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By David E. Pearson

"Western Canadian coking coals are located in the Rocky Mountains arid foothills of British Columbia and Alberta. They are typical of non-marine coals, characterized by total sulphur contents of less than one per cent and with ash contents of 10-30 weight per cent. This mineral matter is composed principally of kaolinite and quartz.The petrographic compositions of most of the coking coals which constitute the 2.065 billion tonnes of British Columbia's measured reserves, and the compositions of the metallurgical coal currently exported from Alberta, show them to be rich in the inertinite macerals, macrinite, fusinite and semifusinite. When the mean maximum reflectance of vitrinite in oil/Romax) is used as the coal rank parameter, this high inertinite content is reflected in the lower volatile-matter yields, but the relatively inert character is also displayed by lower free swelling indices (PSI), lower maximum dilatations, lower maximum fluidities and lower coke strengths than other coals of the same rank, but richer in the reactive macerals, vitrinite, exinite and semifusinite. Despite these reduced values in the so-called caking tests, inertinite-rich coals produce strong coke.A system of classification of coking coals is introduced which is based on rank, as indicated by Ro max, and either petrographic composition, maximum dilatation, maximum fluidity or, to a lesser extent, PSI and volatile-matter yield. Six principal coal groups can be distinguished among coking coals using this versatile classification. Inertinite-rich coals are assigned to the Keystone Group (GI), Balmer Group (G3) or Moura Group (G4), each group being named for a coal typical of that population ofcoals. Reactive-rich coals are assigned to the Pittston Group (G2), Kellerman Group (G5) or Big Ben Group (G6). A multiple-regression analysis of coal quality versus price shows how the value of coking coal in the Japanese market appears to be related to reflectance and the free swelling index, and confirms the economic viability of the classification.British Columbia's measured reserves of coking coal contain representatives of four of these groups; Balmer Group (73%), Moura Group (/6%), Pittston Group (3.4%) and Kellerman Group (7.6%).This analysis of the quality of Western Canadian coking coal indicates that despite the need for large proportions of inertinite-rich coking coal in blends produced in the Japanese steel industry, there is nevertheless a demonstrated overabundance of Balmer Group and Moura Group coals available to the international coking coal market."

Jan 1, 1980

By John Petty, John Loviza

As a blaster, have you ever had that uneasy feeing in the pit of your stomach as a codes enforcement official drives onto your jobsite? Have you ever needed an ally in a court of law against an unjust damage claim? Have you ever wished for a better and more open relationship with the guys who wear the badges?

Jan 1, 1996

By W. Smith, F. G. Rinker, D. Beggs

Early in 1965 the Surface Combustion Division of the Midland-Ross Corporation was awarded the contract to engineer and construct a taconite pelletizing plant for the National Steel pellet plant, administered by the Hanna Mining Co., near Keewatin, Minn. This plant, which will have an annual capacity of 2,400,000 long tons, will produce pellets from magnetite concentrate using a new process developed through a joint research program by Midland-Ross, Hanna Mining, and the National Steel Corp. The work that culminated in the decision to construct this plant is the result of a research program for the development of the Midland-Ross heat fast process for the production of prereduced or metallized pellets. PELLETIZING PROCESS There are many acceptable methods for producing oxide pellets from ground iron ores and concentrates, and all of these give an acceptable product for blast furnace utilization. The vertical shaft furnace, the traveling grate, and the grate-kiln have been installed in many pelletizing plants in the northern hemisphere; therefore, the acceptance of these methods and the problems associated with them are well understood. However, this research project investigated a method for improving upon these processes to produce a high quality oxide pellet at a low operating cost.

Jan 9, 1966

By W. W. Bake

INTRODUCTION IN IN JUNE, 1943, the main pillars of the Beattie Mine glory hole failed, allowing over a million yards of wet clay and debris to flow into the mine, completely filling all workings to within seventy feet of the 3rd level. The resulting Job of clearing these workings and rehabilitating the mine represents a unique and hazardous operation, seldom, if ever, previously encountered in Canadian mining. The purpose of this paper is to describe one phase of this operation -that of cleaning and rehabilitating the mine from the 6th to the 9th level -to outline briefly the events which led up to this work and to describe the techniques and costs involved. It will be noted that such costs, methods, and performance figures as are dealt with in this paper refer only to work in the internal shaft and adjoining workings from the 6th to the 9th level, previous work having been done under other supervision and management. The Beattie mine is in Duparquet township, northwestern Quebec, twenty miles northwest of the town of Noranda and twenty-three miles southeast of the town of La Sarre. The mine and the town of Duparquet, which it?supports, are accessible by highway from Noranda throughout the year. Production at the Beattie mine began in May, 1933, and up to June, 1943, twenty-one million dollars in gold and silver had been recovered from five and a half million tons of ore.

Jan 1, 1951

By Nikkam Suresh

Dense medium cyclones have been in use for washing coarse and small coals for more than 50 years. There have been modifications in its design and today these units have become indispensable for washing of Indian coals possessing difficult washing characteristics. About 53 percent of the Indian coals (coking and non-coking) are being washed in jigs, about 38 per cent are washed in dense medium cyclones while the remaining 9 per cent is treated in other units like Barrel Washers, Heavy Media Baths and Drum Separators etc. The present paper deals with the attempts made for design of industrial Dense Medium Cyclones for enhanced coal recovery. Two industrial units of 500 mm diameter and 650 mm diameter were designed with their washing capacities being 200 m3/hr and 350 m3/hr, respectively. The results of the pilot tests conducted on 500 mm cyclone treating very high Near Gravity Material coals crushed to -3.0+0.5 mm gave an ash reduction of up to 19.5 percent with the new design i.e., from a feed ash of 34.5 percent to 15.06 percent in clean coal with an appreciable yield of 45 percent in one stage.

Sep 1, 2012

By Kazuhide Nakaniwa

In this research, we devised a measurement method using total stations (TSs) which have ?the Baum? which is a concentric circle reticle, as substitute for crosshairs. The Baum owes its name to the similarity between the concentric circles and trees (Baum in German). By setting one circle on both of edges of cylinders, operators can set their sights on points on the center line of the cylinders, and also can measure positional coordinates of the points. Also, by measuring two different points on the center line, operators can measure the position and tilt of the axes of the cylinders. Furthermore, we developed a pile driving navigation system. Foundation piles are used for various structures, and their forms are generally cylindrical. Especially, although it is difficult to drive tilted pile foundations, their usage are expected to expand due to their high earthquake resistance. Yet, a method to accurately measure the tilts of piles has not been established. However, we proved that operators can obtain adequate accuracy to control foundation piles through the measurement experiment using this system. Using this system, the information of the pile is measured using a TS, transferred to a PDA, and displayed from the operator?s view of the piling machine.

Aug 1, 2013

By Hidekatsu Takeuchi, Masaru Sakakibara, Shigeo Tanabe, Kenji Harada, Akihiko Suzuki, Shoji Morihana

"Deep mixing (DM) method, one of the most commonly used solidification methods, is based on the principle of solidifying soft ground. It can be classified into two categories such as Cement Deep Mixing (CDM) method and Dry Jet Mixing (DJM) method which apply hardening agent in slurry condition and in powdery condition respectively. In recent years, DM methods have undergone changes that have evolved them from the traditional method to meet the needs of the diversifying market. Among them, the Contrivance-Innovation Clay Mixing Consolidation (CI-CMC) method is a DM method which mixes a cement-type hardening agent in slurry condition mechanically with soils in situ and incorporates the innovative technique, “atomized ejection” that has been developed to allow faster installation of larger diameter columns without sacrificing quality compared with conventional methods. At this technique, the atomized hardening agent is discharged together with compressed air through a device incorporated into the mixing blade. It also has advantages of performing the works with low-displacement of the surrounding soils in consideration of environmental friendliness and with higher penetration capability against hard ground.This paper presents the technological outline of the above-mentioned CI-CMC method, focusing on the atomized-ejection technique, followed by some construction examples, applied to the self-earth-retaining wall, to the hard ground and the area adjacent to the existing structures.INTRODUCTIONAccording to the accumulation of its case histories, Deep Mixing method has been receiving the demands of its application to more challenging conditions, such as harder ground condition, and requirement of lower displacement of the surrounding ground during its operation. In addition, to match its price against the other cheaper methods and widely receive its benefit of higher quality, the cost reduction of Deep Mixing is also one of the major challenges. For the cost reduction, higher productivity and lower consumption of the material to obtain the equivalent strength and homogeneity with the conventional method are required.The Contrivance-Innovation Clay Mixing Consolidation (CI-CMC) method has been developed to meet these demands. CI-CMC incorporates the mist ejection that has been developed to achieve faster installation of larger diameter columns without sacrificing quality compared with the existing methods. Normally, we obtain cement columns of about 1.0 m in diameter by using Deep Mixing method. To increase the productivity, it is not preferable to drastically increase the penetration and withdrawal speed of the mixing blades because of the hardness of the ground and restriction by minimum number of passage of rotating blades per a certain height of the soil cement. Instead, the expansion of diameter of the columns will simply increase the productivity. The development of the new mist ejection system, as shown in Photo 1, has enabled the diameter of soil cement columns to 2.0 m on single axis while 1.6 m on double axes. Mist ejection means that the hardening agent slurry is sprayed into the ground in mist form together with compressed air thereby achieving homogeneous mixing and reducing the resistance on rotating blades."

Jan 1, 2015

By H. O. Hofman

(Canal Zone Meeting, November, 19]0.) THE sudden decease, April 1, 1910, in Chicago, of Dr. Franklin R. Carpenter was a shock to his- many friends. He died in his sixty-second year, of heart paralysis. To most fellow-members of the Institute who have followed the progress of the. last twenty-five years in the mining and treatment of non-ferrous ores, the work of Dr. Carpenter in that line is familiar ; but very few, even of those who knew him well in the later years, are acquainted with his earlier struggles to satisfy an inborn hunger for knowledge. The story of his life resembles that of the pioneer who opens up new country; overcoming hardships with indomitable courage, meeting doubts and difficulties with an alert and open mind, and exercising in the face of reverses an unconquerable perseverance. It seems appropriate to place on record in the Transactions a brief outline of the life and work of this eminent engineer. During the past 15 years of his life Dr. Carpenter was much interested in genealogy. In the pursuit of this study as an avocation, he traced his own ancestry to the time when ?Hugh," called "le Charpentier" on account of the dexterity with which he had swung his battle-axe as a crusader, settled in Sussex on lands received from William the Conqueror. The Carpenters came to this country with William Penn. A prominent member of the family was Joshua Carpenter, the founder of Christ Church, Philadelphia. Dr. Carpenter's branch of -the family moved from Pennsylvania into that part of Virginia which is now West Virginia, where his grandfather settled in Harrison county, while the grand-uncle went further west, and built the first iron-furnace at Hanging Rock, Lawrence county, Ohio. In fact, since early times, the Carpenters appear to have been iron-masters. Franklin R.. Carpenter was born, Nov. 5, 1848, in Parkers-

Aug 1, 1910

By William B. Millar

IN ONTARIO development of the gold mines is being rapidly pushed, while the intensity of the search for new mines has probably not been equaled at any time in the past. Even to outline the results of recent prospecting activity in Ontario would be a big undertaking, but it would be timely and, I hope, interesting to Institute members to review some generalities regarding the work of the prospector and then to discuss in some detail the growth of Ontario's most promising prospect area, the Swayze district, where serious mining operations are already under way. Probably no one writing about prospectors and pros¬pecting can resist hoping that his article will not reach the eyes of a certain portion of the uninformed general public and cause a further influx of "prospective prospectors" into any given area. It is somewhat mystifying how so many people reach the conclusion that prospecting is in

Jan 1, 1933

By A. van As, J. McGaughey, M. J. Mol, R. Tosen

Geotechnical monitoring is a key element of the successful management of a block cave mine. The interrelationships between production and various monitoring datasets are often not realized due to a lack of data integration and appropriate 3D visualization. Timely delivery of information to ensure best cave management practices is only possible with an integrated cave management system. At Rio Tinto, a state-of-the-art cave management system (CaveCAD) has been designed and developed in cooperation with Mira Geoscience to integrate and analyze vast datasets and report this as instructive information regarding the current \u201cstatus\u201d of the cave.

Jan 1, 2014

By R. V. Norris

The anthracite coal trade, with a shipment averaging about 70,000,000 tons per year, differs essentially from other coal business, iii the fact that the larger sizes, comprising about 65 per cent. of the total, are used almost exclusively for domestic purposes, principally during the winter months; and that for proper combustion close-sizing is imperative, so that eight sizes are made; broken, egg, stove, and nut, known as prepared sizes, and pea, buckwheat, rice, and barley, known as steam sizes. These sizes are made in the regular course of preparation, and but little variation in the natural percentage of each is practicable. Thus it is necessary either to work the collieries intermittently, or to dispose of all the varying sizes in their fixed proportions. Unfortunately, the market does not at all times absorb the coal in proper proportions, and rather than interfere with the regular operation of the mines it has been found economical to provide storage for the excess. While the cellars of' the consumers are the great storage-plants of the country, this capacity is not under the control of the trade, except so far as reduced prices during the spring and summer months may tempt the use of this reserve. The same remark applies but with less force to the retail yards, which, though usually small, store in the aggregate a large amount of anthracite. While every effort is made to utilize to the utmost the individual storage-capacity of the country, there still remains the necessity for taking care of the irregularities of the market by the construction of storage-plants under the direct control of the producers. Such plants are usually the property of the railroads, and are situated at points most convenient from a traffic stand-point.

Jan 1, 1912

By J. H. Wilhelm

Continuous thickeners can be sized either from previous experience, continuous pilot-scale test results, or from batch settling tests. Although it is a relatively simple process to size full-scale thickeners when previous experience or pilot-scale operating data are available, batch testing is often the only realistic method for sizing thickeners due to time restrictions, budget limitations and availability of sample material. Many authors have, therefore, suggested means of running batch tests and analyzing the resulting data. Fundamental thickening theory had its beginning with the work o£ Coe and Clevenger(1). In order to determine the size of the thickener settling area, they proposed that a series of batch settling tests be run at various initial concentrations. The solids handling capacity at each concentration can then be determined and the lowest capacity (maximum area requirements) used to size the thickener. Kynch(2) developed a mathematical analysis in which the relationship between solids concentration and settling rate can be obtained from a single batch settling curve. Talmage and Fitch(3), Yoshioka(4)(5) and Dick(6), have enlarged upon these works to give a basis for methods of sizing thickeners.

Jan 1, 1979

By G. H. K. Schenck

Weather changes of a daily, weekly, or seasonal period affect mineral production and cause significant losses that are considered unavoidable. Private weather forecasting services are available on a contract basis that can significantly reduce the uncertainty associated with weather-induced changes in the production of and demand for minerals. This paper provides examples of current practice and reviews the opportunities that await those producers who incorporate weather services as an integral part of their operating, scheduling, and planning procedures. Private weather forecasts can be highly accurate because atmospheric trends such as conditions and movement tend to persist and are related to previous meteorological events. Commercial meteorological services are prepared to deal specifically with a mineral producer's special problems (Table 1). Tactical use of private forecasts is a major advance over the severely restricted value of public forecasts which, of necessity, are general in nature and cover a dispersed geographic territory. Private weather services provided on a consulting fee basis offer the mineral producer the opportunity for tactical and strategic response to weather conditions at an acceptable cost. This contrasts with the too-frequent current tendency to view weather as a random variable the costs of which are unknown and about which nothing can be done.

Jan 1, 1970

By Michal Topolnicki

"Discussed is the use of wet Deep Soil Mixing, generally executed with single mixing tools 0.8 to 1.6m in diameter, employed in the foundation of viaduct supports. The applications involve economical patterns of ground improvement, covering in average about 40% of the foundation area or less, which contribute to the competitiveness of DSM solutions when compared to traditional piling. The focus is on selected aspects of the geotechnical design, applicable for geo-composite systems in which the interaction between the stabilised and the native soil should also be considered. Evaluation of settlement can be carried out with simplified methods, accounting for punching effects, or with more advanced FE models in case foundation tilt or differential settlements become important. Potential bending of DSM columns should be considered when evaluating column stresses, especially when dealing with deep deposits of soft soil and/or foundations loaded with overturning moments and/or high horizontal forces. Statistical evaluation of UCS data using lognormal distribution is recommended, and a new classification system for DSM application is proposed. Field investigations and monitoring data from completed projects are also presented.INTRODUCTIONThe first applications of wet Deep Soil Mixing in foundation of road viaducts constructed across and along the newly built A2-highway in Poland took place in 2002. Following detailed analyses, it was concluded that 39 viaducts, originally designed to rest upon large diameter piles in order to reduce excessive settlement of individual supports, could also be founded directly on the ground improved with DSM columns, fulfilling all relevant requirements of serviceability and ultimate limit states (SLS and ULS, respectively). It was also noticed that shorter construction times and lower costs of ground improvement with DSM contributed to substantial economical savings as compared to classical piling. Since then, more than 250 road and railway viaducts have been successfully founded on DSM treated ground in Poland, and wet soil mixing is now seen as a reliable and widely accepted technology for this purpose. These applications, together with a parallel use of wet DSM for foundation of buildings, industrial halls and wind turbines, have drawn international attention to the state of practice of wet DSM in Poland for foundation of engineering objects. What follows is an attempt to summarise experience gained during planning and execution of DSM works for foundation of the majority of road and railway viaducts constructed in the last 13 years, with emphasis on selected design aspects and evaluation of collected data and observed performance.The design process of DSM treatment is iterative, as described e.g. in Annex B of EN 14679, and typically involves two main steps, i.e., the selection of the design strength of cemented soil, called soil-mix design, and the adoption of suitable column pattern, referred to as geotechnical design. Soil-mix design was initially based on purposely arranged simple laboratory tests, involving mixing of soil specimen with different cement types and dosages and subsequent strength testing. However, with a growing number of completed projects the accumulated field strength data of different stabilised soils have been more and more frequently used, reducing the need for preceding laboratory testing of soil-mix to special projects only. Information on cement factors utilised in Poland and the range of recommended compressive strengths for different stabilised soils, as well as on mixing tools and characteristics of the wet method applied, can be found in Topolnicki (2008). Consequently, soil-mix design is not further discussed herein. Selected aspects of the geotechnical design are the main focus."

Jan 1, 2015

By William C. Morel, Sidney Katell

This report covers the period January 1964 through December 1964; it is a continuation of the series that began with the publica- tion of Information Circular 7516 in October 1949. Also, it is the sixth in a series of reports prepared under a cooperative agreement between the Bureau of Mines and the American Association of Cost Engin- eers. The agreement provides for the publication of an annual cost bibliography with the work load involved in the preparation shared equally. The abstracted articles, concerned with all facets of cost engineering in the field of chemical and petroleum plants and related subjects, are from the following sources: 1. American Association of Cost Engineers Bulletin. 2. Bureau of Mines Information Circulars. 3. Bureau of Mines Reports of Investigations. 4. Chemical Engineering. 5. Chemical Engineering Progress. 6. Chemical Week. 7. Coal Age. 8. Coal--Today and Tomorrow. 9. Cost Engineering. 10. Hydrocarbon Processing and Petroleum Refiner. 11. Industrial and Engineering Chemistry. 12. Nucleonics. 13. 011 and Gas Journal. 14. Petroleum Management. 15. World Oil.

Jan 1, 1965

By P Card

“Let’s get discipline and quality into easy to understand evaluations!” Project Managers and MetPlant Operators accept poor quality evaluations because they are generally unaware of what they should expect.The 2010 draft AusIMM ‘Guidelines for Techno-Economic Evaluations’ were collated by a subcommittee of practitioners and are regarded as best practice.They apply directly to projects and metallurgical plant evaluations, including those with a heavy technical basis. They can be applied to technical problem solving where there are no monetary computations. Project Managers and MetPlant Operators should demand that economic models and evaluations follow the six principles. They should become working tools which are easy to understand, fit for purpose, consistent, rigorous, record sources of input data, have key graphs and are rapid to audit.

Aug 8, 2011

"In an environment of rising energy prices and mining at greater depths, cost-efficient loading and hauling equipment is essential. Conducted at an underground mining operation, this study analyzes the energy consumption and gas emissions of diesel and electric load-haul-dump machines (LHDs) with similar bucket capacities. Based on energy prices from the first quarter of 2014, results of discrete event simulation show that energy costs for diesel and electric LHDs are US$0.24/t and US$0.07/t, respectively. Also, diesel LHDs emit 2.68 kg CO2 per litre of diesel fuel, whereas using electric machines reduces the need for ventilation to mitigate engine heat and emissions and reduces energy costs.RÉSUMÉ Dans un contexte de croissance des prix de l’énergie et d’exploitation minière à des profondeurs de plus en plus grandes, il est essentiel d’avoir des équipements de chargement et de transport les plus rentables possible. La présente étude, effectuée dans une mine souterraine, analyse la consommation énergétique et les émissions de gaz de chargeuses-navettes (LHD) au diésel et à l’électricité ayant des capacités de godet similaires. En se basant sur les prix courants de l’énergie, les résultats d’une simulation d’événements discrets montrent que les coûts énergétiques pour les LHD au diésel et à l’électricité sont respectivement de 0,24 $US/t et de 0,07 $US/t. De plus, les LHD au diésel émettent 2,68 kg CO2 par litre de combustible diésel alors que les machines utilisant l’électricité réduisent le besoin de ventilation pour atténuer la chaleur des moteurs et les émissions en plus de réduire les coûts énergétiques."

Jan 1, 2015

By Alan E. Gallie

One of the requirements for the successful waging of war is an unlimited supply of iron ore. In the spring of 1941 the demand for iron ore was expected to exceed the supply. This was particularly so in the case of high-grade lump iron ore, essential to the open-hearth process of making steel. The bulk of Canada's iron ore was imported from the United States. At this time, Canada was making every effort to conserve United States funds for more vital purchases. For these reasons, the development of Canadian iron ore resources became of prime importance. Several companies undertook investigations and one of these examined the old Josephine deposit. Location The Josephine property is in the district of Algoma, in the Michipicoten area of the Sault Ste. Marie mining division of Ontario. It is 120 miles north of Sault Ste. Marie and 20 rail-miles east of Michipicoten harbour, on lake Superior (see Figure 1). Transportation in the area is furnished by the Algoma Central and Hudson Bay railway. The Michipicoten branch of this line passes within a mile of the Josephine mine. Michipicoten harbour provides a port through which iron ore is currently shipped. Power in the area is supplied by the Great Lakes Power Company, with generating plants on Michipicoten river, on Montreal river, and on St. Mary's river at Sault Ste. Marie. A series of transmission lines cover the district and one of these is connected to the Josephine mine by a 3 ½-mile branch line. History The Josephine property was staked by Alois Goetz in 1899. Before the claims could be recorded, the township in which they are located was given to the Algoma Central & Hudson Bay railway as part of a land grant. As a result, the ownership remained in dispute until August 24th, 1906, when a settlement was arbitrated by the Honourable Frank Cochrane. His ruling is interesting and is quoted in part.

Jan 1, 1947

By Joseph B. Cummings

"Occurrences of fluorite on the Packard property were first examined by an engineer3/ of the Bureau of Mines in July 1943 as the result of receipt of an application for an access road. In August of the same year the showings were examined by a geologist4/ of the Federal Geological Survey. The property was again examined by an engineer5/ of the Bureau of Mines in March 1944. This last examination resulted in a proposal that access be gained by construction of a truck trail and that the Bureau of Mines undertake to explore the fluorite showings.The truck trail was constructed by the Public Roads Administration, which began the work on February 17, 1945, and completed it 8 days later.The Bureau of Mines exploratory program was completed on May 16, 1945. It consisted of stripping overburden, trenching, test pitting, tunneling, sampling, and topographic mapping.In addition to being described in some detail, the extent of the work as well as results are shown in accompanying tables and figures.Mrs. Rhoda A. Packard, Mrs. Nora 1. Cline, and C. B. Pettingill, all of Tonto Basin, Ariz., own the property, which comprises four contiguous, unpatented lode mining claims recorded at Globe, Ariz., as the Walnut and the Bluebird 2, 3, and 4. The claims are situated in T. 6 N., R. 11 E., Gila County. David L. Roscoe of Tombstone, Ariz., holds a lease and option to purchase.Access to the property is by Highway 88 from Globe, 34 miles to Roosevelt, thence 24 miles by a graded county road along the west side of Roosevelt Lake to Tonto Basin. Here the Greenback Ranch road, constructed by the Forest Service and maintained by the county, crosses Tonto Creek and continues easterly to the foothills. The truck trail leaves the road 8.5 miles east of Tonto Basin and runs 2.5 miles in a southerly direction to the property. (Fig. 1.)The fluorite deposits lie in and along a small canyon in a rough, rocky area at an altitude of about 3,400 feet, Vegetation is scant and of the usual desert variety. The summer climate is dry and hot and the winter climate moderate. Rainfall at the Forest Service Station in Tonto Basin was 11.4 inches from May 1944 through March 1945."

May 1, 1946

This paper presents an overview of a program PC-BC developed for application to the design and evaluation of block cave operations. Conventional mine planning software tools are not well suited to the evaluation of this type of deposit. The paper looks at the modelling approach as applied to a block cave mining project. The following steps are described:Initial preparation of data including block models, draw point footprint geometry and draw cone geometry. Computation of individual draw point reserves. Procedure for modelling of vertical mixing of material within each draw point and subsequent determination of the best height of draw for each draw point based upon an economic cut-off value. Smoothing of draw heights amongst neighbouring draw points to produce a realistic draw envelope. Mineable reserves within the envelope are then computed. Tools for preparation and evaluation of various production schedules. This includes definition of draw rates, and rates for commissioning new draw points. In an operating mine, the capture and analysis of daily draw tonnages is important. How PC-BC accommodates this is described as well as the processes for depleting the draw column reserves. In the 12 years since the program was first developed, it has been used on a number of projects for feasibility studies and operating mines. Some practical examples of the use of the program in these projects are presented. Finally, some commentary on the sensitivity of various parameters is presented. Particular emphasis is placed on the overall footprint design.

Jan 1, 2000