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By J. P. Downey, T. Salisbury, M. Berlin, E. Rosenberg, G. Pinson, R. Christianson, K. Gleason, W. Gleason, S. Davis

"Direct digital manufacturing offers promise as a technique for fabricating complex hydrogen purification membrane support structures. Free form fabrication methods can produce parts with complex structures, and sintering parameters can be controlled to adjust the density, pore structure, pore pathways and strength in catalytic substrate constructs. Efforts are underway to define the influence of selected process variables on the chemical and mechanical properties.IntroductionThe Center for Advanced Mineral and Metallurgical Processes (CAMP), in collaboration with the Metallurgical and Materials Engineering Department at Montana Tech and the Chemistry Department at the University of Montana, is engaged in the development of new methods and materials for hydrogen purification membrane production. Because hydrogen readily passes through palladium, a structurally sound palladium-based membrane is capable of separating relatively pure hydrogen from other gases. In order for this technology to succeed, a suitable substrate material must be identified.High purity hydrogen is produced by various means. A common method involves a two-stage process for separating hydrogen from a hydrocarbon gas stream: 1) hydrogen-rich syngas is produced by the catalytic reaction of natural gas or another light hydrocarbon gas with steam, and 2) hydrogen is separated from the other syngas components by pressure swing adsorption (PSA) (US. Energy Information Agency, 2011). In PSA, gases enter a column that is packed with a material that absorbs gases as the chamber is filled and pressurized. As the pressure is slowly relieved, the absorbent material releases hydrogen at a higher pressure than the impurity gases. PSA processes produce 99.99% pure hydrogen at a high recovery rate. These systems typically demand a high capital investment due to the high pressure and multiple stages (columns) needed to attain high hydrogen production rates.Research geared toward reducing hydrogen production cost is focused on the development of improved catalysts and adsorbent materials as well as more effective single-stage separation processes. An interesting method combines hydrogen reduction catalysis and filtration. Nascent hydrogen is separated from other gases as it selectively permeates the filter. Catalyst filters may be made of gold, silver, platinum, palladium or precious metal alloys (Davis, 2009)."

Jan 1, 2012

By R. V. Higgins, G. B. Shea

"FOREWORDIn the second year of World War II, the petroleum industry in California was taxed to near capacity to satisfy the expanded war demand for petroleum products, particularly fuel oil. With discoveries of crude oil in California declining and known reserves being depleted rapidly, conditions appeared to warrant study of the possibilities of utilizing the outcropping bituminous sandstone deposits in California for obtaining new sources of oil if the war should he prolonged. At conferences in Washington, D. C., with members of the Petroleum Administration for War and the Geological Survey, Bureau of Mines engineers emphasized the importance of determining the extent of those outcropping deposits of oil-impregnated rocks and of developing a practical process for commercial recovery of the contained bitumen to assure, if necessary, a supplementary supply of fuels. The desirability of such a study was recognized, and in July 1943 the Petroleum Field Office of the Bureau of Mines at San Francisco, Calif., in cooperation with the Geological Survey and the Petroleum Administration for War, initiated a study of the bituminouss sandstone problem. It was agreed that all mapping and geological work in connection with the study would be done by the Geological Survey, all engineering studies in developing a process for extracting the oil would be carried out, by the Bureau of Mines, and that the Petroleum Administration for War would aid in final adoption of the results in the field if circumstances warranted such action.Deposits of bituminous sandstones in California occur principally in the immediate region of the Coast Range mountains, notably at Pt. Arena, in Mendocino County, about 110 miles north of San Francisco; near Santa Cruz, in Santa Cruz County; in the Edna area in San Luis Obispo County; in the Sisquoc area in Santa Barbara County; and in the Ojai and Santa Clara Valleys in Ventura County. 4/ In addition oil-bearing sands outcrop near McKittrick and Maricopa, in western Kern County, and along the east edge of the Kern River oil field. Among the several prominent deposits of these source materials, those occurring near the cities of Santa Cruz and San Luis Obispo, and the town of Sisquoc are the largess."

Oct 1, 1948

By T. M. Barczak

This U.S. Bureau of Mines report investigates shield mechanics and component stress development in a two-legged longwall shield for unsymmetric canopy and base contact configurations. Previous studies analyzed shield behavior for symmetric contact configurations. The goals of these efforts are to improve longwall support selection and design. This study provides vital information that will help develop improved procedures for performance testing of longwall supports and will benefit future research to improve support design through stress optimization and evaluation of failure mechanisms. Combinations of six canopy (three symmetric and three unsymmetric) and six base (four symmetric and two unsymmetric) contacts provided a total of 36 configurations for evaluation. Of these 36 configurations, 10 were eliminated because of fixture limitations or shield instability. Controlled vertical and horizontal displacements were applied by the Bureau's mine roof simulator to the remaining 26 configurations. Component responses were determined from pressure transducer and strain gage instrumentation in order to identify contact configurations and boundary displacements that produced maximum loading in each of the support components. This report describes these test results and provides conclusions relevant to critical contact configurations for performance testing of longwall supports.

Jan 1, 1990

By Ernest E. Thurlow

The Geology Division of Northern Pacific Railway Company has adapted to its exploration efforts field procedures for geochemical sampling and semi-quantitative analysis which have been developed through research by the U. S. Geological Survey. The sampling is done in conjunction with reconnaissance geologic mapping on aerial photographs or during field checking of maps which have been prepared largely by photogeologic interpretation.. Stream sediment or soil samples are taken and readily soluble combined heavy metals are extracted with ammonium citrate followed by colorimetric titration with dithizone at the sample site. The effectiveness of this approach has been demonstrated both in positive and negative results, thereby assisting in the elimination of large areas of land from further immediate attention and in providing targets for followup exploration. An occasional sample is submitted for spectrographic analysis as a check on the possible presence of other elements of economic significance. Field laboratory procedures are also being implemented for determining molybdenum, mercury, and other metals which may be valuable in themselves or useful as pathfinder elements in outlining mineralized areas. A lead-zinc occurrence in Oregon and a copper deposit in Montana were readily detected and outlined by stream sediment and soil sampling and a heavy metal anomaly that lacks obvious interpretation has been found in northwestern Montana. Detailed mapping and additional sampling are followed by other exploration techniques if warranted.

Jan 1, 1964

By Robert E. Sorenson

EXPLORATION for deep-seated orebodies in the Silver Belt area of the Coeur d'Alene mining district is complicated by meager surface expressions of diagnostic criteria, lack of knowledge of the significance of specific alteration phenomena, and the great expense involved in the exploration for ore shoots, the tops of which often occur near sea level elevation or below and as much as 4000 ft or more below the surface. Except for the early studies of Ransome and Calkins in 1903 and 1904,[1] little geological work was done in the Coeur d'Alene district for many years, and it is only during the last 15 to 20 years that complete and careful geological mapping has been applied to most of the mines in the area. Much early information, which now would prove invaluable, is lost in hundreds of miles of caved and inaccessible mine openings not mapped by mining geologists. In more recent years mining geology has become a tool of greater use in the district, and some measurable progress is being made in the accumulation of observations that are adding gradually to the knowledge of ore deposits in the district.

Jan 7, 1951

By J. A. Scott, K. Moreau, H. Shang

"Trials of automated technology at underground mine sites around the world have reported increased production and the potential for lower energy consumption. Autonomous mining eliminates a range of delays related to operator downtime and travel to the workface and facilitates continuous operation in conditions that are unsafe for workers. Automation also introduces complexities and safety hazards arising from equipment–personnel interactions; automated processes must be isolated from other stope-cycle–related activities such as production drilling, development, loading, and backfilling, poten¬tially requiring changes to the mine design to maintain an efficient and safe operation. This paper reviews and discusses the implementation of automated equipment in deep underground mining operations and the challenges and advantages associated with the technology. ¦ KEYWORDS Automated equipment, Emissions reduction, Energy, Productivity, Sustainability, Technology, Underground mines RÉSUMÉ Des essais de technologies automatisées dans des sites miniers souterrains aux quatre coins du monde ont indiqué une production accrue et la possibilité de réduire la consommation d’énergie. L’exploitation minière autonome élimine tout un éventail de retards liés aux temps d’immobilisation des opérateurs et aux déplacements vers le front de taille, et facilite l’exploitation continue dans des conditions qui s’avèrent peu sécurisées pour les travailleurs. L’automatisation introduit également des complexités et des risques pour la sécurité, qui surviennent en raison des interactions entre l’équipement et le personnel. On recommande d’isoler les procédés automatisés des autres activités liées au cycle des chantiers telles que le forage de production, le développement, le chargement et le remblai, ce qui pourrait entraîner des changements au niveau de la conception de la mine afin de préserver rendement et sécurité dans l’exploitation. Cet article examine et aborde la mise en oeuvre de l’équipement automatisé dans des exploitations minières souterraines profondes, ainsi que les enjeux et les avantages associés à cette technologie. ¦ MOTS CLÉS durabilité, énergie, équipement automatisé, mines souterraines, productivité, réduction des émissions, technologieINTRODUCTION As the mining industry continues to exhaust easily accessible orebodies, the need for efficient, deep (typically below 2,500 m) mine operations increases (Atlas Copco, 2013a); however, the mining process can become economically infeasible at great depths because operation costs drastically increase. This has resulted in investigations into automating mining operations as the industry strives for improved productivity (Schunnesson, Gustafson, & Kumar, 2009) and ways to remove personnel from hazardous work areas."

Jan 1, 2019

By P. R. Jones

The Bureau of Mines has written a computer program for the design and cost of a shell and tube type heat exchanger, in which a change in phase occurs on the shell side. The total cost, which was minimized, includes the annual fixed charges and annual operating costs. The program was written to meet the following requirements: (1) Triangular pitch, (2) single or multiple pass, and (3) heating or cooling. Price optimum design was obtained for four standard tube diameters and pitch. Standard heat exchangers whose area equaled or exceeded the required area are also listed. The program was made adaptable to various fluids and to various tube dimensions by including many of the required data such as physical properties of the fluids, tube data, and standard shell data as input data.

Jan 1, 1969

By J. Alton Burks

When acoustical materials are used in a mining environment for noise control purposes, they are subject to environmental deterioration from hydraulic fluid, moisture, and dust. These and other factors can cause physical degradation of the material, which can lessen its ability to absorb sound. In this study, the Bureau of Mines measured the sound absorption properties of 16 different acoustical materials after 4 sample treatments: (1) being kept clean and dry (as received from the supplier), as a control or reference standard, (2) immersion in water and draining, (3) immersion in lOO-pct-petroleum-type hydraulic fluid and draining, and (4) exposure in a coal mine. The last three treatments were used to approximate the type of physical degradation that can be experienced in actual use. The impedance tube or standing wave method was used to measure the normal absorption coefficient. It was found that the absorption coefficient of most materials was adversely affected by the retention of either oil or water, with oil having the greater effect. The only class of materials that was affected by neither oil nor water was neoprene foam.

Jan 1, 1990

By R. S. Austin

One third of the world's and most US kaolin is produced from Late Cretaceous and Early Tertiary sedimentary strata in Georgia and South Carolina. The kaolin is part of a belt extending to Arkansas of aluminous lateritic deposits, including bauxite. Original sediments were profoundly altered by chemical weathering during Early Tertiary time. Mining exploits those uncommon deposits where extreme leaching and chemical recombination have produced a clay of nearly pure mineral kaolinite. . Its whiteness, brightness, fine particle size, platelet shape, surface chemistry, and chemical composition make kaolin an important pigment, filler, extender and chemical compound in the paper, paint, plastics, ceramics and catalyst industries.

Jan 1, 1998

By Pierre Pelletier, Christian Pichetie, Dany Pelletier

"IntroductionDuring 1994, Barrick Gold Corporation, or American Barrick at that period, acquired Lac Minerals Ltd. properties. One of them was the Bousquet Complex. The Bousquet Complex is divided into three distinct sites: one mine (Bousquet 2), one mill (Est-Malartic Division) and one analytical chemistry laboratory (Les Terrains auriferes).The Bousquet 2 orebody was discovered in 1986. An extensive drilling program was initiated during 1987. Its purpose was to define the orebody extent. At the end of 1997, gold production from Bousquet 2 mine reached 1 290 000 oz of gold from a cumulative tonnage processed of 4 175 000 M t.From 1980 to 1990, the Est-Malartic mill was used for the treatment of ore from the following mines: Bousquet 1, Doyon, Francoeur (Richmont mines), Buckshot and 1-20 stope. At present, the mill receives ore from the Bousquet 2 mine.HistoryThe Est-Malartic mill is located close to the town of Malartic in northwestern Quebec. The mill has been in production since the mid-1930s processing mainly clean, free mill gold ore. Active mining from the Est-Malartic mine ceased in 1979 and the mill was switched to custom processing of ore from La Mine Doyon located some 45 km to the west. This custom processing arrangement continued until 1987 when the expanded mill at Doyon became available to process all of the Doyon production. In 1987, Lac Minerals commenced development of a second mine at the Bousquet site located 40 km west of Malartic. This mine, Bousquet 2, is the down dip extension of the La Ronde mine developed by Agnico Eagle. During pre-feasibility evaluations, it was determined that it would be economically more attractive to modify the existing Est-Malartic mill than building a new facility on site. The Est-Malartic mill modifications for processing the high-copper/gold ore from the Bousquet 2 mine began in late 1989 and new circuits were commissioned in mid-1990. Modifications included the addition of both gravity and flotation concentration circuits to recover coarse, free gold and the copper. The existing leaching circuit continued to operate on the copper flotation tailings with some minor modifications to the solution handling systems. A S02/Air cyanide destruction circuit was also added at that time."

Jan 1, 2000

By Ned H. Snyder

In recent years the Government and other large consumers of coal have appreciated more and more the desirability of definitely determining by chemical analysis and test the character and quality of the coal they purchase. Higher prices for coal point forcibly to the need of giving more study to engine room and boiler room efficiencies and economies; this implies an intimate knowledge of the character and quality of the fuel used. Analyses and tests of delivered coal furnish data whereby power plant results can be comprehensively studied and a continuous check maintained on the coal and on the conditions of plant operation. Under authority of acts of Congress making appropriations for technologic investigation of fuels and the analyzing and testing of fuels belonging to or for the use of the United States Government, a laboratory is maintained at the Pittsburgh station of the Bureau of Mines, where samples representing deliveries of coal purchased for Government use are analyzed and tested.

Jan 1, 1923

By B. W. Smee

Glacial lake sediments or glaciolacustrine deposits form a significant portion of the Canadian, Scandinavian and Russian landscapes. Furthermore, 50 per cent of the Archean volcanic belts within the Canadian Shield area are covered wholly or in part by these deposits. Because of the high electrical conductivity and low hydraulic conductivity of these compact sediments, the application of geophysical (electrical) and geochemical techniques in such areas becomes a difficult task. The presence of these sediments has therefore hampered exploration for metallic sulphide deposits in some of the most important metallogenic environments of Canada. Similar problems exist in some tropical countries, such as Australia, where the overburden may be very conductive. In this paper, the extent and provenance of the glaciolacustrine deposits within the Canadian Shield are described. The geochemical and geophysical factors that hinder exploration in the clay belts are reviewed, with case histories of successful and unsuccessful applications of some of these techniques. The most successful geochemical technique used within glacial clay belts is the sampling of lodgement till beneath the clay cover, and the analysis of the heavy mineral fraction of that till. Surficial sampling has not been successfully applied. Some geophysical techniques, more specifically electromagnetic and magnetic induced-polarization techniques, have detected mineralization beneath substantially deep clay or saline overburden layers. Some suggestions have been made, such as the use of anions in hydrogeochemical surveys and the use of wide-band multi-frequency EM systems. When implemented, they will hopefully make the current geochemical and geophysical methods more effective in exploration for base metal sulphides within clay-covered terrains.

Jan 1, 1979

By James Westfield

This publication covers the work of the Division of Coal Mine Inspection, Bureau of Mines, as performed under provisions of the Federal Coal Mine Safety Act. It presents background information and data since 1952 when the Act became effective and includes up-to-date statistics for the calendar year 1962. During that year, approximately 9,704 coal mines were active in the United States, and the Bureau made 12,810 regular inspections. BACKGROUND The Federal coal-mine inspection program was established to carry out the provisions in Public Law 49, 77th Congress, (H. R. 2082) approved May 7, 1941. This act has since been amended as Title I, Advisory Powers Relating to Health and Safety Conditions in Mines, under Public Law 552, 82d Congress, approved July 16, 1952, which also included Title 11, Prevention of Major Disasters in Mines. Public Law 552 is known as the Federal Coal Mine Safety Act.

Jan 1, 1963

By Jon A. Carlson, W. Scott Williams

The EKATI"" Diamond Mine commenced operation in October 1998. It is operated by BHP Diamonds Inc., which is a part of the Non-Ferrous and Industrial Materials Division of BHP Minerals, a business unit of BHP Company Ltd. of Melbourne, Australia. The EKATI"" Diamond Mine is a joint venture of BHP Diamonds Inc. (51%), Dia Met Minerals Ltd. (29%), Charles E. Fipke (10%) and Dr. Stewart L. Blusson (10%). In December 1993, an office was opened in Yellowknife, Northwest Territories specifically for the then Northwest Territories Diamonds Project (EKATI"" Diamond Mine) development. EKATI"" Diamond Mine is located 300 kilometres northeast of Yellowknife and 200 kilometres south of the Arctic Circle in the Northwest Territories of Canada (Figure 1 ). The site is located in a remote tundra area of continuous permafrost, north of the tree line, which is part of the Canadian Shield. Wekweti (Snare Lake), a Dogrib community approximately 180 kilometres southwest of the project, is the closest neighbour. The mining area and facilities lie within the 10 960 hectares land leases held by the joint venture. The total claim block (core zone and buffer zone joint ventures) covers 344 000 hectares. To date, more than one hundred kimberlite pipes have been identified within the claims. Five of these provide the basis for the present mine plan. Total capital investment in the project is over C$700 million. At full production employment will be about 600, including employees and long-term contractors, with over 33% being Aboriginal from the Northwest Territories.

Jan 1, 2001

By Francisca Tapia, Jorge Blázquez, Paulo Couceiro, Patricio Vergara, Luis Manriquez, Luis Martínez, Juan Navarro

Efficient energy transmission is critical for effective rock fragmentation in open-pit blasting. However, in zones with highly fractured or soft rock, mismatches in acoustic impedance between the explosive and the rock can lead to significant energy loss. These mismatches reduce fragmentation efficiency and, when energy input is increased to compensate, can trigger unintended side effects such as NOx fume generation. This paper presents a novel methodology that integrates the Fragment Size Energy Fan model with acoustic impedance theory to dynamically optimize explosive energy delivery. A redefined impedance formulation captures volumetric energy transfer and enables the calculation of a Rock Impedance Factor (RIF), calibrated through non-linear regression. To operationalize the model, rock impedance is estimated using the X-4Traits Model—a meta-learning algorithm that interprets Measurement While Drilling (MWD) data from both autonomous and manually operated drills to produce high-resolution, spatially distributed impedance maps. The methodology was calibrated and applied at Minera Escondida Limitada (MEL), using data from over 218,447 blastholes and 526 blasts. Two case studies illustrate its application: Expansion 1 demonstrates improved fragmentation consistency and a 10.7% reduction in powder factor by aligning explosive energy with local impedance variations; Expansion 2 highlights the model’s utility in managing NOx emissions in fractured zones by optimizing energy distribution and confinement without compromising fragmentation. This impedance-based framework provides a robust tool for improving fragmentation outcomes, optimizing energy use, and enhancing control in geologically variable blasting environments.

Jan 26, 2026

By J. Grignon, C. Fleming

It is possible to reproduce the performance of an operating CIP or CIL plant in the laboratory, in small scale batch kinetic tests, coupled with mathematical models that translate kinetic data into predicted steady state gold profiles across multi-stage adsorption circuits. Once the performance of the commercial plant has been mimicked by the model, the plant operating parameters can be varied systematically in the model, and the likely response of the plant to the step wise change can be determined. In this way it is possible to inexpensively optimize the operating conditions of an existing plant, with no disruption to plant operations and no economic risk to the mining company. This approach had been adopted by IAMGOLD to optimize the performance of their Rosebel CIL plant following several major expansions in mill capacity since 2004.

Jan 1, 2011

By John C. Cosgrove

IT was just five minutes past midnight, on Wednesday, Jan. 5, 1938, that Mrs. Cosgrove and I sailed from New York City. Our trip was to completely circle the globe, to cover over 40,000 miles and stop at thirty ports-from New York to Trinidad, to South America, via South Africa to the Orient, to India, to the Malay States, to Indo-China, the Philippines, Australia, New Zealand, Fiji, and across the Pacific home via Honolulu. It is not my intention to make this a complete, technical study of coal or coal mining in the various countries that .we visited but more to outline the general in- formation that the mining engineer and coal operator would absorb in his travels. Coal is the universal fuel and is in use wherever there is commerce and industry. Even on our ship, which, like practically all ocean liners was an oil-burner, a considerable quantity of coal was used for cooking.

Jan 1, 1939

Several primary ingot producers have introduced price changes for July. Howmet Aluminum Corp., Revere Copper and Brass, Inc. and the Anaconda Co, will increase late-July prices of 99.5 percent unalloyed aluminum ingot by 3 cents to 56 cents per pound, Prior to this, Kaiser Aluminum and Chemical Corp. had advanced June ingot values by 4 cents to 57 cents and Consolidated Aluminum Corp., 4.5 cents to 57.5 cents. Domestic merchants held June quotes at a range nearing 50-50.8 cents per pound. ANTIMONY Although NL Industries, since April of this year, stopped publishing prices for RMM and Lone Star antimony grade, values of domestically-refined antimony in alloy are being made available to industry, The current price of this material is $1.75 per pound of antimony contained in alloy, New York dealer-marketed metal was available in June at $1 -13-$1 .20 per pound. Important industrial uses of antimony are for flame retardants, storage batteries, chemicals, pigments, rubber, plastics, glass, ceramics and machinery.

Jan 1, 1978

By H. C. Cooke

Those who have followed the geological developments in connection with the copper deposits of Quebec will recall that on many properties the sulphide bodies occur as replacements of fault breccias or tuff breccias, and exhibit a pronounced distaste for the more massive lavas. At the same time the rocks around the ore-bodies are profundly altered, first by addition of silica and sericite, later by conversion of these minerals into chlorite. It has been known for some years that at the Amulet and Waite-Ackerman Montgomery mines these conditions do not prevail. At both mines the ore-bodies are replacements of massive lavas, and at the Amulet they are associated with a very peculiar rock christened ?spotted dog', or 'dalmatianite'. Accordingly, when in 1929 the writer had the opportunity to make a further examination of these properties, two problems presented themselves for solution. The first was to determine, if possible, the conditions under which massive lava, rather than breccia, is replaced by the sulphide masses; the second, to find out the exact nature of dalmatianite and its relations to the sulphide bodies. The first of these problems is believed to have been solved; the second has been found very complex, and will require further work before it is satisfactorily settled.

Jan 1, 1930

By C. McLachlan, J. R. Donald

"Positioned at the forefront of the seafloor minerals industry, DeepGreen Resources is on track to becoming a leading producer of base and strategic metals obtained from vast high-grade seafloor polymetallic nodule deposits. DeepGreen believes the seafloor minerals industry is an opportunity for developing a more environmentally and societally attractive way to produce cleaner base and strategic metals. Polymetallic nodules contain nickel, manganese, copper, cobalt and other base and strategic metals. Polymetallic nodules represent an exceptional multi-metal-bearing resource, and no current metallurgical operation or flowsheet exists that can recover the primary metallic values while managing the distinct mineralogy. DeepGreen Resources is developing a new process to maximize the business outcomes consistent with the highest environmental standards, including targeting a near zero waste facility. The present paper discusses the history, context and driving forces of polymetallic nodule project development. An overview of DeepGreen?s Nauru Ocean Resources Inc. (NORI) project is presented along with a literature review of polymetallic nodule processing and the on-shore project development scope and plan at DeepGreen Resources is outlined.INTRODUCTION AND CONTEXT Polymetallic Nodules in the Clarion-Clipperton Zone Containing nickel, cobalt, copper and manganese, polymetallic nodules occur in most oceans of the world. The nodules lie on the seafloor sediment. The largest deposit in terms of nodule abundance and metal concentration occurs in the Clarion-Clipperton Zone (CCZ) on vast abyssal plains at a depth of 4,000 to 6,000 metres. The CCZ is located almost entirely in international waters as presented in Figure 1. It has been estimated that the CCZ contains (International Seabed Authority, 2010): •,>21 billion tonnes of nodules; •,>270 million tonnes of nickel; •,>6 billion tonnes of manganese; •,>234 million tonnes of copper; •,>46 million tonnes of cobalt. There are several active hypotheses for the mechanism of formation of the nodules including precipitation, hydrothermal decomposition of basaltic debris, and involvement of microorganisms. Nodules require a nucleus to start forming, which could be a piece of pumice, a shark tooth, old nodule piece, basalt debris or even microfossils like radiolaria and foraminifera. Nodules form concentrically with layers of iron and manganese hydroxides around a core. Although composed mainly of Mn, Fe, silicates and hydroxides, it is the significant content of Ni, Cu, Co, Zn and Rare Earth Elements (REE) that is generating the economic interest in harvesting these deposits. Nodules vary in size from micro-nodules to about 20 cm, the common size being two to eight centimeters. A typical polymetallic nodule and polished cross-section is presented in Figure 2."

Jan 1, 2017