A New or Improved Method of, and Apparatus for, Producing Basic Cupric Acetate.
Year: 1898

page_text: Date of Application, 21st Sept., 1898-Accepted, 17th Dec., 1898
COMPLETE SPECIFICATION.
A New or Improved Method of, and Apparatus for, Producing Basic
Cupric Acetate.
I, ADOLF GUTENSOIN, of Crown Works, 90, Park Street, Limehouse, London, E.
Metallurgical Chemist, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
The hitherto known methods of producing basic cupric acetate or basic acetate
of copper require much time and labour and are therefore only carried out m
countries where local conditions are especially favourable.
My new or improved process is not in any way dependent upon local conditions
and admits of speedy and economic production of basic cupric acetate.
The material serving as base for my process is cupric sulphate (sulphate of
copper), which I dissolve by means of a carbonate, such as carbonate of sodium or
the like, preferably in such a manner that both salts are melted in their water
of crystallization; the soluble sulphate is extracted by water, cupric carbonate
(carbonate of copper) remaining as a sediment.
al
For decomposing the cupric sulphate I prefer to employ the ordinary soda of
commerce, which is everywhere obtainable at low price and quickly melts in the
water of crystallization, but if necessary I may also use magnesia. In the latter
case a certain quantity of water has to be added, the water of crystallization of
the cupric sulphate not being sufficient to prevent the formation of
firmly adhering hard crust upon the sides and bottom of the vessel
used for effecting the decomposition. If calcined magnesia, deprived of
its carbonic acid, is employed it naturally results that the product is not cupric
carbonate but cupric hydrate, which latter material is better adapted for further
treatment than the former as no frothing takes place. Frothing may also be
avoided by using caustic soda, but this material is not recommended on account
of its price and the inconvenience caused by it to the workmen.
The sulphate resulting from the decomposing process, be it sulphate of sodium,
of magnesia, or any other sulphate, is then concentrated and crystallized, while
the cupric carbonate or cupric hydrate, as the case may be, dissolved in acetic
acid. In order to utilize the acetic acid to the best advantage it would be necessary
to dilute it; this would result in the serious disadvantage of having to concen-
trate a comparatively large quantity of liquid, requiring time and expenditure of
heat, and furthermore it is to be considered that cupric acetate may easily be
decomposed by continued heating, or the temperature reaching too high a point
owing to carelessness of the workmen or from other causes.
In order to obviate the aforesaid disadvantage, I may use commercial acetic
acid of 30 degrees as it is, or I may dilute it with one third part of water, and
bring the liquid to boiling point, and gradually add as much cupric carbonate or
cuprie hydrate as the acid solution may be able to absorb. In this manner I obtain
a liquid compound of such strength, that upon its cooling very fine crystals of
cupric acetate are formed; these crystals are dryed and are then ready for com-

page_text: merce, or the product may be mechanically ground up to the required degree of
fineness and passed through sieves of suitable grading.
This manner of proceeding will obviously result in great waste of acetic acid,
if the latter were allowed to escape freely. In order to obviate such waste, I
either collect the vapours and pass thein through a convenient distilling apparatus,
or I preferably use the escaping acid fumes for acting upon one or more super-
posed layers of cupric carbonate or cupric hydrate, whereby the said materials
are prepared or readied for subsequent stages of manufacture.
For the purpose of attaining the said twofold advantage, I have found it ex-
pedient to employ a specially constructed apparatus, illustrated in the accom-
panying drawings, of which
Fig. 1 represents a vertical section of the device, part of the upper portion being
shown in side view, and
ll
Fig. 2 is a top view of the lower and stationary portion of the apparatus.
A mantle or jacket b, made of sheet metal or other convenient material and
being either round or of other suitable shape, is connected with the base plate
and left open at the top. A, preferably, wooden cover d consisting of two flaps or
parts each of them having a semicircular piece cut away, so that if the cover is
placed in position on the jacket-mantle a circular aperture is formed for the
reception of a vessel c containing the acid solution. In this manner a nearly
steam-tight chamber is formed, and if steam is allowed to flow into the said
chamber through inlet-pipe s it will keep the contents of the vessel c at a high
temperature and ultimately escape through exit-pipe s¹.
preferably made to have the same diameter as exit-pipe s', in order to obviate too
The inlet-pipes is
high a pressure of steam in the chamber. In a suitable position at the bottom of
the chamber an outlet cock may be provided to admit of any condensed water
collected at the bottom of the chamber being drawn off.
For the purpose of utilizing the fumes or vapours rising from the heated acid
solution contained in vessel c, in the hereinbefore described manner, a super-
structure, adapted to be easily removed and replaced, is erected upon the rim of
vessel so that all vapours rising from the heated acid solution are forced to pass
through the component portions of the structure before escaping into open air.
The said superstructure consists of a chamber e, cylindrical or otherwise shaped
<according to the shape of vessel, and adapted to rest upon the rim of the latter,
an overlapping hoop e¹ being provided to embrace the said rim and firmly maintain
the chamber in position. The chamber e is preferably censtructed of sheet metal
such as copper or the like.
Upon the upper edge of the chamber e a series of cylindrical frames f having
overlapping hoops or flange rims f¹ are placed one upon the other, each of said
frames being provided with a sieve-like grating g on which suitable quantities of
cupric carbonate or cupric hydrate are laid for the purpose of exposing the material
to the action of the vapours rising from the acid solution, and thus preparing it
for further treatment as described. In the side of the chamber e a suitable door
may be provided to admit of the liquid in the vessel e being drawn off by means of
a syphon or in a similar manner, and to refill the vessel with fresh solution.
The mother ley is strengthened with a sufficient quantity of fresh acetic acid,
so as to produce in the refreshed liquid the same percentage of acetic anhydride
as the liquid originally contained. The solution may then be heated and used
again in the manner described.
For the formation of crystals, especially those resulting from easily decomposed a
solution, vessels of various forms may be used; a series of experiments proved that
earthenware basins of about 15 inches diameter at the top and 8 and 1 inches
at the bottom and about 5 inches deep glazed inside and holding about one gallon
of liquid, are best adapted for the purpose; when filled with hot liquor and placed
in a warm room the cooling proceeds slowly and gradually, the crystals being 5
very brilliant and of excellent colour and of such size as to be easily turned into
coarse powder ready for the market. If larger crystals are desired, the liquid is

page_text: drawn off from the basins and replaced by freshly concentrated liquid, and so
on until the crystals are of sufficient size.
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.) A new or improved method of producing basic cupric acetate, in which
cupric sulphate is treated with a suitable carbonate, such as carbonate of sodium,
carbonate of magnesia, or the like, the resulting cupric carbonate or cupric hydrate
being dissolved in a solution of acetic acid of convenient strength, and the
saturated solution allowed to cool in, preferably, flatbottomed earthenware or
similar basins, when small-sized crystals of basic cupric acetate will be formed on
the solution being cooled, substantially as set forth.
2.) In the process forming the subject of Claim 1, the employment of an
apparatus for saving and utilizing the acid fumes or vapours, consisting of a
chamber e and a convenient series of superposed frames f having gratings g sub-
stantially as and for the purpose set forth and illustrated in the accompanying
drawings.
Dated this 21st day of September 1898.
CAMBIE & WINCKELSETT,
40, High Holborn, London, W.C.,
For the Applicant.