Search Documents

By John J. Baz-Dresch, Kenneth L. Bickel, Winthrop F. Watts

Catalyzed diesel particulate filters (CDPF's) reduce the concentration of diesel particulate matter (DPM) and may reduce the emissions of carbon monoxide (CO) and hydrocarbons (HC) in diesel exhaust. Asamera Minerals' Cannon Mine first installed CDPF's in 1987, and currently has 12 diesel- powered vehicles equipped with CDPF's. The Cannon Mine and the U.S. Bureau of Mines collaborated to evaluate the durability and performance of a CDPF. One of the CDPF's used at the mine was periodically evaluated in the USBM's diesel emissions laboratory after 839, 1,584, and 2,881 h of in-mine service. The objectives of this report are to present results from the USBM's evaluation of this CDPF, to describe the Cannon Mine's experience and cost analysis of using CDPF's, and to make recommendations for the future use of CDPF's. CDPF's improve air quality at the Cannon Mine, but they frequently become plugged and are subject to excessive mechanical shocks and stress, shortening their useful life. Mine records indicate that CDPF's account for 0.8 to 4.9 pct of the vehicles' operating cost at the mine. CDPF life to date has ranged from 1,671 h to more than 5,992 h. Laboratory tests of the CDPF determined that DPM removal efficiency decreased and regeneration temperature increased over time.

Jan 1, 1994

By Tristan Worsey, Nathan Rouse

The Florida legislature allocated funding for the Florida State Fire Marshal (FSFM) to review the applicability of the United States Bureau of Mines (USBM) Report of Investigations (RI) 8507 blast vibration limits with respect to Florida and its soils. The study also discusses whether the current blasting vibration limits set by statute are still appropriate, including a review of measured vibration amplitudes and frequencies, structure responses, and theoretical analyses of material strength and strains

Jan 1, 2019

By E. A. Sarver

The Fe(II) regeneration process is an important aspect of Alternate Anode Reaction Technology (AART) for copper electrowinning (EW). In AART, Fe(II) is oxidized to Fe(III) at the anode during EW, and it must be regenerated to maintain recyclable electrolytes. Regeneration is achieved via Fe(III) reduction by SO2(aq), and the reaction is catalyzed by activated carbon particles. To better understand this process, a kinetic model was developed and experimentally validated for the Fe(II) regeneration in the current work. The investigation focused on the primary reaction mechanism and the reaction rate dependence on four variables: carbon particle size, flow rate, initial Fe(III) concentration and initial SO2 concentration. The Fe(II) regeneration reaction is mass-transfer controlled in the presence of activated carbon. Carbon particle size and initial Fe(III) are the most influential factors under the conditions tested. Initial SO2 concentration is insignificant to the reaction rate.

Jan 1, 2007

By Peter A. Oshust

The EKATI Diamond Mine has successfully completed the development and commissioning of the Panda Underground Project to extract the ore below the Panda open pit. The dominant kimberlite domain of the Panda Underground, intermixed olivine-rich and mud-rich resedimented volcaniclastic kimberlite (RVK), is very similar to the kimberlite domain characterizing the open pit portion of the pipe. A sublevel retreat mining method is in operation underground at Panda; near-vertical blast rings are drilled and blasted into an open void. Broken ore is mucked with load, haul and dump trucks (LHD?s), sized underground then moved to surface through a conveyor system to the process plant. An advanced feasibility study is in progress at the Koala Underground Project. The Koala pipe is geologically more complex than Panda. The pipe below the open pit is comprised of at least five distinct kimberlite domains. There is a 100 m thick zone of incompetent low-grade mud-rich RVK between the open pit and the stable high-grade olivine-rich primary volcaniclastic kimberlite where mining will be initiated. As a result, it is proposed that Koala will employ sublevel caving; each blast ring shot would be confined and mucked in sequence to maintain the cave of the over-lying low-grade RVK ore. The sublevel cave method seeks to safely defer the mucking of the low grade ore to the latter part of the mine life.

May 1, 2006

By Paul M. Wiltcher

This paper discusses how benefits in engineering design can be achieved from combining existing GRP concrete design guidelines with carbon steel design codes primarily made possible due to the increase in the constitutive properties of modern composite rebar or GRP. It also examines the technical and practical considerations necessary to both construct and ensure the integrity of composite rebar during transportation and handling on site and the measures taken by Franki-Cementation Joint Venture to ensure the safe deployment of the GRP in the workplace on the Noord/Zuidlijn Project in Amsterdam between 2003 and 2006.

Jan 1, 2006

By C. H. Dionne, J. A. Holmes, B. J. Huls

"Falconbridge Limited is presently developing flowsheet alternatives for implementation at the Strathcona Mill. The main thrust for change arises from the need to reject more pyrrhotite from the concentrate. To maintain appropriate levels of sulphur in the smelter concentrate, however, enhanced removal of non-sulphide gangue minerals must be realized. This could best be done in the Non-magnetics flotation circuit.Laboratory investigations were followed by an on-stream pilot test at Strathcona. The application of a column cleaner on the Non-magnetics concentrate resulted in significantly lower levels of fine gangue at equivalent sulphides recovery.This paper discusses the laboratory and pilot testing and results, with a focus on piloting. Also included is a discussion of the Strathcona Mill Flowsheet and the role of the Nonmagnetics flotation circuit.INTRODUCTIONFalconbridge Ltd. is currently developing means to reduce atmospheric sulphur dioxide emissions. One alternative is a reduction in the amount of pyrrhotite in Strathcona Mill concentrate, which reports to the smelter. Pyrrhotite in the Falconbridge ores contains an average of 39 percent sulphur and 0.64 percent nickel. By comparison, pentlandite contains an average of 33 percent sulphur and 34 percent nickel.A consequence of the rejection of pyrrhotite is a decrease in the sulphur assay in the remaining concentrate. This decrease causes downstream difficulties in the roasting process. Therefore, the content of non-sulphide gangue in the mill concentrate must also be reduced in order to maintain sulphur grades adequate for roasting. The resulting concentrate will have lower sulphur dioxide emissions while maintaining nickel production."

Jan 1, 1991

By Forrest T. Moyer

INJURY experience and employment data are presented in this chapter for metal and nonmetal mines, stone quarries, sand and gravel pits, iron blast-furnace slag plants, and metallurgical plants (including ore-dressing and nonferrous reduction plants and refineries) in the United States. Employment and injury experience data for all mineral industries are given in volume II. The 1962 figures are preliminary summations which are subject to revision. They were compiled from all reports from producers received by the Bureau of Mines through April 15, 1963. The data for metal, nonmetal (except well and brine operations), stone, and sand and gravel operations were collected by a mandatory reporting system under the provisions of the act of September 26, 1961, Public Law 87-300 (75 Stat. 649). The act authorized the Secretary of the Interior to study the various aspects of safety in metal and nonmetal mines (excluding coal mines) and report the findings 2 years sub-sequent to the enactment of the law. Data on nonmetal well and brine plants and nonferrous reduction plants and refineries were reported voluntarily by the operators. METAL MINES Preliminary data for the metal mining industry comprise reports on 1,871 mines and pits. The combined fatal and nonfatal injury-frequency rate was 31.95 per million manhours in 1962, a decrease of 8 percent from the similar rate of 34.54 in 1961. Metal operations reported a total of 61 fatal and 3,201 nonfatal injuries.

Jan 1, 1963

By John C. Machisak

THIS CHAPTER of the Minerals Yearbook (volume III) contains overall injury experience and employment data at bituminous-coal, lignite, and anthracite mines, coking plants, metal and nonmetal mines, metallurgical plants, and stone quarries in the United States for the calendar year 1956. Volume I of the Yearbook includes injury experiences and related employment data in the metal, nonmetal, and quarrying industries, and in the milling operations connected with the mining of those commodities. Volume II contains the injury and related employment experience of the coal mining, coking, and oil and gas industries. Reporting is voluntary on the surveys conducted by the Bureau of Mines to collect injury and employment data in the mineral industries, except in the coal-mining industry, where operators are required by Federal law to furnish the information requested.

Jan 1, 1958

By Stephen Gay, Dewetia Latti

"When improving a plant a mineral processing engineer would like to know the mineral composition distribution. In order to assess this distribution in particles, as compared to the corresponding distribution in particle sections, a procedure needs to be applied to the observed particle sections. Such a procedure is called a stereological correction. There exists many stereological correction procedures, but one group of such procedures is based on using those stereological equations that do not require making assumptions regarding particle shape or texture. These equations are called geometric probability equations.Davy derived a geometric probability equation to estimate the covariance of mineral composition distributions for particles from both particle sections and linear intercepts. This covariance can be used to measure the variance of the particle composition distribution of each mineral. The equation as presented by Davy requires textural information; however the equation was modified by Gay to be more directly applied to particle sections and linear intercepts. The variance obtained from applying this equation is fundamental to the binary stereological correction procedures developed by Gay and his colleagues; the covariance is fundamental to the multiphase stereological correction.Thus far, validation of both the binary and multiphase stereological correction has been achieved using numerical simulation. This paper shall present results comparing the covariance (and variance) estimates from Gay’s equation with actual three-dimensional information obtained from serially sectioning particles. This involved mounting a set of particles and continuously sectioning all particles uniformly so that the three dimensional structure of the particles could be obtained.The mineralogical data to which the equations described above were applied were derived from two individual size fractions from a hard-rock titanium deposit. The deposit contains a range of minerals and of mineral textures and the two size fractions selected were:"

Jan 1, 2003

By John A. Mathews

D R. CHARLES W. ELIOT, the great educator and philosopher-he of the five-foot book shelf-recently gave expression to a thought I had long been cherishing as a private opinion, when he said: "It is obvious that standardization has become a dangerous adversary of progress in both education and industry." This idea must have been more widespread than either of us knew, for some five years ago a writer of verse for one of the comic papers dealt with it at great length. I will quote only a few of his stanzas to illustrate his understanding of "A Standardized Existence" : A visitor at large, I stand Beneath a standard sky- Where everything is standardized To please the standard eye. Each tree is of a standard height, Each building is the same; Each man is uniform in height, And has a standard name. Above there is a standard star Beside a standard cloud, And a standard weather here prevails To please a standard crowd. With standard joy, and standard gain, The standard people live; And if there is one bit of pain T?is such as standards give.

Jan 1, 1926

By C. Steve

ABSTRACT: In this paper, the stability evaluation and bifurcation criteria are presented for the Jinping arch dam structure. The bifurcation models in failure status of the arch dam are derived from the uniqueness of the controlling equation of dam behaviours, and the relative phenomena between positive definition of dam structural tangent stiffness and bifurcation are given in the paper. Then the structural collapse criteria for arch dam are discussed based on the energy mode. A stability criterion of dam based on the connection of yield zones is proposed according to the implementation of elasto-plastic FEM (finite element method) numerical analysis. In accordance with this judging method, nonlinear FEM analysis is used for Jinping arch dam. The failure process of the Jinping dam was simulated and yield zones were found under the overloading condition. Keywords: Stability evaluation, bifurcation, failure process, Jinping arch dam ZUSAMMENFASSUNG: In der Verliegenden Arbeit wird ein integrater geomechanisch Modellversuch fuer Jinping Bogenstaumauer Vorgesstellt. Die Bogenstaumauer liegt aut der komplizerten felsformationen. Der Zerstoerungsmechanismus, die Stabilitaetsfaktoren und die Interaktion zwischen der Bogenstaumauer und den Seiltichen. In der Vorliegenden Arbeit wird eine dreidimensionale finite element analyse fuer die seitlichen. Gestein sauflager mittels dem Bruchmodell Vorgestellt, da fuer Jiniping Bogenstaumauer angewandet wird. Ein Bruch mechanismus model einschliesslich der statistischen parameter der Gesteinfes tigkeit wird entauckeit. RÉSUMÉ: Das ce documènt a été faite une analyse d’elemt limité de trois dimensions dn fondement de construction de roche faisant appel au modéle de l’endommagemnet à fracture, analyse appliquée an fondement du bar ragevoute de Jinping. Ce documènt décrit le test de modéle géomecanique intégral pour le barrage-voûte de Jinping L’ampleur du modéle en question constitute l’une de plus importantes en China. Ils correspondent par faitement anx calculs des résultats.

Jan 1, 2003

By Chang-Dong Li

Cadmium ingot and nickel powder were prepared by high-temperature distillation, solvent extraction and liquid phase reducing method with spent Cd-Ni batteries as raw material. The impacts of the temperature in the distilling stage, the concentration of H2SO4 in the leaching stage, the pH value in the extracting stage and the dosage of hydrazine in the reducing stage were discussed respectively. The as- prepared samples were characterized by the means of X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic absorption spectrometry (AAS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). The results showed that the recovering efficiencies of Cd and Ni reach 99.5% and 99.3%, and the purities of Cd ingot and nickel powder were higher than 99.90% and 99.80%, respectively.

Jan 1, 2009

By Gerald T. Homce, James C. Cawley

Arc flash generally refers to the dangerous exposure to thermal energy released by an arcing fault on an electrical power system, and in recent years, arc flash hazards have become a prominent safety issue in many industries. This problem however, has not been effectively addressed in the mining industry. MSHA data for the period 1990 through 2001 attributes 836 injuries to “non-contact electric arc burns”, making it the most common cause of electrical injury in mining. This paper presents results from several elements of a recent NIOSH study of arc flash hazards in mining, and provides information and recommendations that can help reduce these injuries. Characteristics of past arc flash injuries in mining are first outlined, such as the electrical components and work activities involved (based on MSHA data). This is followed by a review of important concepts and terminology needed to understand this hazard. Next, methods for identifying, measuring, and managing arc flash hazards on a power system are covered, with emphasis on recommendations found in NFPA 70E, Standard for Electrical Safety in the Workplace. Finally, results are presented from a detailed arc flash hazard analysis performed on a sample mine electrical power system using IEEE 1584-2004a, focusing on components and locations presenting severe hazards as well as engineering solutions for reducing the risk to personnel. Index terms – electrical arcing, electrical burns, mining, arc flash hazard analysis

By Lewis A. Martin

Researchers from the Spokane Research Laboratory, National Institute for Occupational Safety and Health, in cooperation with engineers from the Department of Mining and Geological Engineering, Montana Tech, Butte, MT, conducted tests to evaluate the tensile strength, fiber count, and adhesion of shotcrete applied to panels at the Chief Joseph Mine, a research and training facility operated by Montana Tech. The tests were conducted in the mine ramp 45 m (150 ft) inward from the access portal at a 15.25-m- (50-ft) long test area divided into five 3-m- (10-ft) long sections. The shotcrete was applied with an Aliva 240.5 machine fitted with a predampener. Different amounts of fiber were entrained for each panel. Background data for the tests were obtained from earlier tests in Nevada, where the typical amount of fiber in the shotcrete is 6.54 kg/m3 (11 lb/yd3). All shotcrete was applied to a minimum thickness of 76 mm (3 in). Cylindrical cores were drilled at the wall-rock interface, and adhesion was tested after 28 days of curing. The goal of this research is to reduce the need to install multiple supports at the advancing face by creating a safer mining system that limits the time miners are exposed to unprotected roof.

Jan 1, 2004

A new personal respirable dust monitor developed by Rupprecht & Patashnick Co., Inc. in a multi-year project funded by the National Institute for Occupational Safety and Health (NIOSH) generated promising results in underground coal mine testing performed by NIOSH and industry representatives during the summer of 2003. The mine data showed that the personal dust monitor (PDM) performed similarly to co-located manual reference samplers for full-shift samples at all four underground coal mines at which the evaluation took place. The technology that forms the heart of the PDM, called the tapered element oscillating microbalance (TEOM system), is unique in its ability to collect suspended particles on a filter while simultaneously determining the accumulated mass with National Institute of Standards and Technology traceability. Because the monitor measures the true particle mass collected on its filter, its results do not exhibit the same sensitivity to water spray as do optically based measurement approaches. The technique achieves microgram-level mass resolution even in the hostile mine environment, and reports dust loading data on a continuous basis. Using the device, miners and mine operators have the ability to view both the cumulative and projected end-of-shift mass concentration values, as well as a short-term 15- or 30-minute running average. During underground mine trials in the summer of 2003, technical personnel used the readings from the PDM to identify and correct several abnormal dust generating scenarios. These events demonstrated the potential of the PDM to be used as an engineering tool to evaluate the effectiveness of various dust control strategies. In a separate evaluation performed by CONSOL Energy, Inc., the mine operator evaluated the benefit of a proposed new water spray-based dust control system. Engineers measured the dust concentration upstream and downstream of a production location under different dust control scenarios using two PDM units. By evaluating the change in the dust loading between the upstream and downstream monitoring sites, the company was able to determine in a few hours which hardware configuration would yield the greatest benefit to the workplace environment. BACKGROUND Measuring underground coal mine dust concentrations is an essential part of protecting miners' health. The U.S. Secretary of Labor and the Federal Advisory Committee on the Elimination of Pneumoconiosis among Coal Mine Workers has recommended that better monitoring of coal miner dust exposures be used as a method to improve miner health. In consultation with labor, industry, and government, NIOSH issued a contract to Rupprecht & Patashnick Co., Inc. (R&P), Albany, N.Y., to develop a one-piece PDM. The object was to miniaturize TEOM technology into a form suitable for a person-wearable monitor that would enable accurate end-of-shift dust exposure information to be available to miners. Furthermore, any person-wearable dust monitor should minimize the burden to the wearer by incorporating the monitor into the mine worker's cap lamp battery, with exposure data continually displayed during the shift to enable workers and management to react to changes in dust exposure. In the summer of 2003, NIOSH conducted extensive testing of the PDM to determine its laboratory and in mine performance. In addition, anecdotal information collected in the mines showed several occasions where miners were able to identify situations that produced high levels of respirable coal mine dust The PDM's response to unplanned changes resulted in action being taken to keep dust exposures as low as possible. In another case that demonstrated the PDM's versatility, a mine was seeking to find a better dust control solution on its longwall headgate stageloader. In this instance, the PDM was used as a diagnostic tool by the miners to quickly evaluate the control technology. [ ] HOW DOES THE PDM WORK? The PDM is configured to provide accurate respirable dust personal exposure information in a form that is as convenient to wear as a normal cap lamp (See Figure 1). Respirable dust exposure data displayed by the device has two main objectives: providing the miner and mine operator with timely values to avoid overexposure to dust, allowing them to make any necessary changes during the course of a work shift; and computing an accurate end-of-shift statistic for a miner's average respirable dust exposure. The mass sensor embedded in the PDM, holds the key to the accurate, time-resolved dust concentration measurements. The inertial, gravimetric-equivalent, mass measurement technique used in the device typically provides a limit of detection on par with that of the most sensitive laboratory-based microbalances.

By Bruce Clements

The Bagdad mill, located near Bagdad, AZ, was built in 1977 with a designed mill capacity of 36.3 kt/d (40,000 stpd). An autogenous mill-ball mill crusher (ABC) grinding circuit was chosen. The original mill contained three independent grinding circuits. Each contained one 9.75m-diam x 4-m-long (32-ft-diam x 13-ft-long) fixed-speed autogenous mill, a4.7-m-diam x 6.7-m- long (15.5ft-diam x 22-ft-long) ball mill and one 2. 1-m-diam (7-ft-diam) short head cone crusher. Total installed power per grinding circuit was about 8.4 MW (11,350 hp), with 5.9 MW (8000 hp) in the autogenous mill, 2.2 MW (3000 hp) in the ball mill and 261 kW (350 hp) in the crusher (Fig. 1). The autogenous mills were designed to be able to operate semi-autogenously. However, they were never converted to semiautogenous grinding (SAG) mills. As a result of this design, only about 4.1 MW (5450 hp) of the designed power is used in the autogenous mills. The grinding circuits are closed, with 2.4 x 6 m (8 x 20 ft) double-deck vibrating screens. A series of conveyors re- turn screen oversize underneath the mill coarse ore stockpile to feed the crushers. Variable speed belts feed the crushers and control power draw. Crusher product reports directly to the tail end of the autogenous mill feed belt (Fig. 2). A magnetic sensor detects tramp iron in the autogenous mill-crusher circuit.

Jan 1, 1992

By C. N. Harman

Steel is the most versatile material which has made the progress in every aspect on this earth possible. There are hundreds of varieties of steel because for each application it has to be made with specific properties to get the most optimum usage. It is well known that the basic constituent of steel is iron. But it is the proportion of other elements in it, which give each type of steel certain specific properties. These elements are added in liquid iron inform of Ferro alloys to get the desired composition and properties. Thus, Ferro alloys are important additives in the production of steel. It can be said that no steel can be made without use of one or more of the several Ferro alloys. They form the backbone of steel. Thus, the Ferro alloys industry is vitally linked for its growth and development to that of the steel industry. Ferro alloys industry in India has never been globally competitive, despite its rich ore deposits and low-cost manpower, essentially due to a) Insufficient availability and high cost of electric power b) Increasing ores and reductants cost c) Non-availability of low ash, low phos. coking coal in the country for the production of desired coke with low ash, and low phos. contents, making import of such coke at a high cost imperative d) High-cost and insufficient infrastructural facilities (both road and rail) for rapid transportation of ore from mines to plants e)Stiff competition from producers and exporters of Ferro alloys in other countries like South Africa, Kazakhstan, China, Russia, Australia etc. due to global trade agreement which has made drastic reduction in customs duty on imports necessary. f) Wide fluctuations in the International price of Ferro alloys depending on demand versus supply. To over come these challenges plus adhering to stringent pollution control norms innovations are inevitable in the process technology, and plant equipment design, along with frequent changes in product mix, to be more cost-effective. An attempt is made in this paper to address the innovations that took place in the past and those that further need to be made, considering the future of this industry.

Jan 1, 2007

Gold mineralisation at the Macraes Gold Project is hosted in the Hyde-Macraes shear zone and can be traced for ~30 km along strike, although economic resources are confined to a seven kilometre section in the vicinity of the Macraes  township. The shear zone, which typically dips at a low angle (~20¦) to the NE, is bounded by an upper hanging wall shear and a lower footwall fault. Mineralisation occurs along the hangingwall of the shear zone as well as in low angle concordant shears and stockworks. Ore types include graphitic cataclasites with variable amounts of quartz veining, 'lode schists' and quartz-vein stockworks. Mine geology and grade control activities are designed to ensure accurate definition of ore and waste as well as the accurate prediction of ore grade. Grade control involves an integrated process of blast hole sampling, geological mapping and geostatistical modelling. Geological mapping is carried out post blasting by means of excavating trenches across are zones defined by assay data. Conditional Simulation is used to model raw assay data to define ore-waste contacts and estimate ore block grade, although, geologically defined contacts have precedence. Low angle ore zones impart a wedge shaped geometry to many ore blocks. These ore blocks are bounded by contacts that can be selectively mined to, thereby reducing misallocation of ore and minimising grade dilution.

Jan 1, 2001

By Frank E. Cash, John A. Johnson

"INTRODUCTION During the 6-year period, 1940-45, 481,485,000 gross tons of iron ore was shipped from the Minnesota, Michigan, and Wisconsin mines of the Lake Superior district. Approximately 367,000,000 tons, or 76 percent, of this ore was shipped from open-cut mines. The production of this large tonnage of iron ore from the open-cut mines of the Lake Superior district during the recent war was an outstanding achievement. It is questionable whether this record-breaking tonnage of iron ore, vitally needed for the successful prosecution of the war, could have been produced without the modern equipment and mining methods used in the district, The transportation of iron ore from the open-cut mines of the district is the most important phase of the mining cycle. Although some of the mines still use rail haulage advantageously, this method of haulage has been replaced at most nines with motor-truck haulage or a combination of motor-truck and belt-conveyor haulage.SCOPEThe transportation of iron ore in this report covers (1) power shovels, (2) rail haulage, (3) trucks, (4) belt conveyors, (5) shipping pockets, (6) accident statistics, and (7) safety rules pertaining to open-cut transporta¬tion. The purpose of the report is to discuss briefly and disseminate to the mining industry the modern methods, equipment, and safety practices used in transporting iron ore at the open-cut mines of the district.The 25 open-cut mines covered herein, located in the Marquette, Cuyuna, and Mesabi iron ranges of Michigan and Minnesota, shipped approximately 44,000,000 tons of iron in 1945, which amounted to 72 percent of the open-cut iron ore shipped from the Lake Superior district."

May 1, 1948

By M. K. Eryadin, I. Yildirim, R. Asmatulu

Novel dewatering aids were tested on various coal samples from the U.S. and Canada in laboratory and pilot-scale filtration experiments. The reagents substantially improved the dewatering kinetics and reduced the cake moistures. The cake moistures were typically reduced from 20-30% by weight to 8-14% range in vacuum filtration. When the reagents were used in conjunction with a pressure filter, higher degrees of moisture reductions were achieved. In the present work, the novel dewatering aids were tested using different types of pilot-scale vacuum filters. The results were consistent with those obtained in laboratory experiments.

Jan 1, 2003