Improvements in the Production of Basic Lead Carbonate, Chloride, Phosphate, Oxalate, Silicate, Borate, or other Insoluble or Sparingly Soluble Salts of Lead.
Year: 1888

page_text: Cate of Application, 17th Aug., 1888
Complete Specification Left, 17th June, 1889-Accepted, 20th July, 1889
UVIDIŪNAL DIECIFICATION.
Improvements in the Production of Basic Lead Carbonate, Chloride,
Phosphate, Oxalate, Silicate, Borate, or other Insoluble or
Sparingly Soluble Salts of Lead.
We, WILLIAM EDMUND BRANDFORD BLENKINSOP, of Garden Wharf, Church
Road, Battersea, S.W. Manufacturer, and FARNHAM MAXWELL LYTE of 60 Fin-
borough Road, Redcliffe Square, S.W. Analytical Chemist, do hereby declare the
nature of this invention to be as follows:-
--
This invention relates to the production of basic lead carbonate, basic lead chloride,
basic lead phosphate, basic lead oxalate, basic lead silicate, basic lead borate, or other
insoluble or sparingly soluble, salts of lead by the double decomposition brought about
by the contact of basic sulphate, or basic chloride, or other basic salts of lead with a
salt or salts the electro negative constituent of which is that of one of the above
named substances, but other than that of the substance treated. Of course it is
preferable, as being more rapid, that the basic salt of lead should be treated with a
soluble salt (as, for instance, basic sulphate by sodic carbonate) but many of the so
called insoluble salts produce this change (as, for instance, magnesite or dolomite
with normal or basic lead sulphate, or other appropriate salts of lead) so that it is
difficult to say whether the decomposition takes place by actual contact or in virtue of
the slight solubility of, say, the magnetic or calcic carbonates. However this may be,
the decomposition occurs, even with several of the so called insoluble salts, and we
desire to claim the reaction.
It is best to use a small excess on the theoretical proportion when employing either
of the above named salts in order to ensure complete and rapid decomposition. When
sodic carbonate is employed to convert basic lead sulphate into basic lead carbonate,
5% excess suffices, but we do not wish to limit ourselves to these proportions
although we find them to answer well. Heating or boiling appears to accelerate the
transformation.
We further find that mixtures of similar basic salts of lead of different degrees
of basicity and mixtures of different basic lead salts (as basic carbonate and basic
chloride) seem to possess greater value as pigments than any given basic salt of lead
alone.
Basic lead chromates may also be formed of various shades by treating basic
sulphates or chlorides or other basic salts of various basicites (for instance, such as
are produced under the Patent No. 11,88986) with the sodic or other chromate. Basic
chromate of lead may also be formed by the method given in the Specification of the
Patent No. 10,2988. Basic salts of lead being treated with a soluble sulphide, produce
a finely divided lead sulphide.
Dated this 17th day of Anunt 1000
W. E. B. BLENKINSOP.
F. MAXWELL LYTE.
By A. M. & Wm. Clark,
53. Chancery Lane, London, Patent Agents.
COMPLETE SPECIFICATION.
Improvements in the Production of Basic Lead Carbonate, Chloride,
Phosphate, Oxalate, Silicate, Borate, or other Insoluble or
Sparingly Soluble Salts of Lead.
We WILLIAM EDMUND BRANDFORD BLENKINSOP, of Garden Wharf, Church Road
Battersea S.W. Manufacturer and FARNHAM MAXWELL LYTE, of 60 Finborough
D

page_text: Road, Redcliffe Square, S.W. Analytical 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 relates to the production of insoluble or sparingly soluble basic salts
of lead (e.g. basic. lead carbonate, basic lead chloride, hasic lead phosphate, basic lead
oxalate, basic lead silicate, or basic lead borate) by the conversion of basic sulphate
basic chloride or other basic salt of lead into a different basic salt of lead, by the
double decomposition brought about by the treatment of said basic salt of lead with a
salt or salts the electro-negative constituent of which is that of the salt it is desired
to produce and is other than that of the salt treated.
It is, of course, preferable that the basic salt of lead should be treated by a soluble
salt (e.g. basic lead sulphate by sodic carbonate, as mentioned in a former Patent)
but many of the so-called insoluble salts produce the desired reaction or decomposi-
tion (as, for instance, magnesite) so that it is difficult to say whether the decomposition
takes place by actual contact or in virtue of the (slight) solubility of, say, the magnesic
carbonate which is used.
In order to ensure complete and rapid decomposition, the salt used as the reagent
should be slightly in excess beyond the theoretical proportion. Thus, when sodic
carbonate is employed as the reagent to convert basic lead sulphate into basic lead
carbonate 5% excess of the theoretical amount of the sodic carbonate employed has
been found to answer well but these proportions may be varied.
We find the best method for the conversion of, say, lead sulphate into lead carbonate
by the use of, say, magnesic carbonate is to mix the latter in a fine ground state with
the lead sulphate and then boil with a sufficiency of water to dissolve all the magnesic
sulphate formed. Or, further, we may blow carbonic dioxide into the above mixture,
according to the Schaffner and Helbig process, and thus hasten the reaction.
Heating or boiling appears to accelerate the transformation.
Basic lead chromates may also be formed of various shades, by treating basic lead
sulphates or basic lead chlorides or other basic lead salts of various basicities (for
instance, such as are produced under the Patent No. 11,889 of 1886) with sodic or
other chromate.
Having now particularly described and ascertained the nature of the said Inven-
tion and in what manner the same is to be performed, we declare that what we
claim is;
The herein described method of producing insoluble or sparingly soluble basic salts
of lead by the reaction of a basic salt of lead with a salt or salts (such, for instance,
as magnesite) the electro-negative constituent of which is that of the salt it is desired
to produce and is other than that of the salt treated, substantially as specified.
Dated this 17th day of June 1889
Dated this 17th day of June 1889
W. E. B. BLENKINSOP.
F. MAXWELL LYTE.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.