Search Documents

By J. B. Hadaway

The operation at Phu Kham commenced design and construction in early 2006 and was commissioned in May 2008. This paper will examine and discuss the project from the inception of flow sheet development and equipment selection, equipment design and manufacture, construction, commissioning and ramp up to full production. The paper will touch on the strategies employed to achieve a short schedule and the efficient use of capital, but with the main emphasis on the grinding circuit. Various challenges during the early years of operation will be discussed including the effect of ore characteristics, including competency, on the performance of the grinding circuit. Actions to overcome these challenges and to enhance performance will also be discussed. Finally, current and future plans to improve the performance of the grinding circuit and the overall plant will be summarised.

Jan 1, 2012

El Indio, eighty percent -owned by Compania Minera an Jose Inc., a subsidiary of St. Joe Minerals, and twenty percent-owned by private Chilean investors, will open their new flotation and Carbon -In -Pulp plant near La Serena, 480 km (300 miles) north of Santiago, Chile, in early 1981. The underground mine, at an altitude of 4,270 m (14,000 ft), will produce about 1,270 mt per day (1,400 st per day) of ore containing about 2. 2570 Cu, and gold and silver to the extent of 16 and 254 g per mt (0.47 and 7.4 oz per st) respectively. While construction of the plant was underway, development ore, containing some 1,400 kg (45,000 oz) of gold, was shipped to the United States for recovery in a copper smelter. At El Indio the underground ore is rail-hauled to the mill a short distance from the portal where it is crushed, ground, and floated to produce a copper concentrate containing both gold and silver. The crushing plant also crushes waste for use as mine backfill. Approximately 92% of the copper and 60% of the gold and silver are recovered in the flotation concentrate. Flotation tailings, at a grade of 19 g Au and 116 g Ag per mt (3.4 oz Au and 0.55 oz Ag per st), are cyanided for 72 hours in six Pachucas with auxiliary air lifts for pulp transfer. Lime, cyanide, lead nitrate, and a phosphate are also fed to the cyanidation Pachucas. After cyanidation, the pulp is treated in four air lift Carbon-In-Pulp tanks equipped with external vibrating screens for carbon advance. Loaded carbon is stripped in two pressure vessels in parallel. Pressure stripping must be used because of the high altitude. Stripped carbon is dewatered in a spiral classifier before being reactivated in a rotary kiln and returned to the C. I. P. circuit. Pregnant solution is then sent to four banks of four Zadra cells for gold and silver recovery on steel wool. Zadra cell cathodes.are washed with the slimes being captured in a plate and frame filter. The filter cake and the washed cathodes are then dried on an infrared dryer and smelted in two stages to bullion bars. Published reports indicate that the total investment for this unique operation was in the neighborhood of $80 million.

Jan 1, 1981

By Z. Naziemiec

Since several years in Poland a huge demands on mineral aggregates occur, for the reason of intensive development of housing and road industry, as well as industrial building. Limitations in re-sources of broken aggregates in Central and Northern parts of Poland cause, that both the non-waste production of aggregates with high quality and the production of alternative aggregates from recycling gain greater importance, nowadays. It entails increase in demands for crushing devices, which are easy and reliable in operating as well as inexpensive and enabling to obtain a good quality products. Jaw crusher, regarded as the most spread in Polish industry, meet these requirements, however, their crucial disadvantage is a large content of irregular grains in crushing products. Numerous investigations show, that the shape of grains is a significant feature of aggregates, which influences on durability and quality of produced concretes. The advantage of jaw crushers is their easy operation, low price as well as low amount of dusts (wastes) generated in comminution products in comparison to other types of crushers (i.e. hammer crushers).

Jan 1, 2014

By E. W. Dean

In the early winter of 1919 the Pittsburgh petroleum laboratory of the Bureau of Mines undertook the work of testing fuel oil samples representing purchases of the United State Shipping Board for ships sailing from the port of New York. fuel oil was, at this time, being bought on a contract which involved specifications issued by the United States Navy under dace of October 2, 1920 (See Bulletin 1, Oil Division, U. S. Fuel Administration.)The object of the Bureau of Mines in undertaking this inspection work was twofold. (1) The Bureau was in position to give, and the Shipping Board needed, reliable laboratory service for checking the quality of the fuel oil purchased, the value of which ran into millions of dollars for,year's supply. (2) It was believed, and later demonstrated, that the existing specifications did not insure the obtaining of a reliably satisfactory quality of oil.The objection to the specifications concerned the employment of a clause limiting the gravity of the oil. The inadequacy of gravity specifications for several types of petroleum products has long been recognized, and there was every reason to reason to believe that they were no more desirable for fuel oil than for gasoline, kerosene, or lubricating oil. A first and obvious objection was the fact that it is somewhat difficult to make accurate gravity tests on ""heavy"" residuum fuel oils. (The Bureau found it necessary to employ or such tests a rather tedious procedure involving the use of a picnometer and an accurate balance, as the simpler methods, employing hydrometer or displacement balance, proved unreliable in a large proportion of cases.) A second and more important objection was that gravity tests, even when accurately made, do not provide a reliable index of the actual quality of the oil.

Feb 1, 1921

By Joanne L. Johnston

Researchers at the U.S. Bureau of Mines have developed a new technique for bonding strain gauges to rock bolts. These instrumented bolts are used to determine load at intervals along the length of the bolt so that reliable, consistent measurements for the design of support systems can be obtained. In this Information Circular, this technique is described in detail and should result in improved miner safety in underground mines.

Jan 1, 1993

By Earl Oliver

SEVERAL notable papers, and free discussion on many controversial subjects, marked the various sessions of the Petroleum Division at the annual meeting. The Division first convened on Tuesday afternoon, Feb. 16, and wound up with a dinner and technical meeting on Thursday night. H. C. Fowler presided at the opening session, which was devoted to problems of engineering research and production engineering. Joseph Chalmers abstracted his paper on the flow of air and gas through porous media, in the preparation of which E. L Rawlins and D. B. Talia-ferro contributed. G. H. Fancher told how much he and his associates at Pennsylvania State College were interested in this field, and described the problems they had met in conducting test work. He made a plea for standardization of testing methods. Mr. Fowler then read an abstract of written discussion by Professor Barb, which was followed by discussion by Dr. Fancher and Mr. Chalmers of technical points in connection with the Chalmers' paper. H. H. Hill abstracted written discussion from Messrs. Wilde and Moore, of the Humble company. The second paper, by K. B. Nowels, on computing pressure drop in the pipe of flowing oil wells, was abstracted by the author. Messrs. Blair Smith, G. W. Coggeshall, and I. I. Gardescu participated in the discussion, and the chairman abstracted written discussion prepared by Mr. Rawlins. Most of this had to do with the viscosity of gas¬oil mixtures, on which subject Mr. Nowels said there was great need of accurate technical information.

Jan 1, 1932

By A. F. Edwards

The Main Pass sulphur and oil deposit is located at Main Pass Block 299 in the Gulf of Mexico, 30 miles east of Venice, Louisiana, in 210 feet of water. The deposit was discovered by Freeport-McMoRan and its joint venture partners, IMC Fertilizer and Homestake Mining, in late 1988-early 1989. The sulphur deposit contains 67 million long tons of recoverable sulphur. The sulphur occurs in bio-epigenetic limestone replacing anhydrite caprock on top of a salt diapir. Recoverable reserves of 39.4 million barrels of oil and 9.1 billion cubic feet of gas are also contained in the limestone caprock and in supracap sandstone stringers.

Jan 1, 1992

By John D. Price

R. W. Campbell (Jones and Laughlin Steel Carp., Pittsburgh)—As usual John Price has presented an excellent paper. I know of no one who has devoted more time and conscientious thought to this subject than he has, and his efforts have produced scientific data and conclusions of real value. Results of similar studies made by the Jones and Laughlin Steel Corp. on the blending of Pennsylvania coals may be of interest. During 1935 the late F. W. Wagner and the present writer developed an empirical physical fuel value formula for evaluating the combined physical tests of metallurgical coke, see Table IV. In the development of the formula, the tumbler test, shatter test, screen test, and porosity of coke have been taken into consideration. Each of these tests brings out some physical property not expressed by the others, and in estimation of the importance of these tests as a medium for evaluating coke for the blast furnace, their worth has been graded as follows: It was thought that some additional penalty should be applied to cokes that do not show a uniform screen size, assuming that coke larger than 4 in. was not desirable and that this size was an indication of irregular size. Therefore the screen test factor is further corrected by applying a penalty of 1 pct for each 1 pct material greater than 4-in. size as shown by the screen test. The physical fitness of coke for blast furnace use depends upon four fundamental characteristics: l—gen-era1 strength, as indicated by the shatter test; 2— abradability, or the resistance of cell walls to reduction in size by attrition, as indicated by the tumbler test; 3—porosity; and 4—size and uniformity. Each of these characteristics is not of equal importance, but surely, in an attempt to determine an accurate physical value, the individual value of each should be taken into consideration. The formula is used as a yardstick, so to speak, in determining variations in the normal production of metallurgical coke and in making comparisons between normal coke and experimental blends with other coals. Table IV gives results of coking tests on raw and washed high volatile coals and these same coals with blends of coke breeze, anthracite coal, char and low volatile coals, all from Pennsylvania. The table also gives the source of the coals and coke breeze, as well as their proximate analyses. It will be noted that the washing of the raw high volatile coal increased the physical fuel value from 26.17 to 39.16, showing the effect of removing shale and slate which produces a detrimental fracturing and weakening of the coke. It is a well known fact that many Pennsylvania high volatile coals contain an excess of resinous material or binder which has a tendency to weaken the coke, owing to its high evolution of gases during carbonization. Tests were therefore made with coke breeze, an inert material, in an attempt to alleviate this condition. Blends of washed coal with 5 pct and 7.5 pct coke breeze collected from the coke plant quenching sump (82.9 pct through 1/8-in. screen) resulted in cokes with a physical fuel value of 20.75 and 16.73 respectively, lower than results obtained from 100 pct raw high volatile coal. It will be noted that the percentage of + 4-in. coke increased but that the tumbler test was very low. Undoubtedly better results could have been obtained if the coke breeze could have been crushed extremely fine. During World War II the government asked the coking industry to consider the use of anthracite coal as a substitute for high quality low volatile coal, which was extremely scarce at the time. The next series of tests was made with blends of raw and washed high volatile coals and 5, 10, and 15 pct Pennsylvania No. 5 buckwheat anthracite (100 pct through l/8-in. screen). It was necessary to use some raw high volatile coal in these blends because of insufficient washer capacity at the time. It will be noted that the physical fuel values

Jan 1, 1954

By Raúl Carretero de la Hoz, Leonardo Soares Chaves, João Paulo Soares Toneli, Francisco Felipe da Silva Dantas, Marcos Peres Lopes, Marcus Vinicius da Silva Gonçalves

The mining activity results in environmental impact and thus requires the adoption of techniques to minimize its effects. The rock blasting process is required to break up and move the rock enabling the haulage of the material, however, it might also cause undesirable effects such as flyrock, overbreak, excessive ground vibration or air-blast at the neighboring communities and damage to civil or geological structures located nearby. The Serra Sul mine, commonly referred to as S11D project, has obligations to preserve two natural tropical montane lakes and several maximum relevance natural cavities whose legal preservation radius represents constraints to the mine development and operation. Controlling measures are undertaken to ensure preservation of the cavities, especially during rock blasting stage, with limitations of the maximum instantaneous charge (MIC) and ground vibration control. The demand for high productivity and the large areas with hundreds of blastholes to charge are challenging factors to the charge control. This work presents the development and field application of a map for limiting explosive charges in the rock blasting process at the Serra Sul mine, used for the definition of maximum charges according to the blast location, ensuring the preservation and compliance with the defined ground vibration limits for each cavity. The map is applied at the mine for every blast and when there is a charge constraint, the map helps to define the areas with different charging profiles in the field contributing to higher charging productivity.

Jan 21, 2025

By F. A. Baczek

The Electroslurry TM electrowinning concept has been incorporated into a process flowsheet for recovering copper from smelter flue dusts. The process has averaged 96% recovery of the copper as high-grade electrowon while at the same time removing a majority of the impurities that degrade drawn copper as a result of recycling flue dust and liberator cathodes: The dust is processed through several stages consisting of leaching, copper precipitation, Electroslurry TM electrowinning and waste liquor treatment. The process may be integrated into a smelter operation and become an effective and feasible means of maintaining good product purity.

Jan 1, 1980

By N. Barton

Large scale tests were conducted on quartzitic gravel and crushed sand-stone to investigate pertinent geotechnical properties for backfill support of egress shafts. Such shafts are envisaged for rapid launching of deep-based missiles. The backfill support is designed to resist shaft closure under dynamic loading, and must also drain rapidly to a lower catch chamber to allow launching. Large scale tilt shear tests were performed to measure the internal shear strength of the two backfill materials. Shaft filling and emptying tests were conducted in a 12 ft deep, 3 ft diameter model section of shaft drilled in sandstone. One half of the model was smooth bored, the other half rough-surfaced to represent drill and blast surfaces. Vertical and horizontal pressure cells indicated that stress only built-up during the first 1 to 1 ½ diameters of filling, due to the high-sidewall friction of 38° for the rough shaft and 31° for the smooth shaft. Interface sliding tests were performed to confirm these figures. Static and dynamic deformation tests were also per-formed, and indicated moduli as high as 56,000 psi, which will give excellent shaft support. Both the shaft support characteristics and the ease of emptying of gravel look particularly promising.

Jan 1, 1983

By N. Samman, S. N. Lau

"A series of new, grease-based, solvent free open gear lubricants were developed to meet the demanding service requirements of mining equipment. The use of these products has resulted in better performance under conditions of temperature extremes and in terms of longer component lives. They have gained widespread acceptance within the mining communities for such applications as the lubrication of mining shovels, draglines and ball mills.These products are WHMIS non-controlled and are environmentally acceptable. The benefits and advantages of using this type of product to lubricate mining equipment as well as the field evaluation and experience will be discussed."

Jan 1, 2002

By John W. Sweeney

The southeastern phosphate industry is investigated to determine its role in supplying the United States and world phosphate demand. The report shows that the southeastern (Florida, Tennessee, and North Carolina) phosphate industry is the leading domestic and world producer of phosphate rock, The report emphasizes size and organization, production capacity, transportation, and marketing of the southeastern phosphate product, Factors affecting the supply- demand relationship of the southeastern phosphate industry and world phosphate production-consumption relationships are analyzed and related to the southeastern phosphate industry. Past trends are projected and the future role of the southeastern phosphate industry is analyzed to determine its ability to supply the United States and rest-of-the-world phosphate requirements in 1985 and 2000. The projections show that southeastern resources are ample to supply domestic and export requirements at the projected rates of consumption well beyond the year 2000.

Jan 1, 1970

By O. A. Carson

"IntroductionTHE ZINC-BASE die casting alloys in common usage contain approximately 4 per cent aluminum as the major alloy element. In addition, they contain about 0.05 per cent Mg .and may• have a small amount .of copper. These are usually the only •elements intentionally present.Small amounts of some impurities have been shown to have a deleterious effect on the properties of these alloys and therefore the impurities are kept low by starting with '99.99%' zinc.The reasons for holding the aluminum content at 4 per cent are not clear. Some statements appear in the literature that higher aluminum increases the brittleness, but probably the chief reason was the relative price of zinc and of aluminum when 4% alloys became firmly established. At that time, aluminum was three to four times the price •of zinc on a weight •basis. Recent prices, roughly equivalent per lb., make aluminum considerably cheaper than zinc on a volume basis and suggest that increased aluminum content would result in a decrease in the cost per piece due to the lower density of the alloy.Little information could be found in the literature and, therefore, it was decided to determine some physical properties of the higher aluminum zinc-base alloys made from high-purity zinc."

Jan 1, 1953

By H. S. Auvil

[The shrinkage of coke after formation is one of the variables that effects the net expansion of the change in both industrial and test ovens. Various test results5/ have been interpreted as indicating that cokes from certain coals shrink to a marked extent and that other cokes show very little shrinkage; but no comprehensive experimental study of the shrinkage of coke after its formation and of the factors influencing this shrinkage has come to the attention of the authors.]

Jan 1, 1940

By A. Mahmoudkhani

There has been a continuous interest in chemical aids for processing Canadian oil sands by hot water extraction process since the first commercial industry operation in 1967. Several inorganic and organic chemical systems have been introduced, of which sodium hydroxide is the most widely used extraction process aid by major producers. Use of NaOH, however, results in accumulation of sodium ions in recycled water, causing higher clays dispersion and producing tailings with poor geotechnical properties that turn into mature fine tailings. This is especially true for low grade and oxidized ores, which present the greatest challenges in bitumen recovery and produce the major portion of fine tailings. In this paper, we are presenting a novel method based on use of inorganic polymers as process aids for various low grade oil sands ores. Denver flotation cell and a laboratory scale hydrotransport loop were utilized to evaluate the effect of chemical dosage and operating parameters on the processability of oil sands samples from Athabasca region. Process tailings were examined for properties such as water chemistry, suspended solids, settling rate and the ease of tailing treatments. Our results demonstrate that the use of inorganic polymers during the froth process lead to a significant improvement in bitumen recovery from low grade oil sands and can improve further tailing treatments. This offers a viable solution that can be easily incorporated into current processing facilities and deliver several operational and economical benefits. Advantages in use of inorganic polymers versus sodium hydroxide are presented in details.

Jan 1, 2012

By Z Tong, M Gao, X Wang

In response to the need for improved magnetic separators for beneficiation of fine grained iron ores that have been finely ground to liberate the iron minerals from the gangue, a series of high efficiency wet drum permanent magnetic separators (T-GCT) has been developed by Maanshan Tiangong Technology Co Ltd. These magnetic separators have high efficiency for separating superfine strongly magnetic minerals and the ability to produce high-grade concentrates with high recovery. They are ideal replacements for conventional drum magnetic separators, especially for treating superfine particles.

Jan 1, 2009

By C E. Woolley, A Hosseini, J Foster

Northern Star’s Thunderbox Open Pit C-Zone cutback was designed to maximise extraction in a short life excavation; In fresh rock on the western wall this included 20 m to 30 m bench heights with 6.5 m to 10 m berm widths and a 90° pre-split angle. Rock mass quality in this area is generally fair to good, however, there are sections where the dominant foliation runs parallel with the designed pit wall, and more closely spaced, altered, foliation is present: these areas are difficult to predict and prone to failure. Stringent controls and monitoring were required in order to safely access below these areas, in particular the use of slope stability monitoring radar, Trigger Action Response Plans (TARPs), re-entry procedures, visual inspections, drone inspections and day-to-day personnel awareness of the hazard. Robust and comprehensively planned remediation was also required after two significant slope failure events where long reach equipment and rope access techniques were utilised to remediate the areas in question safely, but also in a timely manner, such that expected production targets were impacted as little as reasonably practicable. This combination of rigorous risk management and well planned remediation resulted in a successful and complete extraction of the C-Zone cutback with no impact to operational safety.

Jun 22, 2022

By W. D. Dietzman

This Bureau of Mines report presents a continuation of statistics pertaining to distribution of petroleum reservoirs (or fields), wells, and production by depth and producing rate classification in the United States. These statistics show the change that has occurred since results of a similar study were published by the Bureau of Mines in 1967. Data are presented in tabular form by State for the 18 principal oil-producing States and by subdivision for the two largest oil-producing States, Texas and Louisiana. Tabular summations and graphical illustrations are presented for the Nation. The data are classified by 4-barrel-of-oil-per-day rate increments up to 36 barrels and one increment of greater than 36 barrels of oil per day and by 2,000-foot depth increments up to 8,000 feet and one depth increment of greater than 8,000 feet. The overall average producing rates for States and the Nation have been published for many years, and although such rates are useful, they are very general descriptions of producibility. A breakdown of production, wells, and reservoirs by various depths and rates and by State or by State subdivision provides a more detailed description of producibility.

Jan 1, 1975

By T. Wajima

"A novel carbonaceous immobilizing agent for heavy metal contaminated soil was prepared from rice straw using sulfur immersion and pyrolysis, and the lead immobilization in artificial contaminated soils using sulfur-impregnated carbonaceous material was estimated. The rice straws were cut to 1 cm pieces, and then immersed in 0.1 - 1 M K2S solution for 0 - 24 h to prepare sulfur-immersed materials. The immersed-materials were heated at 400 oC for 1 h in nitrogen gas to produce the sulfur-impregnated carbonaceous material by pyrolysis. The abilities of the product to immobilize lead from aqueous solution were examined to obtain the product with high lead immobilization ability. With increasing K2S concentration, the immobilization ability of the product for lead gradually increases and then above 0.5 M K2S those are almost constant, while 15 min is sufficient for the immersed time to obtain the product with high lead immobilization ability. The product prepared from material immersed in more than 0.5 M K2S solution for less than 15 min has a maximum immobilization ability for lead ion. The lead immobilization using the sulfur-impregnated product is sustainable due to the formation of leadhillite [Pb4SO4(CO3)2(OH)2] and anglesite [PbSO4]. The product can immobilize lead ion in various artificial lead contaminated soils. By mixing artificial lead contaminated soil with the sulfur-impregnated product, the eluted solution became neutral, and the eluted concentrations of lead ion dropped below the Japanese elution standard for soil.INTRODUCTION Soil contamination with heavy metals is a worldwide problem. Accumulation of heavy metals in soils affect soil ecology, agricultural productivity, quality of agricultural products, water resources, and serious health problems for human and animal (Raicevic, et al., 2005). In the United States, for example, approximately 63 % of the sites on the National Priority List (NPL) for the treatment of contaminated soils are contaminated by metals, and lead is the most common metal, found at 15 % of the sites. In Japan, according to a report by the Ministry of Environment, 43 % of the contaminated sites that exceed the environmental quality standards are contaminated by lead compounds. Soil contamination by lead compounds is also prevalent in other developed and developing countries where lead compounds are used extensively in industrial activities without careful contamination management. Lead is a ubiquitous heavy metal pollutant in soils due to their use widely. The primary sources of Pb contamination include industrial activities such as mining, smelting of metals, and the use of Pb-containing products such as paints, lead-acid batteries, bullets, gasoline and pesticides (Cao, et al., 2009). It can damage human nervous (especially children) and reproductive systems (ATSDR, 2007). The high concentration of Pb in the soil poses risks to human and animal health by the leaching of metals from the soil into water and the consumption of edible plants growth in the contaminated soil. Therefore, proper remediation is necessary to reduce metal availability in soil for protecting human health."

Jan 1, 2018