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By B. R. Mohal, F. F. Aplan, S. Chander

"ABSTRACTThe wetting behavior of coal has been determined in the presence of nonyl and octyl series of nonionic surfactants containing polyethoxy groups of different sizes. The wetting behavior was determined by a modified Walker technique and contact angle measurements. The results show that the wetting rate of coal varies with coal rank, structure of the hydrocarbon chain and number of ethoxy groups in the hydrophilic group of the surfactant. A close relationship has been observed between the wetting rates and the short-time advancing contact angles.INTRODUCTIONNonionic surfactants are used in many applications to improve wettability of solids. They can be used as dispersing agents [ 1 ] or dust suppressants [ 2-5 ] and to control the flotation, flocculation, filtration and flowability of particulates. This study was undertaken to study the effect of a series of nonionic surfactants on the wetting behavior of coal. Two series of surfactants, namely, ethoxylated nonyl and octyl phenols were used. The nonyl phenol series contains a linear hydrocarbon chain containing nine carbon atoms ( CH3( CH2 )8-C6H4,- ( OC2H, ) n, where n is the number of ethoxy groups) . The octyl phenol series contains a branched hydrocarbon chain containing eight carbon atoms ( ( CH3 ) 3CCH2C ( CH3)2-C6H4- ( OC2H4) n ).Initial wetting rates — modified Walker techniqueWalker et al. [ 6 ] developed a sink test to determine the wettability of coal particles. In this technique, coal particles are dropped individually onto the surface of surfactant solutions of different concentrations, and the most dilute concentration in which coal would sink ""instantaneously"" is determined. This technique is a variation of a procedure initially developed by Draves and Clarkson [ 7 to determine the effect of surfactants on wettability of cotton fibers. In this procedure commonly known as the Draves test, the concentration of a surfactant required to give a 'sink time' of 25 s is determined.Other investigators have used slight variations of the Walker method to study the wetting of fine particles [ 8-12 ] , by measuring the time for wetting a given amount of powder. There are differences in the manner in which the time of wetting is measured, however. Some investigators measure the time for the last trace of coal to disappear [ 8,11 ] whereas others determine the time for the vast majority of particles to sink [ 10 ] . Some investigators report a wetting rate [ 11 ] which is a value calculated on the basis of the time for the 'last traces of particles to sink'. The differences in choice of criterion for wetting can result in different values for wetting rates as illustrated in Fig. 1 which is based upon our measurements of the amount of powder wetted as a function of time. The procedure for wetting rate measurements is described in the next section. The technique in which time for disappearance of the 'last traces of particles' is determined gives the smallest value for the wetting rate, while the technique in which the time for wetting of the 'vast majority' of particles is determined will give intermediate rates. The terms 'last traces of particles' and 'vast majority of particles' are usually not defined explicitly and can lead to large differences in wetting rates measured by different investigators. Since our measurements show that the wetting rates for an assembly of powder decreases with time, we have used the initial wetting rates to compare the wetting behavior of coal in solutions of different surfactants."

Mar 1, 1989

By J. O. Lewis

"The significant facts in the problem of the relation between the production of crude petroleum, and the ever-increasing demand for petroleum products are that in spite of continually increasing production, improvements in methods of refining and utilization, and heavy increases in imports, demands grow still more rapidly and we seem always faced with a shortage at hand or lust ahead. On the other hand, our foremost authorities warn um of entirely inadequate domestic reserves. Looking abroad we find some large fields and many of speculative promise, 'tut the situation is complicated by international relations and demands by other countries which promise to be even more insistent than oars. This is the situation, then. We can not rely upon our own Crude Petroleum to meet the Ever Increasing Demand for Petroleum Products.I wish to follow this somewhat alarming statement by saying at once that the Bureau of Mines is not pessimistic in facing this situation. To my mind those who discuss the oil situation may be placed in three categories; the pessimists, the optimists, and the super-optimists. The pessimists I call those who see darkly and will concede no possibility of solution. According to them a few years will see the automobiles piled in windrows of 'dilapidated junk, I have no sympathy with this point of view and deem it vicious and entirely unwarranted.The optimists I term those who believe that there is a solution and that we shall be able to meet all of our reasonable requirements for as far into the future as can be foreseen, yet who recognizes that this desired end can not be attained without prevision and energetic effort.The super-optimists are those who will say to you, ""There is nothing to this talk of shortage, whenever we have needed oil we have always found it and always will."" To these gentlemen the possibility of an inadequate supply of oil is as incomprehensible as the possibility of the extinction of the passenger pigeon was to the early settlers who saw flocks that hid the sun for days during their passage. The passenger pigeon disappeared within two generations thereafter, and I deem this point of view as being perhaps more vicious than that of the extreme pessimist. It seems to me it is nothing less than improvidence lulling us into a false sense of security. There is an old proverb to the effect that ""The Lord helps him who helps himself."" I believe that we shall solve the oil problem, but I do not think it will be solved by vague optimism. It is going to call for our most energetic efforts and I believe we shall have to do a lot of ""helping ourselves."""

Oct 1, 1920

By G. E. McElroy

"The development of certain mines in the East Tintic mining district, Utah, has been hindered considerably by the presence in the rock strata of heavy irrespirable gases which at times flood the lowest working places, as well as by abnormally high rock temperatures in the lower horizons. A study of these features was completed in the spring of this year, and the information obtained is summarized here.Heavy gases.Only four mines have been affected to date by the presence of heavy gas, and only one of these is producing lead-silver ores in quantity. These four embrace a territory extending about three miles north and south and about two miles east and west, while both within and fringing on this territory are a number of prospects which have not been affected.Thus far no fatalities have resulted from gas inflows, but a number of men have been temporarily overcome, and a few have had narrow escapes from death by suffocation. That the record is not more serious is mainly due to the fact that the gas inflow, as a rule, is relatively slow, mining operations have been quite carefully conducted, and the presence and extent of a gas inflow can be easily determined by its extinguishing action on the flame of miners' lights.When first encountered, about 1910, gas inflows occasioned much lost time. In some months the lost time averaged as much as ten days, while one mine cites for a certain month a maximum of 26 days lost out of a possible 28 working days. With improvements in mechanical ventilation and the passing of time, interference with work from the presence of gas has gradually lessened. During the last few winters, the main trouble has been with the mines being flooded with gas overnight when fans were not operated, although men have been driven out of the lowest development openings several times each winter with fans operating. At present, the main danger is in the lowest development openings having only one exit, wherein men might be trapped and possibly suffocated during an unusual and extremely rapid inflow of gas, or during an ordinary inflow, should the one source of power for the fan be disabled."

Aug 1, 1921

By Albert E. Long

Since December 10, 1945, the Mount Weather Branch, Mining Division, Bureau of Mines, has been maintaining detailed performance and cost records on the diamond coring bits used throughout the United States by the Bureau of Mince. Figure 1 is a copy of a typical master record sheet showing the scope and type of information recorded for each bit. It is the intention of the Bureau of Mines to issue analytical reports covering the effects of diamond size and quality on the cost of core drilling in different rocks as the information on a significant number of bits used in any one type of rock is accumulated. This report is the first of such a proposed series and is based on the diamond loss and bit costs incurred in the use of 539 AX bits in coring operations on 10 different projects involving 6,097 feet of drilling in gneiss. The 10 projects were located in New York, Pennsylvania, and New Jersey (fig. 2). As a result of the information accumulated on the use of diamond-coring bits in drilling in gneiss, it has been found that the type of bit, the matrix, the percent of core recovered, and the size and quality of diamonds used have a definite effect on the cost of bits per foot drilled.

Jan 1, 1950

By Jr. Watts, B. K. Cantrell, D. H. Carlson, K. L. Rubow

"The use of diesel equipment in underground coal mines is controversial because ""whole diesel exhaust"" is regarded as ""a potential occupational carcinogen"" by the National Institute for Occupational Safety and Health (NIOSH). Threshold limit values (TLVs) are recommended for the gaseous pollutants; CO, CO2, NO, NO2, SO2, and some hydrocarbons emitted in diesel exhaust. There is, however, no TLV recommended for diesel exhaust aerosols (DEA) nor is there a standard method for sampling these aerosols.The University of Minnesota and the Bureau of Mines have collaborated to develop a personal diesel exhaust aerosol sampler (PDEAS) which utilizes size selective, inertial impaction and gravimetric analysis. During the field tests of this sampler, numerous air quality measurements were conducted in underground coal mines using diesel equipment. The objective of this report is to present these data and to assess the impact of diesel face haulage equipment on mine air quality.Air quality data were collected in four underground coal mines using continuous mining methods with diesel haulage equipment. Daily samples were collected at the section intake, haulageway, and on haulage vehicles. Both full-and partial-shift samples were collected using a variety of aerosol instruments, including the PDEAS and the micro-orifice, uniform deposit impactor (MOUDI) which sample the mine aerosol diesel exhaust fraction. Two of the mines were also monitored for the major gaseous constituents found in diesel exhaust CO, CO2, NO, NO2, and SO2. These measurements were made by either collecting bag samples for subsequent gas analysis or by Palmes dosimeters.The concentrations of CO, CO2, NO, NO2, and SO2, were well below regulated levels. The mine average DEA concentration determined by the PDEAS in the haulageway for the three mines surveyed using this instrument was 0.79 mg/m3, with a standard deviation of 0.19 mg/m3. DEA contributed 65% of the respirable aerosol, at this location. These results were the same as the mean DEA concentrations calculated from size distribution measurements obtained using the MOUDI. This was 0.78 mg/m3, with a standard deviation of 0.22 mg/m3."

Mar 1, 1992

By O. C. Blade

"INTRODUCTION This report on the properties of aviation gasolines and aviation jet fuels produced in the United States during 1952 was mode under a co¬operative agreement between the American Petroleum Institute and the Bureau of Mines of the United States Department of the Interior.Analytical data are presented for 94 samples of aviation gasoline which include for the first time in this series of reports, data on five samples of grade 108/135 aviation fuel. Data also are given for 34 samples of aviation jet fuel. The analyses were made on samples typical of the manufacturers' production in their laboratories and the results sub¬mitted to the Bureau of Mines for compilation. The products of 20 manufacturers of aviation gasolines and of 16 producers of aviation jet fuels are represented.SUMMARYA comparison of certain properties of the commercial aviation gasolines produced in the United States during 1950, 1951, and 1952 is presented in table 1, the 1952 data being average values from tables 3 through 7 of the present report. Trends in certain characteristics of these fuels may be seen in figures 1 through 5 which also indicate the minimum and maximum values. As may be observed, the properties of commercial aviation gasolines have not varied greatly during recent years. A list of aviation-fuel survey reports published by the Bureau of Mines is given on page 7.Table 2 presents a summary of data from table 8 and compares properties of aviation jet fuels of 1952 with summarized data on jet fuels of October 1951."

May 1, 1953

By Robert W. Freedman, Robert L. Craft, William G. Humphrey

As part of a continuing effort to reduce the weight and bulk of equipment that mining personnel must carry underground, the Bureau of Mines and the Mining Enforcement and Safety Administration (MESA) investigated accurate and convenient gas samplers for use by mine inspectors in sampling mine atmospheres. The samplers are septum-stoppered glass vials commonly used for routine blood sampling. These lightweight, compact samplers yield results comparable with those obtained with conventional bottle samplers of 250-ml nominal capacity.

Jan 1, 1975

By J. W. Eckerd, W. S. Sanner, P. L. Woolf, R. E. McKeever

The Bureau of Mines experimental blast furnace was operated successfully with anthracite metallurgical briquets . Tuyère pressures were higher and more erratic than for operations using coke , and furnace " hangs " occurred more frequently . Higher hot - blast temperatures were required to maintain the quality of the metal . By using higher hot blast temperatures , the fuel and production rates and slag volumes were comparable to those obtained for all - coke operation . The anthracite metallurgical briquets exhibited excellent mechanical strength and descended through the shaft of the furnace with little breakage or reduction in size .

Jan 1, 1964

By Boyd Guthtrie

[Methods of distilling topped crude oils and distillates under vacuum, accompanied by good fractionation, have taken a place of major importance in the refining industry. In the refining of petroleum products it is generally desirable to produce a distillate of good quality, and this objective is attained by fractionation of a high degree. The laboratory and commercial practice have proved chat by varying the amount of fractionation the quality of the distillate car be changed, and refiners are cognizant of the advantages of good fractionation. Distillation-under high vacuum, however, is a relatively new practice in petroleum refining, and only during the last few years has there boon an indication that that this method ray become a general practice in the industry. Vacuum distillation offers many advantages over older methods of distilling petroleum products. Vacuum combined with steam distillation, for example, is replacing straight-stream distillation because the quality of the products of vacuum and, steam distillation surpasses that of those produced by straight-steam distillation. Although the injection of varying amounts of steam in a vacuum unit is common practice, the amount of steam used is becoming less as the vacuum within the unit is increased. This report describes tie construction of a visible-action laboratory batch still and fractioning; column and. gives curtain data pertaining to the operation of the apparatus under vacuum for the production. of lubricating distillates. The apparatus was designed and built to produce lubricating distillates under as nearly ideal conditions as possible, in order that a subsequent study of the characteristics of the distillates could be made.]

Jan 1, 1932

By Thomas E. Popplewell

This paper is one of a series being prepared for and published by the United States Bureau of Mines describing the mining and treatment methods and costs obtained in sand and gravel plants throughout the United States. These papers are designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total costs. It is recognized that publication of total costs might in many instances cause embarrassment to individual operators as well as to the industry as a whole. On the other hand operating costs are essential to the technical discussion and study of the methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulations shall ensue.

Jan 1, 1932

Case 1: A driller-helper was pulling a winch cable toward a stack of drill steel when the cable contacted a 12,000-volt power line. The helper was killed, and the driller at the rig controls was severely injured. [ ] Case 2: A crew was preparing to remove a pump from a well when the hoist boom contacted a 4160-volt power line. The hoist operator was electrocuted. [ ]

Jan 1, 2005

Coal miners, especially roof bolter and continuous miner operators, work in a hazardous underground environment where they are often exposed to poor roof conditions. Nearly 500 rock fall injuries are reported each year, and 99% of them are caused by rocks falling from between the roof bolts. These loose rocks that injure miners are usually just a few inches thick, but on average weigh 280 pounds. NIOSH has found that most rock fall injuries can be prevented by installing roof screen during the bolting cycle. Roof screen is a sheet made of steel wires in a grid pattern. When screen is bolted up against the mine roof, it provides far more coverage than any common surface control used in the mines today. Because more mine roof is covered, there is less chance that a rock will fall and injure a miner. The facts about roof screen are shown in the new NIOSH video entitled “Make It Safer With Roof Screen.” Using extensive underground footage, the 7-minute video shows how well screen keeps loose rock from falling in difficult roof conditions. Techniques for installing screen from both outside-controlled and walk-thru roof bolting machines are shown. The video also provides safe handling tips, best practices, and information about machine technology that can greatly improve material handling. Throughout the video, a coal mine safety manager and a shift foreman talk about the tremendous difference that roof screen has made at their mines. An instructional booklet supplements the video with additional information. It presents compelling data from mines that have practically eliminated rock fall injuries with a roof screening program. Other sections of the booklet discuss in greater detail roof screen installation, tips for manual screen handling, a material handling system for roof screen, and use of the personal bolter screen, which can be easily handled by one person. Screen specification and custom ordering are described, including the sizes of screen, grid sizes, reinforcing (indicator) wires, edge cut options, and screen strength. A list of additional sources of information is also provided. Nearly every mine eventually encounters poor roof. Screen is one of the most powerful control techniques available. This new video will help make mine managers aware of screen, and it can help them in developing a roof screen installation program. It also serves as an information source and teaching tool for safety managers and trainers. The video can easily be integrated into new miner training programs or annual refresher training.

Mar 1, 2005

By Pedro Lilienfeld

The objective of this program was the development, design, and fabrication of six personal-sized completely self-contained dust monitors capable of real-time as well as time-averaged monitoring of the concentration of respirable particles in coal mines, in the range of 0.1 to 100 mg/m3. The operation of these monitors is based on light scattering and passive air sampling. The design stressed overall miniaturization, ruggedness, simplicity and versatility. These instruments incorporate a single-chip CMOS microprocessor to perform all signal processing, data display and storage, and timing functions. The overall dimensions of these devices are, approximately, 10 by 10 by 5 cm.

Jan 1, 1982

By J. A. Rowland

Magnesium alloys containing nickel, nickel and manganese, lithium, lithium and manganese, and lithium and aluminum were investigated. Melting, casting, and mechanical working techniques and the heat treatment of various compositions were studied. Amenability to cold and hot working was shown for many compositions. The magnesium-nickel and magnesium-nickel-manganese alloys failed to develop superior mechanical properties and were very low in resistance to corrosion. The magnesium-lithium series, although entirely plastic, had low strength properties. The addition of small amounts of aluminum to the Mg-Li base did not affect greatly either the ductility or the strength; further additions developed increased strength, but only at room temperature, and the alloys became brittle with age. Continued study, concentrating on the ductile lithium-rich beta phase as a base composition for ternary and quaternary systems, is recommended.

Jan 1, 1956

By Larry D. Nichols

Poroplastic membranes containing ion exchange liquids were studied for separating cobalt from nickel-containing solutions similar to ammoniacal laterite leaches. The driving force for cobalt transport was differences in pH and composition between the leach and extraction streams. Using a diketone ion exchange liquid, a leach pH of 6.5 to 7.0, and a strip pH of 2.3, cobalt was extracted from a 750 ppm solution containing 2500 ppm of nickel at rates ranging from 1 to 10 µg/cm2 .min in single membrane cells, and from 10 to 100 in more closely spaced multiple membrane cells. Rates were variable, with evidence that cross -membrane flow pasterns were a key factor; a reproducible rate of 30 pg/cm .min would be economically viable. Loss of transport observed after several days of continuous operation was restored by flushing membranes with fresh ion exchange liquid. A major effort was devoted to preparation of thin, leak-free membranes; the resulting membranes endured operating conditions without mechanical failure.

Jan 1, 1982

By K. O. Bennington

The thermodynamic properties of aegirine, of composition [(Na0.869Fe30+7362 Fe20+16Mn0.03Ca0.1121)(A10.141Sil 9738)(06)], were experimentally determined at the Bureau of Mines as part of its efforts to advance minerals technology. The standard enthalpy of formation determined by hydrofluoric acid solution calorimetry is AHf298 = -641.12±0.73 kcal/mol. The standard enthalpy of formation from the oxides is AH298 = -37.136±0.509 kcal/mol. Low-temperature heat capacities were determined by adiabatic calorimetry from 19.1 to 304.6 K. The derived standard entropy is S298 = 38.03±0.14 cal/mol?K. The heat capacity was measured over the range 348 to 1,198 K by differential scanning calorimetry. These experimentally determined data were combined with data from the litera¬ture to calculate the Gibbs energies of formation and equilibrium constants of form¬ation over the temperature range of the measurements. Standard enthalpies of forma¬tion are given as functions of temperature. The standard Gibbs energy of formation at 298.15 K is AGf298 = -600.36 kcal/mol.

Jan 1, 1984

By E. C. Lane

Although motor gasoline marketed in the United States in January of this year was, on the average, slightly more volatile than that sold in January 1925, the improvement in quality is too small to be of importance. In other words, there is no evidence that any radical change in the quality of gasoline is being made at the present time. During the past six years the Bureau of Mines has made semi-annual surveys of the gasoline marketed in the United States, the survey just completed being the thirteenth in the series. The cities in which samples have been collected have been chosen as representative of the more important marketing territories as it is obviously impracticable to obtain a sample of every gasoline sold in the entire country.

Jan 1, 1926

By Michael J. Klishis

It was the goal of this project to develop training materials specific to two areas of the mining industry: (1) safe use and care of the self-contained self-rescuers, and (2) awareness and avoidance of electrical hazards. This report describes the development of the following training material: Instructor's modules for the OCENCO EBA 6.5, CSE AU-9A1, and PASS 700E self-contained self-rescuers; and a textbook, slide tapes, and accident case study scenarios for mine electricity, and a computer based instructional package on mine electricity and electrical hazards. The report concludes that additional efforts are needed in mine training and four recommendations are made: (a) tailor existing materials to fit specific mine sites, (b) develop and evaluate computer based instructional material, (c) develop parallel training materials for metal and non-metal mines and, (d) develop additional training materials for preparation plants and surface areas of underground mines.

Jan 1, 1985

By Paul T. Allsman

This paper describes metal- mining practices at the Harrington -Hickory lead - silver - zinc mine at Milford , Beaver County , Utah . The operations of the Harrington-Hickory incorporate a number of features that should prove of interest and value to other operators of small mines . These features include employee participation in profits , a well- laid -out electrical system, adequate financing , a well - balanced equipment and supply inventory , a well - organized system of bookkeeping , adequate roads , and good management . As crude ore is shipped directly to smelters and mills in the Salt Lake Valley , close attention is paid to see that the ore is segregated by classes and treated where it can bring the greatest not return . A combination of these features has resulted in maintaining relatively low costs, considering the grade and size of ore shoots at a time , during and following the war , when equipment , supplies , and labor were costly and difficult to obtain . The period covered in this report includes two war years and two years following , from April 1, 1944 to June 30 , 1947 .

Apr 1, 1949

By Foster Fraas

The Bureau of Mines investigated a method for calculating values of adsorption energy; the goal was to devise an equation consistent with experimental data accumulated in the investigation of adsorption as related to ore separation processes. Numerical identification of the constants of a previously formulated equation provided an equation by which values of adsorption energy could be calculated. Values thus calculated checked with those obtained by calorimetric measurement.

Jan 1, 1965