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By Toivo Toivanen

The paper begins with a brief history of the nickel industry in Finland, and then deals with the introduction of the flash smelting process. The main part of the paper is devoted to nickel refining, which is studied under four main headings -grinding, leaching, electrolyte precipitation, and nickel electrowinning. Flowsheets are illustrated, and the equipment used is described. Analyses of the material in the various stages, from concentrate to high-grade nickel matte, are also presented. N ICKEL made its appearance in the Finnish mining industry forty years ago, when a nickel deposit was discovered at Petsamo in Lapland. Mond Nickel Co. received the concession for this deposit from the Finnish Government, and the Petsamon Nikkeli Company constructed a mine and a nickel smelter (1), the completion of which was prevented by the 1939 Winter War. The mine and smelter were, however, completed soon afterwards in spite of World War II,

Jan 1, 1964

By J. Butra

The underground research presented in this paper was carried out in the two Polish copper mines: Rudna and Polkowice-Sieroszowice. The aim of the research was to determine stress field parameters. The measurement method and measuring positions are described as well as the measuring technique adapted to the geological and mining conditions of the Rudna mine and the Polkowice-Sieroszowice mine. The identified values and directions of principal stresses and horizontal stresses and their importance for optimization of mining operation and safety improvement are discussed.

Aug 1, 2013

A direct comparison has been undertaken between laboratory wind tunnel experimentation and computational fluid dynamics simulation of a 3D manufactured analogue for a body of fractured broken rock, created with CAD/CAM techniques. Detailed descriptions of the ?design? of the analogue (using a discrete element analysis multi-body simulator), its manufacture (using computer aided design and 3D printing technology) and the laboratory experimentation (inserting the physical analogue into a laboratory scale wind tunnel) are presented. The agreement of the results of direct experimental observations on the manufactured analogue with the values from CFD simulations of those experiments justifies the utilization of a CFD environment for the practical investigation of geometric factors controlling air flow and heat exchange in complex assemblages of broken rock blocks. The ultimate goal is described, that of developing functional relations between bulk properties of such assemblages (such as their porosity and bulk density) and the low-level geometric factors that dictate the air flow behaviour, such as the equivalent perimeter length of the cross-sectional area available for flow, or average flow path tortuosity. A practical application area of the work in the mining context is also described; equivalent continuum air flow and heat transfer constitutive models developed on the CFD tool from such functional relations are useful in characterization of seasonal heat storage in large scale bodies (approximately 1 km3) of broken rock.

Aug 1, 2013

By J. A. Folinsbee, Andre Robitaille, Tony Y. Chong

"Conventional crushing and grinding is followed by gravity concentration to recover free milling gold. Refractory gold, finely disseminated within the pyrite and arsenopyrite matrix, is recovered by flotation followed by pressure oxidation, cyanidation, and cementation. Non-refractory gold is recovered by cyanidation/CIP processing.A comprehensive test program aimed at improving flotation recovery was initiated in June 1995. Plant testing indicated that flotation tails value could be significantly reduced using mechanical flotation cells. Based on these test results, a flotation circuit that incorporates one of the three existing flotation columns followed by mechanical scavenging and cleaning was developed. Detailed engineering was completed in September 1996. Construction started in February 1997 and was completed in 3 months at a cost of $3.2 million. An on-stream X-ray analyzer was installed to provide real-time arsenic and iron analyses and inferred sulphur value on some of the flotation streams.The new flotation circuit proved to be an instant success. Flotation tails values were reduced by 27%. Final tails solids and solution was reduced from 0.035 to 0 023, and 0.0014 to 0.0006 oz/ton Au, respectively. Based on a mill throughput of 1,620 stpd this decrease in tails value will result in an increased gold production of 7,500 ounces per year. The payback for the project is estimated to be around one year.This paper describes the evolution of the project from bench scale testing to commissioning. Also, the operational and economic impacts on down stream processing are highlighted"

Jan 1, 1998

By Paul E. Lamoureux

Introduction The Author As the pail of smoke and wartime destruction gradually rises from the surface of the earth, from all countries, statesmen assemble to discuss and prepare pacts and treaties which are designed to, once more, bring people of all nations to understand each other and live in harmony. Scientists and engineers throughout the world are also undergoing a drastic reconversion in their ideas and objectives. No longer do they think only in terms of destruction and twist their brains to develop more devastating weapons or to surpass production records of war machinery. They have turned their eyes and ambitions to more pleasant tasks and are taking stock of wartime developments in materials, fabricating procedures, and equipment, many of which had been carefully shrouded with a veil of secrecy, and are applying their new knowledge to the fabrication or improvement of the tools of peace. The next few years will see the gradual elimination of scores of substitutes and makeshifts, expedients which the constantly changing law of supply and demand' under wartime stress necessitated. The universal search for satisfactory substitutes, however, has resulted in a general awakening of plant engineers to the possibilities of materials with which they were relatively inexperienced, with the result that, in many instances, what was considered a substitution at the outset turned out to be more satisfactory than the original material, and, in reality, can be considered a worthwhile development. Not only have materials been explored, but existing fabricating processes have been reviewed, and others, built around the properties and characteristics of new materials, created.

Jan 1, 1947

By S. Abu-Samra

By virtue of its complex nature, the construction industry comprises a wide spectrum of interrelated variables and factors. This multifaceted character of the construction industry puts the use of engineering modeling tools and techniques on top of project management necessities. This research introduces a macro-level earthmoving management system using Genetic Algorithms (GAs) to reach the optimum allocation of earthmoving equipment. The Earthmoving Equipment Management System (EEMS) functions through four integrated modules: (1) A Central Database containing information about projects and available equipment; (2) An Equipment per Segment Selection module that calculates the cut and fill quantities, plots the Mass Haul Diagrams, and selects the equipment types to be used for each segment; (3) An Equipment Pool module which determines the production and cost for each available equipment, based upon the project site conditions; and (4) An Optimization Engine equipped with a GA optimization solver. This engine formulates the optimum earthmoving cost for all projects, by changing the number of allocated equipment. The Optimization Engine takes into account the number of available equipment and calculates the weekly equipment allocation. The EEMS model was implemented on an earthmoving company conducting five different projects on hand. The model proved to be an effective tool in providing decision makers with optimum equipment utilization on a multi-project scale to minimize the earthmoving cost. The results were then compared with the company?s existing micro-level management system, demonstrating better performance on the level of savings, amounting to 13% of total earthmoving cost.

Aug 1, 2013

By B. D. Sparks, I. E. Puddington, F. W. Meadus

The continuous separation of bitumen from Athabasca tar sands, with a high clay content, has been demonstrated. Recoveries of 95 per cent or higher have been obtained. Further processing of this product, to produce an accept-able type of crude oil, would require less heat than currently used in the hot-water process. Also, by comparison, substantial savings in equipment and operating costs are indicated.

Jan 1, 1971

By W. D. Mulholland

"I ASSUME that any effort on my part to deal with the question of the importance of the mining industry is going to be largely an exercise in preaching to the converted, but there are one or two aspects that I'd like to particularly mention.The first is that, in terms of almost all factors, the mining industry is a very important industry in Canada. It is important in terms of employment in relation to the gross national product of Canada and it is particularly important in the international trade of Canada. So far from being insignificant domestically, it is also an extremely important factor in the international picture. That's an important point to bear in mind, because as we talk about all the other matters we never can lose sight of the fact that mining management always has to be conscious of its international competitive position. It is something that one forgets at one's peril, and to a somewhat greater extent than is true of many other industries, those managements have to compete in an international context for their markets, to some extent for their people for specialized skills and of course for finance. In the evolution of domestic policies it is a very, very perilous step to take to impair that competitive ability of the domestic mining industry."

Jan 1, 1972

By Harry R. Oldale

This paper first covers the general and economic geology of the Coxheath Hills area, and then outlines the exploration and mining development that has been carried out since the first discovery of copper in the area in 1875. The work of Mariner Mines Limited from 1963 to the present time is detailed, particular attention being paid to the recent discoveries of copper, silver and lead mineralization that have greatly enhanced the potential of the area.

Jan 1, 1967

By R. Heikkilä

A large research and development program called RYM PRE (Process Re-Engineering) has been active in Finland since 2010. As a part of the program, a work packet Infra FINBIM is focused on the development of new national process model, specifications and requirements for the whole Finnish Infra Industry. In the Infra FINBIM, total 15 companies and main owners and 3 research organisations are included. The work is further continuing. The main achieved results up today have been the first specifications and requirements of the BIM based total process for infra sector, about 30 different pilot projects for testing of the new design and construction process models producing a lot of results and observations, a new open information transfer format Inframodel3 based on LandXML standard, the achieved acceptance of the Building SMART organization for support of international development, utilization and extension of the format within the whole infra industry, processes, software and other technical equipment. An evaluation of the results and this work will be drawn.

Aug 1, 2013

By G. P. Contractor

Many factors affect the forge ability of steels. One of the major factors is chemical composition.' This article discusses the individual effects of alloying elements and the effect of the resultant modification of microstructure onforgeability. INTRODUCTION T HE use of alloy steels is expanding considerably and the fabrication procedures for such alloys are becoming more complex. An attempt is made in this article to describe the effect of alloying elements on the hot-workability of steels. Most of the data reported here are taken from the studies of Ihrig, Clark and others (Refs. 1-4). Chemical composition is not the only controlling factor. Grain size and surface condition of the material, forging temperature, and speed of deformation are also important. Certain conclusions can be drawn regarding the effect of various alloying elements on the hot-work-ability of forging stock. The results of hot-twist tests are considered useful in this connection as the number of twists to failure has been taken as the level of forgeability at a particular temperature. The peak in the "Number of Twists -Tem--

Jan 1, 1962

By G. R. Larocque

"The Loss Prevention Program and management style applied at Kidd Creek enabled them to maintain a 1.02/200 000 man-hours accident frequency over a 20-year period. Falconbridge Limited, Kidd Creek Division operates a major zinc, copper, silver mine, two gold mines and a metallurgical facility in Timmins, Ontario. The metallurgical site and the base metal mine are 17 miles apart and joined by their own railroad. The minesite consists of two shafts, one 3000 feet deep and the other to 5200 feet deep, as well as the necessary maintenance and service shops. The metallurgical site consists of a 14 000 STPD concentrator, a zinc refining plant, copper smelter, copper refinery, and the necessary maintenance shops. The two gold mining operations are adjacent to the metallurgical site.At the time of writing this paper the workforce consisted of some 2500 people divided between the two sites. Nine hundred and ninety-two employees are stationed at the minesite, with the remainder at the metallurgical site and gold mines. The workforce in the Timmins operation is non-unionized and reflects the belief that employee interests are well served.Beside providing competitive wages and an excellent benefit package, Kidd Creek takes special pride in its employee relations practices and continued efforts in communication.In each of the programs referred to, there have been equal involvement by both management and the employees. Each crew, under the direction of a supervisor, makes up its own health and safety committee. To maintain a successful Loss Prevention Program, it is essential that management and the employees work closely together and provide meaningful input and effort to succeed.At this point, refer to the lost time injury frequency as a measure of failure and refer to the opposite end of the scale as the measure of success. The ultimate goal of every operating company is to have a zero frequency, therefore denoting 100070 success. The company uses most of the tangible safety aids found in other mining operations, such as safety posters, safety reminders, check lists, and the use of the Neil George Safety System. The difference is the manner and style of management at the Kidd Creek Division. Their ""open door"" policy and the close association, between management and the employees, has always served them well. Also, at Kidd Creek they believe they have a well-trained and dedicated workforce."

Jan 1, 1989

By V. G. Papangelakis, A. Dani

"Alkaline pressure oxidation, particularly in the presence of trona as additive, can be used to oxidize high carbonate refractory gold ores as it prevents the formation of CO2 in the autoclave. However, the presence of silica in the ore can lead to the encapsulation of pyrite due to the solubility of silica in alkaline solutions and its subsequent reprecipitation on the reacting pyrite surface, leading to the formation of a passive layer. This fundamental study investigates the chemical composition and thickness of the passive layer on a rotating pyrite disk using XPS and SEM, as a function of process conditions at 230°C, in an aqueous slurry containing silica sand, sodium carbonate and calcium carbonate under 100 psi of oxygen overpressure.INTRODUCTIONAlkaline pressure oxidation (POX) has been used successfully to treat high carbonate refractory gold ores, which contain carbonates in addition to sulphides, most notably at Mercur and Goldstrike mines operated by Barrick Gold. There are several advantages to using alkaline POX over its acid counterpart, especially due to high carbonate content. First, it eliminates the production of CO2 in the autoclave without resorting to pre-acidification, which allows for high oxygen utilization. Second, alkaline POX suppresses the formation of elemental sulphur and intermediate sulphur oxyanions (such as thiosulphates and dithionates), which reduce gold recovery. Third, the use of sodium hydroxide or salts prevents the formation of anhydrite scale by forming soluble sodium sulphate. Other advantages are the use of cheaper materials of construction and the formation of non-acidic residue that do not require further treatment prior to cyanidation (Thomas, 2005).Sodium carbonate in particular is a promising reagent for alkaline POX because it was shown to significantly accelerate the kinetics of pyrite oxidation by molecular oxygen, when compared to other reagents such as sodium hydroxide, sodium borate and calcium hydroxide. This has been attributed to the following factors: a) the faster oxidation kinetics of Fe2+-CO3 complexes compared to Fe2+ oxidation, b) the buffering effect of carbonate ions on the acidic pyrite surface, and c) the increased solubility of oxidizing Fe(III) species due to carbonate complexation (Caldeira, 2010)."

Jan 1, 2012

By L. H. McKay

Tailing Dams Three types of dam have been structed to impound tailings from the Allenby mill: 1.- By classifier unit 2.- By earth dam 3.- By direct deposition of tailings The first type, which includes two dams, was built across a shallow valley which sloped down to Similkameen river, just below the mill site. Two earth embankments, one below the other, were built across the valley. Tailings were then piped to Akins classifiers mounted on wooden wheels. The classifiers were set up at one side of the valley and gradually moved ahead on the sand embankment created by the sand discharge from these classifiers, the slime overflow going to settli.ng ponds formed by the dams. Decanting wells were built in the settling ponds by placing four six-by-six timbers vertically in the ground, two feet apart, to which two-by-six tongue-and-groove boards were nailed. The elevations of the ponds were raised, as required, by nailing additional two-by-six boards on the well and bolting on more six-by-six timbers when required. The bottoms of the wells were attached to a covered launder made of three-inch lumber laid on a one per cent grade. This launder carried the overflow through the dam. The second type of dam was built across a long, narrow valley, known as Hitchen's Flat, the upper ~n d of which was about 2½ miles north of the mill. This valley, an ideal tailings site, was 4,000 feet long and from 600 to 800 feet wide. An earth embankment with a concrete spillway through the top was built approximately 28 feet high across the lower end of this valley. Tailings were then dumped into the upper end of valley, with no further expense until the basin was filled up to the level of the flume where this entered the valley. When the upper end of the valley was filled to this point there was still room for more tailings at the lower end. Therefore, a pump was installed to elevate the tailings to build a wall around the upper end of the valley by depositing sands from a launder built up on 20 foot supports and sloping both ways from the pumping station around the upper end of the basin.

Jan 1, 1950

By J. S. Fox

It is generally recognized that the interpretation of bedrock geochemical data in volcanic terrains can be improved by adjusting for rock-type. Various chemical attributes of volcanic rocks have been put forward in the literature as rapid indicators of rock-type, but there is some question as to which of these is the most reliable . Only one such attribute, total iron, seems to have seen systematic use in geochemical mapping in the Flin Flon region. Discriminant analysis of 500 basalts, andesites, dacites and rhyolites suggests that SiO2 is the most important rock-discriminating variable and that MgO, CaO, TiD2, AI2O3 and FeOtot, are successively poorer discriminators. Lithological normalization in the subalkaline volcanic environment should therefore be made over ranges of this variable. Trace-metal data from drill core through the sulphide orebody at Hanson Lake, Saskatchewan are used to demonstrate various approaches to lithological correction, including silica normalization, factor analysis and trend analysis. All of these extract economically important information from the core that is not apparent in the raw data logs. However, silica normalization does not seem to be subject to as many serious limitations as factor and trend analysis in this case, and therefore seems to provide the most reliable basis for the interpretation of subsurface exploration geochemical data.

Jan 1, 1978

By E. Krause, V. G. Papangelakis, S. Garg, R. Mahadevan, E. Edwards

"Bioleaching uses iron and sulfur-oxidizing bacteria to extract base metals from sulfide minerals. As bioleaching involves breaking the iron-sulfur bonds by ferric attack, the biologically mediated rate of iron oxidation is recognized to play a key role in influencing the overall kinetics. In this study, we investigate the catalytic ability of an indigenous AMD culture for oxidizing Fe(II) in solution. This culture was subsequently adapted on pyrrhotite tailings (0.6% Ni) by gradually increasing the solids loading. Results from this study show that such an adaptation reduces the initial lag phase in the biotic oxidation of Fe(II), thereby allowing for a higher Ni extraction when compared to experiments with an un-adapted culture at a similar solids loading. The use of adapted cultures also helps to reduce the residence time for bioleaching of Ni from pyrrhotite tailings. INTRODUCTIONAs the world demand for pure base metals grows; the mining industry is increasingly faced with the burden of processing lower grade ores and mining waste streams in order to recover the occluded metal VALUES ((Watling, 2006). The extractive metallurgy of nickel from sulfide minerals focuses on using a combination of mineral processing, pyrometallurgical (smelting) and hydrometallurgical techniques to extract Ni from its ore bodies.Pyrrhotite (Fe1-xS) is commonly found in association with pentlandite and chalcopyrite in sulfidic Ni ores, such as those found in Sudbury, Ontario, and in Russia, e.g. Norilsk. The vast majority of this pyrrhotite needs to be removed using mineral processing techniques, in order to minimize the Fe and S contents of the concentrates that proceed on to smelting. If all pyrrhotite were left in the concentrate, much more slag and SO2 would be produced, and the smelter throughput would be limited. Beneficiation of Ni sulfide ores leads to the rejection of unwanted constituents as mining wastes, which may still contain extractable amounts of Ni (Edgar Peek et al., 2010)."

Jan 1, 2012

By Min-Yuan Cheng

Heavy rainfall and typhoon oftentimes cause the collapse of hillslopes across mountain roads. Disastrous consequences of slope collapses necessitate the approach for predicting their occurrences. In practice, slope collapse prediction can be formulated as a deterministic classification problem with two class labels, namely ?collapse? and ?non-collapse?. Nevertheless, due to the criticality and the uncertainty of the problem, evaluating the collapse susceptibility of an area is a challenging task. This study proposes a novel Artificial Intelligence (AI) approach, named as K-Nearest Neighbor Based Bayesian Classifier (KNNBC), to deal with slope collapse assessment. In the proposed model, Bayesian inference is used as a framework to achieve probabilistic prediction of slope collapse. Meanwhile, K-Nearest Neighbor (K-NN) is employed as a density estimation technique. Equipped with probabilistic outputs, the K-NNBC is able to yield predictions with different levels of confidence and diminish misclassified cases. Experimental results point out that the proposed model is very helpful for decision-makers in slope collapse assessment and disaster prevention planning.

Aug 1, 2013

By Charles Amoah

Abosso Goldfields Limited has been optimizing the comminution circuit at the Damang Mine Operation for the treatment of 100% primary ore. The optimization process started at a base rate of 343 tph when treating primary crushed primary ore, and was increased to above 600 tph with partially crushed primary ore. Abosso Goldfields engaged Orway Mineral Consultants (OMC) to assist with the optimization process in 2009 and the two companies have been working together since, to further refine the process. Continuous improvement was achieved through crushing circuit modifications, changes in operating processes and grinding control system utilization. This paper discusses the improvements developed for the increase in milling capacity and improvements in final product size.

Jan 1, 2012

"Some of the tools developed for the processing of nickel laterite ore by resin-in-pulp (RIP) may be applicable to the remediation of metalliferous mine drainage (MMD). In both cases, recovery of metal value and production of a stable waste stream appropriate for long term storage is desired. MMD typically has the additional challenge of management of toxic low-value metals. Seen in this light, innovations in RIP reactor configuration, selective elution strategies and novel synthetic ion exchange resins become useful tools for taking on the MMD challenge in a way that maximizes both environmental and economic benefit. INTRODUCTIONAcid mine drainage (AMD) is a common problem in any country with significant past mining activity. When sulphide containing minerals, tailings or slag are exposed to water, oxygen and sulphur oxidizing bacteria, AMD will result. Abundant and reactive iron sulphide minerals leach first, providing acidity and the ferrous/ferric couple that can enhance the oxidation kinetics of other minerals. If this runoff contacts encounters acid consuming carbonates or silicates, the acidity may be neutralized, but certain heavy metals remain in solution and can continue to be an environmental hazard (Gray, 1997). For this reason, the remainder of this paper will refer to the broader term metalliferous mine drainage (MMD) rather than acid mine drainage. In either case, such drainage, containing high heavy metal concentrations and often significant acidity, is toxic to aquatic life and can lead to significant damage to ecosystems and to public watercourses. MMD is a problem most commonly associated with now defunct sulphide mineral mines, but similarly toxic streams can result from many types of waste, such as poorly stabilized leach tailings, slag heaps, and coal flotation tailings (Johnson and Hallberg, 2005; Lee et al., 2002; Sainz et al., 2002; Schüring et al., 1997). In any case, the management and remediation of MMD is an important ongoing problem for the resource industry, particularly for the many mines in Canada closed before the advent of more stringent environmental standards. MMD remediation represents a significant long term expense for the resource industry. Multi-disciplinary efforts to understand and mitigate this problem range from creation of artificial wetlands (Poulin and Lawrence, 1996; Sheoran and Sheoran, 2006) to sophisticated biochemical reactors and precipitation processes (Hatami, 2010). Certain remediation technologies such as ion exchange offer methods to make a saleable product by recovering valuable dissolved metals. This paper will show how these technologies can help defray the cost of remediation, and offer potential to turn a dangerous waste stream into a useful product."

Jan 1, 2012

By M. M. C. Lima, L. C. S. Solimani, M. A. Quintela

Galvanized steel scrap is recycled to B OF converters where zinc escapes from the bath and is captured by the gas control system, appearing in BOF sludge. As BOF sludge contain high iron content, it could be recycled, but due to its zinc content, it is disposed in landfills. In this study techniques were evaluated for zinc layer removal from scrap by sulfuric acid leaching. The effects of coating weight, temperature, time and sulfuric acid concentration were evaluated for three different galvanized scrap. The results showed that the behavior of each galvanized scrap was different. Nevertheless zinc removal efficiency was more than 80% with low dissolved iron in the leached solution.

Jan 1, 2011