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By N. Fragen, H. H. Stroch

"INTRODUCTION A previous paper by H. H. Storch 4 described. three processes for the production of potassium sulphate from polyhalite (K2S01.MgSO1.2CaS04.2H2o), Since these processes depended upon calcination of polyhalite followed by leaching with water at 100°C., the fundamental reactions occurring in these steps were discussed in detail. This paper, which describes processes producing syngenite (K2S04.CaSO4.H2O) and potassium sulphate and gives data concerning the production of by-product magnesia, presents the results of work performed at the Non metallic Minerals Experiment Station of the U. S. Bureau of Mines, maintained at New Brunswick, N. J., in cooperation with Rutgers University.A study of the solubility relationships of the system 5 Ca++ -Mg++ -K+-SO4 = H20 at 25ºC. shows that syngenite is stable in the presence of a concentrated MgSO4 solution, the K2SO : equilibrium concentration being comparatively low (2.6 per cent), The processes described below, which involve the conversion of calcined polyhalite to syngenite, are based on the 25°C. equilibria. It has further been found that syngenite can be decomposed by water at 100ºC, yielding a 9 to 10 per cent K250 solution, the solid phase being potassium calcium pentasulphate (K2SO, 3CaSO.H2O, hereafter referred to as ""pentasulphate""). This latter compound is unstable in the presence of water at 25°C., its decomposition resulting in a solution containing about 3 per cent of K2SO4 and a solid phase consisting of gypsum. This behaviour of syngenite with water at 100°C. and of pentasulphate with water at 25ºC. constitutes the basis of processes for the production of K2SO4 by way of the conversion of calcined polyhalite to syngenite,Syngenite is a product which may be used as a fertilizer per se. As produced in the process to be described, it contains about 50 per cent of K2SO1, and will readily give up its potash content on treatment with water, although the limiting concentration at ordinary temperatures is approximately 3 per cent. This definite but limited solubility should make this product more desirable as a fertilizer then the more concentrated forms of potash salts which have higher solubilities and hence involve the danger or plant injury due to a high local concentration of potash."

Sep 1, 1931

By Foster Fraas

One of the lithium minerals most widespread in the earth's surface is spodumene (Li2O-A1203-4Si02) a lithium aluminium silicate. For some time, deposits of this mineral were known to exist in the Black Rills of South Dakota, but it was only quite recently that Hess4/ pointed out the great magnitude of the low-grade e deposits it s in North Carolina. The theoretical lithia (Li20) content of spodumene is 8.04 percent. The only other minerals with such high lithia content are the phosphates, but these occur only in pockets and are not in extensive deposits5/. Actually, however, the lithia content in spodumene is never found to be this high, being nearly always below 7 percent for the pure mineral, and part of the lithia is apparently replaced by other alkalies.

Jan 1, 1937

Objective The Roof Monitoring Safety System (RMSS) introduced in late 1997 has been modified to improve durability and simplify the measurement of roof or rib movement. Greater knowledge about the stability of roof and rib rock is expected to result in safer conditions for the mine worker. Developing safety tools and methods is part of NIOSH’s mission to prevent work-related injuries and deaths. A mining operation with a proactive approach to control ground conditions is in a better position to make essential decisions related to mine development and take remedial actions in the event of roof or rib falls. Background Falls of roof and rib rock are responsible for a high number of mining injuries and fatalities. Visual inspections and the sound of breaking or cracking rock are often relied upon to indicate unstable roof conditions. In some mines, roof bolt holes are checked for separations or gaps with a scratch tool; this provides further information about the stability of the roof. Monitors such as the RMSS can confirm roof movement that was surmised only by eye or ear, or potentially detect movement that was missed by these means. An added safety feature of the RMSS is the capability of locating the measurement station at a distance from where the monitor is placed in the roof. Stone and other industrial minerals are the basic raw materials used in construction. Continuing economic growth and highway building in particular have resulted in record demand for stone. This high demand, coupled with increasing constraints on surface mining, have caused many new .stone mines to be developed underground. These new mines in many cases will be employing new and inexperienced miners who may not have the ability to recognize unstable ground conditions using just sight and sound. From the initial introduction of the RMSS, it was anticipated that improvements and modifications would occur. We correctly assumed that, once miners and operators were exposed to the monitor. suggestions would evolve. In one case, the RMSS was used to determine if an impact hammer used on a mechanical scaler was causing or increasing instability of roof rock. The test showed little or no movement resulted from this method of scaling under the particular conditions at this mine. In another instance, an operator needed to monitor the stability of a haulageway in a benched area that had very high ceilings. The RMSS requires a 2-in-diam hole for installation; however, only roof bolt holes of a smaller diameter were available, and it was impossible to drill new holes at that height. The operator attached a 2-in collar at the roof line and was able to install the RMSS. These examples illustrate the potential for further enhancements of this tool. NIOSH continues to seek additional candidate sites for use of the RMSS. As usage increases, we anticipate further refinements and additional applications. How It Works The new RMSS, cable, and read-out box are shown in figure l. The read-out box has a green light that stays lit until battery replacement is needed. The red light is set to conic on to indicate movement. The red light can he adjusted for increments of movement as low as .010 inches. The RMSS red light should not be considered as a primary or only means of determining the stability of roof or rib. It is intended to serve as a supplement to existing methods or procedures for determining stability. An overview of the RMSS components is shown in figure 2. Movement of rock layers within the mine roof is measured relative to a fixed-point calibration at the monitor housing. The housing contains a potentiometer, roller switch, plastic rack, and spur gear. Movements are detected by the transfer of electromotive forces

Jun 1, 2000

By C. W. Elder

"INTRODUCTION This report describes a method of horizontal drilling in an oil-producing formation underlying a 400-acre, approximately square plot of land in the Franklin Heavy oil field in Sugar Creek Township, Venango County, Pa. The method, which was developed on two previous projects in Ohio, 3/ consists of sinking a shaft to the bottom of a shallow oil sand and drilling holes in a general horizontal plane outward from the chamber in a pattern similar to that of the spokes of a wheel. The project was undertaken by the Venango Development Corporation in an attempt to find an efficient method of recovering oil from partly depleted sand formations.The Venango Development Corporation is composed of the following oil-producing and oil-refining companies and individuals: South Penn Oil Co., Forest Oil Corporation, Kendall Refining Co., Minard Run Oil Co., Quaker State Oil Refining Co., The Pennzoil Co., Alliance Oil Corpo¬ration, United Refining Co., Franklin Creek Refining Corporation, Canfield Oil Co., Pennsylvania Refining Co., Page Oil Co., Freedom Oil Co., D. W. and D. S. Grant, and J. P. Herrick, C. M. Davison and N. V. V. Franchot. Engineering features of the project were supervised by a committee off three engineers A. J. Saxe, chairman, W. M. Shoemaker, and C. N. Pfohl, who supervised the excavation of the shaft and the drilling of the first two holes by alternately spending a week at a. time at the project. The drilling method was under patent license from Leo Ranney, who served as technical advisor to the Venango Development Corporation; in addition, he furnished the design for the shaft and work chamber."

Sep 1, 1944

By R. F. Abernethy

Recent investigations in the United States and in other countries have produced considerable information on the nature and occurrence of minor elements in coal. The possibility of recovering certain elements, particularly germanium and uranium, from coal ash and other coal products has received considerable attention. Some flue dusts are potential sources of germanium, and certain lignite deposits are potential sources of uranium, but industrial recovery of these elements has been limited to small quantities for technical and economic reasons. Considering the large amount of coal mined annually, a small percentage of a rare element may have industrial significance if an economical method of recovery can be developed. In 1944 information on the occurrence of rare elements in coal was reviewed in Bureau of Mines Technical Paper 669 (46).3 This report is a revision of that paper with the view of summarizing published information available for United States coals, and pertinent information concerning coals of other countries. Selected references from the original paper are retained. New references do not include all preliminary reports when more permanent literature describing complete projects is available. Consequently, the list of references should not be considered complete.

Jan 1, 1963

By H. R. Shell

The work on synthetic mica and related subjects is being reported in a series of technical articles (see Supplementary Bibliography), each of which describes some special aspect of the subject. This is the final report on chemical analysis of the fluoride-containing silicates. A condensation of this report has been published (26).3/ Chemical analysis affords one of the best means of ascertaining the final com-position of either a heterogeneous mass or a single pure crystal, particularly where some constituents may be volatile. The analysis of fluoride-containing silicates was not so well known or understood that highly accurate results were commonplace. For example, on synthetic mica a university laboratory reported 11.6 and 9.2 percent fluoride when at least 13.3 and 11.3 percent were present, respectively; a commercial testing laboratory reported 9.14 percent as compared to 12.6 percent; and a glass company reported 7.0 percent as compared to 9.0 percent present. No intimation is made that these analysts could not have done better, but the point to be stressed is that the methods in use were long, tedious, and generally required a certain familiarity for best results.

Jan 1, 1956

By John C. Machisak

THIS INFORMATION CIRCULAR contains injury and employment data for all stone quarries in the United States for the Calendar year 1960. This publication contains statistical data on injuries and employment pertinent to the stone quarries and related operations, such as the manufacture of cement and lime, rock dressing etc., but excludes statistics for clay and sand and gravel operations. Data for these commodities may be found in other Bureau publications. Reports received from the operators are voluntary responses to the Bureau's request for information; therefore, the figures may not be complete for the industry. However, since these data contribute greatly to the promotion of safety, every effort has been made to make them representative of the industry.

Jan 1, 1963

By John C. Machisak

THIS INFORMATION CIRCULAR contains injury and employment data for all stone quarries in the United States for the Calendar year 1960. This publication contains statistical data on injuries and employment pertinent to the stone quarries and related operations, such as the manufacture of cement and lime, rock dressing etc., but excludes statistics for clay and sand and gravel operations. Data for these commodities may be found in other Bureau publications. Reports received from the operators are voluntary responses to the Bureau's request for information; therefore, the figures may not be complete for the industry. However, since these data contribute greatly to the promotion of safety, every effort has been made to make them representative of the industry.

Jan 1, 1963

By Fred N. Kissell

This handbook describes effective methods for the control of methane gas in mines and tunnels. It assumes the reader is familiar with mining. The first chapter covers facts about methane important to mine safety, such as the explosibility of gas mixtures. The second chapter covers methane sampling, which is crucial because many methane explosions have been attributed to sampling deficiencies. Subsequent chapters describe methane control methods for different kinds of mines and mining equipment, primarily for U.S. coal mines. These coal mine chapters include continuous miners and longwalls, including bleeders. Coal seam degasification is covered extensively. Other coal mine chapters deal with methane emission forecasting and predicting the excess gas from troublesome geologic features like faults. Additional coal chapters contain methane controls for shaft sinking and shaft filling, for surface highwall mines, and for coal storage silos. Major coal mine explosion disasters have always involved the combustion of coal dust, originally triggered by methane. Thus, a chapter is included on making coal dust inert so it cannot explode. Methane is surprisingly common in metal and nonmetal mines around the world, as well as in many tunnels as they are excavated. Accordingly, a chapter is included on metal and nonmetal mines and another on tunnels. Proper ventilation plays the major role in keeping mines free of hazardous methane accumulations. The ventilation discussed in this handbook, except for the chapter on bleeder systems, deals only with so-called face ventilation, i.e., ventilation of the immediate working face area, not ventilation of the mine as a whole. The omission of whole-mine ventilation was necessary to keep this handbook to a reasonable size and because a huge amount of excellent information is available on the subject.2

Jan 1, 2006

By E. C. Perkins

As part of a program for developing methods of using domestic titanium deposits, the Bureau of Mines investigated methods for chlorinating titanium slags prepared from titaniferous minerals by electrosmelting. Titaniferous slags were made from ilmenites in the following deposits: Valley County, Idaho; Trail Ridge, Fla.; Aiken, S. C.; and Maclntyre, N. Y.; titaniferous magnetite from Iron Mountain, Wyo., were also evaluated. The tests were made in two chlorinators, a 4-inch and a 36-inch unit. Preliminary testing was done in a 40-millimeter bench-type unit. Chlorine gas was contacted with a loose mixture of titaniferous slag and carbon at a high temperature to form titanium tetrachloride. The moving-bed system used in this work involved a downward movement of feed countercurrent to the chlorine flow, and residues continuously removed from the bottom of the reactor. The performance characteristics of these slags depended on their composition, which varied widely according to the geographic source of the ore. The results showed that all but two of the slags could be chlorinated as effectively as rutile, converting 70 to 80 percent of the titanium to the tetra-, chloride. The two slags that proved difficult were made from New York ilmenite and Wyoming titaniferous magnetite. These slags contained enough magnesium to cause clinkering, which necessitated that the bed be prematurely withdrawn before more than 70 percent of it could react. The iron content of the slags did not interfere with operating the chlorinators. The data from the 4-inch and the 36-inch units were in agreement on the relative amenability of the slags to chlorination.

Jan 1, 1962

By R. E. Zane

[The Northwest Experiment Station of the Bureau of lines, in cooperation with the College of Mines, University of Washington, has completed a detailed investigation of the physical and chemical properties of western cokes made or used in the Pacific Northwest, as evaluated by standard methods. 4/ One of the chemical properties determined, to which more or less importance has been attached, was reactivity or combustibility. As no standardized procedure is available, it was necessary to develop a workable method for evaluating this property. The combustibility of coke is usually measured by the formation of carbon dioxide with time at a particular temperature or by the reduction of carbon dioxide to carbon monoxide. Analysis of the resulting gases commonly is required to evaluate the result. The method described in this paper is simple and direct in that the sample of coke or other carbonaceous material is weighed as it burns; the loss in weight and time is indicated by a balance and clock arrangement. Gas analyses are not rewired. Methods similar in principle have been used by Tu, Davis, and Hottel6/ and by Oshima and Fukuda7/ for determining the combustion rate of carbon and for studying the effect of ash on combustion characteristics. Both methods: are more elaborate in procedure and apparatus required than teat described here. Brief the method comprises burning a sample of coarsely grained. coke or]

Jan 1, 1940

Minerals are a fundamental component of the Nation" material and economic base. Without a continuous supply of minerals to meet growing and changing needs, the basic character of our society would be very different. The importance of minerals to the United States was reemphasized by the Congress in I970 when it enacted the Mining and Minerals Policy Act, which stated that it is the continuing policy of the Federal Government in the national interest to foster and encourage private enterprise in (I) the development of economically sound and stable domestic mining, minerals, metal and mineral reclamation industries, (2) the orderly and economic development of domestic mineral resources, reserves, and reclamation of metals and minerals to help assure satisfaction of industrial, security and environmental needs, (3) mining, mineral, and metallurgical research, including the use and recycling of scrap to promote the wise and efficient use of our natural and reclaimable mineral recources, and (4) the study and development of methods for the disposal, control, and reclamation of mineral waste products, and the reclamation of mined land, so as to lessen any adverse impact of mineral extraction and processing upon the physical environment that may result from mining or mineral activities.,.

Jan 1, 1977

By Joseph L. Condon

Fifteen shots of three explosives with charge weights of 0.52, 1.1, 3.1, and 5.1 kilograms were fired in a pond to study the seismic effects of detonating explosives in water. Shock pressures and bubble periods were measured with pressure transducers in the water. Vibrations were measured on land in three orthogonal directions with particle velocity gages. Statistical tests indicated that a charge weight exponent of 0.43 best scaled the data. While shock pressures and bubble periods showed considerable differences in explosive performances, the amplitudes of ground vibrations showed less difference, and one prediction equation was therefore derived to estimate vibration amplitudes from all the explosives.

Jan 1, 1970

By Eugene T. Sheridan

The annual survey of the fuel-briquet industry by the Bureau of Mines, United States Department of the Interior, revealed that 21 fuel-briquet plants in 11 States were in operation and reported production in 1956. The demand for fuel briquets in the United States has gradually declined since 1948, and the number of operating plants has decreased from 36 to 21. Also, the annual productive capacity of the industry has decreased, although not a proportionate amount because most of the plants that were abandoned were small and in most instances had a designed capacity of less than 25,000 tons per year. In 1956 the 21 active plants had an annual capacity of 3.7 million tons (table 2), which was only 20 percent less than the total capacity of the 36 plants in 1948. This indicates that most of the larger plants have remained active, even though operating at reduced rates, and the average capacity of the industry has increased from 130,000 tons per plant in 1948 to 177,000 tons in 1956. Since 1948 operating rates have decreased from 67 percent to 41 percent of annual capacity.

Jan 1, 1958

By J. R. Thoenen

This circular is part 5 of the third paper (entitled "Excavation") of a series summarizing the technical problems involved in the production and preparation of sand and gravel. Part 1 discussed the use of power shovels, draglines, and excavator cranes; part 2, power scrapers, slackline cable-way excavators, and hydraulic monitors; part 3, hydraulic, clamshell, ladder, and dipper dredges; and part 4, haulage systems in general, with particular reference to locomotive and car, hoist and car, and remote-control systems. This circular discusses the use of motor trucks, conveyor belts, pumps end pipe lines, barges and towboats, and aerial trams. MOTOR-TRUCK HAULAGE During recent years motor trucks have gained considerable ground as a successful competitor of locomotive haulage for quarries and gravel pits. Often where trucks have displaced locomotives and cars the operators readily admit an increase in both labor and total haulage operating costs but point to some other advantage as offsetting the extra expense. In other instances haulage costs have beep reduced by the use of trucks. In still others operators, having replaced locomotive haul with trucks, have again returned to the earlier method. Obviously gasoline-driven motor trucks cannot successfully compete with other types of haulage under all conditions. The apparent' growth in the number of advocates of truck haulage, however, indicates that it has passed the experimental stage and become a permanent competitor to other tyres.

Jan 1, 1936

By Eugene T. Sheridan

The 22d annual survey of the packaged-fuel industry by the Bureau of Mines, United States Department of the Interior, revealed that 26 plants in 8 States were in operation and reported production in 1956. The demand for packaged fuel in the United States has declined gradually since the end of World War II, and the number of operating plants has decreased from 70 in 1946 to 26 in 1956. Annual productive capacity of the industry has decreased also during this period, and the decrease in capacity was about proportional to the decrease in operating plants. Packaged-fuel plants are relatively small, and 85 percent of the active plants in 1956 had an annual capacity of less than 10,000 tons. The same situation prevailed in 1946, when 84 percent of the plants had a capacity of less than 10,000 tons. Total capacity for the 26 active plants in 1956 was 174,600 tons, an average of 6,715 tons per plant. Operating rates in 1956 were the highest since 1951, and the rate of production for the industry averaged 37 percent of capacity.

Jan 1, 1958

By William P. Diamond

A 3-inch pilot hole was directionally drilled to intercept the Freeport coalbed horizon horizontally at Mather, Pa., as part of a Bureau of Mines degasification project. The original concept was to continue the horizontal drilling into the coalbed, after the initial intercept, with a total of three horizontal holes eventually being completed. However, the erratic thickness (0.0 to 4.3 feet) of the Freeport coalbed at Mather was not sufficient to support the horizontal drilling degasification technique, and the site was abandoned after six attempts to locate adequate continuous coal thicknesses. The drilling of coreholes in the immediate vicinity of proposed well paths to evaluate coal thickness is essential prior to future slant hole operations. Although mechanical failures of the new directional drilling equipment, mud pump and rig breakdowns, directional control problems, and exploratory horizontal drilling in the Freeport horizon more than doubled the anticipated cost of the pilot hole, continuing improvements in directional drilling equipment and techniques should significantly reduce the time and costs of future drilling operations.

Jan 1, 1977

By David C. Oyler, Herbert H. Fields, William P. Diamond

A 3-inch pilot hole was directionally drilled to intercept the Freeport coalbed horizon horizontally at Mather, Pa., as part of a Bureau of Mines degasification project. The original concept was to continue the horizontal drilling into the coalbed, after the initial intercept, with a total of three horizontal holes eventually being completed. However, the erratic thickness (0.0 to 4.3 feet) of the Freeport coalbed at Mather was not sufficient to sup- port the horizontal drilling degasification technique, and the site was abandoned after six attempts to locate adequate continuous coal thicknesses. The drilling of coreholes in the immediate vicinity of proposed well paths to evaluate coal thickness is essential prior to future slant hole operations. Although mechanical failures of the new directional drilling equipment, mud pump and rig breakdowns, directional control problems, and exploratory horizontal drilling in the Freeport horizon more than doubled the anticipated cost of the pilot hole, continuing improvements in directional drilling equipment and techniques should significantly reduce the time and costs of future drilling operations.

Jan 1, 1977

By T. J. Ballard

"The Hog Creek mine, in lot 92 of the 17th district in Towns County, Georgia, was examined in 1890 by F. P. King, who reported the existence there of a 4-foot vein of corundum. The mine is about 2 miles west of Hiawassee, on the southern side of Ramey Mountain. Ed Burch, of Hog Creek, holds the surface rights, and the mineral rights appear to be vested in the heirs of William R. McConnell, who formerly owned and prospected the property.Examination by the Bureau of Mines showed the workings to be caved, but it was thought advisable to open the mine and uncover the reported vein. The Bureau's work consisted, of trenching and cleaning out the pits and shaft.William R. McConnell, the former owner, prospected the property in about 1890. At some tine during that operation, the prospect was visited by Francis P. Kings a geologist with the Georgia Geological Survey.3/King reported that a 4-foot vein of corundum was exposed g feet below the surface in the main cut and was opened for 20 feet along the strike. He also reported that the so-called ""Georgia rubies"" were taken from this mine.The main mine is about 2,000 feet- north of Hoc Creek on a timbered southern slope of Ramey Mountain. It lies at an altitude of about 2,100 feet, approximately 100 feet above the high-water level of the Catuga reservoir, which floods Hog Creek to a quarter of a mile above its confluence with the Hiawassee River. The nearest water is a small branch about 1,000 feet to the west.Chlorite schist is the principal host rock. It has been intruded by irregular masses of a very herd periodtite rock possibly troctolite. The schist near the surface is extremely weathered, presenting white and red laminations parallel to the schistosity. At a depth of 40 feet in the cross-cut it appears as a fine-grained green-chlorite schist. The schist strikes about N. 350 E. and dips 800 to the southeast.No corundum vein was found, and if any existed it must have been mined out after King's visit. In the pit, about 15 feet west of the shaft, approximately 150 pounds of zoisite and an occasiona1 small crystal of corundum were found imbedded in schist about 18 feet below the surface, near hard, dense troctolite."

Mar 1, 1946

By Graham W. Marks, RALPH MILLS, FRANK COSSEY

To determine the focal length of lenses or the performance of lens systems before mounting them permanently , it is desirable to have a device in which one or more lenses can be mounted easily and their positions relative to a light source and screen changed readily . We have designed and constructed such an optical bench and lens holder . The bench is similar to that of Houstoun5/ but has been modified , whereas the lens holder is , we believe , a new design .

Jan 1, 1948