Improvements in Extracting Metals from Alkaline Solution, Scrap, or Waste Materials.
Year: 1889

page_text: Date of Application, 17th Aug., 1889-Accepted, 21st Sept., 1889
Improvements in Extracting Metals from Alkaline Solution, Scrap,
or Waste Materials.
I, NINA MARIA DE LA ENCARNACION TENISON-WOODS of No. 263 Camberwell New
Road, London, in the County of Surrey, Gentlewoman, 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:-
Various successful processes have been patented for the purpose of separating tin
from iron, copper, brass &c. by means of alkaline solutions.
The difficulty hitherto experienced has been in the direct way to separate such tin
from alkaline solutions immediately in the metallic form, without the intervention
of secondary processes.
By my invention, saturated or nearly saturated solutions of oxides of tin, and other
metals soluble in an alkaline medium, such as zinc, cadmium, lead, and tungsten are
placed in a cast, or wrought iron, or any other tank. Should lead be present in the
form of plumbate of the alkali used, sulphate of the same alkaline mediums such as
potash, soda, &c. is added, which precipitates the lead in the form of sulphate of
lead a perfectly insoluble compound-which sinks to the bottom, and the fluid is
separated by decantation. By this process no other of the above mentioned soluble
metals are affected.
The solution containing all other metals is then transferred to a wrought or cast
iron boiler with fire underneath. It is then heated to a temperature at or approaching
boiling heat. An open wrought iron wire cage is filled with refuse zinc scraps, but
preferably with refuse galvanized pans, pails, cases, or other refuse scrap containing
zinced iron, and refuse galvanized iron roofing. A communication is made by a
copper or other sufficient electric conductor, between the insolated cages containing
the zinced scrap &c. and the periphrey of the iron pan. An immediate development
of nacent hydrogen takes place on the inside surface of the pan, caused by the electric
action of the soda or other alkali in contact with the zinc-the positive pole-and the
iron pan the negative pole-in a heated solution of soda or other alkali.
The tin is reduced and thrown down on the inside surface of the iron pan in the
form of powdery crystaline deposit in the metallic state, which falls to the bottom of
the pan owing to its specific weight; the zinc in the positive crate or basket being at
the same time dissolved and replacing the tin in the alkaline solution, leaving the
scrap galvanized iron-if such should be used-in a marketable condition as iron.
The fluid containing the other soluble metals is decanted. The tin powder is then
collected and melted for commercial use, and is very pure.
To recover the zinc in the alkaline solution, and the soda or any other alkalies from
such solutions, a current of carbonic acid gas is passed through them-by any of the well
known apparatii for the creation of the same, until the whole of the zinc is precipitated
in the form of Carbonated Oxide of Zinc, which is insoluble in the carbonate of soda,
Potash, or other alkalies used and created at the same time. This is separated from
the carbonate of soda or other alkalies, and heated, producing a well known valuable
article, namely, pure oxide of zinc. The carbonate of alkali in solution will then be
recaustified by boiling with milk of lime, and the caustic alkali can then be used again,
less manufacturing waste.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
The separation, in the metallic state, of pure tin from alkaline compound solutions
of tin oxides combined with other metallio avidas soluble in alkaline mediume
لحم

page_text: the recovery of such other metallic oxides soluble in alkaline mediums as may be
contained in the original solutions, and more particularly for the recovery and
utilization of the zinc and zinced iron used in these processes by the manipulation
above described, being practical methods of doing the same not hitherto in use for
the same purposes, by which valuable but hitherto waste materials can again be made
of worth.
Dated this 17th day of August. 1889.
NINA MARIA DE LA ENCARNACION TENISON-WOODS.