IMPROVEMENTS IN SEPARATING SILVER FROM ITS ORES OR OTHER COMPOUNDS
Year: 1853

page_text: LETTERS PATENT to Alexander Parkes, of Birmingham, for the
Invention of "IMPROVEMENTS IN SEPARATING SILVER FROM ITS ORES
OR OTHER COMPOUNDS."
Sealed the 20th February 1854, and dated the 16th December 1858.
PROVISIONAL SPECIFICATION left by the said Alexander Parkes
at the Office of the Commissioners of Patents, with his Petition,
on the 16th December 1853.
I, ALEXANDER PARKES, of Birmingham, do hereby declare the nature
of the Invention for "IMPROVEMENTS IN SEPARATING SILVER PROM ITS
ORES OR OTHER COMPOUNDS " to be as follows:-
My improvements in the treatment of silver ores and other com-
pounds of silver consist, first, in the employment of uncalcined
sulphuret of lead (galena), and in much smaller quantity than has
heretofore been employed by silver smelters, in mixture with the ores
or other compounds of silver, with other fluxing agents, if required.

page_text: The proportions I employ are from two to five cwt. of galena to one
ton of silver ore, and two cwt. of stone coal with fluor spar, oxide of
iron, or other fluxing agent, if I find the ore difficult of fusion. The
sulphurets of silver and lead thus produced I afterwards treat to
obtain the silver, either by fusion of the regulus with metallic iron, to
reduce the lead and silver, or I calcine the reguline compound, and
reduce with carbon and fluxing agents. The silver is refined in the
usual manner. Secondly, I' reduce 'silver ores by fusing them with
metallic iron, oxide of manganese, fluor spar; granulated copper slag,
sulphate of baryta or lime, litharge, sulphurets of lead, oxide of iron,
sulphurets of iron, one or more of these substances, together with and
without carbon, in such proportions that will produce from two to five
cwt. of lead, or of a reguline compound of silver, which I treat in the
usual way to obtain the silver. Thirdly, I reduce silver from its ores
by fusing one ton of silver ore with from four to 6 cwt. of galena
(sulphuret of lead) not previously calcined, and with from two to five
cwt. oxide of iron, and two to four cwt. of carbon, stone coal by pre-
ference; and if the ore is stiff to melt, I add from one to three cwt.
fluor spar, copper slag, lime, baryta, or other fluxing agent. The
lead will be reduced to the metallic state, having combined with the
silver. The silver I separate from the lead in the usual way. Fourthly, I
employ alkaline, earthy, or metallic compounds, when treating silver ores,
in order to separate arsenic, antimony, or other impurities therefrom,
and prevent loss of silver by volatillization during the fusion or cal-
cination of such ores. I roast or fuse one ton of ore, with the addition
of from two to five cwt. sulphuret or sulphate of iron, or other metallic
sulphuret or sulphate, one to two cwt. of caustic soda, potash, lime, or
baryta, or the sulphates or sulphurets of these alkalies or earths, with
or without from two to three cwt. of carbon, and other fluxing agents,
if required, to render the matters fusible. A regulino compound is
produced, which I either disintegrate by water or mechanical means,
and afterwards dissolve out the antimony, arsenic, or other impurities
by means of water. The residuary reguline compound I treat for tho
silver, by calcination or fusion with lead or oxide of lead, with fluxing
agents and carbon; or I boil the ore in any suitable vessel with a

page_text: solution of caustic potash or soda, or their sulphurets, when the
arsenic, tin, or antimony will be in part or entirely dissolved therefrom.
After washing the residue with water, I proceed to treat it for silver
by any of the known methods. Fifthly, I mix zinc ores, whether
sulphuret or oxides containing silver, with silver ores, so as to obtain
the silver from both ores at the same time by fusing them with lend,
oxide of lead, sulphuret of lead, or sulphuret of iron, together with
carbon and fluxing agents, if required.