Search Documents

By Herbert Pöllmann

Waste disposals are needed for safe deposition of different kinds of materials which can not be used as secondary raw materials. Often high contents of heavy metals must be bonded tightly to cristalline compounds to protect the environment from contamination. Therefore it is important. to find minerals which are capable to incorporate different heavy metals and protect the ground water. The power of resistance against leaching out effects of highly water-soluble salts can be increased. Mineral groups of metal hydroxy salts, ettringites, apatites, sodalites and calciumchlorosilicates and their hydrates are recommended for their formation in mineral reservoirs. Different wastes as red mud, gasification ash, garbage combustion ash and fluidized bed ashes were included in this study. The formation of different new compounds and their properties were determined.

Jan 1, 1991

By J. V. Thompson

The Powderhorn complex as a source of perovskite (calcium titanate) containing about 1.5% rare earths has been examined in several recent feasibility studies. Much promising exploration and process research has been done in recent years. This paper is presented with cautious optimism and with the acknowledgment that there may be some technical and economic areas yet to be explored. The Powderhorn carbonatite and alkalic stock in Gunnison County, Colorado, lies about 203 airlines km southwest of Denver at an elevation of 2450 to 2750 m (see Figures land 2). All of the mineable ore bodies are owned by Buttes Resources Company of Houston, Texas.

Jan 1, 1990

By Jeanne B. Percival, Paul Ramaekers, Charles W. Jefferson, Pat A. Hunt, Eric G. Potter, Katherine E. Venance, William Davis, Sean A. Bosman

"A 10-cm thick clay-rich layer near the top of the Manitou Falls Formation of the Athabasca Group is unusual in its breccia texture, alteration, and detrital mineral composition relative to the adjacent overlying and underlying sedimentary beds. This layer is composed of angular quartz grains set in an illite >> kaolinite + dickite matrix. Deformed clay-rich fragments within the layer have very similar mineral assemblages. The presence of euhedral accessory minerals including Ti-oxides and aluminophosphatesulphate minerals points to a diagenetic/hydrothermal origin. The presence of individual grains of Kfeldspar and amphibole is unusual relative to the typical Athabasca quartz arenite; originally, these minerals were probably included in detrital quartz and subsequently liberated during fracturing. The textures and alteration characteristics suggest that this layer is a hydraulically-fractured unit, which has experienced hydrothermal fluid alteration - a possible pathway distally related to uranium mineralization Une couche argileuse de 10 cm d’epaisseur pres du sommet de la Formation de Manitou Falls du Groupe d'Athabasca est remarquable par sa texture brechique, son alteration et la composition de ses mineraux detritiques qui different de ceux des couches sedimentaires sus- et sous-jacente. Cette couche est composee de grains de quartz angulaires dans une matrice composee d’illite >> kaolinite + dickite. Des fragments deformes riches en argile dans cette couche presentent des assemblages mineraux tres similaires. La presence de mineraux accessoires idiomorphes dont des oxydes de titane et des aluminophosphates-sulphates suggere que ces derniers ont une origine diagenetique / hydrothermale. La presence de grains de feldspath-K et d'amphibole est inhabituelle comparativement aux arenites quartziques typiques de l’Athabasca; initialement, ces mineraux constituaient probablement des inclusions dans le quartz detritique qui ont ete subsequemment liberees pendant la fracturation. Les textures et les caracteristiques de l'alteration suggerent que cette unite a subi une fracturation hydraulique et a ete alteree par un fluide hydrothermal - possiblement en lien avec les effets distaux de mise en place de la mineralisation en l'uranium."

Jan 1, 2013

By Kallam V. K. Reddy, VADAPALLI SANJANA, Veerendra Singh, Gajanan Kapure

This work describes a leaching process for the conversion of high-magnesium peridotite rock, which is a chromite ore overburden, into two valuable products: magnesium salts and micro silica. Under normal leaching conditions, residue remaining after leaching is of a gelatinous nature and thus hinders the filtration process. To address this issue, oxidative leaching with the addition of H2O2 was employed, and it significantly improved the filtration kinetics. Four different approaches for H2O2 addition were tried, and they all proved effective in controlling gelation. The optimum oxidative leaching condition was 70 °C, 2 h time, 2 M H2SO4, 0.5MH2O2 and 400 RPM; under these conditions, 92% magnesium leaching efficiency was achieved. After leaching, the leach liquor obtained was purified and dried into Mg(OH)2 and MgSO4 salts. The leach residue contained mainly silica particles, with size in the 10–30 μm range. This material thus represents an attractive candidate for the production of highperformance concrete for the construction industry. The oxidative leaching process described here enabled the complete conversion of peridotite into valuable products, magnesium salts and micro silica.

May 5, 2020

By Steven R. Ahlfield, Ali Ghandeharioon

A wastewater treatment plant commissioned in 1978 is undergoing a major expansion. Planning various phases of the 8-hectare expansion at this site requires an understanding of the site response during and after construction, and the potential impact on adjacent properties and infrastructure. The expansion project requires nominally 5 m of site grading fill for flood protection. The site is underlain by loose to compact fine sand over firm to very stiff clay stratum that extends to great depths. Ground improvement is required to mitigate the liquefaction hazard in the fine sand stratum, and preloading is proposed to reduce post- construction settlements in the deep clay. Site development and foundation systems for the plant expansion project were evaluated by conducting settlement analyses which accounted for the historic and future site loading and 3-D modeling of soil layers with interpolation between borehole and cone penetration test (CPT) locations. The numerical model was calibrated to match short-term and long-term settlements measured at the plant site. The analyses were carried out to assess the effects of past loading, proposed preload and surcharge heights, lateral extents and durations as well as vibro-replacement ground improvement on post-construction settlements. Two design options were considered for the preload footprint across the site and foundation system for proposed facilities. It is shown that limiting the preload extent and founding some of the proposed structures on deep friction piles reduce the predicted settlements of adjacent infrastructure and result in reasonable performance for the proposed facilities. INTRODUCTION A wastewater treatment plant commissioned in 1978 will be replaced with a new plant on an undeveloped portion of the site to provide wastewater treatment for an expanded service area. The existing facilities must remain in operation until completion of the new plant. The site grade will be raised nominally 5 m for flood protection. The large areal extent of the site grading fill and plant structures will cause stress changes extending to great depths in the underlying soils and result in settlement of the existing and new structures. Historic settlement of the existing facilities has been tolerable for plant operations, but no settlement performance data was recorded during site development and post-construction from 1978 to 2007. Development of the 8-hectare expansion at this site is planned in three phases to reduce the overall construction schedule. Planning for each phase requires evaluating the effects of various site development activities from start to completion of expansion and during the design life (i.e. post-construction period), and the potential impact on existing wastewater treatment facilities and adjacent properties and infrastructure including an adjacent viaduct structure. Figure 1 presents the site plan and three distinct site development phases considered for the plant expansion.

Jan 1, 2019

By C. M. McKinney

This report presents analyses of crude oil from most of the fields in the United States producing 2,500 barrels per day or more. The purpose of the report is threefold : 1) To present detailed analyses of crude-oil samples from as many al possible of the important fields in the United States. On January 1, 1947, there were 340 fields producing 2,500 barrels & day or more. Analyses for 283 of these fie1ds are presented. Fifty-seven fields have been omitted because the Bureau of Mines did not have analyses or the crude oils being produced. As one sample was not representative of the promotion from several of the fields, two analyses are given for each field of this kind. (2) To compile these analyses, many of which have not been published previously in a single report. Since the publication of Bulletin 291 in 1928, there has been no report showing analyses of crude petroleum from fields throughout the United states, but a number of separate reports according to area or state have been issued. Many of these are out of print. (3) To provide a means of ready comparison of the properties of crude oils from different areas of the United states.

Jan 1, 1948

By K. Getsos

Western Greece is a favorable site for exploration and discovery of oil fields. The most important potential source rocks seem to be all the rocks deposited before middle Jurassic under special circumstances, such as reducing conditions, which allowed preservation and maturation of the organic material. In general all the rocks of middle Jurassic to Paleogene are not favorite source rocks. The porosity type was studied on fifty samples using scanning electron microscopy (SEM). Potential reservoir rocks are the porous Paleogene wackestones-packstones with boring, channel and vuggy porosity type. Finally seal rocks are the impermeable mud-stones and wackestones of Jurassic, Cretaceous and Paleogene age. These rocks consist of micrite and whole sells of foraminiferas and the porosity type is mainly intercrystal/interparticle. A Total Organic Carbon (TOC) analysis, conducted on seventy samples using a wet oxidation method, has revealed an extremely low TOC content (less than 0.05 %). This amount is by far less than the minimum organic content amount, required for source rock characterization and characterizes all the rocks of middle Jurassic to Paleogene age. Additionally, 18O and 13C stable isotope analysis was contacted and the results are given in d values. All the rocks within the studied time interval have much lower d values than petroleum source rocks. Clay mineral content was studied in almost seventy samples. As is indicated by the clay mineral content the studied rocks have reached up to the Middle Diagenesis and the temperature during diagenesis was rather low.

Jan 1, 2006

By Basil B. Zavoico

PRODUCTION of crude it in the United States during 1939 totaled about 1.255,776,000 barrels, an average of 3,440,482 barrels per day, 3.41 per cent above the 1938 output of 1,214,355,000 barrels but 1.83 per cent below the record pro¬duction of 1,279,160,000 barrels, in 1937. However only the two-week shutdown of oil fields in the Southwestern States in August and September prevented the domestic crude production from establishing an all-time record in 1939. Demand for all petroleum products for the first ten months of 1939 showed an increase of 7.04 per cent over the similar period of 1938. Domestic demand for all petroleum products was particularly benefited by the increasing industrial activity, advancing 8.37 per cent above the like period of the preceding year equivalent to a volume increment of 256,810 barrels per day; with motor-fuel demand gaining 5.83 per cent and demand for all fuel oils gaining 12.15 per cent over the corresponding period of 1938. The export demand for the first ten months of 1939 was slightly below the export movements during the same period of 1938, declining 0.56 per cent. The European war was a major factor in 1939 for the petroleum industry in the United States, even if, at the end of the year, the war had not yet resulted in the expected large shipments to England and France.

Jan 1, 1940

Water contact angles in the air/water/francolite, fuel oil/water/francolite and fuel oil/water/quartz systems were measured to describe the wetting characteristics of these minerals. It was found that white francolite is more hydrophilic than black and tan francolite both in the absence and presence of fatty acid addition. The contact angle measurement results do not correlate very well with the flotation response and it appears that kinetic aspects of the bubble attachment process play an important role in the francolite-fatty acid flotation system.

Jan 1, 1997

By Gary L. Mowrey

Visible and sometimes audible indications of excessive underground rock pressure such as pillar fracturing, squeezes on chocks, and "roof talk" are familiar to mining engineers. Such signs often precede rock failure on a larger scale and therefore may be used as a warning. Nevertheless, these subjective observations do not provide an adequate means of evaluating the existing rock pressure conditions in a mine. One method which appears to be extremely promising in determining the stability of geologic structures in general is that of monitoring their associated micro seismic activity. Mining engineers generally agree that during the process of rock deformation and failure small-scale seismic ("microseismic") vibrations are produced in the rock itself. These transient vibrations propagate through the rock structure and may be detected at a considerable distance from the failed rock by employing suitable electronic monitoring equipment. Hardy (1) has presented a detailed review of microseismic research in the mining, petroleum, and geoscience areas, and it is apparent that relatively little application of micro seismic techniques have been made in coal mines. This is especially true in North America since here most coal mines are fairly shallow and consequently are not generally subjected to excessive stresses. Furthermore, strict Federal and State mining laws limit the use of electrical equipment in coal mines complicating the use of the necessary monitoring facilities. In terms of both mine safety and economics, monitoring microseismic activity appears to be invaluable in the detection and location of over-stressed pillars and unstable roof conditions caused by development and production work. In 1970 The Pennsylvania State University Rock Mechanics Laboratory became involved in a research project, sponsored by the U.S. Bureau of Mines, to investigate the feasibility of using microseismic techniques to detect and to locate potential regions of instability around a longwall coal-mine operation [Hardy and t10wrey (2); Mowrey (3)]. In this study geophones (velocity gages) located in an array of shallow boreholes drilled from the surface above the active area of the longwall were employed to detect microseismic activity, and a mobile micro-seismic monitoring facility was used to condition and record this data for later analysis. This project is unique in that measurements were made from near-surface geophones rather than geophones installed on the mine itself. Two advantages are apparent, namely that (1) there are no electrical limitations on the monitoring system and that (2) mining operations can continue normally because there is no monitoring equipment or cables in the mine.

Jan 1, 1978

By Robert B. Francini

Longwall mining and pipelines have coexisted since longwall mining was introduced into the United States. How the pipeline operator reacts to longwall mining under their line depends on many factors. This paper outlines the process the pipeline operator goes through to determine the appropriate response when their pipeline is being undermined. Typical mitigation procedures are reviewed. Finally, the paper looks at current design practices for new pipelines that are expected to be undermined during their lifetime.

Jan 1, 2011

By Wei Sun, Xiangsong Meng, Xiaodong Li, Weisheng Huang, Yuehua Hu, Chonggao Cao, Haisheng Han, Wensheng Chen, Runqing Liu, Central South University

"The similar flotability of scheelite, fluorite, and calcite resulted in the difficult separation by flotation. This work revealed the effect of water glass on the flotation of scheelite by FTIR and the wettability change of the usual cleavage plane, and proved that water glass inevitably influenced the flotation of tungsten minerals to a large extend in traditional fatty acid flotation process. A new collector, benzohydroxamic acid complexes, was found to be selective for the separation of scheelite and calcium minerals with little water glass. Hence a novel flotation process was developed for the recovery of tungsten minerals in shizhuyuan mine in China. Normal temperature flotation of tungsten minerals was developed to instead of the classical “Petrov's process” for scheelite-calcite-fluorite type ores. Compared with the traditional process, the recovery was improved by 10% and the grade of scheelite concentrate was above 55%. The disappearance or decreasing of water glass contributed to improving the recovery of tungsten and fluorite and the circulation of water and reagents.INTRODUCTIONChina is rich in tungsten resources and the proved reserves accounted for 60% of the world's reserves (Cai Gaipin et al., 2009). However the wolframite has been dried up and the scheelite resource has become the main resource of the tungsten metal. Scheelite deposits were classified to scheelite-silicate type and scheelite-calcite-fluorite type based on the associated gangue minerals. Scheelite was easy to separate from the silicate minerals. Flotation separation of scheelite from calcium minerals creates difficulties because of the existence of the same cation in the minerals and similar physicochemical characteristics such as solubility, hardness, specific gravity, PZC (point of zero charge) etc.(Arnold & Warren, 1974; Yongxin & Changgen, 1983; Ozcan & Bulutcu, 1993a; Deng et al., 2015, 2016;). The conventional collectors used in the flotation of scheelite ores are generally fatty acids or fatty acid derivatives ( Yongxin & Changgen, 1983; Oliveira & Sampaio, 1988; Sivamohan, 1988; Shi et al., 2014; Bo et al., 2015). It is difficult to separate scheelite especially from calcite with these reagents because the adsorption mechanism of these collectors occurs through chemisorption of the oleate ion onto the mineral surface (Atademir et al., 1979; Changgen and Yongxin, 1983; Hiçyìlmaz et al., 1993; Hu et al., 2011). Therefore, it is almost impossible to separate them by fatty acid flotation without using any selective depressant. Although oleoyl sarcosine was used as a selective collector in the flotation of fluorite and siliceous scheelite ores (Ozcan & Bulutcu, 1993b; Ozcan et al., 1994), this selectivity is not adequate for a low-grade calcitic scheelite ore. Unfortunately, the reagents such as organic colloids (dextrine, starch), quebracho, sodium phosphates, sodium silicate solutions containing polyvalent cations (hydrosols), etc. (Yongxin and Changgen, 1983; Schubert et al., 1990; Shi et al., 2014; Bo et al., 2015) used for calcite depression also depress scheelite to a large extent."

Jan 1, 2016

By Marc Boyer

Modern civilization, modern industry, and modern standards of living, bring into, sharp relief the present-day essentiality of metals .and minerals, and the wide and diversified use which is made of them. Any attempt, therefore, to appraise the international situation today must take into consideration the metal and mineral resources of the world. If, as some believe, the world is divided into two distinct ideologies of political belief, one unalterably opposed to the other, so that armed conflict is unavoidable, then the question of national strength in mineral resources becomes of paramount importance. If, however, it is possible to avoid war by raising the standard of living in the underdeveloped ?areas of the world, thus ensuring all peoples everywhere against the dread spectres of starvation and disease, then the development of the world's mineral resources assumes even greater importance. Today it is difficult to realize that, prior to the industrial revolution in Great Britain, only a few of the metals and minerals now in common use entered into the everyday life of the people. !iron and steel, copper, lead, tin, and zinc, usually in .their unalloyed forms, along with the more common industrial minerals, were those most widely used, and then only in limited amount. With the advance of technology in metallurgy and in fabricating skills, the list of commercial metals and minerals has expanded until today they number more than eighty.

Jan 1, 1951

By M. Misra

The dielectric properties and flotability of different ranks of Argonne Premium Coal samples are presented. The flotability of different ranks of coal are correlated with the dielectric properties and intrinsic moisture (or bound water) content. Measured dielectric properties of as-received coals and other constituents are incorporated into a mixture equation to calculate the dielectric properties of bound water present in the different ranks of coal. The nature of bound water present in low-rank hydrophilic coals is significantly different from that present in high-rank hydrophobic coals. The water molecules present in low-rank lignite have an oriented dipole-dipole interaction and are tightly bound to the surface. For high-rank coals, the water molecules are not bound to the surface and have a randomly distributed clathrate ice-like structure. Controlled thermal treatment can modify the structural nature of bound water present in low-rank hydrophilic coals and increase their flotability.

Jan 1, 1990

By M. Karmis

The determination of the surface area which may be impacted by underground mining is an important consideration in subsidence engineering. A number of parameters have been utilized to identify this influence area, most notably the angles of draw and break. This paper discusses the implications of selecting an appropriate "damage angle" for defining a potential damage area due to mining, within which surface structures may be impacted Furthermore, the influence of both mining and geological factors, such as mining width and depth and overburden lithology, on this angle is examined, using the Surface Deformation Prediction System (S.D.P.S) software. Finally, recommendations are given for applying these concepts in subsidence control.

Jan 1, 1994

By Jorge Alberto Soares Tenório, Denise Crocce Romano Espinosa, Morgana Rosset, Bárbara da Rocha Pereira

High-purity alumina finds application in various electronic industry sectors, with approximately 100 million tons of this compound being produced worldwide. Alumina is acquired through the mining process of bauxite, a rock composed of a mixture of minerals such as gibbsite, kaolinite, hematite, and either anatase or rutile. In 2020, both bauxite and alumina were included in the list of critical raw materials. Due to the demand for high-purity alumina production, the development of a methodology to remove impurities present in the leach liquor from bauxite processing by solvent extraction (SX) followed by precipitation has been widely studied. This work aims to obtain high-purity alumina from bauxite by a solvent extraction process followed by a precipitation step from the sulfur leach liquor obtained by the thorough dissolution of Al and Fe from bauxite. Different parameters were evaluated in the SX step, such as extractant type, pH, temperature, and volume-to-volume ratio. The results indicated that using Alamine 336 as an extractant at pH 0 and room temperature led to an extraction of 90% of Fe and 15% of Al. Aluminum sulfate was completely precipitated as aluminum hydroxide and 55% of Fe using NH4OH. After the calcination procedure, obtaining a 99.9% pure alumina was possible without generating a red mud-similar residue.

Dec 28, 2023

By Daniel T. Rogers

The Bureau of Mines, in its alumina miniplant project to investigate alumina recovery from domestic, non bauxitic ores, has conducted research on the use of a hydrochloric acid leaching, gas sparging crystallization technology. An important element of this research is the efficient separation of undissolved, siliceous residue from AICI3 -bearing leach liquors by continuous, horizontal, countercurrent vacuum belt filtration. In an effort to calculate material balances quickly and to predict material balances based on different belt filtration configurations, the perfect-mixing-cells-in-series model (PMCS) for calculating material balances around belt filters was used. Because of the porous nature of the solids, the model produced erroneous material balances. Therefore a reliable model, the shrinking voids model, was developed postulating the presence of an unwashable voids liquor volume that decreases with decreasing liquor AICI3 concentration. This volume decrease postulation is equivalent to assuming that dilute liquors flow more freely, causing more voids liquor volume to become washable. Least-squares based computer programs are provided, which are useful not only in producing material balances from plant data but also in predicting balances for untested configurations using the same feed materials.

Jan 1, 1982

By K. Becerra, D. G. Almond, T. D. Maru

"Nkomati Nickel Mine in South Africa processes one of the world’s hardest ores in a 375k TPM autogenous grinding circuit. The plant employs an unconventional processing circuit, comprising a primary autogenous mill (AG or FAG) and pebble crushing circuit followed by a secondary hybrid pebble/ball mill and classification cyclone cluster.Advanced Process Control (APC) or Expert Control is now generally accepted as an advantage in most modern high capacity concentrator grinding circuits. This paper reviews the installation of model predictive control at Nkomati and examines the results and benefits of installation in an autogenous mill during plant ramp-up. The paper also demonstrates how predefining process control objectives together with good plant and supplier cooperation can achieve a robust and reliable APC implementation on a very short site program.The results conclusively demonstrate operational and economic benefits during circuit operation with the advanced process control system ON. Production performance and circuit stability were significantly better than during manual control."

Jan 1, 2012

By Wilbur I. Duvall

This report presents experimental data on the propagation of explosion- generated strain pulses in rock. Tests were performed in 5 different rock types, employing 10 different types of explosives. Charge sizes ranged from 0.5 to 50 pounds, and travel distances ranged from 2.5 to 70 feet. Analysis of the data shows that the experimental peak strain data satisfy an exponential decay propagation law of the form: ?R/W1/3 = Ke ?aR/W1/3. For a particular rock, parameter K is a linear function of the calculated detonation pressure or the calculated energy density of the explosive. For a particular explosive, K is a linear function of the elastic parameter of the rock, p2, a result, which is at variance with elastic theory. The absorption constant, a, is independent of type of explosive but dependent upon rock type. However, no definite relation between a and the physical properties of the rock could be established.

Jan 1, 1959

By H. S. Martin

This paper, describing the concentrating practices at the plants of the Utah Copper Co., is one of a series being prepared by the United States Bureau of Mines in which the data are given in as nearly uniform c manner as possible. The Magna mill is 19 miles west of Salt Lake City on the routes of the Lincoln and Victory highways, and the Arthur plant is 1 mile west of the Magna mill. Both are on the main road west of the town of Magna and east of the town of Garfield.

Jan 1, 1931