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By M. Turner-Jones, N. Steenekamp

"The Lonmin Base Metal Refinery treats converter matte from the Lonmin Smelter to produce nickel sulphate crystals, copper cathode as well as a concentrate containing the platinum group (PGM) metals. The original process employed a Sherritt design and utilizes atmospheric and pressure leaches for the dissolution of base metals. This paper describes the original flow sheet and the improvements made to enhance PGM recoveries, product quality and to increase capacity. Changes include the introduction of flash recycle cooling on the autoclave, batch leaches to improve the quality of the PGM concentrate and the implementation of solid-liquid separation with centrifuges. INTRODUCTIONThe Lonmin Base Metal Refinery (BMR) is about 100 km north-west of Johannesburg and treats converter matte from the Lonmin Smelter to produce nickel sulphate crystals, copper cathode and a concentrate containing the PGMs. The plant was commissioned in 1985 based on a Sherritt design to treat 12 tonnes converter matte per day. The original flow sheet consists of a milling circuit, an atmospheric leach and a pressure leach to produce a PGM concentrate which is despatched by helicopter to the Lonmin Platinum refinery in Brakpan, about 40 km east of Johannesburg. The liquor from the atmospheric leach is treated by crystallization to produce a nickel sulphate hexa-hydrate crystal. The leach liquor from the pressure leach is treated by a selenium removal step followed by electro-winning to produce copper cathode. The spent solution from the copper electro-winning is recycled to both the atmospheric and pressure leach steps to provide sulphuric acid for the leaching reactions.Modifications were made to the original circuit to increase the plant capacity, to improve the PGM recoveries and to improve the quality of the PGM concentrate. Capacity increases included all the unit operations, new mill, new first stage, additional autoclaves, additional nickel sulphate crystallizers, new copper electro-winning and new batch leach reactors for upgrading the PGM concentrate. The current circuit is described in this paper and not the detailed history of each plant change."

Jan 1, 2012

By Horace Freeman

Introduction In the aggregate, directly and ?indirectly, the pulp and paper industry ? consumes very large quantities of a variety of minerals, or compounds prepared from minerals. This is especially true in the manufacture of news-print, but fine papers, also, account for some of this consumption, in the processes of loading, coating, and otherwise improving the finish. The more important of the minerals used in the industry in Canada are briefly dealt with in the following pages. The list is by no means exhaustive, however. Thus, barite, lithopone, zinc oxide, zinc sulphide, and titanium oxide are used in small quantities in Canada in filling and coating paper. Up to the present time, however, the quantities of these materials used in the paper industry have not sufficed to encourage their manufacture in Canada. In the case of barite (barium sulphate)-or of witherite (barium carbonate)-it may be said that, should deposits of commercial size be discovered in Canada, the ore would have considerable export value, for use in the paper and other industries. China-Clay (Kaolin) Considerable quantities of china-clay are used for brightening and improving the finish of paper, and there is a growing tendency to use larger amounts of this material in newsprint manufacture. No china-clay suitable for paper manufacture is at present produced in Canada, but samples have been forthcoming recently from a deposit near St. Remi d'Amherst, Labelle county, Que., about thirty miles north of the Ottawa river and approximately midway between Montreal and Ottawa, and plans are under way to conduct large-scale tests with this material. Present sources of supply are the United States, England, and Russia.

Jan 1, 1934

By William Skinner, Jim Pae Lem, Massimiano Zanin

It is well known that the specific density of minerals has adverse influence on the classification performance of a hydrocyclone, particularly when liberated high density minerals such as gold or uranium are present in sulphide ores. These liberated heavy minerals often misreport to the underflow and recirculate to the system. Such phenomena does result in serious issues in a closed-grinding circuit, such as overgrinding, leading to production of flaky particles (as in gold) or ultrafines, in addition to increased energy inefficiency. In plants which present gold liberated at coarser size, loss of gold due to cyclone inefficiency is sometimes prevented by incorporating gravity concentrators into the grinding circuit to recover the gold. The work reported in this paper looks at whether the effect of density will prevent successful rejection of liberated U-bearing minerals in the –10µm size range of a plant re-cleaner feed, which is necessary to minimize penalty U accumulation in a copper concentrator. The study was carried out using a cyclone rig with spigot diameter of 0.25 inches in combination with batch flotation. It was found that the density effect is almost negligible at particle sizes below 10µm. Consequently, the liberated U-bearing particles finer than 10 µm were successfully removed in the overflow stream as rejects and hence U grade in the copper concentrate remarkably reduced, by 16 ppm. Based on the results, de-sliming of the re-cleaner feed was recommended for plant trial and implementation.

Jan 1, 2016

By Daniel Hodouin, Claude Bazin

"This paper examines the economic advantages of adapting the production grade and recovery targets of a flotation circuit as a function of metal prices. The study is periormed using a steady state simulator for a Cu-Zn differential flotation circuit operating under the following strategies of 1) Maintaining constant operating targets, 2) Maximizing individual circuit Net Smelter Return and 3) Maximizing the global Cu-Zn circuit efficiency. Results are compared to assess whether or not one of the strategies produces benefits significantly higher than the others. A discussion of the tools required to achieve such a kind of control completes the paper.Paper not Available at Time of Publication"

Jan 1, 1997

By Mike Robotham

Drum hoists in the 21st century have the same fundamental objective as their earliest 19th century counterpart. And yet a lot has changed in the design of the hoist from those early days of underground mining. These changes are driven by the need for greater productivity and reliability at ever increasing depths without compromising the all important safety demanded by the industry today. This paper reflects on how these changes have influenced design of a modern hoist Director of Engineering, Mike Robotham is a chartered engineer and has been with DavyMarkham for over 30 years. Having completed a craft apprenticeship he later joined the engineering department as a junior engineer. He has a wealth of experience of working on medium to large engineering projects in the field of mechanical, electrical and hydraulic equipment

May 1, 2013

By François Baillargeon

Two types of ore deposit provide the bulk of the world nickel production. They are the hypogene magmatic massive sulfide deposits and the supergene lateritic deposits. Platinum group elements (PGE) are also extracted from magmatic sulfide deposits. Recent sky-rocketing price of palladium has prompted the mineral industry to seek alternative resources. In such a manner has emerged the Lac-des-Iles type of target, a very low sulfide-bearing bulk tonnage type of deposit. Furthermore, unconventional (e.g. non-magmatic) types of deposit are now sought more intensively (Wilde et al., 2003). Considering both this trend of the PGE Industry, and that only a few magmatic deposits account significantly for the world nickel production, someone may wonder if a diversification of the hypogene nickel resources base would not be needed in the near future. Laterites are residual deposits developed on ultramafic rock under wet tropical climate. Are all ultramafic protoliths equal to generate high-grade lateritic deposit? Are some preweathering processes important to generate favourable ultramafic protoliths? The mineralogical heterogeneity of some ?dry? lateritic nickel deposits renders their ore beneficiation difficult. Is the type of nickel-bearing mineral found in the protolith a significant factor influencing the laterite heterogeneity? To contribute to answer all these questions, we have undertaken a research project on the nickel occurrences of the southern Quebec serpentinite belts. Why choosing this specific region for such a project? First because, due to continuous mining of asbestos ore since 1870, the serpentinite belts of this region are among the best exposed and studied in the world. Secondly, this region host a complete spectrum of nickel deposits that have been described before in the scientific literature. Furthermore, this region is slightly to moderately metamorphosed which make it perfectly suited to study the departure from magmatic nickeliferous paragenesis through various metamorphic conditions. As a matter of fact two orogenic events affected this region, the Taconian, in Ordovician time, and the Acadian during the Devonian. The magnitude and the timing of these dynamo-metamorphic events vary considerably through the region (Gauthier et al., 1994). These variations are now well constrained due to precise age dating.

May 1, 2003

By Neil Westoll

Extensive Global Network ?Working together, AECOM provides clients with a unique blend of global reach, local knowledge, innovation and technical excellence. ?43,000+ team members worldwide ?450+ offices ?100+ countries ?6 continents The Changing Climate ?Climate change is ?official??IPCC 2007 ?Climate change will create instability, change and opportunities ?Companies that are resilient and adapt will survive and evolve ?CO2/GHG emissions will be curbed by legislation ?How will this affect the mining industry? ?How can the mining industry adapt to the new realities?

May 1, 2009

By N. T. Avard

THE Joggins coal field, Cumberland county, Nova Scotia, is on the easterly side of Chignecto bay, at the head of the bay of Fundy. In area, so far as proven, the field extends easterly from the town of Joggins about fifteen miles to Chignecto. The distance across the outcrops of the several seams exposed is approximately one mile. HISTORY Early records of coal mining in this locality are somewhat obscure, but it is known that prior to 1750 the French settlers were mining coal for their own use from the seams which outcrop in the floor of the bay adjacent to the shore, where, at low tide, the reefs are bared for a mile or more. Coal was also mined from the seams outcropping in the cliffs. It is known, too, that at Joggins coal has been mined commercially for over one hundred years. At first, all shipments were made by water, but in 1882 a railway connecting with the Intercolonial railway at Maccan was built to serve this field. GEOLOGY Due to the abundance of fossils in the strata forming the Joggins cliffs, this area was for many years a mecca for geological students from all over this continent. A 'sunken fcrest' in the shoreline was of particular interest but, due to constant erosion by the sea, this has apparently been all washed away. On the Joggins shore, the cliffs stand sixty to one hundred feet high, and six workable coal seams, with numerous smaller ones, are there exposed. Others outcrop in the reefs extending from the shore toward the bed of the bay. In working underground, fossilized trees are often found immediately overlying a coal seam, and standing at right angles to the pitch of the seam. This is said to be an unusual condition. In most cases, the bark of the tree is a fine-quality coal, with high carbon content, whereas the pulp has turned to 'stone'. There is a definite tendency for the coal to run out, or turn to shale. One seam, workable two miles from the shore, has almost completely disappeared in the outcrop at the shoreline. ? It was thought that a large area could be mined under the bay from an opening near the shore, but the first submarine level had to be abandoned at a distance of 4,000 feet, where the coal became very dirty and shaly, and the mine able area to the westward became more restricted as the mine was developed to the deep. This tendency is common to all seams.

Jan 1, 1944

By A. B. Szwilski

The paper outlines the factors taken into account for the selection of steel arch supports. The results are based on experience using the long wall system of coal mining where roadway closure can be extreme. Results of tests on scale-model steel arches and full-scale yield elements are also presented.

Jan 1, 1979

By S. Sundararajan, Z. Lin

ABSTRACT Fierce market competition and demand have made it imperative for mining companies to achieve higher productivity and operational efficiency. The selection of the best mining method and equipment combinations will enable companies to meet production and efficiency targets. Continuous mining is increasingly preferred by companies for its high efficiency and low unit costs. We developed simulation models for two continuous mining systems: the continuous surface miner (CSM) system and the at-face slurrying (AFS) system. Considering two different case studies, the paper discusses application of developed models to determine the optimal number of trucks and equipment capacities for the two systems.

Jan 1, 2013

By Osvaldo A. Bascur, Curt Heftier

The lack of integrated information including the Energy/Utility Suppliers with sufficient detail for analysis causes inefficient operation in metallurgical complexes including the Energy/Utility Suppliers . Defining the right context for information use is essential for sustainable operations. This being said, what are we doing to enable people to act upon information and to be aligned to optimize the use of resources like raw materials, energy, water and consumables for an entire metallurgical complex? Collaboration between all company entities is a key component of improving efficiency. Evolution of web technology and object modeling of enterprise assets enables collaboration across the whole business. Operational troubleshooting occurs more quickly as the organization acts on issues to reduce wasteful operation. This paper presents a real time software infrastructure with tools that give users the ability to sift through available data, transform data into information for business continuous improvement and optimization. We will introduce a new technology for analyzing real time data, information and events using multidimensional analysis of information to detect anomalies based on the statistics of the data classified by time events to reduce the information into action. A new paradigm for collaboration at a local and strategic level is proposed to enable the enterprise to become proactive in dealing with wasted time and products. Three examples from the industry will presented and their benefits highlighted.

Jan 1, 2011

During heap leaching of secondary copper sulphide ores operated at low heap temperatures and high levels of leach solution salinity, copper recovery is usually unsatisfactory, due to a slow chemical and bacteriological leaching of the covellite minerals either formed from leaching of chalcocite or naturally occurring in ores. A laboratory test program was conducted to investigate the effect of leach solution temperature in the range of 20 to 50°C on copper extraction during stirred reactor, bottle roll, and short column leaching of fresh or heap leached secondary copper sulphide ores. It was demonstrated that increasing heap temperature is an effective approach for improving recovery of copper from secondary copper sulphide ores. A review of the technologies available for heating heap leach solution or decreasing solution salinity to improve copper recovery from secondary sulphide ore indicates that an integration of copper concentrate pressure leaching with heap leaching is potentially a cost-effective approach. A copper flotation concentrate sample was tested through pressure oxidation with the use of heap leach solutions of varying strengths for the repulping of the concentrate in order to examine its effect on pressure oxidation performance. The test results indicate that use of heap leach solution of high salinity in the pressure oxidation process does not cause a negative impact on the process performance for copper extraction, sulphide oxidation, and recovery of gold (if present) from pressure leach residue, and has additional advantages of removing the bacterially inhibitory aluminum from heap leach solution and generating more acid and ferric iron in the pregnant leach solution. A flowsheet configuration for full integration of the copper concentrate pressure oxidation with heap leaching of secondary copper sulphide ore is proposed and discussed.

Jan 1, 2014

By C. Grisanti, E. Prina Howald

The major of Swiss territory is occupied by mountains. Natural events as floods, debris flows, landslides, rockfalls, and avalanches regularly threaten the safety of people and properties. On the one hand, extreme weather events cause great damages, on the other hand, the enhancement of territory’s exploitation increases the risk. The Swiss Government makes many efforts to deal with the prevention of natural hazards, especially through measures of land management. As stated by federal law, Swiss cantons are obliged to establish hazard maps and to take the risk into account in the land management. Hazard maps are based on the hazard matrix, whose abscissa and ordinate are probability and intensity of the event on site. This project focuses on rockfalls. It consists of three main parts: the creation of a database to collect data on site, the creation of a catalog with all type of measures, and the development of a methodology for the analysis of the effectiveness of protective measures. The creation of the database allows us to collect information: about the site, about protective structures implemented on it, and about failures. With many multiple choice fields and few free text fields, it can collect data in a homogeneous way, without redundancy. The catalog has to be a tool that gives a basis to make decisions. It collects information about all types of protective measures implemented on Canton Vaud’s territory or available on the Swiss market. Free text fields allow for data storage of specifics, to give a complete view of structure’s characteristics and potentials. Methodology consists of four steps. The core of the procedure is the structure’s evaluation following a score system; it allows for calculation of reduction factors that have to be applied to intensity and probability parameters of the structure. Then it is necessary to convert the reduced structure’s intensity value into a residual site’s intensity value. Although the first step enables us to choose suitable measure for a specific site, it is not necessary to perform it. Second step allows us to evaluate structures under scenario 0, where structures are in best conditions. Third step allows us to evaluate structures under six scenarios of possible failings. Fourth step allows us to convert structure’s reduced intensity into event’s residual intensity and to establish the new point on hazard matrix. While the procedure has already been defined, details of score system and conversion have to be developed during the second phase of the project.

Jan 1, 2015

By C. W. Reno

"THE LORNEX MINING PROJECT is one of several large-tonnage, low-grade operations recently placed in operation in British Columbia. It is located in the Highland Valley in the south central portion of the province. This area is described as a divide valley at an elevation range of 4,000 to 6,000 feet and is situated on the divide between two drainage systems. The major drainage to the west flows into the Thompson River and to the east and south the drainage enters the Nicola River system. This open-ended valley lies between low, rounded mountains in fairly heavily-wooded country. Prior to the commencement of copper mining activities, the first by Bethlehem Copper Corporation Ltd. over ten years ago, the valley was only sparsely settled. A few small ranches were in existence on the several Indian Reserves located along the valley bottomland. There has also been a small amount of logging activity in the valley, although much of the area is covered by dense lodgepole pine which has little or no value to the loggers. As the mining interest mounted with further discoveries of the disseminated copper ore typical of the district, much of the valley was covered with mineral claims and exploration drilling was carried on by several companies at various times. At the time Lornex was preparing to commence major construction work in early 1970, there was very little activity of any kind in the Highland Valley outside of the Bethlehem operation and a small amount of ranching."

Jan 1, 1973

By A. M. Hill

"This is an account of the expansion of Texasgulf's Timmins concentrator by the building of a fourth circuit.The original capacity of the mine and concentrator was 3.6 million tons per year of ore. In 1974, Texasgulf decided to increase that capacity by about one third to 4.8 million tons per year. It was planned that the increased capacity would be available by mid-1978.The expansion involved work at the rninesite, increased railroad capacity, and a new circuit in the concentrator, and it is the concentrator expansion which is described here.In 1974, the minesite drew its ore from the open pit. The pit was being phased out and was to be replaced by No. 1 mine. To allow for the expansion, a second mine was required. The railroad was capable of handling 18 car trains. Its capacity had to be increased to 27 cars per train and this, in turn, required two new locomotives. Each of these alone cost half a million dollars.The concentrator building in 1974 contained the concentrating equipment and miscellaneous services (such as machine shop, warehouse, analytical lab). The grinding and flotation sections were divided into three circuits ('A', 'B', & 'C'). 'A' and 'B' circuits treated copper-zinc ore and 'C' circuit treated the much more difficult copperzinc- lead ore. This 'C' circuit had been modified over the years to implement improvements in the metallurgy."

Jan 1, 1979

By R. Heikkilä

In this paper the utilisation of building information models (BIM) and construction automation on building sites is discussed. A lot of research has been carried out to develop new applications for using BIM to assist construction site planning, different operations and logistics. The methods of production control and management on site utilize BIM together with machine control and navigation systems. In Finland machine control systems and the automation of construction equipment is widely used in infrastructure construction. Recently similar methods have been introduced also in building construction. This paper describes some latest Finnish examples where BIM-software is used for the planning, execution and control of building construction operations. University of Oulu has studied methods and technologies to capitalize BIM-models. The research has been mainly in infrastructure construction but the activities have recently been extended to building construction. In this paper a BIM-based tower crane operation and control system is discussed as a case study. The aim of this study was to highlight the potential areas were automation can increase the crane productivity and improve site operations and logistics. The construction site managers and tower crane operators interviewed in this study were experienced in using BIM-models on site.

Aug 1, 2013

By Gerald A. Crawford

"1880s - Unmasking the Sudbury Basin Falconbridge Ltd. turned 60 in 1988 but its roots go back more than a century to the discovery and development of the mineral resources of the Sudbury Basin. Nickel was first identified in the area in 1856 but sustained exploration awaited the early 1880s and the advance of the CPR westward from Sudbury. Rock was laid bare in the right-of-way and by forest fires and logging. Reddish oxidized outcropping or ""gossan"" were exposed, heralding the presence of nickel as the shape of this astounding geological formation gradually began to emerge. Many great mines of the area were opened up in this period on the south rim of the Basin west of Sudbury. To the east the ore dips below overburden, however, and Falconbridge remained a mere dot on the map until the turn of the century when Thomas Edison detected a magnetic occurrence by dip needle."

Jan 1, 1999

By L. Zeka, I. Ndala, J. Frenay, S. Gaydardzhiev

"Reductive leaching of cobalt (III) from a heterogenite bearing ore has been performed. Pyrite was added to the system and simultaneously bioleached in order to provide ferrous iron as reducing agent. Within such arrangement the iron ions are continuously re-circulated inside a Fe 3+ / Fe 2+ loop. As a result Co(III) is solubilized in the presence of Fe 2+ ions in concentrations well below the stoichiometric requirement. The ore has been initially subjected to acid pre-leaching in order to guarantee that the available Co (II) has been entirely removed. Two technological parameters have been studied to show influence on the degree of cobalt leaching: concentration of ferric iron in the inoculum and the presence of bacteria. The bacterial role could be mainly viewed in supplying ferric ions in the system which chemically react with the pyrite to generate ferrous ions used as Co(III) reducing agent. Co(III) dissolution has been less efficient when the concentration of total iron in the system was low, but also when microorganisms were absent. SEM observations on leached heterogenite have evidenced bacterial attack on the mineral; however the precise role of bacterial presence on cobalt (III) leaching is still to be elucidated.INTRODUCTIONCobalt accompanies quite often copper in secondary oxidized ore deposits (Rumbu, 2013). In such associations cobalt is found both as CoII+ as well as CoIII+ (Deliens, 1974). In contrast to cobalt (III), cobalt (II) is leached relatively easy in sulphuric acid solutions. Cobalt (III) when present in mineral form belongs to the heterogenite mineral group with a simplified chemical formulae Co2O3.H2O or CoOOH. In order to be brought in solution, heterogenite should capture two electrons, likewise shown in reaction 1 below:"

Jan 1, 2016

By J. S. Moretzsohn, D. F. Graham

"Airborne Synthetic Aperture Radar (SAR)was acquired over the Carajás Mineral Province, within the rainforests of the Amazon, which hosts the world’s largest Fe-ore deposit(Santos, 1986). Significant chemical weathering exists in this humid environment. PrevalentAu mineralization is thought to be generally associated with deformation zones in Archean schists.Radar data have proven to be very useful as an aid to geological mapping in the tropical rainforests of the Amazon Basin in Brazil. In these densely vegetated areas, a sense of regional structural trends is obtained as a con-sequence of the sensor/terrain geometry. The top forest canopy is the main terrain reflector of X-band radar energy, and consequently is the main terrain surface feature expressed in processed radar imagery. Radar is important for extending t,he continuity of mapped structural lineaments. Differential weathering is related to variations in radar image texture which is used to infer gross lithologic variations and relative age relationships of major rock units. Specifically, quartzites and banded iron formation are highlighted in the radar imagery due to their unique tonal and textural appearance, in contrast to schists, gneisses and metavolcanic rocks. As tropical areas are typically enveloped in cloud or mist, radar data are invaluable in providing information for logistical planning of field mapping activities."

Jan 1, 1997

By F. Goodarzi

"The nature and distribution of the inorganic components and the concentration of certain environmentally sensitive elements, such as, As, Sb, B, Hr, Cd, CI, F, Mo, Pb, S, and Se, or elements detrimental to the utilization by industry such as B, Na, P and S are very important in determining coal quality. The concentration of elements in coal is controlled by the following factors: (1) frequency of occurrence of partings; (2) nature and habit of occurrence of minerals in coal; (3) environment of coal deposition; (4)rank; (5) geological setting; and (6) weathering.Selective mining of coal can reduce the input of undesirable elements such as As and S by eliminating the part of the seam which is enriched in these elements. IntroductionCoal is a sedimentary rock of plant origin and consists of two components: an inorganic component (minerals) which is formed by influx of clastic sediments into the coal-forming environment and also by activities of groundwater, and an organic component (macerals) which is formed from plant debris deposited in the original coal-forming environment. However, coal is a generic term with a broad range of utilization characteristics. A coal that is attractive for use in one market - such as generation of electricity (combustion) - may not necessarily be acceptable for use in another, such as for production of coke (Davis, 1978).The elements in coal are associated with both macerals and minerals. The elements associated with coal macerals, such as C, H and N are termed elements with organic affInities. The concentration of elements with organic affmities (including B, Br, CI, F, I, S, and Mg) often decrease with increasing ash content of coal (Nicholls, 1968; and Finkehnan,1982). FIgure 1 shows such a trend for chlorine. Some of these elements may also be incorporated in coal maceral as very fine mineral grains (Finkelman, 1982). The elements with organic affmities are often volatilized during combustion and carbonization of coal and emitted in the vapour phase. Emission of some of these elements (C, 0, Br, N and S) is of major environmental concern (Lim, 1979)."

Jan 1, 1994