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By J. A. Cole

This paper discusses the modification of the cyanide tailings treatment method from ferrous sulfate to Caro's acid (peroxymonosulfuric acid). An examination of the operating parameters, costs, and chemistry describes how the decision was made to switch to this treatment method. Plant data collected from the last several months will be used, along with considerations from an operator's viewpoint.

Jan 1, 1996

By M. J. Blattman

The problem of measuring the amount of rock removed during a given time interval is faced by most milling operations. Many methods have been developed with varying degrees of success, dependent upon the mining method and the availability of usable data. The Rosebud Mine has been in production for nearly two years, employing several techniques to estimate monthly production from underground production stopes. The use of three-dimensional solids generated from survey data has greatly improved the reliability and confidence of monthly production reports. The authors will summarize the methodology currently being utilized at Rosebud.

Jan 1, 1999

By Dale E. Hirschfeld

The clays in Eastern Washington occur in a variety of forms and are extracted for uses in Face Brick, paper coatings, and aggregates. Not in large volumes in comparison to other areas, not even from impressive large mines. However, mans utilization of these clays has progressed from historical clay tablets to the present technically oriented manufactured products of today. White Face Brick, perhaps the whitest produced anywhere is the unique product produced by INTERPACE CORPORATION's Mica Plant from these unusual clays. It is this basic characteristic feature of the clay's in the Mica area that differentiate them from the other clay's in this belt. ORIGIN The significant properties of clay's used in Face Brick are plasticity, fired color, fired strength, dry and fired shrinkage, the PCE or Pyrometeric Cone Equivalent, and extrudability. Testing clay's for these properties is standard laboratory procedure. No two clays are alike, and seldom can one clay be substituted for another. Mica White Clays respond favorable to all these properties, but more especially, the Mica Clays fire to a brilliant white color, from almost the natural state. The geologic history of Eastern Washington is largely conjectural because of the absence of rocks representing segments of geologic time. The oldest rocks in this area are the argillaceous and arenaceous sedimentary rocks which have been slightly metamorphosed. These rocks have been correlated with the Belt Series of the Pre-Cambrian age, although some may be older. These rocks were subsequently intruded by granadiorites and related rocks that are considered to

Jan 1, 1971

By W. Todd

The Robbins Company has developed a boring machine, with a rubber packer serving as the gripper system, for blind boring of raises without using drill pipe. This machine is the BorPak and has many applications for use in the mining industry which will improve productivity. In addition to the cost savings, the boring method will lead to increased safety in constructing blind raises. The advantages of using the BorPak in a mining environment will be discussed together with possible applications.

Jan 1, 1994

By G. M. Rao

It has been a universal observation that rich grades of ores and minerals are getting depleted, simultaneously the demands for civilization are ever increasing coupled with occurrence of poor grades of ores and minerals posing a problem to the processing engineers. At the same time, the cost of mining and milling are increasing, creating a situation where the management has to handle and process low grade ores at an economic level keeping environmental stipulations and control to be safeguarded which has been an additional cost for the management to comply with.

Jan 1, 1994

By Robert J. Collins

Computer-aided design drafting systems have been employed in plant design for nearly ten years. Current and future systems will include computer-aided engineering as well. This paper will explore the history and development of such systems including computer and workstation hardware, graphics software, and plant design applications software. The paper will also address future systems and will present both the system vendor and the mine mill designer's view. Specific examples of particularly successful applications will be included.

Jan 1, 1985

By James E. Gingrich

The new Track Etch* technique for uranium exploration has been utilized in several survey programs conducted during the last few years. The results from these programs have been very encouraging, and new uranium ore bodies have been discovered by using this new technique. The Track Etch method is being used in several exploration programs in various locations around the world. The Track Etch exploration technique utilizes small pieces of special radiation-sensitive plastic film to detect the presence of radon gas which is released by uranium ore bodies. Because of the selectivity and sensitivity of the technique, ore bodies not normally detected with other surface or airborne monitoring methods are found. Since no large equipment or special training of personnel is needed, the Track Etch technique is easily used in field operations. The basis for the Track Etch method, its application in field exploration programs, and the results obtained to date in locating uranium ore bodies is discussed.

Jan 1, 1974

By T. J. Dudek

To be competitive in automotive applications, polymer composites must be processable by high production rate processes like injection molding (IM), reaction injection molding (RIM), structural rim (SRIM) and compression molding. With current fiber reinforced composite materials, performance properties are sometimes compromised to make them compatible with these processes. This is done by decreasing the amount and length of the reinforcing fiber and the viscosity and molecular weight of the polymer matrix. Sheet molding composite (SMC) and thermoplastic polymer blends are examples of polymer composites which are cost effective in many applications and meet the high speed processing requirements for automotive parts.

Jan 1, 1993

By C. L. Pillar

In many cases, substantial time may elapse between the exploration stage and a serious detailed planning stage which has the objective of putting a mineral property into production. This is always true where properties change ownership and new partners are brought in for joint venture situations. Such conditions make it imperative that the recording of complete and accurate geological data for the property is done during the active part of the exploration phase and accomplished by competent geologists and engineers. This work should not be left to helpers and technicians. Furthermore, it should not have to be redone years after the actual drilling was accomplished, when either those involved have parted company or those present have lost the touch and feel of their part of the exploration program and must rely on a memory sketchy in detail, at the best. All of this emphasizes the importance of thorough geological evaluation and reporting during the exploration program. To evaluate and comment on the application of geological data by a mine planning department, we must assume (1) that sufficient diamond drill holes have outlined the existence of a potentially economic ore deposit, and (2) that the next step is to obtain the required information to allow a detailed feasibility study. This paper will comment on: 1. what types of geological information are required, 2. how it can be obtained, and 3. comments on the application of this information by the mine planners.

Jan 1, 1973

By G. W. Luxbacher

With the advent of acid rain legislation included within the Clean Air Act Amendments of 1990, a great deal of uncertainty with regard to price, source and production quantities has been cast into the coal market. Powder River Basin and other western coals continue a rapidly accelerating migration eastward, South American coals move into the northern markets, states propose legislation to assist utilities in complying with the new regulations in hopes of maintaining their own coal industries, while some utilities question the long term availability of eastern compliance coal. Any major coal producer must make decisions now to assure their continuing presence in the market place; several companies have adopted a strategy to acquire eastern compliance reserves while others have invested in technology to compete as a low cost producer. This paper discusses some of these options in light of the uncertainties of the market place, from an eastern coal producer?s viewpoint.

Jan 1, 1992

By H. B. Weaver

The development of a method to manufacture diamonds has been rated as one of the out- standing scientific achievements of our time. The story is both interesting and significant. This paper will quickly review history of diamond and manufactured diamond. Next, it will discuss manufactured diamond as a product -- how good is it -- and what is the significance of this scientific achievement. And finally, present a few thoughts about the future of this technology and this product. For centuries, diamond was found only in alluvial deposits, primarily in the Golconda fields of India. As a result, man knew nothing of the process by which the stones were formed. In 1860, diamonds were found in South Africa under completely different conditions. Here, for the first time, they were found in volcanic pipe -- their mother ground. These volcanic pipes are roughly cylindrical columns of rock which go deep within the earth. The theory as to the formation of diamond was presented by the geologists in that era. The theory states that molten rock was thrust up through a layer of carbonaceous shale where it picked up the carbon necessary for diamond formation. It was generally agreed that diamond was formed approximately 240 miles below the surface of the earth, thus indicating that extremely high temperatures and pressures were involved.

Jan 1, 1964

By I. R. Miller

The purpose of this discussion is to try to offer some suggestions as to how the zinc and lead markets will perform over the balance of the decade, review some of the factors influencing production and come to some conclusions regarding prices. The past 2 years have been simply awful in terms of consumption, prices and overall profitability for the industry. In looking ahead to the year 2,000, it is probably not a bad idea to look back about 20 years to see where we have been and how we got to where we are. Zinc consumption from 1950 to the early 1970's increased steadily and rather nicely at an annual average rate of close to 4.0%. It was starting in the early 1970's that things started to get volatile and at times, difficult for the industry. The general economic boom of the early 70's was marked by annual consumption rates close to 5.0 million tons, a level not seen again for over 10 years. The First Oil shock of 1973-74 was followed by the sharpest consumption drop in memory. In two years, Western World zinc consumption fell 27%. While our chart shows a rather dramatic recovery thereafter, the average annual growth rate since 1970 has only been a rather modest 1.5%.

Jan 1, 1992

By S. S. Szoke

The concrete masonry industry, represented by the National Concrete Masonry Association has significantly expanded its markets since the industry's inception. The concrete masonry industry has developed and refined concrete masonry units by producing a variety of quality products on automated machines. In the sixties, architectural concrete masonry units gained popularity. In the seventies, the concrete paver market expanded. In the eighties, segmental retaining wall units became popular. The industry continues to research and develop new products and applications for concrete masonry to satisfy the needs of designers, specifiers, installers and owners. Both existing and innovative technologies in the concrete masonry industry are discussed.

Jan 1, 1993

By A. Hekmatnejad

"The objective of this work is to validate a methodology for spatially predicting the fracture intensity, defined as the average fracture area per unit volume. First, using the observations from drill holes, the fracture intensity is directly inferred at the support of drill-hole composites based on a Terzaghi correction. Subsequently, the composite values are interpolated to larger blocks. The methodology is tested on sets of simulated fracture networks, in which each fracture consists of a disc with a random diameter, random position and random orientation. For each of these simulated networks, one can calculate the actual fracture intensity within any region of space, based on geometric considerations. A regular sampling mesh is then defined to emulate a set of vertical drill holes and the proposed methodology is applied to predict the fracture intensity, both globally and locally. The actual and predicted fracture intensities are finally compared, showing that predictions are unbiased, insofar as, on average, the prediction error is always close to zero. Also, the error dispersion increases when the support of the prediction decreases, which is consistent with the well-known support effect. In practice, the proposed methodology allows predicting fracture intensity based exclusively on drill-hole information, without the need for simulating fracture networks in space, hence its interest. INTRODUCTION The characterization of fractures in rock masses is an important part in the evaluation of mechanical and hydraulic properties of rocks. Fractures have a large impact in disciplines such as reservoir engineering, safety of underground storage of CO2 or of nuclear waste, assessment of high-enthalpy geothermal installations, safety of mining exploitations, efficiency of in-situ leaching operations or of extraction by block-caving. As a rock mass property, fractures must be characterized in the three-dimensional space, whereas observations are limited to 1D (drill holes) and 2D (outcrops, drift walls), moreover very often to rather short stations, so that the available data are subject to geometric bias, truncation and censoring. Fracture characteristics includes the number of fracture sets and, for each set, the number, orientation, spacing, location, shape and size of the fractures must be inferred from data sampling. Some important parameters that are considered nearly in all models are fracture intensity and fracture size."

Jan 1, 2016

By C. M. McCulloch

More and more mining underground is being conducted using the longwall method. Likewise, many new surface mines use area or mountaintop removal methods. These methods can have a significant impact on surface and groundwater resources. The overall study of the effects on surface and groundwater from mining is referred to as the probable hydrologic consequences (PHC) determination of mining and reclamation. Collection and interpretation of information concerning groundwater and surface water quality and quantity, as well as detailed geologic analysis, is required to adequately define the impacts of mining. This paper discusses the present day requirements and methodology of preparing a PHC for a large mining operation in the eastern coalfields.

Jan 1, 1995

Design models for belt conveyors used in mines predict both the belt power requirements and belt tensions. Conveyors with slightly downhill profiles are more complex to predict due to the way that models such as CEMA interpret friction. Performance of a particular conveyor in relation to other conveyors in the same system requires an analysis of natural stopping times, braked times and take-up location. A review of CEMA-based PC models is presented for design of underground multi-flight belt systems.

Jan 1, 1995

By C. K. Blankenship

The competitive forces now driving the electric utility industry and the constraints of regulation at all levels are changing the way we will all do business now and into the next century. Utilities are using every technological tool at their disposal to find optimum solutions to challenges in every aspect of operations. In fuel planning and procurement, these tools include models that predict which dispatch line-up will comply with environmental regulations at minimum cost. This paper presents how those tools are being used for Duquesne Light Company.

Jan 1, 1995

By Nic Arrieta

The Arimetco White Cliff Diatomite operation near Tucson, Arizona will be discussed and reviewed across the spectrum of geology, mineralogy, mining, processing and product attributes and market applications. Unique for the operation are the type, quality and the extent of the reserves and several product characteristics of the diatomite.

Jan 1, 1996

By M. Liu

In-situ soil washing using surfactants shows great potential to remove hydrophobic organics from subsurface environment. Lab scale soil washing experiment were performed using Sodium Dodecylsulfate (SDS), an anionic surfactant, and anthracene, a highly hydrophobic compound. The results of this research show that solubility of anthracene increases linearly with an increase in SDS concentration above the critical micelle concentration. Furthermore, SDS can be effective in removing anthracene from contaminated sand.

Jan 1, 1992

By Spencer R. Titley

Nearly three decades of intense research, corresponding with a period of unparalleled discovery and the advent of scientific advances and hypotheses of ore formation, has resulted in a great body process-focused research concerning how ore deposits form. The development of process models and their application has proceeded more or less in step. Discoveries have been made in mineralized regions such as provinces and districts but generally without a comparably developed understanding of why provinces and ore bodies exist and, except in general terms, where ore deposits are within districts and regions. The process of discovery is still referred to as search and exploration budgets are heavily weighted toward exploration drilling.

Jan 1, 1995