IMPROVEMENTS IN THE COMBI- NATION AND MANUFACTURE OF CERTAIN METALLIC SULPHIDES AND SULPHATES, AND IN THEIR APPLICATION TO USEFUL PURPOSES,
Year: 1875

page_text: LETTERS PATENT to Thomas Griffiths, of 28, Panton Street, in the
County of Middlesex, and William Phillips Thompson, of 6, Lord
Street, Liverpool, in the County of Lancaster, Consulting Engineer
and Patent Agent, for the Invention of "IMPROVEMENTS IN THE COMBI-
NATION AND MANUFACTURE OF CERTAIN METALLIC SULPHIDES AND SULPHATES,
AND IN THEIR APPLICATION TO USEFUL PURPOSES,' -Partly a com-
munication from abroad by Monsieur Guion, of Paris, in the
Republic of France.
"
-
Sealed the 9th December 1875, and dated the 8th July 1875.
PROVISIONAL SPECIFICATION left by the said Thomas Griffiths and
William Phillips Thompson at the Office of the Commissioners of
Patents, with their Petition, on the 8th July 1875.
We, THOMAS GRIFFITHS, of 28, Panton Street, in the County of
5 Middlesex, and WILLIAM PHILLIPS THOMPSON, of 6, Lord Street,
Liverpool, in the County of Lancaster, Consulting Engineer and Patent
Agent, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE COMBINATION AND MANUFACTURE OF CERTAIN METALLIC SULPHIDES

page_text: AND SULPHATES, AND IN THEIR APPLICATION TO USEFUL PURPOSES," partly a
communication, to be as follows:-
This Invention consists,—
1st. In taking crude calcium sulphide and exposing it to the atmos-
phere until all oxidizable matters therein have taken up as much oxygen
as they are capable of by such exposure, and then lixiviating it in water
until all soluble matters are extracted. The strained and decanted liquor
we will henceforth call the sulphur liquor.
2nd. Mixing the chloride sulphate or nitrate of zinc as free from iron
as may be practicable with the aforesaid sulphur liquor; an insoluble
white powder is the result.
3rd. There are several ways of making the sulphur liquor or its equi-
valent, some of which may be preferable to the above-mentioned plan.
One is to take the calcium sulphide aforesaid and digest it first with
steam and then with water in a closed vessel (or with steam and water
combined, till it is in great part dissolved. It is then left to subside
and the clear liquor is decanted into another chamber containing the
zinc solution. Or instead of using steam and water in a closed chamber
dilute acid, preferably hydrochloric, can be used instead, the rest of the
process being the same. In this case howover the calcium chloride
formed during the process should be washed out of the product.
4th. In order to use solutions of chloride or sulphate of zinc con-
taminated with iron, which by discolorizing the precipitate afterwards
formed would greatly diminish its value, we first precipitate the iron
with dihydric sulphide and a strong acid and remove the sediment that
after a time collects. We then treat the remaining liquor with ammonia
to pass the neutral point. It is now ready for mixing with the sulphur
liquor, as above described in part 2.
5th. The applications of the aforesaid compound to the arts are very
numerous; its chief use is however as a substitute for artificial or ground
sulphate of baryta, for any purpose not depending on chemical con-
stitution, to which the latter substance is applied. It is also useful for
mixing with sulphate of baryta, and as the mixture should be extremely
intimate it is almost indispensible that they should be manufactured
together. Parts 6 and 7 therefore explain our mode of doing this.
6th. In the manufacture of sulphato of baryta the chloride of barium
is usually employed. This can be obtained in any desirable way, the

page_text: usual plan being the decomposition of carbonate of baryta. by chlorhydric
acid; this is again decomposed by sulphuric acid. We prefer however
to complete the last part of the process 'by an alkaline sulphate, more
especially the natural mineral sulphate of magnesia, instead of using
the sulphuric acid. Sulphate of lime is also applicable, but owing to its
greater insolubility is not so convenient. When sulphuric acid is used
chlorhydric acid is liberated. This we use in making our chloride of
zinc, and precipitate the zinc chloride with the sulphur water already
described. The two precipitates are ground, washed, and calcined
together, then triturated, and are ready for market. Lime, its carbonate
or sulphate, for cheap purposes, can replace the sulphate of baryta, but
are not so good. Alkaline sulphides, such as those of potassium or
sodium, can also replace the sulphur water, but the process is then more
costly. Sometimes instead of neutralizing the chlorhydric acid with zinc
at once we pour in the sulphur water; the sulphur is precipitated and
intimately mixed with sulphate of baryta by agitation. Into the
remaining liquid I pour oxide of zinc, neutralizing at the same time
the free chlorhydric acid with an alkali, so that it shall not attack the
oxide of zinc. The mixed precipitates are now calcined, &c., as before
described.
7th. The combined material can also be made in the dry way by
intimately mixing two parts of sulphate of baryta, or its equivalent,
one part of zinc oxide, with 10 per cent. of flour of sulphur, and 5 per
cent. of carbonate of soda, or its equivalent, and calcining, et cetera, as
before. In calcining in all these cases we prefer to use a kiln or furnace
of such construction that the fumes of sulphur arising from the mixture
can be collected and condensed for sulphuric acid making.
30
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Griffiths and William Phillips Thompson
in the Great Seal Patent Office on the 8th January 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, THOMAS
GRIFFITHS, of 28, Panton Street, in the County of Middlesex, and
WILLIAM PHILLIPS THOMPSON, of 6 Lord Street, Liverpool, in the County
of Lancaster, Consulting Engineer and Patent Agent, send greeting. -

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of July, in the year of our
Lord One thousand eight hundred and seventy-five, in the thirty-
cighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Thomas Griffiths and William Phillips
Thompson, Her special licence that we, the said Thomas Griffiths and
William Phillips Thompson, our executors, administrators, and assigns,
or such others as we, the said Thomas Griffiths and William Phillips
Thompson, our executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE COMBINATION AND MANUFACTURE OF CERTAIN METALLIC
SULPHIDES AND SULPHATES, AND IN THEIR APPLICATION TO USEFUL PURPOSES,”
partly our own Invention and partly a communication to us from abroad
by Monsieur Guion, of Paris, in the Republic of France, upon the con-
dition (amongst others) that we, the said Thomas Griffiths and William
Phillips Thompson, our executors or administrators, by an instrument
in writing under our, or their, or one of their hands and scals, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that we, the said Thomas Griffiths and William
Phillips Thompson, do hereby declare the nature of our said 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 consists,-
1st. In taking the crude calcium sulphide from soda waste and
exposing it to the atmosphere until oxydizable matters therein have
taken up as much oxygen as thoy are capable of by such exposure. It
is then lixiviated in water and thoroughly washed, the water having
to stand in contact with it for hours with occasional or continual
stirring to extract all the strength out of it. The strained and decanted
liquor resulting from this operation we will call the sulphur liquor.

page_text: ticable with the sulphur liquor; an insoluble white powder is the result,
which we will call powder Number 1.
3rd. In taking chloride of barium and precipitating it with mineral
sulphate of magnesia until there is no longer a precipitato; the white
powder resulting we will call powder Number 2. We then take powders
Number 1 and 2, mix them intimately together and calcine them at a.
dull red heat till no more fumes are given off, when they are plunged
into cold water, ground, levigated, and sold as a substitute for oxide of
zinc or sulphate of baryta.
4th. Another, and frequently a better mode of making this mixture
is as follows:-Take sulphate of zinc solution and pour in a solution of
chloride of barium till a precipitate ceases to form; decant and preserve
the precipitate; treat the mother liquid with the sulphur water until
again no precipitate occurs; decant and preserve the precipitate; mix
the two precipitates intimately and calcine, et cetera, as before.
5th. Almost any soluble sulphide will do as well as the sulphur water
but the latter is the cheapest.
6th. The sulphur water can also be made by digesting the crude
calcium sulphide with steam and water under pressure, and allowing it
to stand under pressure, taking care to decant the resulting liquor
immediately into the salt of zinc, as if allowed to stand when exposed
sulphydric acid fumes are given off; our favorite precipitate for the
zinc is however pentathionide of calcium. It is made by boiling sulphur
and lime, or preferably sulphur and calcium sulphide in about the pro-
portions by weight of 65 per cent. of sulphur to 35 per cent. calcium
sulphide until they are in great part dissolved and form a red liquor, the
desired precipitant.
7th. The desired compound can also be made in the dry way by
intimately mixing two parts of sulphate of baryta or its equivalent and
one part of zinc oxide, with 10 per cent. of flour of sulphur, and 5 per
cent. of carbonate of soda, or its equivalent, and calcining as before,
but we do not consider this plan as equal to the wet process already
described in its results. The compound resulting from any of these
processes is used as a substitute for oxide of zinc or sulphate of baryta
for almost any purpose to which these substances are applied not
dependent on exact chemical constitution,

page_text: Having now described our Invention and the manner of carrying it
into execution, we would state that what we claim as our Invention
is,-
1st. The application of the washings of soda waste, or a solution of
one or more sulphides of (or combinations of sulphur with) an alkaline 5
metal or a calcium base as a precipitate of zinc, in combination with the
subsequent calcination of the precipate for commercial or manu-
facturing purposes.
2nd. The application of crude mineral sulphate of magnesia as a pre-
ciptant of baryta for commercial purposes; this is not a necessary part 1
of the Invention.
3rd. The manufacture of sulphide of zinc, substantially as described
in the foregoing Specification, and its subsequent calcination for com-
mercial or manufacturing purposes.
4th. The use of crude sulphate of zinc formed from the roasting and 1
lixiviating of blend in the manufacture of hydrated sulphide of zinc for
subsequent conversion into an anhydrous sulphide or mixture of anhy-
drous sulphide and oxide for commercial or manufacturing purposes.
5th. The manufacture of an intimate mixture of finely divided oxide
or anhydrous sulphide of zinc and sulphide of barium, substantially as 2
described in the foregoing Specification.
In witness whereof, I, the said William Phillips Thompson, on
behalf of myself and the said Thomas Griffiths, have hereunto
set my hand and seal, this 6th (Sixth) day of January, in the
year of our Lord 1876.
2
W. PHILLIPS THOMPSON: (L.s.)
Witness,
EDW. G. COLTON,
6, Lord Street,
Liverpool.
Clerk to the said W. P. Thompson.