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By M. Sharafodin, A. A. Hassanipak

Abstract - The essential aims of additional borehole drilling are to improve the reliability of grade and tonnage estimates in each reserve class and to increase ore tonnages. The "GET" function presented in this paper considers strategies for achieving both of these goals simultaneously, and therefore is advantageous for selecting sites for additional boreholes. The "GET" function is either a linear or a non-linear product of three variables G, E, and T: f(G,E,T,) = G??E??T??where the values of any or all of the exponents ?, ?, and ??may differ from unity at the discretion of the user. G and E are the average estimated block grade and the average estimation error for ore blocks in one vertical column, and T is the compounded ore thickness within the column. To illustrate its utility, the GET function has been used for determination of the most advantageous sites for additional drilling in the Shah-Kuh Pb-Zn deposit in west central Iran.

Jan 1, 2004

By T. M. Ruff

A GPS-based traffic awareness and collision avoidance system has been implemented at mines with long, narrow access roads to help avoid accidents involving two approaching vehicles or vehicles following too close. A simple display in the cab of each outfitted vehicle gives an indication of oncoming traffic and a voice announcement indicates the type of vehicle that is coming as far out as 300 meters. Advanced warning of approaching vehicles is increasing driver awareness, especially around blind corners and in adverse weather such as heavy fog, snow, or rain. Speeding alarms have also been implemented and are especially critical as a vehicle approaches reduced speed areas near single-lane bridges or tight curves. A description of the system, safety improvements seen since its introduction, and implementation challenges will be discussed.

Aug 1, 2013

By M. Nusheh, C. Bumby, A-H. Puichaud

"Vanadium-bearing titanomagnetite ironsand deposits occur along a 480 km stretch of the west coast of New Zealand. In the present study, the leaching behaviour of NZ ironsand was investigated in hydrochloric acid (2–10 M) solution at 50–80°C for 2 h. The resulting leaching liquors exhibited Fe/V ratios in the range 150–180. The distribution of trace element contaminants between solution and solid residue was investigated, and processing conditions have been determined for rapid and efficient dissolution of Fe, Ti and V into the leaching solution. In addition, mineralogical analysis of raw ironsand and leached residues was performed in order to study the leaching mechanism. Samples were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy (EDX), X-ray fluorescence spectroscopy, qualitative and quantitative X-ray diffraction and inductively coupled plasma mass spectrometry (ICP). Results indicate that the dominant dissolution process follows shrinking particle mechanism. However, ironsand particles containing ex-solution lamellae exhibited a different leaching behaviour compared to homogenous titanomagnetite particles.INTRODUCTION Titanomagnetite ironsand (blacksand) forms Quaternary onshore beach and dune deposits and offshore marine deposits (Figure 1) along 480 km of coastline from Kaipara Harbour south to Wanganui on the west coast of the North Island (Christie, 2016). It attracted the attention of scientists from the earliest times (Galbreath, 1998). The principal minerals in ironsand are titanomagnetite (TTM), ilmenite, quartz and ferromagnesian minerals such as augite, hornblende, diopside, and olivine with smaller amounts of rutile and apatite (Mauk, 2016).Several large ironsand deposits have been discovered and exploited since the late 1960’s. The Waikato North Head and Taharoa mines are currently operating and they have a 2015 measured resource of 400 million tonnes in total and provide over 2 million tonnes of concentrate per year by simple cost effective magnetic separation process (Christie, 2016; Christie & Brathwaite, 1997). The concentrate contains not only 7–8% TiO2 and 56–60% SFe, but also 0.3–0.6% V2O5, is both a valuable titanium mineral and a source of vanadium. All the production is used for steelmaking industries. The other potential for utilizing more of this resource without requirement of integration into an iron and steel producing plant is to develop a hydrometallurgical route with advantages of higher efficiency along with lower emissions. Currently, there is no existing commercial process capable of extracting all three of these elements as industrial-grade commodity products. Acid leaching of TTM concentrate with higher degrees of recovery and selectivity is a key step in any possible hydrometallurgical route."

Jan 1, 2017

By David Stephenson, Hugo Granados, Steven Klohn

"HudBay’s Constancia project is a copper molybdenum concentrator located in southern Peru. In 2010 Ausenco was contracted to perform a feasibility study optimization review which resulted in an improved design with significantly increased throughput capacity at a minimal increase in capital cost. Construction began in 2012 with commercial operation commencing in May 2015. This paper outlines the process plant design as well as describing the plant’s major equipment selections, start-up and early operations experiences.IntroductionHudBay Mineral’s Constancia project is located at 4200 meters above sea level (masl) in southern Peru, approximately 630 km south-east of Lima, Peru. The property can be accessed by road from Cusco, Peru, (approximately 110 km to the north), or from Arequipa, Peru (approximately 215 km to the south). Matarani, accessed via Arequipa, is the closest port.Constancia is located within the Yauri-Andahuaylas metallogenic belt. The region contains several large copper-gold-molybdenum porphyry deposits such as Antapaccay (by Glencore) and Los Chancas (by Grupo Mexico), and copper skarn deposits such as Tintaya (by Glencore) and Las Bambas (by MMG). Constancia’s ore reserves contain copper and molybdenum with trace amounts of gold and silver.Ore is mined by an open-pit operation. The process plant recovers copper and molybdenum concentrates, storing tailings in a conventional tailings management facility. Infrastructure at the site includes a grid power supply (via a 70 km overhead transmission line from Tintaya), water supply, workshops and an accommodation camp. Mine life is 22 years.Site construction works began in 2012 with first copper concentrate produced in late 2014. The project was executed for approximately 1.75B$USD.Ausenco’s design approach focussed on developing a capital efficient copper molybdenum concentrator. This paper outlines key features incorporated in the concentrator design, plant layout and equipment selection, as well as start-up experiences and early operational results."

Jan 1, 2016

By R. T. Seaman

There are several hydrometallurgical alternative processing options under development for high enargite and arsenic containing copper concentrates ranging from biological, atmospheric, medium temperature oxidation to total oxidative leaching. The most developed of these options is the CESL process boasting pilot campaigns totaling more than 8760 hours of fully integrated continuous operation, as well as, over two thousand batch scale oxidation tests performed on dozens of concentrates for flowsheet development. This paper reports the observed deportment of arsenic under varying arsenic, iron and acid oxidation conditions; it also describes the impact of iron to arsenic ratios and residue recycle on overall arsenic behavior and its stability in residue. INTRODUCTION The CESL Hydrometallurgical Process (CESL) was originally developed to compete with smelting of clean chalcopyrite concentrates. High Treatment Charges and Refining Charges (TC/RCs) combined with premiums on London Metal Exchange (LME) grade copper from onsite refining made treatment of copper concentrates using CESL a viable option at the time. As world demand for copper increased and a subsidized Chinese refining market developed, smelting contracts became more favourable for the miner and focus was placed on modifying the CESL Hydrometallurgical Process to handle concentrates with elevated deleterious elements. Dozens of pilot campaigns processing concentrates containing elevated concentrations of uranium, fluoride, mercury and nickel all led to further developments of the CESL Hydrometallurgical Process. In 2016 a United States patent was granted for a novel modification of the CESL Hydrometallurgical Process for recovery of copper from arsenic-bearing and/or antimony-bearing copper sulphide concentrates, Henry Salomon de Friedberg (2016). To date, over 2000 bench scale tests along with five fully integrated closed loop pilot campaigns, totaling over a year of online operation time, have been conducted processing arsenic bearing copper concentrates. This paper summarizes the observed behavior of arsenic under varying autoclave and process conditions.

Jan 1, 2019

By H. Son

The three-dimensional (3D) reconstruction of as-built industrial plant models plays an important role in revamping planning, maintenance planning, and preparation for dismantling during the lifecycle of industrial plants. Recently, the 3D reconstruction of existing industrial plants was conducted using laserscan data to make surveying processes more efficient. However, the current 3D reconstruction process from laser-scan data is still limited due to the need for significant human assistance. Although a great deal of effort has been made to efficiently reconstruct 3D as-built industrial plant models, the presence of objects?such as equipment, pipelines, and valves of different sizes and shapes?in existing industrial plants significantly increases the complexity of laser-scan data and makes automating the reconstruction process more challenging in practice. The purpose of this study is to propose a knowledge-based approach for the 3D reconstruction of as-built industrial plant models from unstructured laser-scan data. First, pipelines were extracted from laser-scan data based on surface curvature information and knowledge about pipelines' sizes from existing piping and instrumentation diagrams (P&ID). Once entire pipelines were extracted, they were modeled based on skeleton features. Then, the remaining objects were clustered and grouped separately via the region grouping process. Afterward, clustered objects were retrieved and modeled based on global feature-based matching from the 3D database. Finally, the resulting model was checked to ensure that it was well-reconstructed according to the information regarding the relationships among objects abstracted from the existing P&ID. The preliminary results on actual industrial plants show that integrating knowledge into the reconstruction steps played an important role in the proposed approach and that this approach obtained accurate as-built industrial plant models from unstructured laser-scan data. The proposed approach could be successfully utilized to assist in many applications during the lifecycle of industrial plants.

Aug 1, 2013

By H. Yoshida, H. Hatta, T. Suzuki

"The effect of the copper and magnesium contents and quenching rate during quenching on the age hardening behavior of 2000 series aluminum alloys was investigated. For the higher copper-containing specimens as conventional alloys, like AA2024, precipitation of the stable phases increased as the quenching rate decreased under the as-quenched conditions. The maximum hardness after the artificial aging of air cooled(AC) specimens was much lower than that of the water quenched(WQ)specimens. On the other hand, for the lower copper-containing specimens, coarse precipitation did not increase even in the case of the AC. The age hardening behaviors of the WQ and AC were very similar such that the maximum hardness and aging rate were almost the same. Many parts of the fine precipitates that increased the hardness were thought to be the GPB zone or fine S’ phase for the WQ and relatively coarse S’ phase for the AC. From the calculated CCT(continuous cooling transformation)diagrams, the lower copper-containing specimens could maintain the copper and magnesium in the solid solution state during the AC, so they could be quenched at a rather slower quenching rate like the AC.INTRODUCTIONThe 2000 series aluminum alloys, containing copper and magnesium as the major chemical components, are some of the well-known heat treatable aluminum alloys. These alloys have a high quenching sensitivity, thus the age hardening ability of these alloys decreases with as low quenching rate. To prevent the decrease of the age hardening ability, quenching is done by a method such as water quenching, which is not very efficient in an industrial situation, because the method requires such large equipment. For these alloys, reducing the quenching sensitivity helps them to be produced in a rather convenient way. For example, 6000 series alloys such as A6063 have low quenching sensitivity, thus they could be quenched by only air cooling just after extrusion and they do not need water quenching. Based on these reasons, investigations of these alloys with high copper and magnesium contents have been conducted in the past to find a way to lower the quenching sensitivity by adding transition elements such as manganese, chromium and zirconium (Kanno, Suzuki, & Itoh, 1986; Suzuki & Itoh, 1986; Kanno, Sakuma, Muromachi, & Watanabe, 1988). However, very few studies have focused on the quenching sensitivity of the lower copper and magnesium containing alloys because of their usage for structural components with high strength, and most of the past studies have used only the fast quenching method like water quenching. On the other hand, from our recent results, there is a possibility to lower the quenching sensitivity of 2000 series alloys with lower alloying elements. In this paper, the effect of the copper and magnesium contents with lower alloying elements and quenching rate, especially in case of slower quenching rate than conventional quenching method, on the age hardening behavior of the 2000 series alloys is investigated by the hardness measurement, structure observation and thermal analysis."

Jan 1, 2018

By Michael K. O’Leary, William D. Coplin

"Risks from political instability and government policies restricting equity ownership, local operations and transfers of payments affect the profitability of foreign mining ventures. More than seat-of-the-pants judgments and old-boy networks are required to anticipate these risks and to take actions appropriate to offsetting them. A system for making political forecasts, called the Prince System, and a series of charts relaying risk s to a production of key minerals will be presented.IntroductionFirm s with extractive operations outside their home country do not have to be told that political stability and government decisions play a big role in the success o f their operations. The takeover of copper firm s in Chile during the Allende administration in 1971 and the recent decision by Venezuela to reduce Reynolds Metals equity share in a smelting operation from 50% to 28% are two examples of hundreds of events that have determined the profitability of extractive operations over the past decade. Both risks and opportunities for international firms seeking to produce and market raw materials are heavily affected by political conditions. While news of political events travel much faster than in the past and host governments are more clever in shaping the risks as well as the opportunities, politics has always been part of the mining business.What has changed is the need to be more systematic in approaching the assessment of political conditions and how it affects business. The increasing costs of extractive operations, the need for long-range planning, the importance of financial arrangements and the world-wide scope of man y firm s' activities require that the assessment be updated continuously and be comparable across different countries and different types of investments. Political risk analysis, the assessment o f macro-political changes and specific governmental decision s on the operations of extractive industries needs to become as systematic and integrated into corporate decision -making as economic analysis has become over the past two decade s."

Jan 1, 1983

By K. Aziz

The solutions to unsteady-state gas flow in a radial system have been reviewed in order to aid in the interpretation of drawdown data. It has been the practice to evaluate the time and rate conversion constants, directly or indirectly, by using reservoir data. This paper presents a method of determining these constants from drawdown data. A simplified approach to the de-termination for the various boundary conditions is presented. An example of a problem which illustrates the use of this theory appears in the appendix. UNSTEADY-STATE FLOW EQUATION The solution of any unsteady-state flow problem involves (1) the continuity equation, (2) the equation of state of the fluid, (3) the equation of fluid motion and (4) the boundary conditions. For the Darcy flow of a gas in the horizontal radial plane, the equation is when the viscosity, compressibility and permeability to gas flow may be assumed constant and the medium

Jan 1, 1963

By W. J. D. Stone

"INTRODUCTION Over the past decade, a number of publications have described the advances in High Intensity Wet Magnetic Separation. A number of significant, but small capacity installations were made and are successfully operating. These were followed some three years ago by larger installations treating ilmenite gravity concentrates; at least one machine treating 25 tons per hour of new feed was installed and is successfully operating.However, this still did not result in general acceptance that High Intensity Wet Magnetic Separation could be applied on a large scale. Neither did it dispel the feeling that High Intensity Wet Magnetic Separation was ""expensive"" and hence, confined to small scale – high value applications suchas the cleaning of tin concentrates. In addition, there is the usual reluctance of being the ""guinea pig"" which has resulted in waiting to see ""someone else"" make the first large installation decision. Such a decision and installation has now been made.Therefore, the purpose of this paper is to show that High Intensity Wet Magnetic Separation has been commercially accepted on a large scale and to show its general application to the base metal mineral industry.Examples are confined to a few specifics due to the large volume of preliminary test data that is available. The art has now reached the stage where much of the preliminary work should be taken through to serious evaluation."

Jan 1, 1971

By Jie Zhou

Mining mobile equipment is becoming larger in order to lower operation cost and increase productivity; however, their performance characteristics are often limited by the tire capabilities. Although considerable progress has been made in the field of tire research, the lack of comprehensive knowledge on tire performance characteristics impedes the advancement of off-the-road tires. Longer haul roads, and a severe operating environment make tires more vulnerable than other components of a vehicle. Furthermore, due to a limited availability of large tires, mines are facing shortages. Thus mines and tire service companies are keen to improve tire performance, extend tire life and hence lower operating costs. This paper reviews the relevant tire performance research, analyzes tire interactions with the surrounding environment, tire maintenance practices and operational issues using a case study based on data collected during an ongoing project with Fountain Tire.

May 1, 2006

By K. E. Prince, S. Burling, R. J. Ring, M. K. Maley, W. R. Taylor

Vanadium occurs as a component of carnotite, which commonly occurs in calcrete type ores, and in association with uranium in some sandstone-hosted deposits. Increasing demand for vanadium, which is used in high-strength steel and Vanadium Redox Flow Batteries (VRFBs), is offering some uranium producers a potential option for by-product vanadium recovery to improve project economics at a time when uranium prices are low. This paper presents the results of recent optimisation studies on the Bigrlyi deposit for the recovery of both uranium and vanadium. The impact of carbonate leaching conditions on uranium and vanadium extraction from a range of carnotite-in-calcrete ores is also examined, with vanadium extraction limited by the proportion of non-carnotite vanadium present in the ores. The findings are particularly relevant to developing projects as results show that elevated vanadium content in ore does not necessarily equate to a high vanadium extraction in leach.

Jan 1, 2020

By A. M. Childs, R. F. Mather, K. R. Rawling

"The challenges encountered in the design and construction of mines and their process facilities today are becoming more intense and the engineering more competitive. The need to incorporate new techno1ogy to compensate for ever rising costs is always present, but its application in the harsh environment of Northern Canada increasingly requires the inclusion of new proven methods and innovative approaches to arrive at economically attractive projects.This paper deals with the development of the process design for the Cullaton Lake Gold Mine in the Northwest Territories. Particular emphasis is given to the interaction of the imposed construction and testwork schedules, and their effect on certain process decisions.The challenge that faced the project team may be defined by the following factors:1. A schedule which required that metallurgical testing, engineering, and procurement and delivery of all equipment and construction supplies should be complete within a period of ten months.2. Transportation of all personnel, equipment and supplies to the site by airlift, as no road was available or affordable.3. A six week period when transportation to the site was impossible.4. The extremes of temperature beyond the tree line in the Northwest Territories.5. A complete lack of infrastructure in the area."

Jan 1, 1983

By Paul-Henri Girard

La Mine Agnico-Eagle division Laronde situé à Cadillac, est un producteur d?or, d?argent, de cuivre et de zinc. Cette propriété est situé dans les cantons Bousquet-Cadillac le long d?une des ceintures géologiques les plus productives au monde. La mine Laronde a débuté la production en octobre 1988 à un rythme de 1360 tonnes par jour. Ensuite, elle a augmenté son rythme de production successivement à 1800 TPJ en 1990, 3300 TPJ en janvier 2000 et 4500 TPJ en octobre 2000. Agnico-Eagle, fondé par feu Paul Penna, a toujours eu comme politique la participation des employés aux décisions de la compagnie pour le déveleppement de celle-ci. Cet écrit va permettre de mieux comprendre la façon dont la division fût développé.

May 1, 2001

By R. D. Brown

"Finance Minister Donald Macdonald's budget of May 25, 1976 featured a restructuring of the anti-inflation profit controls and a grab bag of tax changes, some of direct interest to the mining industry. All Canadian taxpayers now will be permitted to write off immediately 100% of mineral and oil and gas exploration expenses included after• May 25, 1976 and before July 1 1979. The cost of acquitting Canadian resource property after May 6, 197.4 from a federal or provincial government will now clearly be included in Canadian development expense, and provincial drilling and exploration incentives received after May 25, 1976 will not reduce exploration and development expense for federal income tax purposes. Under tough new anti-inflation profit controls, all controlled businesses, except distributions, will essentially have one uniform set of rules for• determining allowable profit margins; this allowable margin will be determined by product line or by over-all net margin and will be 85% of the higher of the margin obtained in the five years preceding October• 13, 1975 or the one year preceding May 1, 1976. The basic capital cost allowance system is to continue, but many rates will be revised. The ability to offset losses created through claiming capital cost allowances on leased equipment, etc. against other income will be ended with respect to transactions entered into a/te1• budget night. Miscellaneous other tax changes will raise the low rate base for Canadian-controlled private corporations to $750,000 increase retitement plan contribution limits and reduce the rate of branch tax imposed on branches of corporations resident in a country with which Canada has a comprehensive tax treaty to equal the withholding tax rate on dividends under that treaty."

Jan 1, 1976

By Vu Van Dong

Resource estimation is the science of determining the amount and quality of a given material in the ground that has the potential to be mined at a profit. This is because during this time computers have become more widely available and more powerful and software packages have become more comprehensive and user friendly. Over the past three years The Mining Geology Company with the support from Vinacomin Group has developed the Coal Geological Modelling and Reserve Estimation ? VMG system. The VMG system enables the geological and mining engineer to start at the reserve estimation for the mine design and planning. The VMG system enables the national and international standards (NI43-101, CIM-Canada; SAMREC Code, Africa, and JORC Code, Australia) and user friendly with menu driven thereby permitting the engineer with minimal computer training to rapidly learn and utilize the system. Geological and mining data input through digitized map files and drill-holes information files stored in the database that is an integral part of the VMG system with the main function for collection, validation, and recording, storing and processing of data will include both ?primary? (observation and measurement) and ?interpreted? data. It is recommend that data be stored digitally, using a documented, standard format and a reliable storage medium that allows for easy and complete retrieval of the data. The coal reserve estimation through standard polygon methods with the increased use of these mathematical techniques (geometrical modelling, geostatistical method, least square method, ?) over the last ten years corresponds, to some degree, to a decrease in both the amount of the coal deposit mapping and, in particular, coal seam structural interpretation and modelling, and permit rapidly evaluation of coal seam and overburden quality and quantity. The understanding of the relationship between the coal mineralization of interest and the likely related complicate geological processes and structure that govern its emplacement and geometry within the geological framework is essential to the establishment of the geological controls for coal mineralization. System outputs includes: drillholes summary reports, stratigraphy, cross-sections, isopach maps, structure, contour maps, premining and post mining topography maps, and 3D perspective view on coal seam structure.

Oct 1, 2009

By Carl Bertrand, Patrice Nadeau, Claude Bazin

"Rio Tinto Fer et Titane processes the ore extracted from the Lac Tio orebody to concentrate the hemo-ilmenite (FeO.TiO2-Fe2O3) mineral that is subsequently smelted to produce pig iron and titanium oxide slag. The ore is crushed, heat treated (roasted) and concentrated using dry magnetic separators. This paper describes a model to predict the magnetic susceptibility of the roasted ore and its behaviour in the magnetic separation plant. The model uses a classification of the ore as a function of the size and magnetic susceptibility of the particles. A subsequent division into mineral species allows the simulation of the magnetic separation process. The model is used to assess various operating options when process disturbances occur.INTRODUCTIONOre processing operations consist of ore size reduction followed by the recovery of valuable species in a concentrate that is subsequently sold for its minerals or metal content. The concentration processes are based on the physical and/or chemical properties of the minerals contained in the ore. Flotation is typically used to recover minerals of base metals such as copper, zinc, lead or nickel. Iron ore and other dense minerals are typically concentrated by gravity separation processes. Magnetic separation uses the magnetic properties of the minerals to concentrate magnetite and other minerals, to clean coal concentrate and to recycle ferrosilicon for dense separation processes (Brophy, 1985).Magnetic separators can be divided into low and high intensity separators and high gradient magnetic separators (Gillet, 2008). Most of the low gradient magnetic separators are built as rotary drums that are operated in wet or dry conditions. Dry magnetic drum separators are used by Rio Tinto Fer et Titane in Sorel-Tracy, Canada to concentrate hemo-ilmenite from the ore extracted at the Lac Tio Lake mine near Havre St-Pierre, Canada. The analysis of production data suggests that process improvement could be achieved by identifying key variables for the control of the magnetic separation circuit and/or by modification to the circuit flowsheet. The use of a process model was considered to be an effective approach to conduct a preliminary analysis of the circuit with a view toward process optimization. However, the literature contains few detailed studies dealing with the modelling of magnetic separation processes."

Jan 1, 2011

By A. L. Hinde, H. Dong, J. T. Kalala

"The High Pressure Grinding Roll (HPGR) is gaining acceptance in the mineral processing industry and has become a competitive technology in reducing the specific energy consumption in Mineral processing plants. The amount of samples required for HPGR amenability testwork and HPGR wear tests is usually high and often cannot be available at early stage of projects were only a few drill cores are available.Although HPGR was initiated from small scale piston die compression tests, the development of small scale piston die test to predict the performance of HPGR has been slow.The objectives of this paper was to present the designs, operating procedure of piston-die press and operating conditions which have resulted in similar particle size distribution obtained from a piston die test and HPGR Labwal unit starting from the same feed size distribution. Testwork were conducted using a 2 MN piston-die press and a Labwal HPGR unit on major South African ore types, viz, gold, platinum and iron ores. The results obtained show that piston-die test can generate data to predict energy consumption, product size distribution, and even to evaluate the edge effect."

Jan 1, 2012

By K. Zenger, J. Kaartinen, J. Huuskonen, S. Torttila, S. Lähteenmäki, J. Pietilä

"Pyhäsalmi Mine in Finland has a long history of continuous process development. The concentrator processes Cu-Zn-sulphide ore with high recoveries. An on-line flotation simulator has been developed to maintain and further improve the flotation performance. Consisting of a flotation kinetic dynamic model, and interconnected with process control software, the simulator can be used for training new control room operators in various scenarios. For daily operation, the model parameters are continuously adapted to take into account the changing process conditions. On-line simulator tracking the process can provide the process operator new information in several ways: a) values of unmeasured process variables are obtained by displaying the corresponding simulator values, b) predictions of future process states and outputs are calculated and displayed, c) information of changing process parameters can be used as an indicator of e.g. change in the processed ore type. This paper describes the adaptive simulation system and its usage at the Pyhäsalmi concentrator.IntroductionPyhäsalmi massive sulphide orebody is located in central Finland. Operation of the mine started in 1962 and it is currently producing copper (Cu), zinc (Zn) and sulphur (S) concentrates. The concentrator control and optimization system has a long history of successful continuous development during the past decades (see e.g. Huuskonen & Moilanen, 2010). An on-stream analyzer has been a part of the automatic process control since 1968 (Lähteenmäki, Miettunen & Saloheimo, 1999). First control algorithms based on a flotation mathematical model were developed in 1971 (Koivistoinen & Miettunen, 1985). In 1990’s the development of a froth machine vision systems started (Kaartinen, 2009; Kaartinen, Roine & Hätönen, 2009). More recently Pyhäsalmi Mine Oy has been involved with several national development projects dealing with particle size distribution measurements (Kaartinen & Tolonen, 2008), spectral analysis of flotation slurries (Haavisto, Kaartinen & Hyötyniemi, 2008), and dynamic simulation of flotation processes. The latter topic is further elaborated in this paper."

Jan 1, 2015

By F. E. Senftle

Introduction The usual laboratory methods of uranium analysis are either tedious, time-consuming chemical procedures or elaborate physical methods requiring sensitive equipment. There is thus an urgent need for a method of estimating the uranium content of ore samples by approximate analysis in the field. When a new property is being developed, it is desirable to know, with the least possible delay, the uranium content of channel samples in order to guide the diamond drilling and digging operations. Prospectors, too, require approximate analyses of their hand specimens to evaluate their discoveries. To satisfy the demand for these types of analyses, several field procedures have been tried. Two general plans can be followed. One is fast but will yield only a rough estimate. The other is slightly longer but, if done carefully, will give an assay probably within 10 per cent of the true value. For field operation it is necessary to strip the more accurate laboratory methods of analysis of all refinements because of the limited equipment and skilled techniques at hand. Most of the corrections normally applied, with the exception of that for equilibrium, will not alter the gross analysis to any appreciable extent. When uranium atoms in pitchblende disintegrate, they break down into other radioactive elements, and eventually the number of elements being formed is equal to the number breaking down. The ore is then said to be in equilibrium. Certain geological processes, however, such as leaching, may selectively remove some of these elements and hence reduce the radioactivity of the ore sample. The ore is then said to be out of equilibrium. The field analysis may then be in error by as much as 50 per cent since the apparatus is calibrated with standards that are in equilibrium. However, such a large error due to loss of equilibrium is the exception, and in most cases uncorrected field types of analyr.is are justified.

Jan 1, 1949