Search Documents

By M. S. Safarzadeh

Cu-As feedstocks are among the most problematic copper sources that have been avoided over the past years. The high arsenic content of such ores/concentrates combined with their refractory nature have directed the metallurgical industry towards developing efficient technologies for the treatment of high-arsenic copper ores/concentrates. As the most important member of Cu-As-S mineral system, enargite (Cu3AsS4) is frequently encountered in some of the important copper deposits. Several hydrometallurgical and pyrometallurgical processes have been examined for the treatment of enargite concentrates, but currently, no commercial operation exists. In an effort to develop an original processing option, an acid bake-leach process has been identified and applied to an enargite concentrate containing ~67% enargite, ~27% pyrite (FeS2), ~3% chalcopyrite (CuFeS2), ~6% sphalerite (ZnS) and <1% galena (PbS). Sulfuric acid baking of this concentrate resulted in the transformation of the concentrate to S8, As2O3, HFe(SO4)2?4H2O, PbSO4 and Cu0.47Fe0.53SO4?H2O, all of which (except elemental sulfur and PbSO4) dissolved during the water leaching step. More than 87% Cu and 64% As were leached when the concentrate was baked at 200°C over 7 h with a sulfuric acid to concentrate weight ratio of 1.6. Less than 1% As was lost to the gas phase. Upon water leaching, copper and arsenic were released to the solution at a concentration ratio of about 3:1. While enargite is very reactive during the sulfuric acid baking reaction, other minerals present in the concentrate such as pyrite, galena, and sphalerite may compete to consume sulfuric acid and be converted into their corresponding sulfates at different levels. The purpose of this paper is to evaluate phase transformations during the acid bake-leach process for the treatment of an enargite concentrate, and to study the effect of sulfuric acid dosage on the extraction of Cu, Fe, and As. In this regard, the concentrate, baked concentrate, and the leach residues are characterized and a conceptual process flowsheet is described for the acid bake-leach process for the treatment of enargite concentrates.

Feb 23, 2014

I met Austin Taylor in Vancouver on my way home from my first Pioneer examination. He asked me to examine the unsuccessful old Lorne mine, adjoining and west of the Pioneer. I had no idea that this meeting would lead to one of the outstanding successes and pleasant associations of my career. I knew nothing of Taylor, except that Gen. McRae and associates said that he had been engaged in lumbering and was interested in an oil and gasoline marketing company called Home Oil. But even if the Lorne examination would be only a small one, in the depths of the Depression in 1931, I was glad to have a chance to look at another gold property, so I agreed to visit the Lorne early in August. The start of the trip was not auspicious. I had been working hard on an unproductive study, and was greatly worried by my father&apos;s hopeless illness with tuberculosis. To get a little rest on my way north I had arranged to go from Seattle to Vancouver on the night boat that connected with my train. To my surprise, Bill Boultbee, an associate of Taylor, met me at the train in Seattle at 9:30. He said he would drive me to Vancouver, arriving at one In the morning. I was so tired that I begged off and let him take the drive alone Boultbee was most understanding and friendly, but I knew how I would have felt if I had been kind enough to take the long drive to help a stranger and then had been forced to make the return midnight drive alone. I was lucky they did not call off the examination at once. I got a good sleep on the Vancouver boat and Austin Taylor met me at the Hotel Vancouver for breakfast. After a brief talk he took me to the small steamer that made the 4-hr sail up Howe Sound to the village of Squamish. This was the end of the Province-owned Pacific Great Eastern Railway that was eventually to be a shortcut from Vancouver to the Canadian National main line at Prince George. Because

Jan 1, 1976

By S. A. Elmquist

Research activities performed by Cleveland-Cliffs Research and Hibbing Taconite plant personnel during the last decade have resulted in the development of an improved autogenous mill grinding circuit. Minus one (1) inch autogenous mill trommel oversize material, con-sidered to be a critical size, is magnetically cobbed and then crushed to 100% minus 3/8" prior to reentry into the feed end of the mill. Autogenous mill capacity increases, up to 25%, have been measured in pilot plant tests using this approach and are also anticipated for the Hibbing Taconite concentrator which presently has reached a 15.5% improvement.

Jan 1, 1994

By J. Diao

In order to understand the flotation kinetic behavior of coal and associated mineral matter, a detailed investigation was conducted in a 2-liter Denver flotation cell using three high sulfur coals at three feed sizes, minus 28. 100 and 200 mesh. Subsequently. the flotation products were sieved into different size fractions and analyzed for their ash and pyritic sulfur content in order to delineate the effect of particle size on the rate at which each constituent floats. The results were tested with several different flotation kinetic models and the best model for coal was then chosen. The flotation rate constant and the ultimate recovery calculated from a kinetic model were used to delineate the effect of particle size, collector (dodecane) and frother (MIBC) dosages on the flotation kinetics of coal, ash and pyrite.

Jan 1, 1992

By S. A. Richards

Business planning in the coal&apos; industry revolves around the production and quality forecast. It is difficult to accurately estimate costs and revenues until the production forecast is made. At mines where production comes from multiple sections, quality is tied to each section&apos;s production. Blending becomes a part of the planning process. In order to respond to rapidly changing business climate, a reliable program is needed to accurately forecast the effects of changes in key parameters affecting the production. This paper discusses an efficient, intuitive, and economical approach to underground coal mine planning program which uses a PC-based relational database as the programming platform to forecast production and quality. The program was developed at a major coal company. The relational nature of the production planning data, the programming algorithm, and the underlying principles are discussed in this paper.

Jan 1, 1994

By Bruce K. Cantrell

As part of a continuing study of diesel exhaust aerosol characteristics, the Bureau of Mines has applied Chemical Mass Balance (CMB) model source apportionment analysis to evaluate a size selective sampling method for determining the separate diesel exhaust and coal dust aerosol concentrations in a diesel equipped coal mine. Size selective sampling was used under the premise that diesel exhaust aerosol dominates the submicrometer aerosol size range, while most of the mineral dust aerosol is greater than 1 m. A micro-orifice, uniform deposit impactor (MOUDI) was used as the size selective sampling method. Concurrent samples of mine aerosol were collected using a dichotomous, respirable aerosol sampler. This sampler separated the fine and coarse size portions of its sample at 0.7 m. Trace element concentrations for in-mine aerosol sources and the dichotomous samples used by the CMB model were measured using Instrumental Neutron Activation Analysis. The CMB analysis, applied to both the fine and coarse fractions of the respirable mine aerosol, yielded the mass concentration contributed to each by diesel exhaust and mineral dust aerosol sources. The MOUDI size distribution data were analyzed using nonlinear regression to parameterize the fine and coarse fractions of the sampled aerosol and to estimate the contributions to each fraction from both coal dust and diesel aero- sol sources. For the diesel mine visited, analysis of the MOUDI samples yielded a value for the fraction of the fine aerosol attributable to coal dust of 15[]7% fine fraction coal from analysis of the MOUDI samples versus 25[]4% from the CMB analysis. The remainder of the fine aerosol in the mine was diesel exhaust aerosol. CMB analysis confirms the original premise for such sampling. After correcting for the presence of coal dust in the fine aerosol fraction, analysis of the MOUDI size distributions yielded estimates of respirable mineral and diesel exhaust aerosol concentrations that were accurate to with-in 10% of values determined by the CMB apportionment.

Jan 1, 1987

By Felicia F. Peng

The plant data were collected from three streams around a dense medium drum for coarse coal cleaning operated at various volumetric ratio of medium-to-feed. The effect of the volumetric ratio of medium-to-feed (MF) and particle sizes on the performance criteria, g50 and Ep, of the dense medium drum. These measured data were adjusted and calculated for the yields and balanced relative density distributions by mass balanced method based on the statistic principle. These balanced data were then used to formulate the mathematical models of the separation distribution curves for the various feed size intervals. The correlation equations for the g50 and Ep as the function of inverse of the feed size, and MF and total throughput were established. A numerical algorithm utilizing the Secant method, based on the root searching principle, was developed for yield optimization and simulation of dense medium drum separation to improve the separation efficiency and hence the product yield. The relationships between the direct ash content and relative density of the particles in feed and the products were established and incorporated into the numerical algorithm for predicting the product quality.

Jan 1, 1996

By Levent Ozdemir

An extensive study involving laboratory testing and computer modeling has been performed to assess the technical and economic feasibility of utilizing the recently developed minidisc cutters on roadheaders for hard rock mining. The results show that heavy duty roadheaders fitted with minidiscs can excavate hard rock formations at acceptable production rates and cutter costs. This paper presents and discusses the results of this study together with the ongoing developmental efforts of this technology, which include laboratory testing of a roadheader cutting drum with minidiscs and full scale field testing of a machine in hard rock

Jan 1, 1995

By E. D. Gardner, William O. Vandenburg

This chapter on the square-set system of mining em¬bodies the results of a special study of the subject made as a part of the US Bureau of Mines (USBM) general investigation of mining methods and costs. Data for the chapter were gathered by the authors during visits to mines using square-set mining, from information circu¬lars prepared by consulting engineers to the USBM on mining methods at individual mines, and from articles in the technical press and the Transactions of the American Institute of Mining and Metallurgical Engineers. Al¬though some of the properties discussed are no longer in operation, the methods described are still valid. The square-set system of mining has been very widely applied and is one of the oldest methods in use in the US. It is mainly employed for extracting rela¬tively high-grade ore in heavy ground. It is also useful in taking out pillars left in mining by other methods. It is used to some extent as an auxiliary method with many underground systems and as an alternate with cut-and¬fill, shrinkage, and open-stope methods when heavy ground is encountered. In some cases as much as 50% of the ore may be extracted by square setting at mines listed as using some other method of mining. A large tonnage has been mined yearly by square setting, prin¬cipally in the western states. Due to the high cost of timber and the relatively low average production per manshift, this system generally is not used when the ore can be mined by some other method; it usually is adopted as a last resort. Square setting, however, has a special field in that ore bodies not minable by other methods can be stoped by this system. As square-set mining was widely known, there was a tendency for years to use the method regardless of its suitability. With the increasing need for economy and the development of other methods, square setting has been superseded in many mines by cut-and-fill, top slic¬ing, or sublevel caving methods. The term square-set mining as used in this chapter includes all stoping methods in which the space made by the removal of the ore is timbered with framed sets. The sets usually are square in horizontal section. The stope may or may not be filled with waste rock as stoping progresses. HISTORY OF THE SQUARE-SET SYSTEM Prior to 1860, open-stope methods with stulls for casual support accounted for most of the mineral pro¬duction from underground mines. Attempts to mine large ore bodies that required artificial support resulted in disastrous cave-ins and loss of life. The art of mining received a tremendous impetus following the introduc¬tion of methods for mining the bonanza ore body which was discovered in 1860 in the Ophir mine on the Comstock lode, Virginia City, NV. This ore body was phe¬nomenally rich and eventually proved to be 122 m (400 ft) high, 27 m (90 ft) wide, and 98 m (320 ft) long. The mining of this large high-grade ore body taxed the best engineering talent of the time; the problem was finally solved by Philip Deidesheimer. According to Eliot Lord (1882): "At the 50-foot level the vein of black sulphurets was only 3 or 4 feet thick, and could be readily extracted through a drift along its line, propping up the walls and roof when necessary by simple uprights and cap-posts. As the ledge descended the sulphuret vein grew broader until, at the depth of 175 feet, it was 65 feet in width, and the miners were at a loss how to proceed, for the ore was so soft and crumbling that pillars could not be used to support the roof as in coal mines. They spliced timbers together to hold up the caving ground; but these jointed props were too weak and ill-supported to with¬stand the pressure upon them, and were constantly broken and thrown out of place. The dilemma was a curious one. Surrounded by riches, they were yet un¬able to carry them off and their mass of black sulphurets bade fair to become a white elephant on their hands. The Ophir Company began to wish themselves less for¬tunate, as their miners narrowly escaped burial day after day in their attempts to stope out the ore. "A young mining engineer, Philip Deidesheimer, was in charge of a quartz mine in Georgetown, El Dorado County, Calif., in the autumn of 1860, when this serious check to the development of the lode occurred. At the request of William F. Babcock, a trustee of the Ophir Company, Mr. Deidesheimer left his California mine and crossed the mountains with a letter from the direc¬tors of the Ophir Company, authorizing him to inspect the workings of their mines and make such changes in the method of timbering as should seem to him expe¬dient. After examining the vein he designed, in the course of a few weeks, a system of timbering which proved to be exactly adapted to the requirements of the work. Experiments which he had previously made in California gravel and quartz mines furnished the out¬line of his plan. This was to frame timbers together in rectangular sets, each set being composed of a square base, placed horizontally, formed of four timbers, sills, and crosspieces from 4 to 6 feet long, surmounted at the corners by four posts from 6 to 7 feet high, and capped by a framework similar to the base. The cap pieces forming the top of any set were at the same time the sills or base of the next set above. These sets could readily be extended to any required height and over any given area, forming a series of horizontal floors, built up from the bottom sets like the successive stories of a house. The spaces between the timbers were filled with waste rock or with wooden braces, forming a solid cube when¬ever the maximum degree of firmness was desired. By adjustments of these sets the ore bodies along the line of the lode were extracted with comparative ease and security." Most mining methods are evolved slowly and are the result of the combined efforts of a number of minds; Deidesheimer&apos;s feat was remarkable in that his system was immediately successful. He died in 1916 at the age

Jan 1, 1982

By Nathaniel Arbiter

A fully-instrumented driving mechanism has been constructed to study the power, aerating and solid suspension characteristics of several laboratory flotation machines. Machines operating over normal flotation speed ranges give constant power numbers in liquid&apos; systems indicating that they operate under fully baffled turbulent flow conditions. Owing to lack of geometrical scaling, power numbers for different sizes of cells of the same make are different. Even larger differences occur between cells of different manufactures. For a given impeller, varying the tank size did not significantly affect the power consumption. Tank geometry and baffling has a slight effect on power consumption with shrouded impellers. For a given impeller speed, suspension height decreases while power increases with increasing mass of solids in suspension. While power consumption is hardly affected by particle size and clearance between the impeller and tank bottom, the suspension height significantly increases as clearance increases and as particle size decreases. Aeration was found to affect not only power but also the suspension characteristics of the machine. For closely sized particles drastic sedimentation occurred when a critical value of the air flow number was exceeded. The critical air flow number decreased with increasing particle size. This effect was less marked with a wide particle size range. The self-aerating capacity of flotation machines increases with cell size at a given speed for the same impeller-shroud system, but decreases in the presence of frother and solids. Equations have been established for correlating all of the studied variables. Data taken from the literature were also correlated with these equations.

Jan 1, 1968

By H. Y. Yang, L. L. Tong

For gold recovery, a Chinese refractory, high-sulfur gold concentrate was subjected to biooxidation with high pulp density in a single stirred-tank reactor. The flotation concentrate contained 36.9 percent sulfur (S) and 33.9 percent iron (Fe). Different experimental regimes for biooxidation were applied. With a mixed culture and by controlling the amount of addition of the gold ores and the pH of the biooxidation system, maximum iron oxidation of 82.6 percent and sulfur oxidation of 79.3 percent were achieved. The experimental results indicate that the pH control was beneficial to the biooxidation of this concentrate. Approximately 28.4 percent of elemental sulfur (S8) was found in the oxidizing slags. Two dissolution mechanisms of elemental sulfur are proposed: (1) FeS2 → S80 → S2O32− → SO42− and (2) FeS2 → S80 → SO42−. The high pH had a positive effect on the reduction of the S8. The results of thermodynamic analysis indicate that as an oxidant the dissolved oxygen can effectively reduce the Gibbs free energy of the pyrite oxidation process and, compared with the reaction of ferric iron as the single oxidant, the oxidation of pyrite is easier. The efficiency of the gold recovery was related to the iron oxidation as well as the sulfur oxidation. Gold and silver recoveries of 92.4 percent and 66.4 percent, respectively, were achieved.

By W. C. Meyer

Surface tension and its control are important in the concentration of ores by froth flotation, both in terms of producing the proper bubble size distribution and to render the ore surface of interest hydrophobic such that adhesion to a bubble will take place. The influence a substance has on surface tension has traditionally been measured using static, equilibrium techniques. Yet many applications such as flotation involve rate-related effects of surface tension where equilibrium values are not reached. In the time frame of 1 - 300 seconds, aging effects have been noted for bubbles formed in dodecylamine acetate solutions; a slow decrease in surface tension occurs until an equilibrium value is reached, as studied by Finch and Smith (1972). Since stationary bubbles do not exist in flotation cells because of the turbulence generated by agitation and aeration, it is more likely that the chemical composition of the bubble is determined during its formation, under dynamic conditions. The chemical composition is extremely important because the induction time required for a particle-bubble entity to collide and adhere to each other is augmented by favorable surface tension (wetting) proper- ties between the surface of the particle and the bubble air-water interface or envelope, as considered by Mackenzie and Matheson (1963). Finch and Lyman (1976) have established that the probability of a "permanent" attachment taking place during this contact time is aided by the ability of an oil droplet (viz. bubble) to relieve non- equilibrium surface tension effects which are involved in the water-thinning process. This Maragoni effect, or surface elasticity, can be considered in the context of particle agglomeration addressed by Kao and coworkers (1975). Water drainage leads to the formation of a collector-frother meniscus appearing between the colliding entities, arising from their combined partial immiscibility in the water phase and promoted by hydrophobic bonding within the interface. Together they constitute a liquid bridge whose force of attraction drawing the particles together is proportional to the interfacial tension existing between the water phase and liquid bridge. This adhesive force shows an approximate linear decrease with separation distance until rupture occurs, that is, FX = Fmax (1 ? X/Xr) (1) for a distance of separation X and rupture distance G. The greater the surface elasticity of the bubble, the greater will be the rupture distance and the better will be the force of adhesion. Since van den Tempel (1965) has related surface dilational properties of bubbles to the elasticity, E, of the film as

Jan 1, 1983

By R. R. Klimpel

The use of chemical reagents in flotation has been studied in great detail, e.g. (1, 2, 3, 4). Important progress has been made on the understanding of surface chemistry concepts involved in flotation. However, such scientific studies are often very complex even for rather simple idealized systems. Therefore, the deve- lopment of predictive or quantitative tools for plant engineering evaluation is still in the evolutionary stages. Until further progress in fundamental work is achieved, the operating engineer is faced with semi-empirical physical testing of reagent changes on several sizes of the actual equipment under study to be confident of the economic viability of any change.

Jan 1, 1980

By J. A. González-Anaya

This laboratory work presents a study of the effect of ultrafine grinding on the gold recovery of a highly refractory gold concentrate. The particle size of the concentrate was P80 = 46 µm and the main species present were quartz (28.58%), dolomite (25.63%), pyrite (20.93%), arsenopyrite (15.39%) and 112 g/t gold. After optimizing hydrated lime and lead nitrate additions, standard cyanidation with 1% NaCN, pH = 12.3, 25% S/L permits to recover only 9.4% of the gold. Different particle sizes were submitted to cyanidation. When the concentrate was ground to ultrafine sizes (P80= 4.6 µm), the gold recovery for the same cyanidation conditions increased to 67%, with cyanide consumption of 66.7 kg NaCN/t. Additional tests were performed in order to reduce the cyanide consumption. The reduction of the cyanide concentration in the leaching solution from 1 to 0.5% and the addition of 100 g Pb(NO3)2/t allowed the reduction of the cyanide consumption to 27.6 kg NaCN/t (58% reduction), while maintaining the same gold recovery of 67%. The remaining gold could be present as very fine inclusions or in solid solution in the matrix.

Jan 1, 2011

By P. Zhang

A 1989 FIPR characterization study of the future phosphate resources in Florida showed that MgO would be a problem with both the pebble and concentrate as phosphate mining moves deeper. Since the ratio of concentrate to pebble will become higher and higher in the future, reducing Mg content in the concentrate by a small margin would allow blending of a large portion of the high-dolomite pebble. This research was conducted based on that logic. The following six approaches were tested for reducing MgO content in the flotation concentrate: (1) Adding a dolomite depressant in the rougher flotation step; (2) Dolomite flotation on the rougher concentrate with and without grinding; (3) Dolomite flotation on the cleaner concentrate with and without grinding; (4) Scrubbing the flotation feed; (5) Scrubbing the rougher concentrate; (6) Scrubbing the cleaner concentrate. Successful methods include adding a dolomite depressant in the rougher flotation, dolomite flotation on the cleaner concentrate with grinding, and scrubbing the cleaner concentrate in quartz sand. These techniques could reduce MgO content in the final concentrate by 20-40%. The flotation process could achieve a concentrate with the lowest MgO content, but it is the most expensive approach. Adding a dolomite is inexpensive and easy, but the effect is limited. Overall, scrubbing may be the most promising technology for this purpose.

Feb 23, 2014

By G. Kazonich

The high costs and environmental problems associated with making iron and steel in the United states is driving the development of new technologies to replace the blast furnace. A prototype reactor incorporating rocket technology was designed and built. This rapid rate reactor was operated successfully and consistently made iron metal. Minus 32s-mesh magnetite particles could be reduced to iron metal in less than 50 ms in a high temperature flow through reactor. Iron product was recovered inside the reactor and in a downstream cyclonic separator. The results of typical operation and how parametric changes affected the reduction of iron ore concentrates are discussed.

Jan 1, 1993

By C. L. Lin

A PC image-based on-line coarse particle size analyzer has been developed to measure particle size distributions under plant situations where overlapped particles are being transported on a moving belt conveyor. Although previous testing had shown satisfactory performance of this image-based system for separated particle size measurements (the non-overlapped case), it was necessary to modify original algorithms in order to solve the overlap problem and make the system suitable for plant operations. On-site testing has been conducted at a large copper concentrator in the southwestern U.S. for further investigation of the overlap problem.

Jan 1, 1995

By S. S. Klima, H. Jiang, T. W. Beck, Y. Zheng

Researchers at the National Institute for Occupational Safety and Health (NIOSH) performed a series of lab tests to evaluate the respirable dust removal capacity of an industrial air-cleaning fan. Limestone and coal dust were tested separately in NIOSH’s full-scale drill table simulator at the Pittsburgh Mining Research Division (PMRD). Gravimetric samplers with Dorr-Oliver Cyclones and 37-mm filters were used at two upstream and four downstream locations inside and outside of the drill shroud chamber. There were six tests performed for both the limestone and coal dust experiments. In the limestone tests, an average respirable dust concentration of 98.86 mg/m3 was achieved upstream of the air-cleaning fan. The filter results show that the averaged respirable limestone dust reductions were 7.84%, 8.81%, 10.94%, and 18.02% at the four sampling locations downstream of the fan. In the coal tests, upstream samplers achieved an average of 129.03 mg/m3 of respirable coal dust. The averaged dust reductions were 9.54%, 9.83%, 18.54%, and 19.21% at the four downstream sampling points. The results indicate limited cost benefits of using this technology because of the relatively low dust reductions determined from this laboratory study.

Feb 1, 2023

By J. J. Casey

This paper is one of a series of presentations organized by the Conference of American Society of Civil Engineers with the goal of making significant progress toward an equitable and effective allocation of risks in construction undertakings among the principal parties - owner, contractor and designer. The role I have been assigned is principally one of identification of risk while others will devote greater attention to the allocation of these risks and the contractual arrangements necessary to properly make these allocations. Construction projects are joint undertakings by parties who bring different skills and interests toward a common effort, much as this conference does. A project is not an adversary proceeding and does not benefit from establishment of an adversary mode, as our lawyer friends seek in the resolution of legal issues. Accordingly, I urge upon this Conference the adoption of two basic precepts and guidelines as the criteria for sharing of the risks inherent in construction undertakings toward achievement through mutual effort the common goal of a successful project completed in the shortest time and at the least overall cost. These precepts are: (1) that all risks are rightfully the owners unless transferred to or assumed by another party for a fair compensation; and (2) that the principle guideline in determining whether a risk should be so transferred should be whether the receiving party has both the competence to fairly assess the risk and the expertise necessary to control or minimize it. The sponsors of the conference have provided certain guidelines to the authors. There is, however, no constraint in expressing one&apos;s bias and I suspect that my contractor&apos;s outlook may be inherent in my comments. The guidelines have suggested that I indicate whether the risks identified are ones that can or should be shared or borne by one party alone. In doing so, I will attempt to follow the precepts I have recommended.

Jan 1, 1979

By B. K. Cantrell

The use of diesel equipment in underground coal mines is controversial because "whole diesel exhaust" is regarded as "a potential occupational carcinogen" by the National Institute for Occupational Safety and Health (NIOSH). Threshold limit values (TLVs) are recommended for the gaseous pollutants; CO, CO2, NO, NO2, SO2&apos; and some hydrocarbons emitted in diesel exhaust. There is, however, no TLV recommended for diesel exhaust aerosols (DEA) nor is there a standard method for sampling these aerosols. The University of Minnesota and the Bureau of Mines have collaborated to develop a personal diesel exhaust aerosol sampler (PDEAS) which utilizes size selective, inertial impaction and gravimetric analysis. During the field tests of this sampler, numerous air quality measurements were conducted in underground coal mines using diesel equipment. The objective of this report is to present these data and to assess the impact of diesel face haulage equipment on mine air quality.

Jan 1, 1991