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By Lays Augusta Leal Carvalho, Luiz Filipe Cardoso de Oliveira, Alex Milton Albergaria Campos, Paulo Santos Assis

O agronegócio movimenta a economia de muitos países, sendo que sua produção representa um terço do PIB mundial. Desde a colheita até o processamento de seus produtos, a atividade agrícola gera uma grande quantidade de resíduos que, muitas vezes, não tem uma alocação correta, o que acaba sendo um problema. Esses resíduos tem um grande potencial para substituir parcialmente combustíveis fósseis, como o carvão mineral. O carvão queimado nos altos-fornos é responsável por cerca de 60% das emissões de CO2 na indústria siderúrgica. No entanto, a atividade agrícola pode contribuir para a captura de CO2 na atmosfera à medida que este é absorvido durante a fotossíntese. Portanto, o uso de resíduos do agronegócio pode ser viável para ser usado na injeção de alto-forno, substituindo parte do carvão mineral. Alguns estudos mostraram que o cultivo de cana-de-açúcar e a produção de carvão vegetal no Brasil, os resíduos do cultivo de milho nos Estados Unidos, bem como o uso de resíduos de Moringa oleifera na Índia, podem ser usados gerando economia e diminuindo a emissão de CO2. Neste trabalho, são apresentadas as comparações química, física e térmica de alguns resíduos do agronegócio com potencial para serem utilizados como material pulverizado injetado no alto-forno, junto ao carvão mineral. Além disso, a viabilidade econômica e a possibilidade de reduzir as emissões de CO2 nesse processo são comentadas.

Oct 1, 2019

NEW YORK MEETING PAGE Winchell, H. V.-Geology of Pachuca and El Oro, Mexico. Discussed by Frederick MacCoy, Robert Hawxhurst, Jr 2 WILKES-BARRE MEETING Kynor, Herbert D.-Mechanical Mining of Anthracite. Discussed by C. Evans, Jr., S. J. Jennings, W. J. Richards, Geo. S. Rice, and the author 3 Stein, C. H.-Ashley Planes for Handling Freight Traffic. Discussed by Graham Bright, Douglas Bunting, S. J. Jennings, R. V. Norris, C. H. Strange, Edwin Ludlow, W. J. Richards, and the author 3 Markle, Donald.-Anthracoal: A New Domestic and Metallurgical Fuel. Discussed by William Griffith, Edwin Ludlow, E. M. Chance, Charles Dorrance, E. W. Parker, G. H. Ashley, C. A. Burdick, Geo. S. Rice, and the author :.. 7 Griffen, John.-Slush Problem in Anthracite Preparation. Discussed by Henry Flood, Jr 11 Eavenson, H. N.-Lynch Plant of United States Coal and Coke Co. Discussed by E. V. d'Invilliers, C. Evans, Jr., Graham Bright, Geo. S. Rice, Geo. Otis Smith, A. M. Rodgers, C. T. Starr, C. A. Burdick, and the author 15 Bunting, Douglas.-Mine Fires Extinguished by Sealing. Discussed by Geo. S. Rice, J. B. Warriner, H. H. Otto, Edwin Ludlow, E. M. Chance, F. B. Nold, H. M. Chance, W. L. Jacobus, J. A. S. Ritson, R. D. Hall, Geo. S. Rice, and the author 18 Bright, Graham.-Determination of Electrical Equipment for a Mine Hoist. Discussed by F. L. Stone, Geo. S. Rice, L. F. Mitten, and the author 34

Jan 12, 1921

By Robert T. Davis

An award is a form of recognition given for superior performance in a special field of endeavor. Each year awards are given by the Joseph A. Holmes Safety Association and the National Safety Council to the coal-mining industry's underground and open-pit mines that have worked a specific number of man-hours without a lost-time injury. These awards have a dual significance in that they prove efficiency can be attained without injury to persons. Safety awards do not result from luck or good fortune but do result from sincere desire coupled with sufficient effort and cooperation to achieve a desired goal.

Jan 1, 1964

By Richard N. Spencer

This report describes investigations of the economic merits of multiple zone mining and beneficiation versus selective mining of altered Western phosphate rock. The same deposit was considered in both instances and it was assumed that the grade of selectively mined ore was comparable to the grade of the concentrate from beneficiation. The beneficiating scheme used for the investigation was one proved by small continuous circuit operation. All economic factors were found to favor multiple zone mining plus beneficiation. Capital requirements and production costs were lower, and production life of the deposit was extended 4.5 times. The concentrate from beneficiation would be a uniform high-quality feed for acidulation and would be low in stable metallic oxide (R203) content. Such a feed would permit improved plant operating control, and the low R203 would promote more rapid filtration and minimize sludge formation in the phosphoric acid. With the proposed treatment, the concentrate produced by flotation from this deposit would cost about 1.5 times as much per ton as the concentrate produced by classification sizing. Therefore, inclusion of a flotation step in treatment schemes requires an economic analysis for each ore deposit.

Jan 1, 1971

By K Ilamparuthi, R. K. Madhumathi

"This paper presents the results of 1g model tests conducted on model piles both single and two pile groups embedded in sand by physically inducing lateral soil movement. From the test results it was found that the pile with higher L/D ratio exhibits higher deflection in case of pile embedded in medium dense sand whereas in loose sand the response is vice versa with higher deflection for the pile of lesser L/D ratio. The induced bending moment in piles is more for longer piles than shorter piles irrespective of the density of sand bed. It is also found that the pile head deflection and the bending moment are found to decrease exponentially with increasing distance between the pile and the wall. For pile group arranged in a row parallel and perpendicular to retaining wall, the deflection of single pile is more than the deflection of two pile group irrespective of the depth of excavation for spacing of piles tested. The influence of soil movement on the lateral response of pile is also analyzed through 3-dimensional finite element analysis. The numerical results thus obtained are validated with the results of experiments. The Mohr-Coulomb material model adopted to represent the soil behaviour predicts the response of pile reasonably and compares well with the experimentally observed response.INTRODUCTIONPile foundations are adopted to support structures such as foundations of high rise buildings, transmission towers, offshore platforms, bridge abutments etc., when good bearing stratum is not present at shallow depth to bear the loads of these structures. In the recent past particularly in the urbanized areas structures are built close to one another and nearby excavation will cause a reduction of lateral earth pressure and soil movement behind the retaining wall (Ong, 2004). The reduction in support stress will induce additional movement to the pile and leading to distress in pile foundations located adjacent to supported excavation. In these situations understanding the response of piles next to supported excavations becomes essential.The behavior of piles subjected to soil movement was studied by Poulos and Chen (1996 and1997) through tests on 1g models and the findings concluded that the maximum bending moment was found to decrease with decreasing pile diameter and decreasing pile spacing . Leung et al. (2000 and 2003) studied the effects of excavation induced soil movement on pile foundations in sand through centrifuge tests and established that the restraints on the pile head would cause additional shear force and/or bending moment at the pile head, although the restraints help to reduce the pile head deflection/rotation. In the theoretical studies of Poulos & Chen (1997), boundary element method (PALLAS) was used for analysing the pile subjected to lateral soil movement and charts were proposed for designing the piles. Pan et al. (2002) and Miao et al. (2006) analysed the passive pile behavior through three dimensional finite element analyses. However research works reported on piles subjected to lateral soil movement are limited."

Jan 1, 2015

CONTENTS PAGE ANDERSON, ROBERT J., and ENOS, GEORGE M.-Corrosion of Brass as Affected by Grain Size. Discussed by Henry S. Rawdon, Robert J. Anderson, Francis B. Coyle, William B. Price, and W. R. Webster 1 RAWDON, HENRYS., and MUTCHLER, WILLARD H.-Effect of Severe Cold Working on Scratch and Brinell Hardness. Discussed by W. H. Bassett, John Livermore Christie, John R. Freeman, Jr., W. R. Webster, William B. Price, Norman B. Pilling, D. J. McAdam, Jr., F. G. Smith, Zay Jeffries, F. E. Carter 3 WILLIAMS, ROBERT S., and HOMERBERG, VICTOR 0.-Relation of Heat Treatment to the Microstructure of 60-40 Brass. Discussed by 0. W. Ellis 14 Corrosion of Brass as Affected by Grain Size Discussion of the paper of ROBERT J. ANDERSON and GEORGE M. ENOS, presented at the New York Meeting, February, 1924, and issued as Paper No. 1282, with MINING AND METALLURGY, December, 1923. HENRY S. RAWDON,* Washington, D. C. (written discussion).-So numerous and so varied are the factors that affect the corrosion of metals that particular care is necessary in corrosion tests to eliminate so far as possible all extraneous factors. It appears to the writer that the question may well be asked as to whether all the necessary precautions have been observed in this investigation. It may be that the points to be mentioned were considered by the authors and found to be insignificant; however, there is nothing in the report to show this.

Jan 5, 1924

By Ehsan Alavi, Brian Hagan, Colin LaVassar, Glen Frank, Derek Dugan, Rick Capka, Lisa Mori

"Tunnel face instability is one of the most common issues in EPB tunneling. The evaluation of an ideal face support pressure is a critical element in the design and construction phases of EPB tunneling. In this study, measured tunnel face pressures in three EPB tunneling projects (University Link U230 and U220 projects and the Northgate Link Extension N125 Project) for Sound Transit in Seattle, WA are compared with the calculated analytical methods. This comparison shows that the analytical methods generally overestimate the required tunnel face support. The best practice for managing the face pressure in EPB tunneling operation is discussed based on the experience gained through these projects. Furthermore, the algorithm that is developed for identifying ground loss in these projects is addressed. INTRODUCTION Earth pressure balanced tunneling relies on using muck within the chamber to support the face. Muck is pressurized by controlling the advance rate of the tunnel boring machine and the speed of the screw conveyor. Target face pressure is typically calculated by using the geotechnical assumptions in the geotechnical baseline report. The concept behind EPB tunneling is that the application of sufficient face support pressure will prevent tunnel face instability and the resultant over excavation. Tunnel face instabilities caused by a lack of sufficient face support can lead to ground loss and surface settlement (Anagnostou & Kovári 1996, Kirsch 2010). A certain support pressure must be achieved to counteract water and earth pressure with an adequate factor of safety. While the water pressure can be predicted accurately, the determination of the resultant earth pressure on the face is less precise. This becomes manifested in the relatively high partial safety factors on the earth pressure."

Jan 1, 2016

By Daniel Lachapelle, Nuri Hmidi, Turgut Yalcin

"Simulation can serve as a convenient tool in studying the behaviour and performance of grinding circuits by facilitating the evaluation of various scenarios and identification of optimum operating conditions. This technique was applied to the St Andrew Goldfields Ltd.’s Stock Mine Mill which is a 1300 tpd gold milling facility, offering custom milling services as well as processing the Company’s own ores. Lack of adequate instrumentation in the mill poses a challenge in attaining optimum performance especially with changing ore types and characteristics. The grinding process is monitored essentially by manual measurement and adjustment of pulp densities at various streams. A simulation program was designed to assist in the effective implementation of this mode of grinding control. Product sizes from both the primary and secondary grinding circuits were correlated empirically to relevant process variables using a database formed from the results of past sampling campaigns. The simulator was created in Microsoft Excel whose data analysis and optimization tools coupled with its Visual Basic Programming capabilities were found to provide an excellent environment for the development of a cost-effective, efficient and user-friendly simulation program.INTRODUCTIONGrinding is often a very costly unit process in milling operations, mainly due to the excessive energy consumption associated with it. For example, for a Canadian copper-zinc flotation mill, grinding was listed as being the most costly item taking up 30.4% of the total milling expenses, followed by the flotation cost at 2 1 .O% (Kidd Creek Mines Ltd., 1982). A survey on 45 copper flotation mills around the world showed the average grinding cost to be 34.5% of the total milling cost (Weiss, 1985).Overgrinding aggravates the cost issue, while insufficient grinding either causes loss of valuable minerals to tails or results in low-grade concentrates. Therefore, it is essential that grinding circuits be carefully controlled and monitored. To this end, a great deal of effort has been devoted over the years to the modelling and simulation of grinding systems in order to assist in the efficient running of these processes."

Jan 1, 2001

By Daniella Gomes Rodriguesr

"As mudanças que ocorrem ao longo do recozimento na microestrutura e textura foram observadas no aço inoxidável ferrítico estabilizado ao nióbio, tipo ASTM 430 por meio de Difração de Elétrons Retroespalhados. As amostras deformadas foram recozidas com uma taxa de aquecimento de 23,5°C/s. O recozimento foi interrompido nas temperaturas de 780, 830 e 880°C para acompanhar a evolução da microestrutura e textura. Os resultados mostraram que a nucleação dos novos grãos ocorre preferencialmente nos contornos de alto ângulo. No estágio inicial da recristalização a fibra g é dominante na fração recristalizada, com as componentes 111121, 1111 ,1 2 mais intensas. Na fração não recristalizada a fibra a foi mais intensa. No progresso da recristalização as componentes 11112 1 e 1111 ,1 2 permanecem predominantes, a fibra g torna-se dominante em detrimento da fibra a."

Jan 16, 2018

By Donghai Li, Cheng Pan, Xuewei Lv, Mei Liu, Enguang Guo

"Phosphorite is the main raw material for the production of phosphorus in chemical industry. More attentions have been drawn to the phosphorite concentrate beneficiated from low-grade phosphorite due to the decrease of high-grade phosphorite. For another, the agglomeration process is necessary for the phosphorite concentrate after beneficiation process. The mineralogy and sintering process of the phosphorite from Leshan, China were studied in this work. The result shows that the main phases in the phosphorite are fluorapatite (Ca3(P04)3F), hydroxylapatite (Cas(P04)3(0H)), quartz (Si02) and dolomite (CaMg(C03)2). The yield of the sinter increases with increasing the carbon dosage to 7%, and then decreases when it continuously increases. Similar regularities were found for the strength and the content of P20s of the sinter. The best strength of the sinter as well as its P205 content were discovered when the carbon dosage is 7%. Fluorapatite ((Ca5(P04)3)F) is the main phase in the sinter while fuggerite (Ca2MgSiz01) is the main binder phase.IntroductionPhosphorus is an important foundation industrial raw material of national defense industry, food industry and chemical industry, where it is used to produce red phosphorus, phosphonium hydroxide, phosphorus pentasulfide and phosphoric anhydride[l-2]."

Jan 1, 2013

By William Eathorne

"INTRODUCTION Retsof mine, adjoining the village of Retsof, Livingston County, New York, is about 5 miles northwest of Geneseo and 55 miles (air-line distance) due east of Buffalo. It is a single-bed rock-salt mine having extensive horizontal workings as much as 2-1/2 miles long and 1 mile wide and has been in continuous operation since 1885. Retsof tine is the largest producing salt mine in North America and is reputed to be the largest active salt mine in the world.Retsof is one of three large salt mines operated by the International Salt Co., Scranton, Pa.; T. Forster Courthope is general manager of Retsof and also of the company's Detroit salt mine in Michigan and has held that position for 27 years. He is assisted by Stanley Martin, general superintendent; R. Goetz, Maintenance superintendent; and John Riordan, mine superin¬tendent. All are old-timers at Retsof and, according to Courthope, contri¬buted the ""lion's share in bringing the mine to its present standard of safety.ACKNOWLEDGEMENTThis circular was made possible by the generous cooperation of T. Forster Courthope and his assistants, Stanley Martin, R. Goetz, and John Riordan. The information and time generously given are gratefully acknowledged.GENERAL INFORMATIONThe rock salt as mined contains about 99 percent sodium chloride and requires only crushing and screening to prepare it for the market. With the exception of a large jaw crusher underground, all crushing is done in a mill building attached to the headframe of the main hoisting shaft (fig. 1).Five sizes of salt are produced, ranging from about 1/2 inch diameter down to minus seven mesh."

Sep 1, 1949

By S Udayakumar, S Biswal, N Sarmadi, V Sahajwalla, F Pahlevani

Recent times have witnessed a notable momentum in the interest surrounding technology dedicated to harnessing waste as valuable resources, prompted by the mounting challenges posed by waste accumulation and the swift depletion of natural resources. The carbon dissolution process within a molten iron bath stands as a pivotal reaction within the metal processing sector. The current study explores the utilisation of waste graphite electrodes (WGE) (obtained after being utilised in an electric arc furnace) as a secondary resource of carbon for dissolution into liquid iron. Experimental investigations were carried out at 1550°C using the sessile drop approach. High purity iron powder was used and the carbonaceous substrates were prepared from the ground WGE. The carbon pickup was determined using a suitable carbon analyser. Furthermore, an examination of the interfacial area between the molten iron and the WGE substrate was conducted beneath the metallic droplet, which effectively represents the iron/carbon interface. This interfacial analysis was carried out on two different samples obtained after a varying period of heat treatments at 1550°C. The interface layer was investigated using scanning electron microscopy (SEM) in conjunction with energy-dispersive X-ray spectroscopy (EDS).

Jun 19, 2024

By Lawrence G. Houk

Monazite sand is the only commercial source of cerium, other rare-earth metals and thorium. Although used in rather small quantities, it is essential to many industries. The United Unites is entirely dependent upon British India and Brazil for its supplies. Monazite sand or sand imported under the tariff classification for monazite was shipped to the United States in greater quantities, in 1940 than ever before. About 75 percent of our imports was from British India and most of the remainder from Brazil. If need be, Brazilian production can be expanded to supply all of our essential requirements, and the theater of war expands in the Pacific Brazil may supersede India as the principal source. PHYSICAL PROPERTIES The mineral monazite is generally honey yellow or may vary from greenish yellow to clove brown. The grains are small and resinous in luster, and range from subtranslucent to opaque. The specific gravity varies

Jan 1, 1943

By P. K. Sollars, M. A. Alspaugh

In May of 1996, Twentymile Coal Co. began Longwall mining in the Foidel Creek Mine's East Mine District. These Longwall panels are some of the longest in the world (5.48 km/18,000 ft) with very difficult and challenging geometry. The conveyance system is 1,800 mm (72 in) wide, has a 4,500 mtph (5,000 stph) capacity and employs multiple tripper drives. The trippers include traditional powering designs as well as unique regeneration and braking designs. Several components were developed specifically for this application including a mobile tail brake. Control algorithms were carefully developed and tested via computer modeling. A world production record was achieved in the third month of operation and over 1 million tons were mined in June 1997.

Jan 1, 1998

By E. W. Pehrson, J. W. Furness

THE method of presentation in the accompanying charts is based upon the well-known formula: production plus imports minus exports equals apparent consumption. Thus for each area for which data are shown there are two columns of equal height, one representing production plus imports, the other apparent consumption plus exports. Usually no account has been taken of increases or decreases in stocks. All columns and flow lines are drawn to a linear scale which is supplemented by figures showing the actual quantities represented. Owing to the small area occupied by the European countries on the world map it was impossible to show the details of the trade of the individual countries. All of Europe (except Russia), therefore, is shown as a single unit. However, statistics of production and consumption indicated elsewhere on the charts show the degree of self-sufficiency enjoyed by the major European powers.

Jan 1, 1936

By Luiz Guilherme Isfer Maciel, Marilena Cardu, Fernando Golin, Jacopo Seccatore

"This study applies the concept of the difficulty of tunnelling by drilling an blasting (D&B) to selectedcases from the Brazilian tunnelling industry. The difficulty of tunnelling has been defined in previouswork as the difference of specific drilling (SD) from industrial average trend: easier when SD is lowerthan average, more difficult when SD is higher than average. Results show how tunnels in Brazil tend tobe unrealistically more difficult to excavate when compared to similar excavations in similar geologies elsewhere in the world. It is thoroughly discussed the reason for such anomaly (up to +90% SD compared to industrial average). One reason could be the lack of options amongst explosive products on the brazilian market. Only ANFO and explosive emulsions are available in Brazil. Lacking high VOD(Velocity of Detonation) products might result in reducing the maximum allowable burden amongstproduction holes, therefore increasing SD. Another reason could be found in the tunnel designers’tendency of choosing D&B as excavation method for weak rock masses that would benefit from mechanical excavation. The reason to this tendency can be partly found in the lack of availability of mechanical excavation machines in the brazilian market. Blasting in weak rock masses requires more careful smooth blasting, hence a closer spacing amongst contour holes to avoid costly overbreak: this increases SD. A third reason could be found in the lack of skill amongst the local workforce. When dealing with unskilled workers the blast designers naturally tend to avoid highly optimized blasts thatrequire very skilled workforce to be realized on field. The designer in this case tends to leave the blastdesign simpler but more robust, at the cost of higher specific drilling and specific charge. The conclusions suggest that this unrealistic difficulty when compared to world average could be a simptom of the so-called “Brazilian cost” within the tunnelling industry."

Jan 1, 2017

By R. V. Higgins

The Bureau of Mines investigated the use of electronic computers for obtaining more information about relative permeabilities of reservoir rock to oil and water. It was found that there are many possible combinations of relative permeability curves that will result in virtually the same recovery versus injection) but they require different times and rates to recover the oil even with different mobility ratios. Permeability curves obtained by the use of non-viscous oil and employed for calculating the waterfloods of viscous oils can lead to serious inaccuracies. For viscous oils) the wettability characteristics in the middle portion of the permeability curve affect recovery nearly as much as other portions of the curve; this) however) is not true for non-viscous oils in water-wet reservoir rock.

Jan 1, 1967

By Enrique Levy

Central America is graduating this year into large scale mining with the start up of Inco's multi-million dollar nickel laterite processing plant in Guatemala. In the other extreme of the Isthmus in Panama Texas Gulf Sulphur is doing check diamond drilling and foundation test drilling at the Cerro Colorado copper porphyry. The higher price of gold and silver has spurred development and exploration of several small precious metal mines. The purpose of this presentation is to make a brief resumé of the most important mines operating in the area and a list of significant exploration projects. Also, tables will be shown to compare mining codes and taxes. Unfortunately these tables lack information on Panama. Before starting I like to express my appreciation to Kennecott Copper who permitted the use of some of the data compiled by the author on their behalf during the year 1975. Other persons which did not want to be named also have my gratitude.

Jan 1, 1977

By J. Bruce Clemmer

[Gypsum is one of the mo .. t iJf.l)ortant nonmp.tal1.ic T!1inerals, as is indicat-? ed by the fact that tlle Uni ted states cO!1sUl:Ied p, roximn..tely 3,500,000 tons of natura.l and calcinecl e::,j;-psum in 1937. The b\.'.ilr:.in.; traces \"fe.ro the largest users and required 2,520,000 tons of calcine for the r-roductiop. of plaster,]

Jan 1, 1941

By P Thompson, B W. Atkinson

Water treatment is not æcore businessÆ for mining companies.Just as mineral ores and coals are unique, each requiring detailed characterisation and pilot-testing to determine their optimum beneficiation route, so too are mine waters, each requiring careful assessment to determine the most appropriate treatment. There are many cases of æregret capitalÆ expenditure, whereby mines have installed off-the-shelf equipment only to find it inadequate for their purposes or grossly expensive and labour intensive to operate.Water may be required for potable purposes, ore processing, dust control and/or irrigation. A major driver will frequently be environmental constraints for off-site discharge. Mine water projects can become very complex, and detailed models need to be prepared and optimised to properly consider the raw water sources, the on-site storages, the on-site uses and the off-site discharges, as well as handling the residuals (by-products) of water treatment. By-products may be in the form of concentrated backwash streams or streams of elevated salt content. Careful management of the by-products is required to avoid recontamination of the source water.Regulators often drive mine owners toward reverse osmosis (RO) so that their discharges can be considered as æzero dischargeÆ in terms of potential pollutants. Such decisions need to be based on site-specific information rather than any form of æblanketÆ requirement. An analogy is that many humans like to consume mineral water rather than ænormalÆ tap water. Receiving environments also accommodate or even prefer their æmineralsÆ and so RO is neither warranted nor sustainable in many cases.This paper presents two case studies for operating mine sites, both of which have a significant excess of water requiring environmental discharge. The examples demonstrate a sensible balance between treatment type, environmental constraints, process implementation and residuals management. LIMN« æthe flow sheet processorÆ was used to model one of the case studies due to the complexity of the water system on that site.CITATION:Atkinson, B W and Thompson, P, 2013. Mine water - optimising for site and environment, in Proceedings Water in Mining 2013 , pp 9-14 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013