Bisbee daily review., 1920-04-18

is of peculiar interest because it is such a contrast to the older and bet ter known ways of recovering miner al values. Instead of depending on the fact that the valuable minerals are heavier than the worthless ones and that their seperation can be obtained in this way, advantage is taken of the peculiar, inexplicable fact that the heavy sulphide minerals can be made to float on mineral froth, and the lighter gangue made to sink, in this way making clean separation.
 FIotation Process.
 The Notation process is revolution cry in character and is said to be by far the most important and far-reach- ing in its effect of any development since that of the cyanide process in 1887. Flotation was introduced into the United States in 1911, and since that time has been celebrated for it's efficiency, delicacy, and it's frequent appearance in the supreme court.
 The Notation process, however, has heretofore been thought to be appli- cable only to sulphide ores and not until 1916, when the Shattuck com pany became interested in flotariun was it demonstrated that carbonates could be floated successfully. The Shattuck method of floating carbon lates depends upon preliminary treat ment known as sulphidiZing, wherein the ore to be floated is treated with a dilute solution of soluble sudphide, such as sodium sulphide, to superfi- cially convert the carbonate into Sul- phide. The thin film of sulphide on the carbonate permits the carbonate to float quite as readily as the natur- al sulphide minerals. Technically the process consists of mixing with every ton of the finely ground ore about one pound of oil and two pounds of sulphide chemical, together with three tons of water, and then violently agi- tating the mixture in a specially de- signed Notation machine. The result is mineral-bearing froth that collects on the surface of the pulp in the ma chine and is removed and saved. Mechanical Equipment The ore is handled and milled large ly mechanically. The equipment is all new, complete and the best money can buy. The crude ore is drawn from the course ore bins by steel pan feeuv,. and discharged onto a 20-inch belt con veyor. Here a small amount of cop lper ore is sorted off the belt and ship ped separately. This belt discharges onto 20-inch inclined conyeyor which carries the ore into the crushing plant where it is discharged onto one and one-half inch screen. The oversize is crushed through a gyratory crusher, mixed with the undersize, elevated to a five-eightsinch screen and there separated again into fine and course The fine drops on to 16-inch in clined conyeyoT and is carried to the fine ore bins at the top of the mill and stored. The course size is crushed through pair of 42X16 inch rolls and returned to the elevator for rescreen- ing.
 The mill operators draw the ore from the fine bins as needed by means of Challenge ore feeders which dis charge onto 16-inch belt This belt ipasses over an automatic weighing ma chine with records the weight of the Gre milled. This belt discharges onto a vibrating screen which sends over size to the Mary Ball mills to be ground and the undersiZe 70 Butchart tables to be concentrated. finish ed concentrate is produced oy these tables and the tail, or regect, $ sent to a tube mill for fine grinding. The finely ground product of the tube mill unites with the ground ore coming from the Mary mills and is classified" in Allen cones. These cones separate sand from the very fine slime. The sand is treated on secondary tables which produce a concentrate and a tail. The slime is thickened iii q 34- foot Darr tiCkener, sulphidiZed and pumped to the Notation machines for treatment. Here a high grade cOncen- trate of lead and silver is produced and final tail made. The coIcen- trate is very fine, all passing I5O- mesh screen. and is settled in a Darr tank. thickened and filtered over an automatic Oliver filter to reduce mois- ture before shipping the concentrates to the smelter at Fl Paso. All gravity concentrates are collected, de-watered in Allen cones and loaded into cars for shipment.
 , The average value of concentrates is $1O0 a ton net. They average about D 40 per. cent lear, IS to 20 ounces of I silver and 0.3 of an ounce or abort SC
 gold The concentrates are shipped , to the Fl Paso Smelling works at that l city.
 9 Mill Operation.
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