POUDRES DE ZINC POUR PILES ELECTROCHIMIQUES

ZINC POWDERS FOR ELECTROCHEMICAL BATTERIES

Abrégé anglais

ABSTRACT.
A process for the production of zinc powder for
electrochemical batteries which require the presence of
mercury, in which at least part of the mercury required in
the battery is introduced into molten zinc,
and the molten alloy is homogenized and transformed into
powder by pulverization (atomization).

Revendications

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:


1. A process for the production of zinc powder con-
taining mercury suitable for electrodes of electrochemical
batteries, comprising introducing mercury into molten zinc
and converting the molten zinc/mercury alloy obtained into
powder form by atomisation.
2. Zinc powder for electrochemical batteries in which
each grain consists of the same homogenous zinc-mercury alloy,
as produced in accordance with the process of claim 1.

Description

103~Z95
The present invention relates to a new process for the
preparation of zinc powder intended for the manufacture
of electrochemical batteries, the said zinc powder being
for instance in the form of electrodes obtained by compression.
It is known that in the batteries comprising electrodes
made of zinc powder, alloyed or not, when the battery does not
deliver current a prejudicial escape of gas (hydrogen)
occurs with reduces the electrical capacity available
and creates problems, namely construction problems.
It is known to avoid such gaseous escape by the well
known practice of amalgamating the powder. However, the
amounts of mercury to be used in this process of the kn~wn
art are relatively important and the amalgamation constitutes
;~ in itself an expensive and delicate operation. Moreover,
~- this process has the drawback of a non-homogeneous distribution
of the mercury.
`~ The present invention avoids the above mentioned
draw~acks.
~~ The invention rela~e~ to a process ior the manufacture
~ of zinc powder for electrochemical batteries which
.
require the presence of mercury, characterized in that all or
part of the mercury required in the battery, is introduced
; into molten zinc, alloyed or not, æaid molten alloy being

~ homogenized a~d transformed lnto powder by pulverization
" ; ,
; - latomization).
The powder obtained by the process of the inventiohl
is characterized in that the mercury contained in the powder,

, .,
~ forms an homogeneous alloy with the zinc. As a consequence,
``` mercury will be available in each grain of powder in an equal


and predeterminated amount un~l complete exhaustio~ of the
n
metal.


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