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By P. Personnet, D. Wheaton, E. Couzinie, V. Demetriou, Brooks. W., G. Girault, M. Meyer, L. Charbonnel

A common problem in Gas Treatment Centers (GTC) from primary aluminium smelters is the temperature of the gas to be treated : above a threshold, filtering media are irreversibly damaged. The traditional way of dealing with high gas temperature is to dilute with fresh air, which implies over sizing - and therefore higher cost for - the GTC in order to have the capacity to treat this dilution air without compromising on pot suction. A system was developed which decreases gas temperature without having to use dilution air. This system is based on water pulverization in gas collectors. The water vaporization leads to a temperature decrease of the gas. A pilot system was trialed in our R&D unit. Satisfactory results led to the development of an industrial system based on Envirocare equipment (partnership), which was trialed in our production plant in Tomago (NSW, Australia). This patented system was then generalized in this plant, which is now using it with success during austral summer.

Jan 1, 2006

By Kuiting Wang, Jinshan Liu, Ninglei Sun, Aiguo Dong, Yeda Lu

"Eliminating the environmental threat caused by waste effluent containing magnesium sulfate derived from the process of nickel laterite sulfuric acid leaching and subsequent nickel precipitation is always a focus in the metallurgy field. A new flowsheet whose procedures include vaporization, crystallization, two stages precipitation of magnesium, causticizing treatment of filtrate and ammonia recycle was investigated. Both the details of the flowsheet and its application are described in this article. It is confirmed to be an effective and economical method to prevent the pollution by the waste effluent, simultaneity, a series of magnesium products recovered during the process own good economic returns.IntroductionSulfuric acid leaching is the conventional procedure of extraction valuable metals from ores in hydrometallurgy field. During the process of nickel laterite sulfuric acid leaching, several metals, including Ni, Co, Al Mn, Fe, Mg etc., migrate into the leachate in the form of soluble metal sulfate. After subsequent procedure of purification, precipitation of Ni and Co and neutralization, an enormous stream of waste effluent which contains a concentration of approx. 15-40g/L Mg is exhausted. Such solution containing magnesium sulfate is toxic, which causes diarrhea for both human and animals. On the other hand, large amount of sulfate acid was consumed during the process of leaching by the compound of Mg, which increases cost of a hydro nickel plant.In arid areas, the waste effluent mentioned above is treated via evaporate pond owning large acreage, which needs not only the appropriate meteorologic condition, but occupies much land. In coastal areas, it is directly discharged to the sea, which probably deteriorates ecological system of offshore strip. The most widespread method to treat with the waste effluent is neutralization by lime cream, the residues of which containing magnesium hydroxide and gypsum are transported to residues pool. Neutralization is a simple process, but it never recycles the Mg and sulfate anion into new application, meanwhile, the residues are potential threat to the environment."

Jan 1, 2012

By A. F. Beck

Abstract Canada has opened up a geological province in ?Western Canada which offers a new .stimulus to oil exploration geophysics. The problems of instrumental technique, interpretation, and logistics involved in the exploration of this new territory are presented in this paper and some of the efforts being undertaken to overcome them are discussed. The scope of this programme, its possible trend and extent, especially when viewed .against the background of the exploration effort in the United States, is touched upon. Introduction The science of earth physics was first applied to the search for oil on this continent some twenty-five years ago when torsion balance and refraction seismic methods were initiated in the Gulf Coast area of the United States. Since that time advances in the various branches of the science have been sporadic as new fields for their use opened up in the search for deep salt domes as well as less well-defined geological structures; in the application to well logging as part of the exploitation of petroleum; and in underwater surveys, aerial surveys, etc. In the present paper, attention has been concentrated only on the Western Canada plains area because of the recent remarkable growth of geophysics as an oil finding technique in this region. The other prospective oil areas of the West Coast and the Eastern Provinces of Canada are at present of minor importance, although they will undoubtedly receive increasing consideration in the future as accessibility to markets becomes a major factor and more improved geophysical and geological techniques are developed. A vast province in Canada, covering some 655,000 square miles of prospective oil territory (approximately one-half of the prospective oil area in the United States), has provided the new sphere of activity for geophysics (see Figures 1 and 2). Included in this area are immense inaccessible, uninhabited frozen regions which pose a new problem in logistics and operational techniques.

Jan 1, 1950

By Thunaes, Arvid

Pilot plant test work in 1942 and 1943 showed that by a combination of desliming, fine-size classification, and Sullivan deck concentration it is possible to recover heavy minerals such as cassiterite at least as fine as 10 microns in size. This appreciable improvement in gravity concentration practice has been substantiated by several full-sized plants.

Jan 1, 1950

By Robert P. Dufresne

Electrolytic cells are used in electrowinning (EW) and electrorefining (ER) of non-ferrous metals such as zinc and copper, and are a critical part of the purification process. The cell is a large basin and has an electrolyte or aqueous solution, an anode and a cathode, an insulator, and incoming high amperage. Cells are exposed to unfavourable internal and external factors that have a direct impact on their lifespan. Their deterioration can be caused by incorrect polarity, insufficient magnitude, their construction, tension stress, thermal shock, corrosion and other, and their maintenance and replacement can be time-consuming, costly, difficult and environmentally unsafe. Occupational health hazards and dangers posed by the maintenance and removal of the cell should also be taken into consideration. Modifying the design and fabrication method of the cell, using chemical-resistant reinforcement, and increasing tensile and mechanical strength will defer maintenance for a very long time. This can be achieved by a double hull system that comprises full-length composite reinforcement, polymer concrete reinforced with fiberglass pultruded rods and rebars, fiberglass structural layers, and special resin matrices. This will provide protection against thermal shocks, corrosion, leakage, cracks. The design of this cell incorporates a lifting system that will afford quick and easy install without having to move a great number of cells in close proximity, since it is strong enough to stand on its own and not have to be bonded to adjacent cells. As well, the cell can be anchored with ease as it remains stable. This is especially important because space is limited to lift and manoeuver between the cell and the double-girder overhead travelling cranes. The lifting system can also prevent electrocution and loss in product quality, while increasing efficiency and safety in the workplace. Considerable savings in terms of production downtime are also part of the equation. INTRODUCTION Maintenance and replacement of electrolytic cells in electrowinning and electrorefining are operations that pose many challenges, health and safety concerns, and give rise to substantial operational costs. These problems have existed since time immemorial. Electrolytic cells are made of conventional concrete or polymer concrete, and because of the very nature of their composition and their exposure to severe and environmental conditions, their lifespan is short. Although polymer concrete is composed of high-quality materials, and has good thermal stability and resistance to chemicals, nonetheless, maintenance is frequently required in order to maintain the integrity of the cell and to ensure the quality of refined metals. Repairing concrete is a non-permanent solution as cracks will reappear, and every repair weakens the integrity of the cell a bit more, until it reaches a knock- down point and the structure is compromised. The cell needs to be replaced, otherwise the cell will collapse.

Jan 1, 2019

By D. Yeager

Researchers at the U.S. Bureau of Mines have successfully used a genetic algorithm to tune computer models of three column flotation units simulating a separation circuit. The computer models rely on empirical constants that are selected so that the models accurately predict the performance characteristics of individual column flotation units. Unfortunately, these empirical constants have traditionally been selected using a time consuming trial and error process. A new and more efficient approach to selecting empirical constants for computer models has been developed. A genetic algorithm has been used to select the empirical constants for column flotation models used to simulate a three column circuit. Genetic algorithms are search algorithms based on the mechanics of natural genetics. They rapidly locate near optimum solutions in difficult search spaces. Bureau researchers have used these innovative search algorithms to dramatically reduce the time needed to select empirical constants for column flotation models. The approach is applicable to the selection of empirical constants for numerous other computer models.

Jan 1, 1995

By Frank Littlewood

Research over a period of ten years resulted in the development of an efficient automatic ore feed regulator for mill grinding circuits. The facilities that a large mining company gave the inventor made it possible to develop the control apparatus under actual mill operating conditions. The Littlewood Regulator automatically determines the optimum power input at which a mill should operate, and controls the rate of ore feed to maintain this optimum power for any predetermined operating conditions. It is to be noted that the optimum power varies with many factors such as ball, rod, and mill liner wear, therefore the regulator is designed to automaticall keep itself properly calibrated. To efficiently control the rate of ore feed of a mill grinding circuit the regulator analyzes and interprets all power changes of the mill motor. The critical electrical measurements for this type of control are made possible by a patented device that has the ability to detect and integrate minute changes in power. In ball mill operation the small but significant changes in power serve to select the rate of ore feed in accordance with the rate at which ore accumulation takes place within the mill, and in rod mill operation they serve to select the rate of ore feed in accordance with the degree of rod spread.

Jan 1, 1970

By A. U. Miller

Since the organization of the Federal Bureau of Mines, part of the duties of the field men of the Safety Division has been to teach those connected with the minerals industries how to render the proper assistance to an injured worker between the time of the accident and the time when the injured receives medical attention--in other words, "first aid to the injured." For a number of years after the training was introduced, the response of mine officials and workers was very slow. Many times Bureau instructors devoted at least a week to training 5 to 15 or a few more men. However, in recent years since the companies and the Bureau of Mines have had an opportunity to study the results of first aid training, it has been found that in addition to taking care of an injured worker after an accident and thereby greatly reducing the severity rate, the tendency is for the majority of those who take the training to be more careful in their work, or to be more "safety conscious."

Jan 1, 1938

By Butler, P. B.

TRIPOLI is a rather unusual form of silica, which thus far has been found in commercially valuable quantities only in the neighborhood of Seneca, Mo., although there are numerous deposits of somewhat similar materials in several southern states. The latter have not, however, attained any position of real importance, due undoubtedly to definite structural limitations which have rendered them less suitable for the particular uses that have given tripoli its principal outlets. Raymond B. Ladoo, mineral technologist, says': "Since that time (1880-90) the term tripoli has with increasing definiteness been reserved for the Seneca material, and other siliceous materials of similar origin and physical properties."

Jan 1, 1928

By Paul F. Thiele

The mining industry of Georgia, while not as large as in some other states, is still an important part of the economy. Total value of mineral production in 1966 was $148.6 million.l/ Clays and stone produced the most income, Other minerals included sand and gravel, iron ore, mica, talc, barite, bauxite, cement, feldspar, kyanite, peat, and rare-earth metals, titanium and zircon concentrates. Georgia ranks first among the states in production of kaolin, second in fuller's earth and rare-earth concentrates, third in bauxite and kyanite, fourth in barite and ilmenite, and fifth in feldspar. It is quite likely that phosphates will one day be mined in the south eastern part: of the state, and that alumina will be produced from the extensive kaolin deposits in the central part of the state.

Jan 1, 1968

By John Fallavollita

Conventional gas atomization produces powders that vary widely in size distributions and microstructures, thus making it very costly to produce powders tailor made in a narrow size distribution and microstructure. Furthermore, it is difficult to determine the relationships between atomizer operating conditions and resulting powder characteristics. The Impulse Atomization Process (IAP) was developed at the Advanced Materials and Processing Laboratory to produce powders with narrow size distributions. Powders produced by the IAP were reproducible and their sizes could be easily controlled by adjusting experimental conditions. Characteristics of Zn, Sn-Pb, AI-Cu, and Cu powders will be described to illustrate the flexibility of the process to tailor-make powders.

Jan 1, 1994

By A. von Röpenack

A forecast of the consequences of our techniques and goods produced, at least a technical assessment will be demanded from us as an industry. The hydrometallurgical winning of zinc is therefore at a crossroads. New processes promise not only better economics, better maintenance of resources and simpler operation, but also more harmony with nature. Pressure leaching promises to eliminate roasting and thus one complete process step. The hematite process solves a difficult and always costly iron problem. HOA opens a possible road to a totally new ,generation of electrolysis. Zinc has a long tradition behind it. Its? importance is as great as ever-. There is still room for new production developments. In my estimation there are good chances for successful new techniques? which will benefit our whole industry. Zinc is a modern and forward-looking metal.

Jan 1, 1990

By Henry E. Keniston

In every business today costs come under almost microscopic scrutiny. It's hard to conceive that less than 30 years ago there was no such cost consciousness apparent in overall industry. Railroads, through their almost absolute monopoly on freight handling, were one of the industries where little thought was given to overall costs. True regulation kept rates in line, but railroads did very little in the area of supplying equipment intended to help the shipper minimize his costs and at the same time result in savings to the rail carrier. During this period, except for isolated cases, railroads placed standard cars for loading. Most railroad car fleets consisted of box cars, hopper cars, flat cars and low side gondola cars certain roads having unique movements developed special cars to accommodate the particular product, but seldom did these cars move in general interchange service. Most of you are aware that several large companies built railroads of their own as an integral part of raw materials handling from remote sources to production plants located near concentrations of usage. On these railroads special cars were built with little thought to inter-change service. Examples of such railroads are the Duluth, Missabe and Iron Range, the Elgin, Joliet and Eastern, the Union Railroad, the Bessemer and Lake Erie and the Birmingham Southern.

Jan 1, 1972

By C. S. Ek

As a continuation of previous work, further tests have been carried out to recover silver from the residues obtained in a zinc jarosite process. Selective flotation has been performed with different reagents, and ?cleaning steps have been introduced to upgrade the silver concentrate. Leaching of crude residues, as well as flotation tailings, has been carried out with cyanide and thiourea. Finally, the different beneficiation methods are compared, and the industrial aspects? of their application are reviewed.

Jan 1, 1990

By Guy T. McBride

Mr. Chairman, Fellow Keynoters, Ladies, and Gentlemen: It is purposed to consider the theme of this meeting, "The 1970's - Pivotal Decade for the Mineral Industries," from the particular -- some would say peculiar -- point of view of one engaged in mineral engineering education, and this coign of vantage prompts the textbookish subtitle, "Problems and Solutions (?) in Undergraduate Mineral Engineering Education." Three interrelated problems, or problem areas, will be presented and discussed, and where solutions seem to be emerging or seem worthy to be suggested, they will be identified. The three problems are: 1. The goals, and therefore the course requirements, of the undergraduate curricula are in question, 2. The unit costs of undergraduate education appear excessive to those who bear the charges, and 3. The social ambience of the day affects for the worse the work attitudes and the career motivation of both prospective and in-course students. The Need. - Any discussion of these problems must bottom upon recognized national needs for minerals and a technologically sound minerals industry staffed by competent engineers, particularly at the exploration, development, and production levels, Fortunately, these needs have been recognized and to some extent quantified, and they are even now under further intensive study by some of the most competent members of our society and profession. The latter reference is, of course, to the current work of the National Commission on Materials Policy (U.S.A.) under the executive directorship of Dr. James Boyd. Predating this, and perhaps to some extent

Jan 1, 1972

By O. F. Carter

"Coniaurum Mines, Limited, hold nineteen claims in Tisdale township, in the Porcupine district, adjoining the McIntyre mine on the east. They extend for over a mile along the strike of the Hollinger-McIntyre 'break'. The property has been explored extensively along the ore zone both laterally and vertically. Workings have been carried to a depth of 5,500 feet, and nearly 50 miles of lateral workings (drifting and cross-cutting) have been driven to date in development and in gaining access to the orebodies.Production started at the Coniaurum in June 1928 and has continued without interruption. To the end of 1946 the plant has treated 2,695,725 tons of ore, yielding gold having a value of $21,989,918.The Coniaurum is controlled by Ventures Limited of Toronto. Mr. John Redington, who has guided all operations since work began on the property in 1922, is Managing Director.GENERAL GEOLOGYAge and Types of RocksKeweenawan- Quartz diabase dykes.Algoman - Quartz porphyry intrusive; the veins are probably late Algoman.Keewatin - Lava flows.Brief Description of Rock Types.Diabase DykesTwo quartz diabase dykes traverse the property in a north-south direction, cutting all formations, including veins.Porphyry IntrusivePetrographically all porphyries in the Coniaurum are of the usual Porcupine type- quartz-feldspar with alteration advanced in most instances to the stage where the feldspars are completely dissolved, leaving a wellsheared carbonate and sericite matrix with embedded rounded quartz 'eyes'. Alteration is most extensive in the smaller bodies and in the narrow protuberances from the larger masses; the cores of the larger masses are generally much fresher, with more or less well defined feldspar phenocrysts."

Jan 1, 1954

By L. B. Phelps

Current mining regulations require revegetation in reclaiming surface nines. Excessive soil compaction can be an impediment to successful revegetation in poor soil conditions common to Eastern coal nine sites. A field study was performed to determine the bulk densities of soils that had been spread by either bulldozers or scrapers at a strip nine site. Moisture-density relationships for the soils were determined from the field samples. These were compared with stockpile samples compacted by the Standard Proctor compaction test. The results of the study indicate that the degree of compaction could be lessened through proper soil handling procedures.

Jan 1, 1986

By W. D. Keller

Scan electron micrographs, SEM's, will be shown of representative refractory clays from Missouri deposits, with counterparts from other localities. The story is in the pictures, ("1000 words in each picture"), but clay types include the following. Plastic, semi-plastic, and semi-flint "fire clays" of Missouri have textures which appear to retain certain relic texture of ball clay. Flint clay is composed of tightly interlocking packets, sheaves, and books of kaolinite. Diaspore and boehmite mineral textures characterize those "clays". Surface-boulder diaspore shows very pronounced recrystallization and crystal enlargement from original, unexposed first-grade diaspore.

Jan 1, 1977

By S. A. Falconer

D. A. Dahlstrom—Mr. Falconer has done an admirable job of proving the adaptability of the cyclone to the beneficiation of a very difficult size range in the preparation of coal. The addition of the cyclone to other coarser size methods makes it economically feasible for the coal operator to rigorously control his marketed products at a high and uniform quality level down to the 48 and 100-mesh size. Furthermore, it should be pointed out that by utilizing the cyclone as a deslimer or classifier the —3 200-mesh fraction, usually containing large percentages of undesirable material, can also be quickly and cheaply removed from the clean coal. Advantages of such a step are several: (1) Reduction of ash content, especially where clays and slimes are serious. (2) lower moisture content of the final coal. (3) easier mechanical and thermal de-watering of the fine coal due to higher cake and bed permeabilities. The author has indicated that adjustable control means should be installed on the cyclone operating on a heavy-media slurry. This also holds true for the cyclone acting as classifier, deslimer or preliminary dewatering agent and is worthy of special emphasis. Such controls, while not necessarily automatic, must be simple, rapidly adjustable, and require a minimum of attention. Three methods available to the operator are (1) throttling valve on the feed line, (2) back pressure valve on the overflow, and (3) adjustable diameter underflow nozzles. The first two, while fulfilling the specifications, suffer the disadvantage of restricting capacity if severe throttling is necessary. The third method has little effect on capacity and easily maintains an underflow of correct moisture content. Several designs are possible, but two find the widest application. The first was developed by Robert Piros of The Truax-Traer Coal Co. and uses a simple casting containing two holders for underflow nozzles which can be rotated about an axis parallel to the cyclone centerline. These holders retain the underflow nozzle flush with the conical section walls. When a change in nozzle diameter is required, the new size is placed in the spare holder and rotated into place. A second design utilizes a soft rubber cylindrical tube which is compressed or released from three sides, causing the inner diameter of the tube to decrease or increase. This is achieved by using a machine-threaded,

Jan 1, 1951

By G. A. Brooks

Increasing interfacial area through gas injection is one of the main methods for accelerating reaction between slag, metals, and gases in modern pyrometallurgical reactors. In slag-metal reactors, the generation of a large number of metal droplets into the slag phase through high gas velocity has a much larger effect on the overall kinetics compared to the enhanced mass transfer through mixing. Top blowing technology generates large interfacial areas (>300 m2/tonne) through high impingement gas velocity at short distances between the exit of the injection lance and the metal-slag interface. Phase separation may become a limit at the case of very high interfacial areas, though there is still only limited understanding of the trajectories of metal droplets in slag-metal-gas emulsions.

Jan 1, 2003