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By C. H. McNaughton

The Tennessee Copper Co. operated two mines in the Ducktown district during 1928. The Burra Burra mine is much the larger operation and is the chief source of the ore smelted and treated in the, company's smelter and acid plant rat Copperhill, 4.5 miles from Ducktown. This mine operates steadily and furnishes a regular output of about 40,000 tons per month. The Eureka mine is operated irregularly and produces a much smaller tonnage of high-sulphur ore the rate of output depending upon the demand for sulphur. During 1928 about 60 per cent of the combined output of these mines was shipped directly to the smelter, and the balance was concentrated before shipment in the flotation plant located near the mines. ACKNOWLEDGMENTS The author acknowledges the assistance of Lamar Weaver, Assistant mine superintendent of the Tennessee Copper Co, and of C. F. Jackson, mining engineer, U. S. Bureau of Mines, in the, preparation of this paper, U. S. Geological Survey Professional-Paper 139, by W. H. Emmons and F. B. Laney, has been drawn upon for information contained 'in the paragraphs on history and geology.

Jan 1, 1929

By Robert V. Spencer

"This report describes an examination and preliminary exploration of the Magnet Cove Rutile Co. property in Hot Spring County, Ark. The company in 1944 was producing titania for use in-the welding-rod and metallurgical industries but later ceased operations. The deposit appeared to contain potential reserves of rutile ore, and the Bureau of lanes in 1945 conducted an examination designed (1) to obtain samples for ore-dressing tests and (2) to gather information regarding the grade, character, and size of the deposit. This report presents the data obtained by geologic mapping, geophysical surveying, churn drilling, and core drilling. Beneficiation tests are being made at the Bureau of Mines Rolla, No. station, on the samples taken and will be discussed in a later report.The Magnet Cove operation had been called to the attention of the Bureau of Mines, and in view of the potential reserve of titanium-bearing material, it was decided to obtain samples for ore-dressing tests. Churn drilling was selected as a means of obtaining representative samples, and geologic mapping and geophysical surveying were done to throw more light on the nature of the deposit. Subsequently, a few holes were core-drilled.The property contains the NE1/4, W1/2 fractional NW1/4 and 82 acres of the N part of SE of sec. 18, and -29 acres of the SW1/4 NW1/4 sec. 17, all in T. 3 S., R. 17 W., Hot Spring County, Ark. The mine and mill are about 1 mile by graveled road northeast of U. S. Highway 270, a paved road connecting Malvern, 10 miles south and Hot Springs, 12 miles west. The area is served by two railroads, the Missouri Pacific, which passes through Malvern and Hot Springs and the Chicago, Rock Island & Pacific,,has a line connecting Malvern and Hot Springs an passes about 2 miles south of the property. A natural-gas pipe line and an electric power line reach the property."

Sep 1, 1946

By James J. Dowd

The investigation to evaluate the reserves of coking coal in the United States suitable for the manufacture of metallurgical coke is being made by the Bureau of Mines in three parts: (1) To estimate known (measured plus indicated) recoverable reserves of all coking coal; (2) to upgrade marginal coals through effective preparation; and (3) to study the carbonizing properties of coals and coal blends not now widely used for metallurgical coke making. This is the sixth of a series of reports giving the results of studies by counties under part (1) of the investigation. (See appendix.) This report covers Fayette County, Pa., which comprises the Uniontown and parts of the Brownsville, Connellsville, Donegal, Waynesburg, Masontown, and Confluence, Pa., Morgantown and Bruceton, W. Va., and Accident, Md., quadrangles. (See fig. 1.) A short resume of the chemical and carbonizing properties of the coals ar.9 included. Data on the coal beds in this county were obtained from mining companies, land companies, individual landowners, and other sources of authentic information.

Jan 1, 1951

In 2007, a total of 4,639 stone mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 Stone mines comprised 31.2% of all mining operations. ? Mines producing the primary commodity of limestone (crushed and broken) comprised the largest number of operations (n=2,051; 44.2%). ? Stone mining operations were located in all states and territories except Delaware and North Dakota. ? Pennsylvania had the most stone mines (n=373; 8.0%), followed by Texas (n=352; 7.6%).

Aug 1, 2009

By R. S. Lang, C. C. Merrill

The recovery of zinc from oxidized zinc minerals by the caustic soda leach and electrolytic or chemical precipitation was investigated . With the exception of willemite ( 2 ZnO • Si0₂ ) oxidized zinc minerals were readily soluble in 180 to 240 g / 1 NaOH solutions . A high- grade zinc flake was recovered electrolytically from solutions which had been treated with zinc powder to precipitate copper and lead . Solutions were recycled to the leach stage with a recovery of about 85 percent of the zinc from an ore containing 21.2 percent zinc . Electrolysis was conducted at a current density of 120 amp / ft2 with a power consumption of about 1.5 kwhr /lb zinc . Zinc was also recovered from leach solutions by dilution of the solutions , carbonation of the solution , or the addition of sulfur to boiling solutions . A dilution ratio of 5 : 1 precipitated 59 percent of the zinc in 9 days . Carbonation of the solutions precipitated the zinc as zinc oxide ( ZnO ) and solutions could be recausticized for recycling . Zinc precipitated as the sulfide with sulfur was easily filtered and washed . Approximately half of the sulfur added to solutions was lost in the form of sodium thiosulfate ( Na S₂03 ) .

Jan 1, 1965

By Jon G. Bredeson

A survey of electromagnetic noise reports was performed and a summary of the results are given. Industrial concerns were surveyed for techniques to minimize the effects of electromagnetic noise and are presented. The common types of communication links used in mines today are presented. A mathematical development was presented which determines the probability of bit errors versus distance for various types of communication links designed for in mine use. The probability of undetected errors for the protocols of the communication links is given together with burst error detection.

Jan 1, 1981

By M. M. Tilman

The Bureau of Mines evaluated corrosion resistance of Split Set friction rock stabilizer mine roof bolts to aid in better prediction of useful service life. Electrochemical corrosion testing was conducted utilizing an automated corrosion measurement system. Natural and/or synthetic mine waters from four uranium and two copper mines were the test media for the two types of high-strength, low-alloy (HSLA) steels from which Split Set stabilizers are manufactured, and for galvanized steel. Tests were conducted with waters of minimum and maximum dissolved oxygen content at in-mine water temperatures. Retrieved Split Set stabilizers were also evaluated for property changes. Galvanized steel was found to be far superior to the unprotected steel in general corrosion resistance; limited tests indicate little ten.dency to pitting, contrary to behavior for the uncoated steel. Copper-bearing HSLA steel was slightly more corrosion resistant than non-copper-bearing HSLA steel. Statistical analyses resulted in development of equations relating dissolved oxygen, chloride, sulfate, and magnesium contents of mine waters to corrosion rates of the two HSLA steels (nongalvanized). An equation was developed that relates corrosion rates of galvanized steel to mine water temperature and dissolved oxygen content. Variable conditions in mine environments make corrosion damage difficult to predict and emphasize the need for corrosion prevention and control.

Jan 1, 1984

By Carl W. Kelley

PRODUCTION in the United States of carbon black has increased from 20 million pounds per year in 1920 to over 2 billion pounds in 1964 valued at $156 million, mostly for consumption by the rubber-tire industry, which uses over 90 percent of total production. Production of over 2 billion pounds in 1964 is a 7.8-percent increase over 1963 and is the first time furnace black production has topped 2 billion pounds. Although 1964 channel black production dropped 6 percent below 1963, carbon black produced by the furnace process, which ac-counted for 92 percent of total production, increased 9 percent to 2,053 million pounds. Total shipments during 1964 amounted to 2,245 mil-lion pounds, a 7 percent increase. This growth parallels the expansion of the automotive and petroleum industries. Along with this expansion have been many advances, both in methods of manufacture and in the quality and variety of blacks available to industry. There are several kinds of carbon black, thermal, channel, furnace, lamp, and oil blacks. Until recently, channel has been the important black in rubber compounding. Following the introduction of the synthetic GR-S, and more recently of "cold rubber," it has been found that certain furnace blacks with particle size larger than that of the standard channel black give superior reinforcement. A great advantage of furnace black is that its yield per unit of gas feedstock is higher than that of channel black. The 184-million-pound increase in domestic carbon black sales was partially offset by a 37-million-pound decrease in exports. Decrease in exports especially to Europe, is expected to continue. In Europe, as in the United States, the major end use for carbon black is in the manufacture of automobile and truck tires. Although the number of automobiles in Europe is predicted to grow by about 7.5 percent per year, compounded until 1975, the increased demand will be met by a 20 percent increase in existing capacity and by the new plants being built in Europe by U.S. companies. Also) aromatic oils for producing furnace blacks are plentiful now that western Europe's chemical industry is switching to a petroleum base.

Jan 1, 1965

By E. S. Leaver

Experiments dealing with the dissolution of silver by cyanide from various silver minerals were reported several yews ago.4/ This work showed that the silver in some silver minerals is completely and readily soluble in cyanide solution, whereas other silver minerals must be given special treatment before or during cyanidation to obtain much dissolution of the silver by cyanide. Flotation as a method for treating silver ores has not been studied much, except in the case of base-metal ores carrying silver, particularly lead-silver ores. However, many mills now are concentrating gold ores by flotation, and when such ores also contain silver the recovery of the silver by flotation is of considerable importance. Moreover, many mines contain ore in which silver is the principal valuable constituent. Some of these ores are amenable to cyanidation, but the cost of a cyanide plant may be prohibitive because of limited ore bodies or other factors. In such instances the successful application of flotation would mean that the property could be operated.

Jan 1, 1939

By Thomas E. Lobb, Harry C. Verakis

Significant progress has been made in the reduction of serious injuries and fatalities resulting from mine blasting operations. Despite the progress, injuries and fatalities continue to occur. A leading cause of injuries and fatalities from blasting continues to be inadequate blast area security. Even though significant improvements in technology have been made, insuring adequate blast area security remains a challenge and requires constant vigilance. The advances in technology have created safer blasting products and have improved productivity and economics by enabling large, more efficient and effective blasts. However, as blasts grow larger in size, the complexity of adequately securing the blast area increases even more. Periodically the basic fundamentals involved in blasting safety should be reviewed, particularly for securing a blast site regardless of the size of the planned blast. Factors such as flyrock and toxic fumes must be taken into account to insure the safety of persons and property from the results of a blast. This paper examines the factors related to injuries due to inadequate blasting shelters and blast area security, and identifies mitigation techniques. The key concepts are: (a) accurate determination of the bounds of the blast area, (b) clearing employees from the blast area, (c) effective access control, (d) use of adequate blasting shelters, (e) efficient communications, and (f) training. Fundamentals are reviewed with an emphasis on analyzing task elements and identifying root causes for selected blasting accidents. Mitigating techniques are presented along with discussions and examples.

By R. S. McClain

Continuous-circuit flotation and batch-scale precipitation tests were made by the Bureau of Nines to determine rejection of carbon and recovery of fluorine and aluminum compounds from aluminum reduction plant residues, About 40 to 60 pounds each of aluminum fluoride and cryolite are lost for each ton of aluminum produced. Gasoline and turpentine were satisfactory for floating carbon from both fresh water and saturated solution systems. Soluble fluorine and aluminum compounds were recovered by precipitation with sodium aluminate and carbon dioxide. Over 99 percent of the carbon was removed by flotation. Fluorine and aluminum recoveries up to 77 and 63 percent, respectively, were obtained in a combined precipitate and nonfloat product, In the fresh water system the combined product was mostly cryolite with some gibbsite. In the saturated solution system the product was mostly sodium fluoride, some cryolite, and minor amounts of gibbsite.

Jan 1, 1963

By Jr. Hill

Laboratory metallurgical treatments of three high-iron bauxite ores from Arkansas were conducted to determine the relative effectiveness of experimental methods for recovering alumina and a commercially acceptable iron concentrate. The standard for evaluating recoveries from experimental processes was the Al2O3 recovery from Bayer digests of the crude ores; recoveries from digestion of the three ores were 74.1, 87.4, and 88.7 percent. Flotation, magnetic separation, or various combinations of digestion, calcination, and reduction-sintering, leaching, and magnetic separation of leach residues failed to produce Al2O3 recoveries as high as the standard. A high-iron-bearing fraction, containing between 68 and 78 percent of the total iron, was produced in a three-phase treatment involving a caustic, lime reduction-sinter of the crude ore, water extraction of Al2O3 from the sinter, and magnetic separation of the leach residue.

Jan 1, 1967

By C. W. Huggins

The primary objective of this Bureau of Mines research was to measure the size distribution of respirable quartz collected at metal mines, nonmetal mines, and processing plants to select the best reference standard for use in quantifying quartz in mine and plant dust samples. The secondary objective was to size all the nonquartz particles collected at the same sites. Particle size measurements were made on 29 samples using a scanning electron microscope in the backscatter mode of operation, interfaced with an image analysis system. The Mine Safety and Health Administration, Denver, CO, provided the 29 samples, which were collected at mines and processing plants in 19 states. The accumulated particle size measurements indicate that NBS 1878, minus 5-f.lm Hin-U-Sil, and minus 5-f.lm Supersil would be preferred over Silver Bond B as reference standards for most quantitative determinations by X-ray diffraction and infrared spectrometry. The respirable dust samples collected at sand plants, however, would be better served by a new reference standard having a quartz particle size distribution of approximately 2.2 um, as none of the four existing reference standards matched closely with them. Commercially available NBS 1878 and minus 5-um Hin-U-Sil CQuid be used as reference standards for 28 of the 29 samples studied in this investigation.

Jan 1, 1986

By Lloyd R. Michels, Burke Cartwright, S. F. Ravitz

"INTRODUCTION Frequent attempts have be,made in the electrolysis of molten magnesium chloride to regenerate the electrolyte by allowing the chlorice generated at the anwdo to read with magnesium oxide and carbon within the melt according to the following reactions: (1) MgO + C + CL2 = MgCl2 + CO,(2) 2MgO + C + 2C12 = 2MgC12. + CO2.The principal advantages of such a procedure are that (1) the direct source of magnesium is magnesium oxide rather than the more expensive dehydrated magnesium chloride and (2) it is not necessary to handle or dispose of large quantities of chlorine or hydogen chloride.Grätzll 5/ proposed the use of an MgO carbon feed in a more or,less compact form in the anode compartment, of the cell. In a patent issued to Magall Aktiengecellschaft, 6/ a compact mixture of MgO and carbon is used as the anode itself. Kato 7/ and Backer 8/ add the feed in finely divided form to the surface of the anode compartment. The Bureau of Mines 2/ recently made a pilot-plant investigation of the electrolysis of suspension of MgO and carbon from chloride melts, in which it was found that although,current efficiencies of 60 to 70 percent were obtainable, the formation of sludges containing MgO, carbon, and magnesium seriously interfered with the operation of the cell,"

Apr 1, 1945

By R. V. Ramani

In this report, the application of the Open Pit Materials Handling Simulator (OPMHS) to a mine located in Ohio using a large stripping dragline, and truck and front-end loader (FEL) is described. The specific objective of the study is to demonstrate the application of the simulator to mine planning and coal production. On the basis of the simulations, it was concluded that the production from the haulback operation should be increased to accommodate improvements in both the stripping dragline's availability and mean cycle time. Several alternatives were studied for the best use of equipment if the present operating parameters could not be improved upon. No economic analysis of these proposals were made.

Jan 1, 1977

By J. A. McAllister, H. G. Iverson, K. C. Dean

"INTRODUCTION During the course of the investigation of the occurrence of manganese deposits in the western United States, laboratory studies of concentration were conducted at the Salt Lake City station on a sample of ore from the Lake Valley mines of the Newalpitt Fluorspar Corp. of Deming, N. Mex. The ore was reported to be representative of the type that would be mined for mill feed. The sample tested was found to be amenable to beneficiation by ore-dressing methods for the production of products that, when sintered, assayed over 44 percent Mn.At the beginning of the investigation of manganese-ore beneficiation in December 1940, the only product marketable to Metals Reserve Company was ferrograde manganese grade B, the requirements for which follow: Mn, min., 48 percent; Fe, max., 7 percent; Si02, max., 10 percent; P, max., 0.18 percent; Al203, max., 6 percent; Zn, max., 1 percent, Al2O3,Later the specifications were modified gradually. As of May 15, 1943, manganese products were acceptable if they contained over 35 percent manganese and less than 3 percent zinc and 1 percent phosphorus. Prices were based upon material containing 48 percent manganese, 6.0 percent iron, and 11 percent silica plus alumina. Premiums were paid for manganese content in excess of 48 percent and iron content below 6 percent, penalties being imposed upon products containing less than 43 percent -manganese, or more than 6 percent iron, or more than 11 percent silica plus alumina. The specifications for commercial manganese further required that maximum particle size be 12 inches and that, 75 percent of the product be coarser than 20-mesh. Therefore, fine material such as table and flotation concentrates had to be nodulized or sintered. In addition, oarbcnate manganese ores were not acceptable unless calcined."

Feb 1, 1948

By R. A. Hatch

The United States depends mainly on foreign imports, principally India, for an adequate supply of sheet mica suitable for its many uses in the electrical and electronics industries. Sheet mica has, in fact, played an indispensable role in developing these industries,4/ and, in turn, the products of these industries (radio, radar, electric motors, and many others) have become indispensable to the military forces. Because or these conditions, sheet mica in its better qualities long has been classified as a strategic and critical material, and from this stems the wide-spread interest in substitute materials of which synthetic mica is one potential type. The United States Departments of the Navy and the Army entered into a cooperative agreement with the Bureau of Mines in 1947 to study ways and means of synthe-sizing and growing mica crystals. This is one of a series of reports5/ that describe the results of this program.

Jan 1, 1956

By W. W. Adams, T. D. Lawrence, D. R. White

"This paper presents the results of the eleventh yearly accident-prevention contest, the National Safety Competition of 1935, conducted by the United States Bureau of Mines. Participating in the competition were 336 mines and Quarries in 37 States. Five mining or quarrying companies, each the leader in its group for having established the best safety record during the year, were awarded the national safety trophies 'Sentinels of Safety.Since these annual contests were begun 11 years ago the scope of the competition has been broadened materially, both as to the number of plants participating and as to the number of man-hours of exposure to accident hazards. Moreover, marked progress in the pre¬vention of accidents has been achieved, as is indicated by an almost constant downward course in the accident-frequency rates for the contest group as a whole during the past 11 years. On the other hand, the accident-severity rates for the group showed an upward trend during the first part of the period and a downward trend during the latter part, except in 1930 and 1934, when two disastrous explosions occurred with heavy loss of life, and in 1935, when there was an increase in the number of fatalities although no major disasters occurred. The accident rate for 1935, both as to frequency and severity, was higher than for 1934.The National Safety Competition is conducted by the Bureau of Mines in the interest of safety in the mining and quarrying industries. This object is accomplished directly through the efforts of the competing companies and their employees to win first place in the competition and thereupon receive well-merited and national recognition for their achievement. Indirectly the purpose of the contest is accomplished through studies by the Bureau of Mines of the fasts contained in the accident reports which the competing companies furnish to enable the Bureau to compute the accident rates that are the basis for determining the winners of the contest.The statistics that constitute the basis for determining the winning companies and the relative standing of all companies are prepared uniformly without regard to the States in which the companies operate, or to differences in classes of accidents covered by State laws relating to compensation for injuries resulting from industrial accidents."

Jul 1, 1936

By E. S. Leaver

Experiments dealing with the dissolution of silver by cyanide from various silver minerals-were reported, several years ago.4/ This work showed that the silver in some silver minerals is completely and readily soluble in cyanide solution, whereas other silver minerals must be given special treatment before or during cyanidation to obtain much dissolution of the silver by cyanide. Flotation as a method for treating silver ores has not been studied much, except in the case of base-metal ores carrying silver, Particularly lead-silver ores. However, many mills now are concentrating gold ores by flotation, and when such ores also contain silver the recovery of the silver by flotation is of considerable importance. Moreover, many mines contain ore in which silver is the principal valuable constituent. Some of these ores are amenable to cyanidation, but the cost of a cyanide plant may be prohibitive because of limited ore bodies or other factors. In such instances the successful application of flotation would mean that the property could be operated.

Jan 1, 1939

By P. R. Perry

This publication is a compilation of tested methods for the analyses of titanium tetrachloride, titanium sponge, and various intermediate materials and products. They are presented in concise form without the detail usually found in publication of new methods because many of them are modifications of well known procedures. The Electrometallurgical Experiment Station, Boulder City, Nev., has been developing titanium production methods since 1945. Most of this development was on a modified Kroll Process but also included work on sodium reduction and electrolytic methods. During these years a large variety of samples were analyzed. Most of the analytical problems were solved using published methods or modifications of the same. At the start, there were no published procedures for analyzing titanium sponge using spectrochemical methods. A great deal of study was given to testing several of the well known techniques, and some of them, such as direct sparking of the metal, proved to be completely unsatisfactory. Solution-spark techniques were finally tried, and satisfactory procedures were developed for some of the more common impurities. These spectrochemical methods were then put into routine use for several months before their publication.2/ Some new modifications have been made, and techniques have been developed to determine other impurities found in titanium sponge and tetrachloride. All spectrochemical methods used in 1954 are included in this publication.

Jan 1, 1955