Mining (underground)

“ It is well known that, under present methods of mining, from 10 to 75% of any given deposit of coal is left underground as props and supports, or as low-grade material, or in overlying beds broken up through mining the lower bed first. An average of 50% of the coal is thus wasted or rendered valueless, as it cannot be removed subsequently because of the caving or falling in of the roofs of abandoned galleries and the breaking up of the adjoining overlying beds, including coal, floor, and roof. ”

“ At the time modern mining began they had become mere depressions in the ground. All these workings when examined contained countless stone hammers or mauls, a few wooden shovels, remains of wooden bowls for baking, birch-bark baskets, and some spear or lance heads, and other articles of copper. Opinions and evidence vary as to the age of the operations. Modern miners would regard the whole system as nothing more than prospecting work, and not raining proper, as there were no shafts or tunnels or underground workings. ”

“ Roughly speaking, mining methods may be divided into two general classes: (1) surface mining or open work and (2) underground mining.
Open work is done where a small amount only of worthless material must be removed in order to uncover the deposit. This method is employed, for example, in the iron mines in the Mesabi range in Minnesota, where the ore is covered by glacial drift 10 to 100 feet thick. Such covering may often be stripped off with steam shovels. Where the ore is soft and friable, as in the case of some of the iron ore of the Mesabi range, it too can be removed by steam shovels ”

“ 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. ”

“ These deposits are naturally the first to fail in productiveness, but the neighboring hills are formed of a gold-bearing quartz which is being crushed, night and day, by hundreds of powerful machines; and the works still pay ten thousand miners fair day-wages, besides giving the organized companies who employ them satisfactory dividends. Thus mining has been largely robbed of its adventurous character in this neighborhood, and perhaps also of most of its alluring charm, having become a sort of regular industry, like coal-mining, or even brick-making. ”

“ Indeed, this system of mining partakes of the nature of quarrying rather than that of mining in the ordinary sense, the ore being scooped from the surface of the ground. One naturally thinks of a mine as being subterranean; but in the great open-pit mines in the Lake Superior region, which are the largest mines in the world, all the mining is done at the surface of the earth. ”

“ It exists no more. All mine development work ceased long ago. There are green-stained carbonates on the surface, but there are no copper ore-bodies. The "mines" have been dismantled of their machinery and other equipment, and not even a lone watchman remains to point out to the desert-wayfarer the spot on which was reared the monumental mining-stock swindle of the century. Every dollar invested by the public is lost. ”

“ Upon the bed-rock is a deposit, from three to four feet in depth, of gravel and boulders, in which the gold is hidden. This is called by the miners "pay-dirt," and to remove it to the surface and wash it is the end of mining. It is an expensive and laborious process indeed. The water has first to be controlled; and in mines of not too great depth this is done by a drain ditch along the bed-rock, commenced many claims below. In this all the claim-holders are interested, and all contribute their quota of the labor and expense of digging it. ”

“ These mines, with their prolonged subterranean workings, their stamping and crushing mills, and the smelting works which have been established near them, fill the district with noise, hubbub, and smoke by night and day; but I had turned altogether aside from them into a still region, where each miner in solitude was grubbing for himself, and confiding to none his finds or disappointments. Agriculture restores and beautifies, mining destroys and devastates; turning the earth inside out, making it hideous, and blighting every green thing, as it usually blights man's heart and soul. ”

“ Since the first discovery of lead in this Territory, the number of mines has been much increased, and hardly a season passes without some new discovery. Every discovery of importance soon becomes the centre of mining attraction. As the ore is found in the diluvial soil, it is generally exhausted on reaching the solid rock; and after penetrating a considerable area of the surface with any, or but partial success, the locality is abandoned, and a new one sought. As the mines are worked without capital, and the ore is dispersed over a wide area, the number of localities is almost indefinite. ”

“ 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. ”

“ As their open trenches and pits could be worked only in the summers, and by methods that made their operations much slower than those of modern miners, no great advance of their work was possible during the working time of each season; and yet remains of their mining works have been discovered wherever mines have been opened in our day; and, as previously stated, they are known to exist in heavy forests, where the modern mining works have not yet been established. ”

“ Such companies, with superior mechanical facilities to do much labor, in a short space, will be enabled to go over the whole mineral field, although already dug over by individuals, and reap yet a rich reward of their efforts. And when there will be no more gold washing to be done, then a new era in the mining of the country will commence—we mean a regular system of mining by sinking shafts into the very bowels of the rocks will be entered upon. ”

“ Scattered throughout the region are small mines, and also abandoned mines that were worked in the seventies, eighties, and nineties, when on nearly every lonely creek some miner patiently washed the gravelly sands for gold. Today most of the mining is in hardrock, although some small-scale placer operations are being carried on. Cutting across US 395, State 22 continues northeast along the east bank of the Columbia, which here cuts a tortuous channel through granite and other hard rocks to Northport and the Canadian Line. ”

“ 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. ”

“ In a cablegram recently received from the Company’s administrator on his return from a tour of inspection of the various mining districts he states that new finds were occurring everywhere daily, and that crushings were everywhere successful; that the reefs were improving with depth, and that wonderful development was proceeding in every district. As regards alluvial gold, that large deposits do exist, and that their discovery is only a question of time, is the opinion of all experienced miners. ”

“ No one can appreciate the magnitude of those various movements by a simple perusal of statistics of the mineral wealth which they disclosed. He must pass through the mining belts and note how almost every rod of ground, over vast tracts of country, is filled with prospect holes that attest the miner’s former presence. If the trapper carried the tools of his trade to haunts remote and inaccessible, the miner, with his pick and shovel, certainly outdid him. ”

“ 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. ”

“ But then, again, it is becoming plain to many experts in mining that, in working downwards from the surface itself, the future of their industry offers a wide field for the extension of the open-cut system. In proportion as power becomes cheaper, the expense attendant upon the removal of clay, sand, and rock for the purpose of laying bare the cap of a lode at a moderate depth becomes less formidable when balanced against the economy introduced by methods which admit of the miner working in the open air, although at the bottom of a kind of deep quarry. ”

“ The miners do not support the earth by timber or pillars, as they should; the result is that the whole plot of about two hundred acres is gradually sinking, and this will eventually ruin the industry in that part of the deposit. In another part of the same field, a French company has purchased forty acres, and it is mining the whole tract and hoisting through one shaft by steam power. In that shaft they have sunk to a depth of six hundred feet, and are troubled with water and petroleum. These they pump out very much the same way as in coal and other mines, worked in a scientific manner. ”

“ Several of the mines in the mineral soil have been traced down into the rock, and have been pursued through apertures, closing and expanding in the manner of true veins. In the numerous cases where the rock has put a stop to further mining, and it has exhibited no signs of ore, it may be supposed that the ore has been moved, by diluvial force, from the original position of the mine, and been finally deposited, with the soil, upon unmetalliferous portions of the rock. ”

“ Mill of the Pittsburg-Silver Peak Gold Mining Co., Blair, Nevada.
Water may be too scarce for the needs of a mine or its community. There may not be sufficient to supply boilers or a mill, or for the domestic purposes of the [89] workers. On the other hand, water may be so abundant in the mine workings as to prove a deterrent factor in profitable operation. With shaft mines, having deep workings and low grades of ore, if water must be delivered mechanically, the costs for such drainage are frequently prohibitive of mining. ”

“ We do not, of course, desire to keep our ore and coal in their existing state, because they must be used, but this does not mean that coal deposits and ore deposits should be exploited in excess of need, nor that the processes of mining should be wasteful. With proper care, soil and timber can be so conserved that neither the farm nor the forest will be destroyed. ”

“ This prevents many from engaging in mining on the public lands, and especially those who would be best able to prosecute the business; and of the number who take leases, a great proportion continue to pursue the desultory method of mining in alluvial [20] ground, introduced at an early period by the French, but which is attended with very great uncertainty.
Improvements remain also to be introduced in regard to the processes of mining, the furnaces employed, and the method of raising the ore. ”

“ 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. ”

“ About two-thirds of our gold is obtained from the placers, and one-third from the quartz.
A mine is defined and generally understood to mean "a subterraneous work or excavation for obtaining metals, metallic ores or mineral substances;" but this definition does not apply to our placer mines, which are places where gold is taken from diluvial or alluvial deposits. Most of the work is not subterraneous; it is done in the full light of day. ”

“ A similar sacrifice in the shape of pillars is often necessary to support the surface, either to avoid injury to valuable structures or to prevent a flooding of the mine. As already noted large pillars must always be left to protect shafts, adits and the more important mine-passages necessary for drainage, ventilation and the haulage of mineral. In the early history of mining there was but little attempt at systematic development and working, and the mines were often irregular and tortuous. ”