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By R. K. Borden

Rio Tinto is committed to proactive mineral waste and acid rock drainage management. Corporate requirements are closely aligned with the GARD Guide principles of early geochemical characterization and prediction followed by selection and implementation of management strategies to prevent or minimize ARD. Each operation is required to design and implement an ARD and Mineral Waste Management Plan. Successful implementation of the plan requires commitment at all levels of the company, from senior management, to geologists, mine planners, environmental staff and equipment operators. Examples of the successful integration of ARD management strategies into mine operations are cited from several mines.

Jan 1, 2011

By D. A. Grieve

"Mineable coal seams in the East Kootenay region belong to the Mist Mountain Formation of the Jurassic -Cretaceous Kootenay Group. Three structurally separate coal fields (Crowsnest, Elk Valley and Flathead) are recognized, all of which are characterized by compressional tectonic features such as f aiding and thrust faulting, and by /ate-stage normal faulting. Tectonic history has greatly influenced coal mineability and quality. Coals range in rank from low to highvolatile bituminous, and reactive maceral content ranges from less than 60% to greater than 90%. A wide range of metallurgical and thermal coal qualities is found. Measured reserves (up to 1981) include 1.03 billion metric tonnes metallurgical and 165 million metric tonnes thermal coal. Introduction a) Location -Coal fields of the East Kootenays region occur in the Front Ranges of the Rocky Mountains, within 30 km of the Alberta -British Columbia boundary (Fig. 1). They extend over 175 km north from near the U.S. border, and occupy the regions of the Crowsnest Pass and Elk and Flathead River drainages. The deposits are accessible from Highway 3 (Fig. 1) and various secondary roads. The towns of Fernie, Sparwood, Elkford, Coleman and Blairmore serve the coal industry. East Kootenay coal deposits are contained in three structurally separate coal fields, the Crowsnest, Elk Valley, and Flathead coal fields (Fig. 1). Coal is currently being produced by B.C. Coal (now Westar Mining Ltd.) at Sparwood, by Fording Coal 20 km north of Elkford, by Crows Nest Resources at Line Creek 15 km southeast of Elkford, and by Byron Creek Collieries at Corbin. Westar Mining has also constructed a new mine on the Greenhills Range 8 km northeast of Elkford. Pre-requisite engineering and environmental studies have been carried out on the Elco Mining property, 35 km north of Elkford, and on the Sage Creek coal property near the U.S. border (Fig. 1). b) Coal land tenure -Coal rights in the East Kootenays are either held as freehold land, or are licensed from the provincial government. The former category includes lands acquired under the Railroad Act of 1890. Shortly after this the federal government also obtained 50,000 acres of coal-bearing lands from the Crown Provincial, the so-called Dominion Government Coal Blocks. Major holders of coal rights in the area are Westar Mining and Crows Nest Resources. Large blocks are also held by Fording Coal and related companies, Sage Creek Coal, and Canada Permanent Trust Company as trustee for Elco Mining, and small blocks are held by Byron Creek Collieries and Coleman Collieries. In addition the provincial government holds an area in reserve for possible future use of B.C. Hydro at the extreme north end of the Elk Valley coal field."

Jan 1, 1985

By Malcolm Black

Introduction The circumstances under which the gold mining industry was forced to curtail operations a few years ago are well known to all. The effect of those circumstances is particularly noticeable when one enters some of the larger mills that were designed, in better times, to treat relatively large tonnages. On their grinding floors one will observe that a number of grinding units are lying idle, and the ravages of rust are everywhere in evidence. The same applies to other equipment throughout these mills. In 1941, we found it necessary to reduce tonnage considerably in the Wright-Hargreaves mill. With the assumption that a lower tonnage would be of long duration, we began to focus our attention on some of the idle equipment with a view to re-arrangement of the flow-sheet for greater economy of operation. In an article by the writer published in the Engineering and Mining Journal (March, April, and May issues, 1939) , it was pointed out that in designing this mill there was a very limited floor space available. The choice of thickening equipment was imposed solely by the necessity for space: conservation. Thickening by gravity would have required 5,000 square feet of floor space, whereas Genter thickeners required only 1,200 square feet. As a consequence, the Genters were chosen. The decision to add flotation to the circuit was made primarily to save space. On a cost-plus-tail basis, 80 to 100 hours agitation on all pulp would produce similar overall results, but would require much more space.

Jan 1, 1948

By J. E. Danoczi

ABSTRACT A diamond processing plant is being designed for the Star–Orion South diamond project in central Saskatchewan. Key to the plant is diamond liberation, which occurs in the comminution section and is the process of breaking up kimberlite rock as gently as possible to minimize diamond damage, particularly in larger, high-value diamonds. Kimberlite from the crater area of a volcanic pipe is generally softer than kimberlite from the diatreme zone. Softer kimberlite, comprising the majority of Star– Orion South deposits, can be readily broken up using abrasion and attrition by autogenous grinding mills, the preferred comminution method for minimizing diamond damage.

Jan 1, 2013

By Robert E. Loftus

"The author discusses the growth in the use of ocean-going bulk carriers for the transportation of mineral commodities, and predicts future trends. The various types of tonnage carriers are described, along with the special discharging gear used, the costs involved and the duties of some of the personnel.THE FIRST CONSIDERATION in planning the ocean transportation of minerals is the type of vessel to be utilized. The modern 'Bulk Carrier' bas proved to be the most successful vehicle for the purpose. I would there-fore like to describe this fleet in some detail and at-tempt to show the impact that the bulk carrier bas bad on the movement of bulk materials."

Jan 1, 1968

By H. A. Khorami, T. Wong, B. Velapatino, E. Asselin, T. Donnelly, E. Bryce, R. Dixon

A copper–nickel concentration gradient alloy was designed and fabricated through a powder metallurgy (PM) process. Copper and nickel powders were mixed with different weight ratios from 0 to 100% copper in 10% increments. Each powder mixture was poured inside a cylindrical die and compacted between two punches using a hydraulic press machine at pressures up to 70 MPa, resulting in approximately 1 mm thick layers (discs) of pressed Cu–Ni powder. These 11 Cu–Ni compacted powder layers, i.e. 0–100% Cu with 10% increments, were then compressed together with pressures up to 420 MPa to form a green part. The green part was sintered in a vacuum furnace at 1000°C for 10 hours to form a solid mass (PM part) of Cu–Ni concentration gradient alloy. In the sintering process, Cu and Ni particles fused together and formed a single piece due to diffusion of the atoms across the boundaries of the particles. The diffusion of atoms also converted the stepwise concentration change into a uniform concentration gradient. INTRODUCTION Copper has numerous applications in different industrial sectors due to its superior physical, electrical, mechanical and chemical properties such as its excellent thermal and electrical conductivity, resistance to fatigue, high ductility, and resistance to corrosion. Moreover, copper and its alloys have natural antimicrobial properties. This has opened up new applications for copper–based self–disinfecting surfaces in healthcare in an effort to mitigate healthcare–associated infections (HAIs). HAIs affect millions of patients each year, leading to significant morbidity and mortality as well as financial losses to healthcare systems (World Health Organization, 2016). HAIs spread through three main routes: (a) iatrogenic in which HAIs are a direct consequence of medical encounters and/or treatment; (b) person to person where organisms are transferred between healthcare workers, patients, and visitors; and (c) environmental where transmission occurs via contaminated surfaces and equipment (e.g. doorknobs, railings, toilets/commodes, medical carts). The use of antimicrobial copper–based materials on high touch surfaces could diminish pathogen transmission via this latter rout. This has subsequently led to the development of a variety of copper–based materials for use in healthcare settings and promoted the investigation of the antimicrobial efficacy of copper–based materials.

Jan 1, 2019

Traditionally within the mining industry, single models for both grade and geology of orebodies are created upon which all mine development decisions are based. These models provide a single interpretation of the extent and continuity of the mineralization envelope based on solids and sections interpreted from relatively wide spaced drilling i.e. the models infer behaviour of grade and geology at smaller/local scales based on data available at wider scales. The variable behaviour of grade and geology cannot be derived from single kriged resource models. In recognition of this, Newmont Mining Corporation typically uses Sequential Gaussian Simulation (SGS) to quantify grade variability and to determine its effect on some of these mine development decisions. In most of these studies the mineralized envelope remains fixed and grade simulations are generated within a fixed volume. To account for uncertainty in the geology/ mineralization envelope Newmont Mining Corporation has been experimenting with Multiple Point Statistics (MPS). Multiple-Point Statistics is an emerging technique, which can be used to generate multiple, geologically realistic, realizations of data that displays complex non-linear features. MPS uses a conceptual model of the geology, called a Training Image (TI), to infer these high-order spatial relationships. The multiple realizations allow for an assessment of the geologic uncertainty, which can be further combined with grade simulations to generate a more complete picture of the true uncertainty of a mineral deposit.

Jan 1, 2011

By J. Lee

As the usage of BIM increased in the construction industry, some construction owners started exploring the use of BIM for maintaining their facilities. Construction Operations Building Information Exchange (COBIE), a spreadsheet data format suggested in 2007 to manipulate building information, is considered as one of the solutions that would facilitate the process of transferring information from BIM to applications for facilities management. Several BIM and Computer Aided Facilities Management (CAFM) applications offer functions to export or import the COBIE data. To facilitate the process of generating the COBIE data out of Building Information Model, some add-in applications, such as COBIE Toolkit for Revit, also were developed. However, most of these applications handle a limited amount of COBIE data. Professionals using these add-in applications therefore sometimes end up spending a significant amount of time to add additional data manually to the COBIE data file. To automatically get a data-rich COBIE file, we developed a prototype application that extracts information from Revit, which is one of the BIM authoring tools, stores them in an external database, and then produces the COBIE file using information stored in the database. We applied our application to a pilot project and produced 8 COBIE worksheets automatically, which demonstrated a significant amount of time saving. This paper presents how our prototype application produces 8 COBIE data sets automatically. It also addresses our attempt to handle more COBIE data sets.

Aug 1, 2013

By C. T. Dzgoev, S. S. Gudkov, IRGIREDMET JSC, S. G. Schtoick, A. V. Yepiforov, S. V. Balikov, I. I. Yevtuschevich

The pressure oxidation (POX) and pyrometallurgical process comprises POX of gold containing sulfide and polymetallic lead-zinc concentrates prior to reduction smelting of POX products to generate a lead-silver-gold alloy. Refined lead and gold-silver alloys are then obtained using conventional processes. Zinc and other base metals are recovered from the POX solution. In the course of POX, zinc dissolves in the solution and lead concentrates in a solid residue in the form of sulfate compounds. Sulfur forms the major iron sulfates and jarosites. In order to dissolve sulfur and arsenic from solid residues to the solution, the slurry hot curing was carried out at the temperature of 95°C within 2 hours. After filtration of the slurry, zinc was recovered from the solution. The resulting cake was washed with water and subjected to hot alkaline treatment. After alkaline treatment, the cakes were blended with fluxes and subjected to reduction smelting to generate lead concentrate containing precious metals. This concentrate was refined to obtain refined lead and gold-silver alloy. After iron and arsenic were removed from POX solutions using sodium carbonate, zinc was precipitated as carbonate. After thickening and filtration, zinc precipitate was roasted to generate saleable zinc oxide. Using this process, the recoveries of values to saleable products were 97% Au and 95% Ag to the alloy, respectively, 91% Pb to refined lead and 5% Pb to lead and antimony alloy and 94% Zn to zinc concentrate. The features of the technology is that it has high recovery indices of precious and base metals to saleable products and can be used to process various polymetallic ore and technogenic raw materials.

Jan 1, 2016

By P. Harvey

"Following initial discovery in 1991, BHP Billiton Diamonds Inc. opened Canada’s first diamond mine, the EKATI Diamond Mine (EKATI) in the Northwest Territories on October 14, 1998. Four short years later, on November 29, 2002, saw the opening of North America’s first underground diamond mine, the Koala North mine. Nestled between the original Panda open pit and the new Koala pit, which is in the early stages of production, Koala North represents the only underground kimberlite mining venture in Arctic conditions outside the new underground mines being developed by ALROSA in the Yakutsk region of eastern Russia. Extensive underground kimberlite mining has been practiced in the Republic of South Africa for much of the 20th century and continues today.Underground mining represents a key component of the long-term business plan for EKATI. As various open pits reach their economic limit, continued recovery of high-value ore at depth is dependent upon the ability to productively mine the kimberlite pipes by underground methods. As a function of its location, size, and value, the Koala North pipe is ideally positioned to host the first underground mine at EKATI. Koala North is designed and approved as a learning mine, from which to gain valuable experience in preparation for the potential mining of other larger, higher value pipes by underground methods in the development, the Koala North mine is well into its production ramp-up phase and currently producing at around 1,200 t/day from the first two production levels."

Jan 1, 2005

By E. Faria

"The Santa Rita mine is located in north eastern part of Bahia in Brazil and is owned and operated by Mirabela Mineração do Brasil Ltda. Typical SABC circuit was designed as the preferred option for the 4.0 mtpa (500tph) to produce a P80 of 125um for flotation. Although the SAG was originally designed to operate with conventional radial pulp lifters, later it was fitted with Outotec’s Turbo Pulp Lifters – TPL (Latchireddi, 2005). The milling circuit commenced commissioning on the 24th of October 2009 and the milling circuit achieved the nameplate capacity within days. with small and relatively simple measures to rectify. Since commissioning, the SAG mill has been working in fully autogenous grinding (FAG) mode with no balls (in contrast to the estimated 10% ball charge) and has been consistently treated up to 650tph.This paper examines the comminution design process, the operating philosophies, start-up experiences, post commissioning optimization and future development works. An evaluation of mill performance relative to the design criteria for the project life to date is also included."

Jan 1, 2012

By J. B. De Hart

This paper has been confined to the consideration of the working of thick seams, from six feet to sixteen feet, which are pitching at about thirty degrees to the horizontal. The discussion has been limited to these set conditions because they are the ones of commonest occurrence in the Southern Alberta bituminous coal district, because, from the point of view of safety, thin seams are more easily worked, and because a discussion of all the possible combinations of thick and thin seams pitching at angles varying from zero to ninety degrees with the horizontal would involve a task impossible in the time available. It has been assumed that the mine makes gas freely and that the coal is friable and tends to make inflammable dust which is highly explosive. Since the problem requires the taking into account means of maintaining a high proportion of lump coal, it is further assumed that lump coal commands a price considerably higher than the price which can be obtained for run-of-mine or for slack coal. Figure 1, tabulating the various factors which must be considered and their relation to each other, indicates diagrammatically the complexity of the problem. Any method of working becomes divided into two distinct components, the active workings of the mine and the old abandoned workings. While these are in a measure distinct, they are nevertheless inter-related, as shown in the diagram.

Jan 1, 1930

By Ralph Harris, Javier Jara

"Oxygen is essential in gold cyanidation. It is supplied to the leaching media by sparging oxygen or compressed air into the cyanidation tank. The rate of oxygen transfer is critical to achieve the desired oxygen concentration in solution.The performance of a novel device for gas sparging recently developed at McGill University is compared to the mass transfer characteristics of the two spargers most used in the gold industry: the four lance configuration and the inverted cone. The distribution of gas and the kinetics of oxygen desorption of the three types of spargers was studied in a 140 litre tank. The oxygen dissolution of the new device is three to five times faster than the other spargers. This could increase the leaching rate and/or decrease the cyanide and oxygen consumption.IntroductionIn hydrometallurgical processing, it is often necessary to bubble gas through a pulp to carry out the wanted reactions. The gas can act to agitate the pulp and it can also supply reactant. The rates of the reactions which require a reactant supplied by the gas are often dependent on the rates of mass transfer from the gas to the solution.A common example of this is gold cyanidation which requires oxygen for gold dissolution. Since the gold containing slurry is rich in other oxygen consuming substances (sulphide like pyrrhotite), it is important to provide enough oxygen to allow complete gold dissolution within the residence time of the cyanidation reactors. It has been demonstrated that the rate of gold dissolution is directly proportional to the dissolved oxygen concentration of the pulp which in turn is proportional to the oxygen partial pressure in the bubble 1 2 3. Improving the rate of mass transfer of oxygen increases the dissolved oxygen concentration of the slurry and therefore improves the rate of the reaction.The rate of mass transfer from a bubble to its surrounding solution increases with decreasing bubble size and increasing gas bubble residence time which in turn increases with decreasing bubble size. The generation and dispersion of small bubbles is thus critical to achieving high rates of mass transfer. Different configurations and devices used to inject gas have different effects on the bubble size and the residence time, influencing the overall rate of mass transfer. Therefore better mass transfer can be achieved by adopting a more efficient method.The methods tested in this report are the four lance configuration (wall spargers), the inverted cone and a new device, designated HCD. The wall spargers and the inverted cone are used widely in the industry today."

Jan 1, 1994

By A. Himsley, E. Byleveld

"With reference to the chemical constraints underlying the ion exchange process for uranium recovery, a generalized view is presented on the actual and the achievable efficiency of the process. The area considered is restricted to acid leach circuits in combination with nitrate, chloride or sulphuric acid elution.A comparison between actual plant results and the chemical requirements shows that:(a) Unless new and better ion exchange resins are developed, no dramatic change in equipment size and resin inventory is""anticipated. (b) Elution efficiency, especially for sulphuric acid, may be improved considerably. More concentrated eluates may beproduced at lower chemical consumption. A possibility of achieving additional purification solely by ion exchange is discussed.IntroductionThis paper presents a generalized view of the actual and the achievable efficiency of the ion exchange processes for urannium recovery. The study is restricted to acid leach circuits in combination with nitrate, chloride or sulphuric acid elution. The ultimate efficiency attainable with ion exchange is dietacted by the chemical reactions underlying the process. The most sophisticated technology cannot change the diffusion rates in the ion exchange resin nor make the uranium loading exceed its equilibrium valueThe design of an ion exchange plant for uranium recovery involves a considerable number of parameters as a result of the wide variety of pregnant solutions produced from different orebodies. Therefore, a generalized approach of the ion exchange process inevitably neglects some parameters which maylead to significant variations in apparently identical situations.The uranium concentration in the pregnant solution, together with its pH, are the principal variables which determine resin loading and residence rime in the ion exchange system. On the elution side, the type of eluant and its concentration will determine the contact time required and the amount of eluant needed to strip the resin. The temperature, the properties of the ion exchange resin, the total dissolved solids in the feed solution and the competing ions are other variables that affect the chemical performance; these, however, may be considered as a correction of the principal parameters if one is interested only in general trends."

Jan 1, 1980

By D. E. Keeley

Introduction Gunite is a mixture of sand and cement applied to any surface by being shot by compressed air through a nozzle, where it is wetted just before leaving the orifice. The mixture is transported through a hose from a machine called a 'cement-gun'(l). Guniting of rock surfaces has been standard practice at the Mcintyre Porcupine Mines, Limited, for several years. Where used on walls and backs of cross-cuts; shaft stations, and other rock openings, as an air seal, gunite has eliminated the necessity of constant scaling to keep rock from falling from these places, and, under worse conditions, it has been used in place of timber supports. This has been of definite help in reducing costs, promoting safety, and minimizing fire hazards. During the past year guniting has been quite extensively used here in the rock head-works of the new internal shaft, No. 12, sunk from the 3,875-foot level. Gunite is at present being applied to the stations of that shaft well below a mile from the surface. This paper describes the method of guniting as carried out at the McIntyre, and illustrates how, by the adoption of this process, mining problems connected with scaling and loose ground have been completely solved. It is hoped that the information presented may stimulate discussion and assist in the use of gunite in this and other mines. The guniting method of applying cement was first developed by Carl E. Akeley (2), Curator of the Field Museum, Chicago, in 1907, and was exhibited in New York at the Cement Show in 1910. The museum was located in one of the old World's Fair buildings, built of roughcast and in bad repair. Mr. Akeley, who was a man of inventive nature, set about devising means of applying cement to repair the walls. The cement-gun was the result. Mr. Akeley was a taxidermist of note, a sculptor, and also the inventor of the Akeley camera. In his work, he was in the habit of using fast setting materials to build up foundations for statues, etc.

Jan 1, 1934

By K. Hasselwander, K. Knabel

"A significant area of Outotec’s business involves fluidized bed roasting. With several decades of experience, more than 300 reference plants and strong R&D capabilities, the company provides several industries with optimum processing solutions. Applications include oxidation and sulfation of sulfides found in copper, pyrite and zinc concentrates. Gold production and de-arsenifying roasting are also within this scope. This paper describes the latest furnace developments and includes novel trends. Moreover, hot and wet gas cleaning systems are examined focusing on unit operations related to the removal of components such as dust, SO2 for sulfuric acid production, fumes, halides, Hg, hydrocarbons, nitrous oxides and metals.INTRODUCTIONGenerally, when defining roasting processes, it can be stated that the respective primary pyrometallurgical reaction is exothermic, of gas-solid nature and relates to a value solid product. These processes are a key focus within Outotec’s scope and include: (i) dead roasting (ii) sulfating roasting (iii) partial de-arsenifying roasting and (iv) two-stage, de-arsenifying roasting.Dead roasting involves the oxidation of a given sulfide, thus allowing for a subsequent leaching process, and has been applied to producing ZnO. Dead roasting of pyrite has also been extensively utilized with a primary goal of producing sulfuric acid. In contrast, sulfating roasting involves converting a sulfide to its sulfate, enabling a selective sulfation of components, such as Cu or Co, and their separation from ferrous components during leaching (produced sulfates are soluble). Partial roasting involves partially oxidating the metal sulfide to its oxide with the simultaneous production of gaseous As4O6, which is handled during gas cleaning. The solid product, containing hardly any As, is rich in S and can be fed to a respective smelter (e.g. in the case of Cu). Alternatively, if the production of oxide is required, a dead roasting step is added after the partial roasting step, with the overall process considered as two-stage roasting."

Jan 1, 2012

By J. J. Emery

There is an increasing awareness on an international level of the potential for utilizing many wastes and by-products as construction materials. This has resulted in recent major reviews by OECD and RILEM to supplement national activities by agencies such as CANMET, USBM, BRE and LCPC. Much of this international and national work was reported during an International Conference on the use of by-products and wastes in civil engineering held in November 1978 in Paris. Based on participation in the OECD and RILEM reviews, and the Paris conference, developments in waste and byproduct utilization of particular concern to Canada are described. The major technical and economic constraints involved are also reviewed, so that the over-all evaluation reflects important factors such as inherent variability and transport logistics. Areas requiring further research and development are also identified. Particular emphasis is placed on slags, salvaged asphaltic concrete and surplus sulphur. "Due to the rapid development of China's industry, more than a hundred million tons of industrial wastes are generated annually, which occupy lots of land for storing, bring about environmental pollution, obstruct industrial and agricultural production and cause harm to people 's living. Therefore we must utilize them effectively to create wealth for our country. "

Jan 1, 1979

"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 M. P. Sinha, Rashmi, Tata Steel Ltd., S. Jaiswal, A. Bhatnagar, P. Garg

Reagents form a crucial part of flotation process as they have the power to control the surface properties of minerals. In case of coal flotation, collectors and frothers are two the important and commonly used reagents. But other types of reagents such as promoters, modifiers and depressants are also finding wide applications because of their availability to improve selectivity and increase recovery. Because of these chemicals the scenario has changed from flotation being used mostly for high rank hydrophobic coals to low rank, oxidised or inferior coals. In the present work a case is presented in which two non-ionic surfactants (abbreviated as A & B) known to act as emulsifier have been studied to get a better flotation performance for a preparation plant with varying feed characteristics. Laboratory flotation tests were conducted with both the surfactants using three feed samples of the plant by varying the dosage at three different levels. The highest combustible matter recovery (more than 80%) was obtained for surfactant B at a dosage of 75 ppm (parts per million) for feed 1. But at the same dosage the recovery decreased by 21% and 10.2 % respectively for feed 2 and 3. On the other hand surfactant A showed a consistent result for all the three feed samples giving the highest value at a dosage of 50 ppm followed by a decrease beyond this point. The tests were complemented by contact angle measurements that demonstrated the same trend. In addition to this the reproducibility of data for Surfactant A was checked and found that the standard deviations for both separation efficiency and combustible matter recovery were within the permissible range (less than 5%). Finally an in-plant process optimization study to evaluate the performance and applicability of surfactant A at industrial level was done and has been discussed.

Jan 1, 2016

By Allan F. Lawrence

"I AM SURE you do not expect from me any learned dissertation on the problems and opportunities of the mining industry. Y our program committee must have recognized my limitations when issuing the invitation to speak to you, because they very thoughtfully left the subject wide open.With the leeway thus granted, I hope that you will bear with me for a few minutes while I try to clarify the impressions of the mining industry that I have gained in the very short time I have held the Mines portfolio and some of the parts that government bas or should have in furthering its development.As I see it, it is the duty of the Mines Department, as an arm of the provincial government, to balance the proprietary rights of all the people against the interests to whom the privilege of developing our resources are, in a s e n s e, leased. To strike a fair balance is not always easy, nor is it possible always to satisfy both sides. Still, under the free enterprise democratie form of government to which I think we al! subscribe, no better way of handling the problem has yet been discovered."

Jan 1, 1968