Improvements in the Process of Treating Lime in the Manufacture of Plaster, Cement, and the like.
Year: 1899

page_text: Date of Application, 31st Oct., 1899-Accepted, 24th Feb., 1900
COMPLETE SPECIFICATION.
Improvements in the Process of Treating Lime in the Manufacture of
Plaster, Cement, and the like.
I, CARL SIBAUB, of the Town of Otisco, in the County of Onondaga, in the
State of New York, United States of America, Chemist, do hereby declare the
nature of this invention, and in what manner the same 18 to be performed, to
be particularly described and ascertained in and by the following statement,-
The object of my invention 18 to produce a plaster or cement which will not
shunk or crack, and which will, when exposed to the an, in due time attam
gieat haiduess, solidity and resisting power
According to my process calcium-oxide (calcined carbonate of lime calemed
by the common process) 18 first subjected to a bath of water, the duration of the
bath depending somewhat upon the size of the pieces o lumps of lime stone,
say, for instance, an half-hout, more or less In subjecting the calcium-oxide
to the bath, the quantity of water to be used 18 preferably sufficient to soften
the lumps, so that when heat is applied a thorough breaking up of said lumps
will be effected, in other words, my fust step in the process consists in partially
hydrating the calcium-oxide The second step in my process consists in check-
ng the hydration and subjecting the partially hydrated calcium-oxide to the
action of heat, which may be eftected by means of an oven or by diving it upon
a heated plate on the like The duration of the exposure of the treated calcium-
oxide to the heat, which may be either direct on indiect, depends to some
extent upon the size of the lumps, generally lasting from one to five minutes,
more or less, in any case it must be continued until all moisture is expelled The
action of the heat upon the partially hydrated calcium-oxide, produces a rapid
breaking up of the lumps into smaller particles, which become hardened and
contracted from contact with the heat, and are subsequently ground to a powder,
like plaster of Paris on analogous substances
I desne to have it understood that steam or vapor may be used for the bath
in lieu of water
I do not desire to be limited, however, to the above described process, as other
processes, though inferior perhaps may be employed, the salient feature of
my invention being the breaking up on reducing to powder of the calcium-
oxide by subjecting it to moisture and then aresting further hydration without
allowing it to absorb an undue quantity of water, which latter takes place in
all the old processes of treating lime, and which weakens its adhesiveness and
power of cohesion and causes shrinkage and cracking after it has been formed
into plaster or cement and has become dry I may if desired prepare the cal-
cium-oxide by removing it from the hiln while hot and then rapidly chilling
the same by exposure to a cold blast, or a momentary bath in cold water
procedure causes an almost instantaneous ciumbling of the limestone pieces
Other processes may be employed such, for instance, as taking the calcined lime-
stone in a cold state and dipping it into hot water, preferably boiling, for a
moment or two, and then expelling all moisture. By dipping the calcined lime-
This

page_text: stone into hot or boiling water I obtain a more rapid breaking up of the stiuc-
ture than by the use of cold water Still another way of carrying out my process,
1s to treat the calcined limestone by placing it in a vessel containing water and
suitable salts oi acids in solution such as two to five per cent of calcium sulphate,
011 to 2% of kali o nation in the different combinations with acids, such as
boracic acid, or the like, glue on gum solution, or any suitable admixture which
will tend to delay the slacking of lime, while still allowing mechanical or physical
action so as to allow the stone to absorb sufficient moisture to the core, and
then heating up the so treated mineral till the proper breaking up or almost
ontue pulverization of the same takes place
All the above varied processes serve to break up the stone and contract oi
shink the molecules or granules thereof, and when properly reduced to powder,
will absorb no more water than able to crystallize It will be obvious that
more than the necessary quantity of water may be forced into the forming
bydiate as is the case with all other cements requiing water for their make up
In order to prevent all slacking after the calcium-oxide has absorbed the
equined or proper amount of moisture, said slacking may be checked by sub-
jeeling the calcium-oxide to a change of temperature, as for instance, when it
has been subjected to a bath of cold water for the proper length of time, it may
then be subjected to heat, 01, if the calcium-oxide has first been subjected to
a hot bath, it may afterward be subjected to a low temperature, thus suddenly
changing the temperature and preventing further hydration of the calcium-
oxide.
The lime cement produced according to my process will set like plaster of
Pans, will not shink when cast, and will foim a very consistent and durable
moi tai, superior in every way to the one manufactured by the old process
My product is as inexpensive as the common lime moitai, and is not only able
to bind a greater amount of sand, etc, but 18 80 prepared in the beginning to
save the slacking, usually very imperfectly performed, which consequently saves
much time and labor The product can be made up gradually, thus saving room
and preventing spilling and waste In applying, it shows great superiority ovoi
most cements by being consistent, pliable, light, and at the same time suffi-
ciently tenacious to prevent dropping when applied to lathed walls Tlub lime
cement is easily pulverized and does not for at least a considerable time,
deteriorate
It keeps cool when brought in contact with water, and is therefore in many
respects like plaster of Pains which it will no doubt supercede in the building
tiade
As a common building material for cementing bricks and stones together,
it vastly sun passes the common mortai in handling as well as in consistency and
ability to attain within a few hours so much density and hardness as to safely
stand in a green state, when exposed to heavy rains, for instance any dissolving
action of water, and crystallize in a short time It may be used in winter with-
out incuring danger to consistency by frosty weather. Sifted finely and mixed
with coloning matter it can be used for a wall paint which serves as well out-
side as inside of buildings, since it will within a few minutes of application get
carbonated in the open an, and 18 insoluble in wate As a finish-coat material
it can be used without adding foreign substances to it It does not shink as
commonly treated lime unavoidably does but forms a smooth white surface on
any coat on lath or stone. This calcium cement may if desired be stiengthened
or otherwise improved by the addition of suitable chemical substances, such for
instance as 5 to 8% of chloride of potash, sulphate of alumina or the like
especially destined to form chemically stable combinations with the oxide of
calcium, as well as substances, which physically tend to create greater affinity of
pimary articles
It will be obvious, that in order to make plaster, cement or other analogous
material, or paint, oi a fluidic substance, it will only Le necessary to add or com-
bine therewith water, or water together with sand, or coloring matter, or any

page_text: other suitable ingredients that may be desuable depending upon the material
01 substance required
The addition or combination of the water, or water with other substances, to
or with the treated calcium-oxide may be effected by any suitable and well known
mechanical process
The calcium-oxide used may be in a pure oi impure state
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
claim is:-
1-The herein described process of treating calcium-oxide, which consists, first,
in softening the same, by partial hydration and second in reducing the mass
to an induiated granular form by heating.
2-The herein described process of treating calcium-oxide, consisting of pai-
tially hydrating the same, and then recalcınıng it until all moisture is expelled.
The herein described process of treating calcium-oxide, consisting of pai-
tially hydrating the same; then checking hydration, by finally recalcining it
until all moisture 18 expelled
4-The herein described process of treating calcium-oxide, consisting of par-
tially hydating the same, and then expelling all moisture thereby reducing it
to a cystallized granular form
5 The herein described process of treating calcium-oxide, consisting of pai-
tially hydrating the same; then removing the partially hydrated calcium-oxide
from the water, then subjecting it to the action of heat to expel the moisture
and reduce it to a crystallized gianular form, and finally pulverizing it
G-The herein described process of treating calcium-oxide consisting of pai-
tially hydrating the same in cool water; then removing it from the water, and
then suddenly subjecting it to the action of heat until all moisture is expelled
The heiein described process of treating calcium-oxide, consisting of pai-
tially hydrating the same in water, combined with a substance which will pre-
vent undue slacking; then removing the partially hydrated calcium-oxide, and
finally subjecting the treated calcium-oxide to the iequned degree of heat to
1emove all moisture
8 As a new article of manufacture, lime which has been partially hydrated,
then recalcined to a crystallized granular form, by having all moisture expelled
therefrom, and then reduced to powdered form
Dated this 17th day of October, 1889
Datu
GOOT $1200100 TO AND TULT OTTEL
CARL STRAUB.
Haseltine, Lake & Co,
45, Southampton Buildings, London, W.C,
Agents for the Applicant