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By A. I. Blank, S. E. Maddigan

Many experimental and theoretical investigations have been made on the processes involved in annealing and recrystallization of metals. Most of these, however, have treated the time element as constant and heat-treatments used have been for relatively short times. Aside from the early work by Carpenter and Elam,' the few that have investigated the effect of time on the processes have usually done so for fairly short time periods. During recent years the growing interest in long-time creep properties of metals and alloys under stress has made increasingly important a better knowledge of the recrystallization during prolonged heating. The recrystallization temperature of 70-30 brass given by Clark and White" in 1932 was somewhat above 400°F. (204°C.) but under 500" (260°C.), whereas in our laboratory recrystallization has been observed in creep specimens at 204°C., the lowest temperature of Clark and White's range. Since the creep properties are quite different above and below the recrystallization temperature, erroneous conclusions can readily be drawn by the application of short-time recrystallization data to creep problems. It was thus considered of both practical and theoretical value to make long-time annealing studies near the minimum recrystallization temperature. In this way useful additions could be made to data on recrystallization temperatures and, since the reactions in this range are relatively slow, additional insight could be obtained into the factors involved in annealing. Several comprehensive reviews of recrystallization processes have been written,3-6 therefore only a brief review of the generally accepted facts will be given here. Though the effects of heat-treatment usually are expressed as related to observations with varying temperatures, it is logical to assume that the same order of occurrence will exist with time as a variable. Thus, we may postulate that with increasing time we mill observe the following

Jan 1, 1940

By S. E. Maddigan, A. I. Blank

Many experimental and theoretical investigations have been made on the processes involved in annealing and recrystallization of metals. Most of these, however, have treated the time element as constant and heat-treatments used have been for relatively short times. Aside from the early work by Carpenter and Elam,' the few that have investigated the effect of time on the processes have usually done so for fairly short time periods. During recent years the growing interest in long-time creep properties of metals and alloys under stress has made increasingly important a better knowledge of the recrystallization during prolonged heating. The recrystallization temperature of 70-30 brass given by Clark and White" in 1932 was somewhat above 400°F. (204°C.) but under 500" (260°C.), whereas in our laboratory recrystallization has been observed in creep specimens at 204°C., the lowest temperature of Clark and White's range. Since the creep properties are quite different above and below the recrystallization temperature, erroneous conclusions can readily be drawn by the application of short-time recrystallization data to creep problems. It was thus considered of both practical and theoretical value to make long-time annealing studies near the minimum recrystallization temperature. In this way useful additions could be made to data on recrystallization temperatures and, since the reactions in this range are relatively slow, additional insight could be obtained into the factors involved in annealing. Several comprehensive reviews of recrystallization processes have been written,3-6 therefore only a brief review of the generally accepted facts will be given here. Though the effects of heat-treatment usually are expressed as related to observations with varying temperatures, it is logical to assume that the same order of occurrence will exist with time as a variable. Thus, we may postulate that with increasing time we mill observe the following

Jan 1, 1940

By T. B. Counselman

An iron blast furnace of 1000 tons daily capacity will produce a 100,000 cu. ft. per minute of blast-furnace gas. This contains a 25 per cent of carbon monoxide, and has a B.t.u. value of about 95. gas is used primarily for heating the stoves of the blast furnace, secondarily, under boilers, for steam production. Occasionally it is used in gas engines. The raw gas coming out of the furnace carries about 10 grains of dust per cubic foot of gas, under best operating conditions. With furnace "rolling" or slipping, this quantity may temporarily be gre increased. This dust would, of course, deposit on the checkers o: stoves, or plug the burners under the boilers; therefore the gas : be cleaned. Flow Sheet The first step in the cleaning operation, as shown by the flow s Fig. 1, is a dry dust catcher, of which there are several forms, partially cleaned gas next goes to a primary wet washer, where v sprays knock down most of the solid particles. If further cleani desired, the gas may then go to electrical precipitation. Again, the removed is collected in water. Dry dust catchers reduce the dust col from 10 grains to between 4 and 6 grains per cubic foot, and rec roughly half of the total flue dust in the gas. The wet washers rea most of the remaining dust, reducing the dust content to about 1/4 per cubic foot. Electrical precipitators, if used, further reduce the content to about 0.01 grain per cubic foot of gas. The flow sheet s the dust content of the gas at various steps in the treatment and als content of solids in the water. It should be noted that some plant less water on the primary wet washer than indicated, and that ofte solids content of the scrubber water will be 300 grains per gallon, or much higher. Reasons for Recovering Flue Dust.—There are two main incentive recovering flue dust from the scrubber water: (1) the value of the (2) stream or lake pollution, where such a reason applies.

Jan 1, 1937

By L.W. Eastwood, Arthur E. Bousu, C. T. Eddy

The recrystallization and grain-growth phenomena of cold-worked metals have considerable industrial importance because of their role in the fabrication of metals. For this reason, and because of the general academic interest in the subject, these processes have received considerable attention since the time of J. E. Stead's paper1 on The Crystalline Structure of Iron and Steel. There are considerable differences of opinion regarding the theory of recrystallization and grain growth and also differences in the observation of the modus operandi of the processes themselves. The value of many of the existing quantitative data on grain growth is decreased by the failure to distinguish between the grain sizes just after complete recrystallization and those resulting from coalescence. For this reason also, the value of the diagrams of stable grain sizes, like those produced by Bass and Glocker2 and Czochralski3, is lessened in so far as an interpretation of the facts of recrystallization is concerned. It is hoped that the data presentcd in this paper will help to clarify and to simplify the facts relating to recrystallization, and at the same time will show that some of the present-day conceptions are untenable. A paper on the theory of recrystallization, with additional data, will be completed in the near future by the writers. Since the literature on the subject has been adequately and frequently reviewed, the only referenccs to it in this paper will be those necessary in the discussion of the data presented.

Jan 1, 1935

By Arthur E. Bousu, C. T. Eddy, L. W. Eastwood

The recrystallization and grain-growth phenomena of cold-worked metals have considerable industrial importance because of their role in the fabrication of metals. For this reason, and because of the general academic interest in the subject, these processes have received considerable attention since the time of J. E. Stead's paper1 on The Crystalline Structure of Iron and Steel. There are considerable differences of opinion regarding the theory of recrystallization and grain growth and also differences in the observation of the modus operandi of the processes themselves. The value of many of the existing quantitative data on grain growth is decreased by the failure to distinguish between the grain sizes just after complete recrystallization and those resulting from coalescence. For this reason also, the value of the diagrams of stable grain sizes, like those produced by Bass and Glocker2 and Czochralski3, is lessened in so far as an interpretation of the facts of recrystallization is concerned. It is hoped that the data presentcd in this paper will help to clarify and to simplify the facts relating to recrystallization, and at the same time will show that some of the present-day conceptions are untenable. A paper on the theory of recrystallization, with additional data, will be completed in the near future by the writers. Since the literature on the subject has been adequately and frequently reviewed, the only referenccs to it in this paper will be those necessary in the discussion of the data presented.

Jan 1, 1935

By J. E. Burke, C. W. Mason

In attempting to study precipitation from a tetragonal lattice, using solid solutione of bismuth in tin, it was found that although a Widmanstätten pattern is observed1,4 only a qualitative analysis of the orientation relationships is possible, because of the unusual structural changes that accompany the precipitation process. Microscopical Studies Alloys were made from Chempur tin (Standard samples 42b and 426, National Bureau of Standards), and bismuth (Kahl-baum C.P.) by melting weighed quantities together under palm oil, stirring well, and castilig in a heated graphite mold. The polishing and etching techniques employed largely govern the visibility of the structural changes. The preliminary surfacing operations were similar to those recommended by Villela and Bergekoff,5 through Behr-Manning 3/0 abrasive papers, lubricated by a solution of paraffin in kerosene. A rough metallographic polish was next given, using a thin cotton cloth charged with relevigated alumina (maximum particle size of about 4µ) and soap solution; repeated etching and polishing served to remove disturbed metal. For high-power examination better preparation was necessary. It was found that on such soft metals the threads of the fabric, rather than the abrasive, cause most of the scratching. Cotton outing flannel, which had been brushed so that the nap lay down, was fairly satisfactory, but a heavy grade of silk velvet (not the noncrushable kind) was found to be better, especially after some use. A better procedure was as follows: The metal lap was warmed slightly, and a 4-in. circle of woolen broadcloth was cemented to its center by a thin film of melted paraffin. The broadcloth was then moistened with water, and a 30 to 40 per cent solution of sodium hydroxide heated to about 50°C. was poured over it, allowed to stand for I to 2 min. and then washed off. It was neither necessary nor desirable to remove all the sodium hydroxide from the cloth, since its etching action aided in the removal of the flowed layer from the sample. The cloth was then charged with a paste of the relevigated alumina in water. Since this lap did not remove deep scratches, it was necessary previously to polish the specimen on some material such as the silk velvet. The sodium hydroxide softens and partly gelatinizes the woolen lap covering, permitting a scratch-free polish, but its action continues, and the cloth deterioratcs after about 24 hr. This is not serious, because a new lap can be prepared in about 5 min., and only small pieces of cloth are used. Etching with a strongly acid solution of ferric chloride was found satisfactory for removing the flowed layer. For the final etching, the most satisfactory reagent was that of Tafls,7 the formula for which is: FeC13.6H2O, 2 grams; HC1, 5 c.c.; H2O, 30 c.c.; C2H5OH (95 per cent), 60 C.C. This etchant reveals differences in com-

Jan 1, 1942

By J. E. Burke, C. W. Mason

In attempting to study precipitation from a tetragonal lattice, using solid solutione of bismuth in tin, it was found that although a Widmanstätten pattern is observed1,4 only a qualitative analysis of the orientation relationships is possible, because of the unusual structural changes that accompany the precipitation process. Microscopical Studies Alloys were made from Chempur tin (Standard samples 42b and 426, National Bureau of Standards), and bismuth (Kahl-baum C.P.) by melting weighed quantities together under palm oil, stirring well, and castilig in a heated graphite mold. The polishing and etching techniques employed largely govern the visibility of the structural changes. The preliminary surfacing operations were similar to those recommended by Villela and Bergekoff,5 through Behr-Manning 3/0 abrasive papers, lubricated by a solution of paraffin in kerosene. A rough metallographic polish was next given, using a thin cotton cloth charged with relevigated alumina (maximum particle size of about 4µ) and soap solution; repeated etching and polishing served to remove disturbed metal. For high-power examination better preparation was necessary. It was found that on such soft metals the threads of the fabric, rather than the abrasive, cause most of the scratching. Cotton outing flannel, which had been brushed so that the nap lay down, was fairly satisfactory, but a heavy grade of silk velvet (not the noncrushable kind) was found to be better, especially after some use. A better procedure was as follows: The metal lap was warmed slightly, and a 4-in. circle of woolen broadcloth was cemented to its center by a thin film of melted paraffin. The broadcloth was then moistened with water, and a 30 to 40 per cent solution of sodium hydroxide heated to about 50°C. was poured over it, allowed to stand for I to 2 min. and then washed off. It was neither necessary nor desirable to remove all the sodium hydroxide from the cloth, since its etching action aided in the removal of the flowed layer from the sample. The cloth was then charged with a paste of the relevigated alumina in water. Since this lap did not remove deep scratches, it was necessary previously to polish the specimen on some material such as the silk velvet. The sodium hydroxide softens and partly gelatinizes the woolen lap covering, permitting a scratch-free polish, but its action continues, and the cloth deterioratcs after about 24 hr. This is not serious, because a new lap can be prepared in about 5 min., and only small pieces of cloth are used. Etching with a strongly acid solution of ferric chloride was found satisfactory for removing the flowed layer. For the final etching, the most satisfactory reagent was that of Tafls,7 the formula for which is: FeC13.6H2O, 2 grams; HC1, 5 c.c.; H2O, 30 c.c.; C2H5OH (95 per cent), 60 C.C. This etchant reveals differences in com-

Jan 1, 1942

By Paul A. Beck

While the recrystallization properties of most of the practically important metals are known in considerable detail, those of lead are still relatively little known in spite of some valuable contributions in recent years. This condition probably is due to the difficulties involved in applying the usual methods of investigation. The microscopic method of discriminating between the elongated deformed grains of the familiar lenticular shape and the equiaxed recrys-tallized grains is not successful with fully refined lead: lenticular grains cannot be seen under the microscope with any amount of deformation whatever. The probable cause of this phenomenon was recognized long ago. With large deformation the time of recrystallization at room temperaturc is shorter than the period of preparation of the specimen for microscopic examination; with small deformation the deformed grains arc not noticeably elongated in the first place. However, with small cleformation the migration of the grain boundaries can be observed. The only systematic investigations yet published on the recrystallization of lead, those by R. S. Russell, 1-3 make use of the conditions just described. Russell considered recrystallization completed when no further migration of boundaries could be observed. A serious objection to this method arises from the fact that there is no evidence to support the view that grain-boundary migration results only from recrystallization. If such migration does result from other sources after recrystallization is completed—after the deformed grains have been replaced by new unde-formed grains—the "time of recrystallization" as determined by Russell may be too long. Furthermore, the method is subject to the above.-mentioned limitation because of the unavoidable period of preparation of the sample. According to Russell, even with the fastest technique 5 min. clapsed before the deformed samples were ready for examination, and consequently no reearystallization time shorter than 5 min. could be measured. The lack of success in detecting the recrystallization of lead by the usual hardness or tensile tests is again caused by the time necessary for

Jan 1, 1940

By Paul A. Beck

While the recrystallization properties of most of the practically important metals are known in considerable detail, those of lead are still relatively little known in spite of some valuable contributions in recent years. This condition probably is due to the difficulties involved in applying the usual methods of investigation. The microscopic method of discriminating between the elongated deformed grains of the familiar lenticular shape and the equiaxed recrys-tallized grains is not successful with fully refined lead: lenticular grains cannot be seen under the microscope with any amount of deformation whatever. The probable cause of this phenomenon was recognized long ago. With large deformation the time of recrystallization at room temperaturc is shorter than the period of preparation of the specimen for microscopic examination; with small deformation the deformed grains arc not noticeably elongated in the first place. However, with small cleformation the migration of the grain boundaries can be observed. The only systematic investigations yet published on the recrystallization of lead, those by R. S. Russell, 1-3 make use of the conditions just described. Russell considered recrystallization completed when no further migration of boundaries could be observed. A serious objection to this method arises from the fact that there is no evidence to support the view that grain-boundary migration results only from recrystallization. If such migration does result from other sources after recrystallization is completed—after the deformed grains have been replaced by new unde-formed grains—the "time of recrystallization" as determined by Russell may be too long. Furthermore, the method is subject to the above.-mentioned limitation because of the unavoidable period of preparation of the sample. According to Russell, even with the fastest technique 5 min. clapsed before the deformed samples were ready for examination, and consequently no reearystallization time shorter than 5 min. could be measured. The lack of success in detecting the recrystallization of lead by the usual hardness or tensile tests is again caused by the time necessary for

Jan 1, 1940

By Charles S. Barrett

Recrystallization textures—thc orientations of grains after recrys-tallization—have been studied extensively not only because of their metallurgical importance but also because of the information they yield regarding the atomic movements during reerystallization. Recrystallized grains must possess the same orientations as the submicroscopic nuclei from which they have grown, and thus they offer a direet road by which experimenters can penetrate the submicroscopic realm. Many perplexing results have come of these studies, but one of the most striking has been the apparent difference in behavior between single crystals and polyerystalline grains. For example, Burgers and Louwerse have shown1 that when single crystals of aluminum are deformed by compression and are reerystallized (at 600' C.) the new grains appear with orientations that are different from the orientations of the deformed crystal in which they grew; but polycrystalline specimens, on the other hand, appear to have a [110] fiber texture both before and after reerystallization and thus to retain their texture during recrystallization. This apparent difference between the habits of single crystals and small grains is the subject of the first part of the present research and has been explained by findings reported herein. A similar situation appears to exist for aluminum when elongated or drawn into wires, for single crystals alter their orientation 2,3 and polycrystalline wires retain their texture"5*" upon recrystallization after elongation (at least with high-purity aluminum), and it is possible that the explanation found in this paper for compression can be extended to cover elongatioil and other types of deformation as well. The second part of this paper deals with the theory of reerystallization textures. In the most successful theory for aluminum reerystallized after compression,1 much weight is given to the orientation of highly stressed nuclei in the deformed material. Taylor's "local distortions" arc assumed to exist along the slip planes where displacement has occurred, consisting of fragments rotated in a specific way with reference to the slip plane and slip direction; namely, about an axis lying in the slip plane perpendicular to the slip direction.1,7,89

Jan 1, 1940

By Charles S. Barrett

Recrystallization textures—thc orientations of grains after recrys-tallization—have been studied extensively not only because of their metallurgical importance but also because of the information they yield regarding the atomic movements during reerystallization. Recrystallized grains must possess the same orientations as the submicroscopic nuclei from which they have grown, and thus they offer a direet road by which experimenters can penetrate the submicroscopic realm. Many perplexing results have come of these studies, but one of the most striking has been the apparent difference in behavior between single crystals and polyerystalline grains. For example, Burgers and Louwerse have shown1 that when single crystals of aluminum are deformed by compression and are reerystallized (at 600' C.) the new grains appear with orientations that are different from the orientations of the deformed crystal in which they grew; but polycrystalline specimens, on the other hand, appear to have a [110] fiber texture both before and after reerystallization and thus to retain their texture during recrystallization. This apparent difference between the habits of single crystals and small grains is the subject of the first part of the present research and has been explained by findings reported herein. A similar situation appears to exist for aluminum when elongated or drawn into wires, for single crystals alter their orientation 2,3 and polycrystalline wires retain their texture"5*" upon recrystallization after elongation (at least with high-purity aluminum), and it is possible that the explanation found in this paper for compression can be extended to cover elongatioil and other types of deformation as well. The second part of this paper deals with the theory of reerystallization textures. In the most successful theory for aluminum reerystallized after compression,1 much weight is given to the orientation of highly stressed nuclei in the deformed material. Taylor's "local distortions" arc assumed to exist along the slip planes where displacement has occurred, consisting of fragments rotated in a specific way with reference to the slip plane and slip direction; namely, about an axis lying in the slip plane perpendicular to the slip direction.1,7,89

Jan 1, 1940

By Michael Tenenbaum, T. L. Joseph

In a previous investigation1 the authors studied the effect of pressure on the reduction of iron ores by hydrogen. With hydrogen as a reducing agent, the rate of reduction was increased substantially by increasing the pressure from 1 to 2 atmospheres. The results with hydrogen prompted the present study of the effect of pressure on reduction with carbon monoxide and with mixtures of carbon monoxide and nitrogen. Features of Reduction Process The gas stream in the lower part of the blast furnace always contains sufficient concentrations of reducing gases to complete reduction provided sufficient time is allowed for the reaction to proceed. Reducing gases react immediately with the iron oxide on the surface of lumps of ore. However, as the unreduced surface recedes from the easily accessible exterior of the lump, the reaction proceeds by virtue of the diffusion of the gases into and out of individual pieces. The rate of diffusion of gases, which undoubtedly plays an important role in the reduction of iron ores, depends on several factors, most important of which are: (1) molecular weight or density, (2) pressure, (3) temperature, (4) concentration gradient. Thus, the rate of reduction of a lump of iron ore at any temperature will depend not only on the specific reaction rate but also upon: (1) available surface of unreduced iron oxide, (2) rate of diffusion of the reducing gas to the reacting surface, (3) rate of effusion of the gaseous products of the reaction from the reacting surface, (4) adsorption of the gases on the reacting surface. The various features of the reduction process were discussed in previous work and need not be reviewed. However, in order to explain

Jan 1, 1940

By Michael Tenenbaum, T. L. Joseph

In a previous investigation1 the authors studied the effect of pressure on the reduction of iron ores by hydrogen. With hydrogen as a reducing agent, the rate of reduction was increased substantially by increasing the pressure from 1 to 2 atmospheres. The results with hydrogen prompted the present study of the effect of pressure on reduction with carbon monoxide and with mixtures of carbon monoxide and nitrogen. Features of Reduction Process The gas stream in the lower part of the blast furnace always contains sufficient concentrations of reducing gases to complete reduction provided sufficient time is allowed for the reaction to proceed. Reducing gases react immediately with the iron oxide on the surface of lumps of ore. However, as the unreduced surface recedes from the easily accessible exterior of the lump, the reaction proceeds by virtue of the diffusion of the gases into and out of individual pieces. The rate of diffusion of gases, which undoubtedly plays an important role in the reduction of iron ores, depends on several factors, most important of which are: (1) molecular weight or density, (2) pressure, (3) temperature, (4) concentration gradient. Thus, the rate of reduction of a lump of iron ore at any temperature will depend not only on the specific reaction rate but also upon: (1) available surface of unreduced iron oxide, (2) rate of diffusion of the reducing gas to the reacting surface, (3) rate of effusion of the gaseous products of the reaction from the reacting surface, (4) adsorption of the gases on the reacting surface. The various features of the reduction process were discussed in previous work and need not be reviewed. However, in order to explain

Jan 1, 1940

By Michael Tenenbaum, T. L. Joseph

Recent researches on the reduction of iron ores have stimulated interest in the effect of increased pressures within the iron blast furnace. From a physicochemical viewpoint, it seems logical to suppose that the increased pressure would increase the rate of reduction of the iron ore within the furnace. This increased reaction velocity would in turn be reflected in an increase in the output of the blast furnace. Any substantial effect of elevated blast-furnace pressures should accordingly be of both technical and economic interest to the operator. It is doubtful whether it is possible to increase the pressure in the stack of the blast furnace beyond two or three atmospheres without incurring severe mechanical difficulties. The benefits to be procured by elevations in pressure must therefore be restricted to pressures below two, or at the most, three atmospheres. Within this range it would seem both economically and mechanically feasible to modify the present design of the upper portion of the blast furnace to accommodate these more stringent operating conditions. This investigation was undertaken to study the effect of moderate pressures on the rate of reduction of iron ore with hydrogen. The use of carbon monoxide is contemplated for later work. Although any results that are obtained in the laboratory cannot be interpreted directly in terms of large-scale commercial operations, it is possible, through such an investigation, to ascertain the order of magnitude of the effects of higher pressure. A more quantitative conception of the effects that would result from the use of increased pressures in the modern blast furnace is needed. In some recent work, Diepschlagl found that, all other factors remaining constant, the degree of reduction of iron ores was much greater when carried out under pressure. Pressures as high as seven atmospheres were used. The degree of reduction was determined from the ferrous and ferric iron in the sponge iron. Results were obtained using both carbon monoxide and hydrogen at temperatures of 400°, 600° and

Jan 1, 1939

By Michael Tenenbaum, T. L. Joseph

Recent researches on the reduction of iron ores have stimulated interest in the effect of increased pressures within the iron blast furnace. From a physicochemical viewpoint, it seems logical to suppose that the increased pressure would increase the rate of reduction of the iron ore within the furnace. This increased reaction velocity would in turn be reflected in an increase in the output of the blast furnace. Any substantial effect of elevated blast-furnace pressures should accordingly be of both technical and economic interest to the operator. It is doubtful whether it is possible to increase the pressure in the stack of the blast furnace beyond two or three atmospheres without incurring severe mechanical difficulties. The benefits to be procured by elevations in pressure must therefore be restricted to pressures below two, or at the most, three atmospheres. Within this range it would seem both economically and mechanically feasible to modify the present design of the upper portion of the blast furnace to accommodate these more stringent operating conditions. This investigation was undertaken to study the effect of moderate pressures on the rate of reduction of iron ore with hydrogen. The use of carbon monoxide is contemplated for later work. Although any results that are obtained in the laboratory cannot be interpreted directly in terms of large-scale commercial operations, it is possible, through such an investigation, to ascertain the order of magnitude of the effects of higher pressure. A more quantitative conception of the effects that would result from the use of increased pressures in the modern blast furnace is needed. In some recent work, Diepschlagl found that, all other factors remaining constant, the degree of reduction of iron ores was much greater when carried out under pressure. Pressures as high as seven atmospheres were used. The degree of reduction was determined from the ferrous and ferric iron in the sponge iron. Results were obtained using both carbon monoxide and hydrogen at temperatures of 400°, 600° and

Jan 1, 1939

By W. B. Boggs, J. N. Anderson

Originally, the copper produced at the Noranda smelter was shipped in the form of blister bars to the Laurel Hill refinery of the Nichols Copper CO, New York. In 1930 a refinery was built at Montreal East to refine Noranda copper and copper from the Hudson Bay Mining & Smelting Co., at Flin Flon, Manitoba. After investigation of the probable costs of making anodes at Noranda and at Montreal, it was decided to make them at Noranda rather than to continue to make blister bars there. Fuel is a major item of expense in making anodes, and since less fuel would be required in making them from molten copper than from blister bars, a lower anode-furnace cost could be expected at Noranda than at Montreal. Further, the expense connected -with making blister bars at Noranda would be eliminated. The cost of treating anode and wire-bar furnace slags is a serious item in a refinery, and it was found that the cheapest method would be to ship such slags back to Noranda. With the anode furnace at Noranda, much less anode-furnace slag would be made at the refinery. Against these savings effected by making anodes at Noranda must be set the high operating cost of an anode furnace at Montreal, using only tank-room scrap and the Flin Flon copper. This furnace would be handling a comparatively small tonnage and would have a high cost per ton. The usual equipment for making anodes from liquid copper consists of either a stationary reverberatory furnace or a tilting Tacoma-type furnace together with an anode wheel of the Clark or Walker type. The reverberatory type of furnace has been developed from the furnace used in the old Welsh process of smelting and refining copper, while the tilting furnace is a development of the holding furnace, which is essentially a Peirce-Smith converter without tuyeres and provided with burners. Refining as carried out in either of these furnaces is a batch process; that is, several converter charges are accumulated and then refined and cast. Colonel H. H. Stout recently developed in Arizona a so-called

Jan 1, 1934

By Frederic Benard

The electrolytic copper refinery at Copper Cliff, Ont., is operated by the Ontario Refining Co., Ltd. The associated companies behind the enterprise are the International Nickel Co. of Canada, Ltd.; The American Metal Co.; The Consolidated Mining & Smelting Co. of Canada, Ltd.; and Ventures, Ltd. The plant was the outgrowth of the rapid development of copper resources in the nickel-copper ores of the Frood and other great mines in the Sudbury district, and of the desire to have all primary production units grouped together as closely as possible. The refinery is near the intersection of the Sault Ste. Marie to Sudbury highway and the Canadian Pacific Railway. It is about one mile south of The International Nickel Company's smelter at Copper Cliff. The standard-gage track systems of the refinery and of the smelter are connected by a standard-gage timber railroad trestle that crosses the railway and the highway by means of steel girder spans. The Canadian National Railway has access to the plant by means of this trestle and the nickel company's tracks, so that the refinery has connections with both the Canadian Pacific and the Canadian National railways, as well as a direct connection with The International Nickel Company's smelter, from which the bulk of the copper to be refined is hauled by the latter's electric locomotives. Buildings The refinery (Fig. 1) covers approximately 60 acres, enclosed by an unscalable chain-link fence. The main buildings have a content of 23,000,000 cu. ft., with a total roof area of approximately 600,000 sq. ft. and near them are the substation, cooling pond and main standard-gage track system (Fig. 2). A ladder track for car storage extends 1200 ft. south of the coal-pulverizer tracks and the scale house is on this spur. The intake and pumphouse for fresh water supply are at Kelly Lake, about 3000 ft. south of the plant. Owing to the severity of the winters, when temperatures of from 20" to 40' below zero are to be expected, the building of this refinery involved a number of problems in insulation, layout, ventilation, etc., which were

Jan 1, 1934

By R. M. Murray

Although blister copper has been produced at the Mount Lyell Mining and Railway Company's works since 1896, it is only during the past five years that electrolytic refining has been undertaken locally, this having been done previously at customs refineries, at first in the United States, and afterwards at Port Kembla, New South Wales. Left to right: smelter building, converter building, blower building (in which converter-generators are housed), tank house and anode dock. Wire-bar furnace building in background at center. Possessing a hydroelectric power plant capable of generating power considerably in excess of the requirements of its mines and works at the time, the company was in a favorable position to undertake its own refining work, provided this advantage was not offset by the high cost of coal, which would have to be imported from the mainland, and provided also that the capital cost of the plant would not be unduly large in regard to the relatively small amount of copper to be treated. A study of these several conditions led to the adoption of a high-density plant using blister-copper anodes and equipped with an electric boiler to provide any

Jan 1, 1934

By H. S. McKnight

One phase of Canada's rapid development in mining and metallurgy during the past few years has been the creation of Canadian Copper Refiners Ltd., and the establishment of its modern electrolytic copper refinery at Montreal East, Quebec. Canadian Copper Refiners Ltd. is made up of three well-known metal firms whose combined activities cover the entire industry from the mine to the market. They are Noranda Mines Ltd., Toronto, Nichols Copper Co., New York, and British Metal Corporation, Ltd., London. Noranda Mines is the principal owner and provides the greater part of the raw material received by the refinery for treatment. Nichols Copper Co. designed and built the plant and is operating it under contract. British Metal Corporation acts as sales agent and markets the refinery's products. Montreal East was chosen as the site of the new refinery only after a careful survey had been made of the entire eastern part of Canada. The location chosen offers many advantages, chief of which arc the relatively low costs of power, labor, fuel and bupplies, and the fact that it is situated on Montreal harbor, the nearest seaport to the points of origin of the ram materials. All incoming material is received by rail. A majority of the plant's product is exported through the port of Montreal to European markets, being handled to the docks in railroad cars. A large proportion of the product is delivered by means of an industrial railway to the adjacent rolling mill of the Canada Wire & Cable Co., Limited. The refinery was designed to treat primarily the copper produced by Noranda Mines, Ltd. and Hudson Bay Mining &. Smelting Co., Ltd., and its rated capacity is 75,000 short tons per year. A general layout of the plant is shown in Fig. 1. Its capacity can be readily doubled, as shown by the dotted lines. Figs. 2 and 3 are sections taken through the furnace department and the tank house respectively. Except for the main office and laboratory and an auxiliary building containing the stores, warehouse, change rooms, compressor room and machine shop, the entire plant is under one roof. The type of building construction consists of reinforced concrete foundations supported on concrete piles, a steel structure covered with Robertson Protected Metal siding and a 3-in.

Jan 1, 1934

By H. F. Johnson, C. S. Harloff

The Nichols series system of electrolytic copper refining has successfully maintained its strong competitive position in the copper-refining industry of today; therefore the improvements made in accomplishing this result are of interest. While additional interest would lie in specific comparisons of results obtained in series operation with those in multiple, we have refrained from such a comparison because it can be fair to both only when they are operating under similar conditions on the same grade of materials. Historical The Nichols Copper Co. started a small refinery at Laurel Hill, using its present system, about 1892. The details of the process in its early stage of development were kept strictly secret, so that no information was published or interchange of ideas permitted with the staffs of other copper refineries, where the multiple system was being developed at the same time. However, the fundamentals of the process and type of cell used today differ very little from their earliest form. All operations including loading and unloading of tanks, and all transportation as well, were carried on by hand. The plant remained in this condition with a gradual expansion taking place until the World War forced such a rapid development that little time or thought could be devoted to modernization or mechanical improvement requiring careful design or detailed planning. Considerable progress was made, however. (1) Large refining furnaces were developed. (2) The old expensive air-lift type of circulation was abandoned in favor of the present system. (3) Operating technique was gradually developed to a high point of efficiency. (4) Tank construction and lining were greatly improved, the first concrete tank being installed in 1915. (This tank is still in operating condition.) (5) A new power plant was constructed. (6) Fuel oil was substituted for lump coal on the refining furnaces. (7) Mechanical casting of the finished product was accomplished. During this entire period the plant was particularly fortunate in receiving only high-grade, clean copper bullion coming principally from the Phelps Dodge mines in Arizona. This, together with the lack of

Jan 1, 1934