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By A. B. Fly

This paper presents the equipment and techniques developed to mine subsurface mineral deposits through 16 inch bore holes entirely by hydraulic methods. Use of this equipment for excavating large cavities in oil and water well producing zones is discussed. Results of surface experiments using high pressure jet streams of water to determine the cutting rates of materials are outlined. Various basic shapes of subsurface excavations that can be mined with the equipment are illustrated and discussed. An example of the cost of mining by this method is presented. Problems encountered in the field operations led to the development of a new explosion type slurry pumping system and related slurry handling equipment.

Jan 1, 1969

Canada is a major producer of chrysotile asbestos. In fact, Canada accounts for approximately one third of the world chrysotile asbestos production. Deposits are mined and the fiber processed in Québec, in British Columbia on the West Coast and in Newfoundland in the Atlantic region. Foremost among the Canadian provinces is obviously Québec. Some 85% of Canadian deliveries come from mines located in the Eastern Townships, a region which lies along the southshore of the St. Lawrence River, between Montreal and Québec City. At the heart of this vast territory, five (5) mining towns make up what is called the Québec asbestos region. Total capacity of the five (5) mining producers of Québec is about 1 366 000 tonnes.

Jan 1, 1981

By R. K. Mehta, S. K. Dhar, R. R. Mallepali

Introduction The incentives for developing a distributed form of the comminution model include: • for describing the heterogeneous comminution behavior of multiphase mineral systems (i.e. realistic ore bodies, such as complex sulfide ores consisting of chalcopyrite, galena, sphalerite, pyrite and siliceous minerals) and •for generating, for various locked and free particles, in situ, microscopic, breakage behavior such as the mode of fracture (intergranular vs. transgranular), the relative rates of breakage and the breakage distribution. However, the computational difficulty and the effort made in estimating a large number of parameters (Andrews and Mika, 1975; Wiegel, 1976; Herbst et al., 1985, 1988) do not justify the utility of this approach. Also, obtaining the results experimentally is very tedious and time consuming if using this approach. Although recent work in this area (Choi, Adel and Yoon, 1987; Mehta, Adel and Yoon, 1989, 1990) showed good results for liberated particles, the quality of the estimation and prediction was poor for locked particles. Attributing this to the complex breakage behavior of locked particles, it was concluded that additional constraints, and possibly modification in the breakage distribution functional form for locked particles, were necessary. However, further mathematical analysis revealed that the method previously used was in error. The purpose of this technical note is to present the correct solution methodology used in solving the general model equations of a multicomponent mineral system containing multiple classes of locked particles. Previous work and connection The general form of the comprehensive, distributed-component comminution model has been described as (Herbst et al., 1985) [d (m (0) -[ I - B ] S_ m(t) = A m(t) (1)] where [A] is the fundamental matrix/state companion matrix, commonly referred to, in the comminution literature, as the "mill matrix." Note that for a distributed-component comminution model, this is a full, general, real matrix, unlike a lower triangular matrix for a simple grinding model or a lumped-binary grinding model with one locked-particle class (Herbst et al., 1985, 1988). Also note that all of the underlined letters refer to matrices. Herbst et al. addressed the difficulty in arriving at a closed form of the analytical solution of Eq. (1) via similarity transformation [IT J inv (T)]]. This difficulty occurs for several reasons: •[A], as a general real matrix, may have complex eigenvalues and complex eigenvectors. •More importantly, there is no guarantee that a set of eigenvectors of [A] will turn out to be independent. An attempt was made to solve this problem by implementing a decomposition method. With this technique, the mill matrix was decomposed into a sum of lower and upper triangular matrices [(i.e., A = L + U)]. Then the solution was obtained using similarity transformation (Mehta, Adel and Yoon, 1989, 1990). [e(At) = e(L+U)t = e(Lt).e(Ut) _ [ TL Jt- (t) inv(T_L)] [-Tu Ju (t) inv(Tu)]] [But, unfortunately, e 1+U = e t . eu is true only for scalars and not for matrices (i.e., eL+u# eL- eU) unless they commute. In other words. eAt = e(L+u)t= ekt - eU' if LU = UL. Hence, this decomposition scheme must be replaced by a mathematically acceptable method known as the "splitting method"]

Jan 1, 1994

By S. M. S. Azghdi, K. Barani

The effect of microwave treatment on the surface roughness and wettability of chalcopyrite (CuFeS2 ) and on the chemical composition of its surface was studied. The microwave source was a conventional multimodal oven with frequency of 2.45 GHz and maximum power of 900 W. Pure chalcopyrite specimens and purified chalcopyrite concentrate were used in this study. Analysis using atomic force microscopy showed a decrease in the surface roughness of the chalcopyrite after microwave radiation. This decrease may be due to oxidation of the surface and formation of iron oxide. Moreover, the surface wettability of the chalcopyrite mineral increased with increasing duration of microwave radiation, which was in good agreement with the micro-flotation mass recovery results. The increased wettability of the surface may be attributed to the decreased surface roughness by microwave radiation. Analysis using scanning electron microscope/energy-dispersive X-ray spectroscopy indicate that after microwave radiation, the contents of sulfur and iron increased whereas that of copper decreased on the surface of the chalcopyrite, significantly changing the average atomic number of the chalcopyrite surface.

By Steven W. Hunt, Steven B. Fradkin, Roger J. Maurer

During the 1980s and 1990s, twenty deep shafts were constructed in Milwaukee to depths from 85 to 91 m (280 to 300 feet) through soil and weak rock thicknesses ranging from 37 to 69 m (122 to 227 ft). Adjacent compressible soils, settlement sensitive structures and high groundwater levels required that shafts be constructed without dewatering. Contractors attempted several methods of ground support and groundwater cutoff. Significant problems developed during construction of 11 of the 20shafts. One shaft collapsed; groundwater blow-ins occurred at five of the shafts; and seepage caused unfrozen windows at three of the freezewalls. Ultimately, combinations of grouting and ground freezing were utilized to complete all of the shafts into bedrock. This paper discusses the main design and construction challenges experienced and the lessons learned.

Jan 1, 2003

By Edward D. Elkins

CalMat Co. is one of the largest producers of construction aggregates in the United States. The CalMat Reliance plant is located in Irwindale, California, and is situated on an alluvial fan formed by the San Gabriel River. The fan deposits are of Quaternary age and were derived from granitic and metamorphic bedrock exposed in the San Gabriel Mountains to the north. The sediments are poorly sorted and range in size from large boulders to clay size particles. The coarse material is hard and durable and consists of quartz diorite, granodiorite, granitic gneiss, schist and minor amounts of volcanic rock. The matrix is comprised of silty sand with varying amounts of clay. Thin silt and clay lenses occur sporadically throughout the deposit. The clay content of the matrix and the degree of weathering of the coarse material increases with depth. Based on seismic data, the alluvial fan varies from 200 to 400 feet thick and overlies crystalline bedrock. The Reliance plant was constructed in 1971 and 1972. It has a nominal capacity of 1200 to 1400 tons per hour, and typically produces more than three million tons of aggregate products per year. Alluvial fan sediments are mined from a gravel pit situated adjacent to the plant. The material is fed through a mobile, 48- by 60-inch, in-pit jaw crusher, then transported by conveyor to the main plant to be processed. The plant is modern and highly efficient. It has a typical wet and dry circuit and is capable of producing a wide range of aggregate products. To extend the life of the plant, a 9,000 foot conveyor system is being constructed to connect it to a granite quarry operated by Azusa Rock Inc. The quarry is located north of Irwindale, and is 50 percent owned by CalMat Co. The conveyor will be used to export crushed rock from the quarry to Reliance. The existing plant will be modified to process the crushed rock.

Jan 1, 1995

By Philip E. LaMoreaux

The development of large quantities of ground water for any major use in an area is always of environmental concern to representatives of regulatory groups, citizens, agricultural and industrial users. From these concerns, state and federal congressional representatives receive a variety of impulses from their constituents and in turn begin a series of questions upon which to-base appropriate legislative actions. The kaolin industry in Georgia is substantial to the economy and the welfare of an important segment of east-central Georgia. It uses large quantities of water for processing. This constitutes an important source of income and tax revenue. Pumping test procedures to provide an accurate and efficient dewatering scheme have been developed and carried out at a number of mines in the kaolin district of Georgia. This paper highlights one such test and is directed at an assessment of the impact of this industry on ground water supplies of an area.

Jan 1, 1983

By W. L. Chen

In the United States hydraulic cyclones have been used for thickening, classification and cleaning in coal preparation plants for many years. The cleaning cyclones presently in use are based on using a "heavy medium", such as a fine magnetite and water pulp. The latest addition to cleaning cyclones is the one which uses ?water only?, or simply called "Hydrocyclone". Just as was the heavy medium cyclone, the hydrocyclones were originated in the Netherlands (1, 2). Plants using hydrocyclones were built in Europe (3) and test plants were erected in Canada (4, 5, 6) and India (7). Roberts and Schaefer Company has built four plants using hydrocyclone circuits. One additional plant is in the process of construction.

Jan 1, 1965

By Kenneth A. Gutschick, Harry L. Francis

A large number of minerals and chemicals (Table 1), some mineral-derived, are used in the treatment of both potable water and domestic sewage waste water and solids (Anon., 1990). In water treatment there are ten principal process uses as shown in Table 2 (Anon., 1990), which also lists the major chemicals in each process. Since lime (calcium oxide, calcium hydroxide, and dolomitic lime) is the largest chemical (by tonnage) used in water treatment, this chapter will deal primarily with this product. Note that it is included in five of the process uses shown in Table 2, and that indirectly it is also used in at least one other category (taste and odor control, where lime is used with potassium permanganate to provide optimum pH condition). POTABLE WATER TREATMENT Water Softening The biggest use for lime in water treatment involves water softening, where it serves to reduce carbonate hardness caused by dissolved bicarbonate and carbonate compounds. Currently there are more than 1000 domestic water softening plants (Table 3) located in most sections of the country, but particularly in Ohio, other midwestern states, Florida, and Texas, where limestone bedrock abounds (Anon., 1990). Among the other uses for lime in water treatment are coagulation, disinfection, and removal of heavy metals due to high pH softening, removal of certain radioactive and organic compounds and fluorides, neutralization of acidic water, removal of silica, particularly with dolomitic lime, and removal of color. Most of the above advantages accompany water softening, although at some plants lime is used specifically for one purpose, such as silica removal with dolomitic lime, minimizing pipeline corrosion by addition of lime to correct an aggressive water, and others. Hardness in water comprises two types - carbonate hardness, caused by dissolved calcium and magnesium carbonates and bi- carbonates, and non-carbonate hardness caused by dissolved non- carbonate salts, particularly calcium sulfate, calcium chloride, magnesium sulfate, and magnesium chloride. Total hardness is the sum of the carbonate hardness and non-carbonate hardness. Waters are classified as soft (0 to 75 mg/L as CaCO,), moderate (75 to 150 mg/L), hard (150 to 300 mg/L), and very hard (above 300 mg/L). Most water plants strive to reduce total hardness to about 100 mg/L, although in recent years the tendency in some cities has been to allow a little higher value in order to reduce both chemical costs and the amount of water softening sludges produced. There are four basic types of softening plants: lime softening, primarily to reduce carbonate hardness; lime-soda softening, for reduction of both types of hardness (in some plants caustic soda is used in place of soda ash, but it is more costly); split lime-zeolite, where a base exchange mineral is employed in place of soda ash (this system also requires salt [sodium chloride] to regenerate the zeolite mineral); and finally zeolite softening, which is generally used in small systems for private houses and small municipalities. Principal disadvantages of the latter system are its relatively high cost and the salt requirement, which introduces considerable quantities of soluble salts into the waste water discharge system.

Jan 1, 1994

By A. D. Hoagland

There are large areas on all of the continents with environments which are favorable for deposits of zinc and lead of Mississippi Valley type. In the developed countries, these environments have for the most part been quite thoroughly explored for the near surface deposits, and it will be necessary to direct more effort to the search for deeper buried deposits from which much of our future production must come. The difficulties of exploration for deep ore of this type are many and formidable, but the area of permissive environments beneath deep cover is many times as great as the area of the known near surface ore districts. It is a reasonable assumption, therefore, that numerous deposits wait for discovery and development. The finding cost, however, is certain to increase, and it is essential that concepts and techniques of exploration be improved if we are to sustain a reasonably strong productive capability into the 21st century. Exploration for deeply buried deposits requires at the outset relatively large areas of favorable geologic environment. The favorable horizons must be within economic limits of depth for the exploration as well as for the mining techniques which are currently available; and there must be some condition, design or strategy which will assure the explorer a reasonable chance of obtaining maximum benefit from discoveries which he may make.

Jan 1, 1973

By Jess W. Smith

The carbonaceous Monkemeyer sandstone member of the Creede Formation on Bachelor Mountain hosts alteration and mineralization which contrasts with other silver deposits of the Amethyst system. More than 20 million ounces of silver are contained in disseminated mineralization in the volcaniclastic conglomerates and sandstones. Hydrothermal fluids entered the Creede Formation directly from the Amethyst fault system and mixed with flowing meteoric ground waters trapped beneath the Monkemeyer sandstone. Portions of the basal rocks of the Creede Formation were argillically altered by more dense acidic fluids generated by boiling. The carbonaceous base of the Monkemeyer and much of the conglomerates below were mineralized and well silicified. Deposition of the mineralization resulted from two processes: (1) reduction by carbon in the Monkemeyer, and (2) fluid mixing in the conglomerates. Monkemeyer mineralization is confined to the carbonaceous basal material and silver content is relatively consistent. Silver is contained in acanthite which is commonly associated with traces of galena, chalcocite, covellite and sphalerite. Fluid mixing and mineral deposition in the poorly sorted conglomerates was controlled by the highly variable porosity and permeability. Anomalous silver contents are dispersed throughout a large volume of conglomerates but zones of higher silver content reflect the crude layering of the conglomerates. Acanthite is finely disseminated in pore spaces and partly replaces some detrital magnetite. other metallic minerals are rare in the main zone of mineralization.

Jan 1, 2013

By K. E. Doud

An unusually pure grade of rutile and several grades of aplite rock are produced in a unique mining and mineral dressing operation in Hanover County, Virginia. The ore body is an aplite rock of gnessic structure, having a sari ace exposure extending over several hundred acres, heavily leathered and containing rutile, ilmenite, and other titanium and iron minerals. The physical nature and mineral composition of the ore body has permitted the use of a relatively economical and unusual processing circuit. The flowsheet was designed to take full advantage of the remarkable liberation of the minerals at relatively coarse rinds. It permits flexibility in changing the product mix, and maintains high levels of purity in both rutile and aplite rack. The mineral processing is discussed in some detail below.

Jan 1, 1962

By N. I. Fedunets

The development of variousworks on automatising of operational processes at coal¬extractive and coal-mining enterprises introduces an ever growing necessity to carry out investigations in the wide range of problems concerning the possibitity of joint functioning of different levels, which seems impossible without the use of integrated systems of passing on and prossessing the information on the basis of modern calculating machines and other means of automation. This view on the problem of automation of the enterprise operation presupposes that the structure of automated operational dispatcher control (AODC) should be very closely connected with that of integrated data processing system! In this case the AODC structure from the point of view of automation of its functions (or operations), i.e. from the point of view of informational techniques coinsides in general with the structure of dispersed information and calculating network (ICN), realizing the passing on and processing of the information as well as solving the functional tasks on the basis of local calculating networks of electrical calculating machines with correspond to different levels of AODC and located with regard to productional hierarchy of operational dispatcher control (ODC). In this approach however the use of dispersed, ICN gives opportunity to. realize the possibility of action only with realisation on the CM of algorithmic' task of ODC, when a dispatcher 'is the lastto make a final decision.. At the mining enterprises it's rather difficult for a dispatcher to make a final decision because of the great variaty of productional situations, the presence of contradictions and a number of other subjective factors which often lead to the dispatcher's mistaks causing great material losses of the enterprise. Hence the necessity arises to automize and formalize making a decision and including the expert systems (ES) into the ontour of AODC, which enables the dispatcher 2to get a neeessary advice in different situations, especially in case ofemergency on the basis of establishing the mechanism of logical layout of non-formalized data base (DB) procedures relying upon the background knowledge and experience of experts. The presently presented in this paper theory of establishing the. ISAODC on the basis of dispersed ICN and expert systems is aimed at trasformation ofoperational' tasks of the higher level into the technological ones, at solving the tasks of diagnostics and forseeing of the process of production, with a dispatcher getting an opportunity of making qualitative and effective decision concerrning the choice of operational impacts in actual time on the basis of generalization the realisation of presented conception must, as has been already mentioned, be accomplished only on the basis of the foundatoin of the united dispersed informational - calculating network of electrical calculating machines.. This includes ICN which would be operating in . different operational contours. . From what has just been said it followsthat the ISAODC Structure will conside with that of DICN (in our case) and hence all the problems of ISAODC structure would be regarded as the questions of DICN.

Jan 1, 1992

By John H. White

As production of ground limestone increased our Company found it had an enviromental problem with limestone dust from our hammer mills. With the quarry and processing plant situated within 1 klm of a small township of 5000 people dust collection became essential. Regulations under the Clean Air Act 1972 also had to be complied with. Prior to this any demand for lime flour had been met by the use of a small drier and ball mill. Both expensive to operate. Dust emitting from the mills would amount to over 4000 tonnes per year. The cost savings were obvious. We had a better product which was essentially a by-product. Faced with a surplus of a very useful, but difficult product to handle we considered the possibility of disposing of it on the agricultural market.

Jan 1, 1982

By Charles F. Stack

The A. P. Green Refractories Co. operates clay mines in ten states. Eight of these states have reclamation laws with which we have to comply and indications are that the U. S. Congress will pass a federal surface mining reclamation act in the near future. These regulations, in addition to the value of land in most areas, dictate that mining and reclamation be considered as a single operation. In many instances the land may be more valuable after properly planned mining and reclamation than before. Refractory clay, commonly called "fire clay" is defined as a siliceous clay rich in hydrous aluminum silicates, capable of withstanding high temperatures. It is deficient in iron, calcium, and alkalies and approaches kaolin on composition. Refractory clay is much more limited in occurrence and usage than common clay or shale. During 1971, common clays and shales were mined in 47 states with a total production of 45 million tons. Fire clay production was reported in 22 states with a total production of only slightly over 3 million tons.(1) Many of these producing areas are extremely limited in extent and production. Several are contained within a one or two county area. This reflects the unique geological conditions required for the formation or development of fire clay. The major fire clay producing areas in the United States are shown in Figure 1.

Jan 1, 1974

By T. J. Kim, S. Suh

The purpose of this paper is to evaluate overall prospects of the export market in the Pacific Rim for Illinois steam coal in terms of recent changes in global socioeconomic factors. To pursue this objective, three factors affecting the prospects of Illinois coal in the Asian market were selected for detailed analysis: quality requirements of imported coal, particularly those of the Japanese market; import controls and regulatory factors; and transportation factors affecting the export of Illinois coal. Based on these analyses, alternative long-term strategies are suggested for promoting Illinois coal export in the Asian market.

Jan 1, 1988

By I. Iwasaki, X. Cheng

A series of batch flotation tests was performed on chalcopyrite-quartzite, on pyrrhotite-quartzite and on chalcopyrite-pyrrhotite-quartzite mixtures. Pulp potential measurements in the flotation tests with single sulfide minerals indicated that each sulfide mineral had its own optimal potential range for flotation. When these results were used to select the potential ranges for the separation of the two minerals from their mixture, their flotation responses changed, and the selectivity of separation was adversely affected. A possible mechanism involving surface alteration through galvanic interaction is discussed, and a method to improve the selectivity of flotation separation is proposed.

Jan 1, 1993

By William W. Magnus

The Eastern Magnesia Talc Company has always had the problem of adequate storage at its various mines and mills of not only crude ore and finished product but also material in process. An opportunity arose a couple of years ago with the decision to build a new mill at West Windsor, Vermont, (Figure 1) to come as close to providing adequate space for ore and the ground talc in the new plant as money and judgement would allow. Since our engineering staff did not have the time to design and engineer the new facility, an architectural firm with complete engineering staff was retained. Our original thought was to contract all phases of the construction and installation, however, and I think this is a most important point for any small firm such as ours, we found that with good supervision we, as the contractor, could do the job faster and at a lower cost than the construction firms that bid on the work. For some 50 odd years Italian talc has had a virtual monopoly in the body powder area of the cosmetic industry. Due to the purity, superior lubricity and whiteness, naturally occurring in the talc from Italy, no talc in the Western Hemisphere could capture any but a very small part of the market. When the Italian supply was cut off during World War II, the United States' largest consumer of this talc decided that it was time to develop a domestic source of a satisfactory replacement.

Jan 1, 1965

By Thomas P. Oxford

The impact of recent legislation on Florida phosphate industry operations has been dramatic. The most significant influences are described: the National Environmental Policy Act of 1969; the Federal Water Pollution Control Act Amendments of 1972; and implementation of the Florida Environmental Land and Water Management Act of 1972. Further discussion includes: critical examination of the recently completed EPA Areawide EIS; potential effects of the Resource Conservation and Recovery Act of 1976; the Surface Mining Control and Reclamation Act of 1977; current local and state laws; and summary of studies on radiochemical effects of mining, seepage from gypsum ponds, and dewatering of waste clays.

Jan 1, 1979

By J. J. Snodgrass

Faults, sandstone channels, and abandoned mine workings present severe safety hazards, disrupt mining, and necessitate costly precautions or discontinuance of operations. In addition to fault detection, mining companies have a need to map discontinuities such as seam thinning and previously mined areas in both longwall and room-and-pillar operations. Initial field tests demonstrated successful generation and propagation of higher order guided wave modes. Theoretical studies indicate potential for improved resolution by sensing small details in the coal seam and roof structure. Controlled- waveform source transducers and specialized detectors are particularly useful to preferentially excite and detect the Love (SB) and Rayleigh-type (P-SV) waves, including the higher frequency modes. The distinct observation of reflections using the transducers in the shear wave mode makes feasible the detection of the water-filled voids.

Jan 1, 1984