Improvements in and relating to the Preparation of Sand and like Substances to be Used in Making Moulds and Cores for Casting.
Year: 1898

page_text: Improvements in and relating to the Preparation of Sand and like
Substances to be Used in Making Moulds and Cores for Casting.
We, JOHN HARGREAVES, of Widnes, in the County of Lancaster, Chemist, and
ANDREW POULSON, of 63, Frederick Street, Widnes, in the County of Lancaster,
Foreman Moulder, do hereby declare the nature of this invention to be as
follows:-
Our invention relates to the preparation of sand or like substances to be used
in making moulds or cores for casting metals, and also to methods of obtaining
or forming materials employed in the said preparation or treatment.
Our invention has for its objects, to obtain and apply suitable materials for
the purposes of imparting cohesiveness to sand or other like substances, and is
more particularly applicable to the regeneration of sand or other like substances
which have been used in the process of casting so as to render the same suitable
for re-use in making moulds or cores for casting; to obtain or prepare the treated
sand or like substances, in such a condition that the mould or core shall be
sufficiently porous to readily allow escape of gases evolved, and so that a smooth
or finished surface shall be formed on the metal castings.
For these purposes we, to impart cohesiveness to sand or like substances in-
corporate therewith in any convenient manner, such as by means of edge runners,
a disintegrator or grinding, suitable mixtures of water and hydrates of silica
alumina, silicate of alumina or silicates or aluminates of the alkaline earths,
or like substances in a gelatinous or like condition, with which may be associated
the salts resulting from the reactions forming the gelatinous mixtures; or such
resultant salts may, if desired be eliminated by washing with water before mixing
the said gelatinous or like mixture with the sand, and if of sufficient value the
salts may be recovered. Or, when the presence of the resultant salts in the treated
sand is not objectionable, the said hydrates and resultant salts may, if desired be
directly formed in the interstices of the mass of sand. Suitable carbonaceous
materials may also be incorporated with the sand and gelatinous or like mixtures.
We obtain such gelatinous or like mixtures, by reacting upon a suitable silicate
or aluminate of the alkalies or alkaline earths, or a salt of alumina, or the like
when in a suitable condition, with suitable reagents. The said silica alumina, or
like compound and reagents are preferably mixed together in proportions of
about those indicated by their chemical equivalents to produce the desired results;
and may be if desired mixed together and with the sand in form of a powder,
and the necessary water added or in the form of emulsions, or, and preferably.
in form of solutions of suitable density when soluble materials and reagents are
employed. When the reactions take place in the mass of sand gelatinization is
It will be evident that the
developed within the interstices of such mass.
materials and means employed for obtaining the gelatinous mixtures admit of
considerable variation and modification, and that means described for treatment
of one class of materials may be equally or partially applicable in the treatment
of other materials such as herein referred to.

page_text: It is advantageous to have homogeneously diffused in, or, as part of the said
gelatinous mixtures, a large proportion, or, and preferably, the whole of the
water necessary to moisten the sand, or like substances, sufficiently for moulding;
and also before mixing with the sand or like substances, it is advantageous to
eliminate from the gelatinous mixture such resultant soluble salts of the alkaline
earths, or salts of the alkalies which by crystallisation may disintegrate the face
of the mould, or which do not during the process of casting enter into chemical
combination with the sand or like substances, and also any resultant salts which
during the process of casting may become decomposed and evolve corrosive or
noxious gases as also sulphur compounds or mixtures when in sufficiently large
proportions to injuriously affect the face of the metal casting. It is usually
undesirable to have silicate of alumina in the form of clay, or insoluble salts of
the alkaline carths present in large proportions in sand or like substances em-
ployed as moulds or cores for casting metals; but when their presence in form
of gelatinous or like precipitates is not objectionable in the proportions necessary
to impart cohesiveness to sand or like substances, such precipitates may be formed
in manner hereinafter described.
Gelatinous mixtures of water, hydrates of silica or alumina and resultant salts
for the before mentioned purposes may be obtained by mixing together water,
a silicate or aluminate of the alkalies or alkaline earths and a suitable acid such
as an organic acid when obtainable at low cost. Common rosin containing acid
resins, may be used, or hydrochloric, or other suitable acid.
of water and hydrate of alumina may be obtained by intimately mixing together
A gelatinous mixture
water, a suitable salt of alumina, such as sulphate of alumina, or chloride of
alumina and a suitable alkali or alkaline earth.
A gelatinous or like mixture of water and hydrated silicate of alumina may be
obtained by treating mixed solutions of silicate and aluminate of the alkalies
with sesqui or bicarbonate of soda or potass, or carbonic acid gas, or, by mixing
together water, a silicate of soda or potass and a suitable salt of aluminum,
such as a chloride or sulphate.
A silicate or aluminate of the alkaline earths may be formed and employed
in the manner herein before described by reacting upon an alkaline silicate or
aluminate with a suitable salt of the alkaline earths.
In each case corresponding salts of the alkalies or alkaline earths are obtained.
To reduce the area of rough or irregular surfaces sometimes formed on the face
of the mould or core during casting, and to cause a smooth and finished surface
to be obtained on the face of the casting, we use suitable carbonaceous materials,
it may be in a fibrous or ligneous state and impregnated with any suitable material
to prevent injurious action on face of metal casting or coal in either case reduced
to a suitable finely divided condition or and preferably fusible bituminous
materials such as coal tar pitch, asphalt or the like which should be friable 80
that it or they may be capable of being finely ground; or mixtures of the said
fibrous or ligneous carbonaceous materials or coal and fusible bituminous
materials may be employed. The fibrous or ligneous materials or coal may
be mixed with the bituminous materials such as coal tar pitch when the
said bituminous materials are in a fluid condition. The carbonaceous materials
or any of them is or are in suitable proportions and conditions, incorporated with
the sand or like substances preferably before, but it may be conjointly with or
subsequent to incorporation of the before mentioned gelatinous or like mixtures
of water and hydrates, and if desired the resultant salts of the alkalies or alkaline
.earths, with the sand or like substances. When employing fusible bituminous
materials we have in some cases found that the carbon in such materials assumes
the form of graphite during casting and an unusually smooth and finished sur-
face is produced on the casting which is very easily worked with the tool in lathe
or otherwise.
Or, a gelatinous or like mixture of water, hydrated silica or alumina and

page_text: carbonaceous materials may be formed by, at suitable temperatures, treating
resinous materials such as common rosin, with a solution of an alkaline silicate
or aluminate of suitable composition, density and in suitable proportions.
Dated this Fifteenth day of July 1898.
JOHN HARGREAVES.
ANDREW POULSON.
Improvements in and relating to the Preparation of Sand and like
Substances to be Used in Making Moulds and Cores for Casting.
We, JOHN HARGREAVES, of Widnes, in the County of Lancaster, Chemist, and
ANDREW POULSON, of 63, Frederick Street, Widnes, in the County of Lancaster,
Foreman Moulder, 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: —
Our invention relates to the preparation of sand or like substances to be used
in making moulds or cores for casting metals, and also to methods of obtaining
or forming materials employed in the said preparation or treatment.
Our invention has for its objects to obtain and apply suitable materials for
the purpose of imparting cohesiveness to sand or other like substances, and is
more particularly applicable to the regeneration of sand or other like substances
which have been used in the process of casting, so as to render the same suitable
for reuse in making moulds or cores for casting metals; to obtain or prepare the
treated sand or like substances in such a condition that the mould or core shall
be sufficiently porous to readily allow escape of gases evolved and so that a smooth
or finished surface shall be formed on the metal castings.
For these purposes we, to impart cohesiveness to sand or like substances and
allow of the mould when formed being rendered porous, incorporate therewith in
any convenient manner, such as by means of edgerunners, a disintegrator, or
grinding, suitable mixtures of water and hydrates of silica, alumina, silicate of
alumina, or silicates or alumiinates of the alkaline earths or like substances in
a gelatinous or like condition with which may be associated the salts resulting
from the reactions forming the gelatinous mixtures; or such resultant salts may,
if desired, be eliminated by washing with water in manner such as hereinafter
described before mixing the said gelatinous or like mixture with the sand; and
if of sufficient value the salts may be recovered. Or, when the presence of the
resultant salts in the treated sand is not objectionable the said hydrates and
resultant salts may if desired be directly or locally formed in the interstices of
the mass of sand by causing or allowing the water and other materials to react
upon each other after being mixed with the sand. Suitable carbonaceous materials
hereinafter more particularly described may also be incorporated with the sand
and gelatinous or like mixtures.
We obtain such gelatinous or like mixtures by reacting upon a suitable silicate
or aluminate of the alkalies or alkaline earths or a salt of alumina or the like
when in a suitable condition with suitable reagents hereinafter described. The
said silica, alumina, or like compounds and reagents are preferably mixed together
in the proportions of about those indicated by their chemical equivalents to
produce the desired results; and may be if desired mixed together and with
the sand in form of powder when such form is possible and the necessary water
added or in the form of emulsions, or, and preferably, in form of solutions of
suitable density when soluble materials and reagents are employed as hereinafter

page_text: more particularly described. When the reactions take place in the mass of sand,
gelatinization is developed within the interstices of such mass. The gelatinous
mixture, which contains a relatively small proportion of solid materials, when
dried in the interstices of the sand after the mould is formed leaves the walls
of the mould very porous so as to readily admit of escape of gases formed during
the process, of casting. It will be evident that the materials and means employed
for obtaining the gelatinous mixtures admit of considerable variation and modi-
fication and that means described for treatment of one class of materials may be
equally or partially applicable in the treatment of other materials such as herein-
after referred to.
It is advantageous to have homogeneously diffused in, or as part of, the said
gelatinous mixtures a large proportion, or, and preferably, the whole of the
water necessary to moisten the sand or like substances sufficiently for moulding
and also before mixing with the sand or like substances it is advantageous to
eliminate as much as may be practicable from the gelatinous mixture such re-
sultant soluble salts of the alkaline earths such as sulphate of magnesia or salts
of the alkalies such as sulphate of soda which by crystallization may disintegrate
the face of the mould; or which do not during the process of casting enter into
chemical combination with the sand or like substances; as also sulphur compounds
or mixtures such as may be formed by the use of sulphuric acid or its salts em-
ployed as reagents to produce the said gelatinous or like mixtures, when the
said compounds are in sufficiently large proportions to injuriously affect the face
of the metal casting. Salts which remain soluble in the sand after use may be
It is
eliminated therefrom if desired by washing the used sand with water.
usually undesirable, because of its tendency to reduce porosity of the sand, to
have silicate of alumina in the form of clay, or insoluble salts of the alkaline
earths present in large proportions in sand or like substances employed as moulds
or cores for casting metals, but when their presence in form of gelatinous or like
precipitates is not objectionable in the proportions necessary to impart cohesive-
ness to sand or like substances, such precipitates may be formed in manner
hereinafter described.
Gelatinous mixtures of water, hydrates of silica or alumina and resultant salts
for the before mentioned purposes may be obtained by mixing together, in about
the proportions hereinafter described, water, a silicate or aluminate of the alkalies
or alkaline earths and a suitable acid such as an organic acid for instance pyro-
ligneous acid when obtainable at low cost or hydrochloric or other suitable acid
such as sulphuric.
A gelatinous mixture of water and hydrate of alumina may be obtained by
intimately mixing together water, a suitable salt of alumina such as sulphate of
alumina or chloride of aluminium and a suitable alkali such as carbonate of soda
or an emulsion of an alkaline earth such as magnesia or lime; the said alkali or
alkaline earth being added in sufficient quantity to decompose the said salts
of alumina.
A gelatinous or like mixture of water and hydrated silicate of alumina may be
obtained by treating mixed solutions of silicate and aluminate of the alkalies
with carbonic acid gas or a suitable acid such as hydrochloric acid or by mixing
together water, a silicate of soda or potass, and a suitable salt of aluminium such
as a chloride or sulphate.
A silicate or aluminate of the alkaline earths may be formed and employed in
the manner hereinbefore described by reacting upon an alkaline silicate or
aluminate with a suitable salt of the alkaline earths.
In each case corresponding salts of the alkalies or alkaline earths are obtained.
A gelatinous or like mixture of water, hydrated silica, or alumina and car-
bonaceous materials may be formed by treating a hot solution of silicate or
aluminate of soda or potass with common rosin.
In carrying our invention into practice the following methods of obtaining
gelatinous and like cohesive pasty mixtures may be employed and which are
based upon employing a solution of a salt of the alkalies or alkaline earths of

page_text: about the strengths hereinafter described to which is added a corresponding re-
agent hereinafter described until the said solution of a salt of the alkalies or
alkaline earths becomes neutralized and the said salts decomposed
Suitable hydrates of silica or alumina may be obtained by neutralizing a solution
of silicate or aluminate of soda which may be of about 5 degrees Twaddle density
by adding to and mixing therewith hydrochloric, sulphuric, or an organic acid
such as pyroligneous acid of ordinary commercial strength.
Hydrated silicate of alumina may be obtained by neutralizing solutions of
silicate and aluminate of soda or potass, mixed together in about equal proportions
and of about 10 degrees Twaddle, with an acid such as before described or with
carbonic acid. Or a solution of silicate of soda of about 10 degrees Twaddle may
be treated and neutralized with a solution of sulphate of alumina or chloride of
aluminium of about 10 degrees Twaddle.
A silicate or aluminate of an alkaline earth may be obtained by treating or
neutralizing a solution of silicate or aluminate of an alkali of about 10 degrees
Twaddle with a solution of a salt of an alkaline earth such as chloride of calcium
or sulphate or chloride of magnesia of about 10 degrees Twaddle.
A gelatinous or like mixture of water, hydrate of silica, and carbonaceous
material may be obtained by neutralizing a hot solution of silicate of soda of
about 10 degrees Twaddle by adding thereto sufficient resin in a fine state of
division to neutralize the alkali contained in the said solution.
The quantity of the hereinbefore mentioned materials and admixed water to be
added to spent moulding sand may be varied according to the condition of the
sand to be treated and the degree of cohesiveness it is desired to impart to the
sand.
Under normal conditions the following relative proportions of the said materials
admixed with about twelve gallons of water, and the desired reagent to form a
gelatinous mixture, may be incorporated with each ton of sand to be treated; as
much as possible of the water being in the form of water of gelatinization and con-
taining any desired proportion of the resultant salts of the alkalies or alkaline
earths.
Hydrated silica (estimated as anhydrous) in a gelatinous or like condition about
4 pounds.
Hydrated alumina (estimated as anhydrous) in a gelatinous or like condition
about 8 pounds.
Hydrated silicate of alumina or silicate or aluminate of the alkaline earths or
a mixture of hydrate of silica or alumina and resin (estimated as anhydrous) in
a gelatinous or like condition about 12 pounds.
When it is desired to eliminate any soluble salt from said gelatinous or pasty
mixtures by means of water we prefer that a larger quantity of water than
necessary for moistening the sand be used in forming the solutions of salts of
the alkalies or alkaline earths and the reagents employed, and after gelatinization
has taken place draining away in any convenient manner a part of the water
which will contain some of the soluble salts in solution. By varying the
strengths of the solutions and reagents hereinbefore described a smaller or larger
proportion of the said resultant salts of the alkalies or alkaline earths may be
eliminated as desired.
To reduce the area of rough or irregular surfaces sometimes formed on the
face of the mould or core during casting and to cause a smooth and finished sur-
face to be obtained on the face of the casting we use suitable carbonaceous materials
such as bituminous coal reduced to a suitable finely divided condition or and pre-
ferably a mixture of bituminous coal and fusible bituminous materials such as
coal tarpitch, asphalt or the like which should be friable so that it or they may
be capable of being finely ground before being mixed with the sand. The said
coal and fusible bituminous materials may be separately ground and afterwards
intimately mixed together in any desired relative proportions or, and preferably
the said coal and fusible bituminous materials are mixed together

page_text: before grinding in the proportions of not less than thirty pounds, and
preferably as much more as may be practicable, of fusible bituminous
materials to one hundred pounds of coal, and subsequently pulverized so that the
greater part and preferably the whole of the said mixture may pass through a
sieve of at least thirty meshes per linear inch. Mixing the coal with the fusible
bituminous materials facilitates grinding of the said bituminous materials.
The finely divided coal may be mixed with the bituminous materials such as
coal tar pitch when the said bituminous materials are in a fluid condition the
mixture so obtained being subsequently cooled, and ground to powder as herein-
before described.
The bituminous or carbonaceous materials or any of them is, or are in suitable
proportions incorporated with the sand or like substances. A good proportion
is, for moulds for light casings, about two pounds of the said bituminous carbon-
aceous materials to each one hundred pounds of sand: and about six pounds of
the said bituminous carbonaceous materials to each one hundred pounds of sand
for moulds or cores for heavy castings.
The said bituminous carbonaceous materials are preferably mixed with the
sand before, but it may be conjointly with or subsequent to, incorporation of the
before mentioned gelatinous or like mixtures of water and hydrates and if desired
the whole or part of the resultant salts of the alkalies or alkaline earths with the
sand or like substances. When employing fusible bituminous materials we have
in some cases found that the carbon in such materials assumes the form of graphite
during casting and an unusually smooth and finished surface is produced on the
casting which is very easily worked with the tool in lathe or otherwise.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is
First. The methods described of obtaining gelatinous or like mixtures of water
and hydrates of silica or alumina, or water and hydrated silicates or aluminates
of the alkaline earths or mixtures of the same, or water, hydrate of silica, and
resinous carbonaceous material for the purpose of incorporating such mixtures
or compounds with sand or like substances to impart cohesiveness thereto sub-
stantially as set forth.
Second. The combination of the gelatinous mixtures or any of them obtained
as described with a mixture of sand and bituminous coal or fusible bituminous
materials, to be employed in making moulds or cores for casting metals sub-
stantially as set forth.
Third. The combination of the gelatinous mixtures or any of them obtained as
described, with sand to be used in making moulds or cores for casting metals
substantially as set forth.
Fourth. Mixing finely divided coal with fused bituminous materials cooling
and grinding such mixture and incorporating the same with sand or like sub-
stances to be employed in making moulds or cores for casting metals substantially
as and for the purposes described.
Fifth. In the preparation of sand or like substances to be employed in making
moulds or cores for casting metals, incorporating with such sand an intimate
mixture of finely powdered coal and finely powdered fusible bituminous materials
substantially as and for the purposes described.
.
P
"
1 1000
JOHN HARGREAVES.
ANDREW POULSON.

page_text: Improvements in and relating to the Preparation of Sand and like
Substances to be Used in Making Moulds and Cores for Casting.
We, JOHN HARGREAVES, of Widnes, in the County of Lancaster, Chemist, and
ANDREW POULSON, of 63, Frederick Street, Widnes, in the County of Lancaster,
Foreman Moulder, do hereby declare the nature of this invention to be as
follows:-
Our invention relates to the preparation of sand or like substances to be used
in making moulds or ceres for casting metals, and also to methods of obtaining
or forming materials employed in the said preparation or treatment.
Our invention has for its objects, to obtain and apply suitable materials for
the purposes of imparting cohesiveness to sand or other like substances and is
more particularly applicable to the regeneration of sand or other like substances
which have been used in the process of casting so as to render the same suitable
for re-use in making moulds or cores for casting: to obtain or prepare the treated
sand or like substances, in such a condition that the mould or core shall be
sufficiently porous to readily allow escape of gases evolved, and so that a smooth
or finished surface shall be formed on the metal castings.
For these purposes we, to impart. cohesiveness to sand or like substances in-
corporate therewith in any convenient manner, such as by means of edge runners,
a disintegrator or grinding, suitable mixtures of water and hydrates of silica
alumina, silicate of alumina or silicates or aluminates of the alkaline earths,
or like substances in a gelatinous or like condition, with which may be associated
the salts resulting from the reactions forming the gelatinous mixtures; or such
resultant salts may, if desired be eliminated by washing with water before mixing
the said gelatinous or like mixture with the sand, and if of sufficient value the
salts may be recovered. Or, when the presence of the resultant salts in the treated
sand is not objectionable, the said hydrates and resultant salts may, if desired be
directly formed in the interstices of the mass of sand. Suitable carbonaceous
inaterials may also be incorporated with the sand and gelatinous or like mixtures.
We obtain such gelatinous or like mixtures, by reacting upon a suitable silicate
or aluminate of the alkalies or alkaline earths, or a salt of alumina, or the like
when in a suitable condition, with suitable reagents. The said silica alumina, or
like compound and reagents are preferably mixed together in proportions of
about those indicated by their chemical equivalents to produce the desired results;
and may be if desired mixed together and with the sand in form of a powder,
and the necessary water added or in the form of emulsions, or, and preferably.
in form of solutions of suitable density when soluble materials and reagents are
employed. When the reactions take place in the mass of sand gelatinization is
It will be evident that the
developed within the interstices of such mass.
materials and means employed for obtaining the gelatinous mixtures admit of
considerable variation and modification, and that means described for treatment
of one class of materials may be equally or partially applicable in the treatment
of other materials such as herein referred to.

page_text: It is advantageous to have homogeneously diffused in, or, as part of the said
gelatinous mixtures, a large proportion, or, and preferably, the whole of the
water necessary to moisten the sand, or like substances, sufficiently for moulding;
and also before mixing with the sand or like substances, it is advantageous to
eliminate from the gelatinous mixture such resultant soluble salts of the alkaline
earths, or salts of the alkalies which by crystallisation may disintegrate the face
of the mould, or which do not during the process of casting enter into chemical
combination with the sand or like substances, and also any resultant salts which
during the process of casting may become decomposed and evolve corrosive or
noxious gases as also sulphur compounds or mixtures when in sufficiently large
proportions to injuriously affect the face of the metal casting. It is usually
undesirable to have silicate of alumina in the form of clay, or insoluble salts of
the alkaline earths present in large proportions in sand or like substances em-
ployed as moulds or cores for casting metals; but when their presence in form
of gelatinous or like precipitates is not objectionable in the proportions necessary
to impart cohesiveness to sand or like substances, such precipitates may be formed
in manner hereinafter described.
Gelatinous mixtures of water, hydrates of silica or alumina and resultant salts
for the before mentioned purposes may be obtained by mixing together water,
a silicate or aluminate of the alkalies or alkaline earths and a suitable acid such
as an organic acid when obtainable at low cost. Common rosin containing acid
resins, may be used, or hydrochloric, or other suitable acid.
of water and hydrate of alumina may be obtained by intimately mixing together
A gelatinous mixture
water, a suitable salt of alumina, such as sulphate of alumina, or chloride of
alumina and a suitable alkali or alkaline earth.
A gelatinous or like mixture of water and hydrated silicate of alumina may be
obtained by treating mixed solutions of silicate and aluminate of the alkalies
with sesqui or bicarbonate of soda or potass, or carbonic acid gas, or, by mixing
together water, a silicate of soda or potass and a suitable salt of aluminum,
such as a chloride or sulphate.
A silicate or aluminate of the alkaline earths may be formed and employed
in the manner hereinbefore described by reacting upon an alkaline silicate or
aluminate with a suitable salt of the alkaline earths.
In each case corresponding salts of the alkalies or alkaline earths are obtained.
To reduce the area of rough or irregular surfaces sometimes formed on the face
of the mould or core during casting, and to cause a smooth and finished surface
to be obtained on the face of the casting, we use suitable carbonaceous materials,
it may be in a fibrous or ligneous state and impregnated with any suitable material
to prevent injurious action on face of metal casting or coal in either case reduced
to a suitable finely divided condition or and preferably fusible bituminous
materials such as coal tar pitch, asphalt or the like which should be friable so
that it or they may be capable of being finely ground; or mixtures of the said
fibrous or ligneous carbonaceous materials or coal and fusible bituminous
materials may be employed. The fibrous or ligneous materials or coal may
be mixed with the bituminous materials such as coal tar pitch when the
said bituminous materials are in a fluid condition. The carbonaceous materials
or any of them is or are in suitable proportions and conditions, incorporated with
the sand or like substances preferably before, but it may be conjointly with or
subsequent to incorporation of the before mentioned gelatinous or like mixtures
of water and hydrates, and if desired the resultant salts of the alkalies or alkaline
earths, with the sand or like substances. When employing fusible bituminous
materials we have in some cases found that the carbon in such materials assumes
the form of graphite during casting and an unusually smooth and finished sur-
face is produced on the casting which is very easily worked with the tool in lathe
or otherwise.
Or, a gelatinous or like mixture of water, hydrated silica or alumina and

page_text: carbonaceous materials may be formed by, at suitable temperatures, treating
resinous materials such as common rosin, with a solution of an alkaline silicate
or aluminate of suitable composition, density and in suitable proportions.
Dated this Fifteenth day of T... 1.900
JOHN HARGREAVES.
ANDREW POULSON.
Improvements in and relating to the Preparation of Sand and like
Substances to be Used in Making Moulds and Cores for Casting.
We, JOHN HARGREAVES, of Widnes, in the County of Lancaster, Chemist, and
ANDREW POULSON, of 63, Frederick Street, Widnes, in the County of Lancaster,
Foreman Moulder, 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 ;-
Our invention relates to the preparation of sand or like substances to be used
in making moulds or cores for casting metals, and also to methods of obtaining
or forming materials employed in the said preparation or treatment.
Our invention has for its objects to obtain and apply suitable materials for
the purpose of imparting cohesiveness to sand or other like substances, and is
more particularly applicable to the regeneration of sand or other like substances
which have been used in the process of casting, so as to render the same suitable
for reuse in making moulds or cores for casting metals; to obtain or prepare the
treated sand or like substances in such a condition that the mould or core shall
be sufficiently porous to readily allow escape of gases evolved and so that a smooth
or finished surface shall be formed on the metal castings.
For these purposes we, to impart cohesiveness to sand or like substances and
allow of the mould when formed being rendered porous, incorporate therewith in
any convenient manner, such as by means of edgerunners, a disintegrator, or
grinding, suitable mixtures of water and hydrates of silica, alumina, silicate of
alumina, or silicates or aluminates of the alkaline earths or like substances in
a gelatinous or like condition with which may be associated the salts resulting
from the reactions forming the gelatinous mixtures; or such resultant salts may,
if desired, be eliminated by washing with water in manner such as. hereinafter
described before mixing the said gelatinous or like mixture with the sand; and
if of sufficient value the salts may be recovered. Or, when the presence of the
resultant salts in the treated sand is not objectionable the said hydrates and
resultant salts may if desired be directly or locally formed in the interstices of
the mass of sand by causing or allowing the water and other materials to react
upon each other after being mixed with the sand. Suitable carbonaceous materials
hereinafter more particularly described may also be incorporated with the sand
and gelatinous or like mixtures.
We obtain such gelatinous or like mixtures by reacting upon a suitable silicate
or aluminate of the alkalies or alkaline earths or a salt of alumina or the like
when in a suitable condition with suitable reagents hereinafter described. The
aid silica, alumina, or like compounds and reagents are preferably mixed together
n the proportions of about those indicated by their chemical equivalents to
produce the desired results; and may be if desired mixed together and with
he sand in form of powder when such form is possible and the necessary water
added or in the form of emulsions, or, and preferably, in form of solutions of
uitable density when soluble materials and reagents are employed as hereinafter

page_text: more particularly described. When the reactions take place in the mass of sand,
gelatinization is developed. within the interstices of such mass.
The gelatinous
mixture, which contains a relatively small proportion of solid materials, when
dried in the interstices of the sand after the mould is formed leaves the walls
of the mould very porous so as to readily admit of escape of gases formed during
the process of casting. It' will be evident that the materials and means employed
for. obtaining the gelatinous mixtures admit of considerable variation and modi-
fication and that means described for treatment of one class of materials may be
equally or partially applicable in the treatment of other materials such as herein-
after referred to.
It is advantageous to have homogeneously diffused in, or as part of, the said
gelatinous mixtures a large proportion, or, and preferably, the whole of the
water- necessary to moisten the sand or like substances sufficiently for moulding
and also before mixing with the sand or like substances it is advantageous to
eliminate as much as may be practicable from the gelatinous mixture such re-
sultant soluble salts of the alkaline earths such as sulphate of magnesia or salts
of the alkalies such as sulphate of soda which by crystallization may disintegrate
the face of the mould; or which do not during the process of casting enter into
chemical combination with the sand or like substances; as also sulphur compounds
or mixtures such as may be formed by the use of sulphuric acid or its salts em-
ployed as reagents to produce the said gelatinous or like mixtures, when the
said compounds are in sufficiently large proportions to injuriously affect the face
of the metal casting. Salts which remain soluble in the sand after use may be
It is
eliminated therefrom if desired by washing the used sand with water.
usually undesirable, because of its tendency to reduce porosity of the sand, to
have silicate of alumina in the form of clay, or insoluble salts of the alkaline
earths present in large proportions in sand or like substances employed as moulds
or cores for casting metals, but when their presence in form of gelatinous or like
precipitates is not objectionable in the proportions necessary to impart cohesive-
ness to sand or like substances, such precipitates may be formed in manner
hereinafter described.
Gelatinous mixtures of water, hydrates of silica or alumina and resultant salts
for the before mentioned purposes may be obtained by mixing together, in about
the proportions hereinafter described, water, a silicate or aluminate of the alkalies
or alkaline earths and a suitable acid such as an organic acid for instance pyro-
ligneous acid when obtainable at low cost or hydrochloric or other suitable acid
such as sulphuric.
A gelatinous mixture of water and hydrate of alumina may be obtained by
intimately mixing together water, a suitable salt of alumina such as sulphate of
alumina or chloride of aluminium and a suitable alkali such as carbonate of soda
or an emulsion of an alkaline earth such as magnesia or lime; the said alkali or
alkaline earth being added in sufficient quantity to decompose the said salts
of alumina..
A gelatinous or like mixture of water and hydrated silicate of alumina may be
obtained by treating mixed solutions of silicate and aluminate of the alkalies
with carbonic acid gas or a suitable acid such as hydrochloric acid or by mixing
together water, a silicate of soda or potass, and a suitable salt of aluminium such
as a chloride or sulphate.
-
A. silicate or aluminate of the alkaline earths may be formed and employed in
the manner hereinbefore described by reacting upon an alkaline silicate or
aluminate with a suitable salt of the alkaline earths.
In each case corresponding salts of the alkalies or alkaline earths are obtained
A gelatinous or like mixture of water, hydrated silica, or alumina and car
bonaceous materials may be formed by treating a hot solution of silicate o
aluminate of soda or potass with common rosin.
In carrying our invention into practice the following methods of obtaining
gelatinous and like cohesive pasty mixtures may be employed and which are
based upon employing a solution of a salt of the alkalies or alkaline earths o

page_text: about the strengths hereinafter described to which is added a corresponding re-
agent hereinafter described until the said solution of a salt of the alkalies or
alkaline earths becomes neutralized and the said salts decomposed
Suitable hydrates of silica or alumina may be obtained by neutralizing a solution
of silicate or aluminate of soda which may be of about 5 degrees Twaddle density
by adding to and mixing therewith hydrochloric, sulphuric, or an organic acid
such as pyroligneous acid of ordinary commercial strength.
Hydrated silicate of alumina may be obtained by neutralizing solutions of
silicate and aluminate of soda or potass, mixed together in about equal proportions
and of about 10 degrees Twaddle, with an acid such as before described or with
carbonic acid. Or a solution of silicate of soda of about 10 degrees Twaddle may
be treated and neutralized with a solution of sulphate of alumina or chloride of
aluminium of about 10 degrees Twaddle.
A silicate or aluminate of an alkaline earth may be obtained by treating or
neutralizing a solution of silicate or aluminate of an alkali of about 10 degrees
Twaddle with a solution of a salt of an alkaline earth such as chloride of calcium
or sulphate or chloride of magnesia of about 10 degrees Twaddle.
A gelatinous or like mixture of water, hydrate of silica, and carbonaceous
material may be obtained by neutralizing a hot solution of silicate of soda of
about 10 degrees Twaddle by adding thereto sufficient resin in a fine state of
division to neutralize the alkali contained in the said solution.
The quantity of the hereinbefore mentioned materials and admixed water to be
added to spent moulding sand may be varied according to the condition of the
sand to be treated and the degree of cohesiveness it is desired to impart to the
sand.
Under normal conditions the following relative proportions of the said materials
admixed with about twelve gallons of water, and the desired reagent to form a
gelatinous mixture, may be incorporated with each ton of sand to be treated; as
much as possible of the water being in the form of water of gelatinization and con-
taining any desired proportion of the resultant salts of the alkalies or alkaline
earths.
Hydrated silica (estimated as anhydrous) in a gelatinous or like condition about
4 pounds.
Hydrated alumina (estimated as anhydrous) in a gelatinous or like condition
about 8 pounds.
Hydrated silicate of alumina or silicate or aluminate of the alkaline earths or
a mixture of hydrate of silica or alumina and resin (estimated as anhydrous) in
a gelatinous or like condition about 12 pounds.
When it is desired to eliminate any soluble salt from said gelatinous or pasty
mixtures by means of water we prefer that a larger quantity of water than
necessary for moistening the sand be used in forming the solutions of salts of
the alkalies or alkaline earths and the reagents employed, and after gelatinization
has taken place draining away in any convenient manner a part of the water
which will contain some of the soluble salts in solution. By varying the
strengths of the solutions and reagents hereinbefore described a smaller or larger
proportion of the said resultant salts of the alkalies or alkaline earths may be
eliminated as desired.
'
To reduce the area of rough or irregular surfaces sometimes formed on the
face of the mould or core during casting and to cause a smooth and finished sur-
face to be obtained on the face of the casting we use suitable carbonaceous materials
such as bituminous coal reduced to a suitable finely divided condition or and pre-
ferably a mixture of bituminous coal and fusible bituminous materials such as
coal tarpitch, asphalt or the like which should be friable so that it or they may
be capable of being finely ground before being mixed with the sand. The said
coal and fusible bituminous materials may be separately ground and afterwards
intimately mixed together in any desired relative proportions or, and preferably
the said coal and fusible bituminous materials are mixed together

page_text: before grinding in the proportions of not less than thirty pounds, and
preferably as much more as may be practicable, of fusible bituminous
materials to one hundred pounds of coal, and subsequently pulverized so that the
greater part and preferably the whole of the said mixture may pass through a
sieve of at least thirty meshes per linear inch. Mixing the coal with the fusible
bituminous materials facilitates grinding of the said bituminous materials.
The finely divided coal may be. mixed with the bituminous materials such as
coal tar pitch when the said bituminous materials are in a fluid condition the
mixture so obtained being subsequently cooled, and ground to powder as herein-
before described.
The bituminous or carbonaceous materials or any of them is, or are in suitable
proportions incorporated with the sand or like substances. A good proportion
is, for moulds for light casings, about two pounds of the said bituminous carbon-
aceous materials to each one hundred pounds of sand; and about six pounds of
the said bituminous carbonaceous materials to each one hundred pounds of sand
for moulds or cores for heavy castings.
The said bituminous carbonaceous materials are preferably mixed with the
sand before, but it may be conjointly with or subsequent to, incorporation of the
before mentioned gelatinous or like mixtures of water and hydrates and if desired
the whole or part of the resultant salts of the alkalies or alkaline earths with the
sand or like substances. When employing fusible bituminous materials we have
in some cases found that the carbon in such materials assumes the form of graphite
during casting and an unusually smooth and finished surface is produced on the
casting which is very easily worked with the tool in lathe or otherwise.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is;
First. The methods described of obtaining gelatinous or like mixtures of water
and hydrates of silica or alumina, or water and hydrated silicates or aluminates
of the alkaline earths or mixtures of the same, or water, hydrate of silica, and
resinous carbonaceous material for the purpose of incorporating such mixtures
or compounds with sand or like substances to impart cohesiveness thereto sub-
stantially as set forth.
Second. The combination of the gelatinous mixtures or any of them obtained
as described with a mixture of sand and bituminous coal or fusible bituminous
materials, to be employed in making moulds or cores for casting metals sub-
stantially as set forth.
Third. The combination of the gelatinous mixtures or any of them obtained as
described, with sand to be used in making moulds or cores for casting metals
substantially as set forth.
Fourth. Mixing finely divided coal with fused bituminous materials cooling
and grinding such mixture and incorporating the same with sand or like sub-
stances to be employed in making moulds or cores for casting metals substantially
as and for the purposes described.
Fifth. In the preparation of sand or like substances to be employed in making
moulds or cores for casting metals, incorporating with such sand an intimate
mixture of finely powdered coal and finely powdered fusible bituminous materials
substantially as and for the purposes described.
Dated this Thirteenth day of Amil 1800