this liquid gold
came from a pile of circuit boards
and these days there could be more gold
in a landfill
than in a mine but extracting it
is an expensive and polluting process
often carried out at toxic dumps
now a new zealand startup has found a
cleaner and safer way to do that
and its secret ingredient comes from
nature
microscopic organisms that evolved to
absorb
precious metals but can this complex
process reinvent how we deal with the
world's fastest growing waste stream
we visited the test plan to find out
mint innovation begins with the circuit
boards that are inside nearly every
electronic device
so this is how the electronics circuit
boards is how we receive them
cut up treated into pieces the company
says it sources all raw material from a
local recycler
exporting waste is an absolutely
abhorrent thing for human race to be
doing
the company's founders think that if
it's easier to get valuable metals from
e-waste
countries will choose to deal with it
locally a lot of the gold's wrapped up
in these
chips the first step is to grind the
circuit boards into a sand-like
consistency workers shovel this sand
into a reactor
which mixes it with inexpensive
chemicals those
acids and oxidants are pretty commonly
available industrial chemicals
next machines pump the mixture into a
filter press
to separate the liquids from the solids
this blue fluid contains a high
concentration of copper
tin and other less valuable metals
mint uses electricity to pull out the
copper we simply put that through
a series of plates pass it over that
that have electric current flowing
through them
and that plates out the copper from
solution
the metals that pay the bills are the
gold the palladium
the copper and the tin because they're
most abundant and most valuable
but at this step in mint's process
palladium and gold
are still stuck in the solids they're
harder to dissolve
and require another chemical bath for
the precious metals you need something a
little bit more oomph
so that's why we break into two stages
the next step in mint's process makes it
one of a kind
and it requires the help of nature
we're the first people to use
microorganisms to selectively
concentrate
precious metals we're kind of inventing
the whole technology
along the way
mint's team identified these tiny
helpers in 2017
through a series of research trips to
places like abandoned mines
or fields with rusty equipment given
enough pressure
and time microbes seem to find a way to
thrive in indian environment
they collected species of bacteria and
fungi that evolved to bond with specific
metals
microorganisms recover gold they also
recover a palladium
these are not pathogens by any stretch
of imagination
so would i drink a vial of them probably
not but i wouldn't drink a vial of a lot
of things so
over several hours the microbes will
gain weight as they absorb
precious metal ions and we've now got a
concentrated microbial paste that
contains
a good portion of precious metal when
the paste dries out
the gold particles in it start to appear
purple gold has this funny property that
when it is
in small nano particles as well i mean
gold in color have this hue of blues to
rinse
the mixture is ready for the last step
so this is where the final bit of magic
happens where we burn off
the microbial part just leaving the
metal part
behind that they've captured our product
is a
gold rich ash that goes to a refiner who
is the one who turns it into 99.99
gold it takes one week to extract
150 grams of gold from one ton
of circuit boards the founders carry
around this solid gold coin
to show what that looks like is it pure
gold
that's pure gold super heavy
it seems like a lot of work for a small
payoff
is it really worth the trouble mints
founders say yes
because it's getting harder to mine
precious metals from the earth
the big gold mines are recovering
literally grams
three four five grams of gold from a ton
of rock
81 of gold that's identified today is
already above the ground
and as gold mines are depleted the
amount of e-waste generated globally
has increased steadily over the past
decades
if those trends continue by 2050
we'll have to deal with 110 million
metric tons of e-waste
every year that's like every person in
the world throwing away a countertop
microwave
up to a fifth of all e-waste moves
across borders
likely ending up in developing countries
where workers process it by hand
at illegal dump sites activist jim
puckett
has spent over 25 years tracking how
e-waste ends up
in these toxic environments the entire
life cycle of electronics
unfortunately disproportionately burdens
the global south
with the real environmental harm and
pollution
thousands of people worldwide make a
living extracting copper from e-waste
primarily by burning it inhaling the
fumes
damages workers lungs and increases
their risk for cancer
and other illnesses we are struggling
for a year
because the heat is day where the smoke
they disturb us other studies have found
that large e-waste dumps
contaminate water soil and crops
even if e-waste is properly recycled the
final product still needs to go to a
smelter
the energy intensive endpoint for most
mining operations
mint's long-term goal is to make it easy
and profitable
for cities to process their e-waste
locally
we need to kind of get this you know
really really cranking throughout the
world and that's probably a 20-year
vision
the company is planning full-scale
facilities in australia
and the united kingdom this smaller
plant in auckland new zealand
was built to demonstrate how mint's
process works
it processes about one metric ton of
circuit boards per week
but larger plants like the one they're
building in australia
will process 10 metric tons per day
that would make the bigger plant able to
process about one percent of all the
e-waste australia produces
annually the planned larger facilities
will be almost
entirely automated it's pretty light
touch from a personnel perspective
might have three people on the shop
floor any one time running 24 7.
the small number of employees would have
limited contact with e-waste
keeping them safe from exposure to toxic
compounds
however even if mint can realize its
dream of a plant in every major city
the founders face another problem that's
completely out of their control
unfortunately electronic waste generally
is getting
less and less valuable over time as a
commodity
manufacturers are learning to build
gadgets with less precious metal
mint's team is researching other types
of waste they can run through this
process
like car parts as for solving the global
e-waste problem
jim puckett remains skeptical that any
form of recycling is the answer
i'm not saying don't go ahead with these
techniques we're certainly gonna have
old circuit boards around for a long
time
and we're gonna have to deal with them
so let's move on but
we've got to turn off the tap that tap
is controlled by the companies who
manufacture electronics
most of whom have no legal or financial
incentive
to design products that can be recycled
it's an overflowing bathtub you can't
run around with mops
and say oh my god we got to mop this up
we got to mop that up and we have a
better mop here and a better mop there
when the tap is pouring water into the
bathtub it's overflowing down the stairs
this is the problem we have is the tap
of our waste is not being turned back
you