Arizona republican., 1905-04-28

 clay bed is a mile and a half distant with a good wagon road to a point below the mill a little farther away
 than is the rock quarry, and where there has been constructed Q large clay
 bin into which the wagons dump the clay This bin is also connected with the mill by a track and hoist brings both materials up the tracks to their
 respective bins above the mill. The proportions of the two mate
 rials used are approximately three pounds of limestone to one pound of clay. the material of which most is used as noted above. being the clos est to the mill The proportions are varied of course as the experts deem desirable.
 The limestone is released from the rock bin above the mill into a crush CT and from there the pulp goes into
 rotary dryer. Emerging from it's lower end into a drag conveyer it is carried to the crushed rock bin, thence
 into a ball mill where it is reduced to
 greater fneness and carried into the ground rock bin.
 Similarly. from the top of the mill
 the clay is dropped into a crusher, thence into a rotary dryer. and like | conveyer to the clay grinder. Pass ing through this machine it falls into
 the ground clay bin
 The two materials are then ready for mixing. one being in the ground rock
 bin and the other in the ground clay bin. the bins being adjacent. Beneath each of these bins is an automatic weighing machine which measures the proper proportions of each material and drops them through a pipe or con-
 veyer into what is called the tube mill where they are properly mixed and further ground, the product emerging into what is called the raw mix bin. The pulp is then carried into the rot ary lliins. Of which there are two em- ployed when the mill is running full 1 capacity. both of course performing ] the same function. Here the mixture ! is burned into what is termed cement ! clinker for the reason that it looks ! on emerging more like clinker or slag than anything else that can be easily used for Illustration. The burning ! produces a chemical change for the | explanation of which the reader is re- ferred to the experts.
 Both rotary Iims discharge into a
 rotary cooler and that in turn empties | it's product into a tall structure known as the cooling tower. From the cool l ing tower the cement clinker passes : into another ball mill where it is l crushed into powder. assuming light ! CT hue. From the ball mill the powder ] is carried into another tube mill, some times called a pebble mill, for still more thorough pulveriziaE. This is the final act in the process of cement making and the cement is then placed ! in sacks. barrels or bins and stored ! for curing This last machine derives l it's popular name. pebble mill" from the fact that within 1t are thousands of little pebbles which in their con tinuous rolling against each other grind the powder to a perfect dust ] These pebbles are selected with the ] greatest care. the best of them yet ] known to the art of cement making l coming from Greenland and the EOose- | welt at mill being at present equipped ! with Greenland pebbles. It is thought. l or at least it is hoped. that later on | 9 sufficient supply of pebbles appro- priate for this work will also be found ] somewhere in the vicinity of the stOr- l age basin.
 l By following the above description ! it will be seen that the clay and the [ rock previous to the mixing each pass ! through three bins and four different mechanical devices. After the mixing l the combined material passes through
 one bin and six mechanical devices, l before it becomes fully manufactured l cement. so that altogether there are
 seven bins and fourteen mechanical devices aggregated in the complete plant in addition to which are num-