innovation are closely linked to employee participationand involvement which are likely to be the key to theCanadian mining industry's survival in the years ahead.This presentation follows up on an earlier unpublished paper, given at the 84th Annual Meeting of CIM in Quebec City in April, 1982, which discussed the philosophy and the planning which took place before implementation of the management and employee relations system at Kiena. This present paper reviews and expands on material given in the earlier work. IntroductionThe mining industry, which has always been considered as rather conservative in its approach, has experienced with some regularity, cyclical periods related to metal prices. These cycles, previously foreseeable to some extent have become less coherent over recent years during which time the industry has had to face fierce international competition. The issue to productivity is without doubt the major concern of the mining industry in Canada today and it represents the greatest challenge facing us during the present decade. Developments that have been made in mining technology over the precious two decades have failed to completely produce the significant advancements in higher over-all productivity that were expected."

Jan 1, 1987

By Manqiu Xu, Songtao Yang, Zongfu Dai, Robert Pelton, Carla Abarca

"Fine mineral particles are difficult to process by flotation because of their low collision efficiencies with air bubbles. Decreasing air bubble size and increasing mineral particle size through flocculation are the most common approaches to improve flotation efficiencies. Herein we demonstrate that nanoparticle flotation collectors can be engineered to selectively induce fine mineral particle aggregation and promote flotation.Flotation tests of clean fine pentlandite (Pn) and Clarabelle Mill (CBM) rock tails and pyrrhotite (Po) tails that contained significant amount of fine pentlandite have confirmed that the nanoparticles can serve as both collectors and selective flocculants for fine pentlandite. In the case of clean fine Pn, the nanoparticle collectors virtually can float almost all Pn fines. Scoping tests on CBM tails have shown significant improvement in nickel recovery. Addition of nanoparticles as a flotation aid can recover 20% of the nickel contained in the rock tails and 40% of the Pn contained in the Po tails compared to current mill operations giving 0% nickel recovery from rock tails and no Pn selectivity from Po tails. Ongoing work includes attempts to identify optimal strategies for employing nanoparticles in fines flotation.IntroductionFine particle flotation is an industry-wide challenge in mineral processing. Fine mineral particles are difficult to process by flotation because fine particles have low mass and thus low momentum, which results in their low collision efficiency with air bubbles (Dai, Fornasiero, & Ralston, 1999). In addition, fine particles have not only high specific surface area but also more active surface area, which causes high reagent consumption. For base metal sulphide minerals, particle size between 10 µm and 70 µm is a typical range where high flotation recoveries can be achieved with conventional flotation chemistry and acceptable cell residence times. For pentlandite, the flotation recoveries decrease sharply when the particle size is below 10 µm and hydraulic entrainment is the dominant mechanism, giving recoveries proportional to water recovery and no Pn enrichment. (Jameson, Nguyen, & Ata, 2007)"

Jan 1, 2015

By Bryan A. Bartley

"Jim Macdonald was promoted from Waterworks Engineer to Streetworks Engineer for the Wellington City Council. He thus took over the City quarry and responsibility for its performance. The crushing plant needed upgrading and he thought it would not be difficult to make a crusher to overcome a problem. If he had a longer association with the quarry industry he would have used conventional methods and equipment, so his invention arose from a fresh view of crushing.He invented the Barmac Rotopactor after observing a wear resistant chute with a lining of dead stone trapped above a piece of angle. This idea led to a rotor lined with trapped stone, rotating on a vertical spindle. In trying - a model rotor he observed the impact against a circular rill of stone in half an oil drum and thus was started a very fertile new area of developement in comminution. The writer helped in the developement and shares in the patents. Jim died in January 1982, just as the machine was becoming known and some 200 were in use in various countries. Most were working in hard rock quarries et that time but recent uses have carried the machine into the mining and mineral processing field. This paper is directed at that industry."

Jan 1, 1985

By H. Cay, J. Zachwieja, T. Esplin, R. Ravenelle, T. Olsen-Tank

Barrick Goldstrike mine utilizes a carbon-in-leach (CIL) circuit to simultaneously leach gold into solution with cyanide and adsorb the gold-cyanide complex onto activated carbon for further refinement. If the gold bearing ore contains a significant amount of native carbonaceous material, gold cyanide can be adsorbed at these sites instead of onto the desired activated carbon and the gold is effectively lost to tailings in a detrimental process known as "preg-robbing." The preg-rob effect is considerably reduced by treating the ore with a surfactant, which is hypothesized to adsorb to and passivate the native carbon surfaces. Past laboratory and pilot studies have consistently demonstrated significant gains in gold recovery after treating carbonaceous ore with surfactant. With success in bench and pilot scale testing, a plant trial was conducted at Barrick Goldstrike to evaluate the feasibility of using an alkoxylated fatty amine surfactant (Ethomeen T/12) to aid in the leaching of high preg-robbing ores. This paper analyzes the performance of the surfactant during the plant trial in addition to the problems that occurred during the trial period. Suggestions for improvement are also discussed.

Jan 1, 2014

By Vincent Roy

Numerous on going activities at the Daniel-Johnson Dam : ? Surveillance / monitoring ; ? Structural investigations & evaluation ; ? Injection work ; ? Crack mapping ; ? Instrumentation management (drawings & inventory) ; ? Drainage system state ; ? Foundation evaluation

Aug 1, 2013