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By Edward Marszalek, Boleslaw Firganek

The paper deals with a computer method and algorithm of optimization of the rescue routes for the endangered staff in the case of fire in a given place of the mine. The adapted method is based on the objective function and realizes the algorithm of the shorest path with weighers assigned to it. The objective function is so defined that it reflects possibly all the hazards and difficulties arising during a fire in the mine. The algorithm is enhanced by an empirical formula for calculation of the smoke zone as result of a mine fire. The presented results of computations of optimal routes for several simple examples using the canonical scheme of the mine network and simulated fires are satisfying and prove the method, the algorithm and the coded program to be correct. The program will be a part of the software library of the mine ventilation engineer. The data for the program will be updated on-line from the fire detection systems.

Jan 1, 1989

By D. P. Bryan

An aggregate resource study was done for southern Washoe County, Nevada, which contains the Reno-Sparks metropolitan area and a population of about 300,000. The study included an inventory of existing operations, projection of future demand, identification of potential aggregate resources based on geology, and determination of economic potential of these resources. Economic potential was determined by the integration of GIS layers that included aggregate potential, distance from market, distance from major and minor transportation arteries, and elevation. The investigation resulted in a determination that resources of high quality aggregate sufficient for future consumption are present in southern Washoe county; the limiting factor for future utilization is accessibility.

Jan 1, 1996

Over the years, numerous studies have been conducted to characterize the floatability of coal pyrite. Unfortunately, many of the results obtained using isolated samples of coal pyrite are not directly applicable to actual coal flotation systems where liberation and entrainment may be the major factors affecting pyrite rejection. In this paper, the association of pyrite with other coal constituents is investigated, and the data are presented for feed and product streams obtained from release analysis tests. Release analysis is used to minimize the effects of entrainment. Particle distributions for each stream are presented as functions of size and composition in order to discern the behavior of free and composite particles.

Jan 1, 1992

By W. C. Brice

A cooperative study was undertaken by representatives of the environmental community, the mining industry, and state government to identify and resolve environmental issues associated with base and precious metal mining in a neutral atmosphere before a commercial mining development is announced. The study included testing Minnesota's as-yet-untried non-ferrous mining regulatory program using three hypothetical mining developments sited in environ-mentally sensitive areas where future mining could occur. Results include identification of critical paths for regulatory decision making, identification of particularly sensitive environ-mental issues that will need continued deliberation before resolution, and characterization of data necessary for environmental review and permitting decisions.

Jan 1, 1990

By R. S. Kramer

A bulk compositional chemical analysis often provides incomplete information to help the mineral processor when faced with the problem of removing troublesome contaminants in low concentrations. Michigan Tech has developed a unique approach for addressing this problem. A combination of Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and image analysis was successfully used to characterize the species responsible for phosphorus contamination of less than . 05 weight percent in iron ore. An automated routine acquired the chemical signature of each particle on a back scattered electron image. The few particles containing phosphorus were identified from the hundreds of particles examined, and the phosphate phases present were easily characterized.

Jan 1, 1993

By A. Sadik

The proliferations of media sources and non-profits organizations in Ghana have put the negative impacts of mining on the ?spot?; this has resulted in public outcry about mining. Although, the gold mining industry has responded by implementing several voluntary measures to ensure sustainable mineral development, these critics label such measures as ?green wash?. In this study, a content analysis of newspaper articles of the Ghana Web Database was carried out after the collection of a total of approximately 900 newspaper articles from it. The data were statistically analyzed to chronologically examine the main media view points and the changing perception of mining issues as reported by private and public media. The results showed government, mining industry (Gold), illegal miners and non-profit & community groups as the main media view points and total of twenty-eight related gold mining sustainability issues. The findings of this study could be used by the gold mining companies to improve upon the communications of their unknown sustainable mineral development measures and to design effective communications and education programs for the public.

Jan 1, 2009

By Dirk van Zyl, Lysa Morishita

Mining companies are increasingly approaching the social aspect of sustainable development within the rural communities that neighbour their projects and operations. Rural community engagement requires significant effort and resources, and it can be extremely challenging for mining companies to earn and sustain social capital. The focus on rural, proximal community engagement is not to be understated and has led to significant benefits in many communities. However, opposition to mining projects is often exhibited in urban environments, where there may be potential for mining companies to gain social capital with relative ease. Cities tend to have existing frameworks for community engagement and public activation, such as annual parades and festivals, that make it easy for a mining company to provide financial support or value-in-kind. Local organizations and community groups can achieve the same amount of engagement in an urban environment with significantly less effort required from the mining company. By applying simple marketing principles to community engagement strategies, corporations can increase awareness for their business and encourage city residents to think critically about the origin of resources. Unlike many corporations, mining companies are not marketing or selling products to individual consumers. From this arises the opportunity for a company to use marketing to promote other positive initiatives and, as such, connect their brand with positive messaging thus earning social capital. This may lead to a wide variety of secondary impacts including benefits to recruitment efforts, increased political support, and positive media coverage. This paper explores these matters with special reference to Vancouver, BC, Canada and the mining companies Teck and Goldcorp.

Jan 1, 2017

By Arol, A. I., I. Iwasaki

The presence of calcium ion in iron ore pulps causes heterocoagulation of rnontmorillonite on hematite leading to indiscriminate dispersion. Two methods were investigated to control the adverse effect of montmorillonite: a chemical method using such complexing agents as EDTA and sodium tripoly- phosphate, and a mechanical method involving ultra- sonic treatment. Their roles in controlling the adverse effect were investigated by zeta potential measurements, starch adsorption tests, and flocculation and selective flocculation tests.

Jan 1, 1988

By H. D. R. Browner, D. A. Marsh

The need for a product dewatering step between the milling/classification and leach/carbon stages of gold plants has traditionally been performed by thickeners. Whether these be the 'conventional' or 'high-rate' types both require considerable initial capital outlay even without provision for standby facilities. In addition, their sensitivity (both mechanically and metallurgically) to changing feed conditions often results in these being considered 'high-risk' items of equipment, requiring a high degree of attention from operating personnel.

Jan 1, 1992

By H. Sevim

In long-term open pit production planning, a series of nested and maximum-value pits is usually generated first. These pits are then considered as possible pushbacks over a number of planning periods. To determine the best pushback in each planning period, the pits are evaluated for their technical and economical feasibilities under certain production constraints. Parameterization is a commonly used technique to generate a series of pits. In almost all cases, however, some of the consecutive pits generated by this technique are too far apart from each other. This is called the "gap" problem. It may make the entire pit series useless for production planning purposes. A new pit gener¬ating algorithm has been developed to overcome the gap problem. Through this algorithm, a series of nested maxi¬mum-value pits can be generated with a controllable size increment. The logic of the algorithm is illustrated through a small hypothetical case. Its capability of generating maximum-value pits that are as optimal as those generated by parameterization and its advantages over parameteriza¬tion are presented through an actual gold deposit case.

Jan 1, 1996

By P. K. Ackerman, F. F. Aplan, G. H. Harris, R. R. Klimpel

Fourteen reagents that are potentially capable of chelating with a metal ion on the surface of the major copper sulfide minerals and pyrite were evaluated for their effectiveness in floating these sulfides. The reagents studied fall into the classes of mercaptobenzole mutations, thiouronium, thionocarbamates, thiourea, imidazole mutations, oximes, hydroxyquinoline and xanthogen formate. The best overall copper sulfide collector was an imidazoline (1-Hydoxyethyl - 2-Heptadecenyl), but it also proved to be an excellent collector for pyrite. Its potency as a pyrite collector can be reduced by structural alteration, but at some loss in its collecting power for the copper sulfides. The effectiveness of many of these potential collectors can be changed by minor alterations to the collector molecule and, to a lesser extent, by pH adjustment. The general order of mineral floatability with these reagents is chalcopyrite = chalcocite > covellite =bornite >> pyrite. The flotation of malachite is generally similar to that of the copper sulfides, indicating the special effectiveness of copper in the crystal lattice for collector attachment.

Jan 1, 2000

By D. V. Professor Keller

The production of premium coal-based fuels (<3% ash) and ultra clean coals (<1% ash) using the process of selective agglomeration requires proper selection of raw coal, rough preparation procedures, milling equipment, product coal size distribution, water purity, agglomerants, agglomeration equipment and operational procedures. Each of the variables can contribute a small fraction to the impurity load in the product coal or limit the ability of the process to separate mineral matter-free coal. Each of the variables and their importance will be examined from data produced at the bench by batch and continuous agglomeratons as well as the results from pilot plant and tonnage production units. The results are discussed which have indicated that some standard commercial coals can be produced with ash contents as low as 0.2 % ash (batch/bench) and several tonnage lots of 0.6% ash in as 200 lb/hr pilot plant. In most cases iron pyrite released from the coal matrix and with proper pH control is rejected from the product coal agglomerates.

Jan 1, 1995

By W. S. Urbanski, A. L. Devernoe, M. S. Walker

Theory and practice are described for a new processing method capable of precise mineral separations based primarily on differences in particle specific gravities at specific gravity split points from 1.5 to 21.0 and beyond. Separations are analogous to those achieved using rotating heavy media, except that the effective specific gravity of the fluid is created magnetically using a relatively dilute, low-viscosity, water-based magnetic fluid. Results reported here for a large, laboratory flow-through separator include: 1) 99% grade with 97% recovery in single pass separation of a suite of heavy minerals from quartz at I0 kg/h, 14 tph/rm2 of duct cross section, 2) 90% grade and recovery in single-pass separation of mixtures of sand-size, non-magnetic rutile (4.23 specific gravity) and zircon (4.72 specific gravity) at throughputs of 35 kg/h, 47 tph/rm2 of duct cross section, 3) partition curves having Ep90-10 transition widths 5% or less of mineral specific gravities, and 4) essential confirmation of the theory.

Jan 1, 1991

By J. E. Spencer

Mesozoic and Tertiary mineral deposits in west-central Arizona are commonly associated with Mesozoic thrust faults and Tertiary detachment faults, respectively. Quartz-kyanite rocks and pyritic quartz-sericite schists with local anomalous gold are the product of probable Jurassic argillic alteration of Jurassic volcanic, sedimentary, and plutonic rocks followed by Cretaceous thrust burial and associated metamorphism. Slivers and sheets of Paleozoic carbonates along Mesozoic thrust faults were locally sites of syn-and post-thrust mineralization. Widespread brecciation along Tertiary detachment faults resulted in increased permeability along fault zones. Elevated thermal gradients also resulted from detachment faulting and apparently caused convective aqueous-fluid circulation along detachment faults and associated Fe+Cu±Au mineralization.

Jan 1, 1988

By Eberhard Werner

Existing reports on the effects of mine subsidence on water wells and springs appear to be inconsistent. Some report quick and complete recoveries to pre-mining conditions while others indicate long-term or permanent effects. It is clear that topographic and geological factors as well as precise position with regard to the mine are important in determining probable effects of subsidence on aquifers. Ridgetop aquifers which are well above regional base-level are much more susceptible to disturbance by mining activities than those located topographically lower. Effects seen are attributed largely to increased permeability, both horizontal and vertical. of the aquifer rocks. The deeper aquifers usually show short term losses or water-table declines. but the effects on the ridge-top aquifers persist for longer periods or may be permanent. Subsidence enhances permeability. so that infiltrating water moves much faster to lower levels. causing pond and stream losses and declining levels in wells as well as declining flows of springs of the higher aquifers, while increasing levels and flows of the lower aquifers. Additional effects are shifts of spring locations caused by minor tilts due to differential subsidence and redirection of shallow flows by changes of horizontal fracture permeability. These effects are seen as mining of a panel progresses beneath the site. and are often repeated when adjacent panel mining fronts pass the site. Analysis of water well level and spring flow records indicates that the effects are greatest at the edges of longwall panels in the tensional regime. These effects are amplified for locations close to topographically steep terrain and in close proximity to fracture traces mapped from medium-to small-scale aerial images.

Jan 1, 1986

By William Hodder, Ehsan Alavi, Muhib Hussain

Disc Cutter Wear is influenced by several geological and technical factors and excessive wear can have a major impact on the excavation efficiency of Tunnel Boring Machines (TBM). Disc cutter replacement events cause a disruption to the construction schedule and costs, and should be minimized throughout the project to the extent possible. A well-executed cutterhead inspection and maintenance plan can help mitigate abrupt cutterhead interventions and reduce its effect on project schedule and cost. This paper examines cutterhead inspection and disc cutter replacement events as well as subsequent wear data recorded in the first 7km of the 10.3 km long, 6.3 m diameter Coxwell Sanitary Bypass Tunnel (CBT) project in Toronto, Ontario. The CBT alignment is mainly through Georgian Bay Formation shale.

Dec 1, 2022

By Stephen Navin, Pablo Ferradas, Carlos Silvestri, Alexander Markov, Jon Kaneshiro

In the high Andes of Peru, two tunnels are being constructed totaling nine kilometers in length at an elevation of over 4,500 meters. The tunnels convey freezing and crystal-clear waters from rainfalls, streams, and lakes for the consumption of Lima. The drill and blast 3-meter wide by 4-meter high tunnels are being driven from both ends through folded and sheared volcanic tuff, andesite, agglomerate,and limestone, where groundwater inflow is high. This paper describes the design geological and groundwater inflow investigations and construction.

Jan 1, 1999

By W. Zitz

Incorporation of heat exchangers into drilled shaft foundations is a novel approach to both improve the energy efficiency of building heat pump systems and provide necessary structural support using the same construction materials. In an effort to quantify the structural and heat exchange performance of deep foundations used as ground-source heat pumps, two instrumented test foundations were constructed as part of a new construction project in Denver, CO. They will be integrated into the conventional ground-source heat pump system for the building. This paper focuses on the lessons learned from the construction process for these energy foundations.

Jan 1, 2011

By Douglas J. Uhren, Gary W. Gilbert

This paper describes the risk elements associated with difficult glacial geology, including boulders, heavy groundwater inflow, and potential running soils all coupled with a potentially corrosive service environment. The matrix workshop for the 168-inchfinished diameter sanitary sewer interceptor tunnel in Columbus, Ohio is assembled with the Design Team and the Owner’s design, operations, and fiscal staff. Corrosion protection alternatives are compared against cost and non-cost parameters with relative risk and weighting factors assigned. The Owner working in cooperation with the Design Team uses the matrix workshop to se

Jan 1, 2001

By Paul Eimon

In the world of minerals exploration, computer-oriented data storage and retrieval methods are being talked about, studied and researched. The goal is to facilitate the recording, collating, indexing, recovery, and analysis of mineral deposit-prospect data. A survey has been made of the various report forms, suggested outlines, and computer coding forms that are currently used in mineral exploration to index and/or describe mineral deposits and prospects. These forms have a number of common characteristics: location, commodities, type of deposit, host rock, etc. Such basic mineral deposit-prospect "data units" are part of most exploration programs. "Data units" may be comprehensive bound published descriptions of mines or mining districts or 3x5 file cards or elaborate computer coding forms being developed in Canada. Initial attempts to develop computer-oriented information systems have run into the same roadblock: the lack of a body of organized, processible data describing the basic qualities of mineral deposits and prospects. To solve this problem, international committees are considering coding forms, world-wide semantics, and rules or standards for data collection and description. It appears that mistrust and lack of understanding of the computer; fear of loss of proprietary information; and disagreements over terminology are distorting the picture of what has to be done if the mining industry is to grow into more meaningful information systems for mineral exploration.

Jan 1, 1969