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A Process for the Flotation of Chrysocolla

Sep 13, 2010

By F. G. Scott

This document is a proposed program plan for mining environmental research to be conducted by the U.S. Bureau of Mines in support of industrial oil shale mining and processing. This program plan is one of three research alternatives being considered by the Bureau, each based on a different level of anticipated funding. This report documents the low funding level program plan.

Jan 1, 1980

By David J. Mack

A SURVEY and critical appraisal of published information about Young's modulus was originally made by the writer because of a complete lack of information about this very important quantity in works on mechanics, physical metallurgy, physics, and other sciences. It was felt that a comprehensive summary of such information about Young's modulus might be of general interest and may suggest new problems or lines of attack on other problems that involve E. Hence this paper has been prepared even though it is only a review, with no new ideas or experimental data. The references are only those used in assembling the paper. No attempt was made to compile a complete bibliography on the subject of Young's modulus. CALCULATION OF YOUNG'S MODULUS FROM THEORETICAL OR EMPIRICAL CONSIDERATIONS Many attempts have been made to compute E from theoretical considerations. The earliest calculations were probably those of Tomlenson (1883) and Southerland (1891), but Fessenden 41,42 made extensive calculations a few years later and arrived at the relationship: [2E = 78. 101 (_L V] where V is the atomic volume. In 1923, Peczalski,43 working from the same stand-point but with more information available on atomic structure, arrived at an identical relationship, which he expressed as: [E=B(m) 2] where B is a constant of value about 8 • 10 7, p is density and m is atomic weight; the atomic volume, of course, being m/p. Portevin44 immediately pointed out that while the equations of Fessenden and Peczalski were true of the common metals, they gave low values for the refractory metals with high moduli (Fig. I). He showed (Fig. 2) that much better concordance was obtained by means of an empirical equation of the form: [E _ KT'Vb] where K is a constant; T the absolute melting point; V, atomic volume, and a and b constants of value approximately I and 2 respectively. This constant K in the Portevin equation is not necessarily the same for all elements, as shown by Thompson.45 Other equations for E based upon theoretical considerations have been derived by Honda and Yamada49 and Lasareff. 50 The most recent calculations of elastic moduli based upon quantum mechanics are probably those of Fuchs.46-48 He extended the method of Wigner and Seitz for calculating the lattice energy and compressibility of monovalent metals and computed the elastic constants of lithium,

Jan 1, 1945

The Macraes Mining Company Limited was listed on the New Zealand and Australian stock exchanges in January 1990, and the proceeds of the float were used to purchase a 70 per cent interest in the Macraes Gold Project, previously owned by BHP Gold Mines (NZ) Limited. Macraes Mining has had a 30 per cent interest in the project since May 1984, when it was incorporated. Project financing in the way of a gold loan was secured in February 1990 and construction commenced shortly afterwards. The mine construction activities were completed within nine months and the mine commenced operations in October 1990.

Jan 1, 1991

Block caving is an underground mining method for the profitable extraction of massive, low-grade orebodies. Lately, it has become the mining method of choice, for many mining companies, because of depleted high-grade orebodies, and declining metal market prices. Block cave mining, however, still faces several challenges. Lack of access to the cave remains a major issue in understanding the rockmass response to mining for method optimisation. Improving our understanding of the rockmass response to caving will lead to safer and more productive operations. Combining large datasets from multiple sources with virtual reality scientific visualisation (VRSV) is a viable alternative to understanding complex cave behaviour without access to the cave. This is achieved using immersive environments with the ability to view complex multi-dimensional data (beyond 3D) graphically. VRSV offers a unique platform where it becomes possible to immerse the multi-disciplinary experts, and/or management team, in a virtual mine environment for quick decision making and fast resolution to conflicting conclusions. The underground mining system is complex due to multiple interrelating factors such as geology, excavation geometries, stress and time. Block caving is even more complex than most underground mining methods due to the network of tunnels required, and the use of induced stress, among others. As a consequence of the complexity in the block caving environment, it is vital that the mining system is analysed holistically, as a system, rather than optimizing individual factors one at a time. This paper presents a customised software module developed for use in the Advanced Visualisation Interactive Environment (AVIE) at The University of New South Wales (UNSW), Australia, to enable VRSV investigation into block cave mining systems (BCMS). This approach has the potential to provide a better understanding of the effect of time in in rock engineering, which has proven to be an important factor in hard rock mines (Ma & Daemen, 2006; Malan et al., 1997; Suorineni, 2010) but never validated. This work back analyses the early undercutting phase of a case study block caving operation with the view to understanding time/sequence effects. There is evidence that heterogeneous rockmass time-dependent behaviour governs the seismic response of the rockmass following undercut developments.

Jan 1, 2015

By A Liu, T Ren

Gas explosion in underground coal workings can pose a serious threat to the safety of mine workers and the entire mine operations. Gas explosion is a very complex thermal-chain reaction in a confined underground environment. Based on combustion and explosion theory, three dimensional (3D) computational models were developed to simulate mine gas explosion flame and overpressure wave propagation in a single entry gateroad in underground coalmines. Six different explosion scenarios were modelled and compared with large scale experimental results and AutoReaGas simulations. Model validations show that the use of shear-stress transport (SST) k-? model together with eddy-dissipation model (EDM) produces good agreement with both experimental and AutoReagas simulation results. Modelling results demonstrated that the changes of temperature versus time can be divided into four stages, ie the initial condition stage, and periods of warm-up, active burning, and burnt-out. Assuming a limited volume of methane is involved in the explosion, the maximum temperature decreases as the distance increases from the explosion point, with the highest temperature reaching about 2460 K. Modelling results show that the evolution of the explosion flame shape experiences four typical stages, ie spherical flame, finger-shape flame, flame with the skirt touching the side walls (ribs) and tulip flame, which are similar to the pattern of a duct explosion. The pressure in the gateroad remains the same as the initial value before the arrival of the explosion wave and then increases rapidly to the maximum value. Modelling results from this study will be used for the design of explosion arresting devices and mine seals in underground coalmines.CITATION:Liu, A and Ren, T, 2017. Computational simulation of gas explosion and its propagation in single entry gateroad, in Proceedings Australian Mine Vent Conference 2017, pp 181–188 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By H. F. Feldmann

This work was done to provide thermodynamic, electrical, physical, and compositional data on the seeded combustion plasmas of seven coals for the design of MHD generators. The systems were assumed to be at equilibrium, and the design data were generated by solving for the composition of both gas and liquid phases with a digital computer. The coals reported in this study include a western subbituminous, a Pennsylvania anthracite, and five representative bituminous coals. The data include dewpoint temperatures of both slag and seed. A Mollier diagram for each coal is given to allow graphical generator calculations.

Jan 1, 1970

By P W. Wypych, D Curry, A P. Grima

The market has become highly competitive for engineering and equipment vendors, who are challenged to reduce costs while improving efficiency and productivity of mine operations through plant improvements and expansions. Although conveyor transfer systems account for a small percentage of the infrastructure cost of a mine, they form an integral part of the process supply chain. Malfunctions or suboptimal performance can result in substantial financial cost from delayed start-up, unscheduled downtime, reduced throughput and increased maintenance costs.Discrete element modelling (DEM) is a powerful simulation method used to virtually prototype and test the performance of transfer equipment throughout a design cycle. When developed and applied correctly, DEM can provide insight into performance that exceeds the traditional analytical methods, especially when dealing with complex ore properties, behaviour and/or situations.Using case studies sourced from the authors’ recent research and industrial project work, this paper will address the industry goal to increase efficiency and productivity as well as the methods available to the engineers responsible for delivering designs that meet the aims of this strategic approach.The main focus of the paper will be the new calibration technology, which has been developed by the authors to generate DEM material models that are linked to real-world properties and flow behaviours via unique dynamic testing and innovative parameter calibration methods. These calibrated DEM material models can be deployed by engineers into their existing workflows, whether it be for feasibility studies, concept or final design, plant troubleshooting or optimisation.This new technology allows engineers to gain greater insight than that provided by traditional approaches to the design of transfer chutes and other process equipment and also allows informed design decisions to be made that meet industry efficiency and productivity requirements.CITATION:Grima, A P, Curry, D and Wypych, P W, 2015. New discrete element modelling calibration technology to facilitate the increased efficiency of ore handling and processing operations, in Proceedings Iron Ore 2015, pp 449–464 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Peter Dowden, Trevor Carter, Allan Moss, Bruce Downing, Richard Beddoes

Traditionally (with a few exceptions) tunnel boring machines (TBMs) have been utilized on tunnel projects where the risks associated with deep tunnels (rock burst, squeeze, etc) are low (or expected to be low). This has generally been due to the extremely adverse consequences of entrapping or damaging a TBM under such conditions; but also due to the relative difficulty of dealing with these ground conditions in the confined working area of a TBM, in comparison to a drill and blast heading. This paper review the constraints of operating a TBM in a deep tunnel and discusses related project experience, particularly recent and current experience with TBMs in the deep Alpine Base Tunnels. Potential future applications of TBMs in the development of large, deep underground mines are also discussed.

Jan 1, 2007

By T. M. Barczak, S. C. Tadolini

Pumpable roof supports provide an alternative approach to secondary support in underground mining. Unlike all other supports that are either partially or fully prefabricated prior to being transported into the mine, the pumpable support is fabricated in place in the mine entry. This reduces the underground material handling efforts and thus the injuries historically associated with in-mine support construction. On-site fabrication also facilitates application of the support in areas that are inaccessible to transportation equipment such as scoops or rail cars, making it ideal for many bleeder applications. One of the main advantages of the pumpable support is that it fully bridges from the mine floor to the roof, thereby eliminating the requirement of “topping off” the support with wooden wedges or crib blocks that soften most other support responses. This report examines the development of modern pumpable roof support technology and provides a full description of the performance capabilities of each of the support products now on the market.

By R. M. Waterstrat

X-ray diffraction and metallographic examination of binary Mn-rich alloys with Ti revealed the presence of intermediate phases in this system. A binary R phase has been identified and also a phase having an a-Mn type structure. The X-ray pattern of the phase TiMn3 is presented and a tentative phase diagram for the Mn-rich portion of this binary system has been constndcted. MANGANESE-rich alloys with titanium have been subjected to thermal analysis at temperatures down to 1100°C by Hellawell and Hume-Rothery.1 Their results indicate the existence of an intermediate phase TiMn3 in this binary system. This phase appears to coexist with the Laves phase TiMn2, and with terminal solid solutions based on the allotropes of manganese, at least down to 1100°C. The above investigators did not attempt to determine the crystal structure of this phase, however. Since, by analogy to the binary systems Mn-V and Mn-Cr3 one might expect to find a phase in this region of the diagram, it seemed desirable to obtain X-ray diffraction patterns of alloys in the concentration range in question, in order to ascertain whether the sigma phase or related structures occur. EXPERIMENTAL PROCEDURES Alloys were prepared by arc-melting electrolytic manganese and iodide titanium in a water-cooled copper crucible under a helium atmosphere. Excess manganese was added to each melt in order to allow for losses incurred during melting. The alloys were then wrapped in molybdenum foil and sealed in evacuated quartz tubes for annealing at various temperatures, as shown in Table I, followed by quenching in cold water. Although the inside of the tubes showed evidence for some loss of manganese from the specimen during annealing, there was no evidence of any reaction between the specimen and either the molybdenum foil or the quartz tube at these temperatures. It was later found that the manganese loss was considerably reduced by annealing these alloys in sealed quartz tubes containing one atmosphere of purified argon. As an added precaution the surface of each specimen was ground off before crushing the alloys to -270 mesh powder, using a hardened steel mortar and pestle. X-ray powder patterns were obtained using either FeKa or CrKa radiation in an asymmetrical focusing camera, which gave excellent dispersion of the closely spaced lines. Pictures were also obtained using a Debye camera of 5-cm radius which provided data in the angular region not covered by the focusing camera. The alloy specimens were polished and examined metallographically, using an etchant consisting of 60 pct glycerine, 20 pct nitric acid, and 20 pct hydrofluoric acid. The 10-g buttons were in each case broken in half and found to be well-melted and free of any gross segregation. One half of certain alloy buttons was submitted to chemical analysis in the "as-cast" condition. No appreciable change in composition seemed to occur during annealing . RESULTS The X-ray pattern of alloy Ti1.17Mn0.83 was found to agree well with that of the ternary R phase which was first found in the Mo-Cr-Co system,' and re-

Jan 1, 1962

By J. P. D. Strydom

The transmission of excessive vibration to the human body can cause physical stress that may result in crippling pain or permanent disability. Rock drills are known to transmit high levels of vibration that are difficult to attenuate through conventional approaches to vibration isolation. However, it can be shown that once the ISO frequency weighting has been applied, most of the vibratory effect of the rock drill?s motion is concentrated at the drill?s operating frequency. This observation opens the way for utilizing a concept known as vibration absorption, aimed at attenuating the rock drill?s vibration. In essence this entails using the inertia of a secondary vibratory system to counteract the motion of the handle. This article documents an investigation into the use of such an absorber for attenuating rock drill vibration and demonstrates the feasibility of such an approach. A mathematical model of such an absorbing handle was developed and used for design studies. Based on these investigations an experimental prototype model was manufactured and tested. A significant reduction in vibration levels could be achieved.

Jan 1, 2002

Fire-clay blocks lining the combustion chambers of zinc concentrate flash-roasting, furnaces operating at 1,000-1,200° C. have suffered moderately rapid deterioration due to slagging. The attack is accentuated by high temperatures, and is probably caused by lead oxide volatilized from the roasted concentrate.Resistance of refractories to attack increased with increasing alumina content from 30 to 45 per. cent but at 90 per cent alumina spalling was troublesome. Magnesite bricks were'subject to some spalling, but some types may lie satisfactory. Chrome and chrome-magnesite bricks spalled seriously.Material thought to be suitable for use as a monolithic lining slagged badly and an alternative may be tested.INTRODUCTIONThe Electrolytic Zinc Company of Australasia Ltd. uses two multi-hearth furnaces and four flash or suspension roasting furnaces for the roasting .of zinc concentrates at its Risdon Works. The hearth roasting plant has been described previously by Forster (1949).A brief descriptioI1 of the first three flash roasters was given by Gordon and Forster (1955). A fourth flash roasting furnace began operation early in 1957. This furnace is somewhat larger than the earlier furnaces, and the designed capacity is also higher, auxiliary equipment being altered to suit. An important structural difference between the older furnaces and the fourth flash roaster is that the walls of the combustion chamber of the new furnace are lined with high alumina fire-bricks instead of fire-clay blocks. Thischange was made because the fire-clay blocks in the older flash roasters had shown s-evere wastage due to slagging by lead derived from the concentrate.

Jan 1, 1959

By Thomas Fraser

WHEN the Bureau of Mines initiated the program of large-scale research and development in the field of synthetic liquid fuels authorized in the Synthetic Liquid Fuels Act of April 5, 1044, the Coal Preparation Section was assigned the task of obtaining data on the preparation characteristics of the coal in large reserves that might be adaptable to use in this new industry. It is natural that, as the rapidly developing general research program brought about new concepts of raw-material quality, preferred geographical location, and the like, the orientation of coal-preparation investigations should have undergone some change. The first major assignment was the sampling and testing of a series of typical American coals deemed to he suitable for hydrogenation based on early research work conducted by the Bureau of Mines. This first series of tests has been completed and is reported in this paper.

Jan 1, 1950

By Winton J. Gale

Coal pillar design has been based on generalized formulas of the strength of the coal in a pillar and experience in localized situations. Stress measurements above and in coal pillars indicate that the actual strength and deformation of pillars vary much more than predicted by formulas. This variation is due to failure of strata surrounding coal. The pillar strength and deformation of the adjacent roadways is a function of failure in the coal and the strata about the coal. When the pillar is viewed as a system in which failure also occurs inthe strata rather than the coal only, the wide range of pillar strength characteristics found in the United Kingdom, United States, Republic of South Africa, Australia, People's Republic of China, Japan, and other countries are simply variations due to different strata-coal combinations, not different coal strengths. This paper presents the measured range of pillar strength characteristics and explains the reasons. Methods to design pillar layouts with regard to the potential strength variations due to the strata strength characteristics surrounding the seam are also presented.

Jan 5, 1999

The Bureau of Mines conducted large-scale laboratory copper ore leaching tests to enable improving copper recovery from large dump-leaching operations. This was done by comparing leaching progress when copper was recovered from recycled leach liquor either by cementation or by solvent extraction. Copper was leached from 7-ton ore samples at room temperature using pH 2 ferric sulfate solutions. With are samples containing 11 percent minus 0.5-inch fines, no marked advantage in using either of the copper recovery methods was evident after 416 days of leaching. With ore containing 32 percent minus 0.5-inch fines, solvent extraction of copper was advantageous in that 60 percent of the copper was extracted after 568 days, whereas only 48 percent of the copper was extracted when cementation was used. Less acid was consumed during leaching when solvent extraction, rather than cementation, was used for copper recovery. Iron, contributed by cementation with scrap iron, plugged the ore bed containing 32 percent fines.

Jan 1, 1981

By D. Laguitton, D. Hodouin, V. K. Gupta, R. Spring

"The CANMET SPOC project aims at inducing progress in process evaluation and optimization by developing user oriented software based on state-of-the-art theory. The present work is the result of a joint effort by CANMET, Noranda Mines and Université Laval to develop two computer packages: one (RTD) to calculate the residence time distribution that best describes the material transport through the mill, the other (FINDBS) to estimate the rate of breakage and distribution function of the population balance model in a ball mill. The RTD package can handle data from various experimental methods (impulse or complex tracer feed, with or without recycling, etc...). The FINDBS package provides options for the functional description oj both model parameters Band S. The full detail of the methods and programs appears in a users guide. The program capabilities and several sample runs are presented.IntroductionSimulation of mineral dressing operations by computer has been largely contained within academic and research circles and has not yet gained a status of routine practice in the ore and coal industries. It is however a matter of time before process simulators are available on every process engineer's desk to assist process optimization tasks, flowsheet design and professional training. The CANMET SPOC project (Simulated Processing of Ore and Coal) was initiated in 1980 to assist the Canadian industry in integrating computer-based methodology for process evaluation and optimization(1). Software development, documentation and transfer is one of the main priorities of the project which will mature in 1985 by releasing a complete package of manuals and programs covering sampling, material balance computation, unit modelling, flowsheet simulation and optimization . This paper is a condensed description of a typical project element in its 1982-1983 state of development. The required methodology for ball-mill modelling and simulation was consolidated an d merged to other project elements during a joint study under contract financed by CANMET and Noranda Mines Ltd . The first part of the study dealt with documenting experimental methods and software for ball-mill computer simulation. Université Laval GRAAIM (Goupe de Recherche en Automatistion Appliquée à l'Industrie Minérale) acted as sub-contractor for this part of the study(16,17). A second part dealt with applying the model calibration techniques to a large industrial data base and is reported elsewhere(2,18,19)."

Jan 1, 1984

By Garth Howlett

In 1998 the Matanuska-Susitna Borough formed the new port district at Point MacKenzie, known as Port MacKenzie, located directly across the Knik Arm from Anchorage. In 1991 PND Engineers Inc. (PND), working with the Matanuska-Susitna Borough manager and port director, envisioned a fill structure at Port MacKenzie with a 500-foot-long Open Cell? sheet-pile bulkhead face extending to EL -20 feet Mean Lower Low Water (MLLW) at the face. Now under operation the fill created 5.5 acres of tideland property using local materials for fill. The fill is protected from 2- to-3 foot-thick ice pans and 9 feet per second (fps) tidal currents by an envelope of armor rock. Construction required working in water with 30 to 40 feet of tidal variation. Construction required placement of frozen fill in water depths possibly exceeding 50 feet, creating real concerns about soil consolidation and long-term maintenance issues. A plan was prepared to consolidate the soils using Vibracompaction. Soil Density and consolidation were monitored during the work. In 2003 the port district and NPI, a wood chip export company, formalized an agreement to construct a deep water port facility at Port MacKenzie for cape-class bulk carriers. PND provided planning, studies, geotechnical investigation, design documents and construction inspection for a 500-foot-long trestle with a platform dockhead and dolphins providing 1,100 feet of dock face in EL -70 MLLW as shown in Figure 1. Design included installation of large-diameter spin-fin piles driven on a 2V:1H batter. Also included was a 300-ton tension test of smaller spin-fin piles.

Jan 1, 2006

By J. J. Beresford

The primary function of a support slurry is to provide stability during excavation. Today foundation structures can be designed around the additional friction afforded by the absence of the filter cake attributable to the use of polymeric fluids as support slurries. These fluids use pseudoplastic fluid viscosity to advantage over the fragile thixotropic gel structures of bentonite. Many of today's polymeric fluids are environmentally acceptable for disposal directly to municipal sewers.

Jan 1, 1989

By L. du Preez, J. D. Steenkamp

This paper introduces the concept of clean steel production from a pyrometallurgist’s perspective to the broader metallurgical community. A simplistic overview of the steelmaking process from iron ore to car body manufacturing is followed by an introduction to the South African steel industry and the technologies that it utilizes. The process is illustrated by an overview of the flow sheet and technologies for the production of clean steel at Saldanha Steel, South Africa.

Jan 1, 2015