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By Arthur E. Wells

"The present and possible future commercial production of potash from various sources in the United Status is discussed below under the following heads:1. Potash from the saline lakes.(a) Nebraska lakes.(b) California lakes.(c) Other lakes.2. Potash as by-product from the cement kilns.3. Potash as by-product from the iron blast furnace.4. Potash from silicate rocks.(a) Feldspathic material.(b) Leucite rocks of Wyoming..(c) Sericite slates of Georgia.(d) Glauconite (greensand) of New Jersey.5. Potash from Alunite.6. Potash from organic sources other than kelp.7. Potash from kelp.In this discussion very little more than passing reference, if any, will be given to those projects which up to date have been developed only slightly, if at all, beyond the small scale laboratory stage, or for the development of which there appears to be very little financial and technical backing at the present time. Nether or not many of these proposed projects have merit can be determined only by an actual operating demonstration.Generally speaking, the potash industry of the United States has been hardly more than marking time since the armistice. This is, largely due to the fact that the consumers of potash have been expecting that heavy shipments of foreign potash to the United States would be resumed soon at somewhere near the pre-war prices, and they have not seen owing domestic potash at present prices for many months. The result has been that domestic producers have been unable to sell their product at even cost and many producers of potash have been obliged to close down. Thu Nebraska lake plants were closed down in February. The California saline plants were operating at below capacity, and the only large alunite plant is closed down. Even the cement plants have little or no inducements to recover the potash being lost in their waste gases and the production is very small at present.This condition will doubtless continue until a definite policy is decided upon as to the future importation of potash salts from Germany and. France. If unrestricted importation is allowed at prices even 50% greater than in 1913, only a very few, if any, of the domestic projects will be in position to compete with the foreign potash immediately, and the present industry will probably greatly decline with little or no prospect for a future resumption of the industry."

Aug 1, 1919

Objective: On-the-job training (OJT) is a common means of training workers. By definition, it seems relatively simple. However, to be effective, training must go beyond the simple process of following an experienced worker around the workplace— sometimes called the "follow Joe" method. NIOSH researchers spoke with human resources personnel, safety and health specialists, supervisors, experienced miners, and new miners and found that OJT was of high interest, but was rarely part of a formal or standardized program. Various training methods have evolved to ensure that a trainee will absorb the information presented rather than simply emulate what the instructor is teaching. These methods have been brought together into a published guide for developing an effective formalized OJT program. The guide (Information Circular (IC) 9479) is called "Coaching Skills for On-the-Job Trainers." It contains materials and suggestions for your company or mine to conduct a 1-day workshop for teaching OJT trainers how to be better coaches to less experienced workers. The guide was created by the NIOSH Pittsburgh Research Laboratory and a safety professional from a private mining company.

Feb 1, 2006

The coal-bearing regions of Colorado cover approximately 29,600 square miles, which is 28.4 percent of the state's total area. The most important coal-bearing regions are located in the north western and west-central parts of Colorado. Coal resources vary from lignite to anthracite. More than 70 percent are bituminous; 23 percent subbituminous; 5 percent lignite; and less than 1 percent anthracite. The state's coal reserves total about 17.2 billion tons, 3.5 percent of national reserves. Approximately 8.8 million acres of coal rights in the state are owned by the Federal Government; on about 72percent of this land, the Federal Government controls both the coal and the surface rights. It is estimated that approximately 4.2 billion tons of coal reserves are under federal ownership in Colorado. Permitted acreage of mines in Colorado ranges from 40 to 13,114 acres. Differences in elevation create many climatic zones in Colorado. Local annual precipitation can average less than eight inches in some areas in extreme western Colorado to more than 30 inches in certain mountainous areas. Generally, precipitation rates are low at most mine sites, making revegetation difficult. Colorado gained primacy when its regulatory program was conditionally approved December 15,1980. The Abandoned Mine Land Program was approved June 11, 1982.

Jan 1, 1992

By David White

This paper is the result of a comparative study of ultimate coal analyses made and published by the United States Geological Survey. This study, at first casually undertaken to devise an acceptable classification of coals based on chemical analyses, was continued in connection with a microscopic examination of a number of the coals. The initial comparisons, made from a relatively small number of analyses, not only confirmed a previous conviction that the elimina- tion of oxygen incident to the development of a coal is economically far more important than has been generally suspected, but also showed that oxygen is very nearly as harmful as ash in coal. The immediate purposes of the present study were: (a) To deter- mine more definitely, from a comparative examination of a large number of ultimate analyses, the relative importance of oxygen as an impurity in various coals; (b) to illustrate the transition between various grades of coal of similar origin-transition mainly due to progressive devolatilization, brought about more or less directly by dynamic influences; (c) to ascertain the relative proportions of oxygen, hydrogen, and carbon in coking coals, especially with refer- ence to a theory tentatively framed to explain the coking quality; and (d) to forecast the probabilities of successfully treating a large number of coals so as to render them amenable, in a softened condition, to satisfactory study under the microscope. Although the hypothesis as to coking quality finds but partial support in the chemical analyses, its consideration has led to a method of predicting from an analysis with a fair degree of certainty whether any given coal will coke by the ordinary process. The unbroken transition between coals originally similar but now classed in widely different groups, whether of the same age or of different ages, as a result of dynamochemical action, appears demonstrated by the analyses as well as by field observation. This subject will not be

Jan 1, 1911

By D. Harrington

Every few weeks United States newspapers of 25 or 30 years age ran scare-heads telling of some mine disaster, which was a first-page attraction for a day or two and then was forgotton until another disaster occurred a few weeks later. Interspersed with these disasters were the so-called sniping mine accidents, causing the death of one or two mine workers. The summation of all types of mine fatalities usually exceeded 3,000 a year. In the period 1906-10, inclusive, there wore 84 major explosion disasters (or about 17 per year) in united States coal mines; the fatalities resulting from those disasters numbered 2,388 for the 5-year period. These frightful catastrophies helped to cause the total number of fatalities in our coal mines for the 5 years (including the fatalities from major explosions) to reach the enormous total of 13,288, an average of 2,658 per year. In addition, some hundreds of other typos of mining accidents swelled the annual fatality list to upwards of 3,000. This admittedly deplorable condition created so much Nation-wide comment that Congress was impressed with the necessity of having something done by the Federal Government with a view to trying to halt at least sonic of the excessive loss of life in our mines; in consequence, the Bureau of Mines was created and began to function in July 1910.

Jan 1, 1935

By W. A. Grosh

Records show that much of the lead produced in the Upper Mississippi Valley lead-zinc field was taken from natural openings along crevice systems at shallow horizons or at the surface. During the early history of the district, the shallow deposits were worked intensively; but in recent years the production of lead, except as a byproduct of deeper mining for zinc ores, has not been significant. Considering the methods of early mining, the character of mineralization, and the fact that galena can still be found on the surface of the old digging areas, it was reasoned that enough mineralization might remain on and above bedrock to permit, through the use of modern equipment and methods, economical re-treatment of surface material in the digging areas.

Jan 1, 1960

By J. W. Miller

An investigation was begun by the Bureau of Mines in 1948 to determine the preparation characteristics of American coals. Results of the investigation were planned to be reported on a county basis and, from the data developed, to determine: (a) Which coals, either as mined or after beneficiation by conventional preparation, are suitable chemically under present standards for producing metallurgical coke. (b) Which coals require special and more intensive treatment in preparation than is now practiced. (c) Which coals cannot be considered potential sources of metallurgical coke, regardless of preparation. This report is one in a county series and describes the preparation characteristics of the coals of Logan County, W. Va. According to present-day standards for metallurgical coal, many believe that the sulfur content of the coal should not exceed 1.25 percent? Coal with more than this amount has been used for making metallurgical coke, especially when blended with coal containing less sulfur. In this series of reports 1.25 percent sulfur is used as a gage to determine whether or not a coal will be suited for metallurgical coke.

Jan 1, 1957

By Sally A. Shoop

Thirty-seven blasts have been monitored using either three or four seismographs, at four coal strip mines and at a limestone quarry. Statistical analysis of the data shows that square-root, cube-root, and site-specific scaling methods predict peak particle velocities with about the same (low) degree of reliability. Some mines have peak particle velocities that are significantly lower or higher than the U.S. Bureau of Mines averages (Siskind et al., 1980). This suggests that the option provided by the proposed regulations (Office of Surface Mining, 1983), to adjust blast designs based on site-specific measurements could be highly beneficial both to operators and to the public. The frequency spectra reveal that the predominant frequencies were generally less than 50 Hz but several blasts had a significant amount of energy up to 125 Hz. In some cases the vibration energy was concentrated at frequencies corresponding to the delay intervals.

Jan 1, 1983

By R. G. Burdick

The problems presented by old mine workings affect both present day mining and land development. An automated method of locating these old mines from the surface using electrical resistivity techniques was de-veloped earlier under a Bureau of Mines contract. Subsequent Bureau research has refined the techniques and expanded the area of study to a variety of geologic provinces. During this research, six mining areas in the United States were in-vestigated with the Bureau's automated resistivity method. This report describes the mining areas involved and the results of the resistivity investigations, which showed a high rate of success in detecting old mines. It also describes the field measurement techniques and data analysis procedures.

Jan 1, 1986

By J. A. Markovits

Coal has been hydrogenated in Germany on a lather extensive scale for the past 20 years, but the process is new to the United States. Although pressures up to 15,000 pounds per square inch have been employed on commercial scale in the synthesis of anhydrous ammonia, and there is evidence that valves, tubing, and equipment have been developed recently up to 30,000 p.s.i. working pressure at moderately elevated temperatures for limited industrial production of plastics, such pressure ranges are unusual in American industry, and equipment designed for them is not commonly available. In the Coal Hydrogenation Demonstration Plant at Louisiana, Mo., 10,000 p.s.i. operating pressures are combined with temperatures up to 1,000° F., and the materials to be processed under these conditions range from gases to mixtures of viscous liquids containing high percentages of abrasive solid particles. These service conditions presented unusual engineering problems requiring thorough investigation, Limited financial resources arid rigid time schedules inherent in the synthetic liquid fuels act often forced decisions before the best answer to a problem could be developed. Sometimes the ideal technical solution proved to be beyond the financial limitations of the demonstration-plant program.

Jan 1, 1949

By Raymond B. Ladoo

In order to obtain comprehensive and authentic information on fluorspar mining in the western States , the writer, together with and at the request of representatives of some of the largest fluorspar producers of the Illinois - Kentucky district , spent the month of April , 1922 , in examining all we stem fluorspar deposits ( of which record was available ) believed to be of possible commercial importance .

May 1, 1923

By John W. Nebgen

This report contains findings from a U.S. Bureau of Mines study concerning the inhibition of acid mine drainage formation from underground coal mines. A series of experiments was performed in which three different pyritic materials (wastes from coal production plants) were evaluated using several candidate inhibiting agents. Data obtained from the inhibitor-treated pyrites were compared with data from control experiments in which untreated pyritic wastes were used. The experiments were conducted by placing treated and untreated pyrite in columns, passing moist air through the columns to promote oxidation of pyrite, and washing the columns weekly to collect oxidation products for analysis. Experimental results indicate that quantities of acid mine drainage can be substantially reduced if soluble iron III (ferric) ion is controlled. The best inhibitors are neutral or alkaline siliceous materials such as fly ash, blast furnace slag, portland cement, and cement kiln dust. These materials appear to insolubilize iron III species to make them unavailable for reaction with pyrite. The data strongly suggest that the soluble ferric ion aqueous is a key oxidant for pyrite to produce acid mine drainage. The role of aqueous ferric ion as an oxidizing agent is substantiated further by data obtained using metallic iron (nails) as an inhibitor. The iron nails tended to keep the soluble iron in the iron 11 (ferrous) state. Experimental results indicate that sulfate and acidity levels are reduced when pyrite is in contact with the metallic iron.

Jan 1, 1979

The following is a Maintainability Design Checklist for coal mining equipment. The purpose of the checklist is to provide a summary of design review points for the maintainability assessment of new or existing underground equipment. It specifically focuses on the identification of equipment design features, tasks, or procedures that impact equipment downtime, repair costs, labor hours and maintainer skill level requirements. Some checklist points are general in nature. The checklist was designed to be used across all categories of underground equipment. The intent is to draw attention to design features and maintenance procedures that will increase maintainability requirements. You are encouraged to adapt this checklist to site specific or machine specific requirements by: Inserting specific performance criteria for various categories of maintenance tasks. For example; all hydraulic lines on a shuttle car should be replaceable in 15 minutes or 25 minutes, etc. Adding or deleting checklist items for different categories of equipment. You would include environmental control equipment, for example, on face equipment and not on shuttle cars or man trips. Adding additional checklist items based on site or equipment specific maintenance histories or experience, company maintenance standards, or other factors.

Jan 1, 2000

By Vernon C. Davis

"SUMMARY AND CONCLUSIONSIn initial attempts to mine taconite by conventional open-pit methods, the material tended to break into tabular blocks that were too large to be handled by conventional shovel dippers and were unsatisfactory in an ordinary crusher feed. A great amount of secondary blasting was necessary, which added considerably to the cost of mining.The Bureau of Mines and others are engaged in studies designed to contribute to the solution of taconite-mining problems. These studies concern problems related to drilling techniques and patterns, types and methods of use of explosives, and other factors relative to effecting maximum fragmentation at minimum cost.This report is concerned with study of the application of shaped charges in drill holes, the effectiveness of shaped charges as compared to capped charges in secondary blasting, and the merits of different drilling patterns and methods of detonation of conventional-explosive charges.Fragmentation of taconite at or near the surface is controlled or strongly influenced by joint and bedding planes. Since all tests in this study were made in a jointed and bedded area, a definite conclusion as to the relative effect of a shaped charge in a drill hole, as compared to a conventional charge at greater depths and tighter ground, is precluded. However, application of shaped charges in primary blasting of taconite appears to be of no advantage.In secondary blasting of taconite, conventional, capped charges produced better breakage than shaped charges of the designs tested.Based on the results of conventional blasting practice in horizontal-, inclined-, and vertical-hole tests, no better fragmentation is obtained from blasting either horizontal or inclined holes, compared to vertical holes.Holes drilled in staggered parallel rows that intersect both series of joint planes at the greatest possible angle, give maximum breakage compared to rows parallel to one of the series of joint planes.Methods of detonation made little difference in breakage; but the millidelay caps produced the best conditions for moving the broken rocks."

Jun 1, 1953

By F. G. Schwartz

This circular presents the results of a survey of research on jet fuel thermal stability jointly sponsored by the National Petroleum Refiners Association (NPRA), Tulsa, Okla., and the Bureau of Mines. The development of supersonic planes has led to many problems that did not exist in the operation of subsonic aircraft. One of the most important of these is rapid deterioration of the fuel at the high temperatures to which it is subjected. At higher speeds, aerodynamic heating of the airframe imposes severe thermal problems, and conventional techniques of rejecting the heat to the atmosphere become impractical. The fuel is the only material present in sufficient bulk to be used as a heat sink. Thus, the fuel is subjected to aerodynamic heating and also is used to dissipate heat from lubricating oil, hydraulic fluid, electronic equipment, wheel wells, and cabin air. Consequently, the fuels may have to withstand both moderate temperatures for sustained periods in the fuel tanks and higher temperatures for brief periods during transfer from the tanks to the combustion chamber. Because of high temperatures, insoluble residue or gum may form in the fuel and contribute to heat exchanger fouling and to clogging of the fuel manifolds, nozzles, control systems, and other components of the fuel system.

Jan 1, 1962

By H. S. Auvil

[The shrinkage of coke after formation is one of the variables that affects the net expansion of the change in both industrial and test ovens. Various test results have been interpreted as indicating that cokes from certain coals shrink to a marked extent and that other cokes show very little shrinkage; out no comprehensive experimental study of the shrinkage of coke after its formation and of the factors influencing this shrinkage has come to the attention of the authors. While investigating the reactivity of cokes made by the BM-AGA method,6/ Reynolds7/ found that granular low-temperature cokes shrink considerably then reheated to higher temperatures. This shrinkage was large enough to influence the behavior of the charge (net expansion or contraction) in a coke oven to a marked extent. Since that time the Bureau of nines has investigated the shrinkage of coke different methods, all of thick had one common objective - the elimination of the effect of other factors, such as swelling in the plastic range, which could either partly or completely mask the shrinkage of the coke. Only parts of these studies have been published8/9/ in abbreviated form in]

Jan 1, 1940

By Forrest T. Moyer

All general measures of the safety record of the coal mining industry worsened appreciably in 1970. Injury experience for the year was 260 fatal and 11,552 nonfatal injuries at respective frequency rates of 1.00 and 44.40 per million man-hours of worktime. The fatality total was 57 higher and the rate of occurrence was 18 percent higher than the corresponding figures of 203 fatal injuries with a frequency rate of 0.85 in 1969. The worsened fatality record in 1970 resulted primarily from a major disaster (a single accident which results in the death of five men or more) on December 30, 1970, that killed 38 men. There were no major disasters in 1969. The total of 11,552 nonfatal injuries in 1970 was the highest annual total since 1960. It was 1,635 higher and the frequency rate was 6 percent higher than the corresponding totals for 1969 of 9,917 nonfatal injuries occurring at a rate of 41.76. The injury severity rate of 8,308 days lost or charged per million man-hours was 13 percent worse than that of 7,359 in 1969. Similarly, the average severity of 183 days lost or charged per injury in 1970 was 10 days or 6 percent higher than in 1969. Aggregate worktime of 260.2 million man-hours and production of 609.8 million tons in 1970 were, respectively, 10 and 7 percent higher than in 1969. An average of 144,480 men were at work on an average of 227 active days in 6,316 mines and 544 mechanical cleaning plants during 1970.

Jan 1, 1973

By Steven E. Mischler, Jon C. Volkwein

A diesel particulate matter analyzer capable of direct, real-time measurement of engine exhaust particulate is necessary to effectively institute source control technology currently being used on diesel equipment and to ensure that the control measures are working. To investigate the potential of a differential pressure monitor to measure diesel particulate matter in undiluted exhaust, samples were collected from three different diesel engines-Kubota, Isuzu, and Deutz-running under 12 different RPM and load scenarios. These measurements were compared to elemental carbon concentrations in the sampled exhaust as determined by using the NIOSH 5040 analytical method. Elemental carbon is used as a surrogate measurement for diesel particulate matter. The results of the two data sets were then compared using a linear regression analysis. The coefficient of determination (or R2) was calculated to be 0.98, 0.94, and 0.74 for the Kubota, Deutz, and Isuzu engines, respectively. R2 values of this magnitude indicate that this method can be successful in estimating elemental carbon emissions in the engines tested. In addition, for replicate samples, the coefficient of variation ranged from 7.1% to 10.2% with an average of 8.5%. These data indicate that this method could prove useful to mechanics as they work to maintain engines and DPM control technologies.

By Charles E. Glass

The purpose of this report is to demonstrate the flexibility of rte sensing techniques for providing data with which to implement mined-lands reclamation in an efficient and cost-effective manner. An operational program is presented for using satellite remote sensing data, collateral data, and automated image analysis to provide: 1) an inventory of coal and copper mines and mine waste in Arizona, 2) techniques for periodic monitoring of mining areas using multitemporal classification and image prediction techniques, and 3) delineation of high priority areas for future reclamation and current land-use planning of Arizona mining areas based on environmental hazards indices computed using classified scenes and collateral data.

Jan 1, 1980

By J. P. Connell

The U.S. Bureau of Mines awarded a contract to Morrison-Knudsen, Inc., to evaluate the use of roadheaders in underground mining operations. Road-headers were found to be widely used in mines as construction support units, as development miners, and as stoping machines. However, road-headers were found to have mechanical and electrical problems, to suffer reduced productivity when integrated into the mining cycle, and to create dust problems. Also high capital costs and low utilization and avail-ability cause high amortization costs per ton. This report identifies the roadheader operating problems and offers suggestions for improved mechanical and electrical design as well as manufacturer and owner responsibilities for improved availability. The development of a complex integrated excavation and ground support sys tern is no t warranted until the roadheader itself is made much more reliable.

Jan 1, 1980