Search Documents

By Corby Anderson

The efficient separation of palladium from the transition metals copper, nickel and iron can be effected by passing a leach solution of these metals through a column of the silica polyamine composite material, WP-1, patented by Purity Systems Inc (PSI), Assignee, University of Montana with exclusive license to PSI. The separation can be done at the intrinsic pH of a nitrogen species catalyzed (NSC) oxidative pressure leach solution (~0) and stripping of the palladium from the composite can be effected with hydrochloric acid/ammonium chloride solutions at 50oC. Batch capacities of the composite for palladium are ~ 1.8 mmol/g resin. The possibilities for isolating the metal from the strip are discussed. Given the proven longevity and rapid capture kinetics of the polyamine composites, this new approach should prove to be an economically viable alternative to the multi-step concentration processes practiced in the PGM industry to date.

Jan 1, 2003

By Mark Svinkin

The purpose of this paper is to present an overview of recommended existing criteria of ground vibrations generated by blasting. It is shown that these criteria have limited liability because they were found for specific categories of structures. A new approach based on measurement of structure vibrations is suggested for assessment of damage in structures subjected to blasting vibrations. This approach provides the flexibility of implicitly considering a variety of soil-structure interaction and structure conditions. It is explained a new frequency-independent safe-level criterion of 51 mm/s (2 in/s) for the PPV of structural vibrations. Attention is brought to use seismographs properly calibrated for the required frequency range. Positive flexibility is demonstrated in assessment of structure and component of concern vibrations from blasting.

Jan 1, 2003

"These guidelines set out information on timely disclosure of news releases which are intended to provide, existing shareholders and potential investors, factual information on which a reasoned investment decision can be made.Consider the problems and concerns raised by the following hypothetical news releases:Natural Resource Company""The Company has recently optioned a large and exciting gold property near the ""XXX"" gold discovery area. In describing the property, the Company's independent consultant has said: ""The favourable location of, and some of the results of prior work done on the property give the Company a worthwhile mineral exploration opportunity .... "". The Company proposes to expeditiously conduct a sizeable exploration program on the property as soon as the appropriate financing has been arranged.""Non-Resource Company""Based on discussions with several European countries, the Company anticipates that it will have orders to ship over 200,000 crates of widgets to those European countries over the next two years. These orders, which considerably exceed the Company's forecasts for the first year, represent a projected profit to the Company in excess of $1,000,000 over the next five year period.""GuidelinesTimely disclosure news releases are intended to provide, to both existing shareholders and potential investors, factual information on which a reasoned investment decision can be made. National Instrument 43-101 Standards of Disclosure for Mineral Projects provides requirements for disclosure of a scientific or technical nature for a mineral resource company.The examples do not provide sufficient detail and are misleading because material information is omitted. The following guidelines should be observed when preparing a news release:"

Jan 1, 2003

By A Creighton, C McKenzie

Blasting is a critical task in the development of an open pit. The formation of stable slopes is also essential to the safe and economic extraction of ore. The objectives of a mine blasting department are often considered to be in direct conflict with those of the geotechnical department. This should not be the case. Personnel in the various mining departments need to understand that their goals are the same û to optimise safety and cost-effectiveness of the operation. Blasting has the potential to damage rock that is to remain in situ by generating either excess vibration, and/or pressure. These damage mechanisms are described and guidelines with respect to blast design to minimise the potential for damage are given. A rock mass could be expected to be subjected to varying degrees of damage by blasting, including both intensity of damage and also the extent of damage. These issues have potential to impact significantly on geotechnical design considerations. It is therefore important for the practitioner to define what constitutes damage. In the context of mining, it is recognised that there is a need to balance the requirements for efficient excavation with those of forming stable and cost-effective pit walls. It is therefore important to have a set of key performance indicators (KPIs) against which the performance can be bench marked. These would include cost and time, both of which may be influenced by very diverse factors such as drilling, explosives and their performance, fragmentation, excavator and haul truck performance, requirements for batter clean-up and safe working practices. KPIs are identified and discussed in this paper.

Jan 1, 2003

By Shigeatsu Nakazawa

Activities of Bi and In in the Bi-In liquid alloy were measured over the whole range of composition at the temperatures from 850K to 1050K. An alloy was vacuum-sealed in a quartz cell and heated at the temperature of interest. The absorption for 307nm radiation from Bi lamp was measured for Bi atom vapor in the cell. By heating a pure metal as a standard and measuring the absorbance as a function of the temperature, an analytical curve for Bi atom vapor was constructed and used for conversion of the absorbance to the vapor density. Bi activity was determined as the ratio of the Bi atom vapor density over the alloy to that over a pure metal. The same procedure was applied to the In 304nm radiation from In lamp and In activity was determined independently of Bi. Results showed that the liquid Bi-In system behaves like a regular solution.

Jan 1, 2003

In mid-1998 Atlas Copco Rock Drills AB introduced the first member of a new family of drill rigs. This new family, Rocket Boomer L1C/L2C/L3C, is based on modern computer technology and also on what is characterised as information technology. The design of the drill rigs are modularised both in hardware as in the software. This means that the functionality of the drill rigs is upgradable step by step. Added upon the basic drill rig functions are the new options as ABC Regular (known also as Contour Control), ABC Total, drillplan generator and communication products. The main objectives of these functions are to facilitate real quality drilling.

Jan 1, 2003

By R. Chryst, R. Kus

In the Integrated IT Systems proposed by Przedsie? biorstwo Robót Geologiczno-Wiertniczych—Geological and Drilling Company (PRGW) a network connects a database with all of the departments of a mining division. A key element thereof is the common graphics environment—Micro Station supplied by the firm, Bentley. PRGW’s SoftMine software and GMSI’s CadsMine that are used to design and schedule mining operate in this environment. The digital form of the design project facilitates the verification of information and the integration of technical solutions with SAP R/3 type financial—accounting systems. The system has been successfully implemented in the Brown Coal Mine in Poland.

Jan 1, 2003

By E. Laine

Rock density determinations are necessary for ore resource evaluations from estimated block grades in g/t. Rock density depends on the mineral composition and, thus, it is specific for each rock type. The rock density distributions for different rock types are often symmetric. Hence, the arithmetic mean is a good approximation for the average density for lithological units. However, there may exist spatial variation in density values due to alteration, fracturing and original heterogeneities such as layering. This study compares the kriged density model with the one with constant density values for different lithological units in the evaluation of metal amounts in rock blocks. The case study consisted of rock densities measured from the drill cores at Ahmavaara PGE deposit in northern Finland. The used Ni contents were simulated in accordance with the spatial distribution of rock densities. The Ni amounts in 2x2x2 m3blocks are higher for the kriged densities than for the average densities. The difference is increasing with the increasing metal amounts due to the nonlinear correlation between Ni content and rock density. The final effect on the resource estimation depends on the cutt off grade and prices of the metal, for example, for a very valuable metal the small differences are significant

Jan 1, 2003

"The technical report form provides the headings to be used and content required when a completing a technical report to be filed in accordance with NI 43-101. The technical report is meant to be a summary of the scientific and technical information on the mineral property. The Instrument (NI 43-101) requires that technical reports be filed with Canadian provincial or territorial securities regulators to support certain disclosure of mineral exploration, development and production activities and results in order to permit the public and analysts to have access to information that will assist them in making investment decisions and recommendations. FORM 43-101F1 TECHNICAL REPORT INSTRUCTIONS (1) The objective of the technical report is to provide a summary of scientific and technical information concerning mineral exploration, development and production activities on a mineral property that is material to an issuer.This Form sets out specific requirements for the preparation and contents of a technical report. (2) Terms used in this Form that are defined or interpreted in National Instrument 43-101 Standards of Disclosure for Mineral Projects (the “Instrument”) will bear that definition or interpretation. In addition, a general definitioninstrument has been adopted as National Instrument 14-101 Definitions that contains definitions of certain terms used in more than one national instrument. Readers of this Form should review both these national instruments for defined terms.(3) The qualified person preparing the technical report must use all of the headings of the items in this Formandmay create sub-headings. If unique or infrequently used technical terms are required, clear and concise explanations must be included. (4) No disclosure need be given in respect of inapplicable items and, unless otherwise required by this Form,negative answers to itemsmay be omitted. Disclosure included under one heading is not required to berepeated under another heading. (5) The technical report is not required to include the information required in Items 6 through 11 of this Form tothe extent that the required information has been previously filed in a technical report for the property being reported on, the previous technical report is referred to in the technical report and there has not been any material change in the information. (6) The technical report for development properties and production properties may summarize the information required in the items of this Form, except for Item 25, provided that the summary includes the materialinformation necessary to understand the project at its current stage of development or production. (7) The technical report may only contain disclaimers that are in accordancewith section 6.4 of the Instrument and Item 5 of this Form."

Jan 1, 2003

The relationship between neural network (NN) performance and the parameters that form the architecture of the neural network is complicated. This paper studies an issue that is still controversial—the effect of the number of neurons and number of hidden layers on NN performance. This paper tests if the above parameters affect network performance when the NN is trained according to the quick stop strategy. It was determined that the number of neurons did not have any effect on the NN performance for a single layer or a double layer network. It was also found that the training error and calibration error could be poor indicators of the prediction correlation coefficient.

Jan 1, 2003

By Steve Dillingham

The horrific events surrounding September 11th left Americans with a feeling of sudden helplessness...the shock of being unprepared and powerless. From this tragedy, we can understand the need to prepare for the unexpected, and can apply this hard lesson into operational planning for those involved in the commercical explosives industry.

Jan 1, 2003

By P. Goosen, A. Paterson, E. Paulsen

Ticor South Africa is currently involved in the mining and processing of a heavy mineral oredeposit at Hillendale Mine on the KwaZulu-Natal north coast. The orebody is characterized by a high ultra fine fraction (-45µm) that has a variable rheological behaviour when subjected to shear and hydration. Experience at Hillendale has shown that the ultra fine mineral tailings are sensitive to shear history in terms of shear intensity and shear duration as well as hydration history. This phenomenon expresses itself right through the primary beneficiation process influencing the mineral separation, but is especially prevalent on the residue disposal i.e. slurry transport and deposition on the tailings impoundment. Tube viscometer test work was conducted on the flocculated fine tailings that indicated that there was a change in rheology as a result of shear. This paper presents the results of the on-site test work conducted at the mine to measure the rheology at various stages in the process.

Jan 1, 2003

By Dean E. Harris

The realignment of U.S. Highway 95 in Sandpoint, Idaho, is being designed on a site underlain by glaciolacustrine soil that includes very thick deposits of soft, sensitive clay to estimated depths of greater than 200 m. The highway realignment will include construction of numerous embankments, mechanically stabilized earth (MSE) retaining walls, and pile-supported bridges. The area of the proposed new highway corridor also includes existing historic and commercial buildings, a railroad, sensitive environmental areas, and economically vital tourism/recreational assets. The evaluation of pile axial capacity included the use of a variety of methods, including total stress, effective stress, and empirical methods using the results of piezocone soundings and conventional borehole and laboratory tests. These methods were used along with the findings from an instrumented static loading test to design the piled foundations for the bridges. A critical factor throughout the design of the pile foundations was controlling settlements to levels that could be tolerated by the bridges. Also, because of the proximity of the pile foundations to the existing structures and the proposed new embankments, the project has required careful consideration of the potential interaction between these elements. The analysis of piles also considered the potential for settlement of embankments, drag loads on the piles, and downdrag.

Jan 1, 2003

By M. Pelser, Lorenzen L.

"The presence of calcium and magnesium in the hydrometallurgical processing of base metals, results in a number of process difficulties. These problems range from the contamination of the final product (where the final product is a precipitate) to high energy consumptions and large bleed streams during electrowinning. Calcium poses an additional problem in sulphate solutions owing to the low solubility of its sulphate salts. This can easily lead to a process stream that is supersaturated with calcium sulphate, resulting in unwanted solids formation within the process equipment.A review of literature has proven that there is no conventional method for the control of calcium and or magnesium, although a number of potential processes have been identified. The technologies investigated included precipitation, ion exchange and solvent extraction, for which at least one method was found under each. To make the reader aware of these processes a short description was provided of each within the text.Of these processes, fluoride precipitation was selected for experimental investigation based on the low solubility of calcium and magnesium compared to the base metals. This process involves the addition of a soluble fluoride to precipitate CaF2 and MgF2. The experiments were designed to investigate the equilibrium of the system at varying parameters of which the level of fluoride addition, the ratio of calcium to magnesium, and the identity of the soluble fluoride was reported. In all of the instances the process showed high selectivity towards calcium and magnesium over the base metals. The experiments proofed the process to have a higher affinity towards the removal of magnesium at compositions where the molar ratio of calcium to magnesium was higher than 1:3. It is often the case that the calcium to magnesium ratio is in the region of 1: 10. From this it follows that the fluoride addition has to be stoichiometric or greater for calcium and magnesium combined, if the calcium is to be precipitated. This was demonstrated as well. On the identity of the soluble fluoride hydrogen fluoride was compared to ammonium fluoride, of which the latter was found to be preferred."

Jan 1, 2003

By Florian Kongoli

"Lime ferrite" slag with limited silica content has proven to be a valuable choice in the modem processes of copper smelting and converting due to several advantages that this slag offers compared to classical silicate slags. Nevertheless the liquidus surface of this slag has been experimentally measured only at low oxygen potentials such as in equilibrium with iron or near it and in air. Although most of the smelting and converting processes that use this slag occur at intermediate oxygen potentials, the liquidus surface of this slag is not known at these conditions and the effect of oxygen potential and silica has not been correctly understood. This has brought some confusion in literature as well as in the industrial practice. In this work the liquidus surface of the calcium ferrite slags has been quantified by the means of a new thermophysicochemical model and a new type of liquidus surface diagrams which are very convenient for any industrial process that uses calcium ferrite slags. These diagrams can be easily used to select the lowest liquidus temperature of calcium ferrite slags at a minimum cost and can help design several fluxing strategies in copper smelting and converting processes. The effect of the oxygen potential and silica is also quantified and important industrially related conclusions are drawn.

Jan 1, 2003

By Tapani Järvinen

Non-ferrous metals and metals in general are considered as being non-renewable natural resources. Metals are needed because of their excellent and irreplaceable properties. The consumption of metals, with the exception of carbon steel, is steadily growing by 1-3 % annually, and that of stainless steel as much as 3-6 %. This is a general trend, which is periodically disturbed by cyclical variations. In recent years so-called "New Economy" has become prominent in the public media and the market value of the traditional industry has been well below its real value and importance. Nevertheless, the modem society requires metals today and also in the future, and the companies using the most modem technology in a responsible way and innovative solutions not only in technology, but also in everything they do will survive. This paper describes the role of Europe as a producer of primary base metals and as a supplier of technologies in the base metals industry. It concentrates on the development and commercialization of technologies and project implementation in the metallurgical industry. As one example of a European approach to these matters the paper presents Outokumpu' s response to the future challenges in the base metals industry. Outokumpu Oyj is one of the leading metals and technology companies in the world of stainless steel, copper, zinc, and sales of technology in metals and minerals businesses. Outokumpu applies its knowledge of metals and processing to generate value for its customers and shareholder. Everything we do, we do in an economically, environmentally and socially responsible way.

Jan 1, 2003

By Paolo Bevilacqua, Paolo Antonini, Lorenzo De Lorenzi

"Ceramic production requires large quantities of K-feldspar, which is commonly sourced from granites, alkali-granites, and feldspathic sands. These rocks contain other minerals, such as quartz and plagioclase, which are undesirable for ceramic production. Due to the coarse mineral grains that constitute these rocks, a reasonable liberation is achieved at a relatively coarse particle size.The feasibility of feldspar-quartz separation using a dynamic dense medium separation system has been investigated as an alternative to flotation techniques. The use of a two stages cylindrical vessel (Tri-Flo) was preferred to a conical vessel, due to the improved separation efficiency.In a full-scale processing plant, a dense medium separation process can be used as a K-feldspar preconcentration step. This reduces the amount of material to be treated in the more expensive processes, such as finer comminution, flotation or magnetic separation.A comparison between commercial raw materials for the ceramic industry and the “rich in feldspar” products of the Tri-Flo process is reported, and the validity of the process is demonstrated."

Jan 1, 2003

By P. Wells, P. Quinn

"A moveable flotation miniplant was designed and constructed at the research laboratory of Inco Technical Services Ltd. to address the need for flowsheet development with a limited amount of ore (such as drill cores). It consists of one rod mill, two regrind ball mills, one vibratory screen, 24 flotation cells of various sizes and two Venturi aerated flotation columns. The setup has continuous monitoring capability for pH, dissolved oxygen, oxidation-reduction potential, conductivity and temperature in conditioning tanks and flotation cells. Various options regarding flotation reagents, circuit configurations, and fineness of primary grind and regrind can be readily evaluated. The throughput of the miniplant is 20 – 30 kg/hour ore.Unit operations such as flash flotation, magnetic separation and gravity concentration can also be evaluated as an integral part of an entire flowsheet development.This communication describes the basic design features of the miniplant and some examples of applications are given.INTRODUCTIONInco operates numerous mines in Sudbury and Thompson and will shortly bring the Voisey’s Bay mine into production. It has long been recognized that the ores from different mines or from different depths of the same mine can give different responses in flotation. There is a growing need to properly evaluate the ores before feeding the mill to maximize the return of the mine/mill operation. Inco Technical Services Limited at Sheridan Park, Mississauga, Ontario has developed a batch laboratory procedure to address this issue. The results are considered in the overall economical assessment of new mine operations.For ores that cannot be processed by the existing mill operations or that will be processed by a new mill, it is necessary to develop a flowsheet that can maximize the economical return of the mine/mill operation. While recognizing the importance and contribution of the laboratory batch flotation procedure, it does not generate reliable data for flowsheet simulation and design. A full-scale pilot plant campaign is normally required to obtain the design data but often this is not possible due to a limited amount of ore obtainable from the drill core. A small-scale pilot plant (mini pilot plant or miniplant) capable of processing 20-30 kg/h ore can provide this data prior to a full-scale pilot plant campaign. A miniplant can also be used to optimize the circuit configurations, reagent additions and recycle options of process water before pilot plant work and can be used to test a different flowsheet configuration for an existing mill before re-piping a plant circuit."

Jan 1, 2003

By S. Dessureault

Computer Integrated Mining (CIMG) is a process of using computer networks to transform islands of enabling technologies into a highly interconnected mining system. CIMG involves the integration of advanced technologies at various levels in the mine business to achieve higher flexibility, better quality of processes and control, and improved profitability. Justifying the benefits of CIMG are difficult as many of the advantages are derived from improved flexibility, quality, and control. Justification is based on the evaluation of the benefits to be gained, compared to the required capital investment. Management tools used in mining are currently inadequate in assessing the value of advanced technology whose benefits are primarily qualitative. A key aspect of successful implementation is management acceptance, which has to be won through the capability to justify the technology's financial costs and the true value of all of its benefits. The manufacturing industry faced similar justification difficulties when adopting advanced technology in factories. A significant amount of funding and research was invested into developing management strategies and approaches to justification. Many of the problems that faced the transformation of the manufacturing industry in the late eighties and early nineties are now facing mining. The solutions derived for manufacturing may help mining in its transition to an increased reliance on integration technology. Reviewing the industrial history of computer integrated manufacturing identifies several tools and strategic frameworks that can be adapted for mining. Keywords: Computer integrated mining, justification techniques, CIM, information technology.

Jan 1, 2003

By Ivan Imris

The common problem of new and conventional technology of copper production is the copper losses in the slags, which may be divided into mechanical and physico-chemical losses. In the first group can be included particles of mechanically entrained or floated unsedimented matte particles which coexist with slag. On the other hand, the physico-chemical losses are caused by solubility of copper in the slag in the form of sulphide and oxide. The copper losses in the slags from different processes has been predicted by calculation from thermodynamic data and compared with those determined by microscopic examination and quantitative electron microprobe analysis. Depending on the forms of copper losses in the slag the reduction of copper losses in the slag or the slag cleaning process could be suggested.

Jan 1, 2003