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By Gary A. Kingston

Rolled steel, steel forgings, and steel castings in the Pacific Northwest (Washington and Oregon) are produced principally in the Seattle, Wash., and Portland, Oreg., metropolitan areas. Steel-mill products are rolled from carbon and some alloy &eels by three companies into shapes such as reinforcing bar, rods, rounds, squares, flats, and hot-rolled strips; structural shapes, - such as angles, channels, and I-beams, also are rolled. Carbon and alloy steel ingots are poured and forged at a Seattle plant into ship shafting, drive shafts, billets, slabs, bars, rings, hooks, and other items. Static, shell, investment, and centrifugal castings are produced at 19 steel foundries in a wide range of steel specifications. All Pacific Northwest steel output is based on remelting steel scrap. Local iron ore might be used in the future to supplement steel scrap as a metal source. Ore reduction would probably be achieved by methods other than the blast furnace. Current melt-shop practice and problems are basically the same in Pacific Northwest steel plants as in cold-melt shops in other parts of the country. Quality steel production is receiving more emphasis in this region with the installation of modern analytical equipment and vacuum pouring and melting facilities.

Jan 1, 1962

By A. M. Salomon de Friedberg

"With respect to impurities, HBM&S' copper smelter, located in Flin Ron, Manitoba, is in an unusual position. In addition to the usual concerns, the fact that copper and zinc production at Flin Ron is closely integrated results in the unique situation where feed to the copper smelter typically contains 7% to 8% zinc. This paper discusses the ramifications to copper smelter operations resulting from the marriage of HBM&S' metallurgical plants. Distributions of impurities (specifically Zn, Pb, Ni, As, Bi, Sb, and Cd) are presented and operating practices designed to reduce the impact of impurities on anode copper quality are detailed.IntroductionHudson Bay Mining & Smelting Co. Ltd. (HBM&s), has been operating its metallurgical complex located in Flin Flon, Manitoba, since 1930. The smelter and zinc plant were originally separate entities with respect to production. The smelting operation consisted of traditional multiple-hearth roasters, a reverberatory furnace and Peirce-Smith converters. The zinc plant also utilized multiple hearth roasters and then followed with sulphuric acid leaching, purification and electrowinning. The zinc plant also recovered cadmium from a separate purification/electrowinning circuit.The two plants operated essentially independently of each other until rising zinc levels in the copper concentrate and large stockpiles of zinc-rich leach residues prompted the construction of the fuming plant in 1949. The smelter used pulverized coal to reduce zinc oxide present in the reverb slag and then captured the resulting zinc bearing fume in the fuming plant baghouse. The fume was sent to a separate ""oxide roaster"" in the zinc plant where it was first roasted to remove halogens and then leached to recover the contained zinc. This oxide fume became a major source of feed to the zinc plant accounting for roughly one quarter of the total zinc production. Furthermore, through the smelter's treatment of sulphide leach residue, both copper and zinc recoveries were improved for the over-all complex."

Jan 1, 1993

By N. E. Yasitli

There is a considerable amount of lignite reserve in the form of thick seams in Turkey. It is rather complicated to predict the characteristics of strata response to mining operation in thick seams. However, a comprehensive evaluation of ground behaviour is a prerequisite for maintaining an efficient production, especially when top coal winning by means of caving behind the face is applied. A comprehensive modelling of deformations and induced stresses is vital for the selection of optimum production strategy. In this study, numerical modelling and analysis of a longwall panel at Omerler underground coalmine have been carried out by using the software called FLAC3D developed based on the finite difference technique. Firstly, a 3-D numerical model of the M3 panel has been prepared. Secondly, induced stresses formed around the longwall face have been determined as a function of face advance where the face was located at the bottom of thick coal-seam. Results obtained from modelling studies have revealed that the front abutment vertical stress was maximum at 7 metres in front of the face and magnitude of front abutment stress was found to increase up to a distance of 200 metres away from the face start line. As the face was further advanced after 200 m from the face start line, there was not any significant change in the characteristics of front abutment stresses. Results of numerical analysis of the panel were in good agreement with in situ observations.

Jan 1, 2005

By Charles E. Locke

DEPRESSION in all lines of the mineral industry except gold, which began in 1930 and continued, even worse, through 1931, had its effect on ore concentration. Construction was limited to the completion of plants already begun. Every possible economy was adopted. Changes and improvements involving expense were postponed. Research was largely abandoned. Operations became highly efficient and costs were cut down, although this did not necessarily mean a lower cost per ton because of the greatly reduced capacity at which mills were run. Lower metal prices caused the operators to seek the optimum ratio of concentration and grade of concentrates looking toward maximum economic recovery; that is, net profit. In the crushing field no marked changes occurred. The Symons cone crusher for intermediate work is in use almost everywhere. Its manufacturers claim that 900 machines have been installed in 21 countries, replacing two previous steps of crushing and yielding a product sufficiently fine to form a satisfactory feed for rod mills and ball mills. A new Telsmith crusher has appeared which has curved jaws something like the Symons cone and consequently the same advantage as the latter.

Jan 1, 1932

By Ulf B. Andersson, Christina Dahnér-Lindkvist, Bruno Figueiredo, Jessa Vatcher, Jonny Sjöberg, Joel Andersson

Hydraulic fracturing to precondition the rock mass in high seismic risk environments has great potential. Unfortunately, there are many unanswered questions about how to best implement a hydraulic fracturing program at individual mine sites, and even how to best use our engineering tools to evaluate these plans. To give the hydraulic fracturing field tests at LKAB’s Kiirunavaara Mine the best chance of success, fully-coupled, discontinuum numerical modelling Itasca’s 3DEC code was used together with statistical simulations of the fracture network. For modelling purposes, it was assumed that hydraulic fracturing successfully reduces seismic risk through 1) the creation of hydraulic fractures along a plane at each injection site, and 2) activation of existing discontinuities. A variety of scenarios for the mine were evaluated, which focused on site specific uncertainties (such as the spacing of the pre-existing discontinuities) and practical solutions (such as the hydraulic fracture spacing, selection of injection medium, and hydraulic fracture site location relative to production). The discrete fracture network (DFN) realizations were developed using available statistical data for discontinuities near where hydraulic fracturing was planned.

Apr 26, 2022

By X. G. Liu

Bentonite is an excellent sealant mineral material because of its desirable swelling and self-healing characteristics, low permeability, sorptive qualities, and longevity in nature. A new type of water-swelling building sealant made from bentonite was studied in this paper. The building sealant is prepared by Na-base bentonite, vaseline and paraffin wax under different mass fraction of bentonite (which is 60%,65%,70% respectively). Under unrestricted state, some properties of samples were investigated. The volume expansion ratio at 24 h is 211%, 222%, 256% , and permeability coefficient is 2.86×10-8 cm/s, 4.15×10-8 cm/s and 4.78×10-8 cm/s respectively; low temperature flexibility of the sample (bentonite quality is 65%, 70% respectively) is good, and it does not flow heated for 2 h under 80?. The results of XRD and SEM indicate that bentonite is coated preferably by vaseline, and the spacing of layers of bentonite do not changed. The sample can keep full water swelling ability, and has good molding process. The test results prove that the properties of samples may reach the standard of building sealant.

Jan 1, 2014

By M. J. Ankeny

Coal-mine haulage ranks second as a cause of coal-mine fatalities, and the prevention of such accidents will materially improve progress in safety in the coal-mining industry. Beginning March 1950, Federal coal-mine inspectors were made responsible for completely investigating all fatal accidents in and around coal mines. During these 10 months, Federal coal-mine inspectors investigated 447 fatal accidents. This is a study of 121 of the fatal haulage accidents investigated, which constituted 27 percent of fatalities from all causes. Haulage employees represent only 12 to 15 percent of mine personnel, but, on the basis of accident frequency, their work is the most hazardous in coal mines. Fatal haulage accidents occurred in 53 bituminous coal-producing counties representing 14 States and Alaska. The physical conditions represent a cross section of' producing coal beds. Mining and transportation methods vary, from those of small hand-loading mines to those of modern mechanized mines.

Jan 1, 1951

By ROBERT R. RICHARDS

My. first paper, read at the Cobalt Meeting of the Institute,1 July, 1907, dealt with the behavior of a small Wilfley table when concentrating galena from quartz, the table being fed with natural products, with sized products; and with classified products. Since galena, having a specific gravity of 7.5, is among the heaviest minerals ordinarily concentrated by Wilfley table, it was desirable that a similar set of tests upon a mineral of, lighter weight should be made. Chalcopyrite, of a specific gravity of 4, would have been the best mineral for this purpose, on account of its great importance as an economic mineral, but in carrying out the test, however, I was obliged to content myself with a cupriferous pyrite, the specific gravity of which was 4.68 and the contents in copper 8.80 per cent. Through the kindness of Mr. H. 0. Cummins, this material was obtained from Shasta, Cal.,in very pure, clean, homogeneous condition. It was broken by rolls to 2 mm. in size, taking care to make a minimum of slimes. The quartz used to mix with it was pure, white, New England quartz, broken in the same way to the same size. In studying the accompanying tables, it should be borne in mind that the material concentrated was of low copper-content, and in many cases the quantity fed to the machine was 1 kg: or less.. As a consequence of the smallness of the 'quantity treated it was very difficult to adjust the table and get it in condition to do its best work before the feed became exhausted, and for this reason many results were obtained which appear irregular.

Sep 1, 1908

By D. Hoffmann, S. Plumb

IRUP is an iron-rich ultramafic pegmatite rock that formed due to hot ironrich fluids and gases replacing local stratigraphic zones of the Bushveld Complex. This study focuses on the estimation of the probability of IRUP occurrence on the Merensky Reef at the Marikana Karee Mine. A 2.15 million centare IRUP-rich domain at the Karee Mine was initially defined from the interpretation of a surface aeromagnetic anomaly, and exposures in the mine workings. Surface boreholes (spaced 250-500 m apart) within this IRUP domain contain approximately equal numbers of IRUP-replaced and IRUP-free intersections. Owing to the uncertainty in the continuity of the IRUP alteration (a result of the wide borehole spacing), the risk associated with the development of mining infrastructure within this domain is unquantifiable. Semi-quantitative data comprising visual estimates of IRUP replacement from reef development mapping data and surface borehole reef intersections was interpolated into blocks using indicator kriging estimation. Comparative analyses of the estimate of IRUP occurrences were made by changing the block size and declustering the data systematically. Reconciliations of the probability of IRUP predicted from the block models derived from the different data-sets and sequential indicator simulation models were analysed for four mining study blocks. A quantitative approach to modelling the occurrence of IRUP can be an additional tool for refining the estimate of the geological losses that inform the mine plan in such high-risk zones.

Jan 1, 2015

By J. E. De Waele, J. J. Lee, M. J. Mulheron, Luke R. Deamer

There is increasing demand for geotechnical contractors to commit to carbon reduction, net zero or science based targets. A lot of focus has therefore been placed on using low carbon materials and low emission rigs. However, whilst these are ways to help reduce carbon, there is a need to look beyond just substituting materials and fuels to meet net zero. Using the IEMA carbon hierarchy, there is a need to first look at eliminating and reducing emissions, before considering substitute materials. For example, in geotechnical designs, this may mean considering using ground improvement or reducing the number of piles, before considering using low carbon cements. Equally, for remaining emissions, this hierarchy means considering carbon negative products to offset emissions, such as ground source heat pumps. This hierarchy can also be applied throughout geotechnical contractor organisations. For example, considering video conferencing for meetings, before considering public transport or using an electric vehicle. This article explores the carbon hierarchy and how it can be applied to all areas of a geotechnical contractor’s business. Only through embedding this hierarchy across the business can geotechnical contractors achieve the step change required to meet net zero.

May 1, 2022

By L. Ou

This paper reports on research on leaching pyrite in a germ-free system. The effects of mineral particle size, pulp potential and various oxidation agents on pyrite leaching were studied. The results indicated that a smaller mineral particle size leads to a higher leaching rate of pyrite. The optimum results were obtained with a mineral particle size of -0.037 mm. The pulp potential reflected the leaching process and an increasing pulp potential improved pyrite leaching. The leaching rate rapidly increased with the addition of oxidation agents such as Fe3+ and H2O2. However, the precipitate generated by ferric ion coated the surface of the pyrite and prevented further leaching.

Jan 1, 2007

By C. A. Horne

"The transportation of mineral solids in the form of slurry is a subject most of us are associated with and, in fact, live with on a daily basis. The design parameters of slurry systems and most important the prime movers or cent¬rifugal pumps, are frequent and often controversial subjects due to the lack of practical guidelines which, if known and followed, can increase both reli¬ability and service life of the equipment.In this talk, emphasis has been placed on the practical side or rule-of-thumb approach to applications which, in turn, has been related to successful field results. The theoretical content and complex design criteria associated with actual equipment design has consequently been held to a minimum in the following discussions.I. BASIC SLURRY PUMP DESIGN CONSIDERATIONSFirst, to better understand how a centrifugal pump performs work, a basic description of the operating principles are in order.A. Operation In a pump, mechanical energy is transformed into pressure energyby virtue of the centrifugal force exerted by the rotating impeller. The liquid is discharged by centrifugal force at a velocity required to generate a given head and the volute collects the liquid so useful work can be done by the conversion of kinetic energy to pressure energy."

Jan 1, 1976

By T. L. Barone, J. R. Patts, L. D. Patts, S. J. Janisko

"Controlling float coal dust in underground coal mines before dispersal into the general airstream can reduce the risk of mine explosions while potentially achieving a more effective and efficient use of rock dust. A prototype flooded-bed scrubber was evaluated for float coal dust control in the return of a continuous miner section. The scrubber was installed inline between the face ventilation tubing and an exhausting auxiliary fan. Airborne and deposited dust mass measurements were collected over three days at set distances from the fan exhaust to assess changes in float coal dust levels in the return due to operation of the scrubber. Mass-based measurements were collected on a per-cut basis and normalized on the basis of per ton mined by the continuous miner. The results show that average float coal dust levels measured under baseline conditions were reduced by more than 90 percent when operating the scrubber. IntroductionAirborne coal dust is a byproduct of coal production, and engineering controls exist to deal with both the respirable dust health hazard as well as the float dust explosion safety hazard. Float coal dust, smaller than 75 µm (0.003 in.) in size, can deposit throughout mine entries and propagate explosions that had been initially fueled by methane gas. The inertization of float coal dust with rock dust helps prevent a potential secondary float coal dust explosion, but a preferable course of action is to significantly reduce the hazard by removing float coal dust from the airstream before it has the opportunity to deposit on the mine’s surfaces.Since 1970, disasters due to explosions in underground coal mines have caused 201 deaths in the U.S. mining industry, including 29 deaths in a single mine explosion in 2010 (Wade, 2010; U.S. Mine Safety and Health Administration, 2015). The U.S. National Institute for Occupational Safety and Health (NIOSH) had initiated a fiveyear research project that aims to investigate methods and technologies to reduce the potential for secondary coal dust explosions by the purposeful capture and/or suppression of float coal dust prior to its deposition on the mine roof, rib and floor (NIOSH, 2013). The project aims to evaluate the efficiency of methods to reduce longwall and belt airway float dust in the general airstream as well as methods to capture it at or near the source. Prioritization is given to longwall sections given the amount of coal produced relative to continuous miner sections, but the research is open to technologies that may be adapted from one method of mining to another."

Dec 1, 2016

By J. R. Thoenen

Profits in the crushed-stone industry, as in any other, represent the difference between selling price and production cost. When consumer demand increases rapidly, as occurred in the crushed-stone industry from 1918 to 1927, selling prices tend to rise. Cost of production usually rises, also, owing to the expense of expanding facilities, searching for and developing new quarries, and purchasing, installing, and operating new equipment. Frequently, also, the inattention of managements to the details of operating costs is responsible for their increase. This is not due to negligence but rather to the necessity of confining attention to the problems involved in producing material to supply orders. When market conditions change and consumer demand becomes stabilized or contracts, the producer r s attention usually is directed to assuring the orders necessary to keep his enlarged facilities busy. Hence, competition increases and soiling prices decline.

Jan 1, 1939

By C McGuire, W Harris, S Arsenault, D Witow, B Rogers

Mining deep orebodies is increasingly becoming the norm as the ‘easy’ orebodies are depleted. Deep ore mining requires significant ventilation and cooling infrastructure to not only meet regulatory requirements for air quality but also to achieve acceptable workplace temperatures with the higher strata rock temperatures and increased auto-compression. At the same time, advances in battery equipment technology are turning the possibility of a battery powered fleet into reality. The switch from a diesel fleet to a battery powered fleet offers several positive opportunities for the design and operation of a deep mine.The potential to reduce ventilation and cooling requirements due to battery powered equipment results in significant cost savings for mine development and infrastructure. Battery powered fleets are not subject to the same dilution requirements associated with diesel fleets thus allowing lower ventilation rates. At the low ventilation volumes possible with a battery powered fleet, surface refrigeration plants are limited with respect to the amount of cooling that can be delivered to the workface. Considerations for calculating the optimum air flow and cooling requirements are presented. Considerations for locating the refrigeration plant are also discussed. This paper presents these opportunities and considerations; including a case study comparing the ventilation and cooling system design with a diesel fleet versus battery fleet for a planned mine in Northern Ontario, Canada.CITATION:Harris, W, Arsenault, S, McGuire, C, Rogers, B and Witow, D, 2017. Diesel to electric – creating a positive paradigm in underground ventilation and cooling, in Proceedings Australian Mine Vent Conference 2017, pp 169–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By JOEL H. SWARTZ

During a series of resistivity measurements carried out in 1929 and 1930 a number of questions arose concerning the effect of topography on the character of the curves and the depths attained , the ratio of true depth to certain radii interpreted as representing depth , etc. To answer these questions it was decided to undertake a series of experimental investigations on artificial strata . It is the purpose of the present paper to present the results of the studies thus undertaken .

Feb 1, 1931

A pilot program was undertaken to evaluate a process developed by the U.S. Bureau of Mines to recover nickel, cobalt, copper and chromite from domestic nickel laterite resources. An existing five ton per day pilot plant was modified to accommodate treatment of laterite by the Bureau process, which employs reductive roasting, ammoniacal sulfate leaching, solvent extraction, and electrowinning to extract, separate, and recover nickel, cobalt and copper as high purity cathode products. Three distinct types of laterite i.e., limonite, saprolite and a mixture of limonite/saprolite were processed through the plant during three operating campaigns. Nickel cathode was made during all three campaigns, while cobalt cathode and chromite concentrate were recovered only during processing of limonite. Leach extraction of nickel and cobalt averaged 83 and 67 percent, respectively, while the overall recovery was 80 and 63 percent for nickel and cobalt, respectively. Initially, over-reduction of iron in the saprolitic calcine contributed to poor settling of the leached solids. This problem was overcome by careful control of reducing conditions and flocculant addition. An economic feasibility study was made for a 5000 TPD grassroots laterite processing facility scaled-up from pilot plant data. Estimated (+ 30) percent capital cost for a Nine and plant is $367 million with an estimated $103 million per year operating cost. The study indicates that low-grade domestic laterite may he processed with marginal profit- ability.

Jan 1, 1982

By José Porras

El presente trabajo señala el proceso de optimización en la mina a través del área de Tecnología de la Información, superintendencias y las áreas directas de las operaciones. En ese sentido, durante el diagnóstico de todos lo procesos levantados como geología, planeamiento mina, operaciones mina, mantenimiento, logística, control de gastos, se determinó mejorar las oportunidades que generen valor, como las oportunidades de control y reducción de costos, gastos, y su relación con los resultados obtenidos en su ejercicio.

Sep 9, 2007

By D. A. Greenwood

Dr David Greenwood opened the first technical session of the conference by highlighting the diverse nature of the papers in this session but drawing attention to the common theme that each solved a particular problem. PAPER 1.1 Tony Elliott introduced his paper on deep mix-in-place soil/cement stabilisation by stressing its simplicity. The engineering solution adopted at Elland was detailed in his paper and had formed the key to success of the project. The process itself is not widely used or known in the UK, although it has the potential to achieve significant benefits, subject to proper engineering control being exercised. It was explained that although the concept was not new, development of the technique for soil modification was relatively recent. The alternatives to mechanical mixing are injection, which is very dependent on soil type, site geometry, etc, and jet grouting; both processes are soil-responsive, and not easily monitored or programmed, difficulties which can largely be overcome by mixing. To achieve this at depths to say 30m requires high-powered, high torque machines and has resulted in significant equipment development.

Jan 1, 1991

By I Minniakhmetov, J Ashford

Orebodies constitute naturally occurring, commonly highly variable concentrations of minerals in the earth’s crust formed through varying and highly unpredictable processes. Orebody knowledge is a core foundation of a mining company’s asset base underpinning all decisions about Mineral Resource and Ore Reserves, future production, development and ultimately the profitability and competitiveness of a mining enterprise. The decision to invest in a mineral project is usually based upon a techno-economic evaluation of the project and having clear approval pathways to gain local community support and address social and environmental impacts. The main objective of the techno-economic evaluation is to determine the optimum development sequence for the particular orebody in question and to estimate the economic viability of the project and the future return on investment to its stakeholders, balancing the inherent value of the mineral in the ground against the costs of development and market pricing. With the exception of market-driven commodity prices, virtually all revenue and cost estimates fundamentally stem from the understanding and subsequent modelling of the orebody. A reliable estimate of the ore deposit grade and other geological value-drivers is the foundation upon which the business case for future mine development and operation is intricately dependent. Orebody knowledge is, therefore, the fundamental driver of the mineral project cycle, influencing the progression of studies and consequently, the resource company’s ability to declare Exploration Results, Mineral Resources or Ore Reserves which govern the source and cost of funding available to the project. Drilling provides a ‘vector’ to the true nature of the orebody and effectively buys time to manage the technical risk associated with the orebody. Despite its perceived high cost, in both time and money terms, drilling is the only available technology for acquiring the necessary orebody knowledge to support technical and economic studies and to minimise orebody-driven cash flow uncertainty and volatility. However, like all costs, pressure to minimise drilling budgets is ubiquitous across the minerals industry. Paired with inappropriate key performance indicators, drilling is often regarded as a cost to be minimised, rather than an investment to be optimised. Furthermore, as future deposits get deeper and more complex, the collection of orebody knowledge is increasingly on the critical path for project development. The increasing cost of data collection pertaining to these deposits increases the temptation to minimise orebody knowledge gathering at the cost of long-term value as the reduction or postponement of drilling results in greater orebody knowledge risk at all stages of the value chain. Indeed the true cost of the decision to drill less is rarely known until the mine is in operation, well after the mine project evaluation team has moved on. This paper aims to promote orebody knowledge as the fundamental source of endogenous project financial risk and, consequently, its critical importance in project financial evaluation. Furthermore, the report documents experimental research into the development of an econometric model for valuing orebody knowledge. Using the density of drilling data as a proxy measure of orebody knowledge, the proposed approach integrates well-established stochastic grade modelling techniques with the mathematical mechanics of Decoupled Net Present Value (DNPV) which, combined with stochastic grade modelling (conditional simulation), lends itself to the financial International Mining Geology Conference 2022 | Brisbane, Australia and Online | 22–23 March 2022 3 assessment of orebody knowledge risk. Based on this approach, a metric is formulated, representing the minimum value of the orebody knowledge added by additional drilling

Mar 22, 2022