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By Paul H. Atkinson

"Sampling in the mineral processing industry has always been a subject which has received considerable discussion. There have been many volumes written on theory, techniques and practical application of sampling. However, until recently, the companies were not completely aware of the potential savings available with properly designed sampling systems both to assist in pieces: control and final product values.Definition In our discussion today, we will define sampling as the operation of removing a part, convenient in quantity for analysis, from a whole, which is of much greater hulk, and removing it in such a way that the proportion and distribution of the quality to be tested, i.e. size of particle, moisture content, specific gravity content, mineral and chemical composition, are the same in both the sample and the whole.Application It has been well established that undetected errors can result in large economic losses, thus most firms depend upon some type of sampling and sample analysis as a control in their continuous processing of materials. Despite the large investment in facilities and personnel the ""analysis"" of a sample can be no more accurate or reliable than the sample on which it is being based. The importance of sampling is recognized by a great many but it is appreciated by only a few, largely because it is sometimes one of the items which is taken for granted."

Jan 1, 1976

By Nehad Elsafty

It is always necessary to expand existing buildings, so that they could meet the growing societal needs. Compared with demolishing them and then constructing new ones, the expansion of existing buildings could not only reduce project cost, but also save the use of energy and raw materials in projects. Therefore, it is widely adopted in most under-developed countries. However, the expansion of existing buildings is not an easy task. It has been involved with a lot of issues in defining the scope of work, planning landscape, managing construction activities, etc. This paper investigates the potential challenges in expanding existing buildings. The project of expanding the Al-Agoza Hospital, one of the biggest and oldest hospitals in Cairo, Egypt, is selected as a case study. In the case study, the project documents have been carefully reviewed. The project engineers and the health-care professionals working in the hospital have been interviewed. This way, the point of views from the owner, the architect/engineer, and the contractor have been taken into account. Several lessons are learned through the discussion with these people. The results from this paper are expected to provide pieces of useful advice and suggestion for the expansion of existing buildings in the future.

Aug 1, 2013

By H. R. Huffman

"This paper reviews the history of iron powder production, and outlines the varions production methods. The uses of iron powder and the reasons for its use are also covered. The paper concludes with a look at future trends in powder metallurgy.INTRODUCTION TO POWDERSTHE IRON POWDER INDUSTRY is enjoying a very rapid growth. The annual consumption of iron powder is now at the 100,000-ton level, twenty times higher than it was at the end of World War II, and the yearly in-crease bas been almost consistent at 20 per cent. This is expected to increase, bringing the tonnage to 200,-000, or even (according to some experts) to 270,000, in 1970. In any event, powder metallurgy is expanding at high speed and making an important impact on the production of iron and steel products. Some indication of the faith in the future market may be indicated by the commencement of three new powder production plants in Canada with a total capacity of 136,000 tons annually."

Jan 1, 1969

By Serge Ouellet

Identification and quantification of cementitious phases in cemented paste backfill (CPB) is difficult due to the fineness of tailings and the low binder content used in the mixture. Techniques such as X-ray diffraction and thermogravimetry were ineffective (mainly due to tailing mineral interference) to identify and quantify hydration products in most works reported in the literature. On the other hand, scanning electron microscopy (SEM) was used in many cases but mainly for qualitative purposes. This paper presents the development of a new approach based on a computer program (SEM-XMAP) that combines X-ray dot mapping images acquired by SEM and generates a coloured image representing the mineralogy and the microstructure of a given CPB specimen. The technique is applied to one CPB sample mixed with blast furnace slag (BFS) and acidic sulphated mixing water sampled in a mine dewatering system. The technique allowed identifying calcic matrix, unhydrated and partially hydrated BFS particles, and sulphated phases.

May 1, 2007

By R. R. Klimpel

"SYNOPSISA discussion of the importance of flotation rate in the analysis of mineral flotation is presented. In particular, the highly interactive nature of the flotation ""system"" is emphasized where there are components of chemistry, equipment, and operating conditions simultaneously involved. It is further shown that: 1) flotation rate must be measured in order to economically optimize the performance of an industrial flotation circuit, 2) that consistent patterns exist in both flotation rate and equilibrium recovery when changing various settings of the system components, 3) that knowledge of these patterns is necessary in order to avoid making system changes that are either self-compensating or dramatically re-enforcing in some particular aspect of performance, and 4) the rate related role of the chemistry component (e.g.frothers and collectors) is often much bigger than is sometimes realized (especially in a negative sense involving overdosing of reagents). INTRODUCTIONFroth flotation is widely usedl-6 in mineral beneficiation processes as a method for separating different types of finely divided solids present in a liquid (usually aqueous) suspension. The approach is based on the contacting of solids with upward moving air bubbles in an agitated vessel where the solids are exposed to chemicals (collectors) which create a condition favoring the attachment of a certain portion of the solids to the air bubbles. This selected portion is then removed in a froth stabilized by chemicals (frothers) and subsequently recovered from the flotation vessel. Depending on the settings of the various components of the flotation ""system"" (see Figure 1) it is possible to achieve a wide range of flotation performance."

Jan 1, 1984

By W. W. Culver

The paper explores the substance, circumstances and significance of the Whelpley and Storer Copper Process. The 1866 Whelpley and Storer patent specified a process combining mechanical and chemical engineering. The process called for a down-drafting shaft furnace with a horizontal flue connected at the bottom of the shaft. Powdered sulphide ore was roasted in the shaft and then sent forward fully oxidized to a bath of sulphuric acid and/or calcium chloride. The “water furnace” was developed in Boston, at a time when the city was home to most Michigan copper mining companies. The process was field-tested at Quebec’s Harvey Hill copper mine. In 1865 James Douglas, Jr. took over management of the Harvey Hill mine with the challenge of saving the family investment. He needed a way to make money from low-grade sulphides. Through his relationship with chemist T. Sterry Hunt, Douglas learned of a possible way ahead using the process developed by Whelpley and Storer. The paper confirms the centrality of publications, meetings, and networking in the advancement of metallurgy. The process is of interest historically, as much as anything, because it is one of the pillars of James Douglas’ distinguished career in copper. INTRODUCTION At the 1866 meeting of the American Association for the Advancement of Science (AAAS) in Buffalo, New York, T. Sterry Hunt (1826–1892) read a paper “On the Metallurgical System of Messrs. Whelpley and Storer.” The paper is part of a chain of events that constitute the foundation of James Douglas’ (1837–1918) success in the copper mining industry. To understand the career of Douglas over the early years of modern copper mining, we must necessarily start with Whelpley and Storer. Going back to Hunt’s paper, he concluded his remarks by asserting that the Whelpley and Storer Process was “capable of such wide and varied application, that it is probably destined to have a very important influence on the industry of the world” (Hunt, 1867a). He reached this conclusion reasoning that the process had overcome a critical metallurgical hurdle (Hunt, 1867a). Hunt, a geo-chemist in modern terms, recalled that the chemist of those years easily separated copper from “sulphuretted” ores by converting it to a soluble salt from which pure metal was precipitated by “an equivalent of iron.” The problem was to “…apply this principle in the working of copper ores on a great scale...” (Hunt, 1867a). Hunt noted that this very problem had “…engaged the attention of many metallurgists, and has given rise to various processes for obtaining copper by the moist way, many of which are nearly or quite perfect in their operation, but are lacking in practicability and cheapness” (Hunt, 1867a). Hunt thought Whelpley and Storer had overcome the low-grade sulphide hurdle with a commercially viable engineering breakthrough. Yet in the history of copper metallurgy, the process is missing. What happened?

Jan 1, 2019

By Benedetto Corain

The production and dispersion of metal nanoclusters onto inorganic supports and amorphous carbon rest on well consolidated technologies belonging to the realm of industrial catalysis and of basic catalysis research (1). In spite of the existence of a variety of specific synthetic strategies, their very rationale relies on three main approaches i. e.: A: precursors of both the metal nanoparticles and of the relevant supports (or the support itself) are intimately mixed (even let to react) at ambient conditions and then thermo-reduced according to very controlled protocols (2); B: precursors of metal nanoclusters are let to be adsorbed onto suitable supports from the gas or liquid phase and subsequently thermally decomposed (3); C: metastable size-controlled metal nanoclusters are previously generated in a liquid medium and subsequently transferred onto pre-formed support particles (4). The production and dispersion of metal nanoclusters onto organic soluble supports is also a rather well documented academic praxis (5, 6, 7, 8) able to provide e.g. size-controlled Au0 nanoclusters of 4.4±1.7 nm (5). Our group started in 1997 developing (9) an innovative approach to the synthesis of metal nanoclusters dispersed inside insoluble, albeit accessible (see below) mechanically robust gel-type resins (10), which procedure was tested so far on palladium metal. Metal ions are previously dispersed upon ion-exchange inside of the polymer framework, followed by chemical reduction and by the aggregation of born metal atoms into nanoclusters, the size of which is templated (11, 12) by the three-dimensional intercommunicating meshes that build up the overall polymer framework (Figure 1).

Oct 1, 2003

The uphole bench extraction strategy at EKJV Management Pty Ltd?s Raleigh Mine, requires simultaneous horizontal and vertical exposure of paste filled stopes. In order to prevent excessive ore dilution, the paste fill must be of sufficient strength to prevent failure during exposure. A numerical modelling methodology has been developed to accurately simulate the initial stress distribution within paste filled stopes, together with the strain-softening loading response of paste fill material. Due to the narrow orebody width and high deformation behaviour of the host rock mass, high closure strains are likely to cause a stiff, brittle fill material to undergo crushing failure upon exposure. The stability of paste fill exposures at the Raleigh Mine was determined by conducting a series of three-dimensional numerical models that incorporate the extraction, filling and exposure sequence of paste filled stopes. Stability charts for 2.5 m and 3.5 m wide simultaneous horizontal and vertical exposures have been derived based upon the numerical modelling results. Implementation of the stability charts has proved successful in limiting the amount of ore dilution from paste fill and provides a basis to optimize paste fill cementation and stability throughout the life of the mine.

May 1, 2007

By Luke Keeney, Stephen Walters

"The start up of a new mining and metallurgical facility is a crucial step in the life of any mining project. The mining industries record is poor when evaluating processing plant operation relative to design capacity predictions made during feasibility studies. Multivariate geometallurgical orebody characterisation, using principle component analysis, is a method developed for improving predictive processing performance models during feasibility stages of mine development. This paper outlines the application of multivariate geometallurgical characterisation to the Cadia East deposit located in New South Wales, Australia. Cadia East is a low grade high tonnage copper-gold porphyry system in advanced stages of feasibility analysis. A dataset of ~32000 measurements and 150 comminution parameters (A*b and BMWI) has been used to develop class-based characterisation and modelling methodologies. The results of this study outline the development of class-based ore characterisation and provide a technique for analysing and interpreting large and complex geometallurgical datasets for prediction and optimisation of processing performance. The results enable sophisticated population modelling to be conducted which displays deposit scale processing variability, aiding circuit design specifications and predictions during feasibility studies.INTRODUCTIONA feasibility study is the major technical report on which the decision to proceed to production and on which financing is based (Shillabeer & Gypton, 2003). The mining industry’s record is not very good when actual construction time, costs, and operating performance are compared to the projections made in feasibility studies (Ballard, 1983; Gypton & Ward, 2000; Gypton 2002). A study by McNulty (1998) found that of 41 mineral processing and chemical plants built between 1965 and 1995, only 56% achieved design capacity within two years of commissioning and three were closed after failing to achieve design capacity within 36 months of start up (Shillabeer & Gypton, 2003). McNulty (1998) related this underachievement and failure of start up performance to the use of innovative process technology without appreciating and managing technical risk. Factors contributing to technical risk include inadequate pilot plant testing, scaled up prototype equipment without backup, design flaws and poorly understood complex process chemistry."

Jan 1, 2009

By R. C. Bryce

"Selbaie is located northwest of Joutel, in what is known as the fourth east-west volcanic sediment group in northwestern Quebec. The main metals produced are copper and zinc, with important contents of both silver and gold. Production comes from an open pit mine on the A-I zone and from two underground mines on the B zone and the A-2 zone. Each mine gave rise to important capital investment programs for construction and mine development, all of which were managed and staffed with company-hired, non-union personnel. Production from all sources now exceeds 7000 tonnes per day, with a workforce of540 regular employees. Of particular interest technically is the high recovery of B zone reserves underneath 40 m of overburden cover, the low-cost capital development of the A-2 zone, the computerized control of open pit mining, and the successful copper-zinc separation of the A-1 zone ore. Due to the low grades of the mineral deposits, efficiency in all aspects of the production process, is essential to the success of the operation.LocationThe Selbaie Mine is located 82 km northwest of the locality of Joutel in northwestern Quebec (Fig. 1). Access to the mine is by an all-weather road, 32 km of which is paved. A second road access to the site is via La Sarre, 134km to the southwest. Employee access, materials transport and haulage of copper and zinc concentrates take place over both of these roads."

Jan 1, 1990

By Lorrie Fava

Two needs in the mining industry, to enable overall process improvements, are open systems and network connectivity in underground mines. The Pando project, a collaboration between Symboticware, Vale and Xstrata Nickel, and supported by CEMI, addresses these issues, and leverages the solution platform to deliver intelligent applications. An open system is one that uses publicly available standards for its key interfaces. Vendor-neutrality and ease of information flow are two main benefits that result from the use of open systems. By facilitating the interoperability of systems, open systems allow information to be available when and where it is needed for decision support. Network connectivity in underground mines is typically limited, with hotspots in strategically chosen areas that are relatively static. Mobile equipment moving through a mining work cycle experiences intermittent connectivity; in this situation, seamless remote equipment monitoring is impossible. The Pando project establishes an open technology platform, adhering to the IREDES and OPC UA standards. It enables the collection and integration of information generated by mobile equipment? seamlessly while there is a network connection, and as a store-and-forward gateway to manage intermittent connectivity. The platform capabilities are leveraged to support embedded intelligent applications. This open platform, the SymBot, is a rugged hardware and software device. The platform complies with open standards for industrial automation and systems interoperability. The SymBot platform is capable of providing advanced real-time decision support at the device level, and is designed to be remotely configurable. Applications being developed through the Pando project include engine monitoring, a dynamic load weighing system, machine location monitoring and automated activity monitoring including production and maintenance reporting.

Oct 1, 2010

By J. C. Loretto

"OPENING REMARKS Yesterday and today we have heard some very interesting papers on operating matters and some of you are probably wondering what we are now doing talking about Communications in Plant Design. Let me tell you! Before the techniques we have heard being discussed can be used, there has to be a properly operating plant. It is certainly a fact that many mineral processing plants achieve only limited success and a number of them can even be said to be failures. Some of you sitting here are probably living with operating problems that are clue to errors in the design.If the histories of these problem plants are examined, it will be found that in many cases, the necessary skills were available during the period of the plant design. There was extensive operating know¬ledge together with a full range of project expertise. Why then the failures? In a substantial number of cases it can be traced to the old, old problem of communications. As plants get bigger, money costs more and smooth startups become more important, it becomes less and less economic to fix up any design errors during plant operations.During our careers in mineral processing, nearly all of us will be involved in at least one plant design and I feel that it is as well if we understand some of these communication difficulties that can lead to a problem plant. There is little point in us being experts in mineral processing if the knowledge we have acquired doesn't somehow get incorporated into the plant.I would, therefore, like to present this short paper that mentions a few of the significant communication problems that can occur during the design of mining and mineral processing plants, together with some thoughts on answers to these problems."

Jan 1, 1973

By M. H. B. Nasseri

Barre granite?s samples have been tested for fracture toughness under mode I along two different directions with respect to microstructural fabrics were investigated. 3D objects counter algorithm technique is applied on micro CT images to identify physical properties such as crack induced porosity, crack density, generated total surface area and contribution of individual mineral grains within the damaged zone.The result obtained justifies very well the fracture toughness anisotropy in Barre granite, and explains the difference in the structure of the damage zone evolving as a result of test crack interacting with pre-existing microstructural fabrics. The present study has potential application in the fields of rock mass stability, oil reservoir stimulation, rock fragmentation and damage in blasting and emplacement of dykes.

May 1, 2009

By Patrick R. Stephenson

The current version of the JORC Code was issued in 2004 and since that date the Australian Securities Exchange, in collaboration with JORC, has issued a number of companies? updates to provide guidance on various reporting issues. An interim review will be undertaken during 2010 to meld these updates with the current 2004 Code. This will be followed by a full review during 2010/11 covering all aspects of the Code and focusing particular attention on: ? clauses / guidelines relating to Exploration Results1, exploration targets and the reporting of historical estimates; ? issues relating to the Public Report2, including definition, the requirements for Competent Person sign-off, level of disclosure and mandatory requirements; ? guidance on techniques to quantify resource / reserve estimation uncertainty; ? the level of study required to convert Mineral Resources to Ore Reserves, and disclosure of prices and economic factors; ? expansion of the requirements for reporting of marketable material for bulk commodities; ? the use of language and tone that anticipates new and emerging technologies and techniques for the qualitative and quantitative measurements of data; and ? linkages to valuation and the valuation code (The VALMIN Code). Although the Canadian and Australian reporting regimes for public statements on Exploration Results, Mineral Resources and Mineral (Ore) Reserves are similar in intent and coverage, they differ in detail, sometimes substantially. Canadian requirements are generally more wide-ranging and prescriptive than Australian requirements, including in the need in many situations to publicly lodge a Technical Report, a requirement that does not exist in Australia. Australian-listed companies seeking to list in Canada, and Competent Persons seeking to act as Qualified Persons in Canada, need to ensure that they are fully conversant with Canadian regulations and how they differ from those in Australia.

May 1, 2010

By C. A. Grandison

The economic evolution from an agrarian society to an industrial and service-oriented economy is apparent to most students of history. The long-term trend is almost taken for granted, it does not require explanation — it is accepted as the nature of man to improve his standard of living. However, there are fluctuations around this trend line which have provoked a great deal of thought. The ability to understand and control these fluctuations would yield many benefits, it would eliminate economic waste and public hardship, and would no doubt make a few fortunes. I f it is not possible to control or eliminate these fluctuations, then a reasonable forecast of the tinting, rate of change and magnitude of the fluctuations would be invaluable to industry and government.

Jan 1, 1976

By Glenn D. Lyle

As part of an initiative to improve value in mining, CEMI is developing a handbook on best practice in mine design. Various formats were examined, and of these, the wiki was selected as being most suitable. Being web-based, its global reach and capability of being continuously updated allows the wiki to evolve as new knowledge is generated, and to capture the diversity of experience of practitioners in the mining industry. While wikis have many advantages in terms of organizing content and searching, their ability to be edited by users is often seen as a negative characteristic for quality control. To ensure reliability of information content, author attribution, specific authorship models, and a peer review process have been implemented, in addition to the standard version tracking capability of wikis. The first phase of the project concentrates on topics related to underground hard rock mine design. The scope will be expanded to cover other aspects of mining as the project matures. Strategic partnerships with various organizations, such as the CIM, and CANMET, are being formed to provide a wide range of seed material to stimulate growth of the site. www.minedesignwiki.org

May 1, 2011

By Helen Francis

Over the last decade, lower ore grades and deeper mine environments have demanded that mining companies develop new technologies (tools and processes) to ensure a mine?s economic sustainability. At Inco Ltd., this demand has lead to the focus of technological development within the area of automation. Delineation (Drilling and Interpretation) is a key step in the determination of ore grade and location and therefore was chosen as a priority area for enhancement through automation. Focusing on the tools (the diamond drill) automation, significant benefits have been consistently achieved in terms of productivity, process efficiency, operational safety, cost reduction, component life cycles and machine reliability. It is suggested that optimum benefits have yet to be achieved, and will not be achieved until the human aspects of automation have been properly addressed. Since project inception, the human aspects of automation were recognized as critical to the success of the diamond drill automation project. However, it was only upon the installation of the Automated Diamond Drill in the field and its continued use on a daily basis that this issue received due attention. The human aspects of automation can be broadly addressed as economic, physical and psychological. This paper, with examples from the field, will discuss the human aspects of automation in each of these areas. The paper will draw from observations and experiences acquired throughout this project and recommend implementation strategies that should be utilized in future automation projects to enhance both the acceptance of automation and the success of the automated process itself.

May 1, 2002

By C. Larsen, I. Orford, L. Strah, M. Renaud, P. Radziszewski

"An AG/SAG mill was commissioned at the Brunswick mine concentrator in October 1998. This paper discusses the original shell top hat liner design for the bi-directional AG/SAG mill, observed liner wear, subsequent liner design modifications, and benefits.The original liners were chrome-moly steel Norsteel with rubber grates and rubber-lined pulp lifters. The design was based on experiences of other AG/SAG mills and recommendations by the liner supplier, Norcast. Liner design modifications were made in an iterative fashion after observing the wear rate profile of the liners; over ten liner sets were implemented. Shell liner design improvements were supported by a design of experiments approach in conjunction with discrete element method (DEM) charge motion simulations. Design optimization took into account lining costs and impacts on operating performance. The team approach to the liner design improvements process is described with emphasis on the application of the design of experiments. The liner wear history and mill operating performance are presented."

Jan 1, 2005

By D. Gendzwill, N. Martin

"In early 1987, the Patience Lake potash mine near Saskatoon, Saskatchewan, was closed due to uncontrollable floodingWater inflows were first encountered during routine mining in 1975 at the south boundary of the mine lease. Underground grouting and construction of bulkheads limited the flo but did not completely stop it. Subsequent seismic surveys showed that the mine had approached the edge of a large collapse structure in which the salt and potash had been partly dissolved and removed by groundwater.In 1986, the small flow into the mine started to grow. Despite renewed grouting, the flood increased and outstripped pump capacity. The grouting program temporarily slowed the inflow but was unable to stop it. Eventually, from seismic and drilling evidence, it became clear that the water source was an extensive system of vertical fractures which would be impossible to seal by drilling and grouting from underground. A new plan to install 14 bulkheads underground would have sealed the water source from the rest of the mine but the construction program could not be completed before rapidly increasing inflow threatened to fill the mine. The underground mine was closed and a new solution mine started in 1988."

Jan 1, 1996

By J. Visman

"The Compound Water Cyclone is a concentrator for the wet processing, in bulk, of finely divided materials such as slack coal, fine ores and mineral sands. It was originally developed by the Fuels and Mining Practice Division of the Mines Branch, Department of Mmes and Technical Surveys, Ottawa, for the cleaning of friable slack coals and slurries.Since its introduction in the coal industry in 1962, its application to other materials has also been studied, with special emphasis on simplicity of operation and low over-all cost per ton of finished product .In this paper, a description is given of commercial two-stage units presently available for the processing of granular materials, including wastes a1:1d other low-grade products. A pneumatic control system is used for operating the cyclone under back pressure .and for automatic cut-point adjustment. An account is given of results obtained on coal mineral sands and ores in the Wes tern Regional Laboratory of the Department of Mines and Technical Surveys. Results of several industrial applications are discussed."

Jan 1, 1966