Search Documents

By V. F. Parry

Subbituminous coal or lignite when stored in random riles or in ordinary bins in which the temperature fluctuates and air circulates quickly undergoes objectionable physical and chemical changes, which decrease the utilization value of the fuel and increase its tendency to ignite spontaneously. Slacking takes place, and the heating value decreases. Those changes are accelerated by fluctuations of temperature and by circulation of air through the storage space. When such coals are exposed to the weather they lose moisture rapidly. If evaporation from the surface of a lump proceeds at a faster rate than that at which it is replaced by moisture from the interior, the rate of shrinkage at the surface is greater than that at the interior; consequently stresses are generated at the surface which cause the coal to disintegrate. Likewise, when moisture is absorbed by the air-dried surface the outside layers expand at a faster rate than the interior, which results in further break-down. As these cycles are repeated the lump may disintegrate completely. Therefore, successful storage of low-rank coals depends on control of the factors that influence change of moisture.

Jan 1, 1941

By Jr. Driscoll

The thermoelectric properties of yttrium monoarsenide, yttrium monoanti-monide) and ternary materials from the Y-As-Se and Y-Sb-Te systems were investigated by the Bureau of Mines from room temperature to 1,000° C. The maximum calculated figure of merit for yttrium monoarsenide and yttrium monoantimonide was 2 x 10-5 ° C-1. YAs and YSb were semimetallic conductors with low Seebeck coefficients and electrical resistivities. The values of the Seebeck coefficient and electrical resistivity of the Y-As-Se and Y-Sb-Te materials were between those of the yttrium selenides and tellurides and of YAs and YSb, respectively. The maximum power factor calculated for the Y-As-Se materials was 2 X 10-5 watt/cm ° C2 which yielded an estimated figure of merit of 6 X 10-4 0 C-1. Most of the Y-As-Se compounds had high Seebeck coefficients and moderately low electrical resistivities. The Y-Sb-Te materials were degenerate semiconductors with power factors of 6 X 10-8 watt/cm ° C2.

Jan 1, 1967

By Louis A. Panek

Determining the change of stress in rock based on measurements of the deformation of a drill hole is a procedure that is increasing in popularity. A closely related procedure involves the applicat10n of this principle to determine the existing stresses in a rock medium, by cutting free (core drilling) an annulus containing the drill hole. In this Bureau of Mines report, expressions are derived from which one can calculate the stress ellipsoid--the three-dimensional change of stress, or the existing three-dimensional stress field, as the case may be. Study of these equations shows that the stress components in three dimensions can be determined by measurements in only two drill holes, and yields general principles that are useful in planning an efficient program of drilling and measurement. Procedures are given for calculating the least squares estimates of the stress components and their standard errors, and for evaluating or comparing calculated values by means of standard statistical inferences.

Jan 1, 1966

By P. J. Remington

Field measurements utilizing a seat pad accelerometer were made on 61 surface coal mining machines in order to quantify the vibration levels experienced by the operators. Those data were combined with information on the statistics of the operating times of those machines in order to compare the operator's vibration exposure to the criteria in ISO 2631, ?A Guide for the Evaluation of Human Exposure to Whole Body Vibration.? The comparison showed that about ha]f of all surface coal mining machine operators can be expected to be exposed to vibration exceeding the fatigue decreased proficiency criterion, whereas only on the order of 15% would be expected to experience vibration exceeding the exposure limit. Detailed exposure statistics are presented and the implications of the results are discussed.

Jan 1, 1983

By Edwin W. Meyer

The augered cast-in-place piling technique was used to install deep foundations 20 feet into weathered sandstone. The project involved the upgrading of the Air Quality Control System (AQCS) for a 560 megawatt coal fired power plant located in Stillwater, Minnesota. The site subsurface consisted of 20 feet of overburden overlying weak sandstone. The overburden consisted of sands and gravels with cobbles and boulders, and variable thicknesses of peat. Ground-water at the site was approximately 8 feet deep. Two foot diameter piers were selected to facilitate installation through the cobbles and boulders in the over-burden and to penetrate the sandstone 22 feet. During installation of the first pier, the weak sandstone broke down to sand-sized material that could not be cleaned from the pier hole without the use of slurry to hold the material in suspension. However, the use of slurry would significantly impact both schedule and cost. Since the sandstone could be easily drilled with the pier equipment, it was believed that 2 foot diameter deep foundations could be installed as designed using augered cast-in-place piling techniques. A brief test drilling pro-gram was conducted to evaluate the viability of 2 foot diameter continuous flight augers penetrating 22 feet into the weak sandstone. The test drilling indicated that augered cast-in-place installation techniques should be successful. Following a short delay to mobilize the additional required equipment, construction commenced. Installation of the 2 foot diameter augered cast-in-place piling to a depth of 22 feet into the weak sandstone was successfully performed.

Jan 1, 2006

By Camila Mendonça Romero Sales

O carbono tem atraído a atenção em pesquisas científicas e aplicações tecnológicas devido à diversidade das propriedades estruturais e elétricas. A proposta deste trabalho é produzir diamantes apartir de hidrocarboneto aromático em especial o Antraceno. Este possui uma estrutura de pelo menos 2 anéis aromáticos, de 5 ou 6 átomos de carbono. Com isso, ele foi submetido à pressão de 3,5GPa a uma temperatura de 1000ºC para a realização do processo de grafitização. Após este processo o grafite produzido foi misturado a liga Ni-Mn no sistema catalisador-solvente para o processo de síntese, com uma pressão de 4,5GPa e uma temperatura de 1300ºC com variação no tempo de realização da síntese de 30 a 120s. Para a realização dos cálculos dos parâmetros estruturais foi realizado ensaio de Difração de Raios-X (DRX) e para analisar os aspectos morfológicos foi realizado análise de Microscopia Eletronica de Varredura (MEV). Os resultados apresentam uma evolução dos parâmetros estruturais em relação ao tempoe temperatura de síntese, pode-se observar a presença de diamante nas amostras produzidas por Antraceno com maiores temperaturas de síntese.

Aug 16, 2017

"Quang Ninh province is located in the north east of Vietnam and the coal mining in the province generates two thirds of the province’s GDP. The coal is extracted from both open pit and underground mines for the country’s complete coal export and by a share of more than 90% for domestic coal usage. Overburden generated through open pit mines is piled up nearby in the form of large waste rock dumps. The side-hill fill dumping near open pit mines is the source of environmental degradation in the region. Among the current problems at solid waste rock dump sites are dust emissions during and after dumping as well as Acid Rock Drainage (ARD). One of the major existing problems at waste rock dumps is dump stability (comprising erosion, sliding and subsidence issues). The RAME R&D project (Research Association Mining and Environment in Vietnam) is - among other activities - actively involved in the research for stabilisation and rehabilitation of mine waste rock dumps in Vietnam in the form of several sub-projects. The Institute of Mining Engineering I of RWTH Aachen University is leading the sub-project of mine waste dump stabilisation in co-operation with Chair of Geotechnical Engineering and Brenk Systemplanung GmbH. Mine waste dumping in the form of layers as an alternative to the side-hill fill dumping is expected to bring up environmental and economical benefits by minimising the problems of dump sites with the contribution to a sustainable development. Reduction of the post construction settlements, long term stable dump profile with minimum erosion, improvement of material parameters for geotechnical slope stability through compaction from hauling trucks as well as economical evaluation of new dumping concepts are the areas of the current research. The project has been financed by German Federal Ministry for Research and Education (BMBF). The ultimate aim of the sub-project is the compilation of the project results in the form of a "Best Practice Guide" and software based "Decision Support System" for planning and management of solid mine waste dumps."

Jan 1, 2011

By G. K. Quainoo

In the automotive industry, the awareness to meet Corporate Average Fuel Efficiency (CAFE) standards has evolved the need to reduce vehicular weight in new automobile designs, with the overall goal of reducing gas emissions into the atmosphere (Kyoto protocol), One efficient method has been to use lighter materials such as aluminum in outer body panels, Heat treatable AA6111 is one of the materials employed due to its unique combination of formability, paint bake strengthening and superior corrosion resistance characteristics, Researchers have applied various thermo-mechanical processes on 6000 series aluminum alloys and have found an improvement in the mechanical properties of these alloys, For a formed and painted automobile panel, the final mechanical properties involve a combination of strength components arising from cold work, strain aging and precipitation minus recovery. In this study, the evolution of microstructure resulting from the interaction of cold work and precipitation in AA6111 has been studied by means of transmission electron microscopy (TEM) after subjecting samples to various heat treatments, tensile testing and differential scanning calorimetry (DSC), This has been done to understand the evolution of microstructure and its influence on the properties of the alloy, The results show a considerable improvement in strength with a corresponding increase in strengthening precipitates with increasing level of cold work in the alloy. DSC results following the application of various levels of cold work also show acceleration in the precipitate phase formation, as precipitates are observed to form at lower temperatures, with increasing level of cold work/

Jan 1, 2005

By Y. M. Zhao

Reutilization of waste printed circuit boards (PCB) can not only prevent potential environmental pollution, but also achieve recycling of secondary resources. Study on recycling of discarded PCB belongs to the front edge of environmental pollution prevention and resource recycling. In order to effectively crushing waste PCB, and solve the problem of secondary pollution of fugitive odor and dust during the crushing process, a wet impacting crusher was adopted to achieve comminution liberation of PCB in water medium. 96.79% of the crushed yield was distributed in ?2mm, and metal took 97.18% in this grade of production. Size distribution of PCB particles was characterized double peaks at the sizes of ?1+0.5mm and ?0.074mm. A double Rosin-Rammler function, is called DRR function, is put forward to describe the size distribution of PCB particles. The DRR function of cumulative weight percentage oversize of PCB was non-liner fitted by self-defining DRR function of the Origin 7.0. The evaluation indexes of the fitting results are the correlation coefficients R2 of 0.9994 and residual E of 0.18671, those show that DRR function is perfectly accurate. Based on the research the mechanical separation and material properties of PCB, a wet process of reclaiming metals from PCB using a new style separator ? tapered diameter separation bed (TDSB) in water medium was designed, and the related separation mechanism was studied. The fluid field of the tapered diameter separation equipment was simulated by the Ansys Flotran software, the variation laws of the velocity in each position in the fluid field as well as the equation of axial distribution sectional max velocity were analysed according to the simulation result, the stress change and motion trajectory of the pellet in the certain fluid field were analysed. The results show that the expanding tubular structure of the varied diameter separation bed indicates gradually decreasing velocity of water flow along the axis, assuming a certain angle in the bed, as a result of the gravity?s influence, and there was corresponding change to the distribution of the flow velocity, thus the whole formed a special fluid field where velocity variations exist in different positions. When the material passed through the fluid field along with the water flow, as a result of the difference to the particle density, the granularity and the shape, there would appear the difference to the motion trajectory as well as the movement distance under the action of the fluid: The lower density materials discharge along with water flow, but the higher density materials would be kept in bottom of the bed and discharge through material mouth. Therefore, light and heavy products were separated effectively according to the density. Using tapered diameter separation bed to process the ?1mm size crushed material of waste printed circuit boards, with the discharge of water 5.5m3/h, feed-rate of the material 250g/min and with an obliquity 35°, product with 93.92% in integration efficiency and 93.73% in recovery ratio of the metal were obtained by the primary separation. Compared with other mechanical methods, the range of particle size was broaden using the TDSB to recovery metals from PCB, and lower limit size of separation almost approach to 0. An innovative process of ?wet impact crushing+ classifying+ tapered diameter separation? recycling metals from waste PCB was developed.

Jan 1, 2014

By G. J. Hearn

between particles in the classifying region is then

Apr 1, 1995

By Welton J. Wenger

Apparatus for the analytical distillation of crude oils under an artificial pressure of 760 mm. of mercury has been designed and constructed. This apparatus enables laboratories at high altitudes to make Bureau of Mines routine analyses of crude oils with results similar to those obtained by laboratories at sea level. This is especially important for laboratories in the Rocky Mountain region, where barometric pressures of approximately 600 mm of mercury are encountered. During the past 30 years, the ?Bureau of Mines has made several thousand analyses of crude oils from various parts of the United States and from foreign countries. The first part (stage 1) of the distillation for the analysis is made at atmospheric pressure, and as most petroleum laboratories are near sea level, comparable results are obtained ordinarily. However, the increased use of the method by .laboratories at high altitudes has caused difficulty, as the analyses cannot be accurately compared with analyses from laboratories at sea level. For instance, laboratories at 7,200 feet generally report 2 to' 4 percent (based upon the crude oil) more gasoline than sea level laboratories. The use of the pressurized apparatus developed by the writers makes it possible for these high-altitude laboratories to duplicate analyses made at sea level.

Jan 1, 1949

By J. Wade Watkins, Joseph W. Horne, Arthur Matzick

"A successful procedure for the recovery of a valuable product from weathered tank-bottom settlings has been developed in the laboratories of the Bureau of lines and used in a field pilot plant. These heavy emulsion settlings, generally regarded by the industry as waste material, have usually been drained into open pits or storage ponds and eventually destroyed.Laboratory examination of the waste material shows it to consist essentially of a ""water-in-oil"" emulsion containing a considerable volume of congealed ""paraffin."" This paraffin is mainly high-melting-point wax; known in the industry as microcrystalline wax, for which there is an increasing demand.Because of the physical properties of this wax, the tank-bottom settlings are not responsive to conventional methods used for demulsifying ordinary crude-oil emulsions.The work upon which this report is based was conducted by the Bureau of Mines in cooperation with -the Kansas State. Board of Health and with special cooperative agreements-with the Cities Service Oil Co, Bartlesville, Okla., and the Bareco Oil Co,. Barnsdall, Okla. The studies were made under the general supervision of R. A. Cattell, chief engineer, Petroleum and Natural-Gas Division, Bureau of Mines, Washington; D. C., and H. C. Fowler, supervising engineer, Petroleum Experiment Station, Bureau of Mines, Bartlesville, Okla., and under the direct supervision of Ludwig Schmidt, senior petroleum engineer, Bureau of Mines, Bartlesville, Okla.Gratefully acknowledged are the assistance and cooperation given by the Cities Service Oil Co. of Oklahoma and especially by M. J. Kirwan, manager of production, and by Q. E. Beecher, general superintendent of production, Bartlesville, Okla., and to members of their staff at Oil Hill, Kans.The assistance and suggestions of V. R. Oakley, general superintendent, E. R. Wiles, director of research, L. G. Willis, field engineer in charge crude-oil supply, and Gerald DeWalt, chief chemist, and his staff of the Bareco Oil Co., Barnsdall, Okla., were of much value in the laboratory and recovery work."

Mar 1, 1946

The first metal-mine accident-prevention course was prepared and published in 1942-45 as a series of seven miners' circulars (Nos. 51-57). The course has been broadened in scope, revised, and brought up to date and is being published as a similar series of seven miners' circulars (Nos. 51-57, revised) on accident prevention in metal and non-metallic mines. These circulars are as follows: Injury Statistics (Miners' Circular 51), dealing with general statistics on injuries from accidents at metal and nonmetallic mines, including causes, costs, and the use of investigations and reports of all injuries.

Jan 1, 1960

Utilizing a very large database from a mined-out area on a South African gold mine, the relative efficacy of a method to mitigate the smoothing effect introduced by the algorithmic constraints imposed by kriging was investigated. Smoothing effects arising from limited data availability are differentiated from the smoothing arising from the application of estimation algorithms. Very little can be done to ameliorate smoothing of estimates because of too little data, barring additional drilling or sampling. However, the smoothing effects resulting from the kriging process are shown to be mitigated by use of an alternative algorithm. The primary criterion in the development of the new algorithm was to avoid re-introducing conditional bias. This paper examines firstly the smoothing effects introduced into estimates via the kriging covariance matrix, secondly the process for ameliorating the smoothing effect, and finally it uses a case study to demonstrate the effectiveness of the new algorithm on a very large database. The database was used to introduce a 60 m by 60 m drilling pattern which in turn was used to model the semi-variogram and produce 30 m by 30 m kriged block estimates. The follow-up database was then re-introduced (roughly 5 m by 5 m grid spacing) and averaged into 30 m by 30 m blocks to provide a direct comparison with the initial estimates. In this way the extent of smoothing and accuracy of the estimates before and after the corrections was tested.

Jan 1, 2014

By C. Heath

US coal consumption reached new heights in 1985, but production was constrained by excess consumer inventories. Domestic consumption of coal reached a record 742 Mt (818 million st) during the year. This is a 3.4% gain over the previous consumption high 718 Mt (791 million st) in 1984. An additional 84 Mt (92.7 million st) of US coal were shipped abroad in 1985, up 13.7% from exports a year earlier. Coal production in 1985 totaled 804 Mt (886 million st), 1.1% below the record 813 Mt (896 million st) produced in 1984. The slight decline in coal output is attributed primarily to a 13% drawdown of large consumer stockpiles built up in 1984 in anticipation of a miners strike that never occurred. Coal demand, and hence production, were also restrained by slower economic growth in 1985 and additional gains in nuclear generation of electricity. Domestic market requirements for coal in 1985 were mixed. Electric utility consumption rose 4.4%; coke plants consumed 6.7% less coal; coal requirements in the other industrial sector expanded by 2.1% and consumption in the residential and commercial sector fell 14.8%. The 2.2% increase in electric power generation in 1985 resulted in a 4.4% rise in utility coal consumption, totaling 630 Mt (694 million st) for the year. Twenty-nine of 45 states where coal-fired electric power plants were operating shared in the 26.7 Mt (29.5 million st) increase in 1985. Coal receipts at utilities fell by 16 Mt (18 million st) as these facilities worked off 21 Mt (23.4 million st) from stockpiles during the year. Electricity generation at coal-fired power plants similarly climbed 4.4% to 1.4 trillion kWh in 1985. This gave coal a 56.8% share of electricity generated from all energy sources compared with 55.5% in 1984. The average price of coal delivered to these facilities remained essentially unchanged during the year. It declined on 1.5% from $38.26/t ($34.71 per st) during the fourth quarter of 1984 to $37.70/t ($34.20 per st) in the fourth quarter of 1985. Coal consumption at coke plants continue to reflect a depressed steel industry. After rebounding 18.9% in 1984 for the first time in five years, coal consumption at coke plants again declined 6.7% to 37 Mt (41.1 million st) in 1985. Coke consumption 26.5 Mt (29.3 million st) exceeded production, 26 Mt (28.7 million st), in 1985. This resulted in a 1-Mt (1.2-million st) decline in coke stocks at producer and distributor levels during the year. The average price of coal delivered to coke plants decreased 7.6% from $64.30/t ($58.34 per st) during the final quarter of 1984 to $59.42/t (53.91 per st) in the last quarter of 1985. Coal consumption in other industries, including all manufacturing and industrial consumers except coke plants, totaled 68.3 Mt (75.3 million st) in 1985. This was the highest level attained in more than a decade. But the lower percentage rise last year (2.1% compared to 11.8% in 1984) reflected slower growth in the nation's economy in 1985. The average price of coal delivered to industrial firms declined 4.5% from $42.32/t ($38.39 per st) in the fourth quarter of 1984 to $40.39/t ($36.65 per st) in the last quarter of 1985. Coal-producing states in Appalachia mined 9.8 Mt (10.8 million st) tons less in 1985 than in 1984 for a 2.4% loss. The largest contributors to the region's production decrease to 393 Mt (433 million st) were Pennsylvania, down 14.7% to 60 Mt (66 million st); Ohio, down 8.3% to 32.6 Mt (36 million st); and West Virginia, down 2.9% to 115 Mt (127 million st). Conversely, eastern Kentucky production was up 4.8% to 111 Mt (122.8 million st) in 1985, while production in Tennessee climbed 9.7% to 40 Mt (44 million st). No coal was mined in Georgia last year. Coal production in the interior region in 1985 declined 3.9% to 173 Mt (190.4 million st). Substantial production losses occurred in Indiana, down 8% to 31 Mt (34.5 million st); and in western Kentucky, down 7.9% to 36 Mt (40 million st). Coal production in Texas rose 5.7% to 39 Mt (43.5 million st) in 1985. Louisiana began mining lignite 140 kt (151,000 st) during the year. Production in the western region increased 3.4% to 238 Mt (262.5 million st) in 1985. Wyoming, up 5.3% to 125 Mt (140 million st); and North Dakota, up 16.5% to 23.5 Mt (26 million st) contributing the largest amounts. Production gains were also shown in Washington, Utah and, notably, in Alaska where coal output climbed 72.9% to 1.3 Mt (1.5 million st) in 1985. Most of the additional coal produced in Alaska last year was shipped abroad. Coal stocks held by consumers totaled 154 Mt (170 million st) at the end of the year. This was 27 Mt (30 million st), or 13.7% below the inventory level at the end of 1984. Stocks held by producers and distributors declined by 868 kt (957,000 st), or 2.8% in 1985 to 30 Mt (33 million st). A drawdown in stockpiles occurred in each consumer sector during 1985. Stocks held by electric utilities totaled 142 Mt (156 million st) at the year's end, 13% lower than stock levels at the end of 1984.

Jan 5, 1986

By Joe Shoemaker

Automated Spot Generation ? No Operators below the Highwall ? No Operator Wear and Tear ? Reduced Swing Time ? Single and Double Sided Loading ? Minimized Bench Width

Aug 1, 2013

By J. T. Liu

Packing in a flotation column is one way to increase separation efficiency and effective descending flotation-column height. In this paper, the difference between filling packing and sieve packing is described, and the flaws of filling packing in flotation columns in industrial application are pointed out. A change of flotation process and its effect on flotation results are reported. Based on sieve-plate filling, a high-efficiency mixed packing mode consisting of screen-plate packing and honeycomb-tube packing has been proposed, with the packing mode optimized in the cyclonic static microbubble flotation column in the separation zone. In the mixed packing mode, the honeycomb tubes are used to reduce the vortex effect at the base of the column and weaken the radial dispersion of jetting bubbles, and the sieve plates are used to comminute bubbles in the separation zone, to lengthen the bubble migration path, and to stabilize the foam layer. The superiority of honeycomb-tube packing is analyzed using bubble-particle collision theory, and the dynamic equations of collision probability are derived. The role of mixed packing in guaranteeing mineral recovery is analyzed by the axial dispersion method, and a dimensionless axial dispersion model is derived. When a high-turbulence flow is maintained, a static separation environment is formed in which secondary mineral processing is rendered more effective. In this way, a nonlinear separation environment is formed in the flotation column. Finally, mixed packing was applied in an industrial test. A large vortex developed at the base of the column. It was observed that the bubbles in the radial flow were homogeneously dispersed, the residence time of the pulp was prolonged, and the froth layer became thick and stable. Based on the test data, it was found that the sieve packing has the potential to yield a product of approximately 25.83% copper concentration with 91.78% recovery from a feed concentration of approximately 0.727%. If mixed packing were used, the product concentration could be further increased to 27.60% from a feed of approximately 0.739% concentration with 93.38% recovery.

Jan 1, 2014

By Chris McKee

Quartz has been of interest in occupational health for years because it can cause silicosis after prolonged exposure. New OSHA regulations (Air Contaminant; Final Rule) list perlite as a nuisance dust. They conclude that perlite is nontoxic when air-borne total particulate concentrations are 15 mg/m3 or below and when quartz content is less than 1% crystalline silica. OSHA has established an 8-hour PEL of 15 mg/m TWA for total perlite dust containing less than 1% quartz. OSHA has established a 5 mg/m3 TWA PEL for respirable perlite. These limits will protect workers from significant risk of eye, skin, or other physical irritation. This regulation is based on a Group 2A classification as a probable carcinogen in humans, at the 0.1% crystalline silica level, by the International Agency for Research on Cancer (IARC 1987a, b). IARC found sufficient evidence for carcinogenicity of crystalline silica in animals and limited evidence in humans. Perlite is not listed as a carcinogen by OSHA or the National Toxicology Program.

Jan 1, 1990

By Francis E. Federspiel

In 1984 and 1985, at the request of the U.S. Forest Service, the U.S. Bureau of Mines examined the 87,720-acre South Boise Yuba study area (formerly known as RARE II Wilderness Recommended area I-4553) to evaluate mineral resources. The study area and additions are in Blaine, Camas, and Elmore Counties, 10, about 60 mi east of Boise. Granitic rocks of the Cretaceous age Idaho Batholith occupy the western two-thirds of the study area. A Tertiary age granitic complex has intruded, and broken into small blocks, Paleozoic age sedimentary rocks in the eastern third of the study area. Tertiary Challis Volcanics overlie both of these rock types. Principal mineralized structures are gold-and silver-bearing quartz veins and shear zones trending northwest to easterly in the Cretaceous granitic rocks. Copper, lead, and zinc are accessory metals in many mineralized structures.

Jan 1, 1987

By William R. Oakley

In order to best-discuss the met spar industry let me take the liberty to review our involvement, that is, my company's. Our organization has been involved in the fluorspar industry for approximately thirty-five years. We started our activity in Western Kentucky as a mining company and a beneficiator of spar, that is, grinding and grading. After a few short years, the mine became contaminated and rather than invest in a flotation plant, the property was sold and our spar activity was moved, primarily to Mexico. It was decided not to establish ourselves as a Mexican corporation, so, it was necessary to take the position of backer-financier of numerous mining operations. We served in this capacity for quite some time. We also built processing plants on the border in Texas, that is, sizing, grading, etc. in order to market into the steel industry. In 1957, generally speaking, fluorspar for the steel industry was purchased as gravel fluorspar with a maximum of 10% -1/16". The price of this material was $23.50 to $24.00 per ton f.o.b. railcar at the Rio Grande Crossings and about $26.00 or $26.25 f.o.b. barge, Brownsville, Texas. Usually the material was purchased on an effective basis. As you know, 2-1/2 times the silica total, subtracted from the total CaF2 gives the effective calcium fluoride. This was normally the extent of the chemical specifications. Consequently, material was shipped with no regard whatever, to anything other than effective units. The variations in material was absolutely unbelievable. In addition to this, quite frequently, cars were shipped, as they say in the industry, topped. This being, good material placed in the top of cars or barges over bad or low grade. The entire shipment may very well have met the effective unit spec, but the complete imbalance of the sub grade vs. the high grade more or less guaranteed that the consumer was probably using a great deal of low grade and therefore, his usage had to be way higher than it should have been. He came to the conclusion, that because of these conditions and the new technology developing in the steel industry, it was just a matter of time that the entire raw material industry would have to improve. Rather than spend our efforts directed to a substitute flux, we put together a sizing and grading plant in order to ship a controlled crude product, with independent laboratory analysis confirming size and quality. The age of control was started. We began shipping 70 to 72-1/2, 80 and 85 effective with sizing 1/2" by 2", 1" by 3", and 2" by 5" with absolute control on the amount of fines. A material with no fines was a premium product. Incidentally it sold for $24.50 -60 effective up to $28.50, $29.50 for 80 effective.

Jan 1, 1978