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By I Canbulat, J Emery, L Yao and C Zhang

This paper documents a process of data analytics and machine learning applied to coalmine roof convergence data. It follows a publication documenting the formation of the database. For each set of analyses Python scripts were utilised to extract data from an SQL database, with subsequent analyses also executed in Python, utilising open-source tools such as scikit-learn. Preliminary analyses with classic machine learning algorithms included multiple logistic regression, K-nearest neighbours, decision tree, random forest, support vector machine, kernel support vector machine, artificial neural network (ANN), naïve Bayes and multiple linear regression. Results indicated that relationships were complex and non-linear, with the artificial neural network most suitable. An ANN model was then refined through a standard process of hyperparameter optimisation and data augmentation to arrive at a final model. Due to the black box nature of the ANN further insight into how the parameters interacted was sought and found with Shapley additive explanations (SHAP values). SHAP values utilise Game Theory, where each input parameter or feature is a ‘player’ while the data set is the ‘team’. The SHAP value is the impact of each player on the target value, essentially establishing the contribution of each input parameter. The results from all analyses are delivered in the paper, together with insights, applications, strengths, and limitations of the methodology.

Nov 29, 2022

By J. E. Tiffany, Gaigler. Z. C.

"PREFACEIn presenting this list of permissible explosives and blasting devices, the Bureau of Mines desires to call attention to pages 16 and 21 outlining the conditions in use under which, and only under which, the explosive or blasting device is permissible.In view of a recent publication recounting trade practice favoring the use of a blasting device without stemming, particular emphasis is placed upon condition 4 on page 16 and condition 2 on page 21. An explosive or a blasting device enumerated in the permissible lists of this Bureau is not permissible in use unless it is properly confined with clay or other incombustible stemming.PERMISSIBLE EXPLOSIVES TESTED UNDER SCHEDULE 17CAn active list of permissible explosives was published in December 1937 as part of Bureau of Mines Report of Investigations 3361, under the title ""Active List of Permissible Explosives and Blasting Devices Approved Prior to June 30, 1937.n This list included 196 brand names.Changes in the list that have been authorized to June 30, 1938, placed 7 additional brands of permissible explosives on the active permissible list as a result of tests, changes in brand names, or transfer from the inactive list. Twelve permissible explosives were transferred from the active to the inactive list. The present list contains 191 brand names. The brand names of the permissible explosives placed on the active list are as follows:"

Oct 1, 1938

By W. Graham

"IntroductionEFFLORESCENCE is herein considered to be any deposit of salts on the surface of a masonry structure that is brought from within or through the structure by capillarity and deposited by evaporation. Usually, efflorescence is white although green, yellow, and brown efflorescence is sometimes observed.The common white efflorescence almost always consists of sulphates of the alkali and alkaline earth metals and calcium carbonate, although sodium chloride is frequently present in structures erected near the sea shore.The first and most obvious result of the presence of soluble salts in masonry is the unsightly accumulation of these salts on the surface. This is particularly noticeable early in its life and is frequently fugitive ( 1), as much of the salt is soluble and is gradually washed away by rain. This removal can usually be facilitated by scrubbing; the structure with dilute hydrochloric acid.A more serious effect is the continuous accumulation of soluble salts as a result of ingress of sulphur acids in rain water or water from the ground. This may eventually cause spalling and disintegration by crystallization of salts in the pores of brick and mortar. An example of this type of failure, resulting from the crystallization of calcium sulphate, is discussed by Hardesty (2). Butterworth (3) describes similar failure resulting from •crystallization of magnesium sulphate."

Jan 1, 1954

By Shirley F. Colby

A continued rise in construction activity in 1941 forecasts further increases in the demand for building materials of mineral origin, Recent studies by the Bureau of Mines, United States Department of the Interior, reveal that sales of mine and quarry products and their derivatives as a class have followed the long-term trend of construction activity in the past and are benefiting now by the upswing in all types of building. At present most building materials of mineral origin are holding their own in the competitive arena. A few are slipping behind, but others have forged fax ahead. Prominent among those that have surpassed general construction activity since 1925 are sand, gravel, and crushed stone (used in concrete and road metal and railroad ballast) and cement. Both building stone and roofing slate have followed the building curve closely, although in the last few years sales of roofing slate have risen above the curve and sales of building stone have dropped below it. Clay products and building lime, on the other hand, have lagged behind the general procession. Gypsum sales likewise dropped behind, but during the last few years, this industry, thanks to the wider acceptance of its newer products, has staged a marked recovery so that it now stands in about the same relation to total construction activity as it did is 1927-25.

Jan 1, 1941

By Samuel O. Akande

"Gold occurs as native metal, in electrum, and in a telluride mineral in quartz carbonate veinlets of three vein systems at the Ross Mine, northern Ontario. The 14 Vein System is made up predominantly of concordant veinlets within layered ankeritic dolomite stratabound by, and conformable with, andesite tuff Individual veinlets contain pyrite, sphalerite, galena, chalcopyrite, tennantite, pearceite, proustite, native gold and electrum in a matrix of quartz, dolomite, ankerite and calcite. The 2B Vein System is made up of both concordant and discordant veinlets within andesite tuffs. The veinlets contain pyrite, chalcopyrite, sphalerite, bornite, tennantite and free gold in quartz, calcite and dolomite. The 18 Vein System is comprised of stockwork veinlets in and around intrusive syenite which has both sharp and gradational contacts with enclosing andesite tuff The veinlets contain pyrite, chalcopyrite, bornite, chalcocite, native gold and calaverite. Sulphide and silicate minerals in veinlets and wall rocks are stable assemblages for the regional metamorphism of greenschist rank. ,The 14 Vein System is interpreted as a metalliferous siliceous carbonate chemical sediment, the components of which were leached from the underlying volcanic rocks by convecting sea water and subsequently deposited on the sea floor between the extrusion of flows and pyroclastic rocks. Subsequent regional metamorphism and intrusions remobilized and redistributed the syngenetic stratabound material into dilatant fractures in adjacent tuff, as in the 2B and the 18 vein systems."

Jan 1, 1982

By A. R. Javadi

Pyrite (FeS2), chalcopyrite (CuFeS2), sphalerite (ZnS) and galena (PbS) generate hydrogen peroxide (H2O2) when placed in water, with pyrite generating the most amount of H2O2. The order of these minerals for generating H2O2 in water is: pyrite > chalcopyrite > sphalerite > galena. In previous research, the methods of generation of H2O2 in the grinding mill were studied. In this study, data from experiments were included by using MODDE 9 software for six parameters composed of water, grinding media, particle size; adding collector to the grinding, and adding depressant and pH. Finally the optimal condition was achieved. According to the results, most of the recovery is related to the particle 75 μ size and when using processed water, adding 100% collector and without depressant and pH 10. The most recovery of lead in the case of the use of fresh water is in the case of 100% collector, without depressant, pH 10 and 150 μ particle size. Maximum recovery in fraction size 45 μ in the case of water process is 100% collector, without depressant and pH 10. Maximum depressant of pyrite will be the fraction size 75 μ, distilled water, without collector, 100 depressant. Keywords: Sulfide mineral, hydrogen peroxide, flotation, oxidation

Jan 1, 2020

By John T. Aydelotte, Martin J. Gavin

" Oil shale contains little or no oil as such , but it contains an organic material from which oil may be produced by destructive distillation" . This statement , or others conveying the same meaning, appears in many popular and techni cal articles on oil shale . It is based on the belief that the ordinary solvents of petroleum have but little action on the organic substances contained in oil- yielding shales , although on distillation these same shales may yield upwards of 50 gallons of crude shale oil per ton . A 50 - gallon shale thus yields by distillation 18.73 per cent of its weight as oil ( assuming the specific gravity of the oil to be 0.900 ) , although only a relatively small part of this can be recovered by extraction with such solvents as chloroform , carbon tetrachloride , and the like . In the course of certain experiments designed to determine the solubilities of different shales after they had begun to yield oil by distillation , it was found desirable to determine the quantity dissolved from certain unheated shales by various solvents , at or near the boiling points of these solvents . The method used and results obtained are presented below. These experiments were made in connection with the oil - shale investigations being conducted by the U. S. Bureau of Mines , in cooperation with the States of Colorado and Utah .

Jan 1, 1922

By Allan H. Caverson

Over the past nine years a means for measuring the distance between the mine roof and floor has been developed at the White Pine Mine which yields relevant information utilized in the mining operation. The technique known as "convergence!' is an efficient, low cost way for obtaining large quantities of data for predicting roof falls, caving activity, and overall mine stability. From a limited introduction in 1964 related to monitoring an experimental longwall project, the activity of convergence measurements has been expanded to become a production tool now found in all sections of the mine. Presently, the program involves four main types of activity: 1. Monthly measurements in areas known to be active, and in sample blocks scattered throughout the mine for a long-term stability study. 2. Semi-monthly measurements along vital travel roads, belt drifts and compressor sites. 3. Weekly measurements in areas where men are working. 4. Daily measurements in pillar-recovery and caving operations. Today, one field engineer and six technicians are involved full time in convergence work. Rock Mechanics technicians have installed approximately five thousand stations since the start of the program and of this number, over twenty-five hundred active stations still comprise the mine-wide network spread over the more than five square mile extent of the White Pine Mine workings.

Jan 1, 1973

By John L. Schroder

The demands for increased productivity on the 1967 coal industry have generated new operating trends and fresh approaches to old methods, which have enabled the industry to keep pace with the expanding economy. Changes, while not radical in concept or design, have been plentiful and are marked by the refinement of the already tried, tested and proven. Perhaps not since World War II have there been demands on equipment manufacturers to design and deliver such diversified types of machines as those required by the industry in the past year. Equipment developments-following a plan which calls for higher productivity, lower maintenance costs and greater machine availability- have tended more toward increased horsepower and heavier, more rugged equipment. Electrical and mechanical components, designed in many instances with maximum reliability rather than initial costs as the main criterion, have contributed to the improvements in over-all performance. High-strength, specialty steels are finding use in a wide range of equipment applications. The horsepower capacity of electric motors being installed is more frequently being rated on a continuous basis rather than the former one hr or less and, as a result, fewer failures now occur because of overloading. These developments reflect the pyramiding cost of equipment down-time and represent definitive progress in reducing the magnitude of the problem.

Jan 2, 1968

Develop and evaluate a mechanical position and heading system (MPHS) that provides information about underground mining machine position and heading to aid in the remote positioning of mining machines during face maneuvers. Background While great improvements have been made in mineworker safety, progressive technology continues to create a safer, better working environment for miners by keeping them away from the dangerous face area. In maintaining such high standards of safety, the Bureau is investigating remote, computer-assisted operation of mining systems for underground, highwall, and surface mining applications. A key component of computer-assisted operation is a guidance system. Since there are no guidance systems on any commercial continuous mining machines, the Bureau itself developed and tested the mechanical position and heading system (MPHS). The MPHS is based on linear position transducers (LPT's), and operates on principles of triangulation to provide machine position (xy coordinate), and orientation in the xy plane (yaw or heading). These data are needed in order to keep the continuous mining machine in proper alignment before and during the cutting cycle. The MPHS theory development is in three parts: characterize the sensors used and their configuration; select and define the navigation reference frames; and derive a closed-form solution for determining the position and beading from sensor information. Application of the MPHS theory required the development of hardware, software, and system interfaces.

Jan 1, 1992

By G. K. Burgess

(New York Meeting, October, 1913.) 1. COOLING AND HEATING CURVES BY G. V. BURGESS AND J. J. CROWE. § 22. THE results published in Professor Howe's paper 10 of our determinations on the Ac3 and Ar3 points for a series of commercial carbon steels 11 containing manganese in varying proportion, represent the average temperatures found by taking several (4 or 5) heating and cooling curves. The accompanying curves, Figs. 6 and 7, are, for each steel, the first heating and cooling curves as obtained by' the inverse-rate method of Osmond, using a cylindrical chronograph sensitive to -0.1 sec. for recording .time. Simultaneous observations were also taken by the differential method with a platinum neutral and plotted by Rosenhain's derived differential method and gave substantially the same results, the curves having sensibly the same contours in both cases.12. The observations were taken in vacuo on cylinders 5/8 by 1 in. in length bored to center with a 1/8-in. hole to receive porcelain insulated thereto-couple, and inclosed in an out- and in-glazed Berlin porcelain tube heated electrically by, platinum foil wound on the tube. The vacuum was usually better than 0.1 mm. The heating and cooling of the furnace was automatically controlled by a salt-water rheostat with shaped electrodes, giving a uniform rate of heating and cooling.

Jan 6, 1913

By W. H. Mathews

"The Hardie group of cinnabar claims is in the interior of British Columbia; 25 miles northwest of the city of Kamloops. It is one of a number of mercury; properties scattered along a north trending belt 20 miles long and up to 5; miles wide. In all but one of these properties cinnabar is associated with; dolomite veinlets in zones of carbonate alteration in bedded rocks of Triassic; and Cretaceous (?) age; or in intrusives cutting these bedded rocks. No dolomite alteration or cinnabar mineralization is known in the undoubted Tertiary rocks adjacent to the mercury belt.The mercury showings of the Hardie group lie for the most part in a granitic stock cutting Cretaceous (?) volcanics. The rock in this intrusive shows marked variations in texture and has been described in earlier reports as granite and granodiorice, granite porphyry, and trachyte or dacite porphyry. At Hardie mountain the cinnabar mineralization, unlike that of the other properties, is associated with a fine-grained, almost chalcedoni c, quartz; carbonates, though present, are of minor importance. Some of the most interesting showings are found in an adit in the southeastern part of the property where cinnabar mineralization shows a very distinct structural but not a genetic relationship to a brown porphyry dyke 2 to 8 feet wide cutting a phase of the stock that may best be described as aplitic"

Jan 1, 1954

By Venugopal B, M Kumaran, Thomas John, Vetriselvan A

The initial pile load tests are conducted to ensure the geotechnical capacity of the pile in a particular site condition. Normally kentledge method is adopted for the compression pile load tests. In this method the entire kentledge load is loaded above secondary beams which are supported by concrete blocks above the Natural Ground Level. So, it is important to ensure the SBC (for shear and settlement) of the natural ground. In one of our projects initially it was decided to go with kentledge system for initial compression load test on 56m long 1200mm diameter BCIS pile. The test load and total kentledge load were 2160t and 2700t, respectively. The soil strata mainly consisted of clay with low SPT N value and water table almost at ground level. It was suggested to replace top soil using Granular Sub-base (GSB) with good compaction in order to avoid excessive settlement of concrete blocks placed to support the kentledge weight. When the kentledge loading started, even before reaching 10% of total kentledge load, excessive settlement on the GSB layer was observed. This paper describes the problems faced during normal kentledge method and how it was overcome using the liner pile system for initial compression load tests in this particular site condition for higher test load.

Nov 1, 2022

By JOHN HOMER, KATHLEEN STABRYLA, JACOB L. CARR, JONATHAN K. HRICA, JENNICA L. BELLANCA

Given the recent focus on powered haulage incidents within the U.S. mining sector, an appraisal of collision avoidance/warning systems (CXSs) through the lens of the research literature is timely. This paper aims to evaluate the maturity of CXS technology through the application of a technology readiness assessment (TRA) to research literature identified by systematic search methods. Results indicate that much of the evidence for CXS performance is at lower levels of maturity: that is, components and prototypes tested in a laboratory and in relevant environments. Less evidence exists for CXS performance at higher levels of maturity — that is, systems evaluated within operational environments — despite the existence of commercial products in the marketplace. This lack of evidence at higher maturity levels within the scientific literature highlights the need for more peer-reviewed research to evaluate CXS technologies. Additionally, results of the review reveal that most of the literature relevant to CXS technologies is focused on vehicle-to-vehicle interactions, which contrasts with haul truck fatal accident statistics that indicate most are due to vehicle-to-environment interactions, such as traveling through a berm. Lastly, the relatively small number and segmented nature of relevant studies suggest there is a need for more incremental research that would better facilitate the improvement of CXS technologies. This progression could be achieved through continued long-term interest and support for CXS technology research.

Mar 1, 2023

By James E. Maccariella

Replacement of an existing movable bridge with a new low level fixed bridge would not accommodate potential future navigation traffic. In order to replace the existing bridge in a cost effective manner, while accommodating the potential future needs of the Port of Salem, a new bridge was proposed that would permit conversion to a vertical lift type movable bridge should a potential need for upstream navigation warrant such a project in the future. Drilled shafts were found to be the most desirable foundation type for the replacement of the Route 49 Bridge over Salem River. Their ability to resist scour, be constructed without cofferdams, adequately resist vessel collision forces, and accommodate conversion to a future vertical lift bridge allowed the project to meet both the needs of the New Jersey Department of Transportation and the Port of Salem.

Jan 1, 2005

By Raymond B. Lucas

"Distinction between Tripoli and Diatomaceous EarthMuch confusion exists both in the literature and in the trade as to the proper use of the terms tripoli, tripolite diatomeceons or infusoriai earth, and kieseigunr. All of these terms are often used synonymously by the trade and even in mineralogists and other reference books. Actually, tripoli is a ma- is a material of definite and distinct physical and chemical properties and all of the other terms belong to a different material with just as definite and distinct properties.Originally the term tripolite (loosely called tripole) was given to a diatomaceous cart from Tripoli in Northern Africa. Dena (J.D. Dana, A System of Mineralogy 6th Ed.) calls this material tripolite and gives no authority for the use of the terms tripoli. Between 1880 and 1890 the deposits near Missouri, were opened and the material placed on the market as ""Tripoli"" no doubt due to its resemblance in some respect to the original tripolite or diatomaceous worth from Tripoli. Since that time the term tripoli has with increasing definitenesss been reserved for the Seneca material and other siliceous of similar origin and physical properties, while all siliceous material of organic origin, containing dilators, has been called diatomaceous earth (or its synonyms infusorial earth, kiselguhr, etc.). Rottenstone is sometimes classed with tripoli."

Nov 1, 1920

By MAGNE MORTENSON

IN laboratory work and industrial tests it is important to set forth the results of research, clearly. This is generally achieved by means of some form of diagram or graphical illustration. The most common form for such graphs of flotation research is a simple chart with two curves for percentage and recovery of the concentrate. This may be quite useful, especially for minerals which may be floated: by means of one reagent in variable and another in constant amounts. If both reagents are used in variable quantities the process may be illustrated by means of several diagrams, .keeping one reagent constant in each series of tests. A more useful form of diagram for a. system with two variable - components (reagents) may be established by drawing a chart with the weights of the two reagents as .abscissas and ordinates. Every test is marked down -in the diagram with an indication of the extraction and concentration gained. In this diagram there are drawn lines for equi-extraction and equi-concentration of the mineral that is floated out in the - concentrate. The contour of these lines gives a relatively clear impression of the conditions for flotation by means of .the chemicals used. The best conditions are of course found in diagrams where the 'areas for maximum extraction and high conntration are coincident

Jan 1, 1931

By W. P. Diamond

The Bureau of Mines has been involved in the drilling of vertical, horizontal, and directional coalbed gas drainage boreholes for mine safety since 1964. In that time, boreholes have been drilled in most of the major coal regions of the United States under a wide variety of geologic conditions. Many of the geologic conditions that occur in the coal measures are detrimental to gas drainage; others may be beneficial. Analytical techniques to determine the gas content of coal samples and evaluate regional trends of gas distribution have been developed. Drilling techniques that maximize the acquisition of coalbed gas data and geologic information have been determined. Although some of the geologic factors influencing the placement and potential success of coalbed gas drainage boreholes have been reported in papers on individual projects, a complete, systematic compilation has not previously been available. The objective of this paper is to pro- vide information on specific geologic factors that should be considered prior to, during, and after the drilling of coalbed gas drainage bore-holes. Many of the commonsense considerations that have been learned through many years of Bureau of Mines experience, but have generally not been reported formally, are included for those who may be considering coalbed gas drainage drilling for the first time, or who have not had the opportunity to encounter a substantial number of geologic situations.

Jan 1, 1982

By D. A. Donato

It is often necessary for a mining company to extract coal from a seam underlying a previously mined coal seam. The impact of the overlying mine workings on the stress distribution within the underlying mine workings is very difficult to assess without the use of numerical modeling techniques. This paper demonstrates the usefulness of applying numerical modeling to evaluate alternate startup-room locations for a longwall panel considering the effects of multiple seam interaction. MULSIMIPC, a code adapted by the former U. S. Bureau of Mines, was used to compare stress patterns in two proposed startup-room locations. These model results were not only compared to each other, but also to results from a model with no overlying mine workings to provide baseline criteria for evaluation of the two proposed startup-room locations. The numerical modeling study was successful in providing useful information to the coal company and the regulatory agency (MSHA), resulting in a mine design that was both safe and efficient, and prevented the sterilization of a large volume of coal reserves.

Jan 1, 1996

By J. G. Reid

Nickel is second only to aluminium, of all non-ferrous metals, in energy required to convert the ore to metal. Nickel Laterite ores, which constitute the feed source for approximately 40% of world nickel production, are at a particular disadvantage because of the absence of sulphur, as an energy source, in the ore and because lateritic ores general 1 y are not amenable to beneficiation. The dramatic escalation of oil prices which commenced in 1973 and continued for a decade meant that Nickel Laterite refineries using oil as a primary energy source were placed at a distinct disadvantage relative to refineries utilizing nickel sulphide concentrate feeds. By the late 1970's the continuing large difference in oil and coal prices caused Greenvale to consider converting certain high oil consuming areas of the refinery to coal. These investigations confirmed that the areas of ore drying and power generation, which together consumed 50% of total Plant oil requirements, could be economically converted from oil to coal firing. Construction of the coal conversion facilities commenced in October 1980 and the first ore drying air heater came on line in August 1981. Construction was completed with the commissioning of the coal fired boiler in June 1982. This paper outlines the additions required to receive and utilize coal in ore drying and power generation and how the changeover was completed with minimal process disruption.

Jan 1, 1988