MENTS IN THE TREATMENT OF MATERIALS WHICH HAVE BEEN USED IN PURIFYING COAL GAS. FOR THE RECOVERY OF USEFUL PRODUCTS THEREFROM
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by James Walker at the Office of the
Commissioners of Patents on the 4th December 1882.
JAMES WALKER of 10 Elmwood Place, Leeds, in the County of York "IMPROVE
MENTS IN THE TREATMENT OF MATERIALS WHICH HAVE BEEN USED IN PURIFYING
COAL GAS. FOR THE RECOVERY OF USEFUL PRODUCTS THEREFROM
"
In the Specifications of Letters Patent granted to me and numbered 5269
A.D. 1881. 387 A.D. 1882 and 1561 A.D 1882 for purifying coal gas I state that
I use for that purpose a mixture of coke dust or breeze and hydrate of Lime in
such proportions as therein named. Also I state in the said Specifications that
the coke dust or breeze mixed in the lime by its angularity porosity and natural
affinity, filters, absorbs, and retains tarry matter and other impurities from the gas
that hydrate of lime when used for purifying gas itself will not take up.
I have made a series of experiments proving that the coke dust or breeze when
mixed in the lime not only filters, absorbs, and retains tarry matter naphthaline
and other impurities from the Gas which has passed through it in the purifiers
over and above what sulphur the hydrate of lime mixed therewith has absorbed
and retained but also that the tarry matter naphthaline and other impurities are
soluble in water hot or cold and can be easily and cheaply recovered from the
spent or fouled coke dust or breeze and lime by steeping the same in water, which
becomes by the immersion a sulpho acid liquor containing coloring matter of the
coal tar series and can be used as produced to a profit in making dye colours or
separated into several other useful and valuable products suitable for various
purposes as hereinafter described. I have therefore by my experiments discovered
that the fouled materials contain ingredients of value which have hitherto been
cast away as waste when withdrawn from the purifiers because they were not
known till my present discovery after bringing out, and working my Inventions
protected by my aforesaid Patents for mixing coke dust or breeze with hydrate of
lime for purifying coal Gas nor can they now be recovered from the Gas in purifying
D. ᎪᎯ 1

page_text: it except by using the mixture of coke dust or breeze and lime or breeze by itself
as specified in my aforesaid Patents for purifying coal gas.
For the extraction and preparation of the said sulpho acid liquor from the
aforesaid fouled materials I proceed in the manner following:-
I take the fouled or spent mixture of coke dust or breeze and hydrate of lime
say one part of coke dust or breeze to one part of lime or one part of breeze to two
parts of lime or other suitable proportions after it has done its purifying work
thoroughly on the gas as aforesaid and has been cast out of the purifiers and I
have it removed at once into a house or shed where I store it ready for immediate
operations which I commence to work as quickly as I can that is to say:-after
having provided-suitable cisterns preferably made of 2 or 3 inch wooden planking
two or three widths in depth say 1 10 or 2 9 inches deep and any length or
width and in numbers suitable to the space they are to occupy and the extent of
my intended future operations well bolted together strong and water tight (and
preferably lined with sheet lead) there being a tap in the bottom of each cistern
for the outlet of the liquor when ready for being discharged
I fill into each cistern 10 or 12 inches of water in the proportion of 360 to 400
gallons (heated by a steam pipe if needful) to every ton of the said spent or fouled
breeze or coke dust and lime I place therein breaking up any lumps it may contain
I then rake or stir and agitate the breeze or coke dust and lime well into the
water from all parts of the cistern till it has become lixiviated and creamy in
substance that no portion of the fouled materials may escape the action of the
water.
I let it stand 24 hours in this state raking or stirring it once or twice in that
time as before. If breeze or coke dust by itself has been used in purifying the
gas as described in the Specification of my aforesaid Patents I submit the fouled
or spent breeze to the operations above stated and I conduct the steeping for the
extraction of the tarry matter naphthaline and other impurities it contains as if
it had been mixed with lime as aforesaid. After the last raking of the mixture
in the cistern as above described I let it finally stand to settle into a clear liquor
its colour now being a pale golden shade and at the end of the 24 hours I draw
it off gently by the taps aforesaid and leave all the sediment as far as possible in
the cistern.
If the above named proportions of water and thoroughly fouled materials have
been placed in the cistern I calculate to draw off 320 gallons or thereabouts of
18 Twaddle density clear sulpho acid liquor to every ton of the fouled materials
treated in the cisterns as described including in the said sulpho acid liquor the
coloring and tarry matter naphthaline and other impurities which have been
extracted from the gas as aforesaid.
The liquor is now ready for sale for making coal tar colours therefrom or for
distillation and the addition thereto of the usual chemical and metallic substances
used for varying the colours obtained from one base Also for the separation and
recovery of any spiritous or oily products from the tarry matter naphthaline and
other impurities which the sulpho acid liquor contains.
The residual (if any) of the sulpho acid after such distillation I use as an acid in
making sulphate of Ammonia Carbolic acid or other suitable purpose.
Or I take the sulpho acid liquor as it comes from the cistern and dilute it with
a suitable proportion of water and I apply it for a mordant in dyeing certain coal
tar colours in silk, cotton, flax, hemp, jute, and woollen goods and the cloth used
in calico printing by immersion in the usual way. Or I use the sulpho acid
liquor as I take it from the cistern without distillation as an acid in making
sulpbate of Ammonia or Carbolic acid as it may be found most convenient or
profitable at the works where the operations for the production and preparation of
the sulpho acid are carried on.
The breeze and lime mixture after its immersion for extracting the sulpho acid
liquor is removed from the cistern and replaced by fresh fouled coke dust or breeze

page_text: and lime and the operations of immersion and withdrawing it are continued from
day to day or at any desired intervals as above described.
Finally the refuse is available for manure and having by its immersion lost
its obnoxious effluvia of the bisulphide of carbon and sulphuretted hydrogen which
it before held it can be conveyed from through populous districts without nuisance
to the inhabitants.