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Traditional mineral processing techniques are more and more difficult to recover the increasingly low grade phosphate ores today. Although bioleaching method has been attempted to process low grade ores in hydrometallurgical field due to economical and environmental reason, it has been hardly used in leaching phosphate ore at home and abroad. Strains of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans were collected and separated from the acid drainage of a coal mine in Anhui province of China. Ultraviolet irradiation and Microwave inducement were applied to the bacterial cultivation process to produce strains of Acidithiobacillus thiooxidans and Acidithi-obacillus ferrooxidans able to tolerate extremely low pH conditions and generate sulphuric acid by oxidizing elemental sulfur or sulphide and the mutagenesis can achieve higher leaching rate. The bioleaching result will improve more by the addition of Tween series surfactants.

Jan 1, 2014

By Clarence Hall, CHARLES F. MUNROE

Of the common causes of the larger mine accidents, such as falls of roof and coal, gas and dust explosions, mine fires, and the misuse of explosives, all of which are often closely related, each must be studied and fought in a manner peculiar to itself. The last mentioned, the misuse of black powder and other explosives, is sometimes considered the least important of these causes of mine accidents; but its impor- tance is much greater than the statistics indicate, for the reason that the misuse of explosives is the true cause of many of the fatal mine fires, gas or dust explosions, and falls of roof that are credited to other causes. Both the quantity of explosives used and the number of purposes to which they are applied are increasing. They are now made at about 150 plants, in different parts of the United States, and the product of a single year is estimated at nearly 500,000,000 pounds. Nothing in all this material is a safe or "safety" explosive when in the hands of a careless or ignorant person; and this is true whether considered in connection with the shipment or the use of these explosives. In addition to the large losses of life and property resulting from an improper use of explosives in mining, the recent statistics of the railway bureau for the safe transportation of explo- sives have shown more than 400 persons killed or injured and over $3,000,000 worth of property destroyed by explosives in transit by rail. The fact that three years of cooperative effort under the wise supervision of this bureau has reduced these losses to almost nothing encourages the hope that similar cooperative effort may likewise greatly lessen losses of life and property from the use of explosives in mining. The additions to the large death roll of our mines make a recurring appeal to the public for fair treatment of the coal-mining industry, and to the miner and the manager that they join in every possible effort for greater safety. It may never be possible under conditions such as exist to-day to prevent mine accidents entirely. Little can be accomplished in that direction by either the operators or the miners working alone, but experience in all countries shows that

Jan 1, 1911

By A. Ignatieff

This is the first in a series of Coal Technology Reviews being prepared in accordance with a recommendation voted by the Coal Division in session at the Jubilee Meeting, Vancouver, April, 1948, that the Department of Mines and Resources be requested to arrange for publication by the proper Government authority of a Quarterly Review' of Coal Technology, for distribution among those concerned in the production and use of coal in Canada. This recommendation was subsequently endorsed both by the Council of the Institute and by the Dominion Coal Board. Further reviews (or digests) will appear at intervals in the Bulletin, or will be published and distributed by the Board which, meanwhile, has undertaken to distribute reprints of Mr. Ignatieff's review.-En. * * * The fields in coal mining technology which are considered to demand most attention and study at the present time are reviewed under the headings appearing below. Mechanization In the light of the growing shortage of skilled miners and the necessity of mitigating constantly increasing mining costs, interest continues to centre in mining methods and applications of mechanization chat will produce the maximum reduction of man power. The growth of strip or open-cut mining, also, is a consequence of this trend. Mechanization at the face attracts most attention and the trend is toward developing and adopting machines capable of cutting and loading the coal in one operation instead of having the separate operations of cutting, drilling, blasting, and loading. In Great Britain, where longwall mining is? the general practice, the A.B. Meco-Moore machine still receives much attention, and accounts describing its performance over reasonably long periods have appeared in the technical press.

Jan 1, 1948

By T. K. Bose

According to the Intergovernmental Panel on Climate Change (IPCC), the average global temperature has risen over the last century. If this trend continues over the next century, the IPCC projects a significant increase in temperature and a rise in sea level. The changes in climate could adversely impact human health, agriculture, water resources and ecosystems. Most national and international agencies have concluded that our use of carbon-rich fuel is responsible for global warming through the greenhouse effect. In the future, the situation may get worse if the increased need for energy in countries like China, India and Brazil is fulfilled by burning fossil fuel. Advanced natural gas-fuelled vehicles have the potential to reduce carbon monoxide and reactive hydrocarbon emissions substantially compared to gasoline vehicles. Further environmental benefits can be realized by using a blend of natural gas and hydrogen. Such an approach will help create an infrastructure for an eventual transition to hydrogen.

Jan 1, 2005

By Byung-Su Kim

The recovery of elemental sulfur from sulfur dioxide has important implications for coal- burning power plants and nonferrous metal smelters. The thermodynamic analyses showed calcium sulfide to be suitable for recovering elemental sulfur from sulfur dioxide. At the temperatures of 1023 to 1153 K under the sulfur dioxide partial pressures of 5.0 - 60.1 kPa, elemental sulfur from sulfur dioxide was recovered by its reaction with calcium sulfide. The kinetics of this reaction were measured at the same conditions using a thermogravimetric analysis technique. This reaction scheme would be attractive if the coproduct calcium sulfate can be reduced to regenerate calcium sulfide. This is the topic of another paper. At 1073 K under the sulfur dioxide partial pressure of 25.8 kPa, 48 % of the original calcium sulfide was converted to calcium sulfate in an hour. Under the same conditions, 55 % of the regenerated calcium sulfide were converted to calcium sulfate in an hour even after third regeneration.

Jan 1, 1999

By John Convey

This paper, a follow-up to an earlier study, gives the history of Canadian developments in mineral processing from 1921 to the fall of 1964. It deals extensively with comminution and flotation, and then goes on to cover the fields of gravity concentration, magnetic concentration, cyanidation, the processing of uranium ores, and instrumentation. Several outstanding examples of installations are given. The paper concludes with a discussion of present-day trends in mineral processing. Introduction T HE history of the developments in mineral processing in Canada from its earliest times to 1920 has already been published by one of the authors (1). The present paper is thus a logical follow-up to bring this history to date. From 1834 to 1920, mineral processing in Canada, as elsewhere in the world, was in its formative stage. This, however, prepared the ground for developments that have resulted in a mining empire from the Atlantic to the Pacific, a mining empire which could be said to be almost on par with that in the United States.

Jan 1, 1965

By W. L. Dare

This publication is one of a series prepared by the Federal Bureau of Mines on methods and costs of producing uranium ore on the Colorado Plateau. The information it contains was gathered in 1955-58 and applies to eight small operations. (See fig. 1.) Mining costs have increased since the data were I collected, but the information should be helpful in estimating future costs I at similar deposits. The Bureau of Mines had early experience in the production of carnotite-type ores on the Colorado Plateau.3 4/ Under a cooperative agreement with the National Radium Institute in 1914-16, the Bureau mined and concentrated carnotite ore for recovery of radium, uranium, and vanadium. The ore was taken from claims in or near Long Park Montrose County, Colo., about 3 mi. south of La Salle Mining Co.'s La Salle mine, which is one of the mines described in this report. The Bureau leased the claims from Crucible Steel Mining & Milling Co., a subsidiary of Crucible Steel Co. of America, and from 1914 to 1916 produced 990 tons of high-grade ore, containing 2.6 pct. U308, and about 2,000 tons of mill-grade ore, containing 0.85 pct. U308. The high-grade ore was shipped directly to a radium-recovery plant built in Denver in 1914 under the cooperative agreement. There, commercial methods of extracting uranium, vanadium, and radium from carnotite ores were developed by Bureau personnel. The lower grade ore was concentrated at a small mill in Long Park before being shipped to Denver. The final recovery was 69,000 lb. of U308 and 8.8 g. of radium. The direct mining cost of producing the high-grade ore, including the labor to hand sort and sack it, was $35.96 per ton. Freighting the ore 58 miles to Placerville, Colo., the nearest rail point on the Rio Grande Southern Railway, cost $25.28 per ton, which included $4.55 per ton for ore bags and twine. Four-or six-horse teams pulled two wagons in tandem and made the

Jan 1, 1961

By Lev Filippov, Vyacheslav Severov, Inna Filippova

"Reverse cationic flotation is a very efficient method of beneficiation of oxidized iron ores when you need to separate hematite and quartz. This method can be also applied to reduce silica content in the magnetite concentrates obtained by wet low-intensity magnetic separation. However, cationic flotation in this case is less effective due to the presence of Fe-Mg-Al-bearing silicates as amphiboles in magnetite ores. These silicates are concentrated in magnetic products and determine the difficulties of their separation from iron oxides when amines and starches are used as collectors and depressants, respectively. The recalculation of the results of the electron microprobe analysis of three calcic Fe-Mg-Al-bearing amphiboles used to characterize cation distributions in structural units and to obtain structural formulas in accord with stoichiometric limits was conducted. The Mössbauer spectroscopy was used to examine the validity of the empirical estimation of cation distributions in amphiboles. The studied samples are metamorphic pargasite and ferrotschermakite and volcanic magnesiohornblende. The crystallographic analyses of the amphibole samples exhibited their heterogeneous surfaces explaining worse floatability of amphiboles with dodecylamine at pH 10. The electrokinetic measurements showed that the position of the isoelectric point of amphiboles is related to a substitution of Al3+ for Si4+ in tetrahedral sites and to an amount of Mg2+ cations in octahedral sites. Thus, the dodecylamine adsorption onto amphiboles through electrostatic interactions is mainly affected by a distribution of these cations in tetrahedral and octahedral sites of amphiboles. In addition, the effect of starch on the depression of Fe-Mg-Al-bearing amphiboles during flotation can be attributed to the presence of metal ions on the amphibole surface, which are capable of forming strong chemical complexes with starch molecules."

Jan 1, 2014

By Amar Prakash, V. M. S. R. Murthy, VIVEK KUMAR HIMANSHU, Sufal Mehrotra, Ashish Kumar Vishwakarma

Raises are vertical or inclined openings made to connect two levels of an underground metalliferous mine. They are developed using drilling and blasting-based technique or by mechanical means. Raise boring machines (RBM) have evolved in recent years, which provide quicker and safer raise excavation. The penetration rate using RBM has influenced applied thrust. The required thrust to enhance penetration rate with optimal use of energy would be different under varying geological and geotechnical conditions. In this study, the influence of applied thrust on penetration rate using RBM has been investigated. The investigation has been made for two different rock types, amphibolite (AMP) and garnet-biotite-sillimanite-gneiss (GBSG). The numerical simulation model was developed for this purpose using Ansys-Explicit Dynamics. The induced tensile stress under different conditions of applied thrust has been analysed in the calibrated numerical model. The model output shows the power trend between the parameters. The experimental data on penetration rate was also collected along with the respective operational parameters. A statistical analysis has been carried out for the gathered data. The analysis of data also shows a power trend between thrust per cutter and penetration rate in both rock types and hence validates the numerical simulation-based output. Based on the outputs of the numerical simulation and empirical study of the experimental data, the optimum thrust per cutter for excavation in both rock types is in the range of 12–14 tons. The approach used in this study can be helpful for predicting the optimal operational parameters of raise boring machines under different geological/geotechnical conditions.

May 29, 2023

By M. A. A. de Klaver

Functional Description Figure 1 is a typical flowsheet for a system for solid fuel addition to filter cake. Solid fuel, coal, coal breeze, or charcoal, is fed from a,stockpile to a surge hopper. The solid fuel is metered into a grinding mill. The fuel is dried and ground in a grinding mill. The on-size particles are removed from the mill by air sweeping. The ground solid fuel is separated from the air stream by a cyclone and stored in a surge hopper. The ground solid fuel is then pneumatically conveyed to a small hopper in the balling area. The fuel is proportioned into the filter cake just prior to mixing. An efficient mixer is very important to have a successful operation. The exact flowsheet would depend on a number of factors including what fuel is used, how the fuel is received, and the cnaracteristics of the fuel as received. Availability of floor space in the plant may also affect the flowsheet. For example, drying air may be supplied from the pellet furnace if the grinding mill can be located near the grate, or the pneumatic conveying system and a surge hopper may be eliminated by placing the grinding mill adjacent .to the mixing area. Also, for a multiple line plant, a ball mill rather than a roller mill may be more suitable.

Jan 1, 1980

By R. L. Cosgriff

A commercial, battery-powered mine vehicle has been equipped for remote operation in coal mines. This vehicle is controlled by an operator from the remote station. Command signals originating at the remote station as well as video and data signals originating on board the vehicle are relayed between the remote station and vehicle using a single coaxial line. This coaxial line is normally 2,000 feet in length and is reeled in and out from a drum mounted aboard the vehicle The vehicle has a maximum speed of 6 ft/sec and a minimum speed of 4 ft/sec using 36-volt excitation of the traction motor. If this traction motor is excited by two of the three batteries, 24-volt excitation, the vehicle will travel at approximately 2 ft/sec. The speed can be reduced by the operator to 1 ft/sec. This vehicular system has been tested in coal mines. Presently, the major limitation of this system is associated with fatigue failure of the splices in the coaxial line and lack of mobility caused by its 3-wheel design.

Jan 1, 1974

By D. A. Buckingham

The Bureau of Mines evaluated potential availability of domestic nickel from 23 deposits, Evaluations included an estimation of in situ and recoverable resources, applicable mining and processing technologies, and capital and operating costs. Discounted cash flow analysis with a 15-pct rate of return was used to determine the average total cost of production of each operation, Identified in situ resources contain 9.0 million metric tons (t) of nickel; 5.5 million t is recoverable as nickel metal or ferronickel. Demonstrated in situ resources contain 8.2 million t of nickel; 4.8 million t is recoverable as nickel metal or ferronickel. No nickel is available at a total cost of production equal to the January 1983 market price of $3.24 per pound. Analyses indicate that potential annual production can only meet current consumption levels at a total cost of production of $7.60 per pound of nickel, Nickel's availability is contingent on (1) successful adaptability of nickel processing methods to domestic resources, (2) location of a smelting facility, and (3) marketability of byproducts and coproducts. Analyses were performed on the effects of byproduct and coproduct revenues, energy, labor, and transportation costs, and metallurgical recoveries on nickel's availability.

Jan 1, 1984

By C. Flores

It is well known that manganiferous silver ores containing manganese intimately associated with silver are not amenable to conventional extraction methods. The segregation process has been applied primarily for recovering copper from oxidized and oxide-sulfide ores. A new alternative process combining segregation roasting followed by flotation to recover silver from refractory manganiferous silver ores, was studied using a 23 factorial experimental design. Laboratory investigations have been conducted on a manganiferous silver ore analyzing 0.02% copper, 0.09% lead, 0.33% zinc, 12.55% manganese and 187 g/ton silver to study the effects of additives salt, coke and copper oxide on silver recovery. Results indicate that 79.3% silver recovery can be attained in the absence of copper oxide and 88.4% when the copper oxide content is 1.5% at '750°C, 2% salt and 1% coke and 30 minutes of roasting time. It was concluded that doping with copper oxide improves silver recovery.

Jan 1, 1994

By Jun Xiao, Xiaodong Li, Chunming He, Daixiong Chen

"Benzohydroxamic acid with double dentate can react with copper to form cyclic hydroxyl oxime acid copper chelate, indicating a good selectivity for copper oxide minerals flotation, especially for malachite. The flotation results of the pure malachite mineral show a strong synergistic collecting effect between hydroximic acid and xanthate at a ratio of 3.5:1, achieving a malachite recovery of 95.5% when certain sodium sulphide is used as a sulphidizing agent in the optimal pH range. Thanks to the synergistic collecting effect, the flotation recovery of malachite of a real refractory ore flotation ,can reach over 92% under the optimum condition, a 12% higher than the recovery achieved with the conventional collectors. In industrial application, the flotation of the copper oxide minerals is improved , leading to a high efficiency utilization of copper oxide resources.INTRODUCTIONBeneficiation of copper oxide ore is one of the recognized challenges in mineral processing industry. Copper oxide ore is a vital component of copper resource in the world, which has abundant reserves. Majority of sulphide deposits has oxidized zone on the top, and some deposits are oxidized to become the large and medium-sized oxide deposits (Willam & Chavez, 2001). Most copper oxide ores have problems in processing such as high slime consumption, poor floatability, complex ore property and low flotation recovery, so it is of great significance in beneficiation of copper oxide ores to develop an efficient collector, especially for malachite (Fu & Gu, 1997; Wen, 2010; Riet, Kier & Elford, 1980). At present, sulphidization-xanthate flotation is the most important method for treating copper oxide ore. In recent years, due to the decreasing ore grade, the utilization of refractory copper oxide ore draws more and more attention (Zhou, 2003), except for sulphidization-xanthate method, chelating flotation method (Lu, 2009), chemical beneficiation method (Lenormed, Salman & Yoon, 1979), microwave radiation flotation method, hydrothermal sulphidization-flotation method (Mao, Wen & Fang, 2014) and ammonia leaching of sulphide precipitation-flotation method (Lekang, Stevik & Bomo, 2003) have occurred."

Jan 1, 2016

By Taghi Sherizadeh, Kutay E. Karadeniz, Dogukan Guner, Samuel Nowak

Underground mining environments bring occupational health and safety issues with some severe dangers such as mine disasters like explosions. During such events, miners might escape using main access openings, or find a safe haven like refuge alternatives (RAs) to wait and be rescued and evacuated to the surface. In this paper, RAs are explained with their early and current applications. A classification as permanent and portable is explained depending on the conditions and their abilities. This classification is followed by the utilization and survivability of RAs with the requirements and recommendations of the main mining countries. Based on the utilization and survivability constraints, basic human requirements, waiting for a rescue team, and the required physical specifications of RAs during the events are analyzed in detail for various countries with their regulations. Among these, the specification, resistance to the explosion, is discussed in particular, and the studies in the literature are examined in terms of structural deformation. The highest deformed zones, the beneficiation of reinforcing steel components such as stiffeners, and the simulation approaches are investigated through this review.

Sep 24, 2022

By Nelson Reátegui

El presente trabajo describe los sistemas computarizados utilizados en el centro de operaciones, explotación y beneficio de Hierro Perú, compañía minera localizada en el departamento de Ica. Inicialmente, la función de un sistema computarizado se limitaba a la reducción de costos en la mano de obra y a realizar operaciones básicas en los negocios. Posteriormente, esta situación cambió ya que estos sistemas se utilizan en los niveles de la gestión empresarial.l. Asimismo se explica las aplicaciones de este sistema al comercio, al tipo técnico-científico, así como el cálculo de reservas y el desarrollo del sistema computarizado de performance de equipo.

Nov 20, 1978

By A. F. Baker

Tests were conducted in commercial foundries to determine the suitability of calcined anthracite as a cupola fuel. The calcined anthracite performed satisfactorily at two of the three foundries where iron-melting tests were conducted. Performance at the third installation was unsatisfactory because metal temperatures deviated widely and, in general, were lower than is desirable for the type of castings being made.

Jan 1, 1963

By Claude P. Heiner

While the title of this paper embraces the entire West Coast, the author, in the interest of simplification. has confined the discussion to California-particularly the central section. California's population has, risen 45 pct since 1940. Its electric requirements have also increased, not only because of the growth in industry and population but also because of the widespread tendency of all types of electric consumers to use more electricity than ever before. The growth of California's electric utilities is shown by published data covering operations, of three of its large systems and is given in Table 1.

Jan 1, 1949

By Marcelo Sousa de Carvalho

Os aços inoxidáveis possuem uma alta aplicabilidade nas indústrias de petróleo e gás, química e de papel e celulose, principalmente, devido à suas características de alta resistência à corrosão e alta resistência mecânica. Neste trabalho, estudos baseadas na técnica dos cinco punções foram realizados para avaliar as características de conformação do aço inoxidável UNS S32304. A metodologia baseia-se na caracterização mecânica do material para mensurar suas propriedades, como limite de escoamento e índice de anisotropia. Seguiu-se com uma análise teórica da estampabilidade do material através da simulação computacional do ensaio de cinco punções. Esta técnica analisa tipos de deformações desde o estiramento biaxial até o embutimento profundo. Esse trabalho apresenta uma análise computacional do comportamento desse material com relação à estampagem para os diversos punções. É apresentado o gráfico da Razão Limite de Estampagem teórica para o UNS S32304 em relação aos cinco punções utilizados e a influência do coeficiente de anisotropia normal nos resultados.

Aug 16, 2017

By Milton Gomez, Nico Sutmoller

Low-density cellular concrete (LDCC) was first introduced to the market in the early 1900s and since then has made continuous technological advances. There are two primary types of LDCC: permeable and non-permeable. Both types of cellular concrete offer advantages in different types of geotechnical engineering applications. Because of its unique characteristics of low density, high compressive strength, and high fluidity during placement, LDCC offers an effective solution for a wide variety of engineering applications, and in many cases provides a more cost-effective, labor saving alternative to traditional fill materials. This paper will review the history, characteristics, and technological advances of LDCC, highlighting multiple real-world case studies that showcase the high-performance capabilities of both permeable and non-permeable LDCC.

Dec 1, 2022