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By H. B. Charmbury

In the United States and in Pennsylvania in particular the coal mine drainage problem is of continuing and growing interest to the coal mining industry, the state government, the federal government and the public at large. The 1965 amendments to Pennsylvania's Clean Streams Law prohibit the discharge of acid mine drainage into the streams of the Commonwealth after January 1, 1967. Because of this new legislation, the coal mining industry and state government are extremely aware of the necessity for new techniques for treatment and prevention of the flow of acid mine drainage from the active mines of the Commonwealth in order to keep the coal mining industry in business in Pennsylvania. Approximately one-third of the total volume of mine drainage presently polluting the streams of the Commonwealth originates from "active" coal operations and two-thirds comes from "abandoned" mine discharges. As early as 1963 it became evident that the Commonwealth of Pennsylvania and the coal industry in Pennsylvania would have to take active steps to abate the mine drainage pollution of Pennsylvania's streams and rivers. This became quite clear during the deliberations in Harrisburg which climaxed a twenty year struggle for effective strip mining legislation. The bituminous strip mining law enacted that year made it unlawful to have any acid discharge from active stripping operations.

Jan 1, 1968

By D. R. Buist

The Taharoa plant of New Zealand Steel Mining Limited extracts a 57% Fe titano-magnetite concentrate from a large mineral sand deposit 90 miles south of Auckland on the west coast of New Zealand's North Island. The plant consists of an 18-inch suction cutter dredge which feeds a 750 TPH floating separation plant. An initial gravity/ size separation is obtained using cone concentrators. Finished concentrate is produced by a combination of conventional drum magnetic separators and top fed wet Mortsell magnetic separators. Concentrate is stockpiled by cyclone, and reclaimed by a bull- dozer and tunnel system. Repulped concentrate is pumped by sub- marine pipeline to slurry tankers anchored at a single buoy one mile offshore. Current concentrate production rate is in excess of one million metric tons per year.

Jan 1, 1973

By William Kohan

The industrial grinding process has undergone changes to better address the market and economic needs. Fine grinding of dry materials has developed to the point where classifying linings and fine ball charges improve mill efficiencies. Roller mills as well have wide acceptance due to their power efficiencies. The mill, by its nature, cannot provide the specific particle size or range of sizes which are required for further processing or final use. Therefore, various separators are operated in conjunction with the mill to control particle size. The sizing device helps minimize over grinding and control top size. Rising energy costs combined with increasingly tighter quality specifications have led to increasing study of the grinding and separation process.

Jan 1, 1985

By B. A. Filas

Stabilizing fine coal refuse ponds for reclamation at Monterey Coal Company's No. 1 Mine has been difficult. Entrained water in the stored refuse causes liquefaction as reclamation caps are placed, resulting in additional material requirements than originally projected to stabilize the pond surface. Laboratory results indicate that in-place refuse densities may be substantially improved at No. I Mine by converting from a single-point to a managed slurry distribution system. Increased densities result in improved storage efficiency, less entrained moisture and a more stable refuse mass, thereby providing an improved working surface for reclamation and improved post-closure cover stability.

Jan 1, 1993

By R. S. Shepard

A quick glance at a-portion of the title of this discussion -'Rolling With The Punch" may immediately lead you to assume that I am about to expound on the so-called manly art of self-defense. So that you will not have been misled entirely we will devote our considerations to a far more important art and if I may, I should like to begin by quoting Vincent Van Gogh. According to a literal translation the artist in describing one of his famous paintings said "these peasants are eating their potatoes with those very hands that dug them from the earth' and put them in the dish". Vincent Van Gogh may not have realized at that time, that he could likewise have been describing what is probably one of the oldest of all arts - the art of Material Handling - an art that man with the aid of science has tried to improve since the beginning of time.

Jan 1, 1963

By G. L. Brooke

At present, there are two known cobalt deposits in the 48 contiguous states. This paper is a brief description of one of these deposits. It is a Mississippi Valley type deposit, but somewhat atypical in that the metal of greater interest is cobalt as opposed to lead, zinc, and copper. The history and present work are outlined along with a discussion of the geology and mineralogy.

Jan 1, 1981

By Gunnar Nord

Shifting ground conditions when tunnelling often call for different methods of attacking the tunnel face. In order to overcome problems with local unstable soft ground in a hard rock tunnelling project the Boodex method offers a cost effective alternative. Boodex and variants of it is a combination of two well-known techniques, drilling with Boomer rig using Odex gear. It will give a steel lined hole ready for grouting and the steel pipe has a load bearing capacity that means that a spiling effect is achieved. In this paper the method and some applications will be described with possibilities and limitations.

Jan 1, 2003

By Nikhil Dhawan, Débora Moreira, Yogendra Pratap, Himanshu Tanvar

A glauconitic siltstone sample with a potash content of 10% is investigated as a potential potash source. The fine grain structure comprises potash bearing phases of glauconite, muscovite, and microcline. The as-received samples showed poor dissolution ~ 5%. Planetary ball milling was attempted for the dissociation of the underlying silicate structure for the potash release, and ~ 60% potash was obtained after 12-h milling. Mechanical activation (8 h, 60% NaOH) prior to heat treatment (600 °C, 30 min) was found successful in recovering more than 95%K values from glauconite. The final residue consists mainly of quartz, indicating a complete breakdown of the silicate matrix. The mechanical activation process followed is simple, adaptable, and less energyintensive compared to existing methods.

May 4, 2020

By W. R. Sharp

The ability to target, delineate, excavate, and produce local resources is essential to the establishment of man's long-term presence in space. Many procedures and equipment utilized to mine resources here on Earth may be directly applicable on the lunar surface, while others may need extensive redefinition and development. This paper compares, for a lunar base, the alternative of burrowing into and below the lunar surface with that of surface mining. A conceptual underground mechanical excavator is presented.

Jan 1, 1991

By A. M. Raichur

The selective adhesion of hydrophobic Mycobacterium phlei to coal particles is responsible for flocculation of fine coal from associated ash forming minerals. The driving force for the differential adhesion is the hydrophobic interactions between the fatty acid surface of the organism and hydrophobic nature of coal. The effect of Mycobacterium phlei on surface hydrophobicity, surface charge and mechanism of adhesion on coal and associated minerals are controlled by several factors including hydrophobicity and surface and solution chemistry of the system. Adhesion measurements indicate that maximum adhesion occurs below the isoelectric point (IEP) of the coal particles. While massive adhesion of Mycobacterium phlei is observed on coal, however, negligible amount of Mycobacterium phlei attaches to mineral pyrite and quartz.

Jan 1, 1995

By C. H. Smith

The present interest in beryllium seems to be the result of recent developments in the uses for the metal discovery of significant deposits of disseminated beryllium ores, and the development of chemical and physical processing techniques, for recovering the beryllium values contained in these ores. At the present time most of the new and potential uses for beryllium are in the research stage of development and are not consuming large quantities of the metal. However, they do point to an expanding market. Interesting new discoveries or extensions of previously known deposits have been reported during the past year from the Boomer Mine in Colorado, the Mesquite area of Nevada,, the Chemalloy pegmatites in Canada, the Brazilian and African pegmatite districts and from other areas, However, this paper will discuss only four of the beryllium deposits, which appear to be of special significance due to their; large reserves of ore and promise economic development. The new chemical and physical processing techniques are not discussed in detail, but it should be stressed that the development of an economical process to handle the pegmatitic and low-grade non-pegmatitic beryllium ores is of great importance to the development of the beryllium industry. Scientists in both government and industry are co-operating in this effort and it is expected that commercial processes will be developed in the near future.

Jan 1, 1962

By Joseph M. Chelini

The report shows the sensitivity that nine different cash-flow factors have on the discounted rate of return calculated from feasibiliity- studies on potenital open-pit orebodies of silver, copper, and uranium. Cash-flow factors of "grade", "market value", and "recovery" are. the most sensitive. This verifies the need of reliable estimates for these factors. The cost of evaluation of "preproduction cost" is the least sensitive. This gives credence to the fact that more consideration should be given to compiling sufficient data, as the largest financial losses are not in the cost of evaluation but rather in the abandonment of an unprofitable mining operation after a commitment of capital is made on the basis of an incomplete evaluation. Sensitivity analysis of cash-flow factors enhances evaluation programs by disciplining the collection of data and allowing more realistic distribution of evaluation monies.

Jan 1, 1971

By Arthur S. Cornford

According to Arbiter (Reference 1), the ball mill was invented by Brückner in Germany in 1876 and was first used in the United States on ores about 1905. The basic concept was a simple rotating cylindrical drum in which the tumbling action of the charge of material and grinding media resulted in size reduction of the material. Despite the very low mechanical efficiency of this method a number of factors have caused the tumbling mill to remain, by far, the most widely used piece of equipment for mineral grinding. The principal factors influencing this situation have been simplicity of design, ease of manufacture, ready adaptability to familiar material handling layouts and the absence of practical alternatives acceptable to the industry. In the early mills, the material was ground in batches, the mills being charged and discharged through doors in the shell. The shell was supported by means of solid trunnion shafts resting in plain bearings and the drive was accomplished through one of these shafts. In some later batch mills, the mill shell was supported on rollers which were also used to drive the mill. At an early stage, continuous operation was made possible by feeding and discharging the mill through hollow trunnions, the method still in most widespread use. The mechanical and structural design of the early mills was not an onerous engineering task. Norse sense and good practical knowledge were key qualifications. The mill shells had to be heavy enough to withstand the physical abuse they would receive in the field and the bearings had to have low enough unit pressures and sufficient wear retol to ensure several months of operation before the need for replacement occurred. When these requirements were satisfied, stresses developed in the equipment during operation were insignificant and the majority of structural failures were probably due to the use of inferior materials in manufacture. Over the years, the ever present demand for increased productivity has resulted in a steady Increase in the size of units of production equipment, including grinding mills. Arguments have been presented elsewhere, for and against the Idea of a high throughput single line grinding operation as opposed

Jan 1, 1972

By L. G. Wilson

In our comparison of California and Turkish colemanites, we should first place the discussion in context. In order to exclude technical considerations, which are not germane to this paper, we must make the manifest and basic observation that if colemanite were not acceptable for the production of glass products it would not be used, and we would not be interested in this comparison at all. Suffice it to say that the colemanites, being calcium borates, provide a necessary flux in glass manu¬facture, together with the requisite degree of physical strength and chemical durability which can be achieved only by the use in glass of a. flux substanti¬ally free from alkali; so the sodium borates are automatically excluded from the production of textile fibers. Thus we have today under consideration only California colemanite, Turkish cole mite, and, because it provides a degree of competition to both, ABA, or anhy¬drous boric acid, which, although it is a refined intermediate and of much higher cost, it is also of a much higher degree of purity, and its characteristics can easily be modified to produce a desired end product, so we must include it in any consideration of high quality borates. [Calcim Borate Pentahydrate] Colemanite is a [calcium pentahydrate,] with the formula Ca2B6011.5H20. It has a theoretical B203 content of 50.8%.

Jan 1, 1973

By William F. Butler

I propose to do three things today. First, take a broad look at the role of mining in the Latin American economy; then, review briefly the current situation in four principal metallic mineral exporting nations -- Chile, Mexico, Peru and Venezuela; and. finally, raise some, policy questions that seem to me to be important. The Role Of Latin America In World Mining First, let's consider Latin America's position in world mining markets. Latin America provides more than 5% of world output in 16 metals or ores, ranging from antimony and barite to Tungsten and Zinc. Latin America supplies a fifth or more of the world's antimony, beryl, bismuth, copper, fluorspar, silver and Tellurium.

Jan 1, 1962

By R. J. Roman

Controlled and uniform distribution of the leach solution to a heap is of primary importance to achieving the desired rate of metal recovery and PLS grade from the heap. The step used to engineer the irrigation system are the same whether drips, wobblers or sprinklers are to be used. The mining rate, leach cycle time and heap height influence the heap cell size which along with the irrigation method selected controls the design of the irrigation system. The steps in the design procedure are explained as are the advantages and disadvantages of each irrigation method.

Jan 1, 1996

By J. F. Snyder

Minor elements determined by atomic absorption spectroscopy include: zinc, cadmium, copper, cobalt, nickel, chromium, manganese, and iron. Of these elements, only three; zinc, cadmium, and copper are found to have been introduced with the ore-forming fluids. Iron, manganese, chromium, and nickel were increased in dolo-stone lithologies when compared to limestone lithologies. The uniform distribution of cobalt suggests this element was neither increased nor decreased during ore emplacement nor during dolomitization of the rocks. Zinc increases adjacent to ore result from leakages into open spaces rather than as pervasive aureoles surrounding ore bodies.

Jan 1, 1977

By U. Srivastava

In the processing of manganiferous ore, it is useful to control whether the manganese (Mn) goes to the iron product to produce ferromanganese, or to the slag for extraction as a high Mn product. This can be done by manipulating the thermodynamic conditions for manganese oxide(MnO) reduction to control whether it remains as MnO or converts to metallic Mn. Results are presented showing that during production of iron nuggets, reduction of manganese oxide (MnO) can be controlled by changing the furnace temperature and reductant composition appropriately.

Jan 1, 2010

By M. M. Botz

Cyanidation tailings which are disposed in a surface impoundment experience a loss of cyanide due to natural degradation, frequently reducing the cyanide concentration to very low levels. Quantifying cyanide losses in terms of pond geometry, local weather conditions and feed solution chemistry has been largely empirical though in many cases mining operations rely on surface impoundments to reduce cyanide to below an internally regulated concentration or an effluent limitation. To permit a more quantitative evaluation of cyanide losses in an impoundment, a computer simulation was developed to estimate the losses of free, WAD and total cyanide due to dissociation, photolysis and volatilization. Results of the model are compared against data collected for a North American tailings impoundment during 1998.

Jan 1, 1999

By Felicia F. Peng

The naturally occurring aged manganese oxide coated on the granular media was found to have a catalytic effect on the removal of low concentration of Mn(II) (-1 ppm) from drinking water. Applying this principle, a manganese removal technique was developed for removal of higher concentration of Mn(II) (-100 ppm) from mine drainage by using various aged filter media and synthesized granular media with manganese oxide coatings. Laboratory-scale continuous granular media column experiments were conducted to assess the feasibility of manganese oxide-coated granular media for Mn(II) removal from synthesized mine drainage. The removals of Mn(II) were evaluated as a function of operation parameters including solution pH, manganese oxide concentration coated on the media, interstitial velocity, and oxidant concentration of influent. Higher solution pH and/or higher manganese oxide concentration promoted the removal of Mn(II) on the oxide-coated granular media under low interstitial velocity. Addition of sodium hypochlorite as an oxidant in the influent resulted in continuously regenerated oxidized surface to serve as the catalyst for Mn(II) oxidation reaction on the surface of oxide-coated media.

Jan 1, 1994