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By H. K. Shearer

Oil production in north Louisiana in 1938 was 28,442,910 bbl., a decrease of 225,160 bbl., or less than 1 per cent, from 1937. The principal increases were at Cotton Valley, Lisbon and Zwolle. The greatest decrease was at Rodessa, with small normal declines in production of the old settled fields. Natural gas production from gas wells declined 15.9 per cent from 1937, but casinghead gas increased, so the decline in total production was only 6.9 per cent. Decline in completions was due to lack of proven areas for drilling, as well as price and marketing difficulties; and wildcat activity mas also less than in 1937. The increase in number of dry holes was due chiefly to shallow drilling in the old Caddo and Zwolle fields. Most important events in 1938 were the discovery of the Shreveport deep oil and gas field, extension of the Logansport gas-distillate field into Louisiana, development of oil production in the Bodeaw zone on the flanks of Cotton Valley, opening of deep gas-distillate production at Shongaloo, and completion of one well in a deeper horizon at Bluc Lake (Zwolle field). Geological Notes The deep drilling done in 1938 did not cause any important changes in geological correlation and nomenclature of the formations below the Upper or Gulf Cretaceous. The stratigraphic section of the Lower Cretaceous and deeper beds, with names used in the accompanying tables, as approved a year ago by the Shreveport Geological Society, is as follows:

Jan 1, 1939

By T. Sterry Hunt

Jan 1, 1884

By J. C. Platt

1 desire to call the attention of the Institute to what is believed to be a new improvement in 'the construction of journal-bearings, having for its object the reduction of original cost as well as cost of renewals. In an ordinary railroad car we find the space between the top of the axle and the top of the box is filled with a "brass," weighing from seven to ten pounds. Of this amount of metal a comparatively small portion is subjected to the wear which it is intended to meet. The balance is, practically, a filling material, which from habit has long been constructed of the same metal. The Defreest bearing is made of three parts, namely, a malleableiron back, a bronze bearing-piece, and between them a filling-piece of sheet lead. The bronze takes the wear of the axle, the iron fills up the space and acts as a backing to the bronze, and the lead, being soft, adapts itself to the inequalities in the surfaces of the iron and bronze castings, thus insuring a uniform bearing on all points, and making it unnecessary to bore out the iron or turn off the bronze to bring them to a perfect contact at all points. These three park are joined together by two soft brass rivets, with counter-sunk heads, to prevent separation in handling. A groove is cast in the iron, and a corresponding rib on the bronze, to prevent the latter from turning with the axle when in place. In renewals it is ordinarily necessary simply to drive out the rivets and renew the bronze and lead. The iron part is not subjected to much wear and should last for years. It is evident that the first cost of these journals, and also the cost of renewals, must be much less than the old form. This difference amounts, at the present price of materials, to $9.60 for an eightwheel car, in first cost, and $4.72 for renewals. These bearings have been in use, and found to do what is claimed for them.

Jan 1, 1880

By Warren T. Smith

The Phelps Dodge Corp. Lavender pit is located in the Bisbee mining district near the town of Lowell, Ariz. A quartz monzonite porphyry exists as an intrusive stock and was the source of mineralization for the limestone replacement orebodies being mined by underground methods. Leaching of the upper portion of the stock, and precipitation of the copper as chalcocite on the finely dispersed un- oxidized pyrite in the monzonite porphyry, formed a low grade ore zone below a leached capping varying from 50 to 300 ft thick. Churn drilling starting in 1916 and supplemental churn drilling begun early in 1950 indicated a mineable area about 3100 ft long by 2400 ft wide. In general drilling was on 100-ft centers. The pit was planned with 50-ft benches and wall slopes varying from 1 to 1 to a flatter slope of 1 1/3 to 1 dependent on the character of the ground. Materials within the pit limits, using a 0.6 pct minimum grade cutoff, were estimated at 41 million tons of 1.14 pct copper ore, 31 million tons of low grade sulfides suitable for leaching with an average grade of 0.42 pct, and 70 million tons of waste.

May 1, 1956

By E. A. Koester

Kansas produced approximately 35,434,000 bbl. of oil in 1932 compared to 37,018,000 bbl. in 1931, a decrease of 1,584,000 bbl. or 4.2 per cent. These figures do not indicate the amount of oil that could have been made available from the state for the year. Many of the fields discovered during the year and some discovered in previous years were entirely shut in. Practically all flush production discovered within the last two years has been prorated in some manner or other. Probation Kansas production is under regulation as specified in House Bill 387, passed by the legislature in 1931, which became effective when published May 28, 1931. The principal features of the law are the prohibition of waste, including gas energy, the regulation and prevention of discrimination of purchasers, the marketing of oil ratably from wells in each field when the daily production is above 15 bbl. per well. This act gives the enforcing powers to the Public Service Commission. The Commission, having many other regulatory duties, appointed an Oil Advisory Committee, which, with the aid of the State Umpire, keeps records and makes recommendation for orders as to specific regulation of fields and conditions in each field. At the time the Commission was given authority to regulate production and marketing in flush fields, several of these had already been under voluntary proration and marketing restrictions by agreement of the operators. These gradually came under the control of the Commission by mutual consent. It is the policy of the Public Service Commission to follow the will of the operators so long as they do not have ideas or plans in conflict with the law. The cost of administration of this law is assessed against the operators according to the amount of oil taken from the fields in which ratable taking is necessary. There is a feeling that the whole state should share this expense, which is small, since it is beneficial to the older fields by assuring them 100 per cent market for their output by restricting the flush fields.

Jan 1, 1933

By Michael A. Toole, O&apos

INTRODUCTION The tremendous capital investment required to produce a low grade ore deposit demands a reliable answer to the question: "How much does it cost to drill a well to produce the uranium that geologists have indicated is there in the ground?" However, you will find the answers given will be many and varied, depending on whether they come from the operating company, the drilling contractor, a geologist, a reservoir engineer, purchasing agent, or whoever. Each generally considers only a limited area of the total operation. The operating company usually depends upon the drilling contractors, service companies, and consultants to supply expertise. Because it is often difficult to see the "whole picture" or even to agree upon what the "whole picture" is, planning a well program and its costs is often done piecemeal. Frequently, costs "saved" in one area of the program are needlessly spent in another, because the effect of one area upon the other was overlooked. Since the drilling fluid is such an influential part of the drilling program, it should be given utmost consideration when planning the overall program. As W. D. Lacabanne wrote in 1954: "The drilling fluid system is understandably called the heart of the rotary oil drilling rig. Any other type of rotary rig.... should benefit by the incorporation of mud fluids in the drilling scheme." And G. R. Gray mentions that "The driller recognizes the drilling fluid as one of the useful tools available to solve drilling problems." However, in minerals drilling, only in recent years has the drilling fluid been considered as more than a tool to get through special problem areas. Although there are many similarities between drilling for oil and gas and drilling for minerals, the differences in the drilling equipment used justifies designing specific fluids for the minerals drilling industry. NL Baroid/NL Industries, Inc. has been a leader in introducing such fluids and in providing technical know-how to the minerals drilling industry. The purpose of this paper is: (1) to discuss the selection of drilling fluids to meet specific drilling conditions during both exploration and production and (2) to show the interrelationship among factors present in the exploration and production phases that influence total well costs. DRILLING FLUIDS FOR DRILLING PROBLEMS The drilling fluid is a tool that can be used to improve drilling performance by improving hole cutting, cleaning, stability, and formation productivity. Properly formulated and maintained drilling fluids enable the drilling operation to be carried out with increased efficiency and lower total (overall) costs. However, it should be noted that not all drilling problems can be solved by even the most carefully prepared and maintained drilling fluids. Of the many possible drilling problems encountered in a well before reaching target depth, this paper will discuss only those most likely to be present in the shallow [61 to 610 m (200 to 2000 ft)] drilling operations in South Texas. LOST CIRCULATION Loss of circulation is the most common problem encountered in drilling. Because the losses occur under varied conditions, it is often difficult to determine the exact causes. "Lost circulation" or "lost returns" means the partial or complete loss of drilling fluid to voids in the formation. "Loss of water" while drilling with water may take place into any permeable section and should be distinguished from "water loss" or filtration of fluid through the filter cake of mud solids laid down on a permeable formation. "Loss of water" can frequently be stopped by the addition of colloidal sized clay particles such as high yield bentonites, whereas "water loss" may be controlled with organic polymers. Subsurface conditions that lead to loss of circulation can be classified as: (1) natural fractures, (2) induced fractures, (3) unconsolidated or highly permeable formations (loose gravel), and (4) cavernous formations (crevices and channels). Loss of circulation may occur whenever the borehole pressure exceeds the formation pressure. The greater the differential pressure, the more likely it is that circulation may be lost. To stop loss of whole mud, voids must be bridged so that a filter cake can be laid down on the permeable section. The plugging material must be of the proper size and shape to offer greater resistance to the fluid flow around it than the flow up the annulus. A plugging composition that satisfies these requirements may not be able to be handled by the small rig pump available.

Jan 1, 1979

By H. M. Howe, W. E. C. Eustis

THE processes which form the Subject of this paper have been experimented on in the laboratory of W. E. C. Eustis, but have not passed beyond the experimental stage. The first is the invention of Mr. J. L. Thomson, of Capelton, Quebec, Canada, the others have been invented by the writers. THOMSON'S PROCESS FOR THE EXTRACTION OF NICKEL This consists essentially in first rendering the nickel magnetic, and then separating it from the materials. with which it is mechanically

Jan 1, 1882

By AIME AIME

MORE than thirty members of the Coal Division attended the Coal Land Valuations Round Table on Monday morning. Chairman Dilworth stated that the Committee had been appointed to take up the question and, after reading the list of members of the Committee, pointed out that the object of the meeting was to formulate a plan of action rather than to discuss any phases of valuation, per se. To this end he presented a tentative outline of points to be considered in the future by the Committee. After a lively discussion on the desirability of inclusion of some questions in the agenda of the Committee, the following outline was adopted :

Jan 1, 1931

By Paul H. Hunt

MANY MISUNDERSTANDINGS have arisen regarding -Al the purchase by the Government of 24,000,000 oz. of domestically produced silver annually for the next four years at a price of 64 1/2c. to the producer. Some editorials have an¬nounced rather sarcastically that be¬cause of the strong western silver bloc in Congress, the Administration is paying a bonus of approximately $22,000,000 to a few large silver produc¬ers of the West, the amount being figured on the total purchase of about 100,000,000 oz. and the difference between the Government price and the world price for silver. Actually the Government will make a profit on this purchase, due to seigniorage, of something over $60,000,000. The 96,000,000 oz. of silver, for which the producers will receive approximately $62,000,000, will be produced in association with at least $100,000,000 worth of lead, zinc, copper and gold; the greater part of this $162,000,000 worth of metal will be produced at little profit to the mining companies, as will be shown later, because of the low prices for lead, copper and zinc. This amount of money will be spent largely for labor and supplies, thus greatly relieving the national burden of unemployment. Certainly, western mining, in the purchase of this silver, is not victimizing the Federal Government.

Jan 1, 1934

By Edward W. Parker

IF one is to place any credence at all in the reports published in the daily press, the subject of conservation has been a very lively topic of conversation during the past 60 days, and it does not appear that the temperature of the summer months has been in any way moderated by the discussion. It is a subject in which we are all vitally interested and to which, so far as our mineral resources are concerned, both the Institute and the Geological Survey have liberally contributed. The report of the National Conservation Commission, appointed by President Roosevelt, contains a series of papers on the conservation of mineral resources, all of which were prepared by members of the Geological Survey and were compiled largely from information previously collected by that Federal bureau in the performance of its regular duties. It is not the purpose of this paper to reiterate in extenso any of the material already published. The contributions of the Survey officials to the Commission's report have been published in a separate document as Bulletin No. 394. This docunient is for free distribution and may be obtained upon application to the Director of the Survey. In the preparation of this paper I desire merely to make a few suggestions regarding the possible necessity of some restraint upon or control of one branch of the mining industry with which I have been somewhat closely associated for the past 20 years-that of coal. Most of the members of the Institute are cognizant of the suits brought by the government against the anthracite-operators in Pennsylvania, or the combination of interests commonly known as the ? hard-coal trust." No defense of any illegal combination in restraint of trade is intended, but there are some facts which should not be lost sight of, and unfortu-\

Nov 1, 1909

By W. C. Kerr

ThE distribution of gold is obviously much wider than is Commanly supposed. Resides the usual matrices, vehicles, or associates, such as quartz, pyrite, chalcopyrite, etc., I find it occurring in quite a range of common rocks. For example, at the Rhodes mine, in Gaston County, a body of 9 to 12 feet of decoroposed, light-gray gneiss was worked together with the strings of quartz, and yielded from six to ten dollars to the ton. A mine in Moore County yields its gold mainly from a feldspathic schist. In the famous King's Mountain mine, in Gaston County, the gold is obtained not only from the seams of quartz in a blue, hydromicaceous schist, but a 60-foot ledge of grayish-blue, fine-grained, schistose limestone is quarried out bodily and sent to the stamps. It is gold-bearing throughout. In Montgomery County the singular concretionary, conglomeritic, quartzite schist, which contains Emmons's palceotrochis, is gold-bearing over wide tracts of country. This fact was noticed by Dr. Emmons. But a still more striking and significant fact is, that a large part of the gold of Montgomery, Davidson, and Randolph counties,

Jan 1, 1882

By Morris J. Elsing

FOR MANY YEARS lead and zinc have had the so-called protection of a tariff and it is the purpose of the following brief discussion to show what' such protection actually accomplishes with a view to forecasting the possible results of the present copper tariff. In analyzing the subject, tabulations of the United States production, consumption, imports and exports, including ore and concentrates and all of the metallic products, of both lead and zinc have been made for each year since 1900. Of these data, the relationship of the imports and exports and the relative foreign and domestic prices are shown in Table 1. The conclusions drawn from these figures are listed below. 1. The United States is an exporter of zinc. 2. The United States is an importer of lead. 3. The average price of zinc at St. Louis for the last 32 years has been no higher than on the London market even though zinc and zinc ore have "enjoyed" a protective (?) tariff of varying amounts per pound for 22 years of this period. 4. The average price of lead on the New York market for 32 years has been 1.2c. per pound higher than on the London market, the tariff varying from 0.75 to 1.5c. per pound of lead in ore, and 1 to 2c. or more on manufactured lead.

Jan 1, 1932

By S. J. Page

Introduction Dust from cutter machines and face drills is controlled in most mines by water. However, the large quantities of water used in metal and coal mines for dust control and suppression pose serious operational problems in water soluble ores, such as salt, trona, or gypsum. This paper reviews the strategies to suppress and collect dust on cutter machines and face drills where water usage must be restricted to very low flow rates - typically 3.78 L/min (1 gpm) or less.

Jan 1, 1985

By S. F. Emmons

It was said by many who discussed Professor Posepny's admirable paper on the "Genesis of Ore-Deposits," read at the Chicago meeting of the Institute, in 1893, that its most valuable feature was the clear distinction which it drew between the influence upon ore-deposits of the " vadose " circulation of waters descending directly from the surface, and that of the deep underground circulation of waters generally coming from the depths, and assumed by the author to be ascending through more or less open spaces under the influence of heat. A little later the effect of the oxidizing action of the vadose circulation upon ore-deposits was ably and exhaustively treated by Prof. R. A. F. Penrose, in a paper on " The Superficial Alteration of

Jan 1, 1901

For the year ending February, 1919 PRESIDENT SIDNEY .J. JENNINGS NEW YORK, N. Y. PAST PRESIDENTS L. D. RICKETTS, NEW YORK, N. Y. PHILIP N. MOORE, ST.Louis, Mo. FIRST VICE-PRESIDENT C. W. GOODALE BUTTE, MONT. TREASURER GEORGE C. STONE, : NEW YORK, N. Y. SECRETARY' EMERITUS ROSSITER W. RAYMOND NEW YORK, N. Y. SECRETARY BRADLEY STOUGHTON, NEW YORK, N. Y.

Jan 10, 1918

By P. H. Wendland

Calculations are presented for the design of a silicon photodiode in which the incident light beam makes multiple passes between the detector surfaces. Total internal reflection is used for this "light-trapping" effect. By this means, the optical path length can be extended to several millimeters, while the electrode separation remains less than 102 cm, as required for nanosecond response time. Data are presented for a Schottky barrier photodiode constructed on a multiply reflecting silicon base wafer. It is shown that the long-wavelength response is considerably extended in such structures without a corresponding sacrifice in high-speed response. The development of efficient and powerful lasers at 1.06 p has stimulated interest in detectors which operate at this wavelength. In typical silicon photodiodes, for detecting 1.06 p radiation, the requirements for high speed and high sensitivity are mutually exclusive. Since the absorption coefficient is only 25 cm-', a lo-'-cm path length is required to absorb 92 pct of the incident 1.06 p radiation. If the electrode separation is greater than 10 cm, however, the carrier transit time will be greater than 1 nsec. This problem can be solved by allowing the incident light beam to make multiple passes between the electrodes. The optical path length can then be extended to several millimeters, as required for complete absorption, while the electrode separation remains less than 10' cm, as required for nanosecond response time. In a typical photodiode geometry, one ohmic contact and one rectifying contact are formed on the two opposite surfaces of a base wafer, and the wafer thickness determines the electrode separation. The objective of the multiple reflection design is to allow all 1.06 p radiation to enter the detector front surface and to form the back detector surface so that no 1.06 radiation can exit. Total internal reflection at the back detector surface is well-suited for light trapping of 1.06 p radiation because the relatively large dielectric constant of silicon leads to a critical angle of 16.5 deg for total internal reflection. LIGHT TRAPPING It is well-known that, as light passes from one medium such as air into another medium such as glass or silicon, the angle of refraction is always less than the angle of incidence. In the limiting case, where the incident rays approach an angle of 90 deg with the normal, the refracted rays approach a fixed angle +, beyond which no refraction is possible: this is called the critical angle. It follows from Snell's law that where = critical angle, n - index of refraction of air, n' - index of refraction of the medium. Applying the principle of reversibility of light rays, all internal angles of incidence greater than +, will produce total internal reflection and "light trapping". The index of refraction of silicon at 1.06 p is 3.5,' and the critical angle is thus 16.5 deg. Fig. 1 shows these relationships for silicon. This very small critical angle in silicon is significant because all incident angles between 16.5 and 90 deg will produce total internal reflection and "light trapping". This effect can be implemented with a "prismlike" geometry, so that incident light can be introduced into the sample without loss and "trapped". PHOTOSIGNALS A precise knowledge of the absorption coefficient at 1.06 in silicon is of critical importance to the design of fast and efficient silicon photodiodes for 1.06 radiation. Dash and newman2 show a value of 25 cm-l, and our measurements have corroborated this value. Assuming that the collection of photoinduced minority carriers is perfect, the quantum efficiency of a photodiode is dependent only on the absorption coefficient. It then follows from Lambert's law that where QE is the quantum efficiency in pct, a is the absorption coefficient, d is the optical path length, and the reflectivity at the surface is assumed to be completely suppressed by an optical interference layer. Fig. 2 gives the maximum quantum efficiency for 1.06p radiation of a silicon photodiode with optical path length d, using Eq. [2]. The ultimate response time of a fully depleted photodiode to an incident light pulse can be considered to be the arrival times of all photoinduced carriers at the contacts, i.e., the minority carriers at the junction interface and the majority carriers at the oppo-

Jan 1, 1968

By T. E. Scott, D. H. Sherman, C. V. Owen

It has been established' that vanadium exhibits a ductile to brittle transition temperature which increases with increasing hydrogen content. Optical microscopic examination at room temperature revealed no evidence of hydride precipitate in fractured specimens containing 100 ppm H, but hydrides were present in samples with 800 ppm H. More recently2 the strain rate and temperature dependences of the ductility drop in vanadium containing 6 ppm H were reported. It was argued that the ductile-brittle transition, while dependent on the presence of hydrogen, probably could not be explained by the precipitation of hydride. The bases of the argument were that 6 ppm H would not produce sufficient hydride to alter the ductility to the extent observed and no visual evidence of hydride was obtained. However, the data were not sufficient in these investigations 1,2 to define accurately the ductile-brittle transition temperature. Also, no information was available concerning the terminal solubility of hydrogen in vanadium at the low concentrations employed. westlake 3 has studied the electrical resistivity of vanadium at several hydrogen concentrations. He was able to detect the precipitation of hydride and to extend the hydrogen solvus to the composition and temperature range pertinent to the observed ductile-brittle transition behavior, Westlake compared his

Jan 1, 1968

By R. E. Radabaugh, J. M. Brown, J. S. Merchant

The Gilman district is on the northeast flank of the Sawatch Range in central Colorado. It has yielded a total of 10,000,000 tons of ore having a value of over $250,000,000. Paleozoic sediments intruded by a Tertiary quartz latite sill and unconformably overlying Precambrian intrusives and metasediments comprise the country rock of the area. The sediments strike northwesterly and dip 8° to 12° northeasterly. Structures in the Precambrian are related to the Homestake shear zone of the Colorado mineral belt. Only minor folding and faulting occur in the sediments. The principal ore bodies are massive sulfide replacement deposits in carbonate rocks. They consist of long, pipe-like mantos in the completely dolomitized Mississippian Leadville Limestone and funnel-shaped chimneys of copper- silver ore cutting across the Mississippian and Devonian strata. Mineralization is continuous from the chimneys into the mantos. The principal ore bodies are roughly in the shape of a four-tined fork which points up dip. Smaller manto deposits occur in the Cambrian Sawatch Quartzite, and fissure veins are present in the Precambrian rocks. The principal minerals in the mantos are marmatite and galena in a gangue of pyrite and manganosiderite. The chimneys consist of a central core of pyrite with erratically distributed chalcopyrite, tetrahedrite, freibergite, and occasional galena with a shell of zinc ore on the outer margin. Both the chimneys and the mantos are surrounded by imperfect shells of manganosiderite and sanded dolomite. The mineralization is of Laramide age. Hydrothermal alteration affects all rock units to varying degrees. Clay mineral alteration halos occur around the ore bodies. Hydrothermal solutions have developed sanded rock, rubble filled channels, and banded zebra textures, principally in the Leadville Limestone. Structural control of the ore bodies is not well defined. Both the location of the district and the chimneys are probably related to basement structures. The mantos are largely controlled by stratigraphic factors and a pre-Pennsylvanian karst topography in the Leadville Limestone, which were modified by hydrothermal activity, and by weak zones of northeasterly trending faults.

Jan 1, 1968

By S. F. Urban, G. Derge

AT the time this investigation was initiated variations were observed in the quality of different heats of basic electric-furnace steels, although they had been made under purportedly similar conditions. This indicated that these variations were related to normally unobserved variations in the character of the bath, especially during the "refining" period. Although the slags used for this operation are commonly referred to as "reducing" slags, and are regarded as having a "deoxidizing" action on the bath, no reliable measurements of this action were available. It was decided, therefore, to study the behavior of oxygen in the metal for a large enough number of heats to learn its normal variations and to relate these variations to regularly observed conditions [f] operation. The most important general conclusion reached was that the time a heat is held under a reducing slag should be reduced to a minimum, which was about an hour and a half under the conditions studied. Beyond this time no observable beneficial effects are obtained from the reducing slags, insofar as oxygen and sulphur content of the bath are concerned. It is likely that added time may increase hydrogen content as well as heat costs. The oxygen content of the bath is never reduced below the amount in equilibrium with the carbon. Concurrently with this work, J. S. Marsh1 presented data that supplement and support many of the results of this paper. PROCEDURE The work was done in two different electric-furnace shops of the same plant. The selection of heats was made primarily with regard to the convenience of heat schedules. Companion slag and metal samples were taken just prior to slag-off and throughout the refining period for an initial set of 17 heats, and before slag-off and near tap for an additional 13 heats. Slag sampling presented no particular problem; a spoonful of slag was poured onto a metal plate and when sufficiently cool was sealed in an airtight container. Sampling the metal for oxygen presented a more complex problem. Because of the lack of previous experience in sampling electric-furnace baths, a number of methods were compared. Chilled Wedge Samples2 An unkilled metal sample is removed from tie furnace in a well-slagged carbometer spoon and poured immediately into a heavy copper mold designed to provide rapid freezing. Three different types of molds were used to determine the optimum for electric-furnace heats. The Big Wedge Mold (a) was a 4 by 4 by 4-in. split copper mold, yielding a wedge-shaped casting 1 in. wide, 1 ½ in. long, and ¼ in. maximum thickness, and was finally adopted as the most satisfactory design. The Long Wedge Mold (b) was a 2 by 2 by 5 ¼ -in. split copper mold, yielding a wedge-shaped casting 1 in. wide, 2 ¾ in. long, and ¼ in. maximum thickness. The Small Wedge Mold (c) was 2 by 2 by 4-in. split copper mold, yielding a wedge-shaped casting 1 in. wide, 1 ½ in. long, and ¼ in. maximum thickness.

Jan 1, 1947

By John A. Bonucci

AMAX Base Metals R&D, Inc. has developed technology for extracting and recovering platinum and palladium from spent automobile exhaust emission control catalyst. Our most promising route is a chloride-based hydrometallurgical flowsheet in which catalyst pellets or crushed monoliths are leached in HC1 with an oxidant at 95°C without agitation. Alumina co-dissolution can be limited by thermal pre-treatment of the catalyst. The leach solutions are treated by one of several precious metals recovery techniques to produce a high grade PGM concentrate. For the new generation of three-way catalytic converters which contain rhodium, an H2S04 preleach could selectively extract much of the rhodium while leaving the platinum and palladium behind. Capital and operating costs will be discussed.

Jan 1, 1984