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By K. Konialis

In the last twenty years, the mining industry has made marked efforts to improve its reputation in regard to its social performance. These efforts have been expressed in the 9th ICMM (International Council on Mining and Metals) principle as a commitment to contribute to the social, economic and institutional development of the local communities. Towards this goal, which has been increasingly highlighted because of its importance for sustainable development, a number of practices and methods have been developed. The international development literature describing these practices is full of so-called development buzzwords, such as stake-holder participation, empowerment, capacity building. This paper argues that none of these development catchwords are neutral, but contain assumptions based on a specific view of development. Since capacity building is a central task in development, the paper focuses on this concept and takes a critical look at the assumptions that underlie this concept and influence strategies employed by the mineral sector. It suggests that the notion of capacity building in some earlier approaches implies a set of asymmetric power relationships between developed and developing countries where capacity is transferred from the developed countries to the developing ones. The developing countries are seen as passive recipients while the experts, i.e. the developed countries through their mining companies ultimately control the capacity-building process. The paper also points out that the mainstream capacity development approach has been based on the assumption that local or indigenous communities are mainly made up of needs and capacity gaps. The goal of development projects should then be to address these needs, which are perceived and prioritized by the ?experts?. Critiques of this development model suggest that in order for the mining industry to embrace more successful and sustainable practices, it should rethink the notion of capacity building. It should move towards alternative approaches that see it as a two-way learning process which will serve to enhance not only the capacities of the communities, but also of the development practitioners and which will build on the strengths of the community, and move away from attitudes of superiority and practices of dependence.

Jan 1, 2007

By Lee W. Saperstein

The Research Council of SME, at its Annual Meeting in Reno, NR, in February 1993, held a Research Forum on Technology for the Future. The Forum's purpose was to find out from the members, particularly those from industry, their opinions on research needed in the mineral industries. Panelists were selected for their breadth of knowledge and connections. Many panelists, in turn, solicited opinions from additional contacts. A similar effort is underway with mineral-oriented schools. A parallel mission has been undertaken by the American Mining Congress (AMC) through its Committee on Technology. In particular, AMC is concerned that the needs of industry be transmitted in a timely way to federal agencies, especially the US Bureau of Mines. This article reports to the SME membership the principal findings of the Research Forum. The article is derived from a full report that is available from SME. Many of the calls for research made during the Forum can be clustered into five broad categories. These categories are discussed in the following sections of this article. However, since the time of the Forum, many reviewers of the full report have noticed that fundamental research was not given much emphasis. The Research Council points out that the Forum was organized around industrial needs. There is a call to the academic and research community to organize a similar Forum. The Council emphasizes that this is not the last word on research needs and that the membership is urged to continue to give ideas and opinions to the SME Research Council. There will be an opportunity at its next meeting during the SME Annual Meeting in Albuquerque, NM, Feb. 22, 1994, for open discussion of this report. Because the opinions were intentionally confined to representatives from industry, the problems portrayed and the solutions sought are from the vantage of an operator. It comes as no surprise that many of the espoused research desiderata seek more efficient or cost-effective outcomes for the various mining activities discussed. The order of the Forum was a straightforward set of mining activities: exploration, evaluation, mining and processing.

Jan 1, 1993

By Victor C. Storhok, Batric Pesic, Marlyn D. Ballain

No1ihwest Alloys produces magnesium from dolomite by reduction with ferrosilicon and aluminum. This process produces alkaline by-products in quantities that allow their consideration for use as commercial products. Two such products are dicalci­um silicate, termed as Di-Cal, and magnesium oxide, termed simply MgO. The alkaline properties of these materials offer acid neutralizing power, comparable to traditionally used lime. Thus, the materials warrant study for their use in various appli­cations where neutralization of acidic waters or process solutions are required. One such application is the treatment of acid mine waters with the objective of removing heavy metals. The chem­ical stabilities of the produced metal precipitates are critically important, from an environmental point of view, for their safe disposal in tailing ponds. The EPA regulates waste material dis­posal according to the results from TCLP testing. In this ongoing study, three mine waters were selected for treatment with Di-Cal and MgO. Lime was used as the control for these experiments. The waters were collected from the Bunker Hill mine, Berkeley Pit, and the Blackbird Mine. In addi­tion to testing the chemical stability of produced metal precipi­tates by the TCLP procedure, two other parameters were studied as well. They are: 1. the effect of water pH on stability, and 2. the effect of pH on the stability of resulting precipitates. In the first three months of study, it was found that neutral­ization with Di-Cal results in precipitates that range from equiv­alent to superior in performance as compared to those produced using lime for the waters from all three mines. An additional beneficial characteristic of precipitation with Di-Cal is the fast filtering characteristics of produced precipitates, when compared to the precipitates produced by lime. This property may be of significance when considering the improvement in drainage of tailing ponds and the volume of solids produced. This paper will discuss in detail the stability of metal precipitates with respect to various pe1iinent metals found in mine waters of Berkeley Pit (Cu, Zn, Mn, etc.), Bunker Hill (Zn, Mn, Ni and Co), and Blackbird Mine (Cu, Co).

Jan 1, 1998

By James I. Mathis

Should an arbitrary reduction factor be applied to laboratory compressive strengths when designing pillars? The answer is, as is the main contention of Peng's article, probably not. Many factors affect the strength of the material remaining in the pillar. On the other hand, outside influences will influence the strength testing results from the lab. This is not the first article, nor the last, to discuss the discrepancy between the two strengths. As was discussed in the article, actual pillar strength is affected by several factors. The two mentioned were: • The scale effect of discontinuities. How large must the pillar be so that the increase in discontinuity count with size will not decrease the strength. • Non-uniform strengths and lithologic units within the pillar. The scale effect of discontinuities is important. What size block must be tested so that the rock mass strength is actually measured? For a highly fractured rock mass, or coal with a high cleat density, this sample may be quite small. Conversely, if an unaltered, moderately jointed, quartz monzonite was examined, the sample block would likely be very large. This is the subject of ongo¬ing research. More to the point, if the tested sample is sufficiently large to model the rock mass strength, then no reductions should be made in the lab strength based on this factor alone. Non-uniform strengths and variations in lithologic units will also affect the pillar strength. I am not an expert in coal mines, having gained my experience in hard rock metal mining. These problems, though, are commonplace. However, strength sampling for pillar strength determination involves sampling material from within the lithologic unit that will form the pillar, not from pieces of material found on the floor. In addition, this sampling should cover the entire range of strengths of the material in the pillar-hard units (such as the partings described by Peng), as well as soft units. Testing results should then be included in the pillar design. Contrary to statements in Peng's article, at least one rock mass rating system (Laubscher, 1990) allows for the compositing of strong and weak units into a design rock mass strength that can be used for pillar design.

Jan 1, 1993

By A. D. Hammond

"INTRODUCTION Vanadium deposits in Arizona are distributed all across the state, from the rim of the Grand Canyon to the Tombstone mining district in the southeast corner of the state (Figure 1). The combined past production of vanadium from Arizona and New Mexico ranks second nationwide, after deposits in the Colorado Plateau In the northeast corner of the state, in the Carrizo Mountains and Monument Valley of Apache and Navajo Counties, vanadium was produced as a by-product of uranium in deposits of the Salt Wash and Shinarump members of the Morrison and Chinle formations, respectively. The production took place between 1943 and 1970. Another source of vanadium in Arizona occurs in vanadate deposits associated with supergene enrichment of base-metal vein and replacement deposits. The most important vanadate mineral is vanadinite, a chloro-vanadate of lead. Presently, there are no primary mines of vanadium in the United States. In 2012, a small production of vanadium pentaoxide (V2O5) was reported as a by-product of uranium at the White Mesa uranium mine in Utah1. This paper describes vanadate deposits in Arizona with emphasis in three districts, namely, the Mammoth, Globe-Miami and Banner districts.VANADIUM EPIGENETIC DEPOSITS: VANADATES Almost all vanadium epigenetic deposits occur as vanadates in oxidized zones of lead, zinc and copper veins and replacement deposits. Vanadinite, descloizite and mottramite are the most common minerals in vanadate deposits. Descloizite is a vanadate of lead, zinc and copper. Wulfenite, a molybdate of lead is also present. These minerals replace supergene base-metal minerals, form crusts on faces of open cavities, or are inter-grown with residual clays in pockets. The vanadium content in vanadate deposits is believed to have been leached from the country rock by ground-water and transported through porous rocks until precipitating as a relatively insoluble vanadium compound or until the solution evaporated. Precipitation was brought about by local concentrations of cations of divalent lead, zinc or copper. Lead is a constituent part of almost all of vanadate deposits and the vanadium pentaoxide (V2O5) content in vanadate minerals seems to have a direct correlation with the content of lead in the hypogene mineral. Vanadate deposits are restricted almost entirely to the oxidized parts of vein or replacement deposits. It is rare that oxidized zones extend past 100 ft from the surface. Vanadate deposits are largely restricted to tropical and temperate zones and regions of dry climate. Arizona and New Mexico have the largest concentration of vanadate deposits in North America."

Jan 1, 2015

By Alan T. Nelson, Ronald D. Mariani

The Tilden concentrator was originally constructed in 1974 for the processing of low grade hematite. Flotation is a key concentrating process in the operation, and therefore flotation optimization has been a major concern since the plant startup. This paper will discuss some of the modifications made in the process to achieve optimization. The conversion that now enables the plant to process magnetite as well as hematite also will be discussed. INTRODUCTION The Tilden Mine, located in Ishpeming, Michigan, is managed by Cleveland-Cliffs Iron Company and is owned by Cleveland-Cliffs and two Canadian steel makers. It was constructed and started production in 1974 and expanded in 1979 for processing a low grade, fine-grained hematite iron formation for which there was previously no technology available. Several papers have been written describing the unique character of the concentrating operation. The hematite plant consists of 12 grinding and concentrating lines, which utilize two stages of autogenous grinding with crushing of an intermediate sized product. The ground product is deslimed in a highly dispersed alkaline environment to reject silica. Corn starch, the flocculant, has a high affinity for iron at the operating pH range of 10.5 to 11.0. The ore is upgraded from 35% to 45% iron in the desliming step. The deslime thickener underflow is the feed to flotation. Each flotation line consists of a bank of 10 rougher cells, followed by four scavenging banks incorporating 5, 4, 3, and 3 cells each. The Wemco flotation cells are each 14.1 cubic meters (500 cubic feet) in volume. A total of 12 flotation lines are available. [ ] A reverse flotation process is employed, using a straight-chain, 8 to 10 carbon primary ether amine silica collector. At the levels used in the circuit, the amine also serves as a frother. A final concentrate is produced in the rougher cells. The concentrates from the four scavenging steps are combined and recirculated to the feed end of the roughers, with the fourth scavenger froth being discarded as a final tailing. Upgrading to about 65% iron is achieved, with control of the circuit based on final concentrate silica grade. Starch is again used, this time as a depressant for iron. During the years of operation, several key areas of the flotation process have been targeted for optimization. The most significant improvements have been realized in the following areas: *Grade Control Automation *Control of Water System Chemistry *Flotation Spray Water This paper will focus on these areas, but other minor improvements also will be briefly discussed.

Jan 1, 1993

By Richard H. Follis

Activated carbons used for precious metal recovery from carbon-in­pulp (CIP), carbon-In-leach (CIL) and carbon-in-column (CIC) circuits often become fouled with Inorganic precipitates (i.e., CaCOa, CaS04, SI02), and adsorbed organics (I.e., petroleum distillates from lubricants, dissolution products from wood) (1,2). These contaminants occlude carbon pore structure, such that diffusion controlled adsorption and desorption (elution) of Au(CN)2-and Ag(CN)2· are lmpeded(3,4l. Thus, after only short exposure to the hydrometallurgical environment, the characteristic carbon activity is reduced(5l. By frequently regenerating circuit carbons, activity losses associated with fouling can usually be minimized. Regeneration typically Involves (not necessarily Is this order): 1) elution to remove adsorbed ionic species (e.g., until they are removed from the carbon pore structure, Au(CN)2" and Ag(CN)2-are contaminants )(6l; 2) acid washing with 3-15% (wt/wt) hydro­chloric acid, to dissolve soluble Inorganic precipitates such as CaC03; 3) neutralization and/or water rinsing to remove residual acid; 4) thermal regeneration at 350-650 °C to remove adsorbed and/or pyrolyzed organ­ics; and 5) screening to remove fine carbon particles produced by Impaction and abrasion in the various stages of the hydrometallurgical circuit (i.e., adsorption, elution, and regeneration). The overall process Is purposed to reopen the circuit carbon pore structure, and to maintain the activity and qualities of virgin (new) carbon(7,8l. While most CIP, CIL and CIC operators regenerate circuit carbons, few evaluate the effect of the process on carbon quality in a systematic way. Process control usually Involves Iterating critical regeneration parameters such as: acid concentration; time frames for acid washing and water rinsing; and temperature and residence time for thermal regeneration. Carbon quality control frequently comprises only sporadic activity tests performed on non-representative grab samples dipped from conve­niently accessed carbon storage bins. So, regenerated carbon quality may vary and (at times) be unacceptable for effective hydrometallurglcal circuit operation. To verify the efficacy of the regeneration process and assure accept­able adsorption and elution rates for Au(CN)2· and Ag(CN)2·, operators should systematically assess regenerated circuit carbon quality. This paper, then, suggests methods for effectively assessing circuit carbon quality, Including: carbon sampling procedures; standardized physical and chemical test methods; and criteria and general procedures for comparative adsorption rate (activity) testing. Also, a two tier quality control testing scheme is proposed, and techniques for presenting and interpreting test data are demonstrated.

Jan 1, 1992

By Hugh McMillan

To protect the water supply for the Metropolitan Chicago area, the Illinois legislature, in 1889, created the Metropolitan Sanitary District of Greater Chicago. To insure the quality of the water supply, the Sanitary District collected and diverted the wastes of 750,000 people away from Lake Michigan. Today, the Sanitary District collects and treats the wastes from a domestic population of 5 ¼ million people and an industrial waste load equivalent to 4 ¼ million people. The District serves Chicago and 120 other cities and suburbs in an 858 square mile area. An average of 1300 million gallons of wastewater is treated each day, producing as a by- product about 700 dry tons of solids which contains more than $10,000 worth of plant nutrients when equated to the value of commercial fertilizer purchased in the retail market. The Sanitary District considered several alternatives to past methods for disposing of these solids, and chose land application as a technique to utilize the solids produced by the wastewater treatment process in a beneficial manner.

Jan 1, 1973

By James A. Martin

Evaluation and subsequent development of a quarry in east-central Missouri was based on a general but brief examination of outcrops and core from five (5) test holes. Neither core, outcrops, nor existing quarries in the general area gave any indication of potential major problems. In the third year of operation large areas of collapse rubble, consisting of green shale and large blocks of limestone and sandstone, were encountered. Their size and random distribution resulted in both blasting and quality control problems. By the fourth year of operation, production costs became prohibitive and the site was abandoned. Prior to dismantling the plant a geologic investigation, which included shallow seismic and resistivity surveys, was made of the unmined portion of the lease. The collapse dolines appear to be related to structure and predate development of the modern topography. Surface indications of these features are few. The seismic profiles were especially helpful in plotting their distribution. Geologic relationships and seismic data developed at this site are being related to similar suspect areas in Missouri and have been useful in their evaluation.

Jan 1, 1970

By Noris Del Be1 Belluz

Drilling underground in the Grasberg dewatering drifts has routinely hit water aquifers with high flow rates and pressures. Two types of holes are used. Pilot holes probe ahead of the tunnel development to intersect aquifers ahead of the face. And dewatering holes dewater rock formations that will drain water from the Grasberg pit and allow tunnel development to proceed safely. Recently, static pressures of >8.3 MPa (> 1,200 psi) have been recorded with flows from a 100 mm (4 in.) HQ core hole measured at 5,700 L/min (1,500 gpm). The waterflows can be slightly acidic, necessitating the use of stainless-steel collar gear to resist corrosion. These rates were anticipated and contingencies were planned early on to deal with these conditions. PT Freeport Indonesia (PTFI) established procedures to maintain the safety of the drill crews, to enable coring of the rock, and to maintain the safety of the miners driving the drifts. The collar gear controls the waterflows because these drill holes are a vital source of water for the concentrator.

Jan 1, 1998

By J. M. Scharer, Bruce E. Halbert, Pettit. Carol M., Lysane Bolduc

The ratio of neutralization potential (NP) to acid production (AP) ratio is often employed for predicting acidic discharges from waste rock dumps. The available NP was evaluated in laboratory studies of limestone dissolution in simulated acidic mine water. The available neutralization potential strongly depended on the particle size. Using limestone particles of 114" (6.4 mm) or greater, less than 20% of the total neutralization potential was exhausted at the onset of acid conditions. Apparently, the dissolution of limestone became mass transfer limited. Under mass transfer limitations, the rate of pyrite oxidation may exceed the rate of neutralization by buffering minerals. The implications concerning the controls on limestone dissolution were examined using a geochemical predictive model for sulphide mineral oxidation in waste rock. The results have shown that in case of heterogeneous waste rock piles the NP/AP ratio is a reliable indicator for short-tam predictions only. Kinetic data on the depletion rate of the neutralizing minerals and geochemical modelling suggest that waste rock environments with NP/AP ratios as high as 5.0 may turn acidic in the long term.

Jan 1, 2000

By M. G. Karfakis

This paper examines the chimney occurrences in the Hanna Coal Field, Wyoming. Chimney caving is defined, previously proposed mechanisms involved in the development of a chimney are critically reviewed, and factors controlling chimney cave are identified. The main portion of this paper deals with the identification and characterization of chimney subsidence due to underground coal mining in the Hanna Mining District. In an attempt to characterize the subsidence, sink-hole occurrences are correlated with the depth of coal, thickness of mined-out beds, mining methods, nature of overburden, structural geology, and hydrology. Most sinkholes in the Hanna Basin appear to be conical in profile, with the apex upward. The average diameter is 15 meters (50 feet), with an average depth of 11 feet. Most have developed above an overburden of less than 61 meters (200 feet). The average mining height to width ratio is 5. Much of the chimney development is governed by the thickness and character of the overburden, the width and height of the mine opening, and the in situ state of stress.

Jan 1, 1986

By Kerby Glass, Glenn A. Gruber

Mr. C. A. Hollingsworth introduced commercial column flotation to the Florida Phosphate Industry in 1976, with a six feet diameter prototype cell at the Tenoroc Mine. More than two-dozen column cells have been installed in phosphate beneficiation plants since then. The increased interest in column cells for phosphate flotation, and their potential use in new plant construction, prompted the Florida Institute of Phosphate Research to fund programs to investigate various aspects of column flotation. This report describes a test program, conducted by JACOBS at CF Industries Hardee Complex II, as part of a comprehensive research program awarded to the University of Florida by the Florida Institute of Phosphate Research. The 1.5 feet diameter test column was operated with plant process water and plant reagentized flotation feed. Several variables considered for column cells design and operation were tested. Feed specific capacity, air superficial velocity, and the length to diameter ratio of the column were the variables that influenced phosphate recovery. Concentrate phosphate grade was influenced by concentrate superficial velocity and feed specific capacity.

Jan 1, 2002

By C. K. Jankousky

The midwestern area referred to is the Illinois basin. The coals presently worked are mainly the No. 5 and No. 6 coal seams which vary in thickness from five to eleven feet. Present average of the more important No. 6 id about nine feet. The coal can vary considerably in toughness within the same mine with some coal perhaps rashing very easily and other coal being extremely difficult to cut. Top is generally well laminated shales with some fortunate areas having limestone roof. There are local areas with troublesome top of poorly laminated shales, shale with slickensides and shale intermingled with small partings and traces of coal. The bottoms are generally one to three feet of clay which softens readily on exposure to moisture. The mines are dry although some water is released and collects from rapid penetration of the seam by continuous miners. However, there are locally wet areas. Most of this material refers to mines of the Freeman Coal Mining Corporation. The mining operations written about are underground mines in southern and central Illinois.

Jan 1, 1962

By M. S. Janssen

The development of a design equation for, and the testing of, a constant- flow airlift pump IS described. The predictions of the new airlift model agree with the results of experiments carried out using riser diameters between 0.025 and 0.300 m, submergence depths between 5 and 10 m, suspension densities between 1000 and 1650 kg/m3, and a solids dg of 70 to 100µm. The predictions o the model also agree with data from the literature for submergence depths that reached 130 m. This airlift model was employed to simulate the pulp flow through a series of tanks, each of which was fitted with an airlift pump to transfer the suspension to the next tank. Particular attention was paid to the riser diameter, submergence of the airlift pump, and control of the air supply to the airlift pump during the simulated operation of a series of tanks. The results of the simulation highlight some design parameters that could affect the efficiency and operation of a plant that employs airlift pumps to transfer suspensions.

Jan 1, 1989

By B. Moudgil, Hassen El-Shall

Particle shape and size distributions are among the most important parameters that affect the filtration efficiency of phosphogypsum in wet- process phosphoric acid production. Cost-effective enhancement in filtration rate is desired by phosphoric acid producers for higher plant capacity and lower operating costs. In this regard, numerous research efforts have been carried out in different laboratories as well as in pilot and plant testing. Nevertheless, changes in phosphogypsum crystal shape and size distribution deserve special attention. In this study, the results obtained in the presence of Crysmod and Hiflo-S5 surfactants are discussed. The influence of such additives on crystal morphology and size distribution are studied under different sulfate contents (supersaturation). The obtained data are correlated with process efficiency parameters such as filtration rate, digestion of rock, and recovery of phosphate values. Up to 60% increase in filtration rate is obtained. In addition, an increase in digestion efficiency and P205 recovery is achieved due to addition of surface active agents. The observed beneficial effects are explained in the light of the changes induced in crystal habit, size, and size distribution.

Jan 1, 1999

By Rogério C. Guimarães, Antonio E. C. Peres

Arafertil's oxidized ore presents barite grades that oscillate between 5 and 12%. The barite separation plays a major role in the production of apatite concentrates for the manufacturing of phosphate fertilizers. The selectivity, via flotation, in the system barite-apatite is inherently difficult due to the similarity of the physical/chemical characteristics of these minerals. The evaluation of the relevant aspects of this separation was performed based on the determinations of the electrical surface charge of barite and apatite, the abstraction isotherms of cetyl-stearyl sodium sulfate and fatty acids soaps for barite and apatite, microflotation in a modified Hallimond tube, and flotation tests in a batch column. The results showed that the adsorption of cetyl- stearyl sodium sulfate occurs preferentially onto barite, in comparison with apatite. On the other hand, the rice bran oil soap presents similar adsorption levels onto both barite and apatite. The cetyl-stearyl sodium sulfate was selective as a barite collector in the presence of apatite, a fact that was not observed in the case of rice bran oil soap.

Jan 1, 1999

By J. M. Stewart

The incidence of heat stroke in the South African gold mining industry is today small (less than 1 in 10 6 shifts worked). Acclimatization and selection procedures have been developed and applied throughout the industry, underground working conditions have, and are being improved, and personnel are to-day made more aware of heat stress and its consequences than ever before. Although these actions have, over the years, brought about a steady reduction in the incidence of heat stroke (see Figure 1) the small incidence of heat stroke which persists indicates that heat stress is still a problem. This realization provides the stimulus for the work presented in this paper, which has as its primary objective the development of reliable heat stress limits for men working in South African gold mines. [ ] In keeping with recent trends3I4 the approach followed in this paper is based on the physical principles of heat transfer. Detailed studies of heat transfer from humans have been undertaken,5-l1 and certain of the results form an important aspect of this Paper -

Jan 1, 1980

By Staff

GENERAL DESCRIPTION The Lucky Friday mine is located in Mullan, Sho-¬shone County, Idaho. The mining method is horizontal slice cut-and-fill (with timbering for support or un¬timbered) using hydraulic sand. Cemented sand fill at a 1:17 ratio is used in sill pours and at a 1:7 ratio for the final 152 mm (6 in.) capping in successive stope floor pours. Annual production with 100% cut-and-fill mining is 167 829 t (185,000 st). The average depth of mining is 1296 m (4250 ft) and the average travel time to the stope is 45 min. GENERAL ORE BODY REQUIREMENTS AND LIMITATIONS Size The ore body is 396 to 488 m (1300 to 1600 ft) long on strike, 1421 m (4660 ft) on dip, with an average width of 2.3 m (7.5 ft). Dip varies from vertical to1.2 rad (70°) Ground Conditions, Ore Value, and Production Requirements The ore body contains quite strong argentiferous galena and quartz. The hanging wall and footwall are strongly sheared and fractured. Ore value is $211/t ($192/st).

Jan 1, 1982

By A. E. Hall, K. R. Mutama

The wind tunnel has been used extensively for mine ventilation research and continues to be a valuable tool. The advent of the powerful personal computer has reduced the use of wind tunnels because several flow problems car be simulated and investigated quickly. This paper describes the recent design and construction of a wind tunnel which is now being used for mine ventilation aerodynamic research and teaching purposes. The wind tunnel has a square cross section measuring 900 by 900 mm and is 8485 mm long from the entrance to where it joins the fan. The tunnel was designed as an open circuit suction type and is attached to a 7.5 kW variable pitch axial flow fan capable of producing over 6 m3/s of airflow. The entire length of the wind tunnel can be used for flow investigations and all activities are visible since the sides are made of plexiglass. Results are presented from the test program to show that even without honeycombs and screens air flow symmetry is achieved.

Jan 1, 1993