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By Jim Oehler

The US minerals industry, as well we know, has been hit hard by the recent recession and is faced with what is projected to be a slow recovery. Even so, there was an underlying feeling of optimism at American Mining Congress' International Mining Show in Las Vegas, NV, Oct 11-14. More than 25,000 people attended during a particularly rough financial year, dispelling fears that attendance would dip sharply below 1978's 30,000 plus tally. The equipment expositionheld every four years-was the largest show of its kind this year in the Western Hemisphere in terms of exhibit space, providing an extensive view of mining-related equipment. In addition to the nearly 700 exhibits occupying more than 445 hm2 (11 acres), 20 technical sessions were held covering topics ranging from minerals availability and the state of the mining industries to communications, computers, and accounting. Government officials were well represented, with six US senators and five US representatives participating in various convention functions. Sen. Paul Laxalt (R-NV) was the keynote speaker at the welcoming luncheon. Other senators involved in the show included Howard W. Cannon (D-NV), Pete V. Domenici (R-NM), James A. McClure (R-ID), Frank H. Murkowski (R-AK), and Steven D. Symms (R-ID). Representatives on the program were Joseph M. Gaydos (D-PA), Guy Vander Jagt (R-MI), Don Young (R-AK), Jim Santini (D-NV), and Ceil Heftel (D-HI). There were also many international vistors at the show, including exhibitors from Australia, Austria, Canada, England, Finland, Sweden, South Africa, and West Germany. Equipment Highlights Equipment and services featured at the exposition ranged from aerial mapping to wire rope. Aisle space alone between exhibits exceeded 8 km (5 miles). And the companies represented ranged from small businesses to large corporations. Some of the company products described here are representative of the many exhibitors in attendance. Atlas Copco's extensive display of rock drilling and tunnel and shaft boring equipment featured its Boomer H-201, the newest addition to its line of underground drifting rigs; the ROC 306, a new track-mounted, high pressure down-the-hole drill rig; a new hydraulic surface crawler drill, the ROC 712H, designed for small and medium-size holes in quarries and small open-pit mines; a computerized analysis system, CARE (see page 1570), designed to project productivity and operating costs for various mining operations; several electro-hydraulic loaders, including the new rail bound LM E60 and LM E80, and two Hagg-loaders-the 7HR and 10HR-that use two digging arms to rake and guide muck; a mechanized blasthole charging system; rock bolting equipment and its new Swellex roof bolting method; Sandvik Coromant drill steel and bits; and its new Jarva R200 raise boring machine.

Jan 11, 1982

By Cleland N. Conwell

The term "tender tundra" is a myth---a well-developed myth, but contrary to the fact. Any area that supports herbivores must have a plant base to supply food, In Alaska, herds of caribou migrate and live north of the Arctic Circle. And, if there is enough growth in the moss and lichens and arctic grass to support a caribou herd, the "tender tundra" can heal after it has been disturbed by mining. Another myth is that Alaska is an ice box. Actually, many areas In the state---particularly the Interior---have a high agricultural potential. Nevertheless, the fact remains: whether it is reclaimed by advancing the productivity from forest to agriculture or is allowed to remain a wild-life habitat, Alaskan land will revegetate. Reseeding speeds reclamation, but left to nature, native species will reclaim the land whether it was disturbed by forest fires, roads, villages, or mining. In fact, it is impossible to find many of the old gold mining camps.

Jan 1, 1975

By Marion A. Goudie

The Devonian salt basin, which contains the Saskatchewan Potash deposits, extends from just east of the foothills in Alberta, north as far as the Peace River area, across Saskatchewan and into Manitoba as far east as Range 10 west of the First Meridian and south into Montana and North Dakota. The basin is closed everywhere except to the northwest. The known potash deposits are confined almost entirely to the Province of Saskatchewan, with the exception of a small area in western Manitoba bordering the Saskatchewan boundary. The following discussion will concern only the Saskatchewan part of the basin. The evaporite series in the basin is defined as the Prairie Evaporite Formation of the Elk Point Group, of Middle Devonian age. Recent work done by potassium-argon dating methods has indicated an Upper Middle Devonian (Givetian) age of from 265 to 347 million years for the potash. The Elk Point Group consists in ascending order of the Ashern, Winnipegosis and Prairie Evaporite Formations. The Ashern formation, sometimes called the Third Red Bed, consists of dolomitic shales or shaly dolomites. The Winnipegosis is a reef type dolomite, usually with good porosity, and in many cases oil-staining, although to date no production has been obtained. The Prairie Evaporite formation consists of anhydrite overlain by halite and finally, in Saskatchewan, by the potash beds. In almost all wells which have been cored for potash the lowest potash bed is underlain by one or two bands of anhydrtte, which are used as marker horizons. Cores from a few wells which cored to the bottom of the salt series have shown flecks of potash throughout the halite.

Jan 1, 1959

By James F. Archibald, Ferri Hassani, Jacques Nantel, David O. DeGagné

Operators depend upon the success of backfilling programs to ensure that mine activities run continuously (Archibald et al, 1993) where backfilling is an integral part of the mining cycle. In order to ensure that the backfill is prepared and delivered to the stope possessing the required engineering properties, as designed, and that the backfilling process is safe, mine operators at all stages of the backfilling system must be adequately trained for their tasks and be aware of how their work affects other backfilling stages, both up- and down-stream of their station. Mine operator training is primarily based on learning on-the-job from experienced supervisors or training personnel. Classroom training and the availability of reference manuals are less common. While in use by many industries for some time now, computer-based training (CBT) is becoming more readily accepted by the mining industry for a wide variety of training. It is not intended to replace on-the-job training, but to augment it. CBT offers many advantages to enhance operator learning by utilizing multimedia presentations, interactions and on-line testing to teach complex concepts and relationships. Discussions with many operations revealed that there is an industry need for a backfill guide for frontline operator training and as a reference manual for operators and mine engineers. Sponsored by the mining industry and the CIM, "Mine Backfill, An Operator's Guide" has been developed by the Departments of Mining Engineering at Queen's University and McGill University to fulfil this need. "Mine Backfill, An Operator's Guide" is an interactive multimedia package that incorporates high quality colour images, animations, sound, and video with text to review the main backfill methods employed in Canada, including hydraulic/slurry, paste and rock fill. The Guide is divided into training and reference primer sections. When in training mode, the operator is guided through a presentation of common mining and backfill practices and technologies so that he/she may become more familiar with different aspects of backfill processes. To ensure that key concepts have been learned during training, the operator will be tested after each section using a series of multiple choice and true/false questions. When in reference mode, alternatively, the operator may browse through the information in a more detailed and independent fashion through a series of interactive menus. The Guide focuses on the following main topics: resources, surface preparation, distribution, stope activities, health and safety, and quality control. Special features included in the Operator's Guide are a Buyer's Guide, a Trouble Shooting Guide, and an interactive glossary of backfill and mining terms. Concepts in interactive and computer-based learning are also reviewed in this paper.

Jan 1, 2001

By M. G. Rylatt

The Ekati process plant flowsheet features the common steps in diamond recovery plant design. Primary treatment and concentration is by crushing, scrubbing, high-pressure grinding rolls and heavy medium separation (Fig. 1). Secondary concentration is by an attrition mill; wet, high-intensity magnetic separation and X-ray sorting (Fig. 2). All of these are performed on site, although final sorting of the diamonds into commercial categories will be carried out elsewhere. The initial throughput rate is 9 kt/d (9,900 stpd), increasing to 18 kt/d (20,000 stpd) during the first 10 years of operation. A range of ore characteristics will be encountered that will effect the plant operating conditions during the life of the mine. The adopted design envelope is based on these expected variations. The design is based on the use of large-scale equipment, incorporating the latest and most efficient technology available. Where proven technology exists, no attempt was made to reinvent the wheel. However, where recently developed technology offers a significant advantage, this has been incorporated into the design. The Ekati run-of-mine (ROM) and coarse ore handling facilities are unheated, to take advantage of the better handling characteristics of the frozen ore in winter. The stockpile reclaim features an MMD mineral sizer (a toothed roll crusher) to minimize the problems of handling thawed, sticky kimberlite in the summer and break frozen lumps in the winter. All processing downstream from primary crushing and the coarse ore stockpile is carried out in a temperature-controlled environment in the main process plant building. Personnel involvement in the process is mini¬mized by using a Modicon Quantum series PLC with human-machine-interfaces (HMI) running Wonder-ware software on dedicated personal computers.

Jan 1, 1999

By Michael J. Nicol

Hydrometallurgical processes involve the recovery of metals from ores, concentrates, calcines, mattes and scrap materials by a series of operations involving leaching or dissolution, separation, purification and reduction of metals in aqueous solutions. The underlying theoretical basis of many of these operations is electrochemical in nature and it is the purpose of this review to identify and illustrate, by way of examples from the author's experience and that of others, the central role of interfacial electrochemistry in the understanding, design and control of these operations.

Jan 1, 1993

By Robert L. Bates

United States production of the industrial minerals, ahead of that of the metals since 1946, has shown a steady and rapid growth. By 1963, their value was more than twice that of the metals. Yet papers on the metallic ores continue to dominate the meetings of the Society of Economic Geologists and constitute nearly nine-tenths of the lead papers in Economic Geology. Most of the geological communication that does take place concerning the industrial minerals deals with high-value special-purpose minerals, which are comparable to the metallic ores in geologic complexity. The large-bulk rock products, which are growing fastest in production value, are characterized by relatively simple geology and by thousands of small producing firms, many of which do little or no geological work. The need for geological advice by this very large segment of the industry is bound to increase. In the meantime, a plea is made for more geological communication among those concerned with the industrial minerals of all varieties.

Jan 1, 1966

By Jan E. Stache

Commercial software programs are being utilized to create and maintain a mine subsidence database in conjunction with the U.S. Bureau of mines research on mine subsidence in Illinois. A three-year survey net of monitored structures in an Illinois subdivision was entered as textual information (attributes), on an existing AutoCAD drawing. These attributes can be optionally displayed on the corresponding drawing or extracted as a text file for import to a database program. The database program, dBASEIV, allows combinations of multiple database files for extensive querying capabilities. Subsurface database files can be merged with surface database files to enhance the effectiveness of surface response analyses in mine subsidence research. The geographic information system (GIS), pcARC/INFO, was chosen to integrate existing AutoCAD drawings and dBASEIV database files into a relational database with a graphical representation. The relational database allows users to update either the graphical representation or the database, with the changes being reflected automatically in its alternate format. The increased capacity, through use of a GIS, to query combinations of database files and have the results reflected graphically has significant potential for expediting mine subsidence research.

Jan 1, 1986

By C. Menidiatis

The first cement plant of TITAN Cement Co was founded in Elefsis in 1902. It was the first cement industrial facility to operate in the Balkans and in the Eastern Mediterranean region. Currently have four cement plants in Greece producing 5.4 million tons per annum, and 25 ready-mixed concrete sites producing 1.4 million m3 annually. It has a total of 20 quarries, 14 of which are producing materials used in the making of cement while the remaining six produce aggregates used in the production of ready-mixed concrete. All plants in Greece are accredited for ISO 14001. The restoration of quarries began in 1976 at the company?s limestone quarry of the Patras plant, and was soon extended to all quarries. At that time, a department responsible for all environmental issues was established. To date, over 700.000 shrubs and trees have been planted and maintained at quarries, plants and ready-mixed concrete facilities, while over 100,000 trees have been donated to municipalities, communities, customers and to the Greek state.

Jan 1, 2002

By Fred A. Glover

It's a pleasure to be included with this group. I am not here to sell my services, but rather to share with you some ideas and considerations on using environmental consultants. Environmental consultants have developed some problems as well as created new costs for companies that are as legitimate as engineering costs. Each day the mining industry is becoming more affected by the proliferation of environmental regulations and their interpretations by federal and state agencies. How does a modern mining company cope with all the demands for environmental consideration by regulatory agencies and special interest environmental groups-- yet produce a product and make a profit? One way is to make efficient use of environmental consultants. But, as everyone here knows, this approach has been fraught with seemingly inherent frustrations, difficulties, and much justified criticism.

Jan 1, 1979

By A. H. Morris, W. Harrison

1. INTRODUCTION Roadheaders have a shadowy origin - probably in Eastern Europe - but were introduced to Europe and the West by the importation of a Russian PK3 machine by the National Coal Board in 1961. A number of features rendered this type of machine an attractive tool for coal mine operators: its flexibility of operation, its combined cutting and loading ability, the opportunity it provided of making any shape of roadway, as well as its ability to cut some rocks. Encouraged and sponsored by the National Coal Board, the development of roadheaders was taken up in Great Britain, notably by Anderson Strathclyde and Dosco; in Europe, predominantly in numerical terms by Voest Alpine and Paurat. Over the 24 years since the importation of the first PK3, evolutionary development has taken place to the extent that machines are now available in many forms up to 120 tons in weight. Machine design has altered, partly as a result of increased power requirements and partly in line with the use of a ripping or a co-axial head. However, the basic concept remains: a boom containing a motor and transmission gear, with a driven cutting head at its extremity and capable of universal movement urged by hydraulic rams mounted on the boom turret and on the machine deck. Generally, the turret, hydraulic powerpack and all other necessary equipment are mounted on a chassis, which contains a discharge conveyor, the whole being carried on caterpillar tracks so that a complete machine entity is provided. Figure 1 shows how the weight, power and - non-proportionally - the cutting ability of machines have increased over the years. From

Jan 1, 1985

By R. K. Singhal, D. B. Stewart

A variety of equipment is being used for roadheading and tunneling in the mining industry. In United States drum-type continuous miners are used most extensively. In Europe and Canada mine roadways are driven mainly by roadheaders. The application of tunnel boring machines to coal mining is somewhat recent. Such machines are however being used on major projects driving main mine entries.

Jan 1, 1985

By K. F. Jakob

Sustainable development is a principle for the way we should act in the present. It ensures also options for the future to achieve a balance between social, economic and ecology development. The efficiency of raw material utilisation is being enhanced through technological developments, starting from extraction through all the following stages of the value creation chain. The use of domestically produced resources helps to assure the technological know-how. Additional indicators being collected and published by individual companies are questionable in countries with a tightly regulated legal framework such as in Germany, but make sense in developing and threshold countries. Sustainability in terms of efficient use of raw materials will manifest itself at the next stages of the value creation chain. Examples for efficiency improvement can be found in the steel, the power generation and agriculture industries. The approval procedures for German mining operations entail an internationally extremely strict assessment of the potential impact on the environment. All the mining activities include remediation and recultivation where the practise in Germany has become model character by international levels.

Jan 1, 2005

By J. Libaude

The Changement mine in French Guyana has, since 1983, processed gold ore by classical gravity methods. A large part of the gold is in the form of very small, free or enclosed grains. Recovery by gravity methods is thus limited (25-30%) and the present plant produces about 40,000 t annually of auriferous waste assaying about 6 git. The company therefore decided to retreat the waste by heap cyanidation. After laboratory tests which showed the feasibility of the method, a pilot test was set up on site. An experimental 3000 t heap, composed of waste of 0-8 mm grain size, was laid out by bucket loader on an impermeable pad covered by PVC and geotextile cloth. The upper layer of the heap was reworked by mechanical shovel to break up the area that had been compacted by the passage of the loader so as to restore adequate permeability.

Jan 1, 1998

By R. Kneisley, D. Conover, K. Haramy, K. Hanna

INTRODUCTION Coal mine entry intersections are high-risk areas for roof falls due to inherently wide roof spans, excessive stress, and variable intersection shapes resulting from breakthrough misalignments. Statistics from underground coal mines reveal that a high percentage of injuries occurs from roof and rib falls in entry intersections (Peng, 1980). The U.S. Department of the Interior, Bureau of Mines, is conducting a field research project to investigate failure modes surrounding underground coal mine entry intersections. The research objectives are to (1) develop a method to determine failure modes and stress-displacement relations around coal mine intersections and (2) develop engineering guidelines and empirical relationships for use in designing safer coal mine entry intersections. The basic approach to achieve the objectives is to instrument and monitor intersections before, during, and after intersection development in order to determine contributing parameters, such as in situ stresses, stress changes, strata movement, geology, physical properties, and mining sequence, that may influence the short- and long-term stability of the intersection and adjacent entries. This paper describes a rock mechanics instrumentation program, data analyses, and a comparison of two case studies conducted at two underground mines, designated as "A" and "B", in the Illinois Coal Basin. The instrumentation plans and data collected during development and long-term monitoring of four-way intersections and adjoining entries are presented. Data analyses of pre- and post-mining roof stress, pillar loading, strata movement, roof bolt loading, and geologic features are included. INTERSECTION FAILURE MECHANISM The region surrounding an entry intersection is characterized by different failure criteria than the region surrounding a single entry. Stresses induced during intersection development may result in a high incidence of roof and rib failures. Various numerical modeling techniques have been used to evaluate the failure modes surrounding intersections (Gercek, 1982; Chugh et al., 1975). Numerical modeling techniques include problems associated with the analysis of post-failure behavior, provision for different horizontal stresses (i.e., 01 f 021, and determination of inputs required for any non-elastic behavior. It seems likely that more sophisticated failure criteria, based on actual field data, are needed. The Bureau of Mines has conducted an extensive instrumentation program to investigate actual intersection failure mechanisms and to provide an improved understanding of stresses and deflections using beam and plate theories. Beam theory is not applicable to analyzing intersections (Wright et al., 1964); however, it can be used to explain roof deflection and failure (shear and flexure) of adjacent entries and to provide an improved understanding of stress changes and displacements as the entries, crosscuts, and intersection are developed (Hanna et al., 1985). Beam theory may be used for entries when the roof length is twice the width. When the length is less than twice the width (as in intersections), the roof must be analyzed as a three-dimensional problem, and stress and deflection calculations are based on flat plate theory (Adler and Sun, 1976). The confined-core theory (Wilson, 1972) hypothesizes that within a typical pillar, two regions exist: a confined-core region where the horizontal confining pressure is uniform and approximately equal to the overburden pressure, and a yield zone where the vertical pressure increases from nearly zero at the rib to a pressure peak at the boundary of the yield zone. The strength of coal in the yield zone ranges from nearly zero at the rib to nearly full strength at the confined core. The vertical stress in the confined core decreases from maximum at the yield zone boundary to the overburden pressure some distance into the pillar. Excavation of the adjoining entries

Jan 1, 1986

By F. Habashi

Siberia, a vast country rich in mineral resources and a large number of different ethnic groups. To the east of Lake Baikal is Buryatia with capital Ulan Ude. The Buryat are closely related to the Mongolians. Ulan Ude is connected to Ulaan Baatar (Ulan Bator) the capital of Mongolia by train – a 26 hours trip. Getting a visa to Russia is not a simple case. Visits to metallurgical research laboratories, Lake Baikal, and historical museums are enriching experience.

Jan 1, 2006

By David Wright, Colin Burns

Successful leaching of gold depends on appropriate chemical conditions; contact between leach solution and the gold particles; separation of the leach solution from the solids and extraction of the valuable ion from the solution. Irrespective of the leaching method employed the chemical conditions required are similar as is the dependence of solu­tion/gold contact on liberation. The various leaching methods available vary in the means by which gold/solution contact and solid/liquid separation are achieved. The essential difference between heap or vat leaching techniques and those involving agitation of a slurry is dependence on percolation for effective gold/solution contact. The most significant factor preventing uniform percolation is the presence of fines or clays. The quantity and character of the fines fraction is ore type dependent and may result from crushing, degradation during stacking or leaching, or the natural size distribution of the ore. The problems associated with fines can be aggravated during stacking and preparation of the heap. Segregation during stacking can result in concentration of fine particles at the centre of heaps. Further concentration of fines may also occur during irrigation by the movement of the fine particles with the solution. The end result is that the areas in which fines are concentrated become areas of low permeability. The contact between leach solution and the ore in such areas is, at best, slowed down dramatically and, in some cases, prevented altogether. The consequences of this phenomena are slow leaching and a reduction in recovery. The conventional solution to this problem is well known. Agglomeration of ore prior to heap leaching is practised widely. The effect of agglomeration is to immobilise the fines by causing them to adhere either to each other or to larger ore particles. The net effect is that the ore behaves as if no fines were present. The use of agglomeration is limited only by its cost, the most significant components of which are the cost of binding agent, commonly cement, and the capital cost of the agglomerating equipment.

Jan 1, 1995

By Bryce T. Tripp

Utah's abundant industrial rock-and-mineral resources support a relatively small but important sector of the State's economy. In 1983, six of the top 10 nonfuel mineral commodities (by value) were industrial commodities. Portland cement was ranked fourth, potash fifth, halite sixth, phosphate seventh, construction sand and gravel eighth, and lime tenth. Portland cement was produced by three operators, principally from the Jurassic Twin Creek Limestone. Potash was produced by three companies from Pennsylvanian beds in the Paradox Basin, surface brine of the Great Salt Lake, and subsurface brines of the Great Salt Lake Desert. Halite was produced by eight operators, primarily from surface brine of the Great Salt Lake. Additional production came from salt beds in the Jurassic Arapien Shale, solution mining of the Pennsylvanian Paradox Formation of the Hermosa Group, and subsurface brines of the Paradox Basin. Phosphate was mined by one company from the Permian Meade Peak Phosphatic Shale Member of the Park City Formation. Construction sand and gravel were produced by dozens of operators, primarily from Quaternary Lake Bonneville beach and nearshore deposits. Lime was produced by four operators from Paleozoic formations in the Basin and Range physiographic province of Utah. The future production of these and other industrial commodities, though individually uncertain, is expected to increase gradually as a group. Factors favorable for the future of the industrial commodities industry in Utah include large to almost unlimited resources for the major commodities, a healthy projected population growth, an abundant local supply of relatively inexpensive energy from coal and natural gas, and a favorable corporate tax structure and business climate.

Jan 1, 1987

By Terry P. McNulty

During the last 30 years, at least ten authors have dealt with startup ("ramp-up') times for minerals beneficiation, hydrometallurgical, and/or pyrometallurgical plants. Most have attempted to identity the reasons for delays and some have suggested attributes common to successful startups, as well as those shared by unsuccessful ones. The most recent has advanced a project characterization matrix as a predictive tool for qualified users. This paper will summarize past work, will review cause and effect, will outline an approach for refining our ability to avoid costly delays, and will seek guidance from professionals most likely to use such a tool. INTRODUCTION During the last few decades, many billions of dollars have been lost by investors in mineral industry projects that did not perform as well as their developers had hoped. The most common form of failure has been the inability to generate a profit quickly, and delayed achievement of planned production rate has been the chief cause. Minerals processing projects are by no means the only kind of plant to suffer from startup delays, as some authors cited in this paper considered inorganic chemical plants and other types of facilities. Furthermore, mines are not without fault and there have been many that were closed after years of disappointing performance. However, our interests as a group are most sharply focused on mineral processing and our database for such projects is relatively extensive. It is sufficient to say that the conclusions made or repeated in the following text can be readily extended to most types of projects.

Jan 1, 2004

By Barbara S. Parrish, I. S. Parrish

For two consecutive years the author and his wife have been fortunate enough to have been invited by the Peoples Republic of China to work with Chinese geologists of the Geological Bureau of the Ministry of Metallurgical Industries (MMI). Our visits, each of which lasted 7-8 weeks, took us to northwestern Sichuan, central Anhui, and much of Hebei Province, as shown in the accompanying drawing. We were asked to evaluate, criticize, and offer suggestions on the exploration and mining techniques used by the Chinese. Our commission both years was centered on gold, although we were also to visit other operations when the opportunity arose. In 1986, the visit primarily concerned with disseminated "Carlin" type gold deposits; in 1987, with "Greenstone" type gold deposits. Gold has been targeted by the Chinese as a metal of importance to the nation. Several governmental agencies have received direction and budgets to seek and develop gold properties. Besides the Ministry of Metallurgical Industry, gold is being sought by the Ministry of Geology, the China Gold Corporation, and reportedly the Peoples Army. There is considerable competition among these agencies. It is not uncommon to find two or more agencies working in the same general area. However, communication between the groups is minimal. Last year, we toured a small mine at Bambishan. We could see a diamond drill across the valley. The rig belonged to another Ministry and my guides voiced their curiosity to know what their competitors were finding. Mining, too, is not the monolithic bureaucracy that most Westerners anticipate in China. There are various levels of mining. These differ not only in sophistication, but in ownership. First, for small deposits the state allows "Peoples Mines". These can be owned and worked by individuals. The individual owner-miner may hire relatives or neighbors and give them a wage or he may turn the mine into a joint ownership situation. They

Jan 7, 1988