Year: 1886

page_text: 1, JAMES BALLANTYNE HANNAY, of Cove Castle, Loch Long, in the County of
Dumbarton, North Britain, Chemist, do hereby declare the nature of this Invention to
be as follows, that is to say:-
My said Invention has for its object to effectually treat sewage so as to render the.
water inocuous, and at the same time to form a valuable cement of the kind known as
Portland cement.
In carrying out the Invention lime or carbonate of lime and clay, in the proportions
of about two parts of lime for each part by weight of clay, are mixed with water into
a cream and added to the sewage in suitable quantity in settling tanks or ponds. A
precipitate is formed containing the impurities of the sewage; and after settling and
the running off of the clear water this precipitate or sludge is first dried, next heated
in kilus or retorts arranged with apparatus for securing the tarry, aminoniacal, and
other matters which are volatilised, and finally strongly heated in a reverberatory
furnace. The partly used fire gases of the reverberatory furnace inay be used for
heating the kilns or retorts and afterwards for drying the precipitate or sludge.
The material should be heated to about à red heat in the reverberatory furnace for
about four hours or until it feels slightly harsh to the touch showing that fritting bas
begun. It is then to be drawn from the furnace, allowed to cool, and ground. After
exposure to the air for about a week the cement thus prepared is ready for use.
The lime used should be of the quality which falls perfectly on slaking. The clay
should preferably be of the kind known as fat or rich in alumina, but various clays
work well. When slaked lime is used it gets largely carbonated in precipitating the
sewage which is advantageous in making the cement.
TETIM
EDMUND HUNI,
Applicant's Agent.

page_text: I, JAMES BALLANTYNE HANNAY, of Cove Castle, Loch Long, in the County of
Dumbarton, North Britain, Chemist, 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, that is to say:-
My said Invention has for its object to effectually treat sewage so as to render the
water innocuous, and at the same time to form a valuable cement of the kind known
as Portland cement.
In carrying out the Invention lime or carbonate of lime and clay, in the proportions
of about two parts of lime for each part by weight of clay, are mixed with water into
a cream and added to the sewage in suitable quantity in settling tanks or ponds. A
precipitate is formed containing the impurities of the sewage; and after settling and
the running off of the clear water this precipitate or sludge is first dried, next heated
in kilns or retorts arranged with apparatus for securing the tarry, ammoniacal, and
other matters which are volatilised, and finally strongly heated in a reverberatory
furnace. The partly used fire gases of the reverberatory furnace may be used for
heating the kilns or retorts and afterwards for drying the precipitate or sludge.
The material should be heated to about a red heat in the reverberatory furnace for
about four hours or until it feels slightly harsh to the touch showing that fritting has
begun. It is then to be drawn from the furnace, allowed to cool, and ground. After
exposure to the air for about a week the cement thus prepared is ready for use.
The lime used should be of the quality which falls perfectly on slaking. The clay
should preferably be of the kind known as fat or rich in alumina, but various clay's
work well. When slaked lime is used it gets largely carbonated in precipitating the
sewage which is advantageous in making the cement. When the sewage contains clay
or silica the quantity of clay added along with the lime should be proportionally
diminished.
Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed I declare that what I claim is :-
The treating of sewage with a mixture of lime and clay in proportions suitable to
form cement, combined with the drying and heating of the resulting precipitate and
converting it into cement substantially in the manner hereinbefore described.