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By Alan Bauer

In recent years there has been increasing interest in employing the technique of explosive casting in strip mines. Explosive casting, applied to dragline mining, describes the procedure whereby the overburden is horizontally displaced by blasting causing a portion of the material to be thrown into the previously mined cut. Therefore, it is not necessary to subsequently excavate this waste with the stripping equipment. In addition, allowing the overburden unrestricted movement during the blast most often results in improved fragmentation and enhanced machine productivity. The method is receiving attention because the capital and maintenance costs of stripping equipment has risen rapidly in relation to explosives costs. Improved productivity is necessary to maintain unit costs at an acceptable level.

Jan 1, 1983

By Jehan Rondot, Raymond Marleau

"Des quartzites trés pars ont été découverts au cours de la cartographie de la region du lac des Martres, étape de l'étude géologique de la region de Charlevoix.On distingue quatre groupes métasédimentaires, tons con tenant des niveaux de quartzite dans an mains deux domaines géologique différents, c'est à l'ouest, clans le do¬maine gneisso-charnockitique que se situent les quartzites du groupe des Martres. Quartzite et gneiss à, grenat et sillimanite, en banes épais, constituent la formation de La Galette. A Pest, dans un environnement gneisso-granitique, les deux groupes métasédimentaires de Saint-Siméon, et de La Malbaie comprennent, par contraste, des bancs pen épais et de compositions variées. Les niveaux de quartzite dépassent rarement 50 m d'épaisseur. L'autre groupe métasédimentaires, celui de Saint-Tite des Caps, recoupé de nombreuses intrusions charnockitiques et granitiques, ne possède que de minces niveaux de quartzite.La pureté et la grande épaisseur des quartzites de La Galette suppose une histoire complexe qui se termine par des depots continentaux de climat aride, par opposition aux depots marins des autres groupes. D'autre part, la presence de ces quartzites an sein de roches Presque anhy¬dres et de haute temperature que sont les charnockites leur confére des caractéristiques de fusion sans decrepitation.Parmi la multitude de depots de quartzite qui existe clans le monde, peu sont de qualité supérieure. Or, de par sa composition chimique, le quartzite de La Galette se compare avantageusement à ceux des meilleurs gisements des Etats-Unis, de l'Europe de l'Ouest et de l'Afrique du Sud. D'accès facile pour l'exploitation, les gisements ne sont qu'à une trentaine de milles de Baie Saint-Paul ou de La Malbaie, sur le Saint-Laurent.L'utilisation en metallurgic prévue pour le quartzite de La Galette comprend la production de silicium, de ferro¬silicium et d'autres alliages de silicium. La composition du quartzite est en outre appropriée pour la production de carbure de silicium et de silicate de sodium. Les fines peuvent être utilisées pour la fabrication du verre et comme matiere de charge"

Jan 1, 1977

By Lang Tao, Jun Wang, Wei Xiao, Wenqing Qin, Pan Cao, Guanzhou Qiu, Key Lab of Biohydrometallurgy of Ministry of Education, Central South University

"The effect of metal cations on the rutile flotation using styryl phosphoric acid (SPA) as the collector was investigated by micro-flotation test, bench scale flotation test, zeta-potential measurements and adsorption measurements. The micro-flotation results indicated that Fe (?) and Al (?) ions in low concentrations had obvious activation on the rutile flotation, and Pb (?) ions in low concentrations had smaller activation of rutile, but Fe (?), Al (?), Pb (?), Ca (?) and Mg (?) have strong inhibition of rutile flotation in high concentrations. The bench scale flotation results indicated ethylene diamine tetraacetic acid (EDTA), boracic acid, and sodium hexametaphospate can decrease the metal ions concentrations, and increase the recovery of rutile flotation. Adsorption measurements and zeta-potential measurements revealed that Fe (?), Al (?) and Pb (?) ions were adsorbed on the rutile surface, and had interaction with SPA. But when these ions concentration were over the largest adsorption capacity, residual metal ions could occur chemical reaction with SPA.INTRODUCTIONRutile is one of the favored minerals for production of titanium dioxide white pigment, primarily through the chloride manufacturing process (Stanaway 1994; Hou et al., 2013) However, the majority of rutile ores belong to refractory ores, while flotation is one of the most efficient methods to separate fine rutile from gangue (Dolbear et al., 1937). With the flotation development, many effective collectors were successfully applied in the oxide ore. Many reviews have indicated that organic phosphonic acid collectors showed good selectivity on oxide ores such as ilmenite and rutile (Bulatovic & Wyslouzil 1999; Liu & Peng 1999).It is inevitable that many types of metal cations are present in ore pulp. These metal cations significantly influence the flotation of minerals. Liu et al. (2015) showed that Ca2+ and Mg2+ could improve the floatability of spodumene at pH 12.5 and 10.0, respectively. The authors proposed that Ca2+ and Mg2+ ions readily form hydroxy complexes (CaOH(l) and MgOH(l)) and precipitates as (Ca(OH)2 and Mg(OH)2) in strongly alkaline solutions. Fan and Rowson (2000) investigated the effect of Pb(NO3)2 addition as an activator on ilmenite flotation and showed that it could improve ilmenite floatability. The addition of Pb(NO3)2 resulted in an increase of ilmenite zeta potential in both weakly alkaline and acidic aqueous solutions. Mehdilo, Irannajad, and Rezai (2015) studied three kinds of ilmenite of different origins and discovered that both Mg and V had a negative correlation with ilmenite flotation, while the Mn content seemed to correlate positively with flotation efficiency. A number of studies have also showed that Fe3+ can improve the floatability of ilmenite (Fan et al., 2009; Nuri, Mehdilo, & Irannajad, 2014)."

Jan 1, 2016

By George Chung

"The Iron Ore Company of Canada's Carol Lake Project is Located near the western boundary of Labrador, 960 air kilometers northeast of Montreal (Figure 1).The Concentrator operation was started in 1962 with a capacity to produce 7 million tonnes of concentrate per year. The bulk of the concentrate was pelletized at a 6 million tonnes per year pelletizing plant completed in 1963. The remaining concentrate was sold in the international market. The concentrator was first expanded in 1966 to 10 million tonnes per year capacity with the pellet plant also expanded in 1967 to match the increase in concentrate production. In 1973, the concentrator was further expanded to gear with the increase in concentrate sales. In 1977, more than 40 million tonnes of crude ore was processed to produce in excess of 17.4 million tonnes of concentrate and 10.4 million tonnes of pellets."

Jan 1, 1980

By J. R. Goode

"Coarse ore sorting is here defined as the physical separation of a mixture of coarse (+3/8 inch) ore particles into two or more separate groups of total value greater than that of the unsorted ore. An ore will probably be sortable if the geology of the orebody and the mining practices employed meet conditions outlined in this paper.The paper points out how sorting can substantially reduce tonnage variable operating costs because sorting can double the mill head grade of amenable ores by rejecting waste rock from the mine output. The effect of sorting on ore reserves is outlined. It is also suggested that sorting is a low cost alternative to conventional expansion.The mode of operation of the Ore Sorters Kadel 13 Photometric and MK VI A Radiometric sorters is detailed. The report concludes with detailed descriptions of the photometric sorting plant operated by the Doornfontein Gold Mining Company is South Africa and the Radiometric Sorting Plant presently under construction at the Schwartzwalder mine of Cotter Corporation in Colorado."

Jan 1, 1975

By G. X. Wang, R. E. Siemens, M. C. Fuerstenau, D. Chandra

Soda roasting of concentrates from Mouat, Montana, was performed in a temperature range of 450 to 650 degrees C and chromium was solubilised by water leaching at room temperature. It was found that high extraction yields of chromium were primarily dependent on the conversion of Cr3+ to Cr6+ during the roasting step, and this was enhanced significantly by simple attrition of chromite particles during this step. Gangue impurities (mainly Si) were more detrimental to Cr extraction than lattice impurities such as Al or Mg. It appears that oxidation proceeds into grains along a preferred crystallographic plane in the cubic lattice of the chromite. The effects of roasting time, temperature, soda to chromite ratio and particle size on the extraction of chromium are presented

Jun 18, 1905

By Nessetech Consulting, L. A. Cisternas, E. D. Galvez, S. H. Kuan, L. H. Saw

"In Malaysia, there were two rare earths processing plants namely Asian Rare Earth (ARE) and the Malaysian Rare Earth Corporation Plant (MAREC) in Perak, which were operated until 1992 and were subsequently closed due to problems pertaining to disposal of large amount of radioactive waste. Recently, Lynas Advanced Materials Plant (LAMP) has become one of the largest rare earths processing plant in the world producing rare earth elements (REE) in Gebeng, Pahang. The primary raw material is lanthanide concentrate (LC) which is imported from Mount Weld mine in Australia and shipped to Malaysia. LC is produced from lanthanide ore after mining and mineral processing. The ore has a lower impact than Bayan Obo, Mountain Pass and adsorbed clay deposits, given the small footprint of the mine itself and the remoteness of the location. The type of ore being mined (rare earth phosphates: carbonatite, monazite) may have higher thorium content than bastnasite ore from the Chinese or American mines but still far below radiation concerns. This paper was written to review the processing flowsheet at the Lynas Advanced Materials Plant (LAMP), the environmental impact associated with the processing of the said ores and the sustainability of the operation.INTRODUCTIONRare earth minerals are one of a set of 17 minerals or chemical elements which consists of yttrium and scandium, as well as the 15 lanthanide elements (lanthanum, cerium, praseodymium, neodymium, promethium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium). Despite their importance, rare earth minerals rarely exist in economically viable concentrations and they are usually difficult to extract. Rare-earth minerals create strong magnets when added to magnetic elements such as iron, and are useful for the production of electronics systems as well as electric cars. They are also used extensively in automotive catalytic converters, fluid cracking catalysts in petroleum refining, wind turbines, phosphors in colour televisions and flat panel screens, displays for mobile phones and laptops, rechargeable batteries, and various medical devices. The elements are typically split into two subgroups: the cerium sub-group of ‘‘Light’’ rare earth elements (LREEs) which includes La to Eu and the yttrium sub-group of ‘‘Heavy’’ rare earth elements (HREEs) which include the remaining lanthanide elements, Gd to Lu, including yttrium (Gupta and Krishnamurthy, 1992; Jordens et al., 2013; Trifonov, 1963). Scandium, however, when it is classified as a rare earth element, is not included in either the LREE or HREE classifications (Gupta and Krishnamurthy, 1992; Jordens et al, 2013). Half of the world’s 110 million tons of reserves exist in China while other sizable deposits are found in Russia, United States, Brazil, India, Australia, Canada, and Greenland. The countries known to be actively mining REE are China, Russia, India, Brazil and Malaysia (Hao et al., 2015). Among these countries, China has the largest REE production, accounting for more than 93% of global supply (Yap, 2015). The critical metal report (Moss et al. 2011) listed 14 economically vital raw materials that are prone to supply disruption and concluded that supply disruption would threaten the goal for cleaner transport and sustainable energy since rare earth metals are used in products using green technology, such as hybrid/electric vehicles, carbon capture systems, wind power generation, low-energy lighting, and energy efficient flat-screen displays."

Jan 1, 2016

By Brandon Fryman, Josh Hoffman, Rhys Baker

A post-detonation debris collection project was led in conjunction with a large ammonium nitrate(AN) railcar detonation conducted by the Department of Homeland Security-Transportation Security Administration, Department of Defense-Combating Terrorism Technical Support Office, Sandia National Laboratories, and the U.S. Army Dugway Proving Grounds. This important work will aid in underpinning algorithms used in a Quantitative Risk Assessment (QRA) tool. The test also provided valuable data about the effects and consequences following an AN detonation. The test took place at the Utah Dugway Proving Grounds on April 27, 2018 and the debris collection was conducted the following two weeks with an average of 20 persons per day and an approximate total of 1,400 manhours. A paper was presented at the 2019 ISEE Conference on the collection efforts, challenges, and lessons learned. A complete data analysis effort was completed on the test data in 2019 that resulted in updates to the QRA Railcar Potential Explosion Site (PES)model and AN engine. The analysis included an assessment of the debris data resulting from the Derailed test. This paper is meant to serve as a summary of the analysis effort and findings and as an update to the previously presented lessons learned from the debris collection and analysis effort.

A Study of Extracting Vanadium from Stone Coal Using Cyclic Oxidation

Sep 13, 2010

Effect of Iron on ash fusion temperature and waterwall deposits FeS, H2S on tube material corrosion and erosion [ ]

Jan 1, 2005

IN presenting a'description of milling and treatment methods at the Waihi mine, it is advisable to first traverse a good deal of the past history of the mine, and show the various steps which have led up to present-day practice. The record of the company is one of steady, solid advancement, both in metallurgical and financial results. This is illustrated by the following figures, dating back from 1897...

Jan 1, 1912

By Allan Sylvester

This paper will discuss the design, construction, and performance of the support of excavation on the San Diego State University LRT Station. The vertical elements of the system include drilled secant piles and drilled soldier piles. We will discuss the geo-technical characteristics, design and construction considerations, loading criteria, construction techniques, schedule constraints, and performance of the pile and support of excavation systems. In consideration of the conference theme, there will be a discussion of the successful accomplishment of meeting the interim milestone dates of the Contract. The project team cooperatively worked to design and install approximately 1,100 drilled secant and soldier piles as well as excavate and install the balance of the support of excavation elements in such a manner as to minimize the disruption to campus students and operations.

Jan 1, 2002

By Sidmar Aparecido Ceresani

O presente estudo tem como objetivo demonstrar a cinética de recristalização e o amolecimento da liga C272000 processada na laminação a frio com uma deformação de 75%. Para determinar o modelo cinético Johnson, Mehl e Kolmogorov (JMAK) foi adotado a temperatura de 450° entre 5min. a 50min. Restaurando totalmente a microestrutura deformada plasticamente sendo progressiva a elevação do tempo e da temperatura. A caracterização microestrutural das amostras foi utilizado microscopia óptica e metalografia. Conclui-se que o modelo JMAK satisfaz a forma de nucleação da recristalização da liga C272000.

Oct 30, 2017

By Miguel Arends, Hans Cayo, Patricio Zárate

En la flotación de sulfuros polimetálicos, en particular la combinación Cu-Pb-Zn, la selectividad en la flotación primaria colectiva es clave para el resultado global del proceso. Cu y Pb deben flotar en la etapa primaria y el Zn rechazado. Un diagrama de flujo típico utilizaría depresantes (NaCN, ZnSO4), activadores (CuSO4), espumantes y colectores. Utilizando un mineral polimetálico sudamericano se desarrollaron colectores más selectivos contra el Zn en la flotación primaria sin comprometer la recuperación de Cu y Pb, y a su vez mejorando la recuperación de Zn en la posterior etapa de flotación de Zn.

Sep 29, 2023

By G. D. Jermain

Exploration of the Antimony Peak district by the Bureau of Mines was conducted under the authority of the Strategic Minerals Act of 1939. Antimony was one of the seven metals designated at that time as strategic by the Secretaries of War, Navy, and Interior upon advice of the Army and Navy Munitions Board. As a result of many field examinations, the Antimony Peak property was chosen as one of the most attractive for the possible development of emergency antimony reserves. Exploration by the Bureau of Mines began in November 1940 and was concluded in May 1941.

Jan 1, 1949

By Gu Guohua

The alteration of surface properties of chalcopyrite after biological conditioning with Leptospirillum ferriphilum was studied by adsorption, zeta-potential, contact angle and bioleaching tests. The strains of L. ferriphilum cultured using different energy sources (either soluble ferrous ion or chalcopyrite) were used. The adhesion of bacteria to the chalcopyrite surface was a fast process. Additionally, the adsorption of substrate-grown bacteria was greater and faster than that of liquid-grown ones. The isoelectric point (IEP) of chalcopyrite moved toward that of pure L. ferriphilum after conditioning with bacteria. The chalcopyrite contact angle curves motioned diversely in the 9K culture with and without chalcopyrite powders. The results of X-ray diffraction patterns (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analysis indicated that in the bioleaching process by L. ferriphilum, the surface of chalcopyrite was covered with sulfur and jarosite. Furthermore, iron phase dissolved preferentially from chalcopyrite surface during bioleaching from EDS detection. The copper extraction was low resulting from the formation of a passivation layer. The major component of the passivation layer that blocked continuous copper extraction was sulfur, not jarosite.

Sep 1, 2012

By G. P. Chaudhari, F. Warchomicka, M. Dikovits, V. Pancholi, C. Poletti

"The hot formability of a microalloyed steel with 0.16 wt-%C modified with N is studied by using processing maps. Compression tests of cylindrical samples are carried out using a Gleeble®3800 simulator in the range of temperature between 750 -1000°C and strain rates between 0.01-100 S-1. For this alloy, an Ar3-temperature about 740°C is determined by means of dilatometry. Processing maps are calculated using the modified dynamic material model developed by Murty and Rao for different logarithmic strains. For the instability map, the parameter Kj developed by the authors in previous works is used and compared with other instability values. Softening in the flow curves provoked by induced ferrite during deformation at low temperatures and low strain rates is reflected in the n-value. Light optical microscopy (LOM) and electron back scattered diffraction (EBSD) measurements are used to study the microstructure of the hot deformed samples to determine the deformation mechanisms active and to verify the processing maps.IntroductionProcessing maps offer a good possibility to optimize thermomechanical process parameters and to avoid defects in the products. Prasad et al. [1] developed the processing maps using the dynamic material model (DMM) and Murty & Rao [2] modified it. Processing maps consist of two superimposed maps: the dissipation efficiency and the instability map. The processing maps can be used to detect areas with a good hot formability, which are normally related to restoration of the material by dynamic recovery/recrystallization. For a high dissipation efficiency value and no instabilities, a good hot formability is predicted. In the DMM no storage of energy takes place and so the material is considered essentially dissipative, this is only true for high temperatures and high strain rates [1]."

Jan 1, 2012

By Steven A. Elmquist

INTRODUCTION R&D activities are needed, at a minimum, for a company's competitive survival followed in importance by the growth and diversification of the company. For most industrial companies, however, R&D is the business area that has been the most difficult relative to confident long-range financial commitments and effective control and relative to its value as a long-term investment. Investors look not only at the current profitability of the company but increasingly at the plans, actions, and quality of the personnel in position to improve the market position and profitability of an organization. "The strongest predictor of investment value is the degree of innovation of the 'company.' I believe this is true of both strategic planning and R&D activities." R&D is the lifeblood of a company's future. If this basic premise-R&D for survival and growth-is believed to be true, why is it necessary to "Sell R&D in your organization? My personal experience, in a number of organizations, is that R&D budget is perceived as a business element area that could be delayed or reduced to improve the bottom line during difficult business conditions. I believe the following quote speaks volumes about this subject-"There is only one thing I know for certain about research, and that is it costs money-lots of it." -Unnamed, Hard- headed Financial Executive. A business must make money and be profitable in order to maintain and create jobs, pay taxes, cover working capital and costs of goods sold, and most importantly, create value for its shareholders. The foremost element of selling R&D, therefore, is to consistently demonstrate the R&D group's contribution to the bottom line.

Jan 1, 2004

By Chaitanya "Teny" Mittal

INTRODUCTION A team effort by the Owner, Engineer, and Contractor can help avoid serious problems on a construction project. It can save cost and time for both Owner and Contractor, as illustrated in the following case history of the West Zone and Siouf Keblia Collector System in Alexandria, Egypt (Contract 02-AID-83/84). Under the bilateral agreement made in 1980 between the United States of America and the Arab Republic of Egypt, the United States, through the Agency of International Development (USAID), gives approximately $1 billion per year as a grant to Egypt for various development projects. The Alexandria Wastewater Management System was selected in 1981 as one such project. The Egyptian Government Agency responsible for this work is the Alexandria General Organization for Sanitary Drainage (AGOSD). A joint venture of two U.S. consulting engineering firms, CH2M HILL, Inc., and Metcalf & Eddy, Inc., called Wastewater Consultants Group, along with two local subconsultants, Engineering Consulting Group and Warith Engineering Co., were selected by AGOSD to study the sewer system and develop a plan to serve the immediate and long-range sewage disposal needs of Alexandria. Wastewater Consultants Group is currently involved in Phase I of the Master Plan. This initial step in providing Alexandria with an operating sewerage system for the current and near-term population (year 2000) consists of the design and construction management of 140 kilometers of collector and force main pipelines (including 9 miles of pipe jacking and tunneling in very soft clay), five new pumping stations, extensive rehabilitation of two treatment plants (built in the 1960s but never operated successfully), and installation of a sludge handling system. Phase I is scheduled to be completed by the end of 1991 at a total cost of around $250 million (US) plus 250 million

Jan 1, 1989

By Joseph Taylor

THE Ducktown district is in the extreme southeastern corner of Tennessee, its principal railroad point being Copperhill, on the Blue Ridge division of the Louisville &Nashville Railroad, midway between Knoxville, Tenn., and Atlanta, Ga. The ore deposits were discovered about 1849 and development work was begun in the early fifties. Only the "black copper? ores, products of secondary enrichment, from beneath the gossan outcrops and overlying the massive sulphide deposits, were then mined and smelted for their copper content. Upon their exhaustion, attention was directed to the treatment of the pyritic ore remaining, resulting in the devising of a, process consisting of open-heap roasting, followed by blast-furnace smelting, which was practised until 1903, when semi-pyritic smelting was-adopted. In 1908, the companies operating in the district; on account of litigation brought about by alleged smoke damage to forests and vegetation in the adjoining counties of Georgia, were compelled to erect enormous acid plants to prevent the escape of the sulphur dioxide produced in the smelting operations. The utilization of this sulphur dioxide in the, manufacture of sulphuric acid as a byproduct has added to the revenues of the companies, and at the same time has furnished a valuable source of supply of sulphuric acid to the fertilizer trade of the South, and more recently to the manufacturers of explosives for use in the production of war munitions. The steadily increasing demand for sulphuric acid for the manufacture of fertilizers and explosives, together with the decreasing imports of pyrites, from which the acid is generally produced, now makes it imperative that greatly extended resources of pyrite be developed. While the Ducktown deposits do not predominate in pyrite, they do contain an inexhaustible supply of pyrrhotite, admixed with pyrite, which can be satisfactorily employed to supplement or substitute for pyrite in acid making.

Jan 2, 1918