Bisbee daily review., 1918-02-17

 meath is a mans sized task and will last two years. according to Supt Gerald Sherman. of the Copper Queen. Some of the ore will be uncovered be- fore that time. but it is expected to be two years or more from the time work started before enough has been ex posed to start milling it.
 lt is planned to erect SOOO-ton mill which will handle a million tons of ore annually. This means that it will require seven and a half years to mill 'Sac" hil's ore body. as the reserve there is estimated at seven and a half millions tons.
 The ore is a high grade pOrphyry which averages about two and a quar- ter per cent copper. according to tests. A high percentage of recovery is expected.
 Work on Sac hi1 records the first time in the Warren District that steam shovel operations have been used to : handle the ore from the top instead of tunneling and sinking shafts.
 Overcome Obstacles.
 Many obstacles have been encount cred, but these have been. and are be- ing overcome. as they are met and while the removal of the crest of Sac" 1 hill has been slower than expected. ! the work will move much faster when ! the peak is removed so that addition al tracks can be laid and more shOvels put into operation At pres ! ent only two shovelS can be used. Another feature of tho work which has added to the difficulties is that all Of the blasts have to be fired on the side opposite the Naco road. Ten days were required to drill the 24 toe holes in which the blasts of last Tuesday were shot of. Owing tO the high bench. which is 120 feet. the work is more dangerous than it will be later when 1t will be possible to decrease the height Of the benches !, to approximately SO feet.
 To date there have been two un- avOidable accidents on Sac" hill. due ; to premature explosions. which have resulted in the death of five men. but even greater precautions are now be- ing taken and it is hoped to avoid any l further accidents.
 Expert Powder Men. Working on Sac hill are some or the best powder men in the country. while the powder used is rated as the ' least dangerous to handle of any that can be procured which will do the re- quired work.
 Every possible effort to minimize | the danger to the workmen is taken and partly for this reason the hill has not been demolished as rapidly as eN- ! pected and the work is slightly behind schedule. This is due also tO the ob- stacles encountered in the nature of 1 Assures in the rock which have caus- ed trouble in drilling holes in which to place the chageS Of powder for the blasts.
 The surface of the hill Is extremely hard. but Assures where the fOrma- ton is broken and soft streakS occur often cause the filling up of holes drilled when the softer rock crumples. The distance from the top of the hill down to the ore body Is l50 feet in places. while this varies in other locations to from 60 10 7S feet. Sc curing dumps for all of this waste wasch is being taken off from the top Ol sac" hill. has proved luite prob lem and some of the dirt will be haul ei more than mile
 To Use FIotation Process X mill of the latest type will Dc erected as soon as the work on the reduction cf sac" hill warrants start ' ing work on the concentration. The mos; up to date methods Of reeOver- i ing copper by the Notation process Vlil be used.
 In addition to this body of ore the Copper Queen has another bcdy ot ore which win be miiled in Iisbee. This does not run quite as high In percentage of copper per ton as the Sac hiu ore and it has not been de- cided yet whether it will be mined by the steam shovel process or whether | it will be taken out by sinking shaft. Superintendent Sherman stated that he did not have figures immedi- ately available on the total amount oi powder used in reducing Sac" hil to date. but a surprising quantity has been used and a record amount will no doubt be used before the miniature