KCN setup questions

[GOLDbuyerCA]

with half the targets stripped, 25 remaining, with part gold plating, this is a photo of process, Note the more rustic target, to photo right, which was Acid " Aqua Regia " partial removal. the Techni Strip Au solution when cooled
does not replate the stainless steel targets. the effects of temperature, seem more to speed of action, when the solution is hot, it deplates faster. but holds with gold no matter what the temperature, 50 to 190 F. the solution pictured is now holding ten "10" grams plus, gold with about .7 Liters of TechniStrip Au , Potassium Cyanide, Lead Oxide, safety reference :> http://www.nfc.umn.edu/assets/pdf/msds/technistrip_au.pdf My note to users, i use a bit of oil of peppermint, in my cyanide solutions. use it in your solution, put it in , when you just start your deplate, stripping process. just a few drops, as this aroma will indicate to yourself, and others around solution, if it is escaping in some fashion, and do track it down, where your action in handling , may of caused a spill, or your drag out is incomplete, partial solution remaining. you can smell, where you may of splashed a few drops also, on vinyl, or other moisture holding surface. porous surfaces avoid. , in all stripping processes, careful is the watch word. Know your material, have it clean for stripping, do it on a small scale to get proficient. and have sealable recovery jars / jugs, of a good shatter resistant glass,. or durable transparent plastic.

 

[goldsilverpro]

You might read these threads.
http://goldrefiningforum.com/phpBB3/search.php?keywords=technistrip+au&terms=all&author=goldsilverpro&sv=0&sc=1&sf=all&sk=t&sd=d&sr=posts&st=0&ch=300&t=0&submit=Search

Technistrip AU strips easy and fast and doesn't attack base metal, including copper. However, getting all the gold out of the solution is extremely difficult. Zinc won't get it all out. Technic sells an additive (some type of sugar) that helps to plate out the gold but it doesn't work very well. About the only way I know of that works is a long process using sodium hydrosulfite (sodium dithionite). It can be dangerous. This method was posted in detail on the sciencemadness.org forum. I'll try to find it.

 

[GOLDbuyerCA]

Thank You GSP i concur, i am going to show two methods, or recovery, from final solution, i will illustrate by halving solution, and processing with active carbon filter, a Brita filter with active carbon, and a distillation method. and the firing results of a metal gold, / gold chloride / salt , reduced to metal, and final weights, and efficiency percent . of one run, two runs, and perhaps as many as five runs. i will attempt to be accurate to 2 percent, or better, with a plus and minus of .5 to 1 percent. I did read most of your forum notes "GSP" notes, as you have given very professional and accurate thoughts to correct and safe process " i thank you " As to source material, i like "Geo"s, material to guess at. it is clean, uniform, has good surface area, and makes for a high quality recovery by stripping process. i say this not of envy , but of support, it is hard work, to be consistent, have a good recovery process and have a good return to initial investment.

 

[goldsilverpro]

Here again, I'm talking about Technistrip AU. I would certainly want some method of determining whether or not any gold remains in the solution after you drop it. You might think it's all out when it isn't. The methods I have used to determine gold in cyanide solution are fire assay, wet ashing, and AA. I know of no simple method. I have heard horror stories about people thinking they got all the gold out and then discarding loaded solutions.

 

[GOLDbuyerCA]

Again " i concur At Headly BC a high grade big gold mining operation, the tailings are washed with a Cyanide solution. the liquid recovered, was a light recovery of gold, further studies showed that the propriety solutions used for stripping gold from crushed oar, was not giving up values that were expected. , a review showed that another 8 percent was cast away. " the dewatering ground was resampled, and values found " 8 percent is a lot in a big operation. but, it is less than the losses that Headly Mines, had in its earlier years of operations. Nice to hear your valued thoughts on Cyanide stripping. i have tried to explain to readers, that my target of efficiency , from start to finish, a gold button in hand, is 85 percent or a few percent better. quite a few board members are talking transactional values, of 97 plus percent, myself i am not able to reach this accuracy, " ever it seems " but i do appreciate incremental improvements that i can make in my process of recovery, to have the best return. i have an electrical engineering background,j have worked on galvanic reactions in water systems and in my hobby time experimented with plating, reverse plating, and types of materials that are good to process by electro refining. i have more time now, that my radio days, are behind me. "yet i am still in design work " but the opportunity to make a good recovery, from richer material , is still a goal i would like to have happen, " some call it a major BINGO " i have had my moments. in your three references for a better recovery, " which i concur " AA atomic absorption spectroscopy , i have only used Reference Tubes of Qualative values, rather than Quantative. i appreciative your expertise of Chemical process and recovery process, as much as we would like to quick talk recovery one can not escape the physics of chemical processing. which with your Hydrometallurgy background makes you a leader of contribution on the subject. As much as Shor 'ishor" refining is not in vogue on this forum, their gold drop test buttons, may be a consideration to make a final end point verification, Lifted from their literature """ Testing For The Presence of Dissolved Gold:
To insure that when you pour off your waste water, you're not pouring off dissolved gold, you must test for dissolved gold. This test will detect the presence of as little as 4 parts of dissolved precious metal in 1,000,000 parts of water (less than 1/1,000 gram per batch). It will not detect the presence of particles of gold. """ i make my own detector solution, which is about Ten parts per million accurate. Readers your drag out rinse is important to keep as is your total solution of deplate, and the uncertainty factor of total recovery, " if your NOT sure " keep your solution in a 5 gallon or larger Drum, store in a safe secure location, and run a small evaporator on it. A Chemist such as GSP is more accurate than myself as a practitioner . i appreciate GSP thoughts on getting ALL the Gold OUT. now to see what little i have in my weight of target differential , and amount of expected gold i have in saturated stripper solution

 

[nickvc]

I'm going to say this really isn't a process I'm going to endorse. It's full of hazards and shouldnt be attempted by anyone not sure of exactly what they are doing? The solution will still contain values along with highly hazardous chemicals even after attempting to recover them.
This isn't a process for the amateur this takes experience and full understanding of exactly what's occurring!
Cyanide is wonderfull at gold recovery but it carries many risks....one been death!

 

[GOLDbuyerCA]

Now the care in initial cleaning and weighting comes into play. in this case, number of targets, and weight give a total weight per unit " approximate, there is variation " and a value of recovery per unit, in mg. unit gold value actual over estimate, by subtractive weighing fifty units were started, of the 3 hole cathode targets plated in flash gold, with hard gold overplate. i have started this review with what i thought would be the lowest plate per weight. and i initially estimated 25 mg per target with 50 mg, being the best optimum guess. i would like to point out these are cheap kitchen scales. and not for trade. and they only work per gram, and imo are very non linear, fluctuate a gram or two. but for illustrative purposes, " out side of lab conditions " i continue.

 

[GOLDbuyerCA]

the realized weight after the gold has been stripped is recorded for viewing here. with errors taken into account by scales, i am going to say there is expected 5 grams of gold in solution

 

[GOLDbuyerCA]

nickvc i have not finished my illustrative process, please stay with objectivity of my illustrated process. make your loss values known, what percent do you think is going to be lost ? give your thoughts on neutralizing cyanide in solution, and let us realize that seasoned practitioners here will use the Acid process as well as the Cyanide process, and be well aware of the hazards of both . let us agree safety is a mutual concern. but let us not be alarmist on this form, " as example a cyanide recovery problem just posted " . thank you for your thought, i do not need your endorsement, as this is a thread up to the individual that is experienced and handles process skillfully to a productive end. now i continue .
i would like to say, please read every one of the pane's i have posted here, on my thoughts, on stripping gold from clean targets. this is illustrative of a process that will work. of Potassium or Sodium Cyanide. i have stressed caution all the way through, and to have a procedure and equipment that you put together, as a reader and follower of the Gold Refining Forum. i would like to also say Cyanide, is used daily by thousands of Jewelers, for polishing and re working gold Jewelry all the time. . Yet for one forum members interjection of the hazards of Cyanide, i post this from Recovery and Refining of Precious Metals, by C.W.Ammen page 134. and he says :>

 

[GOLDbuyerCA]

Now we get to the interesting part. we have stripped the Gold, we have it in solution, we got Cyanide in solution, what are some solutions to get the Gold out. this photo shows, Brita manual filter, that uses activated carbon.
it is in granular form and is in the assembly in the bottom spout on the inside of the filter. it is removable, and its functions as a trap for PMG's that are in solution, also fish filters will work , as they use active carbon also, and i have found them to be several times less costly than Brita activated charcoal. i am leaning to Hydor inline filter pump, http://www.hydor.com/backend/prodotti/img_upload/img_zoom/130617110930_prime_famn_xxx4.jpg i have the Hydor 250 unit that takes 3 filters.

 

[nickvc]

GOLDbuyerCA
I can see that you have a very good understanding of this process and are confident and comfortable handling cyanide, I fear many that arrive here on the forum full of ideas of wealth and easy money will not have that and it's towards them I am thinking.
I'm only stressing my point to try to get others to think carefully before even attempting to work with cyanide because as I have said before it gives no second chances.

 

[GOLDbuyerCA]

to continue with a generalization of using a commercial Cyanide stripper in the removal of gold off targets. in this case gold plated over stainless steel, please observe, that the batch work, is small in nature, the targets are clean, being cleaned of dirt, film and in general organics. the size of the glass cell is about one quart, / one liter, and a room temperature, or non boiling temperature is used, by a small regulated hot plate. the object of slow stripping is not to make a lot of bubbles, released gas, but to get a removal of gold into solution, the value of Potassium Cyanide by package detail says 17 percent, and the ratio of solution , is about 2 parts stripper 8 parts distilled water. the process being to add stripper as necessary to just get the gold off. ' into solution " i would like to confirm nickvc has a valid point on safety of drag out water, " i can show what he is inferring to " Chlorides are in the drag out, tapping on a clear glass plate, in what one would think is little or none moisture from the targets is not so. there is a residue , when dried on the glass plate shows up as micro grams of unspent Potassium Cyanide and Gold / chlorides, and other metals, " a cold water rinse bottle is what i use " in a spray rinse of twenty to one at least, then i use a baking soda cloth, to whip down the targets, all the while using latex gloves. Let us all give caution to one another when handling hazardous chemicals. by counting targets, weighing them to 1/10 of a gram in quantity, will give a result of mg of gold, per target, a good thing to know when you are scouting material. in process now, are these gold plated covers

 

[GOLDbuyerCA]

as a third batch is now in process of being stripped, and a average value of target is being firmed up. one can think of how the nature of gold recovery can be made into value, . do a complete strip of all targets, or realize some value that the quality of targets may be useful, in future recovery projects. ie. some of the targets are gold plated targets, over titanium and ss 316 . the plating thickness in this case is the same, the throw power was metered out carefully, by :>
http://www.sterlingplating.com/ a look at the targets in question are shown here. it may be that making targets like this, may cost 5 dollars at least, or more, as some targets have a larger surface area.

 

[goldsilverpro]

Your target of efficiency should be about 99+%. From the parts you are processing, I would find that simple to acheive. I think you're over-analyzing this.

 

[GOLDbuyerCA]

Yes, i do have good material to process. as from this last photo, my magnet is evident in checking the targets, the titanium are lighter 27.3 grams per ten units, and the stainless steel 316 are 47.5 grams per ten units. the gold " imo" is 99.8 or better than 99.9 a very high purity was used as plate for the gas fuel cell. i would like to be able to show, the grams i put into solution and the grams recovered to metal. which as you say, with this overemphasized analysis should be high. i have done this many times. but never described it in details enough, for an average reader, and practitioner to comprehend and reproduce. the titanium is bendable, the ss hardly, the other cathode in dull gray is Platinum,, , This thread of Techni strip Au is Google searchable, from back in 2010 when you put your thoughts down GSP , in a way, i am trying to carry on with for forum members and the general Google public that are results orientated.

 

[goldsilverpro]

You've put a lot of work in this and I sense your enthusiasm. I do, however, find it hard to follow you but I do believe you have something worthwhile to say. Could you do a step-by-step, how to do it, 1,2,3..., of your best shot, as of right now, on exactly how to cyanide strip gold from a particular matrix (your choice) and recover 99%? Then, let's go from there.

 

[goldsilverpro]

All of the material you've shown is perfect, and I mean perfect, due to the size, shape, and configuration for electrolytic cyanide stripping on a rack. Just make a typical ladder-shaped plating rack out of 1/4" square steel, with screwed-on spring steel (piano wire) shaped contacts along the rungs to secure and make electrical contact to the parts. I've made a lot of them. Use non-magnetic stainless sheet as the cathode(s) - 2 is best - one on each side of the rack. The only thing needed is about 5 or 6 ozs of NaCN per gallon. Run it at about 4-5 volts at room temp. The gold will dissolve and simultaneously deposit on the cathode. The same solution can be used many times, with occasional additions of NaCN. There will always be a small amount of gold still in the solution. Don't worry about that. Zinc it out when you decide to retire.

If the base metal is copper or a copper alloy, do the same thing except add 20 oz/gal of sodium hydroxide to the solution. This prevents attack on the copper.

Everything also applies to stripping silver.

The more I think about this, I think maybe the best choice for running those particular parts would be using a rack in a sulfuric stripping tank. It strips gold selectively on about any substrate you can think of and you can use the solution over and over. It works on any gold thickness. I ran all gold IC packages with braze in a sulfuric stripper, on racks (about 300/rack), daily for 2 years and never changed the solution. They took about 20 minutes to strip and all the gold settled out as powder on the bottom. You just collect it when you want or when it starts to short (too much gold powder floating around). Easy money.

 

[GOLDbuyerCA]

For those of you reading along, here are some measured values of the material. "Gold over Stainless Steel "
50 Targets of the 3 drill holes 737.00 Grams, .67 Percent of one percent by weight 4.9 Grams stripped.
35 Targets of the 2 drill holes. 523.50 Grams .67 Percent of one percent by weight. 3.5 Grams stripped. i amazed myself that it would be this close. Technistrip AU works consistently
35 targets of the Mesh holes 139.25 Grams .78 Percent of one percent by weight 1.6 Grams stripped. i thought this would of been better, same plating area "i thought " over a thinner material
however, the surface is considerably less, perhaps one half less by surface area. ' the important part in plating, and deplating, values "

i am getting back into this, from a lay off in 2003, " i just didn't think the time and energy was worth it " and i had other things, to do. This enthusiasm "GSP " speaks of, comes about by
Tekion (Canada) Inc is a private company categorized underFuel Cells, Solid State and located in Burnaby, BC, Canada. ceasing to be in business, and the minor portions , / lesser inventory was sold off by auction.
past auction here :> http://www.ableauctions.ca/flyer/?EventID=BB33D803-F5FA-D231-A1EC827FC4308C71 i bought some obscure lots, and got the items i am displaying, i spent one thousand dollars, and
if not getting my value back, i am having some fun. / experimenting, and process reviewing. to make me a better practitioner at recovering precious metal values.

i would like to give my opinion on my recovery percentum by weight, on stainless steel, or metal pins of Mil spec quality per 1 Kg. merit on recovered pins, to British Columbia Assayer, "report" signed is 4/10 to 5/10 of one percent by weight. this lot, though quality pure plate, is not much better. What you see on Ebay, $ 100 for one lb, 14 oz. troy? is at 45 dollars a gram, about tops. more value is just not there, and buyers, have no . or little head room . in many cases say none. i value the current market, at 3 dollars a lb for pins, gold platted, but the shipping from California to Vancouver costs me another 3 dollars, and my waste " aluminum n crap " takes another 20 plus percent by volume out "
and then 3 to 4 for processing, just makes me 25 an hour clear recovery time and charges. it is a scramble , as you all know.

 

[GOLDbuyerCA]

This thread started 4 years back, by a Gent. asking about the KCN process, and recovery. it has survived over that time by several thousand hits on the forum and by perhaps many more on Google Search. for the product
"" TechniStrip AU as this update was in progress, another Gent. asked for help on a Cyanide recovery process gone thin, " little or no recovery " and has been addressed by "GSP" and others of the forum, GSP giving quite a good overview even for the first day user of the Cyanide question . GSP has encouraged me to be factual in my discussion and contribution. As readers may notice, " and you have " i have more to say on the subject of stripping PMG's by Cyanide, and electro apparatus. I would like to close, by saying i have purchased Technistrip Au, from Techni company :> Technistrip AU
Description: Gold Stripper
Characteristics: Cyanide based gold stripper prepared from dry mix. Removes gold from most base metals. "" with consistent results, for the occasional user, the prepackage gallon, will do all your light duty stripping.
of stripping , i mean, clean gold over metal, , Which may be recovered to a good percentum by active carbon, electro winning, and distillation. " in a small process, i am using all three " you will get an 85 percent return
over all losses, with careful handling, and in distilling come close to 98 percent recovery.

 

[GOLDbuyerCA]

So of recent the question of successfully using Cyanide is again raised. as in this case thus

hallo
I used 100g of NaCN dissolve in 15 liter of water with strong presence of oxygen in an alkaline environment PH = 12 (I dissolve 25 grams of calcium hydroxide) to dissolve 25 grams of gold (10 KG motherboard mobile phone) everything goes very well
in the phase of recovery of gold from cyanide solution I use zinc in reality this is not a very fine powder because I did not find but I scrape a zinc plate for powder in the size of sand or a little less but it gives no result
I tried electrolysis with stainless steel electrodes it gives me that rust (corrision the electrode) a note the color of the solution is a clear yellow problemme I doubt that problemme this is due to excess NaCN in solution
I dont know exactly
can you help me please
thank you

A reply by GSP goes like this, i found it interesting so i include it here, for the continuing value of this thread :>

I use about 3 or 4 times more cyanide, per gallon, and I use, to start, about 25ml of 30-35% hydrogen peroxide - I tumble about 20-40 pounds in 1 - 2 gallons of hot tap water in a cheap cement mixer. More peroxide (often) and, more cyanide (rarely) might later be needed. The idea is to blast the gold off fast, 2 to 3 minutes usually - 10 sometimes - before it starts to eat the copper - heat and strength. If you start off with 140F water, the peroxide can get it to where it's steaming. It always (well, almost always - very rarely you have to use a fresh solution) works and you can get all the gold you can see. On copper or on a very thin nickel barrier layer that mechanically and chemically (slowly) wears off in the tumbling, thus exposing the copper, it can take longer. The solution is only good once.

I then combined all the solutions and rinses into a 55 gallon plastic drum with the top cut out, elevated on a stand taller than the drum, for siphoning purposes. Three or four hundred pounds of material, about a day's work, might generate 40 gallons of solution. I then adjusted the pH of the solution to 12-12.5 with sodium hydroxide and added an extra 10g of NaCN per gallon. I then stirred vertically, slowly up and down, with a plunger stirrer I made from a 5" diameter plastic disk on the end of a 5" piece of plastic pipe. Stir continuously. While stirring, I added zinc dust in small increments though a flour sifter. At first, you will see brown gold power being brought to the surface by the stirrer. Keep stirring. After 1 or more further additions, the powder will start to turn gray. When it's all gray, with no hint of brown, stop adding. Hang 2 zinc bars, near the top of the solution, and let it settle overnight.

Next morning, I siphoned off the solution into another drum, filtered and rinsed the sludge very well with hot water, put the sludge plus paper in a plastic bucket, covered it with water, and added nitric acid in small increments until I got no more fizzing. It got hot. I prefer full strength nitric because it will dissolve silver and copper, which will usually be there. Finally, after filtering and rinsing very well, I dissolved the impure gold in aqua regia with a minimum amount of nitric, and dropped the gold with sodium sulfite. .............
.............................................................

myself i will attempt to put my thoughts towards, Small scale Cyanide process, illustrative, with recovery data, on Au, Pt and Pd. shown below is Au, plated over SS 316 one hundred pads to the bag. with a single and 2 and five representing 99 percent recovery, less one, 98 percent recovery less two and 95 percent recovery less five if in strip and recovery, you get less one, your doing very , very good. i will try to show that 98 percent is possible, with low cost materials.