Fellow Orchidites: Having recently closed my business, which was
a gallery and a manufacturing workshop I have had the
responsibility to dispose of our 24-year accumulation of platinf
solutions and acids. Nitric, Hydrochloric and Sulphuric acids to
be specific. All of the plating solutions contain Cyanide. The
first thing I id was to call the local recycling center, which
has a small business collection program. That’s when the alarm
went off. I was informed that this huge center, which takes in
tons of paints, hazardous wastes and toxic chemicals only can
accomodate an intake of ONE PINT of acid or cyanide A MONTH! I
have an accumulation of approximatly 5 gallons. The only
alternative is to have a hazardous waste disposal company remove
the waste. Estimates range from U$1500 to U$2000. The shocking
realization I’ve had is that as easily as I aquired these
chemicals I never obtained any education as to their disposal.
And I’ve been in this trade for over 30 years. Worked at a dozen
different shops, large and small, in several countries. NO ONE
ever went to any trouble to dispose of the wastes. Most flushed
them down the drains or put them, as I did, in sealed containers
in the back rooms. Guess where all those chemicals are going to
go when they find out the expense & trouble required? I am going
to work out a monthly schedule to slowly dispose of this
accumulation, pint by pint, through the hazardous waste program.
I hope. What troubles me is that here in the Bay Area, a downtown
jewelry center building, has recently gone ‘condo’ and has given
notice to over 35 jewelers to move out. The recycling center will
My question to you all, especially those with chemical
backgrounds, what methods are used to dispose of or negate acids
and cyanides? Are there recycling programs in your areas to deal
with these dangers? What solutions do you use?
Please…any and all suggestions would be greatly appreciated.
Last year our city had a hazardous waste disposal set up for one
day in a huge parking lot.(Free of charge) It had been several
years(10) since the last collection. The line was horrendous!
People sat in their cars for hours to drop off the toxic goo. I’m
sure plenty looked at the line and came up with environmentally
unfriendly ways to eliminate their stuff. The alternative is to
drive extremely long distances to a site that is set up on a more
regular basis. Which most people don’t feel comfortable doing.
Call the recycling center in your area to see if they will be
planning a scheduled hazardous waste collection. Since there will
be so many people in one building facing the same problem maybe
they could set up a collection onsite.
G’day. My suggestions for reasonably safe disposal of such
For any acids, add baking soda until no further bubbles arise
after a few hours. This will convert the acids to fairly safe
neutral salts like sodium sulphate, chloride and nitrate. These
should all be neutralised separately, as the neutral nitrates
can still be hazardous. (a nitrate mixed with organic materials
is potentially explosive as in gunpowder) The neutral sulphate
and chloride can be absorbed in sawdust or shavings, allowed to
dry out and disposed of normally as a solid. It’s pretty
harmless. The nitrate should be absorbed into inorganic
materials, like pumice or even dry earth then scattered after
drying off, for you will have a good fertiliser there if
For cyanides you should add a solution of FERROUS SULPHATE
until no further solid precipitate is formed. Filter off the
precipitate through very fine cloth and allow to dry. Dispose of
as a solid waste, cloth and all; it is now virtually harmless.
Dispose of the liquid in sawdust and allow to dry off before
UNDER NO CIRCUMSTANCES MIX ACIDS WITH CYANIDES; extremely
poisonous hydrocyanic acid gas and cyanogen gas is given off.
This is what some barbaric administrations use to dispose of
their nastier criminals. Cheers,
/ / Johnb@ts.co.nz
(_______) In sunny temperate Mapua NZ -
Keep your chemicals seperate!!! Dose the acids with a
neurtalizer, such as baking soda(careful not to overflow the
container) as much as possible, get a big bag of kitty litter and
gradually pour the cyanide-based solutions into the litter and it
will absorb them. Let the mess stand open and dry out(stur
often.) Then, when it’s all dried up, send it to your refiner, in
several shipments with some scrap and sweeps. They will know how
to process this and even though you’ll pay for it, the cost will
be a lot less. BTW…mum’s the word here! As for the cyanide, I’m
afraid your stuck there. You can’t ship it and you can’t dump
it. I stopped using any cyanide years ago more for health
reasons and never used acids. Anyone else have some ideas?
I’ve read that certain trees and plants are grown in polluted
areas to absorb toxins in the soil. Different species absorb
specific chemicals. They are later harvested for the materials
absorbed. The article mentioned Chernobyl as one place this is
being used. There was another article that discussed how heavily
planted manmade ponds were used to filter sewage at one sewage
treatment plant. The plants are so beautiful that people visit
the area to have their lunch breaks.( How many sewage places can
boast that) Oceans also have been cleaned of pollutants by algae
growth in certain areas. I have these articles in my files but
don’t have time to dig them up. Smithsonian Magazine was the
source of info on the ocean and sewage articles.
Yes, the “toxic waste disposal days” can be horrendous, and they
don’t always like to take things like acids (they’re supposed to
be for “household” stuff, I guess).
I think John’s suggestion of neutralizing, then converting to
solid wastes is a good one. I would suggest using vermiculite if
you do this, rather than sawdust. Vermiculite is a completely
inert material and absorbs up to 50 times its weight in liquid,
more than sawdust will absorb. You can buy bags of it at nursery
supply places (For 5 gallons you will want about an equivalent
volume of vermiculite). It’s cheap.
Another thought - in the Bay Area I’m sure there are several
commercial plating companies. They will have an established
program for disposal of hundreds of gallons of (presumably) the
same kinds of solutions you’re using. It might be worth a shot to
call one or more of them and ask for their help, explaining your
situation as a small business without a huge volume of either
acids or cash. You might offer to pay them some small amount to
be able to “piggy back” your 5 gallons onto their wastes.
Sometimes I’ve found that larger businesses are willing to be
very helpful to smaller artists. You may be able to end-run the
hazardous waste disposal bureaucracy this way. Good luck! I’d be
interested in knowing what happens. I may need to know the
answer to this question too, at some point.
Hi Kim, I would have to agree with Rene as to how to dispose of
the material. A local manufacturer might have the answer for you
or perhaps the refiner you use.
I’ve seen some folks questioning what to do with certain
materials for disposal and this is what we’ve had to set up for
ourselves. First off, OSHA in the US requires chemical
manufacturers to supply material safety data sheets (MSDS) to all
their customers. These datailed sheets tell
everything from storage, disposal, spillage, how to neutralize a
certain chemical, health factors including over exposure,
chemical makeup, and factors as to its flamability. And I
probably left out a few things.
The laws regulating disposal vary from area to area and it is
always required to check with your local city and state
regulations. In NC the local haz mat unit at the fire dept has a
copy of all our MSDS including compressed gas tanks and any other
fire risk they may face. All in all, regualtions aside you’d be
doing yourselves a favor just requesting a copy of the MSDS from
your supplier. Someday it may save a life.
Hopefully somewhat factual,
At the last place I worked I inherited about four gallons of a
cyanide solution used for bombing. I asked the refiner we used
what I should do with it as I couldn’t ship it as is. He told
me to neutralize it with household bleach, boil it to a sludge,
and ship it dried out along with my next batch of sweeps. I
never did do it because I just didn’t feel comfortable with it,
and it seemed like it was going to be too time consuming. The
stuff still sits there after ten years or so. It seems that
I’ve read something a couple times about using bleach to
neutralize cyanide. Maybe try calling a refinery and asking
them. Rick Barnes
Please consider the use of other methods of bring to a shiney
finish instead of some process that might pollute the water we
drink. The magnetic tumbler is the most wounderful finisher is
have found. The rough casting I have found might from time to
time need to be heated to color and then plunged to remove the
copper on the surface. Sometimes I have had to do this with old
gold. Keep a good amount of Coke on hand to fill mixed 1 to 3
with water and then several times you can run with just a good
dash of viniger. This regime will keep your shot bright and the
rough castings very bright consistantly with no harmful
chemicals to dispose.
I remember the time I called the Health Department and asked
how to dispose of cyanide solution and he said “just go out into
the country and spill it on the roadside…but that is between you
and me.” I’m afraid that this is the more common advise given
under the table. I don’t want to drink what you have poured in to
the water system. Please concider other methods for the same
results. Thanks Ron
i’ve heard from people in the hazardous waste disposal business
that what you say is true: household bleach neutralises cyanide.
however one would want to precipitate any heavy metals
(especially the gold) first before neutralisation. if one
neutralises the gold bearing solution first, it will lock the
dissolved gold into the cyanide solution. or so i’ve heard…
one can recover gold from bombing solutions by putting zinc foil
into the solution. there are other chemical treatments that i
don’t recall but can be learned from an audio tape that rio
If would be best to destroy the cyanide first. An excess of
strong bleach should do the job if there is only a small amount
of cyanide. Cyanide keeps the gold in solution.