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By Joseph W. Horne

This report presents the results of an investigation by the U. S. Bureau of Mines in cooperation with the State of Colorado, on the yields and properties of oils produced from oil shale, lignite and subbituminous coal using the standard assay method developed by the Bureau for oil-shale testing,. The purpose of this work, which is part of the general study of oil shales being conducted by the Bureau of Mines and cooperating agencies, was to obtain information on the amount and character of the yield of crude oil or tar from different typical oil shales, the yield of light oil or naptha that might be suitable for use in motor fuels, and other products of shale oil. As the west has large resources both of oil shale and low-grade non-coking coals, it is of interest to know the relative yields of tars, light oils, and combustible gases that can be produced from these coals when retorted under conditions similar to those suited for oil-shale retorting. Source of Samples The coal samples were obtained from deposits on or adjacent to the public lands in the States of the Rocky Mountain region. Many of the mines sampled are operating under Government leases or permits. The number of coal samples secured from the various states are: Colorado, 6; Montana, 9; north Dakota, 6; New Mexico. 1; South Dakota, 1; Wyoming, 9. Of these samples, 14 were lignite coal, 16 subbituminous coal, and a bituminous coal. The standard channel method of the Bureau of Mines was used for sampling. Coal samples received at the Boulder Office weighed about twelve pounds each, and duplicate samples were sent to the Pittsburgh Station for proximate and ultimate analyses. The origin of the samples and description of the deposits are given in Table 1.

Jan 1, 1927

By E. C. Baker

Costs of disposing of steel slag are estimated based on the present method and a proposed alternate method for a steel mill in the Pittsburgh area. Estimated cost data were calculated by the Bureau of Mines and do not reflect the investment and operating costs and credits of a specific steel mill and processing plant. The alternate method of steel slag disposal would result in an appreciable cost savings to the mill and concurrently supply the industrial and commercial markets with low-cost, high-quality construction materials.

Jan 1, 1970

By Richard E. Thill

Engineering properties of rock are essential in most phases of mining from site reconnaissance through mineral processing. Review of the literature indicates, however, that property data is scarce for most coal measure rocks in the United States. The Bureau of Mines, U.S. Department of the Interior, has undertaken a wide-ranging testing program to provide more complete property data for coal strata in the U.S. coal basins. The property data are expected to have application in geophysical exploration, the development of pre- mining and hazard detection probes and instrumentation, mine design, engineering and rock mass classification, subsidence engineering, and ground control. This paper describes the comprehensive program encompassing in situ geological, geophysical, and geotechnical properties and laboratory determinations of acoustic, electromagnetic, physical, mechanical, and index properties and discusses results for 500 ft of coal measures at a minesite in the Northern Appalachian, Eastern Coal Province.

Jan 1, 1982

By N. Rouse

Underground raises and slots are a vital part of underground blasting operations. Raises and slots are vertical shafts or openings used for ventilation, ore passes, or creating voids in stopes. In the author’s experience, raise and slot designs can vary significantly from operation to operation or even within a single operation, sometimes for reasons unknown. The results of the various designs can differ depending on drilling accuracy, geology, and the explosives used in the design. The purpose of this paper is to summarize the recommendations found in published literature on raise and slot design in one document, while incorporating some of the author’s own experience with optimizing raise and slot designs in underground operations. Some inspiration is also included from burn round designs; small versions of raises drilled horizontally in development blasting rounds. This document includes discussion points on drillhole diameter and depth, pattern design and relief requirements, explosive types and loading recommendations, and timing. Ultimately, this document can be useful to those looking to design a raise or slot blast for the first time or for those looking to improve on the results from the raise and slot blasts used at their operations.

Jan 1, 2024

By E. N. Mounsey

Ausmelt Technology was selected by Bindura Nickel Corporation (BNC) as the basis for a new copper circuit to process nickel plant copper leach residue to blister, anode and finally cathode copper and recover PGM values at the Bindura Smelter Refinery (BSR). The process selected, based on Ausmelt Technology to smelt and convert the residue to matte and blister copper and produce a discard slag, is novel incorporating smelting, converting and slag reduction process steps in a single Ausmelt vessel. The process demands a high quality blister copper product with low levels of arsenic and nickel. This paper reviews the project and the initial operational results to the end of 1997 of the Ausmelt Top Submerged Lancing (TSL) smelter and discusses the implications for the wider TSL converter market.

Jan 1, 1998

By William C. McBee

Specialized sulfur concretes were developed by the Federal Bureau of Mines as a result of research for the beneficial utilization of sulfur in construction materials. Materials were developed for use in acid and salt corrosive environments where portland cement concrete has been found to deteriorate. Because the mineral aggregates also come into contact with the corrosive media, concretes were developed utilizing both limestone and quartz aggregates. The sulfur binder used with both aggregates was modified by reaction with 5 pct dicyclopentadiene to improve product durability. Sulfur quartz aggregate concrete was found to have moderately high strength characteristics (6,000 psi compressive) and was extremely resistant to chemical attack by both acid and salt solutions. Sulfur limestone aggregate concrete exhibited very high strength characteristics (9,000 psi compressive) and was extremely resistant to chemical attack of salt solutions. Both types of concretes maintained their strength and integrity after long-term testing in acid and salt solutions and exhibited considerable resistance to damage by the action of freezing and thawing. Potential uses include leach tanks, electrolytic cells, thickeners, bridge decking, industrial flooring, pipe, and tile.

Jan 1, 1979

By G. Reuben Yourt

THIS paper is chiefly a description of the improvements in dust control chat have been brought about in the assay office grinding room at Wright-Hargreaves. The fume exhaust systems are briefly included because they also are important to the health of the employees. There are three chief factors which determine the efficiency of a dust control system: First, the amount of time and thought spent in designing it. Second, how close! y it is kept up to date with the growth of the plant-a system that is adequate for the number of machines operating when it is installed may fall short of fulfilling its purpose as the plant expands. Third, unless someone is held directly responsible, a system is likely to get out of repair and gradually lose its efficiency-this can easily be detected by regular dust surveys. In designing the present system at Wright-Hargreaves, the object kept in mind was to reduce the dust concentration of all operations to a safe limit, chat is, well under 300 particles per cubic centimecer of air. By doing this, a condition would be attained chat would make it possible to discontinue the use of respirators, which at best are not very comfortable and do not remove all of the hazardous fine-dust particles.

Jan 1, 1941

By Serge Rudchenko

A study to determine the potential use of retaining structures in open pit backfilling. Research and review of the open pit mine environment, mine waste disposal, and past and current use of retaining structures. A development of specific structures, the culvert/ tunnel concept, and an anchor block retaining concept. The cost benefit of retaining structures used for in-pit backfilled waste.

Jan 1, 1981

By James R. Jones

The Surface Mining Control & Reclamation Act is a complex piece of legislation signed into law on August 3, 1977. It is the culmination of more than six years of debate by the Congress over the need for a national regulation of surface mining as opposed to the prior concept of regulation by each concerned state. It departs from the more normal type of law in that it includes very specific requirements, limitations and performance standards. In its procedural aspects, it is somewhat similar to the Clean Air Act and the Water Pollution Control Act in that it places primary responsibility at the state level, provided the state meets minimum national requirements. At the time of writing this paper, in late December 1978, the Interim Regulatory Program has been in effect for seven months. The proposed regulations for the Permanent Program, the draft Environmental Impact Statement, and the draft Regulatory (Economic) Analysis ware available for eight weeks before the close of the comment period on November 27. We are now awaiting issuance of the final versions of these documents. The states in which coal is mined, for the most part, have made sere revision to their state laws and are in the process of revising their regulations, or have just completed the revision, to comply with the Initial Regulatory Procedures. They are now faced with another new major effort to analyze and plan for compliance with the Permanent Regulatory Program, which is expected to be promulgated by the Office of Surface Mining of the Department of Interior by the time this paper is presented.

Jan 1, 1979

By Davey Bickford, Johan Hawinkel

Blasting and the use of civil explosives are a critical step in the mining process. Good decisions provide significant downstream benefits and create a safe and sustainable working environment, while poor decision making and judgement can have catastrophic consequences on workers safety, critical infrastructure or the security of the general public. An ever-tightening regulatory framework increasingly exposes manufacturers, transport companies and mining companies to the consequences of breaches resulting from erroneous or ill-informed decisions. In this context, new capabilities are required providing all actors in the explosive supply chain with tools to make better informed decisions allowing the individual to own up to his or her decision. Additionally, the traditional risk-control approach in the explosive supply chain up until usage and waste elimination, through administrative control procedures and processes, is becoming increasingly inadequate. In this era of digitalisation and automation, technology will play a pivotal role in ensuring safety and security in storage, transport and usage of civil explosives using the latest advances in electronics, communication technology and information technology. This paper explores the journey through time of technology in the civil explosives market to provide testing, measurement, analysis and control tools. This ultimately leads to better decision-making, ensures full accountability of the decision maker and uses the same technology to review decisions for process improvement, in the settlement of disputes or for the investigation of incidents. Additionally, the paper discusses the application and integration of electronic and digital technology in explosives and initiation systems as engineering controls for blasting associated risks. Finally, this paper reviews two practical cases of technology integration for risk management and improved decision making; the use of integrated GPS technology in initiation systems as an engineering control in the blast evacuation process and the use of RFID technology in explosive tracking from cradle to grave.

By Ali P. Gordon, James Williams

Joints gasketed with viscoelastic seals often receive an application of a secondary torque, i.e., retorque, in order to ensure joint tightness and proper sealing. The motivation of this study is to characterize and analytically model the load and deflection re-torque response of a single 25% glass-fiber reinforced polytetrafluorethylene (PTFE) gasket-bolted joint with serrated flange detail. The Burger-type viscoelastic modeling constants of the material are obtained through isolating the gasket from the bolt by performing a gasket creep test via a MTS electromechanical test frame. The re-load creep response is also investigated by re-loading the gasket after a period of initial creep to observe the response. The modeling constants obtained from the creep tests are used with a Burger-type viscoelastic model to predict the re-torque response of a single boltgasket test fixture in order to validate the ability of the model to simulate the re-torque response under various loading conditions and flange detail.

Jan 1, 2015

By Jr. Blake

This work was done to determine the technical feasibility of using the Pedersen process to produce cell-grade alumina and an iron byproduct from the high-silica and titania bauxites of the Pacific Northwest. Smelting of these bauxites with lime and coke at about 1,750° C in an electric arc furnace produced calcium aluminate slags in which at least 80 percent of the alumina was leachable by sodium carbonate solution. After a lime-desilication of the sodium aluminate leach liquors, neutralization of these solutions with carbon dioxide resulted in precipitation of an alumina hydrate of sufficient purity for calcination to cell-grade alumina. Recoveries of byproduct iron averaged over 90 percent; however, the iron contained about 1 percent phosphorous and would require additional refining. Additional small scale tests on these slags showed the following: (1) Titania had little effect on leachability if sufficient additional lime was added to form calcium titanate (CaO.TiO 2); (2) a slag containing about 14 percent silica required a slower cooling rate than one containing 7 percent silica for formation of high percentages of soluble aluminates; and (3) high-silica slags leached better at room temperature for long periods than at 65° C for shorter periods, but low-silica slags leached well by either method.

Jan 1, 1967

By Fernando Machuca Pérez

"La minería genera una gran cantidad de desechos de material como lastre, ripios y escorias, que son depositados en un área sin considerar el impacto ambiental que estos producen. En ese sentido, el diseño de escombreras no considera las condiciones ambientales en la industria chilena, y por ello se privilegió el costo mínimo en depositar este lastre sin un diseño que considere esta variable. Por tal motivo, el objetivo general del texto es diseñar los algoritmos de secuencia de llenado de escombreras, considerando las siguientes variables forma, altura, talud y orientación, condiciones meteorológicas y económicas en su diseño, de tal manera que se produzca el menor impacto ambiental por la emisión de material particulado. "

Sep 1, 2015

By E. Van Den Neste

A concise historical review is given of the Overpelt plant and the general principles of zinc hydrometallurgy are briefly outlined, together with a description of the new electrolytic zinc plant ore roasting process and, more particularly, the original Overpelt roasting process. A detailed description of the flowsheet of the zinc electrowinning plant, .with an annual capacity of 100,000 t, successfully put into operation in May 1974, is given. The treatment of the residues is performed following the goethite process ; the purification is continuous in two steps; the tank house is equipped with cells containing jumbo cathodes; the handling and stripping of the cathodes is fully mechanized. Concluding the description, some metallurgical and other features of the project are explained in detail.

Jan 1, 1977

By E. Watkins, S. J. Schatzel, K. Ajayi, V. Gangrade

The National Institute for Occupational Safety and Health (NIOSH) has been conducting research related to unconventional gas wells positioned in abutment pillars associated with active longwall mining in Southwestern PA. The Ventilation and Explosion Prevention Team at NIOSH is working toward predicting and characterizing a hypothetical casing breach and its effect on the safety and health of mine workers, gas well workers, and the general public. An important aspect of this research is to distinguish coalbed gas from shale gas in the mine environment as an indicator of a casing breach. Another noncoal gas source exists in the region in the form of underground gas storage fields which also have the potential to migrate towards mine workings. During a potential gas breach, the addition of excess natural gas to coal mine environments will exceed the anticipated ventilation loading and can create a mine explosion hazard. A methodology has been developed to distinguish these gas sources. Gas samples from the three sources were analyzed by gas chromatography, and interpretive methods were applied to distinguish the populations graphically and statistically. Bivariate plots using the hydrocarbon index and the normalized molecular ratios showed that the sources occupy different regions of the graphs. All samples of non-coal gas contained under 2% CO2, and all coal samples included greater than this amount. A multivariate T-squared (T2) test analysis relating comparing data in pairs showed a low p-value (dimensionality parameter) and a high T2 test statistic for all comparisons, indicating that these sources are different and distinct gas populations. Ultimately, stakeholders from the mining and gas production industries can utilize this method to identify gas sources and a potential casing breach.

Mar 2, 2022

By R. Trammell, O. Eterigho-Ikelegbe, S. O. Bada

In response to the enormous amounts of coal discard generated during coal mining and preparation, the development of an efficient and sustainable strategic use of this resource is essential. Furthermore, the rising urban population over the next decades is confronted with the depletion of quality raw materials for building components. To this end, this study reports new information on the morphology, water absorption, and flexural strength properties of ceramic composites produced from three different coal discards and polysiloxane pre-ceramic polymer (PCP) resin. In addition, test results relating to the continuous operating temperature, chemical resistance, and efflorescence potential of the composites are presented. The results show that the water absorption and flexural strength of the coal composites, up to 1.94% and 36.46 MPa respectively, exceed the requirements for ceramic and clay roof tiles. The continuous operating temperature of composites is found to be more thermally stable than conventional roofing tiles (concrete and ceramic) between ambient temperature and 600°C. In addition, the excellent chemical resistance of the composites (94.43%−99.98%) compared to conventional roofing tiles (67.82%−99.97%) eliminates the need for additional external coatings. The interesting results documented so far suggest that this technique could be used to produce low-temperature application building products such as bricks, panels, roofing tiles, etc. This new recycling technique offers an excellent opportunity to eliminate enormous volumes of coal discard and to advance the circular economy in the coal industry.

Aug 2, 2022

By E. H. Henderson

Introduction Stamp-Milling and amalgamation is, perhaps, one of the oldest processes of recovering gold from its ores. Many papers, theses, and textbooks have been written on the subject of stamp-milling practice in general, but, to my knowledge, there have been no publications describing the modern stamp-mill as designed, developed, and operated in Nova Scotia. Although it may be said that the gravity stamp-mill is the most primitive, and perhaps the crudest, crushing machine in existence, it is at the same time the most satisfactory all-round milling and amalgamating device yet contrived. Originating in Saxony, and used in North America first in Virginia and Georgia, the stamp-mill, in a primitive form, later found its way to California and Colorado. Here, it speedily developed from an affair of wood shod with iron, and operated with the crudest gearing, to substantially its present form. Briefly, it consists (see Figure 1) essentially of a series of hammers (the stamps), which fall upon a mixture of ore and water contained in a cast-iron box (the mortar). The resulting crushed ore (the pulp) is splashed out through a screen on the front of the box. For some years after the discovery of gold in Nova Scotia, in 1861, the ? arrastra and Chilean mill were used to recover the gold from the rich ores. The stamp-mill followed, and various types were used, principally the California and Gilpin County types. Then, in 1895, Mr. M. R. O'Shaughnessy, one of our foremost amalgamators, conceived the idea of a new type of stampmill, which has since become standard in Nova Scotia gold mines. This mill, unique in its design and operation, is specially adapted for the most efficient extraction and recovery of gold as it occurs in our Nova Scotian ores. It is commonly known as the Underwater Feed type, as opposed to the usual Overwater or Top Feed type, and it may be rightly termed The Nova Scotia Self-Classifying Stamp Amalgamation Mill. It is conceded by experienced mill-men that it is superior to any other type of mill for recovering the very coarse and granular gold typical of the ores of this Province. The particular installation and practice to be described in this paper is that of the Guysborough Mines, Limited, at Goldenville, Guysborough county. Emphasis will be laid on certain operating innovations of extreme simplicity and high efficiency.

Jan 1, 1935

By Bill Dershowitz

Consider a deep gold orebody with grade of 4 g/t (0.11 oz/st). At the time of this writing, with gold prices at historic highs, it could be a good, but not great, prospect. But if it is a vein deposit, and those veins are 200 g/t (5.8 oz/st), it would be significantly more attractive if there was a way to produce directly from those veins, leaving the rest of the rock in place. [Figure 1 The red around each of the four injector wells shows areas of high pressure, where the lixiviant fluid is pumped into the rock mass, with orange and yellow indicating dissipated pressure. The black lines indicate some of the fracture pathways through which the lixiviant, with absorbed metal, flows toward the central recovery well where low pressure is indicated in blue. Lixiviant is pumped out through the recovery well. Image courtesy of Golder Associates.] There is a way to do this, in situ leach (ISL) or solution mining. It has been a viable commercial technology for more than five decades.

Jan 1, 2011

By M. S. Fleming

The objective was to evaluate central lubrication systems for potential use on underground mining equipment. Previous use on continuous mining equipment resulted in poor system performance because of improper selection of lubricants, component failures, and an inconsistent delivery of lubricant to the bearings. The principles and operational characteristics of systems are reviewed and evaluated, and it was concluded that systems are available which can provide reliable central lubrication if properly applied, installed, and maintained. The procedures for applying a system to a continuous miner are discussed. Investigation revealed the lack of significant information on lubrication-related equipment failures and injuries related to maintenance and repair operations, the lack of significant failure rate data for central lubrication system components, and the lack of performance standards for central lubrication systems and components. To continue the development of systems for underground mining equipment it is recommended that a data bank on failures and reliability for equipment with and without central lubrication systems be created, and standardized specifications and performance criteria be developed for central lubrication systems and components which will be used on underground mining equipment.

Jan 1, 1979

By C Fricke, R Wood, P Velletri

"In a climate characterised by an ever increasing focus on cost reduction and maximising the utilisation of existing assets and infrastructure, understanding the uncertainty associated with alternative investment and operational choices becomes paramount to minimising the risk of making an ineffective decision. To assist in this process, TSG Consulting has developed an analytic framework to capture the underlying complexity of a mineral supply chain, and then quantify the impact of the uncertainty associated with the key drivers of business productivity. The technical basis of this approach follows three distinct steps: analyse the current system and identify the major factors that drive value build detailed models that can measure the response of the system to potential changes in the factors identified quantify the sensitivity of financial and capacity forecasts to these factors.Each of the above steps draws on a different area from the field of applied analytics, namely: data analytics dynamic modelling and designed experimentation meta-modelling and optimisation.Following the three-step approach described above ensures a rigorous modelling and analysis process is executed to support strategic mine planning decisions. The approach is equally applicable to the analysis of fully integrated system supply chains (pit-to-port), the evaluation of incremental capital investments to targeted areas of a supply chain, or when considering revisions to the operating philosophy of a system in the short term. The basis of each of the three analytic steps is explored in detail in this paper. The result is the definition of a structured mechanism for a business to actively manage risk and drive productivity as a component of the strategic mine planning process.CITATION:Fricke, C, Velletri, P and Wood, R, 2014. Enhancing risk management in strategic mine planning through uncertainty analysis, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 275–280 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 24, 2014