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By J. B. Zadra

Much has been published by various investigators on the use of activated carbon for adsorbing precious metals from cyanide solution and pulp. For the benefit of the reader, a list of these earlier publications appears at the end of this report. The present paper deals only with a process for extracting gold from gold-laden carbon and re-use of the de-adsorbed carbon. At the Getchell mine, Redhouse, Nev., experiments have been in progress for several years concerning the use of activated carbon to adsorb gold from their slime circuit pulp. The experimental work has been successful. Their practice has been to ship the gold-laden carbon to a smelter for treatment, which meant the total loss of the carbon in addition to smelter and freight, charges, all of which proved costly and wasteful.

Jan 1, 1950

By Dennis A. Hansen

As part of a U.S. Bureau of Mines program to develop a more continuous titanium metal extraction process that uses domestic resources, a study was made to determine the extraction of titanium (Ti) and iron (Fe) from New York rock ilmenite using fluosilicic acid (H2SiF6). The effects of leach temperature, acid concentration, and particle size were investigated for the rate at which Ti and Fe are extracted from the ilmenite. Within the leach time studied, the extraction data fit a shrinking-core model; the rate-controlling step was diffusion of H2SiF6 through an ash layer resulting from a heterogeneous leaching reaction. The rate is linearly dependent on the H2SiF6 concentration and is inversely proportional to the square of the particle diameter. Using 2.6M H2SiF6 at 85°C, 49% of the Ti and 53% of the Fe in 44-to 74-µm New York rock ilmenite were extracted in 3 h.

Jan 1, 2010

By Raja V. Rarnani, Robert L. Frantz

"Mining is one of the oldest of human occupations. The awareness of occupational illnesses associated with mining, even in ancient times, is evident from the writings of Hippocrates (460-370 BC), Pliny and Elder (AD 23-79), and Galen (AD 131-210). Georgius Agricola (1494-1535), in his De Re Metallica, refers to the diseases of miners and the need for their control through good planning and operating practices and responsible management (Schwerha, 1989). Coal workers' pneumoconiosis (CWP), often called Black Lung disease, is an occupational disease which results from inhalation of coal mine dust which usually contains relatively small amounts of free crystalline silica.A pneumoconiosis is best defined as the accumulation of dust in the lungs and the tissue's reaction to its presence [Lapp and Castranova, 1993]. Silicosis is the name given to the fibrotic disease of the lungs caused by the inhalation of dust containing silicon dioxide, primarily in the free crystalline form. Silicosis is the older and more well known of these mineral pneumoconioses. In contrast, CWP was not recognized as different from silicosis until the pivotal work of Collis and Gilchrist [1928].The U.S. Bureau of Mines (USBM) still regards worker exposure to respirable aerosols in mines as the most serious health problem in mining [USBM, 1994]. The National Institute of Occupational Safety and Health (NIOSH) is considering recommending a reduction in the standard for occupational exposure to respirable coal mine dust from 2 mg/m3 to 1 mg/m3 [NIOSH, 1993]. The Mine Safety and Health Administration (MSHA) may require new criterion for sampling procedures in the mine that would evaluate the ambient dust concentration in the mine atmosphere based on a single sample, instead of the current practice of averaging five samples (MSHA, 1992; Ramat* 1993). Several high-production longwall mining faces currently have extreme difficulty meeting the existing dust standards, and some already operate at reduced production levels to achieve mandated levels [USBM, 1993]. The importance of adequately protecting the miners from high concentrations of coal mine dust, as well as of reducing the incidence and severity of the Black Lung disease, cannot be overemphasized. The importance stems, first and foremost, from the humanitarian viewpoint and, second, from the perspective of the overall welfare of the coal industry.The histopathologic hallmark of CWP is the coal macule (Balaan, Weber and Banks, 1993). Autopsy or open lung biopsy reveals the coal macule to be an amorphous mass of coal particles, dust-laden pulmonary macrophages, reticulin, and collagen. No pathognomonic signs or symptoms identify workers with CWP. A CWP diagnosis requires that the worker experienced the appropriate dust-exposure setting (e.g., underground coal mining) and duration (usually 10 years or more) and, has the characteristic chest radiograph. Based upon the International Labour Organization (ILO, 1980) international classification, pathologists and radiologists have established case definitions for characterizing the pathology and the appearance of CWP on chest radiography (Weeks, 1993). CWP appears in two principal forms: simple, with small opacities, and complicated, with opacities larger than 10 mm in diameter. For all practical purposes, diagnosis of CWP in the living miner is wholly dependent upon the chest radiograph interpretation."

Jan 1, 1995

By MINE SAFETY BOARD

Mining men and State officials in their efforts to make mining safer are confronted from time to time with various complicated questions . In recent years these questions have tended to increase with the use of mechanical appliances . Twenty- five years ago electricity had hardly been used in mines . To - day there is practically no other means of transmitting energy employed in American mines , except in metal mines where compressed air is used for drilling and small portable hoists . In coal mines there has been a great increase in mechanization and a tendency to concentrate the mining operation , which has resulted in attendant difficulties of ventilation and intensified the danger of coal - dust in bituminous and subbituminous mines . The answers to the questions which arise are not always obvious , as is shown by the fact that even able , experienced men differ in their opinions of the best way to overcome a particular mining hazard . The difficulty of solving the problems is also demonstrated by the varying provisions in mine safety rules , both in official regulations and in the rules of those mining companies who are endeavoring to do more than follow the letter of the law . Such differences of opinion on the best way of meeting a difficult situation are often found within the same mining organization , and so it has been in the Bureau of Mines .

Nov 1, 1929

By R. F. Farrell

A goal of the U.S. Department of the Interior, Bureau of Mines, is the advancement of minerals technology through the development of improved metals and minerals processing. In support of this goal, the Bureau of Mines has developed a general method for preparing solutions from a wide range of metal and mineral samples for chemical analysis. The development of the method from current knowledge of vessel material, pressure dissolution techniques, and the fluoride-boric acid reaction is given. The method uses 7 ml of a mixture of HC1-HNO3-HF acids in a ratio of 3.5:2:1.5 sealed in plastic bottles that act as pressure vessels when heated in a boiling water bath. A final volume of 100 ml is obtained by the addition of 93 ml of a 1. 5-pct H3BO3 solution to the bottles, which are reheated; precipitated fluorides as well as sample residue are dissolved by the fluoride-boric acid reaction. A copper slag and a steelmaking slag treated using this method were analyzed by atomic absorption spectroscopy yielding values for Si, Mg, Ca, AI, Fe, Mn, Na, As, Pb, Sb, and Zn very close to certified values with an average relative standard deviation of 2.13 pct. The low cost, reduction in preparation time, ease and safety of sample handling, conservation of reagents, and ability to dissolve volatile materials without loss make this method superior to traditional wet digestion techniques for many materials, and ideal for use with atomic absorption, and optical emission or X-ray emission spectroscopy.

Jan 1, 1980

By Lee M. Manna

This report summarizes the program to design, fabricate, install and preliminary test a pneumatic braking system for 10-ton mine haulage cars. Major arrangement drawings are reproduced, pneumatic schematics, parts list and actual developed costs. Recommendations as to system improvements are made.

Jan 1, 1977

By B. W. Gandrud

The upper part of the Alabama deposits of crystalline graphite consists of an oxidized ore derived from the underlying unoxidized ore through prolonged Weathering. The degree of oxidation in different sections and at different depths within the bed is not uniform. The original ore is hard and blue-gray; the weathered product is soft and brown and is the only part that has been mined to any extent. Samples of both oxidized and unoxidized ores were obtained from two of the large graphite deposits of Clay County. Three additional samples of oxidized ore were obtained from different portions of a third property in the same region. In this report, ores 1 to 5 are of oxidized material and ores 6 and 7 of unoxidized.

Jan 1, 1934

By Jerome J. Hoeppner, Walter W. Fowkes

The Federal Bureau of Mines has determined the distribution of forms of sulfur for several lignites and gasification chars and noted the changes induced by the gasification process . A method was adopted for quantitatively determining sulfide sulfur that was found to be present in the chars , although absent in the lignites . Changes in the behavior and distribution of sulfur forms were further investigated concerning the ashing of lignites and chars under standard conditions , as well as at various temperatures , and the determination of volatile matter applied to both chars and lignites . The authors concluded that the first and greatest change in the form of sulfur present in natural lignite , upon heat treatment , resulted from the reduction of pyritic and sulfate sulfur to sulfide . Organically - bound sulfur originally present is less reactive , but largely disappears on strong ignition . An appreciable part of the sulfur content of natural lignite is fixed in the char as sulfide and in the ash as water - soluble sulfate and will affect the summation of constituents , to a greater or lesser degree , in reporting the ultimate analysis of a lignite or char .

Jul 1, 1960

By J. W. Thompson

RIGHT OF LIFE TENAN1' TO OPEN MINES. The common-law rule that a life tenant was not permitted to open or share in mines does not prevail in Michigan; but a life tenant by dower right is permitted to share in the royalties, as the strict common- law rule is not in harmony with the spirit of our institutions and the policy of our law and would often result in defeating the purposes of dower statutes. Poole v. Union Trust Co. (Michigan), 157 Northwestern 430, p. 432, March, 1916. SALE AND CONVEYANCE. PURCHASE OF ENTIRE ESTATE--FRAUD. A purchase of land where no exceptions or reservations of minerals were made and the land was bought as property, when nothing is excepted and no qualifications or reservations are embodied in the agreement, was presumptively and by common understanding a purchase of the property in its entirety; and the insertion in the deed of a reservation of mineral rights in violation of the contract of purchase and without the grantee's knowledge or consent was fraudulent. Mtynarczyk v Zyskowski (Michigan), 157 Northwestern 566, p. 569, March, 1916. RESERVATION OF MINERALS--EXTENT AND EFFECL A reservation in a conveyance of land excepting and reserving to the grantor all coals and mines beneath the surface with the sole right and privilege to remove the same, is not as broad as the grant itself. A contract for the purchase of a mine recited that a deed had been executed by the owner and placed in escrow to so remain until the sum of $30,000 should be paid. The contract provided that $1,200 of the purchase price was to be paid in cash, $800 in 60 days, and the remainder out of 20 per cent of the gross output of the mine, such per cent to be paid in five years unless the vein and value of ore should not continue in depth, in which event the purchaser was to have two years longer to complete the payment of the purchase price. The contract contained other covenants to the effect that the purchasing corporation would fit up a certain specified mill and would continue development work at such rate as to keep the mill in operation if ores sufficiently valuable should be found and in the absence of unavoidable accident. The contract also provided 1/ that abandonment of work for a period of six months at anyone time, except as above, on said property," should operate as a forfeiture of the purchaser's right. In an action by the vendor to quiet the title to the land and to have the contract declared void, the court found that the purchaser failed to perform the work on the property and failed to place thereon the improvements as required by the contract and permitted debts to accumulate against the property, taxes to be levied thereon, and that for more than a year the purchaser had not done any work or labor of any sort upon the mine or premises, and that the contract contemplated development work from the time the purchaser took possession of the property, or at least promptly thereafter, and the fact that no machinery was in place for a year or more after the execution of the contract was a breach of the covenant of continued development, and that the clause in the contract" except as above" does not contemplate a delay in the development resulting from a failure to install machinery, but it means that unless prevented by unavoidable accidents the purchaser shouLdhave no valid excuses for neglecting the work for a period of six months or more.

Jan 1, 1917

By N. S. Dalal, X. Shi

It has been known for more than a decade that vanadium (V) stimulates the oxidation of NADH by plasma membranes (1) but the underlying mechanism is still not fully understood. This effect has been attributed to a membrane-associated NADH-dependent vanadium (V) oxidoreductase (1). Subsequent studies suggest that vanadium ( V) can accept an electron from fiavoprotein dehydrogenase that oxidizes NADH (2). The phenomenon ofNAD(P)H oxidation coupled to vanadium(V) reduction has also been demonstrated in other biological systems (3-6). A recent electron spin resonance (ESR) study from our laboratory reported on the accumulation of vanadium (IV) duringthe reduction ofvanadate (vanadium(V)) by the ftavoenzymes glutathione reductase (GSSG-R),4 lipoyl dehydrogenase, and ferredoxin-NADP+ oxidoreductase in the presence of NAD(P)H (7). It was concluded therein (7) that these ftavoenzymes function as NAD(P)H-dependent vanadium(V) reductases. More recently, however, Liochev and Fridovich (8) have argued that the ESR data (7) do not demonstrate that the investigated fiavoenzymes act as vanadate reductases. They suggest an alternative mechanism in which the fiavoenzyme simply serves as a generator ofsuperoxide (02) radical, which acts as a propagator of the radical chain reaction leading to NAD(P)H oxidation (9, 10), as summarized below:

Nov 1, 1995

By H. C. Brunaugh, James Westfield, R. W. Whittaker

"INTRODUCTION The purpose of this circular is to describe the sealing off of a mine fire and subsequent use of carbon dioxide gas to extinguish it.A fire of electrical origin occurred in the Valier mine of the Valier Coal Co., Valier, Franklin County, I11., on March 29, 1949, at about 1:35 p.m. It was discovered about 3:35 p.m. in 5 south west intake airway inby 1 and 2 west panels. The No. 5 southwest airway had caved, and the fire was in the top coal beneath a large fall of rock. All men, except officials, were ordered from the mine. The mine officials decided to seal the fire, and four temporary seals were erected, which isolated approximately 200 feet of 5 south west entry. The seals were completed on March 30 at 2:45 a.m., but on March 31, at 3;40 a.m,, two of them were blown out by an explosion of gas that was produced by the fire. The two seals were rebuilt, the work being completed on March 31 at 12:00 noon, but they were blown out by another gas explosion at 12:10 a.m. on April 1. It was then decided to extinguish the fire with water if possible.To accomplish this, concrete-block dams were constructed. On April 1, about 4:25 a.m., when the dams were about half completed, water was introduced into the fire area through a 2-inch pipe.On April 4, J. G, Crawford, general manager of the Valier Coal Co., notified James Westfield, chief of the Vincennes (Ind.) Branch, U. S. Bureau of Mines, by telephone of the fire in Valier mine and requested assistance to combat it. Westfield, accompanied by F. J. Smith and H. C. Brumbaugh, Federal coal-mine inspectors, went underground and inspected the seals and dams. Later, during a conference with company officials, it was decided that the concrete-block dams were not strong enough to withstand the hydrostatic pressure that would be produced by flooding the fire area. It was then decided to use carbon dioxide gas to extinguish the fire. Four seals were completed, and 5 tons of carbon dioxide gas was introduced into the fire area, which extinguished the fire."

Apr 1, 1950

By R. V. Ramani, P. M. T. White, D. Sutton

Appendix I. Part 1: Description Of Geology & Reserves System Introduction The Ore Evaluation and Reserve programs have been developed to aid in the evaluation of coal deposits, both qualitatively and quantitatively. The "Weighted Moving Average" technique used provides considerable flexibility in dealing with diverse parameters with differing distribution characteristics. Determination of Model Constants "a" and "k" - Unit 1 The flexibility of the method in dealing with diverse value parameter distributions lies in its ability to cater to the individual characteristics of each. These characteristics are embodied in the values determined for constants "a" and "k", namely, local and regional variations in value distributions, respectively. The empirical method used attempts to optimize the "a" - "k" combination. Realistic values for "a" and "k" are entered into the program together with sample values for the required parameters and their respective coordinate location values. All the values within a specified radius from the point being evaluated are used to interpolate a value at that point. (Note, the interpolated point is the location of one of the boreholes, values of which are not used in the calcula¬tion.) 3n a similar manner, interpolated values are calculated for each borehole location and for each parameter. This is done for each possible combination of "a" and "k".

Jan 1, 1974

By L. A. Grant

This paper describing the concentrator practice of the Montana Mines Corporation at Helena. Mont., is one of a series of articles on milling methods and costs being prepared by the United States Bureau of Mines. The Spring Hill mine and mill are located 4 miles south and west of Helena, Mont., near the head of Grizzly Gulch. The mine portal is on the east slope of the gulch, and the mill is directly opposite on the west slope. Grizzly Gulch is one of the tyro gulches which unite at the south end of Helena to form Last Chance Gulch, on which the main street of Helena is built.

Jan 1, 1931

By Jack L. Henry

The Bureau of Mines conducted seven pioneering experiments in a 12-inch-diameter Kroll reduction reactor to examine the feasibility of coreducing the chlorides of Ti, AI, and V to produce a homogeneous titanium alloy sponge. The coreduction studies proceeded in a normal manner, and the yields of sponge were comparable with those of pure titanium sponge made in the same reactor. Vanadium concentration was very uniform throughout the sponge cake when VC14 in solution in TiCl4 was fed into the molten magnesium. More difficulty was encountered in feeding solid VCl2 and AIC13. Vanadium and aluminum concentration in the sponge was not uniform, and mechanical difficulties were experienced with the small-scale screw feeder. Although the sponge varied in composition from region to region, the ingots prepared from it were uniform in composition.

Jan 1, 1974

By G. S. Scott

It is sometimes desirable to know what changes in sizing characteristics would appear in screened coals if screens of different - size openings than those employed had been used . This report is concerned entirely with the application of the Rosin- Rammler law to a solution of this problem .

Dec 1, 1943

By Douglas F. Scott

Researchers from the U.S. Bureau of Mines conducted geologic investigations in an area of the Lucky Friday Mine, Mullan, ID, that included the 5300-107 demonstration stope using underhand longwall cut-and-fill mining. Structural analysis of the area suggested that argillite beds form planes of weakness between blocks of brittle quartzite, and energy may be released along these planes and at the junctures of fractures. Mapping argillite beds and fractures in the stope wall rock showed that the planes of these features diverged and that their attitudes corresponded from one wall to the other. Seismic analysis showed that the number and location of events varied as each cut was mined, with about 39 pct of the total number of events occurring above the cut being mined, about 54 pct below, and 7 pct at the same elevation.

Jan 1, 2010

To quickly and more reliably measure the alignment and deflection of mine guides used to run skips and cages into a mine shaft. The Problem Conventional mine guide alignment measuring systems require the use of a plumb bob and tape measure. This method is not only laborious, but it is time consuming as well. Approach Aware of the drawbacks of the current measuring method, the Bureau of Mines designed a self-contained instrument system that can accurately perform vertical guide alignment and deflection measurements by remote control. How It Works The Bureau-developed instrumentation system, called the Guide Alignment Measuring System (GAMS), is based on conventional mechanical electronics using inclinometers and displacement transducers. The instrumentation system is attached to an operating skip or cage where it functions as a completely self-contained measurement system, operating in conjunction with nor-mal travel of the skip or cage. An on-board tape recorder or a mini-computer with memory can be used to record all telemetry.

Jan 1, 1987

By O. M. Bishop

"INTRODUCTION Early in World War II, the Bureau of Mines realized that reserves of fluorspar ore at many mines in the southern Illinois fluorspar district were not being developed as rapidly as the old ones were being depleted. At some mines the measured and indicated ore reserves were almost entirely depleted, although geologic factors favored new discoveries. The Leo mine, which had not been worked since 1938, was among this group of mining. The Bureau of Mines, together with the Illinois Geological Survey examined the property, studied the mine records and,geologic factors in 1944, and agreed that exploratory drilling was warranted Funds were,obtained for the work in the fiscal year 1945, and drilling was done; between October 27, 1944, and June 15, 1945.The property was owned in fee simple by the Hllside Fluor Spar Mines at the time exploration was begun in October 1944. Subsequently, in 1945, the Inland Steel Co. acquired of the Hillside property."

Jan 1, 1947

By J. K. Whyatt

Researchers at the U.S. Bureau of Mines have been exploring recent advances in the use of strain-softening constitutive laws that approximate shear fracturing. The purpose of these tests is to investigate shear-fracture-related rock bursts in hard-rock mines. The capabilities and remaining problems in the use of strain-softening laws in finite-element, distinct-element, and finite-difference methods are reviewed. Performance of the finite-difference implementation of strain softening is compared to classic experimental results and observations of rock mass behavior in the Coeur d'Alene Mining District of northern Idaho. The results show promise for developing methods to identify the general location and orientation of shear fractures and their sequence of occurrence, but such methods cannot be relied upon to quantify post-fracture loads or displacements accurately. Uncertainty over the amount of energy consumed by failing rock and the dependency of energy consumption on model mesh definition prevent direct application of the results to analyses of rock bursts.

Jan 1, 2010

By W. H. Oppelt

The continuous gasification of lignite in an externally heated alloy-steel re-tort was investigated by the Bureau of Mines, Grand Forks, N. Dak., from 1945 to 1951. The main objective of the long-term experimental program was to obtain data on the mechanical performance of this type of gasification retort, particularly the alloy-steel heat-transfer surface of the retort, when operated on large pilot-plant scale. At the same time, extensive experimental data were obtained concerning the effect of process variables and the effect of a limited number of design modifications on gasifier performance. In the period covered by this progress report 4 pilot-plant runs totaling 2,879 hours of operation were completed with the rolled-plate, 310-alloy reaction tube. Over 30 million cubic feet of gas, having H2-CO ratios from 2.1 to 4.4, was made by the partial gasification of 636 tons of 1-1/2-by 3/8-inch natural lignite. Rates of gas generation were from 8,200 to 14,300 cubic feet per hour. Three of the four runs were carried out with the lowered gas offtake or continuous-annulus design modification of the gasification retort. In the final run of the series, gasification of lignite from seven different mines in North Dakota and Saskatchewan, Canada, was investigated at similar combustion-space temperatures and lignite and steam feed rates.

Jan 1, 1955