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By M. Karmis

The algorithms for the mathematical modeling to predict productivity of underground room-and-pillar mining systems are well known and documented. These algorithms consider the time-varying relationships between mining equipment for a given geometry of operations as well as other constraints. This paper presents WebConSim, a newly developed, Web-based, user-friendly computer simulation tool for the Windows environment. The simulator is easily customized for use by field engineers, planning engineers, and management and will help mine operators plan the optimum mining sequence for different mine geometries and equipment layouts. Program output includes production data and equipment utilization indices, as well as time driven event chains that can be used for virtual reality presentations.

Jan 1, 2001

By J. D. Miller, R. J. Smith

Earl C. Herkenhoff Publication of the article "The Flotation Behavior of Digested Asphalt Ridge Tar Sands" by R.J. Smith and J.D. Miller has confirmed and again spotlighted a most significant and important development in the field of tar sand and heavy oil mining. This is the ability to recover 95 % of the bitumen in dry tar sands by a hot water process. The initial investigation by Miller and Sepulveda in early 1978, "Separation of Bitumen from Dry Tar Sands," was the first blockbuter. It is disappointing that there has been so little scientific and industry ackowledgement that the authors laid to rest the long entrenched belief that the sand grains had to be "water wetted" for a hot water process to be applicable. Dr. Miller and his researchers at the University of Utah used slightly different mineral dressing terminology in describing their process but it is essentially the old, established technique of high solids attrition scrubbing at elevated temperatures with a conditioner or modifier, followed by dilution and froth flotation. Similar techniques were described in detail for other nonmetallic minerals in the mid-1940s by Stuart Falconer of American Cyanamid Co. The authors used a 15-minute "scrub" period (or in their terminology "digester step") at 73% solids and 95°C (203°F) in a 0.3 m solution of sodium carbonate -about 4 kg/t (8 lb per st) of tar sand. Flotation was at 10% solids. Obviously, the scrub is an expensive step with respect to energy input but the high recovery of bitumen appears to justify it. Two basic questions then arise: • What are the effects of shorter scrubbing time, lower temperature, and less sodium carbonate? • Would a two-stage approach be advantageous? That is, could you get the major proportion of the bitumen with a mild scrub and apply the high power and temperature only to the refractory portion? These variables should be evaluated. Apparently, all results were only for rougher flotation. What would the grade and recovery of bitumen be if multiple cleaner flotation steps were employed? We must concede that a 60-62% grade of bitumen leaves considerable room for upgrading. Finally, it should be noted by all executives who approve funds for heavy oil recovery schemes, most of which are variations of in-situ methods, that mining can yield a 95% recovery of bitumen. That is correct, 95%. Imagine what that does to the total barrels recovered from a heavy oil resource compared with the scrawny 30-35% maximum recovery we are getting now. The conclusion-let's mine heavy oil and tar sands. Reply by R.J. Smith and J.D. Miller We, too, share Mr. Herkenhoff s enthusiasm for the mining of tar sands-heavy oil and continue the development of related processing technology. Specifically, it will be noted that by appropriate control of bitumen viscosity in the feed (probably the most important variable for successful separation) the recovery can be accomplished at low digestion temperature and low addition of alkali. A 91 t/d (100 stpd) pilot plant based on our technology is now being operated by Enercor in Salt Lake City (Hatfield, Oblad, and Miller, 1982). In these same pilot facilities, rougher concentrates containing more than 80% bitumen on a dry basis are being produced from Asphalt Ridge Feed. However, the processing of certain other tar sands results in incomplete digestion of bitumen/sand aggregates as discussed elsewhere (Miller and Misra, 1982). Such undigested aggregates are shown in Fig. 1. In this regard, it is intended that a recycle stream will be installed in the pilot plant to provide for redigestion of middling products. Further details regarding surface chemistry aspects of this tar sand technology have recently been published (Misra, Aguilar, and Miller, 1981). References Hatfield, K.E., Oblad, A.G., and Miller, J.D., 1982, "Pilot Plant Recovery of Bitumen from Oil Wet Tar Sands," Processing, Second International Conference on Heavy Crude and Tar Sands, Caracas, Venezuela, Feb. 7-17. Hatfield, K.E., Oblad, A.G., and Miller, J.D., 1982, "Pilot Plant Processing of Oil-Wet Tar Sands," Symposium, Rocky Mountain Fuel Society, Salt Lake City, Utah, Feb. 18-19. Miller, J.D. and Misra, M. 1982, "Hot Water Process Development for Utah Tar Sands," Fuel Processing Technology, Vol. 6, No. 1, April, pp. 27-49. Misra, M., Aguilar, R., and Miller, J.D., 1981, "Surface Chemistry Features in the Hot Water Processing of Utah Tar Sand, Proceedings, "Symposium of Separation Science and Technology for Energy Applications," Gatlinburg, Tennessee, May 5-8.

Jan 11, 1982

By R. P. Proulx

The Meikle Mine is a high grade, underground goldmine utilizing primary-secondary longhole open stoping with delayed backfill to produce 2700 tpd(3000 stpd) of ore. Hot and reactive ground conditions were encountered early on in the mine life. Ground temperatures up to 166°C (330°F) were measured. In the early stages of mining, the mine experienced premature detonations using different explosive products. The learning curve to safely mine this high-grade gold deposit in hot and severely reactive ground was indeed very steep. Currently, the Meikle Mine uses a special buffered bulk emulsion in all blasts to address hot and reactive ground concerns. In addition, exacting procedures are also followed to ensure safe work with explosives. The combination of new explosives technology and strict loading procedures permits high mine productivity with the highest degree of safety.

Jan 1, 2000

By Kazuya Naito, Nobuyuki Okamoto, Natsumi Kamiya

JOGMEC (Japan Oil, Gas and Metals National Corporation) became the first entity to sign an exploration contract for Cobalt-rich Ferromanganese Crusts (Crusts) with the ISA (the International Seabed Authority). The contract was signed on 27 January 2014, and 15 years exclusive rights for exploration activities had started in the contracted area, located in the North-Western Pacific Ocean. JOGMEC had already conducted basic scientific surveys around the contracted area from 1987 to 2012. Activities by JOGMEC that will be undertaken during the first 5 years of the contract include examination of geological and acoustic surveys, environmental baselines surveys, and undertaking basic studies of R&D in mining, processing, and smelting technologies. Geological surveys will include analysis of rock core samples, using BMS (Benthic Multi-coring System). Deep-towed TV Camera will be used to estimate the distribution of crusts deposit and to get basic environmental data of deep-sea megabenthos. Water sampling, marine sediment sampling, and installation of mooring systems on the seafloor will also be conducted as a part of environmental surveys.

Sep 1, 2014

By T. Pool

Introduction After two decades of contraction and consolidation, the uranium industry has seen a recent major expansion. Rapidly increasing uranium prices and the ability to raise speculative capital in share markets worldwide have brought over 300 new participant companies into the uranium industry: “juniors” as they are known. These companies participated in a global land rush for known deposits as well as for prospective land positions in order to secure a “piece of the action” for their respective portfolios. Mostly publicly-traded companies, these “juniors” have captured the attention of world’s investing public with spectacular gains; as much as 1,000s of percent in less than four years. The initial phase is over, however, and these companies must now prove that they can be successful in exploration or production.

Jan 1, 2007

By George A. Mealey

Caving mining methods that are based on a planned caving of rock above and/or at times surrounding the material being mined can be classified in three broad categories: longwall mining, sublevel caving, and block caving. Each of the three methods involves a distinct technology as well as art of operation. Each requires a relatively large, regular, and predictable ore body. As a rule, the effect of mining results in some form of impact or change on the surface. Operationally, underground caving methods are characterized by high productivity as well as a high percentage of extraction of the mineral being mined. A key element for the productivity of this form of mining is the ability to standardize the various elements of work taking place underground. Therefore, work-men may perform a specialized role rather than function as all-around miners. Further, the nature of the mining methods lend them to a high level of mechanization. Operations and manpower can be centralized into a relatively small area where supervision can be concentrated and therefore be more effective. Productivity as well as safety benefits thereby. The caving method is unique in that the exploitation openings are deliberately destroyed by the process of mining. Rock mechanics principles focus on the ensurance and the propagation of the cave as well as the continuance of the mine openings designed to extract the broken ore. As a rule, production operations are designed to maintain a steady, continuous flow of ore from the extraction areas. This steady flow rather than an intermittent flow tends to promote good caving action as well as reduce hangups.

Jan 1, 2008

By G. B. Amicucci

Golden Sunlight Mines Inc. operates an open-pit gold mine and cyanidation plant about 11km (7 miles) northeast of Whitehall, MT. Golden Sunlight is a subsidiary of Placer Dome US Inc. Mining is accomplished with conventional open pit drilling, blasting and hauling methods. The mining rate is about 102 kt/d (113,000 stpd). Gold occurs as fine-grained disseminations in a pipe-shaped breccia and in immediately adjacent country rock. The ore body is low grade, averaging 2 g/t (0.059 oz per st) of gold. The metallurgical plant uses conventional carbon-in-pulp (CIP) technology. Daily throughput averages 6.5 kt (7000 st). Recoveries are enhanced through a sand tailing retreatment facility while a preaeration process reduces operating costs. The low grade ore dictates that maximum mill throughput at the desired grind size be maintained. Therefore, in October 1988, an Armco Autometrics (now Denver Autometrics) particle size monitor (PSM) 400 was commissioned. The PSM 400 is an on-line instrument. It measures particle size and percent solids in a slurry stream. The PSM pulls its own sample, deareates the sample and passes it through diametrically opposed ultrasonic sensors. The unit uses ultrasonic sound to measure the deareated slurry stream's particle size and percent solids.

Jan 1, 1991

By Roger K. McLimans, Venkatramaiah N. Vasudev, Christian Knudsen, Stefan Bernstein, Dirk Frei

Computer Controlled Scanning Electron Microscopy (CCSEM) analyses of sediment samples from coastal regions of Kerala and Tamil Nadu states and the heavy mineral deposits of Chavara, South India, show large lateral differences in the titanium content in ilmenite due to varying degrees of iron leaching. As the depositional environments for the sands with varying degrees of ilmenite alteration are comparable, the cause for the different degree of alteration is due to differences in the primary source of the ilmenite or to differences in the geochemical history of the ilmenite grains during transport from source to deposit. The CCSEM analyses of the heavy mineral fractions show that source of sediments with a high content of titanium-enriched ilmenites, mainly the heavy mineral deposit around Chavara, resides in the khondalite belt of South India (granulite facies metasediments). The less titanium-enriched ilmenites are sourced from other rocks in the area such as the charnokites. Those conclusions are based on the high MgO content in the leached ilmenites, chemical composition of the accompanying garnets (low CaO and high MgO), and the concentration of aluminum-rich minerals in the sands.

Jan 1, 2005

Traditional loading systems have relied for many years on wheel and track loaders, power shovels, conveyor belts, and more recently, hydraulic front shovels. Each has certain advantages and disadvantages, depending largely on job conditions. Hydraulic backhoes were introduced several years ago as still another truck loading option. At first, buckets were small and backhoe use was limited to small earthmoving projects. Now, as backhoes are equipped with shorter sticks and bigger buckets to move larger quantities of earth. The "mass excavation" concept offers an excellent truck loading option in many situations. System Development and Advantages Mass excavation was first used successfully by contractors in site development and highway construction, loading both on-highway and off-highway trucks. Operators were able to take advantage of the excavator's ability to work in poor underfoot conditions and dig in tough materials. The technique was first applied to mining in the kaolin mines of central Georgia. Kaolin, one of the world's most abundant minerals, is used to make paper, paint, ceramics, rubber, plastics, and many other products. Since kaolin clay is slippery when wet, load-out with wheel loaders is very inefficient. Also, kaolin is found in very spotty deposits due to the weathering process involved in its formation. Consequently, draglines are also impractical for kaolin mining since they don't have the mobility to move between clay deposits. In response to these mining conditions and kaolin characteristics, mines began using excavators in mass excavation as early as 1976. They have developed a system that takes advantage of the excavator's •high penetration and breakout force in tight materials; •fast-cycling hydraulics; •ability to work in poor underfoot conditions; and •mobility in comparison to draglines. This loading method has been successful in Georgia's kaolin mines and now can be applied to other mining operations as well. The excavator's ability to carefully dig spotty ore deposits is an asset at uranium mining operations. Any mine can take ad-

Jan 3, 1982

By C. J. Burkhalter, H. Andrade, T. C. A. Gardner, J. P. Campbell

During the 1990’s several copper heap leach facilities treating crushed and agglomerated oxide and sulfide ore were constructed in South America. The majority of these facilities have been in operation for at least three years, during which time the operators have been able to monitor the performance of the heaps. The basis for the paper is a compilation of these operators’ experiences, leading to a discussion of the lessons learned over the past decade. Several key geotechnical issues are examined, focusing upon the integrity of the ore, drainage material and pipe network, along with the success of any inter-lift liners.

Jan 1, 2002

By Ralph W. Barbaro

In the mineral industry, the objective of a mining venture is to extract, process, and market a mineral commodity in such a manner that the profit of the venture is maximized. In a mining venture, a company normally has control over mine production scheduling, the selection and location of processing facilities (mineral beneficiation plants, smelting plants, refineries, or blending facilities), processed ore blending, and the selection of markets. The flexibility of the above factors provides many alternatives to satisfy the needs of each market with regard to quantity and quality of ore. The purpose of this paper is to present a mathematical model for determining the alternative that yields the maximum profit. Production planning is generally concerned with the best utilization of fixed resources, more specifically, with the determination of production and inventory levels to meet fluctuating demand requirements. A mine can be any source of ore such as an entire mine, a production unit within a mine, or an independent supplier. The objective of production scheduling is to determine the times at which each mine will be used and to allocate a required level of production. Production planning and scheduling problems are intimately associated with the location of new and existing mines and processing facilities. Although the location of the mines is usually fixed, there can be considerable flexibility in locating new processing facilities, in the selection of the processing plant, and in blending the ore before and after processing.

Jan 1, 1983

By Y. C. Kim, I. S. Roditis, P. K. Medhi

P. Mousset-Jones I found the article most interesting and timely. I consider it imperative that mine case studies like this one are undertaken and published so that the practicing mining engineer and geologist can obtain a better idea of what is the preferred estimation and grade control technique to use, given the site-specific geology, grade distribution, etc. Mining companies, with operating gold mines, need to be encouraged to either initiate such a study in-house or support a research project by financing a graduate student at a local university. The latter method is preferable since it not only provides research support but also an excellent training opportunity for young mining engineers and geologists. Ideally, what is needed is exploration drill-hole, blasthole, and mine production data that can then be used to assess the efficiency of different estimation and grade control methods by comparing the results obtained using the drill/blasthole data with the actual production data. It is hoped that more mining companies will realize that the rewards from this kind of research greatly outweigh the sometimes perceived problem with releasing data to a university. I noticed that the authors used the blasthole data to represent the actual values, the validity of which relies heavily on the two key assumptions with regards to blasthole assays and in-pit ore-waste selection procedures. Could the authors comment in more detail on these assumptions and what criteria they used to check the validity of the assumptions? Since the article was published, have the authors had the opportunity to compare their estimates with the actual production data? It would be interesting to compare other estimation methods with OK and IK. For example, how well did the polygonal method used at the mine compare with the results given in the paper? I would like to mention that B.L. Kwa completed a similar study (Kwa and Mousset-Jones, 1986) using exploration drill-hole, blasthole, and production data from the Alligator Ridge mine in Nevada. The study compared a variety of estimation methods, including IK, and the final results are shown in Fig. 1. The IK method exhibits the smallest difference between estimated and production results and is closely followed by the indicator moving window (Ind MW) method. Reference Kwa, B.L., and Mousset-Jones, P., 1986, "Indicator Kriging Applied to a Gold Deposit in Nevada," Proceedings, Symposium on Ore Reserve Estimation Methods, Models, and Reality, CIMM Annual Meeting, Montreal, Quebec, Canada, May, pp. 185194. Reply by Y.C. Kim We do concur with Professor Mousset-Jones with respect to the merit of such case studies performed at a local university. In answer to his request for comment on the validity of the two key assumptions made in our paper, we can only say that these are reasonable assumptions that are very difficult to validate. The assumption of blasthole assays being accurate can be partially validated by a careful analysis of the nugget component of blasthole variograms. The assumption that the in-pit ore-waste selection procedure in use was an effective one can only be validated through comparison between the mine estimates of ounces of gold versus the actual recovered ounces of gold at the mill. Neither one of these two assumptions has been validated to date due to several reasons. For example, the mine went through a change in management since the study. Similarly, no compelling reasons have been presented to perform detailed variogram analysis of the blasthole data. We do, however, believe that the obtained results (i.e., indicator kriging performs better than OK in a highly skewed deposit) will remain the same in relative terms, regardless of how valid these two assumptions may be. The most recent comparative study by D. S. Lindsey of the Montana College of Mineral Science and Technology also shows a similar ranking between ordinary kriging versus probability kriging, which is an extended version of indicator kriging. Reference Lindsey, D.S., 1987, "A Comparative Study: Probability Kriging vs. Ordinary Kriging at the Golden Sunlight Mine," MS Thesis, Department of Mining Engineering, Montana College of Mineral Science and Technology, Butte, MT, May, 81 pp.

Jan 3, 1988

By S. Veeramasuneni, C. D. Dunbar

The rate of hydration influences many important physical properties of gypsum. Previous research examined the rate of gypsum hydration and related this to compressive strength and microstructure development using BET specific surface area analysis. The analysis of gypsum porosity in combination with BET surface area and rate of hydration remains to be done. In the present study, mesoporosity is analyzed using the numerical method of Barrett, Joyner and Halenda (BJH) to gain a greater understanding of gypsum hydration and microstructure development. The rate of hydration has a significant effect on mesoporosity of the gypsum matrix. The results reveal the effect of mesoporosity and hydration rate on some macro physical properties of gypsum.

Jan 1, 2000

By V. F. Hollister

Although it is apparent that porphyry copper deposits may have formed in the Andean orogen from Permian time onward, commercial deposits thus far developed appear to have Cenozoic ages only. Following Chilean useage, the porphyry deposits are divided into either: (a) a stockwork, or (b) a tourmaline breccia model. Stockwork type deposits tend to occur on major strike-slip structures which may be either transcurrent or transverse faults related to plate movements, while the tourmaline breccia type may more frequently form independently of regional faults. Stockwork types may be conjugate fractures that intersect and ramify as a network of veins and veinlets, cutting altered rock, and genetically related to a major regional fault, or in other cases they may reflect the intersection of two large fault structures. Circular fracture patterns may more rarely occur in stockwork deposits in response to a specific intrusive. Tourmaline breccia types are characterized by circular and radial fractures genetically connected in some way with tourmaline breccia pipe development or an intrusive piercement that preceded it. Each structural model contains mineralized intrusive8 which have a close time-space relationship to ore and in each model, mineral paragenesis is similar, regardless of age or location in the plate. Also, each model contains the same type of alterntion halos (phyllic, argillic, prophllitic) as are developed in intru- sive centers in porphyry copper deposits found in North America. The potassic zone is exposed best in the older deposits. Examples of each type of deposit are illustrated, demonstrating the feature evolved.

Jan 1, 1973

By H. D. Brenk

"The German Federation of International Mining and Mineral Resources (FAB) is a federation of German companies that are active in international mining and mining related business. The FAB presents a platform for the exchange of information about the worldwide mining commodities in the dialogue with German and foreign institutions. The expertise of the member companies in mining and related activities is based on a long term operation and consulting experience in Germany and abroad. This forms the basis for the special international competitiveness "Made in Germany". The FAB is particularly engaged in the following topics and tasks and acts as a focal point for: • international project developments with the German mining industry, • sustainable mining, consulting and equipment services, • geological and environmental technologies, • project financing and • intermediation of contracts, project enquiries, professional symposia and events. The FAB acts as a contact- and coordination site for international business partners, organizations and governmental authorities. Together with the federal government the FAB organizes bilateral working group meetings in the commodity and mining sector. Project enquiries are being distributed from the FAB among their member companies."

Jan 1, 2011

The speed and internal accuracy of today's electronic calculators can be utilized to write an efficient slurry calculation program. The calculator's input/output printing feature offers additional benefits for data organizing and record keeping. This program allows slurry calculations to be performed without the urgency of immediately transferring a calculated result onto a process flowsheet or specification sheet. The number of flowsheets required for some hvdrometallurgical processes means the number of process stream blocks or ladder diagram entries can become substantial. Slurry calculations for such projects tend to become repetitious and tedious, and the chances for errors increase both in calculation and data entry onto process documents. Using this program has minimized both types of errors. Checking process flowsheets is particularly expedient with the program because you may "walk" through the flowsheet on a weight basis, i.e., solids rate and solids density, and have the program verify and/or correct the volume entries, gallons, and specific gravities. The program was initially used on a beneficiation project to check some 500 data entry values on ladder diagrams covering seven process flowsheets. Numerous hand calculation errors were determined and corrected, and the time for completely checking and correcting the flowsheet ladder diagrams was substantially reduced.

Jan 4, 1981

By M. Lohk, Y. -. R. Pastarus

Oil shale industry of Estonia provides a significant contribution to the country’s economy, but causes a large number of different problems. In spite of high economical parameters of the current underground mining (room-and-pillar) technology it is not effective. Backfill technology will be applicable in condition of Estonian oil shale mines. Nowadays attention has been focused on the use of combustion and mining by-products as filling materials. Use of ash and limestone in mining industry is treated as a part of mining technology, not as a waste disposal. Underground utilization of wastes reduces the volume and area required for surface disposal, environmental taxes. It improves the quality of mining works. The use of backfill technology has great impact on mining practice in Estonian oil shale industry.

Jan 1, 2011

By Sabina Brady

Nearly a decade and a half after the US and China established formal diplomatic relations, and two decades after the two countries signed the Shanghai Communique and established commercial ties, the world, and perhaps China itself, has discovered that a wealth of natural mineral and energy resources lie beneath China's soil and directly off its coast. The country's coal reserves and oil and gas potential are well known. Its ferrous and nonferrous metal reserves are respectable and in a number of instances pre-eminent. According to 1981 Minerals Yearbook estimates - more often than not below those now being claimed by China - the country's aluminous metal reserves are about 907 Mt (1 billion st); iron ore reserves are 40 Gt (44 billion st); and copper reserves are about 46 Mt (54.4 million st) of contained metal. In addition, the country has about 10.7 Gt (11.8 billion st) of phosphate reserves, the fourth largest in the world, and 3 Gt (3.3 billion st) of pyrite. China's national Sixth Five Year Plan promulgated in late 1982 ended a stringent three-year retrenchment or readjustment period in which a number of major development projects involving foreign participation initiated in the late 1970s were shelved. The new Five Year Plan is a signal both within and outside of China that things are now moving again, and that major industrial and service sectors are receiving the kind of funding and flexibility they need for expansion, construction and modernization. The new plan's strategy for growth is measured and much less grandiose and frenetic than it was five years ago when China flung open its doors to foreign companies and invited participation in large-scale development projects. Now, the country's reticence to spend foreign exchange to purchase key equipment, technology, and services -a reaction to these projects and the spending they entailed - is clearly on the wane. In China's effort to quadruple its GNP by the year 2000, there is a new willingness to use some of its substantial foreign reserves. In fact, it is projected that 1983 will witness a $1.9 billion deficit, with a $2-3 billion deficit in 1984 and 1985. The following article discusses implications the Sixth Five-Year Plan has for nonferrous metal development in China. It is the first in a series of three articles on Chinese mineral resource development to be published in Mining Engineering over the next few months. The second article will identify specific nonferrous projects underway, while the third in the series will focus on trade and development opportunities for phosphate and potash producers in China. China's Ambitious Plans In the last few months, the exploitation of China's nonferrous resources and development of its industrial processing capabilities have begun to receive increasing attention on both provincial and central levels. Unlike the earlier modernization drive of 1978 when China's ferrous sector - best typified in the Baoshan iron and steel project - got the lion's share of the Ministry of Metallurgical Industry's (MMI) energy and resources, it now appears that in some respects the nonferrous and industrial sectors are finally moving out from beneath the dominating shadow of ferrous and getting their own day in the sun. Separation of Nonferrous from Ferrous One clear demonstration of this is the establishment in April 1983 of the China Nonferrous Metals Industry Corporation (CNFMIC). The corporation is composed of 819 enterprises with over a million workers, and also includes 12 nonferrous metal construction companies, eight design institutes, and three prospecting companies. Of ministerial rank, CNFMIC is responsible for the development of both the country's nonferrous resources and its processing facilities. Although closely tied to the parent ministry from which it sprang (i.e. MMI), CNFMIC, at least theoretically, is separate and independent from it. One strong indication that this independence is, or soon will become a reality, can be seen from the fact that the new corporation is not headed by the former MMI officials, not even those who made up the ministry's now defunct nonferrous bureau. Instead, its president Qiu Chunfu is formerly of the State Economic Commission and the China International Trust and Investment Corp. Its general manager Fei Ziwen, an engineer in his early 50s, is from the Jiangxi Province Copper Corp. The new nonferrous corporation appears to be powerful

Jan 7, 1983

By Susana Bolhão Muiños, José Hipólito Monteiro, Martin Frank, James R. Hein, Henrique Garcia Pereira, Fátima Abrantes, Tracey Conrad, Luís Gaspar

In spite of all the work that has already been done on ferromanganese deposits, studies on the Atlantic Ocean occurrences are still in their infancy and there is a clear need for investigations concerning the origin, distribution, and resource potential assessment of these deposits. Nevertheless, studies already carried out on northeast Atlantic seamounts indicate the general presence of ferromanganese deposits of hydrogenetic origin, i.e. deposits formed by direct precipitation of colloidal, hydrated metal oxides that are scavenged from the water column on hard-rock substrates. The hydrogenetic precipitation promotes the enrichment of ferromanganese crusts in many trace metals, most of which are of economic interest, such as Co, Ni, Te, rare earth elements, and platinum-group elements and thus ferromanganese crusts are considered an important metal resource.

Sep 1, 2014

By Randall J. Essex

The Construction Institute of the American Society of Civil Engineers recently published the second edition of a 1997 publication on geotechnical baseline reports. The new publication, called Geotechnical Baseline Reports for Construction, Suggested Guidelines, represents a 2-year effort that adds three new chapters to the original publication, as well as capturing practitioner commentary through two industry workshop sessions. The paper will overview the contents of the new publication, particularly the three new chapters.

Jan 1, 2008