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By Baisheng Nie, Longlong Yang, Tao Yang, Wenjie Jia

"Gas adsorption in coal is an exothermic and physical process. Temperature might change during the dynamical process. In order to get the temperature variation of gas adsorption process, the experiment system which can test the temperature variation and analyze the thermal effect was established. Gas adsorption experiments under different conditions were done by using the test system. The results show that temperature increases during the adsorption process. It is an exothermic reaction process. Also, the temperature variation and the variation gradient increase with the increasing of equilibrium pressure. The temperature variation value is smaller if the experiment temperature is higher. The paper will provide basic experimental data for explaining gas adsorption mechanism better.INTRODUCTIONChina is the largest coal producer in the world while it also has the most serious coal mine disasters. According to the statistics, there are nearly a thousand coal mines in China including more than 110 the key state-owned mines risking to happen coal and gas outburst. Hundreds of coal and gas outburst occur each year which often causes serious casualties and economic losses (State Administration of Work Safety, 2007). With the continuing exploitation of the coal resources, the depth of the Chinese coal mines increases about 100 meters every year which causes the situation of gas accident becoming more and more serious (Xie et al., 2006).At present, the real mechanism of gas adsorption, desorption and the diffusion process in coal and the influence factor of it are not so clear. And because of the limit of prediction method and the technological level caused gas accident prevention theory and technology not so valid."

Jan 1, 2015

By Alain Denis, Marcelo Curtes Martins, Jeferson Rocio de Oliveira

In this work we present a study of optimization of a new inhibitor for turbulence pickling line. The efficiency of inhibition was measured and the weight of loss was evaluated in four different materials to optimize the dosage of the inhibitor. In seven months we had 8.7% of reduction in pickling losses.

Oct 1, 2019

By T. B. Jarboe

The 150 MWe circulating fluidized bed (CFB) power plant described in this paper is the product of recent Bechtel experience in the industrial power and steam market, where the economic feasibility of fluidized bed projects has been proven. The inherent ability of CFB boilers to burn low grade fuels makes it possible to also burn low ranking coals or coal wastes, including anthracite culm, coal mine rejects, and coal wash plant waste slurry. The impact of fuel characteristics on plant design is addressed. This includes solids handling, steam generation, sulfur capture, and auxiliary load requirements.

Jan 1, 1988

By F. A. Forward

Introduction The main line of ascent in the development of the nickel industry may be traced back through the International Nickel Company of Canada, Limited, to its earliest antecedents, the Canadian Copper Company and the Orford Copper Company. Mining geology is but one aspect of the overall development of this organization, and the stress it has placed on geology grew according to the need. In the early days, intensive geology was not required because ore supply was not one of the main problems of this or any of the pioneer companies. The difficulty then was to find economic methods for reducing the ores to nickel and copper, and markets for absorbing nickel in the face of a limited demand from consumers heavily prejudiced in favour of the New Caledonia product. "Very early in the history of the region it was patent to everyone that to share in the full benefits of the industry the same individuals or company must control the whole of the operation necessary to manufacture the finished product' (1, p. 45). These conditions were fulfilled for the International Nickel Company in 1902 when the Canadian Copper Company (incorporated 1886), with its ample ore supply, took the initiative to merge its interests with those of the Orford Copper (Refining) Company (incorporated 1887) to form the new company which, with reorganizational changes, emerged as the producer of the overwhelming bulk of the world's nickel. The Mond Nickel Company, Limited, entered the field in 1899 with a refining process, and over a period of years acquired ore through purchase of mining properties. This Company operated successfully and independently until 1929 when its assets were joined with those of the International Nickel Company in order to permit the most economic exploitation of the Frood-Stobie orebody in which both Companies were interested.

Jan 1, 1948

By Alfred James

Some months since, in the Johannesburg gold-fields of South Africa, the attention of the author was directed to certain statements to the effect that the gold-contents of foul or extremely dilute cyanide-solutions could not be effectively precipitated in practice by the usual zinc-method. Such statements caused all the greater surprise, because it is well known that this difficulty is not encountered in other wellknown districts, as, for example, in New Zealand, where solutions containing less than 0.05 per cent. of KCy are regularly reduced in practice to below 1 grain of gold per ton, while in Mexico and the United States almost equally satisfactory precipitations are not uncommon. As a result of these representations, however, the author visited several plants at work in the Transvaal, and noted that while at some few mines the precipitation was really excellent, at others the effluent, after treatment, was much too high in bullion-contents. An investigation into the causes of these unsatisfactory results disclosed the fact that more attention to the close packing of the zinc-shavings in the extractor-compartments tended to improve the results, even with the most dilute solutions. The function of the zinc being one of surface, it stands to reason that a compartment well filled with zinc would be more effective than a half-filled one. Moreover, the quality of the zinc was inferior. This should be in long, tough, thin, light threads; light enough to ignite readily, and tough enough not to disintegrate easily into a slime. The coarse shavings too frequently employed appear to give the reverse of the best practice ; they are brittle, contain less surface, and take up more room. It is almost impossible to pack a compartment properly

Jan 1, 1898

By Yongteng Dong, John P. Quinn, Bradford Wesstrom, Guikuan Yue

With increasingly low-grade copper ores being mined, it is difficult to handle growing concentrations of As, Sb, Bi and/or Fe in the whole flowsheet, especially during copper electrorefining. To better elucidate the effects of those impurities on the quality of cathode deposit and/or current efficiency, a detailed speciation study of the electrolyte under industrial conditions is required to quantitatively describe their distribution in the solution, thereby facilitating their effective control and removal. In the present study, a thermodynamic model of complicated iron-arsenic-copper-sulfuric acid electrolyte under industrial conditions was developed. The main species of those elements involved in the electrolyte were first identified, and their thermodynamic data were collected and critically assessed. Those data were then used to estimate the activity coefficients of species, and to calculate the equilibrium constants from 25°C to 70°C. The developed model provides a mathematical tool that is capable of quantifying the concentrations of free ions and complexes in terms of temperature and solution composition. Finally, oxidation-reduction potential measurements were employed to validate the model. INTRODUCTION In copper electrorefining, impurities like arsenic, antimony, bismuth and/or iron can partially dissolve in the electrolyte and accumulate gradually, and eventually cause problems such as bad cathode deposit (co-deposition with copper or mechanical inclusion from the floating slime), lower current efficiency, etc., which eventually increases the operating costs. The presence of impurities may substantially reduce properties of copper products such as conductivity, corrosion resistance, mechanical properties, and leads to more energy consumption (Schlesinger et al., 2011; Jafari et al., 2017). To remove these impurities, various methods have already been proposed and applied in industrial copper production, such as solvent extraction, ion exchange, chemical precipitation, absorption by activated carbon, etc. (Cunningham et al., 1997; Navarro et al., 1999; Toyabe et al., 1987). In addition, adding reducing agents such as sulfur dioxide and trivalent arsenic could also precipitate arsenic, antimony and bismuth from copper electrolyte, by changing the distribution of impurities with various valence (Braun et al., 1976; Xiao et al., 2007). The disadvantages of those methods include high energy consumption, serious contamination, lower selectivity and efficiency, and so on.

Jan 1, 2019

By Mirian Mamani

Como resultado de la exploración por litio, hoy se conocen ocurrencias importantes (de hasta 3,000 ppm de litio) en la tobas de composición riolítica en la región de Puno, Perú. Para conocer el estado actual de las principales concentraciones de litio en rocas félsicas (granitos y riolitas), se ha compilado información geoquímica (>10,000 muestras) de varias fuentes en el territorio peruano. La distribución espacial y temporal de las concentraciones de litio muestra que los valores mayores a 300 ppm se encuentran en las rocas félsicas, riolitas del Oligoceno-Mioceno y monzogranitos del Triásico del trasarco, y también en los diques de sienitas nefelínicas (30-100 ppm); todas las cuales se ubican en la margen oeste de la franja de Sn, W, Mo. Los valores más altos (mayores a 600 ppm) corresponden a la región de Puno. Sin embargo, niveles de tobas retrabajadas del altiplano que fueron emitidos por las calderas volcánicas del trasarco y sedimentos que desembocan en el lago Titicaca muestran concentraciones de 100 a 400 ppm de litio. Además, las fuentes termales de Tacna y Moquegua contienen entre 10 y 50 ppm de litio, lo que indica que por debajo de los volcanes recientes existen sedimentos con litio. Finalmente, debe indicarse que el mayor potencial de litio (3,000 ppm) está relacionado con los minerales denominados como macusanitas.

Nov 30, 2018

By J. W. Borough

THE electrical conductivity of pure copper is markedly decreased by small amounts of impurity in solution. The magnitude of this effect has been very carefully determined by numerous investigators who studied a wide variety of impurity elements. Much of this work is summarized in an excellent review by Pawlek and Reichel.' The case of zinc impurity in copper is an exception to the above in that there has been no well-documented study of the effect using high-purity starting materials. The values for the effect of zinc on conductivity, which are usually taken from unpublished work by Skowronki, indicate that zinc in low concentration has no effect whatever in lowering the conductivity of pure copper. This effect, if true, is unusual since it is generally known that even in lowest concentration, impurities exert an effect on conductivity which is proportional to the amount dissolved. It is more reasonable to suspect that in the original work on the effect of zinc some of the zinc was oxidized out of solution during specimen preparation. The following experi- and calculated d-spacings based on the unit cell dimensions of Baenziger et al. Since the single crystal studies of Baenziger et al. were limited to (hk0) and (hk 1) data, it was not possible to Compare all the intensities of the powder and single crystal patterns. However, the strongest reflections of both studies, the (321) reflection, agree very well when the appropriate multiplicity factor is used. Good agreement was also found in a number of other reflections of lesser intensity. Despite the precautions taken in annealing the U6Fe powder, an appreciable amount of UO, was detected in the powder pattern after heat treatment. The powder pattern reported by Groganoand Clews is given in Table I. Except for the 3.15A line, which is the strongest line of UO,, their pattern, as far as it goes, compares favoEably with the data from this study. Gordon and Kaufmann have reported a diffraction powder pattern purported to be U, Fe but it bears very little resemblance to the patterns of Table I. ments were carried out to redetermine the effect of zinc on conductivity using high-purity starting materials and processing conditions capable of producing oxygen-free alloys. Materials used in the experiment were ASR 99.999 pct Cu and Cumingo 99.999 pct Zn. Four 1 lb melts were prepared with identical procedure in argon atmosphere with crucibles made from Speer No. 580 graphite. The compositions were 0.0, 0.1, 0.3 and 1.0 pct Zn. Standard No. 14 wire (0.064 in. diam) was made from these melts as follows. The 1 pct Zn sample was first reduced 94 pct by cold swaging with five annealing treatments of 800o for 10 min in hydrogen between swagings, and then reduced 94 pct to the

Jan 1, 1962

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 R Shrimali, P Rajmeny, L Shekhawat, A Joshi

Rampura Agucha open pit mine has successfully been excavated to a depth of 320 m, incorporating multistage working. The key to success is the implementation of presplitting as control blast measures at every stage of mining, including intermediate cut backs, in addition to the final wall. The major challenges encountered in establishing presplitting in the hang wall as compared to the footwall of the mine are:reversely dipping foliation, ie dipping into the hang wall itselfstriking obliquely at an angle of 20–30° with regards to the general strike of the pit wallthe presence of numerous geological planes of weaknesses like major faults, slips, etc.Control blast parameters like hole inclination, spacing and stand-off with buffer row were chosen initially from the literature survey and were subsequently fine-tuned by field trials to the mine geo-mining conditions of the hang wall. Electronic initiation used for trim blasts along with double presplitting in fault-affected zones helped in getting better presplit performance and resultant stability of the hang wall.CITATION:Rajmeny, P, Shrimali, R, Shekhawat, L and Joshi, A, 2015. Establishing the design parameters of a control blast for long-term stability of the hang wall at Rampura Agucha Mine, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 437–446 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Laxman M. Amaratunga

Laboratocy flarmnability tests were perfonned on dust samples from Fraser Mine in a 1.2 L Lindenburg horizontal tube furnace to detennine the percentage of sulphur oxidized during ignition. The explosion pot ential of sulphide dusts depends on their degree of spontaneous oxidat ion, which was measured by the quantitative analysis of so2 gas released during ignition. Test results indicated that dusts with low sulphur content could exhibit a higher degree of oxidation than a sample with high sulphur content. txlst characterisation using image analysis techniques suggests that the structure and the texture of dust are important factors influencing the explosibility of sulphide dust at ignition temperatures. Therefore for safe mine operations% sulphur content cannot be considered as a reliable single index that could be used to predict the potential of a sulphide dust explosion. Physical, chemical and mineralogical characterisation of dust plays an important role in the detennination of suitable indices for the prediction and prevention of sulphide ore dust explosions.

May 11, 1988

By W. Denham Verschoyle

IN designing a pocket instrument whereby any given horizontal or vertical angle may be closely approximated, the following points should be kept in view, if general utility is aimed at 1. The instrument should be light and compact, so that it can be carried in the pocket, or in a sling. 2. It should be capable of observing any angle whatever, horizontal or vertical. 3. Since time is often an important consideration in making a preliminary survey, it should be capable of giving the horizontal and vertical angle at one observation. I do not know of any instrument that will fulfill these requirements, except the one here described. Where the depression- or elevation-angle of the distant object, whose bearing is required, exceeds 50 or 60 degrees, it becomes difficult or impossible with a prismatic compass, for instance, to obtain accurate results; and since it frequently happens, particularly in mining, that much work requires to be done beyond that limit, it is obvious that an instrument which can be used to observe a high angle just as easily as a low one, if not absolutely a necessity, will at least be a great convenience. How this " pocket transit " attains to the required degree of universality will be understood from the diagram, Fig. 1, in which B is a beveled, graduated circle, attached to and freely revolving about the center of the magnet A. Light falling on B is reflected through a window in F (the compass-box), along the line AC, and is again reflected back to the eye at D by the prism C. By a simple arrangement, the sight-line DCE can be completely revolved in the vertical plane DE, which is normal to AC. It is clear, then, that no matter through what vertical

Jul 1, 1907

By I Govender, T L. Moodley

Tumbling mills are grossly inefficient, using only 5 per cent of the total energy supplied for actual breakage. A significant proportion of this inefficiency is unavoidable owing to geometric limitations; rotating drum systems are prone to exhibiting certain regions (energy barriers) that resist particle entry thereby restricting the transfer of energy. Though such systems are inherently inefficient, improved modelling schemes may lead to slightly enhanced efficiency through better microscale predictions of key breakage drivers (stress, force). Central to achieving such incremental advances is the development of a universally accepted rheology for dense granular flows. Armed with a better understanding of these macro-scale ingredients, classical process modelling offers an efficient, spreadsheet friendly framework for recovering the spatial distributions of the comminution drivers. At this real-time level of process control, it should be possible to tune comminution operations towards more energy efficient configurations – the ultimate goal of this research. The present work employs validated DEM data to recover the full continuum field which will ultimately serve as a basis for calibrating process model outputs based on different rheological hypotheses. Such a continuumbased approach captures tensor properties like the shear stress and strain rate – both of which are necessary to developing a dense granular rheology. Moreover, DEM captures this data at the momentum transfer timescale of 10-6 s – no other measurement technique is capable of this level of spatial and temporal resolution. Importantly, the confidence in this DEM data is strengthened because it has been validated at the continuum scale using Positron Emission Particle Tracking (PEPT) kinematic measurements. Validated DEM data is derived from batch experiments conducted within a 300 mm ID laboratory drum using three and five millimetre glass beads at 60 and 75 percent critical speed; such mill speeds are typically encountered in the tumbling mill industry. Dimensional analysis is conducted using critical rheological parameters (shear rate, shear stress, granular temperature etc), which are key to not only developing a granular rheology but ultimately will be used to tune our mechanistic models.

Aug 24, 2022

By J. N. Van der Merwe, D. P. Roberts

The two components of pillar design formula being used in South Africa are pillar strength and pillar load. While considerable effort has been directed to the determination of pillar strength, the other half of the safety factor equation, the load, has not received the same amount of attention. The load acting on pillars has always been calculated using the Tributary Area Theory (TAT). This paper summarises the recent studies on coal pillar loading using various numerical models. It concludes that although there are meaningful differences under certain circumstances, there is still a compelling argument to use the TAT in coal pillar design. Les deux parties composantes de la formule de conception de pilier généralement utilisée en Afrique du Sud sont la résistance de pilier et la charge de pilier. Tandis que des efforts considérables on été dirigés vers la détermination de la résistance de pilier, l’autre moitié du facteur de sécurité n’a pas reçu la même attention. La charge agissant sur les piliers a toujours été calculée avec la Théorie d’Aire Tributaire (TAT). L’étude présente résume les études récentes sur la charge de pilier de charbon utilisant des modèles numériques variés. La conclusion est que bien qu’il y ait des différences significatives selon les circonstances, il y a toujours un argument puissant pour utiliser le TAT dans la conception de pilier de charbon. Die in Südafrika für die Auslegung von Pfeilern verwendeten zwei Formelkomponenten sind Pfeilerstärke und Pfeilerbelastung. Während beträchtlicher Aufwand zur Bestimmung der Pfeilerstärke gemacht wurde, wurde der anderen Hälfte der Sicherheitsfaktorsgleichung nicht die gleiche Aufmerksamkeit gewidmet. Die auf die Pfeiler wirkende Last wurde immer unter Verwendung der Tributary Area Theory (TAT) berechnet. Diese Arbeit fast neuere Studien betreffend der Belastung von Kohlepfeilern unter Verwendung verschiedener numerischer Modelle zusammen. Die Schlussfolderung ist, daß obwohl unter bestimmten Vorraussetzungen bedeutende Unterschiede existieren, nach wie vor ein bezwingendes Argument besteht TAT in der Kohlepfeilerauslegung zu verwenden.

Jan 1, 2003

By J. R. Maxwell

In 1970 expansion was completed increasing mill capacity from 2,000 to 3,000 T.P.D. Actual grinding capacity is 3,400 T,P,D. at a grind of 60% -200 mesh,The ore bodies are vein type, containing about 12% sulphides, with mill heads averaging 2.25% Cu, 0.015 oz.Au, and O.4O oz, Ag. per ton.Summary and Conclusions:During the period Jnnuar-1 1971 to December 1973 inclusive the use of large cells at Opeminka have shown that metallurgy is comparable to when using conventional cells, Operating and maintenance costs are lower, An on stream analyzer with reagents controlled by computer, are being assessed further.Opej1atljn Of Cells:!lo cell level adjustments are required when tonnage is adjusted 20 to 25%.Depending on mill heads and grade of concentrate reagents are adjusted to the first rougher for metallurgical control. Reagents to second rougher and scavengers are seldom adjusted as feed to this section has a maximum variation of about 0.2'~ Cu.Power – Maintenance and Space Requirement :Our total power consumption for 3,400 T.P,D. flotation circuit for operation and air supply is 280 H.P. Previous power drawn using conventional cells was 400 H.P. at 2,000 T.P.D.Total maintenance costs for flotation circuit has averaged $1,100.00 per year for the 3 years of operation, this cost should remain constant.Floor space required for cells and walkways is 2,000 sq.ft.

Jan 1, 1974

By Ricardo Montero

At this time, over 300 tons of Au are used in electronic equipment each year with other precious and strategic metals such as Ag, Pt, Pd, Cu, Nb, Ta, etc. After the use-phase, the electronic devices become electronic waste (e-waste); consequently it is important to consider e-waste as a secondary supply for recovery of these metals. One of the most important components is the printed circuit boards (PCBs) because the amount of their precious metals is ten times higher than rich precious metals bearing ore. This paper presents the recovery of Au, Ag, Cu and Nb from PCBs of discarded computers using leaching column technique. The amount of these metals in used PCBs was: 613 g/ton of Au, 1515 g/ton of Ag, 36 g/ton of Nb and 23.4 % of Cu. The PCBs were crushed with a hammer mill until reaching a particle size between 3.33 mm to 0.43 mm. Then, it was leached with sodium cyanide solution in a glass column using the following conditions: sodium cyanide concentration 4 g/L, flux 20 L/kg PCBs day, pH between 10.5 to 11 and leaching time 15 days. Every day, after leaching, the pregnant solutions passed through a column with activated carbon to complete the closed loop system. The following recoveries were obtained: 46.6% of Au, 51.3% of Ag, 47.2% of Nb and 62.3 % of Cu. The products obtained are: a) loaded carbon that contains the desired metals and b) processed PCBs with precious metal contents. A preliminary technical-economic study shows the feasibility to create a small-scale PCBs recycling plant. The initial investment is on the order of US$ 155 639, considering the recovered metals from loaded carbon. The internal rate of return for 10 years period (IRR) and net present value (NPV) estimated are 27% and US$ 105 926 respectively. Keywords: printed circuit boards, recovery, precious metals, niobium, leaching column

Sep 1, 2012

By H. S. Martin

ALTHOUGH it was known some years ago at the- Utah Copper Co. mills that fine grinding improved flotation recoveries, no accurate data were available until recently as to just how far the grinding could be carried economically. In 1923 the ultimate degree of fineness for flotation feed was supposed to be about 10 per cent. on 65 mesh, with approximately 55 per cent. through 200 mesh, which meant that most of the mineral would pass 100 mesh. At this time Garfield and Wilfley tables were used ahead of flotation and a good deal of the coarse mineral removed prior to the ball mill regrind. Shortly afterwards, mill-scale tests developed the fact that on a feed containing not over 10 per cent. +65¬mesh material flotation alone would give a copper recovery equal to that obtained by the combination of tables and flotation, but that on much coarser feed the recovery with flotation alone was lowered. This was at a time when all the sulfide minerals were floated if possible, so that the only requisite was to grind fine enough to free the mineral from gangue. EARLIEST USE op MICROSCOPIC EXAMINATION OF TAILINGS As early as 1921, the writer had attempted to determine by chemical analysis the relative proportions of copper minerals in tailings from an ore that made extremely poor flotation results. Chemical analysis was not satisfactory or conclusive, and samples of these tailings were sent to the U. S. Bureau of Mines Station at the University of Utah for micro-scopic examination. The question at that time was to determine, if possible, which copper minerals had been lost and why, but R. E. Head, in his report, revealed other interesting data. He said in part: Briefly stated, the mineral particles or grains may be classified into separate groups as follows: 1. Free grains of pyrite, chalcopyrite, chalcocite and bornite, respectively, which contain no other included sulfides; 2. Grains in which all three of the copper sulfides are represented (the core may he of chalcopyrite, partially altered to bornite, these two minerals being entirely surrounded by a shell of chalcocite); 3. Grains composed of equal amounts of bornite and chalcocite or chalcopyrite and chalcocite.

Jan 1, 1929

By V. I. Birss

Planar solid oxide fuel cells (SOFCs) offer great promise as stationary power generation devices, primarily due to their flexibility in terms of fuels, high energy conversion efficiency (when both electricity and heat are captured), and their relatively low fabrication costs. However, the anode performance can be compromised by such factors as exposure to certain sulfur-containing fuels and the deposition of coke when using hydrocarbon fuels. In terms of the cathode, its performance is limited primarily by the slow kinetics of the oxygen reduction reaction, while its lifetime can be negatively affected by factors related to the corrosion of currently used stainless steel interconnect materials. This talk will present an overview of these challenges and some possible solutions to these problems. The presentation will also focus on how electrochemical methods can be used to evaluate and improve the performance of SOFC anodes, cathodes, and interconnect materials. In addition, recent promising research efforts directed towards performance enhancement of SOFCs through the use of nanoscale electrocatalysts will be discussed.

Jan 1, 2005

By Arthur C. Simmons

Oil production and activity in northern and central Pennsylvania was slightly less in 1939 than in the previous year, but owing to higher average prices 1939 was undoubtedly a better business year. The last quarter showed markedly increased activities throughout all of the Pennsylvania fields. Production, Stocks and Price Storage of Pennsylvania crude oil at pipe lines and refineries totaled 5,413,000 bbl. on Dec. 31, 1938, and declined during the year 1,124,000 bbl. to a total of 4,319,000 bbl. at the end of 1939. The stocks of crude at the end of the year represent the lowest point reached in Pennsylvania-grade crude storage in recent years. Stocks increased slightly during April, May and June, but decreased during all other months of 1939. The Bradford field production within the state of Pennsylvania averaged 35,340 bbl. per day throughout 1939, which represents a decrease of 1419 bbl. a day from the 1938 average. The production in central and southern Pennsylvania increased 1176 bbl. per day, averaging 12,159 bbl. throughout 1939. Table 1 includes annual production for the part of Bradford field situated within the state of Pennsylvania, for central and southern Pennsylvania, and for the entire state of Pennsylvania. A definite segregation of production between the Bradford field and central and southern Pennsylvania is slightly ambiguous because a portion of the oil from the newly discovered Music Mountain pool is included statistically in each area. In all probability the entire increase and some small addition to the production from southern Pennsylvania can be attributed to oil produced from the Music Mountain pool. Within the Bradford field, six price changes occurred throughout the year. At the beginning of 1939 the price of Bradford crude oil was $1.80 per barrel, whereas by the end of the year it had risen to $2.50. The weighted average price for Bradford crude during 1939 was $2.059 per barrel.

Jan 1, 1940

By Arthur C. Simmons

Oil production and activity in northern and central Pennsylvania was slightly less in 1939 than in the previous year, but owing to higher average prices 1939 was undoubtedly a better business year. The last quarter showed markedly increased activities throughout all of the Pennsylvania fields. Production, Stocks and Price Storage of Pennsylvania crude oil at pipe lines and refineries totaled 5,413,000 bbl. on Dec. 31, 1938, and declined during the year 1,124,000 bbl. to a total of 4,319,000 bbl. at the end of 1939. The stocks of crude at the end of the year represent the lowest point reached in Pennsylvania-grade crude storage in recent years. Stocks increased slightly during April, May and June, but decreased during all other months of 1939. The Bradford field production within the state of Pennsylvania averaged 35,340 bbl. per day throughout 1939, which represents a decrease of 1419 bbl. a day from the 1938 average. The production in central and southern Pennsylvania increased 1176 bbl. per day, averaging 12,159 bbl. throughout 1939. Table 1 includes annual production for the part of Bradford field situated within the state of Pennsylvania, for central and southern Pennsylvania, and for the entire state of Pennsylvania. A definite segregation of production between the Bradford field and central and southern Pennsylvania is slightly ambiguous because a portion of the oil from the newly discovered Music Mountain pool is included statistically in each area. In all probability the entire increase and some small addition to the production from southern Pennsylvania can be attributed to oil produced from the Music Mountain pool. Within the Bradford field, six price changes occurred throughout the year. At the beginning of 1939 the price of Bradford crude oil was $1.80 per barrel, whereas by the end of the year it had risen to $2.50. The weighted average price for Bradford crude during 1939 was $2.059 per barrel.

Jan 1, 1940