Proper way to dispose of Potassium Cyanide

Discussion in 'Alternative Processes' started by Jim Chinn, Sep 12, 2009.

  1. Jim Chinn

    Jim Chinn Member

    Messages:
    2,512
    Joined:
    Sep 22, 2002
    Location:
    Omaha, Nebra
    Shooter:
    Multi Format
    I am going to begin shooting wet plate in the next few weeks and while I am going to initially fix with regular hypo or rapid fix, I plan to work with KCN after I get my work flow down.

    I have searched here and looked over Quinn's forum but can't seem to find anything about disposal of spent KCN. What do wet platers here do?
     
  2. Martin Reed

    Martin Reed Advertiser Advertiser

    Messages:
    325
    Joined:
    Sep 6, 2004
    Location:
    North London
    Shooter:
    Multi Format
  3. Jim Chinn

    Jim Chinn Member

    Messages:
    2,512
    Joined:
    Sep 22, 2002
    Location:
    Omaha, Nebra
    Shooter:
    Multi Format


    Thanks Martin.
     
  4. Kirk Keyes

    Kirk Keyes Member

    Messages:
    3,267
    Joined:
    Jun 17, 2004
    Location:
    Portland, OR
    Shooter:
    4x5 Format
    While Martin's suggestion should work, also be aware that cyanate ion is formed by that reaction and it is rather toxic as well.

    It may be prudent to take your spent cyanide solutions to a waste disposal facility. If you are using the cyanide solutions professionally, you most certainly will be in violation of federal, state, and local law by treating your own hazardous waste with out a permit to do so. Especially if you dump the "treated" waste down your local sewer without proof that you have properly treated the waste.
     
    Last edited by a moderator: Sep 14, 2009
  5. AshenLight

    AshenLight Member

    Messages:
    156
    Joined:
    Dec 15, 2007
    Location:
    Northeastern
    Shooter:
    Multi Format
    I'd just make extremely sure that nothing acidic goes down the drain before or after KCN without a massive water flush. On second thought, Kirk has the best idea... a waste management company who can deal with potentially very lethal chemicals.

    Ash
     
  6. alanrockwood

    alanrockwood Member

    Messages:
    809
    Joined:
    Oct 11, 2006
    Shooter:
    Multi Format
    A little off topic, but don't work with cyanide if there is no one else around to monitor you. You want to have someone around who can drag you out by the feet while you are lying unconscious on the floor, and then your partner can call the paramedics, hopefully in time to save your life.

    No matter how careful you are, mistakes can happen.

    Better yet, why not forget working with cyanide altogether?
     
  7. Jim Chinn

    Jim Chinn Member

    Messages:
    2,512
    Joined:
    Sep 22, 2002
    Location:
    Omaha, Nebra
    Shooter:
    Multi Format
    According to most of the wet plate folks I have talked to, KCN provides a better final result than fixing a plate in plain hypo or rapid fix. Some folks say the only difference is in the color of the fixed plate but most claim better sepration of mid tones and brighter highlights. I won't know untill I compare fix to KCN.

    AS far as using Potassium Cyanide, I am well aware of the hazards and protocols in its use.

    One option I have is a local metal plating company may be willing to simply take the spent amount off my hands and add it to their used KCN which is professionally disposed of. They go through it by the hundreds of pounds over the course of a year. Otherwise I talked to a university chemist and he agrees with neutralizing with potassium permanganate and then taking it to our local hazmat disposal location.
     
  8. Kirk Keyes

    Kirk Keyes Member

    Messages:
    3,267
    Joined:
    Jun 17, 2004
    Location:
    Portland, OR
    Shooter:
    4x5 Format
    I'd recommend skipping the home-treatment of hazardous waste and just take it to someone for proper disposal.
     
  9. Kirk Keyes

    Kirk Keyes Member

    Messages:
    3,267
    Joined:
    Jun 17, 2004
    Location:
    Portland, OR
    Shooter:
    4x5 Format
    Also note that industrially, cyanide waste is converted to cyanate by using clorine for large installations and bleach (hypochlorite) for smaller amounts. The pH of the cyanide solution is raised to pH 11 with hydroxide and then bleach (or chlorine gas) is added until there is an excess of chlorine present. To test for this excess, either an Oxidation/Reduction Potential (ORP) electrode is used with a pH/volt meter, or more simply, starch-iodide test paper can be used. The starch-iodide paper turns a deep blue-purple-black color in the presence of excess chorine.

    The issue I have with treating it yourself at home is the legality of doing it yourself, your ability to determine when all the cyanide has been neutralized and converted into cyanate, and the additional complexity of how metal-cyanide complexes do not react readily with this type of treatment.

    Free and simple cyanides are treatable this way, but metal complexes, such as iron complexes and especially noble metal complexes like gold, platinum, and palladium cyanide complexes. As you are forming silver cyanide, which is insoluble, I think you'll have some of that left over after your treatment. And with that there, there will still be cyanide in your "treated" waste after you do all the other stuff, which will put you back into problems with the legality of disposing of the solution down your drain.
     
  10. Ian Grant

    Ian Grant Subscriber

    Messages:
    18,040
    Joined:
    Aug 2, 2004
    Location:
    West Midland
    Shooter:
    Multi Format
    Remember that carrying Cyanide solutions in an unlicensed vehicle/by unlicensed carrier (as in transporting hazardous waste) is illegal in some areas. I was involved with maintenance of a license & imposing safety policy for carriage, storage & disposal of Cyanide solutions in the UK and UK regulations ran parallel to many US States.

    But it really depends on the quantities involved, small volumes are often better neutralised as the waste is generated which minimises the ongoing safety issues of waste.storage then transporting it for disposal. It really should be picked up by a fully licensed carrier.

    Find out what other Wet Plate users do.

    Ian
     
  11. mick53

    mick53 Member

    Messages:
    1
    Joined:
    Aug 26, 2015
    Shooter:
    Plastic Cameras
    Hi,
    thanks a lot for all your contributions and apologies if I'm being stupid.
    When dipping the starch paper in the waste solution (with bleach), it didn't turn blue; as well as when dipped in bleach only (4.5% w/w, pH 11.2). It did however turn blue when in contact with diluted bleach.
    The protocol I'm working off doesn't require NaOH before the addition of bleach.
    Could the bleach I'm using be too thick?
    thanks in advance for your help!


     
  12. jnanian

    jnanian Advertiser Advertiser

    Messages:
    19,996
    Joined:
    Jun 21, 2003
    Location:
    local
    Shooter:
    Multi Format
    hi mick53

    sorry to ask this, and apologies if *I'm* being too in your face ( i don't mean to be )
    i don't do wet plate but i know the dangers of KCn .. why don't people who do wet plate work
    just have someone remove their waste, instead of pretreating potentially
    causing dangerous situations. i know of people who died of cyanide posioning,
    know others who pour KCn down their drain, and others who dump it in their backyard.

    a waste hauler doesn't cost much and they will tell you exactly how to pretreat it for them
    if they indeed want you to ...
     
  13. dragosandriana

    dragosandriana Member

    Messages:
    1
    Joined:
    May 2, 2015
    Location:
    Romania
    Shooter:
    Multi Format
    From Christopher James's book "Alternative Photographic Processes", third edition, pag. 455-457:

    "SAFE DISPOSAL OF POTASSIUM CYANIDE


    Neutralizing Potassium Cyanide to a Non-Hazardous Potassium Cyanate

    READ THIS FIRST: Never execute the neutralization of potassium cyanide without adequate safety protection. This means you should wear industrial grade nitrile gloves instead of medical grade, as they are thicker. Potassium cyanide is readily absorbed through breaks in the skin in the form of cuts and scratches. After use, rinse the gloves with hydrogen peroxide and discard. Always work in well ventilated spaces. Wear an apron, dual respirators, and eyewear.
    Before you begin, read these directions twice. Have a back-up person present in the event that something goes wrong. I know this sounds scary, but if you pay attention to detail, and exercise proper safety techniques, this is an uncomplicated process.

    Potassium cyanide (KCN) has an MSDS Health Level Hazard of 3 and a dangerously high pH of 11, depending upon concentration. It is a heavily regulated chemical. It can be detoxified most efficiently with hydrogen peroxide and will be converted to potassium cyanate (KOCN), with an MSDS Health Level Hazard of 1 and a water-like pH of 8 that is unregulated and safe.

    KCN + H202 — KOCN + H20

    You need a 3% hydrogen peroxide (H2O2) (the type found in the drugstore and supermarket and that is the same strength as that used for cuts and minor wounds).

    50 ml of 3% hydrogen peroxide will neutralize 1 g of dry potassium cyanide.

    To Neutralize Dry Potassium Cyanide: Put on eye protection, a respirator, and industrial nitrile gloves. Know exactly how many grams of dry potassium cyanide you are going to neutralize. Place the dry potassium cyanide in a non-breakable beaker. Dissolve the potassium cyanide in cool water first in a proportion of 1 g to 100 ml water. After it is dissolved in the water, oxidize with 3% hydrogen peroxide (drugstore grade is 3%), using at least 50 ml of hydrogen peroxide to every gram of potassium cyanide that you dissolved.
    Place the open beaker in a well-ventilated and VERY SAFE place and let it stand overnight. DO NOT cap the container, as the peroxide may create a gas and that will result in pressure within the closed container. The following morning, dilute this now safe potassium cyanate solution with water at a proportion of 3-4 times the liquid volume you are neutralizing. Rinse everything with hydrogen peroxide.
    An interesting side note: when you neutralize the potassium cyanide, it will turn a milky white. If you leave the neutralized KCN outside in the light, it will turn chocolate brown because of the silver in the fixer.

    To neutralize a 1.2% potassium cyanide fixer solution (a standard dilution for wet plate collodion), put on eye protection, a respirator, and industrial nitrile gloves and place the old potassium cyanide fixer in an indestructible plastic bucket (a drywall compound bucket will work well). Be sure the total volume of the bucket will accommodate twice the volume of the fixer you are neutralizing. If you have an industrial chemical hood you are in luck. Use it. If not, I recommend going outside for this next step.

    Slowly add 600 ml of 3% hydrogen peroxide to each liter (1000 ml) of used 1.2% potassium cyanide fixer. You have now converted a heavily regulated chemical to a non-hazardous, unregulated, potassium cyanate. You will notice that there is a visible reaction between the potassium cyanide and the hydrogen peroxide. This will subside in a relatively short time. Allow the solution to stand overnight in a very safe place out of reach of anyone who may be curious about it. DO NOT cap the container, as the peroxide may create a gas and that will result in pressure within a closed container. The next morning, saturate this now safe potassium cyanate solution with water at a rate of three to four times the liquid volume you are neutralizing.

    Once again: for every 100 ml of 1.2% potassium cyanide (12 g to a liter of distilled water [1000ml] is the standard wet plate fixer concentration) you will use 60 ml of 3% hydrogen peroxide. This is the minimum dilution, but it is acceptable to use more hydrogen peroxide if you wish. It is always better to err. on the side of excess hydrogen peroxide when performing this task.

    Side Note: Even though the cyanide has been oxidized to potassium cyanate, the wet plate fixer still contains silver that may require special disposal depending on state and local regulations. It would have to be treated the same as spent sodium thiosulphate fixer.

    Potassium Cyanide & Sodium Thiosulphate Fixer Warning: There is a published formula that mixes sodium thiosulphate with a small amount of potassium cyanide. This fixer works well but cannot be neutralized in the same manner as described in this section. A mixed thiosulphate/potassium cyanide fixer is a different bag of worms when it comes to disposal! Hydrogen peroxide will not only oxidize the potassium cyanide, it also will react with the thiosulphate to oxidize it to sulphate. Therefore, the 600 ml of 3% hydrogen peroxide per liter of fixer does not apply and this ceases to be a simple disposal problem. Instead it becomes a complex analytical problem of (a) How much cyanide is present? (b) How much thiosulphate is present? (c) How do I detect the end point of the oxidation reaction so the cyanide and thiosulphate are consumed? Bottom line . . . don’t be complacent about using these instructions for neutralizing a hybrid fixer.


    Neutralizing Waste Water After Using Potassium Cyanide Fixer
    You will have wash water from fixed plates (the first two rinses) whether you are working on the road or in the lab. The potassium cyanide concentration will be very low in these rinse baths. Collect your waste water and then add about 300-400 ml of 3% hydrogen peroxide per liter of water and let stand overnight before discarding. After the first two or three rinses, the cyanide concentration should be so low that further treatment is not needed.
    Make sure you clean everything that is touched by the potassium cyanide with hydrogen peroxide.


    Silver Recovery from Neutralized Potassium Cyanide
    Once you have successfully neutralized the potassium cyanide by converting it into an unregulated potassium cyanate, it is a simple matter to run it through a silver recovery system as you would any other fixer used in photography. Please adhere to any, and all, federal and state regulations regarding silver removal."
     
    Last edited by a moderator: Feb 2, 2016
  14. jnanian

    jnanian Advertiser Advertiser

    Messages:
    19,996
    Joined:
    Jun 21, 2003
    Location:
    local
    Shooter:
    Multi Format
    i have talked to the manufacturer of silver recovery devices i distrubute
    ( ion transfer as well as electrolysis )
    they do not recommend using their devices for this procedure.
     
  15. Ian Grant

    Ian Grant Subscriber

    Messages:
    18,040
    Joined:
    Aug 2, 2004
    Location:
    West Midland
    Shooter:
    Multi Format
    Silver Recovery from Cyanide solutions.

    Before neutralising the Cynaide solution slowly add powdered Zinc to the solution, the Silver will precipitate out, let it settle and decant the solution off the precipitate. Then you neutralise and dispose of the Cyanide, Sodium Hypochlorite (household bleach) is a cheaper alternative to Peroxide.

    The precipitant is then also neutralised and then washed. Let it dry out and store for recovery when you have sufficient.

    Ian
     
  16. wolfe23c

    wolfe23c Member

    Messages:
    4
    Joined:
    Feb 25, 2016
    Location:
    Toronto
    Shooter:
    35mm
    I would also agree with Martin Reed, oxidation by potassium permanganate seems to be the best way and the advantage of doing so is that the residue is suitable for treating as a sewage effluent. Also, the sewage can be moved to a garbage bin if rented. I think this is the best way to dispose of potassium cyanide.
     
  17. jnanian

    jnanian Advertiser Advertiser

    Messages:
    19,996
    Joined:
    Jun 21, 2003
    Location:
    local
    Shooter:
    Multi Format
    I wonder how many people who do WP actually dispose of their materials like this or the
    way Ian details...
    I know of a guy who live on wet property and he just pours it on the ground and doesn't
    even care. the well known person who taught him just pours it out too
    ( from what this guy and others have told me )
    the teacher suggests the cyanide is from the earth, and says it is OK to just put it back in the ground ...
    ... it also makes me wonder if the uric acid and other things in the public sewer system ( or septic system )
    are enough to release / free the toxic fumes if someone pours it down the drain thinking
    the the system can handle it .... I'm glad that one can use speed fixer instead of KCn
    so if someone doesn't want to deal with these hazards they can still do WP ...
     
  18. Ian Grant

    Ian Grant Subscriber

    Messages:
    18,040
    Joined:
    Aug 2, 2004
    Location:
    West Midland
    Shooter:
    Multi Format
    In any country the illegal dumping of cyanide waste is highly illegal, it's highly toxic, pouring it on the ground(earth) is still extremely dangerous to others and wildlife.

    It's so easy to neutralise safely with Sodium Hypchlorite which s readily available, the Permanganate route is less ideal.

    Ian
     
  19. alanrockwood

    alanrockwood Member

    Messages:
    809
    Joined:
    Oct 11, 2006
    Shooter:
    Multi Format
    Wow, has it really been five and a half years since I posted this? I see this thread periodically flairs back to life.

    When I talked about having someone drag you out while you are lying unconscious on the floor I wasn't kidding. It was based on an actual case. The difference between the actual case and the hypothetical case I mentioned above was that in the real-life case the victim wasn't working with a buddy, but was working alone, at night, in a chemistry research lab. The only thing that saved his life is that someone happened to walk by and noticed him lying unconscious, on the floor of the lab.
     
  20. pdeeh

    pdeeh Member

    Messages:
    3,432
    Joined:
    Jun 8, 2012
    Location:
    UK
    Shooter:
    Multi Format
    In this case, it's been reignited by spam advertising for waste disposal (I reported it but it hasn't been removed (yet))