The copper era and Morenci leader., 1912-11-22
IN THE M 1 N ES
CONCENTRAT0R AT MIAMI ONE IF THE BIGGEST IN THE
 WORLD

ami Copper Co.,, is one of the largest in the world as well as one of the most complete in labor saving equlp- ment, and it is correspondingly eff cient in it's operation, says the Min ing ant Scientific Press. The plan is designed to take every advantage of natural conditions, such as the lay of the ground, and at the same time, it has incorporated a most complete conveying system into it's design. The importance of the mechanical handl- ing Of ore is recognized in all modern ore treating plants, and most cases the development of ore deposits would not be commercially possible without the use of conveying machinery. The economy of conveyors lies not Cnly in the great saving in labor, but it also permits accurate sampling and mixing as well as allowing uniform feeding
 The shaft, crusher building, and storag., bins are all situated on q ridge. In line with the bins and upon the siue of the hill is the concentrat- ing plant. Under this arrangement,
 
 constantly being carried downward by gravity, thus passing through the process with no further necessity for mechaGical handliag
 Skps f-2 Tons Capacity.
 Ore is hoisted in ' 1-2 ton skips, which are dumped automatically into bins ahove the crushers. From the bins the ore is drawn out by AS in. rotary feeders and delivered to two No. [ J-2 gyratory crushers. From the crlehers the ore passes upon d 30 inch inclined Stephens-Adamson belt conveyor, 257 it. between centers of end rulleys. This conveyor rises in an inclined gallery to a point above the storage bins, where it discharges upon inc horizontal distributing con- veyor. This is necessarily of the same width and capacity, and is 329 in. between centers. This conveyor is carr ieG horizontally in a gallery above q row of six cylindrical steel stora ge-bins of 100 tons capacity each. The conveyor is equipped with an automatic tripper, travelling back and forth Cn a track along the conveyor line and serving the various bins through openings in the gallery floor
 Rise Separate Conveyors.
 On delivering the crushed ore to the ccnveyor leads from each bin to the plant An automatic disc feeder and sampler regulates the feed from the bin to ihe conveyor and, at the same time, ii is arranged that of the ore delivered by every fifth revolution of the feeder disc,a small percentage is automatically diverted as sample. Under tpis arrangement, an analysis of the ore may be made at the time the ore is delivered for treatment and the nature of the treatment is thus de- termined. The conveyors, leading from the bins to the concentrator are each IA in. wide and A fit. between centers leading directly to the reducing rolls ill the concentrator building.
 As ;. protection for the reducing rolls, a power electro-magnet is sus- pended ebove the first conveyor which removes all scraps of iron which have become intermiXed with the ore. This is a pret aution which should be taken in all cases where bits of iron or tools dropped by the workmen are apt to get in the ore, cause serious damage to the crushers or rolls, and conse quent!y delay the entire plant.
 On account of the high position of f IA 1NI, ion1 fo the ccpcentrate-bins near the plant and to bring the railroad to them The method adopted was to place the bins considerable distance from the con- centra or at level more easily ac- cessahle by the railroad Tn order to supply the bins under this arrange ment, it was necessary to construct a long tunnel through which the con- cenirates is delivered from the plant to ihr bins.
 The general construction of the con- centrator buildings is concrete, steel, and corrugated iron. In this connec- tion, q feature which immediately strikes a visitor to the plant is that all buildings and galleries are abso- lutely and scrupulously clean. This is a feature which is more easily pos sible in this plant than in those where the material handled produces quanti ity Of dust, but nevertheless the re- suit is attained only by means of {. certain amount of work, and the con- trast presented to other plants is very pleasing. The various levels of the concenrrator are connected by iron stairways for the convenience of