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By D. C. Seidel, E. F. Fitzhugh

The Colorado School of Mines Research Foundation has developed a hydrometallurgical process for recovering nickel from oxidized ores, including both the iron-rich laterites and magnesium-rich, soft silicates. Known as the HSO-HTCP (Hydrothermal Sulfidization Oxidation-High Temperature Cementation in Pulp) Process, the system consists of feed preparation, sulfidization, oxidation, precipitation (cementation), and calcination and melting. This paper deals primarily with the sulfidization and oxidation phases of the process. Nickel sulfide ores lend themselves readily to concentration before smelting or pressure leaching, but neither of the major oxidized ore types — the iron-rich laterites and magnesium-rich, soft silicates-has been directly concentrated. Upgrading of crude ore in current practice is limited to cobbing lumps of the harder, lower grade rock (protore) from the softer, enriched silicate ore, because only a small percentage of the nickel in these ores occurs in discrete, contrasting mineral particles. There is no apparent mineralogical contrast in the superficial, iron-rich lateritic ores and, in fact, there is no firm assurance that the nickel atoms are within the lattices of the limonite minerals, or else irregularly adsorbed on the limonite. Within underlying, "rotten rock" silicates, occasional veinlets of gamierite and related nickeliferous silicates are found.' The gamierite veinlets, however, are only incidental, and the majority of the nickel atoms occur as erratic replacements of magnesium atoms in the micaceous chlorites of the ore mass. Pyrometallurgical processes account for nearly all the nickel currently being recovered from oxidized ores. Plants in New Caledonia, Oregon, Japan, Brazil and Greece smelt the ores to make ferronickels or a sulfide matte,2 and the ammoniacal leaching3 at Nicaro, Cuba, is preceded by a reducing roasL4 The only fully hydrometallurgical installation has been the politically ill-fated Freeport Nickel Co. enterprise, and this process was limited to lateritic ores.5p6 A hydrometallurgical technique which might handle both laterite and the typically richer silicate ores has been an enticing goal. The technique described here was developed at the Colorado School of Mines Research Foundation, Inc. on behalf of the Republic Steel Corp. It uses sulfur, heat, air and metallic iron to recover nickel from these ores. Inasmuch as the ores are treated as aqueous slurries, the cost of drying a plant feed that normally carried 30% or more moisture is eliminated, and there are no dust problems. Patent applications have been filed by Republic Steel Corp. on the procedures used for getting the metal into solution and on the subsequent recovery without liquids-so l ids separation of the slurry. It is referred to as the HSO-HTCP Process (Hydrothermal Sulfidization Oxidation — High Temperature Cementation in Pulp). THE PROCESS FLOWSHEET The results of various experimental studies have been combined to form the continuous flowsheet illustrated in Fig. 1. This flowsheet serves as a general pattern showing the sequence of the operations which include: (1) feed preparation; (2) sulfidization; (3) oxidation; (4) precipitation (cementation); and (5) calcination and melting. This paper deals primarily with the sulfidization and oxidation phases of the process. Feed preparation: In general, the silicate ores can be considered as earthy rather than hard, and preparation might be carried out before the addition of water in a trommel, or with water in a scrubber or log washer. This breaks up the earthy particles, allowing the hard lumps to be separated by screening. The oversize material from most ores is relatively barren and may be discarded. If there is occasion to control the iron-magnesium ratio in the plant feed, laterite, which normally breaks up readily into fine sized particles, and silicates are mixed in suitable proportions. The fine product slurry from the initial steps is mixed with elemental sulfur and fed to a conventional ball mill, although the amount of actual grinding that takes place is relatively small. The object of milling is to complete the disintegration to natural particle size and to produce an intimate mixture of the ore and elemental sulfur. This pulp, which is almost entirely -200 mesh, has a pH of about 7.0 and normally can

Jan 1, 1969

By John A. Breslin

The Bureau of Mines measured respirable dust in coal mines by means of multiple dust samplers worn by persons moving about the mines. The measurements were made primarily to evaluate the effectiveness of certain dust-control techniques; however, for this report, the data have been analyzed to determine the precision of the personal dust-sampling measurements. A total of 68 sets of measurements were available from multiple personal samplers. The measured dust masses were less than 1.0 mg because the sampling times were short. The coefficient of variation calculated from these data was 18.5 pct, compared with coefficients of variation ranging from about 10 to 30 pct, which were calculated from the most precise and extensive data available for fixed-point dust measurements made in coal mines. From this comparison, it is concluded that dust samplers worn by personnel are as precise as fixed-point samplers in measuring respirabe coal dust; the wearing of the samplers by someone moving about a mine does not contribute significantly to the variation in measurements made with these instruments.

Jan 1, 1983

By A. C. Legg, M. T. Malema

Keywords: Pyrometallurgy, flash, smelting, furnace, nickel, copper, Botswana BCL Limited operates the only Flash Smelting Furnace on the African continent, at Selebi-Phikwe, situated in north-eastern Botswana. The furnace was commissioned in 1973 and produces a high-grade sulphide matte containing nickel, copper and cobalt, which is shipped to refineries in Zimbabwe and Norway for further processing. This paper outlines the recent process improvements and plant expansions that have resulted in a capacity increase from 40 000 to 60 000 tons per annum of metal production.

Jan 1, 2006

By Donald Leroux, Lori Lynn Smith, Robert Hutchison

"The grinding circuit of the Heath Steele concentrator was sampled under five different sets of operating conditions. The balanced results of the sampling campaigns were used to calibrate steady-state rod mill, ball mill and cyclone models using a commercial simulation software package (JKSimMet® ). Thirteen process variables had the potential to affect significantly the performance of the grinding circuit. Statistical-Design-of- Experiments techniques were applied to plan the suite of simulations in order to improve the quality of and minimize the time to find the optimal solution. The effect of each factor on three performance indices (the cyclone overflow size distribution, the circulating load and the cyclone underflow density) was modeled with empirical polynomial relationships using another software package (Design-Expert@)T. he conditions under which the cyclone overflow size distribution was maximized while respecting circulating load and cyclone density constraints were identified using these relationships. Among the most interesting results is the prediction of a set of conditions where the circuit target size distribution is achieved with only three ball mills instead of four.IntroductionProduction at the Heath Steele concentrator (near Miramichi, New Brunswick) started some 43 years ago at a rate of 750 t/d. The plant capacity was increased to 4000 t/d through successive expansion phases in the seventies (Sapiro, 1977; Johnston, 1978). However, as a result of depleting ore reserves, the plant throughput had to be gradually reduced to the current production rate of 2700 t/d. Heath Steele Mines currently have proven and probable reserves which would see it producing until the end of 1999 (Noranda Inc., 1997).An analysis of the grinding circuit of the Heath Steele concentrator was recently commissioned to identify opportunities for reducing operating costs while maintaining budgeted mill throughput and metallurgical performance. Since the plant will likely be operated below nominal capacity for the rest of its lifetime, the possibility of improving grinding efficiency by operating with fewer ball mills and/or crushers was contemplated."

Jan 1, 1999

By P. J. O'Connor, V. Gallagher

examined analytically in relation to the ratio of the

Dec 1, 1994

By C. S. Finney, John Mitchell

There is no field of human thought or endeavor which does not owe much to the past. Yet, surrounded by the prodigious scientific and technological achievements of our day, it is all too easy to forget the extent to which we have stood on the shoulders of giants. The coking industry of the United States is now a little more than one hundred years old. As with the American nation itself, the earliest beginnings of the industry owe a great deal to British influences, and its development owes much to those influences of continental Europe. No serious contribution to the history of coking in the United States can be written, therefore, which does not mention the work of the pioneers of the Old World. It is believed that the use of metallurgical coke dates back to antiquity. The fact that certain coals would soften under the influence of heat to yield a porous solid was known to the ancients of China and India, where a very crude coking operation was carried out by simply setting fire to piles of coal. After active combustion had started, turf or wet straw was used to seal off the pile. The coke obtained was used to forge iron and steel implements and weapons. Perhaps the earliest reference to the coking phenomenon is to be found in the writings of Theophrastus, pupil of Aristotle. In his History of Stones, which was written in or about the year 371 B.C., there appears the following observation. "But the Lipara stone empties itself, as it were, in burning and becomes like the pumice, changing at once both its colour and density; for before burning it is black, smooth and compact.... Certain stones there are about Tetras, in Sicily, which is over against Lipara, which empty themselves in the same manner in the fire." The first comparatively modern reference to coke is to be found in a recommendation for carbonization made in 1584 by Julius, Duke of Braunschweig-Luneberg, owner of the Hohenbuchen mine in the Harz district of Germany. In 1587, Sir Francis Willoughby of. Wollaton, England wrote: "There are twenty rooks broughte into charcoal and laid up in store." A rook of coal was equivalent to some 25 tons, and the coking would probably have been carried out in a manner similar, to that used for the production of charcoal. In 1589, Thomas Proctor attempted to carbonize coal, and in the year 1590 an English patent was granted to John Thornborough, Dean of York, in order that he might "purify pit coal and free it of its offensive smell". Sir Robert Cecil (1595), Robert Chantrell (1607), Simon Sturtevant (1611) and John Rovenzon (1613) were all granted patents for the use of coal or coke

Jan 1, 1961

By H. P. Rosenof

The G2 real-time expert system, a commercial product since 1988, is widely deployed in process, manufacturing and other industries. A number of innovative applications are installed or under development in the mining and metallurgical industries. These include: ? A chemical reagent control system for a mineral concentrator, at a mining company; ? A supervisory control system for a product dryer, at a surface coal mine ? A training system for equipment operators, at a steel mill; ? A scheduling system for furnaces at a hot rolling mill; ? A simulation system for mining operations; ? Several graduate-level research projects in materials handling at a university Realized and projected benefits will be discussed. In addition certain applications installed or under development in other industries will be proposed as applicable in mining and metallurgy. For example, applications for the management of vehicular traffic may find use in mining and shipping.

Jan 1, 1992

By Douglas R. Cook

The Ertsberg East discovery was announced by Freeport in 1979 with proven geological reserves of 45 Mt (49.6 million tons) with a grade of 2.65% copper and recoverable gold values. This recently discovered deposit is one of a cluster of skarn-type copper occurrences found within the limits of Freeport Indonesia's mining con- cession at an elevation of about 3600 m (12,000 ft) in the extremely rugged Jaya Wijaya Mountains of Irian Jaya, the Indonesian half of the island of New Guinea. The Ertsberg East lies about 1.5 km (0.9 miles) east of the Ertsberg ore body, which is also known by the Indonesian name "Gunung Bijih" or "ore mountain." For general background, the original Ertsberg ore body was first discovered by the Dutch geologist Jacques Dozy in 1938 while on a mountain climbing expedition. It was mapped and sampled by Forbes Wilson and Del Flint after a two-week harrowing trek into the mountains from the coastal swamps. A drilling program in 1967- 1968 established that the Ertsberg was a viable mining venture, containing approximately 33 Mt (36.4 million tons) of skarn-type copper ore. The deposit averaged 2.5% copper, with significant values in gold and silver. The first shipment of copper concentrates was made in December 1972, following a capital investment of $200 million. Following the routine production of ore from this deposit, it became necessary to consider additional sources of ore to extend the life of the mining operation. An exploration program was thus started with the initial objective of finding shallow or surface ores which could be blended with the material being mined at Ertsberg. Project geologist Frank Nelson was transferred from Freeport Exploration Co. to the Freeport Indonesia organization at the Ertsberg mine. However, the exploration work was the functional responsibility of Freeport Exploration. Del Flint had overall responsibility for the program from the Reno headquarters office and provided liaison with management in the USA and Indonesia.

Jan 1, 1991

By Kenneth N. Weaver

Introduction and Historical Background State Geological Surveys have been deeply involved in industrial minerals from their inception beginning in the first half of the 19th Century. To Massachusetts belongs the credit of having carried out the first Geological survey under state auspices on the Western Hemisphere. One of the causes leading up to this survey was. Governor Lincoln's message to the legislature of May 29, 1830, from which I quote in part: "Much knowledge of the natural history of the country would thus be gained (from a geological survey), and especially the presence of valuable ores, with the localities and extent of quarries and of coal and lime formations, objects of inquiry so essential to internal improvements and the advancement of domestic prosperity, would be discovered.". Similar phraseology is present in practically all of the initial organic acts creating the first State Surveys. High on the list of priorities for these embryo surveys was an inventory of the mineral resources of the State with particular emphasis on the industrial minerals. Prom these early beginnings, the state surveys have developed a great wealth of geological data either directly or indirectly relating to the development of mineral resources. One can gain some conception of the effort that state surveys today place on industrial minerals studies by noting the projects in which they are engaged as reported in the State Geologists Journal. In 1970, for example, approximately

Jan 1, 1972

By M. L. Smith

The U.S. Bureau of Mines Cost Estimating System (CES) has been used for prefeasibility analysis and mine cost engineering since 1978. In the past, prefeasibility analysis with CES has involved the solution of regression equations. The new generation of CES uses an object-oriented expert system in a Windows? environment. Knowledge bases are structured around generic mine models which access shared knowledge bases for system design.

Jan 1, 1994

By G. A. Alers, F. Borik

Rolled sheet products are elastically anisotropic and a large number of measurements of Young's modulus and rigidity modulus are necessary to completely specify their elastic properties. This paper describes and uses a simple measurement technique to obtain the nine elements of the elastic modulus tensor from which all the elastic The elastic properties of a polycrystalline material are usually specified by giving the Young's modulus E and the rigidity modulus G. Unfortunately, these two moduli by themselves are insufficient to completely specify the elastic properties because the rolling process introduces a preferred orientation which makes the material properties can be deduced. In particular, the variation of Young's modulus and the rigidity modulus in the principal planes of a sheet of ausformed steel were deduced. Furthermore, the variation of Young's modulus in the rolling plane was compared with direct measurements. anisotropic. This anisotropy makes E and G functions of the orientation of the test specimen in the sheet so that a complete description of the elasticity requires many measurements on a large number of specimens. A more fundamental approach to the problem is to consider the sheet as a single crystal and measure the elements of its elastic modulus tensor. Although this appears formidable, there have been developed recently high-frequency ultrasonic techniques which yield these tensor elements directly. The symmetry of a rolled sheet is such that it behaves elastically as if it were an orthorhombic

Jan 1, 1965

By W. N. Best

This paper is not intended as a scientific discussion of the combustion of oil but is written from the standpoint of an operator who has the experience and qualifications necessary to guide others in producing the most economical results in the use of liquid fuels. Oil, in this paper, usually means petroleum or its products but incidental reference is made to other liquid and gaseous fuels, so that the term may be considered as referring to all liquid and gaseous hydrocarbons in comparison with solid fuels, as coal and wood. However, only a few of the principal factors in the use of oil as a fuel can be given. The present, and prospective, high price of coal is causing users of fuel to renew inquiry as to the merits of other forms of fuel for industrial purposes. Crude oil (petroleum) is proving to be one of the world's most valuable mineral resources. The recent discovery that oil underlies a considerable area of the United States, Mexico, and other parts of the world to a greater extent than was formerly believed and the large production of some of the wells in these areas shows the probable quantity of fuel oil that may now be available. Through the energy of Lord Cowdrey, who was one of the pioneers of the oil industry in Mexico, oil has been discovered in England; some prominent geologists believe that it may be found in quantity in Great Britain. For years, oil has been known to be of great value in the manufneture of metals. It has proved incomparable in forge shops, steel foundries, heat-treating furnaces, and wherever accuracy of temperatures is essential, or where a maximum output is desired as well as quality of metal. In some types of equipment, the output produced with oil as fuel is double that obtained with coal and at a reduction of 50 per cent. in the cost of the fuel. For example, in drop-forging plants, the metal is always waiting for the man when oil is used as fuel, whereas with coal, the man must wait for the metal to become sufficiently heated. It has only been since January, 1919, that the oil supply could be relied on for boiler service, owing to the war conditions and the inability to get oil tankers for the delivery of the oil from Mexico to Atlantic ports; but now a constant supply is assured, and many manufacturers are installing it in their power plants. The cost varies with the size of the

Jan 1, 1921

By A. B. Hooker

Investigations at the Pittsburgh Experiment Station of the Bureau of Mines have shown that satisfactory operation of a flame safety lamp depends not only upon proper design and assembly of the lamp but also upon the kind

Jan 1, 1945

By Hongmin Zhu, Qiuyu Wang, Shuqiang Jiao, Guojing Hu

"The equilibrium between titanium ions and metal titanium was investigated in fluoride-chloride molten salt. The electrochemical properties of titanium ions in fluoride-chloride were studied on a molybdenum electrode by cyclic voltammetry (CV) and square wave voltammetry (SWV). The equilibrium constant of the equilibrium between titanium ions and metal Ti was calculated in KCI-NaCl- 2.5wt %K2 Tif 6 at the temperature of 1073K.IntroductionTitanium, the ninth most abundant element in the earth's crust, is endowed with high strength, low density, excellent flexibility, strong spring back characteristics, high-temperature performance, corrosion resistance and biocompatibility. These characteristics make titanium eminently suitable to be used in aerospace, marine industries, and harsh chemical environments. Although it has many excellent properties, the application of titanium in industry was limited by its high-cost. Therefore, many methods have been investigated for producing high-purity titanium at low cost. Electrolysis, involving the extraction and preparation of pure metal from ore using an electrolytic process, is considered a promising method for titanium metallurgy. Many studies have focused on the electrochemical behaviour and electrodeposition of titanium in molten chloride, fluoride, and chloride-fluoride electrolytes (1-IOJ. The electroreduction mechanism of Ti3+ ions in molten alkali chlorides has previously been studied by several workers. Two reduction steps, Ti3+ -Ti2+ -Ti, have been observed in various molten alkali chlorides [IJ. One reduction step, Ti3+ -Ti, has been observed in alkali fluoride molten salts l21. The behaviour of Ti4+ in fluoride or chloride-fluoride molten salts has also been investigated in the literature; it was proposed that the reduction of Ti4+ ions in the molten salts proceeded in a two step process: Ti4+-Ti3+-Ti l3l or a three step process: Ti4+ -Ti3+ -Ti2+-Ti ri. 4l Indeed, the stability of the titanium oxidation states depends on the bath composition l5l. The valence state was Ti2+ in alkali chloride melts, which was a lower oxidation state and correspondingly, in alkali fluoride melts, the higher oxidation states ofTi4+ and Til+ were more stable.The aim of the present work is to explore the effect of F/Cl atomic ratio on the equilibrium between titanium ions and metal titanium in fluoride-chloride at the temperature of 1073K. The electrochemical properties of titanium ions in fluoride-chloride were studied on a molybdenum electrode by cyclic voltammetry (CV) and square wave voltammetry (SWV). The solubility product of the equilibrium between titanium ions and metal Ti was calculated."

Jan 1, 2012

By R. Breña

El "Marconaflo" es un sistema comercialmente económico y patentado por la Compañía Marcona, el cual sirve para transportar concentrados de hierro en forma de pulpa, tanto en buques como en instalaciones en tierra. En este sentido, el objetivo del trabajo radica en describir las necesidades de la industria minera para el desarrollo de este nuevo sistema. Así también se describe el proceso de su operación, proyección en el transporte y la industria minera.

Nov 20, 1972

By Charles L. Morgan

"In 2012 the International Seabed Authority (ISA) established nine “Areas of Particular Environmental Interest” (APEIs) for consideration as future Marine Protected Areas to help preserve the biodiversity of life on the seabed within the Clarion-Clipperton Zone (CCZ) between Baja California, Mexico, and the Hawaiian Islands. The CCZ is believed to have a high potential for future seabed mining operations. Areas under active exploration contracts in the CCZ, plus the areas currently reserved by the ISA for exploration by developing nations, comprise about 1.9 million km2 of seabed area. The currently designated APEIs consist of more than 1.4 million km2 of seabed. Each APEI includes a central primary conservation area of 200 X 200 km, surrounded by 100-km buffer areas on all sides. The 100-km buffers are intended as a very conservative spacing between the primary conservation area and potential mining activities in adjacent seabed. The selection of these nine 400 X 400 km APEIs, has been criticized as possibly not including sufficient representative habitat similar enough to the potential mining areas (identified currently as the exploration contract and reserved areas administered by the ISA within the region) to ensure protection of the biodiversity that might be impacted by mining.An area to the east of the existing exploration contracts and reserved areas is known to have substantial mineral deposits; it is very similar to the adjacent exploration contract areas in its geology, environmental setting, polymetallic nodule abundance and nodule metal content. Because it is located in the northeastern extreme of the CCZ, this area is also likely to have relatively high densities of benthic life, compared with benthic communities further westward within the CCZ. Many options for the designation of this APEI are possible, but the area designation must accommodate the boundaries of the Exclusive Economic Zones of Mexico and France.This paper discusses why the selected region in the eastern extreme of the CCZ is a good candidate for designation as a new APEI.Keywords: polymetallic nodules, Marine Protected Areas, Clarion-Clipperton Zone, Areas of Particular Environmental Interest"

Jan 1, 2017

COUNCIL.* PRESIDENT OF THE COUNCIL. JAMES F. KEMP NEW YORK, N. Y. (Term expires February, 1913.) VICE-PRESIDENTS OF THE COUNCIL. S. B. CHRISTY BERKELEY, CAL. W. A. LATHROP PHILADELPHIA, PA. GARDNER F. WILLIAMS WASHINGTON, D. C. (Term expires February, 1913.) KARL EILERS NEW YORK, N. Y. WALDEMAR LINDGREN WASHINGTON, D. C. BENJAMIN B. THAYER NEW YORK, N. Y. (Term expires February, 1914.)

Jan 1, 1917

By P. B. Venuto, E. T. Strom, S. A. Dixon, W. F. Johnson, T. C. Vogt

Prior to assessing potential for in-situ leaching, it is advantageous to identify the nature of the probable reactants in the ore horizon, including both the uranium species and those in the gangue material. We report mineralogical data on an areally-broad suite of samples from the Westwater Canyon Member of the Jurassic Morrison Formation in the Crownpoint area of the Grants Mineral Belt. Optical microscope, electron micro-probe, X-ray diffraction, spectroscopic and wet chemical analyses were conducted. In these samples, the uranium occurs predominantly as either coffinite or uraninite. The host rock is arkosic sandstone, comprised mainly of detrital quartz and feldspar. The minerals kaolinite and chlorite are present in claystone clasts and calcite occurs as a cement. Major trace elements include molybdenum, vanadium, iron, selenium and sulfur. Carbonaceous organic material is present in the ore and is intimately associated with the uranium mineral when it is coffinite. Geochemical, pyrolytic and 13C NMR analyses indicate organic material is probably a very mature, coaly-type kerogen derived from plant components.

Jan 1, 1982

By H. Ogasawara

To study the preparation process of an earthquake, we should get closer to the hypocentre. In co-operation with ISS International, we had an experimental field (~200 m x~200 m) without dykes and faults in a South African deep gold mine. We have monitored more than 20,000 seismic events (M<2) with borehole tri-axial accelerometers. We used a data acquisition system with 15 kHz sampling and 120-dB dynamic range. In a remnant area at a distance of 100?200 m, an earthquake sequence associated with an M~2 event occurred. Significant changes in seismic parameters such as stress drop, b-value, energy index were observed associated with the sequence. We installed Ishii?s borehole strain meters and could monitor as large a strain change as 10-4associated with mining. However, sampling was only 4 times per hour and 12 bit A/D. A distance from the M2 sequence was ~100 m, being not close enough. Therefore, we found another field with several crosscut tunnels excavated across a fault where an M=2-3 event is expected. We installed the strain meter within several metres of the fault to monitor both shear and normal strains on the fault. The strains are continuously digitized with a 24-bit 25-Hz A/D conversion. The Earth Tide (10-8)is clearly detected. Seismicity induced by longwall mining can be compared to earthquake swarm induced by fluid intrusion to vertical dykes. We also found a decrease in energy index in the source area of M>5events a few days before the major events. Keywords: seismic monitoring, strain monitoring, seismic parameters, preparation process of an earthquake, South African gold mine.

Jan 1, 2002

By Richard K. Thorpe, Francois E. Heuze

The concept of a reusable underground nuclear test facility, named HEDEF, has been under study for some time. This rock chamber would have to be engineered to sustain the repeated mechanical and thermal shocks of internal explosions. In this paper, we summarize preconceptual studies performed in support of HEDEF, including -simple dynamic calculations for internally loaded tunnels, -outline of proof-of-concept tests of proposed reinforcement, - and initial dynamic testing of reinforcement components in an underground high explosive (HE) test.

Jan 1, 1986