Improvements in the Treatment of Alkali waste by Other Materials in order to Obtain Useful Products.
Year: 1885

page_text: Improvements in the Treatment of Alkali waste by Other
Materials in order to Obtain Useful Products.
I FREDERICK STIRLING NEWALL of Washington in the County of Durham
Chemist do hereby declare the nature of my said Invention for "IMPROVEMENTS
IN THE TREATMENT OF ALKALI WASTE BY OTHER MATERIALS IN ORDER TO OBTAIN
USEFUL PRODUCTS," to be as follows:-
The object of my invention is to obtain useful products from alkali waste such
as sulphuretted hydrogen gas and magnesium oxide.
And my invention consists in first treating a mixture of recent alkali waste and
water with sulphuretted hydrogen gas in order to obtain a solution of calcium
sulphydrate and in then decomposing this by a solution of the double chloride of
magnesium and calcium.
I carry out my invention in the following manner.
I have a vessel fitted with an agitator which I call the "mixer" and in which
vessel I produce the calcium sulphydrate solution; I put into such vessel a quantity
of recent alkali waste and water and after thoroughly mixing them I run this
inixture through a coarse sieve in order to extract cinders or other foreign matter.
After which I treat the mixture with sulphuretted hydrogen gas in order to
produce the calcium sulphydrate solution.
I then run this solution into the "decomposer," which is a closed vessel of iron
or other suitable material fitted with an agitator and having valves on its top for
regulating the admission of the solution of the said calcium sulphydrate and also
of the solution of the double chlorides of magnesium and calcium, as well as a
pipe for carrying off the sulphuretted hydrogen gas.
Also at the bottom there is a
suitable valve or opening provided for discharging the contents of the vessel.
I obtain the solution of the double chlorides of magnesium and calcium, by
dissolving dolomite in hydrocholric acid.
"
One of the solutions above named may be run into the "decomposer and
the solution added gradually. This will cause a regular stream of sulphuretted
hydrogen gas to be disengaged by one solution decomposing the other, and at the
same time magnesium oxide will be precipitated.

page_text: A quantity of sulphuretted hydrogen gas must be produced by any well known
means to start the process; but when once started part of the sulphuretted
hydrogen gas liberated by the action of the double chlorides of magnesium and
calcium on the calcium sulphydrate is used for the production of a farther
quantity of calcium sulphydrate, while the remainder is collected in a gas-holder
and is used in the manufacture of sulphur or sulphuric acid or for any other
suitable purpose.
As soon as the flow of sulphuretted hydrogen gas has ceased the contents of the
"decomposer," consisting of a solution of calcium chloride holding in suspension
precipitated magnesium oxide are run off and the magnesium oxide is separated,
either by subsidence or filtration.
The magnesium oxide may be used to form a lining for furnaces, or it may be
converted into magnesium carbonate by saturating it with carbonic acid and then
boiling the solution in the usual way or it may be employed in any other suitable
manner.
W. SPENCE & SON,
Agents for the Applicant,
8, Quality Court.

page_text: Improvements in the Treatment of Alkali Waste by other
Materials in order to Obtain Useful Products.
I FREDERICK STIRLING NEWALL of Washington in the County of Durham
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:-
My Invention consists in treating a mixture of recent alkali waste and water
by sulphuretted hydrogen to obtain a solution of calcium sulphydrate and in
decomposing this by a solution of the double chloride magnesium and calcium.
By this means I obtain magnesium oxide and sulphuretted hydrogen. I carry
out my Invention in the following manner. I have a vessel fitted with an agitator
which I call the mixer and which I use for producing the calcium sulphydrate by
putting into it a quantity of recent waste and water and thoroughly mixing them.
I run this mixture through a coarse sieve to extract the cinders &c after which
I treat the mixture by sulphuretted hydrogen in order to produce the calcium
sulphydrate solution. I then run this solution into the decomposer which is a
closed vessel of iron or other material fitted with a mechanical agitator and having
valves on its top for admitting the solution of calcium sulphydrate and the solution
of the double chloride of magnesium and calcium and a pipe for carrying off the
sulphuretted hydrogen. At the bottom there is a valve or opening for discharging
the contents of the vessel.
One of the solutions may be run into the decomposer and the other added
gradually. This will cause a regular stream of sulphuretted hydrogen to be
discharged from the one solution decomposing the other and at the same time
magnesium oxide will be precipitated.
A quantity of sulphuretted hydrogen must be produced by any well known means.
to start the process, but when once started half the sulphuretted hydrogen liberated
by the action of the double chloride of magnesium and calcium on the calcium
sulphydrate is used for the production of a further quantity of calcium sulphydrate
whilst the remainder is collected in a gasholder, and is used for the manufacture of
sulphur or of sulphuric acid.
As soon as the flow of sulphuretted bydrogen has ceased the contents of the
decomposer consisting of a solution of calcium chloride holding in suspension pre-
cipitated oxide of magnesium are run off and the oxide of magnesium separated by
subsidence or filtration.
The oxide of magnesium may be used for lining furnaces or it may be converted
into carbonate by saturating it with carbonic acid and then boiling the solution in
the usual way.

page_text: Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed 1 declare that what
I claim is
First. Employing a solution of calcium sulphydrate however formed for pre-
cipitating oxide of magnesium from a solution of the double chloride of magnesium
and calcium or from a solution of chloride of magnesium.
Second. The obtaining sulphuretted hydrogen in the manner described.