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By Henrique Silva Furtado

This paper presents the results obtained on the exchange of an original old blow charge model for a new up-to-date state of art global model, employing optimization techniques and process modelling, and, the results obtained in terms of fluxes consumption reduction and the introduction of user friendly tools and practices.

Aug 17, 2017

By John Hanna

Over the years the coal industry in Alabama has generated about 150 million tons of fine waste coal, increasing at a rate of 2 million tons/year, during mining and cleaning operations. Reclamation of the fine-size wastes containing 20-60% by weight clean coal provides, free of charge, mined and crushed feedstocks for coal recovery and eliminates a major source of acid water pollution. Tests were made on the impounded wastes and current plant discharges to recover the coal fraction by sizing, gravity and flotation techniques. Gravity separation of the plus 100 mesh material produced commercial grade coal averaging 8.2% ash, 0.8% sulfur and 13,350 Btu/lb. However, the coal recovery was relatively low at 50-65%. Froth flotation using mechanical and froth column methods gave similar coal products at much higher coal recovery of 87-93%. The coal produced analyzed 10% ash and 1.1% sulfur.

Jan 1, 1991

By John W. Cole

The Bureau of Mines conducted a trenching and sampling project during 1947 on the tungsten-rich granodiorite that outcrops in Henderson Gulch, Montana. During the course of this investigation, interest was attracted to the Sunrise copper-gold mine in metamorphosed limestone in the north slope of the gulch. The mine was examined by S. H. Lorain, Chief, Mining Division, Albany Branch, in May 1948. A trenching and drilling program was recommended to develop a parallel vein indicated by outcrops to lie below the principal productive Queen vein. In the meantime, the Queen Mining Syndicate initiated a trenching program that exposed high-grade lead-copper-silver-gold ore in a nearly vertical vein that strikes N. 600 E. to east. A core-drilling program to develop this vein was initiated in September 1948. This report presents the factual data obtained from the trenching and drilling operations. The Sunrise mine was discovered about 1890. Production has been estimated to be $120,000 in gold from 40,000 tons of ore mined during the period 1892-1903. The tailing from this operation was treated by cyanidation in 1912, with a reported recovery of $3.50 to $4.00 a ton from 15,000 tons of material. Subsequent production of sulfide ore was 7,396 tons treated by smelting, with recovery of 1,569.42 ounces of gold, 10,003 ounces of silver, 352,899 pounds of copper, and 354 pounds of lead.

Jan 1, 1950

By W. C. Dailey

The Groveland Mine. Concentrator and Pellet Plant are located in Dickinson County in the Upper Peninsula of Michigan. The construction of the Groveland Mine in 1959 was the first United States operation for the Hanna Mining Company in mining and beneficiating low grade iron formations. (1) The plant produced concentrates at 675,000 lt/yr. (746,600 mt/yr.) which was used as sinter feed in the steel industry from 1959 to 1963. Upon completion of a pelletizing plant in April, 1963 production increased to 1.6 million lt/yr (1.77 million mt/yr) of pellets. After the plant expansion, mill capacity increased to 2.2 million 1t/yr (2.43 million mt/yr.), producing 2.0 million It/yr (2.23. million mt/yr.) of pellets assaying 63.0% iron and 7.0% silica. (1) Prior to April, 1971 the concentrator operated with a flowsheet consisting of spirals and a petroleum sultonate iron notation circuit. This was presented in a paper by R. R. Smith and E. E. Sougstad, "Flotation at the Groveland Mine" in the 50th Anniversary Volume entitled "Froth Flotation". The ore body at the Groveland Mine consists basically of two types of iron formation (34% total iron, 20% magnetic iron head), the most abundant of which is a bedded magnetite-chert-silicate rock. This is intermingled to varying degrees with non-bedded to poorly bedded hematite-clastic quartz-chert rock. (1) In developing the Groveland flowsheet, Humphrey spirals were used because of their ability to produce a coarse size concentrate at a low cost. Tests run in the lab and pilot plant on the Groveland ore showed a. spiral weight recovery in the 27 to 33% range. (2) However as the ore body was opened up, it became evident that the most abundant ore type did not liberate at the coarse size fraction needed for spirals. Plant recoveries for the first five years operating the spirals only averaged from 10 to 15% weight recovery. In 1971 the weight recovery on the spirals had dropped to a low of 5%. To increase iron recovery and at the same time increase plant capacity with the least effect on the present operations the mill flaw-sheet proceeded from a spiral-notation circuit to an all flotation circuit to a magnetic separator-flotation circuit. During this changeover the concentrate grade also had to be improved to meet market demands. To do this the following changes evolved

Jan 1, 1978

By A H. Gray

Gekko Systems Pty Ltd engaged in the test work, design, manufacturing and commissioning of the pre-concentration plant at Silver Standard Resources Inc’s Pirquitas mine in the north western Jujuy province of Argentina. Testing of the ore at coarse feeds of between 2 and 12mm returned probable recoveries of up to a total of 95% silver into 50% of the mass fed to the InLine Pressure Jigs (IPJ’s). The plant has been designed and built based on the test results to include a preparation screen to bypass the fines that are naturally higher in grade and repulping of the coarse which is then pumped to three parallel trains of 2-stage IPJ roughing-scavenging. The target 50% yield to concentrate passes over a dewatering screen and the solids are returned back to the mill feed conveyor. The IPJ tails are transferred to a dewatering screen and solid rejects are stockpiled off the end of a transfer conveyor. All dewatered underflow products are processed via hydrocyclones to recover dirty water for use back into the IPJ circuit and return entrained fines to the fines bypass line.With the sulphide orebody being processed, the results from operations to date have shown that plant performance is matching the original laboratory sulphide ore testwork data. The objective of the pre-concentration step is to both reject gangue and achieve grades between 300-400g/t Ag to the float circuit as flotation recoveries are maximised within this range. The plant currently achieves overall upgrades of approximately 150% of feed grade with the IPJ only circuit producing an average 180% increase from calculated feed grade.

Aug 8, 2011

By Pamela J. Watson

This report presents a Bureau of Mines literature survey that provides a data base useful for current and future studies in the area of chemically enhanced drilling and cutting. Publications describing laboratory testing and field studies of drilling and cutting with chemical additives are reviewed. Significant results are summarized and tabulated by rock or material type and also by chemical additive, with extensive references. Selected studies related to fluid-enhanced processing or material testing are summarized in the appendixes.

Jan 1, 1985

By Ali Jaberi Zamharir, Abolfazl Shoghian‐Alanaghi, Hossein Aghajani, Arvin Taghizadeh Tabrizi

In this study, the leaching rate of molybdenite concentrate was evaluated in sulfuric medium, and the influence of the diverse oxidants including hydrogen peroxide, manganese oxide, copper sulfate on the leaching rate was studied. Also, the effect of the addition of the ethylene glycol to the hydrogen peroxide was studied and results showed that with the addition of ethylene glycol, the leaching rate is increased 55% from 41% up to 80.3%. The optimum condition is achieved as 0.7 M of H2SO4, 4.4 M of H2O2, and 3.5 M of EG at 30 °C within 4 h of leaching time and 500 rpm. Also, inserting the oxygen with the pressure of 6 bar to the leaching autoclave, the leaching rate is increased more up to 86.4%. Finally, the leaching process was studied kinetically and the determined mode of controlling factor was specified based on the activation energy which equals 46.252 kJ/mole indicating the chemical reaction mode.

Jun 5, 2022

By H. I. Aaronson

ONLY limited studies have been made of pro-eutectoid a morphology in hypoeutectoid Ti-Cr alloys during previous investigations, 1-3 The nature of the eutectoid reaction, ß?a + TiCr2, has been considered in somewhat more detail.1,2,4,4 Inasmuch as the proeutectoid ferrite reaction in plain carbon steels has recently been extensively investigated in this laboratory, advantage has been taken of the opportunity to compare the morphologies developed in two rather different eutectoid systems in order to permit a preliminary estimate to be made of the degree of generality which may be ascribed to the various results obtained. Experimental Procedure The chemical analyses of the alloys used are given in Table I. The 7.22 pct Cr alloy was prepared by the Battelle Memorial Institute from iodide titanium and high purity chromium. The initial ingot was made by arc melting a master alloy and iodide titanium. The resultant ingot was twice remelted. by the consumable electrode technique. Upset forging at 950°C reduced the final ingot to 3/4 in. sq bars. The 10.94 pct Cr alloy was prepared by the Titanium Metals Corp. of America from sponge titanium and chromium of ordinary purity. This alloy was melted twice by the consumable electrode technique, forged at 1200° to a 3/4 in. sq bar, and rolled at 815°C to a 1/2 in. round. Specimens 1/4 in. x 1/4 in. x 1/16 in. were cut from the 7.22 pct Cr alloy; halves of disks 1/2 in. in dlam and 1/16 in. thick served as specimens of the 10.94 pct Cr alloy. These specimens were individually encapsulated in Vycor, Each capsule was evacuated three times to a pressure of 2 to 6 x lo-' mm Hg and flushed twice with a reduced pressure of argon prior to sealing. The inclusion of two small packets of zirconium chips permitted the capsules to be outgassed and internally gettered, without heating the specimen, prior to heat treatment. The specimens were solution annealed for 40 min at 1000°C, isothermally reacted in deoxidized lead pots, and quenched in iced water. Most of the isothermal reaction treatments were carried out at 25" intervals between 725° and 550°C on specimens of the 7.22 pct Cr alloy and at 650°C on specimens of the 10.94 pct Cr alloy. Results and Discussion Morphologies of Proeutectoid a*—Kinetics of the ß?a Reaction: Fig. 1 shows the TTT-curves for the beginning of the proeutectoid a and the eutectoid reactions in the temperature range investigated in the 7.22 pct Cr alloy. The M, temperature in this alloy is below 0°C. The curve for the beginning of the proeutectoid a reaction is in good agreement with that of Frost, Parris, Hirsch, Doig, and Schwartz' for a 7.54 pct Cr alloy, appears at considerably earlier reaction times than the corresponding curve presented by Rostoker4 for a 7 pct Cr alloy, and lies athwart the curve of Spachner and co-workers11 for an 8 pct Cr alloy. Differences in criteria for the beginning of the a reaction and the relatively high rate of this reaction at lower temperatures presumably account for some of these divergences and may also explain, in part, the apparent failure of an iodide-base 7.22 pct Cr alloy to react more slowly than sponge-base 7 to 8 pct Cr alloys. Grain Boundary Allotriomorphs: Crystals of this morphology nucleate at and grow preferentially and more or less smoothly along the matrix grain boundaries.5-7 Allotriomorphs are the first morphology to precipitate at most grain boundaries at reaction temperatures from 725°C, the highest temperature studied, at least through 575°C. Fig. 2 Shows typical allotriomorphs, formed during an early stage of transformation at 725°C. Grain boundary allotriomorphs are not the predc=iaant morphology at late reaction times at any temperature studied. However; from 725" through

Jan 1, 1958

By Henry Kreisinger, J. F. Barkley

This book is one of a series of publications being issued by the Bureau of Mines for the purpose of disseminating information in regard to the methods by which the fuels in this' country may be used most efficiently. A knowledge of the temperature of the gases in boiler settings and in other commercial apparatus using heat tends to develop improved designs of apparatus and better methods of operation, thus reducing waste of fuel. The following pages present, for the benefit of those designing, operating, and testing such apparatus, information as to the accuracy of temperature measurements made under certain conditions and the corrections that can be safely applied.

Jan 1, 1918

By John S. Wakeman

The initial step in the pelletizing of iron ores is the production of green balls. The importance of this step cannot be overemphasized as the physical quality of the green balls has a very significant effect on the subsequent induration process, regardless of the type of the indurating equipment employed. The ability of the green balls to withstand the rigors of handling, distribution, compaction and drying will have an effect on the degree of success of any pelletizing operation. Many factors affect the physical quality of the green balls including the prior processing of the iron ore, the characteristics of the balling feed and the type and quality of the binder used (if any). When working on the development of a new project or studying an existing operation, it is often desirable to determine what effect variations in these factors will have on green ball quality. It is generally impractical to make these determinations on a commercial, or even pilot plant scale, especially when the number of variables to be studied is large. Because of this, many organizations have developed batch techniques for producing green balls to enable them to perform such investigations with a minimum of time and expense. The batch balling method is at best, only an approximation of commercial balling systems. Many practitioners employ the use of pre-formed seed pellets to initiate a batch run. Thus, the growth mechanism encountered in any experiment is essentially snowballing. Unless an instability is introduced into a balling test (such as an excessive initial feed rate or an unusual feed material characteristic) the growth mechanism of coalescence is not present to a significant extent nor is it desirable. In a continuous operation, both mechanisms are present and necessary to sustaining the system. The batch balling technique thus produces pellets in an idealized manner and cannot be used to directly predict commercial green ball qualities. A general relationship does exist however, and the procedure is fairly sensitive to variations in test parameters. Although many refinements to this technique have been introduced over the years, batch balling is still essentially an art and subject to "operator effect". Therefore, to assure consistant and reliable results, skilled technicians who carefully adhere to established practice must be utilized.

Jan 1, 1971

By Ahmad Ghahremaninezhad, Rebecca Radzinski

Arsenic is a highly toxic compound that is naturally found in the environment and is released through the processing of sulphide minerals. Arsenate (As5+) is less toxic than arsenite (As3+) and is soluble in water but can form insoluble precipitates when metal ions are present. The arsenic removal processes used in industry assume that arsenic is in its pentavalent state. Hydrogen peroxide can be employed to oxidize arsenite; however, it is expensive. It has been shown that activated carbon can be used to catalyze the oxidation of arsenite with oxygen as the only consumed reagent at ambient conditions with an efficiency of 99% in less than 24 hours. The mechanism which oxidizes arsenite is not yet understood; however, this study shows that a strong oxidizing agent is formed in-situ. The species and amount of oxidant formed were determined via iodimetric titration and electrochemical methods. The production of oxidant was optimized by comparing the amount of oxidant formed in-situ to the relative amount of arsenite oxidized.

Jan 1, 2015

By D. Preece

The mining and oil industry employs techniques such as geologic mapping, core drilling and electromagnetic and potential field techniques to explore for new deposits. Since new discoveries of major near-surface ore bodies are becoming progressively rare and since traditional exploration methods are unable to resolve ore bodies deeper than about 500m, high-resolution seismic reflection techniques show great potential for exploration to much greater depths down to almost 3km.

Jan 1, 2011

By A. S. Tawadrous

Fines are produced in any blasting application. Depending on the application, fines may or may not be a desirable product of the blast. In most quarry and construction applications, fines are considered an undesirable product since it does not constitute a sellable product and there are costs to the operation for disposal. On the other hand, in most open pits fines do not represent as much of a problem since the ore has to be crushed and ground after being blasted. Therefore, fines in such operations may reduce the energy consumed in the downstream operations.

Jan 1, 2012

By S. H. Ash

THE MAGNITUDE of the drainage problem of the anthracite industry in Pennsylvania's Western Middle field is realized when it is known that in 1951 nine pumping plants in this field pumped nearly 36 billion gallons of water to the surface. This is almost 68,000 gallons per minute pumped against an average hydrostatic head of 350 feet for that year alone. In 1948 over 20,000 gallons per minute was pumped by relay pumps against an average hydrostatic head of 265 feet. In addition to the water pumped to the surface, it is estimated that 15,000 gallons per minute overflows to the surface from underground pools in idle mines. The volume (second-feet) of water pumped and overflow water is almost 1;z times the, average mean flow of the Schuylkill River at Pottsville for the 8-year period 1944--51 (7, 13).4 Mahanov and Shamokin Creeks drain an area of 99 square miles in the Western Middle field, and all surface drainage in this area must traverse some part, of the coal measures before entering these streams. On the basis of 46.03 inches of rainfall (the weighted average of 6 recording stations for 1948), the runoff from the drainage area during that period was 51 billion gallons, approximately 1 times the volume of water pumped by all mine-pumping plants in the Western Middle field. In other words, because of the pervious strata overlying the mine workings, approximately two-thirds of the total runoff in the drainage, area becomes mine water tributary to the pumping plants.

Jan 1, 1953

By B. R. MacKay

Introduction The Corbin coalfield is one of the smallest, and at the same time one of the principal, producing bituminous-coal areas in southeastern British Columbia, and is unique on account of the great original thickness of one of its coal seams and the remarkable concentration of coal in a small area that has occurred through intense folding and faulting of the measures. These are such that the deposit has been referred to at times as "the world's thickest coal seam" and as" a mountain of coal." The determination of the number, thickness, and character of the seams present, and the structure, extent, and geological relationship of the several deposits, are of vital interest both to the operating company in its endeavour to evolve the most efficient method of mining these exceptionally thick deposits and to the Government in estimating the coal resources of the different fields. With the object of ascertaining these data the writer was assigned in 1930 to geologically map and study the Corbin coal deposit. A topographic map covering Coal mountain and the immediate vicinity on a scale of 1 inch =800 feet, with a contour interval of 25 feet, made by the Topographic Division of the Geological Survey, served as the base for the geological mapping.

Jan 1, 1931

By G. T. Jackson

The Alaska Gastineau Mining Co.'s mine is located at Perseverance, about 4 mi. east of Juheau, Alaska. Its property consists of a group of claims, the lode system traversing these claims for a distance of 11,000 ft. (3352 m.). It is shown in Fig. 1. The ore deposits occur in what is known as the Juneau gold belt. This gold belt can be traced for about 50 mi. northwest of Juneau and 40 mi. southeast. It consists of a single band, several hundred feet wide, in which stringers and veins of quartz, carrying gold, occur in a slate formation near its contact with some altered volcanic rock known as greenstone. The Perseverance orebody consists of stringer lodes, having a strike northwest and southeast, dipping about 60° to the northeast. These

Jan 1, 1920

By J M. Fletcher

The responsibility and scope of the Industrial Engineering Department, as organized at the Jeffrey mine, has been broadened to include any study, project or report that could result in more effective use of men, materials and equipment. Although still emphasizing wage incentives and co t reduction, much more varied work is now done, consistent with the in-.creased complexity of industry. Additional activities now include production, maintenance and inventory control improved job evaluation, packaging, labour utilization studies, technical sales liaison, mining, milling and service department n1ethods, plant layout, and specialized project analysis. Additional techniques include the extensive use of work .sampling and standard data. A recent trend has been toward increased emphasis on industrial relations, both in introducing change to the men and in providing requested explanations to Union stewards and officers. These new responsibilities have resulted in the development of specialists in some rather narrow industrial engineering fields, as well as the necessity for industrial engineering assistance in supervisory and job training.

Jan 1, 1963

By D Rattray, D Macfarlane, I Robb, N Halpin, G T. Dale

Mining faces many environmental, social and regulatory liabilities of which water management is just one. Others include site rehabilitation, carbon emissions, biodiversity offsets, strategic cropping land, subsidence, and noise and dust generation. Management of these liabilities is commonly seen as a cost of doing business and each is often independently addressed, bypassing the opportunity to reduce costs through integrated approaches. Furthermore, approaches to dealing with these liabilities tend to be constrained by a prevailing culture of engineered solutions and lack of appreciation of risk associated with alternative and hybrid alternative-engineered solutions. Suboptimal outcomes can also be reinforced by rigid regulatory constraints. While the cost of addressing operational liabilities may be a small proportion of overall mine management costs, failure to do so effectively may influence social licence to operate and, as recently demonstrated by the decision of the NSW Land and Environment Court to block expansion of the Warkworth Mine near Singleton, absolute licence to operate.Integration of environmental, social and regulatory liabilities with value-creating and risk-reduction opportunities such as beneficial water use, carbon bio-sequestration, habitat connectivity, keyline farming, improved grazing design and management systems, windbreaks and visual screens, presents opportunities to reduce risk and create value. This potential may achieve overall improved outcomes in both economic and non-economic mine performance criteria.Two case studies in beneficial use of waste water from the mining and coal seam gas (CSG) sectors (which operate under different legislation) will be used to illustrate the potential to address mine development, operational and closure liabilities by understanding opportunities to reduce risk and create value through a holistic water management framework. The technical requirements and alternative approaches to beneficial use of mine water are addressed, along with the direct economic benefits for mine operational costs and opportunities to positively engage communities and build resilience into social licence to operate. Regulatory barriers to achieving improved outcomes will be discussed.CITATION:Dale, G T, Robb, I, Halpin, N, Macfarlane, D and Rattray, D, 2013. Opportunities for integrated mine management to minimise risk and create value, in Proceedings Water in Mining 2013 , pp 227-234 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By H. S. Kalman

A table of factors for rapid, accurate calculation of the volume of pure helium in cylindrical steel containers, at base conditions of 14.7 psia and 70° F, is presented. The table covers a pressure range from 10 to 10,000 psin in 10-psi increments and a temperature range of 0° to 120° F in 2° increments. The volume of helium is calculated from the observed pressure and temperature of the helium, expressed as a factor from the table, and the known internal volume of the container. The calculation requires a single multiplication. A discussion and evaluation of the accuracy obtainable and a derivation of the formula used (which takes into account compressibility of helium, thermal expansion of steel containers, and the stretch of steel due to internal pressure) are presented. An example showing how the table can be used is given also.

Jan 1, 1968

By Adam J. Szladow

"INTRODUCTIONThe low calorific value and the high moisture and ash contents of run-of-mine (r.o.rn.) lignite limits the utilization of Saskatchewan lignites to thermal power plants in Saskatchewan, Manitoba and western Ontario. On the other hand, the low sulphur content and the low mining cost make lignites potentially attractive for new coal markets, if suitable processes can be found for upgrading. Economic upgrading to a higher quality fuel would make lignites more acceptable for industrial and utility boilers.This paper presents a summary of the process engineering evaluation of coal upgrading technologies conducted in support of a study of selected lignite upgrading processes. The summary presents the relative advantages and offers specific comments on the application of coal upgrading technologies for lignites. ResourcesLignite comprises the largest fossil fuel energy deposits in Saskatchewan. The total resources of immediate and future interest exceed 27 billion tonnes. The measured and indicated lignite resources of immediate interest are large enough to last for over 200 years at the current production rate of about 10 million tonnes per year (Table 1).Saskatchewan lignitedeposits are present in three different geologic formations: (I) the Ravenscrag Formation of Paleocene Age in southern Saskatchewan; (2) the Swan River Formation of Lower Cretaceous Age in central north Saskatchewan; and (3) the Judith River Formation of Upper Cretaceous Age in central west Saskatchewan. The deposits in the Swan River and Judith River Formation are not currently of economic interest.The Ravenscrag deposits are confmed to four lignite basins, namely: the Estevan, the Willow Bunch, the Wood Mountain and the Cypress basin (Fig. 1). The estimated resources of immediate interest in the four basins are over 7 billion tonnes (Table I). These resources include lignite seams at least 1.5 m thick, at depths of less than 45 m.The average quality of lignite varies relatively little between the four basins considering the distance between deposits (Table 2). There is, however, a progressive increase in moisture and ash content, and a decrease in calorific value and carbon content as one moves westward from the Estevan to Wood Mountain and Cypress basins. The Estevan area deposits are of higher rank despite the fact that they are stratigraphically younger than the Willow Bunch deposits (Cameron and Marconi, 1979).In upgrading lignite to a higher quality fuel, it is important to know not only the average proximate and ultimate analysis (Table 2) but also other lignite characteristics influencing the product quality . For example, Figure 2 shows the effect of lignite HIC ratio on the product equilibrium moisture for hydrothermal treatment of lignite. It is apparent that lignites with a higher HIC ratio, or high liptinite content yield much better quality product for the same hydrotreatment conditions. Other examples of lignite characteristics which are important in upgrading include distribution of sulphur forms and mineral matter, maceral composition and degree of surface oxidation."

Jan 1, 1989