Arizona weekly enterprise., 1890-11-22
DRY CONCENTRATING. AN IMPORTANT QUESTION BEING
 SOLVED It's Success Being Demonstrated in Co., chise County--Low Grade Ore
 Worked at a Profit.
Tomhstone Prospeclor.

Tombstone Prospccior.
 One of the most important questions to be solved before Arizona can expect to become prosperous to the degree for which nature has fitted her is that of working the ores that are so abundant i'll every mountain range but which have not been touched for lack of water with which to reduce them. The first at- tempt to cut away from the water propo- sition and experiment with dry process was made, or rather Is being made by the Silver Chief Mining and Milling Co. which has just filed articles of incorporation. The prime movers in the company are John A. Duncan of Kansas City and Capt Tevis one of the pioneer of Arizona. In 1860 Mir. Tevis was at the head of column of troops which camped in the neighborhood of Fort Bowie on the San Simon side of the Chiricahua mountains. It was here Cochise and his tribe were located and where he was shown mug gets as large as a rifle bullet and with which the Apaches were well provided.
 They told him where they had found them describing the place to him, but the war breaking out between the north and south. he was called home and not until 1879 did he have any opportunity to re- turn to search for the place he had not visited for twenty years. He never how ever found the spot but did discover and locate a mammoth ledge of gold and sill yer quartz further down the mountain toward the Dos Cabezas peaks.
 He has done assessment work upon the mines for ten years and after interesting Mir. Duncan, q wealthy Kansas City man, in the claims. they set about to inyesti- gate the proper treatment of the ore.
 Granger roller stamp mill and dry con centrator was a new idea patented but q year previous and to this mans inventive genius we are indebted for a solution of a problem which means much for Arizona. A car load of the ore was shipped to Denver and run through the mill and con centratOrs where Granger, the patentee, lived and the closest inspection of the process by experts as we'll as Duncan and Tevis. proved conclusiyely that the erection of works at the mine would not be an experiment and then and there a contract was closed with A. F. Granger to erect three mills and a concentrator sufficient to handle 40 tons per day.
 The plant clone after erection cost close on to S75.0O0. The tramway which leads from the mine to the mills is one mile long and cost S20,000, The ore is handled but once and after leaving the mine it is not touched until it is in the shape of concentrates. The tramway is furnished with a contrivance similar to an endless chain furnished with buckets which runs itself by the weight of the filled buckets down and empty mp. An automatic arrangement at the bins at the mine fills the buckets at the top and a similar conlrivnnce empties them as they rsach the bottom, where the contents are conveyed to the mills which are self feeding, and from there to the concen- trator Ihe three mills crush forty tons of ore per day of twenty four hours, and and the concentrates represent as com pared to the ore rate of one to five that is, five tons of ore which runs in gold and silver S3O per ton Is reduced to concen- trates worth Sl50. The only water used is for the boilers of the power used to run the mills and concentrator.
 The mill consists of a heavy cast iron wheel l26-inch facel carried upon cen fer shaft. qp which it is cushioned by spiral steel springs.
 1 The periphery oi tho wheel forms a series of fonr cams in alterpation with four Impressions or mortars, The ends of the mortars are closed by side plates, to retain the mass of ore to be stamped.
 4 roller stamp weighing 200 lbs. and resembling Cornish roll, is laid in posi- fion by draw bars and rides the mortar wheel. Motion being given to the latter the stamp rolls mp and off the cams ill succession, striking heavy rolling blows ppon the ore in the mortar
 The roller stamp makes from l30 to 1it inch drops per minute.
 The stock ore is fed by spouts from the gookbreaker to hopper of the machine ti..,oa t.poT, n gqranp Of tla 1acira1 mes h the screenings posing over to the eleva tor boot. thence by elevator directly into the mortars.
 After each blow of the stamp the nor tars dump their contents back upon tht screen. hence the ore mass is continually changing stock ore being fed in auto maticnlly to take the place of the finish ed product passing out through the screen
 ih0 machine occupies A. 5x1 feet fioo space. is 5iI feet high, weighs 10,Wt pounds. is very compact, strong anC durable. Requires 2 horse power. G pacity 12 to 20 tons per day, according tt character of the ore and the requirements
 The ore from the mill is conveyed bi an elevator Cautomatic) to the concentra tor. which is self-feeding, and there t., wonderful part of the process takes place itwogld he 8 very difficult matter to ex plain how the cQncentfGtor handles ant separates the mineral substance from tn non-mineral. 1t is system of dry wash inQ. and if the reader is not conversan yith that process, flaming mill fo separating chaff from grain, and whe seen is as simple as the latter.
 The crushed ore flows into a hoppe end from thence into . revolving scree (cylinder) eighteen feet long. This scree has seven sections, with graduatin mashes, which divide the eIushed ore int eight different classes which in turn carried onto eight vibrating tables. Tn aeitation stratifes the matter the miners substsha0 forming a lower stratum an the non mineral m upper stratum. Ovt each of these vibrating tables is plat glass forming a space or Rig drct whei ;he separation take place. Eight z! nousf fans are placed in the rear of eac table anG below ibcm. The fan draw air from the mill room through this du, and down through marrow openings tho iable, which are curbed to prevent |! mineral. in its slow working to the low, end of tbe table, from working dow through these openings.
 The force of the drau9bt carries off tl top or upper stratum back and dow through these apertures. while the low stratum or mineral substance keeps on downward course Co ths bottom of Il table where it drops off into receptac md is ready for sacking. The cost
 concentrating the ore is by this proce seduaed to it's minimum, and it's invent claims that ten dollar ore can be prof ably worked by bis process. The O
 body at the mine in this instance IS : feet wide and it's inexhaustibls aHant
 bas been determined. The process can
 better undeTstood by an inspection
 the works in operafiGp They are locat
 eight miles from Bowie stftiGn. on
 Southern Paciici irailroad. and on tii6 HqI
 side of the Dos Cabezas mountains,
 ...s. .,,,..fc.,, att...