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By D. Lascelles, J. A. Finch, E. El-Ammouri

Flotation separation is expected to be related to the degree of dispersion of the pulp. For instance, highly aggregated systems may show reduced selectivity, reduced entrainment and increased flotation rate. In an attempt to test the impact of aggregation on flotation, we have taken advantage of the effect of Mg ions. Using combinations of Mg2+ and pH gave a wide variation in aggregation of several Cu-Zn ores (measured by settling rate) and corresponding flotation response was determined by batch tests. The trials were conducted on-site at Louvicourt and Agnico-Eagle. In a majority of cases a similar trend in aggregation and flotation selectivity (grade at given recovery) was observed. At Louvicourt, improved selectivity with increasing aggregation at pH 10.5 was found. At Agnico-Eagle, an analogous association between aggregation and selectivity was observed at pH 11.5. It is suggested that aggregation influences particle entrainment, the increased effective particle size reducing gangue recovery and hence improving selectivity.

Jan 1, 2004

By Richard P. Roberts

This paper will discuss the methods for the cooling of aluminum melting furnace? dross .and their impact on the environment. Also discussed will be a case history of an AROS Dross Processor installation, which is designed to maximize the recovery of metal content of the dross in a manner which is not only environmentally cleaner, but which also prepares the output in such a way as to facilitate downstream processes. Handling of the discharged material will be discussed in regards to the recycling of the preserved metal content and deposition of the unusable-materials.

Jan 1, 1992

By James A. Kiger

We at Colowyo would like to thank you for the opportunity to share with the Society of Mining Engineers of A.I.M.E. the progress of reclamation at Colowyo Coal Company's multiple seam open pit coal mine which is a general partnership of W.R. Grace and Co., and the Hanna Mining Co. First, a brief history of Colowyo Coal Company (Colowyo). The Colowyo operation is located approximately 28 miles southwest of Craig, Colorado, which is in the northwest corner of the state. The Colowyo operation produces coal from a Federal Coal Lease, a portion of which has experienced previous coal mining by underground methods. The underground coal mines were known as the Red Wing Mine and The Streeter Mine, and supplied coal to numerous locations in the Rocky Mountain region.

Jan 1, 1984

By Leonidio Stegmiller

Since the petroleum crisis in 1973, charcoal1 is being considered one of the most important fuel for the Brazilian consumers, mainly for pellet's producers. In replacing fuel by charcoal mixed up with ore, obviously one of the first thing to be investigated is its influence in the product's quality. Special attention has been given to the metallurgical characteristics. This paper infocus the effect of increasing dosings of charcoal to the pellet's porosity and how other physical and metallurgical characteristics will be affected accordingly. This work was carried out using two different finesses of charcoal and dosing varied from 0.5 to 2.0%.

Jan 1, 1982

By Tom George

"INTRODUCTIONNo. 1 Queens Rd was an existing 10-storey office building founded on large pad footings. This project involved the construction of a 6-level, 15m (50-ft.) deep basement excavated immediately adjacent to the existing building and also beneath the existing footprint of the Southern end of the building. The total perimeter of the new basement was to be approximately 200m (656 ft.) all with a retained height of 15m (50 ft.). It was also proposed to add a further 5 storeys to the building. Approximately 18 of the existing columns supporting the 10-storey building were to have the applied column load diverted from the existing foundations at ground level onto the new piles or basement raft 15m (50 ft.) below.The geotechnical profile consisted of fill for the top 1.5m predominately comprising of clayey sand with a high gravel content from 1.5m to 9m (5 to 30 ft.), a medium dense to dense clayey sand and then below was a sandy clay extending to 15m (50 ft.) ranging from stiff to very stiff. From 15m on completely to extremely weathered siltstone was encountered. The groundwater was measured at 9.5m (31 ft.) below the natural ground surface.DESIGN BRIEFThe existing building columns were founded on large pad foundations up to 4.4m (14.5 ft.) square, founded on the dense clayey sand. These pads would require temporary support to enable the excavation to proceed beneath them. Upon completion of the excavation under the pads new columns were to be constructed joining into the existing columns to transfer the load onto the new raft slab, 15m (50 ft.) below. The existing 10 floors were to be refurbished. It was planned to undertake all the temporary support and transferring of loads while the structure above was only able to provide a dead load. It was decided that any movement of the building would have minimum impact on a skeleton structure. During the temporary support of the columns, movements due to construction activities had to be monitored to understand any potential stresses in the structure above.The original design required beams to be installed under the pads and supported at either end by temporary piles that were to be founded below the level of the proposed excavation. (Refer to sketch 1). Wagstaff Piling considered that this methodology had difficulties in construction at all stages and did not provide facility for transfer of the load without significant movement of the structure above. Wagstaff Piling revised the design to attach beams to the columns above the pads using shear collars. (Refer to sketch 2). These beams supported on the temporary piles could then be jacked upwards to remove loads off the pads. This would enable removal of the pads with minimal movement of the 10-storey building above. (Refer to photo 1 and back cover photo)."

Jan 1, 2005

By W. M. Dressel

The objective of the research reported in this publication of the Federal Bureau of Mines was to devise a mineral dressing procedure that would concentrate zinc silicate minerals from certain deposits in southwestern Missouri. The best flotation results were obtained by batch laboratory flotation using sulfidizing agents and ethoxylated cocoamine. The flotation concentrate contained 70 percent of the zinc at a grade of 47.8 percent. Gravity concentration tests showed that 55 percent of the zinc could be recovered at a grade of 48.3 percent.

Jan 1, 1961

By Floyd G. Anderson

Bureau of Mines studies show than an electronic counter can be used for determining just concentrations from midget impinger samples collected in bituminous coal mines. A sample correlation coefficient of 0.91 for data obtained using the electronic counter and the Bureau of Mines microprojector procedures indicates a significant linear relationship between the methods. The electronic counter provides better counting precision and reduces analytical time.

Jan 1, 1968

By Fumitaka Tsukihashi

Phase diagrams of the CaO-SiO2-FeOx-MgO, Al2O3 systems are necessary for the analysis of copper smelting reactions and sintering process of iron ore. The effect of MgO and Al2O3 addition on the liquidus of the phase diagram of the CaO-SiO2-FeOx system at low oxygen partial pressure was observed. The liquid phase area changed by the addition of MgO and Al2O3 with a changing oxygen partial pressure from 10-8 to 10-3 atm (10-1 to 102 Pa) at 1573K. The effect of Fe3+/Fe2+ ratio on the melting mechanism is discussed.

Jan 1, 2003

By J. A. Domenico

A safe and precise mineral separation alternative to heavy liquids is being used for mineral sands exploration on large scale orebodies. The separation process, Magstream®, uses ferro-fluids and magnetic and centrifugal forces to produce precise split points over a range of specific gravities from 1.5 to 18.0 g/cc. This paper describes a commercial scale exploration program treating, roughly, 90 samples per day in Senegal (West Africa). Separation results comparing Magstream® and conventional heavy-liquid separation are presented.

Jan 1, 1994

By T. J. Dudek

To be competitive in automotive applications, polymer composites must be processable by high production rate processes like injection molding (IM), reaction injection molding (RIM), structural rim (SRIM) and compression molding. With current fiber reinforced composite materials, performance properties are sometimes compromised to make them compatible with these processes. This is done by decreasing the amount and length of the reinforcing fiber and the viscosity and molecular weight of the polymer matrix. Sheet molding composite (SMC) and thermoplastic polymer blends are examples of polymer composites which are cost effective in many applications and meet the high speed processing requirements for automotive parts.

Jan 1, 1993

By T. Surkova

For the moment reserves of high-grade ores are practically depleted requiring ever-increased involvement of low assay raw materials, such as black-shale ores, in industrial operations. Black-shale ores are constituted of minerals containing such valuable components as vanadium, uranium, molybdenum, manganese, and rare-earth elements (REE). We studied technogenic solutions of black-shale ores processing, after uranium, molybdenum, and vanadium were recovered. Mentioned solutions contain rare-earth elements in substantial quantities (S REE 70-100 mg/dm3) that is very important factor taking into consideration the world demand ever-increasing last years. Higher concentrations of iron and aluminum inhibiting REE sorption and extraction recovery are found in solutions. We propose a method of hydrolytic deposition to cleaning solutions from impurity elements (Fe, Al). Study of hydrolytic deposition kinetics allowed identifying optimal conditions to run this process. Rare-earth elements may be recovered from purified solutions through sorption process followed by their further deposition from eluates in form of concentrates. Keywords: black-shale ores, rare-earth elements, a method of hydrolytic deposition, impurity elements, sorption

Sep 1, 2012

By G. M. Humphrey

It is a great honour and privilege to be here in this distinguished company of the outstanding men in the mining industry and the political life of Canada. I fully recognize that I am so honoured as a symbol of the combination of American and Canadian leaders in industry who are partners in the sponsor-ship of the Quebec-Labrador iron-ore mining development which we are undertaking, and as such I want to express our great appreciation of the co-operation and assistance we have met on every hand in Canada, and the genuine friendliness and never-failing courtesy which we are always accorded. We are quite aware that it springs primarily from the very high regard in which our partner and sponsor, Jules Timmins, and our other Canadian associates are held. Their high standing among you is well known and we quite naturally fall heir to the benefits of the great esteem in which you hold them. Jules Timmins and his long-time associate, John Knox, were the original inspiration for our participation in this venture. It was their enthusiasm and vision which caught our interest and led to our joining with them in the years of exploration and search which have brought us to the threshold of this great development where we stand today. So much has been written of the details of our exploration and plans for future development that it would bore you for me to review them further here, but there is a phase of this development, and an extremely important phase of it, which I think has passed almost unnoticed and which it may be well worth while for me to bring to your attention this evening.

Jan 1, 1951

By J. H. Perkins

The Bureau of Mines has conducted desorption work on fine coal particles at near atmospheric pressure. An apparatus Iris been developed that uses a capacitance manometer to measure desorption of methane from coal particles up to, 2 inches in diameter and pressures up to 1,000 psi. This will make it possible to duplicate the desorption process as it occurs in its natural underground environment.

Jan 1, 1969

By K. C. Dean

Time and motion studies were made by the Federal Bureau of Mines on the hand and machine dismantling of scrapped auto starter motors, generators, and alternators for recovery of copper, aluminum, and iron. The studies showed that an individual with power handtools and convenient access to a hydraulic press, power bandsaw, acetylene torch, and power lathe could, in an 8-hour day, disassemble about 100 starters, or 150 generators, or 30 alternators. The scrap copper yield would be 280, 390, and 45 pounds, respectively, and the iron yield would be about seven times the copper weight. About 100 pounds of aluminum would be obtained from the alternators.

Jan 1, 1976

By H. B. Brunot

A complete list of permissible mine equipment, tested and approved by the Bureau of Mines previous to January 1, 1947, was published as Information Circular 7432.2/ A list of permissible mine equipment tested and approved by the Bureau of Mines during the calendar years 1947, 1948, and 1949 was published as Information Circular 7569. The present list supplements Information Circulars 7432 and 7569 and includes all of 'the equipment approved during the calendar year 1950. Information Circular 7465, which included a list of permissible mine equipment tested and approved by the Bureau of Mines during the calendar year 1947 therefore is superseded.

Jan 1, 1951

By T. D. Murphy

In the fall of 1988 it became evident that the accuracy of sulfur forecasts for Monterey Coal's No.1 Mine needed to be improved. In addition, it became necessary to predict if any individual train shipments during a month would exceed a contract sulfur limit. The challenge was to develop a forecasting process that would take into account the variability of the coal in the ground as well as the difference between laboratory and preparation plant sulfur reduction efficiency, and the effects of mining coal with multiple units. This paper describes how geostatistics and simulation techniques were used to meet this challenge.

Jan 1, 1992

By R. K. Sidhu, N. L. Richards, M. C. Chaturvedi

Nickel base superalloy IN-738LC, strengthened mainly by the precipitation of y' phase, is extensively used in hot sections of land-based and aero gas turbine engines. Fusion welding, which is one of the most commonly used joining techniques for the repair and fabrication of superalloy components, however, finds a very limited application in case of IN-738LC components, as the alloy suffers from HAZ cracking during welding and during subsequent postweld heat treatment (PWHT). The present paper reports on the two methods studied to reduce the HAZ cracking in as-welded and postweld heat treated GTA welded IN-738LC, viz., the use of various fillers during welding, and the use of appropriate heat treatments prior to welding. The results of the microstructural analysis and crack measurements indicated that the HAZ cracking in GTA welds of IN-738LC was significantly reduced by using age-hardenable fillers with Al+Ti concentration less than that in the base metal in conjunction with a preweld heat treatment developed by the authors.

Jan 1, 2006

By L. A. Henry

The island of Jamaica consists predominantly of Carbonate rocks which vary in chemical & physical characteristics. Currently these rocks are used for construction and road aggregate, landfill and as a raw material in the manufacture of cement. Over the past fifteen years the Geological Survey of Jamaica with assistance from a number of international aid agencies and the private sector have identified deposits of high calcium/high brightness limestones which have the potential to be utilized as a high quality filler and a number of other commercial applications. Geologically, these limestones are formed within the Eocene Swanswick Formation, the Oligocene Walderston-Browns Town Formation and to a lesser extent the Miocene Montpelier and Newport Formations.

Jan 1, 1998

By Larry F. McHugh

Current sulfide ore processing methods involving mechanical sizing of ores, froth flotation, electro-winning, solvent extraction, smelting and roasting are quite effective but typically represent a significant energy and environmental cost. This paper is the subject of a recent patent application and development program involving major improvements in sulfide ore processing. This two-step ?looping oxidation? process effectively removes sulfur while producing materials of adequate purity in an energy proficient and environmentally friendly manner. The first step results in a metal sub-oxide and a highly concentrated sulfur oxide off-gas stream. This gas stream can be processed for recovery in a more effective manner regarding both energy and capital equipment costs. In the second step, this metal sub-oxide is further oxidized to efficiently generate energy that can be recovered and utilized without the typical complications of an ?acid gas? stream process. Additionally, a portion of the final fully oxidized product can be looped back to the first step as the oxidizing agent. This process will be described in detail and compared to existing technologies in the area of energy efficiency, and off-gas environment treatment energy requirements.

Jan 1, 2008

By Patrick R. Taylor

Titanium nitride has been synthesized in a thermal plasma reactor from ilmenite ore concentrate using methane and ammonia as the reactive gases. The product has been characterized by x-ray diffraction and SEM. Results show that a high concentration of methane favors the formation of iron, titanium nitride and titanium carbonitride. The formation of titanium carbonitride can be minimized by controlling the concentration of methane. The formation of TiN proceeds by the progressive reduction of the oxides of titanium to titanium, which is converted to titanium nitride.

Jan 1, 1998