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By P. H. Morris

To achieve the full potential of sub-aerial co-disposal the properties of the co-disposed wastes must be known and understood. A description is given of the morphology and properties of waste deposits that were formed during 19 field trials of sub-aerial co-disposal at the dual Goonyella-Riverside mine in Queensland and at Hunter Valley No.1 and Warkworth mines in New South Wales

Jun 19, 1905

VOLUME II Volume II, in conjunction with Volume I, is a general guide to the selection of cost-effective methods of site data acquisition in all geologic environmental, and socio-political circumstances. The judgement of a generalist or trained specialist must be relied upon in the final analysis to design the optimum program for a specific site.

Jan 1, 1976

Study on Flotation Experiment of Complex Copper-Lead-Zinc Polymetallic Sulfide Ore in High Altitude Area and its Industrial Application

Sep 13, 2010

By X Qiu

According to the temporal and spatial distribution of regional metallogenesis, thePacific Rim can be divided into four global metallogenetic systems. The Asia-Australia W-Sn metallogenetic belt is the typical representative of intracontinental metallogenetic systems. This belt resulted from Mesozoic and partly pre-Mesozoic tectonic magmatism, mainly related to S-type granite of crustal source that was generated by collisional orogeny combined with oceanic subduction in intracontinental and continental margin settings. Based on the concept of metallogenetic series, there is a group of mineralised ore types showing a definite spatial and temporal distribution from endogenetic to exogenetic. These metallogenetic series are widely distributed in the Asia-Australia W-Sn metallogenetic belt, and are well developed in Southeast China. Five metallogenetic series and two petro-minerogenesis evolution models have been established according to their tectonic settings, various types of granitoids and metallogenetic evolution.

Jan 1, 1995

By J. A. Finch, Zhenghe Xu, Z. A. Zhou

Whether the microscopic bubbles generated by the high energy dissipation and high feed-slurry velocities in new flotation cells are stable in solution and what roles they play in particle collection are of great interest for the flotation of fines. Experimental work has shown that, with fast flow of liquid through an orifice, stable microscopic bubbles can form in flotation systems by hydrodynamic cavitation in the absence of gas supersaturation. The minimum flow rate at which bubble formation is initiated varies from 8 to 15 m/s, depending on the design of the cavitation tube, which is within the range of feed slurry velocities of some newly developed cells. Feed aeration enhances the formation of micro-bubbles by hydrodynamic cavitation. The study suggests that the fast flotation kinetics of some new cells may be attributed in some degree to the formation of microscopic bubbles

Jun 21, 1905

By G. X. Zeng

A calculation programme of finite element method has been developed in order to study the behavior of excavation with sheet piling in soft clay. Based on a series of isotropically consolidated-undrained tests (CIU) on Hangzhou clay a linear relationship between the normalized initial tangent modulus number, E1, and stress-path parameter, a, is found for four different stress paths, and stress-path dependent modulus equations derived. Meanwhile, several influence factors, such as embedment depth and stiffness of the wall and soil conditions, were taken into consideration in the programme. Some valuable conclusions were obtained. Finally, a case history was studied by the proposed method of calculation. The result of calculation and the field observation are in good agreement.

Jan 1, 2010

Modelling and Simulation to Design a Flotation Circuit for Gold Concentration

Sep 13, 2010

By Ruth F. Brinkley

This circular describes the activities and publications of the Bureau of Mines, Explosives Research Laboratory4 for the fiscal year 1960 (July 1, 1959 -June 30, 1960). Part 1 describes briefly the principal projects that were active during the report period, and presents some data not scheduled for publication elsewhere in the near future. Certain of the results are only preliminary and should be regarded as tentative, pending the findings of the completed investigation. Publications that appeared during the report period are listed and described briefly in part 2. In general, the research activities reported in these publications antedate fiscal year 1960. The published material relating to activities that are still current is indicated by references in part 1.

Jan 1, 1962

By J. M. Ortiz

Mineral resource evaluation requires defining geological domains that differentiate the types of mineralogy, alteration and lithology. Usual practice is to consider the domain boundaries as hard, i.e. data from across the boundaries are disregarded when estimating the grades within a given domain. This practice may hinder the quality of the estimates when a significant spatial correlation of the grades exists across the domain boundaries. In this paper, several geostatistical methodologies to handle soft geological boundaries are compared through a case study on a copper mine in Chile. The estimation methods considered are: ordinary kriging using hard boundaries between geological domains; ordinary kriging omitting the geological boundaries; traditional and standardized ordinary cokriging of the grades assayed in different domains; ordinary kriging within dilated geological domains, that is, incorporating samples from adjacent domains up to a given radius from the boundary of the domain being considered. The estimations are performed using a set of exploration data (drill hole samples) and are validated using a set of production data (blast hole samples collected for grade control). Results indicate that kriging with dilated domains performs better than ordinary kriging using hard boundaries or no boundaries and better than the ordinary cokriging approaches. It therefore appears as a simple alternative to global kriging (without considering the geological domains) and allows accounting for changes in the grade average, dispersion and spatial continuity with the geological characteristics of the deposit, via the use of grade variograms proper to each geological domain. The maximal distance for searching samples from adjacent domains should be chosen according to the spatial correlation of the grades across the domain boundaries, or via a cross-validation at an early stage of the mine or a jack-knife if production data are available. Keywords: Kriging; cokriging; soft boundaries; hard boundaries; geological control; geological domains.

Jan 1, 2006

By K. O. Bennington

Cancrinite is one eonstituentof "red muds," a high-volume waste product of alumina production by the Bayer process. The Bureau of Mines determined the thermochemical properties of cancrinite as part of a program to provide such data for minerals of industrial importance. Cancrinite [Na7.68(A16Si6024)(N03)1.68 (H2O)4.1] was synthesized by reacting aluminum silicate gel with a solution of NaOH and NaN03, and the composition was determined by chemical analysis, differential scanning calorimetry, and thermogravimetric analysis. The heat of solution was determined by hydrofluoric acid solution calorimetry. The standard enthalpy of formation at 298.15 K, ?Hf°298, is ?Hf°298 = -3,487.97 ±2.6 kcal/mol, and the standard enthalpy of formation from the oxides and NaN03, ?H°298, is ?H°298 = -215.20 ±l.8 kcal/mol.

Jan 1, 1983

By B. W. Gandrud

This report presents the data of one of a series of investigations of the washability of Alabama coals as indicated by float-and-sink tests made by the Bureau of Mines at the Southern Experiment Station in cooperation with the University of Alabama and Alabama coal producers The Klondyke mine, operated by the Blocton Mining Co., is about 1 mile east of West Blocton, Bibb County, Ala., near the southwestern extremity of the Cahaba coal field. The Bureau of Mines already has published three reports that deal with the washability of Cahaba coals - one a washability study of the Clark bed at Marvel4/, one on the tabling of fine coal from the Thompson and Woodstock bed , and the third a washablility study of the Henry Ellen bed at Acmar6/.

Jan 1, 1939

The structure and tectonic setting has had a strong influence on gold mineralisation at the Porgera gold deposit. Here, the structural controls on the mineralisation at Porgera are discussed and placed in a regional tectonic context. The Porgera gold deposit is related to the emplacement of the Porgera Intrusive Complex. Prior to intrusive emplacement at Porgera,Papua New Guinea was affected by a major fold and thrust episode which occurred in response to arc-continent collision in the Late Miocene. After crustal shortening the region experienced a relaxation of compression which is expressed in the deformation accompanying mineralisation at Porgera. The first stage of mineralisation (stage I) is hosted by extension fractures, and is spatially associated with exposed intrusive stocks. A later episode of mineralisation (stage II) is hosted by the faults and fractures of the Roamane Fault Zone, which was active as a dip-slip normal fault during stage II mineralisation. Therefore a change in the tectonic environment from shortening to extensional tectonics can be seen at Porgera before and during mineralisation. Rapid fault-slip during stage II mineralisation may have aided high-grade gold mineralisation by subjecting hydrothermal fluids to changes in pressure, temperature, fluid-fluid and fluid-rock interaction. Uplift to form the highlands of Papua New Guinea occurred after mineralisation and was largely complete by 4.0 Ma.

Jan 1, 1995

By M. S. Klima, V. Choudhry

Coal gasification solid residue (slag) contains unconverted carbon (char) which is considered an impurity for utilization applications of slag. Under this study, table concentration was used to process approximately 24,000 pounds of a nominal -3.4 mm gasifier slag (~85% ash) to separate high (~100%) ash slag from low (~50%) ash char. The results indicated a nearly ideal separation of the slag from the char for sizes coarser than about 1 mm. An overall slag yield of 71% was obtained. The slag was sufficiently clean to be used as feed material for the production of expanded lightweight aggregate. The recovered char had an ash content of about 47% and was a nominal -1 mm in size.

Feb 24, 1997

By Jim Rix, Ken Been, Nihal Bohra, Anthony Rice, Juan Lopez

"A temporary bridge, supported on steel pipe piles, was built to expedite the construction of a breakwater structure off the western coast of Peru. The bridge provided access for dump trucks to the breakwater across a 342 m (1122 ft.) wide navigation channel from a liquefied natural gas (LNG) loading facility, at the end of a 1.3 km (0.82 miles) long permanent trestle, in 15 m (50 ft.) water depth. After the completion of the breakwater, the temporary bridge was removed, and the piles were extracted approximately one year after the initial driving. The bridge deck was typically supported on pairs of 914.4 mm (3 ft.) diameter, 18 mm (0.708 inch) wall steel pipe piles spaced at 7.5 m (24.6 ft.) across the bridge width and 18 m (60 ft.) along the bridge length. In an attempt to reduce the driven pile embedment, an inner closure plate was installed at 2.7 to 7 m (9 to 23 ft.) from the pile toe to force closed-end behavior. The piles were designed to carry 3400 kN (383 tons) axial compression load, and a minimum of 8 m (26 ft.) embedment was specified to provide sufficient resistance to the lateral loads.The subsurface conditions consisted of cemented conglomerate of sand, gravel, pebbles and some boulders, locally known as the Cañete Formation. The driven pile embedment varied widely, between 8 to 24 m (26 to 79 ft.). A significant portion of each pile was above the seabed, passing through seawater and up to the bridge deck, and was therefore unsupported. The extraction of the piles was challenging due to the subsurface conditions, presence of significant water column, pile weight, and the inner closure plate. Several different approaches were attempted before the piles could be successfully extracted. This paper summarizes the difficulties encountered and observations made during the driving and extraction of these piles."

Jan 1, 2017

By Nihal Bohra

A temporary bridge, supported on steel pipe piles, was built to expedite the construction of a breakwater structure off the western coast of Peru. The bridge provided access for dump trucks to the breakwater across a 342 m (1122 ft.) wide navigation channel from a liquefied natural gas (LNG) loading facility, at the end of a 1.3 km (0.82 miles) long permanent trestle, in 15 m (50 ft.) water depth. After the completion of the breakwater, the temporary bridge was removed, and the piles were extracted approximately one year after the initial driving. The bridge deck was typically supported on pairs of 914.4 mm (3 ft.) diameter, 18 mm (0.708 inch) wall steel pipe piles spaced at 7.5 m (24.6 ft.) across the bridge width and 18 m (60 ft.) along the bridge length. In an attempt to reduce the driven pile embedment, an inner closure plate was installed at 2.7 to 7 m (9 to 23 ft.) from the pile toe to force closed-end behavior. The piles were designed to carry 3400 kN (383 tons) axial compression load, and a minimum of 8 m (26 ft.) embedment was specified to provide sufficient resistance to the lateral loads. The subsurface conditions consisted of cemented conglomerate of sand, gravel, pebbles and some boulders, locally known as the Cañete Formation. The driven pile embedment varied widely, between 8 to 24 m (26 to 79 ft.). A significant portion of each pile was above the seabed, passing through seawater and up to the bridge deck, and was therefore unsupported. The extraction of the piles was challenging due to the subsurface conditions, presence of significant water column, pile weight, and the inner closure plate. Several different approaches were attempted before the piles could be successfully extracted. This paper summarizes the difficulties encountered and observations made during the driving and extraction of these piles.

By T. J. Nelson

Natural aggregates, primarily stone, sand and gravel, are recovered from widespread, naturally occurring mineral deposits and processed for use primarily in the construction industry. They are mined, crushed, sorted by size, and sold loose or in concrete products to build roads, houses, buildings and other structures. Smaller quantities are used in agriculture, cement manufacture, and chemical and metallurgical processes. The growth of cities, their buildings and the highways that connect them have created demand for enormous quantities of aggregates. Consumption has now reached 9 t (10 st) per person and continues to grow faster than population. The aggregates industry is the largest mining industry in the United States in terms of production by weight, by volume and by number of active operations. About 80 percent of the concrete pavement and more than 90 percent of the asphalt pavement is composed of aggregates.

Jan 1, 2006

By TvS. von Moltke

Steel is a highly versatile material due to its low cost and good mechanical properties, but typically needs some or other form of corrosion protection due to its tendency to corrode when exposed to atmospheric conditions. In the case of organic coatings, the corrosion protection and functionality of the final product is critically dependent on the adhesion of the coating to the surface of the steel. In this work the effect of contaminants and the nature of the surface layers present on industrial steel products are investigated by means of paint adhesion tests, Auger electron spectroscopy (AES), and X-ray Photoelectron spectroscopy (XPS). It was found that the presence of sodium species on the surface is very detrimental to paint adhesion under wet conditions, while satisfactory adhesion may be obtained even in the presence of silicon and carbon residues. It was also found that the nature of the Fe-O layer, formed under wet conditions is labile and different from that formed in dry air, and that subtle changes in process conditions, such as changing the oxygen content of the quench water, may change the adhesion of paint to the surface of the steel. Lewis acid-base interactions are discussed as a mechanism that may determine the bonding between the steel and polymer coating.

Jan 1, 2003

By Richard Mainiero

In any construction project involving explosives, care must be taken to protect workers from carbon monoxide (CO) generated by blasting operations. CO is an odorless, colorless gas that can cause illness and death by asphyxiation. In general, the first symptoms include headache, fatigue and lightheadedness. At higher exposures to CO, skin flushing, rapid heart rate, and lowered blood pressure occur. At ever, higher exposure levels, decreased attention span is followed by nausea, vomiting, unpaired coordination, fainting, coma, convulsions and, finally, death. The detonation of explosives in blasting operations generates a range of toxic fumes, but CO is the most insidious because it is colorless, odor less, and is long lasting, since it is not readily removed try reaction with ground water, soil or rock. Additionally CO is generated in relatively large quantities compared to other toxic: fumes. CO may continue to seep out of blasted material long after the odor commonly associated with detonated explosives has dissipated. It is never safe to assume as confined space in the vicinity of a blast is clear of toxic fumes. CO may be present even if the area looks Clear and many hours have passed since the last blast.

Jan 1, 2000

By A. T. Yu

On March 18, 1964, the 52,000 dwt ore carrier M/S Houn Maru called at the port of Coquimbo, Chile, on its maiden voyage to take iron ore to Japan. This marked the first time a vessel of this size ever arrived at Coquimbo, and the event promises to drastically accelerate henceforth iron ore exports from Coquimbo province. This was made possible by the use of a versatile shiploading system recently installed by Cia. Minera Santa Fe. Coquimbo has no mechanized loading facilities other than six conventional 5-ton cargo cranes. Limited space on shore further complicates the stocking problems. To make the best of what is available, a meticulously organized semi-hand-loading system has been developed through the years.

Jan 5, 1964

By William R. Wayment

The objective of this investigation was to obtain data on friction-head losses of sand slurries during their transport in pipelines. The data ultimately will be used in designing hydraulic transport systems. Information that was incidental to the primary objective was gathered on degradation, changed percolation characteristics, and critical velocities of the slurries~ Tests were made in a closed-circuit pilot plant, with one type of tailing, through horizontal 2-, 3-, and 4-inch-pipe test sections at various pulp densities and flow velocities. Tests were made in a closed-circuit pilot plant, with one type of tailing, through horizontal 2-, 3-, and 4-inch-pipe test sections at various pulp densities and flow velocities. Approximately 2,000 tests were run in the pilot plant. The ranges of flow velocities used in the experiment were 2.8 to 19 f.p.s. in the 2-inch line, 4 to 14.5 f.p.s. in the 3-inch line, and 4 to 11 f.p.s. in the 4-inch line. Velocities were varied in increments of 0.5 f.p.s. through the entire velocity range in each pipe size. Densities were varied in 3-percent increments from 40 to 70 percent solids by weight except for one series of tests in the 2-inch line; in this series, densities were varied in 5-percent increments from 5 to 65 percent solids by weight.

Jan 1, 1962