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By C. E. Shoenfelt, D. E. Winchester

NO important discoveries of petroleum during 1933 were reported from New Mexico. Lea and Eddy counties were the centers of activity during the drilling season and each had a number of interesting completions. The Hobbs pool, in Lea County, was definitely outlined on the east, north and northwest. Under an agreement reached last summer by state officials and operators, the Hobbs pool was continued under proration throughout the year. One hundred eighty-four units of 40 acres each were being produced at the end of 1933. The allowable was 21,306 bbl. daily at the beginning of 1933, but when the agreement was revised in the spring the minimum was raised to 30,000 bbl., and by the end of the year had been raised to 33,473 bbl. At present the field is being prorated on the basis of 25 per cent on acreage and 75 per cent on potentials except in the southwestern edge of the field, where water encroachment is a problem. In this area the basis of proration is 40 per cent on acreage and 60 per cent on potentials. A corrective method employed in this part of the field has been partly successful. The water is advancing in the upper part of the pay, a dolomitic limestone, and in a number of instances packers have been set in the pay below the water and above the oil. The locating of a satisfactory seat for a packer is difficult and in some instances has not been a complete success. Pipe line runs from the field during the year aggregated 11,413,218 bbl., bringing the total gross production up to 41,093,681 bbl., of which 39,000,-000 bbl. has been produced under proration, which went into effect on July 10, 1930. On Nov. 30, potentials were determined on the assigned pressure basis and the total was reduced 71,165 bbl. daily, to 1,265,-332 barrels. The outstanding completions in the Hobbs pool were three in number, of which the best was the Humble Oil & Refining Company's No. 3B Bowers in sec. 20, 18S., 38E., with an initial production of 11,664 bbl. of oil and 10,000,000 cu. ft. of gas. The Shell Petroleum Company's No. 4B McKinley, in the same section, produced at the rate of 22,940 bbl. of oil while flowing open, but when tubed, flowed at the rate of 6610 bbl. The third outstanding well, No. 4 Hardin of the Tidal Oil Co., and located in

Jan 1, 1934

By MALCOLM FRASER

I was delighted to be invited to be patron of this Joint Conference, but the challenging task you have set yourselves, and your speakers' depth of expertise, deny anyone, even the patron, the opportunity to be patronizing. Australia's history has been inextricably linked with the fortunes of our great mining industry. That link will remain. Just as the gold rushes of the last century, and the discoveries at Kalgoorlie and Broken Hill changed the lives of generations, so the more recent development activity in iron ore, bauxite, nickel, coal, and uranium are having a significant impact on the lives of Australians today. The minerals industry has contributed to Australia's jobs and prosperity. Mining is not free of problems, but so long as safeguards are strong and appropriate the net benefits the mining industry brings Australia will continue to be enormous. We rely on our mining industry to find, prove, develop and sell our minerals profitably, and my Government is committed to maintaining a healthy mining industry. In the past year there have been positive signs of a resurgence in exploration and development. The North-West Shelf ventures are spending $50 million on a feasibility study to work out the extent of future investment in that project; exploration expenditure for minerals other than petroleum increased by 34 per cent in 1976-77 to $134 million; petroleum exploration increased dramatically last year almost doubling to $94 million-this year it is projected to reach $125 million.

Jan 1, 1978

By T. A. Wilson

THE plastic deformation of slender single crystals of zinc has been described in some detail in the paper by Mark, Polanyi and Schmid,1 which has become a classic, and also by one of the present authors in a somewhat shorter account.2 The study of single-crystal zinc is termed classical because zinc single crystals offer, perhaps, the best material yet available for the study of atomic behavior during deformation and the effect known as "strengthening" in metals. A considerable amount of additional work has also been clone on single-crystal zinc, but as it 'is not closely related to the present paper it will not be considered. Throughout all the former work, the mechanism of plastic deformation first described by Mark, Polanyi and Schmid has been assumed to hold. This may be said to offer the strongest confirmation of its correctness. Even so, the picture of the process has never been as completely portrayed as is desirable. The first object of the present paper is to describe work that has been done in this field, and which is even yet being carried on, in the hope that a more complete picture may be obtained. Mathewson and Phillips3 have recently described a new mechanism of the deformation of zinc based on their study of large rectangular crystals. One of their conclusions was that deformation produced twinning with a rotation of some of the basal planes into positions 94° removed from their original position; a position almost the same as that of the prismatic planes before twinning. A second conclusion was that fracture occurred along these basal planes in their new position, and, therefore that fractures previously regarded as prismatic were in reality basal. Such findings are of great significance and they raise a question as to the generality of such behavior. Professor Mathewson's opinion is that even the slender cylindrical single crystals behave in the same manner as his large rectangular crystals when strained by simple tension.

Jan 1, 1927

By T. Egleston

I HAVE to announce with great regret that our distinguished honorary member, Louis Gruner, died in Paris in March last. The Institute, in his death, has lost one of the first as well as one of the greatest of its honorary members. I speak with great feeling, as he was both my instructor and my friend ; and I am sure that if he could hear what I am about to say of him, lie would object to it. Mr. Gruner's modesty was such as even to prevent, except in his own Corps, the thorough appreciation of his work in his own country. I think be mas better appreciated by those who are familiar with his labor in almost any other country than his own. A just man, a thorough scholar, a great investigator, he was so unselfish that almost the last act of his life, and the last letter he signed, only a few hours before his death, had for its ohject to render a service to one of his former pupils. I think no one who mas ever associated with him could forget, in the greatness of his learning, the sincere and earnest friend, mho was always ready to render a service, where such service could be rendered even at great inconvenience to limself. His own motto, "Sein, nieht schein;" that is, "Be, not appear to be," was singularly descriptive of his character; and, what is more than all, he was one of the most earnest Christian men with whom it has ever been mv. good fortune to be thrown in contact. There are few such men. He was one of the greatest metallurgists that Europe has ever produced; a man the more remarkable because, though known to most of us as a metallnrgist, some of the best work of his life was in the domain of geology to which he contributed very important researches and memoirs, which will remain permanently among the valuable additions to the geology of his own country. He was, at the same time that he was the greatest metallurgist in Europe, a brilliant chemist, a thorough geologist, a distinguished professor, and an expert, practical miner, whose advice and methods had only only to be known to be followed. Mr. Gruner was born in Smitzerland in 1809, and graduated from the Polytechnic School of Paris in 1530 and entered the School of Mines, from which he graduated with distinction in the Corps of Government Engineers of Mines at an early age, and was immedi-

Jan 1, 1884

By Henry M. Howe

In my original paper, Piping and Segregation in Steel Ingots, I pointed out1 among other things that, in view of the slighter stretching (virtual expansion) of the crust, and greater opportunity for sagging, there should be less piping in broad than in narrow ingots, and less in slowly-cooled ingots, e.g., those cast in pre-heated sand molds, than in those which cool quickly, e.g., those cast in iron molds. A. A. Stevenson said that neither of these predictions agreed with his own experience. In particular, in a picture which he showed of a wide and of a narrow ingot cast from the same ladleful of steel: the wide ingot had certainly piped much more deeply than the narrow one. At the time I did not see the explanation of these discrepancies, but further reflection makes it evident. One of the most important elements in determining the depth of the pipe is the degree of " top-lag," that is, the degree to which the solidification of the top of the ingot lags behind that of the bottom. Through this lagging the steel of the upper part of the ingot is able to run down and fill the pipe below as fast as it forms. To the importance of this lagging I called attention in my original paper.' Sand us. Iron Molds.—If we compare two like ingots, one cast in an iron and the other in a sand mold, we see that the top-lag is much greater in the former than in the latter, because in the former the lower part of the ingot is cooling off fast while the metal is running into the upper part. It is perhaps easier to look at this as a case of the solidification of the hot-

Jan 1, 1910

By Frederick W. DeVries

Since we first agreed to present this talk we have learned that some of you may have been covering ground we intend to discuss: Bob Schechter, Daryl Tweeton, Don Seidel, Herb Burgman; however, the ideas were original when we began, "novel" as in the title of the talk, and whether our results are news or merely corroborative, we feel they point a direction that could be valuable to all. We worked with many of you in the past on using hydrogen peroxide in in-situ uranium leaching. Our talk today is not directly related to peroxide; it is, I hope, illustrative of Du Pont&apos;s interest in providing service to this industry in any way we can. The scouting work we are presenting was stimulated by field inputs: First, ammonium carbonate leaches cause restoration problems, primarily because ammonium ions exchange on clays with calcium. Second, sodium carbonate solutions, especially in South Texas deposits, can cause intolerable swelling of clays. From discussions with Dr. van Olphen, who wrote the book on clay chemistry, we inferred by comparison of the radii of the hydrated ions of the elements in these clay systems, that since potassium had about the same radius as ammonium, and sodium was much larger, potassium occupied a unique position to solve both problems. We have shown: FIGURE 1 Potassium bicarbonate systems leach uranium without loss of permeability found with sodium Potassium salts are very effective in restoring ammonia-leached sites Before reviewing the details of our work, which was performed by Hazen Research, Inc., I should like to stress its scouting nature. We are trying to assist the in-situ industry by pointing out new, potentially important directions. But, as with our previous work on sodium silicate to restore permeability, we feel the development phases can generally best be carried out in cooperative programs with companies directly involved with operations. DISCUSSION Test Parameters Now for the details: Our leaching tests were designed to note pressure-drop changes across the ore sample as the uranium was leached. Figure 2 shows the apparatus. The [ ] packed length was 20.5 inches (52 cm) with fifteen hundred grams of ore in the two-inch (5 cm)-diameter bed. Pressure drop was measured by manometer and feed rates were maintained constant with a tubing pump. The samples, from a South Texas leach site, were sealed in "Zip Loc" bags, frozen with "dry ice", crushed (still frozen) through six mesh, and blended before placement into the columns. The ores analyzed as shown here: FIGURE 3 Ore Analyses [Sample A Sample B U308 015% 0122% Mo 0004% 0086% Se0012% <0001% Fe3,078%076% Fee- 098% 044%]

Jan 1, 1979

By J. F. Wolff, Anson A. Betts

The following correspondence relating to a paper bearing the above title, presented by J. F. Wolff, at the New York meeting in February, 1917, and published in the Transactions, Volume LVI, page 142, has passed between the author of the paper, and Mr. Anson G. Betts, and is interesting, although it was received much too late for incorporation in its proper place in Volume LVI. Anson G. Betts, Asheville, N. C.—1. I should like to ask Mr. Wolff if he finds from analysis of the iron formation and of the iron ore, and from the relative amounts of each in each unit area of the formation, unleached and after leaching, that the iron remains entirely insoluble and the total quantity still remains present; or whether he finds that some of the iron is removed, or possibly even added by deposition from the water passing through the formation. 2. The water that passed into the iron formation had to go somewhere; was it absorbed by underlying formations through hydration, or, after passing through the ore formation, did it come to the surface in springs at a lower elevation, or how did it escape from the ground? 3. I should like to ask Mr. Wolff whether he finds that the iron formation in the sedimentary series does not come next to the quartzites and generally between the quartzites and slates. J. I?. Wolff, Duluth, Minn.—1. In common with others, you appear to have some hesitancy in accepting the fact of the removal, by solution, of the enormous quantity of silica which has been leached out of portions of the Biwabik iron formation, thus forming orebodies of merchantable iron ore. I believe that even Dr. Waldemar Lindgren once hesitated to accept this fact. However, the evidence is so simple and absolutely conclusive that the fact is established beyond all question. At the contact of orebodies with their rock walls, the bands of iron ore in the orebody can be seen in contact with the corresponding bands of original iron oxide in the rock wall, and the chert layers in the rock wall can be seen to give place to fine granular material (fine silica and iron oxide) and pore space. This is especially noticeable where slumping at the rock walls has not been so great as to displace the layers in the orebody from their contact with their corresponding layers in the rock wall. Although complete analyses of the entire original rocks in the iron series have not been made in any place, to my knowledge, from the best data at hand as to the average analysis of the Biwabik series and the

Jan 1, 1920

By AIME AIME

THE session* on Non-ferrous Metallurgy held Monday morning was conducted in a most satisfactory manner with F. F. Colcord, vice-president, U. S. Smelting Co., in the chair. In spite of the early hour and the fact that members desired to register first, the meeting started quite promptly, with almost every chair in the room occupied. About 65 men were present and during the morning many more came but, not being able to find room, drifted away to other fields of activity. The first paper presented, "Lead Refining Practice of the Bunker Hill Smelter of the Bunker Hill & Sullivan Mining & Concentrating Co.," by Alfred F. Beasley (T. P. 303), was read in abstract by Edward H. Robie, and an animated discussion followed in which Messrs. Johnson (written discussion), Brewer and Jones and Professor Hayward participated. The discussion hinged principally on the liquation of the zinc crusts, but Professor Hayward called attention to the fact that the practice of keeping the gold and silver crusts separate was not new and the present scheme illustrated the axiom that processes based on fundamental principles should not be considered as extinct; one can never tell when it may be found advantageous to make use of them again.

Jan 1, 1930

By D. M. Wade, F. F. Redfield

PRODUCTION at Aguilar started in 1936 and by 1942 the mine had reached a peak of 25,000 tons a month. Present production is only about 60 per cent of this capacity because of difficulties in railroad transportation and the rationing of fuel oil brought about by the war. In the early years, cut-and-fill stopes were tried, but square sets were found to be the most practical method in the southern section of the mine, where blocky, treacherous ground and greater mining widths are prevalent. Square sets and opencut mining were the rule until 1942, when it became increasingly difficult to get mine timber. The ore beds in the northern section of the mine were found amenable to cut-and-fill stoping as the rock was firmer and the veins narrower. At present 69 per cent of the ore comes from cut-and-fill stopes, 27 per cent from opencut, and only 4 per cent from square-set stopes. Massive galena and sphalerite with comparatively little quartzitic gangue constitutes the higher-grade ore. The gangue minerals that can be detected by eye in low-grade ore are rhodonite, wollastonite, and pyrrhotite. Wall rocks range from shale to quartzite, with occasionally a little limestone.

Jan 1, 1947

By C. W. Wark, Fred Wise

The Getchell mine, a comparatively recent gold discovery, is in the old Potosi mining district, Humboldt County, Nevada. All ore is mined from open pits using Diesel shovels and gasoline trucks. Two types of ore are mined, oxide and sulphide. Oxide ores are siliceous or shaly; sulphide ores either gougy, siliceous or shaly. In mining, the sulphide ore is segregated into hard and gougy ore, because the gouge must be dried before it can be crushed. The oxide ore is not segregated. General Metallurgy The oxide ore is the leached outcrop that overlies the sulphide ore body. All of the iron and arsenic sulphides found in the sulphide ores have been thoroughly oxidized. The sulphur and arsenic have been leached out while the iron is present as hematite and limonite. The oxide ore is amenable to direct cyanidation, and although no visible free gold is present it is released at a comparatively coarse grind. The sulphide ore is more refractory, since the gold is all of micron size and some of it is locked in fine sulphides. It has been established microscopically that the free gold is coated with an impervious shell, which is probably some form of iron compound. The sulphide ores contain from 1.5 to 2 per cent of arsenic, which is present as orpiment and realgar with minor amounts of arsenopyrite. The orpiment and realgar are of a later mineralization than the gold and are barren. Roasting and washing of the sulphide ore prior to cyanidation is necessary to eliminate , the arsenic, to alter the gold coating from an insoluble form to a soluble form, and to release the gold associated with the fine sulphides. Washing the ground calcine in weak sulphuric acid, trona, or hot water are beneficial in the order named, but to date the water is the best from an economic standpoint. Metallurgical tests as well as plant practice indicate that a certain amount of gold cannot be recovered even by going beyond economic practices. On this basis metallurgical results are viewed in the light of an optimum tailing rather than a percentage of extraction. Milling Practice Crushing (Fig. I).—There are three primary ore bins, one each for oxide ore, gougy sulphide ore, and hard sulphide ore. In front of each bin a substantial yard is maintained, which makes it possible to Stockpile 2500 tons of oxidized ore, 1000 tons of hard sulphide ore, and 1000 tons of gougy sulphide ore. The bins are fed by a 60-hp. caterpillar bulldozer from the stockpiles. Fig. I shows the method and

Jan 1, 1943

By John L. Boardman

Because of the attention that has recently been given to the health and safety of miners by various organizations such as the A.I.M.E., The American Congress, Mining Section, National Safety Council, as well as the Bureau of Mines and various state mining departments, your committee on health and safety deemed it best to call attention this year to the mine-accident cause that is by far the most important; namely, injuries due to falls of ground, rock, roof and coal. Each of several members of the committee contributed a brief outline of the importance of this accident cause in his district. While these papers were brief, it would require too much time and space to give them in full, therefore we present an outline of each and summation of all. Report of M. D. Cooper, Hillman Coal and Coke Co. M. D. Cooper, Division superintendent, Hillman Coal and Coke Co., Pittsburgh, Pa., contributed the following: During the period from 1930 to 1939, accidents from falls of roof in bituminous mines average 54.3 per cent of all accidents. In mechanized mining, there is a tendency toward reduction in this class of accidents because the operator of the machine is usually at a distance of 10 to 20 ft. from the face, whereas in hand load- ing the miner is close to the face during most of the shift. No doubt the use of aluminum and light steel beams supported at regular intervals by jacks, a common practice in mechanical mining, has contributed to the favorable record so far developed. Report of M. H. Fies, De Bardeleben Coal Corporation Milton H. Fies, Vice-President, DeBar-deleben Coal Corporation, Birmingham, Ala., says: With reference to the types of mining, it is suggested that a clear understanding be had as to the character and thickness of the directly overlying strata, with especial consideration to the strength and in some cases an analysis of it. In coal mining, generally speaking, overlying strata higher in silica than others is stronger. In changing from narrow to wide places, the procedure should be experimental, both as to the width and depth of places and as to the nature of the necessary timbering. Since most of the accidents in coal mining particularly are due to falls of roof and coal, this phase of mining should be attacked with vigor There is no substitute for discipline and, in this connection, under present conditions it is important that cooperation by the labor ornanizations- be sought and that a spirit of fairness prevail. Frequent and thorough inspection of all active working places should be made.

Jan 1, 1943

By John L. Boardman

BECAUSE of the attention that has re¬cently been given to the health and safety of miners by various organizations such as the A.I.M.E., The American Congress, Mining Section, National Safety Council, as well as the Bureau of Mines and various state mining departments, your committee on health and safety deemed it best to call attention this year to the mine-accident cause that is by far the most important; namely, injuries due to falls of ground, rock, roof and coal. Each of several members of the committee contributed a brief outline of the importance of this accident cause in his district. While these papers were brief, it would require too much time and space to give them in full, therefore we present an outline of each and summation of all. REPORT OF M. D. COOPER, HILLMAN COAL AND COKE CO. M. D. Cooper, Division superintendent, Hillman Coal and Coke Co., Pittsburgh, Pa., contributed the following: During the period from 1930 to 1939, accidents from falls of roof in bituminous mines average 54.3 per cent of all accidents. In mechanized mining, there is a tendency toward reduction in this class of accidents because the operator of the machine is usually at a distance of 10 to 20 ft. from the face, whereas. in hand loading the miner is close to the face during most of the shift. No doubt the use of aluminum and light steel beams supported at regular intervals by jacks, a common practice in mechanical mining, has contributed to the favorable record so far developed. REPORT OF M. H. FIES, DE BARDELEBEN COAL CORPORATION Milton H. Fies, Vice-President, DeBardeleben Coal Corporation, Birmingham, Ala., says: With reference to the types of mining, it is suggested that a clear understanding be had as to the character and thickness of the directly overlying strata, with especial consideration to the strength and in some cases an analysis of it. In coal mining, generally speaking, overlying strata higher in silica than others is stronger. In changing from narrow to wide places, the procedure should be experimental, both as to the width and depth of places and as to the nature of the necessary timbering. Since most of the accidents in coal mining particularly are due to falls of roof and coal, this phase of mining should be attacked with vigor. There is no substitute for discipline and, in this connection, under present conditions it is important that cooperation by the labor organizations be sought and that a spirit of fairness prevail. Frequent and thorough inspection of all active working places should be made.

Jan 1, 1941

JESSE L. JONES,* Pittsburgh, Pa. (written discussion?).-The most important criterion on which judgment of the quality of manganese bronze can be based is its freedom from lead. Not over 0.03 per cent. of lead should be present in a good grade of manganese bronze. While it is not questioned that manganese bronze with a high tensile strength and considerable ductility can be made .from materials that will give a lead content of possibly 2 to 3 per cent., there is no doubt that such material, while it may machine readily, will be found to withstand the impact test very poorly, and hence be unsuited for high-grade engineering work. When lead is present in considerable amounts, it forms in small pools in the alloy and the material has little strength at these points; in fact, such spots in the metal are equivalent to nicks in a test bar as far as their effect on tensile strength is concerned. A further objection to a high lead content is the ease with which it oxidizes and its consequent tendency to produce dross. A second characteristic of a high-grade manganese bronze is a low content of manganese. This should not exceed 0.05 per cent.; in fact, very many of the best grades of manganese bronze show, on analysis, only a trace of manganese or no manganese whatever. Manganese is a deoxidizer and its ready oxidation protects the other metals of the alloy; but if it is present in large amounts it will produce considerable manganese dioxide, which does not separate readily from the molten alloy and may produce black specks or drossy spots and render the obtaining of clean castings difficult. Aluminum should be present in a good grade of manganese bronze in only very small amounts. A content of 0.10 per cent. aluminum is ample. Larger amounts have a tendency to increase the shrinkage of the alloy, to give the ingots and castings a white, scruffy appearance, and to prevent the beautiful, golden, oxidization color characteristic of high-grade manganese bronze and a most excellent indication of quality. The work that the author of the paper has done is valuable from a con- servation standpoint, and it will supplement, in a marked degree, the advances that have been made by a number of manufacturers of manganese bronze in utilizing the turnings from this material. A number of firms have succeeded in making a very good grade of ingot metal from turnings and other light scrap, obtaining a tensile strength and elongation

Jan 4, 1919

By John L. Boardman

Because of the attention that has recently been given to the health and safety of miners by various organizations such as the A.I.M.E., The American Congress, Mining Section, National Safety Council, as well as the Bureau of Mines and various state mining departments, your committee on health and safety deemed it best to call attention this year to the mine-accident cause that is by far the most important; namely, injuries due to falls of ground, rock, roof and coal. Each of several members of the committee contributed a brief outline of the importance of this accident cause in his district. While these papers were brief, it would require too much time and space to give them in full, therefore we present an outline of each and summation of all. Report of M. D. Cooper, Hillman Coal and Coke Co. M. D. Cooper, Division superintendent, Hillman Coal and Coke Co., Pittsburgh, Pa., contributed the following: During the period from 1930 to 1939, accidents from falls of roof in bituminous mines average 54.3 per cent of all accidents. In mechanized mining, there is a tendency toward reduction in this class of accidents because the operator of the machine is usually at a distance of 10 to 20 ft. from the face, whereas in hand load- ing the miner is close to the face during most of the shift. No doubt the use of aluminum and light steel beams supported at regular intervals by jacks, a common practice in mechanical mining, has contributed to the favorable record so far developed. Report of M. H. Fies, De Bardeleben Coal Corporation Milton H. Fies, Vice-President, DeBar-deleben Coal Corporation, Birmingham, Ala., says: With reference to the types of mining, it is suggested that a clear understanding be had as to the character and thickness of the directly overlying strata, with especial consideration to the strength and in some cases an analysis of it. In coal mining, generally speaking, overlying strata higher in silica than others is stronger. In changing from narrow to wide places, the procedure should be experimental, both as to the width and depth of places and as to the nature of the necessary timbering. Since most of the accidents in coal mining particularly are due to falls of roof and coal, this phase of mining should be attacked with vigor There is no substitute for discipline and, in this connection, under present conditions it is important that cooperation by the labor ornanizations- be sought and that a spirit of fairness prevail. Frequent and thorough inspection of all active working places should be made.

Jan 1, 1943

By John L. Boardman

BECAUSE of the attention that has recently been given to the health and safety of miners by various organizations such as the A.I.M.E., The American Congress, Mining Section, National Safety Council, as well as the Bureau of Mines and various state mining departments, your committee on health and safety deemed it best to call attention this year to the mine-accident cause that is by far the most important; namely, injuries due to falls of ground, rock, roof and coal. Each of several members of the committee contributed a brief outline of the importance of this accident cause in his district. While these papers were brief, it would require too much time and space to give them in full, therefore we present an outline of each and summation of all. REPORT OF M. D. COOPER, HILLMAN COAL AND COKE CO. M. D. Cooper, Division superintendent, Hillman Coal and Coke Co., Pittsburgh, Pa., contributed the following: During the period from 1930 to 1939. accidents from falls of roof in bituminous mines average 54.3 per cent of all accidents. In mechanized mining, there is a tendency toward reduction in this class of accidents because the operator of the machine is usually at a distance of 10 to 20 ft. from the face, whereas in hand loading the miner is close to the face during most of the shift. No doubt the use of aluminum and light steel beams supported at regular intervals by jacks, a common practice in mechanical mining, has contributed to the favorable record so far developed. REPORT OF M. H. FIES, DE BARDELEBEN COAL CORPORATION Milton H. Fies, Vice-President, DeBardeleben Coal Corporation, Birmingham, Ala., says: With reference to the types of mining, it is suggested that a clear understanding be had as to the character and thickness of the directly overlying strata, with especial consideration to the strength and in some cases an analysis of it. In coal mining, generally speaking, overlying strata higher in silica than others is stronger. In changing from narrow to wide places, the procedure should be experimental, both as to the width and depth of places and as to the nature of the necessary timbering. Since most of the accidents in coal mining particularly are due to falls of roof and coal, this phase of mining should be attacked with vigor There is no substitute for discipline and, in this connection, under present conditions it is important that cooperation by the labor organizations be sought and that a spirit of fairness prevail. Frequent and thorough inspection of all active working places should be made.

Jan 1, 1941

By Fred Wise, C. W. Wark

The Getchell mine, a comparatively recent gold discovery, is in the old Potosi mining district, Humboldt County, Nevada. All ore is mined from open pits using Diesel shovels and gasoline trucks. Two types of ore are mined, oxide and sulphide. Oxide ores are siliceous or shaly; sulphide ores either gougy, siliceous or shaly. In mining, the sulphide ore is segregated into hard and gougy ore, because the gouge must be dried before it can be crushed. The oxide ore is not segregated. General Metallurgy The oxide ore is the leached outcrop that overlies the sulphide ore body. All of the iron and arsenic sulphides found in the sulphide ores have been thoroughly oxidized. The sulphur and arsenic have been leached out while the iron is present as hematite and limonite. The oxide ore is amenable to direct cyanidation, and although no visible free gold is present it is released at a comparatively coarse grind. The sulphide ore is more refractory, since the gold is all of micron size and some of it is locked in fine sulphides. It has been established microscopically that the free gold is coated with an impervious shell, which is probably some form of iron compound. The sulphide ores contain from 1.5 to 2 per cent of arsenic, which is present as orpiment and realgar with minor amounts of arsenopyrite. The orpiment and realgar are of a later mineralization than the gold and are barren. Roasting and washing of the sulphide ore prior to cyanidation is necessary to eliminate , the arsenic, to alter the gold coating from an insoluble form to a soluble form, and to release the gold associated with the fine sulphides. Washing the ground calcine in weak sulphuric acid, trona, or hot water are beneficial in the order named, but to date the water is the best from an economic standpoint. Metallurgical tests as well as plant practice indicate that a certain amount of gold cannot be recovered even by going beyond economic practices. On this basis metallurgical results are viewed in the light of an optimum tailing rather than a percentage of extraction. Milling Practice Crushing (Fig. I).—There are three primary ore bins, one each for oxide ore, gougy sulphide ore, and hard sulphide ore. In front of each bin a substantial yard is maintained, which makes it possible to Stockpile 2500 tons of oxidized ore, 1000 tons of hard sulphide ore, and 1000 tons of gougy sulphide ore. The bins are fed by a 60-hp. caterpillar bulldozer from the stockpiles. Fig. I shows the method and

Jan 1, 1943

By T. M. Williams

DURING the year just ended we have had three great fires in the mines in the Wilkes-Barre district. One at the Empire Colliery, one at the Prospect shaft, and the other at the Baltimore old mine. It is proposed in this paper to give a brief history of the fire at the Empire Colliery, and the methods employed in extinguishing it. The fire was first discovered breaking out in the air-stack, alongside what is known as the " Kidder Plane," about one o&apos;clock on the morning of December 31st, 1873. Subsequently it was ascertained that the fire originated in the return airway somewhere near the steam boiler, located inside the mine, near the head of No. 5 slope. The coal from this slope was hoisted to the shaft gangway, at a point nearly four thousand feet distant from the foot of the shaft. As there were from four to five hundred mine cars hoisted per day from this slope the steam boilers were located at this place. The mines being of considerable extent required a large volume of pure air for ventilation, and no fan having been erected at this slope at the time, the heat from the boiler was made use of to assist ventilation, by conveying the return air from No. 5 slope into the large airway made from these boilers to the surface through the old "Kidder slope" to the stack where the fire was first discovered. The length of this slope or airway was about one thousand feet, with a sectional area of about sixty feet. The quantity of air passing through it must have been over sixty thousand cubic feet per minute

Jan 1, 1875

By T. L. Joseph

THE United States Bureau of Mines has been studying the blast-furnace process for, about ten years. An experimental furnace was developed by the bureau in cooperation with the Minnesota School of Mines Experiment Station, University of Minnesota. Many data have been obtained and published.1 Royster, Joseph and Kinney§(48) found that the particle size of ore had an important effect upon the blast-furnace, process. Kinney(28) stated: Economy in blast-furnace practice depends largely upon efficient gas-solid contact in the shaft of the furnace. If efficient work is not done in the shaft, the hearth and bosh will not function properly. A condition may be readily imagined where the particles of ore in the shaft are so large that the time entailed in the descent of these materials into the bosh is not sufficient to permit proper reduction and preparation prior to the time the ore enters the bosh of the furnace. Another condition may be pictured where the density of the stock column and the flow of stock is such that the ore will take one course and the gas another. Both of these examples will result in insufficient contact between the gas and the ore. Unreduced ore will reach the hearth, and the gas which has not been efficiently oxidized will reach the stock line. The result is the use of an excess of carbon in the smelting process. It is obvious that fine ore particles occurring in the ore as charged, or . formed in the furnace due to heat and mechanical action, place a definite limitation upon the efficiency of the operation. There is also an economic loss of fine material as dust.

Jan 1, 1930

By T. P. Floridis

It was deemed desirable to obtain an understanding of the vacuum desulfurization process. McKechnie1 has reported that the sulfur content of nickel- and cobalt-base alloys is reduced in vacuo. Keverian and Taylor2 have observed that vacuum melting causes desulfurization of iron-carbon-silicon alloys. Garnyk and samarin3 have desulfurized transformer steel by vacuum treatment. Experiments were conducted in order to investigate the desulfurization of liquid iron under reduced pressures, and to establish the effect of some alloying elements, and various crucible materials. A vacuum-induction furnace of 50-lb capacity was used. The charge was Armco iron. Silicon was added as 90 pct ferrosilicon, carbon as electrode graphite, and aluminum as high-purity aluminum metal. Magnesia and silica crucibles were used, their inside diameters were 5 1/2 and 5 3/8 in., respectively. The temperature was measured with an optical pyrometer and it was held at 1600 1 15°C. Samples were withdrawn with quartz tubes of 6 mm ID, without disturbing the furnace atmosphere. Pressures were measured with an alphatron gage. The experimental results are shown in Fig. 1. They indicate that: 1) Sulfur can be removed from liquid iron alloys by vacuum treatment; 2) The desulfurization is enhanced by the presence of silicon, carbon, and aluminum, all these elements increase the activity of sulfur dissolved in liquid iron;4 3) The pronounced effect of silicon indicates that probably a volatile silicon sulfide is formed, Alcock and Richardson5 have observed a similar phenomenon; 4) The same rate of desulfurization was obtained when the metal was contained in either magnesia or silica crucibles. Dr. J. Keverian has contributed many discussions and recommendations. M. S. Sutliff has helped in conducting the heats. The permission of General Electric Co. for this publication is gratefully acknowledged.

Jan 1, 1960

By T. M. Williams

DURING the year just ended we have had three great fires in the mines in the Wilkes-Barre district. One at the Empire Colliery, one at the Prospect shaft, and the other at the Baltimore old mine. It is proposed in this paper to give a brief history of the fire at the Empire Colliery, and the methods employed in extinguishing it. The fire was first discovered breaking out in the air-stack, alongside what is known as the " Kidder Plane," about one o&apos;clock on the morning of December 31st, 1873. Subsequently it was ascertained that the fire originated in the return airway somewhere near the steam boiler, located inside the mine, near the head of No. 5 slope. The coal from this slope was hoisted to the shaft gangway, at a point nearly four thousand feet distant from the foot of the shaft. As there were from four to five hundred mine cars hoisted per day from this slope the steam boilers were located at this place. The mines being of considerable extent required a large volume of pure air for ventilation, and no fan having been erected at this slope at the time, the heat from the boiler was made use of to assist ventilation, by conveying the return air from No. 5 slope into the large airway made from these boilers to the surface through the old "Kidder slope" to the stack where the fire was first discovered. The length of this slope or airway was about one thousand feet, with a sectional area of about sixty feet. The quantity of air passing through it must have been over sixty thousand cubic feet per minute