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By C. Ware, R. Uken, G. Whitmore

The coastal dune cordon of northern KwaZulu-Natal is among the highest in the world reaching heights in excess of 180 m and up to 2 km in width. It comprises a complex system of Quaternary stacked dunes of various geomorphologies, types and ages (Sudan, 1999; Maud and Botha, 2002;Ware et al., 2001; Ware, 2003). The dunes contain economic heavy minerals that have been exploited for the last two and a half decades. Dune units have recently been defined based on sand composition and texture(Sudan, 1999; Ware, 2003). Despite this, little work has been undertaken on the clay-fraction (< 2 um). This work documents the weathering of dunes to form clays. From the documented clay assemblages and relative abundances, a simplified weathering sequence with increasing maturity can be summarized as follows: primary minerals ? illite + vermiculite ?illite +interstratifications ?illite + montmorillonite ?halloysite + interstratifications + kaolinite ?kaolinite. The dominant controlling factors in determining clay assemblages is pH and leaching conditions. The presence of carbonates results in an alkaline pH and high concentrations of Ca2+and Mg2+which favours the formation of montmorillonite and vermiculite. However, vermiculite tends to form under slightly acidic conditions and is indicative of palaeosols where organic acids produce localized acidic pH’s. In contrast to this, kaolinite will only form and concentrate when carbonates have been leached. Kaolinite dominated samples are considered very mature under current climatic conditions(Chamley, 1989). Halloysite represents a transitional phase between montmorillonite and kaolinite (Herbillon et al., 1981). Ion mobility and evacuation is also critical in determining clay assemblages. Past work and field studies indicate that the dune cordon acts as an open system, resulting in carbonates and mobile ions being readily leached and lost from the system. However, when prolonged weathering has caused an accumulation of fine-grained material, the permeability decreases substantially whereby mobile cations and silica cannot be readily evacuated. This results in the formation of montmorillonite rather than kaolinite, even when carbonates have been leached. Illite (sericite) is considered to alter directly from feldspars. However, dune stacking and geometries, vegetation, water fluxes, reworking and erosion complicates this sequence.

Jan 1, 2003

By Paul Tyler

STRATEGICALLY situated in almost the heart of the leading fertilizer-consuming area of the United States, Tennessee long has ranked second only to Florida as a phosphate-producing state. Since 1932 its share of the national output of phosphate rock has increased steadily, and in 1937 its production mounted to an all-time record. More significant even than the increase in tonnage are the forward strides in technology. The Tennessee Valley Authority&apos;s research program has led to quasicommer-cial operations using hydroelectric power to manufacture concentrated phosphatic fertilizer that is used to further the farmer education program designed to streamline the fertilizer business and halt the appalling waste of farm land by soil erosion. Even more stimulating to chemically minded imaginations is the production of elemental phosphorus by a private company that not only has succeeded in extracting it from the phosphate rock in electric furnaces but actually has contrived to capture it and to transport it safely in tank cars. New values have been created for low-grade phosphate deposits, and the economic life of reserves has been lengthened while the waste of former years goes back into the mills for recovery of its values by modernized methods. Tennesse&apos;s phosphate-mining industry dates from the discovery of blue rock in Lewis County in December 1893. Its known reserves are of the order of 101,500,000 tons, which compares with the production of 825,099 tons in 1937; that is, 21 per cent of the phosphate-rock output of the whole nation. The total output reported from 1894 until July 1, 1938, was approximately 19,000,000 tons. Official estimates of reserves are overly conservative and evidence submitted before a joint Con-gressional committee in November 1938 places "probable" reserves at more than 6,000,000,000 tons.

Jan 1, 1939

By L. R. Duncan, W. H. McCracken

Magnesium is the eighth most abundant element in the earth&apos;s crust and the third most plentiful element in seawater. It is found in more than sixty minerals and in brines and seawater as a magnesium salt. One of the more important magnesium minerals is magnesium carbonate, MgCO3, with a theoretical maximum magnesia, MgO, content of 47.6%; this carbonate form represents the world&apos;s largest source of magnesia. The next most used sources for magnesia are magnesia-rich brines and seawater, where it occurs as magnesium sulfate and magnesium chloride. Other commercially important magnesium-bearing minerals are dolomite, CaMg(CO3)2, which serves the aggregate industry as well as the chemical industry; brucite, Mg(OH)2, which is used in the production of both caustic and sintered magnesia; olivine, ([MgFe]2-SiO2), which serves the refractory and heat storage industries; talc, (H2Mg3(SiO3)4), which serves several industries as a filler and as an ingredient in cosmetics; and serpentine, (H4Mg3SiO9). All these minerals are of commercial value because of the desirable characteristics given to them by magnesia and by its placement in the crystal structure. These minerals are the starting raw materials for a wide range of products. These include the production of magnesium metal, and several grades of magnesia used for the production of both sintered magnesia for refractory manufacture and lighter fired caustic magnesia, the latter is used in fluxes, fillers, insulation, cements, decolorants, fertilizers, chemicals, in the treatment of waste water including pH control, and in the removal of sulfur compounds from exhaust stacks. Magnesite is one of several major minerals possessing a dual character, i.e., non-metallic industrial mineral because of its principal end use as a calcined/dead burned raw material in non-metallic end products and magnesium metal. A large percentage of the magnesia used to produce magnesium metal comes from seawater1 brines. The total primary metal production worldwide is about 350 ktpy. This report reviews magnesite solely as an industrial non- metallic raw material. Magnesite for most refractory purposes must have a content of sintered magnesia above 85%, with a preference for those sources that have the potential for 90 to 98% magnesia values. Dolomite, used in large tonnages because of its physical properties in the construction industry, also has a use in the chemical and the refractory industry. In its calcined form, dolomite is used as a slag addition in the making of steel, and it is used in a high-purity calcine to precipitate magnesium hydroxide from brines or seawater. The precipitated magnesium hydroxide is intermediate for the production of deadburned clinker for refractories and the production of magnesium metal. In many cases the high-purity magnesium hydroxide obtained by precipitation with calcined dolomite, or in some cases limestone, has supplanted much of the world&apos;s production of magnesia from the natural mineral magnesite. This is especially true of the United States and in major industrialized areas of Europe and Japan. The best known of the minerals directly and widely exploited for its magnesia content is magnesite (MgCO3), one of the calcite group of rhombohedra1 carbonates, which includes calcite (CaCO3), siderite (Fe2CO3), and rhodocrosite (MnCO3), among others. The members of this group enter into a wide range of substitutional solid solutions when the positive ions have similar radii. The radii of magnesium and iron ions are within 6% of each other; hence magnesite and siderite form a complete series, of which the mineral breunnerite (ferroan magnesite) is a well known end member. The radii of calcium ion is 36% larger than that of magnesium ion and only limited substitution exists at each end of the MgC03-CaCO3 series. Dolomite is not a member of the calcite group, but it occurs when calcium and magnesium ions alternate in equal number in an ordered structure among carbonate ions. The result of this relationship is that calcite and dolomite are commonly found intermixed with magnesite. They occur, commonly, as identifiable crystal entities, which can be separated to a varying degree from the magnesite by benefication techniques. Magnesite, when pure, contains 47.8% MgO and 52.2% CO,. The pure mineral is found occasionally as transparent crystals resembling calcite. Magnesite principally contains variable amounts of the carbonates, oxides, and the silicates of iron, calcium, manganese, and aluminum. Although the genesis of natural magnesite deposits can be complex, it is distinguished in nature in two distinct physical forms, namely crystalline, (with a wide range of visible crystal sizes) and cryptocrystalline, sometimes referred to as amorphous, where the crystal size is not detectable to the eye and will range from 1 to 10 pm. The two types not only differ in crystal structure but in the sizes of the deposits and in modes of formations. The crystalline form has a Mohs hardness of 3.5 to 4.0. The color range is from white to black with shades of yellow, blue, red, or gray. The color is not a significant indicator of purity but in a given deposit an experienced person can often roughly grade the magnesite by observing color and crystallinity. Macrocrystalline deposits occur in relatively few, but generally large, deposits on the order of several million tons. The ore shows a marble-like crystal structure and belongs to the sedimentary or metasomatic groups of origin. The cryptocrystalline variety of magnesite frequently occurs in many small deposits, although there are exceptions. Cryptocrystalline magnesite is typically massive with no cleavage and is sometimes descriptively called bone magnesite. The fracture is usually conchoidal, with a hardness of 3.5 to 5.0. The color is mainly white, but it can have tints of yellow, orange, or buff. Accessory silaceous minerals such as serpentine, quartz, or chalcedony are usually present. Calcium minerals are normally absent or in low concentration, this contrasting with the macrocrystalline form where calcium minerals are almost invariably present and some- times in high concentration. The specific gravity of cryptocrystalline magnesite ranges between 2.90 and 3.00, whereas the value of pure crystalline magnesite is 3.02. In actuality, the normal specific

Jan 1, 1994

By R. M. Bricka, T. J. Olin

Heavy metals contamination is an environmental problem at Army installations engaged in firearms training and munitions production. At these facilities, weathering and corrosion of expended munitions and leaching from wastewater lagoons, landfills and burn pits have resulted in heavy metals contamination of the soil. The principal metals encountered in firing-range soils are lead, copper and zinc. Cadmium and other metals, such as antimony, that are often incorporated in the munitions are sometimes seen in lesser concentrations. Mercury is associated with various propellants and, while present in much smaller concentrations, is of concern because of its acute toxicity. Chromium is primarily associated with plating operations. The transport of metals into groundwater has been confirmed at some locations, which has required treatment of the soil and groundwater at these sites. Certain treatment processes for contaminated soil produce metals-laden extracts, which also require treatment before reuse or disposal. Ion exchange is generally quite effective for removing metals from aqueous streams. However, resins are expensive and must be regenerated, and activated carbon is generally less effective for most metals and also requires regeneration. Therefore, alternative effective and economic sorbents are needed. Twelve sorbents were screened in initial batch testing. These included activated carbon, bark, chitosan, crown ether, corn cob, xanthate, clay (kaolinite and montmorillonite), peat moss, seaweed and reagent-grade zeolite (aluminosilicate, Sigma Product No. Z3125). Of these, zeolite demonstrated the highest capacity for Pb, Cr and Cd. For this reason, zeolite was selected for further testing in batch, kinetic and column studies. Materials and methods Zeolite. The zeolite used in the second-phase batch and column studies was obtained from a natural deposit of clinoptilolite-rich rock located in South Dakota (Rocky Ford SDH) (Desborough, 1996). Large blocks of the material were crushed and sieved into the following three particle size ranges: 0.5 to 1.0, 1.0 to 4.0 and 2.0 to 4.7 mm. This material demonstrates high structural stability in acidic solutions (pH 2.5) (Desborough 1996) and has a measured surface area of 30 m2/g. The measured total cation-exchange capacity (TCEC) was approximately 10 meq/100 g. This is well below what has been indicated for commercially available zeolite, which has been reported to be about 180 to 220 meq/ 100 g. The TCEC test was repeated (Method 9081, SW 846) using sodium acetate. The test resulted in a TCEC of 54.5 meq/100 g. The difference between values obtained for this material and published values for zeolites may be attributable to the greater heterogeneity in the material used in this study, compared to commercially available materials, or to the effect of the relatively large particle sizes utilized. Batch studies. Seven batch studies were conducted using synthetic metal solutions and soil extracts (Table 1). Extract composition: The P-extract was prepared by sequential surfactant extraction of organics from a burnpit soil followed by acid extraction of metals. The pH of this solution is approximately 1.1. A number of metals and organic compounds were present in the soil. Analysis of the extract was restricted to Pb, Zn and Cu concentrations for this study. The FBH extract was produced from a firing-range soil that was oxidized with a 0.01 M CaO solution and then extracted with 0.1 M acetic acid. This was filtered through 0.5-µm Whatman No. 5 filter paper and stored at room temperature. The pH of the FBH extract was approximately 4.5. pH Control: Calcium carbonate (CaCO3) may be present in the zeolite horizon or bed. Calcium ion (Ca") is released from the exchange sites when in contact with solutions containing ions for which it is more selective, such as lead. This results in a rise in solution pH over time. Acid washing removes most of the carbonates, eliminating the need for a buffer. Batch studies were conducted using both acid-washed zeolite (AW) and unwashed zeolite (UW) for performance comparison. The UW zeolite was rinsed with distilled deionized (DDI) water to remove fine soil particles. Both materials were dried at 105°C (220°F) overnight, so that the dry mass could be determined. Column studies. Ten column studies were conducted. Because it was expected to have the best hydraulic properties, the largest particle

Jan 1, 1999

By I. W. Alcorn

THE cost of drilling in the past few years of proration and ever decreasing allowables has received increasing thought and study. It seems to parallel the strides made with respect to pumping problems in 1932 and 1933. Low profit margins stimulate the search for economies. Any discussion of slim-hole drilling involves a multitude of abstract values, and the problem can be attacked only by a study of records and rational thinking. In a measure, traditional methods must be studied with a questioning attitude. The words "slim hole" may be somewhat misleading, as the term is entirely relative. For that reason I wish to define it as used in this discussion. On the Gulf Coast, I would define a normal hole as one in which 10 3/4-in. surface casing has been set and below which a 9 7/8-in. hole is dug. With this as a datum, holes of larger diameter below surface would be called "large holes," with 12 1/4 in. as the "extra large" class and holes of smaller diameter classed in the slim-hole range, 6 1/4 in. representing about the minimum size. The optimum size has not been definitely determined, but the preference is for a program that would call for setting 8 5/8-in. surface casing and digging a 7 3/4-in. hole. Different sections of the country might very properly deviate from this practice because of differences in depth, formations, regulations, or other factors. This paper will be confined to a discussion of the drilling of exploratory wells, as the drilling of this class of wells is quite a different problem from that of drilling a proven field, although many of the same considerations apply in both cases, as will be apparent. Although for many years shallow slim-hole and core-test holes of small diameter had been dug, it was not, I believe, until the fall of 1937 that serious consideration was given to its application in drilling wells 7000 ft., 8000 ft. and 9000 ft. deep on the Gulf Coast. This does not mean that nearly all such wells drilled on the Gulf Coast now are of the slim-hole variety, but only that efforts have been aimed in that direction with very encouraging results and there has been a very definite trend to reduce the size of holes, a trend that probably will continue. As to exploration policy, there appear to be two distinct and opposite views. The one usually followed in the past was more or less designed to "shoot the works" on one well. Generally on the Gulf Coast, the depth at which production might be obtained is limited by the drilling equipment and economics. With this thought in mind, wildcat wells are often planned with the idea of carrying the depth to 10,000 ft., or even 15,000 ft. All of the possible hazards are anticipated and the general drilling and casing programs are so predicated. Such wells contemplate the drilling of large-diameter holes; the setting of at least one protective string of casing and an extensive coring policy, all of which finally adds up to an expensive well. As opposed to this general policy is the slim hole. This, on the Gulf Coast, recognizes that new discoveries represent gam-

Jan 1, 1941

By D. W. Brunton

THE maps of our large mines are usually prepared with the greatest care; and it is somewhat singular that, in comparison with the great amount of time and money spent in surveying and platting, so little actual use is made of them. Almost the only purpose for which a completed survey-map is afterwards consulted, is the determination of the relative position of the different workings to each other, and to the boundary-lines of the property. After the completion of such a map, it should be made the beginning of another, and in most cases a far more important, undertaking, namely, its utilization as -a starting-point for a complete inventory of the company&apos;s underground possessions. The ordinary mine-survey map, being nothing but a record of what has been done, is, in one sense, only ancient history. To increase its value, such additions should be made as will render it a complete statement of the amount and value of ore in sight at any particular time, and a guide for future develop¬ments. Comparatively little extra labor is involved in this undertaking, since the larger and most expensive part of the work has already been completed when the mine has been surveyed and mapped. The necessary additions consist in working out, and platting on the maps, the geology of the mine as exposed in the workings, in such a manner that the geological survey may be of daily use in the development and operation of the mine. The first step towards the production of a geological map consists in tracing individual level-sheets from the general or composite map. The area to be included, outside of the property in question, will depend very much on local conditions; but, for geological, legal and commercial reasons, it should be extended as far as reasonably practicable. The scale to be

Sep 1, 1905

By Maurice C. Fuerstenau

INTRODUCTION The term, chelate, from the Greek for &apos;claw,&apos; has its origin in the pincer-like representation of more than one atom of a single ligand bonded to the same metal atom, forming a ring-like structure. Depending on how many attachments exist on the sphere of coordination around the metal ion, ligands are referred to as bidentate, tridentate, tetradentate, pentadentate and hexadentate According to Calvin and Martell (1952) and Somasundaran and Nagaraj (1984), chelating agents must contain suitable functional groups, and their location within the ligand molecule must enable ring formation that is sterically possible. Typical structures that meet these requirements have been given by Fuerstenau and Herrera-Urbina (1988) and are listed in Figure 1. As noted, the functional groups of these reagents contain electron donor atoms such as oxygen, nitrogen and sulfur. Basic groups, such as amino (-NH,), are those that contain an atom with a lone pair of electrons. Acid groups are those, such as carboxylic (-COOH) which lose a hydrogen ion and coordinate with the metal atom. Examples of each of these types chelating reagents are given in Tables 1-4. The specificity of chelating agents for various metal ions has long been known and was utilized early in the search for new flotation collectors. In 1927, Vivian used ammonium nitrosophenylhydroxylamine as a collector for cassiterite. Holman (1929) tested dimethylglyoxime as a collector for nickel oxide. He also suggested taurin as a collector for oxidized lead ores. DeWitt and von Batchelder (1939) suggested the use of oximes as flotation collectors. Gutzeit (1946) conducted an extensive investigation on the use of chelating agents as collectors and as depressants for gangue minerals. The depressants are those reagents that form soluble chelates with metal ions that could function as

Jan 1, 2005

By J. Y. P. Leite

In a small-scale mining in Brazil?s northeast, scheelite were exploited since 1940?s using a traditional gravity concentration flowchart (composed by jigs and shacking tables) that operates with low efficient for fine particles. Tailing of this plant was submitted to chemical, mineralogical and size characterization. Results pointed 50% smaller than 74µm with a grade of 0.11% WO3. The particle?s size is an important operational variable to heighten recuperation by shacking tables. Tests using Falcon SB40 centrifuge concentrators and shacking table were realized, optimizing their operational variables. Based on the tests results a new flowchart was proposed for concentrating and tailings recovery.

Sep 1, 2012

M. AlbERtson, Chairman. Production Engineer, Shell Petroleum Corporation, Houston, Texas. R. P. McLaughlin, Associate Chairman. General Manager, Burnham Exploration Co., Los Angeles, Calif. Eugene A. Stephenson, Secretary-Treasurer. Professor of Petroleum Engineermg, Missouri School of Mines and Metallurgy, Rolla, Mo. Ezecutive Commillee M. Albertson, Chairman. C. E. Beecher, Empire Oil & Refining Co., Bartlesville, Okla. L. L. Foley, Petroleum Engineer and Geologist, Tulsa, Okla. R. B. Kelly, Division Manager, Pure Oil Co., Fort Worth, Texas. Hallan N. Marsh, Production Engineer, General Petroleum Corporation of California, Los Angeles, Calif. R. E. Somers, Geologist, The Gulf Companies, Pittsburgh, Pa. Production Engineering T. V. Moore, Vice-chairman. Charge Production Research Division, Technical Service and Development Dept., Humble Oil & Refining Co., Houston, Texas. Joseph Chalmers. De Bataafsche Pet. Maatschappij, The Hague, Netherlands. M. L. Haider, Petroleum Engineer, Carter Oil Co., Tulsa, Okla. Emile HUGUENIN, Deputy State Oil and Gas Supervisor, Los Angeles, Calif. Carl E. Reistle, Jr., Petroleum Engineering Dept. Humble Oil & Refining CO., Houston. Texas. Produclion J. Terry DUCE, Vice-chairman. Geologist, The Texas Company, New York, N. Y. Basil B. Zavoico, Associate Vice-chairman. Consulting Geologist, Houston, Texas. Engineering Research R. L. Huntington, Vice-chairman. Associate Professor, Petroleum Engineering, University of Oklahoma, Norman Okla. Economics Sidney A. Swensrud, Vice-chairman. Assistant to the President, Standard Oil CO., Cleveland, Ohio. Refinery Engineering Walter Miller, Vice-chairman. Vice-president, Continental Oil Co., Ponca City, Okla.

Jan 1, 1937

By E. F. Evoy

"The Gunnar uranium deposit was within metasedimentary rocks of the late Archaen Tazin Group. These rocks were intensely altered by albitization so that the immediate host to the ore consisted dominantly of albite, and by the subsequent introduction of calcite. The ore consisted of disseminated pitchblende and uranophane in a pipe-shaped breccia zone. Oxidation of the ore was more intense near surface than at depth, but there was no near-surface enrichment.IntroductionThe Gunnar Mine site is on the tip of Crackingstone Peninsula, on the north shore of Lake Athabasca, Province of Saskatchewan, Canada. The peninsula forms the southern part of the Beaverlodge mining area. The ore consisted of disseminated pitchblende and uranophane in brecciated metasedimentary rocks of the Tazin Group, and the deposit was characterized by extreme albitization and subsequent carbonatization of the host environment.Production from the mine began in 1954 and the ore was depleted by 1963. In that interval the deposit yielded about 5 million tonnes of ore containing about I. 75 kg/tonne U3O8. It was mined initially from an open-pit and subsequently from underground; the open-pit contributed about 55% of total tonnage. Uranium was recovered by atmospheric leaching in sulphuric acid, ion exchange concentration, and precipitation with magnesia.This paper is based on studies made during the productive life of the mine and is concerned primarily with pre-ore alteration of the rocks containing the deposit, and with the ore mineralogy."

Jan 1, 1986

By W. J. Verner, J. R. Lucas

Billions of tons of bulk solid materials are processed through our industrial plants each year, and the tonnage is steadily rising. It has been estimated that for every dollar spent in industry as a whole, approxinlately 30 cents is consumed in the handling of bulk solid materials. It is in this category that tremendous savings are possible through the use of improved techniques. Since World War 11, the mining, steel, chemical, and grain industries, among others have made use of increased materials-handling automation in order to gain some of these savings. However, in a chain of automatic operations, every link must be completely reliable, for if there is a single failure, the whole system immediately becomes ineffective. Only too often the weak link in the chain proves to be the flow of bulk solids from bins. To contribute to the fundamental knowledge in this area, a research study has been continuing at The Ohio State University. The principal objective of the investigation has been to study the internal stresses existing in confined bulk solids. LITERATURE SURVEY Literature studies have revealed that many outstanding people have made contributions to the field of bulk solids. For instance, C. F. Jenkin,1 suggested: a. The pressure on a bin wall is not directly proportional to the depth beneath the surface of material in the bin. b. The vertical pressure distribution on the base of a bin is not actually uniform but is a variable. c. Arches form in bins as a result of very small deformations of the material in the bin. This deformation causes a series of gaps to appear, and consequently causes the disappearance of diagonal forces that cannot act across these gaps. The removal of the diagonal forces causes horizontal forces to be introduced which seem to be the chief cause of arching. 11. A. Janssen,4 in 1895 in connection with his experiments on bins, derived a differential equation to describe both the lateral and vertical pressure in bins with vertical sides. This represents a significant contribution to bulk solid theory, and thus its solution is reproduced as follows: L = KV = RW/U&apos; [l-e -U&apos;KY/R] I where L is the lateral pressure of the bulk solid in psf., V is the vertical pressure of the bulk solid in psf., K is the ratio of the lateral pressure to the vertical pressure at any point, R is the hydraulic radius of the bin in feet, W is the density of the bulk solid in lbs. per cubic feet, U&apos; is the coefficient of friction between the stored material and the bin wall, and Y is the head of material above the point in question in feet. In 1903, Jamieson,6 in an elaborate series of experiments on full sized bins measured vertical and lateral pressures by hydraulic diaphragms. He determined many values for mediums of corn, wheat, peas, and flaxseed. In 1951, Caughey, Tooles, and scheer3 measured both lateral and vertical pressure in deep bins by using strain guages on steel bands. Values were calculated for cement, gravel, sand, soy beans, shelled corn

Jan 1, 1961

By Everett Parker

THIS paper describes the methods used to determine the rates of payment for contract work and the plan of contract supervision in the Elm Orlu mine. A discussion of the theory of wages and the eternal question-what is a just wage-are beyond the scope of this article. In the fall of 1920 the Elm Orlu was the largest mine in Butte using the day&apos;s pay system of payment for stoping operations. High labor and supply costs and a falling market for the product of the mine made economic mining difficult. The mining method had been changed from the square set stoping to timbered rilling to eliminate most of the shoveling. There was no opportunity to reduce the cost of supplies other than more rigid economy in their use. It was recognized, however, that the labor efficiency was low and that the reduction in costs depended on increasing the output per man. While in general, the low man efficiency was a resultant of the high wages paid and the shortage of men during the war and subsequent period of inflation, it was felt that the contract and bonus system used in the other mines was the main factor in that the most capable and energetic men had been attracted to those mines where more than average skill and dili-gence were recognized by more than average pay.

Jan 1, 1927

By T. E. Newkirk

In the past few years there has been considerable controversy on the most suitable material to be used in ventilation doors which will have to serve also as fire doors. For this reason it was thought useful at Mclntyre to find out to what extent our zinc chloride treated spruce doors were fire resistant and what protection we could expect in case of an underground fire. The doors to be tested were constructed of the same material as that used in our regular ventilation doors underground, namely, 2-inch tongue-and-groove well seasoned spuce. It is to be noted, however, that whereas the dimensions of the ventilation doors are 5 ft. by 6 ft., those of the test doors were only 14 in. by 17½ in. The treated doors were made up from lumber that l1ad been treated with chromated zinc chloride, as described in Mr. Keeley&apos;s paper. Two kinds of tests were carried out: a heat test and a flame test. An electric muffle furnace for assaying, equipped with a pyrometer, was used for the beat test, the furnace door being replaced by the wooden door to be tested. In the flame test, the door to be tested formed one end of a rectangular steel box in which was placed a large blow-torch. Air was admitted at the rear of the box. A pyrometer recorded the temperature at the inside surface of the door where flame impinged. The results of the tests are presented in the accompanying table, in which the word &apos;failed&apos; is to be interpreted as meaning that the door had been damaged to the extent that smoke, but not necessarily flame, issued from its outside surface.

Jan 1, 1949

By Franc R. Joubin, Donald H. James

"The Property of Rix Athabasca Uranium Mines Limited is in the Beaverlodge area of northwestern Saskatchewan. The mine is 7 miles by road north from the Lake Athabasca port of Bushell which is 250 miles north by aircraft or boat from railhead at Waterways, Alberta.The Rix property is a portion of the former DD 1 concession, obtained in 1949 from the government of Saskatchewan when private prospecting for uranium became permissible. The concession was prospected in detail during the 1950 and 1951 field seasons and a great many radioactive show-ings were discovered. Development and drilling were concentrated in two and later three of these areas, and by late 1952 enough ore had been indicated in the Leonard series and ""Smitty"" zone to justify underground development by adit-drift and shaft respectively.Four hundred feet of drift development on the Leonard No. 1 vein and the sinking of a two-level vertical shaft with related lateral development on the Smitty zone were completed in 1953. In April 1954 the Smitty section was placed in production at a rate averaging 100 tons per day, thereupon becoming the first privately owned post-war uranium producer in Canada. The ore is shipped for processing 12 miles by truck to the mill of Eldorado Mining and Refining Limited.Until recently all of the Company's production was drawn from the Smitty orebody. In April, 1955, ore production commenced from the faulted west extension of the Smitty structure, known as the Rix 62 zone, and from the Leonard No. 1 vein.The Smitty orebody (see Figure 2) is an intensely brecciated lenticular zone bordering both sides of the Smitty fault. The breccia areas are irregularly mineralized with pitchblende, very sparse galena, and pyrite in a gangue of feldspar, chlorite, calcite, and silica, all thoroughly soaked with fine-grained hematite to produce the locally-called ""red alteration"".Tenor of the ore currently being mined is classified information. The average grade estimated, prior to production, was 0.20 per cent (4.0 lbs.) U308 per ton."

Jan 1, 1949

The objective in controlled blasting is to reduce overbreak to control the final pit wall slope, shaft, drift ditch, bench, etc. to the final planned excavation limit. The six main types of controlled blasting utilized today are: 1) Line Drilling 2) Cushion Blasting 3 Smooth Wall Blasting 4) Buffer Blasting 5) Presplitting or Preshearing 6) Air Deck Presplitting

Jan 1, 1992

By Frank Rausche

The more widespread use of Augered Cast-in-Place (ACIP) Piles has generated increased demand for improved quality control measures. These deep foundation elements are often relatively long and slender and their structural quality depends on the experience of the installers, the adequacy of their drilling and pumping equipment, and of course, the properties of the soil. Since the concrete of ACIP piles is pumped under pressure into the borehole, the piles may achieve a very high unit shaft resistance if conditions are favorable and the piles are well constructed. Three types of methods can help assure that the piles are properly executed. During construction, monitoring the volume of concrete pumped and the pressure applied helps avoid structural defects. After installation, and once the concrete has hardened, the Pulse Echo Method allows for a check of the structural integrity of the shaft. Finally, a load test, performed some time after installation, yields a check of both bearing capacity and structural integrity of an individual pile. Because of their expense and associated construction delays, static load tests are normally done for only a few piles. However, at large construction sites, it may be necessary to perform many load tests either as a planned construction control activity or as a means of spot checking or verifying suspect piles. For smaller sites, however, static load testing may be prohibitively expensive. In such situations, dynamic load testing, originally developed for driven piles, has frequently been employed for drilled shafts and ACIP piles. In the latter case special consideration must be given to the ACIP pile slenderness and their often relatively low concrete design strength, which may not tolerate high dynamic loading stresses even though their unit resistance along the shaft is relatively high. Lately, the dynamic load test has become more feasible with the availability of loading systems that are custom tailored to this particular pile type. These systems produce a low velocity, low stress and high energy impact. Recent developments have also made the instrumentation process simpler: force measurements are now made on the ram rather than on the pile for increased reliability and simplicity. This presentation describes the requirements for successful dynamic load testing of auger cast piles and summarizes results from several projects where the new loading system and newly developed instrumentation was employed. A few cases are presented correlating static load test results with dynamic predictions, calculated by CAPWAP®.

Jan 1, 2001

By David Newman

Multiple seam underground coal mining is ubiquitous in Appalachia. Many coal properties have from two to ten or more economically mineable coal seams. Because of the ability to penetrate 600-feet to 1,000-feet or deeper into the mountainside leaving panels of web pillars separated by barrier pillars, highwall mining is a hybrid between surface and underground mining. As a result, many of the ground control problems commonly associated with multiple seam underground mining exist with multiple seam highwall mining. These include: i) superjacent mines, subsidence and caving propagating to overlying seams and ii) mines, pooled water and the potential for inundation resulting from a iii) breakthrough between an active highwall mine and abandoned underground mines in the same or superjacent seams, the presence of overlying or underlying mine workings where iv) pillar columnization in the active mine is not possible, and v) the question of whether to mine ?top-down? or ?bottom-up.? Case histories are presented from southeast Ohio where the Middle Kittanning No. 6 and Lower Kittanning No. 5 seams are successfully highwall mined with 20-feet to 40-feet of largely shale interburden. A highwall miner was caught in a highwall collapse in the Middle Kittanning No. 6 seam when it was overmining auger workings in the Lower Kittanning No. 5 seam. Multiple seam interaction caused by the overmining transferred overburden stress onto the Lower Kittanning No. 5 seam. The overburden concentrated through web pillars initiated auger web pillar failure, resulting in roof collapse and subsidence in the Lower Kittanning No. 5 seam that propagated up to the Middle Kittanning No. 6 seam. A second case history involves multiple seam highwall mining in southeast Kentucky. The A3 Rider, A3, B2, and C1 seams are being highwall mined around abandoned underground mines in the A3 and B2 seams and augering in the A3 Rider. Because of spoil storage constraints for the surface contour mines, the highwall miner follows the active pits in each seam so a standard sequence of ?top-down? or ?bottom-up mining does not exist. The planning and engineering design considerations associated with each case history is presented along with geotechnical information. In the case of the highwall collapse a back analysis is presented of the stability and safety factors for the auger webs, highwall miner web pillars, and barrier pillars.

Jan 1, 2009

By Paul Staples, Paul Messenger, Greg Lane

"Every project is different. While “conventional” SAG and ball mill circuits will suit many projects, for others there are alternatives, which may produce improved outcomes. This paper examines particular examples of recent front end designs which either went against conventional thinking or which employed “out of the box” thinking to realize the desired results.One such example is the design strategy employed for a small capacity gold plant in Victoria, Australia. The selection of HPGR technology for small capacity projects is not generally favoured, given the relatively high cost of small HPGR machines. However, the unusual size distribution of the gold and its liberation characteristics were expected to lead to improved gold recovery offsetting the higher capital cost.Another example is the first large scale application of milling in acid for copper recovery, at a project in south east Asia. The stainless steel, single stage SAG mill using ceramic grinding media was more expensive than a mill constructed of conventional materials. However, the steps of scrubbing, slurrying, grinding and leaching could all be achieved in a single unit operation and the need for thickening and repulping with acid after milling was eliminated.Rod mills were selected for both primary and secondary milling duties for another south east Asian project despite their somewhat outdated reputation. A review of previous industry experience confirmed that rod mills could outperform conventional rod/ball or SAG/ball circuits in cases where the size distribution of the ground product is critical to downstream recovery.These examples are discussed with particular focus on the key drivers in each case."

Jan 1, 2008

By A. L. Barnes

Residual oil in watered-out reservoirs is a tremendous reserve which has been unrecoverable by established production methods. A study of the new recovery methods indicated that the forward combustion urocess might- recover oil from such reservoirs; however, no thermal recovery operating experience in a watered-out system was available. The Delaware-Childers pilot thermal test was undertaken to test the feasibility of thermal recovery in this watered-out reservoir. The pilot test consisted of a 2.22-acre, inverted five-spot in the 600-ft deep Bartlesville sand. The reservoir in the pilot area had a porosity of 20.6 per cent, a permeability of 118 md and an average sand thickness of 45 ft. The reservoir contains a 33&apos; API, 6-cp oil. Combustion was started Nov. 22, 1960. The initial air injection capacity was 750 Mscf/D, but it was eventually increased to 2,000 Mscf/D. The test was surrounded by an active water flood; therefore, water production was initially high, but decreased as the heat wave moved toward the producing wells. Oil-bank arrival at an individual well was indicated by a drop in GOR and WOR, and an increase in oil production. Combustion-front arrival was evident at three of the pilot producers, and they were plugged. Cumulative oil production from pilot area wells war over 12,000 bbl. Operational difficulties were negligible and only conventional equipment was necessary. The combustion efficiency of this test averaged over 80 per cent. Results from coring showed that the leading edge of the combustion front tended to be wedge-shaped but a nearly complete sweep of the reservoir was eventually obtained. An isopach map based on evidence from 10 core holes and the existing wells showed that 126 acre-ft had been swept by the heat wave. Using this swept volume, an air requirement of 15.7 MMscf/acre-ft was calculated. It was calculated that 275 ,STB/acre-ft was consumed bv the heat wave. INTRODUCTION There is a large amount of oil remaining in reservoirs that have been water flooded. A study of ways to recover this oil showed that the forward combustion process might be applicable. Results from a number of forward combustion tests have been reported in the literature, but none of these tests were conducted in a watered-out system. The Delaware-Childers pilot thermal test was initiated in 1960 to define the operating characteristics of underground combustion in this watered-out Bartlesville sand reservoir, The purpose of this paper is to present the pilot test results in detail. FORWARD COMBUSTION PROCESS The forward combustion process consists of initiating combustion in the formation surrounding an injection well and driving this heat wave through the formation toward offset producing wells. As the combustion front progresses through the reservoir, oil and formation water are vaporized, driven forward in the gaseous phase, and recon-densed in the cooler part of the formation. These distilled liquids, water of combustion and gaseous combustion products, form a bank or three-phase region ahead of the burning front. This bank pushes mobile reservoir fluids toward the production wells. The rate of movement of the combustion front is controlled by the rate at which the nondistill able residue which serves as process fuel can be completely burned off the sand. The production performance from a heat wave conducted in a watered-out oil reservoir will differ from one conducted in a dissolved gas-depleted reservoir because of the difference in fluid saturations. The primary depleted reservoir contains connate water saturation, relatively high oil saturation and some gas saturation. The watered-out reservoir contains a highly mobile water saturation, residual oil saturation and little gas saturation. As the combustion front moves forward in either type of depleted reservoir, it drives the distillable oil, the water in place and the water of combustion ahead, and burns the nondistillable portion of the oil. The heat-wave process in a watered-out reservoir differs from the process in a

Jan 1, 1966

By J. B. Macelwane

Historically whenever application of scientific results to a new problem required the special experimental background, the economic outlook and the practical knowledge characteristic of the engineer, a curriculum in that type of engineering based on the professional requirement grew up in the engineering colleges. This is precisely what is happening now in geophysical engineering. THE Mineral Industry Education Division of AIME has long been interested in geophysical education. Organized in 1938, a Committee on Geophysical Education presented a number of reports in succeeding years. The AIME is an engineering society; hence it might be expected that the interest of the Mineral Industry Education Division would have centered about the relation of courses in geophysics to engineering education. However, this was not the case. The burden of the discussion held under the auspices of the Committee on Geophysical Education bore on geophysics in general and particularly on its relation to geology. In the decade that has passed since those meetings much water has flowed under the bridge. Not only have the geophysical sciences developed at an extraordinarily rapid rate but the practical importance and the range of their applications have spread in ever widening circles and have even assumed a very prominent place in research programs of the military, the Army, the Navy and, particularly, the Geophysical Research Directorate of the Air Force at Cambridge, Mass. So enormously have the geophysical sciences as such grown in scope and in degree of specialization that no one man in a lifetime of study can hope to master the theoretical and experimental complexities or even to follow intelligently in the published literature all the varied accomplishments of basic research in these fields. As in the other sciences, most of the results of geophysical research have potential economic value and are being applied to a wider and wider range of human needs. Here we see a parallel with the older sciences and their relation to engineering. Whenever the applications of scientific results required the special experimental background, the economic outlook, and the practical knowledge characteristic of the engineer, a curriculum in that type of engineering grew up in the colleges and universities. In the words of the "Report of the Committee on Adequacy and Standards of Engineering Education" in the January 1952 number of the Journal of Engineering Education: "Engineering education in America was not developed after a preconceived plan. It evolved in parallel with the needs of a growing country, a country engaged in the development of a vast industrialization. From the first it filled a practical need, and its design emanated largely from an evaluation of the professional requirement." The advent of the railroad created a need for scientifically trained engineers and the response was the curriculum in civil engineering. The development of steam power created the demand for a curriculum in mechanical engineering. Neither of these types of engineers was trained to cope with the requirements of electrical power, and so there came to be a curriculum in electrical engineering. The advent of radio communication and of electronics during the first World War and in the years that followed resulted in the establishment of electronics engineering, sometimes within the curriculum in electrical engineering and sometimes independent of it. The complexities of industrial management have created an ever increasing demand for industrial engineers and the consequent building up of a curriculum in industrial engineering. The wide industrial application of chemical processes required a type of engineer whose background was training in chemistry but who was able to design processes and plants on an industrial scale; hence we have the curriculum in chemical engineering. The advent of the airplane created an entirely new set of problems which were solved by the training of aeronautical engineers. Many of these have called for more and more science and mathematics. Such was the history of the older engineer-

Jan 1, 1953