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By Mark A. Koestel

Cobalt-sulfide mineralization can he found in potentially economic quantities where permeable, basal Cambrian formations "pinchout" against Precambrian pal eotopographi c highs. These environments are common around the Saint Francois Mountains of southeastern Missouri and they share many similarities with the geologic environments of Zambia and Zaire in South Africa. Exploration for this type of deposit involves test drilling targets identified by trend analysis from past drilling, geophysics, geochemistry and a comprehensisve study of regional geology and isopach maps. Innovative ideas, new exploration concepts and insoluble residue geochemical methods may provide the necessary "edge" needed to complement basic geologic understanding leading to ore discovery.

Jan 1, 1987

By William H. Walton, Clyde N. Baker Jr., Darren S. Diehm

"A 51-story concrete core and steel frame commercial office tower was recently constructed on the site of the former US Gypsum building in downtown Chicago, Illinois, USA The structure foundation reused several caissons from the demolished US Gypsum building supplemented with new belled caissons bearing on silty clay hardpan. Extensive in-situ pressuremeter testing was performed during the geotechnical investigation to determine allowable bearing capacity and better estimate building settlements. Problems during foundation construction along the south side of the building frame required remediation of two caissons. One caisson was supplemented with micropiles, while the second caisson was abandoned and replaced with a straight-shaft rock socketed caisson. To determine the effectiveness of the repairs, the building foundation settlements were monitored during construction.IntroductionIn 2001, The John Buck Company began development of a new office tower at the southeast corner of West Monroe Street and South Wacker Drive in Chicago, Illinois. The site was formerly occupied by the 18-story US Gypsum (USG) building. Mr. Clyde N. Baker, Jr. (Senior Principal at STS Consultants, Ltd .) served as the foundation engineer for USG which was completed in 1962. The building was founded on a forest of belled caissons bearing at elevation -56 Chicago City Datum (CCD). For reference, the ground surface at Upper Wacker Drive is approximately elevation +20 CCD. The bearing material was a hard silty clay, locally described as Chicago Hardpan. The foundation caissons were designed using an allowable bearing pressure of 16 ksf (766 kPa). In 1996, the USG superstructure was razed, and the three-level basement was converted to an underground parking ramp.South Wacker DevelopmentThe 51-story high-rise building was completed in 2005 with a structural height of 681 feet (208 m), and an internal space of more than 1,000,000 square feet (93 ,000 square meter). The typical floor size is 27, 700 square feet (2, 570 square meter). Renderings of the building are provided in Figures 1 and 2. The largest single tenant is the accounting firm of Deloitte & Touche, which occupies roughly 45% of the building space with over 3,000 employees."

Jan 1, 2005

By F. G. Loper

Simulation as a mathematical technique is not new. However, recent increases in digital computer speeds and the ease of programming with languages such as Fortran have centered a good deal of attention around simulation in the last few years, Many sophistications of the method have been developed during this time. However, the ability to simulate mathematically still hinges on the ability to ignore unimportant details which would complicate the mathematics and make simulation impractical, Thus, with this attitude in mind, it becomes very easy to design a pseudo- simulator which will predict average conditions very well, but can not truly allow a detailed study of the system being simulated. Most simulations fall into this category, along with the case mentioned here. This paper is not intended to be a critical treatise of the simulator used to study a particular mining system. Instead, it will be used to illustrate the aspects of simulator development. The steps in the development of any simulator are described, along with same detail of the phosphate mine simulator itself.

Jan 1, 1966

By G. H. Khoe

Although some hydrometallurgical process liquors contain significant amounts of ferrous and arsenate ions, no reliable thermochemical data for the aqueous complexes and the solubility of the ferrous arsenate precipitate are available. The complexation of iron(11) with arsenate has been investigated using the potentiomemc titration method. The results indicated that virtually no complexation of iron(@ with arsenate has been observed. This is in contrast to the significant complexing reported for iron(1n) with arsenate. The solubility product of the precipitate was calculated using the concentrations of appropriate arsenate species pertaining to the observed precipitation pH's. The fit of the observed precipitation points on the solubility curve of the computed stability diagram was used to assess the appropriateness of the equilibrium model.

Jan 1, 1991

By A. M. McKim, J. S. Ambler

"The iron ore of the Scully Mine is upgraded from 36 per cent Fe to 66 per cent Fe through single-stage crushing, wet autogenous milling, sizing by vibrating screens and two-stage spiral separation, followed by a process in which the concentrate is dried and then further improved by high-tension separators. The capacity of the concentrator is 17,000 long tons of concentrate per day. Discussion of the operation will recognize the special problems encountered in handling preponderantly fine ore, relate issues of interest regarding wear and review mechanical innovations found to be advantageous at Wabush. The modern trend toward big equipment, thoroughly instrumented, has been the theme of design. Effects on availability must be a consideration in this choice, and sectionalizing of circuits to minimize these consequences is as important as streamlined maintenance."

Jan 1, 1969

Upgrading of MgO in Dolomite Ore by Froth Flotation

Sep 13, 2010

By Donovan J. Benton

Photogrammetric methods are advancing rapidly and show considerable promise as a ground control research tool. The ability to quickly capture three-dimensional geometry, especially changes in geometry, in underground and laboratory settings is a significant advance from point distance measurements. Photogrammetry is being applied in both of these settings as part of the NIOSH ground control research. This paper describes these applications and the equipment and software being employed. It also describes tests conducted to quantify the accuracy of these systems. Accuracy varied with system specifics and procedures. A factory-calibrated camera produced results within 1/32 of an inch, plus 0.04%. A user-calibrated camera was found to be less accurate, at 1/20 of an inch, plus 0.24%. These calibrations demonstrate that photo grammetry can produce research quality measurements in laboratory and mine settings.

Jan 1, 2014

By Shoji Taniguchi, Lifeng Zhang

"In this paper, firstly the 3D single-phase turbulent steady fluid flow in a vessel with four baffles stirred by a single impeller is mathematically simulated. Turbulence is modeled by using the standard k - e model. Sliding-grid method is used to model the impeller. The flow domain is divided into two cylindrical, the inner one rotates at the same speed as the impeller, and the outer one is fixed with the baffles. Results indicate that the high-speed zone is near the paddles, and larger stirring speed generates larger fluid flow velocity. The calculated stirring intensity data are used to analyze the experimental results. Secondly the effects, such as filter pore size, gas flow rate and NaCl concentration, on bubble size are studied by experiment. For the particle removal rate by bubble flotation in this vessel, first order kinetics is adopted. The effects of initial number of the particles, gas flow rate, particle and bubble size, stirring speed and surface condition, on the removal rate constant are discussed, and an empirical equation is derived by experimental data. At last, a simple model is developed to study the particle attachment probability on bubble surface under turbulent flow conditions. IntroductionIt is well known that inclusions have a bad effect on steel quality. Trying to remove inclusions from liquid steel as many as possible is one of the main objects for the metallurgical workers. Lots of ways are developed to remove inclusions from liquid steel. Gas injection is an effective one. This technique is used to achieve homogeneity in the temperature and metal composition and to assist in the removal of second phase and dissolved impurities from molten steel. Gas injection is commonly applied to the secondary metallurgy processes and continuous casting, for example the ladle argon gas treatment, RH vacuum degassing, and the gas injection in the Submerged Entry Nozzles (SEN) of continuous casting mold, etc. The development of these processes focuses on achieving two conditions: fine bubbles and good mixing. Fine bubbles provide a large gas/liquid interfacial area and a high attachment probability to inclusions, and good mixing enhances the efficiency of impurity transfer."

Jan 1, 2000

By L Cain, C Every, S Mirlatifi, J Ashley

This paper presents a geographic information system (GIS) based method for the prediction of ground movement and the associated impact on existing buildings and structures due to tunnelling in the North West Rail Link (NWRL) project. The NWRL is a priority rail infrastructure project for the New South Wales (NSW) Government and includes 15 km of twin tunnels between Bella Vista and Epping, which will be Australia’s longest rail tunnels. The NWRL tunnels will be constructed in an urban environment where the prediction of ground movements induced by tunnelling and the associated impacts to existing structures must be assessed in the early design stages of the project. An assessment process was developed using GIS able to respond to design changes.An iterative GIS analysis methodology was developed to generate ground settlement contours and identify impacted buildings and structures in response to multiple changes in tunnel alignment during design development stages. The GIS analysis undertook to rapidly provide detailed and accurate parameter information including tunnel depth from surface, tunnel separation, diameter and sample point proximity to the tunnel and assess ground movement contours along the project alignment. Determination of the ground surface settlements were based on empirical methods proposed by Peck (1969) and Mair (1993). The control parameters and the relationship between damage categories and risk classifications for impact assessment were based on Burland, Broms and de Mello (1977), Rankin (1988) and Boscardin and Cording (1989) methods.The GIS-based ground movement impact assessment approach adopted for the NWRL project demonstrates an efficient, iterative and robust approach and could provide an initial framework for other similar tunnelling projects where rapid design changes and early understanding of tunnelling impacts are required to bring greatest benefit to all stakeholders.CITATION:Mirlatifi, S, Cain, L, Ashley, J and Every, C, 2014. An iterative geographic information system based approach for the assessment of tunnelling impact to existing buildings and structures, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 647–652 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

In the last five years, new iron ore pellet plants have been built with significantly reduced air pollution levels compared to the older generation of plants. European and American pollution controls are more stringent that in China and Brazil. The recent American plants have successfully employed circulating fluidized beds for sulfur control, baghouses for particulate control, activated carbon injection for mercury and a new design of specialized low-NOx burners.

Jan 1, 2015

By Tadashi Nishida

Subsidence due to mining caused various kinds of damage to the surface structures, and actually great deal of mining damage becomes the severe social problem at some time in many coal fields, but the most of mining damage was restored at present. Recently, the effect of old coal working on the deformation of newly constructed structures has become into question, because it was obliged to plan many engineering structures in old mining areas for the shortage of adequate construction sites and the difficulty of getting location. That is, building, dams, bridges for railroads and highway, power plants, tunnels, storage tanks and so, have to be built on the ground which has old coal working.

Jan 1, 1982

By Theodore M. Olson

The Washington State Highway Department consists of seven geographic dis¬tricts. District offices are located in Seattle, Wenatchee, Olympia, Vancouver, Yakima, Spokane and Bellevue. District is covered from the Spokane office, and is responsible for the six counties in the northeast corner of the state (Fig.l). It is bordered on the north by the International Boundary, on the south by the Snake River, on the east by the Washington - Idaho border, and on the west by a north-south line thru Lake Roosevelt. The landslides to be discussed in this paper are at Colfax, Washington, which is located in the southeast corner of the district. The town of Colfax is situated in a narrow valley eroded into the Tertiary volcanic basalts by the Delouse River. The valley walls are steep and generally colluvium mantled. State Highway 1°c, from Spokane to Colfax, descends into the valley from just north of Colfax on a bench cut into the valley wall. The highway department designed a widening project to increase the misting two lane roadway to three lanes, thus providing a passing lane for uphill traffic. The third lane was constructed as a cut section for the entire length. Construction excavation was begun at the top of the hill in silts of eolian origin. Proceeding downhill, excavation encountered three individual basalt flows with two zones of palagonite tuff separating them. The upper palagonite zone was dry, and excavation proceeded across this zone with no mishaps. The lower palagonite zone carried considerable groundwater. As excavation crossed the lower zone landsliding became contemporaneous with excavation, due to removal of toe of slope and saturated conditions. Remedial measures for landsliding consisted of designing shot rock buttresses across the palagonite zone and also the installation of horizontal drains to reduce hydrostatic pressure.

Jan 1, 1971

By S. O. Ogden

As most of you have probably surmised from the title of my paper, I am here today to talk with you about the use of diesel engines in the American mining industry and whether or not the free choice to use such equipment will continue to be available to mine operators. Of course, I will present to you my prepared remarks, however, these remarks may be essentially academic in light of a news release, parts of which I would like to read to you. Washington, D. C., The Department of Health, Education, and Welfare today announced proposed new regulations to reduce occupational health risks to workers in the U. S. mining industries by requiring the removal of all diesel powered equipment from American mines by December 31st "While we do not have complete and conclusive information to quantify these health risks we feel it is prudent to undertake this restriction on the use of diesel powered equipment without waiting for the completion of studies that are currently underway to identify and quantify these health risks," said a Department spokesman. HEW has been concerned about the health risks of diesel emissions in the underground coal mines for some time and have investigations underway designed to conclusively demonstrate the nature and magnitude of any health risks. However, HEW has decided to proceed with these regulations without waiting for the final results of these investigations. Further, HEW feels there is sufficient probability that diesel health risks do exist in all mining applications and consequently, the proposed regulations will apply to all surface and underground mining operations. It goes on a little further and indicates that due to the necessity of finalizing these regulations without delay, a period of fifteen days has been provided to receive comments regarding these proposed regulations.

Jan 1, 1978

By G. Anger, J. Enser, H. Antrekowitsch, S. Koch

Homogeneous chemical composition and microstructure are always necessary, but not always attained in practice. As-cast aluminium alloys tend to have a segregation microstructure. Features of the cast structure, which affect subsequent processing or properties, can be altered by the homogenization. The main task of the Department of Nonferrous Metallurgy was to investigate the effect of homogenization treatment on precipitation hardening of aluminium alloys 6061 and 6082. The effect of the solution heat treatment (SHT) temperature on the mechanical properties was also analyzed. The homogenized and non-homogenized rolling slabs were produced according to the usual conditions and methods. The metallographic investigations were carried out on the as-cast samples, after homogenization, after the hot and the cold rolling mill, and after natural and artificial ageing. Then, Brinell hardness measurements and tensile tests were conducted on both alloys in order to examine the influence of the homogenization.

Jan 1, 2006

Safety remains a critical priority for the Australian mineral resource industry and will receive increased focus in the future. This is particularly evident in underground coal mines where reserves are becoming deeper and more hazardous to extract. The CSIRO, through its Exploration and Mining Division, have recently delivered on two projects aimed at providing step-change capabilities in real-time risk management and hazard control. This paper describes the key outcomes of these projects.

Jan 1, 2005

By W. W. Agey

As a result of a field examination made during the Bureau of Mines intensive manganese program, three lots of ore were procured from the famous old Paymaster District, 7 miles from Midway Wells, Imperial County, Calif. This district is an old producer and shipped approximately 10,000 tons of 45-percent manganese ore during World War I. A 2-ton lot of ore was taken of a Bureau engineer from the exposure of a small fissure vein in conglomerate on the Turtle Group of claims; 1 mile east of the Pacific Coast Manganese Corp. claims. The vein material consisted of manganese oxides, calcite, and quartz in fairly coarse association.

Jan 1, 1949

By F. Liu, H. A. Meier, D. M. Valiveti, P. A. Gordon

Hydraulic fracture is a frequently used technique in the Oil and Gas industry to create high permeability pathways for extraction of hydrocarbons. Numerical simulation of this method poses challenges such as representation of 3D fractures, propagation of randomly oriented fractures in 3D media, enabling fluid leak-off from fracture to poro-elastic medium. We have developed a numerical model using the Generalized Finite Element Method (GFEM) to simulate fluid driven fracture in a poro-elastic medium that addresses these challenges. In the GFEM framework, special enrichment functions are used to augment the solution space in the displacement and pore-pressure fields in order to accurately capture the response in the vicinity of the fracture. Adaptive refinement of the finite element mesh is also employed to facilitate accurate and efficient solution of the model. Our model fully couples fluid flow in the fracture, represented with the lubrication approximation, to the geo-mechanical behavior of the bulk poroelastic rock, comprised of an elastic rock skeleton saturated with fluid. Fracturing fluid exerts traction on the fracture surface and is also allowed to leak-off into the poroelastic medium using a transfer function approach. Stress intensity factors (SIFs) are evaluated based on the Contour Integral Method, accounting for the fluid pressure on the fracture surface. The SIFs are used to govern a full 3-D evolution of the fracture. Verification of the model is performed for known behaviors for the poroelastic response and fluid flow in the fracture.

Jan 1, 2015

By R. W. M. Lai

The study of flotation kinetics was first reported by Garcia-Zuniga1 in 1935. Since then, literature on the subject has grown with the time. 2-19 Although there is an abundance of flotation kinet¬ics models available in the literature to describe flo¬tation systems, they are mostly of academic interest and are seldom applicable for use in the industrial environment. Several reasons contribute to the wide gap in the industrial -application of the academic models. These include: 1) the lack of generality in the model, e.g., the model is limited to certain size ranges; 14 2) the academic models involve complicated mathematics; 5,6,10,11 3) confusion about the order of the flo¬tation rate, e.g., several authors proposed a first order rate model, 1,15,16 whereas the others propagated a second order rate model: 2,17,18,194) the use of an unrealistic rigid value, such as the use of a maximum recovery of 100%, 5,8,19 which is unrealistic in industrial operations; and 5) the use of graphs that confuse the reader rather than interpret information. 2,3,10 This paper intends to introduce a simple and easy to understand empirical flotation kinetics model along with a way of presenting the model in an informative graphical form, which should stimulate the interest of other practical engineers to become concerned with practical application within the mineral industry.

Jan 1, 1982

A study was made to determine the effect of increasing concentrations of dissolved oxygen on the floatability of galena pyrite and chalcopyrite. Adsorption, flotation and contact-angle tests were done in deoxygenated, in air-saturated and in oxygen-saturated solutions. The results showed that the adsorption of collector increased as the concentration of oxygen increased. Adsorption followed the exponential law r = kC'/"• Discontinuities in the curves were observed after the adsorption of several monolayers of collector. Although adsorption increased with increasing oxygen concentration, the floatability of the pyrite minerals did not increase, because oxidation had adverse effects on the floatability of these minerals. The floatability of galena was maximum in oxygen-saturated solutions, pyrite was depressed and chalcopyrite was also slightly depressed. Contact-angle tests proved that a bubble could not be attached to large flat surfaces in deoxygenated solutions, because sufficient surface free energy was not available for adhesion after the deformation of the bubble. In the presene of air, all the minerals yielded the same maximum angle of 72 degrees, characteristic of isopropyl xanthate.

Jan 1, 1970

By Peter Fischer

A demonstration plant for QSL technology with a continuous through-put of up to 10 t/h concentrate has been in operation at the Berzelius smelter, Duisburg, Germany since early 1981. In the QSL-process, both oxidation and reduction steps are performed in a single horizontal long cylindrical reactor. In the present demo-reacior, 2.5 M diameter by 22 M long, these steps are separated by a low partition wall with an underflow opening, to prevent backmixing of slag. -Tests on a variety of concentrates, including high-lead Missouri-type material and lower grades, have shown recoveries and consumables indicating very attractive economics. Investment cost estimates further enhance the economic attractiveness. Environmental protection afforded by the QSL system is a major advantage. The process has proven its reliability and versatility and is now ready for commercialization. Continued test work, including smelting secondary lead materials, is planned.

Jan 1, 1983