IMPROVEMENTS IN PROCESSES FOR TREATING SOLUTIONS USED FOR PURIFYING COPPER ORES AND PRECIPITATE "
Year: 1882

page_text: LETTERS PATENT to David Watson of Manchester in the County of Lancaster
Metallurgist for an Invention of IMPROVEMENTS IN PROCESSES FOR TREATING
SOLUTIONS USED FOR PURIFYING COPPER ORES AND PRECIPITATE
"
PROVISIONAL SPECIFICATION left by the said David Watson at the Office
of the Commissioners of Patents on the 12th August 1882.
DAVID WATSON of Manchester in the County of Lancaster Metallurgist...
"IMPROVEMENTS IN PROCESSES FOR TREATING SOLUTIONS USED FOR PURIFYING
COPPER ORES AND PRECIPITATE
"
This invention has for its object the removal of arsenic and phosphorus from
alkaline solutions which have been employed for the purification of copper ores
and precipitate thereby rendering these solutions again suitable for use for that'
purpose.
These alkaline solutions are to be boiled or heated with agitation with lime in
sufficient excess in which operation alkaline arsenates and phosphates are
decomposed, insoluble arsenate and phosphate of lime are produced and caustic
alkali remains in solution.
The amount of lime to be employed must vary with the amount of arsenate or
phosphate in the solutions to be treated.
The solution thus treated after separation from the insoluble lime compounds
may be again used for purifying copper ores and precipitate.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said David Watson in the Great Seal Patent Office on the 8th February
1883.
DAVID WATSON of Manchester in the Connty of Lancaster Metallurgist
" IMPROVEMENTS IN PROCESSES FOR TREATING SOLUTIONS USED FOR PURIFYING
COPPER ORES AND PRECIPITATE
"
This invention has for its object the treatment of certain liquors to be hereafter
described which proceed from the treatment of copper precipitate for the removal
of arsenic and other impurities in order to render these liquors again available for
use in the purification of copper precipitate and ores.
The liquors referred to are those proceeding from the treatment of copper
precipitate or ores by solutions of alkaline sulphides hydrates or carbonates (as
directed by the Specifications to Letters Patent of David Watson N° 1305 bearing
date 17th March 1882 and of Frederic Claudet N° 5271 bearing date 2nd December
1881.)
These liquors contain alkaline arsenate and sometimes alkaline phosphate and
where alkaline carbonate was employed in the purification probably alkaline
carbonate. Other alkaline salts as the chloride which may be present lie outside the
intention of this invention.
These liquors which may be of various degrees of concentration are to be boiled
or heated with agitation either under the ordinary or increased atmospheric
pressure with calcium hydrate in sufficient proportion in which operation the
alkaline arsenate and phosphate are decomposed (and under certain circumstances
the carbonate) insoluble calcium arsenate phoshate and soluble alkaline hydrate
being produced.
The liquor filtered from the insoluble residue of calcium arsenate phosphate
hydrate and in some cases carbonate are now again available for the purification
of copper precipitate or ores.
I find it convenient to employ for treatment liquor which will yield not more
than ten per cent of caustic alkali after treatment although more or less concentrated
liquors may also be treated and I prefer to use three times the amount of caustic
lime theoretically required for the chemical decompositions that take place.
Having stated the nature of my Invention and described the manner of
performing the same I would have it understood that I do not limit myself to the
details given as they may be varied or modified and―
I declare that I claim.
The treatment of the solutions described above by calcium hydrate in the
manner and with the object herein described.
:
In witness whereof I the said David Watson have hereunto set my hand and
seal this seventh day of February One thousand eight hundred and eighty
DAVID WATSON (L.S.)