Los Angeles herald., 1908-11-15
LIMESTONE SUPPLY
IS WITHOUT BOUND
SLOWER MOUNTAIN YIELDS
GREAT QUANTITY
Fully Equipped Cement Mills Turn
Out Twenty-Five Thousand Barrels
Day-Electric Power
Is Used

located at olONeI NOunbdllAlB AAOdA -
ton. 1t is the cement plant of the call
fornia. Portland Cement company, and
they have practically an inexhaustible
supply of the purest limestone for the
manufacture of their product. Inc
company has two fully equipped, ce-
nIent mills. One of these mills is
located on the northern slope of the
limestone hill, and has been in opera
ton since the inception of the com
pany in 1891. The other mill was com
pleted in November, 1907. The capacity
of the original mill is 500 barrels per
day, but the output had for some years
been insufficient to supply the demand
for the cement produced, so that the
construction of a larger and more up
to-date mill became necessary. The
construction of this mill commenced in
March, 1907, and in November OF the
same year was turning out cement.
This is believed to be the worlds rec
ord for construction work of mill
of this size.
The mill has daily capacity of 25OO
barrels. 1t is located on the south
side of a hill of nearly pure limestone
rock that rises to a height of 500 feet
above the valley in which it is locat-
ed and about a mile from the other
mill. The equipment of the mill is
driven entirely by individual alternat-
ing current motors supplied with three
phase 50-cycle 440-volt Vcurrent Power
to operate is obtained from the Edison
Electric company, and is delivered at
SO 900 volts, from which voltage it is
stepped down to the operating voltage
by transformers in the mill.
The clay that is used in connection
with the limestone is obtained from a
large deposit on the Santa Fe line at
Fleming, located some distance from
the mill and quarry, but directly on the
line of railroad connecting with the
plant. The mill has also direct con-
nection with the Salt Lake and South
ern Pacific railroads.
The quarry from which the rock is
obtained is in a bench cut in the side
of the hill, we'll above the mill. All
of the rock in the quarry requires blast
ing. The loosened rock is loaded into
end-dump steel-body cars having a
capacity of eighty cubic feet, and is de-
livered by hand on down grade to
tipple at the crusher house. Here the
cars are dumped by compredded air
holsting cylinder suspended over the
track.
The crlsher house contains two Gates
No gyratory crushers. Each crusher
deliverssinto a continuous bucket ele-
vator The crushed stone is raised to
an overhead drag conVeyor, which eX-
tends over a rock storage bin adJoln-
ing the crusher house. This bin has
capacity of 5000 TONS and is 40x70 feet.
1t has 10-inch reinforced concrete walls,
and covered with galvanized iron.
The dryer house contains three 5x5O
feet rotary dryers, placed together in q
! row, two for crushed stone and one for
clay. All three dryers are geared to a
line shaft belt driven by a 30-horse
power continuous speed motor, friction
clutches being provided so any one
dryer may be operated without rela-
ton to the other two. The dryers arc
all arranged to operate on waste heat
from the cement kilns, each being
from the cement kilns, each being
served by a 3.5x60-foot steel stack on a
reinforced concrete base.
A verticle bucket conveyor is pro-
vided at the discharge end of each
dryer to elevate the output of the latter
to an overhead horizontal flight con-
veyor leading to dry materials storage
bins in the raw grinding building,
which adjoins the one side of the dryer
house. The elevators serving the two
stone dryeds both discharge into an
overhead flight conveyor, which is Y
feet long and delivers to a 500-ton ele-
waited storage bin in the raw grinding
building. The clay elevator is also
served by a separate flight conveyor
which delivers to an ELEVATOR storage
bin. The elevators and conVeyors are
driven by a 50-horse power continuous
| speed motor
The elevated dry stone and dry clay
bins have side and ends built of 2x6-
inch plank laid fiat, in crib fashion
and are on a heavy monolithic con
crete base. A reinforced concrete tun-
mel extends longitudinally under this
base. Through this tunnel two-foot
gauge track j laid, on which dumT
car is operated. Dry clay is drawn
into the car through under cut gates IN
the bottom of the clay storage bin, and
is trimmed to a predetermined weight
on platform scales at that end or the
track The car is then shunted under
the dry rock bin, where it is filled with
crushed stone and pushed to a second
platform scales at the other end of the
tunnel track and there trimmed to the
proper weight to produce the neces-
sary proportions of clay and stone.
The proportioned loads are dumped
from the tunnel car into the boot or
vertical bucket elevator of the con-
tinuous bucket type. This elevator
discharges on a horizontal belt con-
veyor extending over a row of three
No q Allis-Chalmers bail mills. The
elevator and conveyors are driven by
twenty-horse power continuous
speed motor.
The ball mills discharge directly in
to a screw conveyor placed longftudin-
ally in the concrete base on which the
three mills are mounted. The material
is then conveyed over row OF ten
Fuller-Lehigh pulverizer mills on tne
opposite side of the building from the
ball mills. One 30-horse power continu-
Gus speed motor drives the screw con-
veyor under the row of ball mills, the
high-speed bucket elevator and the two
overhead screw conveyors. Each OF the
mills is belt driven by 5O-horse power
continuous speed motor. The rather
coarse product of the ball mills, as
eouipped, is ground by the pulverizlng
mills TO an average fineness of S6.2 per
cent through a 200-mesh sieve and 97.7
per cent through 100-mesh sieve. The
mills discharge into a screw conveyor
laid longitudinally under the row of
mills. This conVeyor delivers into a
high-speed perfect discharge bucket
elevator at the end of the row of mills,
which elevator raises the pulverized
raw materials to a screw conveyor ex-
tending over a row of elevated supply
bins at the charging end OF the cement
kilns.
The raw materials supply bins at the
charging end of the cement kilns are
directly in front Of the discharge ends
of the rotary dryers, the materials
making the circuit from the dryers
through the raw grinding building and
back to these bins. The latter are
built of reinforced concrete. and have
a capacity of $50 tons. At each of the
a,ro ,at,,ay,f Iff1ns et1pn1fa1 from than