Improved Process for Manufacturing Light Bricks for Building Purposes from Gypsum and the like.
Year: 1890

page_text: Date of Application, 22nd July, 1890-Accepted, 27th Sept., 1890
GUMI DVI DIETTIVATION.
Improved Process for Manufacturing Light Bricks for Building
Purposes from Gypsum and the like.
1, AUGUST BUECHER of the Town of Heidelberg in the Empire of Germany, Doctor
of Philosophy do hereby declare the nature of my said invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by the
following statement
My invention relates to a process for manufacturing light bricks for building
purposes from gypsum or sulphate of lime etc. The employment of gypsum for
making bricks for building purposes has heretofore been very limited. The difficulties
in the manufacture are caused, partly through the rapidity, with which the mass dries,
besides which the bricks bind badly with the mortar, the plaster of Paris bricks are too
heavy, the finished bricks shrink too much and are proportionately expensive, so that
they could not compete with ordinary bricks, and for this reason the manufacture of
bricks from calcined gypsum had to be abandoned.
All these disadvantages are entirely overcome by employing any invention, by means
of which the calcined gypsum is made very light and firm, so that the same is
admirably adapted for building purposes. According to my new process the
gypsum
stirred with water can be made so light and porous that it will swim like cork on.
water, and densed or more porous masses can be made at will according to the quantity
of additional matter employed. The weight of a well dried ordinary gypsam brick of
the size 25 x 12 x 6 centimeters, or round 10 x 5 x 21 is 2250 grammes, that of a
burnt clay brick of like size 2300 to 2500 grammes. The weight of a Rhenish tuff
brick 25 x 12 x 10% is 2300 grammes.
m
The weight of one of my improved light gypsum bricks of like size is 900 and at
the utmost 1000 grammes, that of a light gypsum brick of tuff-brick size 25 x 12.
× 10% is 1650. The advantages of my light gypsum bricks consist in the slight
load on the building in consequence of the lightness of the bricks, and the direct
employment of the light gypsum bricks for the walls without mortar plaster, thus
excluding all vermin which cannot live in walls made of gypsum bricks.
The materials employed in making light gypsum bricks are water, calcined gypsum,
carbonate of lime or chalk, carbonate of baryta, carbonate of protoxide of iron,
concentrated sulphuric acid, these being used in about the following proportions.

page_text: as substitute Rhenish tuff bricks.
1900 parts water,
"
1.500
5
"
45 parts carbonite of lime
"
sulphuric acid
gypsum, 25
carbonate of baryta.
Denser, that is, less porous and heavier bricks are usually obtained when carbonate
of lime is used and the mixture, after adding the carbonate, is well stirred, whereas
lighter and more porous bricks are obtained when whitening (elutriated chalk) is
used, the mass stirred once after adding the same and then allowed to stand until
the inass can be poured out as a thick pulp.
My process is carried out in the following manner:
Calcined gypsum is fed in small quantities' into the water and stirred so as to form
a homologeous mass. Sulphuric acid is now successively added by continuous stirring,
and when the mixture has become more consistent, the intimate mixture of carbonate
of lime and carbonate of baryta or carbonate of protoxide of iron is successively added
in small quantities. If ochre is used for coloring the bricks, this must be first added
to the water. When the main generation of carbonic acid is completed, the entire
mass is poured into the form which can be removed in about 10 to 15 minutes, after
which the light bricks are exposed to the air for 2 or 3 days, and subsequently dried
at 100° Centigrade.
According to the use to which the bricks are to be applied, the same can be painted
with size and lime (25 parts of glue is dissolved in 1000 parts of warm water and
160 parts of slaked lime stirred into the same), or surrounded with a layer of mortar,
(1 part lime to 3 parts of fine sand), or the bricks can be used as they come from
the drying room or kiln.
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. A process for rendering sulphate of lime, (gypsum) light, hard and porous, by
adding carbonate of lime, carbonate of baryta, carbonate of protoxide of iron and
sulphuric acid to the same in about the proportions, substantially as given in the
foregoing Specification.
2. My improved process for manufacturing light bricks for building purposes,
substantially as described in the foregoing Specification.
Dated this 19th day of July 1890.
W. P. THOMPSON & BOULT,
Agents for the Applicant.