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By M. Wang, Z. Sui, T. Lou

After smelting, the associated mineral ore accompanying Valuable Metal Compounds (VMC),such as titania and borate in BF., most of the VMC were separated from the metal into the molten slag that is an associated slags. Based on several case studies in laboratories and in a practice in a pilot plant on the associated slags , there occur a feasibility to recovery VMC from the slags by anew process- Selective Precipitation Technique (SPT) on which three continuous steps are involved: (1) The selective enriching the dispersed VMC into a designed mineral phase in the molten slag; (2) The selective coarsening the designed mineral phase with large crystal grain size;(3) The selective separating the coarsen phase from tailing by mineral dressing or hydrometallurgical process . Some results on the recovering the VMC from the associated slags by SPT were summarized as examples in present paper. Keywords: selective precipitation technique, associated slag, recovering metals from slag.

Jan 1, 2004

By LaTasha R. Swanson, Jennica L. Bellanca

Proximity detection systems (PDSs) for mobile machines have the potential to decrease injuries and fatalities. Early adopters of the technology have identified some challenges, which present an opportunity to explore and improve the integration of mobile PDSs in underground coal mines. The current research study applied the task-technology fit framework to investigate the fit between mobile PDS technology and mining relative to health and safety, from the perspective of leaders at two coal mines. Quantitative results from the study show that mine leaders evaluated mobile PDS favorably for training and ease of use, system feedback, user authorization and experience, and less favorably for safety, compatibility, task completion, and reliability. Qualitative results reveal specific task, mine, and system characteristics that may have influenced leaders’ evaluations. The study includes considerations and suggestions for safe technology integration

By A. Habibi

The ventilation survey was conducted in an underground longwall trona mine. The mine is relatively shallow and categorized as a gassy mine. The ventilation system consists of nine shafts (three intakes and six exhausts). Three surface based axial fans ventilate the mine configured in a blowing arrangement. Following the ventilation survey airflow quantity, frictional pressure losses and air psychrometric characteristics have been quantified. An accurate resistance survey has been conducted to calculate the pressure drop with regard to moving cages and skips in the shafts. This paper discusses the benefits of utilizing high accuracy digital pressure transducers and psychrometers in a ?leapfrogging? survey to gather data needed to build the computer ventilation model. Two underground booster fans with VFD are currently idle but available at the mine. The ventilation model has been used to determine the optimal booster fan locations to decrease the overall operating cost by reducing the load carried by the main fans. A leakage study has been conducted to evaluate the effects on the system of additional pressure from a booster fan. The study finally prepares a future ventilation model for the next fifteen years of mine operation and investigates the effect of proposed scenarios.

Feb 27, 2013

By S. J. Gerdemann

In support of its objective to improve mine safety, the Bureau of Mines has searched for better materials and systems to anchor roof bolts. TIlis report describes a study on the effects of mine waters upon accelerated gypsum, one of the materials under consideration. The accelerated gypsuw dissolved at an appreciable rate relative to an assumed 10-yr life span of a roof bolt. Surface orientation, initial ion concentration of a dissolving solution, and flow rate of the solu-tion had substantial effects on the dissolution rate. Factors such as water-cement ratio, accelerator content, wax capsule additions to the gypsum in cartridge-installed bolts, surface area, temperature, and curing duration had little effect. In an actual roof-bolt environment, dissolution will occur in static solutions to the solubility limit of gypsum (~2 giL) and cease, result-ing in minimal damage; but in flows of unsaturated solution as slow as 1 L per month, a loss of up to 10 pct will occur in 2 yr. Since miners cannot readily measure the flow or ion concentration of static-appearing water at every roof-bolt site, all such water must be assumed to be pure and flowing. It is recommended that gypsum-bonded roof bolts be confined to dry roofs only.

Jan 1, 1983

By G. A. Christie

This paper presents a vision system capable of providing an accurate estimate for the volume of stockpiles using 2D images. By imaging a stockpile from multiple viewpoints with a two-camera system, a 3D point cloud of known scale is generated using image-based 3D reconstructions. With a small amount of user interaction, the points that correspond to the surface of the stockpile are extracted and used to measure the volume. The hardware required for the two-camera system is light enough to be carried by a small unmanned aircraft and is a cheaper alternative to LiDAR while still being competitive in terms of accuracy. When testing the volume measurement algorithm on a stockpile of known volume, the measured output was found to have less than a 3% error from the ground truth.

By K. A. Stanley, N. A. Karl, D. R. Wilburn

"This summary of international mineral exploration activities for the year 2014 draws upon information from industry sources, published literature and specialists in the U.S. Geological Survey (USGS) National Minerals Information Center. The summary provides data on exploration budgets by region and mineral commodity, identifies significant mineral discoveries and areas of mineral exploration, discusses government programs affecting the mineral exploration industry and presents analyses of exploration activities performed by the mineral industry.Three types of information are reported and analyzed in this annual review of international exploration: 1) budgetary statistics expressed in U.S. current dollars provided by SNL Metals & Mining (SNL) of Charlottesville, VA; 2) regional and site-specific exploration activities that took place in 2014 as compiled by the USGS and 3) regional events that affected exploration activities including economic, social and political conditions, which were derived from published sources and discussions with USGS and industry specialists. Commodity and regional compilations are presented in this summary. Because multiple sources are used to develop these compilations, statistics may differ depending on the source and type of data that are being reported.The SNL data summarize planned company budgets for worldwide exploration activities in 2014 for 19 nonfuel mineral commodities based on company surveys. Research focused on precious metals (gold, platinum-group metals and silver), base metals (cobalt, copper, lead, molybdenum, nickel, tin and zinc), bulk commodities (iron ore, phosphate and potash), and specialty mineral commodities (diamond, lithium, niobium, rare-earth elements, tantalum and uranium). Information on uranium exploration activities was included for the first time in 2007. Data on lithium, niobium, phosphate, potash, rare-earth elements and tantalum were compiled for the first time in 2010 because of their increased significance. Since 1999, companies with exploration budgets of $100,000 and greater were included in the SNL compilations. SNL budget estimates exclude bauxite, coal and oil and gas. Exploration budget estimates for iron ore have been compiled since 2011 but reported separately. The 2014 SNL company survey is reported by SNL to cover an estimated 95 percent of the world’s nonferrous, nonfuel mineral exploration budgets. The 5 percent that is not covered includes companies that chose not to participate in the SNL survey, private companies that do not publish their budget data, and government-funded exploration activities"

Jan 1, 2014

By M. C. McCall

When electric current of any appreciable magnitude flows from a power line into the earth, a change sometimes takes place in the conditions of resistivity immediately surrounding the electrode or medium of contact. If the conducting medium is composed of moist earth or clay the effect is to increase rapidly the resistance. If the conducting medium is coal or a coal bed, the effect is one of slowly decreasing resistance as the coal is carbonized, If, however, the flow of current is not enough to carbonize the coal, it will dry slowly, with a resultant increase in resistance. Measuring ground resistance, or impedance, with conventional commercial ground testers does not always indicate the current that will flow in the earth circuit from a direct-current or an alternating-current power circuit. The exact reason for this has not been determined however, it is thought to be due to the comparatively minute currents used for such testing. A typical ground, tester used by the authors for this work indicated a maximum current of 25 milli-amperes. The frequency of this testing current also has an effect on the readings in all probability. While the possibilities of the effects of varying frequencies has by no means been fully explored in this investigation, there are very definite indications that the impedance of a circuit through a section of earth will vary in some inverse relationship to the frequency of the applied voltages. This is evident at ordinary power-line frequencies ns well as at higher frequencies up to 200 kilocycles, which was the highest frequency available for tests in this investigation. This report is written in the hope that it will stimulate further investigation of the possibilities suggested for communication and the development of safety devices for increased electrical safety in coal mining.

Jan 1, 1952

By Peter Cain

The paper presents previously unpublished results derived from an unique interaction moitoring program conducted in the Sydney Coalfield of Nova Scotia. An abandoned, sealed longwall gateroad was re-entered and instrumented prior to extracting a longwall face 140 m below it. Instrumentation included piezometers connected to a constant head tank to monitor subsidence, and horizontally mounted extensometers to measure strains associated with subsidence. Survey levelling data was also collected. The monitoring results have allowed a number of significant conclusions to be drawn, all of which were either unanticipated or contradict current mainstream thinking. Firstly, interaction subsidence was less than anticipated. Secondly, the effects of rate of face advance on the development of the subsidence profile are evident. Thirdly, compressive strains are shown to remain in the subsided strata. Finally, strata response to undermining was almost immediate. The impact of these findings on the extraction of longwall panels beneath flooded workings in the Sydney Coalfield are discussed.

Jan 1, 1996

By B. T. McClure

Oxidizing catalytic converters are sometimes used by underground mine operators as an emission control device to reduce odor, hydrocarbon (HC), and carbon monoxide (CO) emissions from diesel equipment. The objectives of this report are to quantitatively assess the effects of catalytic converters on diesel exhaust emissions and to make recommendations for their use. Information in this report is from a literature survey and contract research supported by the Bureau of Mines. Catalytic converters are effective in reducing CO, HC, and odors when the exhaust temperature is high enough so that the converter remains above 250° C. Converter temperature is dependent upon engine duty cycle. Catalytic converters increse sulfate emissions and slightly in- crease oxides of nitrogen (NOx) emissions. If low sulfur fuels are not used, the increase in sulfate and nitrogen dioxide (NO2) emissions can offset any advantages of the catalytic converter as measured by the emissions quality index (EQI). In addition, in vitro bioassays have shown that catalytic converters produce soluble organic compounds, which have increased mutagenic activity with respect to untreated exhaust. Based upon criteria recommended by a joint Canadian-United States research panel, catalytic converters should only be used in special circumstances in underground mines. Vehicles equipped with catalytic converters should operate under moderate to heavy load conditions, and use fuel with a sulfur content less than 0.1 pct.

Jan 1, 1988

By H. Jang, Y. Kawamura

Unplanned dilution and ore loss directly influence not only the productivity of underground stopes, but also the profitability of the entire mining process. Stope dilution is a result of complex interactions between a number of factors, and cannot be predicted prior to mining. In this study, unplanned dilution and ore loss prediction models were established using multiple linear and nonlinear regression analysis (MLRA and MNRA), as well as an artificial neural network (ANN) method based on 1067 datasets with ten causative factors from three underground longhole stoping mines in Western Australia. Models were established for individual mines, as well as a general model that includes all of the mine data-sets. The correlation coefficient (R) was used to evaluate the methods, and the values for MLRA, MNRA, and ANN compared with the general model were 0.419, 0.438, and 0.719, respectively. Considering that the current unplanned dilution and ore loss prediction for the mines investigated yielded an R of 0.088, the ANN model results are noteworthy. The proposed ANN model can be used directly as a practical tool to predict unplanned dilution and ore loss in mines, which will not only enhance productivity, but will also be beneficial for stope planning and design.

Jan 1, 2015

By E. A. Anundsen

The prevention of accidents is considered a necessity at all branches and divisions of the Phelps Dodge Corporation copper-producing operations, and since there is a continual exchange of data on safety accomplishments between the various units, their safety programs are fundamentally similar. Variations in accident-prevention methods result from a difference in emphasis rather than from a difference in the elements themselves. The main copper-producing operations of the corporation ore conducted in Arizona and distributed as follows: Copper Queen Branch, mines division, Fisbee, and smelter division, Douglas, Aria.; Morenci Branch, mines division, Morenci, and smelter division, Clifton, Ariz.; New Cornelia Branch, Ajo, Ariz.; and United Verde Branch, mines division, Jerome, and smelter division, Clarkdale Ariz. As it is not feasible to describe here the safety programs of all branches and divisions, the program at the Clarkdale smelter has been selected for discussion. The United Verde Brach includes the mine and smelter purchased by the Phelps Dodge Corporation in February 1935 from the United Verde Copper Co. The mine at Jerome and the reduction works at Clarkdale are designated, respectively, as the mine and smelter divisions.

Jan 1, 1939

By W. P. Yant

Canister-type gas masks Pave become an essential part of the equipment of many industries, not only for use in .emergencies, but also in performing normal operations of industrial processes and procedures, particularly where ventilation is not practically or economically feasible. They are also used widely for enhancing safety of operations which previous to the development of gas masks had been performed in harmful atmospheres. Since the inception of industrial gas masks the Bureau of Mines has been actively engaged in endeavoring to increase the efficiency and safety of these devices, and this bureau bas become a source of advice to manufacturers in producing devices of good quality and to industry in the proper selection and use of these devices. In order to give first-hand information and keep current with the demands and needs of industry it is necessary to perform investigations from time to time. This report deals with tests of certain types of commercial gas-mask canisters for protection against mercury vapor.

Jan 1, 1932

Greater use should be made of lineations in investigations of the engineering properties of rock masses and in structural studies guiding prospecting programmes.A prominent alignment of elongate mineral grains and stretched pebbles usually marks the primary direction in which metamorphic rocks have been extended by flow. In local adjustment zones separating masses that have extended different amounts, this lineation has been a direction of slip. Kinks and crumples resulting from this slip lie in secondary lineation directions transverse to the primary mineral lineation.During deformation relatively mobile materials move into dilatant zones caused by irregularities in primary flow directions. This secondary movement transverse to lineated, primary-flow directions is the cause of crenulations and folds with axes parallel to flow lineations.INTRODUCTIONThe arrangement of inequidimensional particles in rocks is rarely statistically random. Platy minerals tend to be parallel to bedding and foliation planes. Elongate particles and linear structures lie most frequently in certain lineation directions. The types of elongate particles in lineated rocks include needle and blade shaped mineral grains, sheared out segregations, and stretched pebbles, amygdules, and aolites.Crenulations and kinks are the most common of the linear structures involved.Faint lineations are readily overlooked. Even strong lineations have been ignored. This is unfortunate as even weak lineations may be important.Use of lineation information Well-developed lineations influence the mechanical properties of rocks. Quarry workers have long known that the mechanical properties of rock masses vary directionally...

Jan 1, 1965

By V. Tathavadkar

Worldwide TiO2is extracted from natural ilmenite, rutile, and anatase minerals via the sulphateand chloride processes. The sulphate process generates large volumes of less toxic wastes, whereas the chloride process, including the ilmenite-chloride process of DuPont, yields much lower volume of wastes, which are highly toxic and hazardous. The treatment and disposal of such hazardous chloride wastes is both expensive and difficult in terms of long-term monitoring. Besides the waste management and disposal, there is also a shortage of high-grade titanium dioxide minerals in nature, which consequently yields much larger tonnages of sulphate and chloride wastes. In the present investigation we report the results of an alternative titaniferous mineral beneficiation process based on soda ash roasting of minerals. Compared to the conventional processes for beneficiation of TiO2- ores, the alkali roasting of titaniferous offers several advantages including the zero process wastes. In the soda ash roasting process, the mineral is mixed with sodium carbonate and heated above 1023 K in air. The oxidative roasting of ores yields several complex alkali compounds, some of which produce a liquid mixture above 1123 K. In this paper, we have attempted to characterize the composition and physical chemistry of alkali-rich liquid phase. The phase equilibria in the Ti-(M:Fe)-Na-O system are evaluated and compared with the phases formed as a result of roasting reaction. The experimental results revealed that the composition of complex alkali liquid at the reaction interface plays an important role in determining the transport of O2-ions and decomposition of ilmenite. The roles of the crystal structure of mineral phases and their energetics are also emphasized in controlling their decomposition during alkali roasting. The presence of molten alkali in controlling the partitioning of water-soluble alkali salts and insoluble sodium titanate is also explained. Keywords: ilmenite, anatase, alkali roasting, phase equilibria.

Jan 1, 2004

By D. Nag, J. Fernando

Hazelwood Power Mine is one of the largest open pit brown coal mines in Australia. The removal of overburden is the first step in coal winning operation. The primary aim of construction of overburden dump is to provide an effective stable working surface for stacker. The paper discusses site investigation techniques used to determine dump soil properties, stability analysis method using GALENA and GWEDGEM, results of stability analysis. The paper concludes with recommendation for a safe dumping strategy for level 2 stacker dumping.

Jan 1, 2003

By J. Grumer

The Bureau of Mines, under the sponsorship of the Space Nuclear Propulsion Office, conducted a laboratory-scale hydrogen safety study which determined several combustion characteristics of hydrogen diffusion flames. Experiments show that ambient air may enter the top of a hydrogen flare stack when the hydrogen flow is low. A new concept, supported by photographic evidence, predicts that diffusion flames burning in air on a wide, upright pipe (stack) and fed with slow, upward flows of buoyant gas will induce a downward flow of air along the walls of the pipe that can support combustion within the pipe. Predicted flamedip limits agree roughly with experimental values determined on 6-, 12-, and 18-inch-diameter stacks and increase with increasing stack diameter. Measurements were made of the limiting flow at which a hydrogen diffusion flame blows out in still air. By means of an empirical application of the critical boundary 8 velocity gradient concept, these data lead to a blowout limit of about 10 reciprocal seconds for a hydrogen diffusion flame. Burning rates of large hydrogen diffusion flames ranging from about 0.03 to 1 ft/sec were used to predict approximate flame heights on flare stacks. Temperatures of larger hydrogen diffusion flames up to about 3,600° F were observed, but the most representative value appears to be about 2,600° F. It was found that crosswinds do not strip significant amounts of unburned hydrogen from its diffusion flame and that water-cooled flare stacks are not likely to be damaged when flame is blown back into them by opposing winds.

Jan 1, 1970

On a worldwide basis trackbound transportation is on the decline. As mining operations progress from open cast operations to underground operations, most utilise mechanised equipment. However, in South Africa hard rock mines, only a small percentage (¦10 per cent) of the production can be generated by mechanised methods and therefore trackbound mining methods will remain the dominant means to transport ore. In the Australian context there may be occasions where the nature of the orebody would dictate the use of rail transportation with the ore being transported from drawpoints by means of locomotives and hoppers. This paper focuses on horizontal rail haulage systems from the stope loading boxes to the shaft station area and will be largely based on South African experience. It is intended that this document will provide a practical guideline for mine designers and planners during the design process. The paper looks at trackbound transport systems and evaluates such items as construction and management of an underground rail haulage system. Current transportation systems for personnel, material and rock transportation are evaluated, gaps in technology highlighted, and recommendations made.

Jan 1, 2005

By Lloyd Williams, R. E. Hershey, B. W. Gandrud

"1. The investigation shows that the Sewanee bed is the only bed of major importance in Marion County, 97 percent of the coal mined in the county having come :from this bed. There are coal reserves in minor quantity in the Battle Creek bed, and production from this bed depends on a few small truck mines. The Richland bed, or Lower Sevanee has been mined in the past, but no coal has been produced from it in late years. There are no production records of any other beds in the county, although some coal has been produced from them.2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and on l,800 tons per acre-foot of coal in place, are estimated to be 61 million short tons as of January 1, 1953. Of this total, 55 million short tons is in beds 28 inches and more thick. Areas in each bed ·were omitted from the estimate where available data relative to the bed characteristics are too meager to permit making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.3. Recoverable reserves of coal are estimated in beds 28 inches and more 'thick. This recovery is based on total thickness of coal in the bed (less partings 3/8-inch thick or more), rather than on the thickness of the coal actually mined. This thickness is about the minimum now being mined by hand loading onto conveyors in the Appalachian Region. The combined weighted average recovery for the Sewanee and Battle Creek beds in Marion County, as determined by this investigation, is 60.9 percent. Based on this, the recoverable reserves of coal in Marion County are estimated at 34 million tons."

Oct 1, 1955

By Oyku Selimoglu

The key to successful mine production plan and subsequent operation is efficient mine layout design and optimization. Pit layout design and optimization allow the delineation and extraction of mineable reserves and the minimum waste subject to slope stability, economic, quality and quantity constraints. Many design and optimization software packages have been developed to aid this intensive and challenging process. These packages include VULCAN, SURPAC, DATAMINE, GEMCOM, MICROLYNX, MEDSYSTEM and MINESIGHT. These software packages are developed as integrated computer-aided systems used for database creation, survey, geological and geostatistical modeling, mine planning and production optimization and environmental modeling. In Turkey, many mining companies still plan and design mine layouts with traditional hand methods. In this study, VULCAN has been used to design and optimize the Eti-Bor A.S. Kestelek Boran Open Pit Mine in Western Turkey. The main objective is to show the company the superior advantages of mine planning software for designing and optimizing mine layouts over the traditional hand methods. Drill hole data used by the company to estimate the reserves for planning are used in this study. The ore grade varies between %1,04 B2O3 to %47,33 B2O3. The pit toe and crest strings are projected using variable batter angles and berm distances. On the north side, batter angle is 180 and berm distance is 25 meters, on the south side, batter angle is 320 and berm distance is 15 meters. In addition to that open pit bench height is 10 meter. The concepts of block modeling are applied to the Kestelek open pit mine with detailed ore grade modeling for each block. The Lerchs-Grossmann?s algorithm is used to optimize this mine based on the block model, the economic block values for each block and the underlying field constraints. The results from VULCAN were similar to the estimates by hand. The reserve estimates from VULCAN is 13,192,870 tons compared with the hand estimate of 13,200,000 tons, overburden estimates of 15,622,889 m3 compared with 15,000,000m3 obtained by hand with a stripping ratio 1.18:1 (m3:ton) from VULCAN versus 1.14:1 (m3:ton) from hand estimate. Vulcan improves the efficiency, speed and reproducibility of the planning results. It provides mining engineers, geologists and surveyors with a cost-effective modular system for assessing and planning the mine layouts. Furthermore, Vulcan?s specific modules allow efficient access and manipulation of databases, open pit mine design, block models, optimized 3D mine layouts, and more. However, for competitive business in Eastern Europe, VULCAN should improve its software support. Effective training, help desk support systems and nearby distributors with just-in-time solutions to company problems will generate competitive business for VULCAN.

May 1, 2007

By A. R. Kinkel

Robert T. Walker and Woodville J. Walker (Walker Engineering Corp., Salt Lake City)—Mr. Kinkel's article embodies, in condensed form, the results of the first detailed and complete geological survey that has ever been made of the long neglected but potentially very important West Shasta Copper-Zinc district, in Shasta County, California. In view of the difficulties of the terrain and the complexity of the geological structure, this represents a notable achievement, and it is with regret, therefore, that the writers find it necessary to differ from Mr. Kinkel's conclusions on two important points. The first has to do with the interpretation of two members of the stratigraphic column of formations in the district; for purposes of comparison, the description of these two members according to Mr. Kinkel is shown parallel to the description of these members according to the writers, see Fig. 14, Mr. Kinkel's nomenclature being used. The first member, which Mr. Kinkel terms the upper unit of the Balaklala rhyolite, consists of a single, massive, homogenous body of very silicious igneous rock, consisting almost wholly of quartz and albite, and averaging about 80 pct silica. Most geologists of the U. S. Geological Survey who have previously inspected the district have called it an alaskite. It is not a pile of several members, but is a single unit, without internal subdivisions. It has the form of a recumbent lens, approximately flat on the bottom and arched on top, several miles in diameter, and attaining a maximum thickness of 1000 to 1200 ft. It varies in texture from porphyritic to holocrystalline, and contains unusually large quartz phenocrysts up to 4 mm diam. Mr. Kinkel considers this formation to be a thick lava flow that is older than the overlying Kennett shale, while the writers interpret it as being intrusive, constituting a domed sill or laccolith that is younger than the Kennett shale. Their reasons are as follows: 1) This formation shows none of the features which within the writers' experience invariably accompany very silicious lava flows. Nowhere is it vesicular; nowhere does it contain any glass or its devitrified equivalent; nowhere does it contain flow breccia; and nowhere has it a ragged top, in spite of the fact that there is no evidence of surface erosion, which might have removed such a top.

Jan 1, 1957