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Copper mineralization associated with minor molybdenum, silver, and gold occurs in a hydrothermally altered brecda within a granodiorite mass of Upper Permian age. A dyke system of rhyolite, dacite, and andesite forms plug-like bulges near the breccia and probably caused mineralization as a late stage effect.Base metal sulphides occur as disseminations, fracture and cavity fillings in the breccia. A pyritic halo in hydrothermally altered granodiorite surrounds the breccia and grades into unaltered granodiorite. Drilling during 1969 indicated the grade is subeconomic.

Jan 1, 1972

By E. G. Davis

The flash reduction of fine iron ore in a dilute-phase system was investigated at 500° to 900° C within a heated stainless steel tubular coil. Alabama brown iron ore and Mesabi semitaconite ore were fed into the coil concurrently with reducing gases of hydrogen and reformed natural gas, so that the velocity of the gas at the reaction temperature was sufficient to entrain and pneumatically transport the solids through the coil. Reduction is very rapid with retention time of the ore in the coil varying from 4 to 15 seconds. Variables affecting reduction are temperature, ore feed rate, and gas flow or velocity. Results of the studies show that a partially reduced product (10-to 25-percent reduction) can be made which, on subsequent magnetic concentration, yields a concentrate containing 64 to 70 percent iron with a 90-to 94-percent iron recovery. Maximum reduction of 77 percent was obtained when hydrogen was used in a four-stage reduction test to yield a product containing 61 percent metallic iron.

Jan 1, 1972

By M. E. Holter

"Five main lignite seams occur in the Tertiary Ravenscrag Formation in the Eastevan area, at depths of 100 feet or less. They are named, in ascending order: the Boundary, Estevan, Souris, Roche Percee and Short Creek seams. A total sequence of approximately 250 feet is represented by the coal beds and interstratified clays, silts and sands. Strata dip to the southeast at 25 feet per mile or less and trike northeast. Large areas underlain by coal seams at shallow depths are delineated. Reserve calculations are dependent on detailed information on seam thicknesses and feasible stripmining depths. The stratigraphically higher seams are thinner on the average than lower seams and this, together with the increase in elastic size fractions in higher strata, suggests a retreat of a Tertiary marine margin to the south during the closing depositional history of coal seams and associated strata."

Jan 1, 1972

By Northcutt Ely

This volume summarizes mining and petroleum legislation in 22 jurisdictions of the Near East and South Asia. Within these jurisdictions, primary attention is given to requirements that must be met in each country for acquisition of rights to permit development of mineral resources. Coverage includes : First, identification of the controlling laws or statutes governing minerals acquisition and reference to the administrative authority; second, analysis of the laws governing mines and quarries and their products; and third, analysis of laws applicable to natural gas, petroleum, and related materials. Where pertinent, sections dealing with historical background or administration have been added. In countries where minerals are subject to control of states or provinces, those areas are considered separately from the central government.

Jan 1, 1972

By E. E. Maurer

Kerr-McGee has operated the Ambrosia Lake uranium mill since startup in 1958. Tonnage milled per day has varied from 3500-7000 tons. The mill capacity is currently rated at 7000 tons per day. The process consists of two parallel circuits following crushing and sampling, \\lhich include open circuit rod mill grinding, sulfuric acid leach, cyclone classification, and counter-current washing circuits of sand classifiers and slime thickeners. Pregnant solution is clarified and polished by precoat pressure leaf filters prior to amine solvent extraction. Yellowcake is precipitated from the pregnant strip solution with ammonia, filtered and dried.

Jan 1, 1972

By Rejean Gagnon, Fernand Rochefort

"Haulage costs, in most operations, represent a large portion of total cost. Quebec Cartier Mining Company came to the conclusion t hat an electric trolley assist providing more horsepower than available from dieselgenerator sets presented the best oppor tunity for improvement. Accordingly, a testing and development program was carried out which resulted in the design, installat ion and application of a practical system. This paper describes the development of the system, the equipment used as well as the actual operation. A projection is also made to indicate further improvement in productivity. A comparison is made of truck operating data before and after activation of the trolley assist system in order to determine its economic impact."

Jan 1, 1972

The oxidation of ferrous sulphate to ferric sulphate with air and oxygen in a gas lift percolator was investigated with initial Fe2+ concentrations in the range 0·01 M to 1·0 M,temperatures in the range 20-80°C, and pH in the range oto 2.The rate of formation of Fe3+ was found to be well described by the rate expressionEquation 1and a consistent mechanism is proposed.The presence of Cu2+ was found to cause an increased rate of oxidation, the effect being greater with Cu2+ concentrations increasing in the range 0·001 M - 0·01 M in 0·2 M Fe2+. The effect of other solutes containing Ni, Zn, Mn, Co, Hg, Cl, Mo, NH4, As, Cr, or Na at a concentration of 0·001 M in 0·2 M Fe2+ was negligible.

Jan 1, 1972

By R. J. Bielicki

A sorption apparatus for measuring the equilibrium sorption isotherm and the rate of diffusion of methane from fine-sized coal was designed and constructed. Preliminary work that used Pittsburgh and Pocahontas No. 3 coal shows that the diffusion coefficient varies with pressure and that the fracture spacing in these two coals is substantially different.

Jan 1, 1972

By Stephen Gerard Sawyer

This report presents a Fortran IV computer program for the structural analysis of space-frame protective canopies used in underground mines to protect equipment operators from falls of roof, face, or rib. This program entitled CANOPY permits rapid calculation of the elastic strength of a canopy for a variety of static loading conditions. Stresses in, and displacements of each structural member are computed and printed out. Additionally, identification of all members that have commenced yielding, weight of the canopy, total loads on the canopy, and maximum loads that the canopy can sustain elastically are output. Program description, input instructions, program listing, and two example problems are included.

Jan 1, 1972

By E. G. Davis

The Bureau of Mines investigated gaseous direct reduction of low-grade iron ore concentrates in a continuous fluid-bed reactor. These studies were made in a 4-inch diameter fluid-bed reactor using hydrogen alone, and oxygen-or air-reformed natural gas as the reductants. The percent reduction is directly dependent on the mole ratio of hydrogen in the reducing gas to the oxygen associated with the iron oxide in the ore. Two-and three-stage fluid bed tests were simulated by repeated continuous tests. The results showed that percent reduction of the final product was dependent on the mole ratio of the quantity of hydrogen in the gas of each stage to oxygen in the iron oxide of the initial ore feed. Reduction as high as 87 percent in the single stages and as high as 94 percent in the multistages was obtained when either hydrogen or reformed natural gas was used as the reducing gas. Magnetic separation and concentration of the highly reduced fluid-bed product yielded a high metallic iron concentrate analyzing 85 percent total iron and 80 percent metallic iron with total iron recovery as great as 90 percent. Agglomeration of the high-grade metallized concentrate produced hard pellets analyzing 85 percent total iron and 78 percent metallic iron. Green pellets, with good strength, were made without any binder in a drum pelletizer. Direct melting of the high-metallic fluid-bed product in a basic lined arc furnace produced a nearly pure iron which contained 0.09 C and 0.01 P with 95 percent recovery of the metallic iron in the metal.

Jan 1, 1972

By J. D. Vincent

The Henderson mine site is located at Red Mountain on the eastern slope of the Rocky Mountains, approximately 50 miles west of Denver, Colorado. The mill site is on the west slope of the Rockies and mine and mill will be connected by an underground railroad. All designs were for a 30,000 ton per day molybdenite processing plant with provisions for future expansion up to 50,000 ton per day if required. This plan did not just happen, but slowly evolved over the course of about three and one-half years. Many plants cannot afford such a delay, but the Henderson project will take about 10 years from the time it was first discovered until production starts, and these 3 !1 years were well spent in determining the best possible plant site and flowsheet. This paper describes some of the problems and the decisions made in arriving at the final location and flowsheet. The paper does not go into the specific details of how protection of the environment went hand-in-hand with all other project considerations. This particular aspect of the planning has been well-reported on other occasions and considerable information on it is readily available.

Jan 1, 1972

Horizontal holes are drilled underground into coalbeds to control methane flow from ribs and active face areas and to make gas pressure measurements in coalbeds. Gas pressure measurements are made by drilling the same hole incrementally. After each increment, the hole is filled with some type of packers and allowed to reach equilibrium before a gas pressure reading is taken. As the length of hole increases, more packers are required to effect a seal and obtain a reliable pressure measurement. Problems have been encountered in obtaining satisfactory packer seals due to the friable nature of the coalbed. New methods of packing the holes must be used. Therefore, this project was established to evaluate materials and develop a new technique in which a semiliquid and/ or rigid type grout could be placed in the hole to provide satisfactory sealing.

Jan 1, 1972

By W. E. Lamont

Flotation studies of phosphate-bearing waste pond materials, low-grade washer products, and raw ores, all from the Tennessee brown phosphate district, showed that these types of materials could be treated without des liming to recover high-grade phosphate concentrates. The investigation showed that fine grinding before flotation was a requisite for increased recovery of the phosphate values and that the optimum pH conditions were in the range of 10.0 to 10.5 when using anionic collectors. Multiple-cleaning of the rougher phosphate concentrate was required to produce high-grade concentrates. Phosphate recoveries ranged from 60 to 82 percent and were inversely related to the grade of concentrate produced.

Jan 1, 1972

The Tasman Orogenic Zone is regarded as a single metallogenic province (the Tasman Province) with four SUb-provinces corresponding with its major tectonic components: the Lachlan, New England, Hodgkinson.and North Queensland orogenic provinces. Within the Tasman Province there are four main ore-rock associations.These are1. manganese and iron with sedimentary and basic volcanic rocks,2. zinc-lead-copper and copper with intermediate-acid volcanic sequences,3. minor chromium, platinum, and osmiridium with ultramafic complexes, and4. tin, wolfram, gold, and copper with syn- and posttectonic granitic intrusions.Whereas the ores of ultramafic and volcanic associations form geographically-restricted metallogenic districts, the ubiquitous granitic ores may be subdivided into twenty-one districts that cover almost the entireOrogenic Zone. The Tasman Province is notably lacking in uranium ores and Mississippi Valley-type deposits.There is a distinct tendency for ores of each association to be progressively younger to the east and north, thus paralleling the progressive growth and stabilization of the Zone. Similar ore-rock associations are present in repeated phases of mineralization from the Cambrian to the Permian-Triassic, reflecting the essential homogeneity of the Tasman Province, and the similarity of the successive tectonic cycles.

Jan 1, 1972

By R. C. Diehl

Coal, fly ash, and flue gas samples were analyzed for mercury (Hg) by double gold amalgamation-flameless atomic absorption spectrophotometry. The purpose of the study was to elucidate the fate of the trace mercury in the coal when the coal is burned. Samples were collected from a bench-scale 100-g/hr combustor, a 500-lb/hr combustor, and three coal-burning powerplants. In all cases mercury was found in the fly ash. The amounts ranged from about 9 to about 70 percent of the mercury in the coal that was burned.

Jan 1, 1972

By V. Dinesen

"Grinding is simply the function of reducing particles in size or creating new surface areas. This may be accomplished by many means but we will only concern ourselves with the continuous grinding process as performed in a revolving drum or mill, containing a grinding media. Such a mill consists essentially of a feed head, a cylindrical shell section and a discharge head. To prevent internal wear of these parts it is customary to attach replaceable linings over the wear areas. The specification and design of these mill liners is more important than generally conceded. As they reduce the effective internal volume of the mill, they will consequently affect the whole mill ·design and operation.A number of mill designs of various sizes are available for combined crushing and grinding of materials within a wide size range. For simplif1cahon purposes we will refer 1n particular to conditions relating to standard mill shapes having a length which is greater than the diameter. Such mills usually rotate at speeds between 60% to 85% of the critical speed and may, depending on the grinding media used, be classified as rod mills, ball mills and pebble mills.LINER MATERIALSA great variety of materials have been and are being used for mill linings. These include wood, ceramics and cements, rubber and plastic compounds, rolled and forged steels, cast steels and cast irons, both plain, alloyed and specially treated.The choice of a liner material depends on many factors. In both dry and \\.:et grinding, it may be necessary to consider product purity, colour, chemical reaction etc. but for our purpose we \viii refer to wet grinding operations as generally used within the mining industry."

Jan 1, 1972

The economic significance of a fundamental understanding of the mineral pyrrhotite is dis- cussed. Particular emphasis is placed on the relationship of other sulphide minerals to the pyrrhotite when it is the major sulphide mineral present in an ore body. Studies of the Kambalda nickel deposit are used to give a better under- standing of (a) the genesis and other character- istics of a particular ore body (b) the textural relationships between pyrrhotite and other sul- phide minerals (c) magnetic properties of natural pyrrhotite, and (e) the oxidation and supergene processes that take place in a sulphide ore body.

Jan 1, 1972

By Leo R. Love

A comprehensive study of the environmental conditions of the area affected by the Colfax and Cheswick Power Stations is of extreme importance to Duquesne Light Company. The residents in the valley where the two plants are located have complained for many years about the emissions from the Colfax Plant which is of the 1920 to 1930 vintage and which has a capability of generating approxi¬mately 200 Mw. They were extremely happy to hear that the Company had plans for shutting it down, however, they were extremely unhappy to hear that we were planning to build another even larger one to take its place in the same vicinity, namely the Cheswick Plant with a capability of 570 Mw. They had visions of a plant twice the size of the Colfax Plant and belching out twice as much smoke. A few of the citizens from that area were most vehement at the public hearings that were held by the Allegheny County Air Pollution Bureau for obtaining an installation permit. With two power plants already existing in that area (Duquesne Light Company's Colfax Plant and West Penn Power's Springdale Plant), the primary concern of the Allegheny County Air Pollution Control Bureau was that the Cheswick Station might increase air pollution levels beyond what they considered to be dangerous limits. It became very evident that the Allegheny County Air Pollution Control Bureau would be extremely reluctant to grant installation and operating permits unless they were satisfied that the new plant would not increase local pollution levels and that we were taking sufficient steps to monitor the emissions from our plants and also the ambient air in the general area. We concluded that an extensive air pollution monitoring program must be conducted in the area to determine the effects of the operation of our plants. The program was conceived with our consultants, NUS Corporation of Rockville, Maryland, and was begun in June, 1968. It was designed to accomplish several things: 1. Determine the effect on the ambient air of the operation of each of

Jan 1, 1972

The passage of chloroform vapour in a carrier of oxygen through two nickel sulphide ores heated to 380°C converted the nickel to the water soluble chloride form. In one ore the nickel (2·75 per cent) was presentas violarite ((Ni, Fe)3S4) whereas in the second it was present as pentlandite, ((Fe, Ni)9S8) (4·9 per cent Ni).A similar technique was utilized to convert nickel in nickeliferous laterites (1·6 per cent Ni) into a soluble chloride using town gas instead of oxygen as a carrier.With both techniques greater than 90 per cent extraction was achieved.

Jan 1, 1972

By T. R. West

Planning for urban development in many locations is based largely on 0.10 factors, 1) soil conditions and 2) socio-political aspects of the region. A more widely based approach is necessary, however, if a complete and functional plan is to be obtained. Under this unified approach, the overall field of earth science is included in the planning process. As considered here, the earth sciences comprise a large segment of the natural sciences; that is, geology, pedology, geomorphology, reengineering geology and ground water hydrology. A number of shortcomings can develop when using the restrictive, two-factor approach for urban development planning. These deficiencies are discussed in the paper. The specific considerations for each earth science area are examined and land use considerations for various urban requirements reviewed in light of these specialties. To illustrate the potential of the unified or earth science approach, Tippecanoe County, Indiana is presented as an example. The current area planning system for Tippecanoe County is examined to determine how well it compares with the unified approach and some of the shortcomings of the current plans are discussed.

Jan 1, 1972