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By R. Roufail

"Energy consumption in stirred mills has been studied, in the last couple of decades, on a macro scale. Effective operation and meeting particle size required for downstream operations used to be the main objectives behind energy utilization of stirred mills. In this paper, three energy terms are defined to assist in understanding the breakage mechanism for various types of minerals versus mill operation. The types of minerals studied had diverse physical and mechanical properties that are summarized as specific gravity, hardness and crystal structure. The minerals utilized in this study were quartz and galena. The effect of quartz and galena mix has been addressed as well as Lead-Zinc ore sample from SAG mill discharge. The energy input to the mill is function of the agitator speed, therefore three agitator speeds were evaluated, 1000, 1500 and 2000 RPM, respectively. The energy terms studied are specific energy (kWhr/ton). Effective energy is the ratio between net energy and total energy consumed by the mill. Last type of energy is the specific breakage energy, which is the net energy consumed by the mill per one-micron breakage. Results showed that specific energy and specific breakage rate are functions of mineral type, while effective energy is only function of mill input power (agitator speed).INTRODUCTIONGrinding is the largest energy consuming component of a mineral processing operation and typically consumes about 50% of the total energy used at a mining operation (Botin, 2009). Over the last two decades, stirred mills have been extensively utilized in mineral processing operations due to increased mineralogical complexity of ore bodies. Stirred mills grind particles to less than 10 µm by applying a high power intensity. The technology has been the focus of several research studies to investigate mill energy and grinding mechanisms. Becker, et. al. (2001) studied the relationship between different types of energy including input energy, specific energy, volume/mass specific energies, to stress intensity and final product particle size. Other studies such as by Kwade (1999), Kwade and Schwedes (2002), Blecher et al (1996), Partyka and Yan (2007), Stender et al (2004), focused on mill design and/or stress intensity distribution. Peukert (2004) studied the effect of mechanical properties of the grinding media and ground material on the comminution process."

Jan 1, 2016

By P. E. Weidmark

Allard, M., Hucka, V.J., Das, B., and Borchtch-Komponietz, V.I., "Investigation of seismic vibration due to large blasts in Gaspe Copper Mines"; (in Russ); The Industry of Chemical Raw Materials; Referativnyi sbornik; 5:18-20: 1978. Askew, J., McCarthy, P.L. , and Fitzgerald, D.J ., "Backfill research for pillar extraction at ZC/NBHC"; Mining with Backfill; Proc 12th Cdn Rock Mech Symp; May 23-25, 1978; Sudbury; CIM Spec Vol 19:100-lJO; 1978. Barrett, J.R., Coulthard, M.A., and Dight, P.M., "Determination of fill stability" ; Mining with Backfill; Proc 12th Cdn Rock Symp; May 23-25, 1978; Sudbury; CIM Spec Vol 19:85-91; 1978.

Jan 1, 1979

By D. Gagnon, B. Dubreuil, J. -M. Lalancette, D. Lemieux

"The pilot scale extraction of gold with a brine of sodium chloride and bromide at 30 ºC, in an atmosphere of halogens at atmospheric pressure, leads to gold chloride with 95% gold recovery. The use of dilute hypohalites (1 – 3%) instead of free halogens, which is strong enough to oxidize hypobromite into bromine, simplifies the recycling of halogens by electrolysis. With the recycling of water and brine, the regeneration of hypohalites and with a barren solid that is inert and stable. The Nichromet Extraction technology is a green process where the protection of the environment does not preclude profitability.INTRODUCTIONThe use of chlorides for the extraction of gold predates the discovery of chlorine by Scheele in 1774. In the Plattner chlorination process (Christy, 1888) sodium chloride and copper salt were used to promote gold recovery by amalgamation with variable results. The introduction of the cyanide technology in 1889 has led to a general use of this method for gold recovery. In the last decades, a return to chlorine in extractive processes has been noted (Ferron, Fleming, O’Kane and Dreisinger, 2002), mostly because of environmental pressure for non-cyanide technologies.This paper describes a closed circuit proprietary approach (Lalancette, 2009) developed and piloted by Nichromet Extraction Inc. for the extraction of precious metals with recycled mixed halogens; chlorine and bromine from hypohalites. DESCRIPTION OF THE PROCESSThe attack of gold by halogens can vary significantly. The rate of reaction is substantially higher with bromine (Br2) than with chlorine (Cl2), by a factor of more than five, although the oxidation potential of Cl2 is higher than Br2, as shown in Equation 1a and Equation 1b (Latimer, 1952)."

Jan 1, 2012

By I. Colquhoun

Current practice tends towards "integrity as an afterthought". That is, integrity is treated as an isolated aspect of operations and maintenance. In fact, this works quite well. But it would work so much better and with less uncertainty if integrity management measures were introduced at the design phase and addressed the entire life-cycle of the pipeline asset. The talk will address the measures and metrics that can be implemented on a new pipeline during design to optimize integrity and deliver a comprehensive operating manual and integrity management program for the pipeline system. This deliverable should describe the risks to be assessed and monitored, and the actions to be taken to control these risk adequately. Properly executed, integrity by design will provide a good working estimate of the life-cycle integrity management costs and maximize system reliability.

Jan 1, 2005

By Suzie Poulin, N. Geoffroy, G. P. Demopoulos

Most metallurgical industries generate toxic waste that must be treated prior to being released to the environment. However, in a lot of cases, the waste materials are poorly characterized or the analytical results are not well interpreted. These shortcomings often result in the development of inefficient industrial procedures, thus causing economic waste and difficulty meeting environmental regulations. Fortunately, a wide range of analytical techniques are available to guide researchers and engineers into making sound process development decisions. In this work, an industrial selenium and mercury removal process is used as an example to illustrate the application of X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) coupled with Energy-dispersive X-ray spectroscopy (EDX) and powder X-ray diffraction (PXRD) on solid waste. Furthermore, samples of analytical results are presented and interpreted and the modifications to the industrial process that resulted are explained. Finally, a brief description of the advantages and limitations of the aforementioned analytical techniques is given with an emphasis on industrial solid waste material.

Jan 1, 2011

By D. P. Goodall

THE development of the oil and gas resources of Western Canada is not, as many suppose, a new industry. For more than half a century an intensive search for these valuable products of nature extended from near the western edge of the Precambrian Shield to the Pacific coast, and from the International boundary north to the Arctic circle. The chief centre of interest to the oil prospector has, however, always lain in that region lying east of the first range of the Rocky mountains and confined largely within the boundaries of the Province of Alberta. Although there are many geological problems yet to be worked out in this Province, the oil-well driller has helped in no small way in determining sub-surface conditions and distribution of rock formations. The chief geological conditions as they affect the drilling of wells are generally re-cognized, and for this purpose the Province may be partitioned into three main divisions: first, the disturbed belt or foothills region extending along the eastern edge of the Rocky mountains; second, the Alberta geosyncline, a broad trough lying to the east of and parallel to the disturbed belt and from which the formations rise eastward to level off and form, third, the plains ? ? region, extending over the rest of the Province. A relatively small area in the northeastern part of the Province is underlain with Precambrian rocks and may be excluded from this classification, as it is of no interest to the oil prospector. The foothills, or disturbed belt, has presented the greatest difficulty to drilling, though it has produced the largest yield of oil within the Province to date. Within the foothills belt, the rock formations consist largely of hard shales interspersed with layers of abrasive sandstones, which wear out drilling bits at an alarming rate. The strata, in most flaces, dip steeply and are cut by numerous thrust faults. Although some o the faults have great displacements, their presence may easily be overlooked or the extent of the fault misinterpreted. Many a prospect well has been located on what appeared to be a suitable geological structure only to find, after drilling through a normal succession of rocks for 4,000 feet or more, that the drill had passed through a major fault plane to a younger formation than that in which drilling was started. Only a repetition of formations already drilled could be expected at greater depths.

Jan 1, 1942

By Roger Francis

There is increasing use of acid leach extraction methods at elevated temperatures and pressures by the mining industry. In many locations there are limited supplies of fresh water, and waters with higher chloride contents must be used, making conditions more corrosive. The fluids downstream of the main autoclave are hot, acidic, oxidizing and contain chlorides and present a challenge to the mining community to ensure reliable operation. Zeron 100 is a high strength superduplex stainless stee, that offers high corrosion resistance at a cost effective price. The paper presents a combination of laboratory data and service experience, particularly in the aggressive fluids found in downstream processing.

Jan 1, 2010

By Ed McConaghy, P. LaRochelle

The Ambatovy Nickel Project comprises the development of mine, hydrometallurgical processing facilities and necessary infrastructure in Madagascar, positioning Ambatovy as one of the world’s largest producers of nickel and cobalt from lateritic ore. SNC-Lavalin successfully provided comprehensive Engineering, Procurement, Construction Management (EPCM) services for this major capital project which, apart from its sheer size, scope, and engineering design, represented significant location, infrastructure, labour, environmental and climatic challenges. Today, the project has reached 90% of its nameplate capacity and is in its final performance optimization stage. This paper will discuss the significant project management effort that was required to successfully address the complexity of this major project. It will cover the main project management control systems and the engineering tools and processes used during the detail engineering, procurement, and construction phases to achieve optimum project execution.

Jan 1, 2015

By N. Shi, T. G. Joseph

ABSTRACT Before any large plant is moved onto an oil sands dominated surface, particularly those surfaces encountered in-pit, it is imperative that the ground be evaluated for bearing capacity. A 2230 tonne mobile in-pit hopper/crusher facility designed for operation in the Canadian oil sands was modeled. This evaluation focused on track and outrigger pad versus ground interactions as the key performance indicators of appropriate ground performance below the unit in both operating and repositioning propel modes. A study of cyclic oil sand behaviour was also inferred from laboratory cyclic plate load data as an extension of the simulation model indications.

Jan 1, 2013

By William H. Emling

With profitability pressures in heavy industry increasing, many producers are turning to predictive maintenance as a means of harvesting untapped value from their production assets. Corporations are losing their maintenance and processing core competencies through attrition. As capital budgets are being trimmed, manufacturers are consolidating operating units into fewer, more profitable routes. Maintenance functions, however, typically receive low priority when investment is made, since many companies consider maintenance costs as ?overhead?. Condition-based monitoring, integrated to Level I and Level II process inputs, is seen as the most cost-effective solution to the implementation of predictive maintenance strategies. This paper will review the evolution of preventive and predictive maintenance programs, highlighting examples of successful application of integrated condition monitoring.

May 1, 2001

By M. Azzaz

In this paper, we report on new mechanical tests, at high temperatures, performed with a supposed better aluminium nitride (A1N) material, containing fewer oxygen. Our purpose was twofold: (i) check whether creep resistance is modified and hopefully enhanced and (ii) determine the elementary mechanisms controlling plastic deformation through transmission electron microscopy (TEM) observations of deformed samples up 10% strain in compression at elevated temperatures (1823-1923 K) under constant stress in the range 150¬250 MPa. Stationary rates are lower by an order magnitude than those previously measured in MN with higher oxygen content. All dislocations imaged by TEM look undissociated, which clearly relates the formerly observed wide dissociation to oxygen in excess.

Jan 1, 2004

By J. H. Baek, S. Alexandrovskii, D. W. Lee, B. K. Kim

Nano-phase titanium carbide was synthesized by Mg-thermal reduction process using a novel route of Mg-thermal reduction. The processes are based on I) feeding of TiC14+CxC14 x = 1, 2 ) solution into liquid magnesium, 2) Mg-reduction of metal chlorides, 3) TiC formation by the reaction of released Ti and C atoms, and 4) vacuum separation of residual liquid phases of Mg and MgCl2. In this study, the process for titanium carbide production with composition close to stoichiometry and the minimum content of impurities was optimized with the various process parameters such as concentration of initial solution, its feeding rate and reaction temperature, as well as a kinetic study.

Jan 1, 2004

By D. M. Xue, T. B. Li

"With the increase of human engineering activities, global climate change and active plate tectonics movement, the giant landslide frequently occurred in southwest China, which caused huge property and human losses. Besides, the potential landslides pose severely threaten to the construction and operation of airports, railways, highways and power stations etc. In order to provide accurate guidance for the landslide investigation, stability analysis and mitigation, the giant landslide is redefined according to landslide volume, depth of slip surface, complexity of landslide mechanisms, and degree of landslide mitigation difficulty, and classified with the typological classification approach based on the twofold attributes of landslide behavior including formation mechanisms and reactivation features. Finally, the threefold particularity of the giant landslide is also summarized, which enables a more effective landslide mitigation design.INTRODUCTIONWith the increase of anthropogenic activities, global climate change and active plate tectonics movement such as continual uplifting of Qinghai-Tibet plateau and strong earthquakes, the occurrence of giant landslides was in ascending trend in southwest China (Huang, 2009), which caused serious destruction, and greatly endangers such engineering construction from safety, time and economic aspects as airports, railways, highways, power stations, etc. Giant landslides have huge scale, complex formation/reactivation mechanisms and mechanical behavior. They may not be identified during the hazard investigation, but may be firstly initiated or reactivated due to the following engineering activities, heavy rainfall or strong earthquakes. Consequently, the landslide mitigation is inevitable and costly. However, it is difficult to control the deformation of giant landslide with lack of a correct understanding of genetic mechanisms (Marui, 2012; Zhang, 2000) and the excessive large sliding forces of the slide blocks calculated by the conventional limit equilibrium method. For instance, the failure of anchored pile wall for the No.102 giant ancient landslide (Zhu et al., 2012) and stabilization measures for the Sidi Rached viaduct landslide(Guemache et al., 2011); four rows of piles had not prevented the occurrence of the No.12 landslide in a high fill slope in the Panzhihua airport (Li et al., 2012)."

Jan 1, 2015

By W. O. Karvinen

"In the Timmins area, a close spatial and chronological association exists between gold deposits and two major stratabound carbonate-rich members and related quartz-feldspar porphyries. Synvo/canic and metamorphogenic are the two main types of mineralization recognized. Synvolcanic ores include the stratiform quartz-ankerite ""veins"", pyritic carbonates and chert-carbonate-tuff sedimentary rocks and epigenetic ventrelated breccias and stringer zones. Metamorphogenic ores consist of quartz-carbonate fracture fillings in dilatant zones developed during various phases of regional deformation and metamorphism. They are classically epigenetic in character.The evidence suggests a primary syngenetic enrichment of gold on the ocean floor and in vent areas during submarine felsic volcanism and related exhalative-hydrothermal activity followed by further enrichment into quartz-carbonate stockworks during regional deformation and greenschist metamorphism.Although normally thin (a few hundred metres), carbonate members in Archean volcanic terrain represent intense hydrothermal activity which could have transported and enriched gold. They should be used to locate fossil vents and structurally favourable zones where economic concentrations of gold may be found."

Jan 1, 1982

By Gordon E. Agar

"The effectiveness of two this compounds for copper sulphide depression in molybdenite flotation has been examined with batch bench scale tests.Both thioglycollate and trithiocarbonate proved to be good depressants producing results similar to those f or cyanide and hydrosulphide. Ferrocyanide was ineffective on the samplematerial tested.The depressing effect of thioglycollate was readily reversed by an addition of xanthate.IntroductionThe separation of molybdenite from copper sulphide minerals has been practised for a long time(1,2). The predominant scheme is to depress the copper sulphides while capitalizing on the ready floatability of molybdenite to effect the separation. There are many recipes for depressing the copper minerals(3), among them the addition of sodium cyanide, particularly if the copper is present primarily as chalcopyrite; some form of sulphide whether as sodium sulphide, sodium hydrosulphide or phosphorous pentasulphide when there is a mixture of copper sulphides such as bornite, chalcocite and chalcopyrite; potassium ferro cyanide may be used when chalcocite is the principal copper sulphide; peroxide or hypochlorite; as well as heating in the presence of lime. There are different mechanisms by which these reagent s depress the copper sulphides. Sodium cyanide and the sulphide-producing compounds apparently reduce the potential of the copper sulphides to the point where they ar e rendered unfloatable by xanthates . Another study(4) showed that after cyanide addition, chalcopyrite was rendered un floatabl e until the REDOX potential (measured with a gold electrode with a saturated calomel reference) had become more positive than -250 mY. If the chalcopyrite pulp was conditioned after the cyanide addition the REDOX potential increased slowly, whereas if air was introduced during the conditioning the potential r ose much more rapidly. The difference in time to reach the desired level of - 250 mV was as much as 20 minutes' 25 minutes being required when air was absent but less than 5 minutes when air was admitted . These observation s demonstrate some of the problems encountered when using cyanide to depress sulphides such as chalcopyrite . The system adjusts to counteract the depressing effect of the additive. To overcome this tendency it is necessary to either add an overdose at the beginning or to more or less continuously add the regulating reagent. In this study cyanide solution was added under automatic control to maintain a specified REDOX potential."

Jan 1, 1984

By G. F. Vander Voort

Over the past twenty years, steelmakers have introduced improved practices for reducing the inclusion content of steels. The success of these practice changes can be monitored in a variety of ways. Chemical analysis of the bulk sulphur and oxygen contents provides a relatively simple means to assess the impact of these changes. However, microscopical test methods are still needed to assess the nature of the inclusions present. Traditional chartbased measurement methods have wide acceptability, and their data are well understood by both purchaser and producer for heat acceptance purposes. However, these methods do have inherent weaknesses which limit their usefulness for quality control, SPC, and database applications. Image analysis-based chart measurements are an improvement over manually generated chart ratings, but the data still do not lend themselves to databases and statistical comparisons. ASTM Committee E-4 on Metallography has developed a stereologicallybased image analysis standard test method, E 1245, which provides the necessary data in a form which is easily databased and analyzed statistically. This paper describes E 1245 and shows how data from different heats and melting practices can be compared statistically to ascertain valid test differences.

Jan 1, 1998

By J. R. D. Gravel, D. A. Poland

"The induration of iron ore pellets has always utilized prefired pellets to protect the pallet cars from the environment of the induration furnace. This paper presents the process used to obtain superior upper sidewalls. These heat resistant castings are used on induration pallet cars, and their life improvements by as much as 400% is a significant step towards the reduction of the prefired (or hearth layer pellets.) The benefit to the industry in the removal of the hearth layer is improved overall productivity. IntroductionThe Iron Ore Company of Canada (IOC) operates with production facilities located in Labrador City, Newfoundland and Sept Iles, Quebec. It has recently been acquired by North Limited, an Australian based resource oriented company. Prior to its acquisition, IOC has examined several methods of operational cost reductions. One of these was an examination of indurrating pallets. Pallets are composed of numerous assemblies and sub-assemblies. The examination of the upper sidewalls began as an intent to increase the operational life of the component. The anticipated net effect was to be a reduction in the overall pallet maintenance cost. All of the components and assemblies have undergone a severe scrutiny. IOC has found that the success of the project has depended upon not only the technical competency of all parties involved, but also upon the ability to share risk, to be innovative, and to find a partner with whom the development can proceed without fear and yet with accountability. IOC has found in Cast Steel Products (CSP) such a partner in the field of pallet development. This paper will undertake to explore the progression into the arena of partnering between IOC and CSP. CSP and IOC met in the fall of 1994. The work of re-engineering the pallets began with an initial order for 36 pallets in March, 1995. The work on the upper sidewalls involved segregation of the effect of alloy development versus physical geometry development. The nature of partnering between the two companies allocated alloy development to IOC and physical geometry development to CSP, yet no advancements were made in either area without the close co-operation or the involvement of both partners."

Jan 1, 1999

By M. du Plessis, G. More O’Ferrall, A. Hartzenberg

"Lonmin Platinum has experienced several cases of large-scale hangingwall instabilities during the extraction of the Upper Group 2 Chromitite Layer (UG2) at a number of the Marikana operations along the Western Limb of the Bushveld Complex. These instabilities were all attributed to the presence and interaction of prominent geological features and highlighted that assumptions made in the design of the stable pillars and stable span were potentially overly simplistic in these areas. Investigations into the various case studies over the past ten years have resulted in the identification and classification of the rock mass characteristics of the geological structures causing the instabilities.In order to get a better understanding of these instabilities, it is important to understand the structural geology in general, and the sequence of events that led to the formation of the Bushveld Complex in particular. The tectonics involved in the formation of the various layers around the economic mineralized layers has been investigated, and the influence of these tectonic events on the stability of the UG2 stopes hypothesized.Following this investigation, the behaviour of the various layers in the hangingwall of the UG2 is better understood. This paper presents a description of the ground conditions being experienced in the underground stoping environment, the possible source of the associated structures and the resultant behavioural mechanism of these structures causing the rock mass instabilities."

Jan 1, 2015

By P. Nelson, B. Salt, J. A. Scott, H. Shang

ABSTRACT In a nickel smelting process, large amounts of off-gas emissions are generated, which can cause serious environmental and plant hygiene problems if not properly treated. With increasingly stringent environmental regulations, an enhanced understanding of well-controlled, off-gas cleaning systems is vital. In this paper, dynamic models for an industrial smelter, off-gas system tackling hazardous sulphur dioxide, carbon monoxide, and carbon dioxide are developed using mass continuity, momentum, and energy conservation laws. The effect of air in-leakage is explored under different operating conditions. The developed models provide an enhanced process understanding and a necessary basis for highperformance control analysis of smelter off-gas systems.

Jan 1, 2011

By R. Esteban, D. Runnels, J. Torrealba-Vargas, G. Couture

"Data handling is an important step in the development of a simulator of a mineral processing circuit. The model requires representative data of the scenario to be modeled. The model development involves protocols that must be followed very closely to complete a successful project.Data handling of large and diverse datasets (metallurgical test results, geological data, mining models, historical data, etc.) is a key element of the model. The information needs to be processed, reconciled, interpreted, modeled and presented to support the design or the optimization of a mineral processing plant.Best practice recommends that teams from different disciplines (such as mining, metallurgy, geology and environmental) interact to define the most important variables that could influence the simulator. For example by adopting a geometallurgical approach in the earlier stages of the project, it is possible to consolidate the number of main ore rock types in a testwork program (saving money and time) by involving geologists and metallurgists in the sample selection and data interpretation.Planning the development of a model involves an understanding of the software capabilities but also the limitations and the magnitude of the data required to calibrate the model in case of changes in the project.A successful model requires a deep understanding of the circuit to be modeled and thus plant personnel should be considered as members of the team.This paper describes the use of the "state of the art" tools for data analysis, simulation and optimization; and shows three practical examples of the use those tools in the design of mineral processing plants."

Jan 1, 2015