Arizona republican., 1904-02-23

the OnlteQ states. IL IS very pie- turesque landscape and with an un- surpassable climate the year around. | Cananea as we speak of it is scattered from the Mesa up into the mountains, for a distance of a dozen miles to the topmost mine, Clinita, 1000 feet above sea level, and 1000 feet above the re- duction plant The ore is loaded from the bins alongside the narrow gauge railroad into the cars and haul ed down grade to the concentrator and smeiter from one to ten miles. The mineral belt is situated toward the north end and on the east slope of the Cananea range and dipping north-the general strike being east and west. A long, narrow strip of carboniferous limestone averag ging less than a quar- ter of a mile in width, and extending about seven miles in length at places dipping under the surrounding coun- try rock. Nearly the whole surround ing range is of quartz -porphyry, strongly impregnated with iron: inn mense iron capping marks the contact of the lime and porphyry, and along this contact the ore deposits occur, similarly to the copper deposits of Bisbee. The general character Of the ores found in the different mines are essentially the same, with one eXceo- tion. The Veta Grande mine, which produces the native copper and chal- cocite, probably has its origin in solutions from below. This mine is considered by some to have the most lasting qualities of them all. The other mines are producing largely a decomposed sulphide and some chalco- pyrite. The heavy deposits of iron ore are very striking and undoubtedly have played an important part in the deposition Of the copper ores. The heavy copper ores of the camp carry very little gold and silver is found only in a few of the workings.
 All classes and grades of ore are to be had in this group of mines and nearly all the low grade ore can be easily concentrated. This is being done in the first mill built at the rate of 5OO tons per day. and another mill is under construction to handle 1000 tons more daily. Concentration is one of the few processes for the profitable handling of low grade ores. and brief description of this mill might be cf value 10 any one interested in mill ing.
 The crushing is done by fine 10x2O- liANi ipldht VI ISAiGlS WHICH dlt ltu from a Robbins belt conveyor The ore from the crushers falls into a bin under fine sets of 16x36-inch Cornish rolls which are fed automatically by plunger feeders after passing through these rolls. It is passed into the con- centrator proper by a Robbins belt conveyor travelling at the rate of 400 feet per minute. while the course ma teIial that passes through the griZZle two inches apart, is conveyed by 30- inch belt directly to the top of the mill This belt travels 100 feet per minute, and the native copper and heavy sul- phides are picked by hand from it on it's way to the concentrators. The ore from the crushing plant. that has passed the pickers is dumped in large bins and from these is fed. au- tomatically into an elevator, which dumps into two 3s-inch trommels, the oversize goes to the coarse bull jigs and the screened material passes into the %-inch trommels. The oversize from the B trommels goes to the fine bull jigs and the undersize to the sec ondary trommels. The coarse eoncan- trates from the large and small bull jigs are sent to the concentrates bin
 and the coarse material passes through
 an unwatering trommel-(merely to segregate the water)-and then down through the 36x14 rolls. From the rolls the pulp is elevated and discharged | into the secondary trommels alcrg
 with the screened material from the primary trOmmels.
 The oversize from 3-16 trommels pass to four double compartment tigs of ! the Hart pattern and the screenings are run into 1-10-inch trommels. The oversize from the 1-1O-inch trommels | to four three compartment jigs. The | screenings go into slime separators. The concentrates from all the jigs are dumped into the bins by a system
 of conveyors and elevators and the light gauge material from the jigs goes through another unwatering l trommel and then through a set cf
 2Tx14-inch rolls and is run again l through the secondary trommels | These screen everything down 10 -10- inch before allowing it to enter the
 slime separators. The shines are run
 from the top of these separators into
 spitzkastens-V shaped tanks. The
 coarse material from the slime tanks is discharged into a four com partment hydraulic classifier. The 1 coarsest from the hydraulic classiners l goes to two three compartment jgs
 and is mixed with the under screen
 middlings from the secondary Iig. The other material from the classifiers
 goes to Willy tables. The Wa ,er fl om
 the unwatering boxes, and the tails | from the two compartment secondary 1 jigs, is distributed to five Bryan mil s. | The product from the Bryan mills | goes into a slime tank through a 2G-
 inch screen. From this tank the light material with the shines goes to d Isspitzkasten and is delievered to twelve Wilfeys. The remaining pulp from I the slime tank is classified and dis 1 tributed to another set of Wilfeys. The
 midlings from all the Wilfey concel-
 trators will be run over frue vanners. The above description is for one-half
 of the mill, the other side is a dupli-
 cate of the first, which is now TUT ming.
 | The screens used are punched, still i the new mill will be on this same I order only much larger and will l handle 2,0O0 tons of ore daily
 The tailings are dumped into the I gulch below and the water is reverted