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By Alf Hartling

"Most of the Paleozoic section of the Williston Basin is a thick accumulation of numerous carbonate to evaporite, shallowing upward, cyclic sequences. These sediments were deposited in broad epeiric seas, and the deposition of the evaporite facies marked the final stage of each cycle. Many of the sequences display a pervasive replacement dolomite in the uppermost portion of the carbonate units. This secondary dolomitization is, at least in part, an early diagenetic event, synchronous with evaporite deposition.The inception of evaporite precipitation resulted in the seepage of a dense, Mg-rich brine into the underlying sediment. The heavy brine moved down the gentle regional dip displacing the more normal marine interstitial pore fluid and dotomitized the primary calcitic sediments en route. The supply of Mg-ions decreased away from the source, and correspondingly, the degree of dolomitization decreased and larger crystals formed because of slower nucleation at fewer sites.The seepage refluxion of dolomitizing brines gave rise to the frequently observed textural variation of cryptocrys talline, impervious dolomite grading into a finely sucrosic, permeable dolomite down-dip. This diagenetic facies change provides the critical up-dip barrier for potential hydrocarbon reservoirs. The lateral pool boundaries are controlled by either structural relief or a similar diagenetic facies change. The reservoirs are capped by the tight evaporites.Hydrocarbon production is attained from diagenetic traps in the Mississippian Oungre Zone and the Ordovician Red River 'C' Zone . Reservoir creation and the pooling mechanism are the result of dolomitization by the seepage refluxion of dense, Mg-rich brines beneath restricted, hypersaline lagoons. When formulating an exploration/ exploitation program for these oil prone horizons, it is essential to understand the complete geological history in order to establish where the reservoirs will be found and to define the areal extent of each accumulation."

Jan 1, 1984

By Youjun Tao

Falcon centrifugal gravity separation tests were conducted to study desulfurization and de-ashing performance with different size fractions of a high-sulfur Chinese -0.5mm fine coal in a dense medium. Performance indicators such as combustible recovery, ash and sulfur rejection, and desulfurization efficiency were used to evaluate the separation efficiency. The results show that for -0.5 mm coal particles, all performance indicators except ash rejection are higher for the Falcon concentrator than for flotation. More specifically, for the +0.125 mm size fraction, Falcon centrifugal separation produced better ash and sulfur rejection performance than froth flotation. However, the Falcon concentrator also showed higher combustible recovery but lower ash and sulfur rejection than froth flotation for the -0.125 mm size fraction.

Aug 1, 2013

By G. Merle, David L. McKay, Elmar Randveer

"THE ENGINEERING AND TECHNICAL SERVICES department is responsible for supplying the following services:1. Administration and co-ordination of the work required for capital projects.2. Engineering, design and drafting services for inplant changes or improvements as requested by the operating• and maintenance departments.3. Rock mechanics.4. Preparation of plans and layouts required for efficient extraction of the ore as mutually agreed with the mine operating departments.5. Mine planning and long-term schedules in co-operation with the mine operating departments.6. Grade control (long term and short term) and the preparation of ore and waste removal schedules to maintain a uniform grade of mill feed. This also includes the calculation of metal reserves and metal production forecasts.7. Surveying, underground and surface.8. Operations research at the mine site.9. Industrial engineering.10. Chemical analyses and assays.11. Instrumentation.12. Environmental control.A staff of approximately 35 supervisors, engineers and scientists, and 80 technicians, supply the foregoing services. Consulting engineering and drafting firms are used to supply specialized services and technical personnel in-house at Timmins to handle overloads on capital projects under the direction of Ecstall engineers.The operating and maintenance departments depend on the engineering department to supply engineering, design and drafting services for any new facilities or for any planned alteration to existing facilities. To do this efficiently requires a high level of communication and co-operation with these departments. This has been a major factor in developing the present organization of the department shown in Figure 63.The organization is predicated on a strong central technical and engineering resource from which personnel can be assigned responsibilities for different projects, and in different areas, as the work load demands. Job satisfaction is very high because of the variety and challenge in the tasks. Additionally, participation in projects with production and maintenance personnel broadens each technical employee's knowledge of operating and maintenance problems."

Jan 1, 1974

By N. Waters

"Nickel saprolite ores are normally mined as feed to Fe-Ni smelters or Ni matte smelting operations. The smelting processes typically require high Ni cut-off grades of approximately 1.5 to 2.2% Ni, depending on the operation. These very high cut-off grades result in a significant portion of the saprolite profile being regarded as “waste” and hence having little to no value. The Starved Acid Leach Technology (SALT) was developed to recover nickel and cobalt from nickel saprolites and Caron plant residues. Relatively small amounts of acid are applied to ground saprolites or Caron residues in order to selectively leach nickel and cobalt. The leaching is performed atmospherically under low free acid conditions. Nickel and cobalt may be recovered from the leachate as a mixed hydroxide. The mixed hydroxide may be added directly to a saprolite smelting operation or refined separately. InCoR Technologies is advancing the application of SALT at a number of sites. Bench scale testing has provided a relationship between acid addition and nickel extraction in leaching. Conceptual engineering studies have been completed by SNC Lavalin. The simplicity of the SALT technology provides the benefits of low capital and operating cost and an expected rapid ramp up to full production.INTRODUCTION The recent history of hydrometallurgical nickel laterite treatment plants has demonstrated mixed financial and operational performance. Table 1 summarizes the next generation plants built after the financial and/or technical failure of the Bulong, Cawse and Murrin-Murrin plants in Australia. The Coral Bay plants (Line 1 and 2) stand out (and now Taganito) as relatively low capital cost, simple (no acid plant, production of mixed sulfide product), and modest in scale (10, 12 and 36 kt Ni/a). However, the other plants in the list (Ravensthorpe, Ramu, Goro and Ambatovy) are all characterized by financial and technical challenges. All plants have a very high capital cost ($67,000 to $120,000 USD/annual t of Ni production). Ravensthorpe was sold by BHP Billiton after a poor startup. Ramu has had a steady ramp up but only produces mixed hydroxide for refining by others. Goro has had an extended construction period (since 2001), is high cost and has been very slow to ramp up to design production rates. Ambatovy has had a steady ramp up."

Jan 1, 2017

By T. B. Williams

A SEARCH of the records indicates that evidences of accumulations of petroleum and natural gas within the boundaries of British Columbia were discovered at approximately the same time as were those of Alberta. They probably would have been developed as soon bad it not been for the fact that they are in such uninhabited parts of the Province. Even today, the seeps of the Flathead area, and the later discovered extensive seeps of the Peace River area, have been seen by very few people. From the geological evidence, there is reason for believing that British Columbia soon will be a petroleum producing Province. Fifty-eight operators, both companies and individuals, are now backing the money and the effort which they have invested with us, for the most part within the last three years, in a belief that this is so. The promulgation of the Petroleum and Natural Gas Act in 1947 marked the beginning of a new phase with regard to the exploration and the development of our petroleum and natural gas resources. Since August 15th, 1947, the date on which the Act came into force, the area under exploration bas increased from a few thousand acres, held by lease under the Goal and Petroleum Act, 1986, to 10,460,115 acres, including all active permits, licences, and leases. In addition there are 192,720 acres under application, bringing the total under issue and application to 10,652,835 acres. The total area is comprised of 105 permits, 20 licences, and 26 leases under the 1986 Act. The permits and licences, which ?represent active exploration and development, are held by a total of 82 companies and 26 individuals.

Jan 1, 1951

By J D. McDonald

This paper outlines the function of the Safety and Compensation Division of the Mining Association of British Columbia. After a general discussion of safety and the safety program now being followed in B.C., the author goes on to describe the wide-ranging aspects of compensation payments and company assessment rates. Special attention is also given to the problem of silicosis in mining operations. In appendices to the paper, the experience rating plan of the mining industry is compared to that recently adopted for the construction industry. Introduction The Mining Association of British Columbia consists of fifty-five member companies, including virtually all the producing mines as well as the larger exploration, contracting and development companies. On completion of an extensive study of safety and compensation in the mining industry, the Mining Association of British Columbia instituted a Safety and Compensation Division in 1954. The director of the Safety and Compensation Division reports to the Executive Committee of the Association. There are two main functions of this Division. First is the prevenion of accidents by encouraging

Jan 1, 1965

By M. Krasowska

Dynamics of collision and kinetics of the bubble attachment to hydrophobic solid plates (Teflon) of different surface roughness were investigated. The experiments were carried out in such a way that probability of the collision and probability that the detachment will not occur were equal always 100%. Thus, it was possible to determine effect of the surface roughness on the bubble attachment (three phase contact formation, TPC) only. A high-speed camera (1182 Hz) was used to record the velocity variations, bouncing and time of attachment of the bubble colliding with Teflon plates having different surface roughness (5 different plates). Roughness of the plate surfaces was modified in a mechanical way using different abrasive papers. It was found that the roughness had a crucial influence on the time-scale of the TPC formation and attachment of the bubble colliding with the Teflon plates. Despite high hydrophobicity of all plates (contact angles 1100 -115º) it was observed that at the smoothest surfaces (called "Teflon I" and "Teflon II" and having surface roughness below 1 um) there was no attachment during the bubble first collisions. Prior to the attachment four or more "approach?bouncing" cycles of the colliding bubble were observed there and simultaneously the bubble shape varied rapidly within time intervals below 0.85 ms. Time of contact of the colliding bubble with the Teflon plates was very short; 2-3 ms. These results indicate that during that short time of the collision the liquid layer separating the colliding bubble and the solid surface did not reach a critical thickness of its rupture.

Jan 1, 2006

By Jonathan Peck, Carl Hendricks

"Global Positioning Satellite (GPS) based positioning and navigation systems have been recently developed and implemented by AQUILA Mining Systems Ltd. on blast hole drills and electric cable shovels in Canadian open pit coal and iron ore mines. These systems enable the location of the drill bit or the shovel tracks to be accurately determined in three dimensions. The position of the drill or shovel is displayed to the operator via a real-time, Moving Map Display (MMD) on an LCD-VGA screen. The MMD allows the operator to accurately navigate the drill from blast hole to blast hole or maintain a desired shovel grade or face position, with respect to displayed bench features. The maps for the MMD are downloaded from the mine office via laptop or radio link as required or as mining plans change.To obtain reliable, accurate and real-time3D positions of mobile mining equipment, proven GPS technology has to be utilized. The GPS components need to operate reliably under the severe environmental conditions that exist on board mobile mining equipment. In addition, they have to contend with varying pit geometry’s and satellite configurations, with little or no performance degradation. These issues were initially examined in December1993 during a feasibility project between AQUILA and Gregg River Resources Ltd., in relation to implementing GPS systems on blast-hole drills.To achieve certain design objectives, AQUILA Mining Systems Ltd. has developed navigation systems for cable shovels and blast-hole drills based around off-the-shelf, high precision GPS components. These systems utilize the AQUILA Advanced Monitoring Platform (AMP), to display graphically, via the MMD, shovel grade and drill position to the operator to within ±12 inches of design coordinates. Production prototypes have been installed on a Marion 301 cable shovel and a Bucyrus-Erie49-R Series III drill at the Fording River Mine in August, 1995, at the Wabush Mine on a Bucyrus Erie 190-B shovel in June, 1995, and on a GD120 drill at Gregg River Resources Ltd. in January, 1996. All these systems have undergone field trials to test system components and functionality’s under actual production conditions. This paper will discuss these GPS-based positioning and navigation systems in subsequent sections."

Jan 1, 1997

By James R. Hunter, Sandra K. Zacharias, Ursula M. Franklin

Archaeometallurgical remains can be a valuable source of information about past technological activities and, by inference, the societies that undertook them. Material traces of former metal-producing or metal-working centres can include raw materials, products, or metallurgical installations such as mines, furnaces or forges. Of these remains, the most common is slag, often left undisturbed since its original production. Physical and chemical analyses of archaeological slag and metal can often reveal the processes and materials involved in their formation. Mineral composition and softening temperature of a slag, for instance, can indicate the conditions of the metallurgical operation, such as temperature and atmosphere and, thus, help identify metallurgical processes which took place at a site(1). The present report illustrates the value of such analysis. Metal-working remains from Sainte-Marie among the Hurons, near Midland, Ontario, on the south side of Georgian Bay have been analyzed in order to determine the techniques and processes used by the 17th-century blacksmith who worked at the mission headquarters from 1642 to 1649. Samples were selected from a very large collection of blacksmith refuse which was excavated from the site by archaeologist Kenneth Kidd in 1941-42(2).

Jan 1, 1999

By Robert B. Parsons

"Once all the hullabaloo about Finance Minister Wilson's April 27 budget died down (or was it an April 26 budget?), the pain of the budget papers began to sink in. Individuals and corporations will have to dig deeper and pay more taxes - and government will continue to dig deeper and spend more. The irony of the situation is that higher tax rates actually make flow-through shares more attractive as a tax-deferral investment - a bittersweet ""bravo"" for the mining industry.INTRODUCTIONFor the first time in Canadian history, a major budget address has taken two days to deliver. Of course, it's not a case of long-windedness, but rather a case of a hastily called press announcement on April 26 in response to a budget leak, followed by a formal budget speech on April 27.The general reaction of the business community to the budget was to the effect that the tax hikes are acceptable, but the government's failure to curb spending is less than acceptable. Mr. Wilson's reported response indicated that the government had never promised to cut spending, and that increased government spending would actually benefit the country. That age-old debate will doubtlessly continue for generations.In any event, three noteworthy components of the budget papers are:• Personal income tax rates increase effective July I, 1989;• A ""large corporations tax"" (in effect 'a corporate ""minimum tax"") is effective July I, 1989; and• Federal sales tax increases are effective from June 30, 1989, to be replaced by a national sales tax in 1991.A brief overview of these and other budget proposals follows."

Jan 1, 1989

By G. Wren

As base metal sulphide resources become increasingly challenging to process, producers seek alternative options to treat concentrates. This study considers the mineral, elemental, and leaching character of a West Australian nickel sulphide deposit (Cosmos Nickel Project). After a brief review of the published work bench top leach tests were conducted to examine the factors which impact the kinetics of nickel sulphide leaching such as particle size, temperature, acid strength and type, concentration of copper sulphate and sodium chloride, and oxygen partial pressure. The effect of sodium chloride was considered due to the common occurrence of hyper saline water at West Australian nickel sulphide mine sites. Ultrafine grinding to an 80% passing size of 10 µm resulted in high nickel leaching efficiency. Moreover, higher concentrations of acid, copper(II) and sodium chloride also gave higher nickel and cobalt leaching efficiencies but arsenic precipitated as FeAsO4. Under the most suitable conditions the extractions of nickel, cobalt and arsenic at 90oC after 6 hours were >95%, 90% and <5%, respectively. The comparison with results from high pressure operations indicates the possibility of using a hydrometallurgical flowsheet based on fine grinding and atmospheric pressure leaching and warrants further investigations.

Jan 1, 2014

By Allan P. Fawley

ONE hundred miles from Vancouver, at an elevation of 4,000 feet, is the Pioneer mine. It is situated on Cadwallader creek, a tributary of Bridge river, and is reached by travelling from Vancouver to Squamish by boat, a distance of thirty-two miles, from there by train to Bridge River (one hundred and seven miles), and finally by automobile across Mission mountain .(7,000 ft. elevation) to the mine (fifty-six miles): a total distance of one hundred and ninety-five miles. Prior to 1924, many Companies had examined the Pioneer, which had been developed by shaft to a depth of 200 feet, but, while values were good, the small size of the ore-shoot discouraged large investors. In July, of that year, opera-tions were re-commenced by the late David Sloan and, on sinking further, the ore-shoot was found to lengthen greatly as well as to ex-tend in depth, while remarkable gold values also were encountered. When, later, the price of gold rose from $20 to $35 per ounce, the mine was in an excellent position to take full advantage of the increase + and not only became an extremely profitable enterprise itself but its success greatly stimulated the search for and development of other 1-gold properties in British Columbia.

Jan 1, 1937

By Phillip I. Merritt

"IntroductionDuring and since• the war, it has been my privilege to work closely with those in Canada who are responsible for the vital raw materials needed in our co-operative atomic energy programme. The understanding which has developed between our two groups in this all-important enterprise has been a great source of pleasure. We in the United States are aware of the importance of the contribution made by Canada to this project, and we look forward to continuing our mutually advantageous relationship.The impact of World War II, and the decision by Canada, Great Britain, and the United States to join in a programme for the development of atomic weapons, created a sudden and immense demand for uranium minerals. Early in the raw materials programme, it was evident that sufficient raw materials to fulfill war-time atomic weapon requirements could be secured from three sources: the rich pitchblende deposits of the Eldorado , mine at Great Bear lake; the Shinkolobwe mine in the Belgian Congo; and as a by-product of the vanadium industry of the Colorado Plateau in the United States. In the early part of the programme, therefore, our joint efforts were directed toward obtaining immediate maximum production from these localities. The contribution made by Eldorado Mining and Refining (1944), Limited, both in supplying and refining raw materials, was and continues to be of vital importance.In addition, it was also obvious from the first that in this programme, as in any mining enterprise, exploration activities directed•toward the discovery and development of new sources of uranium ore were essential if production were to be maintained over an extended period of time. In order to satisfy obvious security requirements during the war, it was necessary to proceed with this exploration programme, both in Canada and the United States, as secretly as possible. With the end of the war, and the revelation that an atomic weapon had been developed, however, secrecy in exploration was no longer required. The important thing was to get on with a broadened exploration programme."

Jan 1, 1950

By P. Cleyle, K. McDermott, M. Hall, C. A. Harris

"This paper describes the implementation of an expert system for monitoring and control of the NO. 4 autogeneous mill and spiral circuits at Wabush Mines.This process control system incorporated the mill operating expertize of Wabush Mines operating personnel and was implemented to improve spiral iron recovery and mill productivity by:1. Continuously monitoring the mill power draw and ensuring that the mill feedrate is regulated to prevent damage to the mill motor, while simultaneously maintaining the feedrate at or as close as possible to the maximum feedrate determined by the process supervisor.2. Improving control over the spiral density and feed rate.3. Improving control over both tbe rougher and cleaner wash water.4. Reducing the frequency with which pumps are plugged.5. Allowing modifications to be made easily and quickly to test various operating strategies.This system was installed using COMDALE/C, a real-time Expert System for Process Control. It was readily accepted by the process operators and produces higher production performance in comparison to the other 5 parallel mill lines at a lower power draw."

Jan 1, 1992

By Karl J. C. Harries

"8.1. INTRODUCTIONThe purpose of this chapter is not to provide precedents or examples of provisions, but rather to offer some comments that may be worth considering in the negotiation or review of an agreement. These comments are not intended to be exhaustive. It must also be noted that, although the chapter is written in the context of a common law joint venture, the concepts and concerns for the most part apply equally to a corporation that is owned by only a few shareholders for the purpose of participating in the project held by the corporation.The corporation has the advantage of having much of its organization established by local corporate law, but the particular wishes of the shareholders will appear in a shareholders’ agreement. The principal differences will be surprisingly small, save for the acquisition provisions that appear in a farm-in agreement1 and the substantial portion of the joint venture agreement devoted to creating and organizing the joint venture entity. Where the joint venture agreement refers to venturers and committees, the shareholders’ agreement will refer to shareholders and the board of directors, but both will have to deal with such basic matters as decision-making, default, dispute resolution, first refusals, funding, and carrying out work on the project. For convenience, this chapter usually refers to “venturers”, which may be taken to include shareholders.Negotiations give rise to many varying circumstances and concerns, and the main asset of the negotiator is an open and flexible mind. A desired result can often be accomplished indirectly in circumstances where the other side has adopted an inflexible position on a suggested approach. As precedents and standard forms tend to focus a negotiator’s thinking, they can be counterproductive. It is after the deal has been agreed to that a precedent can be of great assistance to the draftsman.The concepts are arranged in alphabetical order for convenience, not to suggest their sequence or position in an agreement or their relative importance. An agreement should adopt a progression of subjects in what the parties consider a logical sequence to read and work with. However, experience has indicated that it is best to set out in a single article the substance of the deal (i.e. the terms relating to the farm-in and what the acquiring party has to do to acquire his interest), preferably near the beginning of an agreement. The acquisition of the interest is, after all, the first order of business. The joint venture provisions will then follow in a reasonable sequence. It is also worthwhile to devote a single article to any special provisions that may apply during the earn-in period. For example, it may be provided that, although all work is to be done by the acquiring party as operator (with the duty of care, liability, and reporting requirements as set out in the joint venture sections of the agreement), but during the acquisition period, the acquiring party, acting as operator, may be at liberty to do such work as he wishes, without the need for any committee or other approvals, and committee meetings may be suspended.2An agreement is divided into paragraphs and articles to make it easier for the parties to read and understand, and to assist a party in finding “that provision” when the need arises. A comprehensive table of contents will also assist the parties who must work under an agreement. An added benefit of a table of contents is that in preparing it, the draftsman sees the overall structure of the agreement and will often catch and correct flaws."

Jan 1, 2003

By Jason J. Ballentine

This paper presents a case study of how an asset strategy and zero based budget was developed for an existing crushing plant that had been purchased from the contract service provider by an Australian Iron Ore miner. The goal was to directly align the strategies and budget to the business goals. This however was not a simple task due to poor historical records and a general lack of information. These challenges were overcome and the benefits of a documented maintenance strategy, a justifiable zero based budget and employee engagement were realized.

May 1, 2007

By J. B. Hadaway

The operation at Phu Kham commenced design and construction in early 2006 and was commissioned in May 2008. This paper will examine and discuss the project from the inception of flow sheet development and equipment selection, equipment design and manufacture, construction, commissioning and ramp up to full production. The paper will touch on the strategies employed to achieve a short schedule and the efficient use of capital, but with the main emphasis on the grinding circuit. Various challenges during the early years of operation will be discussed including the effect of ore characteristics, including competency, on the performance of the grinding circuit. Actions to overcome these challenges and to enhance performance will also be discussed. Finally, current and future plans to improve the performance of the grinding circuit and the overall plant will be summarised.

Jan 1, 2012

By R. Hans

Removal of toxic anions from aqueous solution was studied using a Magnetic Ion Exchange (MIEX) resin which is a polyacrylic, strong base resin. Gravity based settling is made more efficient due to the magnetic nature of the resin which is advantageous over conventional ion exchange resins. In addition, the magnetic microspheres of MIEX have larger surface area in comparison to conventional ion exchange resins. Over the years MIEX has been successfully used and has gained significant popularity for efficiently removing dissolved organic matter from wastewater and groundwater. In the present study the efficiency of the MIEX resin was tested for the removal of chromium(VI), molybdenium(VI), vanadium(V) and arsenic(V) anions. Effects of pH (2-10) and temperature (25oC-55oC) were examined. In general, low solution pH values were favorable for anion uptake by MIEX. Except for chromium(VI), the metal ion uptake was significantly increased by the increase in solution temperature. The adsorption data were analysed on the basis of chemical speciation and heterogeneous kinetic models.

Jan 1, 2014

By Robert Hamilton

Aur Resources is Canada&apos;s leading copper mining company with producing mines and development projects in North, Central, and South America. Copper production from Louvicourt Mine in Quebec, Quebrada Blanca, and Andacollo Mines in Chile had a record of 245 million pounds in 2001. Located 600 km North of Montreal, Louvicourt Mine is a joint venture between Aur Resources (30%), Teck Cominco (45%), and Novicourt (45%). Aur Resources is the mine operator with 280 employees working to produce a copper and zinc concentrate. In operation since 1994, the mine has produced a total of 12,606,000 metric tonnes of ore grading 3.6 % Cu, 1.5 % Zn, 26gr./m.t Ag, 0.9gr.m.t Au. This highly mechanized mine reached full production in August 1995 at 4,000 tpd. From 1996 to 2001, the average mine production rate was more than 4,300 tpd. The Louvicourt Mine continued its record of solid performance in 2002 and is expected to continue to do so for the balance of its 2.5 years mine life.

May 1, 2003

By D. Mas Ivars, K. Suzuki, J. A. Vallejos

"A comprehensive geotechnical characterization has been undertaken at the El Teniente mine to describe and determine the rock mass behaviour strength properties of the primary copper ore. The Synthetic Rock Mass (SRM) modelling approach is used to simulate the mechanical behaviour of this heavily and unfractured rock mass. The micro-parameters of the model have been calibrated against mechanical properties and scaling laws for intact rock and veins, in order to represent virtual samples of four different geotechnical units. Results can be used to predict the rock mass scale effects, anisotropy, and brittleness properties that cannot be obtained using empirical methods.INTRODUCTIONThe primary copper ore at the El Teniente mine is described as very competent and massive, given that it exhibits a brittle behaviour (Rojas, Cavieres, Dunlop, & Gaete, 2000). This description is coherent with the geological description of the rock mass, which does not have discontinuities match as the definition provided by International Society of Rock Mechanics (ISRM, 1981). Only faults can be classified as discontinuities, but they are widely spaced. The primary copper ore has a high frequency of veins, where the cooper mineralization is hosted, these vein network structures are known as stockwork. Soft veins containing weak minerals as infill (chalcopyrite and anhydrite) control the disassembling of the rock mass during caving (Brzovic & Villaescusa, 2007).Presently, there are mainly two traditional methods used to estimate the strength of the rock mass: 1) determination of the strength envelope of the rock mass using scaling parameters from laboratory tests and 2) using numerical modelling based on back analysis of previous experiences of failure observed and measured in mining or civil excavations. The primary copper ore of El Teniente mine has no fractures; therefore, it is difficult to determine a rating that would enable to scale laboratory data, such as, RMR (Laubscher, 1977) or GSI (Hoek, 1994). This is the reason why the first option is not valid unless the entry data is manipulated or adjusted in order to obtain reasonable results. The second option requires, in general, a good characterization of a previous failure event in the rock mass, which is not always available. In recent years, new techniques of numerical modeling have been developed (PFC3D, ELFEN, Abaqus). Those methodologies are the third way to estimate the strength of the rock mass, but they are still in development. Particularly, the concept of SRM developed by Itasca is implemented in this study (Pierce, Mas Ivars, Cundall, & Potyondy, 2007; Mas Ivars et al., 2011), aiming to capture the real behaviour of the rock mass."

Jan 1, 2015