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By Max J. Spendlove

This Bureau of Mines publication reviews current recycling trends in the United States. Although near-term prospects are poor for recycling most present wastes, urban refuse is an important exception. Such wastes comprise a mine above ground, and much less processing energy is normally required to recycle the constituents of urban ore than to obtain them in equal amounts from natural raw materials.

Jan 1, 1976

By Susan P. Taite, Alain R. Charest, Peter D. Lewis

The El Sauzal deposit is a classic, high sulfidation, epithermal gold system located in the southwestern Chihuahua state of Mexico (Fig. 1). A Francisco Gold geologist discovered the prospect in1995. El Sauzal was encountered as a result of an extensive grassroots exploration program in the rugged, dissected volcanic terrains of the Sierra Madre Occidental, around the historical Batopilas silver camp. At El Sauzal, high grade gold is hosted within a series of more permeable, low-dipping, lithic and fine-grained dacitic rocks of early Tertiaryage. The mineralization appears tobe structurally and lithologically controlled. The alteration characteristics are typical of a high sulfidation system, including kaolinite, illite, alunite, dickite and pyrophyllite.

Jan 1, 2005

By Jian Wu

In this paper, the surrounding rocks and the supports in a longwall are taken as an integral, i.e. a system. The structural characteristics and behavior of the system are discussed based on in-situ observations. A set of equations, which describe the interaction among the support, immediate roof and main roof, are developed. These equations can be used to design the longwall powered supports more reasonably and economically.

Jan 1, 1989

By David W. Zeeb

The use of an ordinary VHS video camera and a four-head player can be an effective tool to analyze surface blasting. The necessary equipment can be purchased for under $1,300 and will allow frame by frame or slow motion viewing of a blast in 33.33 millisecond increments. Rock breakage, movement, and timing can be studied in high quality slow motion. These studies can result in improved blasts by showing things that the eye can miss in real time.

Jan 1, 1992

By Geoffrey D. Collins

This paper deals with the construction of the Effluent Outfall Diffusers which form part of the outfall for the Deer Island sewage project. The work was executed 15 km out to sea in Massachusetts Bay and required the drilling, installation, grouting and accurate determination of the actual position of 55 riser shafts in 33.5 m deep water. Although not strictly a "foundation", the contractor's approach to the installation of the diffusers was a logical development from many marine foundation projects executed by the Contracting companies over the last decades. The only previous application of this design of outfall had been in Australia where offshore oil drilling techniques had been adapted for use in riser installation.

Jan 1, 1994

By James R. Boyle

The value of mineral production in-creased 13% in 1977. Nearly all commodities registered an increase in production and value, continuing a trend that started in 1976. In addition, practically all commodities registered an increase in unit value. Alabama led the Nation in the production of crushed marble, was second in bauxite and scrap mica third in kaolin and oyster shell, and fourth in bentonite, dimension marble, and fire clay.

Jan 1, 1981

By B. D. Sparks, I. E. Puddington, F. W. Meadus

The continuous separation of bitumen from Athabasca tar sands, with a high clay content, has been demonstrated. Recoveries of 95 per cent or higher have been obtained. Further processing of this product, to produce an accept-able type of crude oil, would require less heat than currently used in the hot-water process. Also, by comparison, substantial savings in equipment and operating costs are indicated.

Jan 1, 1971

By K. A. du Preez, P. J. van Staden, M. van Rooyen

Mine-impacted water, including acid mine drainage (AMD), is a global problem. While precipitation of dissolved metals and neutralization of acidity from mine-impacted water is accomplished relatively easily with lime addition, removal of sulphate to permissible discharge limits is challenging. This paper presents a high-level comparison of four sulphate removal technologies, namely reverse osmosis, ettringite precipitation, barium carbonate addition, and biological sulphate reduction. Primarily operating costs, based on reagent and utility consumptions, are compared. Each process is shown to be subject to a unique set of constraints which might favour one over another for a specific combination of location and AMD composition. Access to and cost of reagents would be a key cost component to any of the processes studied. The total cost calculated for each process also depends on the type of effluents that are allowed to be discharged.

Oct 1, 2021

By Elizabeth Cruz

The paper point out innovative energy management techniques that lead to energy recovery and uses it back in the process as heat, mechanical work or power with a consequent impact on operating cost and operating cost and operation cost and a reduction in the overall enviroment impact.

Sep 14, 2009

By S. K. Oraee

Most management decisions at all levels of the organization are as directly or indirectly depends on the circumstance of future. With regard to predict the future events in the process of decision-making plays a main role, therefore, forecasting is very important for every organizations and institutions. There is a variety of methods to predict time series. In general, these techniques can be divided as following: statistical, artificial intelligence and analytical techniques. Two of the most common methods for time series prediction is autoregressive integrated moving average (ARIMA) and artificial neural network (ANN) methods, these methods are the subset of statistical and artificial intelligence techniques respectively. In this paper, a hybrid model of ARIMA and ANN models are employed to predict the number of fatal injuries in the USA underground coal mines. This research showed the result of hybrid model is better than split model.

Jan 1, 2011

By Kenneth K. Humphreys, R. M. Quinlan, Stan Venkatesan

INTRODUCTION 1 * The coal industry in the United States has undergone significant economic changes in recent years. For example, the price of coal remained relatively constant from 1950 to 1969 (see Figs. 5-1 and 5-2) but steam coal prices tripled and metallurgical coal prices doubled from 1969 to 1974. This price structure has created a new economic environment for coal preparation. Contributing factors to these price trends include: 1) Coal Mine Health and Safety Act of 1969. 2) Mid-East oil embargo of 1973.

Jan 1, 1979

We did install one 100% brick bottom in our #33 furnace which is basically the same design as Inland's furnace. We had previously embarked on a program of replacing all bottoms in our 300 ton furnaces every 2nd campaign which would be about every 2000 - 2300 heats. This had been necessitated by the effect of our rather high oxygen blowing rates and our desire to maintain a minimum bottom interval level. This meant that we were able to compare bottom performance of various types of materials on a realistic bas is. Since furnace availability is critical to our operation, we are organized to employ every piece of equipment and all the necessary man power to complete a rebuild in the shortest possible time. A 300 ton furnace requires 7.5 days to rebuild. If a new bottom is to be installed an additional 2.5 days is added - 24 hours for tear out and 36 hours for bricklaying - making a total of 10 days.

Jan 1, 1972

By Mark Abernathy

When most people think of a motor vehicle accident, the direct costs resulting from that accident, such as vehicle repair or towing charges, are generally easy to quantify. However, the indirect costs associated with an accident are often overlooked. These indirect costs can take a tremendous toll on a company in more ways than you might think.

Jan 1, 2006

By Huleatt M, Perkin D, McLeod I, Mock C, Pratt R, Gourlay A, Timoney E, Knight N, Ward J

Generally speaking, Australia's reserves of its more important minerals (in terms of export earnings) are adequate to sustain forecast rates of production to the year 2000. The rate of forecast production increases of these commodities (aluminium - whether as bauxite, alumina or metal, black coal, iron ore and ferro-alloy minerals, base metals, tin, uranium, and mineral sands) reflects a well- ordered and sustained growth phase of Australia's mineral industry.

Jan 1, 1981

W. O. OWEN,* Washington, D. C. (written discussion?). Few people appear to realize that the time to reach the crippled soldier is when he is first hurt. In my own judgment, the best time to reach him is before he is hurt, by showing him what other cripples have themselves clone of their own initiative, without Government-support, rendering themselves self-supporting, able to bear a little bit more than their own weight, so that they may lay aside a little bit for a rainy clay and some for a little fun in

Jan 5, 1918

By David B. George

In spite of the many well-known problems inherent in Pierce-Smith converting, it remains the dominant copper converting process. Continuous copper converting and direct concentrate to blister smelting have been commercially available for over 25 years and now produce approximately 15% of copper smelter production. The two fully commercialized continuous converting processes, Mitsubishi MI Process and Kennecott-Outokumpu Flash Converting, and several emerging converting processes are reviewed with view of their potential, limitations, and environmental performance. Some myths regarding these technologies and Peirce-Smith converting are also challenged.

Jan 1, 2002

By M. J. King

Non-ferrous metals such as copper, nickel, lead, zinc, gold and platinum group metals are often found in sulphide mineral deposits. Various pyrometallurgical and hydrometallurgical processes are employed to extract the valuable metals from their minerals. These processes result in the production of sulphur bearing by-products or wastes. This paper provides a review of sulphur bearing by-products and the techniques used for their production. It focuses primarily on elemental sulphur, sulphuric acid and various fertilizer options. Liquid sulphur dioxide, oleum and gypsum by-products are also discussed.

Jan 1, 2009

By Bartrop S. B

Mount Isa mine has a long history of successful exploration since discovery 70 years ago. Remaining reserves, although substantial, exist in a scheduling framework which involves long-term production from new ore sources with attendant technical risk and major capital investment. Current exploration aims to incrementally increase reserve tonnage to maintain existing production levels as well as to provide a buffer for potential start-up delays from new ore sources. Exploration also aims to increase the net present value of the operation by discovering new major orebodies around the Mount Isa and Hilton mines.

Jan 1, 1993

By A. Wahab Khair

This paper presents an analysis of surface ground movements recorded from two longwall mines in Northern West Virginia which operate in the Pittsburgh Seam. The instrumentation areas consisted of four panels, two at each mine, covering various sections with unique topographic features. Instrumentation consisted of survey monuments on 25 to 120 ft. spacing. Vertical and horizontal ground movements were measured at specified intervals to determine subsidence rate, developing and final subsidence profiles, angle of draw, horizontal displacements and associated strain profiles. A relationship between panel depth and width and the subsidence factor was also developed.

Jan 1, 1988

The law relating to the Treaty of Waitangi is developing rapidly at present. A number of separate, but related, developments can be identified.

Jan 1, 1988