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By D. W. Loucks

There is plenty of evidence to indicate that at least one of man's chief interests in life is to make himself as comfortable as possible. If you doubt this, just watch the fellow next to you for the next half hour trying to find the most comfortable position that a hard chair has to offer. Comfort, however, does not always mean an easy chair. To some, it may mean a wealth of money: to another, freedom from worry. But to most of us, it means first of all a comfortable atmosphere in which to live, and to a great many of us it probably also means freedom from that annoying task of firing the furnace. Today more than ever before, automatic heat is one improvement that is placed high on everyone's list. Perhaps this is because automatic heating is becoming relatively cheaper. Perhaps it is because of a good publicity campaign on the part of the oil and gas men or maybe it is just that we are getting lazier day by day. At any rate, almost every issue of Better Homes and Gardens, House Beautiful, or your other favorite home magazine carries an article extolling the virtues of this or that automatic heating system.

Jan 1, 1949

By AIME AIME

THE MILLING PROGRAM on Monday required a morning and afternoon session with a special luncheon of the Milling Committee in the Engineers Club at noon. Grinding and flotation were the main subjects of the papers which drew an attendance of fifty or more at each session. Under the direction of Chairman Arthur F. Taggart in the forenoon, all papers on flotation and general milling were considered, leaving the, after- noon free for crushing and grinding, with Dr. Galen H. Clevenger in the chair. The high spot was the first public presentation of the idea of size reduction of minerals by explosive shattering.

Jan 1, 1932

By Tom Westgarth

As papers are placed before you upon large gas-engines in Belgium and Germany, it was considered that some information should be given upon the same subject in Great Britain. I therefore agreed to compile these notes, which I have made very short in view of the somewhat full nature of the other papers presented to this meeting, and considering the complete nature of the many publications which have been made recently upon the subject of large gas-engines. I give below Tables I. to VI., showing the number and particulars of large gas-engines which have been built or are building by British makers, and in view of the growing size of gas-engines I have concluded that engines less than 500 h.p. cannot now be included in the category of large gas-engines, and therefore I have not considered engines under that power.

Nov 1, 1906

By Wittenau, E.

OPERATION of a pilot mill of 100 tons' daily capacity during 1930 and 1931 proved that the copper minerals of the Colorado and Clay sections of the Morenci ore body could be successfully concentrated by the flotation process. Economic conditions caused postponement of further testing work until late in 1938 when the former No. 6 Concentrator at Morenci was converted into an experimental mill of 1500 tons' daily capacity which was known as the Test Concentrator. The Test Concentrator began continuous operation on April 3. 1939, using such crushing and grinding equipment of the No. 6 Concentrator as was appropriate. Modern classifiers and certain flotation machines were installed and later other types of flotation machines, a large grate-type grinding mill. mechanical screens, a short-head cone crusher, and a disk filter were added to the test equipment. Operation was uninterrupted until Dec. 31, 1941.

Jan 1, 1942

By Karl V. Lindell

THE Jeffrey mine of the Canadian Johns-Manville Co., Asbestos, Que. has operated for a number of years, supplying the parent company, Johns-Manville, raw material for asbestos products. The mine is situated in the 70-mile-long serpentine belt running from Asbestos, Que. on the west to East Broughton on the east. This district is the most important producing area in the world of quality spinning-fiber asbestos, with 11 operating mines supplying 70 pct of the world's needs. The Jeffrey mine, located 90 miles from Montreal and approximately 35 miles southwest of Thetford, accounts for 50 pct of the Canadian asbestos output. Production from the Canadian serpentine belt is the chrysotile asbestos, which is considered the best available for spinning. Consumers in the United States prefer the clean, fine fibers of the Canadian chrysotile of the type produced by the Jeffrey mine. Mining In 1881, when the mine was first opened, all work, including drilling, was done by hand. The deposit, located on a hillside, was first worked as a sidehill cut by hand drilling 15-ft holes and blasting with black powder. The fiber was chiselled from the broken rock. Hand derricks, later powered by horses, were used to raise the rock as the pit deepened. Eventually, the pit became so deep that derricks were, by necessity, replaced by aerial tramways. In the late 1930's, further deepening of the open pit, with the resulting constriction of the pit bottom brought about the need for altering the mining system then in use. The high ratio of overburden to be handled to mill ore mined and the value of surface structures, not company property, that would be destroyed in expanding the area of the pit, definitely indicated vertical rather than horizontal expansion would have to be used. One exception to this was that a small area on company property to north and east of the pit could be opened up. The mining problem then resolved itself into two phases; make the small lateral expansion and as rapidly as possible choose a mining method that would expand the mine vertically. Several methods for vertical expansion were studied and rejected. Methods considered included shrinkage stoping, block caving, glory holing, and various modifications of open workings. Block caving was finally accepted as the most suitable method of underground development. Cost factors and production were important factors in the decision, also, the asbestos mines in the Thetford area were already having success with this method. Original plans provided for the lateral expansion of the open mine where possible and beginning the underground operation. This program was based on the open pit being worked out in 1954, with the underground development and production gradually increasing until the open mine was depleted. In 1949, the plan was changed to allow underground development to progress at maximum so that underground output would be 550 tons per hr by 1951. Any deficit in ore would be mined from the open pit. This change permitted extending the life of the open pit through 1964 and in this time would make available a large quantity of readily attained ore. Block Caving at The Jeffrey Mine Plans for the underground operation were formulated on a 12,000-ton-per-day basis, and the adaptability of block caving methods to high production presented a desirable situation. As shown in the main-haulage plan, a continuous loop was laid out for smooth operation of the underground railroad from the loading points to the underground crusher. A feature encountered at the Jeffrey mine, as well as other asbestos mines using caving methods, is the large size of caved material, requiring that ore be crushed before hoisting.

Jan 1, 1952

By George A. Guess

THE increasing demand for greater speed and more accuracy, in making daily assays of ores and products from mills treating material containing but very small quantities of lead and copper, has caused the older analytical methods to be supplanted by new ones devised to meet the needs of modern work. For " control " work in copper analyses, I had, previous to the present equipment, introduced in my laboratory the ordinary electrolytic method, using hollow cylindrical electrodes, and with these I began a series of experiments in determining the lead-content of daily mill-samples and controls. The results, proving accurate and satisfactory, I then devised, with Mr. H. E. T. Haultain, a cheaper electrode than the ordinary jacket electrode, which costs from $15 to $20,-the expense of the older form making the installation of many units very costly. The form of cathode finally adopted as the most satisfactory, shown in Fig. 1, is cut from 0.001-in. platinum foil. It is 12.5 cm. long, and is divided into a blade 4 cm. wide and 6.25 cm. long, and a tongue 0.7 cm. wide and 6.25 long, the immersion area being 50 sq. cm. and weight 1.5 grams. The blade is first sand-blasted and then corrugated lengthwise, in order to impart the necessary rigidity. Strips of platinum foil 0.001 in. thick, 12.5 cm. long and 0.5 cm. wide, having a median corrugation, form the anodes. Three electrodes are used in each cell, one anode in the middle and one cathode oil each side of the anode. These electrodes are connected to slotted alumi¬num terminals, in which they are held by contact pressure. The terminals are -in. rods, projecting 2 in. horizontally in front of the wall of the cabinet.; at the back the middle electrode (anode) is connected with one pole of the current, and the two outer ones (cathodes) with the other pole.

Nov 1, 1905

By Edward H. Robie

PONCA CITY proved an ideal selection as a place of meeting for the Petroleum Division this fall. The accommodations at the Conoco Club were just what was required for such a gathering; the committee having the arrangements in charge functioned with the efficiency of veterans and the enthusiasm of neophytes; and the members and guests followed the speakers with close attention, entered the subsequent discussions with gusto, and divulged the "low-down" at private conferences. No one minded the drizzling rain on the first day, which only served to keep up the attendance in the auditorium; the weather then cleared up in time for a group picture before the gathering went their separate ways.

Jan 1, 1932

By B. C. Riblet

THE president of a large smelting and refining company once telegraphed me that they had acquired extensive mining interests in northern Peru and requested me to inspect their properties as it would be necessary to install a system of aerial tramways between their mines and treatment plant. The concentrator was about 50 mi. from the coast, reached by a fairly good motor road. From the concentrator an aerial tramway would he required, about 6 mi. long, to their first property, a gold and silver mine. The lower terminal of the tramway was at an elevation of 4000 ft. and the mine at an elevation of 9500 ft.

Jan 1, 1937

By James A. Clem

Approximately 2000 years ago, the Lord admonished the scribes (lawyers) and pharisees (religious leaders of that time) that they had paid the tithe but had omitted the weightier matters of law, judgment, mercy, and faith. (Matt. 23:23) I want to talk about "The Weightier Matters of Law." In a situation where big government is trying to have an effect on even small details of a work activity, otherwise simple situations become complex. Regulations are written to such detail that constant compliance with strict interpretations can be a nightmare-not to mention off the target of the intended purpose for the regulation. One soon recognizes the onerous characteristics of federal statutes. Another admonition the Lord gave those lawyers and pharisees back then was that they tended to strain at a gnat and swallow a camel! He meant that the pharisees were given to devoting themselves to the strict interpretation of law by writing hundreds of subrules or interpretation to law. In doing so they eventually lost sight of the original purpose of the law. I think they were being told, keep the law-but don't neglect to humanize it Keep it simple Recognize the purpose of why the law. "Mix in" a common sense approach. Someone once said, "Common sense is instinct -enough of it is genius." Today, as 2000 years ago, we need more "genius" displayed by legislators in considering the weightier matters of law. First of all true legislature genius calls for a declarative statement about the purpose of the statute and a fair, objective analysis of the ground rules by which it will be implemented. In the Health & Safety Act of 1969, the "findings and purpose" as set forth in Section 2 do define its purpose. I believe most of us affected can be in accord with the reasons advanced for the legislation. However, beyond those well-intentioned few paragraphs, we very quickly run into trouble. Congress complicated the simplicity of the statement of purpose by mandating government intervention into areas that cannot be effectively legislated, nor even should be legislated. The Act provided for broad gaged regulation which is unnecessary, inappropriate, and tremendously costly. Frankly, it detracts from a constructive, cooperative effort by the parties involved. These are strong negatives which characterize inappropriate legislation. Appropriate legislation and subsequent regulation, which is realistically conceived and practically enforced must be born of an honest desire for improvement, based on a working knowledge of common problems which are thoughtfully analyzed. Then the legislation must be written in clear concise language so that there can be little or no doubt as to its literal meaning and intent. To be practically enforced, it must be understood by all who will enforce it and by all who are subject to it. That is to say, an effective law or standard cannot be fixed or inflexible so that it cannot be tempered in human judgment. There must be an elasticity in the statute to provide for consideration of all of the relevant facts of a given situation. Such elasticity makes the compliance effort as meaningful as it can be for the time and dollars invested. Meaningful compliance requires room for common sense. Today, we in business along with our associates in government and labor, urgently need to pause, and assess our current situation. The problems arising from the 1969 Act have been intensified through the Mine Safety & Health Act of 1977. After reading the "findings and purpose" of this legislation, and by process of elimination, we should all clearly see what is and is not the purpose of the Act. 1) It is not to turn the management of private industry over to government. 2) It is not to impair the efficient operation of business. 3) It is not to reduce productivity and profits. 4) It is not to reduce national unemployment. 5) It is not to perpetuate the bureaucracy. 6) It is not to increase the tax burden on an already overburdened people. 7) It is not to increase our balance of payments deficit. 9) It is not to replace management/labor relations in working together to solve problems.

Jan 1, 1981

By David W. Brunton

(San Francisco Meeting, October, 1911.) MINE-DRAINAGE and the ever-increasing demand for water on the plains have within the past few years necessitated the driving of a great number of adits and tunnels, including many of considerable size and great length. In most instances, ex isting conditions have called for extreme rapidity of execution; and this necessity, coupled with the high altitudes at which most of the work has been carried on, excessive freight-rates, and difficulty -of access, has involved many complex and interesting problems. One of the most rapidly executed undertakings of this class is the Laramie tunnel, recently completed for the Laramie-Poudre Reservoirs & Irrigation Co. This tunnel is driven through Green ridge, a spur of the Continental Divide, which separates the Laramie river from the Cache-la-Poudre in Laramie county, Colo. Green ridge is extremely persistent, and further northward in Wyoming is known as Sherman hill, the highest point on the Union Pacific railway. At the point where the tunnel is driven, two opposing bends bring these streams within 2.5 miles of each other, with a difference in elevation of 500 ft. The rock exposed on the banks of the two rivers does not differ materially in hardness; and, without a geological study of the conditions involved, it would appear that the difference in the depth of erosion of the two streams is due principally to the greater volume of water at this point in the Cache-la-Poudre, which has a drainage-area above the tunnel-portal of 110 sq. miles, as against 30 sq. miles of natural drainage for the Laramie. To increase the water-supply at the tunnel, however, this latter amount has been augmented by two side collection-canals, which bring the available drainage-area up to 84 square miles. The nearest railroad shipping-point to the eastern portal is

Apr 1, 1912

By HORACE V. WlNCHELL

Location. THE St. Helens mining-district, indicated in sketch-map, Fig. 1, is chiefly in Townships 9 and 10 North, Ranges 5 and 6 East, of the Willamette meridian, in Skamania county, Wash. There is no railroad or even a wagon-road at present connecting it with any base of supplies; access is usually by wagon-road for FIG. I.-SKETCH-MAP OF THE STATE OF WASHINGTON. about 50 miles from the town of Castle Rock to Spirit lake, and from that point by pony-trail from 6 to 10 miles farther. History. Nearly 20 years ago two German farmers, totally inexperienced in prospecting, penetrated this region upon a hunting and fishing-trip. Their attention was drawn to numerous joints and crevices filled with black, glistening tourmaline, and con-

Oct 1, 1912

By Ernest N. Patty

WHEN an Alaskan prospector makes a new mineral discovery he stakes out his claims and then starts prospecting for a near-by landing field. This may be a convenient lake but more often it is a gravel bar along a river, where, by cutting off some brush and throwing the larger rocks to one side and then tying a flour sack to a pole, he may decoy some intrepid aviator into testing it gingerly with the wheels of his plane. It was only a few years ago that .the fence around the baseball park at Fairbanks, Alaska, was taken down so that planes could get in and out of the ball park without ripping off boards. Today the grandstand is lost among the modern hangars which line one side of a modern and busy airport. Planes come and go all during the day, and in summer, when there is no darkness, the night stillness is frequently broken by the hum of a motor overhead. Fairbanks is the hub of interior Alaska and from that hub airplanes radiate in all directions to mining camps large and small. An air industry of comparable size is based at the town of Anchorage, and in fact there are but few towns of more than 200 population in the Territory that do not have one or more planes based there.

Jan 1, 1937

By E. W. Engelmann

RAPID progress has been made during the past year in the copper mills throughout the country. Particular efforts have been made to increase the fine-grinding efficiency by the installation of larger classifying units operating in closed circuit with ball mills, such as the 78-in. high-weir Akins installation at the Phelps Dodge plant at Ajo, Ariz.; also the Type "FX" Dorr classifiers of Nevada Consolidated at McGill. Nev. and the "FX" Dorr bowl classifier of the Braden Copper Co. in Chile. Some of the copper milling plants in the Southwest, such as Chino in New Mexico and Ray Con. in Arizona, have replaced rolls operating wet in their fine-grinding circuit by rod mills. At Hollinger primary rod mills were formerly used in open circuit followed by pebble mills in closed circuit with classifiers. They now have primary ball mills in closed circuit with large extra heavy classifiers and no secondary mills. This new installation is producing the same grinding on 5000 tons per day with a reduction in cost of nearly 4c. per ton. At the Braden plant, in Chile, short-head Symons crushers have replaced 54-in. rolls, thereby in- creasing crushing capacity with some saving in maintenance cost.

Jan 1, 1939

By Ira B. Joralernon

THREATS of a coming metal famine in the United States have filled many columns in magazines and newspapers in the past three years. This asserted menace has diverted attention from the actual results of recent exploration. Because no one had bothered to look into the facts, the statistical experts assumed that little ore was being found. They often subtracted the staggering tonnage of metals produced during the war from earlier published reserves, and assumed that the difference was all we had left. Naturally, they shuddered, with all possible publicity. For their figures showed an imminent lack of nearly all the metals needed for an industrial civilization, as well as for mechanized war. They concluded that only wholesale imports and development and production of metals by Federal agencies could avert the famine.

Jan 1, 1948

By Peretti, E. A.

Since its development about forty years ago by J. V. N. Dorr (Cyanidation and Concentration of Gold and Silver Ores, McGraw Hill Book Co., 1936, 1-5), and others, continuous countercurrent decantation has not only become one of the standard methods for extracting gold and silver from their ores, but has also found wide application in other metallurgical and chemical industries. In 1917 L. B. Eames published an excellent paper (Countercurrent Decantation, Trans AIME, 1917, 57, 143- 158), in which he determined the effects of grade of ore, ratio of solution precipitated to ore treated, variations in the density of the thickener spigot discharge and variations in the value of the barren solution upon the gold assay of the solutions discharged from the thickeners in the system. Eames showed that, other things being equal, the dissolved gold lost in the tailing varies directly as the value of the ore and as the value of the barren solution. The tailing loss de- creases rapidly as the ratio of solution precipitated to ore treated is increased to about three or four to one. Beyond this point the improvement is negligible.

Jan 1, 1949

By G. H. BUCHANAN

ALTHOUGH the nomenclature of the chemical tools of flotation is probably familiar to you, it will do no harm to review it; . In order to make the terms more real I have employed an illustration which likens flotation to an old-fashioned balloon ascension, such as we witnessed in boyhood at the county fair. The mineral to be floated is the aeronaut, conspicuous in his gilt-spangled tights, who is to be separated from you and me and the other small boys who are standing about, said boys being the g-a-n-g-u-e, or g-a-n-g, as we would have spelled it. The oil film surrounding the bubble is the counterpart of the silken fabric of the balloon, and bubble and balloon will rise for. the same reason, namely. that the fluid outside it is heavier than the fluid within. In flotation reagent nomenclature the material of which the bubble is made is called the "frother.",

Jan 1, 1930

Jan 1, 1883

By Carlo Massa

THE Societá Auonima di Miniere e di Alti Fourni, familiarly known as the " Elba Company," works the rich ore-deposits of the Island of Elba under a long-term contract with the Italian Government. The ore-deposits are scattered over the eastern and southeastern coast; but as those parts of the island are not well provided with ports, the blast-furnaces were built at Portoferraio, the principal town of the island, situated on the northern shore, and possessing a magnificent natural harbor where even vessels as large as the battleships of the Italian navy can comfortably anchor. In the selection of Portoferraio. the cost of transporting the iron-ore from the different mines to the blast-furnaces has been reduced to a minimum, and shelter has been provided for the Company's flotilla of tugs and barges, as well as for the steamers carrying coal and pig-iron. The whole plant, of which a general view is given in Fig. 1, comprises 1. A discharging-pier with unloading-cranes. The ore and coal are transported from this pier by means of an aerial cable-rail¬way to the coal- and ore-storage yards. This cable-railway is supported by an iron bridge extending from the pier to the shore and by a wooden trestle extending from the shore to the yards. , 2. Blast furnaces, two in number, with all the accessory appa¬ratus, such as blowing-engines, dry purifiers, Cowper hot-blast stoves, hoists, etc. 3. Coke-ovens, two batteries, with coal-bin, crushers and boilers. 4. Engine-house containing the blast-engines and the electric generating-station. 5. Pumping-plant. 6. Narrow-gauge railways.

Mar 1, 1905

By George S. Rice

MECHANIZATION in coal mining is a phrase which has attracted world-wide attention, and those persons not engaged on the practical side of coal-mine operations seem to regard mechanization as a panacea for many difficulties of the industry. The term "mechanization" as now employed by experienced mining men is restricted to mean mechanical loading of coal at the face. In a broader sense mechanization in coal mining was begun nearly half a century ago with the introduction of compressed-air undercutting machines and locomotives and, later, of electrically operated locomotives, undercutting and shearing machines, and drills. The use of coal-cutting machines, which has increased until now about three- fourths of the bituminous coal produced is being mechanically cut, first displaced hand-picking except in a few long-wall mines, and later gradually displaced the dangerous and coal-smashing method of blasting-off- the-solid.

Jan 1, 1929

By JOSEPH MACDONALD

STRIPPED of its romantic possibilities, mining is a commercial business, carried on for the profit there is in it, and the business of the manager, in its ultimate analysis, is to make the profit as large as possible. The general manager of a mining company should keep himself personally familiar with all the details of its operations. If be fails to do so, chaos results, labor becomes inefficient, costs go up, and profits go down. Nowhere is this emphasized more than in Mexico. If the mining operations are extensive and complex, involving, besides the work of mining the ore, its transportation and treatment by various milling operations, and the marketing of the products, the business, to be carried on properly, must be divided into a number of main departments, which are subdivided into minor departments. Each main department should be under the immediate charge of a superintendent, or a foreman, and each minor department under a shift-boss. Organized in this way, and with all the principal centers of activity connected by telephone, the manager can keep in touch at all times with the details of every branch of the business, and be in a position to perform effectively the full duty of manager. The ?total cost of mining operations may be broadly divided under the heads of Labor, Supplies, and Marketing. Of these, it will be found, on averaging a number of cases, that the cost of labor will be about two-thirds of the total cost. The importance, therefore, of an efficient labor-department will be apparent. This department must be sub-divided and organized differently, according to the peculiar conditions at each mine, and no one system, however well suited for one particu-

Jan 1, 1909