XVIII. THE MINERAL INDUSTRIES

MINING AND ORE DRESSING

CHARLES E. LOCKE

The Mining Industry.-The year | activity is exampled by the produc1916 will go down in history as one tion of 40,000 tons of ore per day by of great prosperity for the mining in- one mine, the Utah Copper. With dustry in the United States, due pri- operators straining to increase promarily to the demands of the Euro- duction under the stimulus of high pean War. Prices have made new prices, it still seemed impossible to high records, and hence operating meet the demands. Pig iron was scarce mines have been worked to full ca- even though the production is at the pacity, old mines have been reopened, rate of 40 million tons per year. The and search for new mines has been shortage of coal, especially anthracite, stimulated. For example, copper has became somewhat serious toward the ranged between 25 and 33 cents per end of the year. pound against a normal price of 12 cents; silver, 55 to 77 cents per ounce, normal, 55 cents; lead, 5.5 to 8 cents per pound, normal, 4 to 4.5 cents; zinc, 9 to 18 cents, normal, 5 cents; antimony, 12 to 45 cents, normal, 8 cents; quicksilver, $80 to $300 per 75 pounds, normal, $45; pig iron, $30 per ton, normal, $15; tin, 40 to 50 cents per pound, normal, 35 to 40 cents. Some metals, such as antimony, quicksilver and tungsten, reached their very high prices during the first half of the year and dropped back during the last half. ( (See also other articles in this department; and XIII, Economic Conditions.)

Lake Superior iron-ore shipments to Oct. 1 were a record at 48,816,650 tons, an increase of 14,147,084 tons over the same period in 1915, indicating an estimated tonnage of 62,000,000 for the entire year. Copper reached the highest price in 40 years and the fact that much copper has been sold ahead into 1917 assures a continued high price. Lack of refinery capacity has prevented any accumulation of a surplus of this metal. In the case of lead ores, the Utah smelters had to refuse some offerings of ore and thus reduced production. Old graphite and manganese mines in the South have received attention and have been started up again and worked profitably. The tremendous

Increased dividends have resulted and profits have been shared almost universally with the workmen, either in the form of increased wages or bonuses. The sliding wage scale, based on the selling price of the product, has been perhaps the most satisfactory arrangement. In spite of all this, labor has not been satisfied. Three serious strikes have occurred: in the Clifton-Morenci district of Arizona, in the Mesabi iron region of Minnesota, and at Youngstown, Ohio; other minor disturbances have taken place elsewhere. Practically all may be attributed to agitators, and have ended in partial or entire defeat for the strikers (see also XVI, Labor). In spite of increased wages, there has been a shortage of labor in many districts. This, coupled with higher costs of material and decreased efficiency of labor, has prevented profits from keeping pace with increased price of product. As an example of increased cost of supplies, dynamite may be taken. There is a shortage of glycerine and an increased demand for it for war use. The price of straight nitroglycerin and gelatin dynamites has made them almost prohibitive to the miner, who has had to be satisfied with the ammonia compounds.

Considering developments in individual sections, the Oatman gold field in Arizona has progressed satisfacto

rily and gives promise of being a big alone. Stripping of overburden by low-grade camp. A new gold district hydraulicking instead of by the usual is reported at Gold Lake, Manitoba, steam shovel method has been used at but it is too early to decide regarding the Hillcrest iron mine in Minnesota. its value. Similarly, big nickel-plati- The Inspiration automatic hoist at num deposits are reported in north- Miami, Ariz., is reported to be a perwest Canada up toward the Arctic fect success. Hammer drills are findCircle. Butte, after many years as a ing a larger field, notably in sinking copper center, is developing a big large shafts at Ironwood, Mich. zinc industry. Lake Superior every (Woodbury shaft), and elsewhere. year develops new copper mines, and Compressed-air locomotives for unshows evidence that even after 50 derground haulage have replaced elecyears of work the ground has hardly tric trolley in one or two instances, been scratched. The Calumet and solely for reasons of safety. Hecla Co. had a big celebration of its semi-centenary during the year, and there appears to be no reason why it should not be working 50 years hence. The southeast Missouri lead district is expanding beyond the limits of St. François County into Washington County. Alaska may be said to be progressing slowly. In August the first train of coal from the Matanuska coal fields came out over the new government railroad. The Alaska Gold Mines Co. has not come up to the promise of its promoters, but it is expected that ultimately it will reach a profitable stage (see also VIII, Alaska). The Anaconda Copper Co. of Montana has followed the lead of other large interests in acquiring large copper deposits in Chile. In Mexico alone has there been no progress and most of the mines have been idle owing to unsettled conditions.

The "safety-first" movement is to be credited with still further decrease in accidents and fatalities. Agita tion for revision of the United States mining law still continues, but it is opposed by the slowness of Congress to take action. A bill to appoint a commission to report a revision of the law passed the Senate but died in the House Committee on Mines.

Mining Methods.-Regarding improvements in mining it is always true that a boom period is not the time of greatest progress, since the operators are too busy making money to attend to all the economies of operation. Large steam shovels up to eight cubic yards capacity and lifting material up to a height of 65 ft. are used on coal mines, and under special conditions, in iron mines. The boom is as long as 90 ft. and the whole shovel revolves instead of the boom

Ore Dressing.-In ore-dressing, flotation still continues to be the sensation, although yet undergoing the difficulties of litigation. In the latter part of the year, the Minerals Separation Co. won their case against Miami in the District Court of Delaware, this being directly opposite to their previous defeat in the suit against Hyde in California (A. Y. B., 1914, p. 492). The U. S. Supreme Court, however, at the end of the year reversed the Hyde decision and gave a decision in favor of the Minerals Separation Co. Figures for 1916 without question will show a great increase over the 1915 total of over three million tons of ore treated by flotation. The process is still rule of thumb, although much investigation has been made during the year, seeking knowledge of the fundamental principles.

Flotation has turned attention largely away from leaching for copper sulphide ores and has an advantage over cyaniding on silver sulphide ores, both in cost of plant and in cost of operation. On copper oxide ores it still has a rival in leaching, as evidenced by the new leaching plants of the Inspiration and New Cornelia companies in Arizona, and the Utah Copper Co. in Utah. On Lake Superior native-copper ores it seems destined to play a big rôle in increasing the saving. Broken Hill, Australia, may still be said to be the home of flotation and its modifications along the line of preferential flotation. There, the Bradford, Owens, Lyster, Palmer, Horwood, old DeBavay film, and various adaptations of the Minerals Separation process are in use at various properties. (See also other articles in this department.)

COAL, COKE AND PETROLEUM
R. DAWSON HALL

Coal Mining. For many years the steam shovel has been used in the anthracite region for the uncovering of coal, the thickness of the deposit and its relatively high price in the market making the removing of several feet of soil feasible. In the bituminous region, where the shovel is now making great progress, the seams are thinner and the coal of less value.

Some progress has been made in the introduction of revolving dumps such as are in universal use in England. There one car is dumped at a time. The Ramsey dump in revolving unloads several at one operation. At the Lemont No. 2 plant of the H. C. Frick Coal Co. 18 11⁄2 ton cars are reversed at one time.

The electric cap lamp is making The maximum depth of the deposit satisfactory progress. It appears to workable by shovel, of course, is lim- have only one fault, it will not indiited, but in cases where the coal is cate gas. Though it is perfectly safe, available for stripping, the spoil need it fails to show the presence of dannot be loaded into cars. All that ger, and gas may then be ignited by a is necessary is to lift it with a shov- spark from a pick, the flare of an exel having a long boom and drop plosive, an arc at an imperfect conit in some other place, from which tact of two electrically connected coal has already been excavated or in surfaces, or by some other means. which coal was not to be found. The The acetylene safety lamp is almost work is heavy, its character is uni- inevitably heavier than the naphtha form, and consequently the shovel lamp and hitherto has been regarded needs to be and can be fitted to the as anything but safe. When a blast job. There is no problem connected or a jar extinguishes the lamp, unlike with continuous change of location as the naphtha lamp it fills with an exin railroad construction, where the plosive gas of its own making. The work of moving, the uncertainty of relighting of a naphtha lamp is danoperation, the variation in material gerous in a gaseous atmosphere even to be moved and the limitations of with an internal igniter because of rolling stock make the construction of the fact that the internal explosion large shovels somewhat undesirable. may pass the gauze. The explosion As a result the stripping shovel is de- of an acetylene lamp is more violent veloping features of its own, the shov- and hotter and therefore far more el itself holding as much as 8 yds. dangerous than that of a naphtha and the boom being of great length. lamp, and the escaping acetylene may Wonderful results are being obtained, give the methanized atmosphere outthe low cost of mining by this method side a power of receiving flame it having a demoralizing effect on the would not otherwise have. In the T. old-fashioned mines. The mine work- M. Chance lamp it is thought with ers and the owners of underground much reason that this risk is remines do not favor the innovation, moved. The burner is double and beand the public in the strip area de- tween the flames is a piece of alloy nounces freely a system of mining which becomes white hot. Should the which leaves the ground unfit for flames be extinguished they are infarming or any other purpose. In Il- stantaneously relighted by the incanlinois the depth of cover averages descent alloy long before the gas with3.86 times the coal thickness; in Ok-in and around the gauze can become lahoma it is 10 times the thickness of the coal uncovered, the coal averaging only 22 ins. The greatest thickness of cover removed is 26 ft. Stripping is being performed also in places by drag scrapers, in another place by a drag line excavator, and in still another, part of the surface is hydraulicked. In one place an apron conveyor takes the waste to a spoil bank.

impregnated with the explosive gas, generated by the lamp, and before the gauze can be filled with an explosive atmosphere from without.

A new cap lamp has made its appearance which has a bulb with two sockets and a straight tungsten filament. The filament runs tangentially to the head of the miner and the bulb is seen lying athwart his cap instead

of standing out from it. Some acetylene mine lamps are being made with the flame passing obliquely across the reflector instead of at right angles to its optical axis. This gives better illumination and a straighter and more easily cleaned passage for the gas, which is apt always to carry dust and so tends to clog the burner.

stead of naphtha and the gasoline recovered by distillation. Gases containing less than three-quarters of a gallon per 1,000 cu. ft. can be utilized for the production of gasoline. The average gasoline production secured from 1,000 cu. ft. of the gas hitherto used for that purpose has been 2.43 gals. The dry-gas product will be much less per 1,000 cu. ft. but the great volume of the consumed gas now untreated (in 1914 35 times the volume of the gas subjected to treatment) suggests the possibilities of the new method. C. A. Burrell, P. M. Biddison and G. G. Oberfell have discussed this recent development in gasoline recovery before the Natural Gas Association of America.

As to the Rittman process, it was reported in May that 20 factories were licensed to use the method. By this process gasoline can be produced at a cost of 12.8 cents per gallon from a fuel oil which sells at $2.10 per barrel with the gasoline removed. Using a

Mine Rating for Compensation Insurance. In Pennsylvania the new workmen's Compensation Act went into effect on Jan. 1. Several large insurance companies banded together to take this somewhat hazardous form of insurance in common. They provided for an elaborate system of mine rating somewhat similar to that adopted in the determining of fire hazards for insurance purposes. The companies instituted a careful system of inspection so as to make the rating equitable. In this system the state coöperated by engaging the inspectors appointed by the private corporations. Thus the rating basis was made uniform. The basing of rates on the haz-fuel oil costing 50 cents per barrel the ards of the mine has produced the same effect as the rating of fire insurance on the basis of fire risk, and large sums have been expended accordingly in improving the physical condition of the Pennsylvania mines. The workmen's-compensation insurance in West Virginia is now based on past records of each mine instead of being made a uniform charge on all the coal mines in the state.

cost of gasoline will be 6.9 cents per gallon. These figures are the result of an official test lasting five days.

Petroleum. The plan of strengthening the flow from producing oil wells by flooding non-productive holes with water or putting them under air pressure is being put to some use. In West Virginia a suit has been brought against an oil company which attempted to increase its output by the latter method. The plaintiff declares that the air enters the casinghead gas and so lowers the gasoline production of the well. The law requires that fresh water must be cased off in wells and also when they are abandoned they must be plugged in order to keep water out of the sand, but apparently there is no provision to keep the producer from deliberately flooding his well.

Gasoline. The demand for gasoline has caused the producers of natural gas to develop to large dimensions the production of what is known as casing-head gasoline, which is made by the process of compressing and condensing the liquefiable constituents of "wet" gas. At many plants the product is stabilized by the use of naphtha. Despite the large quantity of gasoline obtained by distillation and fractionization of oil and from The gasoline content of the Cushing gas at the casing head, the demand is oil is decreasing as the field grows by no means equal to the supply, and old. Among important new developit is believed that another important ments are the Shamrock field in Oklasource, about five per cent. of the homa and the Augusta field in Kanpresent output, will be found in the sas. Another interesting field is that absorption of gasoline from so called at Graybull, Wyo., where the wells dry gas, the absorbent being a cur- are shallow and the product rich in rent of naphtha. The naphtha thus gasoline and kerosene. Their output enriched is then sold. Other oils is not large but enough to make operheavier than gasoline may be used in-ation profitable.

IRON AND STEEL

J. E. JOHNSON, JR.

Commercial Conditions.-The iron ate those too fine for immediate use and steel industry in 1916 has been in the blast furnace and those high characterized more by commercial ac- in sulphur, continues to grow at a tivity than by technical advance. The healthy rate. demand for steel has been so great and the prices to which steel products have been forced so high, that all the energies of the steel-mill staffs have been directed to production rather than to making new advances. The fluctuating nature of the steel industry puts it at a disadvantage in certain respects. In dull times the staff must be reduced and even then, in periods of great depression, becomes an undue burden on manufacturing cost. When prosperity revives, which it generally does with great suddenness, it is impossible to augment the staff in proportion to the increased duty thrown upon it and the energies which in normal times are expended upon betterments of processes or improvements to the quality of product, are all directed to getting out tonnage. The scientific side of the steel business receives during such periods only the attention necessary to insure good quality. (See also XIII, Economic Conditions; and XIX, Manufactures.)

By-product Coke Ovens.-No technical advances of importance have been made in by-product coke ovens for a year or two past, but purely commercial reasons have brought about the introduction of this oven in 1916 at a rate two or three times as rapid as ever before, so rapid in fact that the handwriting is on the wall for the complete elimination of the beehive oven as a factor of any importance in producing blast-furnace fuel. The principal cause which has brought this about has been the enormous value of all the chemical byproducts recovered from these ovens, but especially of benzol and toluol, used for the making of picric acid and trinitrotoluol respectively, these being the explosives used in high-explosive shells. The value of these compounds with that of the sulphate of ammonia and tar recovered has gone far to pay for both the coal and the cost of coking it under the conditions existing during the year, and has left the net cost of the coke almost nothing. Plants are now under way for converting these materials into medicines, dyes and other products, and we may reasonably hope that benzol and toluol will never again be almost waste products in the coking industry of this country as they were at one time. (See also XXIV, Industrial Chemistry.)

Ore Treatment. In regard to iron ore there have been no developments of note. The appreciation of concentration is growing, especially of metamorphic rocks containing iron in magnetic form but in quantities far too small to permit calling them "ore." It will probably continue to grow for a long time to come and will have an effect of no small importance in The Blast Furnace.-The only new prolonging the life of the world's ore development at the blast furnace dursupplies and deferring the day when ing the year also has been a result of very lean material may have to be put the situation brought about by the through the furnace without concen- war. It has been found that the tration. The washing of the lean amount of potash in the blast-furnace ores on the western Mesabi is another charge was frequently larger than had development of importance. Certain been suspected, that a large part of ores in the East and South have been this is volatilized through the heat washed for two generations, gener- in the hearth, and passes out of the ally for the removal of clay, but on stack as a part of the fume which the eastern Mesabi a large part of the makes the gas of normal working problem is the removal of sand, so blast furnaces white. It has been that the methods developed for the further found that the dust which older districts only afforded part of settles out in the bases of the hotthe solution in Minnesota. The sin blast stoves and other points of depotering of iron ores, both to agglomer-sition contains very substantial qua