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By J. E. Elliott

ALTHOUGH the firm in which the writer is a partner is not exactly the pioneer in the coring of rotary-drilled wells in Southern California, it has taken the lead in bringing coring to its present status. To the Shell Company of California belongs the, honor of having first used the core drill in its endeavors to locate subsurface structures west of Santa Fe Springs. Following those operations, similar work was done near Wasco in the San, Joaquin Valley. Results of the latter core drilling were successful, in that they made it possible to determine the under-ground structure. At, about the same time that the Shell Company was doing the work at Wasco, it was experimenting in the use of the core drill in connection with rotary-drilled holes. The oil sands in its dis¬covery well at Signal Hill were located by means of the rotary core drill. In 1921, in view of the trouble that the operators were having in the fields of Southern California, and particularly at Huntington Beach, R. E. Collom, of the State Mining Bureau, called their attention to the possibilities of the core drill for eliminating many of the serious problems that were facing them. It was this same difficulty encountered by the operator in locating the oil sands that caused the writer to enter into con-tract core drilling; late in 1921 the California operators became converted to the advantages of that method, and in the short space of one year core drilling in rotary-drilled holes has risen from a theory to an established practice.

Jan 10, 1923

By D. L. Paulson

The Bureau of Mines used 50-and 800-kva electric-arc furnaces to confirm the feasibility of producing ferronickel in electric-arc furnaces from pre-reduced concentrate from the Yugoslavian FENI project. The relationships were established among metallic iron concentrations (degrees of prereduction), ferronickel grades, and nickel recoveries. Smelting the concentrate containing 1.27 wt-pct nickel and metallic iron levels between 2 and 3 wt-pct, produced 15 to 20 pct ferronickel. Higher or lower metallic iron concentrations were compensated by adding oxide pellets or carbon to the electric-arc furnace charge. Over 90 pct of the contained nickel was recovered when up to 20 pct ferronickel was being produced. Data obtained while smelting 16 tons of prereduced concentrate in the 800-kva electric-arc furnace indicated ferronickel can be recovered at an energy consumption of 530 kwhr/ton of prereduced material.

Jan 1, 1977

By Ray Hammond Misener

THE purpose of this paper is to describe the installation of the pumping station on the 3314-ft. level of the Carlos Francisco mine of the Sociedad Minera Backus y Johnston del Peru, at Casapalca, Peru. However, so much preliminary work was necessary before the actual installation could be started that some of that work will be described briefly, in order to clarify the discussion of the main subject. The Sociedad Minera Backus y Johnston del Peru, a subsidiary of the Cerro de Pasco Copper Corporation, owns and operates a group of mines in the Casapalca district, of which the most important are the Carlos Francisco and the Aguas Calientes. These two mines, one mile apart, are connected on their 2100 and 2700-ft. levels. These are motor-haulage levels, equipped with 3 ½ -ton Baldwin-Westinghouse locomotives operating from a 260-volt d.c. overhead trolley. A 38-cu. ft. hopper-bottom car is used. Each mine has a 2 ½ -compartment, inclined (70°) winze shaft. The Aguas Calientes shaft, operating between its 2100 and 2900-ft. levels, is used only for men and materials; whereas the Carlos Francisco shaft, between the 1700 and 2700-ft. levels of that mine, is the main operating shaft for the district. All the ore from the Carlos Francisco and the Aguas Calientes mines is hoisted through the Carlos Francisco shaft. The ore produced in these mines is by-passed to the 2700-ft. level, where it is gathered by the electric trains, taken to the Carlos Francisco shaft and dumped into an ore pocket in front of the shaft. The ore is hoisted to the 1700-ft. level in 2-ton self-dumping skips and emptied into a 150-ton loading pocket. There it is loaded into electric trains and despatched to the concentrator through the Backus and Johnston tunnel, which is the main entry from Casapalca to all the mines in the Backus and Johnston group. DEVELOPMENT PROGRAM In 1934 the following development program was outlined for the Carlos Francisco and the Aguas Calientes mines: (1) to deepen the Carlos Francisco shaft from the 2700 to the 3400-ft. level, (2) to deepen the Aguas Calientes shaft from the 2900 to the 3300-ft. level, and (3) to connect the two shafts on the 3300-ft. level with a motor-haulage crosscut. Each mine was to be developed also on intermediate levels (2900 and 3100). The three levels were to be spaced 54 meters (177 ft.) floor to floor, measuring from the 2700-ft. level along the incline of the shaft. The Carlos Francisco mine, together with the section between it and the Aguas Calientes mine, produces 10,000 gal. of water per minute. A fault to the north

Jan 1, 1943

By Takashi Furuyama, Sukeyuki Mori, Abel Bissombolo

"In flotation practice, a good recovery of minerals largely depends on the degree to which the valuable minerals have been liberated from the associated gangue during the grinding process. Therefore, a regular measurement of the degree of liberation can provide data for the assessment of the quality of separation and predicts the effect of changes in the grinding-classifying circuit on flotation process. Generally, the standard procedure for measuring the degree of liberation requires the preparation of polished sections - a time consuming operation that also has the disadvantage of providing an overestimated number of free particles because of the stereological nature of produced samples.The present work is an alternative approach to avoid these miscalculations and establish a system of control for fluorite flotation plants. The system deals no only with the state of liberation but also the dynamic behavior of individuals particles and mineral components within the grinding-classifying and flotation circuits. It involves methods such as sieving, x-ray diffraction analysis, study of polished sections and microscopic counting of preliminarily sieved minerals particles from a fluorite processing plant, randomly dispersed on a glass slide, but not embedded in a resin mounting medium. If a complete information on the textural properties of minerals in the ore (including its mineral components distribution) can be obtained through x-ray diffraction analysis and study of polished sections, the microscopic counting is used to determinate with enough accuracy the mineral liberation, estimate the grade of fluorite ore and products, determinate the deportment and approximate recovery of individuals particles and mineral components within the investigated circuit. For a count of 100-1000 particles in each n-size range, the counting method was found to be a particularly reliable and less time consuming operation that could substitute the chemical analysis of fluorite ore for an estimate of the grade:"

Jan 1, 2003

This paper discusses the type of scaling operations presently in use in underground mines. It defines a scaling factor that is expressed as the area necessary to scale to extract 1 t (1.1 st) of ore. The problems associated with conventional scaling methods are discussed as well as recent developments in mechanized hand-held scaling de- vices and methods of loose detection. The elements of the scaling process are further analyzed. The conception and design of a mechanized scaling device, developed at Universite' Laval is also described. The results of field tests conducted in Quebec hard rock mines are presented. The experimental findings show that the mechanized hand-held scaling device shows potential in improving the productivity and safety of underground mining operations.

Jan 1, 1996

By A. B. Isaeva, A. Yu. Lein, A. A. Karpenko, V. V. Serova, A. P. Lisitzin, V. Yu. Rusakov, V. N. Lukashin

Abstract - The flux of sediment matter was determined using sediment traps near a black smoker ("Saracen’s Head," Broken Spur hydrothermal field) and the mineral and chemical compositions of the settled matter were examined. The metallic minerals are represented by Fe sulfides (pyrite and pyrrhotite), and Cu and Zn sulfides are also found in small and equal quantities. The hydrothermal suspended matter contains abiogenic calcite in amounts comparable to that in Ca sulfates. The content of silica and, specifically, of amorphous Si is unusually low. Such correlations between chemical elements and minerals, together with the isotopic compositions of S and C, are characteristic of a relatively young and active stage in the evolution of a hydrothermal system. Sediment traps within and under neutrally buoyant hydrothermal plumes collected biogenic material in addition to hydrothermal components. Microbial chemosynthetic production of organic carbon near the hydrothermal vent is comparable to primary production in the euphotic layer. Fe, Zn, Ca, Si, Ba and P are enriched in particulate matter in comparison to the background. A vast compound plume containing the discharge of multiple hydrothermal vents was found to the south of the Broken Spur hydrothermal field.

Jan 1, 1999

By Robert B. Hoekzema

This Bureau of Mines report describes the history, characteristics, distribution, and mineral development potential of 21 lode gold deposits in or near the Chugach National Forest (CNF), AK. It includes findings from a 4-yr (1979 to 1982) mineral evaluation of the CNF conducted by the Bureau and the U.S. Geological Survey (USGS). This evaluation, undertaken to provide the U.S. Forest Service with mineral resource data for use in making decisions on land use, included site-specific mapping and sampling of more than 200-lode gold deposits. The data presented here were compiled from the findings of this 4-yr evaluation and from existing literature. Fourteen of the 21 lode gold deposits described in this report contain a combined identified resource of 117,750 short tons (st) averaging 0.55 oz/st Au and 0.2 oz/st Ag. Two mineralized felsic dikes in the Summit Lake-Palmer Creek area contain a combined identified resource of 18 million st grading 0.02 oz/st Au and 0.16 oz/st Ag. Identified resources were not determined for the remaining five deposits because of a lack of information.

Jan 1, 1987

By Chaves AP, Delboni H. Jr

Thermal comminution is an industrial process specially suited to very abrasive material, when contamination with Fe from wearing parts of conventional crushing and grinding equipment must be avoided. It involves an initial step of heating the material to be comminuted, followed by sudden cooling (quenching) and finally by a conventional mechanical process to disassemble the particle aggregates. The thermal step is, in fact, a pre-fracturing process. The heating operation causes changes in phase of the minerals and changes in volume of these minerals and other substances included in pores and cracks. The cooling operation causes thermal shock reversions or the phase transformation and consequent generation of internal stresses, high enough to fracture the solid.

Jan 1, 1993

By A. Alwasel

Musculoskeletal disorders (MSDs) threaten the wellbeing and livelihood of a large number of construction workers incurring a significant cost to society. We present a new method to monitor and diagnose MSD risks in the workplace. The sensing unit of the system is an optical encoder encompassed within a non-intrusive exoskeleton to measure the joint angle of interest. This sensor can be applied to ball-and-socket and hinge-type joints of the human body, such as the shoulder, elbow, and knee joints. The system is contactless and does not require markers or cameras. Angle measurements are acquired directly without mathematical post-processing, thereby avoiding numerical noise and drift challenges. The system is a simple, robust, and deployable, but it currently lacks resolution of parallel degrees of freedom.

Aug 1, 2013

By Edward B. Walker, Michel Grosmangin

The geological and economic conditions peculiar to the Greater Oficina area are presented to demonstrate the necessity of a low-cost, well-site method of distinguishing gas-bearing formations. The method of gas detection with the neutron log is briefly discussed and its limitations are explained. A new method is described which consists in running a second neutron log with a larger source-to-detector spacing. Field data indicate that under favorable conditions the larger spacing response is proportionately more influenced by the virgin gas zone than is the shorter spacing response. One important condition is that the gas sands be invaded, with a diameter of invasion equal to about two to three times the hole diameter. The calibration of the longer spacing log is made so that the two logs read the same deflection in shale and in a known water or oil sand. Under such conditions, gas is indicated by a positive separation, i.e., the curve for the longer device is displaced to the right of the curve for the shorter device. Because of the non-linearity of the long spacing response, low porosity formations also show positive separations. In sands with large porosity variations, the gas sands can no longer he located visually. They can be detected on a plot of shorter spacing vs longer spac-ing deflections. INTRODUCTION In the Greater Oficina area of Eastern Venezuela, the rapid and accurate detection of gas from well logs is of primary importance because of a combination of economic, geologic, and operational conditions. Briefly, these conditions are: economic—there is no market for gas at the present time; geologic—a single well may contain as many as 30 or more oil or gas sands for which intervals -to be tested must be selected; opera-tional—first, once opened to the casing through perforations, gas sands are extremely difficult and expensive to squeeze off, and second, gas detection must be rapid because the geologist must decide immediately, at the well, which sand to perforate. During the early period of exploitation in Greater Ofi-cina, when clay base muds were used, sidewall samples, together with electric logs, gave fairly good distinction between oil and gas sands. When exploitation became concentrated on deep fields of poorer sidewall sample recovery, and after the advent of oil emulsion muds, now the standard drilling fluid in Greater Oficina, the regular neutron log became the most reliable indicator of gas. In 1953, R. Norelius devised the dual-spacing neutron technique for gas detection. The dual-spacing neutron log has proved to be highly successful in detecting gas and has been adopted as a regular survey by all of the oil companies of the area. Several hundred dual-spacing neutron logs have been run in Eastern Venezuela and several tests per well are available for positive evaluation of the logs. The findings outlined below are based upon this extensive field experience. GEOLOGICAL CONDITIONS OF THE GREATER OFICINA AREA The Greater Oficina area lies on the south flank of the Eastern Venezuela Basin (Fig. 1). Nearly all accumulations of oil and gas in the area are trapped, in whole or in part, against normal faults. All known oil and gas reservoirs in Greater Oficina occur in the Ofi-cina formation (Miocene-Oligocene) or in the "U" sands. The U sands are the lithologic equivalent of the Merecure group (Otigocene-Eocene), which contains oil in many fields north of Greater Oficina. Most of the petroleum produced in Eastern Venezuela is from the Oficina formation.

Jan 1, 1958

By C. P. Lazzara, R. A. Franks, G. F. Friel, J. C. Edwards, J. J. Opferman

A fire detection research program conducted at the National Institute for Occupational Safety and Health (NIOSH) Pittsburgh Research Laboratory (PRL) recently demonstrated the advantage of multiple fire sensors for early fire detec¬tion and nuisance alarm discrimination in underground coal mines. As an example, research has shown that an appropriate combination of smoke, CO, and metal oxide semiconductor (MOS) sensors has the capa¬bility to detect a smoldering conveyor belt fire which produces low visibility due to smoke, but CO concentrations too low for an early fire alarm. Such a sensor combina¬tion has the additional advantage of being able to distinguish a nuisance alarm event such as those produced by diesel engines or acetylene torches from mine fire products¬-of-combustion (POC) produced by a real tire. Research has also shown that the problem of hydrogen (H2) gas cross-interference with chemical CO sensors at battery-charging operations in diesel-emissions backgrounds can be resolved with a smoke sensor and a MOS sensor sensitive to NOx associated with diesel emissions. Other underground conditions, such as rock dust, exacerbate the problems with sensors. NIOSH has developed a neural network that takes many of these variables into account as it assesses real-time sensor data to discriminate nuisance alarms.

By Thomas A. Davidson

The Bureau of Mines Helium Field Operations has developed a method for determining the helium-3 CHe) content of natural gas and mixtures eontaining 0.5% to 100% helium. The helium is preconcentrated by passing samples through anhydrone, a liquid-nitrogen-cooled chareoal trap, and a titanium absorption trap. The mass spectrometer used to analyze the samples is tuned to 3He at mle ::=; 3.016. Hydrogen deuteride (HD+) interference is minimized by the titanium absorption trap and high instrument resolution. Sample measurements are compared with identically made measurements of a gravimetrically prepared primary standard. The method has a limit of detection of 0.15 ppb with a relative deviation of 13% below the 1~ppb level. The relative deviation is less than 7% for gases eontaining over 100 ppb 3He. The helium isotope ratios of natural gases from the Bureau's Tuck-Trigg Dome Red Cave, the Bush Dome Red Cave, and the Bush Dome Brown Dolomite Formations are distinguishable from one another and from the isotope ratio of crude helium produced from the Panhandle-Hugoton Gasfield.

Jan 1, 1990

The following list contains the names of members of whose deaths notices have been printed in MINING AND METALLURGY during the year ending April 1, 1939. Biographical sketches published in MINING AND METALLURGY are indicated in the last two columns.

Jan 1, 1941

By E. W. Bauman

The important role that mineral aggregates assume today in the construction and chemical industries is best attested to by the astronomical tonnage figures for the annual production of aggregates in the United States as reported by the U. S. Bureau of Mines in their "Minerals Yearbook." For 1965, latest publication available, the tabulation shows a total of 1,716,000,000 tons made up of 30,000,000 slag, 908,000,000 sand and gravel, and 778,000,000 crushed stone. A much more favorable statistical position for slag can be established by listing the world-wide tonnage. According to Dr. A, W. Lee, Director, British Slag Federation, in a paper presented before the 8th Annual conference of the British Institute of Works and Highway Superintendents, he estimates that the probable world consumption of slag is in the order of 100,000,000 tons showing--Great Britain with 10,000,000 tons, Germany, 15,000,000 tons, France, 1$000,000 tons and the United States with 30,000,000 tons. Thus it is seen that the United States accounts for almost one-third of the world's consumption of slag and the 3 west European powers another third.

Jan 1, 1967

By Mosusu N

Geothermal anomalies of different types occur within distinct geological/structural settings in Papua New Guinea. According to R.F. Herring, geothermal occurrences in Papua New Guinea can be classified into two types, those related to vulcanism (Lihir, Rabaul and other series of islands along the volcanic arc) and those resulting from a regional heat flow probably caused by radiogenic sources, for instance those in the Wau/Bulolo area. The manifestation of this potential source of energy generally coincides with either converging or diverging tectonic plate boundaries. Previous inventories on thermal waters were carried out by vulcanologists from the Rabaul Observatory in the early 1960s. However, these studies rarely included chemical analyses of water and gas emissions and the investigations were carried out in an ad hoc manner, generally as a secondary activity. The most recent investigation on thermal waters was conducted on Lihir Island in connection with the development of the open pit gold mine. These studies included detailed exploratory drilling to a maximum depth of 730 m, and a water chemistry isotopic sampling and analysis programme. The hydrothermal waters were not considered as an energy source but as a hazard during the development stage of the mine. Nevertheless, the geothermal anomaly observed at Lihir includes hot springs emerging along the coastal zones with temperatures that approach 100¦C, steam, and thermal borehole waters with temperatures that exceed 200¦C. Chemical analysis results of thermal fluids from Rabaul, Talasea and other areas in Papua New Guinea generally show high total dissolved solids and low pH. In contrast, recent results from the deepest and hottest thermal source at Lihir shows a neutral pH, a Na-CI-SO4 composition and temperatures above 200¦C. Despite the concentration of chloride being similar to that of sea water, other chemical results and stable hydrogen and oxygen isotopic compositions of thermal fluids imply the source to be mixture of local meteoric water and deep thermal water rather than sea water. Results of geothermal modelling suggests that the total geothermal uptlow is equivalent to 54 MW.

Jan 1, 1997

This paper describes a plant built at The Broken Hill Associated Smelters, Port Pirie to sample lead sinter automatically. As the plant is still in the commissioning stage results on the precision and accuracy of the sampling are not yet available, but some of the difficulties experienced during commissioning are discussed.

Jan 1, 1976

By J. O. Claassen

"Homogeneous populations are required to perform descriptive, probabilistic, and inference statistics and to support stable, predictable mining operations. The geological and downstream processing environments are, however, highly heterogeneous. The complex nature of mining environments requires means to identify and define multipopulation environments that could affect the performance of mining value chains. A study performed at several operating mines suggests that the impact of heterogeneous or variable geological, mining, and plant processing environments on overall mining value chain performance may not be a key focus area at these operations. This was illustrated through the use of basic and spatial statistics, which included the log-probability plot, a modified range equation, and chronovariography. The findings reflect high relative variability in the geological and processing environments studied and mining operators’ inability to effectively deal with the sources and consequences of variability. The study suggests that a focus on heterogeneity in complex mining operations may significantly enhance overall mining performance. IntroductionHeterogeneity and why it mattersHeterogeneity refers to a state or quality of being variable/diverse and comprising different non-compatible elements or parts. In statistical terms a heterogeneous population can refer to a population comprising different non-compatible sub-populations or a multipopulation environment. The latter is commonly found in natural environments such as geological environments (Bardossy and Fodor, 2001). The inherent heterogeneity of complex geological environments is also referred to as spatial heterogeneity. Heterogeneity or variability, however, also occurs over time at mining operations. A case in point is variable ore composition on a conveyance system feeding a processing plant or product stockpile.Heterogeneity associated with the mining environment can significantly influence key aspects of day-to-day mining operations such as sampling, the use of descriptive, probabilistic, and inference calculations, and an operation’s ability to manage and control the mining value chain as a whole."

Jan 1, 2016

By Claus Guenter Goetzeil

(New York Meeting, February, 1937) The object of this investigation was to determine whether silver alloys could be used instead of the currently employed insert of high-expansion Average Coefficient per Deg. C. over Range 20° to 200° C. Pure aluminum..................................... 24.6 X 10-6 Cast low-expansion Si-Cu-Ni-A1 piston alloy............ 20.0 X 10-6 High-expansion austenitic Cu-Ni cast iron.............. 19.3 X 10-6 Cast steel (0.25-0.35 C, 0.40-1.0 Mn).................. 12.6 X 10-6 Cast iron (3.15 total C, 2.16 Si)....................... 12.8 X 10-6 Pure silver.......................................... 18.9 X 10-6 austenitic ferronickel alloy, to reduce the wear of ring grooves in light metal pistons. A typical example of a piston containing a ferronickel insert is shown in Fig. 1. The high coefficient of expansion of silver made it worthy of consideration, while the small size of the insert would render its use feasible in Germany as an emergency measure. The coefficients of linear expansion of several metals and ailoys are as shown in the table above. Obviously the melting point of the insert must be high enough to prevent it from melting when the light alloy is cast around it. This imposes a lower limit of about 850" C. for the solidus of the silver alloy. Pure silver melts at about 961" C., so that the tolerable depression in the solidus is rather small. To avoid deformation of the insert during use a Brinell hardness number of at least 60 appears necessary.

Jan 1, 1937

By Robert A. Westin

Polychlorinated biphenyls (PCBs) are a group of chlorinated chemicals that were used in many different fire resistant hydraulic fluids, heat transfer fluids, and in electrical equipment as dielectric liquids. PCBs were manufactured primarily by Monsanto Chemical Company under the tradename Aroclor, and were used by many different electrical equipment manufacturers. PCBs are noted chiefly for their extreme chemical inertness. This resulted in exceptional fire resistance and long life in applications involving exposure to high temperatures and intense electrical fields. This combination of properties resulted in PCBs being widely used in electrical equipment used in mines, including transformers, capacitors, and some electric motors. PCBs were also used as working fluids in some heat transfer and hydraulic sys terns. The same chemical resistance that gave PCBs long life in industrial applications give PCBs essantially eternal life when they are released into the environment. PCBs are not highly toxic in the sense that exposure does not cause immediate health problems. However, PCBs accumulate in the human body and neither degrade nor are eliminated from the body, and long-term exposure to PCBs can result in changes in liver function which may increase susceptibility to the carcinogenic effects of other chemicals. PCBs also accumulate in the food chain; the concentration of PCBs in fresh water fish may be several hundred thousand times as high as in the water the fish are taken from.

Jan 1, 1981

A zone rich in-fish debris in the Rolling Dow= Group in the sub-surface of the Great-Artesian Basin has been discovered a Further research has shoe i this zone to-be of very wide distribution in the Artesian Basin and to occur. at the base of the Ta?nbo .f ormati'on resting on the Roma forma-tion. The zone gives a very characteristic curve on the electric and' gamma ray logs and is thus an excellent correlation marker in the sub-surface over a very wide area. It is probably to be correlated sith.the Toolebuc member described from: outcrops east of Boulia. There .are apparent similarities between the Fishecale zone of the Great Artesian Basin in' Australia and the Fishscale sand of the Western Canada Sedimentary Basin.

Jan 1, 1962