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By Sidney M. Cohen

[Portland cement is a product made from a combination of limestone and argillaceous material which would supply the necessary amounts f calcium, silica, alumina and iron to form cementious compounds when fired at high temperatures. The resulting mixture, usually around 80% limestone and 20% argillaceous, is ground nine (80% -200 mesh), blended and then fired1 (2600-2700°F) to produce a cement clinker from which the final cement product is produced by grinding. The argillaceous component can be shale, clay, slate or other sources of the individual components of silica, alumina and iron. This paper deals with a case where a clay component was under consideration. The planned Plant site was to be located at a well defined limestone deposit. When it came to the argillaceous component, the nearest uniform deposit of clay was over 50 miles away and would require purchase of land or clay from the owner plus the daily delivery costs to the plant site. This situation made the plant site economically questionable. It was decided that a local clay deposit, which was available at the plant site but was orginally not considered due to lack of chemical uniformity and its high free silica content, would be reconsidered.]

Jan 1, 1983

By Frank E. Cash

Although during the past 10 years Alabama has attained an enviable position by its coal-mine accident experience and, like most of the other coal-mining States, has made progress in the safer operation of coal mines, there is still room for improvement, which can be realized only by still greater efforts on the part of employees and employers. From 1993, when accidents were first recorded by the Alabama State Mine Inspection Department, to 1934, inclusive, 3,451 men lost their lives in the production of 569,722,676 tons of coal. The primary purpose of this report is to bring to the attention of the mining industry in Alabama end elsewhere statistics of fatal accidents for 1931-34, with the hope that a study of the causes may lead to reduction of similar accidents in the future.

Jan 1, 1936

By James P. Bennett

To identify construction materials for emerging technology in chemical and metallurgical processes, the Bureau of Mines investigated the acid resistance of ceramic materials. Eight commercial ceramic materials comprising two red shale, two fire clay, a silica, a five-claybonded silicon carbide, a carbon, and a high-alumina brick were evaluated. Samples were exposed for 110 days to 20 wt pct HCl at 50°, 70°, and 90° C and to 30 wt pct HCl at 70° C. Statistically significant changes in cold crushing strength, volume, and weight were generally small or not detected. The leach rates of Al, Ca, Fe, K, Mg, Na, Si, and Ti ions were monitored. The carbon brick sample had the best acid resistant properties with a maximum total leached ion weight loss of 0.004 wt pct. The silicon carbide, the silica, and one of the fire clay bricks also had excellent acid-resistant properties.

Jan 1, 1983

By John J. Barakso

A summary of geochemical dispersion processes is presented. Secondary and tertiary dispersion of uranium was examined at several uranium prospects in British Columbia. The vertical migration of uranium from bedrock (primary dispersion) through overburden into the various soil horizons, and into snow and plants, was studied, and relationships were sought to explain the dispersion patterns in the secondary and tertiary environments. Soil developments were examined to obtain information on factors affecting the dispersion of uranium in soil profiles and tertiary substances; samples were analyzed for a number of elements. Biogeochemical data indicate that plant geochemistry is a possible exploration aid in areas of heavy overburden owing to the high selectivity of certain plants for specific elements. Some new data on the geochemistry of snow are discussed as a matter of research interest in the tertiary dispersion of uranium. Analytical techniques and problems are discussed, particularly extraction techniques, which must be carefully chosen to give reliable information on uranium dispersion.

Jan 1, 1979

By M. S. Enders, L. M. Rogers

The Little Rocky Mountains host epithermal gold-silver bearing vein and stockwork deposits in a syenite intrusive complex. Pegasus Gold Ltd. is currently mining these oxidized deposits by open-pit methods and recovering gold and silver by heap-leach processes. A geologic program has been designed to effectively determine the basic ore characteristics; 1) mineralization; 2) oxidation; 3) structural setting; 4) lithology; 5) alteration; and ultimately, 6) the leachability of the ore. Geologic mapping, sampling, drilling, assaying, and testing are routinely used in exploration, development, production control, mine planning, and ore reserve estimations. Timely and accurate assay results are essential for the program's success.

Jan 1, 1984

By K. P. V. Lei

The Bureau of Mines investigated molten salt electrorefining 'n helium atmosphere cells as a means for the production of ductile vanadium. 'Electrolytes composed of NaCl-VCl2, LiCl-NaCl-VCl2, BaCl2-KCl-NaCl-VCl2 KCl-LiCl-VCl2, and CaCl2-NaCl-VCl2 were tested. Two electrolytes, KCl-LiCl-VCl2 and CaCl2-NaCl-VC12, were selected for laboratory-scale production tests. A molten salt electrorefining process was developed for the production of ductile 99.6 percent vanadium from a commercial 90-percent grade. Using the CaCl2-NaCl-VC12 electrolyte, an 87-percent recovery of ductile vanadium was made; an 85-percent recovery was made with the KCl-LiCl-VCl2 electrolyte.

Jan 1, 1967

By C. A. Pickles

Nickeliferous limonitic laterite ores contain considerable free moisture. In this research, the application of microwave radiation for the drying of this ore was investigated. The effects of sample mass, initial moisture content and porosity on the microwave drying rate were studied and the results were compared to those obtained with conventional drying. Microwave drying rates of two to three times the conventional values were achieved. Further enhancement of the microwave drying rate was realized by increasing the flow rate of air over the sample or by operating at reduced pressure. The high microwave drying rates were attributed to the inverted temperature gradient which resulted in internal heating and boiling and this in turn promoted movement of the water, both as liquid and vapour, to the surface.

Jan 1, 2005

By C. A. Campbell

"There has been a significant reduction in maintenance hours and improved performance by maintenance crews at the MacLeod mine since the introduction of a Maintenance Control system which includes the use of maintenance standards. This paper deals with the steps taken to develop and implement the program. The objectives of the program and the organization and training of the control group are outlined. The work-order system, standards application, classification of work and the preventive maintenance procedures will be discussed.All maintenance information is processed on a Model 360-20 IBM computer, which turns out maintenance records and control reports for management action. Information in these reports, and reasons for reporting, will be discussed and the benefits resulting from the program reviewed."

Jan 1, 1973

By K. Yamaguchi

To contribute highly efficient and environmentally conscious copper smelting process, several topics in chemistry of the continuous converting were discussed. Through the reviewing the authors' thermodynamic simulations, it is recognized that small amount and low copper content of the coexisting slag is preferable. Some discussions were added to the Takeda's diagram for Cu20-Fe0x-Ca0 ferrite slag, and the activity curves of the constituents were derived. Thermodynamic calculations were carried out on the copper contents of the slag during the blister copper formation. The dissolution of copper in slag decrease somewhat with increasing temperature, but the effects of increasing S02 pressure and decreasing %S in copper are considerable to increase in copper content of the slag. The optimum oxygen enrichment in the supplied air, and regulation of the oxidation degree for the blister copper are important in practice. The gypsum phase separation in the calcium ferrite slag was also evaluated thermodynamically, and concluded that decreasing temperature, increasing CaO content or S02 pressure, and extensive oxidation of the blister copper tend to separate CaS04. 0

Jan 1, 2007

By Maria I. De Rosa

The U.S. Bureau of Mines conducted experiments for predicting materials' ease of combustion (smoldering onset, smoldering, flaming, and decomposition rates) by means of submicrometer smoke particle characteristics for the development of a simple test method. The experiments were carried out in an approximately 20-L furnace, with a 10-L/min airflow through the furnace for a 14-min duration, at set furnace temperatures of 150°, 250°, and 1,000° C. The variables studied as a function of time were the onset time of smoke particles, time and duration of maximum smoke particle generation, average concentration of smoke particles, and particles' average diameter, mass weight loss, and furnace temperatures. Results show that the onset time of smoke particles is predictive of materials' ease of smoldering, and the time of maximum smoke particle generation and its duration, coupled with mass weight loss, are predictive of materials' ease of smoldering and flaming (depending on the experimental temperatures), and decomposition rates.

Jan 1, 2010

By R. L. Bullock

For the past 30 years there has been a gradual evolution of mechanical excavating systems in underground hard rock mining applications. This paper traces many of the tests of various tools and methods to break hard rock, up to the present. The tools include impact hammers, boring machines, disc on boom mining machines, disc on revolving wheels and drums, picks and drag bits on revolving hubs, rock splitters, slot cutting systems, and with customized explosives/powder mini-blasting. While the progress has been slow, successes are being achieved in hard rock and more opportunities exist today than ever before.

Jan 1, 1995

By T Raynlyn, S Hapugoda, V Nunna

The predominant phase in most Marra Mamba, channel iron deposits and detrital iron ore deposits is goethite. Goethite abundant iron ore fines tend to have complex mineralogical associations and fine dissemination of gangue material. These ores are typically challenging to process using conventional beneficiation methods. With declining ore grades, there is a need to develop new processing routes for low-grade goethitic ores/fines.Comparative process amenability studies were carried out using two different processing options to recover iron with low alumina and silica content from a low-grade goethite-abundant iron ore fines (-2 mm) sample from the Pilbara region of Western Australia. The first option involved dehydroxylation at 350°C and 400°C, followed by grinding dehydroxylated samples to 100 per cent passing 106 µm and magnetic separation. The second option was processing raw sample by gravity separation using a Floatex density separator. The performances of the two processes are discussed in terms of the iron grade-recovery responses, and an optimal processing route is proposed based on the findings from these tests.CITATION:Nunna, V, Hapugoda, S and Raynlyn, T, 2015. Process amenability studies on goethite-abundant iron ore fines, in Proceedings Iron Ore 2015, pp 165–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By W. G. Sinclair

THE North Texas district presented in this paper includes the counties of Archer, Baylor, Clay, Cooke, Foard, Hardeman, Jack, Knox, Montague, Wichita, Wilbarger and Young. It corresponds with the Texas Railroad Commission's district No. 9. Table I conforms with the nomenclature of pools as designated by the Commission. Most of the oil and gas produced in this region, generally referred to as the Red River uplift, comes from the Pennsylvanian strata. In recent years, however, increasing amounts are being developed in both the Mississippian and Ordovician.

Jan 1, 1946

Mainland China To Pay Japanese Company On Contract Claim. - Mitsubishi will receive $39 million from Red China, half of what was asked, for China's having, curtailed work on a 5369 million steel rolling mill at Baoshan near Shanghai. Copper Found in Chile. - Utah International Inc., in conjunction with Getty Oil Co., has discovered a cooper deposit in northern Chile. Early drilling reveals an enriched zone grading 1.2% to 2 3% copper. Chile already has tie world's largest Cu reserve base. Soviets To Aid Laotian Tin Industry. - The U.S.S.R. has agreed to help strengthen the tin industry in Laos, a client state. In the past, Laos has only produced small amounts of tin concentrate, 500 tons to 1,000 tons per year presumably shipped to smelters in Singapore or Penang, Malaysia. Under the agreement made in June, the Soviets are to supply equipment to increase the out put of tin from the Phontieu, Neng, and Nongsen mines and help Laos with the construction of a tin smelter. The U.S.S.R. itself is a net importer of tin, although a substantial producer of the metal.

Jan 1, 1981

By H. Sevim

An innovative approach in designing the haulage systems for underground coal mines is discussed in this paper. The haulage systems are formed by serially connected components. Therefore an economic and efficient design of the entire system is necessary. The computer model that uses a heuristic algorithm solves this design problem globally in a single run. It is a probabilistic model because it considers the probabilistic aspects of face operations. It is versatile because it can accommodate any type of mining and belt conveyor network configuration. The hoisting section can be used to design drum or friction hoisting systems for single or multiple level operations. These systems can have two skips in balance or a skip and a counterweight in balance. The model also has the option to internally determine the capacity of bunker(s) and shaft-bottom bin. The objective is to minimize the expected cost per ton of coal hauled from the coal faces to the surface. At the end of the paper is an example that illustrated the capabilities of the model.

Jan 1, 1987

By K. Janghorban

Multilayered ceramic-metal composites were produced by solid state diffusion bonding of polycrystalline alumina and three Al alloys containing 1 to 2%Sr, 2% Mg and Mg + Si (5057 Al alloy), The multilayered structures were fabricated at 610°C under a compressive stress of 3 MPa for 2 hours in He-5%H atmosphere, The ceramic-metal interfaces were studied by SEM and TEM equipped with energy dispersive spectrometer (EDS). Addition of 1 wt % Sr to Al promoted good adhesion, without producing any interfacial products, while the Al-2%Sr was poor in this regard due to the presence of dispersed A14Sr which is an intrinsic phase in the Al-Sr phase system, The Al-2%Mg alloy produced a continuous film at the interface, which was characterized to be MgAl2O4. Al alloys containing Mg and Si (5057 commercial alloy) produced not only the spinel structure (MgAl2O4), but another phase rich in Mg and Si (close to Mg2Si), These latter interfacial reaction products were not the intrinsic phases in Al-Mg alloys, and were reaction products at the Al2O3 ?Al alloy interfaces.

Jan 1, 2005

By L. J. Han, Y. J. Zong, S. Y. Wen, J. J. Wei

"Stress strain curves characteristics, deformation and strength properties, and failure process and characteristics of sandstone samples under different stress states were analyzed through triaxial compression tests carried on using TAW-2000 microcomputer control electro-hydraulic servo rock triaxial test system. The experimental results reveal that peak strength, residual strength, elasticity modulus and deformation modulus increase linearly with confining pressure, and failure models transform from fragile failure under low confining pressure to ductility failure under high confining pressure. Macroscopic failure forms of samples under uniaxial compression was split failure paralleling to the axis of samples, while macroscopic failure forms under uniaxial compression was shear failure, the shear failure angle of which decreased linearly with confining pressure. There were significant volume dilatation properties in the loading process of sandstone under different confining pressure, and then based on acoustic emission damage and volumetric dilatation damage the damage evolution properties of samples were analyzed, and damage constitutive model were established, realizing the real-time quantitative evaluation of samples damage state in loading process. INTRODUCTIONDamage is a phenomenon that micro defects in material under monotonic loading or reloading will lead to progressive decrease of the cohesion and damage of volume units. Many scholars at home and abroad have carried out systematic researchers on damage evolution characteristics and constitutive model of rock, and have achieved a series of remarkable results in this field. Lu Y.D. (2004) studied the complete stress-strain curve’s characteristics of marble under triaxial compression, and established the bilinear elastic-linear strain softening-residual ideal plastic damage constitutive model. Ren J.X. (2001) studied the damage evolution laws of coal and rock mass by computerized tomography triaxial loading system, realizing the quantitative evaluation of damage state. Zhang Z.L. (2011) studied the deformation and failure mechanism of strong weathered sandstone by triaxial compression test, and analyzed the damage evolution processes and established the damage evolution equations based on the density method. Li X.J. (2012) studied the microscopic damage characteristics of siltstone under triaxial compression by scanning electron microscope and digital image technology, and analyzed the statistical distribution characteristics of cracks azimuth angle, length, width. Zhou J.W. (2012) studied the strength, deformation and fracture damage characteristics of sandstone by uniaxial cyclic loading and unloading tests, and defined damage variable based on linear damage mechanics theory and acoustic emission (AE). Cao W.G. (2006) established a new damage model and a statistical damage constitutive model of rock under specific confining pressure according to the force of damaged part and undamaged part in rock on the base of statistical damage theory. Li S.C. (2014) studied the damage evolution characteristics in the whole uniaxial compression process of sandstone by electrical resistivity and AE, and proposed a status qualitative criterion for rock damage."

Jan 1, 2015

By J. H. East, D. Harrington

"INTRODUCTION Shaft mines, coal and noncoal alike, have a common hoisting problem that remains largely unsolved - how to obtain a mechanical device that will suspend a cage or skip in a mine shaft if the hoisting rope should break or become detached from the cage or skip and that will function effectively under all conditions of service. Safety catches, or safety dogs, as they are commonly named, are installed on nearly all mine cages and many skips operating in American mines, but often, if the hoisting rope breaks, the cage or skip falls to the bottom of the shaft in spite of safety devices, causing much property damage and often fatalities.Available information relative to safety catches for mine cages and skips, desirable characteristics of safety catches and methods of testing safety catches to determine whether they are functioning correctly has been assembled in this publication for the convenience of those responsible for the safe operation of mine cages end skips and, more particularly, to focus attention on the need for a device that actually will stop and suspend a falling cage or skip under all conditions of use and do it without killing or maiming the occupants."

Feb 1, 1948

By W. S. Dyer

The lignite deposit at Onakawana on the Abitibi river is of particular interest at the present time, since the Ontario Government has recently decided to proceed with the extension of the Temiskaming and Northern Ontario railway to James bay. Forty-five miles of steel will be laid this year to the crossing of the Moose river. This will cross the lignite field. It has been known for many years that lignite occurred in the Moose River basin, but it was not until drilling was commenced at Blacksmith rapids (or Onakawana, as the camp is now known) in June, 1929, that a seam of economic thickness and extent was found. Early in 1929 the Ontario Legislature voted $25,000 for the carrying out of a drilling programme in the Moose River basin. This came as a culmination of two summers' exploratory work by the Geological Branch of the Ontario Department of Mines, and as the result of a report which said; in effect, that further information concerning the mineral resources of the basin could only be obtained by drilling, and that such a drilling programme was well worth while in order to establish once for all whether lignite, fire-clay, or oil or gas did or did not exist in economic quantities in the region.

Jan 1, 1930

By M. du Plessis, J. P. Gouvea

Mesh based areal support is commonly applied in South-African deep-level gold mines. It forms part of an integrated support system that can cater for both rockfall and rockburst incidents. The application has been successfully applied over many years. Operations have different geotechnical conditions and practical considerations, which has led to the development of various types of mesh and integrated mesh-based support systems (i.e. meshing and lacing versus welded or chain-link mesh sheets). Typically rolls or sheets of mesh is pinned with rockbolts to the surface of an exposed excavation. Applications vary from hangingwall coverage in a conventional stope gully to complete excavation coverage in footwall drives of conventional mines or on-reef drives in massive mechanised mines. It is however critical to understand the behaviour of the rockmass and apply suitable support systems.

Apr 26, 2022