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By Guillermo P. Selas

Perhaps this is the first time that an analysis of the industrial minerals panorama has been made in Mexico for that type of commodities. Because the non-metallic minerals lack the glamour of the metallic minerals and are usually of less unit value than metallics, a comparative study of these commodities has seldom been attempted. Sulphur, fluorite, barite and few others are an exception. Consequently, the statistics on the lowest per unit value industrial minerals, such as limestone, dolomite, gravels, sands, etc., are usually scarce and not always accurate. The following, then, will be an attempt to show a general status of the industrial minerals in Mexico with due reservations regarding volumes and values. According to Kruger (1971), this group of minerals surprisingly very little known, and called non-metallics because the lack of metallic luster, is the largest group of the mineral kingdom. It constitutes perhaps 75% of all the mineral varieties. For the most part, these minerals are compounds of common acids, sulphides, hydroxides and two elements carbon and sulphur. The list of non-metallic minerals is therefore very long. It includes the borates, carbonates, chlorides, fluorides, nitrates, phosphates, silicates, sulphates and less commonly arsenates, chromates, molybdates, sulphides, tungstates and vanadates. The latter group and many of the oxides are sought usually for their metal content.

Jan 1, 1974

By K. Nielsen

The paper presents a brief overview of the mineral industry in Norway, followed by a description of the mineral policy and relevant legislation including the roles of the Norwegian Directorate of Mining and Geological Survey of Norway in this context. The discussion then proceeds to describe the land use planning framework on a national, regional and local level, the interaction between land use planning and the Directorate of Mining and the Geological Survey respectively, and how this impacts on the mineral industry and the exploitation of mineral resources. Some recent Norwegian examples of land use planning conflicts are also presented.

Jan 1, 2005

By Lee W. Abramson

Performing risk analyses on tunnel projects has become common place and on many projects it is required from an owner or regulatory perspective. After the project is planned, designed and constructed, the data concerning identified risks, assumptions, costs, probabilities and mitigations is generally long forgotten and buried in some file somewhere. A study was performed comparing predicted risks versus actual events on several recently constructed tunnel projects. Probabilities and costs for selectively common risks on tunnel projects have been studied and re-evaluated. Conclusions are presented that can guide future projects and the veracity of the tunnel risk analyses performed.

By J. Wiese

Recently the operating philosophy at concentrators processing platinum bearing ores has started to move from a recovery dominated system to one in which the production of high grade concentrates at the expense of some recovery would provide greater benefits in the further upgrading of the platinum group minerals (PGM). The low grades usually obtained are associated with the presence of naturally floatable talcaceous gangue minerals in all PGM ores. Polysaccharide depressants such as guar gum and carboxymethyl cellulose (CMC) are used to improve the grades of the concentrates. Recent testwork has shown that the use of high depressant concentrations can prevent any naturally floatable gangue from reporting to the concentrate. The only gangue present in the concentrates would be due to its entrainment in the froth. Under these conditions much higher grades can be achieved. The sulphide minerals themselves, however, become susceptible to depression at high depressant concentrations. This work examines how the recovery of sulphide minerals in two Merensky ores was affected by the type and concentration of the collector in the presence of high depressant concentration (500 g/t) and that the response of the sulphide minerals was also dependent on the type of depressant used (guar or CMC).

Jan 1, 2009

By R. L. Virta

Four companies mined ball clay in four states during 2005. They included H.C. Spinks Clay (owned by Franklin Minerals), Kentucky-Tennessee Clay (owned by Imerys), Old Hickory Clay and Unimin. Production was estimated to be 1.32 Mt (1.45 million st) valued at $53.3 million, based on the results of a preliminary survey of the ball clay industry. Production in 2004 was 1.22 Mt (1.34 million st) valued at $54.1 million. Tennessee was the leading ball clay producer state with 61 percent of domestic production, followed by Texas, Mississippi and Kentucky.

Jan 1, 2006

By G. Abramov

The 20th Century saw the modern mining industry enriched by one outstanding method of extracting of mineral resources called Borehole Mining (BHM). Mean while, despite its successful track record in wide ranging locales, few specialists are yet aware of this technology. The intent of this article is to introduce borehole mining to a wider spectrum of drilling and mining professionals. The BHM method is based on in-situ water jet cutting of rock mass. On Fig. 1 the schematic of the method is presented. The borehole mining tool 1 is lowered into the borehole 2 and high pressure water 3 is pumped down. At the bottom part of the tool, one portion of that water comes out through the hydromonitor nozzle 4 in a shape of water jet 5 and cuts the material 6 creating slurry 7. The other portion of high pressure water then comes to the hydroelevator 8 (jet pump, eductor) which produces a vacuum. When the slurry reaches this vacuum zone, the eductor sucks the slurry and pumps it up to the surface, where rock parts are separated from water in a tank 9 or a pond and clarified water is pumped down again closing the re-circulating BHM water supply system. The borehole mining tool is suspended on a drill rig tower 10 which allows the tool to rotate and move vertically along the borehole axis. While extracting rock mass, underground caverns (stopes) 11 are created. If necessary, compressed air 12 can be injected to the raising slurry flow to create an airlift effect. Also, a secondary agent 13 (such as oil, foam, etc.) can be added to the stope through the gap between the tool and the casing. As seen from the illustration, BHM is the remote mining method of extracting of mineral resources through boreholes by high pressure water jets.

Jan 1, 2001

By Aram Grigoryan

This paper addresses the challenges of designing the underpinning of major sub-way station with 4 operating tracks. No. 7 subway extension crosses under the existing 42nd street subway station on the 8th Avenue line. Understanding the history of the original construction, of the current structures and their condition were instrumental in developing a feasible underpinning design that is integrated with the design of the new tunnels. The existing 8th Avenue subway station has a lower abandoned level. Several alignments and corresponding underpinning schemes were studied. The design allows new tunnel construction under the station without interruption of station operations.

Market confidence is on the rise and industry leaders turning toward the vast and diverse region of Latin America are faced with abundant, yet daunting, opportunity. From the iron orebodies of Brazil to the renowned copper mines of northern Chile, drilling teams in Latin America are often faced with abrasive, broken ground. These types of ground conditions tear up coring bits rapidly, making it extremely difficult for even the most seasoned drilling teams to maintain effective productivity. The drilling challenges faced in this rich and opportune region are being met today by advanced coring technology, bringing with it the potential for increased productivity in Latin American mineral exploration.

Jan 3, 2010

By Douglas B. Silver

Super Cycle future The final topic is mining?s future. The most important questions are ?How much longer is the Super Cycle going to last? What should we expect to see going forward? How will the Super Cycle end?? Three possible scenarios follow. Scenario one: Super Cycle has peaked Kathy Casey-Kirschling is officially the first Baby Boomer. She was born Jan. 1st, 1946. If you google ?first baby boomer,? she?s the one that shows up. A Baby Boomer is anybody born between 1946 and 1964. In the United States, it represents about a quarter of the population ? approximately 76 million people. The Baby Boomer generation is going to change the economics of the world because there are so many in the generation. A review of spending patterns indicates that the largest amount of discretionary spending occurs between the ages of 49 and 52. Retired people tend to live on fixed incomes so they have less discretionary income. They also tend to downsize their house, which may contribute to the housing glut and the need for a lot less metal. Therefore, the upcoming retirement of the Baby Boomer generation could result in a massive shift in economic spending resulting in the peaking of the Super Cycle. Figure 1 is an index graph from the Toronto Stock Exchange (TSX). The index has recently peaked. A lot of people see that as a sign that bad things coming our way. A careful review of different commodity prices also suggest that the peak has occurred and it does not seem to matter which commodity prices are considered. Copper prices have seen a peak as have nickel prices. Nickel and molybdenum displayed the same trend with a peak in 2005 as did zinc. Uranium, which has single-handedly tried to behave like the dot com craze, has also peaked.

Jan 1, 2008

By Franklin J. Stermole

L. Alan Weakly, member SME, is a senior staff engineer, Exxon Co. Weakly chaired a Mining Engineering committee formed to solicit materials for six planned "personal skills" articles, to be used in ME this year. What follows are Weakly's introductory comments to the series. Upon graduation from college several years ago, I thought that I was sufficiently prepared to embark in my chosen profession. A short time later I realized that several years of on-the-job training was going to be required before I could use my technical training effectively. It never occurred to me that, professionally, I was seriously lacking in any other skills. My spelling could use a little upgrading, but this was not a serious deficiency. I have been very fortunate to have had two employers that recognized that their engineering professionals did lack other skills and made every effort to give them training to correct these deficiencies. The skills I am referring to are those in administration and interpersonal relationships. Most mining engineers and geologists receive very little, if any, college training in these areas. In addition, many companies do not provide this training and many mining engineers and geologists are unaware of their deficiencies. It is for this reason the subject of personal skills development is being introduced in Mining Engineering. The mining engineer or geologist can pursue one of two basic career directions, managerial or technical. In today's technically sophisticated society and highly competitive business climate, both orientations require administrative and interpersonal skills. Most of us are technically qualified and we continue to upgrade our technical skills. But many studies indicate that we, as a group, are significantly weaker in administrative and interpersonal skills than other professional groups. In addition, these studies indicate that engineers, in general, take longer to reach managerial levels and fewer do so. This series in Mining Engineering, then, should help readers strengthen and broaden their professional capabilities. In all industries, including mining and petroleum, economic analysis of potential investment projects is done to select the projects that will give maximum future value from the investment of available capital. Rather than looking directly at the future values to be generated by investing capital in alternate ways for economic decisions, evaluators usually use either rate of return, present value, annual value, a profit to investment ratio, or various break even analysis results to reach economic analysis decisions in evaluating alternative investments. Alternative economic evaluation techniques are used in industry to properly analyze the economic potential of various investment projects. "Discounted Cash Flow" analysis is the phrase commonly used to describe these techniques. Whether you want to analyze projects in mineral, petroleum, real estate, refining, pipe-line transportation, or any other industry, proper application of discounted cash flow analysis techniques enables you to fairly compare the economic potential of alternative projects as well or better than you can using any other project evaluation approaches. It should be pointed out that investment analysis generally involves more than economic analysis. Financial and intangible considerations sometimes are as important or more important to investment decision-making than economic considerations. Economic analysis refers to evaluation of the profit generating potential of projects, that is selecting which alternative projects will generate maximum future value possible from available investment capital. Financial analysis, on the other hand, relates to analysis of where money is going to come from to finance various projects. Regardless of the economic potential of a project, if financial analysis indicates that we cannot finance the project, it likely will be shelved for financial reasons even though it may be economically satisfactory. Many evaluators use the terms "economic analysis" and "financial analysis" interchangeably, but this author considers that to be undesirable. Intangible analysis relates to project factors that are difficult to quantify in

Jan 2, 1984

By P. L. M. Wong, N. W. Johnson

Surface analysis by X-Ray Photoelectron Spectroscopy (XPS) of samples taken from the galena flotation section of the Hilton Concentrator of Mount Isa Mines Limited are presented. Flotation rate and pulp chemical data taken during the sampling period are also presented and discussed. Surface analysis suggested that, under normal operating conditions, an overlayer of precipitated calcium sulfate existed at the surface of the sulfide minerals. In particular, there was a decrease in the surface concentration of calcium sulfate for the concentrate samples relative to that occurring on the tailing samples. This suggests that the flotation process was selective against minerals which have calcium sulfate predominating at the surface. Heterocoagulation of hydrophilic calcium sulfate on to the galena surface considerably reduced galena flotation rate. Methods to control calcium sulfate precipitation, which include sodium carbonate treatment of the pulp, are also discussed. Sur- face analysis results of samples taken from the Hilton Concentrator during sodium carbonate addition to the grinding circuit are also presented. This shows clear evidence for the removal of calcium sulfate from the mineral surfaces without concomitant surface precipitation of calcium carbonate. Reasons for the apparent dispersion of precipitated calcium carbonate are discussed. Galena flotation rate was increased by the addition of sodium carbonate apparently due to the removal of interfering calcium sulfate.

Jan 1, 1995

By R. Unger, L. Mallett

The use of virtual reality (VR) technologies to train miners is an evolving area in research and development. In July 2006, representatives of 14 international organizations met to discuss current VR-related efforts and explore ways to employ VR in the future. This paper gives an overview of the various approaches presented at the meeting and discusses directions for future implementation. An example of a training package that teaches mine map-reading skills is presented. The meeting was the first step to building collaborations for furthering VR applications for mining. Planning has begun for a 2008 meeting open to broader participation.

Jan 1, 2007

By K. A. Lapakko, D. A. Antonson

Fourteen samples of pyrite-bearing Archean greenstone rock (d < 6.35 mm, 0.04% < St < 1.22%) were characterized (particle size, chemistry, mineralogy) and subjected to laboratory dissolution testing. The only sulfide and carbonate minerals identified were pyrite and siderite, respectively. Quartz, chlorite and sericite typically comprised 90 to 98 percent of the mineral content. For the first 60 weeks, seven samples with sulfur contents less than or equal to 0.16% produced drainage pH values exceeding 6.0. Over this period, six of the seven samples with sulfur contents greater than or equal to 0.20% produced drainage pH below 6.0, with minimum values ranging from 3.2 to 4.7. The seventh sample (0.72% S) had a siderite content of 18%. Small amounts of magnesium and, to a lesser degree, calcium carbonates present in the siderite apparently dissolved to neutralize acid and maintain drainage pH above 6.0. Sulfate release rates generally increased as sulfur content increased, and the rates of pyrite oxidation estimated for individual samples were roughly half to five times that reported in the literature for the abiotic oxidation of pyrite by oxygen. Observed neutralization potentials ranged from 0.2 to 2.0 g CaCO3/g rock.

Jan 1, 2002

The Pogo Mine, near Delta Junction, Alaska is a new 2500 STPD gold operation. The control system of the mine and milling operations are a hybrid of DCS (Distributed Control System) control and PLC (Programming Logic Controller) control. A DeltaV DCS system serves as the main control and operation platform while the PLCs operate a multitude of vendor specific packages. The communication backbone of the DCS system is a hybrid of star and ring fiber optic topology, which provides reliability and flexibility. The communication between the DCS and PLCs is typically facilitated by serial communication. This communication insures the integrity of the whole control system.

Jan 1, 2008

By L. You

Theoretical and analytical analyses of three mitigative measures- plane fitting method, trenching, and tension cable led to the development of a total protection plan to eliminate or reduce damages to the residential structures subjected to surface movements caused by underground longwall mining. The protection plan was applied to twelve residential houses and two external garages. The success rate is overwhelming. This paper describes the methods employed for protection and results of those case studies.

Jan 1, 1986

By Klaus Rieker

The main train station of Leipzig in Germany is currently being upgraded from a head station to a partially thru station. In order to achieve this, significant ground improvements are necessary. Soil freezing for example is used to create the excavation box retaining walls. The freezing works will be carried out from two tunnels with an inner diameter of 2.4 m (~ 8ft). The tunnels were constructed by the pipe jacking method. The cutter head of the machine was equipped with discs and scrapers. Driving and excavation was carried out using a bentonite supported face. Due to the small arrival shafts, the machine had to be lifted out in components. The essential limitation of settlements during the drives was achieved even better than expected.

Jan 1, 2008

By M. Maier

Geographic Information Systems (GIS) has evolved into a powerful tool for analyzing spatial and attribute data in many industries including mining. Modern field data collection techniques add another dimension to the use of data in the field and enhance the utilization of GIS for mining applications. This discussion will review how field data is collected and how office data and maps can be taken into the field to be analyzed and verified using pen-based computers and differentially corrected GPS.

Jan 1, 2001

By D. P. Richards

Tunneling in carbonate sedimentary rocks such as lime stones and dolomites can be difficult when solution channels or voids are anticipated. Addressing the risk aspects associated with these formations can be done effectively through the Geotechnical Baseline Report (GBR) by properly characterizing the ground and ensuring that the Owner?s and the Contractor?s interests are represented and protected. This paper presents a review of tunneling difficulties in these rocks and includes a review of site investigations, geologic characterization, and presentation in the GBR. Key construction issues are also discussed, including appropriate excavation technology, mechanisms of face support and groundwater control, and quantifying grout takes.

By F. M. Jenkins

Improvements in miners? safety and health, as reflected by injury and illness statistics, have reached a plateau and even been reversed. Research into miners&apos; OSH is a necessary adjunct to regulatory enforcement. Under the National Occupational Research Agenda (NORA) mining experts have come together to draft a national agenda for this research. The Mining Sector Council, one of ten NORA Sector Councils, has produced a draft national research agenda to guide all mining research entities: academia, government, and industry. The agenda has seven major objectives, each of which has a sequence of sub-objectives: Reduce the likelihood of disasters in mines; Improve mine disaster response; Improve the health of miners; Improve atmospheric control (ventilation) in mines; Improve health and safety through behavioral research; Improve mine design, systems operations, and management performance to enhance mine health and safety; Apply ergonomics, human factor engineering, to increase health and safety. Long-term maintenance of the Mining Research Agenda requires input from the public, both here and abroad, monitoring of the impact of research results using OSH data, and partners who will translate the research to practice.

Jan 1, 2012

By Paul C. Schmall

The link between artificial ground freezing and the mining industry stretches back more than 140 years, and across an ocean. Patented by the German scientist F.H. Poetsch in 1863, the technique is reported to have first been used circa 1862 in the coal mining valleys of South Wales. In the United States, the first ground freezing application, to a depth of 30 m (100 ft), occurred in 1888 for the Chapin Mine Co. in Iron Mountain, MO. In England in 1901, the Poetsch method was used for the first time to successfully sink two shafts through 24 to 27 m (80 to 90 ft) of wet sand and boulder clay at the Washington Glebe Colliery, near Sunderland. British mining engineer T.H. Cockin, in his 1905 Class-Book of Practical Coal-Mining, noted that, ?This method of sinking through thick beds of very wet quicksand has met with great success; it is one of the recognized methods of sinking on the Continent.? Mine shaft freezing soon became relatively common in Europe where the project could bear the cost of a major refrigeration plant construction. However, it was not until 1952 that the second North American ground freezing project was completed to facilitate the sinking of a 4.5-m- (15-ft-) diameter, 233-m- (765-ft-) deep shaft at a Potash Company of America (PCA) mine in Carlsbad, NM. Nowadays, ground freezing is used worldwide for both mining and civil applications. In small mine shafts of 3 to 6 m (10 to 20 ft) in diameter, excavations have been carried out to depths of more than 820 m (2,700 ft) within the protection of unbraced or unlined frozen walls. In fact, for deep mines, no better method has yet been established for sinking production shafts through deep, water-bearing ground. Major deposits of coal, potash and salt would still be inaccessible if not for artificial ground freezing. There are several advantages of ground freezing unique to the construction of shafts. Proper instrumentation can provide complete assurance of the integrity of the freeze to full depth prior to excavation. The frozen wall allows construction to be scheduled without evaluating the in-shaft time necessary to probe ahead, place additional sup-ports or deal with ground water. The freeze can be implemented perfectly through the soil/rock interface, which is often the most difficult geology in which to create a ground water cutoff by other methods. At increasing depths, any discontinuity

Jan 1, 2007