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By K. J. Miller

A laboratory electrophoresis column was designed to separate pyrite from fine coal by utilizing an observed difference in the electrophoretic mobilities of the two materials in water. The apparatus worked well when tested with synthetic mixtures of coal and pyrite, but some modifications in design and procedure were necessary to provide a sharper separation. After these changes were made, the column was tested with a high-pyritic-sulfur raw coal sample. The column successfully fractionated the sample, removing not only the pyritic refuse, but a siliceous refuse as well. The invest ion demonstrated on a laboratory scale that pyrite and other impurities can be separated from fine coal by electrophoresis.

Jan 1, 1970

"The effective thermal conductivity (ETC) is one of the most important thermo-physical properties of porous media. Due to the lack of higher precision influence of temperature on thermal conductivity, we took 6 groups of experiments on rock samples (including igneous rock, sedimentary rock and metamorphic rock) under different operating temperatures from 20? to 50? by 7 acquisition points. The general equation of thermal conductivity drives the value of it increasing along with the decreases of the temperature. While in our experiments, it is easy to find a singularity among them for each sample. The experimental investigations we attempted to observe and interpret the alteration mechanism. According to the Heat Capacity Theory in solid state physics, this research gives the explanation about the “singularity” from 3 understanding of specific heat, average free path, and thermal conductivity. Our research divided the condition of the rock thermal conductivity into 3 different types. INTRODUCTION The effective thermal conductivity (ETC) is one of the most important thermo-physical properties of porous media(Huang & Han ,1988; Peierles ,1955). This parameter is necessary for analysis of heat transfer(Vaferi et al, 2014;Hans-Dieter & Rudiger,2003). It’s well known that a general equation for ?(T) was set by Sass et al. (1992) which based on the coupled effect of composition and temperature on the thermal conductivity(Jesse et al, 2013; Mongelli et al,1982).The equation was further successfully verified for other rock (Zumrud et al,2010;Abdulagatova et al,2009;Seipold& Huenges,1998).Thermal conductivity is also related to other physical proper ties of porous rock, such as thermal diffusivity, heat capacity(Brettmann et al,2011;Abuel-Naga et al,2008). It is well known that ETC and other thermo physical properties of rock materials are affected by various factors, such as temperature, pressure, mineralogical composition, porosity, stratification, size and shape of the components, and nature of pore fluid, etc. (Tiedje & Guo, 2014; Touloukian et al,1970).The understanding of heat transport processes still requires the knowledge of thermal properties of rocks."

Jan 1, 2015

By John W. Buch

At a meeting of the Anthracite Investigations Advisory Committee in July 1944 at Washington, D. C., the initial work and objectives of the Anthracite Mechanical Mining Section of the Federal Bureau of Mines were discussed. It was learned that interest existed in an improved performance of mining thin, steeply pitching beds above the gangway by mechanical methods. One company offered the use of one of its mines for experimental work, and this offer was accepted. Following acceptance, an effort was made by Bureau engineers to devise a mechanical method with a performance better than that of a new hand method proposed by company engineers for an actual mining condition. The method proposed by the Bureau was to drive 30-degree slant chutes across a 10-foot bed pitching 85 degrees. These chutes were to be advanced by using a lightweight, compressed air-powered, shearing machine of German origin that had been tried in a flat Pennsylvania anthracite bed in 1934, and which did not then prove successful because of blasting difficulties. An attempt was made to obtain one of these machines from England, where it was known machines of this type had been used. Shortly thereafter John W. Buch was sent to Europe as a member of the Solid Fuels Mission to the European Theater of Operations organized by the Technical Industrial Intelligence Committee of the Joint Chiefs of Staff. Through his efforts the Bureau of Mines obtained two such machines, known as the Eickhoff model DEK, one from England and one from Germany. This report covers the preliminary testing of these machines in order to obtain mechanical operating data for use in determining the power requirements for cutting anthracite with machines of this design.

Jan 1, 1949

Evver since it first displayed an autonomous mining truck at the 1996 MinExpo show in Las Vegas, NV, Caterpillar has been building the blocks to a fully autonomous mine. In May, the company unveiled another block in that progression, the new Cat MineStar System that it says is ?the industry?s broadest, most comprehensively integrated miner operations and mobile equipment management system.? The full system is comprised of five capability sets ? Fleet, Terrain, Detect, Health and Command ? to help operators define the size and scope of their management system based on the needs of their mining operations. Michael Murphy, technology and autonomy manager for Cat Global Mining, explained that the customers were not ready for an autonomous mining truck in 1996, but that many customers wanted the building blocks to eventually get to autonomous mining. After 15 years of work, Murphy said the building blocks have come together in the form of the Cat MineStar System.

Jan 1, 2011

By J J. Robinson, B N. Noller, D M. Franks, G McIlveen, D R. Mulligan, A T. Soro

Fiji is a developing nation that relies on economic opportunities and recently experienced increased interest in mining and mineral exploration that could potentially benefit the country. In order to understand the lack of, or failure of, past rehabilitation activity, this study applied risk-based approaches to identify the significance of activities or actions applicable to rehabilitation of post-mined land in Fiji. This involved the use of qualitative, semi-quantitative and quantitative risk methodologies, which allow assessment and evaluation of mechanisms of mining administration and practices, as well as rehabilitation methods and approaches that have been applied successfully to post-mined land in other countries with similar environmental and climatic conditions and social and regulatory environments to Fiji. The semi-quantitative risk-based technique followed an earlier approach applied for mine closure by Laurence (2006) and provided a systematic way to assess and evaluate rehabilitation issues that were identified on-site by assessors, who were able to estimate through expert judgement the likelihood and consequences based on conditions, situations observed and circumstances on-site. It demonstrated that experienced professionals could reproducibly score likelihood and consequence of selected items relevant to mine site rehabilitation, despite the wide-ranging issues identified during post mined land rehabilitation. The quantitative risk-based approach was adopted as a method to determine environmental bonds for mining projects using the assessment of consequences and likelihood results from the semi-quantitative approach, then incorporating unit cost of materials or activities for local conditions required to fully rehabilitate each issue at net present value. Application to both an abandoned mine site and a newly opened mine site in Fiji showed that this approach could provide a risk-based estimate for rehabilitation cost and demonstrated potential applicable in the Fijian context.CITATION:Soro, A T, Mulligan, D R, McIlveen, G, Franks, D M, Robinson, J J and Noller, B N, ?2014. Risk-based Rehabilitation Strategies for Post-mined Land in Fiji, in Proceedings Life-of-Mine 2014 , pp 165–180 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By Yuchen Wu, Jing Mei, GUOZHONG LIU, KE GAO, Songjie Tian, Jianwei Cheng, Yu Wang, Yuhang Wu, Hui Wang

The stability and integrity of protective coal pillars between the longwall working face and development roadways are greatly affected by the mining activities such as the development face advancing or retreat mining. Due to underground strata pressure, the coal pillar cracks could be further developed and then the air leakage passages (mainly cracks) could be produced greatly. The air circulation caused by the atmospheric pressure difference between the two sides of the coal pillar may also provide suitable conditions for the possible spontaneous combustion of the residual coal in the mine gob. In this paper, a typical the protective coal pillar in a Chinese coal mine is studied. The deformation and stress of coal pillars during the mining process of longwall working face are simulated by using FLAC3D. The displacement and strain of coal pillars are analyzed. Two indexes, the linear fracture rate (LFR) and area fracture rate (AFR), are introduced to characterize the development of internal cracks’ development within coal pillars. By using field measurement, the air leakage intensity distribution due to coal pillar cracks is obtained; the equation of air leakage resistance of coal pillar under the influence of mining is derived. Then, the possible location of large air leakage of coal pillar is determined, which can be used as guidelines to study the possibilities of coal spontaneous combustions happening in pillar or mine gob. The research results help to control such potential hazards in advance.

Jun 16, 2022

By Y. Lin

It is difficult to remove arsenic and bismuth from antimony in the process of crude electro refining. The electro refining of antimony has been studied using ammonium fluoride-antimony sulphate electrolyte system. The Influence of temperature, current density and additives on arsenic and bismuth removal from crude antimony has been investigated in this paper. Optimum process parameters, namely, temperature of 25?, current density of 400A/m2, distance between anode and cathode of 50mm, electrolytic period of 24 hours, oxalic acid dosage of 10g/L and complexon III dosage of 0.2 g/L have been ascertained.

Jan 1, 2014

By H. Simpson

Middelburg mine is an opencast export mine operating in the Eastern Transvaal Coalfields of the Republic of South Africa (Figure 1). The mine was commissioned in 1983, to its original design capacity of 4.25 million sales tonnes which was subsequently raised to 5.5 million sales tonnes in 1989. This increase in export tonnage was brought about through an increase in the mines export allocation and the revision of management strategies. The maintenance of this increased tonnage with minimal additional capital has been achieved through improved operational efficiencies and the upgrading of planning operations through the purchase of an Enhanced Mine Scheduling Software Package (EMSSP/MINESTAR). Simultaneously with this requirement were additional factors that contributed to the implementation of the EMSSP. The mine was owned by a joint venture of two partners and is operated by Middelburg Mine services (Rand Mines Pty. Ltd) (Figure 2). This structure of ownership required the evaluation of numerous planning options to be under-taken concurrently and hence the need for an efficient streamlined scheduling pack-age that could fulfill this requirement. Compounding the EMSSP needs further, were the problems experienced in the export market, these being the external pressure from current and new suppliers in the market place which obliged management to provide solutions to rapidly changing market conditions. These fluctuating market conditions have had a direct effect upon the mine's planning strategies because of the large percentage of the mine?s sales sold on the international spot market. The sanction factor for all South African exporters has had a negative effect upon price and this was compounded further through internal competition in 1987 via suppliers attempting to maintain the market position.

Jan 1, 1991

By Bret N. Lingwall, Byron Foster

The problem of reliable extreme event modeling of large diameter piles under enormous structural or kinematic loads has gained more attention in recent years. In particular, the soil response around the foundation and impacts to buried adjacent infrastructure has gained interest. One of the principal shortcomings with analysis of large diameter pile foundations under extreme event lateral loading is the reliance on conventional beam on elastic foundation methods, which do not model the soil field response around the pile. These methods are limited for large displacement problems, and for large diameter piles. However, the fundamental interactions between steel and concrete, and structure to soil are difficult to constrain, especially in large strain problems where the structural elements become inelastic. The non-linear interaction of the structural materials and soil is desirable so that assessment of stress changes in the field and effects on adjacent facilities can be modeled. A numerical modeling methodology that addresses these shortcomings has been developed. This method utilizes the interaction of brittle concrete with discrete steel reinforcing and casing in a robust manner capturing inelastic non-linearity in both soil and structure. This paper presents a comparison study of the method, wherein three different validation studies were made to data from full scale laterally loaded pile testing. INTRODUCTION Extreme event lateral loading of deep foundations comes in many forms including earthquakes, landsliding, tsunamis, hurricanes, surface fault rupture, liquefaction induced lateral spreads and many more. These extreme events induce loads on foundations far greater than service or strength loads. Perhaps the most dangerous extreme event loads are those of large soil displacements such as landslides, lateral spreads, and surface fault rupture, wherein the soil surrounding the foundations can move laterally 100 mm to 3 m! In these extreme event loading scenarios, small diameter foundations are pushed past their limits and many engineers prefer large diameter deep foundations for these situations. These deep foundations of diameter 900 mm or greater may be auger cast in place piles, cast in drilled hole piles, cast in steel shell piles, cased or uncased drilled shafts, bored precast piles, etc. For convenience in this paper, large diameter deep foundations will be referred to as Large Diameter Shafts (LDS). In LDS, steel may or may not used as a shell around the perimeter of the concrete and/or as internal tensile reinforcement. The interaction between brittle concrete and ductile steel within and/or along the perimeter of the LDS is critical to understanding the non-linear inelastic behavior of LDS for problems of large lateral displacements from extreme events.

Jan 1, 2018

By Edward K. Davison

The so-called "construction aggregates," sand and gravel, crushed stone, and several kinds of metallurgical slags, are used principally in the construction and maintenance of all kinds of roads, engineering structures, buildings, homes, airports, etc. Production of these aggregates is approaching two billion tons annually. In terms of tonnage produced, sand and gravel has been the leading mineral since 1954, with crushed stone gradually approaching an equal tonnage. Sand and gravel is of widespread occurrence and of wide variation in suitable gradation and quality. It is a low-value, heavy-loading, short-haul commodity. These characteristics account for the historic concentration of production tonnage in and near urban areas where construction activities are concentrated. The combination of improved urban and near-urban highway systems and the steadily rising rail rates for short-haul traffic has fostered a consistent change since World War II from rail to truck transport, with trucks now accounting for more than 807 of the tonnage moving away from the production sites. While there are increasing numbers of exceptions, truck transport of sand and gravel is generally limited to about 30 miles. The expansion of the urban and near-urban areas of even moderate density, which became so pronounced after World War II, has been the source of most of the sand and gravel industry's environmental difficulties. Dust, noise and truck traffic associated with the operations -- particularly truck traffic -- have, of course, generated public complaint. This has been particularly true in those many cases where housing developments have approached and even surrounded sand and gravel operations which were in operation before the development started.

Jan 1, 1974

By G. F. Livingston, F. K. Shelton, J. C. Stahl, R. E. Churchward

"INTRODUCTION An investigation of the metallurgy of cobalt from domestic ores has been in progress since February 1940 and has resulted in the formation of a hydrometallurgleal process for the production of electrolytic cobalt metal. Previous reports of these investigations have been given by F. K. Shelton; 7/ and Ruth E. Churchwrd, F. K. Shelton, and G. Knickerbocker. 8/ Briefly, the process, as applied to ores containing cobalt oxide, consists of leaching with H2SO3 or, preferably, with H2SO3 and H2SO4, to dissolve the cobalt. The cobalt solution passes through one or more purification stages to remove iron and elements of the copper group, and cobalt carbonate is precipitated under carefully controlled pH conditions. The cobalt carbonate is dissolved in on acid electrolyte containing sulfuric acid, boric acid, and sodium fluoride. The electrolyte then proceeds to electrolytic cells where cobalt is plated as a metal and sulfuric acid is regenerated.The present paper contains the results of several investigations signed to give a more complete chemical and engineering understanding of different unit processes involved in the electrowinning of colbat. Some work has been done to broaden the process to include arseniferrous cobalt ores as well as the oxide ores upon which the investigation was initiated. Most of the data presented herein have been obtained since the release of the previous reports; any changes suggested heroin that conflict with recommendations in earlier reports are based on more complete data and usually are preferable."

Nov 1, 1945

By J. A. Marts, R. C. Gilmore, Jr. Bogin, S. A. Saki, J. F. Brune, J. W. Grubb

"Colorado School of MinesResearchers at Colorado School of Mines (CSM) have developed computational fluid dynamic (CFD) models to study gas distributions and explosion and fire hazards in longwall gobs. In underground coal mines, methane continuously emitted from surrounding strata mixes with air from active mine workings and may form explosive gas zones (EGZs). Some western United States coal mines are also prone to spontaneous combustion (spon com). Insight into oxygen concentrations within the gob is crucial for assessing spon com hazards and mitigation strategies. Nitrogen injection used in conjunction with progressive gob sealing can reduce EGZs and spon com hazards by forming a dynamic seal that separates the methane in the gob from the air that ingresses from the face. This paper describes CFD modeling simulations studying the formation of such dynamic seals by optimizing the nitrogen injection locations. The impact of nitrogen on oxygen ingress and formation of EGZs is discussed. Optimum nitrogen injection quantities and injection locations were determined. Dynamic seal formation is most effective if the headgate nitrogen injection locations are split between the first crosscut inby the face and a second location about 300 m (1,000 ft) further inby. INTRODUCTION Underground longwall coal mine ventilation systems are designed to dilute hazardous gases and to provide breathable air to miners working in the area. Methane gas is liberated as the mining process extracts the coal and disturbs the surrounding strata. Methane mixes with the ventilation air and often produces explosive gas zones (EGZs) within longwall gobs (Brune 2013). Past CFD modeling research of underground coal mine ventilation systems has shown the effects of face air quantity on EGZs (Worrall 2012) and nitrogen injection to control spon com (Balusu et al. 2005; Ren et al. 2012; Ren et al. 2011; Smith and Yuan, 2008; Yuan and Smith, 2014). Other modeling approaches include network ventilation models of oxygen ingress (Dziurzynski and Wasilewski, 2012), and coupled Linear Network CFD algorithms (Wedding 2014). In a project sponsored by the National Institute for Occupational Safety and Health (NIOSH), CSM researchers are using Fluent®, a CFD software package by ANSYS, Inc., to model gas compositions and flows in underground longwall gobs. Figure 1 shows a progressively sealed gob with a U-type ventilation system in a three entry development. As the longwall advances, seals are constructed along the headgate in the crosscuts between the center entry and the gob. Additional gob isolation seals are built to block off the headgate entries inby the face. Nitrogen is injected through the seals in the first two crosscuts on the headgate side and at the first crosscut inby the face on the tailgate side, as shown in Figure 1."

Jan 1, 2015

By Peter Barker, Terry Jones

"The Kelsey Centrifugal Jig (KCJ) utilizes the application of centrifugal force (and the resultant enhanced gravitational field) to conventional jigging technology principles to successfully and efficiently process materials where the valuable constituent particulates are very fine and/or where there is a small specific gravity differential between these and the gangue minerals.The KCJ is applicable to a broad range of fine mineral recovery duties, with current installations in the mineral sands, tin, tantalum, gold and nickel industries. Other areas of application are being developed with mineral commodities including tungsten, base metals, iron ore, chromite and apatite/feldspar.Information on the principles of operation of the KCJ, typical performance figures in a number of application areas, comparison to centrifugal concentrators, key elements for a successful KCJ operation and recent developments with the KCJ are presented in this paper to demonstrate the capabilities of the KCJ.INTRODUCTIONAfter a number of years of development by inventor Chris Kelsey, the first commercial KCJ unit was installed at the Renison Bell tin mine in Tasmania, Australia, in 1992. The subsequent decade saw the installation of further KCJ units in applications including tin, tantalum and mineral sands.Development and improvement in KCJ hardware continued and culminated in the introduction of the high-capacity Model J1800 KCJ and standard features such as an automatic screen cleaning system. This opened up further markets and resulted in Model J1800 KCJ installations in the gold and nickel industries, as well as further KCJ installations in the mineral sands and tin industries. In recent years, work has continued on application of the KCJ to many other duties in industries including tungsten, base metals, iron ore, chromite, apatite/feldspar, etc."

Jan 1, 2007

The Australian minerals sector has a shortage of skilled professionals to satisfy an industry that is experiencing renewed vitality. Graduate numbers are low throughout Australia and the world, while economic rationalisation is seeing many educational institutions downsize, or even close, their minerals-related programs. In addition to requiring more entry-level graduates, minerals producers are looking to update the skills of their current workforce to keep up with the industryÆs continuing technological revolution. To address the issue the Minerals Council of Australia (MCA) endorsed collaboration between several Australian minerals producers and a team of universities to generate the Mineral Tertiary Education Council, or MTEC. MTEC recently initiated a venture to increase the availability of professionals with relevant skills to the minerals industry. Primarily aimed at delivering postgraduate programs, the initiative will allow graduates from other disciplines to æconvertÆ to the minerals sector as well as provide professional development training to an existing work force. This venture represents a novel approach in that courses will be delivered by more than one institution and will employ innovative teaching materials with flexible and remote delivery formats. The programs will cater specially for professional development in the minerals sector, which generally requires high flexibility due to the nature of work conditions and locations.

Jan 1, 2004

Carbon sequestration in planted forests provides an immediately available, low cost option to address the greenhouse impacts of coal mining and coal utilisation in a carbon constrained world. In addition, planted forests also offer the opportunity to address other environmental issues, particularly salinity and loss of biodiversity. Given salinity is characteristically associated with agriculture in the 500 to 700 mm rainfall belt, then where such forests can also produce commercial timber products, they offer the additional opportunity to establish new, diversified rural employment in both timber growing and processing. In the majority of Australian catchments affected by salinity, where rainfall is generally less than the 700 mm limit to conventional forestry, and where groundwater reserves are often saline, the objective of achieving economically viable forestry production presents a significant challenge. In 1996, Saltgrow commenced a collaborative breeding program to combine the salt and stress tolerance of E camaldulensis, with the growth rate, stem form and wood properties of the commercial species, E grandis and E globules. This program aimed to produce trees with the potential for commercial rehabilitation of saline landscapes. Results covering a range of site conditions from SaltgrowÆs network of over 100 trials around Australia are presented. The opportunity for commercial plantations integrated with agriculture in low to medium rainfall areas to address salinity and sustainability will be discussed. In addition, the significant potential for partnerships between land-rich, cash-poor farmers, catchment management authorities seeking to invest in public good projects that enhance environmental sustainability, and major carbon producing industries with either mandated or voluntary requirements to curtail net emissions will also be discussed.

Jan 1, 2005

By Matthew John M. Krane, Patrick E. Krane

This study examines the operations of the Cowper stoves attached to an iron blast furnace from a Second Law perspective. The exergetic efficiency of a 3-stove system operating at cyclic steady state is determined using a model accounting for the thermal, mechanical, and chemical flow exergies of the top gas and blast air, as well as the thermal exergy stored and released in the stoves. The analysis covers the heating and mixing of blast gas in one on-blast stove, and the combustion of top gas and its use to heat two on-gas stoves. The effect of different cycle times, and blast furnace operating conditions on the exergetic efficiency of the cycle is examined, and the optimal cycle time for different blast temperatures found. In addition, a study of the combustion parameters quantifies the advantages of using enriched oxygen in the combustors.

Mar 1, 2018

By Andrew Allan

During recent years underground production for the Pennsylvania anthracite region has reached the lowest output per man per day figure of the last decade and a half. This fact, combined with increased unit costs for labor and material, has forced the market price of anthracite ever higher. Over the years the mines have become deeper, and haulage distances have increased, thus adding to the mining costs. The industry now recognizes the need for new mining techniques to offset increasing costs. The Federal Bureau of Mines, through its Anthracite Research Laboratory, is engaged in a program of underground-mining research in cooperation with anthracite-producing companies to aid in reestablishing the economy of the region by introducing methods and/ or machines that will reduce underground-mining costs and, at the same time, enhance the safety of the workmen.

Jan 1, 1953

By Robert C. Horton

The Getchell Mine is located on the east flank of the Osgood Mountain Range in the Potosi Mining District, Humboldt County, NV. Mining in the area first began in 1883 for copper, lead and silver in skarn-related deposits. Tungsten was discovered in the skarns in 1916 and was mined sporadically until 1957. The first major discovery was made in 1933 when two Winnemucca prospectors, Edward Knight and Emmett Chase, found gold at the present site of the Getchell gold mine. In 1934, after a small amount of preliminary prospecting, the claims were purchased by Noble H. Getchell of Midas, NV. The Getchell Mine Inc. was organized and exploration and development work began on a broad scale. Major funding was provided by George Wingfield and investors he assembled. Laxalt described Wingfield’s immediate history prior to his financing of Getchell as follows.

Jan 1, 1999

By C. B. Manula

The application of computers to materials handling problems has recently been investigated by various mining groups. This approach has been found, especially useful where a large amount of alternatives must be investigated prior to arriving at a final decision. These alternatives may be expressed in terms of man hours, units and types of equipment such as trucks or conveyors, or the allocation and operation of proposed or existing haulage facilities. The decision problem becomes especially evident when we consider the mechanical revolution which has flooded the mining industry in recent years. The industry has become highly competitive, with the need to keep low profit materials away from high cost production faces ever increasing. The capital investment required for the highly sophisticated equipment that is necessary to perform this function is generally great, and management is faced with decisions which must all too often be made without sufficient data.

Jan 1, 1967

By R. P. Walters, M. J. Lynch, D. R. Flinn

The Bureau of Mines evaluated tthhee feasibility of substituting platinum- coated metals for bulk platinum shapes as a means for conserving platinum . Platinum coatings were prepared using four different methods of electrodeposition , then tested and evaluated . In order for platinum coatings to be useful in process environments , they must be thick , adherent , stress - free , and pore - free . The Bureau evaluated direct - current , current reversal , cathode shielding , and pulsed- current plating techniques for producing a pore-free platinum electrodeposit from a molten cyanide bath . Aqueous corrosion tests of Fe - 10Cr substrates coated with approximately 25 μm of platinum showed that pulse plating yielded the most corrosion- resistant and , hence , the most pore -free coatings . The morphology of coating cross sections was in all cases columnar . The average grain size of pulse -plated deposits was independent of thickness , while all other plating techniques produced grains that increased in size as the coatings became thicker . It is believed that the constant grain size in the pulse - plated deposits resulted from better mass transport during the electrodeposition .

Jan 1, 1965