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By A. H. Larson, T. P. McNulty

RECENTLY, an investigation of the absorption of sulfur dioxide gas in molten binary copper alloys was conducted. A Sieverts-type apparatus, consisting of a mercury-filled gas dispensing buret and a mercury manometer, was used initially for determining the volume of gas absorbed as a function of pressure. The equilibration behavior of the alloys studied indicated that the mercury in the gas measuring system was absorbing sulfur dioxide. Owing to the widespread use of mercury as a displacement medium in absorption studies, an investigation was made to determine the nature and magnitude of the mercury - sulfur dioxide absorption effect. The gas measuring system was modified by substituting a Worden Quartz Products Type PDHV fused-quartz-spiral pressure gage for the mercury-filled dispenser and manometer. The dispensed gas volume at known temperature and atmospheric pressure was measured by evacuating a Pyrex vessel of known volume and by admitting sulfur dioxide into the vessel until the attached quartz pressure gage registered atmospheric pressure. Atmospheric pressure was measured concurrently with a separate mercury barometer. The volume of the empty sample chamber and its attendant apparatus was determined by measuring the equilibrium pressure accompanying the addition of a measured volume of sulfur dioxide into the initially evacuated system. The volume of the mercury sample was calculated from the density of mercury at the temperature of the study (25°C). Measured volumes of sulfur dioxide were then dispensed into the system and the equilibrium pressure accompanying each gas addition was determined. From the difference between the system volume and the mercury volume, the number of moles of gaseous sulfur dioxide remaining in the system at each pressure was calculated. The difference between the number of moles of gas dispensed into the system, denoted Enso2: and the number of moles of gas remaining in the system after absorption equilibrium had been attained, denoted nso2(g), was equal to the number of moles of absorbed gas, denoted nSO2. The number of moles of absorbed gas was then converted to absorbed volume, denoted VSo2, in cu cm at stp conditions of (PC and 760 mm Hg. Table I contains calculated values of Snso2, nSo2(g), and VSo2 for different sulfur dioxide pressures. In the original system, denoted Run I, volume limitations of the gas dispensing system prevented absorption studies at equilibrium pressures near atmospheric pressure, so a different gas dispensing system, denoted Run 11, was used for determining the last pressure reading in Table I. The data in Table I are expressed in terms of the absorption of sulfur dioxide in 49.68 cu cm of mercury. In Fig. 1, these data are expressed in terms of the absorption of sulfur dioxide in 100 cu cm of mercury. Since the absorption data plotted in Fig. 1 show a linear relationship, the volume of sulfur dioxide absorbed in mercury is a function of the first power of pressure. The absorption reaction is So2(gas) = SO2 (in Hg) The first-power pressure dependence, coupled with the fact that the sulfur dioxide could be removed from the mercury by applying vacuum, indicated reversible

Jan 1, 1967

By Frederic H. Lahee

After abandoning two dry holes, on the Mrs. Daisy Bradford land, C. M. Joiner finally completed his No. 3 on Sept. 8, 1930, at a total depth of 3592 ft. This well is 735 miles somewhat north of west of the town of Henderson, in Rusk County. Between Oct. 2 and Oct. 6, this well made numerous heads which indicated that it would produce about 300 bbl. daily. By Nov. 27, two dry holes,' completed near the Joiner well, taken in conjunction with the small production from this well, served to dampen any enthusiasm among those who hoped for a major pool; but by December 18 three other producers had been completed. On Dec. 28, 1930, E. W. Bateman's Lois Della Crim No. 1 drilled itself in with an estimated daily yield of between 10,000 and 15,000 bbl. from a depth of 3650 ft. This well, 10 miles north of the Joiner well, also in Rusk County, initiated the leasing campaign that led to the later orgy of drilling. On Jan. 25, 1931, Moncrief, Farrell and others completed their J. K. Lathrop 1 as another big producer, 7 miles east of Gladewater in Gregg County and 14 miles N. 20" E. from the Bateman Crim well. The Lathrop well, 3574 ft. deep, flowed 320 bbl. in 1 hr. through a ½in. choke. The first well completed in Smith County was Cook No. 1, drilled by Guy Lewis et al. in the James Jordan Survey, 4.7 miles west of the Joiner discovery well. On Mar. 30, 1931, it flowed 137 bbl. in 33 min, through a ¾-in. choke. The top of the pay sand was found at 3672 ft. Finally, in Upshur County, on May 5, the Mudge Oil Co. et al. completed the Richardson No. 1, which flowed 274 bbl. through a 4 2/64-in. choke in 2 hr. This well is 4 miles northwest of the Lathrop producer. Development It is unnecessary to give a lengthy description of the rapid development of the area discovered in these five far-separated wells, or to discuss the speculations offered as to whether there were several pools or only one.

Jan 1, 1932

By Frederic K. Bunton

The smelting plant of the British Columbia Copper Co. at Greenwood, B. C., now closed because of the decline in the price of copper due.to the European war, is of special interest to metallurgists for several reasons. It was successfully smelting in blast furnaces the lowest grade copper ore of all plants in America. In order to do so, it had to run at very hig~; efficiency, which necessarily required a large tonnage per square foot of hearth area, together with the minimum amount of labor and other costs. The furnaces smelted daily 2,250 tons of ore (6.62 tons per sq. ft. of hearth area), carrying 0.85 per cent. of copper, at a smelting cost of 81.18 per ton. The entire plant required 130 men to operate it and keep up repairs, showing a labor efficiency of about 17.5 Dons per man per day. In the present paper, the method of obtaining these results is shown. Most of the information contained in this description I obtained as Assistant Superintendent, during the two years preceding the present shutdown. Other sources of information to which I am indebted are: The British Columbia Copper Co., Ltd., by ALfred W. G. Wilson, in The Copper Smelting Industry of Canada; Greenwood Smelting Worlrs, by J. E. McAllister, Engineering and Mining Journal, vol. xci, pp. 1011 to 1015 (May 20, 1911); and Description of the Copper Smelter of The British Columbia Copper Co., by W. L. Bell, in Transactions of the Canadian Mining Institute, vol. xvi, pp. 151 to 154 (1913). II. Location and Connections The smelter of this company is about half a mile south of GreenGood, in the Boundary district of British Columbia, on the Columbia & Westerg branch of the Canadian Pacific Railway. It was originally built in 1900 by Paul Johnson, to handle 600 tons of ore a day in two small furnaces of 300 tons capacity; but in 1907 the old furnaces were torn out, the plant was remodeled, and three blast furnaces, 48 by 240 in. at) the tuyéres, were installed. In 1910, two of these were enlarged to 51 by

Jan 1, 1916

By Edward Pesout

The McGill smelter started operations in the year 1907. The smelter furnaces were fired with run-of-mine coal on grates until April 1911, when oil firing was introduced. Oil firing continued until April 1918, when the initial coal-pulverizing plant was started.' Early Pulverizing Plant Various alterations were made to that plant during its operation, one of the more important being in connection with the system for delivering pulverized coal. In order to minimize coal-dust explosions and fires, the return portion of the main delivery line was eliminated in the year 1928. Thereafter coal-dust explosions and fires were greatly reduced. Pulverized coal was prepared at this plant primarily for the reverberatory furnaces, but for several years it was also delivered to the converting plant, roasters and power-plant boilers by a system of auxiliary fans and delivery lines. During the period March 29 to April 8, 1929, one reverberatory furnace was fired with pulverized coal produced by an Aero, type J, unit coal pulverizer with a rated capacity of 5 tons per hour. This machine actually pulverized its rated capacity but the product was too coarse. After certain regulations, a her product was obtained but the pulverizer capacity decreased and this resulted in insufficient coal for efficient furnace operation. Table I gives a comparison of the average screen analyses of the pulverized-coal products from the impact-type unit pulverizer and the regular coal-plant installation. It was definitely proved that this size and type of unit pulverizer could not furnish sufficient coal of proper fineness to give smelting results comparable to that obtained with the regular coal-pulverizing plant. The coal from this unit pulverizer was so coarse that it did not ignite or burn properly and thus did not produce the proper heat for efficient smelting. During the latter part of 1929 and the early part of 1930, experimental work was conducted with a 7-ft. o-in. by 48-in. Hardinge conical ball-mill coal-grinding unit, which was installed alongside a furnace in the reverberatory building. Results obtained from the test run indicated that this unit would furnish sufficient coal of proper fineness for good smelting.

Jan 1, 1947

By Edward Pesout

The McGill smelter started operations in the year 1907. The smelter furnaces were fired with run-of-mine coal on grates until April 1911, when oil firing was introduced. Oil firing continued until April 1918, when the initial coal-pulverizing plant was started.' Early Pulverizing Plant Various alterations were made to that plant during its operation, one of the more important being in connection with the system for delivering pulverized coal. In order to minimize coal-dust explosions and fires, the return portion of the main delivery line was eliminated in the year 1928. Thereafter coal-dust explosions and fires were greatly reduced. Pulverized coal was prepared at this plant primarily for the reverberatory furnaces, but for several years it was also delivered to the converting plant, roasters and power-plant boilers by a system of auxiliary fans and delivery lines. During the period March 29 to April 8, 1929, one reverberatory furnace was fired with pulverized coal produced by an Aero, type J, unit coal pulverizer with a rated capacity of 5 tons per hour. This machine actually pulverized its rated capacity but the product was too coarse. After certain regulations, a her product was obtained but the pulverizer capacity decreased and this resulted in insufficient coal for efficient furnace operation. Table I gives a comparison of the average screen analyses of the pulverized-coal products from the impact-type unit pulverizer and the regular coal-plant installation. It was definitely proved that this size and type of unit pulverizer could not furnish sufficient coal of proper fineness to give smelting results comparable to that obtained with the regular coal-pulverizing plant. The coal from this unit pulverizer was so coarse that it did not ignite or burn properly and thus did not produce the proper heat for efficient smelting. During the latter part of 1929 and the early part of 1930, experimental work was conducted with a 7-ft. o-in. by 48-in. Hardinge conical ball-mill coal-grinding unit, which was installed alongside a furnace in the reverberatory building. Results obtained from the test run indicated that this unit would furnish sufficient coal of proper fineness for good smelting.

Jan 1, 1947

By M. A. Mosher

Most modern electrolytic copper refineries have found it expedient to build and operate a complete secondaries plant for the treatment of the electrolytic slime accumulated in the cells during the corrosion of the copper anodes. In the earlier years this was done for the sole purpose of promptly recovering in marketable form the silver and gold contained in the slime. Later, improvements in refining methods made possible the recovery of the more precious metals such as platinum, palladium, osmium and iridium, and in recent years, due largely to an increasing market, many secondaries plants have undertaken the commercial production of selenium and tellurium. The complete up-to-date secondaries plant, or silver refinery as it is usually called, is therefore equipped for the production in marketable form of from six to eight metals. The physical plant and operations may be separated into six main divisions: 1. Slime treatment, in which the raw slime is treated by wet methods for the removal of its high copper content and portions of other impurities such as arsenic, selenium and tellurium. 2. Furnace refining, in which the remainder of the base-metal content of the slime is removed by fluxing and fire-refining. 3. Electrolytic parting and refining, in which the silver and gold are parted and obtained in the pure state. 4. Melting of silver and gold into marketable form. 5. Recovery and refining of the more precious metals. 6. Recovery and refining of selenium and tellurium. The Silver Refinery of the Raritan Copper Works at Perth Amboy, N. J., is a complete secondaries plant and the following description of its equipment and processes is, in a general way, typical of other plants of its kind. Slime Treatment The raw slime, pumped with a minimum amount of cell solution from the electrolytic copper refinery, is discharged into the center of circular settling tanks 15 ft. in diameter by 8 ft. deep, where the slime settles out and the solution overflows peripherally to return to the copper refinery by gravity. The slime is then dropped through a bottom outlet to a

Jan 1, 1934

By William Hamilton Merritt

In this paper, which I have the honor to submit to the Institute, it is my intention to treat especially of that part of the North Staffordshire field which converges to a long tongue in the neighborhood of Congleton, and which includes the villages of New Chapel, Ford Green, Norton, Biddulph, Bradley Green, Gillow Heath, and the immediate vicinity. My object-is not so much to give a minute description of the geology or systems of mining and smelting, as by a general review, some idea of the extraordinary facilities for the production of excellent iron, which have enabled this district to maintain its position more successfully than any of its rivals against the late depression in trade. The North Staffordshire coal field has the Cheshire and Laucashire fields some thirty-five miles to the north, those of Derbyshire and Nottinghamshire forty miles to the east, those of South Staffordshire and Shropshire, about thirty miles to the south, and the Denbighshire and Flintshire fields some forty miles to the west. It is highly probable that the coal continues under the new red sandstone to the Western and Southern fields as the dips on both sides, and absence of large faults, make it impossible to come to any other conclusion. In a section of this coal field, from Chatterly to Whitfield, thirtytwo workable seams of coal are shown, of an aggregate thickness of 130 feet, varying from 2 feet 6 inches to 7 feet, and thirteen seams of ironstone, 24 feet, averaging from 2 to 4 feet. All of these seams have been minutely described in a paper by Mr. Charles J. Homer, read in 1875 before the British Iron and Steel Institute. In the northern part, to which I especially wish to direct your attention, the beds lie in a V-shaped basin, the underlying millstone grit and Yoredale rocks rising and forming escarpments on either side of the valley containing the coal. Throughout this district, at the outcrop of the coal, there are indications of old workings. A shaft 4 to 5 feet in diameter reaches the coal at about 14 yards from the surface, and from it the coal has

Jan 1, 1880

Prof. J. W. Richards, South Bethlehem, Pa. (in reply to several questions):—The cut representing some of the round briquettes which were under test shows that, at the brcaking-stresses, they break into lumps, and do not disintegrate into powder. The process is simplicity itself. I have followed the different processes for sintering iron-ores and flue-dust, am interested in all of them and wish them all success; but this process appealed to me strongly by its simplicity. It is in line with a method which I once tried to work out myself, but which never came to anything, namely, the agglomeration of fine iron-ores by means of Portland cement. As small an amount as 5 or 6 per cent. of Portland cement will enable fine ore to agglomerate and set into a briquette, but when I came to estimate the cost, I found it was a little too high. The Schumacher process, curiously enough, does not work well on iron-ore, but flue-dust thus treated does harden and give a strong briquette. In my attempts to find a reason for this difference, it has occurred to me that possibly the particles of flue-dust had been coated over with some sublimed silica, which might be an agent in the setting. But I found by experiment that neither sublimed silica, nor ordinary silica, nor ordinary alumina, would briquette. Chemically pure iron oxide briquetted quite hard; but the application of pressure is a necessary part of the operation. If simply moistened with the solution and allowed to stand it does not set hard, but the more pressure applied to it the hardcr it sets. Evidently the flue-dust particles must be pressed very close together in order to get the small proportion of active material wet, so that the particles shall act at their points of contact; for it is evident that only at the points of contact does the cementing action take place. The reactions are facilitated by considerable pressure, bringing the acting particles close together, and may go on with

Jan 1, 1913

By R. E. Lindstrom, D. G. Peterson, H. J. Heinen

Alkaline alcohol solutions were investigated by the Federal Bureau of Mines for improving the desorption rate of gold and silver from metal-laden activated carbon generated in gold processing circuits. Factors affecting the desorption, such as temperature, alcohol content, type of alcohol, and alkalinity, were studied. Nearly complete metal desorption was obtained in 5 to 6 hr at 80º C using a solution containing about 20 vol-pct alcohol and 1 pct sodium hydroxide. Sodium sulfide was shown to be effective for selectively precipitating silver from the carbon strip solutions, thereby providing a means for producing high- purity gold by subsequent electrolysis.

Jan 1, 1976

PAUL. D. MERICA, Bayonne, N. J. (written discussion*)..-The mode of intercrystalline oxidation which the authors" have so well observed and described is characteristic of nickel that has been exposed' to: the action of an oxidizing atmosphere at higher temperatures, such as, those at which; it is annealed or heated for rolling or forging. Oxidation under such conditions proceeds inward from the surface along the, crystal boundaries' producing a net-work, probably of oxide; which causes a very brittle condition of this surface material. This, in turn, generally results in surface cracking and checking during further, rolling and a defective sheet or other product is produced. An example of this is shown in Fig. 2, which shows the surface, of a badly surface-cracked sheet of nickel produced by incorrect heating con-ditions. A cross-section of this sheet etched with nitric acid is shown in Fig. 1, which reveals the intercrystalline oxidation network adjacent to both surfaces.These layers are so brittle that it is not possible to deform them by rolling without severe cracking along these lines or, planes of weakness. The best, and possibly only, remedy for this condition lies in its prevention by the maintenance of a neutral soft flame for heating and annealing nickel during the entire course of its manufacture. I should like to suggest that, those making microscopic investigations of nickel and nickel-rich alloys try the use of acetic-acid .solutions of nitric acid for etching these metals rather than aqueous solutions, of nitric acid. I have found that a solution containing 50 per cent. nitric acid, from 25-45 -per. cent. acetic acid, and from 25-5 per cent. water gives excellent results with. Wrought and cast nickel and Morsel metal and superior results to those obtained with nitric acid, alone. The acetic. acid seems to inhibit the passivity that nickel often assumes toward nitric acid and much more uniform etching may, be obtained. The proportions of nitric and acetic, acid may be varied somewhat from those given without mate-rially altering the quality of the etching, although without any distinct improvement in it.

Jan 12, 1919

By W. Rostoker

IN the course of the development of the phase equilibrium diagram for the system Zr-Cr,' the structure of an as-cast allov having the composition ZrCr2 was analyzed and established to be isomorphous with MgZn2 (C14, hexagonal lattice, 12 atoms per unit cell). In a recent paper on the same system, Hayes, Roberson, and Davies' report for the ZrCr2 phase an isomorphy with MgCu2 (C15, cubic lattice, 24 atoms per unit cell). It appeared that this conflict might be resolved by assuming a high and low temperature modification for ZrCr2. That this was the case with the phase TiCr2 has recently been demonstrated by Levinger." Specimens of ZrCr2 annealed at 1200°, 1100°, 994", 900°, 834", 800°, and 700°C, respectively, and subsequently quenched were examined by X-ray diffraction analysis. It was successfully demonstrated that a transition from the MgZn, structure at lower temperatures to the MgCu, structure did occur at some temperature between 900" and 994°C. Table I lists the observed structures at the various annealing temperatures. In Table II, a summary of line spacings and intensities is given for each of the allotropic modifications. The first six lines of the MgCu2 structures have been located in the table to illustrate the close similarity between the patterns. Lattice parameters of the two modifications were calculated by a least squares solution of equations for interplanar spacings for a series of high angle lines. The results are as follows: MgZn2 type - c = 8.262 kX, A = 5.079 kX. MgCu2 type — a = 7.195 kX. It is interesting to note that TiCr2 behaves in reverse fashion yn that the MgCu, structure is the low temperature modification and the MgZn2 structure is the high temperature modification. References lR. F. Domagala, D. J. McPherson, and M. Hansen: This issue p. 279. 'E. T. Hayes, A. H. Roberson, M. H. Davies: Trans. AIME (1952) 194, p. 304; Journal of Metals (March 1952). 3B. W. Levinger: Trans. AIME (1953) 197, pp. 195-196; Journal of Metals (February 1953).

Jan 1, 1954

By Edward Pesout

THE McGill smelter started operations in the year 1907. The smelter furnaces were fired with run-of-mine coal on grates until April 1911, when oil firing was introduced. Oil firing continued until April 1918, when the initial coal-pulverizing plant was started.1 EARLY PULVERIZING PLANT Various alterations were made to that plant during its operation, one of the more important being in connection with the system for delivering pulverized coal. In order to minimize coal-dust explosions and fires, the return portion of the main delivery line was eliminated in the year 1928. Thereafter coal-dust explosions and fires were greatly reduced. Pulverized coal was prepared at this plant primarily for the reverberatory furnaces, but for several years it was also delivered to the converting plant, roasters and power-plant boilers by a system of auxiliary fans and delivery lines. During the period March 29 to April 8, 1929, one reverberatory furnace was fired with pulverized coal produced by an Aero, type J, unit coal pulverizer with a rated capacity of 5 tons per hour. This machine actually pulverized its rated capacity but the product was too coarse. After certain regulations, a finer product was obtained but the pulverizer capacity decreased and this resulted in insufficient coal for efficient furnace operation. Table I gives a comparison of the average screen analyses of the pulverized-coal products from the impact-type unit pulverizer and the regular coal-plant installation. [ ] It was definitely proved that this size and type of unit pulverizer could not furnish sufficient coal of proper fineness to give smelting results comparable to that obtained with the regular coal-pulverizing plant. The coal from this unit pulverizer was so coarse that it did not ignite or burn properly and thus did not produce the proper heat for efficient smelting. During the latter part of 1929 and the early part of 1930, experimental work was conducted with a 7-ft. 0-in. by 48-in. Hardinge conical ball-mill coal-grinding unit, which was installed alongside a furnace in the reverberatory building. Results obtained from the test run indicated that this unit would furnish sufficient coal of proper fineness for good smelting.

Jan 1, 1945

By F. Cadena

Hiwassee Darn, now under construction by the Tennessee Valley Authority on the Hiwassee River, a tributary of the Tennessee River, will require aggregate for approximately 800,000 cu. yd. of concrete. Near the damsite deposits of natural sand or gravel are not available and graywacke, a rock that is found in abundance, suggested itself as a likely source of manufactured aggregate. Graywacke is a metamorphosed sandstone composed principally of a mixture of quartz (65 per cent), mica (25 per cent), and feldspar (10 per cent). Other minerals are present in negligible amounts. The rock varies in different parts of the quarry from very fine to a coarse grain containing particles of about ¼ in. maximum size, although the bulk of the deposit is medium grain. Extensive tests showed that graywacke would be suitable as a source of both coarse and fine aggregates. The aggregate plant available for use at Hiwassee Dam consisted of the coarse-aggregate and sand plant used on the Norris project. The coarse-aggregate plant had also been used at Chickamauga Dam. Although most of this plant equipment is now in use at Hiwassee, the present flowsheet is not only different from that at Norris and Chickamauga but is also unique as compared to the flowsheet of the average crushed-stone aggregate plant. It is hoped that this paper will show the importance of proper arrangement of equipment if the optimum in flexibility and capacity is to be attained. Flowsheet Rock is ioaded by 3-yd. electric shovels into 12-yd. dump trucks, which carry the rock to the primary crusher, a 42-in. Superior McCully gyratory unit set at 4¾ in. (Fig. 1). The primary crusher discharges directly onto a 42-in. inclined belt conveyor, which carries the product to a surge storage pile with a maximum live storage capacity of approximately 3000 tons. A concrete tunnel under this storage pile houses the feed end of a 36-in. belt conveyor (conveyor B) fed by a 36 by 66-in.

Jan 1, 1942

By F. Cadena

Hiwassee Darn, now under construction by the Tennessee Valley Authority on the Hiwassee River, a tributary of the Tennessee River, will require aggregate for approximately 800,000 cu. yd. of concrete. Near the damsite deposits of natural sand or gravel are not available and graywacke, a rock that is found in abundance, suggested itself as a likely source of manufactured aggregate. Graywacke is a metamorphosed sandstone composed principally of a mixture of quartz (65 per cent), mica (25 per cent), and feldspar (10 per cent). Other minerals are present in negligible amounts. The rock varies in different parts of the quarry from very fine to a coarse grain containing particles of about ¼ in. maximum size, although the bulk of the deposit is medium grain. Extensive tests showed that graywacke would be suitable as a source of both coarse and fine aggregates. The aggregate plant available for use at Hiwassee Dam consisted of the coarse-aggregate and sand plant used on the Norris project. The coarse-aggregate plant had also been used at Chickamauga Dam. Although most of this plant equipment is now in use at Hiwassee, the present flowsheet is not only different from that at Norris and Chickamauga but is also unique as compared to the flowsheet of the average crushed-stone aggregate plant. It is hoped that this paper will show the importance of proper arrangement of equipment if the optimum in flexibility and capacity is to be attained. Flowsheet Rock is ioaded by 3-yd. electric shovels into 12-yd. dump trucks, which carry the rock to the primary crusher, a 42-in. Superior McCully gyratory unit set at 4¾ in. (Fig. 1). The primary crusher discharges directly onto a 42-in. inclined belt conveyor, which carries the product to a surge storage pile with a maximum live storage capacity of approximately 3000 tons. A concrete tunnel under this storage pile houses the feed end of a 36-in. belt conveyor (conveyor B) fed by a 36 by 66-in.

Jan 1, 1942

[ ]

Jan 1, 1938

By F. W. SUTTER

IN order to have ore available on the completion of the beneficiation plant at Clifton and to provide for continuous production while underground development was carried out, it was decided to develop an open-pit through the crest of a long hill in which the ore outcropped, using 40-ft. vertical benches.

Jan 1, 1943

By Louis D. Huntoon

CANADIAN gold production is forging ahead annually and the prospects are that it will continue to do so for many years. Table 1 shows recent annual increases. Production for 1933 will probably reach $70,000,000, and further increases are likely in 1934 and 1935. (Data for November and December, 1932, are estimated throughout this article.) The depression sent many prospectors to the woods so during the last two years many new gold areas have been discovered and are attracting real capital for exploration and development. Several mills came into production in 1932 and mills now under construction will start production in 1933. The offices of mining lawyers are busy. Capital for this new work is obtained from well financed mining companies, syndicates, and individuals who were fortunate enough to invest in the dividend-paying gold mines of the north country in the early days. Prospectors and capital are cooperating. An interest is always retained by the prospector or vender and usually a small amount of real money is given the prospector.

Jan 1, 1933

By Wm. Hamilton Merritt

IN this paper, which I have the honor to submit to the Institute, it is my intention to treat especially of that part of the North Staffordshire field which converges to a long tongue in the neighborhood of Congleton, and which includes the villages of New Chapel, Ford Green, Norton, Biddulph, Bradley Green, Gillow Heath, and the immediate vicinity. My object is not so much to give a minute description of the geology or systems of mining and smelting, as by a general review, some idea of the extraordinary facilities for the production of excellent iron, which have enabled this district to maintain its position more successfully than any of its rivals against the late depression in trade. The North Staffordshire coal field has the Cheshire and Lancashire fields some thirty-five miles to the north, those of Derbyshire and Nottinghamshire forty miles to the east, those of South Staffordshire and Shropshire, about thirty miles to the south, and the Denbighshire and Flintshire fields some forty miles to the west. It is highly probable that the coal continues under the new red sandstone to the Western and Southern fields as the dips on both sides, and absence of large faults, make it impossible to come to any other conclusion. In a section of this coal field, from Chatterly to Whitfield, thirty-two workable seams of coal are shown, of an aggregate thickness of 130 feet, varying from 2 feet 6 inches to 7 feet, and thirteen seams of ironstone, 24 feet, averaging from 2 to 4 feet. All of these seams have been minutely described in a paper by Mr. Charles J. Homer, read in 1875 before the British Iron and Steel Institute. In the northern part, to which I especially wish to direct your attention, the beds lie in a V-shaped basin, the underlying millstone grit and Yoredale rocks rising and forming escarpments on either side of the valley containing the coal. Throughout this district, at the outcrop of the coal, there are indications of old workings. A shaft 4 to 5 feet in diameter reaches the coal at about 14 yards from the surface, and from it the coal has

Jan 1, 1880

By Herbert Banks Johnson

DURING the past 10 or 12 years very little information has been made generally available concerning the commercial possibilities of separating materials by means of static electricity; and yet during that same period important improvements have been made in various branches of the science of electricity, which, when taken together, and applied to electrostatic separation, have resulted in important improvements in that art as well. For example, much improvement has been made in high-voltage electrical equipment such as full-wave vacuum-tube rectification and improved mechanical rectification. Great strides have likewise been made in the development of insulators for high-voltage work, not only in the materials used but also in the design of the insulators themselves. Again, in another field, the development of air-conditioning equipment has improved the technique of controlling the surface condition, through drying or humidifying, of the various materials that are passed through the electrostatic separator. In many authoritative publications and textbooks, the electrostatic separation process is declared to require a balance far too sensitive for general commercial application. For example, one publication1 in the past has referred to an unfavorable effect on the process caused by varying atmospheric conditions such as humidity. Some2 have even gone so far as to state that sunlight and shadows may seriously affect the separating efficiency of the process. Such statements may have been true in the early development of the art, when the source of static electricity was derived from a friction disk machine, such as the Wimshurst. The Blake Mosher equipment and the work of Huff in applying motor- generator sets, transformers and mechanical rectification overcame much of this kind of objection to the commercial application of the electrostatic separating process. Another objection made periodically is that it is generally considered necessary to feed the particles into the electrostatic field in a stream that

Jan 1, 1938

By Frederic Benard

PRIOR to 1936, the Ontario Refining Co. received all incoming blister copper from The International Nickel Company's smelter in the usual form of 460-lb. cakes, or slabs. These were received in open cars in lots of 250 pieces. At the refinery the cakes were unloaded onto narrow-gauge cars, for convenient handling and pickup by charging cranes. In March 1936, an investigation was started on the feasibility of trans-ferring converter copper in the molten state from the smelter to the refinery anode furnaces, a distance of 114 miles. Although common in steel practice, the transportation of blister copper in this form had not previously been attempted and a preliminary study of the various factors involved was therefore necessary. For this purpose, a series of experiments was made in which molten copper, removed at different stages during the furnace cycle, was held in a small portable holding furnace. This vessel was essentially a refractory-lined steel cylinder provided with ports for filling and emptying, heated by an oil burner. Dimensions of the steel shell were 3 ft. 10 in. diameter by 7 ft. 3 in. long, and thickness of refractories depended oil the design and combination used for the particular experiment. The vessel was filled with approximately 2 ½ tons of copper at a predetermined temperature, the lining having been preheated to a definite point by means of an oil burner. All openings were well luted and temperature readings were made every 15 min. by means of an immersion-type thermocouple. In this manner the rate of heat loss resulting with different refractory design could be developed. The ratio of exterior surface to weight of metal was taken into consideration in comparing the experimental results with what might be expected for a full-sized unit, and observations were also made on type and degree of slag accretion. It was not possible to get as much information on this latter point as desirable, but all evidence showed that the problem would be control of slag build-up rather than attack oil refractories.

Jan 1, 1938