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By S. P. Kinney, P. H. Royster, T. L. Joseph

An investigation of the production of iron in the blast furnace is obviously not an easy subject for research . Enough is known of the mechanical , thermal and chemical conditions existing inside the furnace to say certainly that they are complicated. Furnace operators have found that the process is sensitive to a number of known and to many unknown operating conditions . In order to form any conclusions of value , it seems necessary to collect a large amount of data taken with considerable care and accuracy. These facts make a blast furnace research difficult but not impossible . The most serious obstacle in attacking the problem comes from the fact that it is useless in the design and operation of the blast furnace to use the method of " trial and error , which has proved valuable in so many other industrial problems . The variables are so interrelated and are so dependent one on the other that the number of experimental combinations to be tried is enormous . There are certainly not less than twenty factors in furnace operation and design that are known to influence the results . This is apparent if it is remembered that a phrase like " size and shape of the furnace" includes height of the furnace , height , diameter and angle of the bosh , inwall batter , stockline diameter , and furnace volume ; and that a phrase like " chemical and physical properties of the fuels charged " includes size and shape of the lumps , density, porosity and strength of the coke , in addition to its chemical analysis . Let us suppose that we need choose for each of twenty factors one of two values , for example , suppose we must say only that the furnace shall be " tall " or " short , " that the bosh angle shall be " flat " OF "steep , that the ore shall be " coarse " or " fine , " or that the blast has to be "hot" or " cold , " the number of resulting combinations is more than one million . In putting twenty pennies on the table , either heads up or tails up, the number of permutations possible is the twentieth power of two , slightly more than one million. It is obvious , therefore , that some sort of mathematical relationship , a set of rules of thumb , laws , curves or the like , are needed . Whether the relationships , curves or formulas are derived from experiment , from theory, or from mere guess -work, makes no difference provided they agree with the known facts . If they do not agree with known facts , they are worthless no matter what their origin or how weighty the " authority" vouching for them. Few such relationships have appeared in blast- furnace literature , and it may be doubted whether such formulas can be discovered .

Sep 1, 1923

By David M. Hyman

The Bureau of Mines has developed two experimental designs for deter- mining the volumes and relative proportions of the various gas species, particularly methane (CH4), occluded in rock salt. To date, the rock salt samples analyzed have been relatively small (400- to 1,000-gram) grab samples from Louisiana Gulf Coast domal salt mines. The results obtained are comparable to results in Polish domal salt mines, in terms of occluded gas volumes per mass of rock salt. The notable difference between the Louisiana and Polish occluded gas mixtures is in the relative proportions of the individual gas species. The two methods used by the Bureau are ballmill crushing and dissolution. Of the two, the dissolution method appears to be more versatile because it can be performed in situ. The relevance and applicability of data on the occluded gas contents of rock salt are dependent on sample size, sample collection method, geologic context of the sample, and the correlation with gas emissions that occur as a result of mining-induced fractures and pressure differentials.

Jan 1, 1982

By L. P. Kleinmann

To control the formation of acid drainage at its source, the Bureau of Mines has investigated the role of iron-oxidizing bacteria in the oxidation of pyrite. In laboratory tests, it was determined that Thio-bacillus ferrooxidans could be controlled in coal refuse using anionic surfactants, with an associated decrease in acid production of about 75 pet. Based on these results, large-scale tests were conducted at an 8-acre active coal refuse area in northern West Virginia and an 11-acre inactive refuse pile in southern West Virginia. Acid production was decreased 60 to 95 pet for 4 to 5 months after application of 55 gal/ acre of 30-pct sodium lauryl sulfate solution. To date, effluent surfactant concentrations have been extremely low. Either a hydroseeder or a road-watering truck can be used to apply the surfactant. Since the surfactant solution must reach the pyritic material to be effective, sites that have been reclaimed are generally not amenable to these procedures. A simple laboratory test is described that provides an estimate of adsorption potential; this can be used to calculate a safe application rate.

Jan 1, 1983

By T. R. Strombotne

The purpose of this report k to document a contract undertaken by TSA Systems, Incorporated for the United States Bureau of Mines to develop a commercially available source of a continuous, working,, level detector for the measurement of radon daughter products in various working environments. The basic radon measuring technique was devised by Robert Droullard and Robert Holub and has been applied here. For further details or purchasing information contact: TSA Systems, Incorporated 4919 North Broadway Boulder, Colorado 80302

Jan 1, 1982

By John Nagy

Experience and research have shown that an effective way to reduce structural damage from explosions is to provide adequate pressure-relief vents in the walls of equipment and buildings within which explosions might occur. In general, free or unrestricted openings represent the most efficient type of vent. However, in many manufacturing operations it is impractical to use free vents, and it becomes necessary to cover the openings with diaphragms or blow-out disks, hinged panels, or other devices, in order to give protection against weather changes, to prevent the efflux of dusts or vapors from equipment during normal operations, or for other reasons. A few data on the pressure-relieving capacities of hinged panels and a paper diaphragm were published in Bureau of Mines Report of Investigations 3924, which covered the first phase of the dust-explosion venting study made by the Bureau. The present report describes recent experiments that were made to determine the relative effectiveness of an unrestricted vent and 22 types of closures, including various paper, cloth, and metal-foil diaphragms, hinged doors or panels, and several kinds of scored and unscored glass panes. The tests showed that many of the vent closures were effective in releasing the explosions rapidly during their incipient stage, so that the development of destructive pressures was prevented. Vents of this type should prove useful in safeguarding industrial equipment from severe explosion damage. The experiments disclosed that the venting capacities of the diaphragms are approximately inversely proportional to their static bursting strengths.

Jan 1, 1950

By A. L. Engel

This report is a compilation of results of brief preliminary tests on sulfide ores that contained gold and silver and, in some cases base metals. It is a companion paper to a recent similar report on oxide ores. Simple treatment methods employing the least possible equipment sometimes produce satisfactory results on marginal ores and in small-scale operations. Investigations of typical ores from newly discovered or recently explored mining districts have been made in continuation of a long-established part of the hydrometallurgical and ore-dressing program of the Reno station, Bureau of Mines. The purpose of such investigations is to encourage the search for and development of mineral resources and particularly to assist in the economical exploitation of low-grade and marginal ores as well as the conservation and recovery .of values in products that were discarded from former operations because of inability to treat them profitably. Several of these investigations have been limited to preliminary tests of samples from prospecting operations, whereas same involved samples of old dumps or tailings piles. The test work in these cases was not extensive enough to warrant publication as individual reports, but is of considerable interest inasmuch as it indicates the possibilities as well as the limitations of treating the respective materials. The samples were representative of the districts from which they wore obtained, so this information should be helpful in the future development of these districts.

Jan 1, 1951

By A. J. Barry

This report presents observations made by Bureau engineers regarding hydraulic-powered roof supports that are currently being used or have been used on nearly all operating longwalls in the United States, A comparative summary of specifications for various types of powered supports with a brief description of the mine conditions has been compiled to enable mining engineers and mine operators to readily evaluate the differences in design data. Some of the support data furnished in the field may vary from those listed in manufacturers' brochures because of the trend to customize various support components to meet specific mine conditions. A method of estimating support requirements for different assumed operating conditions is presented. Similar computations for specific mine conditions may be used to make preliminary estimates of support requirements.

Jan 1, 1969

By R. F. Abernethy

A modified Unterzaucher method was applied to the direct determination of oxygen in coal. Coal samples were pyrolyzed in a nitrogen atmosphere, and the gaseous oxygen compounds liberated were converted to carbon monoxide by a platinized-carbon catalyst at 9000 C. After passing over heated copper and through a tube containing soda-asbestos and magnesium perchlorate, the purified carbon monoxide was oxidized to carbon dioxide by iodine pentoxide--liberating an equivalent amount of iodine. The iodine was titrated with 0.02 ~ sodium thiosulfate; in a few tests the weight of carbon dioxide produced was determined. Direct oxygen determinations of coal included organic oxygen from the coal substance, plus a small quantity of inorganic oxygen derived principally from carbonate minerals and from combined water of silicates in the mineral matter. The influence of mineral matter on the direct oxygen determination was investigated by testing (1) untreated coal, (2) demineralized coal from which most of the mineral matter except pyrite was removed by treatment with hydrofluoric and hydrochloric acids, and (3) coal samples treated with dilute hydrochloric acid.

Jan 1, 1966

By W. W. Simpson

The Bureau of Mines conducted research to determine the effects of potassium trithiocarbonate (KTTC), a degradation product of potassium ethylxanthate (KEX), on flotation of chalcopyrite and molybdenite. Small amounts of KTTC were identified in fresh and aged solutions of KEX using thin-layer chromotography. Hallimond tube flotation tests on pure minerals showed that KTTC acts as a weak collector for chalcopyrite. Both KEX and KTTC tend to depress molybdenite, but the depression effect is easily overcome by addition of a small quantity of fuel oil. The results of the Hallimond tube tests were confirmed in batch flotation tests using a porphyry copper ore.

Jan 1, 1983

By V. M. Benson

A simplified, routine method for determining lithium in lithium-bearing rock is presented. The sample is decomposed by repeated treatments with nitric, hydrofluoric, and perchloric acids. Since this procedure does not appreciably dissolve beryl, interference by beryllium (the principal interfering cation) is minimized for most samples. The salts are brought into solution with water and enough citric acid-ammonium citrate buffer is added to make the final volumetric dilution 0.20 M with respect to citrate. The addition of citrate greatly reduces anion interference in the hydrogen-oxygen flame, slightly increases the intensity of the lithium 671 millimicron emission line, and reduces the effect of most of the interfering cations to the extent that analytical separations are not necessary. The accuracy of results of single determinations of lithium in a pegmatite containing spodumene, lithium-bearing mica, and beryl are approximately equal to that obtained by other flame methods, INTRODUCTION This investigation was undertaken in Bureau of Mines laboratories to develop a reliable, rapid, routine analytical method for determining lithium in lithium-bearing minerals. The requirements of the procedure were that the method should be applicable to the analysis of a variety of lithium-bearing ores and test products, and the results would be reasonably accurate for materials containing 0.05 to 8 percent Li20.

Jan 1, 1961

By Robert S. Sanford

In April 1948, the Bureau of Mines was requested to evaluate the graphite deposit' known as the Benjamin Franklin and Just mines in Chester County, Pa. After preliminary investigation, it was recommended that the Bureau core-drill, trench, and sample the deposit and make beneficiation tests on the ore. During the first and second World Wars, flake graphite was in short supply, and a number of deposits in the United States were exploited. In 1942, the Defense Plant Corporation, through its lessee, the Benjamin Franklin Graphite Co., purchased 70.263 acres of graphite-bearing land and built a complete mining and milling plant with a capacity of 300 tons of crude ore per 24-hour day at a cost of $426,250 (Plancor No. 1254).

Jan 1, 1949

By J. J. McClelland

The face area of a continuous mining section of an underground coal mine is the most dangerous area in the mine. Workers there are at nearly twice the risk of death or disabling injury than those in other parts of the mine. Despite extensive training of miners and improved equipment and mining methods, fatality and injury rates have remained constant during the past few years. It is clear that advanced research is necessary to apply new technologies or modify work procedures to solve the continuing problem of the loss of lives and the numerous injuries at the mine face. A U.S. Bureau of Mines research program is developing a Reduced-Exposure Mining System (REMS) that relocates personnel operating the mining machinery at the face away from the hazards to a nearby haven of relative safety. REMS uses proven technologies of computer automation and robotics to help control the operation of the mining machines at the face, while personnel are moved away to a nearby, safe control room. In this protected, well-ventilated environment, they can supervise or control the operation of the machines while viewing what the machine is doing using video and graphic display monitors.

Jan 1, 1994

By Karl C. Dean

The Bureau of Mines stabilized 10 acres of windblown copper mill tailings at McGill, Nev., by a combination chemical-vegetative procedure. Legumes, winter wheat, wheat-grasses, and wild rye were seeded, and the area was subsequently sprayed with a resinous adhesive chemical to stabilize the sands until the vegetation could grow. During the year since treatment, the area has been well stabilized against wind erosion. The established vegetation appears to be capable of self-perpetuation and renewal without irrigation. The cost of stabilizing the area was $135.50 per acre.

Jan 1, 1969

By W. W. Agey

The Calico silver-barite deposits near Barstow, Calif., are a potentially important resource. Exploration performed by two major mining companies out-lined large tonnages of ore that assayed at 2 to 3 ounces of silver per ton and 7 to 15 percent barite. Laboratory beneficiation work was done by the Bureau of Mines on four samples to develop methods for recovering the silver and/or barite. Cyanidation recovered from 47 to 60 percent of the silver from ore ground to approximately 100 percent minus 325 mesh. Salt roasting minus 10-mesh material, followed by regrinding and cyanidation, recovered 75 to 85 percent of the silver. From 75 to 90 percent of the barite was recovered in a plus 92-percent barite product from either the natural ore or from cyanidation residues. Salt roasting before cyanidation precluded recovery of the high-grade barite concentrate from the leach tails.

Jan 1, 1973

By George A. Morgan

The production and processing of crude petroleum and natural gas are the dominant economic sectors of the Middle East. The 15 countries that constitute the region accounted for 28% of world crude petroleum output, 17.2% of world natural gas plant liquid production, and 5.3% of world dry natural gas production. Only Cyprus and Lebanon were not crude petroleum producers. About 66% of total world crude petroleum reserves and 31 % of total world natural gas reserves are in the Middle East. Transportation and port facilities in the region are geared to expediting efficient and rapid shipment of these materials. Export sales of these fuels provide funding for further diversification of the mineral industry. Additional development of downstream facilities for producing energy-intensive metals such as aluminum and byproducts of the fuels such as petrochemicals and fertilizers can be expected. Earnings from the industry are also channeled by several Governments in the region to mineral industry projects in Africa and elsewhere. Several countries in the region own major petroleum refineries and distribution facilities worldwide. Petroleum prices rose overall during the year owing to the invasion by Iraq of Kuwait in August 1990. Output from both countries, the fourth and fifth largest producers, respectively, in the Middle East, was negatively affected by the war. Kuwaiti crude oil wells and pipeline facilities suffered extensive war damage while exports of petroleum and petroleum refinery products by Iraq ceased owing to a U.N. embargo. The embargo also impacted Jordan, an exporter of phosphate and potash. Shipments of crude petroleum by pipeline from Iraq through Saudi Arabia and Turkey and by vessel through the Persian Gulf were terminated. However, the loss in production from Iraq and Kuwait was more than made up by accelerated output from other Middle East and world producers. Saudi Arabia, in particular, with its excess production capacity, accounted for the largest portion of the increase.

Jan 1, 1992

By F. S. Crawford

During the course of a study of the safety organizations of the various iron mining companies in the Lake Superior district considerable in¬ formation regarding the methods of safety inspection in use was obtained which may be of value to other companies beginning safety work or contemplat¬ ing changes in their methods. A short description of the safety-inspection methods of eleven of these companies is given in this paper, and in the appendix are illustrated a number of forms used for safety inspections by several of the companies. Most of the companies whose methods are described use few forms for formal inspection. The one long form (10) attached which is used for a general in¬ spection by the safety inspector appears to present a good method for enabling the inspector to check all branches of his inspection and to assure himself that everything has been covered. All names of companies have been deleted from this paper and from the forms because the object is to disseminate information of constructive value rather than to point out the methods of particular companies by name.

Aug 1, 1931

By Charles L. Kimbell

In overview, the world's mineral industry in 1989 registered gains over its 1988 performance, but these gains were by no means as pronounced as had been those of 1988. The traditional statistical measures of mineral industry performance, namely production, trade, and consumption levels, reflected significant growth in most industry sectors from crude material extraction through the gamut of down- stream processing. Growth in market economy countries generally exceeded growth in the centrally planned economy countries as a result of a variety of causes that will be covered subsequently, but even among the centrally planned countries there were some upturns. In contrast to these measures of the soundness of the industry, the situation for nonfuel mineral and metal prices was less satisfactory than in 1988, and low crude oil prices continued as a problem for the all-important petroleum sector, despite some gains during the year. The oil price situation mitigated against price increases for competitive fuels. Although this was unfavorable for fuel producers, it remained advantageous to consumers, including nonfuel mineral producers, processors, and transporters. Thus it cannot be viewed as a negative factor for the whole of the global mineral industry. Global crude mineral output value was estimated at nearly $1,420 billion in current dollars, an increase of 9% over the 1988 level, and an increase in current dollar terms for the seventh consecutive year. Measured in terms of constant dollars, however, adjusting for inflation, the increase was only 4.7% compared with the 1988 level. Despite the prolonged growth trend, the 1989 crude mineral output value level was still 3.2% below the record high set in 1980, which was $1,467 billion in terms of 1989 dollars.

Jan 1, 1992

By Peter N. Gabby

A mineral purvey of 40,000 acres of the 42,213-acre Little Humboldt River Wilderness Study Area was conducted by the U.S. Bureau of Mines in 1985 at the request of the U.S. Bureau of Land Management. There are no identified mineral resources but anomalous gold, silver, mercury, and arsenic concentrations were found. The study area is located in Elko County, NV, in the Owyhee Upland geomorphic subprovince. It is underlain by mid- to late-Miocene-age rhyolite, basalt, tuff, vitric ash, and tuffaceous siltstone. On the south side and partly within the study area, a mining company recently (January 1986) located 125 contiguous claims over an area of hydrothermally-altered volcanic rocks that have anomalous surface concentrations of gold, mercury, arsenic, and silver. Anomalous gold-silver concentrations in altered rocks were encountered at several other widely scattered localities in the study area. These elevated metal concentrations and associated hydrothermal alteration indicate gold resources may be present in the study area. A 20-ft-thick bed of diatomaceous earth, which contains 60 to 85 percent diatoms, crops out 0.3 mi north of the study area. Elsewhere, three samples of altered volcanic tuff taken within the study area contain from 46 to 70 percent zeolite (clinoptilolite). The diatomaceous earth and zeolite sampled are not of sufficient quality to compete with materials presently being marketed. There has been no mineral production from the study area, but a caved adit, about 25 ft long, and six prospect pits were found.

Jan 1, 1987

By Robert J. Hundhausen

This report describes Bureau of Mines investigations of a low-grade scheelite-bearing granodiorite intrusive situated on Henderson Creek, Granite County, Mont. The intrusive is in a narrow, V-shaped valley at the head of extensive placer workings. Since May 1943 the H. & R. Mines Co. of Portland, Oreg., has recovered scheelite sand and gold from the placer workings. A modified Yuba, 4?cubic foot bucket dredge was used in the operation. By February 1947 this operation had recovered and marketed over 215,000 pounds of scheelite concentrates containing 63 percent WO3. The scheelite in the placer was found to be derived principally from erosion of the granodiorite intrusive. The intrusive is one of a series of four similar, dikelike masses of granodiorite whose outcrops are aligned along a 10-mile zone of weakness trending N. 60° E. The intrusive has a triangular outcrop exposed over an area of 57 acres. Trenching and sampling by the Bureau of Mines demonstrated that scheelite is sparsely distributed throughout the granodiorite. This work delimited the outcrop of the intrusive and indicated a large submarginal reserve of low-grade tungsten mineralization. The deposit is ideally suited for exploitation by large-scale, open-pit mining operations; it would be easily available in a national emergency. Additional exploration would be necessary, however, before large-scale production plans could be made efficiently or accurately.

Jan 1, 1949

By Michael P. Moore, Christopher J. Rise

"Over the past twenty years, there have been numerous studies which have attempted to correlate the prevalence of Coal Workers' Pneumoconiosis (CWP) with different characteristics of the coal seam. Some investigators have tried to find a relationship, or the lack of a relationship, between the rank of coal seams and the incidence of CWP. Others have attempted to show that there is a positive correlation between the mean mass of respirable dust in the mine atmosphere and the prevalence of CWP. Still others have tried to determine the influence of the quartz content of respirable dust on the incidence of CWP. Unfortunately, many of these different investigations have conflicting conclusions.One area of research with conflicting conclusions deals with the relationship between the rank of the coal and the incidence of CWP. For example, an inves¬tigation conducted in Pennsylvania and West Virginia coal mines concluded that the prevalence of CWP increases with an increase in coal rank (1). A study in Great Britain also observed a close relationship between the rank of coal and the prevalence of CWP (2). However, another study involving 312 Appalachian coal miners concluded that the association between coal rank and CWP might be fortuitous and that other factors may be more important (3). In addition, an investigation involving 2,600 miners during a period of twenty years in Great Britain established that there is only a weak correlation between the prevalence of CWP and the rank of the coal (4). Consequently, it appears that there is still uncertainty as to whether or not the rank of the coal seam has an influence on the development of CWP.Another area of investigation concerns the relationship between the mean mass of respirable dust present in the mine atmosphere and the prevalence of CWP. A study involving 4,122 miners over a period of ten years in Great Britain noted a high correlation between the mean mass of respirable dust and the incidence of CWP (5). Another investigation involving 3,154 British face workers con¬cluded that the overall mass of respirable dust is the factor most closely related to the ten-year attack rate of CWP (6). However, a study conducted in thirty-one mines in the United States concluded that it is doubtful that the quantity of respirable dust alone is responsible for the difference in the prevalence of CWP (7). Even though there are conflicting conclusions, there are many more investigators who confirm, rather than deny, the relationship between the mean mass of respirable dust and the development of CWP.The third subject of investigation is the role of quartz in the incidence of CWP. For example, two studies in Great Britain concluded that the quartz content in coal mine dust has no relationship to the prevalence of CWP (8,9). But a study involving 312 Appalachian coal miners revealed that the level of exposure to free silica plays an important role in the development of CWP (10). Once again, the conclusions reached by different researchers are conflicting.Probably the most important factor in the discrepancy among the studies is the variability among different coal mines. A mine operating in an inherently ""dusty"" seam may have a low concentration of respirable dust while a mine operating in a less dusty seam may have a high concentration of respirable dust. This discrepancy is a result of variables such as the effectiveness of ventilation or the efficiency of the water sprays. Consequently, it is very difficult to compare the dustiness of different coal seams by in-mine measurements of the respirable dust concentration. A laboratory test would more accurately characterize a coal seam according to its respirable dust production."

Jan 1, 1988