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Agenda ? Where?s Victor ? What work was done to get approval to spend $982m ? a brief history ? Some project facts ? The triple bottom-line accomplishments to date ? Construction A Brief History of Victor ? 1960?s ? first sampling in area ? 1980?s ? stream samples and Victor kimberlite discovered ? 1990?s ? test / bulk samples ? 1999 / 2000 ? large bulk samples ? 2000 / 2003 ? technical evaluation through to Feasibility Study, permitting process

May 1, 2006

By A G. Cuison, B V. Andam

Three well-known copper and gold deposits in northern Luzon, Philippines are located in the Mankayan Mineral District. These are the Lepanto Copper-Gold Deposit, the Far Southeast Porphyry Copper Deposit and the newly discovered Victoria Gold Deposit. The latter discovery led LCMC to shift from a predominantly copper mine to a gold mine. The pre-Eocene Lepanto basement andesite and the middle Miocene Balili volcaniclastic sequence underlie the Mankayan Mineral District. They are intruded by tonalitic to gabbroic Bagon Intrusive followed by diorite-quartz diorite intrusions. Diatreme emplacement of late Miocene-early Pliocene Imbanguila dacite pyroclastics and porphyries took place much later. Faults in the district mostly form a conjugate fracture pattern dominated by north and northwest trending shears, east-west trending extensional fractures and few north-south trending fissures. Victoria is an epithermal gold-base metal rich quartz vein deposit. The veins occur along tensional structures and it is common to observe crustiform and banded features among the sulphides and gangue minerals. It is an open space infilling type of mineralisation. The Victoria vein systems are divided into zones based on continuity. In each zone are major veins and associated spits. Dacite pyroclastics and porphyries predominantly host the major veins with a few narrow veins hosted by the Balili volcaniclastics and the Lepanto metavolcanics. The veins generally trend east-northeast with 75 - 80 dips towards the south. The longest vein can be traced fairly continuously for a horizontal distance of about 600 metres. The vertical persistence of major veins exposed on three level drives has a range of 150 metres and can reach as much as 400 metres based on drill hole intercepts. The vein widths vary from two to eight metres. Right lateral movements of either the NW or NE shear faults could have produced the east trending tensional fractures. The development of ore shoot patterns was recognised and has been helpful to the mining operations. Cymoid loops with defined pinch and swell features are noted both laterally and vertically. Complementing the structural pattern is the distribution of gold values along veins where lateral and vertical continuity is also observed. Gold is associated with quartz, sphalerite, galena and chalcopyrite. In relatively high gold zones, the abundant sulphides are sphalerite and galena. In relatively high copper zones, there is an abundance of chalcopyrite and tetrahedrite. Galena is always associated with sphalerite but less in abundance. Chalcopyrite occurs either as separate bands from or associated with sphalerite-galena. Chalcopyrite and tetrahedrite appears contemporaneous with sphalerite and galena but in some portions the former cuts the latter sulphides. The predominant gangue minerals are quartz, carbonates and gypsum. Rhodochrosite is the predominant carbonate gangue. Few sulphides are found in the carbonates. Gypsum (anhydrite) is found cross-cutting early mineralisation. It carries very few sulphides. The alteration halos around veins are relatively narrow. In an outward sequence, the silicic alteration occurs very near the veins, followed by sericitic-argillic alteration then to propylitic zones. It is also common to observe veins bounded by propylitic alteration. Preliminary paragenetic studies show apparent three stages of mineralisation, the early-quartz (-gold) stage followed by a carbonate stage and a late-gypsum stage. The abundance of base metals relatively decreases towards the gypsum stage. The Victoria gold deposit could have some genetic associations with the Lepanto Cu-Au deposit and probably indirectly with the FSE porphyry system. It is relatively apparent that the Victoria quartz-gold-base metal veins could have occurred similarly as the quartz-gold roots overprinting the Lepanto enargite mineralisation. This overprinting signifies the waning stages of the entire hydrothermal system.

Jan 1, 1999

By OÆShea P. J, Dickson T. W

In April 1994 the Victorian Premier announced new State initiatives, collectively termed the Victorian Initiative for Minerals and Petroleum (VIMP), for exploration totalling $16.5 m over three years. The program, initially centred on the northwest of Victoria, the Eastern Highlands and the Otway Basin, is due for completion in June 1997 and has been designed to attract explorers to highly prospective but currently under-explored parts of the State. Major components of the program include acquisition of geophysical data (including airborne magnetics and radiometrics, gravity and seismic data), stratigraphic drilling, geological mapping and mineral resource data compilation. At the completion of the current program, 70 per cent of the State will have been covered by airborne magnetic and radiometric coverage at 400 m line spacing or better (Figure I) while 20 per cent of the State will have been covered by new geological mapping. The completion of database compilations for geochemistry, mine data and exploration licence summaries during the VIMP program is shown in Figure 2. The new airborne geophysical surveys have been flown partly under the VIMP program and partly by AGSO under the National Geoscience Mapping Accord (NGMA). Data from these surveys have been interpreted and incorporated into the geological mapping in order to enhance the quality of map products, especially in areas of Cainozoic cover. The first series 1:250 000 scale geological map coverage of Victoria was completed by the Geological Survey of Victoria (GSV) in 1977, and was based on compilation of historical geological mapping with minor field checking in most cases. The first metric 1:50 000 scale geology maps were also commenced in the 1970s, but were discontinued in the 1980s in favour of 1:100 000 scale map production. Driven by customer survey findings and with the benefit of detailed airborne geophysical data in the 1990s, the GSV reverted to 1:50 000 scale map production in 1995, with 1:10 000 scale maps made in areas of significant gold production. Geological reports still cover standard 1:100 000 scale map areas, but are now accompanied by four 1:50 000 scale maps. These new series 1:50 000 scale geological maps have been supported by comprehensive mine data and exploration licence summary databases in addition to the new geophysics, and benefit from the advances made in structural geological interpretation over the last decade. The new phase of geological mapping in Victoria, commenced under the NGMA in 1990 and accelerated under VIMP in 1994, has been focused in the central Victorian goldfields and eastern Highlands areas of the State (Figure 1). Results to-date have led to a number of major advances in the understanding of the eeoloeical evolution of Victoria.

Jan 1, 1997

By Y. D. Lee, J. H. Park, D. S. Kim, H. S. Song

The viscosities and the infrared spectra of the CaO-SiO2-MgO-CaF2(or Al2O3) slags were measured to enhance our understanding of the interrelationship among the thermophysical property, microscopic structure, and chemical thermodynamics of molten slags. The structural role of CaF2and Al2O3in the calcium silicate melts can be explained by a change of the degree of polymerization (DOP). The effect of CaF2on the viscous flow of molten slags is based on a decrease in the DOP by F-as well as by O2-ions and this was confirmed by the infrared (IR)spectra of the quenched slags. The effect of Al2O3on viscosity increase can be understood from an increase in the DOP by the incorporation of the [AlO4]-tetrahedra into the [SiO4]-tetrahedral units and this was also confirmed by the IR spectra. An amphoteric behaviour of Al2O3in the aluminosilicate melts could be correlated to the effect of ionic species of alumina, that is [AlO4]-tetrahedra and [AlO6]-octahedra, on the stability of silicate polyanions by taking the activity coefficients of slag components into account. Keywords: viscosity; infrared spectra; degree of polymerization; amphoteric behaviour; stability; activity coefficient

Jan 1, 2004

By A. L. Field

A. W. FAHRENWALD, Socorro, 'N. M. (communication to the Secretary*).-When asked to discuss Mr. Feild's paper, I felt most highly complimented to have the privilege of commenting on such a worthy and needed piece of apparatus. In consideration of the importance of the viscosity of blast-furnace slags and the relation existing between the' melting point of a slag and its viscosity, the introduction of this apparatus should be a welcome means or assistant in the study of the physical properties of a slag. Up to the present time, it is A fact that this side of the practical working of the blast furnace has been sadly neglected by those investigating slags. It is easily seen that the fluidity of a slag is of as great importance as its melting point. It is not necessarily true that a slag having a low melting point will have a correspondingly low viscosity or be highly fluid. For example, a slag having a melting point of 1,100° C. may have to be superheated to, say,1,300° C., in order to have as high a fluidity as another slag whose melting point is, say, 1,250° C. The latter in this case would be the more economical. This point has been brought out very nicely by Mr. Feild. Before discussing this paper further, I think it will be well to outline some of the points, a discussion of which may be in order:

Jan 3, 1917

By A. L. Field

WOOLSEY McA. JOHNSON, Hartford, Conn. (written discussion).¬When ;we regard the number of British thermal units running into the billions that-must be applied to metallurgical slags in the United States, we cannot but conclude that the physical chemistry of-slags is a very important subject when measured in dollars and cents. A further contemplation of the subject shows us that it has been hitherto treated in too purely a practical manner. It is needless to comment at length on the cost of these heat units and on the cost of fluxes to produce these metallurgical slags, for, it amounts to tens of millions of dollars annually. Accordingly, this research is of value to the country. But we must,all balance our results against our efforts. Therefore, while the speaker is unwilling to criticise unduly this meritorious research, lie does criticise it in the interest of the profession for the reason that it seems to him too highly theoretical. The article is much too, scientific to produce results at a minimum cost. Let us explain our meaning. It has been said that there are always two sides to a question. It may be further said that there are always three sides to a question, the two extremes and the middle ground. In any industrial research there are the highly theoretical side, the purely practical side, and the theoretico-practical side. To study a slag and be practical in the studying, there is something needed that represents in the laboratory (or in microcosm) what actually happens macrocosmically in the blast furnace. There is such a thing as the art of metallurgical research occupying the middle ground between theory and practice.

Jan 4, 1917

By J. M. Toguri

The viscosity of the molten FeO-Fe2O3-Si0z system in the composition range of interest to copper smelting has been investigated using a rotating cylinder technique. The silica content of the slag was varied from 20 to 35 wt percent while the oxygen pressure of the system was varied from 10-7 10-11 atm. The temperature range investigated was from 1200 to 1350°C. It was found that the viscosity of the slag generally decreased with increasing temperature and increasing oxygen pressure. As the silica content was increased, the viscosity was found to increase.

Jan 1, 1976

By B. C. Blakey

Unlike most hydrometallurgical slurries, those containing significant concentrations of goethite are typically highly viscous and shear-thinning, even at solid volume fractions below 5%. The viscosity may also depend upon time. These characteristics must be taken into consideration in slurry transport and heating. The technical literature is replete with apparent contradictions regarding the viscous behavior of these slurries, which may be due, in part, to variations in viscosity-measuring techniques. We present techniques that yield consistent results suitable for use in process design. A striking degree of time-dependent behavior is demonstrated for a laterite slurry. Reliable methods to design and analyze tubular transport and heating systems for time-independent slurries are summarized. Rules of thumb are then offered to account for the effects of time-dependency.

Jan 1, 2000

By Dave Stefanuto

Voisey?s Bay Project Components ? Mine/Mill Port In Labrador ? Mini Plant in Mississauga ? Demonstration Plant in Argentia ? Supply Vessel (Umiak1) ? Transshipment Facility (Quebec) ? Concentrate Handling & Transport to Sudbury/Thompson ? Cobalt Refinery Upgrade (Thompson) Project Setting ? The Project is on the traditional lands of the Labrador Inuit and the Labrador Innu ? Canadian courts have held that Aboriginal peoples in Canada possess special rights to traditional Aboriginal lands Those rights can include requiring resource developers to enter into Impacts and Benefits Agreements (IBAs) on traditional lands to set forth how lands can be used and benefits to be received by Aboriginal people

May 1, 2006

By Robert H. Hooff

The Vor-Siv Dewatering and Classifying Unit was developed by the Polish Coal Industry because of a need for a unit that would dewater and classify high volumes of solids in water slurry. To be practical, the unit needed to be relatively small in size, simple in design, involve low operating costs, and be able to give a dewatered product of less than 30% moisture. The answer to the above mentioned criteria was the Vortex Dewatering Sieve or, as we refer to it, the Vor-Siv. The original installation of the unit, as we know it today, began in 1963 when the Pols installed the unit in a full scale pilot application. By 1966, at least 30 of these units were installed throughout the Polish Coal Industry. This equipment was originally introduced in the United States in 1966 at the Fifth International Coal Preparation Meeting in Pittsburgh, Pennsylvania. The first installation in the United States was not achieved until 1970, when Mr. Fred Sachs of The Valley Camp Coal Company, Triadelphia, West Virginia, installed a Vor-Siv in a retrofit application. To date, there are 36 Vor-Sivs installed in this country and 29 in the process of being installed or delivered.

Jan 1, 1976

By C. M. Anson

Introduction The prosperity of any country today is dependent upon the efficiency and growth of its primary steel industry. The ?march of the United States of America to its present commanding position in world affairs parallels the growth of its steel industry. The remarkable growth of that industry was possible only because bountiful providence endowed that country with adequate supplies of the raw materials necessary for steel making -coal and iron ore. If we accept this hypothesis, and surely we must, then to what extent can we envisage the future of our own country? This symposium deals with the most important of the raw materials required for steel making -iron ore. If we are blessed with a bountiful supply of iron ore, then surely a glorious future awaits only our taking advantage of that blessing. It is becoming increasingly evident that Canada has immense iron ore deposits. It is my privilege to make you acquainted with one of these, one that can only be classified as among the more important ore reserves in the world. I refer to the Wabana ore deposits in Newfoundland. Location These deposits lie under the floor? of Conception bay, off the east coast of Newfoundland. They consist of a series of beds which outcropped for a distance of about three miles on the northeastern shore of Bell Island, dipping at approximately 8° toward the northwest. This three-mile outcrop is the only key to the occurrence.

Jan 1, 1951

By Timothy R. Eby

"The Wabush Mines project was formed in 1956 to develop a large iron ore property in Western Labrador. The town of Wabush along with the mining and concentrating facilities are located 640 air miles from Montreal, and 734 air miles from St. John's. The operation has been in production since late 1964.While mining and concentrating operations are located in Labrador, the pelletizing facilities are situated 275 miles south at Sept-Iles, Quebec. Dedicated in 1965, Wabush produces six million tons of high quality iron ore pellets annually. The company employs 1, 550 people at Wabush and the Pointe Noire plant at Sept-Iles.Wabush Mines is an unincorporated joint venture of three companies -The Steel Company of Canada, Dominion Foundries and Steel Ltd. and the remaining 58% by the Wabush Iron Co. Ltd. Wabush Iron Co. Ltd. is in turn owned by six companies: The Youngstown Sheet & Tube Company, Inland Steel Company, Interlake Inc., Wheeling Pittsburg Steel Company, Finsider International S.A. and Pickands Mather & Company which is also managing agent.The town of Wabush is set in a remote part of Northern Canada accessible only by rail and air transportation. But this in no way has hindered the growth and development of the area. Modern housing units, shopping facilities, airport and of course, recreational facilities are all patt of every day living amenities, an accepted aprt of southern communities, but quite unique for northern isolated mining localities."

Jan 1, 1978

By R. Hoffmann

THE Waelz process produces oxides of volatilizable metals from ores, metalliferous products and residues. The process was originally used for recovering zinc and lead, where tailings and residues containing those metals had accumulated at mines or smelters, but it is applicable for obtaining tin, arsenic or other volatilizable metals. It is useful when other methods of obtaining the metals from the ores or residues are too difficult or expensive or show too low a recovery. FIG. 1.-DAILY CAPACITY OF WAELZ PLANTS RUNNING OR BEING ERECTED. The Waelz process was developed in 1923 for the treatment of large calamine dumps in Upper-Silesia, which showed zinc contents of 8 to 10 per cent. and lead contents up to 3 per cent. The rapid development of the process, from the first trials up to the plants now working or in course of erection, is shown in Fig. 1. -The first industrial Waelz plant was started in 1925. Within two years the capacity of the working plants reached 700 tons material per day of 24 hr. During the year 1928 the daily capacity of the plants now at work or in course of erection will rise

Jan 1, 1928

By P Blattner

The Late Miocene gold-silver bearing epithermal system at Waihi has some close similarities in its paleo-thermal and geochemical structure with modern, volcanic-hosted geothermal systems such as Ohaaki-Broadlands. At Waihi an extensive braided quartz vein system is enveloped by hydrothermally altered andesites with minor tuff breccias and tuffs. A main stage of vein filling consists of multiple phases of chalcedonic quartz and fine to medium grained quartz, which are accompanied by pyrite, sphalerite, galena, chalcopyrite and acanthite below the base of oxidation. Platy calcite is present locally. Fluid inclusion studies indicate that the main stage quartz was deposited at temperatures of 189¦-273¦C from dilute (Tm of -0.1 to -1.0¦C) fluids that were locally boiling. Homogenisation temperature Th versus Tm data points lie within the field enveloped by dilution and boiling/gas loss paths determined for the Ohaaki geothermal field, and indicates that the parent hydrothermal fluid for the Waihi epithermal system had a similar composition to that at Ohaaki, ie 0.2 wt% equiv NaCl and 3.3 wt% equiv CO2. The hydrothermal alteration mineralogy and the isotopic composition of vein calcite indicate that the hydrothermal fluid contained relatively high concentrations of CO2 , as at Ohaaki. Oxygen isotope analyses of main stage quartz range from 6.1 to 11.6 %0 and of vein calcite from 2.29 to 9.4%0. Calculated d18Owater values for the hydrothermal fluid that deposited the main stage quartz range from 2.0 to -5.7%0, with a trend to less negative values with depth. They are similar to those in the deep chloride fluid in active geothermal systems with a substantial fluid throughput. A high fluid throughput at Waihi system is also evident from the extensive high intensity hydrothermal alteration and large volume of quartz deposited in the vein system.

Jan 1, 1995

The areas of concern lay in the processing of, and the subsequent hearing into, Waihi Gold's resource consent applications to extend Martha Mine. The proposed amendments to the Resource Management Act 1991 might see the introduction of contestability in the processing of applications - which would have assisted Waihi Gold; and the use of commissioners to hear the applications, with a right of appeal to the Environment Court on points of law only. It is also proposed to have major applications heard directly by the Environment Court. If Waihi Gold's applications had been heard at first instance by the Court, the delays in time and associated costs would have been reduced. However a hearing by commissioners only would not have been satisfactory, there being no right of appeal against the conditions of consent, which if implemented as granted by the Councils would have had a significant impact on the costs associated with the extended project.

Jan 1, 1998

By R L. Brathwaite

The gold-scheelite-quartz lodes of the Wakamarina valley were the most productive of the mesothermal gold-bearing areas in the Marlborough Schist. Most of the production came from the Empire City and Golden Bar mines which worked the Golden Bar lode. Only 134 m of its 1800 m strike length are accessible, in the No.2 level of the Golden Bar Mine. A fault has downthrown the Golden Bar Mine section by = 47 m and displaced it left-laterally by 18 m. The lode is a typical ribbon-banded mesothermal vein, averaging c. 1.75 m wide, and enclosing narrow horses of schist country rock. It is composed of bands of milky æbuckÆ quartz with thin laminae of schist. Scheelite occurs in short strings of grains within quartz on the footwall side of the lode and also in small quartz-carbonate veinlets in the foot wall and hanging wall schist. The lode quartz contains only localised traces of pyrite and arsenopyrite. They are more abundant in the wall-rock schist.   The Golden Bar lode lies within a steeply dipping normal fault, which, on its footwall side, is adjacent to a 40 m-wide, shallow-dipping mylonite shear zone. Within 1 m of the lode, the shear foliation has been dragged down to nearly parallel the lode footwall. Wall rock alteration is manifested by a marked increase in K and Rb, which correlate with abundant illite/muscovite and K-feldspar within 2 m of the footwall of the lode. Amphibole, stilpnomelane, and pumpellyite show a progressive decrease towards the lode. As and Sb increase close to the lode, but are at background levels within the lode itself. Enhanced Cr (150-430 ppm) in the quartz, relative to the schists (~40 ppm), suggests that the source hydrothermal fluids passed through and leached mafic rocks, such as the metabasites from the hanging wall of the lode (~400 ppm Cr).

Jan 1, 1995

By R L. Brathwaite

The mesothermal quartz-scheelite lodes of the Wakamarina valley are one of twelve known mined or prospected gold-bearing areas in the Marlborough Schist. Recorded production was 556 kg gold, a little silver, and c. 390 t scheelite. 134 m of the 1800 m long Golden Bar reef are accessible in the No 2 level of the Golden Bar mine. The reef is a typical multi-banded mesothermal vein, mostly c. 1.75 m wide, enclosing narrow horses of schist country rock. Scheelite is sparsely distributed, and is more common in small veinlets in the hanging wall schist. The country rocks are textural zone I-1m schists of prehnite-pumpellyite to pumpellyite-actinolite metamorphic facies. Their geochemistry suggests they are part of the Caples Terrane, and of calc-alkaline volcanogenic arc origin. The associated Wakamarina Quartzite is strongly recumbent folded, and of the same metamorphic grade, with abundant pumpellyite, stilpnomelane, and garnet, presumably spessartine. Although it has geochemical signatures of a deep sea sediment, it is depleted in Cr and Cu, and greatly enhanced in K and Ti, when compared with a standard chert. It also has trace element characteristics of a calc-alkaline arc-related sediment. However, associated greenschist has MORB-like incompatible element chemistry. The Golden Bar reef lies within a steeply dipping, normal to transtensional dip-slip fault adjacent to a shallow-dipping mylonite shear zone, which, at least on the footwall side, is 040 m wide. The shear foliation has been severely dragged down to nearly parallel the Golden Bar reef within 1 m of the quartz lode. Preliminary structural analysis suggests that the shear zone is extensional. X-ray diffraction analyses of the wall rocks show a progressive depletion of amphibole, stilpnomelane, and pumpellyite towards the reef, and enhanced illite/muscovite and Kfeldspar adjacent to the lode, along with possible graphitic carbon within 10m. Two zones of intense quartz veining occur, one adjacent to the hanging wall for 12 m and one from 40 m outwards. Quartz vein systems in the country rock are complex and span from pre-schistosity to post-mylonite. They include multiple generations of quartz, actinolite, stilpnomelane, pumpellyite, albite, adularia, chlorites, illite/muscovite, calcite, and scheelite. Metal analyses across the Golden Bar reef showed gold values of 0.13.1 ppm, and low tungsten values, consistent with the observed sporadic scheelite occurrences. As and Sb are at background levels, but enhanced Cr (150 - 430 ppm) relative to the schists (30 - 41 ppm) suggests that the source hydrothermal fluids passed through and leached mafic to ultramafic rocks.

Jan 1, 1994

Gold mineralisation was first noted in 1983 at the Wapolu Point area of Fergusson Island, Papua New Guinea (PNG) during a follow-up regional reconnaissance program. Subsequent exploration programs through to late 1987 completed 22,147m of costean trench sampling, 553 aircore/RC/diamond core drill holes (16,970.5m total) and metallurgical testwork, predominantly on the Wapolu grid in two mineralised areas.Subsequently in 1988, geostat-istical global and polygonal resources were calculated for the main mineral-ised zones, Didigayagaya and Dagwalala. In 1992, a 'probable total reserve' of 1.9Mf @ 2.4g/t with a 1.2g/t cut-off was calculated for these prospects.

Jan 1, 1994

Gold mineralisation at Wapolu lies within an exposed arcuate zone at the decollement contact between a basement dome of high grade metamorphics and an overlying ophiolite sequence. This contact was originally a thrust fault which has since become a decollement zone for gravity sliding in association with basement doming. Hydrothermal models for the gold mineralisation postulate an epithermal system in which fluids were channelled up the decollement with boiling of those fluids causing hydrothermal brecciation and subsequent gold deposition. The alteration assemblages, fluid inclusion data and geochemistry indicate that the upper levels of the system are exposed.

Jan 1, 1987

By Jan M. Mutmansky

"When, in 1973, a limit was placed on the amount of dust in the coal mine atmosphere, restricting the average exposure of a coal miner to 2 milligrams of dust per cubic meter of air (mg/m'), skeptics in the United States and abroad Said the standard could never be achieved. They cited much more lenient standards already established in other countries and refused to believe that the United States could meet the world's most stringent requirements in mines where dust had never before been regulated. Yet 10 years later the goal had largely been achieved and miners were working underground in a cleaner atmosphere than ever before. It was a major achievement and a big stride in what had become a war on coal workers' pneumoconiosis (CWP), the black lung disease prevalent among miners in underground coal mines.Although the health hazards caused by working in a dust-filled mine atmosphere have long been recognized, the problem became particularly acute in this century with the mechanization and increased productivity of underground coal mining. The United States was much slower than some other countries to address the problem of respirable diseases among miners. While dust levels in South African gold mines were first regulated in 1912, in the United States it was only when 476 workers died of silicosis while blasting a tunnel through a mountain near Gauley Bridge, West Virginia in the 1930s that widespread public attention became focused on the plight of workers in dust-filled environments. Another 30 years passed before regulation of dust finally became law in the Coal Mine Health and Safety Act of 1969.With a stringent new standard imposed in all underground coal mines, the industry was faced With the daunting problem of reducing levels of airborne dust from perhaps 6.5 mg/m' to 2 mg/m', in an inherently dusty operation carried out in the close confines of underground passageways. Most of the coal dust is made by the cutting operation in which the continuous miner or longwall machine can produce several thousand milligrams of respirable dust for each ton of coal mined. Other dusty operations such as drilling holes for roofbolts, loading and unloading coal on shuttle cars, and the operation of conveyor belts contribute to the overall problem.Since the institution of the new dust control standards, a number of strategies have been adopted for reducing the coal dust in the mine atmosphere. These strategies involve engineering and design improvements that help lo prevent the generation of particles, keep particles of dust from becoming airborne, carry dust away from the working area, and isolate the dust from the workers in the mining operation. These procedures have been pursued vigorously by the Bureau of Mines, and many successful methods have been developed to reduce the mass concentration to which the workers are subjected. The mining companies were reluctant at first to confront the problems but after a period of trials and gradual improvement, they joined with others in the fight to reduce the dust concentrations in the working place."

Jan 1, 1990