Search Documents

By Marc-André Villiard, C. St-Onge, V. Silla, J-C Milot

Rio Tinto Fer et Titane (RTFT) operates a metallurgical complex in Sorel-Tracey, Canada. In the Ore Preparation Plant (OPP), ilmenite ore is roasted through four parallel rotary kilns generating 95% of the plant wide sulphur dioxide (SO2) emissions. RTFT proactively set an annual emission cap for SO2 to be achieved by 2015. To achieve this targeted SO2 reductions, a technology evaluation and selection exercise was carried out, followed by detailed engineering and implementation. After a detailed evaluation of SO2 scrubbing technologies, the Circulating Dry Scrubber (CDS) system was selected as the most appropriate desulphurization system for this application. The system was implemented and commissioned from 2013 to 2015. General performance testing conducted in May 2015 demonstrated that the system achieved and surpassed the anticipated design values in terms of SO2 removal efficiency and hydrated lime utilisation. This paper summarizes the SO2 technology selection process, design features of the selected technology, project implementation and final performance testing of the SO2 abatement system.

Jan 1, 2015

By John G. Holmes

The generation of low cost power is but one phase of the TVA program for regional development. During the 36 years since TVA began, growth in its generation of electric power has necessitated a shift from a predominantly hydroelectric power system to a combination steam and hydroelectric system. The addition of steam-electric power plants to TVA's generating system was necessitated by the rapid increase in the traditional and defense demands for electric power in the 80,000-square-mile area served by TVA, the need to firm up the hydroelectric power, and the fact that all available sites for sizeable hydroelectric projects had been developed. At present TVA owns and operates 40 power plants--29 hydroelectric and 11 steam-electric plants. The total generating capacity of the hydroelectric plants is 3,105,430 kw, and the capacity of the steam plants is 13,951,135 kw. This provides a total generating capacity of 17,056,565 kw for the plants operated by TVA. Individual capacity of the 112 hydroelectric units ranges from 10,000 to 67,500 kw, and the individual capacity of the steam-electric units now in operation ranges from 60,000 to 950,000 kw. In addition to this generating capacity, TVA distributes the power from 6 U. S. Army Corps of Engineers hydroelectric plants on the Cumberland River. These plants contribute an additional 725,000 kw. Also, under an agreement with the Aluminum Company of America, TVA directs the stream flows and generation of their 423,715-kw system on Tennessee River tributaries and shares with Alcoa in the increased generation resulting from this coordinated operation.

Jan 1, 1969

By C Fricke, R Wood, P Velletri

"In a climate characterised by an ever increasing focus on cost reduction and maximising the utilisation of existing assets and infrastructure, understanding the uncertainty associated with alternative investment and operational choices becomes paramount to minimising the risk of making an ineffective decision. To assist in this process, TSG Consulting has developed an analytic framework to capture the underlying complexity of a mineral supply chain, and then quantify the impact of the uncertainty associated with the key drivers of business productivity. The technical basis of this approach follows three distinct steps: analyse the current system and identify the major factors that drive value build detailed models that can measure the response of the system to potential changes in the factors identified quantify the sensitivity of financial and capacity forecasts to these factors.Each of the above steps draws on a different area from the field of applied analytics, namely: data analytics dynamic modelling and designed experimentation meta-modelling and optimisation.Following the three-step approach described above ensures a rigorous modelling and analysis process is executed to support strategic mine planning decisions. The approach is equally applicable to the analysis of fully integrated system supply chains (pit-to-port), the evaluation of incremental capital investments to targeted areas of a supply chain, or when considering revisions to the operating philosophy of a system in the short term. The basis of each of the three analytic steps is explored in detail in this paper. The result is the definition of a structured mechanism for a business to actively manage risk and drive productivity as a component of the strategic mine planning process.CITATION:Fricke, C, Velletri, P and Wood, R, 2014. Enhancing risk management in strategic mine planning through uncertainty analysis, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 275–280 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 24, 2014

By Steven J. Schafrik, Michael Karmis, Zacharias Agioutantis

3-D or pseudo 3-D visualization of orebodies and mining related processes such as loading and tramming, are now commonly used by the mining industry. An approach is presented that can aid the engineer in creating the visualizations necessary for accurate presentations for use in public relations, safety training, production projections, reclamation plans, etc. It is shown that the creation of such digital representations of mining environments are independent of the mining package used to create the original mine design. Once a proper model has been created, any view of the areas is possible. These views can be taken from any number of stationary points or entered into an animation showing the progress of a mining construction. The paper focuses on the presentation of the steps used to accomplish the visualization and an example is for a quarry fill placement project.

Jan 1, 2002

By R. F. Abernethy

A modified Unterzaucher method was applied to the direct determination of oxygen in coal. Coal samples were pyrolyzed in a nitrogen atmosphere, and the gaseous oxygen compounds liberated were converted to carbon monoxide by a platinized-carbon catalyst at 9000 C. After passing over heated copper and through a tube containing soda-asbestos and magnesium perchlorate, the purified carbon monoxide was oxidized to carbon dioxide by iodine pentoxide--liberating an equivalent amount of iodine. The iodine was titrated with 0.02 ~ sodium thiosulfate; in a few tests the weight of carbon dioxide produced was determined. Direct oxygen determinations of coal included organic oxygen from the coal substance, plus a small quantity of inorganic oxygen derived principally from carbonate minerals and from combined water of silicates in the mineral matter. The influence of mineral matter on the direct oxygen determination was investigated by testing (1) untreated coal, (2) demineralized coal from which most of the mineral matter except pyrite was removed by treatment with hydrofluoric and hydrochloric acids, and (3) coal samples treated with dilute hydrochloric acid.

Jan 1, 1966

By Gerald E. H. Verbeek

As the number of driven concrete piles with Embedded Data Collectors increases, it has become possible to compare the widely used Beta Method to assess pile damage (using the change of pile impedance) with the so-called Measured Pile Integrity (MPI) method (a combination of two approaches using both the change of pile impedance and the change in pile pre-stress levels). After a brief introduction of both methods, this paper presents the outcome of that comparison based on data from more than 400 concrete piles driven in Florida, which brings into question the reliability of any damage assessment method based solely on the change of pile impedance (such as the Beta Method), especially to detect damage near the pile toe. Moreover the paper demonstrates the need to re-assess the damage classification used for the Beta Method as well as the use of Pile Driving Analysis (PDA) to detect pile toe damage.

Jan 1, 2011

By G. Danko

MULTIFLUX, a new thermal, hydrologic, and airflow model and software is being developed to solve the flow of heat, moisture, and air in and around an underground opening. MULTIFLUX couples two distinct domains that are solved separately first and re-coupled as an iterative task: (1) the rockmass, and (2) the airway. The airway is solved with a lumped-parameter Computational Fluid Dynamic (CFD) module which is an embedded part of the MULTIFLUX code. The CFD model includes convection, conduction, and radiation for heat, as well as convection and diffusion for moisture transport in an air-filled opening. The CFD model also solves for the airflow field. The surrounding rockmass model may be from any analytical solution, or from a complex thermal-hydrologic numerical model such as NUFT or TOUGH2. The rockmass model is interfaced to MULTIFLUX using a novel technique called Numerical Transport Code Functionalization (NTCF). The method provides fast convergence on a personal computer platform. The paper reports the results of MULTIFLUX simulations for a mine drift, comparing calculations with a known mine climate software, CLIMSIM, and with measured data. Through this validation example, the performance of MULTIFLUX is demonstrated. The results show excellent agreement due to the use of realistic modeling assumptions and boundary conditions.

Jan 1, 2009

By Jerry D. St. Clair

A multidisciplinary team of scientists and engineers at Wont has been working to understand heavy metal contamination of DuPont process waste streams and technologies for abatement of these metals. As part of this effort, an extensive study was made of a specific waste stream of importance in DuPont's environmental commitment. This 200 gpm stream contains 5-5000 ppm of nickel plus a variety of inorganic and organic constituents. The chemical complexity of the waste rendered conventional. alkaline precipitation ineffective, and only through the simultaneous application of analytical characterization, fundamental chemical understanding, and process engineering did effective technical approaches emerge. In this instance, ion exchange, sulfide precipitation, and caustic digestion ultimately proved successful in reducing the nickel to below the 1 ppm target. The results of this study will be presented, along with key learnings about the process of solving heavy metal contamination problems.

Jan 1, 1994

By P. Aguirre

Recovery of zinc, copper and nickel from electroplating waste solutions was achieved 'by using a Pulsated Percolated Porous Electrode "3PE" reactor on a pilot plant scale. Intensity - potential curves were used to study the possibility of metal removal and to define the working potential range. The present study describes the use of the 3PE reactors in several electroplating industrial units for the decontamination of their effluents. These effluents were issued from different industrial solutions such as cyanide, sulfate, chloride and Watts baths. Using the stripping curves, deposition rates and electrical efficiencies were determined as function of the metal concentrations in these effluents. Their decontamination could be achieved to the level of few ppm of metals with reasonable current efficiencies. The recovery rates of zinc and copper were about 93 and 99 %, respectively. The. treated effluents contained less than 7 and 1 % of the initial contents of Zn and Cu, respec¬tively. This process allows the recycling of the recovered metals and leads to water saving.

Feb 13, 2014

By E. F. Kingsbury

ONE of the well-known and important uses of the noble or precious metals has been for electrical contacts. In fact, the elements of this group, comprising gold, silver and. the six platinum metals, have been called "noble" because of their ability to resist heat and corrosion, properties which. were early found to be of importance in good contacts. Of these, platinum and its iridium alloys, palladium, and silver, have been extensively used. In recent years the electrical industry has been responsible for about one-eighth of the total consumption of the platinum metals in the United States. Information is not available as to what part of this one-eighth has been used for contacts but it is certainly an important one. SUBSTITUTES FOR PLATINUM During the past 20 years a considerable number of contact alloys have been proposed in the patent literature largely with the aim of more or less replacing platinum by gold or silver, and some of these alloys are finding increasingly widespread application as the reliability of their performance becomes established. From even the partial data at hand it appears that this substitution by the less precious metals has replaced at least one-half of the amount of platinum that the entire electrical industry would otherwise be consuming at the present time. While the subject is of considerable interest to the metallurgist it is even more so to the electrical engineer and it is surprising that the literature records no systematic and' comprehensive investigation along these lines. Practically all the scattered work on noble metal contacts has centered around platinum as a standard and has had two more or less distinct aims. One of these has been the replacement of platinum by cheaper materials, and the other, the development of materials of superior electrical performance. The merit, of a contact metal has been assumed to be dependent on its infusibility, and since the more precious metals have the higher melting points there has naturally been an association of the two qualities in the sense that the more precious were

Jan 1, 1928

By DONALD H. McLAUGHLlN

Few factors have had more influence in maintaining the strength and stability of the United States than our persistent habit of providing .checks and balances to the dynamic powers of free enterprise on the one hand and to the controls and guidance exercised by the State on the other. .Indeed, it is this same concern for matching forces against each other that has given our republic its ability -to preserve a democratic basis of life for its citizens, and yet maintain a ,government that is able to protect the rights of all and to resist and minimize the danger of excessive concentration of authority. Our current efforts to clarify the nation's mineral policies and to define more clearly the role that the governmental agencies should play in conjunction with the functions of private -enterprise again reveal the desirability and advantages of maintaining our traditional controls. At times, the equilibrium has been temporarily disturbed by too great enthusiasm for one or the other of these basic concepts. Sooner or later, however, the balance has been restored by the healthy opposition that is always created by excesses of one sort. At the current stage in our history, the swing toward undue enlargement of the powers of the State seems to have gone dangerously far and we would be untrue 'to our traditional behavior if the group that must demonstrate the virtues of free enterprise did not rally to its support with the utmost earnestness.

Jan 1, 1949

By Ron Hatch, M. K. Witte

"INTRODUCTIONThe proper selection of carbon for a gold carbon in pulp (CIP) circuit involves careful evaluation of several physical, chemical and economic factors. A series of evaluations are required to maximize gold recovery at the lowest capital and operating costs, whether the carbon is selected for an existing gold mill circuit or a new mill under design.Although evaluation may proceed through various stages, it is the intent of this paper to outline some of the preliminary testwork that should be carried out to screen potential carbons for a particular application.An examination of the specification sheets supplied by the various carbon manufacturers may indicate some desirable properties on which to make cursory selection. This exercise by itself will not provide the basic data needed for selecting the best carbon for a particular ore pulp and metallurgical circuit. The necessity of further metallurgical evaluation is indicated by the fact that different carbons perform differently depending on the physical and chemical nature of the leach pulp. In the case of an existing mill, actual leach slurries using mill water are available and should be used for testwork. In the case of new mills, leach pulps must be prepared to simulate the proposed circuit.Five coconut shell activated carbons were obtained from various suppliers, all reported to be 6 x 16 mesh carbons recommended for CIP circuits. A metallurgical evaluation was made utilizing two leach pulps with significantly different characteristics. This paper describes the test procedures utilized and the results obtained from the testwork."

Jan 1, 1985

By D. M. Lane, J. M. Berkoe

Engineers and Owners share a common desire to build reliable, efficient plants on schedule at reasonable costs. This paper describes one tool that Bechtel finds can integrate these objectives by “putting innovation into practice”. Examples of such innovative engineering practice include the use of computational fluid dynamics (CFD) to determine efficient designs. This paper outlines several examples of CFD applications on actual Mining and Metals Projects from around the world. The focus here is to highlight the modeling objectives, analysis strategy, actual benefit obtained from the work, lessons learned to improve future efforts and the common mistakes that can obscure the correct or best results, despite impressive graphics. The tools are powerful, and the results are more powerful when applied with skilled and well-directed human effort and ingenuity.

Jan 1, 2000

By Jorge A. S. Tenorio, Girley F. Rodrigues, Joner O. Alves, Denise C. R. Espinosa

"Rock wools are mineral fibers composed of amorphous silicates, due to their thermo-acoustic characteristics this material has a broad consumer market in the construction, automotive, and electric-electronics industries. This work studied the recovery of wastes from ornamental rocks (granite and marble) as partial raw materials in the production of rock wools. Residues from granite and marble cuttings are industrial wastes with considerable production and limited applications. These wastes should be appropriately managed because when discharged in rivers or lakes can cause siltation, and also they can cause serious human health problems, such as silicosis. Samples of produced materials with thickness smaller than 500µm were characterized by chemical analyses, XRD, and DTA. Results showed that the rock wools produced using granite or marble wastes have important properties, especially the melting point. This process decreases the extraction of mineral resources and provides a profitable destination for the ornamental rock wastes.IntroductionThe ornamental rocks industry is a sector with large production of wastes. During the granite and marble extraction processes and specifically during the rocks cutting (see Figure 1), approximately 35 tons of powdered rock per month can be produced. These residues should be appropriately managed, because when discharged in rivers, lakes or watersheds, they can cause siltation. Also, these wastes can cause serious human health problems, such as silicosis [1].Currently, the granite and marble wastes are mainly used in civil construction to produce materials in the form of mortar, bricks and tiles. However, due the current produced volumes and the average growth of world production estimated at 6% per year, new applications for these wastes are necessary [2]."

Jan 1, 2011

"This research aims at improving the beneficiation of coals and minerals in fine and ultrafine size fractions. A widely used method for upgrading fine and ultrafine particles is froth flotation, which is generally classified into mechanical flotation and column flotation. The present work is focussed on column flotation. A flotation column equipped with a conventional bubble diffuser/sparger was used with oscillatory air supply generated using a fast-switching solenoid valve. The flotation tests were carried out for coal particles and mineral particles, respectively, and a comparison in flotation performance was made between oscillatory air supply and steady air supply. It was found that use of oscillatory air supply with a proper valve switching frequency and on/off time ratio to replace steady air supply could lead to increased recovery of coals or minerals by more than 14 percentage points and substantial reagent cost savings. The improved flotation performance was attributed to enhanced gas dispersion and flow conditions. This research offers a simple new approach to improving the beneficiation of fine coals and minerals with using flotation columns.INTRODUCTIONFroth flotation has been widely used for the separation and concentration of fine coals and minerals by exploiting the difference in their affinity to air bubbles in aqueous medium. Froth flotation is an effective method for beneficiation of coal and mineral particles in a certain size range. It remains difficult to upgrade ultrafine mineral particles. One of the reasons for the ineffective flotation of fine particles is the low probability of bubble-particle collision in the collection zone (i.e., the pulp zone). According to Reay and Ratcliff (1973) and Yoon and Luttrell (1989), the probability of collision is significantly affected by bubble size and particle size, and the collection zone recovery can be increased by decreasing the bubble size."

Jan 1, 2018

An efficient and portable mathematical model has been developed for simulating heat transfer in six-in-line slag-resistance-heating electric furnaces for smelting sulphide ores to produce base metals and platinum group metals. This model is a steady-state one relating furnace conditions and performances to various control and input parameters. Some transient effects occurring in electric furnaces are neglected for computation efficiency. This article describes the model development and modelling results. The present model is capable of predicting: (i) temperatures at various locations in a six-in-line furnace, such as slag bath, matte bath, solid charge, freeboard space, freeze lining, cooling water, and air gaps between solid material components, etc. (ii) freeze lining thickness, (iii)smelting rate, and (iv) heat loss rate, etc. A typical feature of the model is that it is easily portable to different application platforms and sufficiently efficient with execution times less than a few seconds. Therefore, it is possible to apply the model for online prediction and control of heat transfer and freeze lining thickness in industrial electric furnaces.

Jan 1, 2011

By Shaw Bill

The paper describes of the JORC Code in terms its background working environment and reasons for success, and provides references to papers which cover the subject in more detail. It then discusses the two major developments in Australasian reporting standards in the last two years: the revision of the 1999 Code, and the introduction in early 2003 of the “ROPO” (Recognised Overseas Professional Organisation) initiative. The purpose of the JORC Code is to provide a minimum standard for reporting of Exploration Results, Mineral Resources and Ore Reserves in Australasia, and to ensure that public reports on these matters contain all the information which investors and their advisers would reasonably require for the purpose of making a balanced judgement regarding the results and estimates being reported.

Apr 22, 2003

By Paul Guliov

Potash dominates the industrial mineral scene in Saskatchewan accounting for 44% of total provincial mineral production in 1981. More than 7 million tonnes of potash have been produced annualy in recent years; ten underground mines are presently (1983) active. Sodium sulphate and cement are also important mineral products. Construction aggregates, clay products, bentonite, salt, peat moss and sulphur complete the list of industrial mineral products.

Jan 1, 1984

By K. Kawagishi, K. Matsumoto, Y Koizumi, H. Harada

A new burner rig for cyclic and hot corrosion testing of Ni-base superalloys and high-temperature coatings has been developed at the National Institute for Materials Science (NIMS) in Japan. The concepts of the rig design include: use of kerosene as fuel, easy operation for materials research and multi-specimen testing capability per test run. The burner rig consists of six blocks including combustion block, corrosion-solution injection block, furnace block, specimen block, controller block and outdoor facility block. During verification testing, it was confirmed that the rig had accurate specimen temperature control within ±1? from 600 to 1100? and automated easy operation. Cyclic testing of several Ni-base superalloys was conducted. The results from 50 cycle testing indicated that a new NIMS alloy developed for 1700? class gas turbine had higher oxidation resistance than CMSX-4. This new burner rig testing capability at NIMS can be very useful for future oxidation, hot corrosion and coating durability studies.

Jan 1, 2010

By Bernard MacDonald

Introduction. OF the treatment of the slime-pulp of gold- and silver-ores by cyanidation, agitation is an essential part. When prepared for treatment, this pulp, consisting of ore reduced to such fineness that approximately 80 per cent. of it will pass through a 200-mesh screen, is mixed with a certain proportion of water, carrying in solution the quantity of cyanide (KCN) and other chemicals required. The water-constituent of the pulp thus prepared usually ranges from 1 to 2 parts by weight to 1 of the dry ore. Thus constituted', the pulp is charged into treatment-tanks, the shape and capacity of which vary, according to the quantity of pulp to be treated daily and the method of agitation to be employed. Tanks have no other function in a cyanide-plant than that of being economical and convenient containers or receptacles for holding the pulp, solution, or water used in the operations. It is by agitation that the solids in the pulp charged into the tanks are kept in suspension in, and mixed with, the solution in the proper proportions required for the treatment. If the proper mixture of solution to solids be determined to be 2 to 1 by weight (which is, approximately, 5 to 1 by volume), this proportion should be maintained in every part of the charge ; -that is, each solid particle of the pulp, whether it be of 180- or 400-mesh size, should, be surrounded by five times its own volume of solution throughout the whole period of treatment. The reason is, that the amount of chemicals ascertained to be necessary for dissolving the gold and silver contained in the solids, is held in uniform solution in the water-constituent of the pulp, and, therefore, the determined proportions of solution and solids must be maintained at all times during treat-

Apr 1, 1912