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By M. D. Flavel

The paper describes the physical aspects of the compression and impact crusher types along with the information needed to apply, install and operate them to best achieve designed performance levels. It reviews key performance parameters such as energy size relationships for crushing processes and how automation devices can optimize machine productivity. Weaknesses of existing application engineering methods are discussed. The use of pilot plant information and appropriate laboratory testing procedures are reviewed from the point of view of the application design engineer so that the best type of machine can be selected for a proposed installation.

Jan 1, 1982

By R. S. Shoemaker, R. M. Darrah

Expanded markets for copper in the past few years and a consequent search for new ore bodies have revitalized the widely known but seldom applied method of producing copper called heap leaching. Heap leaching is defined here as the process applied to oxide ores which have been mined solely for the purpose of leaching. In this case, all costs of mining the ore become a part (and a substantial one, as will be shown) of the cost of the copper produced, whereas in dump leaching the mining cost has already been accounted for as a stripping cost for the sulfide ore. Of course, with newly opened ore bodies, stripping costs may be divided through accounting procedures, between the copper produced by the mill and that obtained by leaching, but in general this type of operation must be economic on the basis of the sulfide ore alone. Heap Leaching Requires Low Capitalization Heap leaching, as a beneficiation method, is unique in that it is the only process used for the recovery of a metal in which the time involved from mining the ore to metal production is measured in months instead of hours or at the most, days. Then too, after the ore body has been depleted and mining has ceased, metal production will continue for some substantial period of time. Heap leaching is also unique because unlike any other method of beneficiation, metal recovery cannot be accurately forecast ahead of time and recovery will never approach that of a conventionally milled sulfide ore or even that of a vat leached oxide ore. Counter-balancing this drawback, however, is the relatively low capital expenditure necessary to put a heap leaching operation into production and the consequence that smaller ore bodies which would not support the higher capital cost involved in a vat leaching plant can be made into producers. Stated more simply, in heap leaching the operator accepts low recovery in exchange for low capital costs and low break even point. Whether the operator chooses vat leaching with its higher recovery and higher capital costs, is a mater of economics which depends in part on the nature of the ore to decide. For instance, an ore that will vat leach in 7 to 10 days using 7 pounds of sulfuric acid per pound of copper produced might use double or triple that amount of acid during the months that are required for heap leaching.

Jan 12, 1968

By Arthur Fleischer

The Kalunite process+ for the production of metal-grade alumina from alumina-con-taining ores is applicable, considered from a general point of view, to any aluminous raw material that can be converted to potassium alum or equivalent normal alum. This result of modern technology has been the subject of a continuous study and development since 1929, on a laboratory and test-plant scale, with initial emphasis on the utilization of alunite as the raw material. The research and developmental program was carried out by the Kalunite Company and its successor, Kalunite, Inc., an affiliate of the Olin Corporation of East Alton, Illinois. The process is now approaching the time for a major test in its history with the completion of construction of a plant having a capacity of IOO tons of alumina per day in Salt Lake City for the conversion of Marysvale, Utah, alunite ores to alumina and potassium sulphate. The Salt Lake Alumina Plant is a Defense Plant Corporation project. Production of Aluminum: The known existence of alunite deposits, especially in the Marysvale district, furnished the motive for the original inquiry into the utilization of this raw material for aluminum production. The deposits in this region were actively explored during World War I and utilized for the production of potassium sulphate, an essential fertilizer, of which a shortage of monumental proportions then existed. Up to the twentieth century—for alunite is a mineral with an ancient history—it was used in Europe and in China as a source of potassium alum. It never had been used successfully in this country as a source of oxide for reduction to metal. Although the known reserves of this ore, which undoubtedly will be greatly expanded with a commercial outlet for this ore, are recognized to be sufficient for only a part of the present-day needs of aluminum, it has a definite place in the aluminum industry. Academically it points the way for future raw materials. The aluminum industry has undergone a remarkable growth in the past few years as a result of defense and war requirements. Its expansion in many ways has been beyond belief and prediction, both in volume and location. This wartime status of the industry has accelerated the consumption of bauxite to such an extent that a re-evaluation of the raw material reserves for the future peacetime industry and for eventual wartime reserves is seemingly of concern. The generally accepted picture of bauxite ore reserves in the United States, especially in raw material suitable for treatment by the Bayer process, focuses attention on other possible sources of raw material of metal-grade oxide. The perspective for the development of a suitable process may have changed in the interim since the original work by Kalunite, but the ultimate goal is the same.

Jan 1, 1944

By W. C. Weslow

AN extended program devoted to the development of a matrix for holding diamonds of a size and. kind not heretofore generally used is being carried on by the Carboloy Company, and this paper describes the part of the development that affects mining and its allied industries. Labora-tory and field work so far has indicated the following: 1. Tungsten carbide and cobalt form the most desirable known matrix material for the holding of diamonds for drilling work. 2. Industrial bort diamonds in sizes and of a class not generally heretofore acceptable and therefore less expensive can be successfully held in this cemented carbide matrix. 3. In exploratory drilling, the combination of bort diamonds, impreg-nated throughout a matrix of tungsten carbide and cobalt, when fabri-cated onto drilling crowns, is an indicated economic substitute for drilling crowns in which the diamonds are set by hand, mechanically or by casting. 4. This impregnated type of drilling crown or bit has definite possi-bilites of revolutionizing the drilling of blast holes, particularly in the harder formations. This will be brought about by the development of high-speed light-weight rotary equipment using an impregnated diamond bit to replace the percussion drill now in general use. (The development of this rotary equipment is well past the laboratory stage at this time.) 5. That the use of a rotary bit is a preventive measure in the fight against silicosis. The development of this product was started by G. F. Taylor at the Research Laboratories of the General Electric Co. It was early recog-nized that it had possibilities in the drilling field and the present product is the result of considerable experimental work with other powdered metals as well as with tungsten carbide and cobalt.

Jan 1, 1940

By Benjamin S. Lindsey, James Norman

BARITE (BaSO4) is the most important industrial barium mineral from the standpoint of quantity consumed. In 1938 the amount was 365,000 tons. Its uses are numerous, some of the more important being in the production of pigments, as an inert filler in a wide variety of products, as a weighting material in oil-well drilling muds, in the manufacture of some kinds of glass, and in the production of barium chemicals. The barite studied in this investigation occurs as the massive variety in a shale replacement formation near Magnet Cove, Ark. It is intimately mixed with quartz and small amounts of iron oxide and residual shale. Complete liberation of barite and quartz is not obtained when the rock is ground to 100 per cent through 325 mesh. The crude rock with which all test work was done assayed 85.1 per cent BaSO4, 11.11 per cent Si02, and 2.85 per cent R203. Its specific gravity was 4.03. It was found in the course of the investigation that the barite contained a small amount of uniformly distributed carbonaceous material, so intimately dispersed that it could not be seen with the microscope, but gave a definite gray cast to the barite concentrates. The color of the barite in polished sections of the crude rock ranged from gray to almost black, while finely ground powder ,was a reddish gray. The reddish hue was due to the iron oxide present. In 1939, under the supervision of Oliver C. Ralston,* the Bureau of Mines, in cooperation with the Milwhite Company, of Houston, Texas, undertook to study the flotation of barite from Magnet Cove, Ark. Flotation of several southern barite ores had already been investigated by the Bureau of Mines.' The Magnet Cove barite was unique, however, in that it had to be ground to such an extremely small particle size for liberation. The flotation of nonmetallic minerals in the presence of a large amount of slime is usually very difficult, and when done is an innovation calling for conditions different from those under which granular material is separated. LABORATORY FLOTATION WORK Preliminary investigation showed that the flotation reagents recommended by O'Meara and Coe1 for separating barite and siliceous material were suitable, but much larger quantities of reagents were required to separate such finely divided material. Moreover, it was found that careful control of the frothing was necessary. When oleic acid and sodium silicate were used a voluminous froth was observed at the beginning of a test, and toward the end there was not enough froth to effect complete recovery of barite. The addition of pine oil as a frother gave proper frothing for the duration of the test, and the substitution of coconut fatty acid (crude lauric acid) for oleic acid produced a more heavily burdened froth. Two different paper-mill fatty-acid products were tested

Jan 1, 1941

Without having asked for it, the writer has apparently been drawn into the discussion regarding relative hoisting capacities which was started by Woodward Iron, egged on by Joe Haller of Cleveland-Cliffs [Mining Engineering, August p. 642] and Axel Kjelgaard [November p. 919], who took exception to Mr. Haller's remarks of tonnage hoisted and avers that they do better in Sweden. It does not appear to the writer that Mr. Haller was inclined to refer to the tonnage hoisted at Cleveland-Cliffs in a manner to imply that they claimed any hoisting record, but rather as a statement that they had hoisted a certain amount of ore during the year 1950. Mr. Haller has been in the mining game long enough to appreciate what Mr. Kjelgaard did not apparently take into consideration, that length of haul, shifts hoisted, nature of ore, method of loading and the many other factors which influence the hoisting cycle make a comparison of tonnages hoisted of two given mines almost an impossibility. Mr. Cheyette sent you .a copy of his letter to Bob Manegold relative to the capacities of the Orient #2 mine. There are several mines around the Country which constantly set up records about which little or nothing at all is ever heard. We cite the Snow Hill Coal Co. mine at Terre Haute, Ind., which has an automatic Nordberg hoist and which hoists 12 tons per trip or 700 tons per hr from 700 ft. This is a counter-weighted installation and a complete cycle is made every 62 seconds or 58 trips per hr. Another mine, The Potash Company of America mine at Carlsbad, N. Mex., has a Nordberg automatic hoist, hoisting eight tons per trip from 1150 ft on a one minute cycle. The materials hoisted in these two mines are ideal for automatic hoisting-they are free flowing so that no hang up is anticipated and hoisting is continuous. Multiplying out the above figures you will find that it is possible to hoist 11,000 tons in two shifts at Snow Hill or over 3 million tons in 300 days per year and over 2 million tons at Potash. Other mines have records which can be pointed to with pride. When a record for one year is established, it doesn't stand too long as here in America the ambition of all the men connected with the operation forces them on to larger tonnages. T. C. WIEDENHOEFER MANAGER MINE HOIST DEPARTMENT NORDBERG MANUFACTNRING CO. MILWAUKEE, WIS.

Jan 1, 1952

By James Norman, Benjamin S. Lindsey

Barite (BaSO4) is the most important industrial barium mineral from the standpoint of quantity consumed. In 1938 the amount was 365,000 tons. Its uses are numerous, some of the more important being in the production of pigments, as an inert filler in a wide variety of products, as a weighting material in oil-well drilling muds, in the manufacture of some binds of glass, and in the production of barium chemicals. The barite studied in this investigation occurs as the massive variety in a shale replacement formation near Magnet Cove, Ark. It is intimately mixed with quartz and small amounts of iron oxide and residual shale. Complete liberation of barite and quartz is not obtained when the rock is ground to I00 per cent through 325 mesh. The crude rock with which all test work was done assayed 85.1 per cent BaS04, II.II. per cent SiO2, and 2.85 per cent R2O3. Its specific gravity was 4.03. It was found in the course of the investigation that the barite contained a small amount of uniformly distributed carbonaceous material, so intimately dispersed that it could not be seen with the microscope, but gave a definite gray cast to the barite concentrates. The color of the barite in polished sections of the crude rock ranged from gray to almost black, while finely ground powder was a reddish gray. The reddish hue was due to the iron oxide present. In 1939, under the supervision of Oliver C. Ralston,* the Bureau of Mines, in cooperation with the Milwhite Company, of Houston, Texas, undertook to study the flotation of barite from Magnet Cove, Ark. Flotation of several southern barite ores had already been investigated by the Bureau of Mines.' The Magnet Cove barite was unique, however, in that it had to be ground to such an extremely small particle size for liberation. The flotation of non-metallic minerals in the presence of a large amount of slime is usually very difficult, and when done is an innovation calling for conditions different from those under which granular material is separated. Laboratory Flotation Work Preliminary investigation showed that the flotation reagents recommended by O'Meara and Coel for separating barite and siliceous material were suitable, but much larger quantities of reagents were required to separate such finely divided material. Moreover, it was found that careful control of the frothing was necessary. When oleic acid and sodium silicate were used a voluminous froth was observed at the beginning of a test, and toward the end there was not enough froth to effect complete recovery of barite. The addition of pine oil as a frother gave proper frothing for the duration of the test, and the substitution of coconut fatty acid (crude lauric acid) for oleic acid produced a more heavily burdened froth. Two different paper-mill fatty-acid products were tested

Jan 1, 1943

By James Norman, Benjamin S. Lindsey

BaritE (BaSO4) is the most important industrial barium mineral from the standpoint of quantity consumed. In 1938 the amount was 365,000 tons. Its uses are numerous, some of the 'more important being in the production of pigments, as an inert filler in a wide variety of products, as a weighting material in oil-well drilling muds, in the manufacture of some kinds of glass, and in the production of barium chemicals. The barite studied in this investigation occurs as the massive variety in a shale replacement formation near Magnet Cove, Ark. It is intimately mixed with quartz and small amounts of iron oxide and residual shale. Complete liberation of barite and quartz is not obtained when the rock is ground to 100 per cent through 325 mesh. The crude rock with which all test work was done assayed 85.1 per cent BaSO4, II.II per cent SiO², and 2.85 per cent R²O3. Its specific gravity was 4.03. It was found in the course of the investigation that the barite contained a small amount of uniformly distributed carbonaceous material, so intimately dispersed that it could not be seen with the microscope, but gave a definite gray cast to the barite concentrates. The color of the barite in polished sections of the crude rock ranged from gray to almost black, while finely ground powder was a reddish gray. The reddish hue was due to the iron oxide present. In 1939, under the supervision of Oliver C. Ralston,* the Bureau of Mines, in cooperation with the Milwhite Company, of Houston, Texas, undertook to study the flotation of barite from Magnet Cove, Ark. Flotation of several southern barite ores had already been investigated by the Bureau of Mines.' The Magnet Cove barite was unique, however, in that it had to be ground to such an extremely small particle size for liberation. The flotation of non-metallic minerals in the presence of a large amount of slime is usually very difficult, and when done is an innovation calling for conditions different from those under which granular material is scparated. Laboratory Flotation Work Preliminary investigation showed that the flotation reagents recommended by O'Meara and Coe1 for separating barite and siliceous material were suitable, but much larger quantities of reagents were required to separate such finely divided material. Moreover, it was found that careful control of the frothing was necessary. When oleic acid and sodium silicate were used a voluminous froth was observed at the beginning of a test, and toward the end there was not enough froth to effect complete recovery of barite. The addition of pine oil as a frother gave proper frothing for the duration of the test, and the substitution of coconut fatty acid (crude lauric acid) for oleic acid produced a more heavily burdened froth. Two different paper-mill fatty-acid products were tested

Jan 1, 1942

By Benjamin S. Lindsey, James Norman

BaritE (BaSO4) is the most important industrial barium mineral from the standpoint of quantity consumed. In 1938 the amount was 365,000 tons. Its uses are numerous, some of the 'more important being in the production of pigments, as an inert filler in a wide variety of products, as a weighting material in oil-well drilling muds, in the manufacture of some kinds of glass, and in the production of barium chemicals. The barite studied in this investigation occurs as the massive variety in a shale replacement formation near Magnet Cove, Ark. It is intimately mixed with quartz and small amounts of iron oxide and residual shale. Complete liberation of barite and quartz is not obtained when the rock is ground to 100 per cent through 325 mesh. The crude rock with which all test work was done assayed 85.1 per cent BaSO4, II.II per cent SiO², and 2.85 per cent R²O3. Its specific gravity was 4.03. It was found in the course of the investigation that the barite contained a small amount of uniformly distributed carbonaceous material, so intimately dispersed that it could not be seen with the microscope, but gave a definite gray cast to the barite concentrates. The color of the barite in polished sections of the crude rock ranged from gray to almost black, while finely ground powder was a reddish gray. The reddish hue was due to the iron oxide present. In 1939, under the supervision of Oliver C. Ralston,* the Bureau of Mines, in cooperation with the Milwhite Company, of Houston, Texas, undertook to study the flotation of barite from Magnet Cove, Ark. Flotation of several southern barite ores had already been investigated by the Bureau of Mines.' The Magnet Cove barite was unique, however, in that it had to be ground to such an extremely small particle size for liberation. The flotation of non-metallic minerals in the presence of a large amount of slime is usually very difficult, and when done is an innovation calling for conditions different from those under which granular material is scparated. Laboratory Flotation Work Preliminary investigation showed that the flotation reagents recommended by O'Meara and Coe1 for separating barite and siliceous material were suitable, but much larger quantities of reagents were required to separate such finely divided material. Moreover, it was found that careful control of the frothing was necessary. When oleic acid and sodium silicate were used a voluminous froth was observed at the beginning of a test, and toward the end there was not enough froth to effect complete recovery of barite. The addition of pine oil as a frother gave proper frothing for the duration of the test, and the substitution of coconut fatty acid (crude lauric acid) for oleic acid produced a more heavily burdened froth. Two different paper-mill fatty-acid products were tested

Jan 1, 1942

By Benjamin S. Lindsey, James Norman

Barite (BaSO4) is the most important industrial barium mineral from the standpoint of quantity consumed. In 1938 the amount was 365,000 tons. Its uses are numerous, some of the more important being in the production of pigments, as an inert filler in a wide variety of products, as a weighting material in oil-well drilling muds, in the manufacture of some binds of glass, and in the production of barium chemicals. The barite studied in this investigation occurs as the massive variety in a shale replacement formation near Magnet Cove, Ark. It is intimately mixed with quartz and small amounts of iron oxide and residual shale. Complete liberation of barite and quartz is not obtained when the rock is ground to I00 per cent through 325 mesh. The crude rock with which all test work was done assayed 85.1 per cent BaS04, II.II. per cent SiO2, and 2.85 per cent R2O3. Its specific gravity was 4.03. It was found in the course of the investigation that the barite contained a small amount of uniformly distributed carbonaceous material, so intimately dispersed that it could not be seen with the microscope, but gave a definite gray cast to the barite concentrates. The color of the barite in polished sections of the crude rock ranged from gray to almost black, while finely ground powder was a reddish gray. The reddish hue was due to the iron oxide present. In 1939, under the supervision of Oliver C. Ralston,* the Bureau of Mines, in cooperation with the Milwhite Company, of Houston, Texas, undertook to study the flotation of barite from Magnet Cove, Ark. Flotation of several southern barite ores had already been investigated by the Bureau of Mines.' The Magnet Cove barite was unique, however, in that it had to be ground to such an extremely small particle size for liberation. The flotation of non-metallic minerals in the presence of a large amount of slime is usually very difficult, and when done is an innovation calling for conditions different from those under which granular material is separated. Laboratory Flotation Work Preliminary investigation showed that the flotation reagents recommended by O'Meara and Coel for separating barite and siliceous material were suitable, but much larger quantities of reagents were required to separate such finely divided material. Moreover, it was found that careful control of the frothing was necessary. When oleic acid and sodium silicate were used a voluminous froth was observed at the beginning of a test, and toward the end there was not enough froth to effect complete recovery of barite. The addition of pine oil as a frother gave proper frothing for the duration of the test, and the substitution of coconut fatty acid (crude lauric acid) for oleic acid produced a more heavily burdened froth. Two different paper-mill fatty-acid products were tested

Jan 1, 1943

By Benjamin S. Lindsey, James Norman

BARITE (BaSO4) is the most important industrial barium mineral from the standpoint of quantity consumed. In 1938 the amount was 365,000 tons. Its uses are numerous, some of the more important being in the production of pigments, as an inert filler in a wide variety of products, as a weighting material in oil-well drilling muds, in the manufacture of some kinds of glass, and in the production of barium chemicals. The barite studied in this investigation occurs as the massive variety in a shale replacement formation near Magnet Cove, Ark. It is intimately mixed with quartz and small amounts of iron oxide and residual shale. Complete liberation of barite and quartz is not obtained when the rock is ground to 100 per cent through 325mesh. The crude rock with which all test work was done assayed 85.1 per cent BaSO4, 11.11 per cent Si02, and 2.85 per cent R2O3. Its specific gravity was 4.03. It was found in the course of the investigation that the barite contained a small amount of uniformly distributed carbonaceous material, so intimately dispersed that it could not be seen with the microscope, but gave a definite gray cast to the barite concentrates. The color of the barite in polished sections of the crude rock ranged from gray to almost black, while finely ground powder was a reddish gray. The reddish hue was due to the iron oxide present. In 1939, under the supervision of Oliver C. Ralston,* the Bureau of Mines, in cooperation with the Milwhite Company, of Houston, Texas, undertook to study the flotation of barite from Magnet Cove, Ark. Flotation of several southern barite ores had already been investigated by the Bureau of Mines.1 The Magnet Cove barite was unique, however, in that it had to be ground to such an extremely small particle size for liberation. The flotation of nonmetallic minerals in the presence of a large amount of slime is usually very difficult, and when done is an innovation calling for conditions different from those under which granular material is separated. LABORATORY FLOTATION WORK Preliminary investigation showed that the flotation reagents recommended by O'Meara and Coe1 for separating barite and siliceous material were suitable, but much larger quantities of reagents were required to separate such finely divided material. Moreover, it was found that careful control of the frothing was necessary. When oleic acid and sodium silicate were used a voluminous froth was observed at the beginning of a test, and toward the end there was not enough froth to effect complete recovery of barite. The addition of pine oil as a frother gave proper frothing for the duration of the test, and the substitution of coconut fatty acid (crude lauric acid) for oleic acid produced a more heavily burdened froth. Two different paper-mill fatty-acid products were tested

Jan 1, 1941

By James Norman

BARITE (BaSO4) is the most important industrial barium mineral from the standpoint of quantity consumed. In 1938 the amount was 365,000 tons. Its uses are numerous, some of the more important being in the production of pigments, as an inert filler in a wide variety of products, as a weighting material in oil-well drilling muds, in the manufacture of some kinds of glass, and in the production of barium chemicals. The barite studied in this investigation occurs as the massive variety in a shale replacement formation near Magnet Cove, Ark. It is intimately mixed with quartz and small amounts of iron oxide and residual shale. Complete liberation of barite and quartz is not obtained when the rock is ground to loo per cent through 325 mesh. The crude rock with which all test work was done assayed 85.1 per cent BaSO4, 11.11 per cent SiO2, and 2.85 per cent R2O3. Its specific gravity was 4.03. It was found in the course of the investigation that the barite contained a small amount of uniformly distributed carbonaceous material, so intimately dispersed that it could not be seen with the microscope, but gave a definite gray cast to the barite concentrates. The color of the barite in polished sections of the crude rock ranged from gray to almost black, while finely ground powder was a reddish gray. The reddish hue was due to the iron oxide present. In 1939, under the supervision of Oliver C. Ralston,* the Bureau of Mines, in cooperation with the Milwhite Company, of Houston, Texas, undertook to study the flotation of barite from Magnet Cove, Ark. Flotation of several southern barite ores had already been investigated by the Bureau of Mines.' The Magnet Cove barite was unique, however, in that it had to be ground to such an extremely small particle size for liberation. The flotation of nonmetallic minerals in the presence of a large amount of slime is usually very difficult and when done is an innovation calling for conditions different from those under which granular material is separated. LABORATORY FLOTATION WORK Preliminary investigation showed that the flotation reagents recommended by O'Meara and Coe1 for separating barite and siliceous material were suitable, but much larger quantities of reagents were required to separate such finely divided material. Moreover, it was found that careful control of the frothing was necessary. When oleic acid and sodium silicate were used a voluminous froth was observed at the beginning of a test, and toward the end there was not enough froth to effect complete recovery of barite. The addition of pine oil as a frother gave proper frothing for the duration of the test, and the substitution of coconut fatty acid (crude lauric acid) for oleic acid produced a more heavily burdened froth. Two different paper-mill fatty-acid products were tested

Jan 1, 1941

By G. Howell Clevenger, Bhupendranath Ray

Formerly great divergence of opinion existed in regard to the influence of copper in steel, as affecting its various physical properties. More recently the investigations of Stead,l Breuil,2 Wigham,3 Burgess and Aston: Ball and Wingham,5 Miiller; Dillner,7 and others have shown fairly good agreement in the major points. Copper steel has been shown by these investigators to possess special properties which make it valuable for certain uses. The general range of composition of the useful alloys of copper and iron, and of copper, iron, and carbon, has been quite definitely established, for the former by Burgess and Aston,8 and for the latter by Breuil9 and Stead.10 Stead11 has removed one difficulty in reconciling certain of the earlier data by calling particular attention to the influence 'of carbon in copper steels. Another point which caused confusion in the earlier investigations, particularly in regard to " red-shortness," was the presence of sulphur. Failure to note the presence of sulphur often led to attributing " red-shortness" to the presence of small amounts of copper. Turner12 has called attention to the fact that where copper exists in an iron ore it often occurs as the sulphide, so that the presence of copper in steel made from such ores might also, necessarily, mean the presence of sulphur. It is evident that the effect in this case might be quite different than where pure copper was added.

Jan 1, 1914

By Basil Prescott

In the science of evolution of the species, there is a law which, simply stated, avers that the history of the individual repeats the history of the race. Similarly, if unassisted by the experience of others, each SUCcessful engineer would perfect and develop his methods and technique from the rough grab sample up to the carefully taken, recorded and studied samples and observations which now determine and decide the expenditure of the large sums required for modern mining. Hence real progress results from the interchange of experience, as in that way the entire experience of the profession can be made available to every engineer. The literature of this subject is already voluminous, but some progress has been made in the gathering of data and in their compilation or presentation. More Romance than Developed Ore in Limestone Deposits In certain types of deposits, methods little known 25 yews ago have been developed, perfected and standardized to a degree that lifts sampling from the field of manual labor to the plane of an applied science; for instance, the modern methods of estimating the so-called porphyry coppers. With some types of orebodies, we have become familiar, and sometimes on too easy speaking terms, with millions of tons of ore in reserve and tens of millions of dollars; while with others even these once marvelous figures sink into insignificance before the array of ciphers that are presented. .In such company, the average limestone replacement orebody is entirely out of place, for its reserves seldom reach a figure to arrest the attention of the modern engineer, and more often are insignificant. It is only when the records of the production of some of the older camps are studied, which show them to have continuously produced over very extended periods, that a realization is borne home that occasionally this type is worthy of consideration even in these days of gigantic tonnage.

Jan 1, 1925

By EDWARHD HALSE

Discussion of the Paper of Dr. H. M. Chance, presented at the Lake Superior Meeting, September, 1904. EDWARD HALSE, Puerto Berrio, Colombia, So. Amer. (communication to the Secretary*) : The Taviche mining-district is generally known as a Taviches," being named from the two villages called respectively San Pedro Taviche and San Jeronimo Taviche. It is so called by José G. Aguilera, in his paper on the Geographical and Geological Distribution of the Mineral Deposits of Mexico;' and in published reports by the late N. W. Rudston Read ;2 and by Juan de Dios Villarello.3 The region is a large one, measuring about 24 miles long and 7 miles wide. Dr. Chance, in his interesting paper, tells us very little about the nature of the ores, and, with regard to the geology of the district, contents himself with observing that ? the country, as a rule, consists of eruptive rocks; and no evidences of sedimentary strata appear near the mines.? The latter part of the above statement is hardly correct. The formation is mainly eruptive, being hornblende-audesite of Tertiary age, which is limited on the east by the calcareous (Cretaceous) formation, and on the west by the Huronian rocks of Ocotlan. Limestone is seen close to the Santa Càtarina mine, at the northern end of the region. In the surface-working known as La Cueva, a little northeast of San Pedro, limestone forms the eastern wall of the deposit which consists of spots (moscas) of pyrargyrite in white opaque or transparent quartz. Ill one place the ore is associated with stibnite, and the quartz frequently exhibts a

Sep 1, 1905

By AIME AIME

ON Thursday, Oct. 9, oil men from far and wide gathered at Beaumont, Texas to participate in a three-day celebration of the fortieth anniversary of the completion of the famous Lucas gusher well at Spindletop field just south of Beaumont, and to pay tribute to Anthony F. Lucas, for whom the Lucas Medal of the A.I.M.E. is named. In the afternoon the gathered host drove to the site of the discovery well to dedicate a 58-ft. granite monu¬ment erected on the spot where the original derrick stood. Representatives of the A.I.M.E. took a prominent part in the dedication ceremonies, giving the two principal addresses of the afternoon's program. Everette DeGolyer, past President, paid a personal tribute to Capt. Lucas, as a pioneer producer, an engineer, and a friend and well wisher of all young engineers. He gave a splendid picture of the useful and full life of Capt. Lucas who always took a great interest in the activities of the Petroleum Division of the Institute, from its inception to the time of his death.

Jan 1, 1941

By E. Gaujot

IN connection with the question of coal waste and economy in mining, we would call the attention of those interested to an apparatus invented by M. Dernencourt, Superintendent of the Anzin Division of the Anzin Coal Company, North of France. This apparatus is known in France and Belgium under the name of prop screw-jack (vis botte), and has been used with good results in the above-named countries for some years past. M. Ponson gives, in his " Trait6 de I'exploitation des Mines," a description of it (page 533), but as the description given is old, the work not widely known in this country, and as some valuable improvements have been made since, I thought it might be useful to give a description of it, having seen it in 'operation in 1867, while in Europe to attend the great Exposition, and on a scientific tour to the mining districts of France, Germany, Belgium, and Italy. The prop screw-jack is composed of the following pieces : I. The body or column B, Fig. 4 [Plate (I)], of oak or yellow pine, sawed square, the bark taken off, and any length, proportionate to the vein. The smallest are 10 inches diameter at the base, and 9 inches at the top, the height being from 12 to 15 inches less than the size of the vein. In the axis of this column, and at the top end, is a cylindrical opening or hole, C, 22 inches diameter, 10 inches deep, for the screw, S. II. Two wrought-iron rings, R R, to strengthen the two extremities of the column ; the rings must be put on hot. III. A cast,-iron washer, E, with hole in centre a little larger than the screw, to be put on the top of the column, and on which the nut is to rest; the top side of this washer must be faced on the lathe, also the bottom of the nut, to prevent friction. IV. The screw, S, having a total length of 12 inches and a diameter of 24 inches (for very high veins this diameter may be increased to 3 inches), and has on its top a wrought-iron plate, T,

By J. R. Linney

Demand for eastern magnetite in 1948 necessitated practically all eastern magnetite industries to operate on a six-day week, with the result that over 11,000,000 long tons of crude ore were mined, and the shipping products amounted to approximately 5,000,. 000 long tons. Reports indicate that operating on a six-day week and doing maintenance work on the seventh day was satisfactory and resulted in excellent continuity of operation. In the Port Henry district, Republic Steel Corp. once again set new all-time records for the production of crude ore and total shipping product; 1,868,000 long tons of crude ore were mined, 945,000 from the Old Bed mine, 408,500 from the Harmony mine, and 514,500 from the Fisher Hill mine. Of the 969,000 long tons of shipping products, 663,800 long tons were sinter, 181,000 lump ore, and 115,200 con¬centrates.

Jan 1, 1949

By Nobuhiro Takahashi

PROLOGUE The Yaguki mine, which is located near the southern end of the Tohoku region, Japan, near the coast of the Pacific Ocean, had had a long history as a copper mine, but had not been operated since 1925. About 30 years later it was reopened by Nittetsu Mining Company, and in 1958 a small flotation and magnetic separation plant, a so-called test plant, started production. The ball mill the author first met, a 8x4x4x7 ft tricone mill, called No.1 mill, had started running at that time. With his experience in initial, running of this mill he realized that the ball mill was not simply a preparatory process to flotation, but a determinant factor for flotation performance, an energy-consuming and costly process, and that its operation control was an important task in the plant (1). The working part of an operating ball mill is the ball load inside, whose properties govern the grinding performance. Its size distribution affects the efficiency greatly and the capacity is nearly proportional to its weight. When a ball mill operates for a long period of time with a constant and consistent addition of renewal balls, wear and renewal of balls are balanced, and an equilibrium ball load is formed. A stable equilibrium load is the primary requirement for a stable ball mill operation. However, renewal ball size would be the most influential factor affecting efficiency and capacity of operating ball mills. To improve efficiency, to increase capacity, or to get finer product, attempts to find out the optimum size assortment of renewal balls should be made. When re-

Jan 1, 1976

By K. L. Komarek

Based on theoretical and experimental evidence a discussion follows of the behavior of phosphorus -bearing iron ores in the R-N Direct Reduction Process and suggestions are made of methods of reducing the amount of phosphorus in the metallic end product. In ferrous metallurgy a direct reduction process is one in which iron ores are reduced to metallic iron with gaseous or solid reductants without the appearance of a liquid phase. A number of attractive features have induced several companies and government agencies to invest in the development of direct reduction processes. A summary of all direct reduction processes up to 1954 has been given by Barrett,' and Wiberg,2 and Willems3 have reviewed the most recent developments in this rapidly expanding field. Many difficulties have been encountered in direct reduction processes and the nature of these difficulties has varied from process to process. One problem common to almost all of them is the removal of phosphorus which is one of the reasons for the rather pessimistic outlook given by some government publications4'5 to direct reduction processes. In this paper an attempt is made to give a theoretical explanation of the variations in phosphorus removal observed in the R-NY Direct Reduction Process. However, many conclusions are general enough to be applicable to other processes. Most iron ores treated by the R-N process yield products lower in phosphorus than the original ore. A qualitative account of the factors has been given by Stewart, Reed, and Herasymenkoe but the erratic removal of phosphorus from some ores and the general importance of this problem make a more careful analysis of the theoretical aspects desirable. In the R-N process mixed ore or balled fines, ex-

Jan 1, 1963