Search Documents

By S. D. Michaelson

Open pits and quarries are the major sources of all "hard rock" tonnage mined today. Normally, ore is fractured from the pit face by blasting and then truck-hauled to a primary crusher where pro- cessing begins; overburden (or waste) is generally truck-hauled from the pit to dump areas. Truck haulage of blasted ore and overburden accounts for some 25 to 50% of total mining costs in a typical open pit and commonly is the largest single cost factor. Obviously then, cost reduction efforts should properly focus on improving existing haulage systems and developing new breakthrough techniques for material transport. Continuous flow systems for large tonnages ordinarily will result in a lower cost than batch systems such as truck or rail haulage. Continuous flow with pipelines for liquids and slurries, or conveyors for medium to coarse dry materials (in the -8-in. range) are the economic answers for bulk materials handling over reasonable distances.

Jan 11, 1968

By T. H. Janes

NATURAL abrasives of some type are found in all countries of the world. In order of their hardness the principal natural abrasives are diamond, corundum, emery, and garnet, which are termed high grade, and the various forms of silica, including pumice, pumicite, ground feldspar, china clay and, most important, sandstone. The properties qualifying materials for use as abrasives are hardness, toughness, grain shape and size, character of fracture, and purity or uniformity. For manufacture of bonded grain abrasives such as grinding wheels, the stability of the abrasive and its bonding characteristics are also important. No single property is paramount for all uses. Extreme hardness and toughness are needed for some applications, as in diamonds for drill bits, while for other purposes the capacity of the abrasive to break down slowly under use and to develop fresh cutting edges is of greatest importance, as with garnet for sandpaper. In dentifrices, soaps, and metal polishes, of course, hardness and toughness are objectionable.

Jan 10, 1954

By A. L. Mular

Optimization strategies of possible interest to mineral processing are reviewed and typical strategies initiated in processing plants to date are discussed. Both On-Line and Off- Line optimization procedures have been employed by industry, assisted either by operators or by digital computers. In every case, dollar benefits have accrued.

Jan 1, 1976

By M. P. Nackowski

Geological engineering expanded its role and significance during 1966 in the areas of construction, raw materials exploration and inventory, water supply and pollution, mechanical properties of earth material and regional environmental planning. Efforts varied immensely in scope and magnitude, in simplicity, difficulty and importance. Observations, measurements, and analysis encompassed both simple and sophisticated procedures. CONSTRUCTION Activities in construction ranged from preliminary to detailed evaluations of sites, development of preventative measures and designing corrective measures following construction failures. Most investigations concerned dam sites, highway locations and slope stability, building sites, tunnels and underground storage facilities.

Jan 2, 1967

By Alvin Kaufman

At the turn of the century the U.S. had a gross ALVIN KAUFMAN Mineral Economist U.S. Bureau of Mines area slightly in excess of three million square miles, a population of 76 million, a gross national product of $37 billion (constant 1929 dollars) and a mineral production valued at $2 billion (1929 dollars). Some 60 years later its area had increased by 600 thousand square miles, population had risen 140%, gross national product was seven times greater and mineral production had grown to a value five times that of 1900. Of perhaps greater significance, however, were the changes wrought by technology. It was during this period that the "American Way of Life" was revolutionized by the introduction of the airplane and the automobile; man also took his first probing steps in the utilization of nuclear energy and pre- pared to unlock the secrets of space. It was during these six decades, also, that he learned to create additional new materials, some of which were from old sources such as plastics from petroleum and coal. These new materials have created competition and attendant problems for the traditional materials such as iron, copper, lead and zinc. Additional problems undoubtedly will be created by technologic advances in the future.

Jan 2, 1963

By Alexander R. Troiano, Eugene P. Klier

SINCE the very early work on quenched structures, where the products of the martensite transformation had been recognized, this transformation has provoked much interest and study. Theoretically it was desirable to account for the extreme changes in physical properties resulting from the formation of martensite, as that information might lead to results of practical importance. Desirable information, therefore, was on the kinetics of transformation from austenite to martensite as well as on the physical constitution of the martensite. It has been known for years that certain steels quenched to room temperature will contain persistent austenite as well as martensite. Other important and now well- established features of the martensite reaction are the progress of the reaction on cooling only and the independence of Ar" with cooling velocities exceeding the critical velocity. These facts have been experimentally determined by various methods and investigators. Notable among the early investigators were Tammann and Scheill and Wever and Engel.2 Unfortunately, all investigators did not fully interpret their results, which, coupled with several investigations that yielded conficting results, caused a state of confusion that was not clarified until quite recently. X-ray investigations of martensite in steels3-6 indicate it to be a supersaturated solid solution of carbon in alpha iron. This supersaturation is evident from the appearance of a body-centered tetragonal structure with the addition of sufficient carbon. The dimensions of this tetragonal structure are alinear function of the carbon content within the limits of accuracy of the determinations. Slight tempering of tetragonal martensite leads to the destruction of the tetragonal structure, which is converted to a body-centered cubic structure. This phenomenon has precipitated a controversy concerning the nature and mechanism of the tempering of martensite. The facts in the case have been outlined by Epstein7 and more recently by Antia, Fletcher, and Cohen.8 The significance of Ar" on theoretical grounds is not clear, however, although considerable study has been devoted to its determination. The precise position of Ar" as a function of carbon content was first stated by Greninger and Troianos for steels covering a range of approximately 0.7 to 1.8 per cent carbon. The effect of alloying elements on Ar" has recently been the subject matter of investigation by various methods.

Jan 1, 1945

By AIME AIME

AN entirely new type of classifier is being put on the market by The Dorr Co., following three years of development and the experimental use of thirty machines of the improvement design in various parts of the world. It is known as the Multizone classifier. Compared with the older type the lower or overflow end has been decked over and is surmounted by one or more circular overflow columns. Feed is introduced near the middle of the machine and passes downward and under a vertical baffle, then along the underside of the deck to the base of the overflow columns. Under the baffle there is a restricted turbulent zone of high pulp velocity which holds the fine and critical size particles in suspension, preventing

Jan 1, 1937

By C. H. G. Bushell, M. Malnarich

Reagent control in flotation is more an art than a science. Operators vary the amount of re- agents used according to the metallurgy obtained. The amount of collector may be increased, for example, if tailings losses are high and decreased if concentrate grades are low. Often control decisions are based on only one assay, such as the tailings analysis by microscopic or quick assaying techniques. This method of control has given reasonably satisfactory results but is clearly far from perfect. No adjustment in reagent addition can be made until information is received that metallurgy has deteriorated, that is, until the optimum time for adjustment has already passed. The first adjustment probably will be an overcorrection or an undercorrection, and time will be required to establish the best new addition rates. The seriousness of the problem depends on variability of the ore. In ore of continually shifting composition and complexity, mill results will shift back and forth from excessively high concentrate grades and high tailings losses to excessively low concentrate grades and low tailings losses. Economic incentive for improved control also increases with increasing size of mill. Even a small improvement in percentage recovery in a large mill pays for expensive control equipment.

Jul 1, 1956

It is claimed that the first mining of copper by Americans in Arizona was done at Ajo, near the Mexican border, in 1854,* a year after this region had been added to the United States, under the terms of the Gadsden purchase. A group of adventurers, organized at Los Angeles under the name of the Arizona Mining & Trading Company, came, to the district. This party of prospectors consisted of 20 men, led by Major B. Allen, J. D. Wilson, and William Blanding. † They went first to Yuma, where the party divided, some of them going southward into Mexico while the remainder took the trail to Tinaja Alta, where they heard of the copper deposits of Ajo, which is 85 miles southeast from Yuma.‡ They found attractive outcrops of copper ore, and set to work energetically, but their operations suffered many interruptions, because that part of the country was still controlled by the Mexicans, who were uncertain about the exact position of the new international boundary. The Mexicans tried to expel them, but they held their ground. The first shipment of ore, consisting of native copper and cuprite, came from what is now the western end of of the New Cornelia workings; it was hauled in ox-carts to San Diego, 400 miles across the desert. § Later shipments were hauled to Yuma and floated on barges down the Colorado river to the Gulf of California, whence the ore was loaded on

Jan 1, 1932

By Aug. J. Jr. Bowie

(Read at the Wilkes-Barre Meeting, May, 1877.) Brief Outline of the General Topography of the Gold Regions of California. THE topographical features of California, as demonstrated by the explorations of the State Geological Survey, are found to be exceedingly simple. Three equidistant parallel lines can be used in conveying a general idea of the physical geography of Central California. A straight or " main axial line," whose course would be north 31° west, passing through the culminating peaks of the Sierra for a distance of five hundred miles, can be assumed as the eastern boundary of the State. A second parallel drawn fifty-five miles west of the " main axial line" will skirt the western base of the Sierra Nevada, along the edge of the foot-hills. A third parallel run equidistant from the second will represent "as nearly as possible the western base of the Coast Ranges." These parallel lines divide the State into three belts, namely, the Sierra, the Great Valley of California, and the Coast Ranges. " This arrangement of the physical features holds good for a length of four hundred miles in the direction of the main axial line, comprising almost the whole of the agricultural and the greater part of the mining districts."* The section of the country which is of immediate interest to the miner is the western slope of the Sierras. These mountains, rising in a short distance from the Sacramento plains to elevations of over seven thousand feet, with occasional peaks ten and twelve thousand feet high, are cut by numerous deep and precipitous gorges or capons, through which drains the immense watershed of the Sierra, supplying the main rivers of the State and ultimately emptying into the Pacific Ocean. Between these capons, ridges or divides are formed, on top of * See vol. i, p. 5, Geological Survey of California. J. D. Whitney, State Geologist.

Jan 1, 1878

The War Department is appealing to skilled workmen and scientifically or technically trained men to enlist in any one of a large number of engineering troops needed for immediate action in France. Any registrant under the selective service law, who has not actually been called to service, may be immediately inducted into an engineer organization at his own request. Application for induction should be made to the Chief of Engineers, giving a complete statement of the applicant's qualifications. Any man who is physically qualified, between the ages of 18 and 21, or between 31 and 40, may voluntarily enlist for an engineer organization, provided he proves to the recruiting officer that he is experienced or skilled in any engineering trade, or is a handy main who is' especially suited for engineering work. There are about 600 recruiting stations in the United States, and an officer at any one of these will enlist a candidate for an engineer organization if he is suitable. Enlistment is in the grade of private. Subsequent promotion to the rank of non-commissioned officer is secured by merit. It is intended to fill many of the vacancies which will occur from time to time among the commissioned officers by selection from the ranks. A few of the special services, of most interest to mining and metallurgical workmen, urgently needed by the army, are as follows: Crane Operating and Maintenance Regiments; Depot Detachments; Electrical and Mechanical Regiments; General Construction Battalions; Mining Regiments; Quarry Regiments; Battalions for the construction, maintenance, and operation of railways; Road Building Battalions; Sapper Regiments; Supply and Shop Battalions; Surveying, Ranging and Map Reproduction Regiments; Water Supply Companies; and many others. All of these organizations will be assigned to such duties as competent

Jan 4, 1918

By J. P. Carson

(Read at the Wilkes-Barre Meeting, May, 1877.) THE works of the Tula Iron Company are in the Republic of Mexico, State of Jalisco, twenty-eight leagues southwest of Guadal¬ajara, ten leagues northwest of the town of Sayula, through which passes the projected line of the Mexican National Railroad. Its geographical position would be about: latitude, 20° 10' N., longi¬tude, 4° 35' W. of Mexico City. The surrounding country is a roll¬ing plateau, 6000 feet above the sea, enjoying the most magnificent climate in the world, the average temperature being about 70°. The works were commenced in 1850 by a company with very small capital, having not the least idea of the undertaking. They soon fell into the hands of the money-lenders, and after changing

Jan 1, 1878

By Gen-ichi Nakazawa, Masamichi Fujimori, Ichiro Doi

INTRODUCTION The major products of nickel industry in Japan are the electrolytic nickel (E-Ni), the ferro-nickel (Fe-Ni) and the nickel oxide sinter (NOS), totaling in production to 90 - 100 X 103 tons/year in terms of pure nickel content, and sharing approximately 20% for E-Ni, 10% or less for NOS, and the rest for Fe-Ni. The raw materials to be used for these products depend totally upon the imports from abroad; matte, the raw material used in the production of E-Ni, is from Australia and Indonesia; matte for the NOS is from Indonesia and New Caledonia; and garnierite, the raw material for Fe-Ni, is imported in bulk from New Caledonia, Indonesia and the Philippines. This report describes the acquisition of these raw materials, the production processes, trend of supply-demand, problem areas and the measures taken, and so forth, in connection with the nickel industry in Japan. ELECTROLYTIC NICKEL 1. History The nickel industry in Japan began in 1939 by the Sumitomo Metal Mining Co., Ltd. (SMM) with 150 tons E-Ni/month under the blast furnace smelting and the metal anode electrolysis. This was temporarily suspended after the end of last World War II, but resumed in 1952 with garnierite of New Caledonia as a raw material. Since then, the production capacity has been expanded incidentally to the increase of demand. However, since the smelting of garnierite contained about 2% nickel was very costly, the smelting process had been changed to smelt the briquettes of the mixture of garnierite and nickel sulfide concentrate imported from Canada and Australia. In 1975, this smelter was closed, and SMM's nickel refinery used matte from Western Mining Corp. (WMC) of Australia as a raw material. The refining process had been the metal anode one. The crude nickel oxide derived from roasting the high grade nickel matte had been melted and reduced with coke in the electric furnace and cast into anode. In 1970, a new refinery was constructed to produce 1,000 tons Ni/month under the matte anode process, and further, in 1976, the old refinery was converted into the matte anode process, thus resulting in the total production capacity of 1,690 tons Ni/ month today under the matte anode process. Shimura Kako Co., Ltd. began in 1951 to produce a little of E-Ni, and in 1955, they constructed a shaft furnace smelter with New Caledonian garnierite as a raw material to begin the E-Ni production under the matte anode process. Its monthly production reached 400 tons in 1957, but it discontinued its smeltering in 1963 to convert to the matte import from S. Le Nickel, WMC and INCO. In 1979, it changed the source of matte supply from the above to Soroako of Indonesia, discontinued the E-Ni production in 1979, and arranged for a total toll contract with Sumitomo. Meanwhile, SMM has developed a very distingished process for nickel-cobalt separation and refining by a solvent extraction method from nickel and cobalt mixed sulfide generated as a by-product in the nickel recovering process from laterite under the Nicaro process. Nippon Mining Co., Ltd. (NMC) also developed its own process. The plants under these processes were constructed in 1975, with the monthly production capacity of 230 tons of nickel and 130 tons of cobalt by SMM, and 300 tons of nickel and 110 tons of cobalt by NMC. SMM imports the raw material from the Marinduque Mining and Industrial Corp. of the Philippines, while NMC from Queensland Nickel Pty. Ltd. of Australia. 2. Production Status 2.1 Producers and materials Today, SMM holds the monthly E-Ni production capacity of 1,920 tons, of which 1,690 tons are from the matte anode process, and the remaining 230 tons are from the mixed sulfide as a raw material. NMC also uses the mixed sulfide as a raw material for a production of 300 tons/month. [ ] Most of SMM's raw material, nickel matte, is imported from WMC of Australia, partly using the Soroako matte from Indonesia. An example of material analysis is given in Table 1. Matte is a raw material for E-Ni and NOS, and the major sources of matte supply at present are Australian WMC and Indonesian Soroako, occupying ap-

Jan 1, 1982

By Harold R. Bradford

EXPANSION initiated during and after the war has placed industrial plants in new areas and increased reduction and manufacturing facilities in communities already established. With added expansion interest has grown in possible area contamination from waste products. Evolved flue waste contains many chemical contaminants that may or may not cause concern; however, atmospheric pollution has always been a problem to industrial communities. For some time effects attributed to small quantities of compounds of fluorine in various waste gases have been studied by industrial, medical, agricultural, and associated interests.1,2 Aside from an article by Churchill, Rowley, and Martin in 1948,3 little has been published on the subject of fluorine in coal except by foreign investigators.

Jan 1, 1957

Reports from the Geological Survey, Department of the Interior, indicate that although considerable drilling has been clone in the state of Utah, no oil has been produced in commercial quantities. Sandstone saturated with asphalt and other hydrocarbon compounds and small showings of oil in wells at several places suggest that oil may be found, in commercial quantities where the rocks are favorable for oil accumulation. In some places the structure appears to be very favorable for the storage of oil which may probably be reached by drilling to a depth of 3000 to 4000 ft. It is admitted that this will be wildcat drilling for it is not known whether the unexposed rocks carry oil and there are no surface indications of oil. This entire subject is discussed in United States Geological Survey Bulletin No. 711-A, and most of the report will be found to be contrary to the claims that have recently been advanced for oil properties in Utah.

Jan 9, 1919

By William Kent

DURING the discussions at the Philadelphia meeting in February last, † several speakers expressed their doubts of the general accuracy of chemical analyses of steel made by "iron works chemists," and especially of determinations of manganese. Since the meeting,. the discussion of the "practical value of chemical analyses" has been continued at some length in the columns of the Iron Age. †Transactions, vol. ix, p. 529.

Jan 1, 1882

By L. W. McKeehan, W. C. Elmore

The magnetic powder method, long used for roughly mapping magnetic fields, has recently been refined1, "or investigating the microscopic variations in the surface magnetization of ferromagnetic crystals. Bitter2 first discovered regular powder patterns connected with the crystal structure of such specimens. Several other investigators:' have used Bitter's original technique, with slight modifications, to study the variation of the patterns with variations in the magnetizing field applied parallel to the surface, and their dependence upon the state of strain, of polish and of crystal cut. All of the explanations of these patterns on metallic ferromagnetics have been couched in general terms. In a preliminary report we have described an improvement ill the powder technique which led us to the discovery of a new effect throwing considerable light on the magnetic secondary structure of alpha iron4 and of nickel5 single crystals. We now report additional evidence confirming the existence and stability of a magnetic block secondary structure. Specimens The following list describes the specimens used in the present investigation. Designation Description A1 Silicon ferrite furnished to us by Dr. W. E. Ruder, of the General Electric Co., for which lie gave the following typical analysis: C, 0.05; P, 0.038; S, 0.026; Mn, 0.15; Si, 3.24. Disk, 0.60 cm. diameter, about 0.05 cm. thick. By X-ray analysis angles between disk normal and [100] 75o, [0101 76" [00l] 21o. A2 Same as A1 except: diameter 0.75 cm. A, Same as A1 except: diameter 0.68 cm.

Jan 1, 1936

By L. W. McKeehan, W. C. Elmore

The magnetic powder method, long used for roughly mapping magnetic fields, has recently been refined1, "or investigating the microscopic variations in the surface magnetization of ferromagnetic crystals. Bitter2 first discovered regular powder patterns connected with the crystal structure of such specimens. Several other investigators:' have used Bitter's original technique, with slight modifications, to study the variation of the patterns with variations in the magnetizing field applied parallel to the surface, and their dependence upon the state of strain, of polish and of crystal cut. All of the explanations of these patterns on metallic ferromagnetics have been couched in general terms. In a preliminary report we have described an improvement ill the powder technique which led us to the discovery of a new effect throwing considerable light on the magnetic secondary structure of alpha iron4 and of nickel5 single crystals. We now report additional evidence confirming the existence and stability of a magnetic block secondary structure. Specimens The following list describes the specimens used in the present investigation. Designation Description A1 Silicon ferrite furnished to us by Dr. W. E. Ruder, of the General Electric Co., for which lie gave the following typical analysis: C, 0.05; P, 0.038; S, 0.026; Mn, 0.15; Si, 3.24. Disk, 0.60 cm. diameter, about 0.05 cm. thick. By X-ray analysis angles between disk normal and [100] 75o, [0101 76" [00l] 21o. A2 Same as A1 except: diameter 0.75 cm. A, Same as A1 except: diameter 0.68 cm.

Jan 1, 1936

By I. J. Polmear

Earlier work revealed that small amounts of silver (< 0,l at. pct) may exert a marked effect on the structure and aging characteristics of certain a1loys based on the Al-Zn-Mg system. Silver additions have now been made to other age-hardening aluminum alloys, and significant effects have been observed in the Al-Mg system and in several Al-Cu-Mg and Al-Mg-Si alloys. Similarities exist between the behavior of alloys from all four systems, notably that in each case silver stimulates nucleation of an intermediate precipitate which forms when the alloys are aged in the medium temperature range (-120" to 220°C). The mechanism for this effect is uncer- IT has been shown that small additions of silver (<0.1 at. pct) may have a marked effect on the structure and age-hardening characteristics of tain although it is suggested it originates in a preferred affinity between magnesium and silver atoms. There is evidence to indicate that the effects of silver are unique to that element. It is suggested that silver atoms interact with vacancies during low-temperature aging of Al-4 pct Cu and certain Al-Cu-Mg alloys. Silver had little effect on Al-8 pct Zn aged at any temperature. Preliminary observations indicate that silver may have interesting effects on the strength properties of Al-Mg alloys, md a the commercial Al-Cu-Mg alloys designated as 2024 and 2618. many alloys based on the Al-Zn-Mg* system.1"&apos;*

Jan 1, 1964

By A. S. Michaels, M. C. Porter, A. Stancell

Previous laboratory studies have demonstrated that the injection of small quantities of reverse wetting agents during water displacement can increase oil recovery from unconsolidated porous media.9 In the present investigation, an attempt has been made to determine more fully the effects of reverse wetting treatments and to clarify the mechanism by which increased oil recovery is effected. Water-oil displacements were performed in beds of 140-200 mesh silica sand. Hexylamine slugs (injected after 0.25 pore volume of water throughput), when adequate in size and concentration, were effective in promoting additional oil recovery. Their effectiveness increased with the quantity of amine injected. However, slugs of sufficient size and concentration to stimulate oil production at water flow rates of 34 ft/day did not do so at 4 ft/day. Visual studies in a glass grid micromodel have shown that the stimulation of oil production, via ayueous hexylamine, is a result of transient changes in the oil wettability of the pore walls. if the amine slug is of sufficient size and concentration to induce significant changes in the adhesion-tension, large continuous oil masses will be formed. if the superficial water velocity is high enough to result in rapid desorption of the amine, a favorable "wettobility gradient" may be established across the masses; under such conditions, high oil mobility is observed, and increased oil recovery results. INTRODUCTION It is generally agreed that the efficiency of oil displacement by water in porous media is limited in part by capillary forces which cause the retention of isolated masses of oil — resulting in the so-called "irreducible minimum oil saturation". Recent estimates10 indicate that there are about 220 billion bbl of petroleum in United States reservoirs which are not economically recoverable with present techniques (such as water flooding). This amounts to almost five times the known recoverable reserves. It has been recognized for some time that a suitable alteration in the water-oil interfacial tension and/or the contact angle, as measured between the water-oil interface and the solid surface, should result in better displacement efficiency. Surface active agents can be used as interfacial tension depressants to accomplish this objective,1,2,7 but unfortunately, the additional oil recovery is seldom commensurate with the treatment cost. In contrast to interfacial tension depressants, the effect of contact angle alterations on water-oil displacements has received relatively little attention in the literature. It is known that the wettability affects the displacement process.3,4,11 Displacements in water-wet systems generally result in lower residual oil saturations than those in oil-wet systems. The effect of "&apos;transient" wettability alterations concurrent with the displacement process have been investigated by Wagner, Leach and coworkers,4,11 wherein it has been demonstrated that the establishment of water-wet conditions during water flooding of oil-wet, oil-saturated porous media is accompanied by significant increase in oil displacement efficiency. Michaels and Timminss studied the effects of transient contact angle alterations resulting from chromatographic transport of reverse wetting agents through unconsolidated sand. It was demonstrated that chromatographic transport of short-chain (C4 through C8) primary aliphatic amines can improve oil recovery and that the recovery increases with the quantity of amine injected (i.e., with either the amine concentration or the volume of the slug injected). Circumstantial evidence indicated that the increased displacement efficiency resulted primarily from transient changes in wettability of the porous medium. In the Present investigation. additional information has been obtained on the effects of reverse wetting treatments and the mechanism by which increased oil recovery is accomplished. Hexylamine slugs of varying size and concentration were chromato-

Jan 1, 1965