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By Thomas F. Evans

This study shows that statistics on the rate of coal dumping can measure the effectiveness of freeze conditioning agents. The use of appropriately indexed dumping intervals or interval logrithms provides a more sensitive indication of unloading problems than does a simple calculation of average loading time because of the abnormal form of the distribution of dumping intervals. The paper presents information that indicates suitably applied coal freeze conditioning agents are effective in reducing coal handling problems attributable to frozen coal. Graphs and figures show that the severity of coal freezing potential due to subfreezing temperatures is proportional to the exposure time and average departure of the temperature from the freezing point.

Jan 1, 1982

By Walter H. Voskuil

Illinois supplies coal to seven states in the Upper Mississippi Valley —Illinois, Missouri, Iowa, Minnesota, Wisconsin, and portions of the Dakotas, Nebraska and Kansas. In this same area are marketed large quantities of coal from West Virginia, Kentucky, Pennsylvania, and elsewhere; fuel oil from the crude petroleum supplies of the Mid-Continent fields, and natural gas from Louisiana, Kansas and the Texas Panhandle. The boundaries of this "Illinois coal-market area" are determined by competition from other coal fields and from other forms of fuel. Within the area so described 90 per cent of Illinois coal is marketed. Thus in the Southwest, an abundance of fuel-oil supplies and natural gas dominates the market almost to the exclusion of coal. The westward movement of Illinois coal in Kansas, Nebraska and the Dakotas is met by an eastward flow of high-grade coals from Colorado, Wyoming and Montana. In the lake-shore counties of Minnesota and Wisconsin, the market is dominated by Appalachian coals, cheaply carried over the Great Lakes and reaching the ports of Lake Michigan and at the head of Lake Superior. Illinois coals find their largest market in the southern and western sections of these two lake states. Only small quantities of Illinois coals are shipped east of the state line. This market area is occupied entirely by the neighboring coal fields of Indiana and the Appalachian coal fields in Ohio, West Virginia, Kentucky and Pennsylvania. Illinois Coal-makket Area , With these factors in mind, the map of the Illinois coal-market area may be drawn. Within this boundary is the area that is logically and economically served by Illinois coal. However, this area is by no means exclusively dependent upon coal from Illinois mines. The preponderance. of Appalachian coal in Wisconsin and Minnesota has been mentioned. Appalachian coal, also, moves in large tonnages into Illinois itself, particularly the Chicago district. The Iowa and Missouri local coals share the market with imported coal from Illinois; throughout the market area, fuel oil and natural gas are important factors in the total energy supply.

Jan 1, 1936

By Walter H. Voskuil

Illinois supplies coal to seven states in the Upper Mississippi Valley —Illinois, Missouri, Iowa, Minnesota, Wisconsin, and portions of the Dakotas, Nebraska and Kansas. In this same area are marketed large quantities of coal from West Virginia, Kentucky, Pennsylvania, and elsewhere; fuel oil from the crude petroleum supplies of the Mid-Continent fields, and natural gas from Louisiana, Kansas and the Texas Panhandle. The boundaries of this "Illinois coal-market area" are determined by competition from other coal fields and from other forms of fuel. Within the area so described 90 per cent of Illinois coal is marketed. Thus in the Southwest, an abundance of fuel-oil supplies and natural gas dominates the market almost to the exclusion of coal. The westward movement of Illinois coal in Kansas, Nebraska and the Dakotas is met by an eastward flow of high-grade coals from Colorado, Wyoming and Montana. In the lake-shore counties of Minnesota and Wisconsin, the market is dominated by Appalachian coals, cheaply carried over the Great Lakes and reaching the ports of Lake Michigan and at the head of Lake Superior. Illinois coals find their largest market in the southern and western sections of these two lake states. Only small quantities of Illinois coals are shipped east of the state line. This market area is occupied entirely by the neighboring coal fields of Indiana and the Appalachian coal fields in Ohio, West Virginia, Kentucky and Pennsylvania. Illinois Coal-makket Area , With these factors in mind, the map of the Illinois coal-market area may be drawn. Within this boundary is the area that is logically and economically served by Illinois coal. However, this area is by no means exclusively dependent upon coal from Illinois mines. The preponderance. of Appalachian coal in Wisconsin and Minnesota has been mentioned. Appalachian coal, also, moves in large tonnages into Illinois itself, particularly the Chicago district. The Iowa and Missouri local coals share the market with imported coal from Illinois; throughout the market area, fuel oil and natural gas are important factors in the total energy supply.

Jan 1, 1936

EDWIN M. CHANCE (communication to the Secretary?).-The subject of miners' lamps. has long interested me and it would seem that the thought that has been given to it by the Bureau of Mines, and the users

Jan 6, 1917

By Haydn H. Murray

Although alumina constitutes about 15% of the earth's crust, it is expensive to separate and purify for the production of aluminum with the exception of the alumina in bauxite. The United States has a variety of nonbazurite resources that could substitute for bauxite, including high alumina clays, alunite, dawsonite in oil shale, anorthosite, and nepheline venite. Each of these resources is discussed from the standpoint of geology, geography, processing, and potential recovery. Potential byproducts include alica from clays, potash and sulfuric acid from alunite, soda ash from dawsonite, and soda ash and potash from anorthosite and nepheline syenite.

Jan 1, 1983

By Charles Malcolmson

AN elaborate series of experiments has been conducted during the past three years at Irvington, N. J., which has resulted in the perfection of a process for the manufacture of smokeless fuel from high-volatile coals, and for the recovery and refinement of the coal-tar products derived therefrom. These experiments have been financed by Messrs. Blair Co., of New York, and were conducted under the direction of Charles H. Smith, a member of this Institute, and the inventor of the process. The low-temperature distillation of coal has interested investigators for many years. Sporadic attempts have been made to solve the mechanical problems, but until the Smith process. was developed, they were not carried to conclusions of economic value. The present coal shortage and the increasing demand for smokeless fuels make this subject one of timely interest.

Jan 5, 1918

Jan 1, 1908

By J. C. Jaeger

It frequently happens in engineering and mining situations that "bad" rock is encountered which consists of rock broken up into blocks a few inches or less in diameter by a network of intersecting joints. These joints may be open, or filled by veins of solid material, or covered with weathering products. Essentially, the material consists of an aggregate of small interlocking blocks. In such circumstances, major joint systems usually can be recognised and studied, but there are probably many minor planes of weakness which may cause the blocks to be of almost random shape. It is extremely difficult to determine the properties of such materials. Measurements on small specimens give the properties of the constituent rock and not the jointed material. At the other extreme, the material has occasionally been tested as loose aggregate in large triaxial pots, but this gives no information about the strengthening effect of the interlocking of the small blocks of rock. One simple approach, which has been much used, is to regard the rock as randomly jointed on a small scale and to apply soil mechanics theory to it. In this case, the normal and shear stress at failure are related by [ ] where the coefficient of friction p and the cohesion c will be those of the individual joints. Even in very bad rock, it is usually possible to drill core in small diameters of 1 to 2 in. which will contain a number of joints, both open and filled. The testing of such joints provides one simple method of determining some of the properties of closely jointed rock and will be discussed in detail in the next section. Calculations based on Eg. 1 with values of c and µ obtained in this way may be expected to give a lower limit for the strength of structures in rock.

Jan 1, 1970

By Charles E. Packard

Many coal producers have been faced recently with the problem of arranging their production facilities to accommodate recent trends in the transportation of their product. Each operator is normally faced with a different problem requiring a system to meet his specific needs. It may be that he would be required to load a seven or eight thousand ton integral train each day which would naturally call for a large storage pile, high loading rate, accomplished in a minimum of time On the other hand, it may be that he is faced with furnishing coal to make up one-half of a unit train that is to be assembled twice a week. Whether the problem is large or small, many considerations must be given to each specific problem to be certain that the proper scheme is applied. The operator actually has several choices as to what type of storage and loading facilities he may consider. The storage pile, for instance, may be open type, conical in shape, kidney-shaped, or long and wedge-shaped. It may also be enclosed by steel or concrete

Jan 8, 1964

By L. S. Chabot

INTRODUCTION THE bibliography of mining methods in the past few years has contained many articles dealing with the use of the diamond drill for blasthole drilling. In the Canadian mines, this method has been used with great success in stoping at Noranda, Aldermac, Waite Amulet, East Malartic and Sladen Malartic mines in the Province of Quebec. It has also been used at the Dorchester and Beattie gold mines in Duparquet, Quebec. The method has found useful application at Copper Mountain mine, British Colombia, and at Flin Flon mine in Manitoba. In the United States, the diamond drill blasthole method has been used at Cornwall Iron Ore Mines in Pennsylvania and at the Republic Steel Corporation magnetite properties in the Port Henry district of northern New York. In the Lake Superior iron district, the method has been used at the Anvil-Palms mine of Pickands, Mather and Co. at Bessemer, Mich., and is also used at the Book mine of the North Range Mining Co. at Alpha, Mich. Other companies in the district have also experimented in some degree with the method at some of their properties. This paper is being offered as a preliminary report on the use of the diamond drill method of stoping at the Book mine. Sufficient work has been done with it to prove its worth and it is the purpose of the article to present some results, operational details, equipment ideas and recommendations which we have found in its use at our mine. LOCATION AND DESCRIPTION The Book mine is situated about a mile north of the village of Alpha, in the NE-NE ¼ and the SE-NE ¼ of sec 12-42-33, between the Dunn mine and the Balkan-Judson mine, and about four miles southwest of the village of Crystal Falls, on the Menominee Range of Michigan. The property was found to have ore near surface in sufficient quantities for open-pit operations and stripping was begun in the latter part of 1942 to prepare it for ore production in 1943. During 1943, 288,447 tons of direct shipping ore were produced from the open pit and 382,933 tons in 1944. While the mine was being operated as an open pit some 350,000 tons of lean ore were stockpiled for later treatment. This material is being treated in a washing and jig plant and concentrates are produced during the shipping season. The ore bodies at the Book mine are characteristic of the Menominee Range. They are found on the flanks of sharply folded anticlines which have a fairly steep pitch to the northwest. The open-pit operations in 1943 and 1944 revealed two of these anticlinal structures. A detailed study and classification of the old diamond drill records, coupled with the information of some new holes drilled, has established the

Jan 1, 1947

Jan 1, 1952

By G. L. F. Powell

g samples of Cu-20 wt pct Ag alloy have been mdercooled to a maximum of 197°C by melting under a slag of commercial soda-lime glass in a vitreous silica crucible. No grain refinement of the primary copper was observed in samples undercooled to the maximum of 197°C. When the samples contained a small amount of oxygen, the copper dendrites were partially recrystallized at undercoolings greater than 97°C. In previous papers'-3 reporting the grain structure of undercooled silver and copper, it was observed that grain refinement was dependent on both undercooling and oxygen content. Grain refinement occurred in undercooled silver when the degree of undercooling exceeded the range 153" to 175"C, while in Ag-0 alloys (0.12 wt pct) fine equiaxed grains were exhibited when undercooling was greater than 50°C. Similarly, copper samples undercooled as much as 208°C displayed fan-shaped growth from a single nucleation site, while the grain structure of Cu-O alloys (0.08 wt pct) was fine and equiaxed at undercoolings larger than 150°C. Thus the presence of oxygen greatly reduced the undercooling at which grain refinement occurred. It was also observed that the change in grain size resulted from recrystallization and was not due to an enhanced nucleation rate in the liquid-solid transformation. It is possible that the influence of oxygen on recrystallization is due primarily to its presence as a solute element. walker4,' reported that, although a grain size change did not occur in pure nickel until the undercooling exceeded 150°C, small grains were observed in samples of Ni-Cu alloy solidified at small and large degrees of undercooling. Jackson et al.6 suggested that the fine grained structure of the Ni-Cu alloy resulted from the melting off of dendrite arms during recalescence. This remelting process may occur in alloys as a result of segregation during freezing which causes a variation in liquidus temperature from point to point within a dendrite. It was therefore decided to undercool copper with a metallic alloying element to ascertain whether the presence of a metallic solute would have a similar effect to oxygen in inducing grain refinement. A Cu-Ag alloy was chosen, since both metals had been shown to behave similarly on undercooling. The alloy Cu-20 wt pct Ag was selected since the eutectic constituent outlines the initial growth form of the primary copper, so that the as-frozen grain structure is not obscured if subsequent recrystallization occurs. This paper describes the results of undercooling experiments carried out with Cu-20 pct Ag samples undercooled to a maximum of 197°C and the effect of oxygen content on the grain structure of the undercooled samples. EXPERIMENTAL Melting was carried out in a small cylindrical resistance furnace using "fine" silver granulate and oxygen-free high conductivity copper. The procedure adopted was to melt the required quantity of silver in air in a clean vitreous silica crucible for approximately 15 min, freeze, and add granulated commercial soda-lime glass to form a complete surface slag cover, after which the sample was melted and frozen several times to reduce the oxygen content. The glass slag cover was approximately 3 in. thick. Pieces of copper (=50 g) were added to the crucible until the required quantity to make 350-g samples of alloy had been charged. Each piece was added quickly to the crucible which was held at a temperature slightly above the melting point of silver. The piece was quickly pushed beneath the glass to minimize oxidation and any oxide coating usually decomposed before the piece had settled down into the silver. After the full quantity of copper had been added, the melt was stirred with a silica rod to hasten homogenization and a Pt/Pt 13 pct Rh thermocouple enclosed in a vitreous silica sheath inserted for temperature measurement. Heating and cooling curves were recorded on a potentiometric chart recorder fitted with a zero suppression unit. The milli-voltage range of the recorder was adjusted so that temperatures could be read to 1°C. Heating and cooling curves were taken every hour until three consecutive readings gave the same solidus-liquidus range, consistent with the solidus-liquidus range for this alloy composition by reference to Hansen and Anderko.7 Metallographic examination of samples frozen at this stage, failed to show any variation in composition from bottom to top of the ingot. Consequently, it was considered that the melt was homogeneous at this stage and undercooling experiments were then car-

Jan 1, 1970

Jan 1, 1913

By W. E. Hess

At the Vesta mines of Jones & Laughlin Steel Corp. on the Monongahela River, 35 miles south of Pittsburgh, JCM Joy continuous miners and 6-SC shuttle cars are used for pillar extraction in the Pittsburgh seam. The entire output of the mine goes into coke production for blast furnace operation. Because this coal, which has high metallurgical qualities, is close to the place where it is ultimately used and because supplies with these properties are being rapidly depleted, complete recovery is essential wherever possible. With the introduction of the continuous miner into the Vesta mines, therefore, it was necessary to plan a project which would facilitate development and provide for future total recovery. Use of continuous miners under varying conditions has necessitated changes with regard to roof action, method of development, method of pillar attack, and innovations in mining. In the following pages these changes will be discussed.

Jan 2, 1955

By J. Farkas

A techno-economic assessment for the recovery of several elements from seawater is presented. Gold recovery has been used as an illustration for the economic evaluation of several processes. Current technology does not present any economically viable alternative to recover gold from seawater because its concentration is several magnitudes too low. However, with the increasingly larger availability of concentrated seawater, mainly from desalination and other processes, coupled with advances in technology, especially genetically modified specific microorganisms, may make the recovery of gold and other desired elements from seawater a reality in the near future.

Jan 1, 1984

By H. R. Wenk

This paper describes a workshop on deformation mechanisms and texture development in rocks. Empahsis is on relating macroscopic mechanical properties with microscopic structures and the methods of their quantitative analysis.

Jan 1, 1982

Jan 1, 1969

By A. Bauer, P. Calder, N. H. Carr, G. R. Harris

Smallwood mine is part of the Iron Ore Company of Canada's Carol Lake operation and is situated in Labrador, 240 miles north of Sept-Iles, Quebec. Last year, 15 million tons of crude ore were crushed to yield 6.3 million tons of concentrate and pellets. This year the figures will be 17 million of crude and 7 ¼ million tons of concentrate and pellets, which is the full plant capacity. Carol Lake ores consist primarily of specularite and magnetite mixed with quartz. Since both rotary and jet piercing drills are used, it is often desirable in planning to know in which regions of the orebody, or new orebodies, a particular drill will be most economic. This makes it necessary to establish a correlation between drillability and pierceability and some physical rock property. For the rotary drills a good correlation was found with penetration rate and grinding factor index. The jet piercers were found to have a reciprocal relationship in the sense that the best rotary ground was the worst jet ground and vice versa. It is also indicated how an economic comparison could be made using these penetration rate versus grinding factor index curves, the hole size distribution curves for single pass and chambered holes, and the mine distribution curve for grinding factor index.

Jan 9, 1965

Jan 1, 1955

By George I. Adams

Peru is divided into three regions—the coast, the ~ierra, or high mountainous region, and the " montaiia," or forest region of the Amazon basin. The Coast.—The coast is an arid region. No rain falls excepting in the extreme northern part, which borders the Gulf of Guayaquil. There is, however, a slight precipitation in the form of mist (gcirua), which occurs on the coast hills during the so-called winter months. The aridity of the coast is due principally to the antarctic, or Humboldt, ocean-current, which, being cold and having a temperature lower than that of the land, absorbs rather than produces vapors. The coast mists occur during the season when the land is relatively cold. N ear the Gulf of Guayaquil the antarctic current diverges from the coast, so that in the Tumbes valley and adjacent country the conditions in the summer months are such as prodnce rains. In the remaining valleys of the coast, agriculture is made possible only by means of irrigation, and is accordingly very limited in extent, although rich and varied. In the northern and south-central portions of the coast, plains extend inland from the sea, while in the southern part there is a coastal plain separated from the Pacific by a range of coast hills. Between the northern and south-central plains, as well as between the south-central and southern, the foothills of the sierra descend to the seacoast. The Sierra.—The sierra embraces the high land dominated by the lofty cordilleras of the Andes. In the southern part of Peru there are two cordilleras, the western and the eastern, which enter from Chile and Bolivia respectively, and inclose between them the Titicaca Lake basin. To the north of Lake Titicaca these cordilleras unite in the knot of Vilcanota, south of Cuzco. From this knot three cordilleras, known as the western, the central, and the eastern, extend to the northward, reuniting in the

Jan 1, 1909