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By Horace Freeman

The sulphur consumed in Canadian pulp mills and acid plants is worth approximately three million dollars annually and amounts to one hundred and fifty thousand long tons, all of which is imported from the United States. Concurrently with a decline in the value of newsprint there has been a gradual increase in the price of this raw material. Most pulp mills in Canada are situated within reasonable distance of domestic pyrite deposits; nevertheless it has not yet been found possible to mine these deposits and utilize the contained sulphur in competition with the imported material. It is the purpose of this paper to elucidate the reasons therefor, and to describe? a commercial-scale experiment undertaken with the object of introducing a native raw material into the Canadian pulp industry on the purely economic basis. Reasons for the Preferred use of Sulphur The known sulphur deposits in the United States are very large, so that at least a twenty-year supply of this material is assured. It is recovered cheaply and in pure condition. Although large deposits of pyrite are known in Canada, nothing has yet been developed to compare in size, cost of mining, or purity with the United States material. It has been necessary to handle and transport more than two tons of pyrite to equal a ton of sulphur.

Jan 1, 1930

By R. Duncan Gardner

This paper describing the milling practice at the concentrator of the Harmony Mines Co. is one of a series being; prepared by the Bureau of Mines on milling methods and costs in the United States. For the period February 15, 1929, to June 1, 1929, the concentrator treated 200 tons of copper ore per day containing 3.84 per cent copper and recovered 99.2 per cent of the total copper in concentrates averaging 26.61 per cent copper. Milling practice at the Harmony Mines is in most respects similar to the usual practice at the average flotation concentrator producing bulk flotation concentrates. The exceptionally high recovery is due to a number of minor conditions. These minor details will be stressed throughout this paper.

Jan 1, 1930

By L. G. E. Bignell

Surveying what was done in 1929 in meeting problems of oil-field equipment corrosion, one is struck by the fact that fewer meetings were held for discussion of these problems and fewer papers written than in any year since the subject engaged the attention of petroleum engineers. This does not mean that progress has not been made, for a great deal actually has been accomplished. Recommendations that accompanied field reports have been put into actual trial and some results obtained are gratifying. The type of papers prepared also has undergone a change, for they now deal with things accomplished rather than recite damages and suggest possible remedies. Some of the most notable work pointing the way for future solution of many pipe line problems is that done for the U. S. Bureau of Standards by Dr. K. H. Logan and Dr. Gordon N. Scott, dealing with tests of pipe coatings and reports on soil conditions. Many facts of great importance have been isolated and defined by these two men, not only indicating what may be done in some instances to retard corrosion, but showing that things formerly considered of importance have little bearing apparently upon the practical results. All-aluminum Storage Tanks In April, 1928, an all-aluminum 500-bbl. field storage tank was put into actual field use in Crane County, Texas, together with another tank of the same capacity but made with steel bottom and lower section of side sheets and aluminum upper ring of side sheets and deck. In April, 1929, after a little over one year's use these tanks were opened and examined by a group of engineers and chemists. The results of the test were enlightening. Other tanks made entirely of steel and used in the same battery with the two test tanks had some of their side and bottom sheets destroyed by corrosion in six to nine months, but the all-aluminum tank was in actual use for 18 months before holes were found corroded through the bottom, when the tank was examined for a second time in September, 1929. This field test of the aluminum tank confirmed the already known

Jan 1, 1930

By Walter Weeks

CONSIDERABLE difference of opinion seems to exist as to whether the rate of air flow when a fan is placed on a given duct should be determined by the use of static pressure or total pressure characteristics. A little study will show that both methods are correct. Assume that a fan is connected to a duct by an expansion piece as shown in Fig. 1, and that steady flow is established. Considering the atmospheric pressure as zero pressure, let the static head at the outlet of the fan be h and the velocity at this point be v1. The total head at the outlet is then h + v1/2g? The total head at this point must be equal to the total head at the end of the duct plus the losses that have occurred between the two points. Let f be the friction loss in the straight duct, s the shock loss in the dif- fuser, and V2 the velocity at the end of the duct. Then h+ v12/2g=v22/2g + f + s FIG. 1.-FAN ON DUCT. A curve showing the value of the left-hand side of the equation for different rates of flow is the total pressure characteristic of the fan, while a curve showing the value of the right-hand side is the total pressure characteristic of the duct. If these two curves are plotted on the same chart, the intersection indicates the rate of flow when steady flow is established.

Jan 1, 1930

Jan 1, 1930

By C. S. Corbett

EARLY in the development of every oil field, the operators of relatively large tracts of land must decide upon a spacing plan for the wells to be drilled upon their respective tracts. Usually it is desirable to have a system of regular spacing laid out over the entire tract, making such adjustments as may be necessary near land boundaries. Unless the dip of the producing formation is very steep, the equilateral triangular arrangement is the one most generally preferred, for the very good reason that it gives the maximum amount of drainage area for the wells up to the limit at which mutual drainage interference begins. Assuming that the equilateral triangular pattern is to be used, there still remains to he decided the matter of distance between wells. Many variable factors enter into the problem of proper spacing, some of which are physical and some economic. It is not the purpose of this paper to discuss these factors, as that has been done in several comprehensive articles during the past few years. In the end the decision must be based upon an estimate of the relative importance of various factors which apply to the field in question and to economic conditions in the oil industry at the time the development is getting under way. Even if the best possible spacing distance should be chosen when the problem arises, changing economic conditions and variation in physical conditions in different parts of the field may cause the original choice to become more or less unsatisfactory. Obviously, it is advantageous, once a spacing plan has been adopted, to avoid alteration of it as the field becomes better known or as conditions in the industry change, and yet be able to vary somewhat, the acreage per well in extending the area of development. Or, it may be desired to provide for an ultimate spacing considerably closer than conditions seem to warrant early in the development of the field. With these contingencies in mind, it is of interest to examine the possibilities which the equilateral triangular system affords. Orientation of Coordinate System In this system the well locations may be considered as the inersectionst of three sets of coordinate lines, the lines of each set intersecting those of the other two sets at 60. For convenience in placing such a system

Jan 1, 1930

THE CHAIRMAN.- This meeting is under the auspices of the American Institute of Mining and Metallurgical Engineers, and I think the germ of the idea originated in the steel business. Last year there was a meeting of prominent people in the steel industry with the idea of getting together and discussing practical phases of their business, so that everybody could contribute and from that there might be benefit derived for the industry. Several months ago when Mr. Bain was in Salt Lake City, he and Mr. Oldright asked me what I, as an individual, thought of it. From that originated this idea of having the copper people come together to discuss reverberatory smelting and all its phases. In starting out, it seemed the best plan to ask members what particular subjects they wished to discuss first; that is, the ones that would be considered more important. We asked Mr. Oldright, or suggested sometime ago that the meeting be postponed until May because May is a lovely month in Salt Lake. There are a number of attractive features around the city. We have a number of smelters here and I think that probably the most of the benefit will be derived from talking in an informal way and visiting the various plants around. the valley. At any rate, speaking as a resident of Salt Lake, I am glad to see all of you gentlemen here, and hope you have an interesting and instructive time. The tentative list of subjects for discussion at this conference is as follows: Construction Walls, etc. Walls, proper design and thickness of brick for various types of charging. Bottoms, construction of. Binding steel, correct weight and arrangement, where thrust of arch should be taken. Refractory materials, feasibility of using different material in various parts of the furnace. Water jackets, where applicable. Should bricks be used inside of same. Gas space, proper design for, height of roof above bath, etc. Roof Shape of Roof, in hot zone and elsewhere, longitudinally. Construction of roof, in various zones, around openings.

Jan 1, 1930

IF lead be heated with concentrated sulphuric acid two distinct actions will usually be observed. In the first, bubbles begin to be evolved more or less rapidly from the lead, and in the second, which occurs at a higher temperature than the first, hydrogen and sulphur dioxide are evolved, free sulphur is liberated, and leadsulphate is formed. The second action may be violent and usually continues till the lead is all consumed.Attempts have been made to apply these reactions, by means of a standard procedure, as a "Flash test" for the acid resisting qualities of chemical sheet lead. The purpose of this article is to comment on the best method of performing the test, on the various phenomena which may be observed during the course of it and on the interpretation of the results when obtained.PREVIOUS WORKIn 1919, Barr...

Jan 1, 1930

By F. D. DeVaney

[In the course of the investigation by the U. S. Bureau of Mines and the Missouri School of Mines and Metallurgy at the Mississippi Valley experiment Station at Rolla, Mo., on the beneficiation of the low-grade manganese ores of the country, some samples from the Cuyuna District, Minn., have been examined. The work was done under the direction of W. H. Coghill, supervising engineer of the Mississippi Valley Experiment Station. Josoph and Kinney5 in venting about the relative importance of Minnesota deposits of low-grade ore compared to the total reserves say:]

Jan 1, 1930

By H. M. St. John, T. Rynalski, G. K. Eggleston

Maintaining a satisfactory structure in brass and bronze castings has always been a foundry problem of great practical importance. While metallurgists and scientific investigators have not entirely ignored this matter, it has received less of their attention than has been given to iron, steel and the wrought copper and aluminum alloys. Investigation in this field has probably been discouraged to some extent by the complicated nature of the alloys involved. Hundreds of alloys are in more or less common use, most of them containing copper, zinc, lead and tin in widely varying proportions. They also contain appreciable percentages of iron and antimony as impurities, and often phosphorus, which has been added as a deoxidizer and fluidifier. Small amounts of sulfur are usually present. It is not uncommon to find nickel, sometimes in rather substantial quantities. Traces of other metals are frequently present. So complicated and variable a mixture obviously offers difficulties in any investigation of the various factors that influence the structure and other properties of the casting. Incipient Shrinkage Bolton and Weigandl have called attention to a type of structure characterized by intercrystalline fissures and large dendritic crystals which are frequently tarnished to an orange or reddish brown color. This intercrystalline porosity they term "incipient shrinkage" and attribute to the presence of carbon monoxide in the atmosphere under which the metal was melted. The defective structure to which Bolton and Weigand refer has become a brass-foundry problem of major importance, because it occurs with distressing frequency in leaded brasses and bronzes when these are melted in a neutral or reducing atmosphere. Since the electric furnaces, now coming into general use in brass foundries, normally operate with such an atmosphere and, in fact, depend upon it in part

Jan 1, 1930

By Alexander L. Field

In the light of the experimental data on equilibrium for the reaction C + FeO = Fe + CO in molten steel recently obtained by Kinzel and Egan,l it is necessary to revise current theories regarding the nature of equilibrium between carbon and FeO in the basic open-hearth furnace. According to the measurements of these investigators the equilibrium constant m for the above reaction for a pressure of dissolved CO equal to 1 atm. is equal to 0.0005 at 1550" C., when concentrations of carbon and FeO are expressed in percentages by weight. Their work also shows that, with the pressure of CO fixed at 1 atm., not only is the product of carbon and FeO constant, but carbon and FeO are each independently constant—a circumstance which might have been predicted from theoretical considerations. At 1550" C., carbon is constant at about 0.025 per cent. and FeO at about 0.020 per cent., with the pressure of dissolved CO equal to 1 atm., the product of these two constants being equal to the originally mentioned constant of 0.0005. Available data on the dissolved FeO content of samples taken from the metal bath at practical slag-metal equilibrium prove that this FeO content is determined solely by temperature and the effective FeO content of the slag. The distribution constant r at 1550" C., as determined by Herty, Gaines, Larsen, Simkins, Geruso and Watkins2 is equal to 0.0086. A slag would have to contain 0.020 = 2.3 per cent. effective 0.0086 FeO or less in order to prevent the metal from containing more dissolved FeO than that required for equilibrium with CO at 1 atm. pressure. Such low percentages of FeO are never found in basic open-hearth slags at the completion of a heat when rate of carbon drop has become practi-

Jan 1, 1930

By W. P. Yant

[At the majority of mines where flame safety lamps are used either as working lights or as a means of detecting gas, no check it made on this condition of the various parts of the lamp and their assembly other than a visual ink inspection. Although this inspection should be made carefully in view of tae serious consequence that may follow Vie use of a faulty lama, In many instances the inspection is of a perfunctory nature. The Bureau of Mines has therefore designed a small box or gallery for testing lamps for defects and improper assembly before they are taken into the mine. The test simulates the condition when a lamp is extinguished by its introduction into an explosive mixture and the operator attempts to relight the wick while the lamp contains the explosive mixture. This test is more rigorous than merely subjecting a lighted lamp to an explosive methane-air mixture. In the latter test the products of combustion tend to blanket the propagation of flame from within the lamp to the exterior, especially if there are defects at the top of the gauzes. Moreover, when the lighted lamp is subjected to an explosive methane-air mixture the methane builds up slowly within the lamp until the lower inflammable limit is attained, whereupon a feeble explosion occurs within. If the nonlighted lamps is first filled with the methane-air mixture that gives the maximum violence and is than ignited, the dampening effect of products of combustion is obviated and the strain on defects is]

Jan 1, 1930

By E. C. Lane

This paper is a preliminary report of the results of the Bureau of Mines' twenty-second semiannual survey of motor gasoline marketed in the United States. A more detailed discussion of the whole survey is in preparation and will be published as a companion, report. The second paper, in addition to giving a more complete summary of the data included in this report, will present results of the determination of copper-strip corrosion (method 530.22),5 color (method 10.11),6 sulphur content (method 520.11) copper-dish evaporation residue (method 520.11),7 and gum content as given by the Bureau of Mines steam oven method.9 The retail price at the time the sample was taken and try will also be stated for each sample. The present paper deals specifically with data relating to gravity, vapor pressure, and distillation.

Jan 1, 1930

By W. P. Yant

The hazard to health from contamination of air by a noxious gas depends not only on the potential harmful response attending exposure, but also on the warning properties, which in effect may be termed the "accompanying warning response," This warning may be manifested as an odor, taste, irritation of the eyes, nose, or throat, or perhaps headache, vertigo, or nausea. These manifestations may be painful and even slightly harmful, but to a much lesser degree than the primary injury of exposure. The warning response mitigates hazards directly in proportion to the degree of Intolerability which accompanies injurious exposure, and accordingly its absence augments hazards. This accounts for the fact that the actual health hazards from a non-odorous or non-irritating gas or vapor of comparatively low toxicity sometimes equal or exceed the hazard from a considerably more toxic substance, but one which possesses a marked odor or produces eye, nose, or throat irritation in advance of harmful exposure. When a substance lacks the properties for giving warning, it is often possible to impart them by the addition of a small amount of another substance which has an exceedingly high warning intensity. The vapors of this substance, commonly termed a "warning agent" or "tracer gas," escape and mingle with the gas or vapor which lacks warning properties and thereby apprises persons of the latter's presence. The amount of the warning agent added is that which will give adequate warning in advance of serious physiological harm from the dangerous gas or vapor.

Jan 1, 1930

By H. C. Gunning

In spite of the fact that mining has been more or less active in the northern part of Vancouver island since the late 'nineties', there seems to be a remarkable lack of information regarding the nature and development of the region. Recently the operations at the Old Sport mine of the Coast Copper Company, Limited, and spectacular copper discoveries in the vicinity of Nimpkish lake, have directed the attention of the mining fraternity to the district. The writer spent the summer of 1929 making a reconnaissance examination of the general geology and mining properties of the area between Quatsino sound and Nimpkish lake, and he feels that a short paper describing the nature and mining possibilities of the region should be of interest at this time. A more detailed account of the ?geology and of the mining properties will be published in the forth- coming Summary Report of the Geological Survey. A short paper dealing with the Nimpkish Lake district was presented at the Annual Meeting of the British Columbia Division, held recently in Vancouver.

Jan 1, 1930

By Edward A. Capillon

The problem of scrap is probably of greater importance in the pro duction of gold, silver and other precious metal alloys than is the case for base metals and alloys. Remelting of gold and silver scrap in the shop is always a costly process because it involves losses by oxidation of thc base metals in the alloy with a consequent increase in the percentage of precious metal. This is most marked in the case of alloys containing the low-boiling and easily oxidized metals zinc and cadmium. Since it is not generally feasible to assay every shop remelt it follows that the possibilities of lost values arc large. So-called rolled gold and silver plate is made by soldering or welding the precious metal alloys onto base metal. Such plate when defective must be sent to the refinery to recover the gold and silver values, thereby involving additional expense in the form of refining charges. It is obvious therefore that gold and silver alloy scrap is an important item in manufacturing cost and must be reduced to a minimum. The amount of scrap resulting from poor metal will depend on a number of factors in the manufacturing operations, not least among which is the melting and casting practice. The notes which follow are a summary of experiments performed at various times to determine what variables in melting and casting are influential in the production of sound alloys. Metals Used in Alloying Pure gold, that is, gold of 24-kt. value is very much too soft for jewelry purposes and it is therefore always alloyed with other metals to increase its hardness and resistance to wear. For the same reason pure silver is seldom used alone but is alloyed with copper, the standard alloy being sterling silver which contains 92.5 per cent. silver and 7.5 per cent. copper. The metals commonly used for alloying gold are silver, coppcr, nickel and zinc. In addition to hardening the gold and producing alloys of different karat values the use of these metals makes possible the production of gold alloys of various colors such as yellow, red, green and white. The gold-silver-copper alloys vary in color from light greenish-white through green, yellow and red depending on the relative amounts of the three metals. Green or yellowish-green colored golds

Jan 1, 1930

By Alfred Beasley

LEAD-REFINING practice at the. Bunker Hill differs to some extent from that of other United States refineries using the Parkes process, in that the Bunker Hill-has reverted to a custom used years ago of making two kinds of skims, or crusts, in the desilverizing kettles. Also, this was the first refinery to adopt the liquation process for silver skims as developed in Australia. Both of these ideas were brought to the attention of the operator by H. S. J. Sommerset, in the summer of 1924, while he was visiting metallurgical plants in the United States, when he was general superintendent of the Broken Hill Associated Smelters Pty., Ltd., of Port Pirie, South Australia. Since Mr. Sommerset's visit, United States patents on the liquation process have been issued to George Kenneth Williams, of Port Pirie, South Australia. At the Bunker Hill, the lead bullion is conveyed from the blast furnaces to the refinery in brick-lined cast-steel pots, each having a capacity of 5 tons, by a 20-ton electric crane, to which is suspended a Fairbanks-Morse suspension-type scale on which the gross, tare and net weights are obtained. The bullion is poured from the small bullion pots into either one of two kettles of 105 tons capacity, and when a kettle is entirely filled the heavy dross is removed by skimming it into a 5-ton pot suspended by the crane. The crane operator becomes proficient in the manipulation and a kettle is skimmed in a very short time. After the kettle is skimmed clean the bullion is pumped to a kettle of the same size alongside, where the bullion is cooled until it has almost frozen. By using two kettles for the drossing operation, one to accumulate the bullion where the heavy dross is removed, and then pumping to a clean kettle comparatively free of hangings, etc., it is possible to reduce the copper content much lower than if only one kettle is used in the operation. The average yearly analysis of bullion is given in Table 1.

Jan 1, 1930

By Harmon E. Keyes

Many organizations, including the Bureau of Mines, have made intensive studies of the application of leaching methods to relatively small low-grade disseminated deposits of copper ores, containing both oxide and sulphide minerals. One of the principal difficulties has been to obtain a solvent that could be made at a low cost and would effectively dissolve the copper minerals. Another drawback has been the high initial cost of a plant and the refined type of mechanism ordinarily required by standard practice for carrying out the leaching cycle. The Bureau of Mines has attempted to develop a cheap and efficient solvent that would especially meet the requirements of smaller plants. (See Bibliography.) It has been known that dilute ferric sulphate-sulphuric acid solution is an excellent solvent for most copper minerals, such as chalcocite, bornite, and oxidized forms, but not for chalcopyrite and certain silicates. A method of producing this solution from sulphurous products and waste liquors was developed by the bureau and tried successfully on a test-plant scale at the Southwest Experiment Station in cooperation with the department of mining and metallurgy, University of Arizona, Tucson, Ariz. However, this work did not involve the actual leaching of ores with the solutions thus produced or the cyclic use of the iron solutions in the regenerator cell. Except for certain laboratory tests, in which known impurities were added, no data were available to show the effect on regeneration if accumulations of impurities were built up in the leaching circuit.

Jan 1, 1930

By C. G. Maier

The fundamental chemistry of zinc smelting, especially that part dealing with the chemical reduction of the zinc-oxide content of a roasted zinc ore, has been discussed by metallurgists in some detail, but, in the light of present knowledge, unsatisfactorily. A considerable portion of the information available has been qualitative, or quantitative in a sense that could not be interpreted chemically. A number of attempts to elucidate the physical chemistry of zinc oxide reduction have been based upon unsubstantiated and, as is now known, incorrect equilibrium data. To write upon the chemistry of zinc smelting at this time, when electrolytic methods for the production of zinc metal from ore are becoming increasingly widespread, may seem a belated effort. So, for example, C. A. Hansen,3 in the communicated discussion of an article by the author,4 writes as follows:

Jan 1, 1930

By Chas. F. Jackson

During the past year a special study was made of shrinkage stoping A large number of mines in the United States and Canada which employ this method were visited and their practices were discussed with the operating staffs. The operating data obtained are appended hereto. Data were also abstracted from the literature on other mines and are combined in tables with data personally secured by the author. References are made to these published articles, some of which have appeared as information circulars of the United States Bureau of Mines, in the Transactions of the American Institute of Mining and Metallurgical Engineers, and the Engineering and Mining Journal. Several of the mines referred to which have not been described in individual papers will be described in detail in information circulars to be issued by the bureau. Eventually it is planned to combine and condense the information in these circulars and present the data in bulletin form.

Jan 1, 1930