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By H. M. Smith

The production of oil during the early development of new oil fields is usually accompanied by large quantities of natural gas. Since in most fields gas under pressure is the main source of the energy causing the oil to move through the sands into the wells and thence to the surface, coincident production of natural gas will continue as long as present-day producing methods are used. Generally the use of this gas is restricted, since markets are not readily available. Consequently, a large portion of the gas produced is often wasted by being blown into the air. The magnitude of gas waste is well brought out in the following statement by Miller:5 Only a few outstanding examples need be cited to show the enormous production of gas that accompanies the discovery of new sources. In April, 1927, the Ventura field produced approximately 210,000,000 cubic feet of gas a day; and during the summer of 1927 Alamitos Heights reached a peak gas production of 102,000,000 cubic feet a day; on December 1, 1928, as a result of the summer's deeper drilling in the Long Beach field, surplus gas production amounted to 125,000,000 cubic feet a day. It is estimated that in January, 1929, the Santa Fe Springs field will have a daily gas production of 387,000,000 cubic feet from the recently discovered Buckbee oil zone. Of this amount 274,000,000 cubic feet a day will be the surplus above the amount required for field and plant fuel, taken out by utility corporations, and that used in repressuring the Meyer sand which lies above the Buckbee zone.

Jan 1, 1931

By Johne Jesus Mol Peixoto

No modelamento matemático do reator RH, a penetração do gás no líquido na perna de subida é o fator chave para determinar a distribuição do gás injetado e obter uma previsão confiável da taxa de circulação do líquido entre a câmara de vácuo e a panela. Neste trabalho, através de simulações numéricas via CFX, investigou-se o efeito das forças de arrasto, de sustentação, de lubrificação da parede, dispersão turbulenta e de massa virtual. A distribuição do gás na perna de subida e os valores de taxa de circulação previstos via CFX foram validados com resultados de modelo físico. A melhor predição da penetração do gás e da taxa de circulação foi obtida na simulação com incorporação da força de massa virtual e da força de sustentação, cujos coeficientes foram iguais a 0,3 e 0,1, respectivamente. A força de lubrificação deve ser utilizada para evitar o acúmulo de gás próximo às paredes da perna, mas possui efeito desprezível sobre a taxa de circulação. Os resultados dos modelos físico e matemático se ajustaram com a equação de Kuwabara para taxa de circulação.

Oct 30, 2017

By Frank B. Amon

Highland Valley Copper had to make some significant changes in the way it was working in order to counter the effects of ever-increasing costs and decreasing metal prices. A mine/mill optimization plan started in 1997 introduced new technologies and management approaches that resulted in a dramatic drop in cash breakeven costs. The changes involved employee training, added authority and responsibility for staff, better communications, and a consistent approach to setting and achieving property-wide goals. The net effect was to change the culture of the organization from one that was fragmented and focussed on local objectives to one that is cohesive and has common goals. These changes have allowed the mine to remain in business during a protracted period of low metal prices, and have positioned the mine favourably to benefit even more from any future increase in prices.

May 1, 2004

By W. L. Doyle

SLAG weights were taken on a series of twenty-eight 6-ton bottom-pour heats. These weights varied from 573 to 1050 lb. Of these, four were chosen for study of the effect of cleaned and uncleaned foundry scrap on the variations of slag weights. Data regarding the make-up and results of the heats are given in Table I. For heat No. 3 the actual slag weight was checked, using the Mn-MnO calculation method-weight 1050 lb. [5,600 X 0.0055 = 30.80 heads and gates 6,000 X 0.004 = 27.00 plate scrap 800 X 0.0083 = 6.64 pig iron 450 X 0.0034 = 1.53 iron ore]

Jan 1, 1947

By M. M. Zarnan

This paper presents the results of s study involving characterization of ground subsidence of abandoned lead-zinc mines in northeastern Oklahoma. Two coordinated efforts were undertaken: (1) collection and analysis of available data such as driller's logs, geologic cross-sections, structure contour naps and stratigraphic sections, and (2) development of a numerical (finite element) technique for prediction of collapse and mine subsidence. An in-depth analysis of a major collapse in the region was conducted. The factors which contributed to this collapse were identified.

Jan 1, 1989

It is the purpose of this paper to produce some evidence on the accuracy to be expected from normal assay procedure using the usual first class equipment, and to examine the effect that many assaying inaccuracies have on reported metallurgical recoveries.Generally speaking, the evaluation of the gold content of a mineral ore sample by the fire assay method is a relatively simple process.A weighed quantity of finely ground ore is fused with suitable fiuxes including litharge and a reducing agent to give a button of lead and a quantity of slag. The shower of lead produced by the reduction of the added litharge collects the gold and silver present in the ore, concentrating the values into the lead button.The button of lead, after separation from the slag, is, on heating in an absorbent cupel in a current of air, reoxidised to litharge and absorbed into the cupel leaving a gold and silver bead in the cupel. This bead' is heated in a solution of nitric acid to dissolve the silver, leaving the gold undissolved to be dried and weighed. Knowing the original weight of the ore and the weight of the gold prill the value of the ore is easily calculated.Summarising1. Fusion Process.-Ore plus fiuxes give a slag plus lead button.2. Cupellation Process.-Lead button is re-oxidised to litharge leaving a gold and silver bead.

Jan 1, 1952

By Rolf Birger Pedersen, Alden Ross Denny

"Synthetic Aperature Sonar (SAS) is a powerful tool for ultra-high resolution marine survey. The Kongsberg HiSAS system deployed on the HUGIN AUV has a rangeindependent resolution of 3x3 cm for sonar image and ~10x10cm for the interferometric bathymetry product [1]. This resolution is achievable for areas up to 50 km2 on a single survey mission providing huge multi-attribute datasets. This technology, originally designed for military and oil-industry applications, has the potential to revolutionize scientific seafloor mapping. The extreme resolution of this technique allows for deposit mapping in and around seafloor hydrothermal systems, including the discovery of extinct venting structures. By clearly distinguishing between volcanic and hydrothermal landscapes based on features below the resolution of conventional multibeam systems, SAS enables an entirely new level of hydrothermal deposit survey. Additionally due to the extreme resolution of this survey technology, repeat survey and change detection should allow centimeter-scale changes in deposit morphology to be routinely detected over an entire hydrothermally venting region. In collaboration with the EU funded MIDAS project, the Centre for Geobiology at the University of Bergen will deploy the HUGIN AUV this summer at two distinct shallow venting systems on the Arctic Mid-Ocean Ridge system. The AUV will collect repeat bathymetry at the Jan Mayen Vent Field, and extend the SAS coverage to include newly discovered venting sites. We will present the preliminary findings of this expedition, including the first deposit estimations made from full-resolution SAS mosaics."

Sep 1, 2014

By Maurizio Siepi, Stefano Trevisani, Pagliaccim Federico, Daniele Vanni

"Abstract: The paper describes a large innovative project completed in 2012-20123 by Trevi Group, to develop equipment capable to install ultra-deep diaphragm wall. The project highlights the capacity of SOILMEC to design and build a new hydromill able to reach an unprecedented depth of 250 m, including new devices for monitoring and correct the verticality. The entire project can take advantage of the long and solid experience matured by Trevi and Rodio (now part of Trevi Group), developing in house or, else, select the elements necessary for a high quality product in the ground.The paper describes the results of different systems used to monitor and control the verticality and the twist of panel during excavation, together with the method used to pour concrete. Finally, the results of verification coring and lab tests on concrete samples recovered at various depths are discussed. The test field has been supervised by representatives of three of the major Italian Universities, and lasts almost one year from August 2012 to June 2013.The verification holes made use of an innovative combination of directional drilling and coring, to check the quality of the plastic concrete for the full length of the panel. The data confirmed that the test panel has high quality concrete, meeting or exceeding to the prefixed requirements.With this test, super-deep cut-off walls reaching depths of 250 m have become a reality. This would change the perspectives of dam engineering both for existing dams rehabilitation and for new dams design and construction. With the execution of this test panel, the technology of milled concrete cutoffs has made a ”quantum leap”, pushing the limit of practicable dams."

Jan 1, 2014

The development of a noise attenuated compressed air driven fan is described. The fan, which employs the jet reaction principle, possesses blade extension pieces which penetrate into an acoustically treated annular chamber. The dominant noise source, namely the air jets, is thereby partially suppressed. In addition, the increased moment arm of the jets leads to an improved propulsion effect which contributes to the improved aerodynamic performance of the unit.A typical measure of the improvement of this type of auxiliary mine ventilation unit is a 4 per cent increase in efficiency and a 10 dB (A) drop in sound level for a fan duty of 0·5 kPa and 1600 litre/s. This degree ofattenuation corresponds to at least halving the loudness level, a subjective noise measure.

Jan 1, 1973

By Luis Martín Tejeda

El presente texto señala cómo los parámetros geotécnicos de resistencia y deformabilidad pueden generar mayor confiabilidad en un estudio técnico. En este sentido, la literatura geotécnica indica que los resultados obtenidos a través de métodos numéricos son sensibles a la variación de estos parámetros y que algunas propuestas de cálculo son más satisfactorias. Para ello, se utilizó el criterio de falla de Hoek & Brown en términos de Mohr–Coulomb, donde se presenta un ejemplo aplicativo para mineria superficial, en el cual el factor de seguridad y la probabilidad de ruptura del macizo rocoso son calculados mediante métodos geoestadísticos aplicados a la ingeniería de rocas (FOSM - First Order Second Method y puntos de estimación de Rosenblueth).

Sep 19, 2006

By L. Adler

Any design of a mine roof in bedded deposits which ignores differential deflections at the supports can quickly lead to dangerous overstressing. As illustrated by the typical case presented on page 1029, if one support deflects only 0.1 in. more than its neighbor, stresses 50 pct higher than anticipated will result. Previous studies1-3 have assumed that the mine roof acts like a beam clamped at both ends, with no deflection or slope' at the supports (Fig. 1). Essentially this assumes:5* ?A = ?, = ?b and dA = dB = 0. However, a host of conditions can cause differential sag or deflection at one support, and even an apparently trivial deviation can have major consequences in the beam: variations in spacing, size, and material of supports; local settlement due to floor heaving or lower mine openings; non-uniformity in wedging or bolt tensioning.8 In one particular instance concrete pillars, poured in place, shrank away from the roof upon setting.' When understood and controlled, differential sag becomes a definite advantage, permitting the transfer of loads from one support to another. Where one support is a bolt or prop and the other a pillar or rib, the load on the former can be reduced while the load on the pillar or rib is increased. This means two things: 1) savings can be effected by using smaller artificial supports such as props and bolts and 2) loads can be increased in the rib to induce eventual failure for longwall caving. In this last respect, another factor underlying coal bumps becomes understandable. The design of a mine roof by beam theory assumes that when a bedded formation is homogeneous, iso-tropic, and elastic, it will act like a uniformly loaded beam, fixed or clamped at both ends,6 s in Fig. 1.'" These are important assumptions. The uniform load is the weight of the beam itself or its body load. For a beam of unit width, this load becomes per foot: w = yhb. w = uniform load y = specific weight, lb per ft3 h = depth or thickness of beam, ft b = width of beam, ft Since b = 1, w - yh [ 1 ] A beam fixed at both supports is statically indeterminate to the second degree, that is, two equations in addition to those for static equilibrium are required to determine the reactions at the supports. These equations result from the geometry. From statistics: ^F,= 0;RA + RB — wL = 0 [2] wU S,M0 = 0 ; MB H------------MA — RBL = 0 [3] it Using superposition in which the left support is kept intact and the right one resolved into an active force and moment, we obtain from Fig. 2:" ?b = ?m + ? b2 + ?B3 = 0 dB = dB1 + dB2 + dB3 / wU Ma RBL \ V d°=(-r+-2—r)-zr [5] Where: Subscripts refer to position on axis of beam R = force, lb M = moment, ft-lb w = uniformly distributed load, lb per ft L = span, ft 0 = slope, radians d = deflection, ft E = Young's Modulus, lb per ft" 1 = Moment of inertia about the neutral axis, ft4 Solving Eqs. 2 through 5 for the four unknown reactions, we obtain: 2 L3 Fig. 3 is obtained by plotting MA and M, vs d, and then plotting RA and R, vs d, and adjusting their scales to coincide with MA and M, vs d,. It should be noted in Eqs. 6 and 7 that as dB increases, MA increases the same amount that Mn decreases. Eqs. 8 and 9 show a similar relationship between RA and R,. Proof that MA is the maximum absolute moment occurring in the beam is as follows: where M, = moment at x wx-When where M,., = maximum positive moment Eqs. 6 and 8 into above: For small dn: MA> M,,,

Jan 1, 1960

By Guy Chevalier, Jean-Guy Chartrand, Louis Barrette, Daniel Michaud, Michel Fortin

"COREM has developed, specifically for the mineral industry, a mobile laboratory using the Laser-Induced Breakdown Spectroscopy (LIBS) technique. It has been used to perform onstream analysis (OSA) of the chemical composition of slurries in both gold-ore and iron-ore processing plants. Industrial tests have been carried out respectively at La Mine Doyon (Cambior), a gold-ore processing plant near Rouyn-Noranda, Quebec, and at QCM's iron-ore pelletizing plant in Port-Cartier, Quebec. The aim was to demonstrate that the LIBS technique is capable of providing information that meets the needs for process control. C, Si, Ca, Mg, Mn and Al were the elements targeted on iron ore while Cu, Fe, Ag and Au were targeted for gold ore. The results obtained meet or exceed the requirements for process control and consequently clearly show that the LIBS technique is suitable for industrial applications.The feasibility of OSA, through in-plant validations using COREM’s LIBS mobile laboratory, has been demonstrated in four essential aspects: slurry sampling, LIBS chemical measurement, robustness for continuous operation, and functionality for industrial operators.INTRODUCTIONThere is a general need for optimization in the mineral industry. Process control is a favoured means to achieve this goal (McKee 1991). Real-time knowledge of process status is the key to effective control (Da Silva 1994). Only a few techniques, such as XRF, NMR and digital imaging, are currently amenable to chemically monitor industrial processes (Braden 2002). LIBS is an emerging technique with appealing characteristics for on-line and real-time measurement of bulk material (Lorenzen 1992, Palanco 2000). While our ultimate goal is to provide our industrial partners with performing monitoring tools, a shorter-viewed objective is to demonstrate the feasibility of developing a LIBS system for OSA. The LIBS technique has shown interesting capabilities for measuring solids, liquids, dusts and gases. Our work has focused on mineral slurries (Barrette 1999 and 2001, Turmel 1999). Special equipment is needed to perform in-plant validations. A mobile laboratory based on the LIBS technology has been assembled for this task."

Jan 1, 2004

By Robert K. Guthrie, James W. Amyx, D. B. Taliaferro

"INTRODUCTION Secondary recovery of oil by water-flooding is practiced more extensively in North Texas than in any other section of the State, and the progress and experience of the operations in that area are of continuing interest to all branches of the oil industry. The first Bureau of Mines report on water flooding in North Texas 7/ chronicled the activities from December 7, 193f', when the Railroad Commission of Texas granted The Texas Co. the first permit to inject water into an oil-bearing sand, through 1944. This second report has been prepared as a supplement to Report of Investigations 3906 to show the progress and expansion of water-flooding. The format of this report is almost identical with what of report of Investigations 3906, except for a few miner changes. For the sake of brevity, certain basic information contained on the first report has not been repealed, and the reader is urged to consider the two reports as corporation writings.The North Texas area, as encompassed by the two reports, corresponds Railroad Commission of Texas Districts 7P and 9. Oil-development operations in the two districts, since oil was discovered in 1904, have resulted in the recovery of approximately 1,400,000,000 barrels of oil from a proved area that has been estimated to exceed 413,000 acres. During October barrels of oil was produces by primary and secondary-recovery methods from 1,746 flowing wells and 25,211 pumping wells, a daily average 6.6 barrels per well. Of this total volume of oil recovered in October 1947, 47,965 barrels (0.87 percent) was recovered from leases on which water-flooding operations were in progresses."

Feb 1, 1948

By Sharpe E. J

The Triton lode is a schistose feldspar biotite chlorite rock with quartz, carbonate, pyrite and some pyrrhotite. Its more chloritic sections strongly resemble the enclosing greenstones, its more feldspathic portions are indistinguishable from the flne-grained phases of the porphyry dyke into which the southern extremity of the ore body merges. The ore body' has a length of 880 ft. and an average width of I2t ft.; in places this widens to as much as 30 ft.The average dip is 85° west and pitch of the ore shoot 75° south.METHOD OF SAMPLING.With the exception of a limited amount of channel sampling (a reference to which is made elsewhere in this paper) all the sampling is by chip sample.The samplers use a hammer weighing approximately 11 lb. and chip directly into the sample bags. Sampling is generally carried out over 3-ft. sections and portions thereof to the nearest half foot-thus a face 8t ft. wide is divided up into two sections of 3 ft. each and one section of 2 ft.-no measurements of less than 4 ft. are used and calculations are all in feet and dwt. per long ton.In the oxidised stopes wp.ere the lode is much narrower, .i.e., 6 ft., sampling is over 2-ft. sections. All borehole samples are over 2-ft. sections, this corresponding approximately to steel changes.(a) DEVELOPMENT SAMPLING.Driving.-This is done by following the east wall and each face is sampled-this corresponding to an advance of 5 ft. If the full width o,f the lode is not exposed boreholes...

Jan 1, 1938

By RALPH BALTES, AMIR EHSAN KIANFAR, FABIAN UTH, ELISABETH CLAUSEN

As indoor positioning provides particular challenges due to the unavailability of GPS signals, various systems such as ultrawideband (UWB), radio frequency identification (RFID), ultrasound, and wireless local area network (WLAN) have been proposed in recent years. Some of these technologies are currently being marketed and some are still being developed. UWB technology allows for higher precision while also reducing power consumption. Hence, the underground automation and localization systems can use this technology for more accuracy and robustness. This article discusses new robust UWB modules used for underground positioning and collision avoidance with regard to human safety in underground mining operations.

Jul 31, 2020

By Fiseha Tesfaye, Pekka Taskinen

"Thermodynamics of the equilibrium phase assemblage Ago_9Cul.lS-Cu2-xS-CuS have been studied by an EMF -method. The ternary phase was synthesized from the pure Cu2S and Ag2S in vacuum furnace at high-temperature and mixed with appropriate compositions of Cu2S and CuS to form the cathode electrode. The EMF-measurements were made on the solid-state galvanic cell Pt(-) I Ag I RbAg,ils I Ago9Cu1.1S-Cu2-xS-CuS I Pt(+), in a temperature range from 316 K to 498K.Based on the measured EMF vs. T relations, thermodynamic functions (?fG° , ?fS and ?fH°) of stromeyerite (Ag0.9Cu1.1S) in equilibrium with Cu2-xS and CuS have been determined. The obtained experimental values have been compared with the available literature values. New experimentally determined thermodynamic properties of the solid solution (Ag,Cu)2Sss were determined.IntroductionDue to intense mining of high grade sulfide ore minerals in the past, recently, the available sulfide ores are poor in metals and becoming increasingly complex; such that, the production of high grade metals by the conventional pyrometallurgical processes is compromised. Consequently, smelters are in need to modify their operating flow sheets and strategies for processing more complex feed materials economically, while meeting the strict environmental regulations. To make the appropriate modifications, accurate thermochemical data of phases and phase assemblages which exist in these complex ore minerals are essential.Silver-bearing sulfosalts are encountered in ore minerals for the production of base metals and are common sources of silver. Among the silver-based sulfosalts, stromeyerite (Ag0_9Cu1.1S) is relatively common ore mineral in most hydrothermal vein and replacement deposits [1]. Recently, the ternary chalcogenide compound Ago0.93Cu1,07S has been studied, intensively, due to its high ionic conductivity and gradual disorder in the sequential phase transitions [2]. Therefore, accurate knowledge of the thermodynamic properties of stromeyerite has considerable fundamental and practical interest in many aspects of extractive, chemical and physical metallurgy."

Jan 1, 2014

By Helga Larravide

A new on-line database of literature about copper has been created through a joint undertaking by the Copper Development Association Inc. and PROCOBRE-Chile, with funding provided in part through the International Copper Association, Ltd. The new database will permit Spanish-speaking technologists to access publications maintained by PROCOBRE-Chile by means of standard keyword searches. In addition, a new Spanish- English thesaurus has been written to enable Spanish-speaking individuals to search d access the Technology and Environmental databases of the Copper Data Center, which together comprise more than 80,000 publications dealing with the production, properties, uses and environmental effects of copper. Planned expansion of the new Spanish literature database is described.

Jan 1, 1999

By Peter K. Strangway

During 1973, a 20,000 net ton (18 100 metric ton) formcoke test was carried out at Inland's 26.5-foot (8.08-meter) hearth diameter on NO. 5 Blast Furnace. The formcoke briquettes were produced from Elko1 coal by FMC at their pilot plant in Kemmerer, Wyoming. The briquettes were shipped to Inland in open railroad cars and most of them were placed in an outside storage field until a sufficient amount was available for the actual blast furnace test. The test consisted of three phases: an initial four-week base period; the actual 33-day formcoke test period; and a final three-week post-test base period. During the formcoke test period, the regular coke skip loads were gradually replaced with skips of formcoke until, after a three-week period, the replacement ratio reached 80%. The furnace operated smoothly and quality hot metal was produced. The burden remained permeable and it was possible to maintain wind rates 9 of over 100,000 scfm (47 Nm3/s) without significant blast pressure increases. Dusting from the formcoke was not a problem either in the stockhouse or in the top gas. The formcoke briquettes maintained their original shape and density as they descended through the furnace. When the 80 percent replacement level had been reached, the inwall temperatures became higher than normal (about 2000 ºF (1090 ºC)) and followed an unusual steady pattern. In addition, the top gas temperature became higher than normal, and the hot metal analyses and temperatures began to fluctuate unacceptably. In general, it is felt that the high inwall temperatures were a result of channeling of the hot furnace gases along the stack walls. This channeling appears to have been promoted by a change in distribution of the burden in the top of the furnace which, undoubtedly, was caused by the increased increments of formcoke. Since it was felt to be unsafe to operate the furnace for an extended period of time with the inwall temperatures at the high level, a decision was made to remove the formcoke from the furnace. When this was done, the inwall temperatures returned to normal. Once the inwall temperatures had returned to normal, the remaining 3,800 net tons (3450 metric tons) of formcoke were used in the furnace at a nominal 40% replacement level for five continuous days. The furnace operated smoothly during this period, and the results were representative of satisfactory furnace operation with partial replacement of regular coke with formcoke. The test was successful in proving that formcoke can replace up to about 50% of the regular coke in a large furnace operating at high wind rates. However, additional work will be required to develop acceptable charging practices for using higher levels of formcoke replacement.

Jan 1, 1977

The principal dirnensions of the chimney were fixed as follows: Height from formation to coping, 328 ft. 8 in.; inside diameter concrete shell, 13 ft. Gin.; inside diameter of the 4~-in. brick lining. 11 ft. (j in. ; shell thickness above flue inlet at a point 39 ft. above formation, 1 ft. 8in.; shell thickness at coping, 6 in. That is, the inside of chimney is cylindrical, wldst the outside is gradually stepped inwards with of 1 in. and less until the shell is 6 in. thick only at the top. With these dimensions in mind, it will be seen that some close thought was necessary to ensure a satisfactory of fonn which could be kept rigid and plumb to a height and at the same time provide safe working conditions for the labourers employed.FOUNDATIONSThe spread base of the chimney is 45 ft. in diameter, and foundations were carried down to a depth of 8 ft. 6 in. below natural surface into good hard clay which was known to be the best foundation obtainable in the vicinity being capable of withstanding, when dry, a load of 3 tons to 4 tons per square foot, whereas dead load is 1A tons per square foot and the maximum load expeeted under the most severe wind condition is 2 tons per square foot to ensure the foundation being kept dry and unaffected by ground water, the site was surrounded by a ring drain at a distance of six feet from edge of concrete foundation and at a minimum depth of one foot below bottom of concrete. Open-jointed pipes were laid in the bottom ofthe drain and graded to a pipe drain with outfall clear of the site.

Jan 1, 1924

Soon after the Rosebery concentrator commenced operations in 1936, an investigation was begun in an attempt to discover a substitute for cyanide in lead flotation. Cyanide is an excellent depressant for zinc and iron, but it also powerfully depresses the copper, silver and gold bearing minerals present in Rosebery ore, thus allowing them to pass through to the zinc concentrate or final residue where they are of little or no value.The investigation was not entirely successful, but it did indicate that sodium bisulphite or sodium sulphite could be used as a depressant for zinc without depressing the copper, silver and gold bearing minerals. The sulphites were, however, much inferior to cyanide as apyrite depressant.At about this time, I. W. Wark, using the captive bubble technique, had shown that, at the concentrations normally used, sodium aerofloat is not a promoter for pyrite or galena in alkaline solutions (see his book "Principles of Flotation", p. 188). Some preliminary tests on the production of a copper concentrate from Rosebery ore were therefore carried out using sodium sulphite as depressant and sodium aerofloat as promoter.The results of this work were promising but, since Rosebery ore usually carries only about 0·5% copper, there did not seem to be much incentive to carry the work further. With the outbreak of war, however, Australia became desperately short of copper and the relatively small amount in the ore. became of sufficient importance to...

Jan 1, 1952