Officials
are
collecting
baseline
data
and
carrying
out
technical
assessments
of
safer
gold
processing
technologies
in
Mashonaland
Central
Province.
This
week,
officials
from
the
Department
of
Metallurgy
under
the
Ministry
of
Mines
and
Mining
Development,
the
Environmental
Management
Agency,
and
the
Planet
Gold
Zimbabwe
project
visited
two
sites
in
the
province.
They
went
to
Kuzivakwashe
Mining
Syndicate
in
Mazowe
District
and
to
Chiweshe
Rosa
Mine.
The
visits
were
to
check
whether
mercury-free
gold
processing
centres
could
be
set
up
there.
Reginald
Chidawanika,
an
official
from
the
Department
of
Metallurgy,
said
the
assessments
are
part
of
a
plan
to
develop
and
roll
out
alternative
gold
processing
methods.
The
aim
is
to
protect
miners
and
the
environment
from
mercury
pollution.
He
said
three
methods
are
currently
being
assessed.
“The
primary
one
is
the
leaching
and
precipitation
method,
where
we
use
ordinary
bleach
and
hydrochloric
acid.
When
they
are
mixed
together,
they
release
chlorine
gas,
which
dissolves
the
gold,”
Chidawanika
said.
“When
the
gold
gets
into
solution,
we
can
separate
the
gold-bearing
solution
from
the
siliceous
gang
material
through
filtration.
“After
recovering
the
solution,
the
gold
can
then
be
reprecipitated
using
sodium
metabisulfite.”
Chidawanika
said
the
second
method
is
for
ores
that
contain
coarse-grained
gold
that
is
easy
to
separate.
“After
milling
the
ores
and
recovering
concentrates
using
conventional
gravity
concentration
equipment,
miners
can
further
grind
the
concentrates
before
cleaning
the
gold
using
Falcon
concentrators,
Nelson
concentrators
or
Gemini
tables,”
he
said.
“After
recovering
the
gold,
it
can
be
taken
straight
for
smelting.”
He
said
miners
whose
ore
does
not
have
much
free
gold
could
use
cyanidation
or
other
leaching
methods
instead.
These
methods
do
not
need
mercury.
Chidawanika
said
the
new
technologies
are
affordable
for
small-scale
miners.
They
use
reagents
that
are
easy
to
find
and
simple
processing
equipment.
He
added
that
some
ore
samples
have
already
been
sent
to
South
Africa.
Accredited
labs
there
will
carry
out
metallurgical
tests
and
give
expert
advice.
“I
would
like
to
think
that
by
year-end
we
would
have
established
some
of
these
methods
at
some
of
our
small-scale
mines
because
we
are
now
at
the
stage
of
developing
mercury-free
technologies,”
said
Chidawanika.
The
initiative
will
reduce
mercury
use
in
small-scale
gold
mining
by
4.85
tonnes
over
five
years,
said
Planet
Gold
Zimbabwe
project
manager
Nyaradzo
Mutonhori.