Year: 1888

page_text: I, GEORGE GATEWOOD MULLINS, of Los Angeles, in the State of California,
Inventor, do hereby declare the nature of this invention, and in what manner the
same is to be performed to be particularly described and ascertained in and by the
following statement :-
:-
The object of this invention is greatly to improve cast-iron, make superior foundry
product, and to enable the founder to use mixtures of refractory and cheap irons,
such as scrap, refuse scrap, and mill irons not heretofore easily and profitably
employed.
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29
The invention relates to the regular treatment of the iron in the cupola with Silica
as a friend and ally, to charge, purify, and strengthen and give "life" or " body
to the resultant metal. By Silica is meant simple Silica or Silex (S₁ O₂), pure as
it can be found in nature, in the form of silicious sand, massive sand, sand-stone when
pure, quartz, crystal, and flint.
The quantity of silica used in each heat is varied with the ascertained character
of the iron to be used, the burden, and the blow or intensity of heat to which it may
be submitted, which is determined by principle, and the experience of the operator.
I use of the silica from one half of one per cent. to five per cent. in weight of the
iron charged in the heat. The general rule is to adapt the silica so as to insure that
at least a small per cent. of it, in the state of fusion, shall come into immediate contact
with the iron at a high degree of heat, and consequent liquid fusion, and to have just
such a quantity of silica as not to scour, or to clog the furnace..
In carrying out this invention this method is used:
'
In charging the ordinary cupola there is first placed the usual bed of coke or fuel.
Upon this is placed a layer of silica; upon this is placed a layer of iron.
In using a
flux it is placed upon the top of the iron. The sequence of coke. silica iron and flux
is repeated until the cupola is fully charged.
After the cupola is thus charged the manipulation proceeds in the usual manner
well known to those skilled in the manufacture of iron.
These are the salient features of the process. Many details may be varied. The
silica may be placed in as loose or lump sand, quartz, &c. But to obtain highly

page_text: beneficial results with loose sand it is preferred to place it in carriers, such as balls
of clay, pieces of pipe &c. Also, it is preferable to have the silica distributed over
the layer of coke, but for the most part near the centre. Even in arranging the
layers it is not absolutely essential that the silica should be below the iron, though
such is vastly preferable.
.
When the heat ascends, and the silica is fused, the iron requiring less heat than
the silica is also fused, and, running down, comingles with the silica. The silica
and iron being thus at the point of fusion, become fused together, combining to form
a silicated iron, the silica becoming thus an ally to the iron.
After the product is run from the cupola it is run direct into the moulds or
chills.
The product is wonderfully homogeneous, rather fine grained, dark grey, and of
bright metallic lustre ; it is free from blow-holes, and not honey-combed. It is very
strong and tough; yet is soft, and can be easily bored or drilled, and it chips well
under the chisel.
It is to be distinctly understood that this invention is not limited to any special
arrangement of, or way of placing the silica in the cupola. The invention consisting
broadly in the principle that silica when properly united with iron in a cupola
produces a result not obtainable hitherto by any other process.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The process for making silicated iron castings which consists in charging a
cupola with layers of silica, iron and fuel, arranged in sets, then manipulating the
charge in the usual way, as set forth.
2. The process for making silicated iron castings; which consists in charging a
cupola with a layer of fuel, a layer of silica, a layer of iron, and a layer of flux;
then repeating these layers in the same order until the cupola is charged, then
manipulating the charge in the usual way, as set forth.
Dated this 27th day of November 1888.
ALLISON BROS.,
Agents for the Applicant.