Stamp-mill.
1. (
Metallurgy.) One in which the rock is crushed by descending pestles which are lifted by water or steampower.
The ordinary form consists of a row of vertical stamps lifted by cams upon a shaft, which rotates in bearings in the standards of the frame.
The shaft is driven by steam or water power, and the cams are arranged upon it in a spiral series, so as to lift the stamps consecutively instead of simultaneously.
This makes the draft upon the power of the engine more uniform, as one or more of the stamps are constantly being lifted while others are descending.
 |
|
“Fly” stamping-press. |
In the accompanying cut the upper platform is that from which the broken rock is fed to the stamps, which descend into a box whose perforated sides retain it until it is of sufficient fineness to pass through the meshes.
It is then discharged by a spout to the amalgamator or other machine, by which the valuable portions are separated from the earthy.
Another form of stamp-mill is that in which the stamp is directly connected to the piston-rod of a steam-engine, in the manner of the steam-hammer, both the blow and the recoil being by the force of the steam in the cylinder above.
Such is that in the illustration,
Fig. 5551, next page.
The broken ore is fed into the bell mouth of the chute and conducted to the stamp-box: the ascending and descending rods work the induction and eduction valves of the engine.
 |
|
Monogram-press. |
Cosgriff's stamp-mill (
Fig. 5551) has four stamps
a a, surrounded by a screen
b (the front is not shown in the illustration), and attached to the rods of pistons working in cylinders, which, with the steam-jacket
c and sole-plate
d, are cast in one piece; the whole is adjustable to different hights upon the pillars
e e by means of nuts, so that it may be lowered as the stamps wear away Steam is admitted alternately above and below the pistons by slide-valves working horizontally in the chests
f, and operated partly by the steam and partly by the conical upper ends of the piston-rods rising and falling in the chaps
g g, through levers
h h and connecting-rods.
Each piston and its stamp may be worked independently.
 |
|
Stamp-mill. |
The stamping is done wet; the ore is fed into the hopper
i, and, falling centrally between the stamps, is equally distributed to each.
The crushed material passes through the screen into
[
2306]
the annular trough
k, into which a constant stream of water flows; the finer particles are carried off by spouts into the exterior trough
l.
 |
|
Stamp-mill. |
Fig. 5552 shows a mill of two batteries of six stamps each, worked by an undershot water-wheel.
2. (
Oil.)
The stamping-mill for the trituration of oleaginous seeds, nuts, and fruit does not differ substantially from those used for the comminution of ores.
The mortars are arranged in a row beneath the stamps, the latter sliding in guide-bars as they are alternately lifted by the wipers on the horizontal shaft, which is driven by gearing.
Each stamp makes two blows at each revolution of the shaft.
 |
|
Stamp-mill. |
At the ends of the machine are two wedge-presses, wherein the oleaginous magma is pressed after the pounding of the stamps See oil-mill.
