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By A. A. Brant

"Improving geological and geophysical evaluation should serve to reduce the early-stage risk assessment and there-by contribute to exploration expenditure stimulation. The limitations of present-day methods are reviewed, particularly as to anomaly causes, depth penetration and quantitative physical interpretative abilities. Some of the problems now under study are discussed. Future developments expected include the treatment of quantitized geologic and geophysical data, as well as continuing attempts toward computerized interpretation."

Jan 1, 1967

By W. Beres, Li. J.

The finite element method (FEM) has been applied to investigate the stress fields and deformation of a TiN/Ti-6A1-4V coating/substrate system subjected to nanoindentation. MSC Patran and MSC Marc were used to prepare the three-dimensional finite element models and to perform the simulations of the Vickers nanoindentation experiments. Pure silicon and TiN/Ti-6A1-4V coating/substrate system were analyzed. The properties of the materials were assumed to be homogeneous and isotropic with a linear hardening behavior. The reverse method was used to extract material properties, such as the yield stress and strain hardening coefficient, from the numerical results by comparing the simulated indentation load vs. penetration depth (P-h) curves with those obtained experimentally. Both non-linear elastic and non-linear elastic-plastic analyses were carried out for the coating/substrate system. The results are given for four different coating thicknesses.

Jan 1, 2004

By Gordon Nelson

The Homestake gold mine is one of the largest and oldest continuously operating gold mines in orth Ame rica. To date this mine has produced in excess of 128.000.000 tons of ore containing almost 34 million ounces of gold . Gold mine ralization is restricted to the Homestake Formation. This unit is a metamorphosed iron-formation which is enclosed by pellitic metasedime nts below (Poorman Formation) and a pellitic to qua rt zitic unit (Elli son Formation) above. The e ntire Precambrian sequence. in the Lead area. has been subjected to a multi-stage defo rmation episode which ha c reated an extremely complex structural setting for the Homestake orebodies. Metamorphic grade inc reases from greenschi st ro amphibolite in a northeast d irecti on acros the mine area. Present thickness of the Home take fo rmation va ric from O to »400 fee t. The amount of thicke ning and th inning which is attributable to tectonic deformation or original sedimenta ry di fferences is not known. Orebodies constitute onl y a small pe rcentage of the Homestake Formation and do not occur along a pa rticul ar stratigraphic pos ition within the unit. Gold i assoc iated with inc reased py rrhotite and a rsenopyrite concentrations within the iron formation. Inc reased \ cin qua rt z development and chl oritic alteration usuall y accompany this minerali zation. Local remobilizati on of mine ralization due to metamorphi sm has occurred. Homestake mine ralization has been shown to be of sy ngeneti c origin . Because no feeder zones have yet been recognized a di stal source for the mine ralization is inferred .

Jan 1, 1986

By J. F. Shirley

"Very seldom, if ever, is a molybdenite by-product plant operated exactly the way the process design engineer visualizes it. The best thing the design engineer can do is provide a sound, basic circuit with enough room and flexibility in order that the operating staff can make the necessary modi fi cations to optimize the process. The plant, with minor modifications, should be capable of handling more than one process. This is especially true when the client is having the plant designed for a new process.The writer would like to propose the following ten ""rules-of thumb"" for designing by-product molybdenite plants where the molybdenite is floated out of a copper concentrate. The term rules-of-thumb is used, because there are probably valid reasons for not using one or more of them in a particular plant design. In fact it was 1980 before the writer was all owed to start up a plant where all of these rules were honored in the plant design. This was after 19 years of experience in the design of molybdenite by-product processes and plants. The main reasons for not following the rules are available capital, available space, and the client's experiences based on pilot plant and laboratory test results."

Jan 1, 1981

By W. J. Bennett

WHEN Dr. Horace Fraser, your President, invited me to speak to you today I advised him in confidence that I was leaving my present positions on April 30th. In the circumstances it seemed to me that this audience might prefer to have as its speaker one who wo.uld J1ave a continuing association with the atomic energy programme. Dr. Fraser was kind enough to suggest that my re-marks might he of special interest to you, since I would be able to sum up my views on the atomic energy programme. I hope that I will not disappoint him or you on that score. I am particularly pleased that my last public appearance in my present positions should be at the Annual Convention of the C.I.M. since, as all of you know, a very important part of my work has been in the mining field. As it happens, my first public address on the subject of atomic energy and its raw material -uranium -was made at your Annual Convention in Montreal in April, 1949. It seems fitting that my final address should also be made at this convention -nine years later.

Jan 1, 1958

By B. Burger, T. Bester, S. Deonarain, L. S. Schultz

"This paper details the process followed to raise drill and equip a 6.1 metre diameter vertical service shaft at Glencore’s Mindola Deeps project in Kitwe, Copperbelt Province, Zambia. The project scope comprises a shaft collar, bulk air intake, a pre-sink to -90 metres and raise drilling the shaft from surface to a final depth of 1,892 metres underground, in four separate lifts of approximately 475 metres each. Equipping of the shaft steelwork, headframe erection and commissioning the shaft for hoisting. In addition, the scope included the development of a decline down from 5430’ level underground to the new shaft position on 6205’ level. This paper will provide some insight into the successes and challenges encountered during execution of the shaft works to date and provide some learnings for future projects of a similar nature. INTRODUCTION The Mindola Mine is situated to the west of the city of Kitwe in the Copperbelt Province of the Republic of Zambia (Figure 1). The mine is owned and operated by Mopani Copper Mines Plc (MCM), whose shareholders are Glencore AG (73.1%), First Quantum (17.9%) and ZCCM Holdings Plc (10%).Productivity at the Mindola mine has been adversely affected because of significant ventilation and ore re-handling challenges, which are caused by the dilapidated infrastructure, and design of the existing vertical and sub vertical shaft system. In the circumstances, it was apparent that it was necessary to sink a new vertical shaft that would increase the volume of fresh air down the mine, improving the underground working environment and the current hoisting restrictions, resulting in an increase in productivity and efficiency. Because there were two existing levels ideally situated and perpendicular to one another and because a third level was in close proximity to that perpendicular and because the mine required a ramp down to shaft bottom in any event, consideration was given to raise drilling the shaft as opposed to using conventional blind sinking methodologies."

Jan 1, 2019

By Robert B. Parsons

"Canada doesn't really have a tax system for mining - it has eleven separate tax systems! The consequent maze adds some undefinable margin of difficulty to making investment decisions in Canada. But, this 11U1Ze is not likely to be simplified. Solution: learn it and sell it! Intricate Network of Winding PathwaysWebster's New World Dictionary defines the word ""maze"" as follows: ""a confusing, intricate network of winding pathways; labyrinth ... a state of confusion or bewilderment"". Webster's does not go on to give an example of a maze, but the dictionary could easily have referred to the taxation of a Canadian mining operation. The uninitiated would almost certainly look upon such taxation as a maze of the most perplexing sort.Twenty years ago, Canada's tax system was really quite simple. It is true that Canadian mining profits were subject to three levels of taxation (federal income tax, provincial income tax, and provincial mining tax), but this didn't pose a problem. Prior to 1974, at least the provincial income tax systems were somewhat the same in terms of rules .and rates, and even the provincial mining tax systems resembled one another. Mining profits were subject to pretty much the same rules, no matter what province or territory hosted the mine. Those were the “good old days” one could even dare to generalize about tax rates without fear of being labelled an imbecile!"

Jan 1, 1994

By G. G. Bowser

PERUSAL of a list of present-day commercial explosives perhaps does not convey a full realization that there has been a great deal of improvement since the original dynamite was discovered nor that, in recent years, great developments have taken place in specialized explosives. This is true particularly of high-explosives for use in metalliferous mining or what is more commonly termed 'hard-rock' mining. Not many decades ago, only two or three types of explosive were avail-'able for commercial use. One was black blasting powder. Another was ordinary nitro-glycerin dynamite in various strengths. Black blasting powder remains with but very little change. Despite its ancient lineage, it is still with us as perhaps the sole explosive in use today which is almost identical in appearance, physical properties, and working ability or execution co the original. Which dynamite the story is different. Its evolution may be likened to that of the dog, nitro-glycerin as first discovered being the counterpart of the wild dog and, like it, dangerous and hard to control. The original dynamite as made by Nobel might then be considered as representing the first domesticaced species. This original dynamite, however, has been 'crossed with other bloods' until one sees now many distinct 'breeds' in the list. Present-day explosives still have the 'bark' and the 'bite', but with control and research have come many improvements; and types have been created which are specially adapted for particular kinds of work. We still have the direct descendant of Nobel's dynamite in the form of an improved nitro-glycerin dynamite. This C-I-L explosive, Polar Dynamite, is no longer the best type to use in the hunt for gold, silver, iron, and other metals. There have been developed other explosives more suitable for chat work. In Canada, such explosives are accomplishing this work effectively, not only where climatic conditions are moderate but through the rigours of our northern winters, with their sub-zero temperatures.

Jan 1, 1938

By J. Dubinski

Poland is the ninth largest coal producer in the world and Coal Company is the largest Polish producer of this deposit yielding 51% of national production. Coal Company mines are located in the Upper Silesian Coal Basin. These are underground mines which operate in difficult geological conditions at great depths of up to 1200 m. One of the most common natural hazards in Polish mines are rockburst and seismic hazard impacting on surface infrastructure and habitants. In the assessment of the rockburst and seismic hazard methods of mining seismology play a leading role. This paper presents progress that was achieved in the last few years in the implementation of new seismic monitoring systems and seismic interpretation methods for the prevention of hazard deriving from seismicity induced by mining. This progress in assessment of rockburst hazard and impact of seismic activity on the surface infrastructure was achieved through close cooperation between the Coal Company and Central Mining Institute ? the country?s leading scientific institute in the field of mining seismology. New theoretical solutions are in the process of testing in mines of Coal Company where seismic monitoring systems are installed and controlled by well-qualified personnel. Some directions of further joint actions to increase the effectiveness of rockburst and seismic hazard assessment are presented as well.

Aug 1, 2013

By E. Sharifi, B. Komishke, R. Heffel, D. Schwartz

"The oil sands resources in Canada are one of the world’s largest hydrocarbon deposits. Processing of oil sands uses hot water to extract bitumen. The process generates tailings slurry that must be settled for final deposition. The tailings contain fine material, with poor water release characteristics which makes water recovery challenging. Polymer flocculants are added to assist in settling and dewatering the fine tailings. The amount of polymer addition is dependent on tailings characteristics, including the particle size distribution (PSD). If the PSD of the tailings is unknown, an excess amount of polymer needs to be added in the dewatering stage to flocculate the particles. Over flocculation also has a detrimental effect on the water release characteristics. Measuring the particle size distribution using an on-line analyzer could have major benefits over common laboratory methods as it provides online and fast insight into the process enabling the operators to implement required changes to minimize the reagent consumption, while achieving optimal flocculation. Online measurement of PSD using laser diffraction has long been used in base metals beneficiation processes. A series of test work using Outotec PSI500® particle size analyzer on oil sands samples from different operations have been conducted. Tests were performed by recirculating the slurry in closed circuit to simulate real plant conditions. This paper presents a summary of the results.INTRODUCTION Canada’s oil sands are the third largest reserves of crude oil in the world, with an estimated 165.4 billion barrels of recoverable oil (Government of Alberta 2016). Oil sands are a mixture of sand, water, clay and bitumen. Bitumen is a form of oil that is too heavy or thick to flow or be pumped without being diluted or heated. About 20% of bitumen reserves are close enough to surface to be mined. In mining methods, oil sand is transported from an open pit mine to the processing plant and bitumen is separated from solids and water. The separation process involves ore preparation, such as addition of hot water, steam and caustic (NaOH), followed by gravity separation and froth treatment (Masliyah et al. 2004). A general scheme of the extraction process is presented in Figure 1."

Jan 1, 2018

By Harry Jomini

Introduction The Wakefield plant of the Aluminum Company of Canada, Limited - a member of the Aluminum, Limited, group of companies - produces magnesia, magnesia fertilizer ingredient, and hydrated lime, from brucitic limestone. Wakefield is on the Gatineau river in Wakefield township, Quebec, some 22 miles north of Ottawa. The plant is near the western bank of the river adjacent to the Ottawa-Maniwaki highway and branch line of the Canadian Pacific railway. The plant is unique in the sense that it is the only place in Canada where brucite is processed. It is also distinguished for its outstanding safety record, as not a single lost-time accident occurred during either 1948 or 1949. The plant is amply provided with safety and comfort provisions in keeping with the standard practice in all of the twelve plants operated in Canada by Alcan and its associated companies. History Following the identification of brucite in the Rutherglen and Bryson districts in Ontario, occurrences of the mineral were discovered in the Wakefield area, Quebec, in 1939. After exploratory work on these deposits and investigation by the Bureau of Mines, Ottawa, on a method of extracting the brucite from the ore, a plant for treating the ore from the Maxwell property was built in 1941 by the Aluminum Company of Canada and commenced operations in early 1942. The process used is more or less in accordance with the method worked out by Mr. M. F. Goudge of the Bureau of Mines.

Jan 1, 1950

By G. Vibert Douglas

"Gold occurs in Nova Scotia in three ways, saddle reefs, fissure veins, and fossil placers. Of these the saddle reefs are the commonest. They have been the source of most of the gold and have also been the subject of most of the literature on the gold occurrences.The Meguma or Gold-bearing series of Nova Scotia is a conformable succession of quartzite's and slates, possibly Precambrian in age, which have been folded into a number of anticlines and synclines that strike (Fig. 1) roughly east and west. This folding has been termed Acadian and is probably a westward continuation of the Caledonian revolution in Britain. It may have started in the Ordovician and continued through the Silurian and into the Lower Devonian. It was followed by the intrusion of the great Devonian granite batholiths. It is thought that the mineralization is connected with the late phases of the cooling of the granite. As the name saddle reef implies, the veins form on the crests and flanks of the anticlines, possibly in the synclinal troughs as well. The beds favoured by the solutions are the slates. The reason for this is apparent when it is realized that in order to fold over 30,000 feet of sediments (the thickness of the Meguma according to E. R. Faribault) through p radians of arc it is necessary to have a differential movement between the top and bottom beds of p times the thickness of the sediments. In the case of the Gold-bearing series, in which strong quartzite beds lie between incompetent slate beds, most of this differential movement was taken up in the slates. The evidence for this is the remarkably fine drag folding and the intense shearing and comminution of some of the beds of slate (Fig. 1). The quartzites exhibit some shearing and faulting, but there is little doubt that the greater permeability lay along the incompetent slate beds. The mineralizing solutions followed these beds and also passed from one slate bed to another through a joint or fault in the intervening bed of quartzite. These joining veins are called angulars in Nova Scotia. Within the veins the gold is in shoots and the real problem is to find out what controls the position and extent of the shoots."

Jan 1, 1954

By V. Vekris

A diverse patent portfolio and an effective intellectual property strategy are vital in today’s small business world. Not only does a diverse patent portfolio enable a company to secure a monopoly within the market, it greatly increases the value of a company’s intangible assets and keeps competitors at bay. An overview of the patenting process as it pertains specifically to the materials science-related start-ups will be given, together with a summary of some general patenting strategies and a review of some patenting errors to be avoided, such as premature disclosure of the invention to the public. Additionally, a review of new “green technology” initiatives recently adopted by Patent Offices around the world is also provided. These initiatives are expected to greatly benefit patent applicants in the fields of metallurgy and mining, where research efforts are often directed to environmentally-friendly products and processes. INTRODUCTION Patents are playing an increasingly significant role in the business world. A diverse patent portfolio can enable a company to secure a monopoly within the market, which can provide a competitive advantage over competitors. At the same time, patent portfolio of any size can greatly contribute to the total value of a company’s intangible assets. As an example, Nortel entertained bids in 2011 for its portfolio of about 4000 patents, a large portion of which were directed to 3G- and 4G-mobile communication technologies. The portfolio was eventually sold for $4.5 billion to a consortium including Apple, EMC, Ericsson, Microsoft, Research in Motion, and Sony. Copper mining, and indeed the global mining industry as a whole, is facing challenges. Ore deposits are increasingly low grade, complex, and deeper in the ground, rendering copper mining operations more difficult and costly. Production costs are increasing. According to one study, the cost of producing copper has increased by an average of 10% per year since 2005 (Cantallopts, 2017). To illustrate, the cost of producing a pound of copper in 2005 was 90 cents, but had increased to 217 cents by 2014.

Jan 1, 2019

By L. P. Chrismas

"IN 1975, Nova Scotia produced 1.8 million tons of coal with a FOB mine value of $47.6 million. Of this total, about 30 per cent or 600,000 tons was coking coal and the remainder was steam and industrial-grade coal. The Nova Scotia Power Corporation consumed 630,000 tons in three generating stations and 570,000 tons were sold to Sydney Steel for making coke for its steel operations. Exports, principally to Great Britain, comprised 370,000 tons in 1975 in addition to the 300,- 000 tons shipped to other provinces for use by cement and pulp and paper companies. In 1975, just over 100,000 tons of coking coal were imported into the province from Alberta. Before 1975, low-volatile coking coal was traditionally obtained from the United States. In 1975, production came from seven individual mines and one project involving reclamation from mine dumps in Pictou County. Of the seven producers, four are owned by the Cape Breton Development Corporation, a federal Crown corporation; the remaining three are small independent mines, but, even though small, they are sizeable contributors to the economies of their local areas. After 101 years of continuous operation, Devco's Princess mine was closed in 1975. The Nova Scotia coal industry, in terms of value, accounted for about half of total mineral production in 1975. The industry provides jobs for 3,000 men and women. It is also significant that in 1975 Nova Scotia produced about 6.5 per cent of Canada's total coal production of 28.3 million tons. Detailed statistics on Nova Scotia's coal industry appear in the Appendix."

Jan 1, 1976

By R. Bonifaz

The Chagres Smelter, part of the Anglo American plc group situated 80 Km north of Santiago in Chile, completed a series of operational improvement in 2005 resulting in an optimum capacity in its operational units. At present the Chagres Smelter has developed an operational strategy which seeks to reduce bottle-necks in the production process. In this way we have managed to lower operational cost, decrease energy consumption and maximize the capacity of the Acid, Oxygen, and Smelting, Converting, Refining and Casting units. A constant application of international benchmarks together with continuous staff improvement and the latest smelter technology have combined to place Chagres among the finest smelting works in the world. In response to environmental challenges, we have studying various options for investment suitable for a profitable business of benefits to both Anglo American and Chile as a whole. The most relevant technical indicators are the figures : Energy consumption less than 6,3 GJ/ton fine copper, Intensity of smelting rate in Flash Smelting unit of 6900 ton of copper concentrate/m2 settler of furnace area and be one of the top five smelter in direct cash cost .

Jan 1, 2007

By K. Regl, J. Berneder

"AMAG investigated different aspects to improve the resistance against grain coarsening in aerospace alloys during recrystallization and was successful in finding several opportunities to minimize this effect. The studies show that one aspect to counteract grain coarsening is the chemical composition and subsequently all phases that are formed during homogenization. Starting with a fine grain (~ 50 µm) can lead to a final grain size of few mm. On the other hand with a coarse initial grain size (approximately 150 µm) and the right chemical composition the grain size can stay almost constant despite different deformation steps. Additional we investigated different sequences for the component production to eliminate the problem of grain coarsening as a coarse grain has a detrimental effect on product performance.INTRODUCTION In the aircraft industry, aluminium sheets are most commonly deformed in their soft state, followed by solution heat treatment and natural or artificial aging. If the preceding deformation is in a critical amount, during the recrystallization at solution heat treatment grain coarsening can occur. A subsequent deformation to this condition leads to an orange peel surface, which requires additional polishing. Next to this extra effort the coarse grain size produces a drop in the mechanical properties, often below specification limits. If there is no subsequent deformation, this effect is not visible and without destructive testing there is no possibility to detect the error. As mentioned before, this effect occurs during recrystallization, which is a process that is driven by the stored energy in the microstructure. The two most important aspects for an increase of the stored energy are the increase of the grain boundaries fraction (smaller grain size) and the increase of the dislocation density caused by deformation. The increase in dislocation density during the deformation arise from trapping of existing dislocations and from the generation of new dislocations. During recrystallization all grains are built completely new, so all dislocations are removed (Humphreys & Hatherly, 2004). There are three requirements for recrystallization:"

Jan 1, 2018

By T. G. Joseph, M. J. Bolster

ABSTRACT This paper explores passive seismic measurement as an alternative, nonintrusive approach to conducting annual brake testing on surface mine sites. Dictated by the test site location, this evaluation adhered to the brake testing procedure as per British Columbia occupational health and safety regulations. Results showed excellent correlation to those reported via conventional practice: Comparing stopping distance, time, and velocity for the proposed instantaneous passive seismic versus conventional approaches, less than a 0.5% variance was evident. A viable alternative, the passive seismic approach, allowed an entire fleet of trucks to be sequentially evaluated for annual brake testing without disrupting operations by installing mechanical testing equipment.

Jan 1, 2012

"A method is described for determining the viability of hard rock orebody extraction by block caving. Using a very limited amount of geotechnical data, the procedure enhances Laubscher’s empirical stability graph method by using the complex structural modelling system (ChaSM) to assess cavability and block cave tonnages.IntroductionIn considering the selection of suitable mining methods, block caving has gained popularity over other extraction systems in recent years (Butcher, 1999). This has been ascribed to the fact that block caving is the lowest cost per ton mining method, with orebodies that were in the past considered unsuitable for caving, now being successfully mined. However, even though all orebodies will cave, a problem exists in the evaluation of economic viability — it is necessary to be able to predict both when the orebody will cave and what will be the sizes of the initial ore fragments (and the associated tonnages) that report to the drawpoints. This problem is compounded by the fact that, during the scoping study phase of a project, only limited geotechnical data may exist on which to base an assessment of whether block caving is viable or not. Empirical and numerical methods of cavability assessment do not account for the full effects of geological discontinuity trace lengths, nor for the stress regime. Those require significant geotechnical data to be available. The result is that uncertainty may exist as to whether block caving is an economic option. This uncertainty is complicated by the fact that limited experience exists with the caving of more competent orebodies.This paper describes a method for assessing cavability, and for predicting the size of initial ore fragments and the tonnages reporting to block cave drawpoints, using only the level of data normally available during a scoping study. Fragment size and tonnages are assessed by identifying potentially unstable blocks and wedges in the undercut back using statistical joint data. The effects of lateral confining stresses are accounted for by comparing the in situ stress orientations with the joint orientations. To evaluate the accuracy of the method, a back analysis exercise was conducted to predict cavability and initial tonnage for a mine in which the actual behaviour is known. The method is then applied to cavability and tonnage predictions for a hard rock orebody."

Jan 1, 2002

By SangHyeok Han

Selecting the best possible cranes and identifying spatial conflict-free locations on sites can result in productivity and safety improvements for large-scale industrial construction projects. In the current practice, experienced lift engineers select cranes based on the heaviest lift and/or the largest lifting radius of the identified crane. This practice is relatively time-consuming, and optimization of the crane?s use and location is also difficult. There are many factors which need to be considered during the crane selection process, a reality which further complicates the process. This paper presents a framework which aims at developing a decision support system to enhance the crane selection process and collision-free path planning for large-scale construction projects. This paper utilizes an innovative crane selection matrix in order to establish a process for optimized crane selection for construction projects. The study considers more than 40 different factors in order to reduce time and improve safety for crane operations. Following finalization of crane type (mobile crane versus tower crane), a visualization model to simulate crane operation and identify collision-free crane operation paths is proposed. This process can assist project managers to plan the lifting process more effectively and efficiently. A case study-based approach was utilized to demonstrate the proposed methodology. The methodology was tested in the planning and construction process for boiler house structures in Mannheim, Germany. The project entailed numerous challenges: one of the major tasks was to lift a 102-ton load on the top of the boiler structure through crane collaboration; space limitations on site also presented several challenges related to crane selection, location, and operation processes. Based on the project constraints, the proposed crane selection framework, and the visualization models, two tower cranes were selected and successfully implemented in the case study.

Aug 1, 2013

"Chairman - To start this discussion off, I wonder if Mr. Dave Livingstone or Mr. Jeffrey of Granisle Copper would give a description of the crushing plant at Granisle since it is somewhat different from the usual plant, W. N. Jeffrey - Granisle Copper The main difference between the Granisle crushing plant and many others is the Livingstone method of putting the screens under the crushers instead of above them. This method allows a more compact arrangement and eliminates the heavy superstructure required to take care of the screen vibration when the screens are mounted above the crushers. There is a small surge bin above the tertiary crusher which takes care of the variation in circulating loads.All three crushers are gyratory crushers. There is no grizzly ahead of the primary crusher but the fines are removed from the primary crusher discharge at the first screen and sent directly to the fine ore bins. E, Thornton - Sullivan GroupDo you have any coarse ore storage outside?w. N. Jeffrey - Yes, there is about 6000 tons live storage, We have very little trouble with freezing even though it is open storage.E. Thornton - Sullivan GroupDoes rain cause any problem?w. N. Jeffrey - It sometime creates a problem because the storage area is on a slope. It is mainly a problem of keeping the drainage ditches open.Question – What is the size of the primary gyratory crusher and how does it work on run of mine size materials, in other words, do you have a problem with oversize material and how do you handle the oversize rock?w. N. Jeffrey - The primary gyratory is a 42 x 65 with a nominal open side setting of 61'. We do at times get a run of oversize material. For anything too large for the crusher to handle, we use what is known as the Esco hook, which is a type of grapple used to remove oversize rocks.The disadvantage with this equipment is that the crane is too slow. I am sure there must be better arrangements than the one we have,"

Jan 1, 1971