Mining equipment

“ The difficulty in dealing with the subject from the point of view of production cost arises from the fact that, except possibly in the case of banket gold and some conglomerate copper mines, the life of a metal mine is unknown beyond the time required to exhaust the ore reserves. The visible life at the time of purchase or equipment may be only three or four years, yet the average equipment has a longer life than this, and the anticipation for every mine is also for longer duration than the bare ore in sight. ”

“ But even there, [155] we should have to grant the presence of some few men, for it would not be possible to keep all the machines working without human, intelligent control. In such a mine, it might be possible to maintain a large production with very few laborers or overseers. Fewer men means less wages, less labor trouble, fewer fatalities, and less time occupied in handling men into and out of the workings.
In some ways, copper mines are ahead of gold mines in their equipment. Coal mines have adopted car loaders which as yet and without any very good reasons metal mines have not. ”

“ Such reports must embrace details of ore extraction, metal contents, treatment recoveries, construction of equipment, and the results of underground development. The value of mines is so much affected by the monthly or even daily result of exploration that reports of such work are needed very frequently,—weekly or even daily if critical work is in progress. ”

“ In net result, no mineral deposit of speculative ultimate volume of ore warrants an initial equipment of the sort that will meet every eventuality, or of the kind that will give even the maximum efficiency which a free choice of mining machinery could obtain. ”

“ When speaking of operations that are typical of some foreign mining districts and especially those that possess ore-bodies whose extents are readily calculated, no clever prophecy is required to ascertain the proper amount of equipment. ”

“ The industry has also profited by the improved methods adopted to facilitate the transfer of the ore in transit and especially by the use of machinery and the mining operations themselves. Furthermore, in the principal mining range—Mesabi—the ore is sometimes found so near the surface that with the removal of a few feet of earth it is mined by the open-pit method, the ore being scooped by huge steam shovels directly from the pit to the car. ”

“ Steam shovels, weighing from sixty to seventy-five tons each, do the work. Like a great hand one of these shovels dips down into the soft mass of ore, buries its great dipper until it holds from four to eight tons, and then, groaning and rumbling, slowly lifts its burden aloft, swings it over a car, and the actual work of mining is done. A thousand times a day it will repeat this operation, lifting from three thousand to eight thousand tons of ore. ”

“ If he takes any thing in that line, let it be the best mining pick and spade he can{181} find, with a stout sheath-knife, and a horn for crevassing. The “cradle” is found any where in the settlements or in the mines. If it is intended to engage in the quartz-crushing operations, the most simple machinery is the best. The very complicated and expensive machinery which has, in several instances, been taken to the mines, has been useless. The least breakage will delay the whole work for months, till it is replaced from the States.
By all means avoid companies which are got up at home for mining. ”

“ Access to the buried deposits is gained by vertical shafts. Actual mining is now done to a large extent by continuous miners, machines which bore or rip the potash ore from the face and load it into shuttle cars in one continuous operation. The shuttle cars then transport the ore to conveyor belts which move it to the shafts for hoisting. Working conditions and safety are excellent and have led to high productivity from these mines. ”

“ Some mines cannot be economically operated without the treatment of the ores upon, or close to, the mining property. With certain sorts of low-grade ore, or with those kinds of ores that may be concentrated before shipment, provision should be early made for the erection of appropriately designed mills. We say the subject should be considered early, but we do not advocate the premature erection of any mill. ”

“ Rock and earth on the one hand, and metal and ore on the other, are filled into buckets separately and drawn up to the open air or to the nearest tunnel. If the shaft is not deep, the buckets are drawn up by a machine turned by men; if it is deep, they are drawn by machines turned by horses.
It often happens that a rush of water or sometimes stagnant air hinders the mining; for this reason miners pay the greatest attention to these matters, just as much as to digging, or they should do so. ”

“ Not so with silver and gold mines. They are most unreliable in both quality and quantity. Costly buildings and machinery are often erected to economize the mining of the ore, only to find no mine to operate by the time the buildings are completed and the machinery is working. ”

“ But, of course, more is wanted on a mine than a man who can direct the sinking of shafts, driving of levels, and stoping of the lode. Much loss and disappointment have resulted in the past from unsuitable, ineffective, or badly designed and erected machinery, whether for working the mine or treating the ores. To obviate this defect a first-class mining engineer is required. ”

“ Thus, in Minnesota, in that wonderful Lake Superior country, that is famous as the world's greatest known producer of iron ore, tremendous tonnages are handled every year by the modern steam shovel, which works in natural light by day and by electric lamps at night. In Utah and Nevada we find similar operations conducted in the excavation of copper ores. In Australia, the famous Mount Morgan mine is using open air methods in the mining of precious metal ore. ”

“ Where power has to be generated on the Page 82 mine, the saving by the use of direct steam, generated at the winding gear, is very considerable. Moreover, the cost of haulage through a shaft for the extra distance from tunnel-level to the surface is often less than the cost of transferring the ore and removing it through the tunnel. The load once on the winding-engine, the consumption of power is small for the extra distance, and the saving of labor is of consequence. ”

“ This ore is frequently almost as hard as iron itself, many of the pieces thus dislodged being too large for convenient handling, either by the steam shovel or in the chutes at the wharves, and must be still further broken up. This is sometimes done by the men with picks; but in mining on a large scale, where the deposit is all of a very hard nature, crushing machines are used. ”

“ An ore must be an aggregate or association of natural [20] minerals, or a single mineral, from which metal may be profitably recovered. Mines are excavations in the earth from which ore, coal or gems are taken. Mining is the art or practice of operating mines.
Throughout the subject, we see the inseparable idea of profit. The work of carrying on operations in a railroad tunnel is not mining; the driving of adits through barren rocks to reach ore bodies is not mining; the sinking of shafts through worthless "wash" or rocks with a view of opening avenues for the removal of ore is not mining. ”

“ The limit, nevertheless, has been reached in many rich mining districts. Pumps of the most approved type, and driven by the largest and most economical steam-engines, have done their best in the struggle against the difficulty; and yet the water has beaten them. Rich as are the lodes which lie beneath the water, the mining engineer is compelled to confess that the metal value which they contain would not leave, after extraction, a sufficient margin to pay for the enormous cost of draining the shafts. ”

“ The introduction of a certain amount of mining machinery, such as steam drills, thawers, and powerful pumps—applied more particularly to the deposits of the benches and hillsides—coupled with a more definite method of conducting extensive operations on a comparatively economic basis, has given fresh impetus to the work of mine holders, and made largely remunerative that which had promised to be little profitable. ”

“ The ore as taken from the mine concentrates four tons into one, which has a gross value of one hundred dollars, and with the first concentrator, whose capacity was one hundred and twenty tons daily, returned three thousand dollars per day to the owners. The company employ one hundred and fifty men, and are well equipped for profitable mining. ”

“ When we have to use drainage tunnels for our mines we carry the water off from the mouth of the tunnel in a flume, placing quicksilver in the riffles, and if it is a copper mine we place scrap iron in the water and we also use the water for power to assist us in mining, so that at the present time we extract and reduce ore at a lower rate than in other parts of the world, for there is no wastefill management and no overproduction, for in all our mining operations we work those that cost the least, and we operate our coal mines in the same way. ”

“ The want of capitalists in the mine country, and of practical skill in the boring, blasting, sinking shafts and galleries, oppose obstacles to the [Pg 160] successful progress of mining. There is but one regular hearth-furnace for smelting in the whole district; and that is on the modern plan of English furnaces. There are not over four or five regular shafts in about forty mines; there is not an engine, either by horse, steam, or water power, for removing water from the mines, several of which have been abandoned on this account, with rich prospects of ore in view. ”

“ Crucibles and chemicals are ranged round a long room with an iron roof. The tenant has borrowed a mortar-box, two stamp-heads, shoes, and dies, and has fitted them with wooden stems and cam-shafts. He proposes to drive them by two-man power, in order to crush three tons of ore per diem and to test a new patent amalgamator.
I breakfasted with the scanty staff and then walked down the western valley to the Tákwá establishment, the oldest of the new mining-industries in the Protectorate. ”

“ The great advances in the quantity of steel produced have been made possible by corresponding advances in methods of winning the iron ore from the earth. Mining machinery has been revolutionized at least twice during the last half century, first by improved machines driven by steam, and again by electricity and compressed air. Ore is still mined to a limited extent by men with picks and shovels, but these implements now play so insignificant a part in the process that they cannot be considered as important factors. ”

“ The very woods cut down on the site of the mines afford the necessary charcoal for smelting. The whole of the processes described are conducted by the Chinese. The miners are scattered over the island, according to the direction of the mines. Besides the immediate laborers in the mines, many others are connected with them, being engaged either in raising [162] food and necessaries, or in fabricating the tools and other materials required in the processes of mining, washing, and smelting. ”

“ Manifestly, if the ore-supply to a particular roadway is insufficient to keep a mule busy, the economy soon runs off.
Mechanical Haulage.—Mechanical haulage is seldom applicable to metal mines, for most metal deposits dip at considerable angles, and therefore, unlike most coal-mines, the horizon of haulage must frequently change, and there are no main arteries along which haulage continues through the life of the mine. Any mechanical system entails a good deal of expense for installation, and the useful life of any particular roadway, as above said, is very short. ”

“ Upon the Rand, South Africa, a territory dominated by Englishmen, every mine is equipped with its own mill, and all notions of mining cover the inseparable idea of local ore treatment. Here, in our country, there are many, many mines which have absolutely no means of treating their own products and the managers give no thought whatever to metallurgical or milling lines. There are, on the other hand, many companies that have erected private plants at their mines for the extraction of metallic contents from the ores. ”

“ The miners work is as follows; first they sink a shaft so many feet down, and then when they get down deep enough they start sapping forward, putting up timbers as they go. They have to work very quietly as Fritz also does some sapping and if too much noise is made the miners themselves are liable to go up in the air and come down in pieces, and I do not think that anybody would relish that idea. Mining is done now on a very large scale. ”

“ Probably in no other mines in the world does massive machinery play so great a part in mining operations and hand labor so little. Work in the Mesabi Range began in 1892, and the output grew rapidly until 1901, when it amounted to 9,303,541 long tons. The Southern iron region shares with the Northern Appalachian region in the advantage of having coal and limestone, two essentials in the reduction of the ore and found in close proximity to the ore itself. The South has the additional advantage of cheap labor, but it is under the disadvantage of having a limited local market. ”

“ On mines worked from near the surface, where depth is gained by the gradual exhaustion of the ore, the only prudent course is to put in a new hoist periodically, when the demand for increased winding speed and power warrants. The lack of economy in winding machines is greatly augmented if they are much over-sized for the duty. An engine installed to handle a given tonnage to a depth of 3,000 feet will have operated with more loss during the years the mine is progressing from the surface to that depth than several intermediate-sized engines would have cost. ”