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By G. A. Bezuidenhout, J. P. T. Kapusta, D. K. Chibwe

"Peirce-Smith converters (PSCs) are extensively used in the copper, nickel, and platinum group metals industries. The typical converting operation involves lateral purging of air into molten matte through a bank of tuyeres. This blowing operation occurs at low pressure from the blowers, resulting in a bubbling regime that is considered inefficient from both a process and an energy utilization perspective. Inherent drawbacks also include recurrent tuyere blockage, tuyere punching, and low oxygen efficiency.Western Platinum embarked on a full-scale industrial evaluation of generating a jetting regime by using sonic injection. Prior to industrialscale tests, a numerical assessment to ascertain the feasibility of implementing sonic injection into a PSC was conducted. The work included flow characterization at high-pressure injection achieving sonic velocity at the tuyere exit. The 2D and 3D simulations of the three-phase system were carried out using the volume of fluid method together with the RKE turbulence model to account for the multiphase and turbulent nature of the flow.This paper discusses the key findings in understanding plume extension, velocity distribution, shear wall stress analysis, and phase distribution characteristics in the system. Plant trials are also discussed with reference to the commercial aspects of a full-scale implementation of sonic injection in the smelter."

Jan 1, 2015

By R. P. Harvey, J. E. Walstrom, A. A. Brown

In view of the large number of wells directionally drilled from offshore platforms and urban drillsites, greater interest is being focused on the directional survey and on the uncertainty inherent in calculating the position of the bottom of the hole, or other benchmarks in the wellbore. Of the two methods presented here for evaluating this uncertainty, the first is analytical and uses the principles of probability and statistics. The second method uses Monte Carlo simulation to generate a pattern of the scatter of possible bottom-hole locations. Both methods are based on a model for which the usual assumption is made that the curvilinear axis of the wellbore is adequately represented by a large number, M, of linear segments joined end to end from the top to the bottom of the hole and closely following the course of the hole. The errors due to this approximation are assumed to be negligible and are not studied here. One form of the model is to consider that for a given hole there exists a perfect set of data describing it, of the above form. Each linear segment has an angle of inclination with the vertical 7, in radians, an azimuthal angle from true north xi in radians, and a length Si, in feet. The subscript variable, i, extends from 1 to M. Each of the M linear segments representing the axis of the wellbore has three components in the X, Y, and Z directions. These components are calculated from the equations: The bottom-hole coordinates as determined from the reference set of data for the wellbore are given by the following for i = 1 to M: X=SX, Y = Sy, Z=SZ; . (2) A directional survey instrument, lowered into the wellbore to the M segments, or stations, measures the values of the 7; and the 3,. In general, because of errors from various sources, the resulting angular measurements will not be precisely equal to the 7" and xi. Random variables l, and Ai are therefore considered with associated probability density functions fi(li) and gi(Ai), respectively, which represent the distributions of potential survey measurements for this hole. Since it is assumed that the values Si are accurately measured they are treated deterministically. The random variables corresponding to the surveyed bottom-hole coordinates are given, for i = 1 to M, by:

Jan 1, 1970

By William G. Schultz

Sylvite of Canada, a wholly owned subsidiary of Hudson Bay Mining and Smelting Co., operates an 8000 TPD potash mine and refinery located nine miles North East of Rocanville, Saskatchewan. Prior to Hudson Bay's entry in 1968 into potash mining and refining, it was one of the more traditional and conservative Canadian Mining Companies whose principal business had been for many years a successful copper-zinc mining and smelting operation located at Flin Flon, Manitoba. The potash reserves being mined by Sylvite were acquired through the acquisition of Francana Oil and Gas. This acquisition was at the time when several major potash mines were being developed or had recently been brought into production in the Province. These mines are owned by either very substantial Canadian Mining Companies or Multi-National Mining Companies with considerable potash mining experience. At that time, it became very apparent because of the new mines coming into production, potash mining and refining would quickly become a very competitive industry. Because of long term considerations, Hudson Bay decided to proceed with the development of its potash reserves, recognizing the Mine and Refinery would have to be the most advanced available in order to successfully operate. This report deals with the mining operation at Sylvite and the degree of success Sylvite has achieved.

Jan 1, 1972

THE Yallourn chimney has aroused interest, as it is, for the time being, the tallest structural erection in Australia. Its height was not decided on, however, with the object of breaking records, but is purely incidental to the purpose which it serves. Theboiler plant at the briquetting works (first instalment) consists of five Babcock and Wilcox land-type water-tube boilers, each of 4510 sq ft. heating su:r£ace and 225 sq. ft. grate area in the form of step grates. Four boilers will normally produce 73,000 lb. of steam per hour at a gauge pressure of 265 lb. and a temperature of 6500 F., the fifth boiler being a reserve. Each boiler will consume about 100 tons of Yallourn coal per 24 hours. Provision is made for future installation of economizers, should it be found desirable. Designing for this condition, and allowing for a waste gas temperature of 3500 F. and an air temperature exceeding 1000 it was found necessary to have a draft of about 1.3 in. (water gauge) at the base of the chimney, and to deal with about 2000 cub. ft. of gases per second. Estimates were made of the cost of providing the necessary draught by means of fans and by means of a tall chill).ney. The annual charges of the two methods differed only slightly, and the tall chimney wasselected as being the more general practice in briquetting factories.Estimates were prepared for brick and concrete chiIlllleys. Yallourn bricks at that time were hand-made, and, while very suitable for domestic work, were not capable of withstanding high compressive stresses. The chimney design to suit these bricks thus required to be on very ample lines, resulting in high cost. Machine-made bricks from Melbourne would cost about £5 10s. per thousand on the site, with extra for radials, so that high cost again resulted. On the score...

Jan 1, 1924

By James A. Schneider

The successful installation of long piles driven into very dense sands relies on the occurrence of the reduction in local friction with increased pile embedment, a phenomenon known as ?friction fatigue?. The underlying mechanisms controlling friction fatigue are poorly understood, with some design methods including an adjustment for the influence of pile diameter while others do not. This paper back calculates the installation resistance of 0.356m to 2m (14in to 78in) diameter open ended piles driven into very dense sands using wave equation analyses. Cone penetration test data are used to link soil properties to installation resistance. The study illustrates consistent interpretation of a variety of case histories of open ended piles driven in very dense sands using newly developed analysis techniques and normalized parameters. Results provide information on methods for incorporating friction fatigue into drivability studies as well as a discussion of mechanisms related to pipe pile installation resistance in sandy soils.

Jan 1, 2010

By Fabrice Mathieu

The Cutter Soil Mixing (CSM) provides a cost effective solution for the rapid construction of retaining and cut-off walls using new equipment developed from diaphragm wall cutter technology. CSM consists of cutting and mixing drums mounted on compact hydraulic motors. Soletanche Bachy CSM has been designed to leave the space above the tool free, thereby mixing the soil efficiently during all the phases of the wall construction, with high penetration rates. The precise positioning and verticality of the wall is achieved using a kelly bar and full monitoring. Soletanche Bachy CSM is a versatile equipment which can be mounted on various carriers: pile rigs, hydraulic crane, carrier equipped with telescopic mast. The major phases of Soletanche Bachy CSM development are presented, including the results of an extensive trial carried out in Le Havre (France). The soil consists of hydraulic fill with soft soil lenses overlying sandy deposits. 20m deep panels were constructed to support a rectangular shaft. During the construction, and after its completion, the shaft was subjected to an extensive series of tests followed by a partial excavation. The paper discusses also the future development of the technique and its potential applications.

Jan 1, 2006

By M. Bwalya, L. Mabokela, L. C. Woollacott

This paper presents a study on the ability of the King stratification modelto describe density stratification patterns that are achieved under idealizedconditions. Tests were conducted in a batch jig using artificial particles inseven density classes. All particles in a density class had essentially thesame density, size, and shape. Tests were conducted for particle systemsinvolving from two to seven components. Good agreement was obtainedbetween measured and modelled data to an extent that gave strongendorsement of the mathematical appropriateness of the core equation inthe King model. Somewhat ambiguous results were found with regard toclaims about the independencies of the single experimentally-determinedparameter required by the model.

Jan 1, 2015

By F Pirajno

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. China’s mineral deposits are the result of metallogenic processes associated with the geodynamic evolution of tectonic plates and eventual amalgamation into their modern configuration. The principal tectonic provinces of China comprise the North China Craton, Yangtze Craton, Cathaysia Craton, Tarim block, Altay-Tianshan-Hinggan orogens (part of the Central Asian Orogenic Bel), Central China orogens, Songpan-Ganze orogen and Alpine-Himalayan fold belts, which are part of the huge Tethysides. These tectonic elements are testimony to a complex geological history spanning more than 3000 million years. This contribution will focus on selected areas of the Altay-Tianshan, the fold belts surrounding the North China Craton and Yangtze Craton and the mineral systems along the Ailaoshan-Red River fault zone. Mineral deposits in these provinces include gold, copper, molybdenum, tin, antimony, nickel, platinum group elements, lead and zinc.CITATION:Pirajno, F, 2015. Metallogeny and related tectonic settings in China , in Proceedings PACRIM 2015 Congress, pp 17–24 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Conny Postupack

To make money in mining coal you have to sell it for a lot more than it cost you to get it out of the ground. And yet, every year it cost us more and more to stay inbusiness, while the price we get for coal does not increase at the same rate.

Jan 1, 1990

By Lon Santis, Dale Ramsey

The use of aircraft to support blasting operations in mines, quarries and construction sites goes back to the early days of aviation. Invaluable at times, aircraft use has been limited by cost, the unpredictability of weather impacts and other factors. Recently several technologies have matured to open up a new way to acquire aerial data with unmanned aircraft systems (UAS), commonly called drones. Equally important, the U.S. Federal Aviation Administration has recently implemented an exemption process and rulemaking to implement the commercial use of UAS into the United States’ National Airspace. The skies are opening for many applications of UAS. The most notable may be photogrammetry, which is the science of making measurements from photographs, especially for determining the exact positions of surface points.

Jan 1, 2016

By Bruno Bussière, Michel Aubertin, Anne-Marie Dagenais, Johanne Cyr

A five steps remediation program was commissioned in 1998 for the acid generating Lorraine mine site, located in the Témiscamingue region, Quebec, Canada. It included, as the main expenditure, a cover with capillary barrier effects (CCBE) used to limit oxygen migration. After construction of the cover, instruments were installed on site to monitor the CCBE performance. Modified oxygen consumption tests were also done to measure the oxygen flux through the cover. Results from water content and suction data, measured from 1999 to 2003, show that the capillary barriers effects are effective and that the water retention layer stays near saturation throughout the years. Oxygen fluxes estimated from monthly water content measures are generally below 10 g/m2/year. Results from modified oxygen consumption tests made on the site give almost similar oxygen fluxes. A two dimension numerical model of the Lorraine mine site was also constructed to verify that mathematical models could predict realistically the in situ conditions on such a large scale site. Numerical results obtained for three years show a good concordance between measured and calculated values. The results obtained form these different evaluation methods for the performance of a CCBE concur and confirm the efficiency of this cover in limiting acid mine generation.

Jan 1, 2005

By J Kokado, N Hatta, S Yabushita

A theoretical model is described for prediction of the capacity of fines from porous ores, such as cokes and sintered ores, to be removed by a pneumatic, horizontal-type classifier prior to charging into a blast furnace. First, the influence of variation in the apparent density and drag coefficient of porous ores on removal efficiency is analysed from a stochastic standpoint. The effect on efficiency of collisions between particles in the classifying region is then examined analytically in relation to the ratio of the mass flow rates of particles and air (the loading ratio). Finally, a theoretical model is constructed that takes these factors into account. Theoretical and experimental results are compared and classifying efficiency is discussed from both experimental and theoretical viewpoints.

Dec 1, 1993

Nowadays, technology has improved to extract dimensional stone blocks at quarry sites and also to process these at processing plants for making slabs and tiles. In the process of quarrying and processing, performance evaluation of machinery is very important to achieve optimum output at minimum cost with improved technology. Cost analysis of improved technology includes parameters such as manpower, energy consumption, tool consumption, depreciation, maintenance and also others. The chainsaw machine with long boom and rail in marble quarries and multi-diamond wire saw machine for slab making from granite blocks at processing plants have recently been introduced in India. Thus, a study was carried out under a research project on these machines to assess their suitability. In this paper, performance evaluation and cost analysis of chainsaw and multi-diamond wire saw have been carried out with existing machines on the basis of research findings.

Dec 6, 2010

Models are used in engineering to reproduce reality as faithfully as possible so that the expected response of a system for given actions or inputs can be determined. In the field of rock engineering, both empirically based and numerical models are widely used to determine the likely response of the rock surrounding excavations. Many of the empirical models are developed from statistical analysis of case histories or from direct observation; however, empirical models are limited because they should be used only within the range of conditions of the observational database. Synergy exists between empirical and numerical models, because empirical models can be used to calibrate and validate numerical models. The empirical approach can benefit from the capability of numerical models to investigate specific mechanisms, which would not be possible using observations alone. Two cases are presented in which the synergy between empirical and numerical models is demonstrated. The first case examines the analysis of discontinuity effects on the strength of slender pillars in limestone mines, and the second case evaluates the effects of stress orientation on coal mine entry stability. It is concluded that numerical model calibration and verification comprises an important first stage in the successful application of models in rock engineering design. Application of numerical models allows mechanisms and interactions of various parameters to be analysed, greatly improving the understanding of the system. The improved understanding can be used to extend the application of empirical design methods, resulting in improved safety and efficiency of rock engineering designs.

Jan 1, 2014

By Nilce Alves Santos, Vânia Lúcia de Lima Andrade, Keila Lane Carvalho Gonçalves, Harold Wyslouzi1

"When confronted with the difficult decisions on advancing an exploration project to the feasibility and construction stages, it is important to know how various regions of the ore body will react in the milling and concentration processes. While bench scale test work is common and inexpensive, the results and information provided are somewhat limited due to the difficulty in accurately predicting the effects of recirculating middling streams or gradual changes in solution chemistry.Conventional Pilot Plants, processing 100 to 1,000 kg/hour of sample ore, provide the detailed engineering data required to develop a final process flowsheet and to size the equipment. They are, however, expensive to set-up and operate, and are really only viable for major projects that are well advancedIn the latter part of 1999, the Mineral Development Center at CVRD (MDC) purchased a new piece of mineral processing equipment which can run continuous flotation tests using drill core samples. To evaluate its performance, and to compare it with conventional testing methods, various types of flotation tests were carried out using two different types of copper ore. The limitations and advantages of open circuit and locked cycle bench tests, as well as the Mini Pilot Plant and the Conventional Pilot Plant were evaluated.Open circuit tests carried out at the bench scale only provide basic information. More complete and trustworthy information is obtained, in terms of the recirculation of flows and reaching a permanent and stable flotation regime, as the dynamics and complexity of the tests increases. The data obtained showed that the MPP’s metallurgical performance was equivalent to that of a conventional pilot plant."

Jan 1, 2002

By Scott Chesman

Increased TBM performance is leading the way for resurgence in tunneling activity in NYC. Tunnels will be excavated in the same geologic formations as previously excavated D&B tunnels whose construction records are providing valuable insight into the prediction of rock mass behavior. This report compares an eight mile stretch of NYC Water Tunnel #2 with the recently excavated eleven mile stretch of the TBM driven Water Tunnel #3. Comparisons of the type and amount of rock support installed as well as water inflows and grout quantities are made. Rock mass characteristics specific to TBM performance are also evaluated.

Jan 1, 2005

By M. Faraji

Inclusions formed in a high-carbon, manganese-silicon killed plain steel (Fe-0.77C wt%) were studied. Various techniques were used to characterise the inclusions, and the latter were classified according to their chemical composition, size and morphology. The main constituent elements entering the inclusions were Mn, S, Al, and oxygen. Alongside MnS and some Al2O3 inclusions many non-metallic inclusions appeared in complex forms, consisting of silicates, sulphides and oxides. Duplex oxy-sulphides, mainly MnS combined with Al2O3, or SiO2 were the most common complex multiphase inclusions in this steel. The nanoindentation technique was used to assess and rate different types of inclusions and data of the hardness and elastic modulus of individual inclusions at room temperature are presented.

Jan 1, 2010

By Bhaskar B. Thapa, Michael T. McRae, Johannes V. Greunen

This paper describes the preliminary design of the fourth bore of the Caldecott Tunnels along State Route 24 in Oakland, California. The paper focus is on two major aspects of the project: initial support system design and seismic design. The initial support system was designed based on the New Austrian Tunneling Method (NATM).NATM provides the required flexibility to accommodate the variable ground conditions in the weak, folded, and faulted rock along the alignment. The seismic design provides a final lining system that meets serviceability requirements for a 1,500 year seismic event with an estimated peak ground acceleration of 1.2g.

Jan 1, 2007

By S. Don Brown

Between 1987 and 1988, the Bureau of Mines studied the mineral resources of the White River National Forest and part of the Arapaho National Forest to appraise the resources present and to determine the types of deposits, and their location, that could be mined economically if sufficient demand and metal prices existed. The study included a comprehensive literature search and a limited amount of field investigation of minerals and mining activity in and near the Forest. Mineral resource information indicates that in the Gore Range the area between Tennessee Pass and Gilman may contain large base-and precious-metal deposits, and could be the focus of exploration activity in the near future. The Breckenridge mining district was found to have a moderate to high likelihood for mineral exploration and possible development of gold. Recent exploration and minor development work has occurred in several other areas: Montezuma, Kokomo-Tenmile, and Upper Blue River districts, and portions of the Sawatch Range. Limestone, marble, sand and gravel, rock for crushed aggregate, and other industrial rocks have been recently mined or Quarried in the Forrest, and will likely be mined or quarried in the near future. Currently coal is being produced at one mine in the Forest, and extensive identified coal resources are located in the Forest. Parts of four known gas fields lie within the Forest west of Glenwood Springs; there is current production at one field.

Jan 1, 1990

By E. Snyders

The upgrading process of an inferior grade of zircon to a superior opacifier for ceramic applications was investigated. A calcining process in the presence of mineralizers was used to produce the product in a conventional muffle furnace. A pre-milled inferior grade zircon concentrate, with a relatively high iron and alumina content generally not suitable for high quality ceramic applications, was used in this study. The influence of the upgrading process on the opacifying properties of the zircon material was compared to that of commercially available prime grade zircon opacifier products currently being produced in South Africa. The influence of a calcining step in the presence of mineralizers with regard to the milling characteristics of the treated zircon material was also evaluated in this study. The morphology of the treated and untreated zircon opacifier samples were investigated by SEM micrographs and the colours of zircon samples were characterized on the grounds of the Commission Internationale de l`Eclairage (CIE) standard procedure (CIE L* a* b* measurements) after application on a bisque ceramic tile. It was found that the treatment improved both the milling as well as the opacifying properties of the treated inferior grade zircon concentrate and renders it equivalent to or better than prime grade zircon opacacifiers currently produced. Keywords: ZrSiO4; opacifier; colour; milling; calcining.

Jan 1, 2005