Search Documents

By Isabel C. B Rodrigues, Flávia D. Reis, Versiane A. Leão, Rosa M. F. Lima

Attention has been focused in recent decades upon the precipitation of metal sulphides from acid mine drainage (AMD) and pregnant leach solutions, due to the advantages of the sulphide precipitation process over traditional methods employing hydroxides. The aim of this work was thus to explore technologies for copper precipitation using either Na2S or biogenic sulphide. The recovery of copper sulphide was improved when the initial pH of the solution containing each metal was 4 or excess sulphide was employed. In such, a condition the removal efficiency was 99.9%, corresponding to a residual level of 0.1mg/L for copper in solution. Kinetic parameters for precipitation were determined from the particle size distributions using the method of moments, where the growth and nucleation rates, as well the agglomeration kernel, were calculated. The biogenic sulphide was a suitable alternative to sodium sulphide for copper removal as either sodium sulphide and biogenic sulphide can be utilized to precipitate such a metal allowing the effluent to be compliant with environmental legislation.

Jan 1, 2014

By Sharpin PC

The countercurrent gas-solid-heat transfer during the drying of brown coal briquettes in the pilot carbonization plant at Morwell has been analysed and theoretical gas and solid temp-erature distributions through the drier have been calculated. Although the calculations rest on several simplifying assump-tions, to be corrected as the experimental work develops, the theoretical temperature distributions compare well with those observed in practical operation. Valuable conclusions are reached as to the effects of changes in drier operating con-ditions on the rate of drying of the briquettes which-controls the 2 strength of the char produced. The analysis shows why a limitation was reached in the improvement of char-strength in the pilot plant in 1961 and a prediction is made of ' a way ' in ' which the limitation could be overcome.

Jan 1, 1963

By R. M. Hernandez

The Bureau of Land Management (BLM) constructed four passive biochemical reactor systems (BCRs) to treat mining influenced water (MIW) in the Bunker Hill Superfund area near Coeur D?Alene, Idaho between 2002 and 2003. Initially, the BCRs operated very effectively. However, in the past couple of years, the zinc removal effectiveness of the four BLM BCRs has declined [1]. The central objective of this study was to characterize the microbial communities and substrate present within the BLM BCRs and to use these factors to propose strategies to promote sustained sulfate reduction levels. Microbial communities were characterized by quantifying total bacteria and sulfate reducing species. Substrate was characterized by quantifying the percent organic, acid soluble organic, acid insoluble organic, and bioavailable material within the BCR. The results suggest the depletion of bioavailable organic substrates is the primary cause of the decline in zinc removal and not the microbial community structure. The ability to assess the amount of bioavailable organic substrate and microbial community is important to the understanding of the sulfate reducing capacity of the BLM BCRs and developing strategies to facilitate performance enhancement of the current BLM BCRs. The characterization of organic substrate and microbial community structure are also important to improving design of future passive treatment systems for mining influenced waters.

Jan 1, 2010

By Roy E. Dickerson

CUBA differs considerably from the other Greater Antilles in many geologic fundamentals. Cuba is geosynclinals; whereas Jamaica, Hispaniola. (Haiti), and Puerto Rico are geoanticlinal. (Scliuchert, Chas., Historical Geology of the Antillian. Caribbean Region, p. 13, 1935.) Rocks of lowermost Cretaceous age exist in large volume in Cuba, where- as they are generally absent in the other islands. Since many of the surface indications of petroleum are intimately associated with lowermost Cretaceous rocks, the Vinales limestone,, this difference is most important. The Vinales limestone in many places in Pillar del Rio and Santa Clara provinces reeks with light tars when broken with a hammer. The late David White and his associates on the U. S: Geological Survey studied

Jan 1, 1937

By S. P. Rivers

The stainless steel industry re1ies on nitric-hydrofluoric acid (HNO,/HF) pickling solutions to remove surface contaminants and maintain the corrosion resistance of the steel. More stringent environmental guide1ines are expected to be placed on the disposal of these solutions which could significantly increase processing costs. The U.S. Bureau of Mines has been conducting research to develop a process for recycling depleted pickling solutions, thus reducing the quantity of by product acids generated. Research has shown that F- can be liberated from the predominant iron fluoride species (FeF,') by using oxalic acid in an electrodialysis cell. Ion selective membranes allow dissolved metals in the depleted solution to be replaced with hydronium ions by metathesis, thereby regenerating the HF. The regenerated HN03/HF is then retained in the pick1ing solution. This paper reports on the research effort at the U.S. Bureau of Mines Rolla Research Center to apply electrodialytic recycling to HN03/HF pickling solutions.

Jan 1, 1993

By Oliver Bowles

From the most remote periods of civilization stone has been used to perpetuate the memory of individuals or to immortalize their noble achievements. Ancient memorials ranged from simple piles of stone (cairns), or single markers, to great obelisks and pyramids or magnificent mausoleums. The Taj Mahal at Agra, India, built of white marble by Shah Jehan in memory of the Empress Mumtaz Mahal, is one of the most beautiful and costly memorials ever built. It was erected between 1632 and 1650 at an estimated cost of $50,000,000 or more and is today an object of unusual interest for travelers. Other magnificent memorials both ancient and modern are to be found in many lands. No sharp line can be drawn between buildings and monuments, because the larger types of memorials such as the Bok Singing Tower, Lincoln and Jefferson Memorials, and mausoleums of various types have features in common with buildings. However, great care must be exercised in selecting a site for a quarry that will produce acceptable monumental stone because appearance as well as quality is of prime importance. The deposit must be of uniform texture and attractive color and must be notably free of knots, hairlines, impurities, incipient seams, or other defects. Many memorials are of polished stone, and spots or streaks that might be virtually Invisible on a natural rock face will appear distinctly on a polished surface. Hence, stone to be polished must be selected with unusual care. However, less flawless stone may be used for hammered surfaces.

Jan 1, 1955

By Keiji Watanabe, Hiroyuki Tobo, Yasutaka Ta, Hisahiro Matsunaga

Recently, effective utilization of by-product slag as aggregate for concrete has been expected from the viewpoints of depletion of natural crushed stone and suppression of environmental loads. We developed a new process for continuous solidification of blast furnace slag as coarse aggregate. In this process, molten slag is continuously poured into molds, and the slag is solidified at the thickness of 20–30 mm. The flow rate of the molten slag is 1 t/min, and maximum production per ladle is about 30 t. After solidification, blast furnace slag coarse aggregate (BFG) is produced by crushing and adjusting the particle size of the solidified slag. The new BFG has water absorption of less than 1%, and concrete containing the BFG has the same fresh property and compressive strength after 28 day as concrete using natural crushed stone aggregate.

Mar 1, 2018

By Ben E. Lusk

First of all let me say what a genuine pleasure it is to be here. Acapulco certainly is a beautiful change. I'm going to spend sometime talking about change, because frankly I'm astounded at the rate of change in our world today. One good example of this, reminds me that the first time I spoke before the AIME two years ago, we were at the Ramada Inn in Beckley, West Virginia. Today we're at the Princess Hotel in Acapulco, Mexico. Now that's what I call a change. Seriously though, I'm sure you've all heard it said that the most consistent thing about our society is its constant change. Five years ago, no one could have predicted the changes we experienced in the United States during the first half of the 1970's. In the past twenty-four months alone, we have seen two presidents, three vice-presidents and hundreds of administration and government personnel changes. We have stumbled from one social crisis to another, while suffering through rising inflation, major energy shortages and labor unrest that could plunge us into a full scale economic depression. In view of these constant and unpredictable changes around us, it's obvious that we must learn to deal with change and "roll with the punches" if we are to survive. A controversial book published recently, explores in detail the various aspects of change and its impact on man.

Jan 1, 1974

By Thomas P. Meloy

Theoretical development of comminution models has come about in the last 10 years. These models assume that the material being broken is homogeneous and that the compression or energy wave is uniform throughout the specimen. Obviously, this is not the case because most comminuted materials are rocks with either many phases and/or definite grain size. The mathematical models deriving the size distribution of daughter fragments resulting from the comminution of brittle, single particles are of two schools. The first model, proposed by Gilvarry in 1961, was based on the concept of volume, surface, and edge flaw activation. The second, proposed by Meloy in 1960, was based on the concept that the crack density is a function of the energy in the comminution wave. The flaw theory has run into increasing theoretical problems and is now being abandoned. On the other hand, the crack density theory has been expanded and has successfully considered the case where there are inhomogeneities in the comminutive wave. However, the main constraint of a homogeneity in the solid being comminuted has hitherto never been overcome. In this paper, a very general derivation of the crack density model is made for inhomogeneous solids by replacing the assumption of homogeneity with an arbitrary function, P(y), which describes the susceptibility of the material to comminution as a function of position. The restraints on this function, P(y), are very broad and, hence, the derivation is extremely general. General use of the equation derived necessitates a detailed a priori knowledge of both the fracture process and of the physical properties of the material being fractured; this knowledge is expressed in open form as, P(y), the linear probability density that a plane of fracture intersects at point y on an arbitrarily oriented line segment of total length xo through the original particle. From these assumptions, a general expression for the cumulative mass distribution of particles resulting from fracture is then postulated. It is: [ ] where, B(x), is a cumulative mass of material finer than size x, r is the average number of crack,, (y), is defined above and xo is the initial particle size. It is shown that suitable assumptions reduce the expression to the theoretical results of Gaudin and Meloy and to special forms of the empirical equations of Rosin-Rammler, Gaudin and Schuhmann. Semi quantitative agreement is demonstrated by Grimshaw with experimental results of a very complex fracture of heterogeneous sandstone blocks. A need is expressed for more theoretical development of P(y), and a more extensive experimental study of both homogeneous and heterogeneous fracture. The full mathematical derivation is presented for the first time in this paper. The general implications of the equation and its application are also discussed.

Jan 1, 1968

By Edward D. Thimons

As U.S. mines go to greater depths, the high temperatures and humidities characteristic of such depths make it difficult to maintain a comfortable environment in working areas. Better techniques for cooling these deep working areas are needed. At the Homestake gold mine in South Dakota the Bureau of Mines has tested a water spray cooler inserted into the fresh air vent tube entering a warm stope. The cooler supplied more than 6 tons of refrigeration to the stope air, which dropped from an inlet temperature of 83° F dry bulb and 75° F wet bulb to 73.5° F dry bulb and 71.5° F wet bulb. These preliminary results show the water spray cooler to be a feasible concept. However, there is a need for substantial refinement and further testing, and work on the concept will be continued under contract to the Bureau.

Jan 1, 1979

By J. J. Jakosky

"This report is the second of a series dealing with electrical methods of underground communication nd signalling, and is a discussion of some of the factors involved in -applying radio in mines.A previous report2 described the results obtained by the use of the ""T.P.S."" of ground-conduction method of signalling, and outlined in a general way the requirements for a practical mine communication apparatus.The popularity of radio, the development work on new apparatus, a desire to render humanitarian service to entombed miners, and an endeavor to find new uses and applications for radio stimulated many persons to attempt the application of radio to mine rescue purposes. A number of experiments on underground reception from surface broadcast stations have been conducted by different experimenters in various parts of the country and the widespread interest in the subject is shown by the fact that these tests have been con¬ducted in many States, The Bureau of Mines has received information regarding, underground tests in Illinois, Pennsylvania, Arizona, Utah, Idaho, Colorado, Michigan, Wyoming, Kentucky, New York, Connecticut, and in England, Germany, Italy, and Franc.From occasional press notices and illustrations in different papers it may appear that radio communication in mines and in tunnels being excavated is en established fact, and that the method is comparatively simple. As a matter of fact the reverse is the case."

Apr 1, 1924

By M. Soleimanifar

With more and more industrial construction projects implementing RFID and other sensor-based technologies on fabrication and project sites, new innovative processes are needed to help automatically read and re-position RFID tags while reducing the cost to deploy RFID infrastructure over large areas. RFID tags are being used on construction sites to help identify the location of materials, equipment and personnel to aid in finding project critical materials and equipment required to construct the industrial facility on time and on budget. This research provides a cost-effective process for reading tens of thousands of RFID tags over large project sites from outdoor laydown yards, to warehouses to the workface where the materials and tagged equipment are installed. Based on the collected RFID and sensor data, localization mechanisms determine the most recent coordinates of the tagged components. The paper will cover analysis of RFID collected data and key lessons learned from a commercial deployment of the SiteSense® system with one Alberta-based industrial contractor, JV Driver Fabricators, at an 80-Acre module, pipe spool and structural steel fabrication site.

Aug 1, 2013

My roots span four generations. My great grandfather, Christian Frederick Fisher, along with twenty-one others was drowned in the New Australasian mine disaster at Creswick in Victoria in 1882. My grandfather, also named Christian Frederick Fisher, escaped and then followed a career of shaft sinking for large companies and operating small mines (very unprofitably according to my father) when funds allowed. My father, an excellent practical mining and mechanical engineer, was also a small miner and my early entry into the industry was, like many before me, very basic. My introductions to the business end of a No. 4 shovel, drilling with hand steel and later with jack hammers without the benefit of airlegs, feeding heavy cordwood to hungry boilers and felling trees for mine timber soon dispelled any illusions I had that mining was a bed of roses.Before it became well known I knew "Life was not meant to be easy".In a family-owned small gold mine in a remote part of Cape York Peninsula in far north Queensland I was fortunate in obtaining an excellent grounding in reef and deep alluvial mining. Operating in vertical and underlie shafts the variable ground conditions often required close timbering. Steam pumps were used underground and steam winders for hoisting.The complete absence of municipal or government infrastructure in this remote mining field threw responsibility on each mine operator to be self-sufficient, and responsible for mine development and installation of crushing and milling equipment, accommodation and water supply. Conditions, although harsh, were acceptable in the 1930s, and fostered great self-reliance.The first crushing from our Black Cat Mine in 1935 returned nearly 200 oz from 10 tons of ore. Gold was then worth $13 an ounce compared to about $400 an ounce today; but in those depression years of the 1930s our operation was profitable.This basic education not only returned dividends when confronted with difficult mining problems, but created a deep respect for the miners who develop the small mines and who continue to contribute to the industry today, often under difficult conditions.Australia and mining are synonymous. The industry has been immortalised by the famous historian, Professor Geoffrey Blainey, in his book "The Rush that Never Ended".Initial gold discoveries were concealed and exploration was frowned upon by authority as being disruptive to early rural development. But with the discovery of gold in the Bathurst area of New South Wales by Hargreaves in 1851, the rush to the gold fields began followed by an influx of migrants. The traumatic effect on industry and society that followed, created the pattern of the love-hate relationship that at times became temporarily submerged, but is so evident today.In the harsh economic climate of the 19th century with low wages and no welfare, the opportunity to wrest riches from the earth was literally "rushed" by the adventurous, the poor, the rich, people from all walks of life. Pressures developed on preFederation Governments to provide law, order and infrastructure to the rushes that have never ended.

Jan 1, 1984

By Jorge Nelson Rivera Guillén

"La tierra es una unidad de un complejo astral que se observa desde la antigüedad en sus aspectos exteriores y su dependencia del sistema solar. En ese sentido, el presente texto señala la génesis y evolución de los minerales comprendido en la tierra a través de cuatro libros denominados ""Los misterios del planeta tierra"", donde se mencionan los aspectos tectónicos preliminares y preparatorios para la disgregación de la Pangea Nueva, cuya “lenta explosión” ocasionó la separación de las placas tectónicasy la acción de fuerzas distensionales que actuaron sobre los fragmentos que generan desequilibrios barotérmicosinternos y la formación de zonas magmáticas y metalizaciones."

May 1, 2015

By Patrick R. Taylor

United States Antimony Corporation, at its Yankee Fork property in central Idaho, is currently using a combination of flotation, gravity-amalgamation, and concentrate cyanide leaching, silver sulfide precipitation, and activated charcoal loading to recover both silver and gold. Tine processes of flotation, milling, gravity concentration, amalgamation, concentrate leaching, sulfide precipitation and gold recovery via charcoal are discussed. The flow sheet illustrates the use of cyanidation as an alternative to shipment to a smelter.

Jan 1, 1984

By Earl Bardwell

(Butte Meeting, August, 1913.) THE structural relations existing between cuprous oxide and copper were first systematically studied by Heyn1, who suggested that a study of the microstructure of refined copper might be substituted for the analytical methods in vogue for determining the oxygen content of copper coming .;from the refining furnace. Hofman, Green and Yerxa,2 in their paper A Laboratory Study of the Stages in the Refining of Copper, working along the lines suggested by Heyn, showed that a study off the microstructure could be made to yield a correct estimate of the oxygen content of the specimen of refined copper under examination. In order to determine the oxygen content of the specimen of refined copper under examination a photomicrograph was first made. From the relative areas of copper and eutectic, the percentage of cuprous oxide and the corresponding percentage of oxygen were then readily calculated. It was found that the values for oxygen thus obtained corresponded closely with the analytical results. With the idea of utilizing, this method of determining the oxygen content of each charge dipped from the refining furnaces at the Boston & Montana Reduction Plant, the physical testing laboratory was equipped with suitable apparatus for carrying out the work. It may be of interest to describe certain of the methods which have been worked out in, this connection and give such data as have been obtained bearing on the effect of the oxygen content of refined copper upon its conductivity.

Jan 7, 1913

By C. M. EYE

IN the spring of 1905 I was employed by Messrs. Bradley and Requa, under our fellow member, Thomas Cox, on the mill plans for the Nevada Consolidated, when an opportunity came to go to the Philippines to erect a small mill on the property of the Benguet Consolidated. This I accepted, expecting to be away eight months or so, but it was seven years before I got back. .I sailed in May, on the Coptic, having as room-mate as far as Kobe, A. E. Drucker, who was going out to Korea for the Oriental Consolidated. It was the first trans-ocean trip for either of us, and we had some rather unusual experiences. This was toward the close of the Russo-Japanese war and the Russian fleet was known to be on the way from Suez to Asiatic waters, but it was a matter of doubt whether they would risk a passage between Japan and the mainland, or take the longer but obviously safer route outside of Japan. The Coptic carried much contraband of war for Japan, so naturally did not care to meet this fleet. No definite word being available at Honolulu, we went to the Midway Islands, but the cable station there had very little information to offer, so we proceeded cautiously toward Japan. On the last afternoon out, we steamed due north at half speed for several hours, and finally sneaked into Yokohama at night, to learn that ' the Russian fleet had met the Japanese the day before and had been annihilated. We sailed over the spot in the Sea of Japan a week later, and when we got to Manila we found three of the Russian boats interned and being guarded by the monitor Monadnock and a cruiser. This was only a matter of form, as the Russians were only too glad to be there for the rest of the war, and the boats could not have gone far anyway, for they were literally shot to pieces. The Admiral's flagship had a hole within 3 ft. of the water line, for ward, through which a man could enter by stooping.

Jan 1, 1929

By James T. Wood

Stratigraphy, structure and closure of the Paloma field are discussed, with some details regarding the present state of development. The Paloma anticline, a large dome modified by faults, is the largest single closed dome in the southern San Joaquin valley without surface outcrop or topographic expression. It owes its discovery to geophysics. Of nine wells drilled to the Stevens sand, seven are productive. The ultimate productive area may approximate 3000 acres when the limits of the field are determined. Introduction The Paloma field derives its name from the Paloma school, ½ mile north of what is now the center of the field. The field is 17 miles southwest of Bakers-field, in the south central part of the San Joaquin Valley (Fig. I). The present developed area and its expected extensions are in townships 31 and 32S., R.26E. It is the most southerly of several fields that produce from the Stevens sand zone. The first well to produce condensate was a joint test drilled by the Western Gulf Oil Co. and The Texas Co. near the center of sec. 3, T.32S., R.26E., well No. 54-3. This well was completed on Aug. 31, 1939, at a depth of 10,178 ft. The initial production was 2280 bbl. a day of condensate and 14,750,000 cu. ft. of gas (½-hr. gauge) through a ?-in. bean. Prior to the drilling of this well, the Ohio Oil Co. discovered and developed a small gas field, which embraces a part of three townships about their common corner but lies chiefly in secs. 31 and 32, T.31S., R.26E. The first well was completed on July I, 1934, at a plugged depth of 5239 ft. after having been drilled to 7957 ft, production was found in a 59-ft. zone IIO ft. below the Fourth Mya bed, within the Sari Joaquin clays. Until recently this field was known as the Buena Vista gas field. It is now carried by the Division of Oil and Gas as the Paloma gas field. Production within the Paloma gas field is derived from six wells, producing from several different zones in the interval from 4177 to 5548 feet. Geology Stratigraphy The sediments penetrated by wells in the Paloma held range in age from Recent to Upper Miocene. The entire section, which exceeds 10,000 ft. in thickness, conforms generally to the standard section of the south central San Joaquin Valley. The producing zone, sometimes called the Paloma sand, is the approximate equivalent of the Stevens sand zone of the Ten Section, Canal, Coles Levee and other fields. The stratigraphic section is shown in Table I. Paloma Producing Zone* (Stevens Sand Zone, Upper Miocene) .-The Paloma producing zone (Fig. 2), frequently referred to as the Paloma sand, is encountered at depths ranging from 9950 to 10,300 ft. In general, it is a massive, firm to hard, not too well sorted, fine to medium fine sand. It is interbedded with thin, hard, calcareous sand shells of similar texture and cherty

Jan 1, 1942

By James T. Wood

Stratigraphy, structure and closure of the Paloma field are discussed, with some details regarding the present state of development. The Paloma anticline, a large dome modified by faults, is the largest single closed dome in the southern San Joaquin valley without surface outcrop or topographic expression. It owes its discovery to geophysics. Of nine wells drilled to the Stevens sand, seven are productive. The ultimate productive area may approximate 3000 acres when the limits of the field are determined. Introduction The Paloma field derives its name from the Paloma school, ½ mile north of what is now the center of the field. The field is 17 miles southwest of Bakers-field, in the south central part of the San Joaquin Valley (Fig. I). The present developed area and its expected extensions are in townships 31 and 32S., R.26E. It is the most southerly of several fields that produce from the Stevens sand zone. The first well to produce condensate was a joint test drilled by the Western Gulf Oil Co. and The Texas Co. near the center of sec. 3, T.32S., R.26E., well No. 54-3. This well was completed on Aug. 31, 1939, at a depth of 10,178 ft. The initial production was 2280 bbl. a day of condensate and 14,750,000 cu. ft. of gas (½-hr. gauge) through a ?-in. bean. Prior to the drilling of this well, the Ohio Oil Co. discovered and developed a small gas field, which embraces a part of three townships about their common corner but lies chiefly in secs. 31 and 32, T.31S., R.26E. The first well was completed on July I, 1934, at a plugged depth of 5239 ft. after having been drilled to 7957 ft, production was found in a 59-ft. zone IIO ft. below the Fourth Mya bed, within the Sari Joaquin clays. Until recently this field was known as the Buena Vista gas field. It is now carried by the Division of Oil and Gas as the Paloma gas field. Production within the Paloma gas field is derived from six wells, producing from several different zones in the interval from 4177 to 5548 feet. Geology Stratigraphy The sediments penetrated by wells in the Paloma held range in age from Recent to Upper Miocene. The entire section, which exceeds 10,000 ft. in thickness, conforms generally to the standard section of the south central San Joaquin Valley. The producing zone, sometimes called the Paloma sand, is the approximate equivalent of the Stevens sand zone of the Ten Section, Canal, Coles Levee and other fields. The stratigraphic section is shown in Table I. Paloma Producing Zone* (Stevens Sand Zone, Upper Miocene) .-The Paloma producing zone (Fig. 2), frequently referred to as the Paloma sand, is encountered at depths ranging from 9950 to 10,300 ft. In general, it is a massive, firm to hard, not too well sorted, fine to medium fine sand. It is interbedded with thin, hard, calcareous sand shells of similar texture and cherty

Jan 1, 1942

By Roy H. Poston

This paper sets forth the mode of ore occurrence, characteristics of ore and country rocks, methods of exploration, development, and. ore extraction, and the costs of underground operation at No. 8 mine of the St. Louis Smelting and Refining Works of the National Lead Co. located near the southern extremity of the Southeast Missouri lead district. The author acknowledges the assistance of E. T. Campbell, geologist, in the preparation of the paragraphs on the geology of the ores. HISTORY The first record of mining in St. Francois County, Mo., concerns more or less shallow semisurface "diggings" which were worked about the year 174-2. In 1864, however, the discovery of the disseminated deposits, the present source of lead, was made on property near the town of Bone Terre. Winslow has estimated the lead-ore production in this county prior to 1869 to be 59,526 tons.3

Jan 1, 1929