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By W. P. Campbell

Introduction OWING to the necessity of curtailing the length of this paper, nothing like an exhaustive treatment of the subject will be attempted. Instead, merely a few aspects will be considered, viz., water trouble in wells, sampling of waters, analysis, methods of reporting analysis, and the comparison of a few typical waters. The waters discussed will not be confined to those occurring in areas where oil or gas has already been found, but will include samples from areas in which drilling is being carried on in the hope that oil or gas may be found, i.e., from unproved fields. The Water Problem The problem of dealing with water encountered in oil and gas producing areas has engaged the attention of petroleum engineers from the early days of the industry. Water was not always considered a menace to oil sands; indeed, a certain amount of it was considered beneficial in some areas, but if such exist today they are very exceptional. In some fields, the problem is more acute than in others, and at times has baffled all attempts to solve it satisfactorily. Wells have been brought-in with promise of good production, but after a brief period have 'gone to water'. Whether ?it has always been a case of poor engineering in the form of unsuccessful water shut-off of 'top' or 'bottom' water, or because 'edge' water was present and water and oil were in such close contact it was impossible to remove the one without the other, is hard to say.

Jan 1, 1929

By Simon D. Handelsman

?Artisanalmining ?Application of human energy (e.g. pick & shovel) directly to produce minerals ?majority no technical skills and lack adequate working tools ?Small-scale mining ?Application of modern technology for limited scale mineral production Significance of ArtisanalMining ?15 million people in artisanaland small scale gold mining ?55 developing countries ?Use of mercury damages health of 100 million people

May 1, 2006

Determination of Flotation Kinetics of Coal Grain Types in a Pilot Scale Jameson Cell using Coal Grain Analysis Method

Sep 13, 2010

By Matti Kongas, Kari Saloheimo, Antti Remes

"The paper studies the control performance of the flotation process as a function of the measurement accuracy and sampling frequency of an on-stream XRF analyzer, using a simple dynamic model. An additional aim is to assess how the economical result of a mineral flotation process depends on the quality of process control based on the on-line elemental assays.An on-stream XRF analyzer measures the concentrations of slurry lines in a continuous cycle from several process points. The control performance depends on the analytical accuracy and sampling frequency of the concentration measurement. With a long cycle time, the state of the process changes before a new measurement becomes available. With short measurement times the statistical variance of the counted X-ray pulses increases, increasing the random error in the analysis. In addition, the measurement accuracy depends on the concentration of the component to be measured from the slurry.To quantify the effect of analysis error and frequency to process control, a simple dynamic process model is created in the Matlab environment. Data from a copper flotation circuit is used as a test case. The process model comprises a first order reaction equation and the grade-recovery -relationship estimated from process data. The control was modeled using the control strategies implemented into a rule based advanced control system.The economical performance of the control was studied by calculating the overall net smelter return at various analyzer parameter combinations. The economical performance of the process declines strongly when the sampling cycle is increased. In studied case the sample measurement time did not have a significant effect on the results. The economical performance of the simulated process corresponds to an almost uncontrolled process when sampling cycles longer than 40 min are applied."

Jan 1, 2003

By J. W. Hunter, J. H. Jacobs

"Approximately 355 tons of nodules from Chamberlain; S. D., ore were processed in the 1-ton-per-day electrolytic-manganese pilot plant of the Bureau of lanes at Boulder City, Nev., in a continuous 3-month operation. The ore, ground to minus 48-mesh, was found to be amenable to leaching with acid directly or after roasting under reducing conditions in a Skinner muffled multiple-hearth furnace.Unroasted ore gave an acid-leach extraction of 84 to 88 percent of the manganese, which after neutralization showed an over-all extraction of between 81 and 85 percent of the manganese. The amount of iron extracted varied, but it was always,enough to permit the use of ammonia for neutralization.Roasted ore showed an acid-leach extraction of 89 to 91 percent of the manganese. A large amount of iron went-into solution, so that it was not economical to neutralize it entirely with ammonia. By neutralizing with calcine to a pH of 5.0 and completing -neutralization with ammonia to a pH of a.5 an over-all manganese extraction of 84 to 86 percent was obtained. The slight increase in. extraction on roasted ore probably would not justify the cost of roasting.Acid consumption averaged 1.75 pounds per pound of manganese extracted. Settling rates of the residue in leach solution were to slow to permit clarification in thickeners, but a Moore vacuum leaf filter proved to be satisfactory. Purification of raw leach solution was .accomplished readily by hydrogen sulfide with a low gas consumption. Electrolysis was normal, without difficulty, and with -current efficiency ranging between 62 and 66 percent.The use of Chamberlain modules for the production of electrolytic manganese would result in an operating cost of 0.8316 cent per pound higher than the cost of producing electrolytic manganese from Three Wids ore."

Mar 1, 1946

By W. A. Tiller, W. C. Johnston

The solute distribution ahead of an advancing solid-liquid interface is controlled by varying the momentum boundary layer thickness in the liquid adjacent to the interface. Single pass zone-melting experiments on Pb-Sn alloys are described in which the liquid is caused to rotate in the plane of the solid-liquid interface due to the influence of a magnetic .field rotating in this plane. The variation of the diffusion boundary layer thickness with field strength is determined. DURING the freezing of an alloy a partitioning of solute occurs at the solid-liquid interface, the magnitude depending upon the difference in the solid and liquid solubilities at the interface temperature. Because the diffusion coefficient is so small in the liquid relative to normal freezing rates, either a pileup or a depletion of solute occurs at the interface when the partition coefficient, kO, is either less than or greater than unity, respectively. This solute distribution is completely characterized by i) the solute concentration in the liquid far from the interface, C) the ratio of freezing velocityf, to diffusion coefficient, D, iii) the partition coefficient, ko, and iv) the thickness of the diffusion boundary layer, 6,, at the interface (this assumes that an electric field is not applied across the interface). For a particular system, C ko and D are fixed so that the character of the solute distribution can be changed only by a variation of either f or 6c. As is well known, the freezing velocity can be changed by varying the thermal environment of the alloy. Whereas, the thickness of the solute rich layer can be changed by varying the fluid flow conditions in the liquid. It is the purpose of this paper to describe a technique for controlling the fluid flow conditions in the liquid. During most solidification experiments the driving force for fluid flow arises from either mechanical mixing, thermal convection or electromagnetic mixing. The momentum boundary layer thickness, 6m at the solid-liquid interface, within which negligible movement of the liquid occurs, has been calculated for the special case of mechanical mixing where crystals are solidified by the Czochralski technique.l,2 The calculation of 6m for the case of thermal convection has also been made.3 In some calculations it has been assumed that the momentum boundary layer thickness, 6,, may be equated to the thickness of the diffusion boundary layer 6c, at the interface. However, as may be seen from Appendix I this is only true in very special cases and in general where a is a constant of magnitude determined by the particular liquid alloy. Neither calculations nor experimental data exist for the dependence of upon electromagnetic mixing. In this paper experiments are described in which the liquid is caused to rotate in the plane of the interface due to the torque developed on it by a magnetic field, H, rotating in this plane. The variation of is controlled by the variation of H. A magnetic field rotating in a plane perpendicular to the interface has been used for the purification of aluminum. Experimentally, we determined the variation of 5C with H by using the zone-melting technique of pfann5and a theoretical relationship of Burton et a1.2 pfann5 has shown that, after the passage of one molten zone through a long cylindrical charge of uniform concentration, CO, the solute distribution, C,, in the solid is as shown in Fig. 1. The equation describing this distribution is

Jan 1, 1962

By N Coplin

Australian Coal Association Research Program (ACARP) project C25073 was proposed by industry stakeholders seeking a potential solution that improves underground air quality and reduces operational costs associated with technology used to control diesel particulate emissions in the underground coal mining environment.The need to protect workers from diesel particulate matter (DPM) has lead the underground coal mining industry to install disposable filter systems on their vehicles. While the disposable filters are efficient at removing significant amounts of DPM, the following major issues have arisen:- high cost of operations; disposable filters cost $A250–300 each and need to be changed at least once per shift resulting in an estimated cost of up to $A164 M/a, in filters alone, to the NSW underground coal mining industry- improper installation, damaged seals and lack of installing a new filter when the old filter is removed; workers are still being exposed to excessive amounts of DPM.The ACARP project successfully demonstrated significant DPM emissions reduction comparable to the incumbent disposable technology on a proof-of-concept wall-flow diesel particulate filter (DPF) system, as well as satisfactory system robustness when assessed using an industry representative test cycle representing operations of a load haul dump (LHD) vehicle typical of that used by the Australian underground coal industry. It was noted in testing that the technology increased modal NO2 formation, but was compliant over typical operational duty cycles.One of the key benefits with the use of a wall-flow DPF system is its tamper-proof design, mitigating the risk of operating unfiltered diesel plant in poorly ventilated areas. Elimination of the need for continual replacement of disposable filters provides significant operational savings estimated to be up to 80 per cent of the incumbent technology.In addition to the above, the project also delivered a number of significant contributions to the knowledgebase of the Australian and international coal industry with regard to the characterisation of operations and control of emissions.CITATION:Coplin, N, 2017. Wall-flow type diesel particulate filter system to replace existing wet element filter systems used in typical LHDs in underground coal operations, in Proceedings Australian Mine Vent Conference 2017, pp 119–128 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By Paul S. Fisk, Arne Fareth, Julie Frietas, Francis Lo, Fidel L. Mallonga

INTRODUCTION This report describes the inspection of parts of the New Croton Aqueduct (NCA)undertaken for the New York City Department of Environmental Protection (NYCDEP)by Parsons Brinckerhoff Quade & Douglas, Inc., (PB) in association with Montgomery Watson Engineers of New York, P.C. (MWH). Support for the inspection was provided by AFC Enterprises, Inc., under Construction Contract CRO-333, “WM-11 New Croton Aqueduct Rehabilitation and Inspection Program.” The scope of the inspection work under CRO-333 included assessing the condition of the 10.3 km (6.4 mile) long, pressurized section of NCA and inspection of shafts, head houses and blow-off structures in both the pressurized and gravity sections. The CRO-333 inspection continued investigation work begun under ContractCRO-196, which ran from 1993 to 1997. The CRO-333 inspections were conducted from November 2004 to September 2005. Background The New Croton Aqueduct was put into service in 1891 to deliver water from the Croton River Watershed in Westchester County to consumers in New York City. Figure 1 shows the location plan of Croton Water Supply System. The design flow into Jerome Park Reservoir was 12.7 m3/s (290 mgd) and into the135th Street Gate House, further south, was 10.9 m3/s (250 mgd). The NCA has been operated as a gravity conduit from Croton Lake to Gate House No. 1, just north of Jerome Park Reservoir, since its original construction. The length from Gate House No. 1to 135th Street, which includes a major siphon under the Harlem River, has been operated under pressure. Croton Lake gate house, the north end of the alignment lies at Station 4+75; Shaft 33, the south end of the alignment lies at Station 1628+05. The diameter of the tunnel is 3.2 m (10.5 ft) in the siphon and 3.7 m (12.3 ft) in the Bronx and Manhattan sections. The pressurized sections, constructed in rock, consist of a brick lining surrounded by a mortared and grouted rubble backing. Figure 2depicts a typical tunnel cross section. The objective of the shaft and tunnel inspections was to locate and document defects, such as leaks, deterioration of lining material, cracks, spalls, delaminations,

Jan 1, 2007

By T J. Sprott, Associates

A number of people have expressed concern, understandably, that if mining operations take place in the Coromandel, the flows of mineralised ground water which exist will be intercepted. This water in many cases contains toxic metals including mercury, arsenic and lead and it is thought that if this water is allowed to enter streams or the waters of the Hauraki Gulf, it could endanger natural marine life and possibly established fisheries. This paper seeks to explain in simple terms the geology and the process of deposition of the various mineral deposits in the ground, the chemistry of the reactions between these minerals and the rain water falling on the ground, the hydrology and behaviour of this mineralised groundwater as it moves through the ground until it eventually enters the sea.

Jan 1, 1981

By G. R. Speich, D. J. Mack

The transformation of was studied by isothermal methods. At all temperatures, the ß transforms quickly to fine grained ß" which develops silver-rich striations. At higher temperatures the striations disappear, the final structure being Widmanstatten a in ß'. At lower temperatures, the striated ß" is consumed by pearlite nodules of a + ß' which in turn form the Widmanstatten a in ß'. The transformation is unlike any previously reported for a eutectoid. AS part of a general program of study on the eutectoid reaction, the Ag-Cd eutectoid seemed particularly attractive because the ß phase which undergoes the reaction is another of the typical "electron compounds," AgCd, having the disordered body-centered cubic structure. This work deals with the eutectoid which occurs at 50.5 wt pct Ag, and not with the eutectoid which has been reported at 42.9 pct Ag.' There has been no work reported specifically on the Ag-Cd eutectoid which was studied. The only information available on this eutectoid is that work done in the determination of the phase diagram. For the most part, the terminal portions of the diagram, Fig. 1, are well established; however, the region from 40 to 60 pct Cd is still somewhat in doubt. The X-ray evidence'..' in this region is in conflict with the results of thermal analysis. X-ray analysis3 does not show a polymorphic transformation at about 240°C as indicated by thermal analysis.1,5 Even the X-ray evidence, within itself, is confusing in this region of the diagram. One investigator2 reports the ß phase as hexagonal close-packed and has found three phases in the one-phase ß field. Other X-ray investigators"' ' report the ß phase as body-centered cubic. The authors believe that much of the confusion resulted from incomplete homogenization of the alloys. It was found that it takes almost a week to produce a completely homogeneous two-phase structure at 370°C. Another possible source of error is the volatilization of cadmium from the surface and cracks of the specimen during annealing with the possible formation of a cadmium-poor phase. The only metallographic data available on this eutectoid alloy are those of Durrant1 and Fraenkel and Wolff.5 his information is very limited. The phase diagram chosen as most nearly correct is that in the Metals Handbook," which is almost identical with the phase diagram suggested by Durrant.1 Materials and Procedure The alloy was prepared from high purity silver (999.5 plus fine) and high purity cadmium (0.02 Pb, 0.005 Cu, trace Fe). The metals were melted in carbon under a nitrogen atmosphere. Some cadmium was lost by volatilization but by remelting several times and adding cadmium a 200 g ingot of approximately eutectoid composition was obtained. Because the CdO fumes are quite toxic, the exit gas from the furnace was led through a water trap to condense the CdO. The ingot was homogenized at 650°C for 24 hr, no attempt was made to prevent decadmiumization. This resulted in a narrow decadmiumized rim on the ingot which was removed. Filings for analysis were obtained from cross sections of the ingot. Silver was determined by the Volhard thiocyanate method,? cadmium by difference. The ingot analyzed 50.8 pct Ag at the top of the ingot and 50.7 pct at the middle and at the bottom of the ingot. This alloy was only slightly hypo-eutectoid compared to the accepted value of 50.5 pct Ag and was used for the isothermal studies. It was felt that further attempts to adjust the composition might be futile because of the volatility of the cadmium. The ingot was sectioned to specimens approximately 3/4 x 3/4 x 1/8 in. These specimens were "austeni-tized" for 3 hr in air at 650°C to yield homogeneous ß and then quenched into a salt bath held at constant subeutectoid temperatures where the transformation

Jan 1, 1954

By J. O. Winget

Phosphonic acid and iminodiacetic acid chelating resins were investigated to assess their potential as selective ion exchangers for separating lanthanide elements and yttrium . The affinity of phosphonic acid resin for lanthanides increases with increasing atomic number , and that of iminodiacetic acid resin for lanthanides increases with atomic number to a maximum for element 62 and then declines with atomic number throughout the remainder of the series . Elution sequences of the elements with mineral acid eluants corresponded favorably with equilibrium data , whereas the elution sequence obtained with chelating eluants was proportional to the relative values of the stability constants of the chelating agents with the lanthanides . Separation of lanthanide mixtures into groups of light and heavy elements with iminodiacetic acid resin appears feasible .

Jan 1, 1964

By Fred D. Wright, Philip B. Bucky

FOREWORD By E. D. Gardner[$] THE present known petroleum reserves are limited, and unless important new fields are discovered the Nation will be dependent, in the not too distant future, upon imports or upon synthetic liquid fuels to supplement domestic petroleum supplies. As a national defense measure, it would appear desirable to develop a substitute source of liquid fuels within the borders of the country if new discoveries of petroleum should prove disappointing. Congress undoubtedly had this in mind when it passed the Synthetic Liquid Fuels Act (78th Congress, approved April 5, 1944). The act directed the Bureau of Mines to construct and operate demonstration plants for producing synthetic liquid fuels from coal and oil shale, and from forestry and agricultural products. As a part of this program, the Bureau of Mines has built a demonstration plant at Anvil Points, near Rifle, Colo., for retorting the oil shale, and has developed a mine to supply the plant with oil shale. At the beginning of mining operations, the physical qualities of the oil shale, which would have a bearing upon the selection of mining methods and practices for exploiting the deposits, were largely unknown. A comprehensive mining-research program has been set up to determine the best methods and practices to follow to obtain the lowest overall practicable mining cost for producing the oil shale on a large scale. Unusually low mining costs will be necessary for shale oil to be produced commercially. Consideration now is being given to exploiting a series of flat-lying beds 70 ft thick by a room-and-pillar method of three benches with the advance heading at the top. This report is one of a series giving the results obtained in research on mining problems. INTRODUCTION The structure and physical qualities of the oil shale indicate that the 70-ft interval of the oil-shale measure can be safely mined in open stopes; studies indicate that this method would be the most economical one to use.1 As labor will be a major item of expense, the largest equipment that could be operated efficiently in the workings would be required to obtain the lowest practicable mining cost. It was therefore desirable to know the maximum safe span of unsupported rooms and the size of pillars necessary to support the overburden. This paper describes the work done at the Columbia School of Mines Barodynamic Laboratory in determining the maximum safe unsupported roof spans and the minimum safe pillar dimensions for the oil-shale mine at Rifle, Colo.

Jan 1, 1947

By F. Halverson

"The theory of flocculation usually is in a state of flux, involves many diverse phenomena, and is complex and sometimes contradictory in details. Instead of attempting a general discourse, I shall discuss selected observations made at our Stamford Laboratories, which impinge on theoretical aspects in two somewhat distinct areas of flocculation. Since some of you many not be familiar with flocculation, and :.n order that we all attach the same meaning to the jargon used, I first would like to review briefly a generalized picture of what goes on.Assume we have a suspension of particles in water, with a distribution in the sizes of particles. The surfaces of the particles interact to some extent with the water--· tending to alter the extent of hydration, may generate some ion exchange, all being somewhat variable with time--developing a surface condition which is very complex in details. We refer to this suspension as the ""substrate.""In the usual situation, if the suspension is allowed to stand quietly, the large particles settle out first, with somewhat smaller particles settling more slowly, and then there is a portion of very fine material which takes a long time or doesn't settle out at all. This resistance to settling t~ the very fine particles results from many factors, but all relate back to the size and density of the particles, to their surface properties, and to the other components in the aqueous suspending medium."

Jan 1, 1978

By D. Brady

When deciding to deploy rescue teams underground the decision makers need to be able to determine that there won?t be an explosion whilst the rescue teams are underground. Previously general body concentrations in areas likely to be travelled were compared to explosive limits on a one off basis with no formal process looking at trends or other areas. A new approach is being adopted that takes into account the rate of change of gas concentrations with triggers set to enable a withdrawal of personnel prior to a possible explosion and influences such a barometric pressure changes. This paper explains the rationale behind the changes made and the advantages and implications of adopting such an approach.

Jan 1, 2012

By R. Cao

Geostatistics was initially developed in the mining sector, but has been extended to other geoscience applications, including forestry, environmental science, soil science, and petroleum science and engineering. This paper presents methods, workflows, and pitfalls in using geostatistics for hydrocarbon resource modelling and evaluation. Examples are presented of indicator variogram analysis of categorical variables, lithofacies modelling by sequential indicator simulation and hierarchical workflow, porosity modelling by kriging and stochastic simulation, collocated cokriging for integrating seismic data, and collocated cosimulation for modelling porosity and permeability relationships. These methods together form a systematic approach that can be effectively used for modelling natural resources.

Jan 1, 2014

By Yajie Wang

Traditionally, roof falls are usually attributed to bad roof strata and high vertical stress related to the overburden depth. However, roof falls under shallow overburden depth are oflen caused by a high horizontal stress field. Recent studies have proven that the high horizontal stress field, if existing, plays a major role in roof stability. Also the roof conditions are related to the entry diredions under a horizontal stress field. Questions are: How to orient the entry to a favorable direction to prevent the roof falls? If the entry cannot be oriented, how to support it? Through a case study in mine A, this paper analyzes the horizontal stress effect on roof stability. The guideline for the entry orientation is given based on the results of analysis. Additionally, suggestions are made for those entries that cannot be oriented to a favorable direction.

Jan 1, 1998

By R. P. Fischer

A large production of vanadium during the war helped Germany to meet her critical requirements for the ferroalloy metals. Vanadium was needed not only in the ordinary high-speed too1 steels, but in other as a substitute for chromium, nickel, and molybdenum, which were scarce. Lacking a source of vanadium ore, however, the vanadium was obtained as a by-product of the steel industry—va-nadium-bearing pig iron smelted from iron ores containing about o. I per cellt V was blown in converters to yield vanadium-rich slag, from which vanadium was recovered by chemical treatment. The production capacity obtained was said to be about 6,500,000 lb. of vanadium a Year. Although the general Processes of Preparing vanadium-rich slags as well as the recovery methods described herein are known, some of the details presented may be of interest to both the American steel industry and the vanadium producers. No adequate data on the cost of the vanadium produced in Germany are known, but it seems likely that the cost exceeds the commonly quoted domestic price of about $1.10 per pound of contained VzOa. Information on the German vanadium production was obtained by a team of geologists from the Geological Survey* United States Department of the Interior, during investigations in May and June 1945 of the German utilization of low-grade raw materials. These investigations were sponsored by the Chief of Engineers, War Department. It is a pleasure to acknowledge the aid obtained from Messrs. H. C. Smith and J. D. Dickerson, investigators assigned to the Army Ordnance section of C.I.O.S., and Mr. C. F. Park, Jr., of the Geological Survey team. The data on vanadium recovery from iron ores were obtained from the Kaiser Wilhelm Institut fiir Eisenforschung, the Hermann Goring steel plant at Watenstedt, and from notes made by other investigators at other German steel plants. Preparation of Vanadium-rich Slags Most German iron ores contain only about 0.1 per cent vanadium, or even less, but some of the scandinavian iron ores available to the German iron industry in the past contain a little more than 0.1 per cent. In general German practice of vanadium recovery, nearly all of the vanadium in the ore goes into the pig iron, which is blown in the Thomas converter, yielding a slag containing about I per cent V. This slag is remelted, the vanadium again going with the iron, which is again blown in a converter, yielding a slag that averages about 10 per cent V. This slag is treated at special chemical plants, by the process of a sodadizing roast, water leach, and acid precipitation of vanadium oxide. The Herman Goring steel plant at Watenstedt used the low-grade Salzgitter iron ores, the average composition of which is shown in Table I, column I. The acid and basic iron produced in the blast furnaces contained about 0.3 per cent V. A Thomas

Jan 1, 1948

By R. P. Fischer

A large production of vanadium during the war helped Germany to meet her critical requirements for the ferroalloy metals. Vanadium was needed not only in the ordinary high-speed too1 steels, but in other as a substitute for chromium, nickel, and molybdenum, which were scarce. Lacking a source of vanadium ore, however, the vanadium was obtained as a by-product of the steel industry—va-nadium-bearing pig iron smelted from iron ores containing about o. I per cellt V was blown in converters to yield vanadium-rich slag, from which vanadium was recovered by chemical treatment. The production capacity obtained was said to be about 6,500,000 lb. of vanadium a Year. Although the general Processes of Preparing vanadium-rich slags as well as the recovery methods described herein are known, some of the details presented may be of interest to both the American steel industry and the vanadium producers. No adequate data on the cost of the vanadium produced in Germany are known, but it seems likely that the cost exceeds the commonly quoted domestic price of about $1.10 per pound of contained VzOa. Information on the German vanadium production was obtained by a team of geologists from the Geological Survey* United States Department of the Interior, during investigations in May and June 1945 of the German utilization of low-grade raw materials. These investigations were sponsored by the Chief of Engineers, War Department. It is a pleasure to acknowledge the aid obtained from Messrs. H. C. Smith and J. D. Dickerson, investigators assigned to the Army Ordnance section of C.I.O.S., and Mr. C. F. Park, Jr., of the Geological Survey team. The data on vanadium recovery from iron ores were obtained from the Kaiser Wilhelm Institut fiir Eisenforschung, the Hermann Goring steel plant at Watenstedt, and from notes made by other investigators at other German steel plants. Preparation of Vanadium-rich Slags Most German iron ores contain only about 0.1 per cent vanadium, or even less, but some of the scandinavian iron ores available to the German iron industry in the past contain a little more than 0.1 per cent. In general German practice of vanadium recovery, nearly all of the vanadium in the ore goes into the pig iron, which is blown in the Thomas converter, yielding a slag containing about I per cent V. This slag is remelted, the vanadium again going with the iron, which is again blown in a converter, yielding a slag that averages about 10 per cent V. This slag is treated at special chemical plants, by the process of a sodadizing roast, water leach, and acid precipitation of vanadium oxide. The Herman Goring steel plant at Watenstedt used the low-grade Salzgitter iron ores, the average composition of which is shown in Table I, column I. The acid and basic iron produced in the blast furnaces contained about 0.3 per cent V. A Thomas

Jan 1, 1948

Mining Systems and Technology - Synchronous Electric Drives for Grinding Mills

Sep 13, 2010

The Development of a Non-Roasting Technology for Polymetallic Gold and Silver-Bearing Sulfide Concentrates Treatment

Sep 13, 2010