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By Anton Gronningsater

AS we know, Sir Henry Bessemer introduced Bessemer converting in the steel industry about 1855. It was not until twenty years later that the principles were adopted by non-ferrous metallurgists. In 1880, Manés first produced blister copper from matte in a converter, a very important forward step in copper metallurgy. For thirty years, up to about 1910, bessemerizing of copper matte was carried out in the acid-lined converter. It is not necessary here to enumerate all the shortcomings of that operation, one of which was that it strictly limited the grade of matte that could be treated; a 35 per cent matte was low in those days. From the early days of copper converting, many and repeated attempts were made to use a basic converter lining, and the older metallurgists will remember the numerous reports and discussions in connection with such experiments. These make interesting reading. I quote from a book published in 1900: ?'The siliceous lining is as much a part of the process of copper converting as magnesia lining is in the basic bessemer treatment of phosphoric iron, and it is suicidal to attempt any other kind of lining, either water-jacketed or basic.' "Even if the silica could be introduced in this way (through the tuyeres), it would still produce another trouble in the converter. The small particles of silica, being cold, would combine very imperfectly with the iron oxide and produce granulated and pasty slags, which could not be skimmed or poured out of the vessel".

Jan 1, 1942

By Alex Cormode, Carlos Perucca

"Sylvinite ore from the Saskatoon area typically contains about 5% insolubles, occurring as clays and carbonates. These insoluble slimes must be removed sufficiently well to permit an efficient subsequent potassium chloride flotation, due to their high adsorptive capacity for amines used as potash collectors. The insolubles are liberated from sylvinite by high attrition scrubbing in a slurry. The liberated slimes are separated by multistage cycloning or by a selective flocculation-flotation process.An outline of the potash processing operations at Agrium Vanscoy Potash Operations is given, emphasizing the insoluble slimes froth flotation separation process. This process was originally implemented at the Agrium plant in the mid- 1970's and replaced a hydrocyclone system.IntroductionAgrium Vanscoy Potash Operations is located 40 Km southwest of Saskatoon, almost midway between the communities of Vanscoy and Delisle. Processing operations started in 1969, and the annual production capability was subsequently increased to the current 1.8 MM tonnes per year of muriate of potash.The mining operation at Agrium Potash which was described in a paper by Jones and Pruggerl , is done underground using four large continuous double rotor boring machines for the main production with development done by heliminers. Annual ore production is 5.5 MM tonnedannum. Ore is hoisted 1,100 m to surface for processing."

Jan 1, 1999

By Gordon DM

Tyres account for 25-30 per cent of the operating costs of large capacity haul units as used in open-cut mines.Tyre operating costs can be substantially reduced and often contained in real terms by applying knowledge that is now available.This paper describes certain specific advances in tyre management, namely batching, bias adjustment, cumulative plotting and the so-called "pressure-temperature" system of tyre pressure control, originated on the Mt Newman Mining Company's Newman minesite, and discusses the contribution that each has made to improving tyre management and reducing costs.

Jan 1, 1983

By N. L. Ayres

Tendon support systems have been successfully used to stabilize excavations. Tendon support systems are routinely designed using the axial load-bearing capacity of tendons, namely the tensile strength. To attain tensile strength the tendon must be loaded along its length, which often does not occur in practice. Tendons should optimally be installed at 90° to the surface of the excavation to achieve maximum penetration depth, yet this is often not physically or practically possible, and installations at angles less than 90° occur. Furthermore, the intersection of geological features within the rock mass frequently results in complex loading situations on tendons. The position and angle at which loading occurs results in different combinations of tensile and shear forces acting on the tendon, which can impact on the support performance of each unit and ultimately the whole system. All factors that influence the support system should be understood and taken into account to ensure a sound support design. Combination loading situations are further investigated and tested to obtain a better understanding of the mechanisms involved and the effects on tendon load-bearing capacity. Tendon support units were tested at different installation angles to establish the tendon performance, mechanical behaviour, and load capacity during these loading situations. The results and outcomes are aimed at providing rock engineers with additional data and improved understanding of how tendons could perform under certain conditions.

Jan 1, 2014

Gold was determined directly in eight different mill cyanide solutions, by atomic absorption spectroscopy in an acetylene-air flame. Some of the mill solutions were diluted with water to bring them into the most sensitive absorption region (5-50 p.p.m. Au) whereas those solutions with very low gold content «2 p.p.m.) were concentrated by evaporation.Calcium was complexed with ethylene diamine tetra-acetic acid (EDTA) to avoid the undesirable effect of a precipitate on atomization.When added to standard gold solutions, EDTA had no effect on absorption, nor did any of the impurities common in mill cyanide solutions.Known amounts of gold, ranging from 2 to 30 p.p.m., were added to mill solution'aliquots and recovered to within 100 ± 2·5 per cent. For duplicate determinations under normal worKing conditions, standard deviation was 1·32 p.p.m.Excellent agreement was found between atomic absorption gold values and accurate fire assay values.INTRODUCTIONAtomic absorption spectroscopy has been shown to offer a rapid and accurate method for the determination of trace amounts of a number of metal ions. In the field of primary metallurgy atomic adsorption has been used for routine determinations of lead, copper, silver, zinc, cadmium and iron in a variety of raw materials and intermediate products.The scope of atomic absorption spectroscopy was reviewed recently by Willis (1963).The noble metals silver, gold, platinum, rhodium and palladium were determined by atomic absorption from chloride solutions by Lockyer ·and Hames (1959). In their determination of gold down to 1 p.p.m., they found no interference from the noble metals, nor from considerable excess...

Jan 1, 1964

By Thomas Passlick

By means of further developed machines and techniques and with growing experiences in jet grouting, the challenge of this building method becomes more and more complex. To keep the concerning risks as low as possible, the requirements on the quality assurance continuously in­crease. The construction of a 37.0m deep seated slab for the Amsterdam metro station Vijzelgracht in marine clay represents such a complex task. This paper summarises the required measures of quality assurance. In particular a new hydraulic measuring device is introduced with which it was possible to detect the column diameter of 2.6m at a depth of 37.0m during the production process and with a very high accuracy.

Jan 1, 2006

By Nicholas Adrian Barcza

"What affects and influences one’s perspective of the mining and metallurgical industries?One’s perspective of the industry we work in changes over time as a function of our experience as well as from the interaction we have with colleagues locally and probably even more so with those internationally. Furthermore, the ever-changing environment continues to impact the context in which one sees things. Living mostly in South Africa through its changes in the past fi fty years but also having the opportunity to travel extensively and work on projects abroad adds an invaluable richness to this more global perspective. One of the greatest challenges is how best to use this experience to endeavour to support the many potential opportunities in southern as well as sub-Saharan Africa. However, one has also to face the realities of how the best interests of the country and its peoples are sadly often not well served for various unfortunate reasons. Investment, education, regional stability, and good governance are some of the most critical considerations for the prosperity and survival of the region.The mining and metallurgical industry in southern and sub-Saharan Africa changed significantly during the post-colonial and apartheid eras as a result of global and regional developments that have impacted the ownership of businesses, the technologies used, and products produced in a manner that was not envisaged even fi fty years ago. Southern Africa’s mining and metallurgical industry has progressed from one based mostly on diamonds and gold in the late 19th century to a much more diverse one that involves the production of a variety of other precious, base, and ferrous metals and minerals as well as coal and industrial minerals. The infrastructure and manufacturing capacity was largely developed to meet the needs of this industry during its growth phases, but even though the dynamics have changed there is still a need for more efficient and effective support systems in the region."

Jul 1, 2019

By Amy McBrayer, Andrea Brickey

Area mining is a surface mining method that allows for efficient mining and contemporaneous reclamation of tabular or bedded deposits, e.g., coal. Mine planning methods for area mines differ from those of open pit metal mines. Area mines in the Powder River Basin (PRB) use various processes for mine planning at both the strategic and tactical stages. With the ever changing commodity markets, it is becoming increasingly important for mine operators to be able to react quickly to the changing business environment. Tools that allow for the development and rapid comparison of production schedule scenarios are key to ensuring agile mine operations. A survey of mine engineers responsible for mine design and production scheduling at coal operations provides clarity on the current mine design and production scheduling processes in the PRB, as well as a discussion on potential solutions to upcoming challenges. In this article, we describe various mine planning processes used by the coal producers in the Powder River Basin. The survey identifies a clear gap in the ability to create comprehensive schedules associated with limited tools and lack of engineering labor needed to frequently conduct the mine design and scheduling process.

Jul 8, 2023

Tunnelling under squeezing ground conditions poses significant challenges. There are fundamental differences in the choice of support for mining as opposed to civil engineering. This paper reviews ground support strategies that have been used to control large deformations in mining excavations based on field data from five different mines in Australia and Canada. Recommendations are made for improved ground control strategies in squeezing rock conditions.

Jan 1, 2008

Disseminated gold mineralization in the Vunda River area 12 km SE of Lautoka in Viti Levu occurs sporadically in shoshonite volcanics within an alteration area of some 6 km2. No definite intrusions have yet been located though possible intrusions occur toward the centre and on the eastern margin of the area. The nature and distribution of alteration suggests the presence of a co-magmatic mineralizing stock just below the surface.The gold occurs within close spaced fractures and occasionally around the c1asts of breccia and agglomerate.Various types of alteration compatible with porphyry mineralization occur, but to date show no zoning or defined correlation with incidence of gold which occurs in various alteration facies.It is suggested that the gold and trace copper mineralization at Vunda arises from the sub-volcanic intrusive phase (monzonite) of the Sambeto shoshonite (5 m.y.) and is part of an E-W zone of porphyry-type mineralizationtrending easterly to the Kingston porphyry copper deposit at Navilawa.There is a close similarity between the Vunda mineralization and some of the porphyry deposits of alkali affinity in British Columbia, Canada.

Jan 1, 1978

[Module 10. Internally Cued Operating Contingencies Prerequisite: Modules 1-7 - Estimated Instructional Time: 2.42 hrs. Module Abstract Trainees, using programmed instruction, describe the cues, consequences, operational sequences, and possible causes resulting from loss of air pressure from power fluctuations, and from a failure of the automatic lubrication system. Although some of the contingencies may be initially signaled by an alarm or from the oiler, each trainee will demonstrate proficiency in the appropriate operating techniques and procedures. This module also includes a review component for those trainees identified in the assessment exam as requiring less detailed instruction.]

Jan 1, 1976

By Ron Bromenschenkel

The State of California, Department of Transportation is currently retrofitting a major interchange near the San Francisco area. The project is located in a highly traveled area of Oakland with light rail commuter service near many footings. Over 600 micropiles are being used in conjunction with CIDH piles for footing stabilization. A specially designed Soil Nail pile will support footings for a new light rail utility structure. Pile testing features in this contract serve as points of interest for future foundation designs. The presentation focuses on substructure issues of this incterchange retrofit. Both design and construction considerations will be covered. Design Considerations: ? Project Description ? Structure inadequacies ? Design criteria ? Design contraints ? Retrofit strategy ? Consultant analysis ? Pile Designs and Test Sites ? Contract Specifications ? Construction Plan and Cost

Jan 1, 1998

By V. Eu. Anufriev

Despite of significant cost advantages and the positive expierence roof bolting is limited up to 15-20% of all workings at the Cuzbass mines. The low level of application of the technology is the result of specific mining and geological conditions and defects of organization and technical support. When analysing mining and geological conditions of development working maintenance and geomechanical aspects the necessity of changing of technological schemes of preparation and extraction of mine sections is obvious. The prospects of large-scaled transferring from frame support to roof bolting are connected with introduction the technology of support with the help of non- expanding bolt classes including bolts with mineral filler fixation. The design of bolters with mineral filler fixation is given here. The results of testing of bolt load characteristics in artificial holes and in situ are proved the technology efficient. For increasing of drilling works efficiency it is necessary to master the production of oilless compressor and heading machines with the manipulator. For bolt dimension forecast it is recommended to use the relations of measured parameters of "dome" to roof shifts. Effective monitoring of rock pressure in the junctions is connected with the use of support of conventional bolts together with bolts of deep installation with simultaneous supporting of face ends with special mechanical sets, which compensate face length change.

Jan 1, 1996

By Erdal Ünal

The computer program introduced in this paper is based on design guidelines developed for selection of support systems used in mine roadways. The support types considered include rock bolts as well as rigid and yieldable steel arches. Using the computer program, the design engineer can select the type, pattern and specifications of the support systems suitable for various roof conditions. The concepts utilized, assumptions made, support selection criteria and description of the computer program, developed for the PC, are included.

Jan 1, 1989

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 Ed Beswick

Resource Update Drilling Program ? Pre-feasibility ? Exploration Metallurgy Program ? Grindability ? Metallurgical Optimization ? Hydrometallurgical Options Preliminary Mine Development Design Environmental Permitting Infrastructure Development

May 1, 2008

By Brendan Demich, Joseph McGuire, Emily J. Haas

Near misses recorded and reported by workers can provide awarenessto the potential causes of injury and prompt safety management initiatives. Although most companies require near-miss reporting, it is unclear what the value of these reports are, if any, and how they influence subsequent actions or controls to reduce on-the-job risks. Researchers at the National Institute for Occupational Safety and Health (NIOSH) conducted a case study with an aggregates company in which near-miss reports were analyzed at each of their locations over an entire quarter during the summer of 2018. Within that quarter, workers recorded 249 near misses. Of those, 167 were valid near misses that occurred at work. Researchers coded the reports using a qualitative 5 × 5 risk matrix. Of the 167 near misses, 19% were deemed low risk, 25% moderate risk, 30% high risk, and 26% critical risk. Several patterns in the near-miss incidents were documented, including classification of incidents and common corrective actions referenced (i.e., elimination/substitution, engineering control or redesign, work process/procedures, and personal protective equipment). The analysis provides insight into ways that risk communication and management programs can be improved to reengage workers and their situational awareness on the job.

By L. A. Matthews

The embrittlement of the Ti-6Al-4V alloy by hydrogen dosing at elevated temperature has been investigated. Metal coupons were subjected to isothermal treatments in a partial hydrogen atmosphere in the temperature range from 650ºC?950ºC and the degree of embrittlement after treatment was determined by drop-weight impact testing. Embrittlement was found to be inversely related to reaction temperature as a result of the combined effects of greater hydrogen absorption and titanium hydride precipitation at the lower isothermal temperatures. Keywords Titanium, hydrogen embrittlement, impact energy

Jan 1, 2011

By Bertram Price

Libby, Montana is the site of a large vermiculite deposit that was mined between 1920 and 1990 to extract vermiculite for commercial applications such as insulation, gardening products, and construction materials. The Libby vermiculite deposit also contains amphibole minerals including tremolite, actinolite, richterite, and winchite. Historically, Libby mine workers experienced high exposures to amphibole structures, and, as a group, have experienced the health consequences of those occupational exposures. It has been suggested that Libby residents also have been and continue to be exposed to amphibole structures released during the vermiculite mining operations and therefore are at increased risk for disease. The Agency for Toxic Substance and Disease Registry (ATSDR) conducted two epidemiological-type studies of residents living in Libby and the surrounding areas to assess these risks. The Environmental Protection Agency (EPA) collected and analyzed exposure data in Libby and used those data to project risks of asbestos-associated disease for Libby residents. The EPA has placed the Libby Asbestos Site, which includes the mine and the town of Libby, on its National Priority List of hazardous waste sites in need of clean up. This article presents a review of the exposure studies conducted in Libby and an analysis of health risks based on the data collected in those studies. Libby mine workers have experienced elevated levels of asbestos-associated disease as a consequence of their occupational exposures to amphibole structures. Libby residents? exposures typically are substantially lower than mine workers? historical exposures, and the health risk projections for residents are, accordingly, substantially lower. © 2007 Published by Elsevier Inc. Keywords: Libby; Montana; Vermiculite; Amphibole minerals; Asbestos; Asbestos-associated disease

Jan 1, 2007

By William R. Yernberg

The Fifth International Heavy Minerals Conference (HMC) was held Oct. 16-19, 2005, at the Marriott Sawgrass Resort in Ponte Vedra, FL. With SME as sponsor, the 2005 conference marked the first time that the HMC was held in North America. The conference is held every two years and provides an important forum for professionals in the heavy minerals and related industries to meet and discuss issues related to heavy mineral exploration, mining, processing and marketing. Previous locations included Australia and South Africa. The conference consisted of technical presentations, field trips to heavy mineral operations, a trade show and social activities. It was appropriate that Ponte Vedra was selected as the location for the conference. Ponte Vedra, located on the Atlantic Coast 17 km (10 miles) southeast of Jacksonville, FL, is the birthplace of heavy minerals mining in North America. Ponte Vedra beaches were mined from 1916 to 1929 in what was then called Mineral City. Though Ponte Vedra is now a golf and beach resort, there are still four heavy mineral mines operating within an hour’s drive. Today the Ponte Vedra Country Club and Golf Course is situated in the center of the former mining site.

Jan 1, 2006