IMPROVEMENTS IN THE TREATMENT OF SOAP LEYS TO. OBTAIN PRODUCTS THERE. FROM
Year: 1885

page_text: I OTTO CHRISTIAN HAGEMANN of Buckingham House Twickenham in the
County of Middlesex Chemist do hereby declare the nature of my invention for
"IMPROVEMENTS IN THE TREATMENT OF SOAP LEYS TO. OBTAIN PRODUCTS THERE.
FROM" to be as follows:-
This Invention has for its object improvements in the treatment of soap leys to
obtain products therefrom.
At the present time soap leys are frequently treated for the extraction of
glycerine. By my invention I first extract other products of commercial value
and in so doing I prepare the leys for the better production of glycerine.
I prefer to proceed as follows:-
I add lime to the leys and thereby convert the carbonated alkali which to a
greater or less extent they always contain into caustic alkali-I then boil down
nearly to the point at which common salt would commence to be deposited and
I add rosin to saponify the alkali-The rosin soap together with unconverted rosin
floats on the surface it is skimmed off and removed. The rosin soap is afterwards
used in the manufacture of a marketable article and so the article is utilised.
If the original leys were comparatively pure the manufacture of, glycerine and
the recovery of common salt may at once be proceeded with but if the leys were
impure and especially if of the class known as Lancashire leys which contain
as impurities, Hyposulphites, Sulphides, Sulpho-cynates, Cyanides, Ferro-cyanides
and others I proceed after removing the alkali as above described or otherwise
to add per chloride of iron-A precipitate results containing Ferro-cyanide of iron
and fatty impurities in the form of a metallic soap. This precipitate I separate
and I afterwards treat it to recover the Ferrocyanide in a marketable state.
I now proceed to remove sulphur compounds from the liquor by the addition of
Hydrochloric or other strong acid. I blow hot air through the liquid continuously
and sulphurous acid is liberated whilst sulphur is precipitated and removed. In
this way most of the sulphur is removed from solution. The separation is rendered
complete by the introduction of Chlorine-The clear liquor is afterwards treated
for the recovery of common salt and glycerine.

page_text: Products therefrom.
I OTTO CHRISTIAN HAGEMANN of Buckingham House Twickenham in the
County of Middlesex 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:-
This invention has for its object improvements in the treatment of soap leys to
obtain products therefrom.
At the present time soap leys are frequently treated for the extraction of
glycerine. By my invention I first extract other products of commercial value
and in so doing I prepare the leys for the better production of glycerine, I proceed
as follows:-
I add. lime to the leys and thereby convert the carbonated alkali which to a
greater or less extent they always contain into caustic alkali.
About 1 per cent of lime will usually be suitable for this purpose but the
quantity requisite is in each case easily ascertained by experiment. I separate the
resulting carbonate of lime. I then boil down the leys nearly to the point at
which the common salt which they contain would commence to be deposited and
I add rosin to saponify the alkali. The quantity of alkali which the leys contain
at this stage I ascertain by the examination of a sample and I add somewhat more
rosin than the alkali will saponify about ten per cent excess is suitable. By
boiling for a short time the convertion of the rosin into rosin soap is effected.
The rosin soap together with the unconverted rosin will now float on the surface
and it may be easily skimmed off and separated; this would not be the case if no
excess of rosin were employed. Or in place of skimming off the rosin soap the
liquor may be drawn off leaving the rosin soap in the vessel; into which then the
ingredients for producing a fatty soap may now be introduced; the process is
proceeded with in the ordinary manner and a combined soap is obtained. In any
case the rosin soap is incorporated with, a fatty soap and then forms part of a
marketable article; so the alkali'is utilized.
After the separation of the alkali from the leys by means of rosin I proceed with
the treatment of the leys in the following manner.
If the original leys were comparatively pure the liquor may at once be treated
in the manner described in the Specification of the Patent granted to Charles
Thomas and Albert Domeier No 2462 in the year 1881. But if the original leys
were impure and especially of the class known as Lancashire leys which contain as
impurities hyposulphites, sulphides, sulpho-cyanates,, cyanides,, ferro-cyanides and
others I first neutralize the leys with mineral acid and I then add perchloride of
iron to the leys so long as a precipitate is obtained. The precipitate which consists
mainly of fatty matter and Prussian blue is separated; it has a marketable value
and the blue can be purified by well known methods. The leys from which this
precipitate has been obtained are still unfit for the production of a pure glycerine;
sulphur which they contain has now to be separated from them. For this purpose

page_text: I add three or four per cent of strong hydrochloric acid or other mineral acid may
be used but hydrochloric is usually most economical. I then blow air through the
liquid continuously for several hours whilst the liquor is kept in a hot state by the
air or otherwise.
Sulphurous acid passes off together with the air and this is allowed to escape.
Sulphur also is precipitated in the liquor. To render the decomposition of the
oxidisable sulpho compounds as complete as possible chlorine is introduced in tho
form preferably of a solution of so called chloride of lime of which a small
quantity is added until free chlorine is found in the liquor. The sulphur is
removed and the leys are neutralized The liquid now obtained is fit to be boiled
down for the recovery of common salt, and the production of glycerine by
distillation.
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 :-
1. The treatment of soap leys which have been rendered caustic by the addition
of lime by boiling them down to the salting point and then saponifying the alkali
with rosin whereby a rosin soap is obtained and the alkali in the ley utilised
substantially as described.
2. The further treatment of leys from which alkali has been recovered by
perchloride of iron thereby obtaining a precipitate containing ferro cyanide of
iron substantially as described.
3. The further treatment of leys from which alkali has been recovered and from
which a precipitate has been obtained by perchloride of iron; consisting in the
separation of sulphur by adding acid and by blowing air through the heated leys
substantially as described.
4. The production of glycerine by distillation from soap leys previously purific
by boiling down and saponification of the alkali with rosin; by precipitation with
perchloride of iron; and by the separation of sulphur by oxidation with air; or by
either of the said processes substantially as described.