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By T. McCallum

Crud is a common concern in SX processes and is formed as a complex solid stabilized emulsion of aqueous and organic.1,3 Crud formation is highly dependent on the amount of solids entering the circuit and is influenced by a number of other operational factors. A common practice for crud processing is interfacial pumping, wherein crud, organic, and aqueous are pumped from the settlers for treatment and utilizes a variety of equipment. These mechanical means of crud processing are effective, however, require significant processing time and require oversight to prevent the return of contaminated organic. Cytec has developed a unique crud treatment process utilizing both chemical and mechanical means to enhance the solid/liquid separation. The use of ACORGA CB? 1000 crud busting reagent allows a rapid separation of solids from the organic phase and provides similar volume recovery to current practices. The process allows operations to return clean organic back to the plant more efficiently and may enable operations to process more crud. In addition, the organic quality of the recovered organic is higher than that recovered by typical means, which can lead to operational cost savings.

Feb 27, 2013

By P. J. Rua

The Piedras Verdes copper mine is a new run-of-mine (ROM), heap leach, solvent-extraction/electrowinning (SX-EW) operation located 21 km (13 miles) north-northwest of the town of Alamos in the state of Sonora, Mexico. The Piedras Verdes copper mine is wholly owned by Frontera Copper Corp. (FCC), a Canadian corporation, through its 100 percent beneficial interest in Cobre del Mayo S.A. de C.V. (CDM), a Mexican registered company. The January 2008, minable reserves were estimated to be 193.6 Mt (213 million st) at a grade of 0.36 percent copper. The overall recovery of total copper was estimated to be 61.9 percent. The property has an additional 17-year life and is designed to produce 31.7 kt/a (70 million lbs/year) of cathode copper. Construction commenced in early October 2005. The first copper cathode was produced 12 months later at a total capital cost of $100 million. Elevations at the site range from 150 to 300 m (490 to 985 ft) above sea level. The area has excellent infra-structure in the form of towns, power, water, roads, rail, airfield and access to the deepwater port of Guaymas (Fig. 1). The surrounding area is also famous for its numerous polymetallic (lead, zinc, copper, silver and gold) epithermal veins. Some of these were mined for more than 200 years and provided the wealth on which the town of Alamos was built. The original village of Piedras Verdes was located in the area of the proposed openpit mine and, consequently, it was necessary to construct a new townsite 6 km (3.7 miles) to the south before project development could commence. The new town site (Fig. 2), complete with power and water supplies, roads, sewer system, schools, clinic and recreational facilities, was completed and occupied by 49 families in September 2005. CDM received its remaining permits from the Mexican environmental authorities on Sept. 20, 2005. This enabled the company to proceed with full-scale development. CDM owns or controls 27 mining concessions covering the resource. Surface rights to the Piedras Verdes project were controlled by four Ejidos (communal agrarian and/or ranching societies) and five individual landowners. CDM has acquired all surface rights necessary for its mining operations and associated facilities either through outright purchase or long term lease agreements.

Jan 1, 2008

In common with general experience in the iron-making industry overseas, Australia has in recent years suffered a deterioration in the physical quality of her iron ores in their suitability as a direct blast furnace feed. The increasing amounts of fines and the more friable nature of lump ore, especially in the ore from the Cockatoo Island deposits in Yampi Sound, Western Australia, have focused attention on problems of ore preparation and agglomeration, particularly sintering.Although very small pilot scale Dwight-Lloyd type sinter machines were operated at the steel-making centres at Newcastle and Port Kembla during World War II, no sizeable capacity was installed, so that ore was charged to the blast furnaces almost entirely unscreened, and the resultant flue dust was stockpiled.Towards the close of the war, the pilot plant at Newcastle was replaced by a small machine, adjacent to the flue dust stockpile, with a rated capacity of some 20 tons per hour. After approximately five months of part-time operation, this plant was closed down in January, 1945. Production was not resumed until December, 1950, when, due to a temporary ore shortage, it was decided to supplement available ore with sinter produced from the large flue dust stocks of about 300,000 tons. In spite of mechanical and process difficulties, inherent to the design of the plant, operation was continued on a two-shift basis, with several shutdowns for extensive overhaul and plant alterations, until September, 1954, when production was put on a three-shift basis. Addition of Yampi ore fines to the sinter machine burden was not commenced...

Jan 1, 1957

By Maurizio Siepi, Stefano Trevisani, Pagliaccim Federico, Daniele Vanni

"Abstract: The paper describes a large innovative project completed in 2012-20123 by Trevi Group, to develop equipment capable to install ultra-deep diaphragm wall. The project highlights the capacity of SOILMEC to design and build a new hydromill able to reach an unprecedented depth of 250 m, including new devices for monitoring and correct the verticality. The entire project can take advantage of the long and solid experience matured by Trevi and Rodio (now part of Trevi Group), developing in house or, else, select the elements necessary for a high quality product in the ground.The paper describes the results of different systems used to monitor and control the verticality and the twist of panel during excavation, together with the method used to pour concrete. Finally, the results of verification coring and lab tests on concrete samples recovered at various depths are discussed. The test field has been supervised by representatives of three of the major Italian Universities, and lasts almost one year from August 2012 to June 2013.The verification holes made use of an innovative combination of directional drilling and coring, to check the quality of the plastic concrete for the full length of the panel. The data confirmed that the test panel has high quality concrete, meeting or exceeding to the prefixed requirements.With this test, super-deep cut-off walls reaching depths of 250 m have become a reality. This would change the perspectives of dam engineering both for existing dams rehabilitation and for new dams design and construction. With the execution of this test panel, the technology of milled concrete cutoffs has made a ”quantum leap”, pushing the limit of practicable dams."

Jan 1, 2014

By W. M. Scheding

"There has recently been a resurgence of interest in unit flotation of mill discharges. At the Kidd Creek concentrator, this technique has been successfully applied to silver flotation in a 3050 mtpd silver-copper-lead-zinc division. The major incentive has been improved silver payment through increased overall recovery and better distribution between the sequential copper, lead and zinc concentrates. A large, but variable fraction of the silver in the ore is present as native silver and, being dense and malleable, is susceptible to overgrinding. Grinding circuit surveys showed high concentrations of silver in both primary and secondary circulating loads. Laboratory testwork confirmed that this was selectively flotable, identified the secondary ball mill discharge as the best feed stream and optimized flotation conditions. A 10 t/h pilot plant campaign confirmed that the rate of accumulation of silver was sufficient to sustain continuous production of a silver concentrate and that flotation of the whole stream was not necessary.The present 30 t/h production circuit recovers from 5 to 50% of the silver in the ore at a concentration ratio between 25 and 250. The circuit also contributes to a better understanding of ore mineralogy, as an 'on-line' indicator of elemental silver content."

Jan 1, 1985

This paper describes a simple finite element (FE) modelling approach which leads to the computation of seismic energy release rate (ERR) and strain energy storage rate (ESR) which result from mining. The concept of critical strain energy is introduced as a means to help evaluate the strainburst potential in mine structures. A new, energy-based, burst potential index (BPI) is proposed. The use of ERR, ESR and BPI is demonstrated by a cut-and-fill stope case study. The merits of using such energy parameters in the interpretation and analysis of strainburst phenomena are discussed. While the study gives promising results, site-specific back analyses would be required to first calibrate the model and fit it with the local mine conditions, before it can be adopted as a routine design tool.

Jan 1, 1999

By Morabito J, Harrop D. W

Uranium exploration was commenced in 1973 and carried out at a regional scale over a wide area of the northern part of the Camarvon Basin of Western Australia by Minatome Australia Pty Limited and their joint-venture partners. As a result, pervasive uranium mineralization has been found in the Cretaceous sandstones near Manyingee Hills in the Onslow Region, which were probably deposited in a near-shore, fluvia deltaic palaeo-environment.Mineralization is generally found in poorly sorted argillaceous sandstones and siltstones near redox fronts formed by oxidizing waters circulating in reduced sediments. The principal minerals found in the two Manyingee deposits delineated so far are coffinite, uraninite with associated pyrite in the reduced zones, and phosphuranylite, siderite and limonite in the oxidized zones. The presence of dissolved uranium in the superficial aquifers, of secondary uranium minerals as coatings on granitic rocks, and of recent uranium-bearing calcrete sediments, suggest that the whole Cretaceous-Precambrian system has been subjected to the formation ofroll-front type uranium deposits since the Cretaceous. Continuing exploration is locating additional uranium occurrences. The deposits outlined so far are being evaluated for their amenability to in situ leaching tests planned for 1982-1983.

Jan 1, 1981

By Hani Mitri

Understanding the interaction between rock bolts and underground rock movement is critical for safe and cost effective underground excavation design. Although early research on this subject involved a balance of theoretical analysis and field measurement, recent work has been heavily focused on analytical and numerical studies. This paper describes technologies that have the potential to redress the balance through instrumentation of rock bolts deployed under routine operating conditions in underground mines. Two new products are presented in this paper. Firstly the U-cell coupler is a load cell device that can be routinely coupled to the threaded end of a bolt prior to installation. It measures the ?series? load at the head of the bolt. Secondly, the d-REBAR involves an array of small-diameter, long-base length displacement sensors recessed into grooves along the entire length of the bolt. Both new instruments are interfaced with on-board digital signal conditioning and telemetry. Methodologies for the deployment of the new instrumentation and guidelines are presented for the interpretation of results based on data obtained from field trials. Successful field installations demonstrate the viability and practicality of these new technologies and, moreover, provide important insight in to rock bolt/rock mass interaction.

Jan 1, 2012

The study of gas emitted from face coal samples at the coal face is part of an investigation of instantaneous outbursts of coal and gas. Normally, seam gas essentially comprises methane of which the origin in the metamorphism of coal is undoubted. The origin of other gases sometimes occurring in high proportion in seam gas, particularly carbon dioxide, is more controversial. A simple meter for rapidly assessing gas in coal was developed. Tests with the meter enabled comparisons of seam gas in face coal at some outbursting and nonoutbursting mines, and under various working conditions. The varying results of widespread testing suggest certain trends, including some prospect of recognising outbursting potential at the coal face.INTRODUCTIONThe aim of this work is identification of differences in gas condition between coals subject to instantaneous outbursts and coals which have not outburst, and between faces of coals which will and which will not subsequently outburst. Any comparative test should be conducted right at the coal face on coal about to be worked and the results of testing should be available after a short period. Moreover, the method and the comparison of results should require no special skill, and be well within the capacity of junior mine officials. Any consistent relation between gas condition and subsequent mining conditions - outbursting or not might be valuable in prediction of outbursts.INSTANTANEOUS OUTBURSTSInstantaneous outbursts (Hargraves, 1958) , are largely unpredictable and unaccountable ejections of coal (up to 5,000 tons) and gas (up to 5,000,000 cu.ft.) from a standing coal face. Usually the gas is essentially methane (CH4 ) but may be essentially carbon dioxide (C02 ), or an intermediatemixture...

Jan 1, 1962

By John Zeni

In Australia during the 1990s, Zeni Drilling took on several demanding shaft boring contracts. This paper describes the safety, operational, technical and environmental advantages derived through the implementation of mechanized boring methods for two of these projects. The paper first describes a 3-meter (10 ft) diameter access shaft blind bored from an underground location to 440 meters (1,444 ft) deep for a gold mine in Tasmania. The construction of a 5.8-meter (19 ft) diameter, 515-meter (1,690 ft)deep ventilation shaft for a longwall coal mine in New South Wales is also described.

Jan 1, 2001

By Jay C. Hanson

Various electrical and electromagnetic (EM) geophysical techniques are currently being evaluated by the U.S. Bureau of Mines for their effectiveness in the detection and monitoring of electrically conductive (1 to 5 S/m) lixiviant (leach solution) to depths of 600 m, either above or below the water table. These techniques include magnetotellurics (MT) , controlled source audiofrequency magnetotellurics (CSAMT), resistivity and focused resistivity, ground-penetrating radar (GPR), frequency-domain electromagnetics (FEM), and time-domain electromagnetics (TEM). Of these techniques, TEM may be the most effective, but CSAMT and focused resistivity also hold promise. Geophysical computer modeling of the borehole TEM technique was conducted based on an idealized geoelectric section (layered earth) with characteristics based on the Santa Cruz porphyry copper deposit near Cas a Grande, AZ. Layer resistivities and thicknesses were obtained from geophysical data and geologic logs available from the site. Modeling of borehole TEM in both preleach and during leach situations was conducted. Simulating the TEM method using computer modeling proved to be encouraging since there were substantial differences between leached and nonleached responses. The modeling does not prove the effectiveness of TEM in the field, but does indicate that detection of deep lixiviant zones is theoretically possible.

Jan 1, 1992

By D. D. Ndenguma

This investigation compares the results from an experimental and numerical study of air flow in a scaled-down underground coal mine model. This was done in order to determine if numerical analysis can be relied upon when searching for ventilation solutions to control high concentration of coal dust and methane gas in underground coal mines. Steady state analyses were used to identify flow patterns and recirculation regions within the mining section while transient state analyses were used to determine the time taken to extract the initial air from the model. The agreement between the experimental and numerical results indicates that numerical modelling is useful in this regard. The study went further to devise a method of determining the optimum position of the jet fan that is responsible for mine-gas dilution at different stages of mining.

Jan 1, 2014

By D. F. Lascelles

D. F. Lascelles (School of Earth Sciences, MacQuarie University, North Ryde, N. S. W., Australia)- The paper contains many misconceptions commonly held by both geologists and soil scientists with regard to soil processes. The analogy between supergene copper enrichment and "nickel laterite" deposits is quite apt and the use of nomenclature from the former in describing supergene nickel deposits is justified. However, care must be exercised with regard to the notable differences in

Jan 1, 1974

By René de Batz

From 1754 to the end of 1895 the production of gold in Russia had been approximately as follows: Kilogrammes. Russia proper (Finland and the Caucasus),. .. 890 The Ural Region,........505,386 Western Siberia,........116,937 Eastern Siberia,........1,218,372 Total,.........1,841,085 of the value of more than $1,200,000,000.

Jan 1, 1899

By D. Gendzwill, N. Martin

"In early 1987, the Patience Lake potash mine near Saskatoon, Saskatchewan, was closed due to uncontrollable floodingWater inflows were first encountered during routine mining in 1975 at the south boundary of the mine lease. Underground grouting and construction of bulkheads limited the flo but did not completely stop it. Subsequent seismic surveys showed that the mine had approached the edge of a large collapse structure in which the salt and potash had been partly dissolved and removed by groundwater.In 1986, the small flow into the mine started to grow. Despite renewed grouting, the flood increased and outstripped pump capacity. The grouting program temporarily slowed the inflow but was unable to stop it. Eventually, from seismic and drilling evidence, it became clear that the water source was an extensive system of vertical fractures which would be impossible to seal by drilling and grouting from underground. A new plan to install 14 bulkheads underground would have sealed the water source from the rest of the mine but the construction program could not be completed before rapidly increasing inflow threatened to fill the mine. The underground mine was closed and a new solution mine started in 1988."

Jan 1, 1996

Characterization of ore and waste-rock material using automated quantitative micro-mineralogical techniques (e.g., QEMSCAN® and MLA) has the potential to complement traditional acid-base accounting and humidity cell techniques when predicting acid generation and metal release. These characterization techniques, which most commonly are used for metallurgical, mineral-processing, and geometallurgical applications, can be broadly applied throughout the mine-life cycle to include numerous environmental applications. Critical insights into mineral liberation, mineral associations, particle size, particle texture, and mineralogical residence phase(s) of environmentally important elements can be used to anticipate potential environmental challenges. Resources spent on initial characterization result in lower uncertainties of potential environmental impacts and possible cost savings associated with remediation and closure. Examples illustrate mineralogical and textural characterization of fluvial tailings material from the upper Arkansas River in Colorado.

Feb 27, 2013

Digital Simulation of Particulate Processes The inherent complexity of mineral particulates (shape, size and mineralogical texture) has challenged conventional simulation model approaches for decades. Much effort was expedited in using mathematical assumptions to accommodate stereological effect. With the advance of instrumental methods such as x-ray microtomography 3D structure can, in many cases, be measured directly. The information derived from such measurements provides direct input to building the structural digital model. In addition digital simulation methods that enable creation of process realistic particulate properties in an efficient digital computer space have demonstrated their effectiveness to model a variety of realistic packing, sorting and multi-phase processes. The paper reviews recent advances in the use of information derived from 3D micro-tomographic imaging and laser scanning technology can be coupled with digital methods to enable simulation of tablet compaction and dissolution, filtration and permeability, column packing and leaching kinetics, packing and cementation of nuclear waste. By assigning 'properties' to a digital zone (voxel) in the computational space it is possible to mimic the realistic characteristics of quite complex particulate mineral processing systems. The system self-adapts to correct the coherent particle characteristics (shape, size, compound, porosity) with time. Such simulations are useful to elucidate the sensitivity of system performance to variations in process parameters. Dimensional scaling of the approach is also possible, as the case studies will illustrate, in deploying the method to both small (micron) and large (m) features. The use of process realistic simulations presents experimental challenges in code validation. It is in this context that other tomographic methods play a role in direct 3D measurement of system behaviour such as electrical and optical sensors.

Sep 13, 2010

By Jack Zhang, Yunguo Tang, Baodong Zhao

"Rare earth elements (REEs) have numerous key applications in both traditional and advanced technologies. A shortage of some critical REEs is expected due to the discrepancy between the REE abundance in REE deposits and the REE demand from the market. For example, Neodymium, Europium, Terbium, Dysprosium, Erbium and Yttrium are expected to be in short supply. REE recovery and separation from secondary resources such as uranium wastes, heavy mineral sands, and recycled materials can balance the shortfall in a cost effective way.The Saskatchewan Research Council (SRC) is engaged in the development and commercialization of complete REE recovery and separation technologies in Canada. One of SRC’s newest developments is the design and commissioning of a heavy rare earth (HREE) separation pilot plant. The pilot plant uses hundreds of stages of solvent extraction (SX) to produce high purity individual HREEs from both primary and secondary resources.This paper presents the design of an HREE recovery process for the particular case of uranium processing wastes. The separation results of a group separation are reported and discussed, as well as the issues and the challenges of the development, commissioning and operation of the continuous SX pilot plant.IntroductionSignificant amounts of strategic specialty heavy rare earth elements (HREEs) are found in uranium wastes in Saskatchewan. It estimated that about 47 tonne/a of heavy rare earth element oxides (HREO) including 27 tonne/a of Y2O3, plus 6 tonne/a of Sc2O3 are in the raffinate of every uranium mill for potential recovery. Since the HREEs are already in the raffinate, cost effective HREE production is promising in Saskatchewan.Selective precipitation including nutraulization, oxalate and double-salts precipitation, as well as sulfide precipitation, ion exchange (IX) and SX are commonly used technologies for the recovery and purification of REE solution. REE oxalate precipitation is an effective technology to remove Fe, Al, Ca, Si and other impurities by taking the advantages of the solubility difference between oxalates of REEs and impurities in acidic solution (Xu, 2005)."

Jan 1, 2017

This modern plant consists of a battery of 72 Otto Wilputte Compound Under-jet Ovens with extensive plant for the recovery by-products. The ovens produce 9000 tons of furnace coke per week together with some 17,000,000 cub. ft. of coke oven gas, which is used for heating purposes throughout the works and for heating the ovens.Coal is supplied from the, company's colliel'ies and is stored under a Coal Handling Bridge of 264 ft. span and 365 ft. overall, capable of handling 250 tons per hour. The coal storage space of 1600 ft. can. be extended to a maximum of 2800 ft.Preparation of the coal for coking involves fine grinding which is carried out as follows:-Coal is dumped from rail waggons on to a conveyer belt which delivers it to a 12 ft. x 22 ft. Bradford Breaker, with a capacity of 400 tons per hour. The coal, then approximately 4 in. in size, passes, to the mixing bins; and after careful blending is reduced in the,hammer mills to a fineness suitable for the ovens.The fire coal is elevated to the main storage bin over the battery for subsequent charging by electric larry car. The average cokingtime is 15 hrs. 36 mins. At the end of ,this period the doors, are removed and the coke pushed from the oven by a mm. The coke, is, then quenched with fresh, water and sent to the Blast Furnace in 50-ton Copper Waggons.The gas is exhausted from the ovens by Brown Boveri turbine, exhausters of 23,000. cub, ft, per min. capacity. Exhaust steam from these is used for various. purposes in the By-Product plant. After removing the last traces of tar by Electrostatic Precipitators', the gas is bubbled through sulphuric acid, the ammonia forming ammonium sulphate, which is subsequently washed, dried and bagged for sa,le as a fertilizer. The gas then goes to the Benzol Scrubber Towers, where benzol and other derivatives are recovered and later redistilled and purified. The cleaned gas is then piped to the main works for heating purposes, being used with tar to fire the steel furnaces, and also the soaking pits and reheating furnaces.BLAST FURNACES.The company is at present operating two Blast Furnaces of 800, and 1000 tons nominal daily capacity respectively. The latter was...

Jan 1, 1938

IN this paper it is proposed to present certain features of operating practice at the Port Pirie works of The Broken Hill Associated Smelters Proprietary Limited, in the smelting in a blast furnace of lead ores carrying a high concentration of zinc.The subject matter selected for presentation is:(i) The effect of zinc on lead blast-furnace operations, together with an outline of the methods adopted in actual practice in dealing with the zinc problem.(2) Development of the height of tuyere above the bottom of the jacket, and the extension of the tapping interval and the combined effect of both factors upon the lead content of blast furnace slag.It will later be seen that one phase of the investigation carried out in connection with the effect of zinc on blast-furnace operations was largely responsible for the decision to increase to a marked degree the height of the tuyere above the bottom of the jacket.Due to this interdependence, it has been considered advisable to deal with the two features above mentioned.The high concentration of zinc in the lead-bearing materials smelted at Port Pirie has brought with it those troubles which are associated with zinc in the smelting operation.In the early stages of the history of The Broken Hill Associated Smelters Pty. Ltd. the trend towards increasing cost for labour, fuel, and stores, etc., rendered it necessary to increase the lead content of the charge, and reduce to a minimum the quantity of barren flux used.

Jan 1, 1931