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By J. E. Danoczi

Shore Gold Inc. (Shore) is presently designing a diamond processing plant for the Star and the Orion South kimberlite deposits in the Fort à la Corne (FalC) area in central Saskatchewan. The first step in the plant is diamond liberation and occurs in the comminution section. Diamond liberation is the process of breaking up the kimberlite rock, as gently as possible so as not to damage the diamonds. Autogenous grinding mills (AG mills) use a combination of impact crushing, abrasion and attrition to break up the kimberlite. The forces that occur during the actions of abrasion and attrition cause the kimberlites to break up preferentially along lines of weaknesses which offers a ?diamond friendly? method of comminution. Hard competent kimberlite is commonly found in the diatreme zone as well as the root zone of the volcanic pipe and is the source of kimberlite for most of the Southern African diamond mines. Softer kimberlite is typically found in and around the crater area of a volcanic pipe and it is this kimberlite that makes up the majority of kimberlite for both the Star and Orion South deposits. These softer kimberlites can be readily broken up using abrasion and attrition imparted by AG mills. In order for Shore to benefit from the softer kimberlite found in the Star - Orion South diamond project, two large (10.97 m diameter x 7.10 m long) AG mills were designed for the comminution section based on extensive test work and simulations by Metso Minerals (Metso).

Jan 1, 2012

By I. Clauzier

"A new method of managing electricity to reduce costs andimprove profits is discussed. Before taking steps to better manage electricity, it is essential to understand the terms peak demand and energy and their effect on an electrical bill. Knowing how electricity is presently used in the plant is the important first step. This goes beyond knowing how much electricity is used at each time of day, the individual contribution of every plant process to the total plant load must be known. At this point, each process is ranked according to importance to production in order to identify possible savings opportunities. These improvements can then be implemented by simply improving operations or in some cases, through the use of an automatic control system. IntroductionIn today's competitive environment, controlling costs is becoming increasingly important. All costs associated with operation must be controlled in an effort to improve competitive position. Electricity is a cost component that can and should be managed.Although the term management can mean different things to different people, the intent is always the same: to make the best possible use of existing resources, whether labour, equipment or electricity.The simple approach to managing electricity presented in this paper consists of four steps.I. Understand Peak Demand and Energy. It is essential to understand the terms, peak demand and energy and their effect on your electrical bill.2. Know Your Present Electrical Use. The present use of electricity in the plant must be known. This goes beyond simply knowing how much is used at each time of day, to accurately knowing how each process is contributing to the total plant electrical load, and ultimately to the electrical bill.3. Identification of Savings Opportunities. With this information, energy savings opportunities for reducing the electrical bill and improving profits can be identified.4. Implementing Improvements. Having identified areas of potential savings, improvements can then be implemented in order of their significance. This could be a matter of simply improving operations, or in some eases may mean the use of an automatic control system.These four steps can result in significant dollar savings."

Jan 1, 1987

By K. Esmaieli

This paper addresses issues associated with ore pass degradation caused by material impact. A series of numerical experiments, using the particle flow code, were undertaken to investigate the influence of various finger raise configuration. This has allowed the identification of favorable configurations. The results of this analysis, when coupled with field observations, can contribute to the design of ore pass systems that can prolong the useful operating life of ore pass systems.

May 1, 2009

By A. Idegami, M. Imamura, S. Heguri, Y. Ozaki

"Nickel powder can be produced by the reduction of a nickel ammine complex solution by hydrogen at high temperature and pressure. To minimize the deposition of fine nickel on the surface of the reactor and other equipment, seed crystals are added to the initial solution to promote nucleation of the nickel powder. Such seed crystals catalyze the precipitation of the nickel particles on the surface of the seed and enhance grain growth. In this study, nickel nuclei were precipitated by the addition of a polymer to the nickel ammine complex solution, resulting in the production of nickel powder. Thus, we herein propose a model that explains the effect of the polymer in the precipitation of nickel nuclei.INTRODUCTIONNickel powder is commonly produced via a hydrometallurgical process from the hydrogen reduction of a solution containing a nickel ammine complex at high temperatures and pressures, and this process was commercialized in the 1950s by Sherritt Gordon (Sherritt International, Canada, Benson & Colvin,1973; The Staff, Research and Development Division, Sherritt Gordon Mines, Ltd., 1958).In the above transformation, upon the injection of hydrogen gas into the solution, nickel is reduced as outlined in Equation(1), ultimately resulting in the production of nickel powder.Ni(NH3)nSO4+ H2?Ni+ (NH4)2SO4+ (n-2)NH3(n:2–6)(1)In this process, seed crystals are added to the reactor to suppress the precipitation of fine nickel (scaling) and to enhance nickel reduction (Benson & Colvin, 1973; Mackiw, Lin & Kunda, 1957). More specifically, iron sulfate and a small amount of dispersant polymer are added, which leads to the formation of nuclei. Upon subsequent hydrogen reduction, the reduced nickel can then be deposited on the nuclei, allowing nickel particle growth to take place. However, this results in iron contamination in the final nickel product, and so the use of pure nickel as a seed crystal is desirable to produce high quality nickel powders."

Jan 1, 2017

By K. Fagerlund, L. Rosenback, T. Mäkinen, Y. Anjala

This paper deals with the nickel smelter and refinery concepts Outokumpu has applied at Harjavalta and several other plants. Also other process routes and modifications developed and tested by Outokumpu during the recent years are highlighted. Outokumpu started nickel production in Harjavalta in 1959. Until 1995 the Flash Smelting - Peirce-Smith (PS) converting route was applied. High grade nickel matte from the converting step was further refined by means of leaching and electrowinning to produce cathode nickel. In 1995 the nickel production capacity was increased from 17 000 t/a to 52 000 t/a based on the Direct Outokumpu Nickel Smelting Process (DON). In the DON process PS converting is eliminated and high grade nickel matte with low Fe-content is directly produced in the flash smelting furnace (FSF). Metal values from the smelting slag are recovered in the electric furnace (EF) as iron containing Ni-matte. The DON process can be operated with either two matte concept, where high grade FSF matte and EF matte are produced, or a single matte concept, where EF matte is recycled to the smelting furnace and thus only one type of high grade matte is obtained. The additional refinery capacity at Harjavalta is based on hydrogen reduction producing.

Jan 1, 2005

By Alessandro Navarra, Roberto Parra, Boyd Davis, Frank Mucciardi

A smelter scheduling algorithm has been developed, which allocates the oxygen production between the smelting furnace and the converter aisle, so as to maximize copper throughput. The algorithm is intended for daily operation planning, controlling the sequencing of the converter cycles, and the oxygen drawn by these cycles. In some cases, it may be worthwhile to decrease converter oxygen allocation in favour of the smelting furnaces. Thus, a better utilization of the oxygen plant can increase primary copper throughput by several percentage points. This principle is demonstrated through sample computations. The approach presented in this paper can be incorporated into smelter management software.

Jan 1, 2015

By H. J. Oterdoom

SMS Group (SMSG) has always been concerned about safety aspects of electric smelter plants for the ferro-alloy and non-ferrous industry. The awareness for safety increased significantly over the past decades and also SMSG contributed with its design features to a safer operation. Today, safety aspects are not only part of the smelter design but also of the overall plant layout. Explosions in electric smelters are rare, but have a huge impact on peoples’ lives, on equipment and on production. For this reason, SMSG wanted to have a better overview of explosions within the smelting industry in order to see if useful statistics could be extracted. Generally, there is a lack of statistics regarding explosions in the electric smelting industry, and not enough information is collected or published. A significant portion of the explosions seems to be water related. Many companies, both operating and engineering, are trying to handle the risks of water, and apply methods to detect water leakages. Installing such a system is a management decision and management has then to make sure the system is properly implemented. The disadvantages and limitations of these systems should be carefully considered and communicated to operators and authorities.

Jan 1, 2015

By A. Blackmore, D. Baker, L. Human

"Mechanical mixing equipment is common in a wide variety of mining, metals and process applications, such as hydrometallurgical reactors, solvent extraction, digestors, and tanks for storage of slurry or hydrocarbons. Computational Fluid Dynamics (CFD) has been applied successfully to single-phase mechanical mixing problems for several decades and is established as a reliable design tool. As computational power and CFD codes have improved over the years, there have been significant advances in modelling capabilities including improved models of turbulence, interaction of rotating and stationary components, multiphase flows, and modelling of free surface interfaces, for example. This paper will provide an overview of the application of CFD to mechanical mixing problems. First, it will review the traditional single phase Multiple Reference Frame (MRF) approach and introduce a range of advanced modelling techniques. Three examples of the application of CFD to industrial mixing problems will be given. It will be demonstrated that CFD is an effective tool for reducing technical risk in design, for identifying the root-cause of mixing problems, and testing modifications to existing operations."

Jan 1, 2015

By E. J. Burrough

MR. J. J. McIntyre (International Coal & Coke Company, Ltd., and McGi1livray Creek Coal & Coke Company, Ltd., Coleman, Alta): Mr. Burrough's excellent paper, Metallurgical Coals of the Crowsnest Area, seems especially timely now, when the need for developing iron industries in the west, as well as in the east, is receiving so much attention. His -thorough review of the 'coking' industry is an especially valuable contribution, along with which the following brief remarks on coking in the Crowsnest Pass area of British Columbia and Alberta may be in order. When the Crowsnest Pass line of the Canadian Pacific railway was built there were great expectations for the non-ferrous metal industry; quite a number of smelter's were al-ready in operation in British Columbia and the northwestern United States, and further expansion was confidently expected. The suitability of the medium-volatile coking coals of the Pass for making metallurgical coke had been recognized from the time the fields were first explored. By the time the mines were fairly well developed there was already a market to war-rant the building of coking plants, and a common belief that expansion of the market would require a large coking industry. The first coke production was from plants built by the Crowsnest Pass Coal Company, Ltd., at Fernie, B.C. in 1903, and the International Coal and Coke Company, Ltd., at Coleman, Alberta. These plants were followed by others built by the Crowsnest Pass Coal Company, at Michel, B.C., by West Canadian Collieries, Ltd., at Lille, Alberta, and by Leitch Collieries, Ltd., at Passburg Alberta, and by a plant at Hosmer, B.C.

Jan 1, 1951

By A. Takala, H. Cline, D. Girard

"This article describes the project development and successful implementation of a particle sorter at the Kensington mine. The Kensington underground gold mine and associated milling facilities are located within the Berners Bay Mining District on the east side of Lynn Canal about 45 miles north-northwest of Juneau, Alaska. The paper describes the project from concept, through the development phase, including test work confirming feasibility, to a discussion of operational data and includes shared experiences from operation and maintenance. The project has proven successful in recovering gold that was previously lost to the waste dump and has already resulted in a positive return on investment. The payback was achieved in less than one year.INTRODUCTION The first paragraphs of this paper describe Coeur Mining and the Kensington Mine, its history, geology, mining operation and mill. The second part of this paper gives a quick introduction to sensor-based sorting in general and X-ray transmission sorting (XRT) in particular. This article does not cover costs or economic impacts apart from the pay-back period for the investment at Kensington. Interested readers find more in information on this in the literature (Kleine & Wotruba, 2010; Robben, 2013). Since the publication about XRT sorting at TGME in Pilgrim’s Rest (Kleine, Riedel, Ketelhodt, & Murray, 2010), this is the first time that a comprehensive data set on gold ore sorting using XRT is published. Following chapters highlight the aim of the project for Coeur Kensington, project development through testing and operation before concluding. ABOUT COEUR MINING’S KENSINGTON OPERATION Coeur Mining is the largest U.S.-based silver producer and a significant gold producer with five precious metals mines in the Americas employing approximately 2,100 people. Coeur produces from its wholly owned operations: the Palmarejo silver-gold mine in Mexico, the San Bartolomé silver mine in Bolivia, the Rochester silver-gold mine in Nevada, the Kensington gold mine in Alaska, and the Wharf gold mine in South Dakota. The Company also has a non-operating interest in the Endeavor mine in Australia in addition to royalties on the Cerro Bayo mine in Chile, the El Gallo complex in Mexico, the Zaruma mine in Ecuador, and the Correnso mine in New Zealand. In addition, the Company has two silver-gold feasibility stage projects—the La Preciosa project in Mexico and the Joaquin project in Argentina. The Company also conducts ongoing exploration activities in Alaska, Argentina, Bolivia, Mexico, and Nevada. The Company owns strategic investment positions in several silver and gold development companies with projects in North and South America."

Jan 1, 2017

By B. K. Bhattacharyya, Morley. L. W.

"The primary purpose of conducting aeromagnetic surveys in mineral areas, and interpreting the data thus obtained, is to aid in the extrapolation of the geology from known to unknown areas-both in a horizontal and vertical direction. This paper describes one of the steps in the process of interpretation which has, in the past, been neglected-that of mathematically or quantitatively treating the data in two-dimensional map form. For this, several techniques are available.These techniques determine the downward and up-ward continuation fields, the second vertical derivatives and the fields reduced to the pole from the total magnetic field data. Second vertical derivatives and downward continuation fields increase the resolution and sharpness in the observed magnetic anomalies and tend to outline the surface traces of causative bodies with a reasonable amount of success in most cases. The 'reduction to the pole' is a mathematical process of calculating the field at the north pole from the observed field so that the un-desirable effects of the dip and declination of the earth's field and of rock magnetization are eliminated.New and accurate means of carrying out these calculations have been developed by the Geological Survey of Canada. In this paper are also presented the results of a method for obtaining the symbol and numerical map of the processed data with the help of the printer associated with the computer. The tedious work of digitizing magnetic field values in a map can be speeded up by the use of a semi-automatic coordinatograph, with the aid of which field values can be accurately transferred to punched cards."

Jan 1, 1966

ABSTRACT The SART (sulphidization, acidification, recycle, and thickening) process is an effective way to separate copper and cyanide in the waste stream of gold processing plants using cyanidation. Factorial experimentation has been conducted to create models of copper recovery, cyanide recovery, acid addition, and oxidation/reduction potential during SART. Economic analysis of the resultant models showed that SART is best operated with a sulphide-to-copper molar ratio of approximately 0.56, pH of 4, and a minimized cyanide-to-copper molar ratio. The experiments also showed th0at residence time can have drastic impacts on SART performance.

Jan 1, 2013

By Kuwauchi. Y., M. Barati

Recycling of dust using a rotary hearth furnace (RHF) has gained considerable attention in the past two decades for the sustainable production of steel with less environmental impact. In order to further promote the recycling of electric arc furnace dust and carbonaceous wastes using the RHF process, a mathematical model was developed to predict the reaction behaviour of dust-reductant composites. The reduction kinetics of zinc and iron oxides as well as the volatilization behaviour of volatile matter in the reluctant were considered. The modeling approach and some preliminary results are presented in this article.

Jan 1, 2011

By W. G. Campbell

"The region discussed comprises approximately eight million acres spreading across the Arctic Circle in Yukon and North West Territories.Encouraged by four years of surface geological and geophysical work, which strongly suggested that suit-able conditions existed for the entrapment of oil and gas, a decision was reached to drill. In due course two holes were drilled; Eagle Plains No. 1 drilled to 9589 in 1957-8 and Western Minerals Chance No. 1 spudded in 1959 is being deepened this year.Thick sections of sedimentary rocks occur on both sides of the Richardson Mountains, however, most of our activities have been concentrated to date on the west side in the Eagle Plains basin. Here are found stratigraphic units ranging from Precambrian to Tertiary age. The drilling of the two exploratory wells proved the presence of these strata at depth and have confirmed the presence of promising structures. A geological cross-section across Eagle Plains presents an interpretation of these conditions.Physical and engineering aspects of exploration in the northern Yukon and North West Territories are de-pendent largely upon seasons and transportation. Reconnaissance gravity and surface geologic mapping by air presents no serious problems. However, seismic operations on the ground are greatly affected by the season, presence of permafrost and mobility of equipment.The actual drilling of the hole may well be the simple part of a wildcat undertaking once equipment and supplies are on location. Over-all planning, assembling supplies, transporting equipment and personnel seems to be the real job. Serious consideration must be given to per-ma-frost effect in the drilling pro-gram and on surface installations as well.Programming for -the various exploration activities should be under-taken well in advance of the actual doing. Considerable extra costs may be the results of crash programs. Costs are high, and the rewards uncertain. Economic evaluation is based •on the long term outlook."

Jan 1, 1960

By J. Lui

At its Copper Cliff Smelter, bulk nickel and copper concentrate is processed in two Inca flash furnaces and Peirce Smith converters to produce Bessemer matte containing 0.6%Fe. After slow cooling and Matte Separation, Bessemer matte is converted into three main products using magnetic separation and flotation technology: (1) a nickel containing chalcocite concentrate (MK); (2) two types of copper containing nickel sulfide (ME and MR); (3) metallics (MYN). MK is further processed in the Inca top blowing bottom stirring MK Reactor to produce semi-blister copper containing ~4%Ni and ~3±1 %S. The semi-blister copper is then purified in the multi-purpose vessels (MPV) to produce blister copper by reducing Ni, Fe and S content through oxidation. High melting point NiO is formed inside the MPVs. The accumulation of solid NiO and other oxides requires periodic cleaning by adding reductant and furnace matte, a unique process called "washout" at Inca. For many years, the reductant used for the "washout" process has been 15%Si Ferro-silicon. With increasing cost and limited suppliers for 15%FeSi, alternative reductants were pursued. This paper summarizes the development and commercialization of new alternative reductants for MPV "washout".

Jan 1, 2007

By J. Paturaud, A. G. Villemiane, J. Y. Buffiere, D. Fabregue, M. Perrier

In this work, a detailed characterization of the cyclic damage mechanisms on duty in car heat exchangers has been carried out in order to improve their reliability. The material which consists in very thin (<0.3 mm thick) sheets formed of 3 co-rolled aluminum alloys (4045 /3916/ 4045) has been brazed in order to obtain metallurgical and surface conditions representative of those of the real components. Fatigue tests at constant stress amplitude have been performed at room temperature and 120°C in order i) to characterize the cyclic resistance of the studied materials and ii) to study the effect of temperature on the fatigue damage mechanism. The mechanisms leading to failure have been identified from post mortem fractographic analysis. The Wohler curves obtained show that, contrary to common structural Al alloys, this type of thin sheet brazed multi material can be cycled for several hundred thousand cycles at very high stress level (> ~ 80 % of the tensile strength). This behaviour is analysed with respect to the microstructure resulting from the brazing process and the low number of grains present in the sample thickness (around 5 grains).

Jan 1, 2015

By Gordon A. Gross

During the last half century major steel industries of the world have become dependent on iron and manganese resources derived from siliceous ironformation sediments. More than two billion years ago vast amounts of iron and manganese were deposited in ironformation sediments on all continents and until recent years their genesis was considered to be a uniquely Precambrian phenomenon. Research work has demonstrated that the origin of the banded ironformations was related to major tectonic features and associated volcanogenic processes that were active throughout geological history. Similar sedimentary-tectonic environments are being explored on the seafloor where metalliferous sediments are forming today. Ironformations are now considered to be a major part of the stratafer group of stratiform metalliferous deposits. They developed in sedimentary basins in areas where deep tectonic fracturing intersected high thermal gradients in the earth?s crust and gave rise to profuse volcanism and the hydrothermal effusive discharge of metals in the vicinity of the volcanic centres. Concepts for the genesis and metamorphism of stratafer deposits as revised in the last half century have had a profound impact in the development of iron ore resources and have had a dramatic impact in the use of metallogenetic concepts for guiding exploration for other mineral resources. They are based on the tectonic history and stratigraphy in the sedimentary basins, the role of hydrothermal volcanogenic processes , as well as environmental and sedimentation factors which influence the deposition of silica, iron , and other metals that were emphasized in the past. Topics of special interest in the genesis of ironformation and stratafer deposits and for guiding mineral exploration are: biomediation in their sedimentation and genesis, the significance of metamorphism in the processing and beneficiation of iron ore and in the genesis of iron ore by natural enrichment processes, syngenetic concentrations of Mn, Ti, Cu. Zn, Pb, Ni, Co, REE, F, Ba, B, As, Hg, W and Au in ironformations and stratafer lithofacies, and the mobilization of gold and other elements by alkaline solutions during diagenesis of ironformation and other stratafer metalliferous sediments.

May 1, 2003

By V. Gangrade

Recirculation is the major concern associated with the utilization of booster fans. In controlled recirculation, a portion of the return air is purposely mixed with the intake air and the mixture is directed towards a working district, while the air quantity and gas concentrations in the air are closely monitored and managed. The objectives of this study were to determine the gas concentration in intake and return airways during controlled recirculation, and to determine the recirculation fraction for multiple headings. Experiments were conducted in a laboratory model to determine the effect of controlled recirculation on the quality of air circulated through the working faces. Preliminary results showed that recirculation is beneficial to ventilation planning because it reduces the build-up of air contaminants at the working faces and reduces the overall power consumptions. The experimental results were used to quantify the recirculation fraction and to calibrate ventilation models of the laboratory model. These models are used to simulate the controlled recirculation and to predict the gas concentrations in multiple headings.

Aug 1, 2013

By John W. Bell

A FEW years ago the writer had the privilege of examining a piece of apparatus in the Forest Products Laboratory of McGill University which engaged his attention. The Forest Products Laboratory has an excellent installation of wood-grinding machinery, and the officials in charge were naturally interested in acquiring means for estimating the fineness of various wood grinds. The problem was referred to Dr. O. Maass ( l ). Dr. Maass designed a piece of equipment to measure the surface of a wood grind and derived an equation applicable in calculating its value, as follows : After inspecting this apparatus, the writer was disposed to believe that, with some modifications, Dr. Maass&apos; ingenious idea might be utilized to measure the surface of mineral powders. Obviously, some difficulty would be found in maintaining an even suspension of mineral particles of high specific gravity compared to that of wood pulp. The writer will not bore the reader with a description of the various machines built and tried out. Some of these were satisfactory enough to obtain some valuable information, and to bring to light a difficulty which threatened to bring the investigation to an abrupt ending. For the mineral quartz, it was found that Kin the formula above stated was not a constant.

Jan 1, 1944

By A. Warczok, T. A. Utigard

"Slags from smelting of copper concentrates contains from 1 to 15% of copper. Copper is present in the form of copper or copper matte inclusions of size from 2 to 1000 micro, and as dissolved cuprous oxide. Removal of the copper requires the slag reduction, primarily reduction of magnetite and co-reduction of cuprous oxide. Thus, the kinetics of the slag reduction play an important role in copper recovery. Instantaneously, at the contact of carbon and a slag the gaseous film is formed. The magnetite and cuprous oxide reduction is going through a gaseous film, separating the slag and carbon of a coke or electrodes. The thickness of a gaseous film grows to a critical value and gas bubbles, containing CO and CO2, are created and rise up in the slag. Results of measurements of kinetic of the slag reduction with graphite showed high value of activation energy, close to the value of activation energy of Boudouard reaction. Strong temperature dependence of the reaction rate points out the thermal instability of the reacting system. It was found that the slowest process in the reduction stages determines the loop of CO and CO2 transfer and magnetite diffusion to the slag/gas film boundary. Strongly endothermic Boudouard reaction seems to cause thermal instability on the reaction surface. So, heat transfer to the reaction surface is very important. Due to low thermal conductivity of a slag the convection dominates in the heat transfer. So, any slag stirring accelerates the rate of reduction and coalescence of metallic copper or copper matte inclusions."

Jan 1, 2015