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By Paul I. Eimon

Mineral exploration involves the selective collection, organization, evaluation, and interpretation of geologic and economic data. The sources for such data are original field observations and existing documented information of various types (publications, reports, maps, company files, etc.). As exploration data are accumulated, their storage, organization, indexing, and J retrieval is key to exploration progress. Initial use of computers by mineral exploration groups indicates that data can be meaningfully handled by machines. A computer system makes possible: 1) the storage, manipulation, collation, and selective retrieval of data; 2) the utilization of data banks developed by geologic service groups and available at relatively low cost; and 3) the retrieval of stored data more rapidly, completely, and effectively than by manual systems. Profitable utilization of these capabilities is conditioned by several factors, particularly by the information selected for the system data base and by the design of the computer system itself.

Jan 1, 1968

By R. A. Holmes

Although manganese is a metallic element and is widely dispersed in nature, it never occurs except as a compound in combi¬nation with other elements. Use of such compounds in the production of glass is known to have occurred in early Egypt. The dioxide of manganese was considered a compound of iron until 1774 when C.W. Schule first recognized it as an element. In the same year, a Swedish mining engineer, J.G. Gahn, became the first to isolate manganese. In 1856 development of the Bessemer process of steelmaking gave economic importance to manganese, and later, in 1882 Robert Hadfield discovered the benefits of high manganese steels. GEOLOGY Physical Properties Elemental manganese is a silver-gray metal, resembling iron but harder and more brittle and used primarily in alloys (both ferrous and non-ferrous) and a wide variety of chemical compounds. Some of the physical properties of manganese include: melting point¬1 245°C; boiling point-2 150°C; density at 20°C-7.43 g/cm3; specific heat at 25.2°C-O.115 cal/g; latent heat of fusion-63.7 cal/g; hardness on Mohs scale-5.0; linear coefficient of thermal expansion from 0 to 100°C-22 x 10-6. Mineralogy There are over one hundred minerals that contain manganese. These minerals vary from those with compositions that are pre¬dominantly manganese to those having only minor percentages of manganese. Distribution of Deposits Manganese ore deposits are found worldwide and were formed in various geological environments, but only a rather limited num¬ber of deposits have high grade manganese ore in sufficient quan¬tities to be mined and utilized economically on an industrial scale. It is worth noting the fact that almost all of the significant deposits can be classified into two types of deposits: marine chemical sed¬imentary deposits, and residual (secondary) enrichment deposits. There are, however, a much larger number of geological types but these are not of commercial significance at this time. Sedimentary deposits are the most common and are usually stratiform or lenticular. Manganese minerals were formed by a chemical process during the deposition of marine sediments. They usually contain manganese oxides and carbonate minerals, some¬times interbedded together or with other sedimentary rocks such as limestone or shale. Examples of this type of deposit are the Russian ore bodies of Nikopol and Tchiatoura, as well as the Kalahari deposits in South Africa and deposits of Groote Elyandt in Aus¬tralia. Residual deposits were formed in a different way: by alteration of existing manganese deposits or by concentration of the manga¬nese minerals when other minerals were washed away by weath¬ering or ground water processes. The Nsuta deposit in Ghana, the Amapa deposit in Brazil, the Moanda deposit in Gabon, and nodules in the residual clays of the US Southern Appalachians are examples of this type of geological process. In the case of the Ghana and the Amapa deposits, this is only true for the outer layers of the deposit containing oxide minerals, the inner part being comprised of car¬bonate minerals including manganese carbonate, probably from marine origin. Some sedimentary and residual-type deposits have been metamorphosed, giving rise to small high grade ore bodies. These deposits are regionally metamorphosed, occurring in mar¬bles, slates, quartzites, schists, and gneisses. Some of these deposits, such as the Franklin, NJ, deposit are rich enough to be commercial without secondary enrichment; however, most of the exploitable deposits have been secondarily enriched. Due to the diversity and complexity of manganese deposits, both with respect to deposition and chemistry, a wide range of impurities are almost invariably present in the ores. Table 1 shows that the reserves (i.e., a measured resource that can be economically and legally extracted) are estimated at 814 x 106 tons of contained Mn, which equates to more than a 100 year supply at the current level of production. The reserve base is made up of the marginally economic reserves and sub-economic re¬sources and are some 4.5 times greater than the proven reserves. Also apparent from study of Table I is the fact that some 75% of manganese reserves are found in two countries, the USSR and South Africa. On the other hand, North America (i.e., the United States and Canada) have few significant deposits. The largest deposit, or at least one of the largest, in the United States is located at Chamberlain, SD. This deposit is sedimentary

Jan 1, 1994

By Robert F. Conley

In the mining, manufacturing and application of inorganic pigments, dispersion contributes significantly. This is especially true with mineral pigments because of the variety, in slurry operations required for their processing. Such operations include any of the following: (1) mine-transport (2) wet grinding (3) flotation/beneficiation (4) wet magnetic separation (5) selective floculation (6) size classification (7) chemical processing (8) spray drying Dosage levels and general economics of dispersant use are broadly variant, being dependant upon the agents employed, from the simplist, i.e., sodium silicate or sodium carbonate, to the more complex, as polyacrylates and organo-phosphates. In certain unit processes the dispersant must exhibit unusual chemical stability and persistence, e.g., in protracted pigment slurry shipments. In others, the agent should be fugitive to prevent secondary reactions from occurring, e.g., with high temperature calcination where alkali salts can act as aggregation fluxing agents.

Jan 1, 1985

By John W. Straton

Following the completion of the paper presented in February, 1972, data were received from many other mines and some original respondents submitted more complete questionnaires. The computer program was changed to permit the results to reflect more clearly all the data reported by the mines. The original paper was revised to reflect the new information. There were significant changes in some numerical values, particularly where the size of the sample changed appreciably. Some limited samples considered originally in arriving at conclusions were not relied on in this revision. The revised tables and text are of the same design and format as the original paper.

Jan 1, 1972

By R. M. Smailer

Detailed description of the development of the FIOR process1 and, subsequently, other technical papers relating to the operation and start up of the FIOR plant2,3 are available in the technical literature. The Fluidized Iron Ore Reduction (FIOR) process plant constructed in the Matanzas region of Venezuela represents the first commercial application of this technology. The FIOR process was developed by Exxon Company during the 1950's and 1960's; and the facility in Venezuela was designed and constructed by Davy McKee with the plant start up in 1976. While there is a minority government ownership in the company, FIOR de Venezuela operates as a private sector company with the majority of the ownership being private capital.

Jan 1, 1981

By Jerry M. Riggsbee, John H. Weber

INTRODUCTION The Washington Metro is a 98 mile rapid transit system that will serve the District of Columbia, southern Maryland, and northern Virginia. The construction work herein described relates to Section B-1 of this system. The contract for this work was awarded by the Owner, The Washington Metropolitan Area Transit Authority, to a joint venture doing business under the name of Ball-Shea-Norair. The partners in this venture were Gordon H. Ball, Inc., Danville, California; J. F. Shea Company, Inc., Walnut Creek, California; and Norair Engineering Corporation, Washington, D. C. The bid price for the project was $33,741,524 with a contract duration of 910 calendar days. Notice to proceed was issued January 5, 1970. The present modified price for the work is $36,866,000 with completion anticipated in July 1974. (About 1,638 days elapsed time.) The work to be done consisted essentially of construction of 3,490 linear feet of cut-and-cover track with side platform, and 600 ft cut-and-cover arch shaped subway stations. Stations are located in Judiciary Square and Eighth & G Street, N. W., areas. Decking of excavation in street areas, maintenance of traffic and utilities, vent and fan shafts, underpinning of court buildings in Judiciary Square and the Smithsonian National Portrait Building, and an electrical substation were included in the contract. Stations were constructed of cast-in-place concrete.

Jan 1, 1974

By Jerry Luttman, Mark Dubay, Anvesha Dogra, Elizabeth Dwyre, Wei Hu

The I-75 Modernization Project (Segment 3) just north of Detroit, MI is being delivered as a Design-Build-Finance-Maintain (DBFM), which is a Public Private Partnership (P3). The project includes design and reconstruction of 5.5 miles of freeway, including a depressed section with a 20,630-ft long, 14.5-ft inside diameter, up to 100-ft deep stormwater tunnel, multiple drop shafts, and a pump station. The project also includes a maintenance term of 25-years. This is the first time MDOT has used a P3 delivery method for a major highway and tunnel project. This paper describes the development of the P3 documents, including performance-based tunnel and shaft technical requirements, and the approach to project risk management, financing, and insurance coverage.

Jun 23, 2024

By Qingqing Huang, Aaron Noble

The Mineral & Metallurgical Processing Division (MPD) of the Society for Mining, Metallurgy & Exploration held the first MPD Student Video Contest during the spring of 2021. The event showcased the work of 18 graduate and undergraduate students from several U.S. and international institutions. The contest began in January when students submitted a onepage abstract for judging. Over the next several months, they developed a three-minute video that further explained their research findings. Both the abstract and video were evaluated by a panel of judges, and the top-placing participant was recognized at an MPD virtual event held on June 10.

Sep 13, 2021

By J. A. González-Anaya

This laboratory work presents a study of the effect of ultrafine grinding on the gold recovery of a highly refractory gold concentrate. The particle size of the concentrate was P80 = 46 µm and the main species present were quartz (28.58%), dolomite (25.63%), pyrite (20.93%), arsenopyrite (15.39%) and 112 g/t gold. After optimizing hydrated lime and lead nitrate additions, standard cyanidation with 1% NaCN, pH = 12.3, 25% S/L permits to recover only 9.4% of the gold. Different particle sizes were submitted to cyanidation. When the concentrate was ground to ultrafine sizes (P80= 4.6 µm), the gold recovery for the same cyanidation conditions increased to 67%, with cyanide consumption of 66.7 kg NaCN/t. Additional tests were performed in order to reduce the cyanide consumption. The reduction of the cyanide concentration in the leaching solution from 1 to 0.5% and the addition of 100 g Pb(NO3)2/t allowed the reduction of the cyanide consumption to 27.6 kg NaCN/t (58% reduction), while maintaining the same gold recovery of 67%. The remaining gold could be present as very fine inclusions or in solid solution in the matrix.

Jan 1, 2011

By John C. Draper

Little precise information is available on the effect of mining on the surface topography. It is often assumed that after mining the surface will simply sink. This is not an infallible conclusion as is well illustrated in two of the three examples herein. This paper describes the results of an attempt to precisely measure the surface movement in the area around coal pillars left in place for three oil wells in a completely mined and caved area at the Harwick Mine of the Duquesne Light Company. The dates when the various measurements were made are shown on the data sheets and indicate the rate of surface movement. These oil wells are identified as wells Nos. 2, 3, and 6. This mine property is located on the north side of the Allegheny River at Cheswick, Pennsylvania, and extends in a northerly and westerly direction about five miles. The three well pillars are situated on the westerly side of the Bessemer and Lake Erie Railroad some 2,000 feet from Rural Ridge, Pennsylvania (Fig, 1).

Jan 1, 1964

By Jeremy Stone, Yiming Sun, John Stolz

The Courthouse Commons Tunnel facilitates the secure transfer of inmates between the County Jail and State Courthouse across a city block in downtown San Diego, California. This shallow tunnel was excavated using the Sequential Excavation Method in soft ground. It passes under 8- and 10-story buildings with a foundation cover of 6 feet, and crosses the active San Diego Fault with a design offset displacement of 18 inches. In this paper, key design challenges of tunnel construction are presented: limiting building settlements without using underpinning of building foundations and incorporating an oversized seismic section with seismic joints and crushable backfill

Dec 1, 2022

Operation of a pilot-scale Floatex density separator was studied using a pyrite concentrate slurry feed. Experimental measurements were further utilized in parameterization of a hindered settling simulation model. The model incorporates particle slip velocity calculation and also a separation efficiency function, adjusted to describe the feed material characteristics. The model was used to compute the overflow and underflow compositions when both fluidization bed pressure and teeter water flow rates were varied. In addition, prediction accuracy and the model validity were evaluated. The simulations gave good results when the teeter interstitial velocities were moderate enough to avoid excessive turbulence in the fluidization. Prediction of the cumulative overflow and underflow size distributions in most experiments yielded essentially less than 10% relative error between the sample data and the estimated value of the 50% passing sizes.

Jan 1, 2011

By J. E. Urosek

In October, 1990, a fire started in a large underground coal mine in Western Pennsylvania. During fire-fighting activities, an explosion occurred and all personnel were evacuated. Safe re-entry into the mine was not possible and the mine was sealed. Recovery efforts began in January, 1991 and continued until March, 1991, when permanent underground seals were installed between the fire area and the mine openings. This paper describes an extensive atmospheric monitoring program conducted by the Mine Safety and Health Administration (MSHA), Pittsburgh Safety and Health Technology Center (PS&HTC) including the analysis of mine fire gases, natural ventilation, fan pressure and air quantity distribution.

Jan 1, 1993

By F. J. Sotillo

Mining in Peru is mainly concentrated on metallic and polymetallic ores of gold, copper, lead, zinc, silver, tin, iron, etc. However, little has been done to develop extensive and rich non-metallic or Industrial Minerals deposits with the exception of some silica and phosphate deposits. This paper presents the characterization and metallurgical studies for the development of a feldspar deposit. These studies showed that the special characteristics of the ore, such as high porosity, high Al2O3 content, low clays content, and sized material allowed us to obtain commercial products applying relatively simple and low cost concentrating unit operations. The characterization studies showed that the feldspar products contained no quartz and about 90% of albite (NaAlSi3O8). The 14x40-mesh size fraction product analyzed 5.91% Na2O, 22.56% Al2O3, 65.73% SiO2, 0.65% K2O, 6.50% CaO, and 0.40% Fe2O3; whereas, the 40x150-mesh size fraction product analyzed 6.22% Na2O, 24.30% Al2O3, 60.80% SiO2, 0.91% K2O, 7.06% CaO, and 0.54% Fe2O3. These products could be used for manufacturing glass, ceramics, refractory, and filters in different applications. In addition, Middlings, could be used as insulation material due to its porosity (bulk density of 0.828 Kg/dm3), analyzing 4.46% Na2O, 15.7% Al2O3, 67.2% SiO2, 2.57% K2O, 3.94% CaO, and 4.24% Fe2O3. The material showed a sphericity of 0.77, a roundness of 0.68, and acid solubility of 13.3025% on only washed and 2.72% effective for clean material suitable for use in these applications. No selective accumulation of the valuable mineral was observed at any specific size fraction. However, iron and titanium bearing impurities trended to concentrate in fine fractions (minus 70 mesh -212 µm-). Metallurgical studies demonstrated that this feldspar ore required sizing at 14x40 mesh and 40x150 mesh to render commercial products. In the case of the 14x40-mesh size fraction, the process involved magnetic separation, gravity separation, and flotation for feldspar (direct flotation) using a blend of primary and condensate amines. However, the reverse flotation for mica-biotite and iron bearing minerals was also possible using petroleum sulfonate. The metallurgical process for the 40x150-mesh size fraction required magnetic separation and reverse flotation of iron and titanium bearing minerals, the feldspar being reported in the sink material. Commercial products from this feldspar deposit for glass, ceramics, refractory, and filtration; and for the manufacturing of insulation material were obtained.

Feb 23, 2014

By J. W. Mustard

The Macmillan Pass tungsten property (MacTung) is the largest known copper-tungsten, calcic, exoskarn deposit in the Western Hemisphere. Located on the border between the Yukon and Northwest Territories in northwestern Canada, the deposit crops out on Mt. Allen within the Selwyn Mountain Range. It was discovered in 1962 by a subsidiary of AMAX Inc. and has since been explored by 16,300 meters of surface and underground diamond drilling and by 800 meters of underground development. Geologic reserves are in excess of 30 million tons, grading slightly less than 1.0% WO3. Scheelite (CaWO3 ) is the main mineral of economic interest. Accessible by road, the property is not in production. Previously estimated reserves at MacTung have been unable to fully utilize all the geological controls on mineralization. In the past three years, however, an intensive program has been underway to improve our understanding of the deposit and to use the resulting information in a more precise way. This paper will discuss the key aspects of the geology as they specifically relate to reserve estimation and will demonstrate how these controls are being used in a geostatistical model of the deposit.

Jan 1, 1985

By Neal Cochran

I consider it a distinct privilege to be afforded the opportunity of discussing the program of the Office of Coal Research. The principal activities I will be discussing are concerned with projects that fall in the utilization area. I will, to be sure, touch on other activities of the Office of Coal Research but am not equipped to discuss these activities in great detail. Research activities of the Office of Coal Research are conducted on a contract basis with commercial, academic, and non-profit institutions. We do not operate any laboratories of our own but we do maintain a very small staff for technical and administrative supervision of our contractors. We have consistently attempted to interest outstanding, creative, and practical research organizations in our program. We are constantly seeking the imaginative new idea that will materially reduce the cost of mining coal, transporting it, or will process it into a more convenient and useable form. In assessing proposals and in developing our program, we search for the improvements that will develop large-scale new uses for coal or coal products or those that support these new uses.

Jan 1, 1963

By Jack D. Melin

The commercial development of the Liwell Screen is a result of a thorough search for a non-blinding and highly efficient screening device capable of handling even the most difficult-to- screen feed materials. A proprietary development of Hein, Lehmann A.G. of Duesseldorf, West Germany, the Liwell Screen utilizes a unique flexible deck motion for sizing a variety of sticky, high surface moisture feed materials including raw coal and lignite at separations ranging from 3/4-inches (19mm) down to 10 mesh (1.5 mm).

Jan 1, 1983

By A. K. Sinha

Research shows that continuous mining sections can normally produce around 950 tons per shift in a seam 5 or 6 ft. thick. The shuttle cars as well as the continuous haulage systems are able to match with the continuous miners in capacity. However, in practice both of the two systems seem to be averaging at around 450 to 500 tons per shift in production. Continuous haulage systems are preferred in thin seams particularly where the floor is soft.

Jan 1, 1981

This one day field trip is sponsored by the Denver Region Exploration Geologists? Society, May 14th 2009. The trip highlights major geologic features and some notable uranium occurrences along the north-south mountain-basin boundary southwest of Denver and continuing north to Fort Collins, Colorado. Uranium deposits visited include sandstone?hosted roll front type and polymetallic veins hosted in metamorphic rocks. A replacement ?episyenite? type occurrence is considered via description and hand samples but is not visited owing to logistical constraints. Recovery methods addressed include underground mining and in-situ leach recovery. Samples of Precambrian basement rocks, deposit host rocks, uranium ore samples, and ore polished sections viewed by reflected light microscopy will be available. A road map showing the locations of the stops serves as the front cover of this field guide. The Robinson episyenite-hosted occurrence (not visited) is labeled as Stop 6. A stratigraphic column is provided which shows the position of the host rocks at each stop (Figure 1-1).

Jan 1, 2009

By Caibin Wu, Chengfang Yuan, Jiaqi Tong, Zhilong Cheng, Ningning Liao, Chong Zeng

In a series of Julius Kruttschnitt size-dependent breakage models, the cumulative percentage passing 1/10 of the initial size is used as a fineness indicator for scientific research and the selection of grinding equipment. However, in industrial practice, it is quite customary to use the mass percentage passing 75 μm as the indicator. In this paper, based on the energy-particle size model, quartz and calcite, two materials with distinctly different hardness, were used as test samples in a conical ball mill. At the same specific energy, the value of the cumulative percentage passing 1/10 of the initial size decreased while that of the mass percentage passing 75 μm increased with finer feed size. The experimental test values of the mass percentage passing 75 μm have a good linear relationship with the model predictions, which suggests that the particle size energy relationship of the mass percentage passing 75 μm and Ecs can be used instead of the cumulative percentage passing 1/10 of the initial size and Ecs. By building family curves, when particle size x < 300 μm, the family curve can be well fitted, and the fine particle size distribution of the whole product can be reconstructed.

Dec 22, 2022