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By G. F. MacDonnell

THE Privateer mine consists of a group of mineral claims situated in the Zeballos area, on the west coast of Vancouver island, approximately 180 miles north of Victoria. Although Zeballos is a comparatively new mining camp, its transportation facilities can be considered exceptionally good. General freight and supplies are brought in by either C.P.R. or Frank Waterhouse steamers from either Victoria or Vancouver. Service by these boats varies from five to ten days and the trip from Victoria takes approximately two days. Passengers may use the C.P.R. boats, or, if speed is essential, they may fly, in which case they have the choice of two flying companies, namely, Canadian Air-ways, Limited, and Ginger Coote Airways. The average flight from Vancouver takes approximately two hours. Excellent unloading facilities are provided at the beach by a government dock for the steamers and a floating dock for aeroplanes. The mine, which is approximately five miles from the beach, is serviced by a fairly good gravel road, which has proved satisfactory for all haulage purposes. Zeballos has the reputation of having one of the heaviest rainfalls on the west coast, but as no accurate records have been kept, no comparisons can be made. H. C. Gunning, in his report, comments on the weather from 1929 to 1932, and one would judge that the practically continuous rainfall did not add to the pleasures of the field work. During the summer of 1938, the opposite condition prevailed and the area had exceptionally dry and pleasant weather. The snowfall is generally light at the lower elevations, but very heavy higher up. No extreme cold weather is encountered during the winter, which is generally short.

Jan 1, 1939

By G. B. Hudson

Previous papers (1, 2) pertaining to the treatment of uranium-bearing ores were concerned with the flotation of the radioactive minerals. In this investigation, the application of flotation to the removal of acid-consuming minerals from uranium ores was considered. Two pitchblende-bearing ores, which, because of the presence if dolomite were abnormally high acid consumers, were studied. In both in-stances commercial reagents of widely varying fatty acid composition proved satisfactory as flotation col-lectors, particularly at a pH of 10.5, for the carbonate minerals. From an economic viewpoint, however, Neo-Fat 42-12 was favoured. A mixture of sodium tripolyphosphate and citric acid was an effective depressant for the pitchblende in the ores. The tailings remaining after the removal of the dolomite by flotation contained, in one case, 88.5 per cent of the uranium in the original sample, and, in the other, 93.8 per cent. Analyses conducted on these tailings and on the original ores showed that

Jan 1, 1963

By Frank Otten, Jochen Greinacher

"In July 2017, Deilmann-Haniel signed a contract with IOO Slavkaliy to sink two 750 metre (m) deep freeze shafts for the Nezhinsky Potash mine in Belarus. This is the second shaft project where this technology is employed after two over 1,000 m deep shafts for a potash project in Saskatchewan, Canada, have been sunk by the application of the Herrenknecht Shaft Boring Roadheader (SBR) technology. Developed to sink shafts for green field projects in soft to medium hard rock, in frozen or unfrozen geology, the machine technology utilizes a roadheader-type cutterhead on a telescopic boom to mechanically excavate the rock, and a pneumatic mucking system to convey the muck from the face into the buckets. This leads to a manless face during the sinking cycle and thus a significant improvement in terms of workplace safety. For the Nezhinsky project, the SBR design was significantly modified in close cooperation between Deilmann-Haniel and Herrenknecht, based on the available experience and the special requirements of the project. Such modifications have been for example the adaptation of the Pneumatic Mucking System to cope with wet material as well as dry as originally planned or the shaft lining moving from shotcrete application to jump for and tubbing installation for which a step-change hands-off tubbing erector for the placement of segments was designed. Further modifications to optimize the machine technology for the requirements during shaft sinking were applied on the two machines for the Slavkaliy project as well as several revisions to match the special project requirements. The SBR is suitable for soft and medium hard rock up to 100 MPa UCS. The main design limits are maximum weight of the machine with 400 tonnes and length or height of 50 m due to the depth of the pre-sink. The Pneumatic Mucking System was changed in all components, sheaves and rope arrangement were redesigned and the concept of the hoist system was also re-engineered. The SBR in Belarus is configured for a daily sinking rate of three metres and all systems behind the cutting boom are not the bottle neck of the whole system. The works on site started in November 2017 including freeze hole drilling, construction works, site setup, installation of hoists winches, permanent headgears and other components required for sinking. The SBRs arrived on site in June/July 2018 and were preassembled on surface and then lowered into the 50 m pre-sink. SBR #1 started full face sinking in mid-December 2018, and SBR #2 in late January 2019. By the end of February 2019, the machines were at 150 m and 100 m depth respectively, and achieved up to 3.6 m/day concrete lined shaft. The SBR and the sinking system, the experiences, problems, technical solutions and performances of this challenging project will be presented in this paper."

Jan 1, 2019

By Silvana Costa

The quality of life in remote mining communities is a significant factor that impacts the mining industry?s ability to attract and retain high quality workers in remote areas. The rapid growth of mining development, along with the shortage of skills and training globally are reflected in an increasing need to identify the ideal conditions for employee wellbeing and investigate ways to improve quality of life of miners and their families in remote locations.

May 1, 2007

By Limao Zhang

This paper presents a BIM-based Risk Identification Expert System (B-RIES) for metro construction, composed of three main built-in subsystems: BIM extraction, knowledge base management, and risk identification subsystems. The engineering parameter information related to risk factors is extracted from the BIM of a specific project where the IFC standard plays a bridge role between the BIM data and metro construction safety risks. An integrated knowledge base, consisting of fact base, rule base and case base, is established to systematize the fragmented explicit and tacit knowledge. A hybrid inference approach, with case-based reasoning and rule-based reasoning included, is developed to improve the flexibility and comprehensiveness of the system reasoning capacity. During the safety risk identification process, B-RIES is able to improve the inefficiencies in engineering information extraction, reduce the dependence on domain experts, and facilitate knowledge sharing and communication among dispersed clients and domain experts. A typical safety hazard identification in the Mingdu station, located in the Wuhan Metro Line Two, is presented in a case study. The results demonstrate the feasibility of B-RIES, and its application potential. B-RIES can be used as a decision support tool to provide guidelines for safety management in metro construction, and thus increase the likelihood of a successful project in a complex environment.

Aug 1, 2013

By R. R. Rogers

Abstract The degree of cathodic protection of steel and the anode corrosion rate were determined when anodes and waters of different compositions were used at temperatures similar to those in domestic hot water tanks. Twenty different anode materials, sixteen of them magnesium-zinc-aluminium alloys, were immersed in six different synthetic waters resembling those to be found in various parts of Canada. The results showed that (1) both the degree of cathode protection and the average anode corrosion rate are affected materially by the composition of the anode material and of the water; (2) poor cathode protection is associated with low anode corrosion rate; (3) when the cathode is fully protected, the anode corrosion rate may be comparatively low or comparatively high, depending upon the composttion of the water; (4) an important relationship exists between the magnesium content of the preferred anode and the composition of the water; (5) the degree of protection is increased as the SO4 + Cl concentration of the water is increased and thus as its specific resistance is decreased. Introduction Fairly recently, the use of the active metal magnesium for the cathodic protection of less active metals has received a considerable amount of attention. This interest has been stimulated by the fact that the wartime demand for magnesium was greatly in excess of the present peacetime demand and there is a natural desire to continue operating the large magnesium plants which were built during the war. Information regarding the use of zinc and aluminium for this purpose also has been published. There is a great demand for domestic hot-water tanks which will resist corrosion satisfactorily. This problem is rather complex in view of the fact that the composition of the water used in such tanks varies greatly and depends upon the locality. The present investigation deals with the effect of water composition and anode composition on the cathodic protection of steel under conditions approaching those which exist in hot water tanks.

Jan 1, 1948

By Arthur B. Yates

"The nickel deposits of Sudbury, discovered in .1885, have probably commanded as much attention as any single group of orebodies in the world. They have been the major source of the world's nickel supply since 1903, when their production first surpassed that from the Pacific Island of New Caledonia. From 1903 to 1914 the production from New Caledonia remained essentially constant, whereas that from Sudbury increased from 13,000,000 to 50,000,000 pounds a year. After 1914 the production from New Caledonia gradually dropped to about 4,000,000 pounds in 1919, where it remained until 1923. During these years the Canadian production increased steadily and since 1923 has gone up at an amazing rate to a peak of over 280,000,000 pounds in 1941. Meanwhile the New Caledonia production increased to about 10,000,000 pounds until the pressure of war raised it to roughly 14,000,000 pounds a year.The Sudbury deposits, because they have been the source of 80 per cent of the world supply of nickel, because of their economic importance to the world of metals, and because they are geologically unique in their occurrence, structure, and genesis, have attracted foremost consideration and the literature relative to their geology is voluminous. This is particularly true in regard to genesis.There is a significant and interesting parallel in time between the advancement of the science of economic geology and the great expansion of the nickel industry. The controversies regarding the fundamental classification of orebodies into generalized types were in full swing during the height of the development and expansion of the great nickel mines, and the Sudbury deposits, being the most important and the only ones of the sulphide type extensively developed, have been the chief source of information in regard to this type. The observations and the conclusions drawn thereon from numerous studies of the various mines of the district have not only influenced, but are the essence of, this chapter of the science."

Jan 1, 1954

By G. Clarkson, M. Hitch, R. Clarkson

"A novel reagent-free method of extracting gold from gravity middling concentrates in the Yukon placer fields is presented in this paper. This method exploits the malleability of gold by submitting concentrates to grinding in a rod mill. Brittle waste minerals are effectively reduced, whereas malleable gold particles are flattened and are then extracted by classification through sieves. Recoveries in the field using a laboratory-sized rod mill regularly exceeded 90%, whereas correlation laboratory tests indicated recovery to be most sensitive to the mill charge size. This method has broad potential, including application to the gravity circuits of large hard-rock processing circuits.RÉSUMÉ Cet article présente une nouvelle méthode sans agents réactifs d’extraction de l’or dans les concentrés gravimétriques mixtes que l’on trouve dans les districts placériens du Yukon. Cette méthode exploite la malléabilité de l’or en broyant des concentrés dans un broyeur à barres. Les déchets miniers cassants sont bien réduits, alors que les particules d’or malléables sont écrasées puis extraites par classification au travers de cribles. Si les récupérations sur le site à l’aide d’un broyeur à barres de laboratoire excèdent 90 %, les essais de concordance en laboratoire indiquent que la récupération est très sensible à la taille de la charge du broyeur. Cette méthode présente un grand potentiel, notamment une application possible aux circuits gravimétriques des grands circuits de traitement des roches dures.INTRODUCTIONExploiting the high density of gold to separate it from waste materials is the oldest known mineral processing technique. This basic technique is still widely used in gravity concentration circuits today; however, gravity processing invariably results in high-value middlings, especially in the Yukon placer gold fields. In addition to having a uniquely high density, gold is also the most malleable metal. This unique malleability can be exploited to extract gold from otherwise inaccessible gravity middlings.The Yukon placer gold industry has been continuously ongoing since the 1860s, and today produces approximately 60,000 oz t (1.87 million grams) of crude gold annually, most of which is from the Klondike region near Dawson City (Van Loon & Bond, 2014). It is important to note that Yukon placer miners do not use any chemical extraction methods; rather, gravity upgrading methods are the sole processing techniques used. Placer deposits are typically coarse, well liberated, and naturally gravity concentrated and recoverable, thus making more expensive chemical extraction unnecessary (Mitchell, Evans, & Styles, 1997). Furthermore, a strict permitting regime, environmental concerns, lack of expertise, and fear of repercussions from regulators prevent miners from attempting more advanced processing methods, such as flotation or cyanidation. Even simple chemical extractions like mercury amalgamation have not been implemented for decades, with one observer noting that, as many as 30 years ago, “the art of mercury for amalgamating appear[ed] to be dying [in the Yukon]” (Osler, 1983)."

Jan 1, 2017

"The Hardy Cross algorithm offers a reliable method of solving network systems of fluid flow and has become widely used for solving water and ventilation flow networks. A limitation is that computational iterations and time to solve a network rises rapidly with the size of the model and modern detailed ventilation networks have typically grown to thousands of airways. Non-linear matrix solving methods can offer improved performance, however these are more complex and may be unstable if initial estimates are poor. This paper presents improvements that can be applied to the traditional Hardy Cross algorithm to greatly reduce iterations and solving time for large ventilation models. INTRODUCTION The Hardy Cross algorithm (Cross, 1936), was originally developed to solve water flow in city and urban pipe networks. Using principles of Kirchhoff’s electricity current laws, Hardy Cross developed an iterative algorithm for solving non-linear equations associated with network water flow. Traditional network analysis research refers to the various members of system networks as branches, nodes and meshes. This terminology has been changed in this paper to airways, junctions and loops respectively which are terms more familiar to engineers in mine ventilation. When Kirchhoff’s laws are applied to fluid networks, the following assumptions can be made: •The sum of fluid flows into a junction must equal the sum of fluid flows out of the junction.•The sum of pressure losses around any loop through a network system must be equal to zero.An iterative solution can therefore be achieved by initially guessing flow in a network, calculatingthe pressure losses around the network loops (Figure 1), and applying flow corrections using Newton’s method for each loop if the sum of the pressure losses does not equal zero. To solve the system, a loop must be defined for every segment or series of segments between a junction of 3 or more airways.The Hardy Cross algorithm has been used extensively for ventilation network analysis since the introduction of the first electronic computers (Tien, 1997), however numerous other variations and methods have since been developed through the use of matrices to solve the required system of nonlinear equations. Commonly used algorithms such as the Newton Raphson method (Brown, 1969), the Gradient method (Todini & Pilati, 1988), the Linear Theory method (Gupta & Prasad, 2000), and Coupled Network Solver (G. Danko, 2008) have found general use in fluid flow network solvers (Rossman, 2000). Despite poor and sometimes unpredictable convergence performance however, the Hardy Cross algorithm still has unique properties that make it attractive for ventilation models. Some benefits are:"

Jan 1, 2019

By M. S. Badollet, W. C. Streib

"AbstractA commercial method .has been developed for controlling the texture of chrysotile asbestos fibers so that they may possess properties comparable with natural sem1-harsh fibers for use in wet •processes.The physical properties of the soft, silky and slimy fibers are partially altered by a flash-heating process which removes a portion of the molecular water.The heat-treated fibers show an improvement in filterability, an increase in bulk, absorption, and surface area and better electrical properties, such as volume resistivity.IntroductionCHRYSOTILE ASBESTOS fibers are found in nature having varying degrees of texture, referred to as soft, semi-harsh, and harsh. Fibers of each type of texture have inherent characteristics which directly affect their usefulness to industry. Visual differences are apparent under a microscope where it is seen that the soft-textured fibers have a silky, serpentine or wavy appearance, whereas the harsh-textured fibers are coarser and spicular. Semi-harsh fibers, of course, have properties intermediate between these extremes.Fankuchen and Schneider ( l) have shown by the use of low-angle X-ray scattering that the diameter of the harsh type of chrysotile fiber is somewhat greater than tha of the soft variety. Surface area measurements on various chrysotiles of different textures tend to confirm their findings. By nitrogen adsorption methods, it was found that the surface areas of soft types of chrysotile asbestos are approximately 23M2 / g whereas for the harsh types they are as low as 11M2/g."

Jan 1, 1955

By A. E. M. Warner, I. E. Hills, C. L. Harris

Since the late Dr. Keith Brimacombe, et al, performed tests at the now-closed Asarco Tacoma smelter and the Inco Copper Cliff Smelter on Peirce-Smith copper converters almost thirty years ago, many Pyro-metallurgists have investigated using the technology. To the best of the authors knowledge, except for shrouded tuyere technologies using substantial oxygen enrichments, the core idea of using high pressure air injection has not been implemented anywhere in the world. This paper reviews the fundamentals of this technology and summarizes the basic economic considerations. It also presents the circumstances of where and when high-pressure injection might be justified.

Jan 1, 2007

By N. J. Duncan

"Coal mining, whether surface or underground, has hazards that make it unique in the field of industrial safety and health. The often soft, faulted and folded sedimentary strata make wall or roof movement a risk to the safe and economic removal of the coal, while the extraction and handling of coal may create an explosion hazard even in surface operations, In Canada, these problems are compounded by the situation of the coal fields which range from deep undersea deposits in Nova Scotia to steeply pitching thick coal seams high in the Rocky Mountains. Climate too can create its own problems, particularly the effect of metals of minus 40°C temperatures, as crumpled dragline booms at prairie strip mines witness. Because of the difficult and sometimes hazardous conditions, Canada's underground colliery managers, in common with those of other Commonwealth coal-producing countries, must have a government ""certificate of competency"" before being appointed as mine managers. Certification of assistant managers (""under-managers"") and foremen (""fire-bosses"") is also a legal requirement for all of Canada's underground collieries, while the province of Alberta requires certification of surface management personnel. Electricians and mechanics who install and maintain the specially designed equipment underground and in hazardous areas of surface mines and processing plants, and mine surveyors who ensure accuracy of the location of underground workings, must also hold government certificates of competency. The requisites for all certification include a minimum work experience and knowledge of coal mining technology and mine safety and health legislation. Despite recognition of the hazards and increasing knowledge of methods of preventing explosions of flammable gas and coal dust in Canada's underground mines, there have been several disastrous explosions such as those at Springhill Colliery in Nova Scotia in 1891 with the loss of 125 lives, at Hillcrest Colliery in Alberta in 1914 with 189 dead, and more recently · explosions and fires in No. 20 and No. 26 Collieries in Cape Breton. Preventing explosions has required developing optimal ventilation techniques, reducing ignition potential, suppressing ignition at source, draining flammable gas before it can enter the air courses, and preventing, or sealing off, autogenous heatings with their associated carbon monoxide or explosion dangers."

Jan 1, 1985

By K. Adham

Both the dry and the wet fluorination systems require hydrogen fluoride (HF) for the process of uranium conversion to uranium hexafluoride (UF6). The dry methods depend on the electrolysis of HF to generate the fluorine (F2) required for the high temperature pyro-fluorination. The wet methods require aqueous HF in water solutions for the low temperature hydro-fluorination (Argonne, 2019). This paper uses the available HF safety guidelines and industry information to discuss the issues of transportation, storage and utilization. Health effects and environmental considerations are reviewed. Safe practices for handling the HF (both as anhydrous and as aqueous) are considered. Proper selection of different materials of construction are discussed, for both the anhydrous and the aqueous HF.

Jan 1, 2020

By C. R. Ross

"THE ASSESSMENT of pneumoconiosis-producing dusts in mines and other industries is usually undertaken for one or more of three reasons: (1) To compare dust exposures at particular operations with standards of permissible dustiness in order that hazards may be evaluated and preventive procedures initiated where required.(2) To study particular operations with the objective of improving dust control devices or procedures by locating dust sources. (3) To obtain data which, along with the results of medical investigations, may assist in understanding the causes of dust-induced diseases or aid in the establishment of permissible standards of dustiness. Most dust measurements are made for the first of these reasons -to evaluate dust hazards so that they may be controlled. For this purpose, four quite different assessment techniques have been in widespread use for many years. One of these is based on the konimeter, an instrument familiar to most .Canadian mining men; a second on the impinger, which is also widely used in Canada, and almost exclusively so in the United States; a third on the thermal precipitator, used extensively in Britain and South Africa; and a fourth on the tyndallometer, a light-scattering instrument used in Germany."

Jan 1, 1960

By J. Lui

At its Copper Cliff Smelter, bulk nickel and copper concentrate is processed in two Inca flash furnaces and Peirce Smith converters to produce Bessemer matte containing 0.6%Fe. After slow cooling and Matte Separation, Bessemer matte is converted into three main products using magnetic separation and flotation technology: (1) a nickel containing chalcocite concentrate (MK); (2) two types of copper containing nickel sulfide (ME and MR); (3) metallics (MYN). MK is further processed in the Inca top blowing bottom stirring MK Reactor to produce semi-blister copper containing ~4%Ni and ~3±1 %S. The semi-blister copper is then purified in the multi-purpose vessels (MPV) to produce blister copper by reducing Ni, Fe and S content through oxidation. High melting point NiO is formed inside the MPVs. The accumulation of solid NiO and other oxides requires periodic cleaning by adding reductant and furnace matte, a unique process called "washout" at Inca. For many years, the reductant used for the "washout" process has been 15%Si Ferro-silicon. With increasing cost and limited suppliers for 15%FeSi, alternative reductants were pursued. This paper summarizes the development and commercialization of new alternative reductants for MPV "washout".

Jan 1, 2007

By John C. Robbins

A new technique for the determination of trace levels of uranium in solution has been developed. A compact laser emits short, but intense, ultraviolet pulses to excite the green fluorescence of a uranyl-complex formed by the addition of a proprietary reagent to the sample. Organic species present in most natural waters also fluoresce quite intensely, but their emission does not last appreciably longer than the excitation pulse, in contrast to the relatively long persistence of the uranyl fluorescence . Electronic 'gating' is employed to separate the long-lived contribution, rejecting substantially the organic emission. Results using the laser fluorescence method on many sets of natural waters of various origins have been compared against corresponding values generated by independent laboratories. Correlation has been generally good over a range from less than 0.1 to more than 100 ppb U. Solid samples have also been analyzed after extraction of the uranium into solution. Accuracies adequate for most exploration purposes have been achieved, but further work is required to determine effects of interferences in samples with complex matrices. The transport and deposition of uranium in natural waters is controlled by the organic and inorganic chemistry of the waters involved. It is suggested that interpretation of very low uranium levels will be aided by additional measurements of conductivity and organic content, with subsequent statistical treatment.

Jan 1, 1978

By C. G. Williams

IN preparing this paper on Canadian mine taxation, there has been no attempt to detail the requirements of the various taxing bodies; but rather to consider the matter from the standpoint of its underlying principles and give a general idea of the methods adopted. I have added an Appendix setting forth the principal features of the various Acts, which should be used for general reference only, since new rulings alter minor details from time to time. In current legislation, many important points are left to the discretion of the Ministers and their deputies. We are, indeed, fortunate in having in Canada an able and conscientious body of permanent officials, who bring a sense of justice and courtesy to their work which is most commendable, and which has done much to simplify the working out of general problems. The production of metals may rightly be deemed a form of manufacture, but differs from the average manufacturing business in three important respects: (1) In its early stages, it is wholly speculative, since it is impossible to make any definite appraisal of value or possibilities. (2) The principal asset of any mine, i.e., the ore in the ground, is a wasting asset, and is irreplaceable. (3) Any additional burden by way of taxation cannot be passed on to the public but must be borne entirely by the producer. Having regard to the first of these differences, it is apparent that, since the risk of loss is great, the reward in case of success must be correspondingly great. This fact seems to be constantly overlooked by those who regard the all too few outstanding successes in Canadian mining history as fit prey for predatory legislation. As an illustration of the speculative nature of early mining development, let us consider the Province of Ontario-and I take this illustration simply because I am more familiar with conditions there, and not because I believe it differs greatly from any other province. From 1907 to 1933, 165,243 claims were staked and recorded, from which 43 mines were developed which paid one or more dividends. There was, of course, some duplication through re-staking; also, on some claims very little work was done, and most mines have more than one claim. But, since staking and recording cost real money and effort, each of these claims must have been considered to have had merit.

Jan 1, 1935

"RÉSUMÉOn discute les principales sources de dilution au cours d’une exploitation souterraine. Les différentes définitions de la dilution en usage sont analysées. Une nouvelle méthodologie de calcul simplifiée et facile à utiliser dans la pratique minière est présentée. Cette méthodologie permet de remplacer les différentes expressions analytiques en usage par les deux facteurs de dilution seulement : un «facteur de dilution planifiée» lié à la sélectivité d’abattage au niveau de la planification minière et un «facteur de dilution additionnelle » permettant de juger de l’efficacité du contrôle de terrain et de la dilution pendant l’exploitation souterraine. L’application de cette méthodologie donnerait un outil nécessaire aux niveaux de la planification, du suivi des travaux d’exploitation et d’éventuelles études comparatives des coûts entre les différentes situations minières.ABSTRACTThe principal sources of dilution during underground evaluation and mining are discussed, then definitions of ore dilution currently in use are analyzed. These definitions vary depending on the authors. A new ore dilution evaluation methodology is proposed, replacing the ten different analytical expressions by only two: the planned dilution factor related to the stoping selectivity, done at the mine planning level, and the additional dilution factor related to the efficiency of the dilution control measures during stoping operations. The conclusion shows that the use of this methodology would be a definitive asset in planning, in stoping operations follow-up, and in future costs comparison studies between mining operations."

Jan 1, 2001

By John L. Rich

A New Field for the Mining Industry A new field for the mining industry is in prospect. This is the recovery of the petroleum which has been left in the ground in the older oil fields whose yield has declined until they are no longer profitable to operate in the ordinary way. The fact that an oil field has reached the economic limit for operation by pumping does not necessarily 'mean that the oil has ? been exhausted. In many such cases not over one-fifth, or even one-tenth, of the total oil content of the field may have been taken out when this stage has been reached. This means that there exists a large reserve of oil which can be recovered by whatever process best takes advantage of the natural conditions under which the oil occurs. Mine drainage is one of the processes by which this oil may be recovered. Its relative importance will depend partly on the ingenuity and wide-awakeness of mining engineers, and on mining capital. The opportunity is undoubtedly at hand. In order that we may be in a position to judge the possible advantages of mining methods for the recovery of this oil, I have reviewed, on the following pages, the methods now in use, and have discussed the physical conditions of the reservoir rocks in which the oil is found, and the suitability of the various recovery processes, in use or proposed, in the light of these reservoir conditions.

Jan 1, 1927

By S. Foged

Umicore and MWH jointly demonstrated that mechanical dewatering of goethite and neutralised tailings significantly increased the life of a 30 ha tailings pond and improved the operation of the pond. Umicore operates one of its zinc production plants in Balen, Belgium. As part of its production process, an excess of neutralised and goethite¬containing tailings is generated. These have historically been stored inside large lined ponds. As the storage area of the current goethite pond was nearing its capacity, Umicore studied the potential for an extension to the existing embankment. However, this extension would face intense regulatory scrutiny, because the environmental and safety impacts were considered important. Together with Umicore, MWH suggested and investigated an alternative treatment approach consisting of mechanical dewatering prior to storage. A feasibility study was prepared where wet storage was compared to dry storage. Differences in safety risks, environmental impacts and economic costs were outlined. The study demonstrated that the life of the tailings pond could be increased from 6 to 22 years, seriously reducing the environmental impacts and safety risks at no significantly higher cost than would have been incurred with the continued operation of the existing pond. The results of the study are presented in this paper.

Jan 1, 2006