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By Mehmet Guney

This article is based on a detailed heat investigation conducted at the Rokana Division of Nchanga Consolidated Copper Mines Limited while both authors were employed in Zambia. Mindola Mine is one of the three underground mines comprising the Rokana Division on the Copperbelt of Zambia, producing about 270,000 tons of ore per month at 1.9% Cu and 0.14% Co. The total volume of air being circulated by means of five primary fan installations slightly exceeds 1,000 m3/sec at standard density. Sectional bulk cooling is practised where air cooling coils are installed at primary splits some considerable distance from the stoping operations. Total capacity of the refrigeration complex is 10,500 kw (3,500 R. tons), of which about 7,000 kw is available as effective cooling power after losses, but the heat removed from the coifs is about 3,500 kw with 61% over-all plant performance. An extension program is planned for a further five production levels with the re-deepening of a sub-vertical shaft. Thermal heat will become a major problem at increased depth associated with higher rock temperature, higher thermal conductivity of the rock groups encountered and fissure water flowing into working areas through the strata with increased rock temperature. This paper describes the ventilation and refrigeration practices in Mindola Mine, with special reference to future thermal heat problems. These are discussed with a view to mining at depth.

Jan 1, 1979

By A. I. A. Salama

The CANMET Western Research Centre (CWRC) has developed a hydrocyclone model simulation of dewatering and fine particle separation circuits. The simulation is based on an existing empirical model. Utilizing a cyclone manufacturer’s published data, some modifications have been developed and integrated into the model. Feed stream characteristics, cyclone mechanical dimensions, and operating conditions are used in the CWRC modelling simulation. The computer results are presented in 3D graphs and corresponding 2D maps showing the cyclone mass recovery, percent solids by mass in underflow and overflow, and cut size as functions of the cyclone apex diameter and cyclone throughput (i.e., inlet pressure or pressure drop). Results of the computer simulation have been used in the economic feasibility and design of several dewatering circuits in oil sand plants.

Jan 1, 2003

By N. Erarslan, M. Serati

"This paper attempts to provide a simple analytical solution for the calculation of the stress tensor induced in a two-dimensional elastic ring of a brittle material subjected to general loading on either its internal or external curved surfaces. Airy stress functions and Michell’s expression in polar coordinates are used, and parametric studies are performed to investigate the influence of loading angle and the geometrical aspect ratio of the ring on the maximum induced tensile stress. INTRODUCTIONA proper and accurate estimation of the tensile strength of a given material is a crucial step in many engineering projects; in particular in rock cutting, since rocks are much weaker in tension than in compression or shear. Both direct and indirect laboratory techniques such as the direct uniaxial pulling test, the Brazilian indirect tensile test (also known as the split cylinder test), and the ring test have been proposed and developed to estimate rock tensile strength. Among these, the ring test, initially suggested by Ripperger and Davids (1946), has become particularly appealing for its ease of sample preparation and its unique breakage mechanism in almost a pure tensile mode. Unlike the Brazilian test in which high shear stresses developed in the vicinity of the contact could interfere with the tensile breakage of the disc specimen, a tensile failure starts away from the loading platens in a ring test (Hobbs, 1964)."

Jan 1, 2015

By K. Sugawaral, W. Tongampl, K. Hiruta, Takasaki Y., A. Hosoi, T. Katol, A. Shibayamal

Printed circuit boards of discarded personal computers, televisions, mobile phones and so on contain a significant amount of valuable metals. For the recycle of valuable metals contained in the printed circuit board wastes (P CB W), the effect of temperature on chlorination-volatilization of metals under chlorine gas flow was studied. The experimental sample used was powder of two types: crushed PCBW (Sample 1) made from PC and industrial machines, and crushed-combusted PCBW (Sample 2) made from Sample 1. The principal element in Sample 1 and Sample 2 was copper, about 13 wt% and 20 wt% respectively. Sample 1 was composed of pure metals such as copper, tin and lead. In comparison, Sample 2 consisted of oxide metals such as copper oxide, tin dioxide and silicon dioxide. The two samples were heated at predefined temperatures (ranging from 300 °C to 900 °C) in chlorine gas. The chlorine gas flow into the furnace was set at a rate of 100 mL/min. As a result, copper in Sample 1 began to volatilize at 600 °C and completely vaporized at 700 °C. While in Sample 2, copper started to volatilize at 600 °C and reached 100% vaporization at 800 °C. For Sample 1, zinc finished volatilizing at 500 °C, while for Sample 2, zinc volatilization reached only about 80% (maximum). Also, lead, nickel and titanium showed similar results. Consequently the volatilization rate of Sample 1 is higher than Sample 2 and the temperature dependency was verified for copper, lead, zinc, nickel, antimony, titanium and chromium. In fact, the volatilization rate of these metals increased with the temperature. This result reflects the difference between pure metal and metal oxide, as Sample 2 was combusted before the chlorination-volatilization test. Moreover, the chlorination reaction may be accelerated by a reductive atmosphere because Sample 1 contains carbon. In this study, the volatilization behavior of some valuable metals in PCBW by chlorine gas was observed. Further improvement in the rate of volatilization can be achieved by optimizing the experimental conditions.

Jan 1, 2011

By W. H. MacLean

The Matagami district lies directly west of Chibougamau on the north side of the Abi tibi greens tone belt. Ores at Matagami are volcanogenic massive sulphides and occur in the dominantly rhyolitic Watson Lake group surrounding the Bell River Igneous Complex. Rhyolites and basalts of this group, and basalts of the overlying Wabassee group in the central part of the district, are tholeiitic; calc-alkaline Wabassee rocks occur in the western part. Massive sulphides occur associated with rhyolite domes that can be delineated by paleotopographic and isopach mapping. They are mainly distal deposits that formed over an extended period of time while several volcanic units were being deposited,

Jan 1, 1984

By R. S. James, S. P. Goff, A. E. Armitage

"Oxide-facies banded iron formation in the Third Portage Lake area is hosted by ultramafic and calc-alkaline volcanic rocks and related sedimentary rocks of the Archean (2.8 Ga) Woodburn Lake Group, 80 km north of Baker Lake. These rocks record at least two phases of metamorphism/ metasomatism. Greenschist facies metamorphism, in the temperature range of 370°C to 520°C and at pressures above 2.3 kbar, has affected all rocks on a regional scale. Later mineralization and alteration of banded iron formation (BIF) and associated volcanic rocks resulted from metasomatic fluids which carried Mg, K, Ca, S, As, Cu and Au. These fluids were confined to ductile to brittle, cross-cutting and layer-parallel micro-shears developed in the thickened hinge region of a shallow plunging recumbent fold. Metasomatic reactions yielded cummingtonite + biotite-bearing assemblages which are associated with strongly mineralized iron formation. Pyrrhotite is the dominant sulfide phase and occurs within ductily deformed iron formation where it pervasively replaces magnetite. Minor fine-grained chalcopyrite and arsenopyrite generally occur as inclusions within pyrrhotite and recrystallized magnetite, and rarely as individual grains. Pyrite is restricted to brittlely deformed iron formation, and to the contact between iron formation and altered ultramafic rocks, where it is associated with quartz veins. Pyrite typically replaces pyrrhotite. Native gold is associated with both pyrrhotite and pyrite, but higher gold concentrations are associated with pyrite. Grunerite/Ca-amphibole + stilpnomelane and sparse pyrrhotite and pyrite characterize weakly mineralized iron formation. Within adjacent ultramafic rocks, metasomatic reactions yielded assemblages of interlayered Ca-amphibole + biotite, and talc + Ca-amphibole + carbonate + biotite. K-Ar geochronology on metasomatic biotite from mineralized BIF yielded a 1791 ± 32 Ma age.An epigenetic model is favored for the emplacement of gold. The age of the gold mineralization in the Third Portage Lake area is uncertain, but may be Proterozoic based on the preliminary isotopic age and by analogy with Proterozoic gold deposits elsewhere in this part of the Churchill Structural Province. Copyright"

Jan 1, 1996

By S. D. Normani

A Deep Geologic Repository (DGR) for Low and Intermediate Level radioactive waste has been proposed by Ontario Power Generation for the Bruce Nuclear site in Ontario, Canada. The DGR is to be constructed at a depth of about 680m below ground surface within the argillaceous Ordovician limestone of the Cobourg Formation. The objective of this paper is to apply paleoclimate boundary conditions to a regional-scale groundwater flow model for the DGR site and to describe the influence of glacial loading and unloading on flow system evolution using the FRAC3DVS-OPG flow and transport model. The regional-scale domain encompasses an area of 18,775km2 extending from Lake Huron to Georgian Bay in southwestern Ontario, Canada. From a hydrogeologic perspective, the domain can be subdivided into a shallow zone, an intermediate zone, and a deep zone comprised of the low-permeability units of Ordovician and the more permeable Cambrian where present. The deep groundwater zone is characterized by units containing stagnant water having high concentrations of total dissolved solids (TDS) that can exceed 300g=L. The high TDS values at depth require density-dependent coupled flow and transport calculations within FRAC3DVS-OPG. The computational sequence involves the calculation of steady-state density independent flow that is used as the initial condition for the determination of pseudo-equilibrium for a density-dependent flow system that has an initial TDS distribution. The 1,000,000 year pseudo-equilibrium heads and brine concentrations are used as the initial condition for the paleoclimate simulations. Over the past 900,000 years, the Canadian Shield has experienced approximately nine episodes of complete glaciation. During the glaciation cycles, the entire Canadian land mass has been covered by a series of continental ice-sheets whose maximum thickness reached 4 km and whose southern extents reached, in some cases, beyond the present-day Canada-U.S. border. The glaciation phase of a single glaciation-deglaciation episode is typically 90,000 years in duration, while the deglaciation portion proceeds relatively rapidly and has an average duration of approximately 10,000 years. Output from the University of Toronto Glacial Systems Model, a continental scale North American glacial reconstruction of the most recent 120,000 year glaciation event developed by W. R. Peltier, is used to supply the paleoclimate boundary conditions used in this paper. Permeabilty reductions due to the presence of permafrost are also considered in the paleoclimate simulations. This paper will demonstrate that the choice of rock properties can significantly affect residual pore water pressures within the rock matrix, as well as the migration of glacial meltwater.

May 1, 2009

By A. Singh

"The flotation of fine minerals less than 10 µm in size is an age old challenge spanning both the precious metal and industrial mineral sectors across a range of commodities. This problem has been brought into sharper focus by the emergence of the practice of fine grinding of flotation feed to effect better liberation of the targeted minerals. However, the ability of conventional flotation cells to effectively float the liberated fines remains questionable. In order to overcome this problem, Gold Ore postulates the “Bringing the Mountain to Mohamed” hypothesis which comprises the steps of gas nucleation on particle surfaces, aggregation of particles and levitation of aggregates. Testing of this hypothesis at Mintek, South Africa, showed a ~180% increase in the Kelsall kfast factor coupled with a projected recovery improvement of ~4 % for the Mach Reactor case coupled with a final concentrate grade of ~2 times that of conventional flotation. These fundamentals were then extrapolated to plant scale with Mach Reactors installed on the flotation feed at Platmin’s Tailings Scavenger Plant (TSP) with the objective of scavenging the fine minerals lost to tailings by the main plant. This paper details the theory, pilot plant results as well as key aspects of the full scale plant design supplemented by operational plant observations after commissioning. This game changing application is regarded as being pivotal to future flotation plant design whilst providing the technology leverage required for the survival of mineral operations in an economically unfriendly environment.INTRODUCTION - THE CONUNDRUM OF FINE PARTICLE FLOTATION“If the mountain won't come to Mohamed then Mohamed must go to the mountain” is an age old saying written into the book of proverbs in 1670. Legend has it that Mohamed promised his people that he would summon a mountain to come over to him so that he could offer up his prayers from its summit. After numerous attempts at moving the mountain went in vain, Mohamed, quite unabashed, said “Well if the mountain will not come to Mohamed, then Mohamed will go to the Mountain.” In this analogy, Mohamed is a fine particle <10 µm and the mountain is a bubble within a flotation system. The age old challenge is how to bring these two together to achieve attachment?"

Jan 1, 2016

By Jonathan Tsang, Ali Merati, Jonathan Beddoes

Due to economic factors, many aircraft in service today have been operating for more than 30 years even though they were initially designed with a service life of 20 years. Improved damage management models are therefore needed for use in life prediction and management of the aging fleets of aircraft. Currently, the generally accepted procedure in fatigue life prediction methodologies is to back calculate the equivalent initial flaw size (EIFS) using established long crack growth data. However, it was observed from studies carried out at the National Research Council Canada that nucleation and short crack growth constitute up to -95% of the fatigue life. As a result, it seems that the significance of the short crack regime has been underestimated and must be further investigated and fully understood before an accurate holistic life prediction methodology can be realized. Unlike long cracks, local microstructural features such as grain boundary, grain size, inter-particle spacing, and texture play dominant roles in the behavior of short cracks. An extensive study has been carried out to evaluate different crack detection and monitoring techniques in the short crack regime for AA2024-T3. The results will be presented in detail.

Jan 1, 2004

By B. C. Legg, G. L. Tiley

"Many of the ore bodies presently being developed are in remote locations and are, or will be, served by electrical power supply systems of limited capacity.The largest single components of the electrical systems of an underground mine are usually the production hoist drives; the power demands of these drives vary continuously throughout each hoisting cycle.Before 1970mine hoists were driven by either wound rotor induction motors or DC motors in conjunction with motor generator sets.Static Power conversion equipment now costs less to purchase and install and is claimed to be more efficient than motor generator sets. On the debit side, however, it can adversely affect the hoist motors, it operates at relatively low power factors, and it produces harmonic currents.This pa per discusses the effects of static equipment on both DC motors and AC power systems, and evaluates the relative consumption of the three classes of drives."

Jan 1, 1993

By C. C. Li

The D bolt is a new type of energy-absorbing rock support element recently developed in Nor-way. The D bolt is not only able to accommodate large rock deformations, but can also provide a load-bearing capacity as high as that of rebar bolts. Furthermore, the anchoring quality of the D bolt is similar to rebar bolts because of its multi-point anchoring design.

May 1, 2009

By H. Matsuoka, M. Kawata, K. Mitsuhashi, C. Tokoro, T. Kato

Copper sulfide minerals such as chalcocite, bornite, and chalcopyrite exhibit high floatability, thus they can be recovered as a froth product by adding only a collector in flotation process. However, when their surface is oxidized, the floatability decreases and the simple addition of collectors is no longer effective. In this case, flotation activators are required to improve the floatability. Sodium hydrosulfide (NaHS) acts as an activator for chalcocite and bornite by re-sulfurizing their oxidized surface portions. Nevertheless, the flotation conditions still require optimization in order to achieve a satisfactory recovery of copper minerals. This work addresses the study of the effect of pH and NaHS dosage on the flotation of a complex Chilean copper ore containing chalcocite, bornite, and chalcopyrite. Flotation experiments were conducted using a Denver-type flotation cell and by investigating the effect of two NaHS dosages (50, 100 g/t) and three pH values (8, 9, 10). Following this process, the surface interaction between the minerals and NaHS were analyzed using zeta potential measurements. INTRODUCTION In recent years in the mining area of metal resources, the complexity of ores and the fineness of grind required to liberate minerals have become serious problems. When ores are complex, several valuable minerals may interact with each other and reactions may become more complicated compared with an ore containing only one valuable mineral. Therefore, more processing steps may be required than for a simple ore. When the valuable minerals exist as fine grains, it is difficult to liberate them and more grinding time is required. Furthermore, the probability of collision of fine particles with bubbles in the flotation process declines and it takes much time to recover them. Flotation is one of the most applied methods to separate valuable minerals from unwanted ones using the difference of hydrophobicity (or hydrophilicity). In the flotation method, the air is fed to a cell filled with the pulp of the mineral of interest and agitation is implemented to introduce air and generate bubbles. The hydrophobic particles attach themselves to the bubbles and float along with the bubbles while the hydrophilic particles remain in the pulp. Copper sulfide minerals such as chalcocite (Cu2S), bornite (Cu5FeS4), chalcopyrite (CuFeS2) are widely known abundant copper resources. Generally, flotation is used to recover and concentrate these minerals. Copper sulfide minerals usually have high floatability. However when their surfaces are oxidized, their floatability becomes lower. When the sulfide surfaces are oxidized, activators are added before flotation to modify the surface property of the Copper sulfide minerals so that they can be floated. Sodium hydrosulfide, NaHS, is known as one of the activators. Zhao (2018) reported that NaHS is often used as a sulfurizer for oxidized sulfide minerals (Becker (2014), Clark (2000), Newell (2006), and Newell (2007)). In earlier work, the authors performed flotation tests on a sample of Chilean copper ore which contained chalcocite, bornite, and chalcopyrite using a Denver-type flotation apparatus. The sample was ground to P80 70 µm with a rod mill and ball mill. In these tests, the following conditions were used: natural pH (about pH 8.5), flotation time of 45 min, 60 g/t AP3477 (sodium diisobutyl dithiophosphate) as collector, and MIBC (methyl isobutyl carbinol) at appropriate dosage as frother. NaHS was applied at the dosage of 0, 67, and 120 g/t, respectively at the conditioning. The concentrates were collected at 6, 18, 30, and 45 min. The weights of the concentrates and tailing were measured and they were assayed for copper by ICP-AES (Optima 5300 DV, PerkinElmer Inc.). The flotation recoveries of the copper minerals were calculated from the results of MLA (mineral liberation analyser) (MLA 650, FEI) measurements.

Jan 1, 2019

By J. C. Glandus, N. Tessier-Doyen, M. Huger

The Young&apos;s modulus of bi-phased model materials (vitreous matrix containing spherical alumina inclusions) have been determined by two complementary approaches: experimental and analytical. If the matrix and inclusions exhibit close coefficients of thermal expansion, the experimental results lie in the vicinity of the lower bound of the Hashin & Shtrikman&apos;s model. If there is a dilatometric disagreement between the components, untypical behaviors, similar to those obtained for a family of industrial refractory materials, were observed when the temperature varies.

Jan 1, 2004

By Jennifer Pell

Dunsmuir Ventures? Nanuq diamond project is located approximately 250 km northeast of Baker Lake and 170 km north of Chesterfield Inlet. It occurs at the intersection of the Wager Bay shear zone with the Keewatin Arch, a major long-lived crustal uplift. The newly discovered diamondiferous kimberlites at Rankin Inlet, Repulse Bay and on Melville Peninsula also occur along this arch. Kimberlite indicator mineral (KIM) sampling has outlined a distinct KIM train more than 35 km long and 6 km wide. Geomorphological studies, boulder displacements and dispersion of magnetite in tills suggest that glacial transport distances were on the order of 4 to 6 kms only. The presence of multiple sources within the main Nanuq indicator train would account for its length and breadth. A second train has been located on the west central part of the property and anomalous concentrations of KIM occur elsewhere. Pyrope garnets (G9?s and G10?s), diamond inclusion field (DI) eclogitic garnets and DI chromites were confirmed by microprobe analyses. Clinopyroxene thermobarometry indicates a cool geotherm, approximately 35 mW/m2, and that mantle within the diamond stability field was tapped. An aeromagnetic survey has identified a number of anomalies. Those with down ice KIM support will have ground geophysical follow-up and will be tested in a spring 2004 drill program. Dunsmuir is optimistic that this will lead to the discovery of a new kimberlite cluster on the Nanuq property.

May 1, 2004

By Earl T. Hayes

This paper briefly reviews the laws enacted in the United States governing the coal miner. It discusses amendments to the Coal Mine Safety Act and describes the provisions of the Metal and Non-Metallic Mine Safety Act.

Jan 1, 1969

By C. Poon

For slope stability, knowledge of major and minor discontinuity sets that form the rock mass fabric is paramount for pit slope designs. Due to the increased awareness of health and safety in mining projects, efforts have been made to limit structural mapping in order to minimize the risk to personnel associated with approaching potentially unstable areas. Recognizing the importance of such safety precautions, Golder Associates Ltd. is applying a combination of techniques including 3D photogrammetry, conventional mapping and drilling with core orientation to enhance structural data collection. Photogrammetry uses digital photographs to produce a virtual model of a rock mass surface. The application of these techniques will be exemplified through an expansion design of an existing open pit. A comparison of stereonets obtained using these techniques showed some agreements, but also highlighted limitations of each method. The application of photogrammetry was found to be very useful in complementing the other existing techniques.

May 1, 2009

By Adrian Daniel

"Dating back to 1934, Con Mine is located directly south to the city of Yellowknife in the NWT, Canada. With mill operations ceasing in 2004, a challenging surface remediation situation resulted which required the treatment of close to 40,000 m3 of Arsenic impacted material.Through much of the period of 1941 to 1970, Con Mine treated their refractory arsenopyrite ore through the use of an Edwards Heath roaster. With mounting environmental pressure and through Canadian governmental studies during 1950 to 1970, attention was directed to the Arsenic Trioxide material being collected by two Doyle scrubbers on the Con’s roaster stack. In 1970, the roaster was decommissioned leaving the resulting Arsenic material in two containment areas on surface.As a result of Con Mine entering into remediation in 2004, the Con’s autoclave, commissioned in 1992, was dedicated to the immobilization of high impacted Arsenic material through the combination of excess Iron under high temperature and oxygen overpressure. Examined, herein, is the history and chemistry of the Con Mine autoclave as well as the two stages of chemistry for the Water Treatment Plant used to remove arsenic, heavy metals and WAD cyanide from tailings water. Simplified capping plans of the tailing containment areas and a high arsenic impacted area are also presented.INTRODUCTION TO CON MINECon Mine (Con) is situated just south of the City of Yellowknife in the North West Territories (NWT) Canada and is bounded locally by Yellowknife Bay (North Extension of Great Slave Lake) to the east and Kam Lake to the west (Figure 6). The discovery of gold at Con was made in 1934 and mineral rights were acquired by Consolidated Mining and Smelting Limited (Cominco) and Falconbridge soon thereafter. Nerco Minerals Limited (Nerco) took control in 1986 and in 1993, was subsequently sold to, Miramar Mining Corporation which in turn was purchased by friendly takeover involving Newmont Mining in November 2007 as a result of acquiring the Miramar’s Hope Bay project. Con’s underground operations ceased in September 2003 and have since entered into the remediation of the site. The current surface lease holdings are about 340 Hectares (Table 1) which sits on top of the Archean-aged Yellowknife Greenstone Belt."

Jan 1, 2009

By P. F. Berry

X-ray fluorescence analytical techniques are fairly well established in the mining and metallurgical industries. In recent years, instruments utilizing radioactive isotopes have been developed which, owing to their more compact size, greater reliability and independence of substantial power supplies, are often preferred to X-ray tube installations. Analyses can now readily be carried out in the field, on the factory floor and in otherwise difficult locations. This paper describes many examples of radioisotope X-ray fluorescence for the analysis of metallic minerals, finished metals and alloys and also for the continuous measurement of metallic coatings, such as tin and zinc, on steel. Radiation scatter techniques are also described for certain analyses and for thickness and density measurements.

Jan 1, 1967

By Boyd Davis, Vladimiros Papangelakis, Douglass Duffy, Michael Carlos

"The processing of lateritic saprolite in hyper-concentrated magnesium chloride brines offers several potential advantages for the hydrometallurgical production of nickel. An aggressive HCl-MgCl2 leach at atmospheric pressure can significantly reduce magnesium dissolution, and offers the ability to recover HCl and MgO by a less energy intensive process than conventional techniques via the formation of magnesium hydroxychlorides. Inevitably, the high chloride concentration renders iron fully soluble during leaching and thus requires subsequent iron control and disposal steps. Experimental measurements coupled with OLITM modeling were conducted to investigate the behaviour of iron in concentrated magnesium chloride brines, in terms of chemistry (nature of iron species) and solubility limits. The solubility of ferric chloride in magnesium chloride solutions of concentrations and temperatures relevant to this process was controlled by a previously unreported solid phase: 2.5FeCl3·MgCl2·7.5H2O. Iron precipitation tests on synthetic leach solutions without seeding indicate a metastable akaganeite precipitate which transitions to hematite upon equilibration. Magnesium chloride solubility in ferric chloride solutions was also investigated to allow the simulation of a ternary phase diagram for the MgCl2-FeCl3-H2O system, in order to determine process conditions that avoid unwanted chloride precipitation.INTRODUCTION In the search for more economical processes to treat lateritic saprolite for nickel production, chloride hydrometallurgy has been increasingly investigated. While High Pressure Acid Leaching (HPAL) can frequently economically treat lateritic limonite, the presence of saprolite negatively affects process economics. The higher magnesium content of saprolite increases acid consumption, because magnesium sulphate, unlike iron and aluminum sulphates, does not hydrolyze in HPAL. This soluble magnesium decreases the sulphuric acid strength by an amount greater than the amount of acid stoichiometrically required to leach magnesium, which must also be disposed of or recovered (Jankovic, Papangelakis, & Lvov, 2009). Due to these issues, pyrometallurgy is most commonly employed to treat lateritic saprolite, via the Rotary Kiln-Electric Furnace (RKEF) process; this process uses a rotary kiln to dry and partially reduce nickel and iron oxides before sending the calcine to an electric furnace for smelting to produce a ferronickel product for the stainless steel market. Although the problems encountered during hydrometallurgical processing are avoided and nickel recoveries are high, high capital and energy costs prevent the application of this process to lower grade lateritic saprolite deposits (De Bakker, 2011)."

Jan 1, 2016

By Alan B. Morrow, William A. Poe

"Minerals processing operations are constantly challenged with improving production rates, yields, energy efficiency and process stability. Advanced Process Control has proven to be an effective tool for improving operations by capturing the full process capabilities consistently. However, the velocity of applying the technology as well as the sustainment of these significant benefits has been hampered by the usability of the software and adaptability of the applications.Some of the new technology developments that improve the usability and adaptability of advanced process control include:• modern and intuitive user interfaces,• customizable models to support unique process behavior,• fast and flexible OPC connection tools,• automated model building,• integration with first principles dynamic models and• improved performance monitoring.This paper will briefly discuss the new technology developments that have improved the usability and adaptability of advanced process control and how this can affect minerals processing operations.In today’s environment, Minerals Processing plant managers continuously face new challenges and requirements including:• higher energy efficiency,• increased run lengths,• reduced product quality variability,• reduced emissions,• higher availability, and• lower operating costsOperating a unit to meet these challenges in real time is not easy for operators and conventional process control systems. However, innovatively using existing technologies in Minerals Processing plants can improve operations on a minute by minute basis and reap significant benefits.Advanced Process Control (APC) can extract the maximum performance benefits from existing equipment while respecting plant operating constraints. Expensive capital projects to upgrade equipment are not always necessary. Advanced Process Control can deliver significant economic benefits by maintaining the plant at its most profitable point as conditions change."

Jan 1, 2016