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By J. B. De Hart

This paper has been confined to the consideration of the working of thick seams, from six feet to sixteen feet, which are pitching at about thirty degrees to the horizontal. The discussion has been limited to these set conditions because they are the ones of commonest occurrence in the Southern Alberta bituminous coal district, because, from the point of view of safety, thin seams are more easily worked, and because a discussion of all the possible combinations of thick and thin seams pitching at angles varying from zero to ninety degrees with the horizontal would involve a task impossible in the time available. It has been assumed that the mine makes gas freely and that the coal is friable and tends to make inflammable dust which is highly explosive. Since the problem requires the taking into account means of maintaining a high proportion of lump coal, it is further assumed that lump coal commands a price considerably higher than the price which can be obtained for run-of-mine or for slack coal. Figure 1, tabulating the various factors which must be considered and their relation to each other, indicates diagrammatically the complexity of the problem. Any method of working becomes divided into two distinct components, the active workings of the mine and the old abandoned workings. While these are in a measure distinct, they are nevertheless inter-related, as shown in the diagram.

Jan 1, 1930

By Christine Hansen

?Kiss my Asteroid? Unofficial Title Human life is tied to minerals It?s worth noting that: The living human body consumes minerals. The minerals we take in multivitamins show the close linkage between human beings and mineral resources. Unlike tourism or specialized manufacturing, a human being could not live without mineral consumption. Minerals and their consumption is a tangible part of human life.

May 1, 2013

By Chester B. White

ARGENTINA is a country that has never been properly prospected. This is my settled conclusion after reporting on mines in this country ever since 1914, crossing all the mining provinces from Chubut, in the South, to the territory of Los Andes, in the North, chiefly on muleback. It is difficult and costly to get from one district to another. Apart from petroleum, some mineral discoveries have been made but they have been the result of casual rather than systematic work. In Neuquen, Mendoza, San Juan, Cordoba, La Rioja, Catamarca, and Los Andes attempts at mine development have resulted in failures, involving in each instance several million pesos.

Jan 1, 1937

By Russell G. Haworth

Three companies, United States Potash Company, Potash Company of America, and International Minerals and Chemical Corporation, are now operating potash mines and refineries in the Carlsbad, New Mexico, area. The three mines are located approximately twenty miles east of Carlsbad. The deposits have been found ideal for mechanized mining methods. This summary has been compiled from information made available by the three operating companies.

Jan 1, 1949

By E. D. Gardner

IN 1947 the metal-mining industry . passed through a year of readjustment; catching up on development work has caused production to suffer. Skilled labor has been short in most mining districts, notwithstanding the highest wage rate paid in the history of the industry. The trend has continued toward increased mechanization and refinements in practices and methods to increase the tons produced per man-shift. Improvements in procedures, however, have not kept pace with rising labor rates; and, in general, labor costs per ton mined have steadily increased since the war years. Prices of base metals have been the highest in a generation, but most producing companies can afford to pay the high wages. Capital expenditures have been approved for improvements to increase the output per man, both to reduce unit labor costs and to increase output. Surveys indicate a continuing

Jan 1, 1948

By Philip B. Bucky

WITH the exhaustion of the sections of iron ore bodies amenable to opencut mining the iron ore miners raise the question: "How can we mine the extensions of these ore bodies in depth with the same costs as obtained in opencut work?" This question brings to the fore the relationship between mineral exploration and research on mining procedures. The iron miners must either find new de? posits amenable to their known methods of mining or develop new mining methods for deep deposits. It is understood that the oil companies will spend $30,000,000 next year in the search for new oil fields. How much the metal mining companies will spend in the search for new ore bodies is unknown, but without doubt the amount will run into several millions of dollars. If the mining companies that concern themselves with metals, nonmetallics, and fuels will set aside a substantial sum for fundamental and applied research in mining methods, they can not only lower their costs but increase their reserves thereby. Any increases in mining efficiency automatically result in increased ore reserves at no cost.

Jan 1, 1947

By Holt, Grover J.

PRIOR to :1937 any discussion of mining and transportation in the iron mines of Minnesota would have been limited largely to conventional methods which have been used for years in the iron ore industry. Today, however, an inspection trip to the crest of almost any open pit on the ranges will re- veal great progress underground mining and the transportation of underground ore have also developed rapidly and if and when underground mining of iron ore again becomes generally economically feasible; these mining methods will probably witness a transformation equal to that which has taken place in the open pits.

Jan 1, 1941

By Samuel M. Dunaway

INTRODUCTION ASARCO Incorporated purchased the East Tennessee Zinc Mines of the American Zinc Company and commenced operating on November 29, 1971. Presently, three mines are operating producing 6620 t/d (7300 stpd). The ore mined is sphalerite which occurs In lower Ordovician carbonates of the upper Knox Group and occurs in open space and fracture filling. Orebodies range from 3 to 46 m (10 to 150 ft) thick with dips from flat to 20º. The mining method is random room and pillar modified by shrinkage and bench stoping. Like other mining departments, the mining group at the Tennessee Mines Division is constantly looking for methods to improve productivity and safety and to reduce mining costs. This involves testing new equipment, trying new ore extraction ideas and making mining plant alterations to meet changes in operating conditions. The areas of change that will be described in this paper are longhole raising, jumbos and LHD loading, shaft sinking, conveyor transport of ore and sublevel haulage developments. LONGHOLED RAISES Raise driving has always been a hazardous occupation for miners and today it is becoming more difficult to get competent people for this kind of work. This problem has led us to seek an easier, safer way in which to excavate raises. The first longhole raises were excavated in the early 1970's using a Gardner-Denver air trac equipped with a PR-123 rock drill. The machine used 38 mm x 244 cm (1 ½ in x 8 ft) round rods with rope

Jan 1, 1977

A mechanised sub-level overhead benching method is used at Cleveland, to produce 22,000 tons per month of ore assaying 0.92% Sn and 0.40% Cu. The ore occurs in a series of vertical lenses which can be mined by open stoping. Levels are developed at 60ft., vertical intervals by jumbos. The ore is silled out and the stope block formed between levels drilled out by long hole drilling. Each row of holes is fired and broken ore within safe reach from the stope brow is mucked out by Wagner ST-5A Scoop Trams. The remaining broken ore is recovered on extraction of the next lower level. Ore is hauled by road to the crusher station from the mine. As mining proceeds below the lowest surface portal a spiral decline will be used for ore haulage and mine servicing.

Jan 1, 1970

By Mitchell M. A

The steeply dipping Mammoth orebody is mined by Gunpowder Copper Limited using a sub- level uphole bench stoping method at a mining rate of 350 000 tonnes per year. of three per cent copper ore. Access to the mine, is provided by 1 in 9 decline which spirals in the footwall connect-, ing all the sublevels, thus maximising mobility and accessibility of trackless mining equipment Sublevels are driven in ore off cross- cuts from the decline every 15 metres vertic- ally. Sublevel drives are stripped out to widths up to 18 metres before cutoff slots are mined at each end. A two boom fan drilling jumbo is used to drill inclined rows of holes to the floor of the sublevel above. Two or three rows are fired at a time which allows broken ore and remnants from the level above to be mucked out by rubber tyred LHD equipment to the brow. Ore widths of up to 80 metres are en- countered at lower levels where ring drilling from longitudinal drill drives will break ore to a draw point system below. Development is carried out with three boom rubber tyred jumbos. All haulage from the mine is in 20 and 35 tonne rear dump trucks. All aspects of the mining operation are discussed including ventilation, pumping and drainage, services and future planning.

Jan 1, 1974

By Samuel Shallcross

THE principal function of the Bell limestone mine, of the American Lime & Stone Co., at Bellefonte, Pa., is to supply raw material to the company's modern rotary kiln plant at Bellefonte. Because mining costs are naturally higher than many open quarries with more favorably lying strata, it cannot compete, except to a limited extent, in the markets for road material and fluxing stone. In the broad sense, mining does have an advantage over the average open quarry when the end products are designed for and controlled by process and final inspection for the exacting demands of the industrial and chemical markets. Approximately 80 per cent of the output of the Bell mine is sold in the industrial and chemical markets. And as higher standards are set each year for construction and agricultural work, the remainder of the mine output goes to these two classes. Mining produces more fines than open quarries, and these fines are difficult to market; on the other hand, owing to absence of contaminating clay and impure rock, a greater percentage of the output of a mine is marketable. Because of the great production of fines, rotary kilns for lime burning are necessary when the stone must be mined. In 1921 the American Lime & Stone Co. operated 19 quarries and 72 lime shaft kilns spread over an area of 40 miles between Bellefonte and Altoona, Pa. At that time the line-production capacity of the 72 kilns amounted to approximately 700 tons per day. After 15 years the company operates three rotary kilns and six shaft kilns, with a combined output of approximately 500 tons of lime per day, concentrated in its single Bellefonte plant (Fig. 1). Its only stone-producing plants are now the limestone mine at Bellefonte and a construction-stone open quarry at Union Furnace, near Tyrone, Pennsylvania.

Jan 1, 1936

By Samuel Shallcross

TO principal function of the Bell limestone mine, of the American Lime & Stone Co., at Bellefonte, Pa., is to supply raw material to the company's modern rotary kiln plant at Bellefonte. Because mining costs are naturally higher than many open quarries with more favorably lying strata, it cannot compete, except to a limited extent, in the markets for road material and fluxing stone. In the broad sense, mining does have an advantage over the average open quarry when the end products are designed for and controlled by process and final inspection for the exacting demands of the industrial and chemical markets. Approximately 80 per cent of the output of the Bell mine is sold in the industrial and chemical markets. And as higher standards are set each year for construction and agricultural work, the remainder of the mine output goes to these two classes. Mining produces more fines than open quarries, and these fines are difficult to market; on the other hand, owing to absence of contaminating clay and impure rock, a greater percentage of the output of a mine is marketable. Because of the great production of fines, rotary kilns for lime burning are necessary when the stone must be mined. In 1921 the American Lime & Stone Co. operated 19 quarries and 72 lime shaft kilns spread over an area of 40 miles between Bellefonte and Altoona, Pa. At that time the lime-production capacity of the 72 kilns amounted to approximately 700 tons per day. After 15 years the company operates three rotary kilns and six shaft kilns, with a combined output of approximately 500 tons of lime per day, concentrated in its single Bellefonte plant (Fig. 1). Its only stone-producing plants are now the limestone mine at Bellefonte and a construction-stone open quarry at Union Furnace, near Tyrone, Pennsylvania.

Jan 1, 1936

By M. G. Jones

AT the Edwards mine a 4 by 81/2-ft two-compartment shaft is used for men and supplies in the older workings down to the 900-ft level. All ore is hoisted through a 5 by 15-ft three-compartment vertical shaft which extends to the 1500-ft level. Ore pockets are on the 1300- and 1500-ft levels. The two-compartment countershaft used below the latter level is 6 by 12 ft inclined at 42°. Ore from the countershaft is hoisted to the 1350-ft level where it flows by gravity to the 1500-ft level ore pocket. One-ton skips are used in balance in the countershaft and two-ton skips, also in balance, from the 1500-It level to the surface. These skips are slung under the man cages. Each level has an ore pocket of 200 tons' capacity. Development at Edwards is similar to that at Balmat except that haulage drifts are only 7 by 7 ft. They are mucked with Eimco-Finlay No. 12 loaders. A drill carriage similar to that used at Balmat is being tried out on the new 2300-ft level, the present bottom of the mine. Drifts are driven below grade and later raised 6 in. and ballasted with waste leaving a ditch 6 by 12 in. at one side for drainage. All development is done on an incentive bonus system, the miner paying for his explosives.

Jan 1, 1947

By J. W. Dougherty

THE Hollinger gold mine is in the Porcupine mining division, District of Cochrane, in the northern part of the Province of Ontario. The adjacent town of Timmins, with a population of 25,119, lies 490 miles by railway north of the city of Toronto. GEOLOGY The property is situated on the northwest limb of a major syncline, which pitches northeast at approximately 50°. The principal rocks of the Hollinger area are of pre-Cambrian age and consist of altered, schistose, Keewatin lava flows intruded by stocks of schistose, quartz-feldspar porphyry generally assigned to the Algoman period. The structure of the Keewatin series is extremely complex as a result of close folding and some faulting. The schistosity, trending north 70° east and dipping steeply to the southeast, is most highly developed along a subsidiary anticline in which the major porphyry bodies occur. The ore bodies, which exhibit three principal structures, consist of quartz veins and associated pyritized wall rock. Some lodes are com-posed of en echelon veins, others exhibit a main quartz body with branch-ing stringers and a third consists of a single definite lead. Gold, in a coarse visible form, may be confined to quartz in some ore bodies but in others it is finely divided and is found not only in quartz but also asso-ciated with pyrite in the adjacent wall rock. In many veins the dis-tribution of gold is such that there are several ore sections, separated by areas of low-grade material, in the same vein although its physical appearance remains unchanged.

Jan 1, 1940

By J. W. Dougherty, J. M. Douglas

THE Hollinger gold mine is in the Porcupine mining division, District of Cochrane, in the northern part of the Province of Ontario. The adjacent town of Timmins, with a population of 25,119, lies 490 miles by railway north of the city of Toronto. GEOLOGY The property is situated on the northwest limb of a major syncline, which pitches northeast at approximately 50°. The principal rocks of the Hollinger area are of pre-Cambrian age and consist of altered, schistose, Keewatin lava flows intruded by stocks of schistose, quartzfeldspar porphyry generally assigned to the Algoman period. The structure of the Keewatin series is extremely complex as a result of close folding and some faulting. The schistosity, trending north 70° east and dipping steeply to the southeast, is most highly developed along a subsidiary anticline in which the major porphyry bodies occur. The ore bodies, which exhibit three principal structures, consist of quartz veins and associated pyritized wall rock. Some lodes are composed of en echelon veins, others exhibit a main quartz body with branching stringers and a third consists of a single definite lead. Gold, in a coarse visible form, may be confined to quartz in some ore bodies but in others it is finely divided and is found not only in quartz but also associated with pyrite in the adjacent wall rock. In many veins the distribution of gold is such that there are several ore sections, separated by areas of low-grade material, in the same vein although its physical appearance remains unchanged. The veins form a very complex pattern in an ore zone which in places attains a length of 6000 ft. and a width of 4000 ft. They are most abundant in the Keewatin lavas in the neighborhood of the porphyry bodies. Few of the veins are persistent for long distances, though some

Jan 1, 1940

By Mech B

This paper gives a general description of mining practice at The Zinc Corporation Ltd., Broken Hill, New South Wales.The basic mining methods are those which have been common in Broken Hill for many years and have been well described in previous Proceedings. The main object of this paper is to indicate developments which have occurred in recent years and to describe changes in layout, mining methods and equipment which are taking place at present.The following headings have been adopted: History Geology and general characteristics of the orebodies, Geology, The lead lode, The zinc lode, General characteristics, Ore reserves, General mining method, Exploration and diamond drilling, Shafts and shaft sinking, Main shaft, Old main shaft, Block 5 shaft, New upcast airway, Development, Level interval, Level layout, Driving and crosscutting, Winzing, Rising, and Stope preparation.

Jan 1, 1946

By L. W. Casteel, E. A. Jones

MINING the lead deposits of Southeast east Missouri has reached a high stage of technical development dictated by the scattered occurrences of low-grade ore through favorable horizons in the Bonne Terre formation. The rock-breaking, handling, and related practices described here have evolved as the best way of mining these particular deposits. These methods are applied in the production of about 19,000 tons of lead ore per operating day from four mines in Southeast Missouri. Development drilling Drifts 10 ft wide and either 8 or 9 ft high are driven in this district on contract. Miners are guaranteed standard wages plus a bonus on the footage advanced, if earned. Labor, fuse, caps, wire, and dynamite used are charged against the contract. Normally the cycle of operations in drifting is performed by a two-man crew, a motor operator and a shovel operator who first load out the rock broken by the preceding shift. The drift crew then sets up two vertical column and mounts the drills. Cleveland HC-10's are used which have a steel lug integral with the cylinder for connection with the air feed. All drilling in drifts is wet. Air pressure is 85 to 100 lb at the face. From 28 to 32 holes are drilled per swing in a pyramid cut. Cut holes

Jan 1, 1947

By Chester Fulton

IN Polk County, Florida, the mining of raw phosphates began some 50 years ago with dredging operations on the Peace River, and in other near-by places by removal of shallow overburden with negroes and wheelbarrows, or with mules and scrapers, and the excavation and screen-ing of deposits found close to the surface. There were many individual operations of comparatively short life. Later steam shovels removed the overburden, and still later hydraulic methods were substituted for the steam shovel. Within the last 10 years large electrically operated drag-lines have almost entirely replaced hydraulic mining for overburden removal. The matrix is still mined by hydraulic giants and pumped to the washer or recovery plant. The many small operations have long since disappeared and the most desirable phosphate lands have gradually been acquired through purchase or merger by the seven companies that are operating in the field today. These companies are producing and selling about 2,000,000 long tons of phosphate per annum, or about two-thirds of what the industry likes to think is the normal output, with 1929 and 1930 in mind. To produce these 2,000,000 long tons of raw phosphate, they mine and treat about 1,000,000 tons of tailings from older and less efficient opera-tions, about 11,000,000 tons of matrix, and remove from above this matrix some 22,000,000 tons of overburden. The mining practice that has made possible the excavation and handling of 34 million tons of material to win but 2 million tons of merchantable product, selling for probably an average of only $4 per long ton when dried, should be of interest to the mining profession, though little has been written of it. The Florida Pebble Field, as it has come to be known, comprises an area (Fig. 1) within a radius of about 18 to 20 miles centering around Mulberry in Polk County, a small town 30 miles east of Tampa, Florida's largest port on the gulf coast.

Jan 1, 1936

By M. T. G. Davis, J. V. Cleasby, H. J. Wright

Mining practice in the Kimberley Division of De Beers Consolidated Mines Limited by J. V. CLEASBY. B.Sc.. A.R.S.M. (Fellow). H. J. WRIGHT. B.Se.. M.Sc.. (Fellow). And M. T. G. DAVIES. B.Sc. (Visitor) T his paper highlights the changes that are taking place at De Beers Consolidated Mines Limited in mining methods, mechanization, and employment practices. De Beers has four underground mines in Kimberley itself (Dutoitspan, Bultfontein, De Beers, and Wesselton), and two open-cast mines outside Kimberley (Finsch and Koffiefontein). Emphasis is placed on the new method envisaged for Koffiefontein when it becomes an underground mine. The paper also includes notes on chemical drilling and on winding practices.

Jan 12, 1975

This paper outlines mining practice in the South Alligator valley between 1954 and 1964. The valley is situated in the Northern Territory 130 miles south east of Darwin and trends north west. The centrally located El Sherana camp is 219 miles by road from Darwin via Pine Creek on the Stuart Highway. 64 miles of gravelled road with low level bridges and culverts which were completed in 1959, connect Pine Creek with El Sherana. This road is often impassable during severe wet season conditions. Earliest recorded production was during the years 1956-57 from the El Sherana and Palette miles, by shallow open cut and cut and fill stoping from small shafts. 4600 tons of high grade ore was processed by hand sorting of massive pitchblende followed by gravity concentra- tion. At the same time 627 tons of ore was won from a small open cut at Sliesbeck 35 miles SE of El Sherana. The second and most important phase of production was to fill two small contracts with the United Kingdom Atomic Energy Authority (U.K.A.E.A.) totalling 700 tons of U 08. About 144,000 tons of ore was mined from widely separated smal' orebodies and mining practice varied from small open cuts to gloryholes, open stoping and cut and fill stoping. In some orebodies a combination of several methods was employed to complete production. Final deliveries were made to the U.K.A.E.A. In 1964.

Jan 1, 1968