Show new use for mill tailings GEO L WALKER IN BOSTON commercial I 1 for several years past I 1 have been conducting a quiet investigation to ascertain what value if any the tailings from the various big copper concentrators may have I 1 feel well satisfied now that I 1 have hit upon a plan by which practically all of the tailings of the lake superior mining companies may be marketed at a substantial profit and also a possibility of turning the tailings of the various concentrators operating on porphyry rock to good account heretofore the value of tailings has been believed to exist wholly in their metallic meta ilic contents or in their adaptability for brick making I 1 have satisfied myself that they have a much greater value for use as a fertilizer ti A company is now making and selling in new england what is known as mineral fertilizer it is simply a metamorphosed lava rock a which ha has been quarried and pulverized it is sold at prices ranging from 15 to 20 a ton this is precisely the same kind of rock that contains all of the copper mined in the lake superior district with the exception of that coming from the calumet hecla conglomerate the company now making and selling this mineral fertilizer calls attention to the fact that soil consisting chiefly of decomposed lava rock which forms the soil of the great fruit and grain belt of washington and surrounding states produces the best crops raised anywhere in the world it has been manufacturing and selling this fertilizer for several years and in its pamphlets it presents letters of strong indorse ment from and farmers some of whom I 1 know personally I 1 am satisfied satis fled therefore that the fertilizer is a success the mining companies of lake superior take out from to tons of rock every day transport it to the shore of lake superior or its branches crush it very fine save the copper and allow the rock to go into the lake as waste material the gross amount of this is approximately 00 tons annually which is sufficient to fertilize 10 acres of ground it is delivered without cost of carrying or crushing at the shore of americas inland fresh water sea which lies practically at the front door of one of the greatest agricultural districts in the world namely that which comprises the valleys of the mississippi missouri wad and ohio rivers undoubtedly these rock tailings couii cou be pulverized to the fineness of wheat flour sacked loaded on ships and delivered at the various lake ports from duluth to buffalo and sold readily at a price which would yield the mining companies a splendid profit the cost per ton of grinding freight and selling probably would not exceed to 3 the mineral fertilizer interests referred to present an analysis which I 1 am comparing with the average of 15 samples of lake superior rock taken from the same formation in minnesota by Por fessor frank F grout of the university of minnesota the comparison follows lake mineral superior fertilizer mine aline rock percent per cent percent per cent potassium oxide sodium oxide calcium oxide magnesium oxide iron 38 sulphur silica rina 1692 phosphoric acid osa it should be perfectly plain that if the mineral fertilizer fer tilzer sold in new england is good the tailings of the lake superior copper mills would be equally valuable as plant food after being thoroughly culvar iced in order to bring this waste rock to a condition w where chere it will give up its chemicals immediately however it would be necessary to reduce it to a pulp the finer tha better if experiments have been or are made without such thorough pulverization their failure is a foregone conclusion the matter of pulverizing igneous rock and using it as a fertilizer undoubtedly will seem absurd to many every geologise geol ogise knows however that vegetable and animal life the decay of which creates our loams coams or humus soils both had their origin in decomposed igneous rocks plant life fed by the chemicals of such rocks released by natural weathering and decomposition in the seas and on dry land created the food supply which made animal life possible everyone who has visited the irrigated districts of the west must know that tremendous crops are being raised on decomposed rock alone which after existing for countless centuries as desert sands and bearing next to no vegetation became highly productive soil when watered and seeded the process of soil decomposition js is still going on continuously but very slowly the total annual decomposition occurring dirring oe in the five or six cubic feet of earth which supports a hill of corn for instance probably amounts to no more than a fraction of an ounce yet crops will grow on the same soil year after year indefinitely without artificial fertilizers though of cour course i se the growth will eventually become so small as to 10 be unprofitable I 1 am satisfied from my investigations that a halt pound of pul lake superior mill tailings under each hill of corn or 1000 to 2000 pounds to each acre of wheat would pay the farmer handsomely even though the cost of this fertilizer to him were 6 to 8 a ton I 1 am convinced that the big mining companies of 0 the lake superior district have an opportunity here which they should not neglect they can well afford to experiment by thoroughly pulverizing a quantity of their tailings this winter and shipping samples of it gratis to farmers in michigan ohio illinois minnesota and wisconsin the result of its use should be carefully watched when the mining companies are satisfied by the testimony of the farmers that the material has great value they should organize a fertilizer company to control the tailings of all the mills manufacture advertise and introduce the product it is not at all improbable that a market could eventually be found which would absorb all the tailings of the lake superior district at a price which would reduce the the cost of copper produced two or three cents a pound not only this but the grinding and pulverization of the tailings probably pio bably would make plates and scales of any remaining particles of copper and in the screening of this pulp the copper possibly could be saved if so it would go 1 a I long way towards defraying the expenses of the operation the development an and d conduct of this fertilizer business by a single company would open up possibilities which its exploitation by individual mining companies would not make feasible for instance it ir the fertilizer could be improved greatly by the addition of phosphorous the flags of certain blast furnaces treating phosphoric iron ores could be purchased pulverized and mixed with it there are various rocks which contain a high percentage of potash notably fel sites and granite which also could be considered for a mixture admixture I 1 have learned that where finely pulverized granite in double quantity was used side by side with the best chemical fertilizer the former produced a better crop of tobacco although I 1 have at hand no analysis of the porphyry rock about tons of aich is being crushed daily by utah copper and nevada consolidated I 1 know that as it belongs to the granite family it should contain from 3 to 5 potash the tailings of those mills thoroughly pulverized undoubtedly could be made to yield up the potash by some inexpensive method of treatment the tons of porphyry rock lock already being treated annually probably contains to tons of pot ash if tons of this could be saved it would go a long way to solve the problem of pota potash sh supply concerning which there is now a governmental controversy between the united states and germany the copper mines of this country are making between and tons of tailings daily this is a condition a situation in itself nothing but the ice age ever before crushed and moved so much i igneous 1 leous rock I 1 have felt for years that these tailings would some time come to have very great value now I 1 am satisfied as to wherein this value lies the use of these tailings for fertilizer will not only increase the profits of copper mining companies very greatly but will inestimably benefit humanity through more productive farming and a greater and cheaper food supply |