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By R. M. Bowen

To help solve problems associated with the optimization of complex coal preparation systems, a mathematical model has been assembled which can simplify calculations pertaining to the core of the plant, i.e. the coal cleaning section. It uses algebraic expressions, derived by fitting hyperbolic equations to Mayer curves, to calculate optimum settings for a specified array of coal cleaning units and feeds. This is done without search procedures, and with usually only minor iteration of a simple calculation to specify optima within 0.02% of specified product ash contents. The key to the calculation is a relationship derived via the analytical geometry of conic sections facilitating easy application of the incremental ash theory of separations. The model has been assembled in a generalised form to cater for N processes in parallel, each giving M separations to produce P final products. Examples are given involving assessment of some complex circuit options.

Jan 1, 1986

By E. C. Skinner

As the program says -we'll he talking about the expectations of the Management of an Industrial Mineral enterprise relative to the activities of geologists engaged in that enterprise. Industrial Minerals is such a large industry both in tons produced and in value of product -and of such diversity and complexity of participating enterprises, minerals and products that I doubt if anyone person can speak for the entire industry as to the expectations of management with respect to the geologist. I'm sure there are major differences in emphasis between segments of management as to the relative importance of the different aspects of the geologists' role in the scheme of things. However, we will try to generalize concerning what we consider to be important factors and to be more specific perhaps of some of the factors with which we have had direct assessable experience.

Jan 1, 1972

By Corby G. Anderson, Sheikh Abdul Rezan Sheikh Abdul Hamid, Sanjith Udayakumar, Ahmad Fauzi Mohd Noor, Teuku Andika Rama Putra

Chemical and mineralogical characterization of Malaysian monazite, a phosphate mineral, bearing rare earth elements separated from the tin tailings originated from Ipoh, Perak, Malaysia, was performed in this paper. The study aims to collect detailed information on the chemical composition, crystal phases, and microstructure of the mineral monazite concentrate that would aid to optimize the subsequent hydrometallurgical processes for high-efficient separation of thorium and other associated rare earth elements. A systematic characterization study of the concentrate was conducted using techniques such as optical microscopy (OM), scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FTIR). These techniques analyzed the morphological details on the surface, elemental analysis, and mineral association assessment and identified the surface functionalization groups. The bulk composition and the mineral phases in which the elements are present were studied by wavelength-dispersive X-ray fluorescence (WD-XRF) and X-ray diffraction (XRD) studies respectively. The XRF analysis confirmed the presence of Ce, La, Nd, Pr, and Y (rare earth oxides: REO’s ~ 60 wt.%) while thorium dioxide (ThO2) accounted for 7 wt.% of the total composition. Traces of Ca, K, Al, Fe, Ti, and Mn were also confirmed by SEM elemental mapping. The XRD results confirmed that the concentrate was primarily composed of monazite (Ce, La, Nd, Th (PO4)) along with minor impurity phases of quartz. Automated mineralogical analysis was used as a confirmatory tool to corroborate the preliminary evidences. Based on the particle size distribution analysis supported by SEM, the majority of monazite grains were found to be present in the size range of 170–210 μm. Strong bands of PO4 and SiO4 were observed in the IR spectra corresponding to the phospho-silicate matrix of the REE mineral.

By Scott G. Britton

This chapter discusses the necessary construction techniques for installing coal mine ventilation devices. Included in the discussion are the major air controlling devices called over- casts, regulators, stoppings, and doors. Under-casts, although a valid device, are used infrequently in coal mining and are not discussed here. Typically, coal mines require a great many ventilation devices to control the air movement. Post-I969 mines have had to design their air systems to comply with the Federal Coal Mine Health and Safety Act (CMHSA) as discussed in Chap. 1. Pre- 1969 mines have had to redesign major portions of their systems to comply with the basic components of the law such as separation of air courses, single unit split ventilation, and minimum air quantities. It is not uncommon, therefore, to find a large mine (2.0 Mt/a) requiring several hundred overcast installations (permanent, as well as repeat construction), plus doors and regulators placed among a thousand or more stoppings. When each of these devices is subject to leakage from installation and weathering defects, the importance of effective construction becomes evident. An historic rule of thumb for average mine ventilation says that about 70% of all the air pressure generated by the mine fan is lost between the portal and the working faces. Of course, this rule is subject to many factors, but the message is clear: there is a tremendous inefficiency in controlling leakage through common air devices. This chapter strives to present a standard approach and design alternatives which can go a long way in reducing this leakage, and hence, ventilation costs. Historically, mine ventilation has progressed from natural, or draft ventilation, to fire-induced ventilation (Fig. l), furnace-fired centrifugal fans and finally, to today's modem mine fans. Underground controlling devices have been in use in the coal mines since the late 1600s, but the CMHSA of 1969 was the real turning point for mine ventilation. Minimum quantities and velocities of fresh air were required for mining, forcing coal operators and engineers to reevaluate and improve their systems. As a consequence, the cost for ventilating air increased. Today, companies face a variety of choices among design alternatives, materials, labor, and costs of ventilating devices for their mines. The best approach for any individual company or mine is determined by (1) the needs of the mine, and (2) the local design parameters. In my discussions of ventilation construction I shall be fairly general in terms of device installation steps, where specifics are warranted for clarification, I will include this information.

Jan 1, 1983

By E. M. - Technical Papers Spokes

A.B. Rushton The work and resulting publications of the Committee on Underground Coal Mine Safety and The President's Commission on Coal were appropriate at the time of publication. The statistics cited in the publications appeared to be valid, and the actions proposed by the committee had merit. Although the actions proposed to achieve further improvements in safety may have been worthy of repeating, to associate statistics (Table 1) that are seven to eight years old with company names is bad. Statistics are readily available from the Mine Safety and Health Administration (MSHA) and are usually within three months of being up to date. A review of the most recent Coal Controlling Co. Report will reveal significant changes in the rankings. The more recent statistics should have been cited, or at least compared with those used in the article. Westmoreland Coal Co. is listed as having a 21.1 disabling injury rate for the period (1/78-12/80). The disabling injury rate for the Company for the year ending 1985 was 7.4 for the underground mines and 6.25 for the total facilities. Through March 1986, the dis- abling rate for the underground mines was 2.86. The management and employees of Westmoreland Coal Co. are committed to safety. The improvements achieved over the past five years attest to that commitment. We are justifiably proud of the achievement and dislike being misrepresented as in the April 1986 article Reply by E.M. Spokes I regret that the lapse of time since the original work gives a picture of safety practice that is no longer true today. That Westmoreland has reduced its disabling injury rate by 65% to 7.4 in 1985 is most commendable, and I congratulate you for this accomplishment. It is typical of the progress sought by the National Academy of Science and National Research Council when they funded the original study and published "Toward Safer Underground Coal Mines" in 1982. If a significant number of companies do as well as Westmoreland, the report will have served its purpose. Since the paper was primarily a condensation of the original report, it would not have been appropriate to seek access to later statistics. The purpose in seeking its publication at the time of presentation was to reach those who might have missed the original report. The fact that publication was delayed has not voided that purpose and may have reminded some who were aware of the original that its recommendations still apply to improvement of underground coal mine safety

Jan 1, 1987

By Roshan B. Bhappu

Based on the classical definition of optimization, flotation plants of today are far from being perfect, effective, or functional as possible. Though considerable efforts have been expanded in the optimization endeavor during the last decade, much more needs to be done in the future to optimize our flotation plants and operations. The major problem in designing an optimum flotation circuit is that the flotation process depends on the interaction of several physical and chemical parameters. In the past, there has been a tendency to only consider the effects of chemical factors such as flotation reagents: collectors, frothers, conditioning reagents, pH, etc. On the physical side, the emphasis has been limited to the liberation characteristics, grinding time, percent, solids in the pulp and flotation time. Its only recently that we are employing particle size analyses, on-stream analysis, oxidation reduction potential and the like, as operating controls. The design, operation and control of a mineral processing plant depends on costs incurred at all stages, from inception (testing for flowsheet development) through plant closure and beyond. To ensure that micro- and macro- engineering technology is transferred to operational levels, the academia, testing engineers, designers, operators, consultants and management must all get involved in the transformation process. Historically, in the 1950’s engineering empiricism was strengthened through micro-engineering based on fundamental and mechanism. Unique scientific apparatus such as zeta meter and infrasizer were used to test new hypotheses. With the advent of computers in the 60s and 70s, complex differential equations were solved to study and understand unit processes and to assess mechanism assumptions. Such efforts contributed to improved understanding of the unit operations such as comminution, flotation, thickening, filtration and the like. In the 80s and 90s with the availability of more sophisticated computer technology involving modeling procedures, advanced numerical methods, image analysis, nonlinear-curve-fitting and data adjustments, it was possible to test newly developed models under the production environments. These innovations are now available to develop simulator and sensors (such as particle size analyses) for macro-engineering purposes including plant design, automatic controls and optimization. Accordingly, it behooves the mining companies and plant operators to take advantage of these new developments to control a large number of physical and chemical parameters involved in the plant operation and optimization. This is especially important in light of declining head grades and increasing operating costs in the U.S. minerals industry if it wishes to maintain a competitive edge in the international marketplace. In regard to the future R & D activities in the field, in order to arrive at useful correlations in micro- engineering research, it is essential to consider a plant operation as an interactive engineering system representing the combined effects of physics and chemistry, equipment and operation. The important issues that needs to be addressed in the future are

Jan 1, 1993

By Kevin Sharman, Peri Mehling

A detailed assessment of acid rock drainage (ARD) potential was conducted at the Quintette Coal Mine site in northeastern British Columbia The site is unusual in that the coal seams contain low sulphur levels as compared to eastern coals (typically less than 0.5%), and the non-coal wastes generally do not to have the potential to generate acid on the basis of static ABA tests. The presence of small iron-stained seeps on the pit walls indicate localized sulphide oxidation, while the overall mine site drainage has remained of excellent quality with extremely low levels of metals after approximately 15 years of mining. Thus the site provides an excellent comparison to more problematic coal mine sites. For the Quintette assessment, static acid-base accounting (ABA) analyses of individual samples were compared to criteria for potentially acid generating materials developed for the U.S. Appalachian coal, as well as criteria developed in British Columbia for hard rock mines. Geologic units were characterized by the percentage of samples, or weighted thickness, that was deemed potentially acid generating (PAG). Links were then made to actual seepage and water quality emanating from geologic units around the site. Seeps at the site demonstrate a large range in pH (2.32 to 8.18). The few acidic seeps (pH < 4.0) were found to contain elevated levels of sulphates, dissolved iron, manganese and aluminum, consistent with the metals typically of concern in Appalachian coal mines. Other heavy metals that were detected in acidic seeps at Quintette included copper, zinc, nickel and cadmium. The use of simple ABA tests, and comparison of individual sample results with the Appalachian and British Columbia criteria, was found to be useful in predicting the probable sources of the small localized acidic seeps.

Jan 1, 2000

By Ch. Roumpos

The present contribution investigates the way of applying benchmarking for large-scale open-pit mining operations based on sustainability indicators proposed by numerous institutions or groups of experts. These indicators have been developed taking into consideration the legal and regulatory framework that are in force. However, their scope is not only to declare the mining company?s compliance with all legal requirements but also to represent its economic, environmental, and social performance. In this way, sustainability indicators allow assessment of a company?s capacity to produce commodities, to meet the environmental quality requirements and to contribute to a long-term economic, cultural and social development of the local communities.

Jan 1, 2007

By L. Alan Weakly

This paper was presented at the ‘17th U. S. Symposium on Rock Mechanics’ on August 29, 1976, at Snowbird, Utah, at the SME-AIME Fall Meeting on September 1, 1976, at Denver, Colorado, and at the Polish-American conference on Ground Control in Room-and-Pillar Mining on August 7, 1980 at Southern Illinois University, Carbondale, Illinois. Introduction The purpose of this paper is to present a viable method of reinforcing rock pillars by utilizing fully grouted reinforcing steel and a cement- fly ash mortar. Although the fully bonded bolt concept is not new as exemplified by the present widespread use of resin bolts within United States mines and by the use of cement grouted reinforcing used as back pins in the Kiruna Iron Ore Mine in northern Sweden, (1)(2)the method of stabilizing mine pillars with fully bonded reinforcing is new. This method, called the "grout-rebar system", was first incorporated at St. Joe Minerals Corporation&apos;s Fletcher Mine in December of 1972. The system was used on an emergency basis before extensive research on the mechanics of the system could be completed. Since Decmeber of 1972, however, approximately 206 pillars have been reinforced at Fletcher and the system is currently being used on a regular basis at two other St. Joe mines and at two competitor mines in the area. Basically, this paper is a case study of the efforts, research and results of utilizing the grout-rebar system, on a selective basis, at the Fletcher Mine. In addition to information about the system, this paper will explain in detail the three rock mechanics instruments developed by St. Joe and used to measure and monitor rock movement to validate the group-rebar system.

Jan 1, 1982

By J. E. Rourke, O&apos

This paper describes the use of index testing to obtain rock properties that are useful in the design and construction planning of an underground development for civil engineering or mining projects. The index properties discussed include: point load; Schmidt hammer hardness; abrasion hardness; and total hardness. The first two index properties correlate to uniaxial compressive strength (UCS) and Young&apos;s modulus. Discussions are given on empirical, normalized relationships of UCS to rock mass properties and the integrated use with semi-empirical, geotechnical design methods. The hardness property indices correlate to construction performance parameters and some relevant experience is cited. Examples of data are presented from an index testing program carried out primarily on siltstone, sandstone and limestone rock core samples retrieved from depths up to 1005 m (3300 ft) in a borehole drilled in the Paradox Basin of eastern Utah. The borehole coring was done for a nuclear waste repository site investigation.

Jan 1, 1990

By R. J. Sweigard, G. T. Lineberry, B. K. Slone, F. A. James III, D. S. Maggard

The depth at which it becomes more economical to use slope access instead of box-cut access for nearsurface coal reserves is termed the "transition depth." The transition depth can be established for a given coal property by considering cost estimates for those parameters that determine respective access methods. Fourteen parameters that influence access cost were identified, and ranges for these parameters were determined. A transitiondepth formula was developed to permit the determination of which is the better method of accessing a reserve, given information such as high wall slope, road width, total bench width, pit dimensions, road grade, belt component costs, pumping costs and the cost of overburden removal and reclamation. In most cases in Appalachia, especially in eastern Kentucky, the observed transition depth ranges from 20 to 30 m (66 to l00 ft). This indicates that actual practice is consistent with the analytical approach used.

Jan 1, 2002

By Jack E. Thompson

Thank you Tom and JM for that nice introduction. The remarks I am about to make rely on a large way on comments made by Barrick&apos;s Chief Counsel, Patrick Garver, to an internal meeting of Barrick&apos;s senior staff. I plagiarized so much from his notes that I thought that I should provide attribution. I did get his consent to borrow so freely. What I have done is take his general comments and used my conversations with CEO&apos;s and other participants in the industry to enhance the message with concrete examples that underscore the points I wish to make. What you are about to hear is my personal view – I am not speaking as a representative of any company. With that introduction, now would be a good time to give you the main theme of my talk: The SEC should change its rule making to a more public cooperative approach. If that were to happen the SEC would avoid some of the harm it has been doing to the companies in this sector and the very shareholders it seeks to protect.

Jan 1, 2003

By D. J. Shields

The Sustainable Minerals Roundtable was established in 1999 to develop a set of national level indicators to measure the contributions of mineral and energy systems to sustainable development in the USA. The U.S. Forest Service and the U.S. Geological Survey are sponsors of the Sustainable Minerals Roundtable, with meetings convened by the University of Nevada, Reno. Eighteen meetings have been held in various regions of the United States to receive input from different communities of interest. Indicators are being prepared under four criteria: legal and institutional, productive capacity, environmental impact, and socio-economic. This paper reviews the process followed by the Sustainable Minerals Roundtable, and presents the priority indicators.

Jan 1, 2003

By J. A. Herbst, Y. C. Lo

This paper attempts to answer whether or not the mill performance at Bougainville could have, in fact, been predicted by the population balance approach, or whether other special considerations are required to explain their behavior. In recent studies, the plant tests were performed at Bougainville and batch tests were carried out at the Utah Comminution Center. In all tests power measurements were made and several levels of energy input to grinding were evaluated. Also, tracer tests were performed for mill residence time determination. The performance of Bougainville&apos;s 5.5x6.4-m mill has been very successfully predicted by population balance methods. The prediction errors are only about 1% on product size distribution and 4% on power with a mill volume scale-up of 3790:1. It is significant that this approach will reduce the risk of failure in large mill design that has been recognized in traditional methods.

Jan 1, 1987

By C. Cassios

The paper covers the principles of Silver & Baryte Ores Mining Company (S&B) integrated Environmental Impact Assessment study for the whole of the extractive activity at the Fokida prefecture, over a time horizon of a quarter of a century. More specifically the paper includes: - The investigation and the evaluation of the environmental and socioeconomic variables of the specific area of concern. - The identification of the present and future impacts of the extractive activity. - An evaluation of the results of related reclamation activities. - Activity planning following a holistic approach, based on the principles of Sustainable Development, including environmental, social and economic aspects. - The monitoring of the procedure?s implementation.

Jan 1, 2003

By Dean E. Albon

In the late 1940&apos;s and early 50&apos;s in southern Illinois, the usual open pit blasting in the coal field consisted of one or two rows of churn drilled vertical holes being shot with instant electric blasting caps. The entire shot detonated at one rime. In southern Indiana and Ohio most mines were drilling horizontal holes and they too were primed with instant EB caps. During the ten years from 1355 through 1965 many changes occurred in drilling and blasting methods. The churn drill in southern Illinois and the horizontal drill in Indiana and Ohio were replaced by the rotary vertical drill. The ammonia dynamites and liquid oxygen explosives were replaced by ANFO. The elctric blasting cap in the hole was replaced by a detonating cord down line and detonating cord trunk lines made the connections between holes and rows of holes. Host open pit mining was in areas far enough from town that the noise and vibration from blasting was, if not ignored, at least tolerated. During the 1960&apos;s open pit mining expanded to account for nearly 50% of the coal produced. Mines came closer to town and towns expanded along the highways with suburban homes and mobile homes. The mines began receiving complaints about the noise and vibrations from blasting operations.

Jan 1, 1976

By S. Mathur

Oxide particles are commonly used as fillers in plastics, paper, rubber etc. (particulate composites). The successful fabrication of such composites is dependent upon the adhesive strength of the filler particles to the matrix. The compatibility of the matrix and the filler particles is generally enhanced by adsorption of surface modifiers such as surfactants and polymers at the particle-matrix interface. In order to develop a scientific basis for selection of appropriate modifiers it is necessary to understand their adsorption mechanism(s). Specifically, adsorption of polymeric additives is attributed to a combination of chemical and electrostatic interactions, hydrogen bonding and van der Waals forces. Hydrogen bonding has been suggested to be the primary adsorption mechanism for non-ionic polymers. However, a literature survey of Poly(ethylene oxide)(PEO)-oxide system suggested PEO, a non-ionic polymer, to be substrate specific. A systematic study was undertaken to investigate the adsorption mechanism(s) of a PEO on oxide particles. It was determined that strong Bronsted acid sites on the surface interact with the ether oxygen, a Lewis base, of PEO to induce adsorption. In this work characterization of PEO binding sites on oxides is reported and the mechanism(s) of PEO adsorption discussed.

Jan 1, 1997

By A. E. Koski

This paper describes the implementation of specialized software in mine planning at the Cleveland-Cliffs’ managed Empire Mine on Michigan’s Marquette Iron Range. The application puts together years of mining experience on the eastern end of the Marquette Range beginning in the early 1960’s. The Empire Mine, in its thirty-fifth year of production, uses the software to model a complex and highly variable low grade magnetite orebody, capturing the economics of mining and processing to the final product. With special attention given to geostatistical methods, the software is used for all geologic modeling, ore reserve estimation, ore control, pit design and short and long range planning.

Jan 1, 1999

By M. Cambridge

During the latter part of the twentieth century exploitation of mineral resources, and gold mining in particular, experienced a resurgence in Europe, with major mining houses and many junior companies involved in exploration and subsequent mine development. Gold projects in particular were actively encouraged and exploration programmes and permitting studies initiated in more than 15 countries, both within the European Union (EU) and the former eastern bloc. During the initial period, governments in many countries provided active support. Following a series of negative environmental mining incidents in the latter part of the century public opinion, often ill-informed, led to political pressure to withdraw governmental assistance. This in turn resulted in the revocation of exploration licenses, and ultimately to the failure to develop a number of potentially world-class mines within the region. Despite these setbacks, gold production in Europe continues, and is probably higher now than 20 years ago. The mining industry is currently coming to terms with both changing attitudes of governments, and the increase in scope and prescriptive nature of legislation. Recent experiences, particularly in Greece and Turkey, exemplify the problems faced by the industry in the region, which are causing major mining companies to reconsider future activities in Europe. The paper presents an overview of European gold mining and its environmental performance in the context of international practice, new legislation, and public perception of mining generally. The rationale of governments in withdrawing support for the industry is questioned, and the feasibility of achieving sustainability where there is no level playing field globally is reviewed. The question is posed to governments, regulators and mining companies alike as to whether there is a future, not only for gold mining, but for the minerals industry in general, within the EU.

Jan 1, 2003

By A. A. Terchick

In 1970 U. S. Steel acquired the physical assets of mine, mine property, and preparation plant of the Crystal Block Coal Company near Thacker, Mingo County, West Virginia. The facility, identified as U. S. Steel Mine No. 20, is administered and operated as a production unit of U. S. Steel Gary District, Gary, West Virginia. Mining operations of the No. 20 mine are conducted in the high-volatile Alma seam. The preparation plant, which originally had a capacity of about 150 tons per hour (tph) of raw-coal feed, had process circuitry consisting of a Daniels heavy-media vessel for cleaning the plus-1/4-inch raw coal, a McNally-Pittsburg feldspar jig for cleaning the 1/4 inch by 28 mesh, and Daniels flotation cells for treating the 28 mesh by 0. No water-classification system existed. Refuse tailings from the plant were pumped to several surface lagoons which were decanted to the stream. The settled solids were removed and trucked to the coarse-refuse disposal area. Water make-up requirements were supplied by a small mine-water surface reservoir and augmented with stream water. Expansion of production from the property required an increase in preparation-plant raw-coal-feed rate capacity from

Jan 1, 1974