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By Srisharan Shreedharan, Gang Huang, Hongqing Song, Sijing Cai, Pinnaduwa H. S. W. Kulatilake

"Subsidence prediction due to ore extraction and backfilling during open stoping operations for an underground iron mine in China is reported in this paper. Geologic complexities including faults and interfaces between different lithologies, and the stoping and backfilling sequence adopted from the mine plans are incorporated in building a 3-D discontinuum numerical model. The stoping was simulated in two vertically stacked horizontal layers (Fig. 6), with a total of 16 stopes. Large displacements of up to 50 cm were predicted by the model along the roof of the stopes, and a maximum surface subsidence of 22.5 cm was predicted by the model . Backfilling was found to control subsequent deformation and subsidence. The extraction of the upper orebody led to relatively higher deformations in extracting the lower orebody. Finally, the predicted subsidences at all locations along a subsidence profile on the surface are shown. INTRODUCTIONThe Luohe iron (pyrite) mine, located in Hefei city, Anhui, is an underground mine in China, being mined through the open stoping and backfilling method. The orebody lies at a depth of about 400 m and has an average thickness of 250 m (Magang Steel Company, 2012a). Discovered in the 1960s, the location has a reserve estimate of 300 million tonnes, which have been mined since 2007. The orebody has been divided by the mining company into an east and a west section to facilitate planning for ore extraction.Figure 1 shows the surface above the underground mine, which is seen to contain many human settlements including villages, pastures and other infrastructure. These locations are sensitive in that they need to be protected from potential adversities due to the underground mining, such as surface subsidence. While it may be near impossible to completely eliminate the subsidence due to ore extraction, operations such as backfilling have been adopted by the mine in an effort to substantially reduce it. Hence, this paper focuses on describing the stability of stopes in the mine and estimates future subsidence in a part of the mining region through numerical modeling."

Jan 1, 2016

By James Lett

The role of pre-conditioning in a caving operation has multiple benefits, ranging from assisting with improved caveability, normalising fragmentation and improving draw point hang-up frequency. At Newcrest Mining’s Cadia Operations, both the Ridgeway Deeps block cave the Cadia East Panel Cave have utilised pre-conditioning using hydraulic fracturing. Seismic response data inside and outside the pre-conditioned volume show the benefit of treating the full caving block. Cadia East has further developed pre-conditioning to mitigate developing seismic hazards associated with major structures (fault-slip events) and managing mine-wide seismic hazards in new caving operations where the potential for large damaging seismic events exists due to high stresses and hard competent rockmasses. A case study reviewing the impact of pre-conditioning to mitigate seismic hazard associated with fault slip is presented. Cadia East operation undertook a targeted hydraulic fracturing program and reduced the overall number of large events as an example of the benefits of pre-conditioning. This paper will review the application of Hydraulic Fracturing at Cadia and discuss the geotechnical and seismological parameters of seismic events that occur within and outside of pre-conditioned rockmass volumes to demonstrate the benefits that Hydraulic Fracturing bring to future caving operations.

Apr 26, 2022

By R. B. Ellestad

Introduction Lithium has been known since 1817, when it was discovered by the Swedish chemist, Arfvedson, while working in the laboratory of Berzelius on the chemical analysis of the mineral petalite, LiAl(Si205)2. Development of the chemistry of lithium proceeded slowly, following the early work of Davy, Gmelin, Bunsen, and Matthiessen. Approximately seventy years elapsed before lithium products assumed any commercial importance, and for a considerable period it was a' very minor industry. Their chief early use seems to have been in medicine, and in the production of lithiated water. Other more important uses were gradually discovered, and the industry has had a slow but steady growth. Chemistry Lithium is classified as an alkali metal, along with sodium, potassium, rubidium, and cæsium. Like these, it is a silvery-white metal, which can be cut with a knife; it is harder than sodium, but softer than lead" It is remarkable in having a density of only 0.53 gram per cubic centimeter, which makes it the lightest metal. On ignition in air, it burns intensely to form chiefly lithium monoxide, Li2O. Like the other alkali metals, lithium reacts vigorously with water to form hydrogen and lithium hydroxide. The later is a strong base, and reacts with acids to form salts. The salts of lithium are in general analogous to those of the -other alkalies, but many of them have unique properties. For example, lithium chloride and bromide are extremely hygroscopic, and have a very high water solubility. Lithium fluoride, phosphate, and carbonate, on the other hand, are all relatively insoluble, unlike the corresponding sodium and potassium compounds. In this instance, lithium exhibits its frequent tendency to resemble the alkaline-earth group of elements (calcium, strontium, and barium). Many of the special and valuable properties of lithium are related to the extremely small size of the lithium ion.

Jan 1, 1948

By David M. Rubio

The Ortiz Mine is an open pit-heap leach gold operation in central New Mexico processing about 3,100 tonnes (3,400 short tons) per day. It is the initial mining property in the United States developed by Gold Fields Mining Corporation, a subsidiary of Consolidated Gold Fields, PLC. This paper discusses the evolution of the present mining and ore control procedures as adaptions to the characteristics of both the rock being mined and the orebody, and with respect to the fact that mining is done by a contractor.

Jan 1, 1984

By Frank A. Stephens

The process of converting iron ore (principally Fe,03 or Fe30,) into iron carbide (Fe,C) to be used as feedstock for steel-making yields complex mixtures of several Fe-containing compounds as a function of processing conditions. In addition to the above compounds (hematite, magnetite and cementite), the mixtures typically contain wustite (FeO) and metallic iron(Fe). Mossbauer spectroscopy has been developed into aquantitative analytical method for monitoring the degree of conversion to carbide from samples periodically extracted from a fluidized bed reactor type of pilot plant. Calibration of absolute quantities of the above five compounds is based on standards prepared from known mixtures of the high purity individual phases. The PC-based spectrometer allows fitting of the well-known spectral components of each of the five phases, the resulting spectral areas then being compared with the calibration curves via PC software to yield the weight fraction of each. Emphasis has been placed on standardizing and simplifying the analysis procedure for routine use in an industrial environment.

Jan 1, 1993

By Robert G. Boutilier

So far, most social performance monitoring systems have not gone beyond listing the impacts on various stakeholders. Executives have had to rely on intuition to devise interventions that would improve the impacts. This paper describes a survey process, known as the Stakeholder 360 (S360), which eliminates much of the guesswork. The paper reviews key studies showing that raising the levels of communication, trust, and common vision among stakeholders leads to the acquisition of the resources needed to improve the socio-economic situation. Therefore, the Stakeholder 360 measures the levels of these three factors in the relationships between a company and its stakeholders, and among the stakeholders themselves. In a validation study at a gold mine in rural Papua New Guinea, the S360 produced a socio-political ?roadmap? that showed management and stakeholders alike which relationships need more communication, trust, or common goals/vision. Management used the findings to create alliances that helped the government move forward on a regulatory regime for the mine closure. The community used the findings to focus its planning for life after the closure. An S360 survey conducted six months later revealed a decline in dependence on the mine and an overall increase in levels of mutual understanding.

May 1, 2002

By S. C. Tadolini, J. M. Goris, J. L. Gallagher

Cable supports offer several advantages over traditional secondary support methods by enhancing stress redistribution to pillars and gob areas, minimizing or eliminating timbers and cribs that reduce ventilation, eradicating material-handling injuries related to placement of crib supports, and providing a cost-effective alternative to secondary support. The U.S. Bureau of Mines (USBM), researching alternatives to traditional roof support methods, designed and installed high-strength cable supports to improve the stability of longwall gate road entries in a western U.S. coal mine. With the cooperation of industry, methods were developed to install and evaluate cable supports in a tailgate area using traditional resin cartridges. The cable-bolted areas successfully maintained roof support throughout the developed entries. Cable supports have replaced wood cribbing as secondary support in the bleeder entry system and have minimized or eliminated the use of cribbing in the longwall tailgate entries. This paper describes the theory, application, and advantages of cable supports and presents some mine measurements made to assess the cable performance during the retreat process of longwall mining.

Jan 1, 1999

By Wilbur A. Haley

One of the purposes of the investigation was to determine and report on how coal augers are used to mine bituminous coal that is near outcrops and may not be mined otherwise by any other present-day method. Such increased overall recovery results in the conservation of coal resources. Other reasons for the investigation were to determine and report the production rates of such operations and the types of equipment used. Auger mining of coal as a means of coal recovery supplementary to strip mining has been introduced and developed since World War II. This type of coal mining has grown rapidly, and bituminous-coal production by auger mining has been estimated at 6,000,000 tons in 1955. Mines were selected for study to give reasonably representative information on auger mining in different types and thicknesses of coal beds in different geographic areas and on different types and sizes of equipment operated under various conditions. This report is based on field studies of 8 auger-miming operations in Pennsylvania, West Virginia, and Ohio and in 5 different coal beds. Operations were observed in active strip mines, in strip mines reopened for auger mining, and along benched coal-bed outcrops. At the time of this study, no augers were reported to be operating in underground mines. The diameters of holes drilled ranged from 26 to 52 inches, and the lengths of holes ranged up to 208 feet. At some operations auger holes often penetrated abandoned underground mine workings.

Jan 1, 1957

By J. M. Kurtz

Ten Methane Monitoring Systems and Machine Control Circuits were examined and tested per the requirements in CFR Title 30, Parts 18 and 27, the Standard UL 913 and the document "Test Requirements For Instruments or Apparatus to be Considered for M.E.S.A. Intrinsically Safe Certification (Tentative)". The test results indicate that none of the products complied with all parts of all requirements as interpreted by Underwriters Laboratories Inc.

Jan 1, 1980

The U.S. Bureau of Mines and the U.S. Mine Safety and Health Administration (MSHA) are participating jointly in a research program to evaluate the strength characteristics and air-leakage resistance of various proposed seal designs for use in underground coal mines. The full-scale seals were constructed in the USBM's experimental mine at the Lake Lynn Laboratory, air-leakage tested, then subjected to pressure pulses of 20 psig or greater. In experiments prior to this study, seven seal designs using solid-concrete blocks were tested. Only the standard-type seal passed the explosion and air-leakage criteria. Tests also were performed on four seals constructed with low-density foam blocks. All four of these seal designs withstood the pressure pulse. In more recent studies, nine cementitious foam seal designs of varying thicknesses and densities were investigated. Six of the nine designs successfully survived the explosion overpressures. Six wood-block convergence seals also have been tested. The typical 3-ft-thick, wood-block seal design currently used in many coal mines did not maintain its integrity, in the absence of convergence forces, following the explosion test. Five modified wood-block seals successfully withstood the 20-psig pressure pulse. Based on these tests, three alternative seal construction materials, cementitious foam, low-density foam block, and wood, have been approved by MSHA for use in underground coal mines.

Jan 1, 2010

By The Staff

BEFORE going into detail on the subject to be presented, a brief outline of the Company's earl y history would not be out of place. Prospecting and mining on a small scale was started in 1876 on the site of the present open pit at Thetford Mines. The property was purchased from the Crown in 1878 and Johnson's Company was incorporated in 1885. It is owned and operated today by descendants of the original shareholders. Many employees, through their fathers and grandfathers, have service records dating back three generations. The principal asbestos deposit at Thetford Mines is pear-shaped, with surface dimensions of about 2,200 feet in length by 1,300 feet in maximum . width. Its long axis strikes northeast and the dip is nearly vertical, but irregular in detail. It is known to extend to a depth 1,200 feet below the original surface, but its area at that depth has not been determined. Ownership of this deposit is divided among three active Companies: the Asbestos Corporation, Limited; Bell Asbestos Mines, Limited; and John-son's Company. Johnson's Company owns a section about 1,000 feet in length and 500 feet in width, bounded on the northeast by the King mine of the Asbestos Corporation and on the northwest by the Bell pit. On Johnson ground, there was originally a large outcrop o~ asbestos rock which dipped toward the south below overburden. This was mined until recently by open pit, the overburden being stripped off as far southward from the original outcrop as was economically possible. As the. pit was deepened, within side walls maintained at a maximum safe slope, its floor area, of course, became progressively smaller, and eventually the pit would have wedged out against the Bell property line. It became necessary, there-fore, to introduce some other method of mining before production became seriously curtailed by a shrinkage of the pit area.

Jan 1, 1941

By Gerald A. Muson, Fremont F. Clarke

"INTRODUCTION The use of scrap mica as an industrial raw material has grown rapidly during the past two decades. Demands by various industries for ground mica for use in the roofing, paint, rubber, plastics, and wallpaper trades as well as for less extensive uses in insulation, oil-well drilling, welding, pipeline enamel, decorative material, and for other purposes exceed present (1947) supplies.A small proportion of the raw material used comes from the Black Hills of South Dakota, where casual recovery has been practiced in the exploitation of pegnatite deposits for more valuable minerals. The annual production of scrap mica in the Black Hills for the years 1939 to 1946 is shown in figure 19. 4/Although small, this production of scrap mica materially augments the incomes of numerous operators.Volume production of mica would offer attractive opportunities for obtaining steady and more economical supplies of the rare minerals as byproducts. Appreciable supplies of beryl, lithia minerals, sheet mica, tantalite-columbite, and cassiterite could accrue. Furthermore, a stable scrap-mica production would complement the production of quality feldspar, for which the Black Hills pegmatites are noted, and would help balance the economy of pegmatite mineral production.Mechanical methods of separation are requisite to production of enough scrap mica to be generally profitable. Various phases of the characteristics end treatment of mica have been investigated by the Bureau of Mines. A bibliography of these reports is appended.In 1945 the Bureau of Mines conducted pilot-plant tests to recover scrap mica by selective screening of crushed pegmatite. More recently the problem has boon studied in the Pegmatite Research Laboratory to aid in developing technological methods by which scrap mica may be separated from crushed pegmatite."

Feb 1, 1949

By BUREAU OF MINES

In 1948 the United States became a net importer of oil. Coupled with an unpre- cedented domestic production of 5,900,000 barrels daily, imports approximating 500,000 barrels made available a total supply of 6,400,000 barrels a day. Thus, by herculean effort, the oil industry was able to meet an extraordinary demand at home and, in addition, to ship abroad almost 400,00 barrels daily of petroleum and products. The country's oil position now differs greatly from that prevailing at the be- ginning of World War II. Then, actual oil production averaged about 4 million bar- rels a day, and productive capacity probably was greater than 5 million barrels a day. As the demand of the military and industrial machine grew with the rising tempo of the drive toward victory, the United States not only met its own needs but pro- duced about two-thirds of the total oil requirements of the Allied Nations, excluding Russia. As a people, we can be deeply grateful that the Nation's petroleum resources were adequate and sufficiently developed to support such a tremendous effort. Even in those critical hours when immediate needs were the paramount issues, a prudent Congress paused to contemplate the importance of an assured long-term supply of liquid fuels. From these deliberations came the Synthetic Liquid Fuels Act of 1944, which authorized research and development work on new sources of oil coal, oil shale, and agricultural and forestry products. ce World War II, a civilian demand for 6 million barrels of petroleum prod- ucts has become the order of the day every day. By drilling as many as 39,000 new wells a year, the production rate has been increased enough to meet domestic require- ments by a bare margin. Some imports were necessary, however, to fill both domestic and foreign demands, and these doubtless will increase. Is this policy of exploration within the United States and the development of oil in foreign countries adequate insurance for the fulfillment of our future national needs? This question has two aspects one purely civilian and economic in character and the other significant from the standpoint of our national defense. There are now approximately 4,000 producing oil fields in this country. At first thought, it would appear that production could decline in a considerable number of these fields without materially affecting the over-all daily output. However, 48 percent of the oil comes from only 111 major fields which contain 50 percent of the total proved domestic reserves. It is apparent, then, that the flow from large fields - having proved reserves of 100 million barrels or more each must be sustained if daily production is to be kept at the present levels. Essentially, this means that new major fields must be discovered about as rapidly or perhaps more rapidly than the older ones lose productive capacity. From 1940 through 1947, only eight major fields with estimated reserves of more than 100 million barrels each, were discovered and proved - an average of one such field a year. The total estimated reserve of these eight fields was less than 1 year's supply at the present rate of use. As drilling continues, some existing fields ultimately will prove reserves larger than those now known. Without a pronounced increase in the num- ber of major discoveries, however, the prospects for increasing our present productive level are not encouraging. Any gap that appears between domestic productive capacity and demand could be filled with supplies from proved oil resources abroad. Assuming cheap pipe-line and tanker transportation to the United States, freedom from exorbitant taxes and charges

Jan 1, 1949

By Parry. V. F., W. S. Landers

"INTRODUCTION Approximately 1,250,000 tons of 2-1/2-inch and 1-1/2-inch slack, representing over half of the output from 40 to 50 mines, is produced in the Denver region each year. Part of this slack is made by crushing lump, and some of it is rescreened to make pea and modified pea sizes measuring 1-1/2 inches by 2-1/2 inches and 3/4-inch by 1-1/2 inches, round-hole. Modified pea is popular as domestic stoker fuel. Approximately 900,000 tons of slack 0 by 2-1/2 inches, 0 by 1-1/ 2 inches, and 0 by 3/4-inch in size are consumed by industrial plants, the principal consumers being a large power plant and the beet-sugar industry. The power plant uses annually 250,000 to 275,000 tons of pulverized fuel and can pulverize slack of any size, while the sugar factories consume about the same quantity of coal in stokers. The sugar factories store about 110,000 tons of 2-1/2-inch slack under water from January to October, and burn the remainder of their consumption directly during the campaign season from October to December. For this purpose, sugar-factory power plants can use any size of slack, which is recrushed to pass a 3/4- or 1/2-inch screen before burning on chain-grate stokers. About one-third of the 2-1/ 2- inch slack produced in the field is used in smaller industrial plants that employ stokers.Certain factors affect the utilization of 2-1/2-inch slack in the Denver region. The increasing production of hydroelectric power has reduced the consumption of coal at power plants slightly. If more hydropower is generated, the trend of consumption of slack might be downward, unless industrial activity offsets this greater output. Rapid increase in number of domestic stokers during recent years has necessitated preparation of greater quantities of stoker coal, with the result that more lump is crushed, and preparation facilities are changed. At present about 19 percent of the coal produced is crushed to meet the constant demand for industrial fuel as well as the increasing but variable demand for the small domestic stoker sizes. The quantity crushed has increased 12 percent during the last 6 years. These factors are shifting constantly. The trend toward the use of clean and smaller sizes for domestic stokers gives a slack having a larger proportion of fines. In future, even greater quantities of small stoker coal probably will be prepared, and the resulting greater quantities of small slack will have to be used for industrial purposes."

Aug 1, 1942

By Lucas G. Thompson

My topic, "The Administration of Mineral Rights'.' is possibly an unusual one, as it deals with a subject upon which many of us have a more than passing interest, I thought ?it might prove consistent with the objects of this meeting, more especially as I propose to deal, not with those broad subjects of nation-wide importance which are often the subject'? of learned (and sometimes futile) academic discussion, but rather with problems in their practical light. To the scientist, the important question is What is it? to the technician, Can it be utilized? to the business-man, Will it pay? All three questions are important, and so quick has been the march of business on the heels of science? that the one question follows the other with astonishing rapidity and all three must be considered in the modern management of a mineral estate. A .good illustration of the force of this can be found in the recent advance of our knowledge of the element helium in which we have advanced from a solution of the first question to the last question in the short period of 55 years. It is to be borne in mind, however, that in the administration of mineral rights, the question "Will it pay?:' is of primary importance. What forms a mineral estate ? A former practice in western Canada in selling lands was to sell the hair with the hide. All transactions sold the lands in fee simple, which included all mines, minerals and rights and privileges whatsoever, excluding only the royal metals, gold and silver, which by imputation, though not by specific reference, in deeds. of title are reserved to the Crown. At that time the country was in the first ?stages of settlement and the value of our mineral resources was hardly appreciated and little understood.

Jan 1, 1923

By I. Cotman

Dimensional stone processing has become an important part of the world extractive industry, and today?s total stone block yearly production is estimated to be around 134.000.000 tons and is still growing by an average yearly rate of approximately 20%. In future, the same production will become an important part of the mining industry and presently, in some countries it represents even the main mining output. New environmental regulations, together with landscape and nature conservation requirements, create a number of difficulties in setting up new open pit dimensional stone quarries. As a result, many dimensional stone producers have recently started to apply underground techniques in order to produce the ornamental stone blocks intended for further processing. Underground production of stone blocks requires special mining methods and so far it has not been a cost-effective excavation method for all types of rocks. Presently, this type of stone excavation is generally applied in sedimentary and marble deposits because the rock has small to no mineral quartz content. When starting a new underground dimensional stone mine, it is necessary to analyse the impact of all primary factors which are crucial to set up a technically and cost effective advanced underground dimensional stone mine. The role of physical and mechanical properties of the rock, geological conditions, mineralogical composition, micro-tectonic state of the site, rock mechanic conditions on the site, durability and saw ability of the stone are decisive factors in foreseeing the future methods of extraction. The laboratory research work as well as the field work, is very important in decision-making aimed to choose the future excavation method. Also of equal importance is the serious market research, because it renders the indication of selling price potential. Having obtained the results from both types of research, mining engineers can design the mining methods which optimize financial return to the mine. The practice approved by 15 years of testing in the underground limestone quarry of Kanfanar gives future producers very useful advice and general data to facilitate the process of exploration intended to establish new similar underground quarries.

Aug 1, 2013

The mining industry has been slow at adopting the latest management philosophies from other industry sectors, such as manufacturing, and in retrospect, with good cause. With the plethora of three-letter-acronyms such as TQM, JIT, TPM and now, BPR each touted as the panacea for profit improvement, you wonder if you must choose one or attempt to embrace them all! In truth, each new insight into organisational behaviour bears some investigation. This paper looks at the underlying principles and elements of successful change strategies, and how several mining companies, including coal mines, in Australia, Chile and Canada, are applying these principles to their operations. These examples illustrate the need to think radically, and to view mining as an overall process delivering value to the customer rather than a collection of functional silos. They also show that often, a continuous improvement initiative is not enough when a fundamental redesign, a paradigm shift, is needed for a performance breakthrough.

Jan 1, 1998

By C. G. Harris, R. Sluyter

The purpose of an undercut is to undermine a block of ore which will then proceed to cave into draw holes just below the undercut. Undercut-ting is the final and most vital phase in the development of an ore block. Since its purpose is to undermine and induce caving into a block of ore, great care must be exercised to avoid premature caving by removing only enough rock to permit undercut development to proceed. Several undercutting methods, used over a twenty-year period, are re-viewed and their suitability is com-pared with ideal requirements.

Jan 1, 1960

By J. C. Wynn

J.R. Hillebrand From the abstract, "A realistic ore deposition model to serve as a conceptual framework." Further, on page 246, "The first area of study was the Josephine peridotite, now identified as an ophiolite terrane, located in northern California and south-western Oregon (Fig. 3). Here, it was felt that we could test the models shown in Figs. 1 and 2 and, if successful, expand the model and test it in other chromite districts in the US and around the world." My comments refer only to chromite deposits in Europe and the Middle East. First, I question that may chromite deposits occur in the idealized ophiolite section shown in Fig. 1. Second, although some podiform deposits (referring to morphology) have been important (Guleman, Turkey, for example), the stratiform deposits are of greater importance in tonnage and frequently grade. Examples include Nada, Yugoslavia; Bulqiza, Albania; Xerolivado, Greece; Saranovsk, Russia; and Abdasht, Iran. Reply by J.C. Wynn Mr. Hillebrand raises two issues that deserve a serious response. One issue is basically subjective and the other is ultimately political. First, the question of where (and how many) podiform chromite deposits are found in the idealized ophiolite section of Dickey (1975). The Dickey model is still perhaps somewhat controversial (Panayoutou, 1980), but our experience in the Josephine ophiolite of northern California (Wynn, 1980; and Albers, 1983) shows that the model works well there. Virtually all the chromite is found in dunite lenses in the tectonite peridotite (harzburgite). Since there are few complete ophiolites exposed in the world, the model will probably never satisfy everyone. The degree of acceptance is a function of any individual's subjective experience. Second, it is well known that stratiform chromite contributes more than 95% of the chromite reserves presently known in the world, and it could be reasonably argued that there is no point in exploring for or exploiting podiform deposits further. The title of the paper, however, was in part 'strategic minerals geophysical research'; chromite is considered a strategic and critical mineral of the US and many other industrialized nations. Stratiform deposits in South Africa and Zimbabwe account for most of the chromite reserves in the world. Unfortunately, experience in modern times with substantial price fluctuations and even resource cartels dictates the wisdom of identifying and maintaining a national chromite reserve, irrespective of the cost. An improved exploration methodology is an essential element in this strategic objective. References Albers, J.P., 1983, "Geological and Geophysical Studies of Chromite Deposits in the Josephine peridotite, California and Oregon," US Geological Survey Bulletin 1546 A-D, 118 pp. Dickey, J.S. Jr., 1975, "A Hypothesis of Origin for Podiform Chromite Deposits," Geochimica et Cosmochimica Acta, Vol. 39, pp. 1061.1074. Panayiotou, 1980, Proceedings, International Ophiolite Symposium, Cyprus, 1979, 781 pp. Wynn, J.C., 1980, "Exploration Geophysical Methods and Strategies, and Their use to Locate and Assess Small Mineral Deposits," Chapter 12 of Meyer and Carmen, eds., The Future of Small Scale Mining, McGraw-Hill, New York, pp. 75-83.

Jan 12, 1983

By Benjamin W. Haynes

The Bureau of Mines, in cooperation with the National Oceanic and Atmospheric Administration (NOAA), has updated a 1977 NOAA report prepared by Dames & Moore entitled, "Description of Manganese Nodule Processing Activities for Environmental Studies." This updated report contains detailed flowsheets and descriptions of the five potential first-generation nodule recovery schemes now considered most likely to be used by industry; they are high-temperature gas reduction and ammoniacal leach, Cuprion ammoniacal leach, high-temperature and high-pressure H2S04 leach, reduction and HCI leach, and smelting and H2S04 leach. The first three processes are three-metal recovery schemes (Cu, Ni, and Co) with the option of Mn recovery from the tailings. The remaining two processes are four-metal (Cu, Ni, Co, and Mn) recovery schemes. All except the HCI process are assumed to use a nodule feed rate of 3 million tons per year (dry basis). Final metal products are Co powder and cathode Cu and Ni. A minor amount of Ni is also recovered as powder, and some Cu and Zn are recovered as mixed sulfides. Manganese in the four-metal processes is recovered as either manganese metal or ferromanganese.

Jan 1, 1983