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By J. O. Lewis, Carl H. Beal

The material for this paper was collected for the most part by C. H. Beal during the years 1916, 1917, and 1918. Many of the conclusions reached in regard to the life of oil wells have already been published by the Bureau of Mines 1 but those presented in this paper deal particularly with the theoretical aspects of oil production. The report discusses some of the fundamental factors governing oil production, taking up first the conditions affecting the. amount of oil in the oil sand, then those factors that control the rate of production of oil wells, and then discusses several related problems, most of which deal particularly with the effect of the production of one well on that of another.

Jan 1, 1921

In Australia we usually define "resource" in purely material terms, and rarely relate it to intellect and human capacity. We look at the sheer abundance of our natural resources and are satisfied with the feeling that we don't really need-to rely on using our brains. Certainly our country is fortunate to have the mineral resources it does, but in many ways Australia's worst enemy is its "lucky country" syndrome because we tend to underutilise the great resource we have in the capacities of our people. Raw material exports will undoubtedly continue to contribute a major share of our export revenue, but to harness the riches our country has to offer most effectively we need the vision and planning necessary to bring together our material and human resources. There is a need not only to find, exploit and process our minerals economically, but to turn as much of our mineral wealth as possible into high value products before it leaves the country. In particular we must use our brainpower if we want to maximise economic benefit from and political influence over the strategic minerals which leave our shores. In the past we have been successful in finding and exploiting minerals because our mining industry has been in the forefront of private sector research and development. But if Australia is to have an advantage over other mineral rich countries in insulating itself from the effects of cyclical swings in commodity prices, then the future of the industry must lie even more in technological sophistication rather than depending. on such considerations as size and location of mineral deposits. To survive, our mineral industry must have the foresight and resourcefulness to make its own luck. There are two keys to increased efficiency in exploration and production and in further processing methods: enhancement of the skills of the workforce and continual improvement of R&D.

Jan 1, 1986

By Carvalho A. Felipe de

The search for environmentally friendly and cost-effective methods for gold extraction has been undertaken in order to provide alternatives to the use of cyanide leaching in the gold industry. Among such alternative reagents is the combination of chloride and hypochlorite ions due to their oxidation of metallic gold and its complexation. Therefore, the current work aims at investigating gold leaching from an oxidized material by means of a solution comprising calcium hypochlorite and sodium chlorite. The sample used in the current research contained 66.1% Fe2O3, 20.4%SiO2, and 35.7 g/t of Au. In addition, XRD and SEM-EDS analysis revealed iron oxide, quartz and muscovite as the main crystalline phases in the sample. For comparison purposes, cyanidation of the oxidized material resulted in 90% gold extraction in 24 h. The reference conditions for the leaching tests with the chlorite-hypochlorite system were: particle size −37 μm, solid/liquid ratio of 10% (w/v), 10 g/L NaCl, 10 g/L Ca (OCl)2, pH 5–6, 3 h of leaching. The effects of the: (i) Ca(OCl)2 concentration, (ii) NaCl concentration, (iii) pHrange and (iv) the effect of pulp density in the extraction of gold were assessed. In addition, the stability of the hypochlorite solutions (OCl−) was investigated. The ideal concentrations of Ca(OCl)2 and NaCl were determined as 25 g/L and 15 g/L, respectively, whereas the optimal pH range was 4–6. Under these conditions, the final gold extraction reached approximately 84%. By varying the solids content of the pulp (10%, 20% and 30%), it was observed that the lower solids value resulted in greater gold extraction (84%). The degradation of the hypochlorite solution and the possible catalytic effect of the presence of the solid were evidenced. To sumup, in the experiment, high gold extractions were achieved in shorter periods of time (3 h), as compared to the cyanidation of the same sample. On the other hand, itwas necessary to use significant amounts of the reagent due to hypochlorite instability at the pH conditions recommended for high gold extractions.

By Hugh P. Godard, K. Winslow

"AbstractA number of panels of various aluminum alloys in different combinations and secured by steel and three types of aluminum rivets were exposed underground at two locations in a Northern Ontario gold mine for two years and then examined to determine the extent of corrosion. The results indicate Alcan 65S-T to possess considerable advantages over Alcan 178-T, which has been employed in the construction of light skips and cages with considerable success for almost twenty years. Information on the behaviour of these alloys when used with steel rivets and in mixed combinations with themselves was obtained.IntroductionBy the complete substitution of aluminum alloys for steel in the fabrication of mining skips and cages, their weight can be reduced as much as 50 per cent. Lesser savings are possible though its savings are possible through its plates, doors, reinforcing members, etc. Reduced weight leads to economy through increased hoisting efficiency.For a new installation, the basis of design is the rate of production, which thus fixes the live load to be hoisted per trip. A lighter skip permits the use of a lighter rope and a smaller hoist. In deep shafts with high-speed hoists operated in balance, the power required for accelerating is considerable. The hoist size is determined by the weight of skip, load, and rope plus the force required to accelerate or decelerate these three elements A light skip may result in a considerably lighter rope. This is important because, even though the skip can be completely balanced this is not true of the rope. Partial balancing is possible, but conical hoist drums or other devices for this purpose are costly; thus a smaller rope results in a smaller hoist, with consequent general reduction in cost of the whole installation. A reduction in power consumption is also obtained as a result of keeping to a minimum the amount of unbalanced load and the weight of all moving parts which must be accelerated."

Jan 1, 1950

By Charles G. Maier

"INTRODUCTION The use of thermodynamic calculations to answer practical problems in metallurgy, especially those that are relatively difficult to test experimentally, is rapidly becoming a conventional method of procedure. Nevertheless, these methods cannot he applied effectively until the fundamental thermodynamic constants used for them have become available either by direct experiment or by recalculation of data already existing in more or less undigested form.In an attempt to collect such data far the compounds of lead and the antimony group the incentive has been to make a preliminary survey that will disclose the gaps or questionable phases of available information and to collect data that may be used to answer certain rather practical problems presented by operating metallurgists.This report comprises three sections; the first gives the basis of selection of the constants which may now be given or estimated, and the later sections discuss the application of the figures obtained to two of the more interesting problems.The reader will discover that many of the quantities involve critical study of a number of more or less discordant observations. Although certain data could be rejected on the basis of thermodynamic comparisons, it must not be overlooked that many of the figures are the results of rational estimates rather than exact experiment. The use of thermodynamic methods to control and partly authenticate such estimates is one of its most valuable characteristics for the practising metallurgist or chemist, who cannot check by direct experiment each property of the materials which he converts to usable form.Nevertheless, while it is definitely possible in certain instances that the final figure selected for the heat or free energy of a process or substance may be in error by as much as a few hundred to a few thousand calories per formula weight, questionable figures are usually revealed by the thermodynamic calculations made. When quantities of such degree of accuracy are, and they often must be, used for estimating an unknown reaction, the result often gives no more than the order of magnitude of the desired quantities. Yet even in these extreme cases the answer is far more reliable and valuable than an unordered guess or a conclusion based on incorrect data."

Dec 1, 1934

The Shortage of Mining and Metallurgical Engineers I N many parts of the Western World attention has recently been drawn to the acute shortage of mining and metallurgical engineers produced by the universities. Naturally, the reasons for this shortage have been discussed, and various remedies for it have been proposed. In this paper, I want to examine some of them. It is now fairly generally ac-cepted among mining men that the easy attractions of modern urban life have left the career of mining in the metaphorical as well as in the literal backwoods. The industry finds it increasingly difficult to recruit adventurous and intelligent young men; for such men now seek their intellectual, if not physical, adventure in more glamorous occupations from a safe social base in suburbia. The salaries, opportunities and security offered by the mining industry do not complete effectively with the rewards offered by other industries and by commerce, taking into account the social disadvantages of a mining life. The excitement and other non-material attractions of mining

Jan 1, 1965

By D. W. Bacon

Plant process optimization programs are often costly, both in technical effort and loss of production. Evolutionary Operation or "EVOP" is a mode of plant operation consisting of controlled cyclical changes in process conditions by which information is provided concerning potential process improvements while both volume and quality uniformity in production are maintained. Its conceptual simplicity and low cost of utilization have led to successful adoption in a variety of industrial manufacturing operations. This paper is an expository account of basic EVOP theory, the problems encountered and the organization required in applying it to a processing plant. Illustrations are provided which indicate the payoff that can result.

Jan 1, 1967

By M. Abdellatif

The production of a 40% Al-Ti alloy was successfully proven at the lab scale, using pure TiO2, aluminium, and lime. These tests were conducted in an induction furnace maintained at 1600?16250C. The introduction of rutile into the feed recipe resulted in an alloy containing between 0.35 and 1.10% Zr, depending on rutile to TiO2 ratio. DC arc production of the alloy was largely accomplished at 40 and then 200kW scale. These tests evaluated various metallurgical and operational factors including target slag composition, Ti-content in the alloy, co-feeding versus sequential, furnace bath depth, and rutile as part of the Ti containing feedstock. Overall, an alloy containing 24?33% Ti was consistently produced with co-feeding of the reactants and with lower taphole tapping. When rutile was added, the zirconium analysis in the alloy remained below 0.2%. The main impurity elements were iron, silicon, carbon, nitrogen, and oxygen.

Jan 1, 2009

By Ulises Crossa Archiopoli

We describe a technique that allows rapid imaging of the thermal diffusivity of the sample by a modified photo-thermal technique. The thermal diffusivity in hardened steels strongly correlates to the hardness. Hence in a noncontact manner and with optical microscope resolution, a 2D map exhibiting the crystallographic phases and hardness of the sample can be retrieved. Two almost collinear laser beams scan the surface, one as a modulated pump and a second as a CW probe. The deflection of the probe carries information on the thermal expansion of the sample and with it, on the thermal diffusivity. It is shown that a single determination of the time delay of the modulation of the probe beam can be used to retrieve the thermal diffusivity.

Jan 1, 2010

By Charles Will Wright

I. INTRODUCTION. THE application of the camera as an adjunct to topographic mapping began practically with its invention, and it has been employed with varying success since that time. With the exception of the camera to be described, the plate-camera has been universally used in this work, thus giving a projection of the area photographed on a flat surface. From such projections or photographs, by the rules of geometry and of perspective, points defining topographic features and seen from at least two camera-stations may be projected upon a ground-plane-the map.1 In 1904 I employed the plate-camera for this purpose in Alaska, but found that the labor necessary to plot the maps, even in a general way, was long and tedious. In 1905 a small Eastman panoramic camera was fitted with spirit-levels, a sightalidade and a transparent scale, introduced inside the camera to register the degree-points in the sky-line of the film-negative; also, arrows to indicate the horizon-line. This was, on the whole, successful; but the details in the topography were not brought out in the views with sufficient clearness, and the photographs were too small. These difficulties were overcome by obtaining a larger and more carefully constructed instrument, which was satisfactorily employed in the field during the year 1906. A panoramic view is made up of an integral number of perspective views upon flat surfaces, and logically is the most ac-

Jan 1, 1908

By D. M. Watson

Mineral discoveries and subsequent extraction have led to the establishment of many small communities, some major towns and a few cities . In Canada, such developments have essentially occurred without benefit of long-range regional or local planning. In the past, this was not a cause for concern. Now, however, rising expectations and reorientation of social values have placed increasing responsibility on government and industry to ensure the long-term viability of communities and regions. Such responsibility means large investments by government in infrastructure and by industry in extractive and processing plants. Uncertainty in the interpretation of ore reserve estimates becomes a critical factor. The traditional methods of reporting reserves - "proven", "probable" , "possible" - may be useful in individual mine production planning, but they are inadequate for planning industrial and public infrastructure, The need for a better information base is critical, with clear and precise definitions of what is being reported, but we are a long way from achieving it. The challenge is therefore to develop a closer professional relationship between government and industry and to tie mineral development to long-range regional strategies.

Jan 1, 1977

By Jackson R. Pressley, Bruce Vandenberg

The knowledge of how and when your explosives go off can help you make intelligent decisions regarding future application of explosives thus removing some of the black magic associated with blasting. The net result will be intelligently set-up shots with timing, explosive charges, and placement more accurately done. Lower operational costs can be achieved when the correct combinations are applied.

Jan 1, 1992

By L. Garrigues, M. Jarvis, M. Halhead, O. A. Bascur

"Large variability of ore types, escalating variables operating costs and increased throughput require large investment in sensors and systems in mineral processing operations. Mining and mineral processing plants collect and manage more data than a small city with much in real-time. The data is changing rapidly as internal and external conditions evolve. As corporations buy and sell assets, and reengineer their staff, the structure and tools that were used to understand this data is lost. This results in significant deterioration in the ability to maintain a smart operation. When data is recognized as a critical asset and managed as part of an infrastructure, it become a key enabler to help transform the entire operations. In many situations, all partners in business collaboration—such as join ventures, contract manufacturer, expert service providers, and operations and maintenance companies—need access to production and asset data. The emergence and maturation of Cloud technologies make it possible to easily connect the plants to external equipment suppliers and operational support service.This paper will share examples of how mineral processors have adopted new data strategies such as self-service business intelligence, cloud computing and internal/external collaboration.INTRODUCTIONOne of the main challenges in mineral and metallurgical processing plants is effective energy and water management. The lowering of ore grades requires higher throughputs while the ores are getting more complex with variable mineralogical compositions. Electrical energy supply is becoming a restriction in many countries. Rising water management costs has a direct impact on the profitability of the operations. Grade recovery versus energy consumption in copper production for both open pit and underground mines has been described by Fuerstenau (2001). Comminution uses over 55% of the energy to produce nonferrous metals while other operations require much less energy (Nelson, Richins, & Lelinski, 2013)."

Jan 1, 2016

By Scott Turner

MY YEAR OF SERVICE as president of the A.I.M.E. came at a time when the mineral industry had suffered severely because of disturbed economic conditions throughout the world. The Institute, an integral part of this industry, had been similarly affected. Its membership and revenues decreased; it was confronted by problems of retrenchment at a time when its vigorous operation was especially important to its members, of some moment to the mining industry, and of value to the nation. Throughout the last year, the recession of activity in our industry continued with slight abatement. Your Board accordingly exercised such economy within the Institute as was possible without impairment of essential functions. It endeavored to aid in sustaining the morale of members, their sense of professional unity, and their interest in maintaining research and the interchange of scientific and technologic data upon which the progress of our industry depends. Effort was made to assist in the difficult task of finding employment for needy members; our endeavors have met with some success.

Jan 1, 1933

By R. G. Vardiman, M. R. Achter

Observations of dislocation structure in niobium are presented using two techniques. Triangular pits developed by electroetching are confined to orientations in the stereographic triangle between the (111) pole and planes of the (1ll) zone and require the presence of carbon. Some unusual electroetching phenomena at other orientations are noted. A chemical etch of dislocations decorated by the addition of carbon to 50 ppm reveals the complete dislocation line structure in a surface layer up to 30 p deep, with a resolution of less than 1 p. This effect is independent of surface orientation. The structure of subboundary nets may be resolved for misorientations up to about 1'. Dislocation structures found in strain anneal grown crystals, such as helices, prismatic loops, and high-density areas, are observed. The measurement of dislocation density is discussed and values obtained in different ways are compared. IN the course of some work on the response of refractory metals to thermal-mechanical treatments, it was desired to examine the defect structure of relatively low dislocation density crystals of niobium in bulk form. Surface and bulk methods for the observation of dislocations have been reviewed by ~melinckx,' and include etch pitting, decoration, and various X-ray techniques. The dislocation line structure has been developed by decoration in a few metals, although observations were limited to certain orientations, or by the coarseness and nonselectivity of the precipitate. The most commonly used technique is etch pitting. In niobium, etch pits have been developed chemically'0," in material of high impurity content and electrolyti-cally'' in relatively pure material. In this paper, etch pits developed electrolytically, and the dislocation line structure of a surface layer developed by decoration and chemical etching, are examined, and observations are presented from both techniques. EXPERIMENTAL METHODS Our starting material was electron-beam-melted niobium, swaged to 4 or -in.-diam rod. Chemical analysis is given in Table I. Single crystals were grown by a strain anneal technique using 1 to 2.5 pct of strain and growth temperatures of 1700" to 2300"~.'~ Some crystals grown by zone melting were also examined. The desired surface orientation was exposed either by spark machining or by sectioning with a cut-off wheel and prepared for etching by electro-polishing.

Jan 1, 1969

By Phillip E. Deering, Robert M. Cox

A model pillar study was conducted in which the engineering principles of dimensional analysis were applied to the problem of coal mine pillar design. The paper reviews the theory of similitude as applied to the model pillar study conducted in the investigation. An example solution of a design problem is included to indicate how the results of the study may be used as a first approximation in the design of coal mine pillars. The design of mine pillars for adequate support with minimum loss of valuable raw materials has always presented a problem to the mining engineer. Most often, for lack of a better method, past practice has influenced the design of new mine pillars. This process has always left doubt as to the safety factor of the pillars. The work presented in this paper is an initial attempt toward adapting the engineering principles of dimensional analysis to the problem of pillar design in underground mines. The use of the dimensional analysis technique is advantageous because all the variables associated with the problem are considered, and by systematic analysis the relative influence of each variable is determined. The model material utilized in this study was taken from the Helena seam of the Cahaba coal field located in central Alabama. The research study was sponsored by The Southern Electric Generating Co. as part of an over-all rock mechanics investigation of the Helena seam area. THEORY OF SIMILITUDE Model analysis is used extensively in engineering today, particularly in the solution of design problems that defy the classical methods of analysis. Such problems arise when materials with a nonlinear stress-strain relationship are involved, when geo- metric boundaries are difficult to define in simple form, when strains become large, or when partial failure occurs. All of these difficulties usually exist in pillar design problems. Those principles which underlie proper design and construction of models, and the interpretation of test results, comprise the theory of similitude. That is, the theory of similitude includes a consideration of the conditions under which the behavior of two separate entities or systems will be similar, and the techniques of accurately predicting behavior of one from observation of the other. The theory of similitude may be developed by dimensional analysis. Dimensional analysis, as a powerful analytical tool, is developed from a consideration of the dimensions in which each of the important quantities involved in a phenomenon is expressed. It is based on two axioms: 1) Absolute numerical equality of quantities may exist only when the quantities are similar qualitatively. 2) The ratio of the magnitudes of two like quantities are dependent on the units used in their measurement, provided that the same units are used for evaluating each. Dimensional analysis, developed from these two axioms, differs from other types of analysis in that it is based solely on the relationships that must exist among the pertinent variables because of their dimensions, rather than on the relationship of natural laws. In itself, dimensional analysis ~rovides qualitative, rather than quantitative relationships, but when it is combined with experimental procedures, it may be made to supply quantitative results and accurate prediction equations. APPLICATION OF THEORY The design of an adequate mine pillar requires the determination of a design equation and the selection of a dimensional system with which to work. Since force plays an important part in the design of mine support, the FLT (force, length, time) system has been used. The factors involved in the dimensional analysis of mine pillars and their dimensions are: A = cross-sectional area L Cp = design strength FL- E, = tangent modulus of elasticity FL

Jan 1, 1969

By David Griffiths

I am not an orator and have never said a word in public during my thirty years' experience in the coal mines of Colorado; but, being requested to speak by our worthy chairman, and as I am deeply interested in the future welfare of this organization, 1 will make an effort to say a few words in behalf of the Rocky Mountain Coal-Mining Institute, which we are about to organize. As 1 understand it, it is the object and intent of this organization not merely to assemble occasionally for the purpose of discussing various problems in coal-mining, and thus to obtain the best possible results in economic operations, but its especial duty will be to devise ways and means whereby accidents in coal mines will be minimized. Figuratively speaking. we are about to plant a tree in the State House of Colorado, and desire its roots and branches to extend over Wyoming on the north, New Mexico on the south. and Utah on the west. So we expect this tree to bear fruit over a vast area. We must remember that the planting of a tree, even in good soil, is useless unless we cultivate, prune, and nurture its development. If we will not do so, the tree will not bear the desired fruit. So, in order to make the Rocky Mountain Institute a success, we must not only start it off in good shape, but we must keep on adding to its strength in various ways, so that it will become a known factor and a recognized power over this broad territory. In other coal-mining states and countries of the world much has been accomplished through similar organizations to reduce loss of life among men engaged in the production of coal, and there is no reason why our institute in the West should not be equally useful and attain the same results. There are many ways by which this organization can be made beneficial to the men engaged, in various capacities, in handling the "dusky diamond." I will endeavor to confine my brief remarks to the necessity of a crusade of an educational nature among three classes of men that are directly and indirectly connected with coal mines. First-We need to educate ouselves. It is amazing how few of our number, holding positions of trust, and having charge of men in and around coal mines, are conversant with our brief mining laws and cognizant of our duties in enforcing them. Going down the line to our company men and miners, I think 1 can safely say that not over 5 per cent of them are in any way familiar with the statutes that have been enacted for their especial benefit and protection. This condition, 1 think, can be, and ought to be, remedied, and. if thoroughly done, the effect in reducing loss of life will soon become apparent. Now, to reach the officers or men in charge I consider an easy matter, which could be accomplished in this manner: Have our general managers or owners of coal properties issue a circular, compelling every superintendent pit boss, fire boss, or other officer having charge of men, to send them a copy of the mining law in their own handwriting every six months. But to come to the masses engaged in coal-mining. to get these men of various nationalities educated in the mining law, will be a difficult task indeed; but I think I have an original scheme that is practical, and which, if put in operation, would work wonders in educating our company men and miners. This plan is as follows: Have every school in every coal-mining district devote one-half hour on Friday afternoon after school hours to the familiarizing of all male pupils between the ages of twelve and sixteen years with the contents of our laws governing coal mines. At the end of each term of school, award small prizes- say, $5, $3, and $2- to those that are best posted, the principal of the school to be the sole adjudicator. Now, someone may say that this is causing extra work to our teachers, with no compensation. In this respect, I will vouch that 95 percent of our teachers will do this work gratis, providing we can show them the benefit of the system. If we go a step farther, and put an incentive before our teachers, probably it would be a good scheme to award a prize-say, $20 or more-for the best set of practical amendments to our mining laws complied by any school and its teachers, judges of the amendment to be members of this Institute and appointed by the President. There is no denying the fact that we need to be educated, and that we should adopt some system that will encourage a knowledge of practical and scientific mining amoung our present forces and the rising generation. Newspaper Men Need Educating Second-Our reporters and press agents need to

Jan 1, 1987

By William C. Martin

"Consolidated Sudbury Basin Mines Limited owns two mines, 4 miles apart, near the southwest end of Sudbury Basin. The Errington mine lies close to the north boundary of Creighton Township and about 18 miles by car from Sudbury. The Vermilion Lake mine is in Fairbank Township, on the south side of Vermilion Lake.The first discovery of base-metal mineralization within Sudbury basin was made by James Stobie in 1897 at Stobie Falls on the Vermilion River, half a mile west of the Errington mine. A few years later Alphonse Oilier made a discovery of massive pyrite with base-metal sulphides near the west end of the present Errington workings.No work of consequence was done on these discoveries until 1924, when Joseph Errington acquired options on a large acreage of ground which was later taken over by the Treadwell Yukon Company Limited. After considerable diamond drilling this company sank No. 1 shaft in 1926. In the next three years, a large amount of underground development was done, a pilot mill was constructed and operated for two years. All operations ceased in 1931 with the fall in metal prices. While in operation the pilot mill treated 186,172 tons of ore the average grade of which was 1·07 per cent copper; 1 10 per cent lead; 4·60 per cent zinc; 0·03 ounces gold; and 1 70 ounces silver.Up to the time of closing in 193 l there had been completed at the mine 26, 790 feet of lateral work and 75,500 feet of surface and underground diamond drilling. The company records, however, showed no figures on ore reserves, except broken ore in stopes amounting to about 60,000 tons. A study of the plans, prior to reopening the mine in 1952, showed 1,450 lineal feet of ore (at 1952 prices) opened up by drifting on the 300-foot and 500- foot levels. It is clear that no comprehensive picture of the structure was had at this time. The orebodies were considered to be very irregular pods scattered through masses of quartzite-carbonate in a sheared zone about 800 feet wide. In some way the ore was believed to be related to the tuff-slate contact zone. With this picture it was impossible to make a reasonable ore estimate or even gauge the tonnage potentialities with any feeling of reliability."

Jan 1, 1949

By M Dunglison, P M. Cameron

Simultaneous mass-balancing of a mineral processing flow sheet results in adjustments to each data point that reflects the accuracy and precision across the full set of data. In this way, all the good work that goes into designing the sampling and analysis protocol for each sample point is leveraged in order to produce a æbetterÆ set of balanced numbers for every sample point in the circuit. Few operating plants employ whole of circuit balancing techniques to produce reported operating results. This situation is changing with the application of mass balancing technology which utilises redundant data for production accounting and metal reconciliation from product to ore source across multiple phases and multiple time periods. Mine and plant data can now generate credible information to improve productivity. Mine and plant personnel can now use consistent data sets for review and planning. Decisions based on balanced data can be made quicker and with increased confidence.

Jan 1, 2005

By D. E. Pollock, Andrew B. Cecala

It has long been known that ventilation is a cost-effective method to lower respirable dust concentrations in all types of mining applications. The National Institute for Occupational Safety and Health has been working on a number of different research techniques that use ventilation as a critical component to lower respirable dust levels at surface and metal/nonmetal operations in the United States. This article presents five such research efforts. The first research area discusses how improving the ventilation flow patterns in an iron ore mill facility lowered respirable dust concentrations by 31 pct throughout the primary grinding area. The second research area examines how respirable dust levels were lowered at a dimensional stone shop by using air cleaning units suspended from the ceiling. A third area discusses how improvements in ventilation at underground limestone mines lowered respirable dust concentrations. The fourth area examines how improvements in dust filtration and pressurization systems significantly impacted the air quality in enclosed cabs of surface mining equipment. The last area presents a newly developed clothes cleaning technique. This technique uses an air spray manifold to blow dust from a worker’s clothing in an enclosed booth, which confines the dust for capture and removal by a baghouse dust collector. These research areas represent an array of different control technologies to lower respirable dust concentrations. Ventilation is an integral part of these control technologies.