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By James Gibbs

In order to provide an initial approach to the deposits of oil shale, nahcolite, and dawsonite in the central area of the Piceance Creek Basin in northwestern Colorado, the U.S.B.M. and associated contractor personnel drilled and cased a 96-inch ID shaft to a depth of 2,371 feet. The shaft was constructed using "big hole" drilling techniques and succeeded in giving access to previously inaccessible deposits of the above minerals. This report documents the construction from its beginning in January 1977 to its completion in January 1978. Procedures used and problems encountered are discussed in derail.

Jan 1, 1978

By D Weatherley, T Baumgartl, L Huang, Q Shao

The stabilities of rehabilitated landforms are often threatened by the altered surface hydrology, especially the excessive surface run-off, which may cause severe water erosion and associated pollutant transport to surrounding areas. These effects would lead to pollution in waterways and render the failure of newly established vegetation. An accurate quantitative evaluation of run-off problems are consequently essential for the proper rehabilitation designs which can help minimise these harmful consequences. For this purpose, in this study a novel run-off model, RunCA, was developed based on Cellular Automata (CA), integrating fundamental hydraulic principles. In this model, a series of rectangular cells were employed to cover the study area. Run-off production within each cell was simulated by determining the cell state (water surface elevation) that consists of both cell altitude and water depth. The distribution of water flow among cells was determined by applying CA transition rules based on the improved minimisation-of-difference algorithm and the calculated flow travelling time. RunCA was applied to various aspects in mined land rehabilitation planning, including landform designs for both hill-slopes and tailings dams, revegetation strategies and cover constructions. Simulation results showed that surface run-off increased with slope gradient and more run-off was produced on convex and straight slopes than on concave and S-shape slopes. Both mounds and rip lines constructed on the tailings dam surface could help reduce the water discharge. Vegetation planted in rows were more effective than those in columns or patches in controlling run-off. Increased cover thickness had the potential in reducing run-off rates, and the covers with an increasing thickness from top to bottom of the slope tended to be more efficient than those with a constant thickness. All these results have demonstrated the efficacy of RunCA as a simulation tool in assessing the hydrologic behaviours of different rehabilitation designs. Compared to the traditional hydrologic models, most of which were developed for the catchment scale studies, RunCA has the potential advantages in capturing the dynamic and spatially varied run-off behaviours at different spatial and temporal scales.CITATION:Shao, Q,?Baumgartl, T, Huang, L and Weatherley, D, 2014. A cellular automata-based run-off model and its application in mined land rehabilitation designs, in Proceedings Life-of-Mine 2014 , pp 81–96 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By Robert Stefanko

A series of workshops were conducted -with invited participants from the coal mining industry to identify the most pressing research and development needs of the industry. Six workshops were held on the following subjects; Research Priorities for Mining-Oriented Universities, R&D Needs-for Surface Coal Mining, R&D Needs for Deep Coal Mining, R&D Needs for Anthracite Coal Mining, R&D Needs for Coal Mine Health and Safety, and R&D Needs far Environmental Control in Coal Mining.

Jan 1, 1975

By Dick T. Atkinson

This report describes the Foster-Miller program that designed, developed, built and tested an automatic, remote control mine car coupler. This new coupler gives the motorman the capability to selectively couple and uncouple cars from the locomotive, to transmit braking intelligence to the coupled car s and to determine if the trip is intact. Hazards due to derailment and runaway cars will be reduced as the brakes are automatically applied in any uncoupled car. Laboratory tests described herein have been completed on the coupler set. Applications include, but are not limited to, the unit train system.

Jan 1, 1976

By W. L. Josey

The Stibnite Project is an open pit/cyanide heap leach gold property located in the Yellow Pine mining district of central Idaho. The gold ore is in an oxidized zone of an epithermal deposit which is associated with a fault system related to Tertiary igneous activity of the region. The faults transect a roof pendant of metamorphosed sediments within crystalline rocks of the Idaho Batholith. Seasonal mining is at a rate of 3900 mt/d (4300 st/d) of ore with a 2:l waste to ore ratio. Gold and silver are recovered through a process of cyanidation, carbon adsorption and desorption, and electrowinning. Disposal of the leached ore requires chlorination of the residual cyanide.

Jan 1, 1984

By L. Forsbacka, L. Holappa

Viscosities of quasi-ternary CaO-SiO2-CrOxmelts in contact with metallic chromium were measured by the rotating cylinder method up to 1750ºC. Twelve slag compositions were selected in the composition range 20–55 wt% SiO2, 10–45 wt% CaO and 10–60 wt% CrOx. Estimation of the amounts of CrO and Cr2O3was made by regression analysis based on the earlier data. Professor Iida’s (Osaka University) viscosity model was applied and model parameters (0CrO,CrOand Cr2O3) were evaluated. The Iida model gave good consistency with the measured viscosity values.

Jan 1, 2004

By Monserrat Rebolledo, John L. Uhrie, Candice Simms

Jetti Resources has developed a catalyst which overcomes the passivation of primary sulfides, enhancing the heap leach recovery of copper from chalcopyrite. It is important to emphasize that heap leaching of copper sulfides, whether with or without the Jetti catalyst, is a biooxidative process. We have demonstrated the efficacy of Jetti’s technology in bioreactors, with a chalcopyrite-dominant porphyry ore. In the presence of Jetti’s technology, optimal bioleaching conditions significantly increase copper extraction by 2.6 times that of the baseline.

Feb 1, 2025

By M. Görnerup, A. Kapilashrami, Seetharaman. S., A. K. Lahiri

Simultaneous reduction and foaming of chromium-rich slag have been studied in a laboratory furnace equipped with X-ray image analysis. Reduction of the metal oxides by graphite generated CO, which caused the melt to foam. The slag composition continuously changed due to reactions and dissolution of lining. Gas generation rate, foam height, and gas bubble size were studied and correlated to slag composition. Viscosity increased significantly during the experiments due to a change in slag composition. Bubble sizes varied little during the progress of reactions but differed considerably for different slags. Bubble sizes were largest for V2O5 containing slag, which is contrary to the general understanding that the presence of strong surface active agents reduces the bubble size. The foaming index did not follow expected trends for bubble size and viscosity, suggesting that foaming index is not a suitable parameter for discussion of foams under dynamic conditions. Keywords: slag, foaming, dynamic conditions

Jan 1, 2004

By E. H. Izen

A thermal imaging borehole probe was designed and fabricated for the purpose of obtaining thermal images, through smoke, of objects and people in underground mines. The effort was basically unsuccessful; electrical noise, and possibly thermal noise, interferred with the desired signals to the extent that spatial resolution in the images was unacceptable.

Jan 1, 1980

By G. H. West, R. L. Sebastian, W. A. Darror

"This bibliography was compiled in the course of research work by the Bureau of Mines on the utilization of magnesites in the West. The results of the research will appear as a bulletin of the Bureau.1. ANALYTICAL METHODS. 11 Knight, X. and Wheeler, W.H. Proc. Iowa Acad. Sci., 13, 1907, 167 (C.A.1, 1370). Describes experience in analysing calcite and dolomite. Reports great excess of oxalate unnecessary and separation of sulphates by alcohol is best.2 Meyerhofer, J. Zeit, Angew. Chem., 21, 1908, 592. Direct determination of Mg as phosphate after removal of SiC2, by keeping R203 in solution with ammonium citrate.3 Merckschen Guano Phosphat Werke. Chem. Ztg., 33, 1909, 545 (C.A. 3, 2281). volumetric analytical methods.4 Popel, M. Zeit. Angew. Chem., 21, 1908. 2082 (C.A, 6, 412). Determination of CaO in presence of CaC03.5 Blasdale, W.C. Jour. Am. Chem. Soc., 31, 1909, 91? (C.A. 3, 2658). Studies of separation of Ca from Mg.6 Hundeshrgen, F. Zeit. Offent. Chem., 15, 1909, 85 (C.A. 3, 1853). Valua¬tion of caustic magnesia by analysis. Volumetric methods.7 Frerichs, H. and Krosberg, W. Apoth. Zeit., 24, 1909. 679 (C.A. 3, 2996). Tecting magnesia alba for Fe.8 Schoorl, N. Zeit. Anal, Chem., 48, 1009, 593 (C.A. 4, 5E9). Microchemical tests for Mg, Li, K. and Na.9 Heyer. Chew. 2Ag., 33, 1009, 1157 (C.A. 4, 1588). Determination of CaO in presence of CaCO3. CaCO3 in soluble in cold neutral solution of NH3 salts. Solubility Is diminished by free NH4OH."

Oct 1, 1923

By Ferron A. Olson

Natural bornite (Cu5FeS4) leached in ferric chloride or in sulfuric or hydrochloric acid solutions with oxygen showed several differences. In ferric chloride 80 of the copper was leached in two stages. The first (30 copper removal) requiring one minute was controlled by mixed kinetics (liquid ferric ion diffusion and chemical surface reaction). The second was controlled by formation of a surface sulfur layer and then diffusion through the sulfur. With oxygen in sulfuric acid reaction was slow and only the first stage was studied. Copper removal had an induction period. The bornite structure disappeared at 12% copper removal (also found with ferric chloride) and covellite formed on the surface with a species inside the particles having an x-ray structure similar to CuFeS2 but with composition Cu3FeS4 (also with ferric chloride). Copper removal was controlled by iron dissolution. Surface iron vacancies filled with Cu+ to give CuS while interior copper dissolution produced Cu3FeS4. Preliminary results with oxygen and hydrochloric acid showed 80% copper removal and sulfur as end products (similar to ferric chloride).

Jan 1, 1982

By C. C. Clark

This report presents the results of tests conducted by the U.S. Bureau of Mines to determine the transport characteristics of highly concentrated paste backfill mixes made from dewatered total mine tailings. The slurry concentrations of the mixes were all above 78 pct by weight with slumps ranging from 6.4 to 16.5 cm (2.5 to 6.5 in). Laboratory material property tests and full-scale pumping tests were conducted using pipe diameters of 102, 128, and 154 mm (4, 5, and 6 in) and a positive-displacement pump. The results indicated that the tested backfill mixes can be successfully transported as a stiff paste and identified the influence of and the interaction among the various mix and system variables.

Jan 1, 2010

By K. J. Liles

Research was undertaken by the Bureau of Mines to determine the technical feasibility of producing lightweight aggregate from the waste glass fraction of municipal incinerator residues. Tests were conducted to determine the amount and optimum size of glass, the amount of sodium silicate, and the method used to form the material to be expanded. The most suitable mixture, 78 percent glass, 20 percent clay, and 2 percent sodium silicate, was pelletized and then expanded by exposure to a temperature of 1,550° F for 15 minutes The resulting lightweight material had a bulk density of 38 lb/cu ft and exhibited excellent pore structure. Concrete test cylinders made from the light weight aggregate had a unit weight of 104 lb/cu ft and a compressive strength of 2,550 lb/sq in after a 28-day steam cure.

Jan 1, 1976

By MARK J. VANARELLI

Estimating groundwater inflows in rock deep tunnels is critical to the safety of personnel constructing the tunnel and the cost of construction. This paper presents two case studies for estimating steady-state groundwater inflows into deep rock tunnels. The case studies included the Chattahoochee and Nancy Creek tunnels. In this paper, statistical methods were applied to packer test data obtained from exploratory borings during geotechnical site investigations. A semi-empirical procedure was utilized for estimating groundwater inflows into these deep rock tunnels. It is the most widely used method/procedure in the tunnel industry. The Chattahoochee and Nancy Creek tunnels are deep rock tunnels which exhibit radial flow conditions. For the radial flow condition, a statistical analysis presented in this paper indicates that the semi-empirical procedure works well; however, variations in the procedure and/or an insufficient amount of testing could lead to underestimations of the inflow quantities. Packer test data plotted in histograms were observed in all cases to be log-normally distributed for the radial flow condition. Modeling using Monte Carlo simulations was observed to be an effective tool for removing irregularities in the distribution of the data and incorporating high-end permeability data to derive reasonable groundwater inflow estimates. This paper is based on the PhD thesis entitled “Improvements to the Current State of the Practice in Steady-State, Groundwater Inflow Estimates into Rock Tunnels based on the Application of Statistical Analysis Methods of Packer Test Data obtained from Exploratory Borings During Geotechnical Site Investigations.”

Oct 9, 2020

By D. S. Burgess

This report summarizes the incidents that preceded the December 9, 1970, propane-air explosion in Port Hudson, Mo., and then attempts to establish the nature of the explosion from the ensuing events. Special emphasis is given to possible ignition sources, the distribution of flammable vapors, and the analysis of blast damage. Both near-and far-field damage indicated that this explosion may be attributed to the detonation of propane in air with an energy release equivalent to that from about 50 tons of detonating TNT.

Jan 1, 1973

By A. V. Pavlov, V. A. Grygorian, Kossyrev, A. E. Semin, A. Korostylev

A new way of producing low-silicon ferrosilicon from iron-ore materials in a new type of aggregate-oxygen reactor is presented. The oxygen reactor process is based on using the calorific combustibility and reducibility of carbon materials inside the aggregate. The key to the process is successful post-combustion of carbon monoxide above a layer of a solid coke bed. Initially the possibility of production of grades of ferrosilicon containing 20 to 25% Si (FeSi20-FeSi25) was studied on a laboratory model of the oxygen reactor. Quartz sand and iron ore concentrates (from Russia and India) were used in the laboratory tests. This test work demonstrated that a ferrosilicon grade FeSi15 could be obtained directly from raw iron ore (containing 75.9 % Fe2O3 and a maximum of 23.8 % SiO2) without using rich iron-ore concentrates. The process was successfully tested on a pilot furnace at Serovsky metallurgical plant. Very promising results and efficiency parameters were achieved. The consumption of materials for 1t of ferrosilicon (15 % Si) production was as follows: 1567 kg raw iron ore, 591 kg of coal (in a composition of ore-coal briquettes), 299 kg of coke (for coke bed formation), and 815 m3 of oxygen.

Jan 1, 2004

By G. L. Oldright

The Metallurgical Branch of the Bureau of Mines, as a part of its duties under the Organic Act, works to prevent wastes in industry and to disuse inmate information on the fundamentals of metallurgical processes. During the war, the necessity of large production was increasingly emphasized. Such duties necessitate from time to time the study of units of full commercial size, the operation of which is beyond the facilities of the Branch. When developments have reached this stage; work has been continued in cooperative agreements with operating companies that have been willing to contribute the use of their plants and staffs and to allow the publication of the results obtained for the common good of the industry.

Jan 1, 1948

By B Whittaker

The paper examines the role of chain pillars in longwall mining layouts as used in several countries. The application of chain pillars in relation to their expected design role is discussed. An important feature is the specification of the pillar design to meet strata loading conditions as imposed by the mining and geological setting. The paper relates longwall width and chain pillar configurations to pillar size to satisfy anticipated loading and strength expectations. Laboratory work is referred to which examines criteria for pillar stability. Comments are made regarding the application of the findings presented in the paper, to different situations involving the use of chain pillars in longwall and shortwall mining systems.

Jan 1, 1987

By J. D. Miller, C. L. Lin

Filtration of fine particles involves filter cake formation and removal of surface moisture by drawing air through the porous structure. Accurate assessment of the transport properties of porous media (in this case, filter cake) is of major importance in the development of improved filtration processes. Implications from these studies are important in the design and operation of filtration equipment in order to enhance the efficiency of this important solid-liquid separation process. The microstructure and connectivity of pore space are important features necessary to describe detailed fluid flow phenomena in filter cake during fine particle filtration. In this regard, 3D characterization of pore structure is essential. The pore structure has to be described by parameters which are of special relevance to the interpretation of fluid transport phenomena. These parameters should be based on directly measured variables of the pore system and not inferred from indirect variables (such as those determined empirically from transport processes) valid only for a particular pore structure. In this way fundamental relationships between pore structure and fluid transport at the microstructure level can be described. In order to achieve this level of sophistication the three-dimensional interconnected pore structure of filter cake must be determined. Study of fluid transport phenomena in filter cake using x-ray microtomography to characterize the complex three-dimensional pore geometry is discussed. On this basis the Lattice-Boltzmann (LB) method is used to simulate and to establish a fundamental relationship between pore microstructure and effective transport coefficients.

Jan 1, 2002

By E. D. Palmes

A new type of personal sampler for quantitative estimation of atmospheric concentrations of contaminant gases was first reported from this laboratory in 1972. The sampler requires no pumps or flow regulators and employs instead the motion of the gas molecules them-selves to furnish the power for sampling. Under this grant, work was completed on development of a kit for the field determination of both NO2 and NO. Detailed instructions for the preparation of the samplers and the use of the kit was supplied to the Technical Project Officer. Attempts were made to adapt the same type of sampler to the measurement of SO2 and CO. Both gas chromatographic and turbidimetric procedures for the final estimation of the S02 proved to be unsatisfactory. For CO no reagent was found which would react sufficiently rapidly with this gas to utilize the essential feature of the diffusion sampler, the maintenance of a diffusion gradient which is at least approximately numerically equal to the ambient concentration. A number of publications on use of the NO2 sampler, both at occupational and community air pollution levels, have resulted from this work.

Jan 1, 1979