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By Adrian Brown

Over the last decade, a number of large slopes have been excavated in rock which contains families of joints or faults which dip steeply into the cut slope. Despite the absence of "adverse" structures, these slopes have exhibited alarming movement rates at very modest heights (as little as 100 meters) and slope angles (as little as 20º). Classical stability analysis suggests that such slopes should be unconditionally stable. This paper describes the toppling mechanism which has been found to be the cause of the observed movements and develops a general method for analysis of it. Simple cases are analyzed in order to provide charts which allow quick evaluation of the likelihood of this phenomenon occurring. The safety implications of such movements in slopes are also examined.

Jan 1, 1982

By R. G. Robins

The processing of gold bearing sulphide minerals which contain arsenopyrite and various complex arsenic sulphides results in arsenic containing emissions and effluents which are suspect in relation to clean air and clean water standards. Removal of arsenic from gaseous emissions is briefly reviewed. The use of lime to stabilise aqueous residues as either calcium arsenate or calcium arsenite is shown to be inadequate for long term disposal since both compounds are converted into calcium carbonate due to the influence of carbon dioxide in the atmosphere. Mixed calcium arsenate-phosphate residues are similarly unstable, but present better stability than the straight calcium compounds. Alternative disposal methods are reviewed whereby the arsenic is converted to more stable compounds, such as barium arsenate, titanium (IV) arsenate, and arsenic sulphide.

Jan 1, 1984

By H. E. Mussey

When the American Institute of Mining Engineers visited the Birmingham district in May, 1888, the four Ensley furnaces (Fig. 1) then completed were referred to as monumental.' Their dimensions are givcn in Table 1. Mr. Gordon stated, with considerable satisfaction, that on the preceding day one furnace had produced 165 tons. The blast was

Jan 1, 1925

By Andrew A. Blair

The increased importance and value of chemical analysis in connection with metallurgical operations is largely, if not entirely, due to the increased accuracy of the analytical methods used for the quantitative determination of the foreign elements always associated with the metal operated upon. This applies especially in the working of iron and steel, and to the determination of the amounts of such elements as phosphorus, carbon, and silicon. The influence of greater or smaller amounts of these elements upon the physical properties of iron and steel will be better understood when the proper experiments shall have been made upon samples whose chemical composition is known with almost absolute certainty. From the present standpoint of analytical chemistry, it is easy to see that at least one reason for the failure of many attempts to solve this problem, is the inaccuracy of the analytical methods used. Even at the present time the frequent want of agreement (over and above the unavoidable error due to manipulation) between chemists working on the same sample, leads one to think that there is still at least a choice in the methods used. It is true that very frequently a faulty method in the hands of a skilful analyst may be made to give corroborative results

By Walter O. Snelling

IN combating mine-fires the use of carbon dioxide as a means of producing an atmosphere in which combustion cannot be sustained, has been many times suggested and frequently tried, generally with a fair degree of success. The carbon dioxide is produced by acting on limestone with dilute sulphuric acid, large wooden boxes being used to hold the limestone, and arranged in such a manner that one box may, be cleaned and refilled with blocks of limestone while another is being used in generating the carbon dioxide. The gas is led by means of pipes of large diameter to the location of the fire, tight brattices having been previously put up as close to the fire as possible on every side, so as to limit the space to be filled with the .gas to the smallest possible volume. The cost of producing Carbon Dioxide has been, however, a decided draw-back to the use of this method, and the danger of producing carbon monoxide by the reduction of the carbon dioxide by heated carbon, and consequently bringing about an explosion, has also tended to prevent the application of this method. The use of sulphur dioxide in combating mine-fires has not, I believe, been previously suggested or tried, and yet the method presents such decided advantages over the use of carbon dioxide that it seems proper to suggest the advisability of considering it as a cheap, convenient, and safe means of fighting stubborn mine-fires. 1. Cost, Preparation, etc.-One ton of brimstone, costing from $20 to $30, will produce about 25,000 cu. ft. of sulphur dioxide gas, and allowing for all sources of loss it is probable that sulphur dioxide gas can be produced for about $1,300 per 1,000,000 cu. ft. For carbon dioxide gas, produced by the action of sulphuric acid on limestone, a good estimate would be $4,000 per 1,000,000 cu. ft., provided that sulphuric acid

Sep 1, 1908

By R. L. Curfman

From January 1, 1965 through July 5, 1970, the very difficult potash ore body of Texasgulf Inc. near Moab, Utah was mined by conventional methods. The mine was gassy, the temperature was high and structural conditions precluded a satisfactory or economical extraction ratio due to the undulating configuration of the ore horizon. In 1966, 67, and 68, alternative mining methods were considered, among which was solution mining of the ore body. Cost studies indicated that the use of crystallizers to evaporate the large amounts of water attendant to solution mining offered no chance of economic success. In 1969 additional testwork and cost studies were carried out utilizing solar evaporation. These studies showed economic potential and justified additional investigation. As a result of these studies, Texasgulf now gathers potash solids from these solar evaporation ponds, (Fig. l), after pumping them from the underground mine as brine. The investigations were concentrated in four basic areas : (1) area evaporation rates and crystal growth habits; (2) underground solution tests including heat transfer rates; (3) accelerated evaporation tests to provide material for metallurgical testing, and (4) tests of evaporation pond lining materials and application techniques, along with area surveys to ascertain if sufficient earth was available in the near vicinity to con-

Jan 1, 1974

By O. P. Hood

.NONE of the methods now in use for the transportation of materials underground is entirely free from more or less serious objection. The great flexibility, ease, of control and economy of operation of electric tramming are accompanied by the serious menace of a trolley-wire distributing system. As the gasoline locomotive has even greater flexibility of application and requires no similar dangerous distributing system, it might be considered a safety device which would make possible the elimination of the dangerous trolley system were it not possessed of other objectionable qualities peculiar to itself. It is found that the exhaust gases from the engine may be injurious to the health of those breathing the air in which the locomotive has been operating. While electric shock may kill the individual who makes contact with uninsulated parts, the gasoline engine may be detrimental to the health of all those who have to work within the atmosphere corrupted by exhaust gases. The degree of pollution meas-ures the magnitude of the menace. This may be negligible at times, but with careless operation it becomes serious. The exhaust gases from an engine are composed of, nitrogen, a little free oxygen, hydrocarbons, hydrogen, carbon monoxide, and carbon dioxide, the last two being considered dangerous. The presence of carbon dioxide as a product of combustion of the gasoline was recognized as an objection from the beginning of the use of these machines, but attention was called to the fact that the amount produced was relatively small as compared to that from other sources of this gas, and it was not likely to be made in dangerous quantities. The effect of carbon dioxide, except in relatively large percentages, is confined to the effect it may have in reducing the oxygen content of the air that is breathed.

Jan 10, 1914

By William Fink

NICKEL is used as an alloying element in several complex commercial aluminum alloys, among which are found some very interesting proper-ties, such as relatively high strength at elevated temperatures, relatively low coefficient of expansion, the absence of permanent growth, ability to take a good polish, and a bright, pleasing as-cast surface. For that reason the aluminum-nickel system was included in the list of binary aluminum systems that are being studied as a preparation for the investigation of more complex commercial alloys. This paper is the fifteenth of a series from the Research Laboratories of the Aluminum Company of America reporting the results of investiga-tions of equilibrium relations in aluminum-base alloys of high purity. The aluminum-nickel equilibrium diagram from 0 to 18 per cent nickel was determined, using the purest material available.

Jan 1, 1934

By J. MURRAY RIDDLELL

AN increase of 18 per cent in the production and consumption of all metals last year was readily met by the mines, but more than an average amount of development work was made necessary. Mining methods were improved appreciably; open-pit operations ad¬vanced more than underground practice: and the transportation phase of mining progressed to a greater extent than the other related functions. A new belt-conveyor system of mining was placed in operation at the Spruce open-pit iron ore mine at Eveleth, Minn. The gathering portion of the belt system was installed beneath the surface of the open pit, following closely the bottom rock, in especially provided drifts; beyond it inclined upward to the surface and finally discharged into a 500-ton shipping pocket. Length of the belt was 4500 ft. net vertical lift 386 ft. and capacity 750 long tons per hour. The mined ore found its way to the belt through one of three vertical raises, whose horizontal section was 10 by 10 ft. Each raise was equipped with a grizzly, crusher, pan-type feeder, and auxiliary equipment. Transportation of the ore from the working faces of the pit was accomplished as follows: (1) Two raises were equipped with tower and anchor stations, 3-cu.yd. drag scrapers, and related power units; (2) the remaining raise was provided with electrically driven power shovels and 20-ton trucks mounted on pneumatic tires. This installation has entirely replaced railway pit haulage and partly eliminated power shovels. In a similar

Jan 1, 1938

By H. H. Kellogg

0. C. Ralston—The fact that none of the organizations that have worked on these ammoniacal leaching processes have contributed discussion of Mr. Caron's papers today is a matter of some disappointment. Adaptations, modifications and improvements have been made by several organizations or individuals and to complete the record I want to document a number of them. The Nicaro Nickel Co. operated a Government owned plant at Nicaro, Oriente, Cuba, during the past war. A report on the project was written for Reconstruction Finance Corp. and is in the document file collected by the Office of Technical Services, Commerce Department and filed with the Library of Congress, where it can be consulted or bibliofilm or photostat copies obtained by asking for copies of PB 97271. Nicaro Nickel Co. has obtained a series of U.S. Patents, my list (probably incomplete) of which bears the following numbers: 2,400,098; 2,400,114; 2,400,115; 2,400,461; 2,400,612; 2,458,902 and 2,473,795. International Nickel Co. has also studied the problem and U.S. Patent 2,478,942 shows that some of the complications involving occasional low extractions have been unraveled. Forward, Samis, and Kudryk, of the University of British Columbia, have also published a study of copper-nickel sulphide concentrate.' Others are interested and it is evident that this type of hydrometallurgy is likely to find a happy application in the not-too-far distant future. Caron's two papers practically amount to a summation of his life's work on the important subject of nickeliferous iron ores and the American Institute of Mining and Metallurgical Engineers is fortunate to have been chosen the medium of publication. M. Rey—The ammonia leaching process has been the subject of certain studies in New Caledonia, but at the present time, the conditions are not very favorable to its adoption. The process is a combination of a thermal and a hydrometallurgical process. As a result, the first costs and the operative costs are rather high. To counteract this unfavorable situation, it would be necessary to make a very high extraction. But unfortunately, the process is delicate and in spite of all of Caron's valuable work, there are still many unknown factors. It is difficult to obtain regularly a high extraction, exceeding 75 to 80 pct. It would be interesting to have the opinion of Inter-national Nickel on the process and to know what the Dutch are doing in Celebes. M. H. Caron (author's reply)—I am quite familiar with the different types of nickel and cobalt ores as found on New Caledonia, and it may be pointed out that the Celebes ores are quite the same in their properties. Their behavior when treating the ores by the ammonia-leaching process is also alike and in my opinion, there is no reason why a high extraction of the New Caledonian ores could not be obtained if the process is properly applied. For the sake of completeness I may add that one of my patents has not been discussed in the papers. This patent deals particularly with the treatment of serpentine nickel ores. (Netherlands No. 62693 40a, French No. 965.786 April 21. 1948. and Cuban No. 13.625 Jan. 1950.)

Jan 1, 1951

By Cecil Hagen

All of the production for Ecuador during 1940 came from the Santa Elena Peninsula, Province of Guayas; the major portion coming from the Ancon field, which is controlled mostly by Anglo-Ecuadorian Oilfields, Ltd. A small amount was produced from the shallow pumpers and pozos, or oil pits, at Cautivo-Achallan, Carolina, Santa Paula, Concepcion, El Tambo and Mina Tigre. Considerable exploration was carried on in the country during 1940 and numerous concessions were in force, as shown by the accompanyiag map. Anglo-Saxon continued its exploratory work in the Oriente by surface geological methods and some geophysical surveys. It is understood that this concern did considerable airplane mapping. International Petroleum, on its large concessions between the Andes and Pacific Coast, did considerable surface work as well as some geophysical. No exploratory test wells were drilled by either of these

Jan 1, 1941

By Cecil Hagen

All of the production for Ecuador during 1940 came from the Santa Elena Peninsula, Province of Guayas; the major portion coming from the Ancon field, which is controlled mostly by Anglo-Ecuadorian Oilfields, Ltd. A small amount was produced from the shallow pumpers and pozos, or oil pits, at Cautivo-Achallan, Carolina, Santa Paula, Concepcion, El Tambo and Mina Tigre. Considerable exploration was carried on in the country during 1940 and numerous concessions were in force, as shown by the accompanyiag map. Anglo-Saxon continued its exploratory work in the Oriente by surface geological methods and some geophysical surveys. It is understood that this concern did considerable airplane mapping. International Petroleum, on its large concessions between the Andes and Pacific Coast, did considerable surface work as well as some geophysical. No exploratory test wells were drilled by either of these

Jan 1, 1941

Optimism over the continued growth of coal ex- ports received a significant shot in the arm September 18 at Norfolk, Va., when huge, new ship coal-loading facilities of the Norfolk & Western Railway were formally dedicated before a large audience of American and foreign dignitaries. Guest of Honor at the occasion was Christian A. Herter, Special Representative for Trade Negotiations, who, in a speech, stated, "The prospects for the expansion of our coal exports are excellent. The competitive pricing and high quality of our coals, whether for the production of coke for steel mills or for the generation of electric power, have won the respect of consumers everywhere in the world. Last year, the United States coal industry exported over 40 million net tons. . . . There are excellent reasons to believe that by 1970 we shall be exporting at double this rate."

Jan 10, 1963

By Harry C. Swanson

TRANSPORTING concrete from mixer to forms has always been a problem. Twenty-five years ago this task was generally accomplished by means of wheelbarrow or concrete buggy. On large dam jobs, as the number of these projects increased, the gantry crane or highline came into use. Today several methods of handling concrete are employed on smaller surface construction jobs, for example, transit-mix trucks or dumpcrete trucks, which have crawler cranes with buckets for placing concrete into forms. In 1944, during early stages of developing Mather mine A shaft, several large underground concrete jobs were necessary. At this time the Cleveland-Cliffs Iron Co, purchased the first pump-crete machine, introduced by the Chain Belt Co. of Milwaukee. The machine was used to pour approximately 200 cu yd of concrete for a dam, or bulkhead, located 400 ft from the shaft. Concrete was mixed on surface, lowered down the shaft 1000 ft in a 2-cu yd bucket hung under one skip, spouted into the bowl of the pumpcrete machine from the bucket, and pumped directly into the forms. Since the day of the first pipeline concrete in 1944 to the present time, other equipment and other methods have been developed to permit transportation of concrete by pipeline through vertical and horizontal distances totaling 1 mile from mixer to forms. Much of the efficiency in present handling of underground concrete can be credited to the Bethlehem Cornwall mines, where concrete was transported through 6-in. pipe for great distances down an inclined shaft and along levels into forms.' During initial development of Mather mine B shaft, with concrete work under way on two or more levels at one time, the pneumatic concrete placer, Fig. 1, was selected as best adapted for underground concrete transportation. The 3/4-cu yd pneumatic placer is a small machine readily moved from one location in the mine to another. It can be equipped with two sets of mine car wheels, which will permit moving on regular mine tracks. It is therefore possible to send concrete through the pipe at great velocity; the pipeline is clean after each shot except for the film of cement adhering to the inside. With the proper slump in the concrete, it is possible to shoot concrete 2000 ft with this machine, using the mine supply of compressed air at 95 psi. This equipment was first used at Mather mine B shaft to concrete slusher drifts, Figs. 2 and 3, and finger raises located about 2000 ft from the shaft. In several instances there were bends into crosscuts and up vertical distances into the forms. For the first pours two placers were used. The first was located near the shaft where the concrete could be spouted into it from a 2-cu yd concrete bucket on the cage. The second was set on the side of the drift at a point approximately 1500 ft from the shaft. The concrete was shot directly into the second placer from the first unit and from the second machine directly into the forms. After completion of several pours with the two machines, a trial pour with only one placer located at the shaft proved that the second placer could be eliminated. Since then all pours have been successfully completed with only one placer underground. As production of iron ore from the mine increased and the development program expanded, use of the cage for handling mine supplies and concrete became a major problem. This brought about the first attempt at shooting concrete vertically down the shaft for 2600 ft. A 6-in. pipeline with victaulic couplings installed during shaft sinking was used for the trial. One placer was set on surface 250 ft from the collar of the shaft so concrete could be spouted directly into it from the mixer. This machine shot the concrete 250 ft horizontally on surface to the shaft, 2600 ft vertically down the shaft, and 100 ft horizontally into the second placer located near the rib of the shaft station or plat. The second machine shot the batch into the forms, about 2000 ft. Total distance horizontally and vertically was 4800 ft. The entire time cycle for a ¾-cu yd batch of concrete from the mixer on surface to the forms underground totaled about 5 min. During the past two years the two-placer method from the mixer on surface to the forms underground has proved a very efficient means of transporting underground concrete. Advantages of using pipeline concrete are as follows: 1—Interference with normal mining operation is eliminated. When the cage, skips, mine cars, or mine openings are used for transporting concrete and materials used for making concrete, mine operation suffers in one way or another.

Jan 1, 1955

By AIME AIME

THE name of Dr. Henry Sturgis Drinker has been added to the short list of Honorary Members of the American Institute of Mining and Metallurgical Engineers, a signal honor rightfully bestowed. To quote the Philadelphia Inquirer, "It is essentially a recognition of the highest achievements, the greatest benefits, and most deserving personalities among engineers themselves." The regard in which Doctor Drinker is held by his friends and associates is reflected in the following comments of the press: Doctor Drinker is distinguished far beyond the confines of Bethlehem and of Lehigh University, to the development of

Jan 1, 1921

By Walter Miller

Any annual review of engineering progress in petroleum refining must of necessity include many features mentioned in earlier reviews. Advances do not spring mushroom fashion to wide acceptance overnight, but rather resemble rolling snowballs, gathering size and velocity as they progress. The new ideas of one year develop through the course of scattered adoption and testing during following years, to be ultimately discarded or to become an integral part of refinery engineering and operation. Polymerization and Cracking As an illustration, the publicity given to the polymerization and cracking of petroleum gases during the year has given many the impression that this is a new art. But patent and technical literature have disclosed active work on the problem dating back a decade or more and a unit capable of making 100 bbl. a day of polymer gasoline was constructed as early as 1930. Important strides have been made during 1935 looking to the more general commercialization of available processes, and some four important groups are furthering this work. In addition to the production of liquid products for inclusion as a constituent of commercial motor fuel, polymerization has also been a factor leading to the installation of a plant at the Houston refinery of The Shell Petroleum Corporation for manufacturing isooctane for aviation use, by making available dibutylene for catalytic hydrogenation Polymerization is not confined to unsaturated hydrocarbon gases as a source of raw material, and has been extended to include a preliminary decomposition of normal saturated gases under suitable heat and pressure conditions into the unsaturated types, which can then be used as raw material for the polymerization process. Thus there is opened up the possibility of eventually using large quantities of natural gas in the manufacture of high-grade motor fuels, although the early commercial growth will be largely on cracking still gases for economic reasons. Such utilization will result in a somewhat lowered drain on crude-oil reserves and a partial elimination of the

Jan 1, 1936

By Walter Miller

Any annual review of engineering progress in petroleum refining must of necessity include many features mentioned in earlier reviews. Advances do not spring mushroom fashion to wide acceptance overnight, but rather resemble rolling snowballs, gathering size and velocity as they progress. The new ideas of one year develop through the course of scattered adoption and testing during following years, to be ultimately discarded or to become an integral part of refinery engineering and operation. Polymerization and Cracking As an illustration, the publicity given to the polymerization and cracking of petroleum gases during the year has given many the impression that this is a new art. But patent and technical literature have disclosed active work on the problem dating back a decade or more and a unit capable of making 100 bbl. a day of polymer gasoline was constructed as early as 1930. Important strides have been made during 1935 looking to the more general commercialization of available processes, and some four important groups are furthering this work. In addition to the production of liquid products for inclusion as a constituent of commercial motor fuel, polymerization has also been a factor leading to the installation of a plant at the Houston refinery of The Shell Petroleum Corporation for manufacturing isooctane for aviation use, by making available dibutylene for catalytic hydrogenation Polymerization is not confined to unsaturated hydrocarbon gases as a source of raw material, and has been extended to include a preliminary decomposition of normal saturated gases under suitable heat and pressure conditions into the unsaturated types, which can then be used as raw material for the polymerization process. Thus there is opened up the possibility of eventually using large quantities of natural gas in the manufacture of high-grade motor fuels, although the early commercial growth will be largely on cracking still gases for economic reasons. Such utilization will result in a somewhat lowered drain on crude-oil reserves and a partial elimination of the

Jan 1, 1936

By F. Z. Schellenberg

Systematic exploitation in the Pittsburg coal-seam on a large scale is simple where the boundaries of the property do not interfere by forcing drainage-, ventilation-, and transport-lines of entries to be run to particular confined fronts. A prime condition governing development is the natural direction of the seam's perpendicular cleavage-planes, giving long lines of smooth faces near together and parallel, bearing about 65' to the left of the meridian and therefore crossing the basins. The gradients of dip into the basins change from 10 per cent. at the east rim to practical flatness northwestward across the great coal-fields, a hundred miles wide; the dip being halved in rate at each successive crossing-over of an anticlinal crest. Elevations above sea-level on this transverse section, in scope of present development, differ by 1,000 ft. between low trough and high outcrop. Local irregularities of dip are found, but the main feature to be recognized is the pitch of the basins—the general rise northeastward at 20 ft. per mile, from 100 ft. below sea-level at the low point near the SW. corner of Pennsylvania to 1,500 ft. and more above tide, and the appearance then, at the surface, of the lower coal-seams carried in the next deeper-lying thousand feet of rock-measures; below which series come the oil- and gas-sands of Oliphant's charted column of strata, reaching down altogether 3,000 ft. below the Pittsburg coal-seam. Because of the general regularity of occurrence of the coal-seam, the mine-map depicting the courses of economic operation to be undertaken and the steps in controlled exhaustion, need be but a projection of two dimensions on the horizontal plane of space, and this for the most part composed of natural, almost unbroken lines, on the face and on the end of the coal, co-ordinating rectangularly.

Jan 1, 1911

By W. J. Sharwood

IN the cyanide process, gold and silver are dissolved from crushed ore as double alkali-metal cyanides, from which they may he precipitated by such positive metals as sodium (amalgam), aluminum, or zinc, or by electrolysis. Two extreme conditions may he noted. Some works, especially slime plants practising decantation, use a relatively large volume of solution-possibly 4 or 5 tons per ton of ore-nearly all of which may require precipitation, so that the solutions handled are of much lower value per ton than the ore. On the other hand, in some leaching plants it is possible to extract with very little solution, and to percolate some of this more than once through the charge before precipitation, so that the solution to be precipitated may he much less than half the weight of ore, and proportionally richer. Solution intended for further use need not have all its precious metal removed, but any that has to be thrown away should be impoverished as far as is economically possible. In spite of certain advantages possessed by other precipitants, zinc in some form has been almost universally used. In some of the first attempts to utilize cyanides as gold solvents, a "piece or plate of zinc" was suggested as a precipitant, but extension of surface was early recognized as a desideratum. Macarthur and the Forrests adopted a "metallurgical filter" of zinc shaving, turned from disks or rolled sheets. They had previously experimented on other forms of zinc, and Macarthur records having tried zinc dust, which had of course been long known as a general reducing agent. It had also been known and used as a precipitant of precious metal from plating and photographic solutions, and comminuted zinc had been patented for recovering copper, etc., from ore leaches. Other inventors proposed the virtual making of zinc powder by the attrition of balls of zinc, and by similar means, during the passage of a stream of gold-bearing solution.

Jan 9, 1917

By Manuel Eissler

The material presented in this paper is an abstract of a thesis submitted by the writer to the faculty of the Massachusetts Institute of Technology, as part requirement for the degree of Master of Science. The investigation was undertaken at the suggestion of Prof. H. 0. Hofman, and it was conducted, under his direction, in the laboratories of the Mining Department of the Institute. The purpose of the work was, first, to study some of the reactions that have been considered as a part of the mechanism of the chloridiz-ing roast, and second, to study the conditions under which nickel oxide and copper oxide may be chloridized. While the production of chlorine gas by various reactions during the chloridizing roast may not be primarily useful in the chloridation of metal oxides and compounds, it nevertheless serves a useful purpose in preventing the dissociation and decomposition of chlorides once they have been formed; for example, the dissociation of cupric chloride into cuprous chloride and chlorine. Therefore it was thought that a study of some chlorine-producing reactions would prove of interest, and the first series of experiments dealt with this phase of the subject. he object of the latter part of the work was to show the possibility of treating heavy sulphide ores, such as those of Sudbury, Ontario, containing much iron and small amounts of copper and nickel, by chloridizing and removing the copper, leaving an iron-nickel oxide product suitable for smelting in the blast furnace for nickel-bearing pig iron. The chloridizing of the copper would, of course, be preceded by a roast for the removal of sulphur, the sulphur oxides being available for the manufacture of sulphuric acid, if under the local conditions this product would be of commercial value. Reactions of the Chloridizing Roast Reaction of Sodium Chloride, Sulphur Trioxide, and Oxygen.—The first reaction studied was that involving the production of chlorine

Jan 1, 1915