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By M. Christou

The LIFE-Environment Demonstration Project ?Treating Waste for Restoring Land Sustainability?(www.bangor.ac.uk/ies/TWIRLS/TWIRLS_home.htm), a project initiated by the University of Wales, Bangor, UK in which NAGREF is a partner, aims to demonstrate the effective use of industrial and municipal wastes for the remediation of post-industrial and degraded sites in urban and rural sites. Within the framework of this project, a schist quarry, which is located in a mountainous area near Athens and which has been exploited in the past for cement production, was chosen for bioremediation experiments in collaboration with the quarry owners, TITAN Cement Co. Three different areas within the quarry were selected representing 3 different topographies. These were a compacted, flat area with seasonal water logging (untreated control), a gently sloping, land formed area; and artificially created mounds of overburden rock material formed on the flat area. Compost produced from mixing municipal waste, green waste and digested sewage sludge at the recycling plant of the Association of Communities and Municipalities in the Attica Region (ACMAR), near Athens was used for nutrient amendment. Six replicates of three treatments were applied with varying compost application rates in order to examine the effect of the addition of organic matter in the establishment of suitable vegetation on the infertile schist material. Pine trees (Pinus halepensis Mill.), 4 per replicate, were pocket planted in a volume of 3 liters of schist or schist-compost mixture (1:2 and 2:1). Tree height, main stem diameter and branching were measured following planting and these measurements will be repeated annually to test hypotheses that compaction and water logging reduce Pine establishment by natural regeneration and that nutrient addition improves establishment of pine on schist waste. The availability of nutrients and variation in other soil physico-chemical parameters will also be studied in each treatment and related to plant growth. As a demonstration project, open days are planned on the site for the public and official bodies involved in municipal waste handling and other relevant areas. The aim of these will be to illustrate the effective re-use of waste for the sustainable restoration of post-industrial and degraded land.

Jan 1, 2006

By Viktor Mukhin

"Among the methods proposed for spent activated carbon regeneration, the most acceptable is, thermal reactivation, because in this case the existing equipment for manufacture of activated carbon can be adapted for this purpose.In order to conduct the process of thermal re-activation of spent activated carbon directly at gold mills, a fullscale drum-type furnace with external electric heating has been developed, i.e. EPV-300 model with a throughput rate of 50 to 120 kg/hour. Its use ensures restoration of the adsorption properties of carbon up to the level of fresh activated carbon with an insignificant (by 0.7%) decrease in strength and with a high (95% to 97%) yield of reactivated carbon.During the recent years, activated powder carbon has been extensively used in flotation processes for treating polymetallic ores at ore treating plants to improve recoveries of main metals (copper, lead, nickel, etc.).Especially large volumes of activated powder carbon are used at the Talnakh concentrator of the Norilsk Mining and Metallurgical Complex in Russia for absorption of residual flotation reagents from recycled water in order to ensure efficient selective separation of minerals with similar physical and chemical properties.IntroductionSorption technology based on active carbons use starts being applied in such an important in the widest sense of the word strategical branch of economics as non-ferrous metallurgy. Thus since the middle ninetieth Russian gold extraction industry began to apply widely the processes of sorption from pulps and solutions by means of high-resistant granulated active carbons. That provided the start of gold ore minefield exploration, increasing of gold extraction from the ore and reducing its loss with the ""tails"" of process. At present more than 40% of Russian gold is extracted with the help of sorption technologies [1].Another field of active carbons application in non-ferrous metallurgy is the processes of non-ferrous ores floatation at ore-mining and processing enterprise. For that purpose powdered (less than l00µm) active carbons are used for providing the effective selection of minerals with similar physicochemical properties. This method not only increases the metal extraction level but provides deeper division of them."

Jan 1, 2008

A. H. Bromly, Zihuatanejo, Guerrero, Mexico (communication to the Secretary*):—The following criticism of what "is offered as a summary which may be found useful by mining engineers," is not dictated by any captious spirit, but in the intereet of historical and scientific accuracy. The States of Queretaro and Oaxaca have produced sufficient silver to warrant more extended notice. Referring to Pachuca, State of Hidalgo, the eomewhat loose and inexact statement is made that "the ore-depdsit is an andesite, intermixed with quartz-veins, rich from the surface." A better description mould be,—the ore-deposits consist of quartz-veins in andesite. It is notable that many of the rich shoots worked in recent days did not come to surface. In consequence, Pachuca is often quoted by the ill-informed as a camp in which values improve with depth, the truth being that the veins carry shoots, or clavos, some of which were exposed at surface and some not. The name of " electric plow," applied to the mechanical stirrer of recent use, is certainly not to be recommended. The stirrer, or agitator, consists essentially of a traversing gang-plow, operated by power through shafting; drums, and wire-rope. The fact that in certain plants the motive-power used is electricity does not make it an electric plow. Such a name suggests a machine of which the motor is an essential and integral part; which is not so in this case. A lathe in a factory driven by water-power is not called a hydraulic lathe. My experience agrees with Dr. Raymond's note as to azulapue, which in some districts is also applied to blue copper carbonate. The El Oro, Esperanza, and Mexico mines should be allocated to the State of Mexico; the Dos Estrellas being in Michoacan, as stated. The El Oro quartz certainly does not appeal to me

Jan 1, 1910

By D. J. Wesolowski, D. A. Palmer, P. Bénézeth, S. Hilic

The equilibrium solubilities of gibbsite, Al(OH)3, and boehmite, A1OOH, have been extensively studied in our laboratory from 30 to 90°C, and 100 to 300°C, respectively, to ionic strengths of 5 mol.kg-1 (NaC1) over a wide range of pH. The resulting solubility constants have been treated with consistent empirical models that incorporate appropriate experimental data taken from the literature. These studies were initiated in part to understand and quantify scale formation in geothermal fields as a result of fluid re-injection from electric power generating plants. Most of the experimental results were obtained through application of a unique potentiometric method that allows for rapid, precise measurement of the in situ pH and allows the approach to equilibrium to be monitored from under- and super-saturation. The experimental program was extended to deal with more basic solutions (e.g., five molal NaOH), in which the dissolution of boehmite was measured for application to the refining of bauxite by the Bayer process. More recent results in strong caustic solutions at temperatures below 90°C were obtained to investigate the dissolution of aluminum-containing sludge from holding tanks at the Savannah River waste reprocessing site. In this case the solubility enhancing effects (kinetic and equilibrium) of triethanolamine were also established and quantified. Finally, potentiometric solubility experiments were conducted (50°C in 0.l mol-kg-1, NaCl) on aluminum alloy sheets to identify mainly the nature of the aluminum oxide/hydroxide surface layer formed under these conditions.

Jan 1, 2004

By C. E. Rodgers

WHEN I was asked to prepare, for presentation at the 1938 Annual Meeting of the Institute, some data concerning low-discharge grinding at the Sylvanite mill, it seemed entirely reasonable to expect to have at my disposal the results of at least four full months' operation after the last unit, as then proposed, was installed. Delays in delivery of equipment, nevertheless, shortened the interval, as will be shown herein. In submitting the data contained in this discussion, I wish distinctly to state that the intention is not to claim that final conclusions can be reached at this time concerning our operation. Test periods, in certain instances at least, have been too short for this purpose, although some, where so stated, have been extended through March and April. It is hoped, however, that an advantageous trend in practice can be shown and that the experience related may be of interest to others who are now operating, or who are considering the operation of, low-discharge grinding mills. In the plant under review, four mills are in use: one primary and three secondary. Present mill capacity (grinding, as shown by screen test, about 99 per cent through-200-mesh and approximately 88 to 89 per cent minus-325-mesh with infrasizer giving about 90 per cent of the latter) averages about 525 tons per day. A brief description of each unit will be given and comments will also be made relating to operation. This will be followed by certain test data from which, in conclusion, operating results are summarized.

Jan 1, 1938

By L. C. de Kooker, K. Esmaeili, I. Musonda, M. Ferentinou

This paper presents the results of an investigation into the effect of pore pressure regime on the factor of safety (FS) and the anticipated critical failure mechanism for a fly ash storage facility. In this study, pore pressure measurements from standpipe piezometers and pore pressure estimated from seepage analysis were used for a comparison of the estimated FS for a fly ash slope. This comparison was applied for static and seismic scenarios. To account for the uncertainties resulting from the limited data available and support a qualitative risk assessment evaluation, a probabilistic analysis was performed. The slope stability analysis was conducted in 2D and 3D, adopting the limit equilibrium analysis approach, and a finite element seepage analysis. The results suggest consistency of failure surfaces for 2D and 3D and an increase in FS values of 5 percent for the 3D approach, limitations of standpipe piezometers. The study demonstrated the sensitivity of the FS value, and the implication of adopting representative material properties, and water table levels, especially in cases where limited data are available, and assumptions need to be made to assess the long-term stability of a fly ash dam facility.

Aug 1, 2024

By A. T. English

X-ray dif action techniques were used to investigate ordering and domain coalescence for the B2 (CsC1) superlattice in this alloy. Essentially complete disorder is obtainable by drastic quenching. isothertmal ordering occurs very rapidly at temperatures between 565° and 680°C, only a few seconds being required for development of substantial long-range order. A very fine antiphase dormain structure, found in samples annealed for short times, undergoes coalescence with further annealing. Domain "size" is found proportional to (t)1/2 . This Yate law can be derived by adapting the formalism of Hillert's analysis 01- metallurgical grain growth. For this Purpose the material is descvibed in terms of a "Swiss-cheese " structure, consisting of two multiply connected, mutually intertwined domain volumes. The observed activation enevgy for coalescence, 70 kcal per g-atom, agrees with an estit~lated value ,for volume diffusion in disordered rrzaterial. It is suggesled that the experimental value vejlects the substantially disordered environment of mobile vacancies located in the moving antiphase domain boundary. The alloy Fe-Co-2V is bcc below about 900'C and orders into a B2 (CsC1) superlattice below about 730c It has important applications in magnetic components, including many requiring extensive cold rolling.* example, Marcinkowski and Brown6 observed a re1atively small as-quenched domain size of about 250Å in B2 Fe3A1. Since there appear to be no published data on domain coalescence in B2 alloys, this process was studied in detail. MATERIALS AND EXPERIMENTAL TECHNIQUES A commercial high-purity alloy, nominally 49 Fe-49Co-2V, was obtained from the Arnold Engineering Co. in the form of cold-rolled sheet 0.004 in. thick. Samples were annealed for 1 hr at 800°C in dry H2 to produce disorder and quenched into iced brine. They were then annealed in a nitrate-nitrite salt bath for various times at temperatures between 525° and 625°C. Estimates of the LRO parameter S and the APD size D were made using established X-ray diffraction techniques. Superlattice peaks are best observed using CoKa radiation, for which the value of (fFe-fCo) is maximized. Peak-to-background intensity ratio was improved by filtering CoKß from the incident beam to eliminate sample fluorescence, and by using a pulse-height analyzer. The LRO parameter S was computed from the ratio of integrated intensities I 100/I 200- Owing presumably to systematic errors associated with the presence of crystallographic texture and X-ray extinction, only rough agreement was obtained between experimental and theoretical (absolute) intensity ratios. For this reason certain experimental refinements (e.g., use of balanced filters) were considered superfluous and were omitted. Emphasis was placed on maximizing intensity in order to reduce the time taken to accurately determine the contour of the very small (loo), peak. This was done by point counting 105 counts at appropriate intervals. Background intensity averaged about 1200 cps.

Jan 1, 1967

By George Cole

WHILE many parts of Canada's pre-Cambrian shield are well served by railway, it is frequently necessary for prospecting purposes to proceed farther into areas in-accessible by rail. To such areas in summer the canoe was at one time the accepted means of travel for the prospector while the dog team was much used in winter. Al-though summer travel was much improved by the development of the outboard motor, the lack of facilities for cheap transporta-tion has been a serious hindrance to the employment of capital in opening up the distant fields. The pre-Cambrian surface of Manitoba, like that of Ontario, is hummocky, with rounded hills and ridges of rock alternating with basinlike depressions and valleys oc-cupied by lakes and rivers or by many low-lying portions covered with muskeg. Routes to the mines have not usually been direct or easy and seasonal vagaries have presented problems in themselves. In summer, water transportation may be the cheapest method for the longer dis-tances but it is not every water route that will satisfy the conditions of loading freight onto a boat or scow and of conveying it without interruption to its destination. By its location, a mine may require a large program of boat transportation in summer over part of its route, to be followed by winter freighting for the remainder. In order to carry on development and produc-

Jan 1, 1940

By Kenneth R. Hancock

Iron oxides are unique in that they are the only significant colored mineral found in a natural state suitable for use as a pigment after it has been pulverized to pigmentary size. The current world production of iron oxide pig¬ments is estimated by the author to be between 450,000 and 550,000 tons based on 1969 data. The fact that highly colored natural deposits of iron ore are found throughout the world ac¬counts for its use in prehistoric man's artistic cave paintings. These early artists did not realize that they had established man's first paint test fence which now has some 20,000 years of exposure. In addition to abundance, constituting about 7 % of the earth's crust, iron oxides have the advantages of low cost, permanency, and are not toxic. Through the centuries, succeeding civilizations have utilized iron oxides as a major source for decoration and protection when coloring was desired. In the last century the chemical industry has improved on nature by developing a complete range of synthetic iron oxide pigments which surpass the pigments pro¬duced from natural iron ores in uniformity, color quality, and chemical purity. In the United States alone, the combined production of natural and synthetic iron oxides produced sales of over $28,000,000 in 1970 (Stipp, 1970). Nomenclature With the increasing importance of the syn¬thetic iron oxides it is necessary to make a distinction between the natural or mineral pig¬ments and the synthetic pigments. Natural pigments are those products which are derived from selected ores and should not be confused with iron ores mined for steel production. Iron ores that are mined for steel must be capable of being mined and reduced to iron on a com¬mercial basis. These ores are selected on the basis of iron content and processing economics. It is therefore unusual when iron ores for steel production are suitable for use as mineral pig¬ments. Natural pigment ore sources are se¬lected for their special physical-chemical prop¬erties and can command a premium price. Synthetic pigments, and in this instance iron oxides, are those pigments produced from basic chemicals. Through chemical synthesis pig¬mentary sized particles are produced as opposed to comminution, the major procedure common to all natural iron oxide pigments.

Jan 1, 1975

A series of physical tests have been conducted to determine the actual performance of bunton to shaft side wall connections typically used in new shaft construction in South Africa. The test set-up is described, together with the applied loading, which incorporates a cyclical load component and a quasi-static load component, in an attempt to simulate actual conditions in the shaft. The test results are given and it is shown that generally the performance is adequate, provided double-slotted holes are not used. Generally the fatigue performance is found to be good, with the only exception being cases where the bottom of the bunton is lower than the seating level for the bunton to side wall connection. Arising from the tests, typical design values of connection stiffness, strength and fatigue life are proposed and a design procedure including these three key aspects of connections is described.

Jan 1, 2005

By A. F. Colombo

The western Mesabi range nonmagnetic taconites containing about 34 percent Fe were evaluated by the Bureau of Mines in a 900-pound-per-hour pilot plant employing a selective flocculation-desliming-cationic flotation technique. The flotation step was a reverse flotation process and involved the flotation of the gangue minerals. The objective of the research was to increase the availability of domestic raw materials for the iron and steel industry. The beneficiated ores yielded concentrates containing 62 to 64 percent Fe and less than 5.5 percent Si02 with accompanying iron recoveries that averaged about 75 percent. Comparable flotation results were obtained with either fresh or 80 to 90 percent reclaimed water. Recycled waters having turbidities as high as 5,000 ppm Si02 did not affect the flotation process. Reclaimed waters containing residual calcium contents of less than 10 ppm gave better flotation concentrates than those containing 15 ppm.

Jan 1, 1976

By C. Blawert

The corrosion properties of the skin and the bulk of semi-solid processed and high pressure die cast AZ91 alloy were studied in 5% NaCI solution by (a) analysing the corrosion morphology, (b) measuring electrochemical polarization curves, (c) performing electrochemical impedance spectroscopic measurements, and (d) immersion tests at constant pH-values. Using XRD, LM, SEM and EDX to evaluate the microstructure of skin and bulk specimens, the corrosion results were related to the microstructures of the particular alloys. However, microstructure and corrosion performance were found to be similar for both production processes, and only slight but distinct differences were found. Generally, the skin corrosion properties are inferior to those of the bulk, with the exception of the high pressure die cast AZ91 alloy, where the finer microstructure of the skin layer exhibits a better performance as showed by impedance studies and confirmed in long term immersion tests.

Jan 1, 2004

By Luben Savov

This paper presents recent research works on the removal of the tramp elements Cu, Sn, Zn and Pb from steel. The evaporation of Cu and Sn in iron-based melts treated at reduced pressure of the gas phase was studied in a vacuum induction melting furnace. The effect of chamber pressure, temperature and melt composition was investigated. Since the main source of contamination of steel with Sn and Zn is the recycling of tinplate and zinc coated steel, respectively, possibilities for the removal of meta1ic coatings in a scrap pre-treatment stage were studied, too. Tin was removed in the temperature range 400-5S0°C by treatment with reactive gases featuring high sulphur potential. Zinc can be removed by evaporation or by a combination of thermal and mechanical treatment. The paper discusses the thermodynamics of Pb in carbon-saturated iron melts, too.

Jan 1, 2001

By M. M. Fine

This report presents the results of laboratory mineral-dressing investigations by the Bureau of Mines of 14 individual or composite character samples from deposits in the Batesville manganese district. It will be noted that some concentrates have met or approached analytical specifications for metallurgical manganese ore although great variations in both physical and chemical composition from once deposit to another make each a new problem. In most cases it is evident that a substantial loss of manganese has occurred in the various slime and tailing products. An important aspect of this work is the research being conducted on manganese-bearing limestones. Recent reconnaissance indicates that this resource constitutes one of the major domestic reserves of manganese. Laboratory study has shown that ferrograde concentrates can be recovered from samples of manganese-bearing limestones from two properties. Research on samples from other areas is still underway.

Jan 1, 1957

About Barrick Paste Backfill at Barrick Goldstrike Rodeo Paste Plant Cyclone Lab Testing Challenges and Lessons Learned Future Barrick Projects

May 1, 2013

By Jean-Guy Deschamps, Allen H. Gipson

Profitability of heap leaching projects could be greatly improved if heap heights were significantly increased. Currently, heaps have been designed to a maximum height of approximately 450 feet. Higher heaps reduce ore processing costs by handling greater quantities of ore per unit area of pad. In areas with high rainfall, higher heaps also offer the benefit of a reduced catchment area resulting in less meteoric water to manage. The concern with high heaps is the functionality of geosynthetics and piping under extreme loads. Knight Piesold in Denver has developed the capability to test geosynthetics and collection piping under loads equivalent to those imposed by

Jan 1, 1996

In February 1974 a continuous synthetic polymer dosing plant was installed at Hamersley Iron Pty. Limited's Pellet Plant at Dampier. The polymer, supplied in a liquid sus- pension, is used to improve the drying characteristics of green pellets. 'Three years of test work were involved in the development of the use of polymers. Polymer is continuously dosed to the balling spray water system at a rate determined by the flow of spray water to the discs. Problems have been experienced with handling the polymer in 44 gallon drums, the increased viscosity of the spray water, disc overloads, increased bed strength and increased "stickiness" of pellet fines.

Jan 1, 1974

By R. A. Lowe, P. B. Malla

Smectite is a common impurity in the kaolins of Georgia.This impurity is harmful to the low-shear rheology of kaolin slurries in concentrations as low as a few weight percent. The deleterious effect of smectite on the low-shear rheology is due to the swelling of the mineral. Montmorillonite containing clays were treated to precipitate a compact brucite layer {Mg(OH)2} in the interlayer region of the expandable layer silicate mineral. This treatment forms ahydroxy-Mg-montmorillonite with characteristics similar to chlorite. This treatment effectively reduces the swelling capacity of the mineral and improves the rheological properties of kaolin slurries contaminated with smectite impurities.

Jan 1, 1999

By A. Smith

After the introduction of mechanized bord-and-pillar development at Dumacol in 1958, pillars were being developed at a much faster rate than they could be extracted by hand loading methods. Efforts were therefore made to increase the rate of pillar extraction by mechanization. Following two partially successful mechanized stooping trials in 1964 and 1971, it was decided that mechanized pillar extraction with 1 m3 cable-reel front-end loaders should be introduced. The first section to employ the new equipment started production in May 1979, and the mine now has four mechanized pillarextraction sections in operation. Considerable improvements in production, productivity, safety, and percentage extraction have been achieved.

Jan 1, 1985

By Thomas L. Barkley, Michael A. Indihar

The new Cyprus Northshore Mining Co. has taken the previous blasting methods of Reserve Mining Co.'s mine in northern Minnesota and adapted them to a new competative Iron Ore Industry. Cyprus was challenged to develop new blasting methods to reduce costs and improve results over the previous mining operation. Many of the older procedures have been kept, but others have been changed in ways that bring the mine operation up to state of the art technology. In addition, unique ideas not previously tried in the North American Iron Ore Industry have been instituted. So far, this has reduced Cyprus's blasting costs by 70 percent.

Jan 1, 1991