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Like the Summer Olympics and U.S. presidental elections, MINExpo comes along once every four years. More than 35,000 people attended the last MINExpo and there is talk that there will be more this time. Just about every company that has anything to do with mining, 1,822 to be exact, will exhibit their wares at the show, but it is the ones rolling in the massive equipment that make MINExpo the show that it is. The following is a glimpse at some of the companies and equipment that you can expect to see at this year?s MINExpo.

Jan 1, 2012

By Peter Kreisman

This paper and four other papers on the MEQB Regional Copper-Nickel Study, presented today at the 1980 SME-AIME Fall Meeting are based on four years of extensive inter-disciplinary research and impact analysis supported largely by the Legislative Commission on Minnesota Resources. This study produced over 180 technical reports, the results of which are summarized in an Executive Summary available from the Minnesota State Planning Agency, St. Paul, Minnesota. Those wishing to examine the many scientific, engineering, environmental, social or economic issues addressed by the study are encouraged to obtain a copy of the executive summary. The executive summary includes a bibliography of all technical reports produced by the Regional Copper-Nickel Study and describes the five-volume, 26 chapter Regional Copper-Nickel Study Report.

Jan 1, 1980

By D. H. De Jager

Fluorapatite is an important constituent of the greater part of the basic and ultra-basic rock members of the Complex. The evidence for and role of primary magmatic processes in the development of concentric zones of dunite, pyroxenite, syenite and carbonatite and its consequent bearing on the distribution of apatite are discussed. The presence of at least two generations of each of the latter three rock types indicates the cyclical nature of magmatic activity. Pegmatitic-metasomatic phases corresponding to the major magmatic cycles resulted in emplacement of pegmatoidal assemblages. The abundance of apatite in the pegmatoid can be traced to the composition of its parent magma and its cooling history. Approximately 2.5 million tonnes of phosphate concentrate are produced annually from ores containing from 10 percent to 25 percent apatite.

Jan 1, 1978

By A. D. Davis

The former Homestake gold mine at Lead, South Dakota, has been selected by the National Science Foundation as the proposed host site for the Deep Underground Science and Engineering Laboratory. The deep laboratory and associated research campus will be developed at approximately the 7700-ft level. Plans also include the development of the Sanford Underground Science and Engineering Laboratory at the 4850-ft level. After the mine?s pumps were shut off in June, 2003, water levels rose to approximately the 4650-ft level by early 2008. Pumps in the 8150-ft deep mine were turned on again for dewatering in April, 2008. Instrumentation is being installed in the mine to measure water-level declines during pumping, for later analysis of permeability and related hydraulic properties of the formation. Pressure-sensitive transducers and data loggers will provide real-time information on water levels that will be available to interested parties. Quality of the water also will be monitored as it is pumped from the mine. I

Jan 1, 2009

By K. R. Griffin

Atmospheric conditions underground are constantly changing and from a safety perspective, it is critical to identify when conditions are trending abnormally. Atmospheric monitoring in underground coal mines allows mine operators to analyze atmospheric conditions underground in real-time. Real-time monitoring can then be used to identify whether atmospheric conditions underground have become problematic. The implementation of a risk assessment and management process allows operators to then use a risk-informed decision making to identify comprehensive site specific ventilation parameters. Establishing risk-informed ventilation parameters and tracking conditions relative to these parameters, management can modify ventilation plans as mine conditions develop to manage evolving risks. Ventilation risk assessment and management allows developing atmospheric monitoring technologies to be fully utilized in order to increase safety standards in the United States. This paper reviews general risk assessment approaches, state of the art ventilation based risk assessment, and the risk assessment and management application within the United States regulatory framework.

Feb 27, 2013

By Omid Asghari, Seyed Reza Ghavami-Riabi, Sajjad Talesh Hosseini

Separation of geochemical anomalies from the background using various methods for identifying areas of higher mineral potential is a critical first step in Greenfield and Brownfield programs. There are several methods for differentiating anomalous regions from the background. The U-spatial statistics is an effective technique that provides the opportunity of reaching this goal by considering the geochemical sample locations in the separation of geochemical anomalies. In this study, a developed form of the U-spatial statistics method is introduced, which not only considers the existence of anisotropic spatial variations in input data but also reduces the computational (CPU) time. While the previous method is based on the isotropic assumption in the study area and a set of search windows at different times, here, the geochemical anomaly is determined by pasting only one ellipsoid window, effectively combining the flexibility of the U-spatial statistics method with the advantages of geostatistical approaches. This paper compares various approaches (the previous and developed version of the U-spatial statistics method, concentrationarea (C–A) fractal model, and probability diagram modeling) for the separation of anomalous areas in the presence of heterogeneous spatial variations. This is done with an application to a Baghqloom porphyry copper deposit located in southeastern Iran. The high potential areas identified via different approaches show an anomalous region in central parts of the Baghqloom area, which partially coincides with an intense potassic alteration area. Compared to other methods, our algorithm separated the high potential areas at a greater spatial resolution.

May 3, 2021

By Toby Mayo, Tassos Grammatikopoulos, Massoud Aghamirian, MARK FEDIKOW

The Zoro pegmatite project in east-central Manitoba occurs 20 km east of the historic mining town of Snow Lake. A composite sample (Master Comp) was prepared fromthree pegmatite zones within Zoro Dyke “D1” including the North, Central, and South Zones for mineralogical analysis and heavy liquid separation (HLS). The mineralogical examination was conducted on a subsample crushed to ca. P80 of 600 μm to determine the overall mineral assemblage, liberation of spodumene, and assess the potential recovery of spodumene by flotation. XRD and QEMSCAN results show that the sample consists of spodumene (10.5%), quartz (29.3%), plagioclase (29.0%), K-feldspars (21.3%), micas (5.1%), tourmaline (2.9%), and Fe-Mn-phosphates (0.1%). Spodumene is well liberated (88%), but also forms complex particles (7%), and middlings with quartz (4%). Liberation of spodumene increases from 81 in the + 600 μm to 95%in the − 106 μm size fraction. Liberation of quartz, feldspars, and micas account for 89%, 94%, and 83%, respectively. Electron probe micro-analyses and LA-ICP-MS showed that the average Li concentration is 3.7% in spodumene, 2196 ppm in micas, 1001 ppm in tourmaline, and 115 ppm in K-feldspars. Thus, spodumene accounts for 96%, micas 2%, Fe-Mn phosphates 1%, and both K-feldspars and tourmaline for < 1% of the total Li in the sample. The mineralogical data indicate the potential to recover spodumene by flotation with minimal Li losses due to other than spodumene carriers. Heavy liquid separation was conducted on the Master Comp which was crushed to − 6.4 mm, while the − 600 μmfractionwas removed fromthis test. The coarse fraction − 6.4mm/+ 600 μmwas subjected to HLS tests with eight heavy liquid-specific gravity cut-points (2.65 to 3.10 g/cm3). HLS indicates that it is possible to produce a high-grade lithium concentrate (close to 6% Li2O) after the rejection of iron silicates with magnetic separation.

Sep 16, 2020

By David J. Hatem

Public-private partnerships (PPP) are gaining in popularity at the federal, state and local levels as the public sector seeks private capital to finance infrastructure and other projects that traditionally have been funded with public funds. In general, a PPP involves a development agreement between a public owner and a private sector concessionaire. Under the development agreement, the concessionaire is responsible for financing, designing, constructing and typically operating and maintaining the completed project for a concession period (often multi-decades in duration). The concessionaire typically enters into an agreement ? the design-build agreement ? with a design-builder to design and construct the project. The concessionaire may secure financing from banks, investors or from a combination of these and other sources (collectively the financier). While the PPP experience in the United States has been modest to date, an increasing number of projects involving tunneling or other significant subsurface work are already being delivered in the PPP mode. Public owners have significant options to address risk allocation for subsurface conditions on PPP projects. The same sound and fundamental principles of fairness in risk allocation that apply in other major subsurface projects should be applied and adopted in the PPP context

Mar 1, 2014

By A. Davis, C. Webb, J. Sorensen

The abandoned Belle Eldridge Mine near Deadwood, South Dakota, is on land controlled by the U.S. Bureau of Land Management (BLM). The mine produced lead and zinc during the first half of the 1900s. Because of acidic drainage and elevated levels of metals in tailings and waste rock, the site was evaluated in 1998 and 1999. After evaluation, the mine was remediated during 1999-2001 by the BLM. Since remediation, values of pH in water samples have been nearly neutral and specific conductance values have been much lower than before remediation. The Grizzly Gulch forest fire of July, 2002, consumed much of the Belle Eldridge site and resulted in greater than normal erosion and sediment flushing during the months following the wildfire. Had the site not been remediated and the tailings emplaced within a capped repository, generation of acidity and off-site migration of heavy metals within sediments could have been severe at downstream locations.

Jan 1, 2007

By J. G. Groppo

A series of performance studies have been conducted using counter-current column flotation to recover a marketable clean coal product from existing preparation plant fine waste streams. The test work was conducted at several preparation plant sites in Kentucky and Virginia and utilized a 0.15m (6 in.) I.D. column that was 5.79m (19 ft.) high. The refuse streams tested included both thickener feed and classifying cyclone overflow with a typical size distribution of 100 mesh X O. The percent solids of the column flotation feed varied from 1.5 to 15% while the ash content ranged from 30-60%. The concentrates produced contained 2-10% ash with BTU recoveries of nearly 90% using 0.12-1.25 kg/ton (0.25-2.5 lbs/ton) fuel oil and 0.12 kg/ton (0.25 lb/ton) MIBC. These results were consistent with or better than results obtained in preliminary laboratory scale column flotation evaluation. Test results from 7 different seams are discussed as well as scale-up relationships utilized to design a full scale installation presently in operation.

Jan 1, 1990

Obtaining financing for mining and exploration projects has been difficult for the last several years, particularly for junior companies. Today, though, the purse strings of investors appear to be loosening, leaving the industry with many questions about financing in the coming years. How have capital markets and exploration spending changed? Are there signs of improvement? Where has capital been raised in private, public markets, stock exchanges, private equity, etc.? What companies successfully raised capital in the last year? How are they spending it? How are traditional and alternative funding sources investing in mining? What are the issues mining companies need to know about when tapping alternative sources of capital? Those were some of the questions that were answered at the Current Trends in Mining Finance conference, sponsored by SME and the New York Section April 26-28. Held in New York City, the conference attracted 115 professionals who work on the finance and economic side of the mining industry. Three of the conference organizers talked with Mining Engineering about the conference and the state of financing in the industry today. Tim Alch (TA) is managing director with Behre Dolbear & Co. Alan Oshiki (AO) is executive vice president with the Abernathy MacGregor Group. Henry Weingarten (HW) is managing director with the Astrologers Fund Inc. Here is what they had to say.

By Cathleen J. Webb, Arden D. Davis

The Homestake Gold Mine at Lead, South Dakota, has been proposed as the host site for the Deep Underground Science and Engineering Laboratory. The laboratory will house neutrino experiments in mine workings at the 7400-foot depth, as well as research in geomicrobiology, rock mechanics, and ground-water flow. Initial plans for the laboratory were developed in 2000 after Homestake Mining Company announced the closing of the underground gold mine. Homestake’s owner, Barrick Gold Corporation, had agreed to donate the mine for a laboratory if it could be protected from environmental liability. That initial agreement was delayed, and Barrick turned off the mine’s pumps in 2003, allowing lower levels of workings to begin to flood with water. In early 2004, the Governor of South Dakota signed an agreement with Barrick that would indemnify the company and eventually transfer ownership of the mine to a state laboratory authority. South Dakota’s governor also announced plans to ask the state legislature for funds to help in the initial construction of the laboratory. A consortium of scientists from several states is currently preparing a detailed laboratory proposal for the National Science Foundation.

Jan 1, 2005

By C. C. Jobes, J. J. Sammarco, D. L. Anderson

Computer-aided control of a mining machine places its operator in a safe, remote location, thus reducing health and safety risks. Sensing systems that provide machine position (xy coordinates) and heading (yaw) are extremely useful in aiding remote positioning of mining machines. The US Bureau of Mines (Bureau) developed two sensing systems for position and heading information: a scanning laser system based on the Lasernet sensor and a mechanical position and heading system based on linear-position transducers. The Bureau is also investigating a system from Honeywell, the modular azimuth and positioning system (MAPS), that employs ring-laser gyroscopes (RLGs). This paper presents a brief background and status of these sensing systems as applied to a continuous mining machine (CM). Included are field test results off each system operating in a room-and-pillar research section at a cooperating West Virginia mine.

Jan 1, 1993

By R. E. Hamilton

Automation is a word whose meaning has been broadened by popular usage to include any labor saving device. We with restrict our usage to the replacement of human judgement by instrumental measurement and mathematical analysis in the control of industrial processes. Mineral concentration is an area which has resisted automation because of the great difficulty in developing measuring instruments which can exist in the rugged environment and can measure useful properties with acceptable accuracy. This is not the only factor limiting progress, but until recently it has been of over-whelming importance. The development of on-stream X-ray analysers, magnetic flowmeters and nuclear density meters for mineral slurries has eliminated this obvious barrier and is enabling us to locate and attack the less obvious problems which still limit our ability to automate concentrators. If we examine the history of automation in industries which are highly automated we find that it has usually gone through three distinct phases. The first phase has been regulation. This is the simplest form of control and involves manipulating some variable whose value is of no importance in order to maintain the value of some other variable which is important at a constant specified value in spite of disturbances which may occur in other variables which affect it. A simple example is the use of a control valve to maintain a constant flow of fluid in a line in spite of changes in pressure in the vessels at the ends of the line. The position of the valve stem is of no consequence, as long as it is within its operating range. Unfortunately we soon run out of variables which can be

Jan 1, 1971

By A. Iannacchione

Longwall mining began within the Pittsburgh coalbed of Pennsylvania (PA) in the early 1970?s. Originally, longwall mine layouts were designed to fit within existing room-and-pillar operations, where panels were limited to that of typical production panels, e.g. a few hundred feet wide by a few thousand feet long. In these early designs, the gate entries were comprised of chain pillars similar to those found along main entry systems or within pillar recovery sections. The modern longwall mine has little in common with their 1970?s predecessors. Today the entire mine layout is designed around the longwall mining method. The longwall panels have grown to well over one thousand feet in width with lengths now measured in miles. In addition, development pillar sizes and shapes are matched to specific performance requirements.

Feb 27, 2013

By James Corcoran, Richard McLane, Joseph DeMello, Eric Carlson, Hans van de Vrugt

The Los Angeles County Transportation Authority’s Purple Line Extension Phase 1 is a $3.12 billion (USD) design-build, underground heavy rail project, connecting an existing station at Wilshire Boulevard and Western Avenue and extending west 3.92 miles under Wilshire Boulevard and terminating approximately 550 feet west of Wilshire/La Cienega Station. The project alignment runs through the heart of the world famous La Brea Tar Pits and one of the world’s largest urban oil elds. This paper presents a case history of the planning, design, and construction efforts to achieve successful construction of the bored tunnels through Reach 3 of the alignment. Further, this paper outlines the proactive partnership between the owner, Los Angeles County Metro (Metro), the Design Builder, Skanska-Traylor-Shea oint enture (STS), and Southwest Geophysics who provided the geophysical services. Specically, the project included background review of historic site data (e.g., oil eld maps, building foundation plans, historic aerial photographs, etc.), geophysical demonstration testing to ascertain the capability of borehole magnetics to detect oil wells, directional drilling of thousands of feet of horizontal and vertical boreholes, collection of high resolution magnetic gradiometer data along vertically and horizontally cased boreholes as well as the collection of surface magnetometer data, discovery (“ground truthing”) of detected geophysical anomalies, and abatement of potential obstructions within the tunnel alignment.

Jun 23, 2024

By P. Clifford

FIPR-sponsored research will playa critical role in enhancing the competitiveness of the Florida phosphate industry as ore grade declines and environmental restrictions tighten. FIPR&apos;s program seeks to improve surface mining and pipeline transportation while reducing the energy cost for pumping phosphate matrix. The development of a reliable on-line analyzer and a modern process control strategy will result in improved processing efficiency. Significant improvement in overall efficiency will also be realized as the industry adopts column flotation technology. Economic acidulation of high-Insol rock will allow the industry to adopt simplified flotation flowsheets thereby reducing operating costs. Various applications of phosphogypsum would save the industry millions of dollars in constructing and closing gypsum stacks.

Jan 1, 1998

By R. A. Jankowski

The U.S. Bureau of Mines (USBM) conducted a series of laboratory tests to investigate the effectiveness of using a flooded-bed scrubber with exhaust ventilation in deep-cut faces of up to 12.2 m in length. An experimental test program to determine the impact on respirable dust levels resulting from changes in face airflow, curtain setback distance, operator positioning, and operating parameters of the external spray system on the miner was completed. Gravimetric sampling was conducted in the immediate return and at three sampling locations on the off-curtain side of the entry. Statistically significant differences in dust levels on the order of 0.5 to 1.2 mg/m3 were observed between specific sampling locations and changes in several test parameters. Dust sampling results indicated that a flooded-bed scrubber and exhaust ventilation can be a viable dust control system for extracting deep cuts up to 12.2 m in length. The impact on methane was not evaluated.

Feb 24, 1997

By J. P. McCluskey

The effects of air quality regulations passed in the last few years have been felt in a more pervasive way by the electric utility industry than by perhaps any other industry. I&apos;m referring especially to those regulations dealing with the control of air emissions from stationary sources, and those specifying the quality of fuel used. Particularly, I would like to describe some of the effects that these regulations have had on the Commonwealth Edison Company. To put the subject into perspective, a brief descrip¬tion of the company will be presented first. Then, a historical outline of some of the efforts at control of electric generating station emissions will be described. Following this will be an indication of the Company&apos;s response to early State and local regulations prompted by the growing pressure for stringent envi¬ronmental control. Finally, the Company&apos;s plans to achieve com¬pliance with the most recent, Federally approved, State of Illinois regulations will be summarized.

Jan 1, 1973

By S. S. M. Chan

The design of most underground support systems has largely been based upon empirical rules. This design method has proven to be satisfactory in most cases as witnessed by the number of successfully completed works. However, the adequacy of this approach to the developing technology of ground support systems associated with deep excavation has not been substantiated. In cases where the material has definite time-dependent behavior parameters, rules of past experience become extremely vague and conservative. The Spokane Mining Research Center is currently engaged in extensive research to develop rational design methods for underground structures which will account for the many interacting factors such as in-situ properties of the rock mass, excavation methods, proposed types of support system, construction sequence, and environmental variables. The information presented in this paper pertains to only a segment of the research program,

Jan 1, 1971