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By Norman R. Paterson

In November 1980 a combined airborne electro-magnetic (INPUT.) and magnetometer survey was conducted by Questor Surveys Limited in the State Line Area, Colorado-Wyoming. The survey was the result of discussions over a prolonged period between the authors and various investigators of the State kimberlite occurrences. As a result of these discussions and literature studies, it was decided that airborne geophysical methods would be potentially useful in the exploration for new kimberlite occurrences. The survey was designed by Paterson, Grant and Watson Limited and conducted by Questor Surveys Limited over an area in which more than 15 kimberlite bodies were known and on some of which ground geophysical surveys had been conducted. The survey was designed primarily to determine the airborne electromagnetic and magnetic responses of the known occurrences and to deter- mine whether these responses would be detectable under similar conditions in other parts of the State Line District and elsewhere.

Jan 1, 1984

By Alan C. Richter

Introduction The East-West Gateway Coordinating Council is an organization of local governments formed in 1965 to identify regional problems and to formulate policies, plans and programs to resolve them. The major goal of the Gateway Council is to improve the quality of life for the citizens of the St. Louis Region. While East-West Gateway Coordinating Council is the organization I represent and it only deals with the St. Louis Metropolitan Area, you will find one or more similar organizations in each of our nation's urbanized areas. As a result, for illustrative purposes, I will use my organization to portray what is happening nationwide. For example, in order to eliminate duplication, the Council reviews local applications for approximately 100 federally funded programs in such areas as highways, mass transit, parks, water treatment, and sewers before they can be sent to the appropriate funding agency. The Council's varied functions place it in a unique position of receiving more and more responsibility for developing strategies of implementation of various environmental regulations. This is due to the fact that environmental control is a relatively new field and we, as a country, are relatively inexperienced. The resulting regulations and guidelines will depend, to a great extent, on what the general public is willing to accept in terms of controls and what price they are willing to pay in terms of taxes and increased costs. Land Use: Growth vs No Growth This is perhaps the most encompassing environmental issue. We, as a nation, are beginning to realize that land is a limited natural resource and that the way we choose to use 'this resource affects many other aspects of our lives--whether we can catch edible fish in the Mississippi, how much we pay for sewer services, if we can swim in a

Jan 1, 1977

By Weijie Wei, Jinwang Zhang, Shengli Yang

In longwall top-coal caving (LTCC) mining with an inclined seam, the recovery rate is low and equipment stability is poor due to the unbalanced top-coal drawing process. To address these problems, this paper proposes the dynamic group caving method (DGCM), whose basic premise is that when the drawn volume of top coal from a support reaches about half, the next support begins drawing top coal, and the drawing process between the two supports is half done. Using particle flow code (PFC), the caving mechanism of top coal under DGCM was investigated. The results are of significance to realize high efficiency and precise caving in LTCC mining with an inclined seam.

By Trevor R. Ellis

In August 2011, the Southern African Institute of Mining and Metallurgy (SAIMM) contacted mining institutes and related societies internationally to assess their interest in participating in coordination of the review of the South African Code for Mineral Valuation (SAMVAL) with reviews of other mineral valuation standards. The main mineral valuation standards are the CIMVal Standard of The Canadian Institute of Mining, Metallurgy and Petroleum (CIM), the VALMIN Code of The Australasian Institute of Mining and Metallurgy (AusIMM), the SAMVAL Code, and the extractive industries? guidance note of the International Valuation Standards Council (IVSC), Valuation of Properties in the Extractive Industries, GN 14, designed for application within the full set of International Valuation Standards (IVSs). By January 2012, SAIMM had concluded that the level of respondent interest was adequate to organize a meeting. A meeting was scheduled for April 18, 2012 in Brisbane, Australia in conjunction with a VALMIN mineral valuation conference organized by the AusIMM. The stated purpose of the meeting was to develop an accord on terms of reference for pursuing harmonization of mineral asset valuation standards adopted by the participating mineral institutes. SME decided that, although it has not developed its own mineral valuation standard, it should participate in the Brisbane meeting and the harmonization process, as also did the American Institute of Minerals Appraisers (AIMA).

Jan 1, 2012

By Joseph G. Selmeczi

Lime and limestone-based SO2 scrubbing processes have demonstrated reasonably good success in removing low concentrations of SO2 from flue gases. While most of the operating problems experienced in the early days of scrubbing have been worked out, problems usually increase and removal efficiency drops with increased amounts of SO2 present in the gas stream. In order to overcome these difficulties, yet still taking advantage of lime and limestone as the lowest cost neutralizing agents, a host of so-called double- alkali systems were developed. These processes take advantage of cations such as Na+ and NH4+ capable of forming highly water soluble bases or basic salts, such as hydroxide, carbonate or sulfite, which having been neutralized or acidified by the absorbed SO2 can be regenerated with a lower cost base such as lime.

Jan 1, 1974

By Mike Ghassemi

It is clear that precise overground and under-ground mapping is an important factor for all designers. Due to rapid changes in underground construction, tunnel designers are increasingly in need of updating project information. This article explains the latest techniques for detecting under-ground utilities as well as underground mapping. Global Positioning System (GPS) is a very ac-curate and popular navigation and mapping system that has been used extensively above ground, but is not used for underground mapping as signals are not strong enough to pass through ground or water. Most underground techniques were developed for military applications during the first and second world wars. Later, the techniques became public. For example, ground penetrating radar was developed for the military in 1970 to be used for locating tunnels under the demilitarized zone between North and South Korea. Later, the same technique was used for detecting unexploded ordinance such as plastic land mines.

Jan 1, 2011

By Fumio Wada

Kuroko deposit is a stratabound massive sulphide and sulphate deposit associated with Miocene submarine volcanics and has been considered to be a prototype of meta- morphosed Palaeozoic and Precambrian equivalents. Since the discovery of Uchinotai deposit of the Kosaka mine in 1959, Dowa and other mining companies have conducted intensive exploration work in the Hokuroku district of northeastern Japan. Dowa has been placing its first priority on the exploration of Kuroko deposits and made a series of remarkable successes in finding the Kuroko deposits, i.e. Uchinotai, 1959; Matsumine, 1963; Uwamiki, 1966; Fukazawa, 1969 and Ezuri, 1975. It is emphasized that our successes have resulted from the proper application of exploration technologies accumulated through our experiences. Firstly we defined the Kuroko horizon and favourable felsic volcanism based on the detailed structural and volczno-stratigraphic study of the Hokuroku district, and then delineated the promising areas by means of the quantitative evaluation of geophysical, geochemical and mineralogical parameters such as the magnetic susceptibility and contents of alkaline and alkaline earth metals in the foot wall dacites and clay mineral assemblages of both hanging and foot wall pyroclastics and dacites. Practical application of these techniques is essential to our routine Kuroko exploration.

Jan 1, 1982

By W. H. Wilson, G. Bjarnholt, D. C. Holloway

This paper describes the results of field tests conducted on a 5x25m bench face to evaluate several new concepts for improving smooth wall blasting. These ideas involved the use of notched boreholes to direct the fractures and unconventional types and placements of explosives. The notches were made with a mechanical broaching tool, a water jet and with shaped charges. Borehole pressures were measured with an inexpensive and expendable pressure transducer developed for this program. The testing showed that at hole spacings 38% greater than normal practice, notched holes with half the normal loading density produced equivalent results.

Jan 1, 1986

By James A. Finch, Xiang Zhou, Yue Hua Tan

Widely used as collectors for nonsulfides, amines also show some frothing properties. Evaluating frother functions of amines and their combination with conventional frothers addresses whether one reagent delivering both collector and frother functions compromises the efficacy of either. From the findings, whether blending with frother confers any benefit requires knowledge of the residual amine concentration. If it is below about 10 ppm, blending eliminated coalescence, but there appears to be no benefit if the concentration is above 15 ppm.

By M. L. Smith

SAG mill throughput is often a bottleneck in increasing metal productivity. Improved size distribution control in the mill feed can be used to increase mill production. This can be accomplished by controlling blast fragmentation as a function of energy input and rock characteristics. Such an approach requires the integration of rock fragmentation and comminution modeling. The optimal mill feed size distribution is determined by adapting a population balance comminution model to a measure of rock hardness or fragility which is also relevant to the rock fragmentation that is achieved by blasting. The relation between the size distribution and fragility of the feed and of the mill's product and the critical size in a SAG mill is examined.

Jan 1, 1993

By J. L. Boyd

The mining and processing of basic metals relies on water as a medium for transport. Metallurgical ores are ground, concentrated, leached and refined in an aqueous medium. Water is used for temperature control during processing and in air pollution abatement during smelting. All of these process steps result in liquid wastes. Many of the aqueous wastes from ore processing areas become the raw product for a second stage and water recycling may begin. The point at which water recycling or reuse has been initiated in the past, rather than water discharge, was where water conservation was manditory due to a shortage, where process conditions would allow or benefit from reuse, and where economic considerations demanded reuse. The Fontana, California plant of Kaiser Steel Corporation is an example of an integrated steel plant that was forced to practice water conservation and reuse due to its location in an arid environment.1 Only a small amount of water required to maintain the water reuse system in balance with respect to dissolved solids and product quality is discharged. The Butte, Montana copper ore processing plant of The Anaconda Company obtains 66% of the water required for production by recycling, after clarification and chemical treatment, 30 MGD of wastewater from its tailings ponds. This operation is estimated to save the company about $1200/day over a once through water system.2 Here plant location and economics favored water reuse.

Jan 1, 1975

By P. J. M. van Heteren

The flotation system is usually distinguished from other physical chemical systems by the importance of interactions at the solid-liquid and solid-gas interfaces. In recent years, numerous quantitative studies have been made of the distribution of common collectors between the solid and aqueous solution phase. Although in flotation the main emphasis is placed on the adsorption process, chemical reactions will also take place in the bulk solution phase, These side reactions are often undesirable and will contribute towards the complex behavior of many a flotation system In sulfide flotation, the precipitation of insoluble base metal xanthates is a well-known phenomenon although the conditions under which the precipitation reaction will proceed and the magnitude of the solubility products are not known with accuracy. A knowledge of the solubility of these xanthate salts will not only be of value in flotation research, but the mill operator might be interested in knowing whether precipitation of metal xanthate can be controlled or completely prevented in the flotation circuit thereby reducing reagent consumption, For these various reasons the solubility of lead, copper, zinc, and silver ethyl xanthate was determined. The experimental techniques and results will be discussed in this paper.

Jan 1, 1958

By Colin C. Brooks

The Ok Tedi gold/copper deposit of almost 800 million tonnes was found in I968 because at that time technology had just developed sufficiently to enable exploration of such an area, world markets and prices for copper encouraged exploration for large deposits of low grade ore, Papua New Guinea law encouraged exploration by groups with men, money, management and expertise necessary for successful prosecution of such a search and such groups were already operating in the country.

Jan 1, 1990

By John E. Kinnison

The Mission mine, located in southern Arizona near Tucson, is a recently developed open pit which produces 15,000 tons per day of copper ore. The mine lies on a wide and gently sloping bajada sweeping northeasterly from the Sierrita mountains. It derives its name from the nearby Mission San Xavier del Bac, built circa 1700. The ore body is everywhere covered by about 200 feet of alluvium, as are the adjacent Pima and Palo Verde mines. The geology of the Mission deposit is known principally through the study of diamond drill holes spaced 150 to 300 feet apart. The open pit is in an infant stage and has not yet revealed much of the deposit, although information obtained there by the operating staff, and from a few thousand feet of exploratory underground workings, has added significantly to the general fund of knowledge. Permission to publish was granted by the American Smelting and Refining Company. I am indebted to Kenyon Richard and J. H. Courtright for criticism of this paper and for their direction during the several years in which I studied the Mission deposit. Acknowledgment is given to consultant in petrography, Robert L. DuBois of the University of Arizona. The only previous publication pertaining directly to the geology of file Mission deposit appeared in 1959 (Richard and Courtright), and may not be everywhere readily available. Cooper (1960) has published a short paper on the district

Jan 1, 1963

By E. E. Malouf

For centuries small amounts of copper have been recovered from acid mine-drainage waters. In recent years, the expansion of copper-bearing waste dump leaching for copper recovery has established a technological basis that is rapidly converting the art of copper leaching' into a science. Leaching of copper, whether from copper-bearing ore or waste, follows well established chemical reactions. These reactions are commonly in an acid circuit, but where leaching of copper is to be made in rock that is a high acid consumer, ammonia and ammonia carbonate, as well as cyanide leach solutions, can be used effectively. Current hydrometallurgical processes are being applied at an ever increasing rate to recover the trace amounts of copper in copper mine waste by in-place leaching. Currently approximately 300, 000 tons of copper are produced annually in this manner where as recently as ten years ago, only one-eighth of this amount of precipitate copper was produced.. Where copper occurs as an oxide in higher concentrations as to be classified as an ore rather than waste, then the hydro-metallurgical processes are applied as percolation or agitation leaching in vats, pachuca tanks, or prepared heaps. This approach gives better control over the recovery of the leach solutions, particularly in the processes where ammonia or cyanide leaching agents are to be used.

Jan 1, 1972

By G. E. McClelland

In recent years exploration and development of low-grade sulfide precious metal ore deposits has increased. Low- grade ores are usually processed using conventional heap leach cyanidation methods. The potential for acid mine drainage from spent sulfide ore heap leached residues remains a concern even though the processed residue is stacked on an impervious liner system. It is therefore of critical importance to evaluate methods for long term prevention of acid mine drainage from sulfide heap leachable ores during the precious metal recovery process rather than mitigation during the closure and reclamation phase. This paper discusses two simple AMD prevention options for the recovery process phase. Laboratory evaluations were made using a modified humidity cell kinetic AMD test method on two low-grade sulfide ores without addition of an alkaline component and on the same ores with natural limestone or acid neutralizing oxide ore blended with the feeds before kinetic testing. Laboratory results are discussed in detail and demonstrate that blending an acid neutralizing component with sulfide ore effectively prevents the production of acid from the processed residue.

Jan 1, 1996

By Josh B. Taggart

Some twenty to twenty-five years ago we saw the beginning of mechanization in our coal mines, It has now progressed to the point Chat as instruments of production the pick and shovel are things of the past, They had to give way to better and more efficient methods--so mechanization, followed by and combined with automation, has become common-place in our mines. Our coal could not keep its competitive position without this progress Without it our industry could not look to the future with any degress of confidence. Today we lock back and see cases of regained and salvaged markets. We see better coal products being produced at decreasing costs. We see better utilization of manpower and a stronger, more confident industry, Our hats arc off to those mining men, equipment manufacturers, labor leaders, and others who had the foresight to work toward these ends and the ability to bring them about.

Jan 1, 1962

By D. B. Sikka

Porphyry type copper ± molybdenum deposits typically occur in the Phanerozoic rocks and have been well documented. During the past two decades a number of porphyry type Cu ± Mo deposits which range in age from 1055 ± 35 Ma to 2970 Ma have been identified in the Precambrian rocks of Australia, Canada, China, Finland, India, Namibia and Zambia. Kalanjkhand porphyry copper deposit M. P., India which is estimated to contain 789 million tonnes averaging 0. 83 percent Cu (millhead-grade); 0.004 percent Mo; 0.2 gm/t Au; 6 gm/t Ag and a cap of 7.532 million tonnes of oxide are averaging 0.8 percent Cu. The economic potential of the expanded copper mining milling, smelting and refining complex to be built in the future at Kalanjkhand, which is the largest porphyry copper deposit discovered to date in the Precambrian rocks of the world is presented.

Jan 1, 1992

By Allen D. Graham

The coal industry in South Africa is briefly outlined. Test- work carried out on bulk samples of coal in the laboratory and used in the design of the Van Dyks Drift washery are described. Factors affecting the selection of equipment and the designed capacity of the plant are discussed. A description of the crushing plant, washery and load out section is given together with performance data obtained in the final acceptance tests. New features incorporated in the Van Dyks Drift plant and in more recent plants of the Group are outlined.

Jan 1, 1982

By C. N. Bailey

Let's review the economic factors in mill design. Talking about engineering economics in mill design reminds me of an old' saying "There are several ways to handle women but nobody knows what they are." I'm sure that the same economic factors do not apply to each of our mill designs, but for the sake of emphasis, it is well to review a few of them. They are so simple that we are apt to feel they are not important. Other speakers today are talking about the engineering factors of mill design, but I'm asking the question "Have we checked the economic factors involved in these designs? Have we checked the obvious? Many great discoveries have resulted from analysis of the things that appeared to be obvious all the time. What are some of these economic factors? Perhaps the most basic one is simply the value of minerals in place if minerals have value in the ground, they have value only because many important and different considerations add up to the probability that the minerals can be mined, beneficiated and disposed of profitably. The size formation and quality of the ore body, the distance from market, and the transportation available to the market area, depreciation rates, taxes, and the ownership interests involved are but some of the factors that must dovetail into the answer of profit, an answer prerequisite to hoped-for financing.

Jan 1, 1961