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By H. Kalsi

"IntroductionRoyal Oak Mines Inc. is currently operating the Parnour No.1 mine located 10.5 miles east of Tinunins, adjacent to Highway No. 101. The operation produces gold ore at a rate of 3300 tpd. A variety of mining methods including bulk open stopes with ITH drilling, narrow vein panel, longhole and open pits contribute to produce 1.2 rnillion ore tons annually. The milling process requires water at an average rate of 1 rnillion gallons per day (700 U.S. gpm). The Pamour No.1 mine has historically had two major problems with regard to water control. The flfSt is the underground pumping system's inability to handle excess inflows of water generated from spring thaws. When the thaw takes place over a short period of time, large inflows of water are created which quickly migrate underground and sometimes result in the loss of the lower loading pocket. During the spring runoff the pumps at Parnour No.1 work continuously for 24 hours at a rate of 1200 U.S. gpm. The system was further taxed in 1991 when the Hoyle mine was connected to the Parnour No. 1 mine and whatever excess capacity the pumping system had for the spring runoff was taken up handling the inflow of mine water generated by the Hoyle.The second problem facing the mine was the lack of water for the mill during the severe cold winter months and dry summer months. At those periods inflows of water into the mine decline and the underground water normally pumped to the mill is severely decreased. In times of dry spells mill personnel increase the water diversion from the Three Nations Lake in order to meet water demands and maintain tonnage throughout. In essence, the mine was going through an annual ""feast or famine"" situation and a solution was needed.A number of options were considered but were narrowed down to the two most practical. The first was to modify the existing pumping system and increase its capacity in order to handle the excessive runoff during spring thaw. This involved a heavy capital expenditure and would have caused additional operating costs (i.e. increased hydro). The option chosen by the management was to divert the spring runoff into an unused section of the mine called The West End. A bulkhead placed at the 2400 level would provide an ultimate underground water storage potential of 150 million gallons. This would also cut down the load on the existing pumping system, save electric consumption in pumping and provide water storage which could be used for milling during the two dry spells. Pumping stored water from the mine could be scheduled for off peak hours to take advantage of lower power rates. To meet these objectives an underground bulkhead capable of withstanding high water pressure up to 2000 ft head (866 psi) was constructed in the spring of 1992. The bulkhead site was at the 2400 level at the Pamour No.1 mine. A major consideration was the requirement to construct a safe bulkhead and to minimize water leakage from the bulkhead.Figure 1 shows the bulkhead location."

Jan 1, 1994

By M. Fafard, D. Picard, J. -F. Bilodeau, G. Soucy

To simulate adequately the behaviour of a Hall-Heroult electrolysis cell, a finite element model must take into account the properties of each material. However, it has some lacking knowledge on the mechanical behaviour of materials, like the long-term visco-elastic (creep/relaxation) behaviour of cathode. A three-dimensional model is then proposed in this paper and will be ready to be implemented in the finite element code FESh++. The model was developed using the three-dimensional model based on thermodynamic of irreversible processes where the choice of the internal variables is based on a phenomenological approach. All parameters of the model are represented by constant constitutive tensors and the temperature and chemical dependencies are taking into account through scalar functions multiplying the constant constitutive tensor. The goal of the first part of this project was to determine the parameters of the threedimensional visco-elastic model at the reference state (virgin material at ambient temperature) of three different cathode materials. This paper presents the theoretical model and the results of creep tests at ambient temperature for the semi-graphitic carbon cathode.

Jan 1, 2006

By M. M. Papic, J. C. Whitehead

"A sample of Hat Creek coal has been extracted using supercritical aromatic solvents in a laboratory-scale extraction unit. Extract yields in the range 21 to 27 per cent of dry-ash-free coal were obtained.These yields are significantly lower than yields available from high-volatile bituminous coal and some lignites. Thus in a combined extraction/hydrocracking scheme for the production of liquid fuels from Hat Creek coal the char product would exceed that required to supply the energy and hydrogen requirements of the process. Excess char could be used for the production of power or gas for sale.IntroductionThe Supercritical Gas Extraction (SGE) process developed by the U.K. National Coal Board operates in two stages: an extraction stage in which a coal extract is separated from mineral matter and undissolved coal and a subsequent hydrogenation stage.The SGE process is based on the ability of a compressed supercritical fluid to dissolve relatively high molecular weight substrates. It is operated under conditions where a hydrogenrich portion of the coal is selectively extracted in a short residence time extraction stage leaving a hydrogen-deficient char. The process schematic shown in Figure I illustrates that the extract produced is separated from the solvent and passed to a conventional hydroprocessing stage while the char product is utilized in the production of heat, power and hydrogen for the process. An extract yield in the order of 50 per cent dry-ash- free coal represents a ""balanced"" case for such a process in which there is just sufficient char for the provision of these commodities."

Jan 1, 1985

By Sina Mostaghel, M. Guo, E. Klaffenbach

The current paper is focused on evaluating the behavior of copper in a copper production slag and the assessment of metal recovery possibilities. For this reason, thermodynamic calculations were carried out to determine the influence of parameters such as slag composition, temperature and oxygen partial pressure on recovery of non-ferrous elements. It was found that the formation of a solid face centered cubic (fcc) phase, mainly consisting of iron, limits the extent of reduction that can be achieved for an industrial process. However, it could be discovered that solubility of iron in the Cu-rich liquid alloy strongly depends on presence of other elements, particularly arsenic. As part of the results of this study, the solubility of Cu in the slag at onset of fcc phase formation is presented as function of temperature, oxygen partial pressure and concentration of MgO and CaO. It was concluded that lower temperature (1200°C) and higher CaO addition (16 mass-% in this study), would result in the highest achievable copper recovery from slag. INTRODUCTION Copper slag is produced as a by-product of the copper production process. The slag is still containing a high amount of copper and other valuable metals. This demands further treatment of the slag as a secondary source of metals. In addition, the physical/mechanical properties of slag allow its use in several applications such as hydraulic engineering, civil engineering, as an abrasive and many more. These applications help reducing the use of natural resources like rock and sand. By decreasing the content of heavy metals such as Cu, Pb, Zn and As in the slag, its application in abovementioned fields becomes more attractive as the probability of releasing these elements to the environment is further reduced. To develop a pyrometallurgical slag reduction process, it is necessary to understand what describes the end point of the reduction. This point is expected at maximum copper recovery without facing operational challenges. Existing literature provide some information on the effect of different parameters such as temperature or concentration of different slag formers, on solubility of copper and heavy metals in different phases. However, due to complexity of industrial slags, equilibrium experiments and accurate thermodynamic modelling are essential to be able to reliably predict the behavior of different elements in the system and determine the end-point of reduction.

Jan 1, 2019

By G. Ergin

The interactions taking place between Al-Mg alloys and the bed media during aluminum filtration are not yet well understood. These interactions were studied using the infiltration technique. The reaction interface was analyzed using different techniques such as SEM and TEM. Only spinel formation was observed at the interface regardless of the type of alumina and contact time. This paper discusses the results of the study.

Jan 1, 2004

By G. J. Desroches, E. Ozberk, M. J. Collins, B. D. Krysa, I. M. Masters

The zinc refinery of Hudson Bay Mining and Smelting Co., Ltd. went through a major modernization in 1993, when the roaster and the calcine and fume leach circuits were replaced by a new Sherritt zinc pressure leach plant. The HBMS plant, in Flin Ron, Manitoba, represents the first commercial application of the Sherritt two-stage zinc pressure leach process, with /00% of the zinc concentrate feed processed in autoclaves. The process design of the new plant required definition of the deportments of elements such as antimony, arsenic, chlorine, cobalt, fluorine, germanium, magnesium, manganese, selenium, tellurium and thallium. This paper describes the deportment of these elements in the commercial zinc plant during the first nine months of pressure leach operation, and compares these results with operations prior to the introduction of pressure leaching, and with the results of tests carried out in the She"itt laboratory during the process development phase.

Jan 1, 1995

By Tommee Larochelle, Henry Kasaini

"Simulation of rare earth element solvent extraction processes for plant design and optimization is complex, requires extensive bench scale and pilot scale testing, and is traditionally performed using proprietary algorithms. The complexity of simulation is mainly due to traditional simulation software solvent extraction modules not being designed to simulate rare earth separation processes because of the interaction between each element. This paper presents an alternative method for designing and optimizing rare earth element solvent extraction separation processes using METSIM to converge each stage of the battery individually until the full battery reached ultimate convergence. A feed-forward controller is used to control the organic to aqueous flow ratio feeding the solvent extraction modules. This method minimizes the complexity of simulating such processes by using inexpensive batch solvent extraction data, and allowing for rapid theoretical optimization, by varying the process configuration and parameters from a graphic interface instead of the traditional code-based interface of most proprietary models. Comparison of the model predictions to pilot plant data reveals that the method can be used to accurately model rare earth solvent extraction processes, as illustrated by its application in the development of Rare Element Resources innovative process.INTRODUCTIONThe Rare Earth Elements (REEs) consist of 16 metals, specifically the 15 lanthanide elements and yttrium, which is typically found in the same mineral deposits as the lanthanides. Scandium can be associated with the rare earth elements, but is usually only present in trace amounts, and therefore omitted. The term “rare earths” originates from an old term used to designate minerals (earths) and their believed scarcity upon their initial discovery. The rare earths designation is now considered a misnomer because it was demonstrated that the crustal abundance of some rare earth elements, such as cerium, is known to be higher than many common metals, such as copper. However, enriched deposits are fairly uncommon compared to other similarly abundant metals. The REEs are typically divided into groups commonly consisting of light rare earths (LREEs), medium rare earths (MREE), and heavy rare earths (HREEs). Light rare earth elements include lanthanum to neodymium, medium rare earths include samarium to gadolinium and the heavy rare earth elements include terbium to lutetium, and yttrium. The REEs exhibit similar chemical characteristics and are usually extracted from the ore and processed into a mixed rare earth concentrate. The rare earth concentrate requires further processing in order to separate the REEs from each other and produce a series of single element products."

Jan 1, 2016

By Z. Liang, Z. Q. Liu, X. F. Li, H. L. Zhang

"Dynamic characteristics of frozen soil is important for the safe, effective and rapid construction in cold regions and artificially frozen engineering. In this paper, dynamic characteristics of frozen clay with various low temperature and different strain rate were studied by using Split Hopkinson Pressure Bar (SHPB) test and numerical simulation test. Variation of dynamical parameters and dynamic stress-strain curves of frozen clay were obtained and analyzed. The results of these test show that: Frozen clay exhibits temperature effect and strain rate effect that the failure type tends from plastic failure to brittle failure with the increase of strain rate or decrease of temperature; Under impact loading, frozen clay exhibits three typical dynamic stress-strain curves as strain rate increases, and the maximum strain of frozen clay only linear increases with strain rate.INTRODUCTIONArtificial freezing technology has been widely used in the construction of underground engineering, such as the coal mine shaft, the deep foundation pit, the urban metro and subsea tunnel, etc. Research on dynamic mechanical behavior of artificial frozen soil will provide supports for these artificially frozen engineering (Xu et al. 1998; Ma 2009). However, the dynamic mechanical research on frozen soil is mainly carried out at low frequencies or small amplitudes of the waves, behavior of frozen soil under impact loads or high strain rate loads has not been made clear."

Jan 1, 2015

By G. Dodbiba, A. Otsuki, T. Fujita, J. Ponou, A. Shibayama

"The different types of nano to submicron particles, which are well-dispersed nano particles, coagulated nano particles or settled submicron particles, have been measured by the interactive force apparatus (IFA). The information is very useful for mineral processing treatment. The IFA can measure the particle size distribution in low to high concentration of particles in liquids and non-light transparent liquids. Here, mainly the emulsion and bubble size measurements are described.Emulsion (w/o type) is prepared with oil and water mixture. The nano to micro emulsion particle size is usually measured by light scattering method. The particle size distribution of emulsion of light oil measured by IFA agreed well with the one by the dynamic light scattering (DLS) method. The water size distribution in emulsions of gasoline is difficult for the small reflection index and C heavy oil is difficult for the black color by DLS method. The IFA can measure both emulsions.There are many methods to measure fine air bubbles, however, the finer nano size measurement apparatuses are DLS method and IFA. A “ghost” peak appeared in the large particle micron meter size in DLS method. The mean diameter in IFA is similar with DLS for the nano meter size. INTRODUCTIONParticle size distribution measurement of nano to submicron particle, emulsion and bubble size distribution are very useful for ultrafine particle separation and characterization of fine particles by the necessity of recent fine minerals separation (For example, Li et al.2016, Mikhlin et al.2016, Wang et al.2013). As for the size measurement of solid particles in liquids, three different types of nano to submicron particles, that are well-dispersed nano particles, coagulated nano particles or settled submicron particles, have been measured by the interactive force apparatus (IFA). The particle size distributions are compared with the one of dried particles measured by TEM or SEM. The well-dispersed nano particle size distribution by IFA is influenced by the nano size surfactant micelles and becomes smaller, when compared with the TEM result. The size distribution of nano size of magnetite particles in water is influenced by the isoelectric point and the mean diameter of coagulation becomes larger. The particle coagulation in diluted suspension is about 2nm smaller when compared with the higher concentration. The submicron nickel particle size distribution is well agreed the result by SEM. The coagulation effect is small in the submicron size of nickel powder in water (Fujita et al., 2013). In this paper, the emulsion and bubble size measurements are mainly described."

Jan 1, 2016

By S. Bantubani, I. Mc Dougall, S. Arjun, H. Joubert, R. Hansraj

The requirements determining the design of the Söderberg electrode columns used in base metal applications are different to those of other industries. There is a strong trend to position the contact shoes above the furnace roof in order to reduce the risk of water leakages directly onto the furnace bath. Tenova Pyromet has adapted its proven electrode column design for application on base metal electric furnaces based on these requirements. The design modifications implemented as well as considerations regarding the overall electrode-roof-furnace arrangement are discussed. Equally important is the management of the Söderberg electrodes to prevent over or under baking. Tenova Pyromet has developed the AutoFurn™ furnace controller to not only optimise furnace operations, but to improve electrode management. An overview of the electrode management control philosophy implemented by AutoFurn™ is provided, focusing on intelligent electrode regulation, slipping and baking. INTRODUCTION Tenova Pyromet has developed an electrode system for use in base metal furnaces, which builds on the experience that Tenova has gained during the past 30 years with electrodes in the ferroalloy and base metals industries. In base metals applications, an important safety consideration is the minimization of water within the furnace and on the furnace roof. In addition, direct contact between copper equipment such as contact shoes and pressure rings and the contents of the furnace is discouraged. In a 3 phase AC furnace, three electrode columns transfer the electrical energy to the furnace bath. Both Söderberg and prebaked carbon or UHP graphite electrodes are in use in base metal furnaces. In each column, the electrode is held in position by a hydraulic slipping and regulating device, a pressure ring and contact shoes. The electrodes can operate in a submerged-arc or brush-arc configuration, where the electrode is immersed in the slag or a short distance above the slag (Mc Dougall 2013). The electrode equipment is divided into an upper and a lower electrode assembly. The self-baking Söderberg electrode is made from lengths of steel casings that are added to the top of the electrode column and welded into place. Carbon electrode paste is added to the inside of these casings and is baked to form a solid tip in the region of the contact shoes. The working platform that surrounds the area where new electrode casings are added, is electrically isolated from the building and each electrode is isolated from the others to ensure the safety of the personnel who perform the electrode casing additions.

Jan 1, 2019

By C. Cekerevac

The paper addresses some geotechnical issues related to the construction of the Deriner dam and HEPP. Design considerations and rock stabilization measures are presented for the excavations which took place in a highly fractured and weathered rock mass prevailing on site. Particularly, the shallow excavations for the overflow spillways tunnels are discussed. These present huge openings that are 12 m wide and 18 m high in portal areas, with an overburden of approximately 20 m, for which numerical finite element analysis and structural discontinuity analysis have been performed to ensure safe excavation process and future operation.

May 1, 2009

By R. C. Bryce

"Accident prevention has been an on-going priorty for five years. In 1987, adherence to the ILCI five-star rating loss control program was started, and a first star was awarded. Extensive training programs have been undertaken to establish standard procedures and upgrade employee skills. Due to its location, Selbaie owns and rents housing in the town of Joutel and contracts a busing service to and from the mine. Employees from other areas are lodged in dormitories and fed in the site dining room. Accounting and warehousing services are carried out in efficient fashion. Employee relations are structured to provide prompt resolution of complaints and differences. No lost time due to industrial relations differences has been encountered during the history of the mine.Safety and Loss ControlAll mines are concerned and occupied with a wide range of activities to ensure the safety of its employees. Selbaie is no exception. Programs to achieve success in safety and loss control have been implanted since the start of construction and development at Selbaie and have followed three interesting stages of evolution."

Jan 1, 1990

By K. E. Waters, N. Brodusch, R. Gauvin, C. Teng, H. Demers

Rare earth elements play an increasingly important role in renewable energy devices and high-end electronics. In this project, the composition and morphology of REEs-bearing minerals are characterized with a field-emission scanning electron microscope at high spatial resolution and high counts rate using an X-ray silicon drift detector system. High spatial resolution imaging and energy dispersive X-ray microanalysis were applied at low and high magnification to obtain the composition of each phase in the minerals. From the standardless quantitative analysis results, the amount of REEs in each phase was measured and the relationships between those phases were identified.

Jan 1, 2014

By R. K. Jonas

Many leading copper and other mineral processors have rapidly adopted advanced controls in last 5-10 years. Almost 600 multivariable predictive controls have been installed in mineral processing, and almost 50% of those are in copper concentrator plants. In most cases, mineral processors rely on 3rd party support to implement these advanced technologies. One challenge facing advanced control user is the selection providers and services for these technologies. The trend has been towards the use of multivariable predictive control and use of technology provider’s services. This paper will discuss status of advanced control, and the merging trends in the mining industry. A review will be presented of how advanced control is being applied in the mining industry over the last decade, and how user challenges are being overcome. Next the emerging uses of multivariable predictive control (such as multi/inter-unit optimization), focusing on the latest trends in concentrator plants. Finally, a review will be made of emerging technology advances in the that can be advantageous to mineral processors. INTRODUCTION Review of advanced control in mineral processing Advanced controls are serving an increasing role to improve processing plant operations and profitability. As advanced control is being installed into more mining processing plants such as copper concentrators, many of these plants are concerned about the selection technologies and vendors to support the installation and maintenance of these controls. In a study by Jonas and Craw (2011), they found that most new users have not had prior experience with advanced controls. It is the author’s experience of almost 30 years in advanced controls that most mineral processers considering advanced controls can benefit from better understanding of the technologies and their support requirements.

Jan 1, 2019

By Robert B. Parsons

"Several recent cases indicate that the Courts may be leaning toward a more favourable treatment of mine closing and related costs. In this article, we look at two recent cases, Burnco Industries Ltd. and Nomad Sand & Gravel Ltd. The former was heard before the Federal Court - Trial Division and the latter before the Tax Review Board.It appears that in certain situations mining companies may now be able to sustain current deductibility of estimated mine closing costs during the productive years of the mine, rather than waiting until either the date on which mining ceases or the reclamation and similar activities commence. This would be of great benefit to the mining industry, as waiting until the bitter end often means that there are no revenues available against which the expenses may be offset and, hence, no tax relief.IntroductionUnder the Income Tax Act in Canada, taxpayers are not permitted any deductions in respect of an outlay or expense in determining income from a business or property, except to the extent that such expenditures are made or incurred by the taxpayer for the purpose of gaining or producing income. In addition, no deductions are permitted for amounts transferred or credited to a reserve, contingent account or sinking fund except as expressly permitted by the Act.In large measure, these provisions are relevant to the mining industry to the extent that they determine the periods during which expenses may be charged against revenues for income tax purposes. Several recent cases have indicated that the Courts are leaning toward a more favourable treatment of accrued costs in the mining industry than was previously considered to be the case."

Jan 1, 1982

By G. K. Quainoo

Investigation by researchers on the application of various thermo-mechanical process histories on 6000 series aluminum alloys have found improvements in mechanical properties of these alloys. However, natural aging, which is unavoidable in the automotive processing line, has been found to have deleterious effect on subsequent artificial aging properties in these alloys. In this study, the evolution of yield strength during natural aging modeled by Lloyd and Gupta has been adapted to investigate the effect of cold deformation on the natural aging kinetics in AA61 11 by means of tensile testing, differential scanning calorimeter (DSC) and scanning electron microscopy (SEM). Also, intermetallic particles in the alloy were extracted from the matrix and XRD performed on them to ascertain their composition and their role on the kinetics in the alloy. The results show that cold work effect on the natural aging kinetics of AA6111 is in very good agreement with the model proposed by Lloyd and Gupta. The kinetics of natural aging in AA6111 aluminum also decreases with increasing level of cold work. This is attributed to dislocations serving as sinks which consume quenched-in vacancies formed during the early stages of clustering. The phases of the intermetallic particles identified in AA6111 are those of a-A15Mn12Si7 and a-A15MnSi.

Jan 1, 2007

By K. S. Coley, M. A. Rhamdhani, G. A. Brooks

Interfacial phenomena in high temperature reactions such as between iron alloy and slag is well documented but not fully understood. It is believed that a gradient of oxygen concentration plays an important role to the occurrence of such phenomena. This article describes the results from the continuation of the study of interfacial phenomena between Fe-Al alloy droplets and CaO-SiO2-Al2O3 slag. Materials characterization techniques involving microscopic observations, depth profiling, bulk, point analysis and were carried out. The roles of oxygen as well as other factors that contribute to the interfacial phenomena were evaluated. The results and their implications to steelmaking will be discussed.

Jan 1, 2004

By M. J. Nicol, C. van Wensveen

The kinetics of the oxidation of thiosulfate by copper(I I) in ammoniacal solutions have been studied in the presence and absence of dissolved oxygen. The formation of an intermediate mixed ammine/thiosulfate copper(II) complex ion has been confirmed and the rate of the reaction monitored by simultaneous on-line spectrophotometric, dissolved oxygen and potentiometric measurements. The rate of the anaerobic oxidation of thiosulfate by copper(II) was found to be orders of magnitude slower than that in the presence of dissolved oxygen and is inhibited in the presence of ammonia and anions such as sulfate and chloride as a result of competition with thiosulfate for the axial coordination sites on the copper(II) tetrammine complex. In the presence of dissolved oxygen, it was found that the copper(I) thiosulfate complexes are only very slowly oxidized while the copper(I) diammine complex is rapidly reoxidised to the copper(II) state. Thus, the initial rapid reaction with copper(II) leads to a pseudo steady-state condition in which the concentration of copper(I) is relatively constant and the rate of oxidation of thiosulfate can be predicted from the measured rate of oxidation of copper(I) by oxygen in ammoniacal solutions. The effects of the concentrations of ammonia and thiosulfate on the oxidation rate can be rationalized on the basis of the above coupled to the species distribution of copper(I) in the ammonia/thiosulfate system. It is shown that, with relatively simple measurements of dissolved oxygen and copper concentrations, the rate of oxidation of thiosulfate can be predicted under typical leaching conditions.

Jan 1, 2005

By Raynald Vézina, Richard Leclerc, Jean Boissonnault, Louis P. Gignac, Gérald Veillette

Since mid-1989, Cambior has increased its producing gold mines from four to six, having acquired the Chima Mine and brought the Silidor Mine onstream. In June 1990, the company announced that the Mouska project would also be put into production. Gold production reached almost 190 000 ounces in 1989 and is expected to exceed 220 000 ounces this year. Cambior has also a non-gold operation with an interest of 50% in the Niobec Mine and has recently signed an option agreement in the development of the Lac Knife graphite deposit in northeastern Quebec. During the past year, the company has extended its exploration activities to the United States and Indonesia, and now has interests in nearly 80 properties. Last May, Cambior signed an option agreement with Golden Star for a gold deposit in Guyana, the OMAI Project, containing at least 2 000 000 ounces of gold in situ.

Jan 1, 1990

By R. Roufail

Mineral liberation is accomplished by comminution and is the first step towards achieving successful downstream processes such as flotation or leaching. In metal mining, one of the most effective comminution methods that is used to grind particles below 10 microns is stirred milling. In this paper the study of particle breakage mode vs. mill operating parameters is addressed. Stirred mills' grinding action is mainly attrition, but operation can be manipulated to include breakage by compression or impact loading. Macro and micro analysis of particle breakage and grinding mechanisms are correlated. Macro analyses convey information that relates grinding mechanism to particle size and shape. It is speculated that the breakage mechanism in the horizontal stirred mills is massive fracture for the coarsest particles and attrition (abrasion) close to the grinding limit where the size reduction ratio approaches 1.0. For micro analysis, the particle breakage mode has a direct impact on fracture type either transgranular or intergranular. Intergranular particle breakage leads to higher mineral liberation compared to transgranular breakage. Similar minerals would have more homogeneous properties that convey a stronger bond compared to dissimilar, heterogeneous mineral bonds. Transgranular fracture requires higher energy than inter granular fracture; trans granular fracture toughness of pure single phase mineral is about 10-14 % higher than the intergranular fracture toughness. This communication presents the results of an investigation to assess how operating conditions can affect trans- vs. inter-granular breakage.

Jan 1, 2009