Search Documents

C. M. GARLAND,§ Chicago, Ill. (written discussion 11).-7--In the development of Mr. Traer's method for the low-temperature coking of Illinois coals, after the principles laid clown by Prof. Parr, it was soon demon-strated that, in order to yield a product of uniform volatile content, the coal must be coked in thin layers, and consequently must be handled in comparatively small volumes. This means, in the first place, that great care must he observed in the design of the coking chambers to prevent the loss of the products of distillation, and, in the-second place, that labor-saving devices must be utilized to the greatest possible extent in order to reduce the cost of handling.

Jan 12, 1918

By Q. Xu, P. Somasundaran

Adsorption of nonionic/anionic surfactant mixtures on kaolinite has been studied, with •Sodium dodecylsulfate as the anionic surfactant, and •Octaethyleneglycol mono-n-dodecylether as the nonionic surfactant. Synergistic interaction between these surfactants was found to cause adsorption of the nonionic surfactant with its hydrophilic chains protruding into the bulk, leading to substantial changes in wettability and dispersion characteristics of kaolinite. Similarly, hydrophobicity changes are observed also for silica particles upon adsorption of nonionic ethoxylated alcohols owing to possible changes in the orientation of the adsorbed surfactant molecules at the interface.

Jan 1, 1993

By P. L. Lavery

A numerical method to derive approximate solutions for stress intensity factors for rectilinearly anisotropic bodies without resolving to complex variable approach is presented. The method is based on the assumption that the crack opening profile can be simulated by a simple curve such as an elliptic function and a relationship is found for the stress intensity factor in terms of near tip displacements. An example solution is derived for a transversely isotropic body and the results are verified with Westergaard's stress function approach. The proposed model has a great potential for the applications to fracture mechanics of anisotropic rock materials.

Jan 1, 1984

By J. Partyka

Fumes produced during blasting operations in underground mines are defined in this paper by an equivalent contaminant source. The primary goal is to establish a method which would allow all those parameters not measured directly to be determined reliably from field data. The parameters to be identified are the diffusion coefficient , and the position and size of an equivalent source. The diffusion-value is computed from the peak concentrations taken by two monitors located in the drift. The first monitor is placed close to where blasting pollutants join the main stream, while a second monitors is moved downstream a some distance from the first point. The position and size of the dust source and the total amount of dust produced during blasting are determined from the data recorded by only one monitor.

Jan 1, 1991

By G Dean Barrett

Just one year ago at the 1986 Annual Meeting of the Society of Explosives Engineers, Dr. Calvin J. Konya presented a paper entitled "Presplitting Granite Using Pyrodex, A Propellant.'' Since that time more evidence has been developed to support the concept that "...gas energy can be the principal splitting force and that the stress wave or shock wave is not necessary to cause the presplitting action to occur." Work done in Vermont and Georgia is presented, and the ability to split granite without causing radial cracking of the bore holes is demonstrated.

Jan 1, 1987

US 4,192,851-Recovery of elemental sulfur and the metal values from a complex sulfide ore containing two or more of the metals zinc, lead, copper, silver, gold and/or other metals. A mixture of ore and sulfuric acid and/or spent electrolyte is flowed at optimum temperature and pressure in a quiescent zone to dissolve selected metals and sulfur and coalesce the sulfur. The coalesced sulfur and unreacted sulfides are separated by flowing the leach slurry with an upward velocity component The separated materials are discharged and further processed by conventional methods as war- ranted. H.E. Hirsch, J F. Higginson, EG. Parker, and G M Swinkels, assigned to Sherritt Gordon Mines Ltd. Mar. 11, 1980. 6 pp. (423-28) Filed. 3-14-78 (886,368). Priority. United Kingdom, 3-15-77 (10800/77).

Jan 1, 1982

By Fulton E, Ring RJ, Waters DJ

The Nabarlek uranium treatment plant of Queensland Mines Limited (QML) is currently treating 600,000 tonnes of ore which was mined and stockpiled in a single four month period prior to commissioning of the plant. During the mining phase, material from the open pit was sorted into ore,'below ore grade uranium material (bogum) and waste using a truck discriminator (radiometric analyser) developed by Australian Mineral Development Laboratories (AMDEL). Ore was stockpiled in a single heap with the location and grade of each truck load being recorded. Bogum and waste were stored separately. From the information recorded, both computer and physical models of the stockpile were constructed. These models are currently used in the planning of day to day reclamation of ore from the stockpile.

Jan 1, 1984

By Persifor Frazer

COMPARATIVE columns expressing the series of rocks of the lower half of the Mesozoic age in this country and in Europe are not yet definitely established. The following represents a co-ordination of the beds in England and Germany,* with a list of materials to be worked in from this country. † * Cotta, " Geologic der Gegenwart." † Section from York to Dillsburg. Report C, 1875; Second Geological Survey of Pennsylvania.

Jan 1, 1877

By Allan M. Hale

The paper discusses past trends in phosphate reclamation, indicating advantages and disadvantages of land and lakes, sand tailings capped with overburden, phosphate slimes capped with overburden, and overburden fill reclamation. In addition, new techniques of reclamation such a clay settling-pond disposal and wetland restoration are discussed.

Jan 1, 1983

By G. C. Hewett

This portion of the State, being the northern half of its Pacific slope, is drained by four rivers, the Gunnison, Grand, White and Yampa or Bear, which, with the Green, flowing south from Wyoming, unite to form the Colorado. These streams, fed by the snows of the Rocky Mountains, fall from an altitude of 10,000 to 12,000 feet, at their sources, to 4000 feet, at the confluence of the Grand and Green in Utah, near the State line. This area, about 150 miles square, was the scene of great development in the periods subsequent to the Carboniferous; but earlier

Jan 1, 1889

By Maurizio Marezio Bertini

Ammonia - ammonium sulfate solutions were sparged in a glass reactor with a SO2/O2 gas mixture (2% SO2 and 98% O2) to leach copper from pure chalcopyrite and chalcopyrite concentrate. The SO2/O2 mixture produces higher and faster extractions than O2 by itself. The effect of temperature, particle size and free ammonia concentration was investigated. The fastest and highest recoveries were obtained at 80 oC from a chalcopyrite concentrate with a d80equal to 13 m, with about 83 gpl free ammonia, an average pH equal to 8.75 and a stirring speed of 500 rpm. The extraction process was controlled by diffusion through a product layer, according to the shrinking core model, with an activation energy of 41 kJ/mole.

Jan 1, 2003

By Richard E. Gertsch

The recent upswing in mining coincided with increased environmental concern. These trends have significantly increased regulation, but have not always provided sound environmental protection. Throughout, mining has remained passive, reacting to initiatives from outside. The high road to environmental protection must be an active strategy. The mining industry must take the lead and develop an environmental program effective in price and protection. It must involve all levels of mining. The mining industry should be the real environmental activist. We have the most to gain by sound environmental protection and the most to lose if the environment decays.

Jan 1, 1991

By Charles W. Merrill

WHETHER the valuable components in a mineral deposit can be mined and separated from the worthless matrix, processed, and marketed depends not only upon the natural factors and the physical and chemical techniques, but also upon many extrinsic factors relevant to the economics of the business of exploring, developing, and producing minerals. To meet a need for proper coverage of this specialized field of economics, the Mineral Economics Div. of the AIME has developed a plan for assembling a volume setting forth important factors affecting mineral enterprises other than those that lend themselves to solution through science or technology. The program has been considered by the Institute's Directors and they have approved it, subject to a decision of the Mineral Economics Div. to carry it out.*

Jan 8, 1954

There is little doubt that the vision (Spectre) of Voisey's Bay has completely spooked the Northern Hemisphere view on nickel to the exclusion of considering any other future nickel project. Voisey's Bay orebody is of world-class and will influence world nickel and cobalt supply for a very long time - but - has the world yet started to consider the enormous cost of acquisition and development of this find or the nickel price it will need to attract to cover these costs and its operating costs and keep its bankers and shareholders happy. That price will be the critical factor in determining Voisey's effect on world nickel and will be critical in ranking other new projects aimed at making up the nickel short fall created by the on-going demand for austenitic stainless steel. In my view, there is little doubt that some if not most of these `other' new projects will be developed in the South West Pacific from lateritic Resources.

Jan 1, 1996

By E. E. Duncan, G. Derce

REVIEW of the literature on hydrogen in steels indicates that inadequate consideration has been given to the influence of temperature gradients on segregation of this element. Even when segregation has been taken into account, the interpretation of the data has been seriously handicapped by incomplete understanding of the mechanism by which it occurred. Recognition of a mechanism which will be described as "thermal segregation" appears to rationalize many of the observed effects so well that it will be reported here with some preliminary experimental evidence. The complete quantitative evaluation of the factors controlling the mechanism will require extensive experimentation. The operation of the mechanism can be described in relation to fig. 1, which shows the temperature dependence of the solubility of hydrogen in iron at

Jan 1, 1951

By L. W. Pommier, L. R. Plitt, F. B. Brien

L. R. Plitt (Assistant Professor of Mining and Metallurgy, University of Alberta, Canada.) — It is indeed encouraging to see rheological studies being carried out in a mineral engineering school. The bulk of the work being done today in applied rheology seems to be concerned with the behavior of polymeric solutions and thus has limited application to the solid-liquid systems encountered in mineral beneficiation. The authors have approached the problem by carrying out a dimensional analysis which showed that for power law fluids the drag coefficient, Ds, must be some function of a generalized Reynolds number which has the form: If the power law adequately describes the behavior of a fluid, the dimensional analyses predicts that the Ds - RN function should hold for all values of n' or any other dependent variable. The experimental evi-

Jan 1, 1968

By James A. Brierley, Rong Yu Wan

Bacterial pretreatment was evaluated as a process for enhancing gold recovery from a refractory ore from Newmont Cold's Cold Quarry deposit. This ore is refractory due to sulfide locking of the gold and preg-robbing carbon. The microbe Thiobacillus ferrooxidans effectively oxidized the sulfide component of the ore, but the preg-robbing carbon continued to be active. Thiourea was examined as an alternative to cyanide for extraction of the gold from the biooxidized ore. The thiourea, coupled with CIL, was effective for gold extraction resulting in up to 89% gold recovery for the sulfidic-carbonaceous refractory ore. The thiourea gold complex appears not to be bound by the preg- robbing carbon of the ore when in the presence of recovery carbon (CIL)

Jan 1, 1990

By C R. Headley, S O. Hille, N P. Jacob

The redevelopment of the Telfer Gold Mine in the Pilbara region of Western Australia was primarily based on the construction of a 17 Mtpa dual train concentrator coupled with open pit and underground mining operations. The unique copper-gold orebody at Telfer requires the application of complex flotation conditions normally reserved for base metal concentrators, where two competing minerals are managed into separate products. This paper describes the commissioning of the flotation circuit, the process modes and the master/slave relationship that flotation has with a variable orebody.

Jan 1, 2007

By Zenjiro Asaki

The copper concentrate particles dissolve quickly into the molten matte in the smelting furnace of Mitsubishi Process, which indicates that the sulfide smelting is essentially a gas/liquid reaction. In this paper, theoretical calculation has been made on the rate of oxidation of FeS component in the matte to form FeO by rising gas bubbles using the penetration theory. The results showed that all the oxygen in the bubble of 1.2 cm in diameter, which is the maximum stable diameter, is consumed in 3 ms. This time required is sufficiently short, and it results in the actual operation of smelting furnace of 1100% oxygen-efficiency. These calculations indicate that most smelting reactions are completed just under the lance, except slag formation.

Jan 1, 2002

By Thomas C. Rube, T S. Bajpayee

The Bureau of Mines conducted research to determine the safe operating conditions for using recycled (used) lubricating oil from mining equipment as a partial replacement for diesel fuel to make ANFO-type blasting agents. The use of recycled oil (RO) saves energy, reduces oil imports, and reduces mining costs.

Jan 1, 1996