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By Frank C. Appleyard

As the environmental movement gained force during the past few years, it was inevitable that attention would be focused on surface mining, and we have seen this method of extracting minerals from the ground come under heavy attack by conservation groups, the press and television, legislators at all levels of government,, and the public at large. It is difficult, and in some situations, perhaps impossible, to measure either the need for, or the results of, land reclamation in absolute terms. Therefore, much of the criticism of surface mining has been based upon subjective analysis rather than hard data, with the result that discussion of the subject often includes a fair amount of emotional response. To be fair, this reaction is not limited to just our critics; even we hard headed engineers sometimes respond in the same way, an observation with which you may agree when I finish this talk. This leads to the thought that whether you are for it, or against it, land reclamation in many respects is a state of mind. That is, our reaction to it can vary considerably, depending on how far we have thought it through. And think it through we must, because the pressures being brought to bear need to be met with positive actions if the problem is to be brought under control, and in the next few minutes I would like to discuss from a management point of view some ideas which might aid in this thinking process. It would be a mistake, I believe, to think that the current energy crisis will suddenly bring the environmental movement to a stop, and therefore, we can relax and go back to running our busi¬ness the way we used to. This is not realistic; on the contrary the energy crisis is focusing attention on the limitations of our natural resources as nothing else could, and with respect to land

Jan 1, 1974

By Ronald R. Bauer

Wollastonite is a little known industrial mineral of the silicate group. The largest and purest known deposit in the free world is being mined and beneficiated in Millsboro, New York by NYCO, A Division of Processed Minerals Incorporated. The associated garnet and diopside are separated from the wollastonite using dry high intensity magnetic separators. Beneficiated wollastonite is used extensively as an additive and filler in the ceramic, paint, refractory, and wallboard industries. Wollastonite acts as a functional filler due to its unique chemistry and physical acicularity.

Jan 1, 1982

By Donald M. Hausen

Microscopic evaluation of trace quantities of metalliferous phases in flotation products requires counting large numbers of particles. Particle counts of many thousands may be required for precision, but not obtained practically by conventional microscopic techniques. A less tedious microscopic method for evaluating trace sulfides in mill tailings was developed for the O'okiep Mining Company in South Africa. Hundreds of thousands of particles were evaluated by this method called "gross-counting." Gross-counting consists of counting microscopic fields rather than point-counting individual particles. Total counts are calculated by multiplying the average number of particles per field by the total number of fields examined over the entire mount. Total gross-counts range from about 20,000 particles for +200 to 100,000 or more for -400 mesh size material in lucite mounts. Sulfides and metallic particles in each field are identified and tallied along with field counts. Totals for each type of metallic particle are divided by the total gross-count to give volume percent which is corrected to weight percent by specific gravity factors.

Jan 1, 1969

By Jing G. Yen

When a solid-liquid mixture is conveyed through a pipe,' four hydrodynamic conditions may develop depending upon the properties of the transporting medium, the properties of the transported material, the properties of the pipeline and the flow characteristics. They are classified as homogeneous flow, heterogeneous flow, intermediate flow and saltation. Heterogeneous flow, which is the subject of the present analysis, occurs when solid particles are coarse, of high density, and the mean velocity of the flow is relatively low, such that the combination allows the establishment of a pronounced concentration gradient in the cross-section of the pipe. In this type of system the suspended matter does not change the rheological properties of the conveying fluid, and solid and fluid phases behave somewhat separately. In recent years much work has been directed toward gaining more insight into the hydrodynamics of heterogeneous flow (1,2,3,4,5,) However, almost all knowledge obtained is empirical in nature and limited in scope. Much effort has been extended to collect experimental information on the energy losses associated with systems of slurry flow (6-13) The work of Durand and Condolios(14,15) represents one of the most extensive experimentations in this field. Through systematic test runs, the effects of the major flow-parameters were studied one at a time. From the results, they concluded empirically that:

Jan 1, 1969

By Paul Basinski

The Northern Reese River Valley is in west-central Lander County approximately 31 miles north of Austin, Nevada in the north-central Basin and Range Province (Figure 1). Authigenic zeolites, which were previously undescribed in the literature, are voluminous in this small sedimentary basin. Uranium mineralization is also abundant in this study area. Until now, what we believe to be cause and effect have not been put together. X-ray diffraction, differential thermal analysis, and scanning electron microscopy reveal clinoptilolite, erionite, analcime, and minor chabazite to be present (Figures 2, 3). Assays show uranium to be present in thicknesses up to 0.7 meters at amounts up to 0.10% eU308. The sediments in the Northern Reese River Valley belong to the Mio-Pliocene Humboldt Formation equivalents. This formation consists largely of tuffacious lacustrine and fluviatile sedimentary rocks. Mudstone is the dominant lithology and intercalated thin zeolite strata (usually less than 0.6 meter thick) are present. Zeolites in the Northern Reese River Valley were diagenetically derived from rhyolitic glass deposited in a shallow, saline-alkaline lake under arid to semi-arid conditions. Clinoptilolite from the study area was K-Ar dated at approximately 4.7 + 0.5 million years which corresponds to Middle Pliocene age (Krueger and Basinski, in press). This age is further substantiated by Middle Pliocene mammalian fauna collected in the vicinity by Deffeyes (1).

Jan 1, 1979

By E. L. Schrader

Statistical Process Control (SPC) is a cooperative arrangement between a component or raw materials supplier and a manufacturing customer. The supplier must analyze his own manufacturing process and determine, predict, and control those variable elements in the circuit which affect finished product characteristics according to the customer's specifications. The results include: control of fluctuations in product characteristics to a narrow range, close communication between supplier and customer, and an increased responsibility for quality control placed on the supplier. In the mining and. processing of airfloated kaolin some unique problems arise with the SPC concept: 1) The SPC system was designed for manufacturing facilities that did not have to deal with natural variations in their raw material; 2) The airfloat process is relatively simple and offers limited opportunity to change processing steps or "fine tune" a circuit for special product needs; 3) Determining adequate sampling frequency for a plant which processes hundreds to thousands of tons per day is statistically difficult; and, 4) Due to the variety of customer industries served, different SPC programs must be set up to deal with widely varying specifications. For airfloated kaolin, SPC is "in line" process control, not after the fact "quality" control. The emphasis must be on statistically valid sampling of the kaolin ore and complete monitoring of its path through the beneficiation circuit.

Jan 1, 1987

By Steve Rogers

Nautilus Minerals was listed on the Toronto Stock Exchange in May 2006. The company now has major mining companies Anglo America (5.7%), Teck Cominco (7.2%) and Epion Holdings (22.4%) as significant shareholders, and has raised approximately $US346 million dollars to develop the world's first deep-water mine. The company is currently targeting high-grade copper and gold in seafloor massive sulphide mineralization, located near plate boundaries in back-arch basins of the Western Pacific. The first mine scheduled to be developed by the company is located in 1,600 meters of water at Solwara 1, in the relatively quite waters of the Bismarck Sea approximately 50 km from the port of Rabaul, within the Territorial Waters of Papua New Guinea. During 2006 and 2007 the company completed detailed environmental and geological studies, culminating in a number of world firsts, including the world?s first NI 43-101 compliant resource statement and environmental impact study for a seafloor massive sulphide system. Permitting is well advanced for the project, with initial production scheduled for late 2010, subject to timely grant of the permits. Extensive government and stakeholder liaison and engagement has been undertaken throughout the projects life, and is a core feature of Nautilus' desire to "do it right" in all aspects of this new industry.

Jan 1, 2008

By A. Iordanidis

Ieropigi Fe-Ni deposit is located in northern Greece, in Kastoria?s prefecture near Albania?s borders. A laterite profile exposed by opencast mining and placed near the basement of the mine was chosen for sampling. Ten samples, representing ?pure? Fe-Ni ore, ophiolite-bedrock, ?red? ophiolite and ?enriched? ophiolite were collected, based on macroscopic observation. The samples were analysed by X-Ray powder Diffraction (XRD) for the determination of the mineral phases. Iron and Nickel concentrations of the same samples were also determined by X-Ray Fluorescence (XRF) methodology. The Fe-Ni ore samples consists predomi-nantly of hematite, goethite, chrysotile (serpentine), saponite and quartz. ?Red? ophiolite samples consists mainly of chrysotile, hematite, quartz, calcite and small amounts of paragonite and goethite. Bedrock and ?enriched ophiolite samples are comprised of chrysotile, hematite, calcite, quartz, nontronite, paragonite and sepiolite. The Fe content ranges between 13% and 49% in Fe-Ni ore samples and between 7% and 10% in ophiolite samples. The Ni content ranges between 1% and 3% in Fe-Ni ore samples and between 0.3% and 4.5% in ophiolite samples (the higher content is observed in the so-called ?enriched? ophiolite). A correlation between Fe-Ni concentrations and mineral assemblages is being attempted in order to evaluate the nickel-rich mineral phases. It is shown that the nickeliferous minerals are serpentine, hematite, goethite and saponite.

Jan 1, 2006

By E. P. Reed

We are proud that one of our predecessor companies originated the phrase "Safety First". That phrase remains today as the guiding principle that governs our total approach to safety and well being in U. S. Steel. U. S. Steel management is totally committed to this attitude and our objective is to have every employee as deeply conscious of his safety responsibilities. Safety is a state of mind but like most things it must have a physical side - both intertwined and inseparable. You might say each promotes the other; and this gives us confidence that with hard work, cooperation from all individuals, and proper application of knowledge and experience, our ultimate objective of frequency "0" will be attained. It is in this vein of thought we present a paper today which gives you briefly our progress, mainly in the physical, or mechanical, protection of miners at work in the Southern District mining operations of U. S. Steel. The Southern District not only includes the underground mining of coal but the underground mining of zinc ore in Jefferson City, Tennessee, and the quarrying of dolomitic limestone near Bessemer, Alabama.

Jan 1, 1970

By J. M. Marek

The determination of the proper cutoff grade for an open pit metal mine is based on economic criteria and the operating philosophy of the mining company. Previous papers have dealt with the balance of a fixed mine production capacity versus economic return. Mine production capacity is often controlled by the amount of mining equipment and the working area in the pit. A complete cutoff grade strategy is a balance of economic return of mining higher grade material versus the capital costs of additional production capacity and the operating cost of moving the waste and low grade material to assure proper ore release. An approach to the problem is presented which is based in part on work by previous authors and provides guidelines to proper cutoff grade strategy encompassing the time value of money and variable commodity prices.

Jan 1, 1985

By Jerry M. Whiting

Greater awareness of the increasing need to develop supplementary energy sources is accelerating us towards many basic decisions regarding future utilization of mined energy materials -- uranium, coal, oil sands and oil shale. The latter material comprises a major potential source of oil which will require creation of unusually large and low-cost underground mining systems. In this paper, the author briefly outlines and analyzes several of the factors which continue to provide the somewhat unique character of oil shale nine planning and mine operation.

Jan 1, 1974

By D. E. Ranta, John G. Stone

One of the steps in an ore reserve estimate is customarily a rigorous calculation of the in situ grade of the orebody itself. The result of this calculation is usually reduced by some purely arbitrary factor to force the calculation to agree with the observed grade of ore actually mined. The failure of the calculation to realistically depict the grade of ore actually extracted is in many instances not the result of either an incorrect calculation procedure or of sloppy mining practice, but is a direct consequence of unsuspected irregularities in the contact between the orebody and the surrounding wall rock. A pattern of holes spaced at 1.5-3.Om foot intervals, drilled as part of a pre-development program, will often reveal that a presumed "regular' ore/waste contact is, in fact, so highly irregular that it will be next to impossible to separate ore from waste during mining. In such an instance, 'fingers' of waste projecting into the mining block will substitute for equal volumes of ore left outside the mining limits. As a result, the grade of material actually mined will be less than the grade envisioned for the orebody. The volume of waste substituting for ore in the mining block is about 0.4X, where X = the average error in projecting the ore/waste contact between alternate holes in the test pattern, and is expressed in units of volume per unit of area of the contact surface.

Jan 1, 1992

By G. J. C. Young

The paper describes the replacement of a conventional filtration, clarification and zinc precipitation plant by a carbon in pulp (CIP) electrowinning plant, with the objective of improving the recovery of gold from cyanide leached, acid plant calcines. The discussion covers the early laboratory studies to the design and erection of the full scale plant. Particular emphasis is placed on the problems encountered with commissioning and the strategies which were employed to solve them.

Jan 1, 1982

By John S. Owens

The National Steel Pellet Project and the Butler Taconite Project are operated by The Hanna Mining Company in the vicinity of the towns of Keewatin and Nashwauk, on the western Mesabi Range. Production began in 1967, after seven years of exploratory and development diamond drilling and reconnaissance magnetic surveys, Previously, direct shipping hematitegoethite ores and gravity concentrates had been produced in the area from numerous open pits and several underground mines since the start of the century. Total shipments of these oxidized ores amounted to more than 200 million tons, but at the present time such reserves are nearly exhausted, and there are no mining operations in the Keewatin-Nashwauk area except at the two taconite projects. The locations of all of the present taconite operations on the Mesabi Range are shown in Figure 1, extending for a distance of about seventy miles from the Butler plant to the Dunka River area. The Butler and National plants have a combined rated capacity of 4.4 million tons of pellets. Their reserves cover a combined strike length of about eight miles on the Biwabik iron formation. All of the intervals between present taconite operations on the Mesabi are potential sources of additional magnetic taconite; in particular, exploration and economic studies have been carried out by Jones and Laughlin Steel Corporation in the Biwabik area between Aurora and Virginia, and by Pickands Mather and Company in the Hibbing area. However, west of the Henna and Butler holdings, it appears unlikely that magnetic taconite exists in commerical quantities at economic depths due to extensive oxidation of magnetite to hematite.

Jan 1, 1968

By S. V. Krishnan

Stability of fine quartz suspensions in process water is of concern in several mineral processing applications. In alkaline solutions, the presence of magnesium ions, arising from such sources as water hardness and magnesium-bearing minerals, leads to the precipitation of Mg(OH)2 which coats the surfaces of quartz. The conditions under which heterocoagulation or surface precipitation of Mg(OH)2 on quartz occur and the manner in which they influence the settling behavior of ground quartz was studied by means of settling tests, coating density determinations, zeta potential measurements and electron microscope observations. Coating density was greater when Mg(OH)2 nucleated on the surface of quartz than when the precipitates heterocoagulated on the quartz surface. The settling curves of quartz suspensions in the presence of different concentrations of MgCl2 exhibited a maximum of maxima which occurred at 10-3M MgC12 and pH 11. Interactions between quartz and Mg(OH)2, and flocculation-dispersion characteristics of quartz suspensions in this system are discussed.

Jan 1, 1983

By R. W. Utley

The purpose of this study was to seek and evaluate possible relationships between the composition of coal refuse, as expressed by washability data, and factors affecting the product ion of a lightweight aggregate from refuse by bloating. The study was related to an intense program in the Department of Mineral Preparation at the Pennsylvania State University to study the possible elimination of air pollution from coal refuse fires by producing a low- carbon secondary refuse. Another phase of this program is considering possible uses of such a secondary refuse. Thus one study was to determine if a lightweight aggregate could be produced from this new refuse material and what effect the nature of refuse beneficiation would have upon the characteristics of a commercial aggregate product.

Jan 1, 1965

By P. Bissert, L. Yan, D. Yantek

"Federal regulations require refuge alternatives (RAs) in underground coal mines to sustain life for 96 hours while maintaining an apparent temperature (AT) below 35°C (95°F). NIOSH research has shown that heat and humidity buildup is a major concern with RAs because they have a limited ability to dissipate heat, and high internal air temperature and relative humidity (RH) may expose occupants to heat stress. The heat transfer process within and surrounding an RA is very complex and is not easily defined analytically nor experimentally. To investigate heat and humidity buildup in RAs, NIOSH conducted multiple in-mine 96-hour tests on a 6-person metal-type RA, a 23-person tent-type RA, and a 10-person tent-type RA. The test results show that when moisture was introduced into the tests to represent perspiration and respiration from miners (wet tests), the average measured internal air temperature at midheight increased by 7.7°C, 9.4°C, and 10.5°C, and the RH approached 95%, 94%, and 88%, respectively. For the dry tests when no moisture was introduced, the average internal temperature increased by 8.4°C, 10.3°C, and 12.6°C, respectively. INTRODUCTION If an accident occurs in an underground coal mine, miners who cannot escape from the mine can enter an RA for protection from adverse conditions, such as high carbon monoxide levels. One of the main concerns with the use of mobile RAs is the thermal environment inside the RA. The metabolic heat of the occupants and the heat released by the CO2 scrubbing system will cause the interior air temperature to increase. Moreover, the humidity within the RA will increase through occupants’ respiration and perspiration and from the chemical reaction within the CO2 scrubbing system. The internal thermal conditions can subject miners to heat stress, which can lead to heat exhaustion, heat stroke, or even death depending on duration and magnitude of exposure. MSHA regulations require that RAs must be designed to ensure that the internal apparent temperature does not exceed 35°C (95°F) when the RA is fully occupied [1]. Apparent temperature (AT) is a temperature-humidity metric for the perceived temperature caused by the combined effects of air temperature, relative humidity (RH), and wind speed. It is used to assess the perception of indoor temperatures when workplaces are not sufficiently heated, cooled, or insulated to provide comfortable or healthy conditions. Before a mobile RA can be deployed at an underground mine for emergency usage, it must be tested to show that its internal AT when fully occupied will not exceed the 35°C (95°F) limit. For practical reasons, RA manufacturers usually conduct their tests at above-ground test facilities. To investigate RA thermal response in an in-mine environment, NIOSH conducted multiple 96-hour tests on a 6-person metal-type RA, a 23-person tent-type RA, and a 10-person tent-type RA in its underground coal mine facility. The work described in this paper could be used by RA manufacturers to determine a final temperature rise based solely on dry and time-reduced testing."

Jan 1, 2017

By M. Yekeler

The critical surface tension of wetting values (Ye) of realgar (AsS), talc [Mg3si401o (OH) 2]' stibnite (Sb2S3), and sulfur (S) were determined by flotation in the absence of conventional flotation collectors as 38.7, 38.0, 35.5, and 30.0 dyne/cm, respectively. The surface tensions of flotation media were arranged by methanol. Separation of binary mixtures of these minerals was performed exploiting their Ye differences-which form the basis of the "ganuna flotation process". One step flotation test showed that sulfur floats preferentially from its mixtures with realgar and stibnite at recoveries of 73.6 and 70.7 % and grades of 81.7 and 91.2 %, respectively. The separation of stibnite from realgar gave a recovery of 4.1 % and a grade of 41.2 % for stibnite, indicate that a minimal Ye difference of 3.6±0.2 dyne/cm is essential for such separation when conventional flotation reagents are not used. This paper presents data and describes the approach employed in these separations.

Jan 1, 1994

By Hugh McMillan

To protect the water supply for the Metropolitan Chicago area, the Illinois legislature, in 1889, created the Metropolitan Sanitary District of Greater Chicago. To insure the quality of the water supply, the Sanitary District collected and diverted the wastes of 750,000 people away from Lake Michigan. Today, the Sanitary District collects and treats the wastes from a domestic population of 5 ¼ million people and an industrial waste load equivalent to 4 ¼ million people. The District serves Chicago and 120 other cities and suburbs in an 858 square mile area. An average of 1300 million gallons of wastewater is treated each day, producing as a by- product about 700 dry tons of solids which contains more than $10,000 worth of plant nutrients when equated to the value of commercial fertilizer purchased in the retail market. The Sanitary District considered several alternatives to past methods for disposing of these solids, and chose land application as a technique to utilize the solids produced by the wastewater treatment process in a beneficial manner.

Jan 1, 1973

By R. Y. Wan

Recent research efforts have shown have shown selective solvation extraction of a gold cyanide ion-pair complex from alkaline cyanide solution is possible with organic phosphorus esters. These alkyl phosphorus esters such as tributyl phosphate (TBP) and di-n-butyl n-butyl phosphonate (DBBP) can selectively load gold to rather high levels, even in excess of 30 gpl. However, traditional stripping techniques are not particularly effective. In this regard, gold recovery by direct electrolysis of the organic phase has been found to be an interesting possibility. Further, the rate of direct electrodeposition from the organic phase can be improved significantly by using an aqueous/organic mixture. Direct electrodeposition of sheet gold from loaded DBBP was successfully accomplished at a current density of 8x10 4 amp/cm2 and 55°C from such a two-phase mixture with the aqueous phase as the continuous phase. No appreciable degradation the DBBP was found after 5 cycles of extraction and, electrodeposition. Finally, the applicability of the process strategy for an industrial situation was demonstrated by the successful treatment of waste gold cyanide electroplating solutions.

Jan 1, 1986