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By J. G. Kirby

The total number of petroleum refineries in the United States decreased during 1951, while the total crude-oil charging capacity continued to increase. There were 350 refineries as of January 1, 1952, compared with 357 a year earlier, according to the annual Bureau of Mines capacity survey. A gain of 369,241 barrels in daily refinery crude through-put capacity during 1951 brings the total to 7,332,885 barrels daily. The capacity of the average refinery to process crude-oil was 20,951 barrels daily, an increase of 1,445 barrels daily over the previous year. Capacity added in the Texas Gulf district accounted for 36 percent of the total increase; the Indiana-Illinois-Kentucky district, 23 percent; the East Coast district, 19 percent; the Oklahoma-Kansas district, 12 percent; and the Texas Inland district, 11 percent. The California district was the only one reporting a decline in crude-oil refining capacity, the total being 14,200 barrels daily below the previous year. Reported as under construction January 1, 1952, was an additional crude-oil capacity of 282,680 barrels daily, an increase of 77 percent over the January 1, 1951, total of 160,100 barrels. The capacity now building is for the expansion of existing facilities, since no new plants had been begun as of the first of the year. Three or four companies have plans to build refineries in the Williston Basin area of North Dakota, but no definite locations or dates when construction will begin have been announced.

Jan 1, 1952

By Ren G. Dong, Dan E. Welcome

Instrumented handles or dynamometers are widely used to measure hand forces and/or the biodynamic response of hand-arm system. To study hand-transmitted vibration exposure, six generations of instrument handles were constructed or initially developed by researchers in ECTB/HELD/NIOSH. This presentation provided a summary of these handles. Their basic characteristics, limitations, and usefulness are described, which may help their appropriate applications and further improvements. Six Designs of Instrumented Handles Handle 1: The conceptual design is recommended in ISO 10819 (1996)1 for glove test. The grip force is measured by detecting bending strains on a measuring beam in the handle. A special handle fixture was designed to connect the handle to a shaker. Except the screws, the handle and fixture were made from aluminum. Handle 2: The design is based on the principle of shear strain measurement.2-3 Both grip and push forces can be measured simultaneously using this handle. This handle was directly designed for a simulated vibrating tool. Handle 3: This design is basically composed of a handle base, a measuring cap, and two charge-based sensors (Kistler 9212) sandwiched between the base and cap. The handle was also made from aluminum. The fixture for Handle 1 was also used with this handle. This generation of handle has three different handle diameters (30, 40, and 50mm).4 Handle 4: This design is an improvement from Handle 3. The handle fixture was totally redesigned and it was much stiffer than the previous one. The aluminum measuring cap was replaced with a magnesium cap. Handle 5: The basic structure of this handle is the same as that for Handle 3. However, the piezoelectric sensors were replaced with two strain gage based sensors (Interface SML-50). Handle 6: This handle includes two measuring caps, four piezoelectric sensors, and a handle centre base. The handle fixture was the same as that with Handle 4. Methods for Handle Examinations The static and dynamic characterizations were performed using the methods reported by Dong et al.5-6 Results and Discussion Handle 1: The static force measurement depended on the hand grip location on the handle. Its natural frequency was less than 200 Hz.5,6 Because the transmissibility of gloves may not vary significantly with the applied grip force, this handle may be acceptable for glove test. However, the force measurements with this handle may not be reliable. Handle 2: The static force measured with this handle was insensitive to the hand acting location. However, when the handle was vibrating, the force signals could be totally distorted. For this reason, it was not used for vibration studies.

Jan 6, 2006

By A Hall, D Kratochvil, P Littlejohn

Economic recovery of gold from complex gold ores, including poly-metallic deposits, is impacted by the presence of cyanide-soluble base metals. These base metals can create both a metallurgical challenge plus waste handling and disposal challenges. Base metals such as Cu and Zn compete for the cyanide reagent and often increase the total cyanide consumption to the point of making precious metals recovery uneconomic. In addition, the accumulation of base metals in cyanide solutions represent a challenge for cyanide detoxification and waste water treatment as these metals report to waste sludge. Such sludge requires safe handling and disposal, with possible long-term liabilities.Base metal interference can be removed with sulfidisation-acidification-recycling-thickening (SART) process technology. SART liberates the base metal from the cyanide complex and precipitates the metal as an insoluble sulfide product that can be recovered as a commercial grade concentrate. With the base metal precipitated, the cyanide can be regenerated as free cyanide and recycled to the gold extraction circuit.BioteQ completed laboratory testing for two projects, one employing cyanide leaching of copper-gold sulfide flotation concentrate and one employing a Merrill Crowe process, to determine the effectiveness of SART to remove and recover Cu and Zn in high-grade sulfide concentrates and to reduce the impact of cyanide-soluble metals on gold recovery and cyanide consumption. This paper will provide an overview of the testing methodology and results along with a review of the potential for SART to be applied to complex gold ores with poly-metallic deposits to improve project economics, operability and waste management.CITATION:Littlejohn, P, Kratochvil, D and Hall, A, 2013. Sulfidisation-acidification-recycling-thickening (SART) for complex gold ores, in Proceedings World Gold 2013 , pp 149-156 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By Michael G. Zabetakis, Glenn H. Damon, Joseph A. Herickes

The flammability and explosibility of unsymmetrical dimethylhydrazine ( UDMH ) were investigated by the Federal Bureau of Mines to evaluate hazards associated with commercial application of this material as a missile fuel . This program included the following determinations : 1. Temperature limits of flammability in air at one atmosphere pressure ; 2. limits of flammability at selected elevated temperatures and pressures ; 3. 4 . 5. spontaneous ignition temperature in air at one atmosphere and at 200 pressure per square inch gage ( p.s.i.g. ) initial pressure ; spontaneous decomposition temperatures in nitrogen at one atmosphere and at 200 p.s.i.g .; shock sensitivity over a temperature range from about ( ca. ) 25 ° to 50 ° C .; 6. shock sensitivity of reference propellants ( hydrazine , nitromethane , methyl acetylene , etc. ) ; 7 . shock sensitivity of UDMH plus small amounts of selected metal catalysts . Part of the corresponding data was obtained for a mixture of unsymmetrical - dimethylhydrazine and diethylenetriamine ( U - DETA) .

Jul 1, 1960

By Aditya Ayithi, William G. Ryan, Dean Herbst

"For rock socketed drilled shafts, it is a common practice not to include the frictional resistance of overburden soils into the nominal capacity estimation. The primary reason often being cited is “overburden soils resistance is negligible compared to that of rock socket resistance.” However, in certain geological conditions, where the rock layer is located at greater depths, friction resistance from overburden layers can be significant. In addition, at such great depths, shaft drilling becomes very complicated and expensive. In these situations, considering the resistance of the overburden layers can be an economic alternative.This paper presents a case study of an Osterberg cell (O-cell) load test conducted on a 161.8 feet long and 78-inch diameter instrumented test shaft. Based on initial designs, a 72-inch diameter rock socket of lengths 23 and 26 feet was required to provide a LRFD factored friction resistance of 3,200 kips. The load test results revealed that the material in the 72-inch diameter socket does not represent a true rock. However, the test results also proved that the factored friction resistance of overburden layers is greater than the required design resistance. Based on the load test results, it was decided to allow the overburden soils frictional resistance to be considered in the shaft design, resulting in significant economic savings.INTRODUCTIONRock socketed drill shaft design guidelines of various State Department of Transportation (DOTs) agencies allow friction and/or end bearing resistance of only the rock socket portion into the design capacity estimation. It is typical to neglect the frictional resistance of overburden soils. However, in certain geological conditions where the rock layer is at greater depths, friction resistance of the overburden soils can be significant. In this case the friction resistance of overburden soils was verified via the specified instrumented O-cell test program and then used as part of the design capacity.PROJECT DESCRIPTIONAs part of I-29 improvement project, Iowa Department of Transportation (Iowa DOT) planned to replace the dual four lane bridges that cross the Floyd River in Sioux City, Iowa with dual six lane bridges (Fig. 1). Expected benefits from this improvement include improved safety, traffic operations and roadway infrastructure conditions.BRIDGE SUBSTRUCTUREThe project consists of two individual bridges; a new south bound bridge and a new north bound bridge. The south bound bridge is 646-ft long and the north bound bridge is 644-ft long. Both are six-span, pretensioned and pre-stressed concrete beam bridges of varying width. Bridge foundations were designed such that the abutments of both bridges will be supported on driven steel piles and the bridge piers will be on drilled shaft foundations."

Jan 1, 2016

By Shiju Zhang, Yongnian Dai, Songli Liu, Wenhui Ma

The BaZrO3 and CaO-doped BaZrO3 ceramics were fabricated at 1750 °C for melting the Ti2Ni alloys, respectively. Employing XRD, OM and SEM, the influence of CaO on the composition of BaZrO3 and the interaction between the BaZrO3 ceramic and titanium alloy was investigated. The results showed that the CaO doped BaZrO3 was consisted of CaO and Ba 1−xCaxZrO3. The grain on the surface of BaZrO3 ceramic was loose after melting, and the thermodynamic analysis indicated that the dissolution-erosion was responsible for the interaction mechanism. An amount of BaZrO 3 refractory was attached to the Ti2Ni alloy bottom after the alloy was cooled. However, no refractory was found on the bottom of Ti2Ni alloy, which was cooled down on the CaO doped BaZrO3 ceramic. CaO additive can effectively reduce the interaction between the BaZrO3 refractory and the titanium melt, indicating that it was a very promising refractory for preparing the titanium alloy.

Mar 1, 2018

By A. J. Jager, D. P. Roberts

The stoping of platinum orebodies in the Bushveld has in the past been accomplished by using in-stope pillars to ensure stability of the workings. In the future, the use of continuous mining machines to mine the platinum orebodies is probable. It is not envisaged that such machines will cut in-stope pillars. This paper describes the alternative support systems that will replace the pillars and the stope geometries that will be required for this type of mining. The paper describes how the support resistance provided by in-stope pillars in current mining was determined and then evaluates support systems that can substitute for these pillars. Conceptual layouts based on existing breast mining layouts are presented. The layouts consist of panels of up to 100 m face length between rigid strike stabilizing pillars. A number of design charts are then proposed that allow for the design of appropriate support systems.

Jan 1, 2004

The Acid Drainage Technology Initiative (ADTI) was initiated in 1995 by federal agencies, the National Mining Association (NMA) and the Interstate Mining Compact Commission (IMCC) to identify, evaluate and develop cost-effective and practical acid drainage technologies. In 1999, ADTI was expanded through the addition of the metal mining sector, which is focused on drainage quality issues related to metal mines. ADTI addresses drainage quality issues from abandoned, active, and future coal and metal mines. The guiding principle of ADTI is to build consensus among industry, federal and state regulatory agencies on acid drainage technology development and technology transfer issues. ADTI is focusing its efforts on mine drainage prediction, sampling/monitoring, modelling and avoidance/remediation. ADTI is not a regulatory or policy development program. ADTI includes the Coal Mining Sector (CMS) and the Metal Mining Sector (MMS) under the overall guidance of the ADTI Operations Committee. The Operations Committee consists of representatives from industry, state and federal government and academia. The Coal Mining Sector includes two committees; a prediction committee and an avoidance and remediation committee. The Metal Mining Sector includes steering committee and work groups on prediction, sampling and monitoring, modelling, mitigation, and pit lakes. The Coal Mining Sector has produced two publications on the prediction and prevention of acid drainage. The Metal Mining Sector has workbooks under preparation covering the work group topics. This past winter, the Metal Mining Sector, working with the US Bureau of Land Management, presented a satellite training session on acid drainage. ADTI has evolved in response to changing needs and technologies as evidenced by the addition of the Metal Mining Sector in 1999. The Operations Committee and the members of the Coal and Metal Mining Sectors will guide future direction in response to identified issues.

Jan 1, 2003

By L. W. Saperstein, Y. J. Wang

The development of computer programs to solve complex ventilation networks has reached a point of refinement where these programs become a necessary tool of the ventilating engineer. Such a program is presented. This program has an increased efficiency over its predecessors; it also includes the important facility of fixed quantity branches. This is in addition to the earlier capabilities of free-splitting, internal or external fans, and natural ventilation pressures. The program is written in Fortran IV with double-precision arithmetic and is listed here. Sample problems with input and output are also given. The recent, and presumably continuing, official interest in mine safety is bound to result in more stringent control requirements for ventilation. Anticipating this requirement, the Dept. of Mining, The Pennsylvania State University, has developed a computer program for the solution of complex mine ventilation networks. It is the opinion of this department that the program has sufficient merit to warrant its use in normal industrial operating conditions. Although the undergraduate mining engineering students of this department are routinely trained to use the program, it was felt that this training did not present a fast enough means of dissemination; consequently, this paper was written. The conception of the program is not new;1; however, the present version incorporates features that changes it from a scientific endeavor to a useful operating tool. These features include those of earlier programs, such as free-splitting, external or internal fans, and natural ventilation processes plus the important ability of handling fixed quantity branches, and of increased efficiency giving reduced cost. The facility for fixed quantities will be discussed in more detail. The solution of any network depends upon satisfying Kirchchoff's laws. These state that the sum of flow at any junction is zero, and that the sum of the pressure drop in branches totals the pressure drop in the mesh constituted by those branches, that is that the pressure drop around any mesh is zero. The terminology is derived from Synge," and is, in fact, that used by Topologists. A branch is any airway of uniform characteristics; a junction is where two or more airways meet (the minimum number of two airways is useful for describing the point where a low resistance airway changes into a high resistance one due to some physical constriction); a mesh is a path, along some branches, that returns on to itself, but does not need to traverse the same branch twice in order to do so; and a tree describes all those branches in a network which, while connected through all the junctions, do not form any meshes. Obviously the branches-in-tree are open-ended and can be shown to be one less than the number of junction (J-1). The branches-out-of-tree, also called basic branches, are equal to the number of basic meshes and are M = N — J + 1, where M is the number of meshes and N is the number of branches. The major difference between this network and an electrical one is that the law attributed to Atkinson for pressure drop is utilized rather than Ohm's law. Atkinson stated that the pressure drop (potential) is equal to a resistance factor multiplied by the quantity squared. This is written H = RlQlQ where H is the head loss. Q? is written in this factored fashion so that H will always have the same sign as Q. A negative sign is used to indicate that flow in a branch is opposite to that of its containing mesh. A mesh takes the direction of its basic branch. Utilizing Atkinson's law in Kirchchoff's second law and bearing in mind that the first law must remain satisfied, the program will determine all quantities, or head losses as they are related, for the branches of the network. The program uses a Geuss-Seidel form of in-teration, starting from an arbitrary Q and using a correction factor of the type first suggested by Professor Hardy Cross' that will handle the nonlinear equation of Atkinson's law. A fuller description of the interative process is included in Wang and Hartman.' Iteration continues until the correction factor is less than or equal to a preset error (E) or until a maximum number of iterations (MAXIT) have been reached. Utilizing an E of 50 cfm, sample problems have had rapid solutions. Rapidity of solution is also ensured by the method of selecting meshes and basic branches. This is done by the computer, which chooses the highest resistance branches, fixed quantity branches, and those containing fans, as basic branches. Natural ventilation pressures are handled as fans of constant pressure and may be assigned to any branch. The computer will generate a fan characteristic by polynominal fitting if a few operating points from the desired fan are input. A fan may be placed in any branch of the network, except those with fixed quantities. The strength of the present program over its earlier versions is its ability to handle fixed quantity branches. This means that certain branches can have their quantity determined, or preset, by the ventilating engineer. Operating under this constraint, the program will analyze the network and output the pressure change necessary to achieve this desired quantity. A call for positive head loss would require an auxiliary fan; negative head loss would require a regulator. This represents a powerful tool for the ventilating engineer who must insure that certain quantities of air pass across the operating faces or through working stopes. McPherson6 suggested that a ventilation program would be useful for determining in advance which branches were receiving inadequate air, and that subsequent calculations would then indicate the necessary corrections. The present program makes these corrections. Thus the mine manager can know immediately the consequences of changes to his system;

Jan 1, 1971

By Ling Yang, John Henderson

Self-diffusion coefficients of copper in molten copper have been measured by the capillary reservoir method in the temperature range 1140o to 1260°C. The results can be represented by the equation D = [(1.46 * 0.01) x 10-3) exp [(-9710 * 710)/RT] cm2/sec. The energy of activation agrees within the limit of experimental uncertainty with that for viscous flow. The relationship between the diffusivity and coefficient of viscosity is best described by the equation D = kT/4pnr cm2/sec. MEASUREMENT was made of the self-diffusion coefficient of copper in molten copper in the temperature range 1413º to 1533ºK, using the capillary reservoir technique and CU64 as the radioactive tracer.The procedures for filling the capillaries, making the diffusion run and evaluating Dcu from the counting results were the same as described previously.1,2 All experimental operations involving the melt were carried out in a purified argon atmosphere. A graphite crucible, enclosed in a McDanel tube, was used as a container for the melt because of its satisfactory nature as a refractory material and the low solubility of carbon in copper. Graphite was also used for the capillary material. A McDanel thermocouple sheath, to which graphite radiation shields were affixed, was used to hold the capillaries. By moving this sheath through a rubber seal at the top of the McDanel tube, the capillaries could be lowered into or raised out of the melt. A Globar furnace with a constant temperature zone (± 2°C) of 2 in. was used to heat the assembly. The temperature of the furnace was the equilibrium value corresponding to a given setting of the transformer. Temperature was measured with a Pt-10 pct Rh/Pt thermocouple and varied during a run

Jan 1, 1962

By C. H. Veloso

"Starch is the most widely used depressant in the reverse cationic flotation of iron ores. There is however, an indication from recent studies, that other polysaccharides may successfully replace them. When starches are used in the flotation of iron ores in the presence of quartz as gangue mineral, their strong adsorption on the surface of iron oxides can be explained by the molecular conformation between the available sites on the mineral surface and two hydroxyls of starches. However, when the gangue minerals are iron-bearing silicates, the strong interaction with starch can occur on these minerals since they have the same surface behaviour as iron oxide. In this work bench scale tests were conducted in order to generate scientific knowledge about other alternatives depressants for the flotation of iron ores. A magnetic pre-concentrate from a skarn iron ore processing plant was used as feed material for flotation tests. The reverse flotation approach was used to upgrade the iron content by removing complex ironbearing silicates. The depressants used in this study were: corn starch, dextrin, carboxymethyl cellulose (CMC) and humic acid. The tests were performed under different pH conditions in order to try to relate the efficiency of depression to the pH used during flotation. The results show the important role of pH as each depressant reached its best performance at different pH values. At alkaline pH the corn starch showed best depression performance while the humic acid is more efficient at pH close to neutrality.INTRODUCTIONIron corresponds to approximately 6% of earth’s crust composition (McDonough and Sun, 1995). It is the most used metal in our lives, some of its properties as resistance and facility to be shaped makes is replacement very difficult. The primary sources of iron on our planet are minerals. The iron-bearing minerals most commonly found in nature and economically exploited are magnetite [Fe3O4], hematite [Fe2O3], goethite [FeO(OH)] and siderite [FeCO3] (L O Filippov et al., 2014). These minerals are commonly associated with other minerals (most of the time not economically exploited) forming the so-called iron ore. Iron ore is the source of primary iron for the world’s iron and steel industries."

Jan 1, 2018

By A. C. Neiva

An energy-dispersive x-ray fluorescence spectrometer was assembled with the aim of analysing alloys and corrosion products of artistic, ethnological and archaeological pieces. The spectrometer is semiportable and consists basically of an 60kV/1.5mA X-ray tube with W anode and a Si-drift X-ray detector with Peltier cooling, with no need of liquid nitrogen. It was used for the analysis of the alloys and occasional corrosion products of several metallic pre-Hispanic pieces of the Museum of Ethnology and Archaeology of the University of São Paulo. Special care was taken to account for the contribution of spurious radiation from both the Pb primary collimator and the Zr detector collimator. The main components of most alloys were Au, Ag and Cu, but Pb, Ca, Fe and other elements were also identified. The characterization of the alloys and corrosion products is important for the subsequent conservation of the collection.

Jan 1, 2006

By B. W. Madsen

The Bureau of Mines conducted a large-scale (6.4 t), long-term (2,165 days) test to gain a better understanding of the leaching characteristics of chalcopyritic ores. An ore sample containing 0.77 pct Cu was leached in a fiberglass column by downward percolation of acidified ferric sulfate solutions. Three sets of leaching conditions were investigated: (1) ambient temperature leaching, (2) elevated temperature (50° to 60° C) leaching, and (3) elevated temperature leaching after inoculation with thermophilic bacteria. Leaching at ambient temperature resulted in a copper extraction rate of 0.44 pct per 100 days. Increasing the temperature to 50° to 60° C resulted in decreased activity of natural mesophilic bacteria, and the leaching rate decreased to 0.22 pct per 100 days. The pH was lowered from 2.0 to 1.6, and nutrient solutions that contained thermophilic bacteria were added. This procedure resulted in an increase in the ferric-to-ferrous iron ratio and an increase in the copper leaching rate. However, the increased leaching rate was not sustained, and 120 days after inoculation the bacterial activity declined, the ferrous iron content increased, and the copper leaching rate decreased.

Jan 1, 1983

By L Stitz, S Kinnear, L D. Fabbro

Sensitive and tolerant species of macroinvertebrates were present across a wide range of conductivity concentrations in the Isaac River catchment in Central Queensland, indicating the need for further ecological studies in the field to underpin the development of regionally-tailored guidelines for conductivity. The Isaac catchment has naturally high conductivity, but there is also increasing pressure on resource companies to ameliorate saline mine water discharge. Recently, catchment management efforts have included a revision of the water quality guidelines that are specific for the broader Fitzroy catchment. These guidelines include the use of macroinvertebrates as indicators of ecosystem health, but developing and applying such guidelines first requires a good understanding of macroinvertebrate ecology and population dynamics, ideally from field validation. To date, studies of macroinvertebrate tolerance to conductivity in southern freshwaters, as well as in laboratory-based ecotoxicological tests conducted in Queensland, have suggested that ranges exceeding 1000 ¦S/cm are likely to have negative impacts on survivorship of all taxa. However, these results may not be transferable to natural populations of macroinvertebrates from the Isaac, where the naturally high-conductivity water may allow the opportunity for adaptation. To test this, macroinvertebrate assemblages were examined at a series of sites in the upper Isaac River catchment at the end of the dry season in 2012. Patterns in the assemblages were examined together with water quality parameters, in order to gauge the ability of macroinvertebrates to survive at conductivity concentrations exceeding 1000 ¦S/cm. The specific conductance of the field sites ranged from 477 ¦S/cm to 9791 ¦S/cm and a total of 39 families from 13 orders were identified. Species richness was not significantly different between sites of differing conductivity. Macroinvertebrate populations were dominated by Dipterans as well as the traditionally more pollution-sensitive families Ephemeroptera and Trichoptera. There was an absence of any correlation between conductivity and species richness (P > 0.050), suggesting that macroinvertebrate taxa richness occurs independently of conductivity, at least in this particular cohort of mining and/or grazing influenced ephemeral systems in Central Queensland.CITATION:Stitz, L, Fabbro, L D and Kinnear, S, 2013. Macroinvertebrate tolerance across a range of conductivities in the Isaac River Catchment (Central Queensland), in Proceedings Water in Mining 2013 , pp 135-142 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By S. Foged

Umicore and MWH jointly demonstrated that mechanical dewatering of goethite and neutralised tailings significantly increased the life of a 30 ha tailings pond and improved the operation of the pond. Umicore operates one of its zinc production plants in Balen, Belgium. As part of its production process, an excess of neutralised and goethite¬containing tailings is generated. These have historically been stored inside large lined ponds. As the storage area of the current goethite pond was nearing its capacity, Umicore studied the potential for an extension to the existing embankment. However, this extension would face intense regulatory scrutiny, because the environmental and safety impacts were considered important. Together with Umicore, MWH suggested and investigated an alternative treatment approach consisting of mechanical dewatering prior to storage. A feasibility study was prepared where wet storage was compared to dry storage. Differences in safety risks, environmental impacts and economic costs were outlined. The study demonstrated that the life of the tailings pond could be increased from 6 to 22 years, seriously reducing the environmental impacts and safety risks at no significantly higher cost than would have been incurred with the continued operation of the existing pond. The results of the study are presented in this paper.

Jan 1, 2006

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

By R. Feenstra

In the course of time, an increasing number of investigations on jet cutting all kinds of material, such as rocks1, 2, 3, metals4, 5, and wood6 have been reported to serve various applications. This paper deals with one particular application of jets, viz deep-well drilling for hydrocarbon exploration and production. A number of papers have been published on this subject 7, 8, 9, some of which refer to jets purposely containing abrasives, termed 'jetted particle drilling'7. Since such abrasives complicate fluid handling considerably and do not appear to be absolutely necessary for making hole we have restricted ourselves to conventional drilling fluids. A large part of our investigation has been performed with the aid of three laboratory-type drilling machines, which permit tests on both micro-bits (12 in) and full-scale bits (62 - 9 5/8 in). In view of the application of jets in deep wells, care has been taken to simulate hydrostatic pressures as they exist in the field on the hole bottom. These have been found to have a major effect on the bit-penetration rate for various drilling fluids. Following experiments with single nozzles, laboratory bits have been designed, improved further and developed for field use. Field runs on 9 5/8 in bits, using conventional equipment and pumps, served to verify the feasibility of the jet drilling concept. Further efforts are evidently needed to evaluate the jet drilling method. It is encouraging that one of these10, a field test programme, is supported by a number of oil companies jointly. Such a combined effort is of paramount importance to evaluate and develop this new method of drilling to its full potential in a reasonable period of time. This paper aims to contribute to that ultimate goal.

Jan 1, 1974

In the future to excavate sufficient coal for power generation, two dredgers would be required to dig overburden or interseam 70010 of the time and three dredgers 40010 of the time. One overburden system was not adequate for this requirement, making coal production reliability vulnerable. TS5 spreader is the new machine element of this system. The selection of the best type of machine configuration to suit the application was then subject to an internal SECV VE Study, a registration of interest and a tender for two machine alternatives. This paper outlines the reasons why SECV planned the Secondary Overburden System and how the Krupp machine met these requirements. It also identifies the main design features of the machine and its constructability which will allow the machine to be operational by the end of May, 1990.

Jan 1, 1989

By David S. Yang

The Cement Deep Soil Mixing (CDSM) method introduces and mixes cementitious materials with in situ soils using hollow-stem rotating shafts equipped with a cutting tool at the tip and mixing paddles above the tip. CDSM generally produces a soil-cement panel consisting of three overlapping soil-cement columns. The soil-cement panel is then extended to form walls, which are effective for excavation support and groundwater control due to the continuity and low permeability of soil-cement walls. Two design approaches could be taken in the application of CDSM for excavation support: 1) single wall design and 2) gravity wall design. The former one is treated as a wall technology and the latter one is treated as a soil stabilization method. This paper will review the CDSM equipment and installation procedures for the construction of these two types of soil-cement walls. Four case examples are used to illustrate the design and application of these two types of soil-cement walls.

Jan 1, 2003

By D. Farrow

Future development of kimberlite mines is now focused on mining at deeper levels. The consequences are increased difficulty and costs of the mining operations. The decisions on investments require accurate resource evaluation and quantification of the risk. In the decision process the first step consists in choosing the number of boreholes sampling the pipe relative to the level of uncertainty that can be accepted. The uncertainty in the volumes of rocks of different types can be assessed as soon as we can estimate these volumes from a given borehole layout and calculate the error by means of its variance for instance. In theory this can be achieved by using geostatistical techniques (‘transitive theory’), but in practice the calculation of the error on volumes can be achieved in very particular cases, assuming some regular sampling patterns. A different approach has been chosen based on simulations, giving maximum flexibility to reproduce the reality of the sampling procedure. The idea is to simulate the geometry of several ‘possible’ pipes with their internal geology and estimate them by kriging. Several experimental errors are obtained on which risk analysis can be performed. The aim is to find a feasible method to perform the simulations with reasonable chance to correctly represent the reality, without data on the pipe extension. The methodology applied is based on some hypotheses that can be assessed by the geologist as well as by the geostatistician. The procedure assumes a geological model based on current knowledge including appropriate geostatistical variation. What make these simulations specific and powerful in this case comes from the fact that the boundaries between the different rock-types can be simulated using a transformation of the real 3D space into a 2D space defined by means of polar coordinates. Ultimate transformations to account for smoother variations with morphological transformations allow the generation of realistic pipe geometries on which sampling pattern can be used to evaluate the estimation errors. By estimating the simulated pipe geometries with different boreholes layouts a risk curve expressing the uncertainty in the volumes of the different rock-types versus the number of holes can be developed.

Jan 1, 2003