The copper era and Morenci leader., 1922-12-01
NEW CONCENTRATOR UNIT AT NO. s IS @ NOW COMPLETE

The work done in No Concen- trator at Morenci during the past month consisted in installing a new Concentrator Unit capable of treating an additional TOO tons of ore daily under the conditions of the new fine grinding and two-stage Notation flow sheet which was developed in the Experimental Mill at Morenci
 No additional coarse grinding equip ment for reducing the ore from Run of-Mine size to six mesh size has been installed as machines already in place have more than sufficient capacity for the additional work re- quired
 The work necessary for taking care of the additional 700 tons start ed with the installation of grinding equipment for reducing the ore from six mesh to minus AS mesh size, at which latter size the treatment of the ore by the Flotation process is started. For this purpose one of the two large Marcy Ball Mills has been removed from the Clifton Con- centrator and set up in No. Con- centrator. On account of it's ex- ceedingly heavy weight the removal, transportation and setting up of the mill proved to be the most ardous task of the reconstruction work
 Installed along side the mill is ~ a Dorr rake classifier the duty of which is to return to the mill all ore which has not been ground to the required degree of fineness' during it's pas sage through the mill. The class ifier also discharges to the Notation system over wire overflow all ma terial which is already ground fine enough. The above installation is Tor the purpose as stated, of reduc- ing the ore to size which will al- low it all to pass through screen having AS openings to the linear inch, known as AS mesh.
 Before the ore receives final treat ment it is found necessary to reduce its size to minus 65 mesh size and another Ball Mill and Classifier in stallation is required to accomplish this work. Ball Mills of sufficient capacity to accomplish this work were already in place but for the over flowing of a product finer than 65 mesh, special form of classifier is
 
 with the fine grinding Ball Mills. This special cfassifier was construct ed in the form of a shallow wooden tank 14 feet in diameter and feet deep. The tank is equipped with central shaft which reaches almost to the bottom of the tank and which carries four radial arms equipped with rakes at its lower end
 These rakes being revolved, carry settled coarse material to the center Of the bottom of the tank where it is removed through a plug discharge opening ana pumped back to the mill for further grinding The ore which is already ground fine enough overflows ten perimeters of the tank, IS collected in a launder which en- circles the tank and is then sent to the final Notation system for treat ment.
 The installation of Dorr Rake Glassifier for unwatering the feed to the Marcy Ball Mill before men, tioned, was also necessary, better grinding results being secured when the feed to the Ball Mills contains a minimum of water. A large number of launders have been installed through which the ore will be tran sported from one machine to the | following one and considerable | amount of work was performed in ! clearing up old equipment to make 1 room for the new
 Since a large part of the flota- tion process equipment has been idle | for the past eighteen months it was found necessary to do a great deal | of renovating in this department. ! going over the tanks and furnishine | them with new canvass blankets 1 Two direct connective Krogb Sand { Pumps have been installed to handle i Notation tailing material and a Will fley Pump to handle the plug dis charge of the tank classifier is to be installed.
 The 130 foot diameter Dorr thick ening tank used for recovering tail ing water has also been repaired as 1t will be necessary to put this tank into commission again when the ton mage is increased. No very heavy concrete work has been needed. the heaviest work of this kind being the foundation piers for the Marcy Bali Mill. The work will be completed by November 30th with the exception of few details which are awaiting supplies as yet undelivered