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By Tyler Luxner

Stillwater Mining Co. (SMC) is the largest primary producer of platinum and palladium in North America. SMC operates two underground mines in south central Montana, along the 45-km (28-mile) platinum/palladium J-M Reef in the Stillwater Complex. The Stillwater Mine exploits 9.6 km (6 miles) of deposit strike length and East Boulder Mine exploits 4 km (2.5 miles) of deposit length. The two mines are 20.4 km (12.7 miles) apart with SMC controlling a considerable length along the entire J-M Reef trace. Production at the Stillwater Mine began in 1986 and in 1988 the first tunnel boring machine (TBM) was commissioned, becoming an integral part of mine development at SMC. TBMs have been used for developing production footwall laterals (FWL) to access new mining blocks at the Stillwater Mine, as well as boring twin crosscut ac-cess tunnels at the East Boulder. Two TBM development expansion projects are currently in progress: the Graham Creek project at the East Boulder Mine, which will extend footwall lateral development 2,591 m (8,500 ft) to the west, and the Blitz project, where a TBM will be commissioned to extend east out of the Stillwater Mine to 3,658 m (12,000 ft) beyond the current production mining front. General strike and dip of the Reef is west to east and to the north, respectively.

Jan 1, 2012

By V. T. McLemore

The mining industry is at a crossroad. To sustain our technically based society, demands for commodities are increasing, and exploration for these commodities is a must. The debate is between sustainable development and the status quo and begins with exploration, where it is determined if a mineralized area contains enough potential ore to be mined economically. Mineral deposits are relatively rare and depend upon certain natural geologic conditions to form and may not always occur in locations that are most suitable to society. Exploration can be compatible with environmental protection and social responsibility, but difficult challenges face the industry to develop a property that is environmentally, economically, and socially responsible.

Jan 1, 2004

By A. Sand

A 2-dimensional computational model based on the discrete element method (DEM) is utilized for modeling of stamp-charged coke making. In this process, a large volume of coal is compacted to one single coal cake before entering the coke oven. Cake densification and mechanical strength development are key factors for the subsequent production of a high-quality coke. An approach is introduced for model calibration utilizing multiple control parameters obtained from a laboratory-scale stamping device. Experimental data on stamper rebound amplitude, attenuation and peak force are compared with simulation output in a pairwise manner by constructing a criteria space, which allows identification of model settings best satisfying the control parameters. The calibration procedure carried out by multiple criteria comparison aided model parameter selection for reproducing stamper behavior in response to the properties of the cake subjected to compaction. This modeling and calibration procedure offers possibilities for numerically studying the densification and mechanical strength development of coal cakes. However, the approach is also more widely applicable to other compaction processes.

Feb 27, 2013

By Robin J. Batterham

We still need to innovate, but it is getting harder. The real price of metals is declining, return on shareholder value is lower than other industries, and there is a shorter-term focus on staying viable in a capital-intensive industry where timeframes for implementation of new technologies can be long (+I5 years). In this environment, the levels of R&D spent by major minerals companies are remaining steady at around 0.2%-0.5% of revenue. This is not large and to remain viable in the future, we need to be smarter about the way in which we do R&D. The mining industry is a knowledge-based industry. Driving down the cost curve demands innovation, which demands knowledge. To be smarter and more effective in our approach to innovation, a new paradigm is required Generating, capturing and using knowledge has evolved from Mode 1 (discipline based and clear distinction between basic and applied research) to Mode 2 (multidisciplinary, team-based approached with flow between basic and applied activities). Mode 2 is now seen to be much more efficient and to deliver better appropriability (Tegart 2003). To survive, we need to innovate, and the best way to do this is collaboratively. Some examples and pointers for the future will be given in this paper. THE CURRENT SITUATION The Rand report and other recent studies have painted a grim outlook for the mining industry. The real price of metals continues to decline (Figure 1) and profit margins remain thin. This is reflected in shareholder returnwhich are well below other industries (Figure 2)-and current management strategies-which reflect something of a "survival mode." The current focus for most mining companies is on short-term, incremental gains

Jan 1, 2004

By Todd S. Webster, Matthew J. Pierce, Brad D. Krumel

With the Working Shafts and Starter Tunnel under way, it became apparent this 4.7-mile, 19-foot diameter wet weather tunnel was going to live up to its name. The shaft’s pre-excavation grouting was completed, and ground water inflows were slowing project progress. As the tunnel drive was approaching 50% complete a cooperative effort was underway between the owner, engineer, and contractor to raise the base of the Retrieval Shaft by 65 feet to avoid ground water infiltration construction challenges. The tunnel alignment needed to be raised in kind. The project was behind schedule and rethinking the cast-in-place adit work was next on the agenda due to the very wet environment in the tunnel. The race was on to finish the project within the owner’s time constraints while completing multiple redesign aspects of the tunnel alignment and associated adit construction. This paper will evaluate original design criteria and actual in-route design modifications and change management to meet the owner’s just-in-time schedule needs.

Dec 1, 2022

By J. Gholamnejad

In open pit mine planning and design, push back mine sequencing is widely used for long-term production planning. In push back design, a series of nested pits is generated and then considered as possible push backs with regard to the minimum push back width requirements. These nested pits are produced by parameterizing on one economic parameters like commodity price, mining or processing cost, stripping ratio etc. The most important characterization of these push backs is that the inner most push back has the highest value per ton, the second inner most push back has the second highest value per ton and so on. These nested pits are generated based on the best estimates of grade within a representation of the ore body in a three dimensional matrix form. Therefore, the inherent uncertainty associated with reserve estimation (for our discussion grade uncertainty) is not taken into account when push backs are designed. These methods do not attempt to establish which part of the deposit is likely to be worth most. This paper introduced a new algorithm that incorporates ore grade uncertainty during push back design process. The suggested strategy tries to seek to schedule risky blocks later in the extraction sequence.

Jan 1, 2007

By M. J. Gula, S. S. Xue, E. P. Horwitz, J. T. Harvey

A study has been conducted to control iron in copper electrolyte streams using Eichrom Industries’s new Monophosphonic /sulphonic acid resin. The resin strongly and selectively extracts ferric ion over copper and cobalt from highly acidic copper electrolytes. The resin has a loading capacity of 27 g/L of iron and can be readily regenerated. In addition, the new resin can be easily synthesized using commercially available starting materials. This paper presents the experimental results for iron control in copper electrolyte streams using the new resin and discusses its potential applications to other hydro-metallurgical streams.

Jan 1, 2000

By J. R. Shultz, R. J. Lambert

One of the present trends in the mining industry is the increased use of mining contractors. In the past, many project owners have utilized mining contractors for topsoil stripping or overburden removal, usually on a short-term or periodic basis. In recent years, mining contractors have not only removed the overburden, but mined the product as well. Why is this change occurring? A prevalent trend in the mining industry appears to be the outsourcing of non-core and non-strategic functions, allowing producers to focus more on areas of technical expertise where higher incremental value is added—that is the processing, refining, and marketing of the product. As capital allocation becomes more critical, this trend is likely to continue.

Jan 1, 2002

By W. E. Roscoe, K. N. Spence

In the Canadian mining industry, there are at present no comprehensive regulations or standards for valuation of mineral properties. In January 1999, the Mining Standards Task Force of the Toronto Stock Exchange and the Ontario Securities Commission recommended that the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) establish a committee to review and advise on approaches and methodologies for the valuation of mineral properties. The authors were subsequently appointed Co-chairs of the CIM Special Committee on Valuation of Mineral Properties (CIMVal). A committee of experts from the mining industry, consulting, financial and legal communities was established with the task of reviewing available information, investigating various valuation methodologies and practices, soliciting input from interested parties, and recommending a Canadian code or standards plus guidelines for the valuation of mineral properties. As an initial stage of its work, the CIMVal Committee organized a one day session at the Mining Millennium 2000 Convention in Toronto in March 2000 on valuation of mineral properties. The 10 invited papers have been published by CIM. As a second stage, CIMVal has requested input and comments from all interested parties. The next stage will be to prepare a preliminary draft with a recommended code or standards and guidelines. This will be circulated for further input and comments prior to revision and publication of another draft. The final CIMVal report should be completed in early 2001. A variety of methods are in common usage for the valuation of mineral properties, depending on the stage of development of the property, the data available and the experience of the valuator. For example, the discounted cash flow method is commonly used for properties in production or at the feasibility stage, but is not generally considered appropriate for exploration properties. Market approaches such as comparable transactions are in wide general use, and various cost approaches are used for exploration properties. The option pricing approach has promise for valuation of marginal properties, but is not commonly used.

Jan 1, 2001

By D. W. Park

Underground room-and-pillar mining operations in the Warrior Coal Field in Alabama frequently suffer instability due to soft floor and thinly-laminated immediate roof. The investigation covered by this paper concerns a mine that was experiencing ground-control problems with weak floor conditions. Four hundred ft above the presently producing seam, another seam has been mined out. Several roof falls occurred locally, and as much as two ft of floor heaves have been experienced. The paper presents the results of comprehensive analysis conducted on floor heave, roof sagging, and the influence of the mined-out seam using instrumentation and numerical analysis.

Jan 1, 1991

By S. K. Samal, B. Mishra, M. K. Mohanty, S. C. Mishra

Steelmaking industries consume the majority of chromium and manganese ferroalloys to impart several properties in steel and also for other purposes. The quality of ore governs the process kinetics as well as the process economy of the ferroalloy industry. The present study demonstrates the thermal transformation behavior of chromite and manganese ores with varying compositions. Simultaneous thermal analysis (DTA/TG) is employed for such ore samples where the transformation of mineral phases is correlated with the thermogram characteristics and quantified. Phase, microstructure, and compositional analysis results of individual ores corroborated with thermal analysis are in good agreement. Chromite samples are ferruginous with goethite and gibbsite contents, whereas manganese ores vary in composition and also exhibit multiple and/or overlapping transformations.

Jan 21, 2021

By W. Hustrulid

"In recognition of his inspiring dedication to the mining industry through education, research contributions and dissemination of practical knowledge, exceptional leadership and excellence in mining engineering practice and for his lecture, “You can't make a silk purse out of a sow's ear.” Recipient of the 2002 D.C. Jackling Award Introduction It is always difficult to decide on the most appropriate title to give to a paper or talk. It is a particularly difficult decision in the case of the Jackling Lecture, because the title becomes part of the award citation. I hope that the significance of this unusual title will become crystal clear as you read the pages that follow. However, to assist you in this journey, I will provide the following few words of guidance. In making a cake, you need the proper ingredients. If one or more of them are missing, it will not be a cake. In addition, the quality of the cake depends on the quality of the ingredients. In my lecture, the "cake" is the U.S. mining industry of the future. A national perspective President George W. Bush in his State of the Union Address (Bush, 2002) delivered on January 29, 2002, defined three national objectives: •win the war on terrorism, •protect the homeland and •revitalize the economy. Under the heading "revitalize the economy," he indicated the importance of "good jobs" and "energy production" by saying: "Good jobs begin with good schools. Good jobs also depend on reliable and affordable energy. This Congress must act to encourage conservation, promote technology, build infrastructure and it must act to increase energy production at home so America is less dependent on foreign oil." I wish that he would have broadened his focus and stated instead that: "This Congress must act to encourage conservation, promote technology, build infrastructure, and it must act to increase materials production at home so America is less dependent on foreign sources." With regard to jobs, all jobs are not equal. To paraphrase John Reeves of MidContinent Resources (Reeves, 2002): "If our nation is to prosper, we all cannot make a living by doing each other's wash. Some of us, at least, must be actively engaged in the primary production of raw materials from the riches of the earth and other Americans must turn those materials into consumer products." The unfortunate trend in our country has been to neglect the primary production of basic materials, even those coming next in line. We have left those responsibilities to others while we concentrate instead on performing various services, i.e., doing each other's wash and flipping burgers. This cannot continue. It must be remembered, especially by those in leadership positions, that all "jobs" are not created equal. Some jobs are much more essential to the security and wellbeing of our country than others. We must be sure that the important ones are in place. We cannot produce the basic materials that our nation requires without access to those materials. This leads to my Proposition 1: You cannot have a viable mining industry without a clearly enunciated, positive U.S. materials policy. Background regarding U.S. materials policy Resources for freedom. In January 1951, President Truman created the President's Materials Policy Commission, with William S. Paley as chairman. As expressed in the invitation letter from the president to Paley: This commission, within the executive office of the president, is to study the broader and longer-range aspects of the nation's materials problems as distinct from the immediate defense needs. The task of the commission is to make an objective inquiry into all major aspects of the problem of assuring an adequate supply of production materials for our long-range needs and to make recommendations that will assist me in formulating a comprehensive policy on such materials. The commission should study, together with any other aspects deemed by it to be pertinent, such questions relating to production materials as: - the long-range requirements outlook; - the long-range supply outlook; - the prospect and estimated extent of shortages; - the consistency and adequacy of existing government policies, plans and programs; and - the consistency and adequacy of private industry practices.

Jan 1, 2003

?Classification System Efficiency (CSE)? is a simple, powerful concept which can be used to measure and improve ball mill circuit efficiency. This paper describes six plant case studies which demonstrate the use of CSE to diagnose and/or improve grinding circuit performance, with related improvements in circuit efficiency ranging from 3 to 30 percent. The increased effective mill grinding energy is recaptured from energy that was going into over grinding, which can greatly benefit downstream mineral separation. The achievable CSE for given circuit design/operating variables is described, providing every plant metallurgist with the means to determine the potential for increasing their particular grinding circuit?s efficiency through increased CSE.

Jan 1, 2012

By T. R. Ellis

Many appraisers/valuers believe that the only valuation method available within the Cost Approach category for Real Property appraisal is the depreciated replacement cost method. Some valuation and financial reporting standards setters also believe the same. This paper introduces the minerals appraiser to a number of useful methods for mineral property appraisal that are based primarily on the principle of contribution to value, the predominant economic principle in the cost approach. Most of these cost approach methods discussed are primarily for use in valuation of exploration tracts and resource properties that have no defined reserves. However, the powerful rural cost method can be used to calculate the contribution of categories of resources, reserves, and other property components to the value of a mineral property. This method can be applied to mineral properties at all stages of development, including producing properties.

Jan 1, 2011

By Brian G. White

The Coeur d'Alene Mining District of northern Idaho is remarkable for its number of large ore bodies and for the amount of its historical production of lead, zinc and silver (Fig. 1). Since veins were first discovered in 1884, more than 127 Mt (140 million st) of ore have been produced from narrow, high-grade veins. Mining continues at the Lucky Friday, Galena and Sunshine mines (Fig. 2). All have been in production for decades. At these mines, more efficient mining and exploration techniques have reduced costs while adding significant new reserves. Even the old Bunker Hill Mine, where ore was first found in 1875, continues operation on a limited basis, partly involving production of world-class pyromorphite specimens. Until recently, the Coeur Mine was also a profitable silver producer. Other large producers have included the Star-Morning, Hecla, Page, Standard-Mammoth, Hercules and Gold Hunter mines (Fig. 2). The first deposits were discovered by prospectors who spilled over from the Murray gold mining district, 24 km (15 miles) to the north. The Bunker Hill Mine was founded the year after the first veins were discovered. Bunker Hill has now operated for more than 100 years. Production includes 2.3 Mt (2.6 million st) of lead, 1.1 Mt (1.2 million st) of zinc and 4.1 kt (132 million oz) of silver. Total district production through 1996 (Springer, 1997) amounted to 7.3 Mt (8.1 million st) of lead, 3 Mt (3.3 million st) of zinc, and 34.5 kt (1.109 billion oz) of silver. This record establishes the district as the largest recorded producer of silver in the world, while also yielding major quantities of lead and zinc. Only Potosi, Bolivia, may have produced more silver, although records are unclear. Despite the district's longevity, historic production and current activity, the published literature on the district lags behind with regard to recent concepts of district geology. The most recent comprehensive US Geological Sur- vey (USGS) bulletins (Hobbs et al., 1965; Fryklund, 1964) are dated. Much research in the last half century has been short-lived or geographically restricted because the district is large and its geology is complex - and even this research tends to remain unpublished. Thus, it has been difficult for in- [ ]

Jan 1, 1998

By D. M. Abbott, H. J. Sandri

The geoscience matrix method has proven useful for valuing metallic mineral properties lacking delineated mineral resources or reserves. However, the method explicitly excludes commodity markets from the factors considered; marketability is assumed. When valuing industrial mineral properties, marketability cannot be assumed, it must considered. Market considerations may also significantly affect the standard weightings of geoscience matrix parameters such as the proximity to known deposits. In some cases, such proximity is desirable but in many cases it is undesirable. Application of the geoscience matrix method to industrial mineral properties therefore requires thoughtful, market-related adjustments to the basic geoscience matrix methodology.

Jan 1, 2000

By Charles G. Zink

Anthracite is widely known as a domestic or space heating fuel. The prevailing market ratio of domestic to industrial consumption was about 80 to 20 up until 1950. Since then it has been shifting until now the ratio index is about 50/50, exclusive of overseas export. Despite a declining domestic space heating market, the demand for industrial anthracite remains good. However, as a result of stringent air pollution regulations, there is a renewed interest in this low sulphur coal which cannot smoke under any conditions. Anthracite serves other important industries such as power generating, metallurgical, cement, ceramic, chemical, water sewage and industrial wastes filtration. Anthracite is an excellent natural source of carbon and may be utilized in many processes.

Jan 1, 1966

By Ray A. Rothrock

The in situ mining of uranium is the process whereby chemical lixiviant is injected by means of wells into, and flowed through, an ore body. The lixiviant reacts with uranium which has been previously oxidized making the uranium soluble. The solution is then brought to the surface by means of producing wells. In situ mining disturbs the ground-water quality in the immediate area. Since ground water is a natural resource used by man, care must be taken not to allow the lixiviant to escape the local mining area. Also, when the ore body is mined out, the area should be restored to as near its original state as is reasonably achievable. The return of ground-water quality to its original state can occur naturally over a long period of time or be enhanced using appropriate technological means.

Jan 1, 1981

By Luminita Calin

King County (Seattle, WA) is on a monumental task of building the new Brightwater System complete with a new treatment plant, three main conveyance tunnels, a new outfall into Puget Sound and other ancillary works. This paper will describe the first conveyance tunnel, Brightwater East currently under construction by the Joint Venture of Kenny (Sponsor) / Shea / Traylor that is scheduled for completion in early 2010. The project located in Bothell, WA (north of Seattle) is in both King and Snohomish Counties. It was the first of the major tunnel projects that was scheduled by King County for the Brightwater System. The East Contract consists of the following major elements: 14,000 ft of 19'-2' EPBTBM mined tunnel using 16'-8' ID bolted, gasketed precast concrete segments for a primary liner; installing and encasing 14,200 ft each of 48', 66', 27', 84' in diameter steel pipes inside the tunnel along with three runs of fiberoptic cable; 2,430 ft of 72' in diameter microtunnel including three caisson shafts and associated structures; one Intercepting Structure (IS) shell to mine from that is 74 ft deep and 74 ft finished in diameter with 130 ft deep slurry diaphragm walls, tremie slab and final concrete wall lining; one Influent Pump Station shell (IPS) 83 ft deep, twin 77 ft inside diameter cells, with 160 ft deep slurry diaphragm walls, tremie slab, and final lining; two short 12 ft in diameter inter-shaft connector tunnels; one extraction shaft 40 ft deep by 40 ft wide and 140 ft long for connection to the new treatment plant piping.

By J. Um, B. Morin, P. H. S. W. Kulatilake

Development of a three-dimensional mine visualization model for a section of the mine is addressed first. Discontinuity orientation and location information was taken from this visualization model for use in slope stability analyses. Estimated shear strength properties of discontinuities and mechanical properties of intact rock from the rock mass samples obtained from the mine are discussed next. The paper is then focused on the calculated maximum safe slope angles based on the performed kinematic and block theory analyses using the mapped discontinuities at the mine. Finally, the effects of water that exist in the rock mass, tension cracks, slope face inclination, overall wedge height and double benching on factor of safety of wedge stability are illustrated through limit equilibrium slope stability analyses.

Jan 1, 2002