Search Documents

By R. J. Henry

This paper describing the mining practices at the Teck-Hughes mines at Kirkland Lake, Ontario, is one of a series being prepared by the United States Bureau of Mines on mining practices, methods, and costs in various mining districts. HISTORY Prospecting was begun in the neighborhood of Kirkland Lake in 1906, but staking did not take place until 1911. Gold-bearing veins were discovered by surface trenching in 1913 on the mining claims which now make up the Teck-Hughes Gold Mines (Ltd.). A small mill was erected in 1916 after the completion of some underground exploration. A transmission' line was built in 1917 to the camp to provide adequate power for a vigorous underground campaign. Also in 1917 the present management took control operations since 1916 have been continuous,' with a steady increase in production to date.

Jan 1, 1930

By Nordau R. Goodman

"IntroductionTHE HISTORY of Nova Scotia's gypsum industry goes back about two hundred years. The extensive deposits found in the Windsor formation, which is Lower Carboniferous, were the first discovered in North America and were known to the earliest .settlers. There has been a steady increase in production from these beds, except for minor setbacks in years of wars and depressions, but at the same time there has been a decrease in the number of operating quarries. This decrease reflects the change from the days of horse-and-cart recovery to the modern, large-scale, highly mechanized operations. In the beginning, almost any outcrop could •supply the tonnage requirements and the most •convenient were selected, but the millions of tons needed to meet present-day needs are not easily found.Despite the size and importance of the Nova Scotian deposits there has been little detailed geological work. Sir Charles Lyell, in 1843 ( 10), established that the beds are Lower Carboniferous and this was confirmed by Sir William Dawson (3) a .few years later. Both Lyell and Dawson agreed the calcium sulphate beds were an original part of a bedded series .but did not consider they resulted from a concentration of sea water. Lyell reached the conclusion that the gypsum was related to volcanic action in the form of heated vapours or hot springs. Dawson believed it was formed by the action •of sulphuric acid on calcium carbonate. The acid, derived from the oxidation •of iron pyrites which was abundant in the older formations, was carried by rivers into basins which were rich in shells."

Jan 1, 1954

By J. W. Craig

CHROME ore, which is used in Canada in the production of ferro-alloys, in a variety of refractories, and indirectly in many chemical industries, is both commercially important and scientifically interesting. The sight of chromium metal is familiar to all of us in the home, the office, the automobile. Chromium is synonymous with armaments: it is understood to be one of several essential metals in tanks, which played an important role in the defeat of France in the spring of 1940. Chromium, in other forms, comes into our daily lives by way of paint and leather, of the familiar green ginger-ale and beer bottles, and more indirectly in every pound of steel produced in the .Dominion. Necessary to our civilization in peace and war, the ores of chromium occur in many corners of the earth. This paper attempts to describe the chemical constitution of chrome ores, their world distribution, and the various chrome products and their industrial applications in Canada.

Jan 1, 1940

By S. F. Guo, Z. F. Zhan, X. L. Huang, Y. Zou, S. W. Qi

"FLAC3D is an important numerical analysis software to study dynamic response of rock slope. In application of the program, the common issues such as absorbing boundary and the method to apply wave have been well studied. However, effects of model mesh size, damping and width of slope are still unknown. In order to make the result more convictive, this article has discussed the above issues systematically. It found that when the maximum mesh size is smaller than 1/10~1/8 of the smallest wavelength, the mesh size is smaller, the computational accuracy is higher. Meanwhile, values of damping and width of slope have no effect on the result. Additional, results of FLAC3D modeling on wave transmission across rock joints agree well with analytical solutions, so it has verified the capability and accuracy of FLAC3D on dynamic response of rock slope.INTRODUCTIONChina is a mountainous country accompanied with many earthquakes. Thousands of geological disasters are triggered by the Wenchuan Earthquake in Sichuan Province, and the majority of the disasters are landslides induced (Xu et al., 2009). Meanwhile, the paper (Li et al., 2003) points out five significant issues about dynamic loading in the area of geotechnical engineering, which includes the study of rock slope stability under earthquakes, and the dynamic response of rock slopes is one of its important study issues."

Jan 1, 2015

By T. Xue, A. Singhal, D. Wrana, I. Mihaylov

"At Vale's Thompson Nickel Refinery, the copper and arsenic in the nickel electrolyte are removed by precipitation using H2S, generating a sulphide precipitate containing about 40% Cu, 8% Ni, 2 to 4% As and 30% S. This residue has been typically stored in impoundment ponds within the plant site. Various options for reprocessing it have been investigated over the years. One of the options involved oxidative pressure acid leach, whereby over 95% Cu, Ni and As were extracted. More recently, an atmospheric alkaline sulphide leaching process for selective removal of 70 to 90% As was developed and mini-plant tested. After alkaline sulphide leaching, the dissolved arsenic is precipitated as stable basic ferric arsenate (BFA) with the addition of ferric sulfate, while the low-arsenic Cu/Ni sulfide is suitable for processing in Vale's operations elsewhere in Canada.INTRODUCTIONVale’s Thompson Nickel Refinery was commissioned in 1961 and currently it has the capacity to produce about 56,700 tonnes per year of electrolytic nickel as cathode slab and rounds products. A sulphate and chloride mixed electrolyte is used in the Thompson refining process and it typically contains 75 to 85 g/L Ni, 50 to 60 g/L Cl, 90 to 120 g/L SO4 2-, 25 to 30 g/L Na and 8 to 9 g/L boric acid. The main impurities in the Thompson anolyte are copper, cobalt, arsenic, iron and lead.The simplified Thompson electrolyte purification flowsheet is shown in Figure 1 (Oliver & Wrana, 2009, Goble & Chapman, 1986); it consists of precipitation of copper, arsenic and lead with H2S, followed by nickel replenishment with ground matte and acid and removal of cobalt and iron with Cl2 and NiCO3."

Jan 1, 2012

"Beneficiation of low grade ores is the process of increasing the grade of a mineral through unit operations that remove and separate the waste (or gangue) material from the valuable mineral that can then be used for further processing or direct use. Important factors when deciding upon a beneficiation program are the feed grade, mass yield and the metal recovery. As lower grade ores are being processed beneficiation is a critical process. How predictive is laboratory test work for “as built” operating projects? Beneficiation includes all or some of the available unit operations to produce a beneficiation flow sheet i.e. associated unit operations including but not limited to optical sorting, radiometric sorting, crushing and screening, coarse cobbing, jigging, dense media separation (DMS), spirals, magnetic separation, flotation, thickening, filtering and drying. Reference to specific projects and the approach developed in formulating a beneficiation flow sheet and a comparison of difficult and simple beneficiation flow sheets are cited. INTRODUCTIONReserves of high-grade iron ores are reducing all over the world, at an alarming rate, over the years as a result of the rapid increase in demand for steel particularly from Japan and then China. The recovery of mineral value from the low-grade ores using present technology is more expensive than DSO ores due to high energy and capital costs. Beneficiation is defined as a variety of processes whereby extracted ore from mining is reduced to particles that can be separated into mineral and waste.Various physical properties of an ore can be exploited to separate a low grade fraction including variation in hardness, density, reflectance, conductivity and magnetism.""Beneficiation"" of iron ores includes concentration, generally by physical removal of unwanted gangue. Also considered beneficiation is the regulation of product size, or other steps such as agglomeration to improve its chemical or physical characteristics prior to smelting."

Jan 1, 2012

Pyrometallurgical reactors constitute a key processing component in the total primary and secondary resource cycle, being involved both in primary smelting, converting and extraction, as well as the reprocessing of scrap, from aluminum cans to end-of-life automobiles. To effectively control the overall resource cycle, one needs to take a systems modeling approach of the whole cycle, seeking to also understand the dynamic process behavior of the individual components of the cycle, and then especially the part that contributes most to the chemical conversion, namely the pyrometallurgical reactor. This paper highlights the role of pyrometallurgical thermodynamics, in the whole resource cycle and specifically places equilibrium thermochemistry in the context of process dynamics where large variable inventories are recycled or maintained within the system. This paper will therefore review the semi-empirical dynamic modeling tools, which are used to model complex systems with the specific goal of developing dynamic predictive models, which also include slag-alloy chemistry, towards controlling the recycling in a feed forward manner. To illustrate the primary processing side, high carbon ferrochrome will be presented as a brief case study. It also will show how the distributed nature of the chemistry of melts in the case of primary extraction, and secondary materials such as recycled end-of-Iife vehicles, have a significant impact on the process outcomes and model predictions. It is therefore argued that the fundamental thermodynamics and kinetics in metallurgical reactors playa final crucial role in modeling the closed material cycle, but only when it is used in conjunction with process systems theory based on reconciled data for parameter estimation and model calibration.

Jan 1, 2003

By J M. F Clout

In the iron ore industry significant emphasis is placed throughout the mining process on meeting chemical composition specifications for the export of fine ores, however, little has been published on the implications of ore chemical composition for iron ore sinter and pellet product quality. The ore bulk composition, together with the nature of the minerals in the fine ore both play a critical role in determining the type of high temperature bonding phases that form during sintering and pelletising. This paper uses the experimental determination of phase relations in model sinter and pellet systems such as Fe2O3-CaO-SiO2 (FCS) and Fe2O3-Al2O3-CaO-SiO2 (FACS) to examine the links between iron ore chemical composition and the temperatures used during sintering and pellet firing. The phase relations help to establish the critical thermal and compositional parameters that control the bonding phase chemistry which in turn influences the physical characteristics of the sinter or pellet matrix. Results show that lower Fe-grade (

Jan 1, 2002

Avoca Resources LimitedÆs Higginsville Gold Project has a resource base of over 1 300 000 oz of gold. The Trident underground mine, which forms the basis of the project development, has a resource base of 927 000 oz of gold. Avoca is building the Higginsville Gold Project based on a minimum ten year vision, producing over 150 000 oz per annum. The project development has taken less than three years from the Trident discovery hole in October 2004 to the first ore production in June 2007. This paper discusses the background work associated with the development of the Trident underground mine in a difficult period for new project development in Western Australia. The resources boom, led by the iron ore industry in the Western Australian Pilbara region, is creating cost pressures and, combined with a lack of people and equipment, is placing cost and timing stress on a small developing project. Avoca Resources has developed a project execution management strategy aimed at mitigating cost blow outs and schedule delays.

Jan 1, 2008

By A. Torrance, M. G. Seo

Velocity of detonation (VOD) is an important variable when evaluating the performance of mine blasts. Typically, for a VOD measurement, individual probes have to be loaded into each blast hole that requires a measurement, which increases the loading time and is not representative of the whole blast. Experimental studies of electromagnetic pulse (EMP) from the detonation of explosive charges show that electric and magnetic field signals are observed when chemical explosions occur in the air, at the ground surface, and in the underground. EMP has the potential to evaluate VOD of the whole blast without impeding the loading process. Due to a variety of physical causes which make the electromagnetic effects complex, measuring EMP of the detonation of explosive charges has not been fully studied yet. Five different antennae were tested with explosives, which are commonly used in mining industry. Among the five antennae, aluminum and copper tape, and wire were successful to detect the EMP. INTRODUCTION The measurement of the velocity of detonation (VOD) helps in evaluating and comparing relative performance of explosives in mine blasts. A VOD of an explosive is usually predicted by empirical mathematical equations or measured in-hole by VOD meters. However, conventional methods to measure a VOD have constraints: only a limited number of holes can be measured because cost of consumables for such systems is very high, and systems only allow a certain number of holes to be measured. The measurement cables have to be placed into the holes prior to loading with explosives which means that preparing to take the measurement is time consuming and has to be well coordinated with the mine. In order to evaluate VOD for a whole blast, there is a possibility of using electromagnetic pulse (EMP) from the detonation of the explosives. As there are many parameters that affect the generated EMP from explosive charges, measuring EMP of the detonation of explosive charges has not been fully studied yet. Most studies conducted relate to military related explosives, not the ones frequently used in mining industry. This research has been performed to have a better understanding of EMP from the types of explosives which are commonly used in the mining industry. To discover a way to detect EMP efficiently, five different types of antennae have been studied in the air and in the underground blasting conditions: coil, monopole rod, log periodic, wire, and aluminum and copper tape. LITERATURE REVIEW Conventional methods of measuring VOD Over the years, demands for more accurate theoretical predictions and physical measurements of the effects of the explosives have increased. Especially when both demand and commodity price decline, mining companies are keen to understand the effectiveness of explosives since it has a direct relationship with fragmentation, which influences their production rate. Since the 1940s, various methods have been devised to determine VOD of explosives.

Jan 1, 2019

By L. Yin, R. B. Haber, N. Sobh, D. A. Tortorelli, R. W. Hyland Jr.

"We optimize continuous quench process parameters to produce a desired precipitate distribution in aluminum alloy extrudates. To perform this task, an optimization problem is defined and solved using a standard nonlinear programming algorithm. Ingredients of this algorithm include a cost function, constraint functions and their sensitivities with respect to the process parameters. These functions are dependent on the temperature and precipitate size which are obtained by balancing energy to determine the temperature distribution and by using a reaction-rate theory to determine a discrete precipitate particle size distribution. Both the temperature and the precipitate models are solved via the finite element method. Since we use a discrete particle size model, there are as many as 105 degrees-of-freedom per finite element node. After we compute the temperature and precipitate size distributions, we must also compute their sensitivities. This seemingly intractable computational task is resolved by using an element-by-element discontinuous Galerkin finite element formulation and a direct differentiation sensitivity analysis which allows us to perform all of the computations on a PC.1 IntroductionThis work addresses the need for an integrated design capability that links microstructure evolution to the process parameters. It is motivated by the manufacture of lightweight aluminum-alloy extrusions for use in automotive structures. Aluminum alloys offer obvious benefits, however, care must be taken to manufacture favorable microstructures that ensure acceptable structural performance. For example, the manufacturing process for 6000-series components involves hot extrusion of cast aluminum billets followed by either an air or water quench process. The bill~t's initial grain structure is dramatically altered during extrusion by massive mechanical deformations and recrystallization processes. The microstructure continues to evolve during the quench, as complex chemical processes determine the formation of precipitates. The control of the precipit'ate size distribution is vital. Indeed, large precipitates located on grain boundaries serve as crack initiation sites which adversely effect structural crash· worthiness."

Jan 1, 2000

By M. C. Harris

"Excess Gibbs energy is a thermodynamic parameter which quantifies the difference between the value of the Gibbs energy for a real mixture and that for an ideal mixture. More specifically the partial molar excess Gibbs energy of a species (i) in a mixture is indicated by the change in the overall excess Gibbs energy of the solution as the number of moles of species (i) changes while keeping temperature, pressure and the number of moles of all other species in the solution constant. Generally it is obtained from the activity coefficient which in turn can be obtained for a species in a mixture using a variety of models. The most widely used method is to use UNIFAC. Flotation is probably the most important process in the concentration of minerals and requires the use of reagents such as collectors and frothers. There is abundant experimental data which illustrates that collectors of different alkyl chain lengths will change the contact angle and that frothers of different structures and molecular weights will result in changes in key flotation properties such as froth behavior, surface tension and critical coalescence concentration. In this paper it is shown that there is a strong linear relationship between measured parameters such as froth volume/height, surface tension, critical coalescence concentration and contact angle and the partial molar excess Gibbs energy of the molecules used. Proposals are made to explain these correlations.INTRODUCTIONAs is well known froth flotation is arguably the most widely used process in the separation of minerals. In broad terms the process relies on the use of reagents known as collectors to adsorb onto a mineral surface and thus render the mineral particle hydrophobic. Alkyl thiolates are very commonly used for this purpose. The hydrophobicity is induced as a result of the alkyl group’s molecular structural properties which results in it forming a non-ideal mixture with the process water. Surfactants (or frothers) are typically alcohols and are known to lower the surface tension of the system and also inhibit bubble coalescence and reduce bubble size. Since alcohols are polar they will also form a non-ideal mixture with water. The hydrophobic mineral attaches to the bubble and rises to the froth phase where the valuable mineral is recovered as a concentrate. Frothers have often been characterized using the so-called HLB (hydrophobic-lipophilic balance) number but recently it was shown that the use of activity coefficients (?) or excess Gibbs energy (G ex ), which is calculated using equation (1) is a much more appropriate way to describe the behavior of these reagents in non-ideal mixtures with water (Corin and O’Connor, 2014)."

Jan 1, 2016

By M. Fan, Z. Long

"This paper presents some studies on recovering valuable elements from Chinese coal by-products, including coal combustion fly ash, stone coal ash, and coal flotation tailings. Both commercialized technologies and economic potential recovery methods are described in this study. Magnetically stabilized air-dense medium fluidized bed separation, tribo-electrostatic separation, froth flotation, and hydrometallurgical methods are discussed in recovering various valuable elements in Chinese coal by-products from different coalfields. These valuable elements include iron, carbon, aluminum, rare earth elements, lithium, gallium, germanium, uranium, titanium, scandium, silicon, vanadium and phosphorus, etc. The ultimate goal is to fully utilize all valuable elements in coal by-product. Each component within coal by-product should be efficiently segregated to its highest value. INTRODUCTION Coal is mainly composed of energy-producing elements carbon and hydrogen. In addition to these elements, coal usually contains many other valuable elements, including iron, aluminum, silicon, rare earth elements, lithium, gallium, germanium, vanadium, uranium, titanium, scandium, and phosphorus, etc. These coal-associated elements are significantly enriched in coal combustion by-product fly ash because of majority of main components, carbon and hydrogen elements, being removed. Table 1 provides the chemical composition range of the main elements oxides in 12 Chinese fly ash samples collected from coal power plants located in Northeast China, Northwest China, Southwest China, and Southeast China. It can be seen from Table 1 that the major mineral components of different ashes are similar, but the bulk chemistry of different fly ashes may vary widely due to the changes of ratios of the mineral components in different coals. The major mineral components in various Chinese coal combustion fly ash are silicates, iron oxides, and unburned carbon."

Jan 1, 2017

The SART (sulfidisation, acidification, recycle, and thickening) process is an effective way to separate copper and cyanide from each other in the waste stream of gold processing plants using cyanidation. Factorial experimentation has been conducted to create models of copper recovery, cyanide recovery, acid addition, and oxidation I reduction potential during SART. Economic analysis of the resultant models showed that SART is best operated with a sulfide to copper molar ratio of around 0.56, a pH of 4, and a minimised cyanide to copper molar ratio. The experiments also showed that thickening time may have drastic impacts on SART performance.

Jan 1, 2011

By Renato S. Costa, Afonso H. Martins, Flávia D. Mendes

"This paper presents some important aspects regarding the ion exchange treatment of an Ni and Co sulphate acidic liquor using chelating resins. Chelating resins possessing iminodiacetic or bis-picolylamine functional groups were compared in terms of nickel and cobalt recovery. The experimental resin with bispicolylamine functionalities (Dowex M4195) was evaluated with respect to Ni and Co uptake, and compared with Rohm &Haas commercial chelating iminodiacetate acid resin. The Rohm & Haas chelating resin, Amberlite IRC 748, with its weakly acidic groups, did not work in acidic solution but exhibited good results at pH 4 and above. The resin that efficiently removed metals from high acidic solutions was the bis-picolylamine resin. Maximum nickel uptake values ranged between 85 g and 112 g Ni per Kg of resin.The experimental part dealt with the working conditions, resin characteristics and the influence upon the resin maximum exchange capacity of the following factors: nickel concentration, temperature, pH and resin-to- solution ratio. Based on the experimental data obtained, it has been proposed a innovative technological treatment."

Jan 1, 2003

By Lin Li, Ahmad Ghahremaninezhad

"In this paper, the electrochemical behavior of ferric and ferrous couple on the pyrite surface was studied by application of the chronoamperometry technique in an acidic solution at room temperatures and atmospheric pressure. The effects of the pyrite origin, ferric and ferrous ions concentration on the electron transfer kinetics of Fe3+/Fe2+ reaction were probed. Tafel behavior of all the test conditions were developed. The results showed that the ferric-ferrous reaction on pyrite electrodes with different origins have a common mechanism, despite different reaction kinetics. The exchange current densities of the redox reaction have the same magnitude of about 10-5 A·cm-2, which is far lower than the value reported for the gold and platinum electrodes, but larger than that of the chalcopyrite electrode. The cathodic transfer coefficients are between 0.4 and 0.5, while the anodic transfer coefficients appear unusual with the lowest value being 0.23. It was also demonstrated that an increase of one order of magnitude of iron concentration has no clear effect on the exchange current density and cathodic transfer coefficients of Fe3+/Fe2+ redox reaction.INTRODUCTIONPyrite, FeS2, is mostly considered as a gangue mineral which frequently coexists with valuable minerals and metals, such as gold, copper and nickel. Its separation from valuable minerals can be a costly process (Chandra & Gerson, 2010). In refractory gold ores, the fine gold particles are locked inside the pyrite structure. Oxidative leaching of pyrite is a hydrometallurgical method to destroy the structure of pyrite and expose the fine gold particles to the cyanide solution in the downstream cyanidation circuit. Pyrite oxidative leaching can be achieved by oxidation of pyrite via oxygen and ferric ion(McKibben & Barnes, 1986). In fact, pyrite oxidation by oxygen and ferric is a significant source of acid mine drainage(AMD), which adversely causes serious environmental problems(V. P. Evangelou, 1995).The pyrite oxidation mechanism is accomplished in three consecutive steps: (i) pyrite is oxidized by oxygen and ferrous ion formation (Eq. 1); (ii) ferrous oxidation by oxygen and ferric ion formation (Eq. 2); (iii) pyrite oxidation by means of ferric ions (Eq. 3). Hence, both oxygen and ferric participate in the pyrite oxidation process (Moses & Herman, 1991):"

Jan 1, 2016

By J Rock, K Bambrook

"Hanwha Mining Services was approached by Glencore Coal to provide a series of (trial) demonstration blasts at its Clermont coalmine. The intent of the project was to trial a bulk explosive product that would be able to provide sufficient energy for the ground type encountered without production of post-blast fume. Three blasts were loaded using the patented XLOAD bulk explosives with a density of 1.00 g/cc. XLOAD bulk products are water resistant explosives that can be loaded at densities much lower than traditional (generic) water resistant heavy ammonium nitrate – fuel oil (ANFO) or pumped blends with significantly reduced risk of fume. In addition, these products have detonation characteristics that generally deliver a higher heave partition than conventional bulk products and hence improve muck pile looseness and digability.The priority key performance measures included the absence of fume from blasting, being at least cost neutral and providing similar if not improved shovel dig rates. The design for the initial blast took a conservative approach to ensure the key blast outcomes of fume control and fragmentation were achieved.The second blast used the same pattern dimensions as the benchmark bulk product used in this area to provide a cost neutral comparison with the benchmark products that had been used over the prior six months. This resulted in a 20 per cent lower powder factor than would have otherwise been used. To test the suitability of XLOAD, this shot was slept for over two weeks between loading and firing in geology where the sleep time is typically kept to a few days to minimise the fume risk.The third blast utilised a slightly larger drill pattern to push the capabilities of XLOAD and provide a cost neutral comparison between the trial product and the traditional benchmark products. All three blasts were fired with no fume observed, no recordable incidents and good fragmentation. Shovel productivity from all three of the trial blasts was excellent with higher average instantaneous dig rates being recorded (average six per cent improvement against the instantaneous dig rates recorded for the benchmark blasts).Citation:Rock, J and Bambrook, K, 2016. Controlling Blast Related Fumes with Unconventional Explosives, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 39–49 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By Ingrid A. Venegas

Los sistemas de protección pasiva contra incendios son importantes en el diseño de todo tipo de proyectos -particularmente mineros- donde los estándares de seguridad son más exigentes. En este sentido, el presente texto describe la importancia de la protección pasiva contra incendios ya que evita una catástrofe y minimiza los daños materiales como salva vidas. El uso de este sistema desarrolla tres tres objetivos: la creación de compartimentos seguros capaces de contener y evitar la propagación de la llama, gases y humos, la protección de las estructuras, lo que evita el colapso prematuro de la edificación y la extracción de humos, principal causante de pérdidas humanas y la extracción de humos, principal causante de pérdidas humanas.

Sep 1, 2013

By R. E. Martin

"The Westerose Leduc (D-3) pool, a Devonian reef reservoir situated in Central Alberta, Canada, has now been producing for over seven years. As a unit operation, the pool pro-vides an interesting example of the full exploitation of gravity segregation tendencies. The reef has a 238-foot oil column, underlain •by bottom water and over-lain by a substantial gas cap. The original hydrocarbons in place were 147.96 million STB oil and 94.4 MMMCF of Taw gas cap gas. Nine-teen producing wells on 80-acre spacing have been completed, most of which are highly productive. Gas injection operations return solution gas to the gas cap. A study of the rock and fluid properties of the pool show it to be conducive to production by gravity segregation at high rates. Monthly average producing rates have varied between 800 B/D and 8,000 B/D and have recently totalled 3,000 BID to 5,000 B /D. Recovery and performance predictions under partial pres-sure maintenance at 10,000 BID indicate an ultimate recovery of 66 per cent of the original oil in place. In the absence of pressure maintenance, recovery would be only slightly less."

Jan 1, 1960

By R. O. Dannenberg

This report describes aperiments by the Bureau of Mines and reviews theoretical aspects of the use of organophosphate solvent extraction for recovering beryllium from sulfate leach liquors. The leach liquors were prepared by sulfuric acid leaching of lime-sintered low-tenor beryl flotation concentrates. The experimental work on sulfate leach liquors showed that the acidic esters of organophosphates extracted beryllium slowly but in preference to aluminum. Three common alkylphosphoric acids, di- (2-ethylhexyl) (EHPA), heptadecyl (HDPA), and dodecyl (DDPA), in order of decrmsing selectivity, yielded a partial separation of beryllium from aluminum.

Jan 1, 1962