Show ELECTRIC ELEU atric MINING IN california scientific AMERICAN electricity for operating mining machinery has reached a high stage of development in nevada county and it is natural that it should typify the progress that california is making in harnessing its moun tain tail streams and utilizing this power for industrial and commercial purposes ses it is not that electricity is displacing hydraulic and hieam power in the old mines so much as it is that it is opening up new mines that were considered inaccessible and reawakening abandoned mines that could not be operated profitably with steam power the cost of getting coal up to the mines was in some cases so great that nothing but the richest returns in minerals could make and profits for the company before tue advent of electricity in the california mining fields there had been developed ideal systems of water and pipe lines and in nevada county many of these systems are in use today ina in spite of this thiis electricity has achieved remarkable results the reasons are not far to seek the mines located above what is called the water line could not be worked nor could many abandoned mines which were known to be moderately rich in ore but that cost too much to work with steam generated from coal the fuel had to be transported many miles over rough mountainous country and its cost at the mouth of the mines often averaged ten and more dollars per ton with her fine system of hydraulic generation of electricity in the sierra mountains california leads all other states in the cheap distribution of electric power gold mines all along the route of her long distance transmission lines have been converted into active scenes of mining lateral lines of transmission run in all directions and some of these extend upward of twenty and thirty miles from the main route so great has grown the demand for electricity for mining purposes that the supply of power for the pacific coast end of the transmission lines is seriously menaced the application for electricity for new mines call for electricity every few weeks the water power of california is thus its ts most precious heritage so important is is this considered that its distribution has been developed into a system that makes both miners alner and farmers dependent upon lt it the location of a mine is therefore the important consideration in opening and working it water is sold and distributed st at so 60 much per miners miner inch throughout the state this appears on the surface a very equitable system and it was before hydraulic power was introduced for generating generates electricity the sale of the miners inch ot water has no bearing whatever upon the head ad of the water one farmer or ml mi ner pays the same for the power as another who is located or more feet lower down in in the valley As each inch used had to be paid for it was not considered necessary to take into consideration the pressure of of the water this condition of affairs has created some peculiar results the miner or farmer who uses the water in the higher altitudes loses a power which another some hundred feet below can convert into electricity power for mine purposes there are a number of instances where one mine develops something like horsepower horse power for each miners inch of water and another feet lower down secures horsepower at the same cost for the water we find therefore that the generation of electricity on a large scale in the lower valleys is more economical than in small ants near the camps higher up most of the powerhouse companies can transmit electric current to the higher camps at less cost than the latter can generate it no matter how efficient the water wheels and motors may be in nevada county there is nearly electric horsepower horse power used for mine operation the power house on the south yuba supplies most of the mines with its electricity tri city but individual companies and groups of mines have organized in the last year to d develop 9 their own electric current there are a number of streams in the mountains which have a head varying from to and the harnessing of these assures permanent cheap power for the mines on the south yuba there are two horse power plants working under feet head and the current is used almost entirely for mine purposes the original machines in this region consisting of two kilowatt motors are still in active operation one working at feet head and aad the other at feet in grass valley there is one mill that is driven entirely by electric synchronous motors there are forty stamps and sixteen concentrators operated there and the current is transmitted from the distant power house and sold by meter it has been found that electricity operates a quartz mill cheaper than any power there are some rather anomalous conditions to be found in nevada county where electricity has displaced steam all the mining machinery was formerly driven by steam and the work of displacing steam was slow in order to save the old machinery the engineers adopted many peculiar devices but electricity has triumphed and steam is practically abolished owing to the high cost of fuel the direct current motors are used for pumping in connect connection iou with compressed air and also in a more limited way for driving drills it is doubtful it if compressed air for driving drills pumps and a few other machines will be displaced by the electric electr fc motor in drilling with compressed air it has been found that the exhaust air proves of 0 great value in ventilation electric drilling cannot offer such advantages unless worked in combination with a system of electric fans while electricity Is is used for driving the compressors working the mine house hoists and operating pumps it has so far made little progress in drilling electrically driven mine pumps have proved popular and profitable in this region and two new ones are being installed one at the foot level and another at the 1000 foot level the success and profits of these new large pumps will naturally influence the construction st of others for mining companies are quick to note the practical advantages of any new departure in the matter of ven ventilation illation by exhaust cants the mines are still inadequately supplied but their introduction is being steadily pushed estimating current at ten cents per kilowatt hour the cost of exhausting cubic feet of air by the slow speed blower has been found to average cents and by the high speed blower only cents the installation of the latter in preference to the former is therefore an assured fact and a number of 20 horsepower horse power motors are used for driving trans frans from six to nine feet in in diameter |