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By Braden Lusk, Paul Sainato, Josh Calnan, Hiago Vasconcelos, Luis Felipe Marinho

"Blasting and rock fragmentation is one the most important unit operations in mining. Since itsintroduction into the mine production cycle, mining has become more efficient in mineral production(Hartman, 2002). Widely used with the main objective of breaking rock mass in smaller fragments to be loaded and hauled at a minimum cost, blasting is optimized when stemming materials properly confine drillholes charged with explosives. Halim Cevizci (2013) performed a stemming application using Gypsum plaster, a kind of material that exhibits solid-like behavior when it is dry. Based on his theory, the present article reports an experiment using another type of material that shows similar behavior, non-Newtonian fluids. The primary goal of this study is to measure the confinement effectiveness provided by a non-Newtonian mixture as the stemming component. The study also analyzes the explosives’ energy propagation throughout the rock mass relating to the stemming materials applied. Currently, mining literature recommends the application of dry granular materials in stemming columns, because of its inertial and high frictional effects (Hagan, 1973). However, the test verified that the mixture added to the stemming column was able to reduce energy and gas losses to the atmosphere, because of the liquid’s property of filling voids in the material. The solid-like behavior of the non-Newtonian mixture was investigated for its capability to improve borehole confinement, since the mixture reacts like a solid when under shear stress. The results were compared to those from sand and air stemming applications, configured in different arrangements. It was concluded that the non-Newtonian mixture yielded high results due to its better confinement effectiveness, a reduction of air overpressure, and an increase of the strain propagation and ground vibration throughout the rock."

Jan 1, 2016

By R. A. Guidotti

The Federal Bureau of Mines has studied the reaction of oxides of columbium, vanadium, and tantalum with ammonia in vertical, gas-solids reactors at temperatures ranging from 300° to 1,300° C with the goal of preparing nitride intermediates for subsequent preparation of the metals by a thermal-decomposition step. The best nitride conversions were obtained in nonmetal reactors. With Cb205, V2O3, and V205 , low-temperature maxima in reaction rates occurred at 800°,800°, and 450° C, respectively, during oxynitride formation (in A1203) at 1 atm of pure ammonia. Conversion of the oxynitride, in a second step, to the mononitride was optimum at 1,200° C for columbium and 1,050° C for vanadium. In the case of Ta205, the rate of reaction to form Ta3N5 (in a single step) was highest at 900° C, where the presence of up to 5 percent methane was found to be beneficial; improved results were obtained by conducting the nitriding in a rotary kiln. Optimum space velocities (in the vertical Al203 reactor) ranged from 5,280 hr-1 for Cba205 to 7,950 hr-1 for V203. Oxide particle size had little effect upon reaction rates. Under fully optimized conditions, products containing less than 1 percent oxygen were readily obtained in under 6 hours.

Jan 1, 1975

By A. R. Barnes, N. O. Lotter

Recoverable economic copper sulphide minerals such as chalcopyrite, bornite, chalcocite and covellite often occur together in varying proportions in the major copper-bearing ores, and have individual flotation requirements and characteristics. Pyrite also occurs in these ores to varying extents as the sulphide gangue, and is problematic because of its natural tendency to float quickly and easily. In a bulk sulphide float, selectivity against pyrite is desirable, particularly if it does not host other paymetals such as gold or silver. At the same time it is a requirement to float all of the copper sulphides despite their electrochemical differences. The electrochemistry and semiconductor properties of these minerals are reviewed, together with implications for flotation with and without collector addition. Mixed collector systems for the improved flotation of these sulphides are proposed as a solution. The use of xanthate and dithiophosphate in the collector suite allows the co-existence of dixanthogen and free dithiophosphate radical because the latter has a higher redox potential requirement than xanthate to oxidise to the dithiolate. Because some of these minerals require dixanthogen, and others, free thiolate, to generate surface hydrophobicity, a bulk flotation of all the species becomes possible in the overlapping area of Eh and pH between the two dithiolate equilibrium lines on the Pourbaix diagram. The arsenic-signature copper minerals are added to the study, since many copper operations encounter arsenic as a penalty element in the saleable concentrate. It is shown that the addition of arsenic to the copper and iron sulphides alters the semiconductor and electrochemistry properties, and in turn, its flotation characteristics. The degree of mineral association and liberation between these minerals can be a complicating factor due to textural associations, and should also be considered in the process as a next step.

Jan 1, 2016

By Kenneth K. Humphreys

INTRODUCTION What is automation? Why automate? Webster's New Collegiate Dictionary defines automation as "the automatically controlled operation of an apparatus, process, or system by mechanical or electronic devices that take the place of human organs of observation, effort, and decision." This definition gives an implied answer to the second question, "Why automate?" Automation, automatic control devices, and process control equipment receive their justification in supplementing or replacing manpower, which results in decreased operating costs. In the past, processes were operated with the minimum amount of instruments needed merely to guide operators. Processes were manually con- trolled by the operator on the basis of simple temperature, pressure, flow, and level indications on a panel. Today the tendency is to design a new plant to operate in a fully automatic manner according to a preset pro- gram utilizing a minimum of manpower. In addition to this direct cost reduction in manual labor, increased equipment capacity results from uniformity of flow and uniform control of process variables. This control eliminates or minimizes surges and permits equipment to be operated at or near its ultimate capacity and, for a given material throughput, permits the use of smaller process equipment. Automatic control, therefore, be it in the field of coal processing or in any industrial field, is simply a problem of economics. Control equipment is justified in terms of its contribution toward increasing productivity, increasing profit margins, or producing a new and salable product at a profit. Instruments and control devices can be divided into two general groups: (1) units which measure and (2) units which both measure and control a process variable.

Jan 1, 1979

By L. B. McConville

The general term "tar sand" has been used to describe sand containing varying amounts of dense, viscous petroleum. Deposits of tar sands have been found throughout the world, often in the same geographical area as conventional petroleum. The largest one by far is known as the Athabasca Tar Sands, and is located in the province of Alberta, Canada. Actually a group of three deposits, these particular sands underlie an aggregate area of more than 12,000 square miles. Current estimates place the contained raw petroleum at about 700 billion barrels, from which as much as 300 billion barrels of synthetic oil may be recoverable under presently developed technology. For comparison, this latter quantity is roughly equivalent to five times the combined total of U.S. and Canadian crude oil reserves. With the ever-widening gap between energy supply and demand, attention is being directed to all possible energy sources - both developed and underdeveloped - and certainly the Athabasca Tar Sand deposit is one of the more important ones to merit such attention. This paper will review some of the more significant developments and attempt to place in perspective the role that this source of energy could possibly be expected to play in the foreseeable future.

Jan 1, 1974

As part or a programme to raise lead smelter capacity from 65.000 to 140.000 tons bullion per annum. one new 1000 sq. ft. updraught area sintering machine replaced eight small downdraught machines.The metallurgical specifications were based on and laboratory tests at Mount Isa. Existing practice filtering concentrate as part of the charge preparation system and discharging wet filter cake to mixing was retained. This dictated a hot return fines circuit to maintain the required feed moisture content at low return sinter ratios.The engineering specifications provided for cenlralized control of plant and process, minimum operating labour, high plant availabi;lity and highest standardsof hygeine. Crushing and conveying capacity was set to cater for the most optimistic level of sintering capacity.On start-up a number of major engineering and hygiene problems became apparent, in addition to normal teething troubles. These problems have largely been overcome and reliable operation. at less than optimum production rate is now being achieved.

Jan 1, 1968

By John E. Lambert

Automatic control of drum head continuous mining machines was investigated as a means of reducing respirable dust generated and operator variabitity. Literature survey, manufacturer interviews and mine visits were the major information sources. Technically feasible automation concepts were Identified to control sump and shear rates, cutter head elevation limits and sumping distance. These are the elements of a programmed cutting cycle which maintains peak penetrating force on the cutter, to maximize depth of cut and therefore reduce dust generation. Based on the industry surveys, successful underground hardware demonstrations must be completed in order to stimulate the market demand for these advanced control features.

Jan 1, 1979

This presentation addresses the sources and weighting of project risk in coarse gold deposits with relevance to experiences at the Ballarat mine and Castlemaine goldfield. With sample representation and reliability often a source of great error in the resource estimation of coarse gold deposits, it follows that this matter should be of greatest risk to a mining project - but is it? What are the costs and efforts required to best quantify the sampling error due to nuggetty effect? After all, the main problem in Victorian gold mining ventures in the current decade is not the amount of gold available, but defi ning which portion of it can be converted to Ore Reserves or more so profitable gold bars. The author postulates that greater risk to the project lies in the geological interpretation and matching resource spatial parameters to mining methods, than the degree of uncertainty related to grade due to nuggetty gold. Recent experience in the Victorian goldfi elds is that the investor market has already severely discounted Mineral Resources reported in accordance with The JORC Code - so if they don't believe in the capacity to upgrade the resource why should we? To this end, Castlemaine Goldfi elds Ltd at its Ballarat gold project does not intend to estimate its gold mineralisation for public release, instead choosing to focus on the geological interpretation and mine planning elements. So with coarse gold deposits, is your Mineral Resource reported with The JORC Code a glass half full or half empty? Our mining forefathers in Victoria had no predictive tools which could define resources to any degree and yet were successful. By over emphasis on the definition of mineral resources and particularly the sampling error, are we ignoring the basics of cost control, solid geological interpretations and maximum mining flexibility. This is an ABSTRACT ONLY. No paper was prepared for this presentation.

Aug 1, 2010

By R. S. Dean

In an earlier paper Dean and Hersberger5/ gave preliminary results a d discussed briefly the use in flotation of organic reagents of the type known in the textile industry as "wetting agents.? These reagents are those with a molecular structure comprising a long hydrocarbon chain attached to a. highly molar or hydrorhile group in such manner that ionization is nearly complete in dilute solution and the resultant ionic grouping has a very considerable hydrophile-lipophile unbalance in the structure. As a result of this characteristic structure these reagents are more or less powerful frothers and emulsifiers. Ten the degree of hydrophile-lipaphile unbalance is sufficiently great and specific chemical factors are absent these compounds behave in flotation as noncollecting frothers insensitive to reason¬able changes of pH.

Jan 1, 1937

By R. S. Dean

In an earlier paper Dean and Hersberger5/ gave preliminary results a d discussed briefly the use in flotation of organic reagents of the type known in the textile industry as "wetting agents.? These reagents are those with a molecular structure comprising a long hydrocarbon chain attached to a. highly molar or hydrophile group in such manner that ionization is nearly complete in dilute solution and the resultant ionic grouping has a very considerable hydrophile-lipophile unbalance in the structure. As a result of this characteristic structure these reagents are more or less powerful frothers and emulsifiers. Ten the degree of bydrophile-lipaphile unbalance is sufficiently great and specific chemical factors are absent these compounds behave in flotation as noncollecting frothers insensitive to reasonable changes of pH.

Jan 1, 1937

By P. W. Bridgman

Flow and fracture are admittedly complicated phenomena of which we are yet only partially masters. There is not even nni-.persal agreement as to the details of the language best adapted merely to describe the phenomena, to say nothing of any theory. Certain points of view, however, are widely held, and there are certain general expectations as to what sort of procedures will prove permissible. A complete description of any situation involving fracture would demand a complete history of all the variables in the control of the experimenter. The experimenter endeavors so to choose his independent variables that they are adequate to determine completely the situation in the sense that when an experiment is repeated on the same initial material and with the independent variables running through the same sequence, all the other measurable properties of the system will also run through the same course. It is, I think, the universal conviction that when we are dealing with phenomena of flow and fracture, the most important of the necessary variables are the external forces acting on the various parts of the body; when the force history repeats, with certain obvious restrictions such as that temperature must be constant and non-mechanical forces, such as magnetic field, must be small enough to be ineffective, then the history of all measurable properties will repeat; in particular the alteration of geometrical shape due to flow will run through the same course, and when fracture comes, the character of the fracture will be reproduced. Complete mastery of merely the descriptive aspects of flow and fracture would demand the ability to predict the entire course of flow and complete characterization of the final fracture for every possible combination of forces, varying in time in all possible ways, when applied to bodies of all possible shapes. This full situation is obviously of prohibitive complexity. The first stage in reduction to manageable simplicity is to resolve the total situation into the sum of contributions made by small elements. Our thesis is that if each of the elements is adequately characterized, the behavior of the whole system is fixed. The element is usually taken of a simple geometrical shape, suggested by the mathematics best adapted to the particular situation. The forces acting across the faces of the elements are ultimately determined by the forces acting across the free faces of the whole system. The detailed process of finding the precise forces on the faces of all the elements in terms of the external forces involves the use of a special mathematical invention, the stress, a constructional quantity consisting of six components. The stress at any point in the body is determined by both the external force system and by the physical properties of the body at all points; quite different stresses prevail at the interior of bodies of the same shape under the same external forces in the elastic and plastic ranges. The forces on the faces of any element are, however, uniquely determined by the stress system at the element. Our fundamental thesis

Jan 1, 1945

By William R. Wayment, David E. Nicholson

The Bureau of Mines studied some physical properties of hydraulic backfills and their paramount characteristics , and made preliminary attempts to compact this type of material . The in- place density of hydraulic backfills affects the properties of strength , consolidation , and water percolation . Dense fills give better support than loose fills . In - place density properties themselves are affected by grain size , grain size distribution , and the particular conditions of sedimentation in a stope ( the amount of work the slurry water does to compact the material ) . Field sampling of in - place densities of fills presently used in four different mines and laboratory and underground compaction tests using a standard concrete vibrator show that the initial in - place density of the cohesionless fill material tested can be significantly increased by vibratory compaction .

Jan 1, 1964

By Adam Chrzanowski, Eugene E. Derenyi, Peter Wilson

"The rapid growth of the mining industry in Canada necessitates a reevaluation of existing mining surveying techniques and the development of new methods. In this connection, the Department of Surveying Engineering at the University of New Brunswick initiated a research program, and the major points of investigation conducted to date are as follows: 1. Based on practical experience and theoretical studies, all factors influencing classical shaft-plumbing procedures were analyzed. Refined methods were developed to increase accuracy. 2. The performance of electronic and optical distance-measuring instruments in underground conditions were investigated. In this connection, test measurements were made in various mines, employing four types of Tellurometers, two models of Geodimeters and a proto-type optical range-finder. 3. Tests were conducted and methods developed for the mapping of large underground chambers by photo-grammetric means. The aforementioned points are discussed at some length in the paper. The authors have also indicated areas where further research is needed and suggested ways and means to improve and modernize mining surveying as a whole throughout Canada."

Jan 1, 1967

By D. A. Dahlstrom

Although the liquid-solid cyclone is a relatively recent innovation in the field of coal preparation, various authors have already indicated three distinct applications to operations encountered in the modern tipple. Driessen's articles and work at the Dutch State Mines exhibited its possibilities in the beneficiation of fine coal with apparently high efficiencies down to the 200-mesh fraction. 1 2 3 4 Other publications point out its use as a recoverer, thickener, and preliminary dewatering agent of fine coal which in too many cases is being wasted due largely to former high operating cost limitations 5 6. Finally, certain authors have emphasized the practicability of applying the cyclone to the elimination of coarse and fine solids from water slurries in the tipple in order to produce a water suitable for recycle purposes containing only minute particles far below the 200-mesh size.6 This would result in a closed water system for many cases, with its accompanying economic and operating advantages to locations where water quantity and quality problems are severe; better operation of washing equipment using a consistent water devoid of injurious fine particles; lowered maintenance costs due to the lesser abrasion resulting when the fine abraiding particles are removed; and the greater ease of disposing of refuse streams of reduced volume containing greater percentages of solids.

Jan 1, 1949

By H. Marquis

The present paper consists of a survey of the literature on the problems of abrasion and wear of metals and materials by suspended matter. This problem is a very general one in industry, and is especially notice-able in the operation of cyclones and other types of dust collectors. The problem of abrasive dust in corrosive gas environments, such as commonly encountered in metallurgical industries, is particularly severe. Very little work has been done in the study of this type of abrasive wear, especially at high temperatures. However, a general review is presented here of all the work published on related subjects, such as that involving sand erosion in turbines and water wheels and the effect of temperature on friction wear. Topics in this paper include: blasting wear by sand, quartz, limestone, silicon carbide and other refractory particles; methods of investigation; effects of velocity, temperature and *Canadian Armament Research and Development Establishment, Valcarter, P.Q. angle of attack; correlation between indentation hardness, scratch hard-ness and resistance to abrasion; the effect of protective coatings; resistance of various metals; etc.

Jan 1, 1962

By V. P. Bhavanandan, S. B. Dubbs

The mucus secreted in the respiratory tract provides the first barrier against inhaled particulate and gaseous toxicants. The major component of mucus which is responsible for the physical properties and protective functions of the respiratory mucus is mucin. We have initiated investigations to determine the effects of coal mine dust on the synthesis of respiratory mucin by rat trachea under in vitro and in vivo conditions. In this study we have established optimum conditions-:ro-r~ the asceptic growth and mucin secretion of rat tracheal explants in culture. The best outgrowth of ciliated epithelial cells and maximum mucin production was obtained in CMRL 1066 medium containing 10% fetal calf serum. The explants continued to secrete mucin even after three weeks in culture. For the estimation and characterization of mucins the tracheae were cultured in the presence of [3H] glucosamine and [35S] sulfate or [14C]leucine. The mucins were isolated from the medium by gel filtration, treatment with hyaluronidase, ion exchange chromatography and CsBr density gradient centrifugation. Precipitation of polyanionic material in the culture media with cetyl pyridinium chloride and fractional extraction with NaCl also yielded mucin free of glycosaminoglycans, but in low yields. The tritium label in the purified mucin was distributed in sialic acid (50%) galactosamine (37%) and glucosamaine (13%). The density of purified mucin as determined by CsBr gradient centrifugation was about l.43g per ml in comparison to l.46g per ml for human respiratory mucin with a carbohydrate content of about 80% by weight. Alkaline borohydride treatment released saccharides which contained about 80% of the radioactivity. The effect of adding varying amounts of coal dust to the culture medium is under investigation. (Supported by U.S. Bureau of Mines Grant G1135142, Project 4210).

Jan 1, 1989

By Paul L. Broughton

"IntroductionThe coal deposits, all of lignite rank, of economic interest in Saskatchewan are associated with the Ravenscrag Formation (Paleocene). Several Cretaceous formations have less significant lignite accumulations (Broughton, Irvine and W'hitaker, 1974). The Swan River Group (lower Cretaceous) and Judith River Formation (upper Cretaceous) have the only coalbearing strata in the shallow subsurface of central Saskatchewan. The Swan River Group coalfield is relatively small and underlies only 15 sq km of the surface approximately 40 km south of La Ronge, Saskatchewan. An estimated 36 billion short tons are within 45 m of the surface. No reserve estimates are known to have been calculated for the coal-bearing Judith River Formation exposed at the surface in the vicinity of the South Saskatchewan River valley in west-central Saskatchewan. Although no coalfields have been delineated, lignite beds up to 1.8 m thick have been intersected in test holes. The coal-bearing upper Cretaceous and lower Tertiary strata of the northern Williston Basin extends the full width of southern Saskatchewan for 650 km, and from the United States border 120 km north to 50° latitude (Fig. 1). Only the coalfields of the Ravenscrag Formation, because of their economic interest, will be considered further. There are four major coalfields. They are, from east to west: Estevan, Willow Bunch, Wood Mountain and Shaunavon (Cypress) coalfields. Cumulative lignite seam thickness for each basin is 10 -15 m (Figs. 2 and 3). The origin of each coal basin, resource calculations, seam stratigraphy, and mining activity are discussed. Regional Setting The Williston Basin is an ellipsoidal depression in the Precambrian basement, centered in western North Dakota and marginal to the exposed craton of northern Saskatchewan and central Manitoba (Fig. 1). The sediments of the basin range from Cambrian to Pleistocene in age and have a maximum known thickness of 4614 min western North Dakota. A maximum of 3200 m is recorded in southern Saskatchewan. Most structural deformation is late Cretaceous to early Tertiary (Paleocene) in age, coinciding with the Laramide Orogeny. The pre-Laramide Williston Basin, with a depocenter near Williston, North Dakota, began developing during the middle Ordovician, or possibly earlier."

Jan 1, 1985

By Jon C. Yingling

Lean manufacturing, pioneered by Toyota, has been credited with the most significant improvements in production efficiency and product quality since the transformation from craft manufacturing to mass production in the early 20th century. It represents a comprehensive philosophy for structuring, operation, control, and management of production systems that is believed to have wide applicability. This paper outlines major lean manufacturing principles and discusses their potential for application in the mining industry.

Jan 1, 1999

By N. Theron, R. F. Meeser

The global emphasis on conserving energy resources has led to the adoption of hybrid power systems in vehicles. Optimally applied, hybrid systems can save up to 40% on fuel costs. To optimally manage a hybrid vehicle's energy flow it is necessary to know, in real time, all the energy requirements to complete a given route. The energy consumption depends mainly on the vehicle mass, speed profile, and route topography. Of these, the topographic profile is the one factor that is only route-dependent and not influenced by the vehicle or driving styles. The heading vs. distance profile is also an example of a route characteristic not influenced by the vehicle or driving style. In this study the topographic and heading profiles are used to identify routes, and are easily measured by means of digital barometric pressure and compass sensors. Correlations between the current route and previously travelled/stored routes are performed based on their topographic and heading profiles in a point-by-point manner. Above-ground tests were first performed using a road vehicle and six routes to evaluate the system. The system consistently and correctly identified a 20 km route within the first 4 km. It also proved to function correctly in underground tests through the implementation of an instrumented hand-held surveyor's wheel. This system finds direct practical application in optimizing the energy management of an underground hybrid locomotive used by the mining industry in South Africa, but can also be of benefit in applications where route identification is required and using GPS is not feasible.

Jan 26, 2023

By George W. Bain

Summary During the last three years the discovery of gold in the belt of volcanic and sedimentary rocks extending eastward from the Porcupine and Kirkland Lake gold-fields has caused a great deal of excitement in mining circles. The area is heavily drift covered, and every aid to the location of veins is eagerly grasped. A knowledge of the physiographic history of the area is of the utmost importance in the application of many of these aids. Evidence is presented to show that glacial erosion has lowered the general elevation very little below the pre-glacial level, and that many glacial erratics have been carried less than three miles southward. Probably a knowledge of the general geology of a: region was never more necessary to the understanding of the distribution and continuation in depth of the mineral veins than in this area. Four distinct granites occur in the region, and gold-bearing veins are genetically associated with only one of these. Two types of quartz-feldspar porphyries have been found, only one of which has any bearing on the locus of the mineral veins. Many other examples of this complexity of associations might be cited, but everyone goes to show that in most cases the economic importance of the deposits can be realized only after the regional geology is understood. A series of sandstone, limestone and shale intruded by granite lies unconformably below the Keewatin lavas. The latter are intruded by a gneissoid granite and are overlain unconformably by the thick series of Timiskaming greywackes and silts. These are intruded by carbonated syenites and syenite porphyries which have since been rendered somewhat schistose.

Jan 1, 1927