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.RC.
04-16-2009, 06:51 AM
These few pages came into my belonging a few years ago, thought a few people might find them handy..Ready made case hardening compounds are not available in this part of the world.. I have not tried it yet, but I am slowly getting the ingredients together.

http://users.beagle.com.au/lathefan/Case%20Hardening1.pdf

garagemark
04-16-2009, 07:41 AM
Thank you very much. Stored in a safe place for future use. I always like to learn stuff like this. I want to try everything (though I am way behind!)

THX again,
Mark

bob ward
04-16-2009, 09:20 AM
Ringer, a couple of years ago I wanted to try my hand at case hardening using Kasenite or one of the other cyanide compound case hardeners.

Phoning various suppliers I quickly discovered that those sorts of cyanide products are off the market in Australia, but during my enquiries I did find a company at Archerfield I think, in Brisbane, which sold bags of pre-mixed charcoal based hardening powders.

I'll have to dig through my notes to find who they were, I'll let you know when I find the name in case that is of interest to you.

GrahamC
04-16-2009, 09:48 AM
Thanks for posting that, I will add it to my pile of reference material.

Incidentally, the process described is for "pack case hardening" - pack it up in a container and let it soak at heat til ready to quench type of process rather than the heat dip, heat dip, quench process that you would use with the likes of Casenite.

The barium carbonate mentioned is a common chemical used by those who practice ceramic crafts. Check some of the local cermic supply houses for this and similar compounds.

By the way, what is "whitting" as mentioned in this document?

http://www.rosemill.com/default.asp?pageid=27391 has a product called "Cherry Red" and might be worthwhile checking into. I don't know if they have kind of distributor available on the other side of the world. Minimum it seems is to purchase 5lbs which is likely a life times supply for the average HSM and at $80 USD seems a bit high.

Rosemill also sells pack case hardening compound and anti scaling compound. A read of the MSDS's for these products suggest they are primary based on borate compounds.

Another Casenite like compound that might be found in that part of the world is a Harris product called "Quick Hard". Same basic product as Casenite but marketed by Harris under their name. The primary ingredient in this product is a common chemical used in the food processing industry as an anti caking compound.

Personally I use the Harris "Quick Hard" product for case hardening and find it works well but I have meaning to try pack case hardening just for the sake of experimenting with the possibility to getting some color case hardening in the process.

cheers, Graham in Ottawa Canada

38_Cal
04-16-2009, 12:40 PM
You also might want to see if you can adapt this information from my former employer on pack hardening: http://tinyurl.com/c24w9q.

David
Montezuma, IA

.RC.
04-16-2009, 06:11 PM
Ringer, a couple of years ago I wanted to try my hand at case hardening using Kasenite or one of the other cyanide compound case hardeners.

Phoning various suppliers I quickly discovered that those sorts of cyanide products are off the market in Australia, but during my enquiries I did find a company at Archerfield I think, in Brisbane, which sold bags of pre-mixed charcoal based hardening powders.

I'll have to dig through my notes to find who they were, I'll let you know when I find the name in case that is of interest to you.

Would that have been Hardite Bob??? I have heard that name mentioned a number of times but Google tells me nothing other then it was available many years ago..

.RC.
04-16-2009, 06:23 PM
By the way, what is "whitting" as mentioned in this document?



Graham, I believe whiting to be powdered chalk or Calcium Carbonate.

GrahamC
04-16-2009, 07:32 PM
Graham, I believe whiting to be powdered chalk or Calcium Carbonate.

Thanks.

this formula is pretty much like the one Guy Lautard published in his "Machinist Second Bedside Reader" in a story called "The Bullseye Mixture". The barium carbonate and calcium carbonate act to help cause carbon from the charcoal to be taken in by the steel being carburized.

cheers, Graham

lazlo
04-16-2009, 07:37 PM
this formula is pretty much like the one Guy Lautard published in his "Machinist Second Bedside Reader" in a story called "The Bullseye Mixture". The barium carbonate and calcium carbonate act to help cause carbon from the charcoal to be taken in by the steel being carburized.

I posted a thread here awhile ago asking about the Bullseye Mixture (there'a a warning on page 197 that says that Barium Carbonate is extremely poisonous). The general consensus, including one of the high-end gunsmith's who lurks here, is that Barium Carbonate is just a carbon absorbtion accelerator that wasn't necessary for home-shop case hardening.

Duffy
04-16-2009, 08:04 PM
You know guys, "extremely poisonous" is a description in the same category as "extremely pregnant!" Toxicity, aka "poisonosity" or poisonousness is quantified by a number that represents the grams per kilogram of body weight of the test animal/subject. It is properly termed the LD50 which simply means that a dose of X grams/kilogram of body weight will kill 50% of the specimens that have been exposed/innoculated or fed. The size of that number is important, or whether it is rated in grams or micrograms.
I checked Patty's "Industrial Hygiene & Toxicology," which states that it is indeed "highly toxic;" about 0.9 grams is fatal. However it is not very soluble in water, so what IS the problem-just BE CAREFULL! Arsenic, on the other hand is REAL MEAN, and milligrams are WAY TOO MUCH! (It was right beside Barium in the book.) Duffy

Evan
04-16-2009, 08:43 PM
Go to your local chemist and ask them to order you some food grade sodium ferrocyanide. It's the exact same thing as Kasenit. BTW, Australia is a producer of same. It sells for about $1000 per tonne.

GrahamC
04-16-2009, 08:53 PM
Go to your local chemist and ask them to order you some food grade sodium ferrocyanide. It's the exact same thing as Kasenit. BTW, Australia is a producer of same. It sells for about $1000 per tonne.

I tried that here in Ottawa. The only place that would deal with "off the street public" would gladly order what I wanted but at the price of $35 per ounce and that was for food grade stuff.

Some of the old time recipes include saltpeter (potassium nitrate). I used to buy saltpeter at the drug store when I was teenager but no longer. Apparently it is on Canada's restricted substance list and is tightly controlled - or so I was told at the same place that would gladly order what I wanted but at a price.

cheers, Graham in Ottawa Canada

bob ward
04-16-2009, 09:38 PM
Doing a bit more reading (googling) about sodium ferrocyanide, I gather that while tonnes of the product are used in food annually, Kasenit etc is banned in the average workshop here by Workplace Health & Safety (WHS) because of the high temperature decompostition products.

Properly equipped heat treaters can still use it of course.

lazlo
04-16-2009, 09:53 PM
I checked Patty's "Industrial Hygiene & Toxicology," which states that it is indeed "highly toxic;" about 0.9 grams is fatal. However it is not very soluble in water, so what IS the problem-just BE CAREFULL!

The concern that someone knowledgable expressed last time we discussed the Bullseye Mixture was that the barium carbonate vaporizes at case hardening temperatures, so you're breathing it, not ingesting it.

lazlo
04-16-2009, 09:59 PM
Doing a bit more reading (googling) about sodium ferrocyanide, I gather that while tonnes of the product are used in food annually, Kasenit etc is banned in the average workshop here by Workplace Health & Safety (WHS) because of the high temperature decompostition products.

That's very interesting. At room temperature, the cyanides in sodium ferrocyanide are completely inert, in fact its a component of food-grade anti-caking agents.

That doesn't necessarily extend to high temperatures, which could concievably free the cynaides from the metal (sodium) bonds, but sodium ferrocyanide is also a common component in welding rods, so that seems counter-intuitive.

.RC.
04-16-2009, 10:18 PM
Doing a bit more reading (googling) about sodium ferrocyanide, I gather that while tonnes of the product are used in food annually, Kasenit etc is banned in the average workshop here by Workplace Health & Safety (WHS) because of the high temperature decompostition products.

Properly equipped heat treaters can still use it of course.

Bob it seems this business sells Hardite powder, although it is a bit expensive

It is right down the bottom on the last page http://www.ejwinter.com.au/catalogue/ejw-materials-8-08.pdf

And this mob sell Sodium Ferro Cyanide although probably only in bulk lots.. http://www.quantumchemicals.com.au/PageId/pg745366919edoras

GrahamC
04-16-2009, 10:30 PM
Bob it seems this business sells Hardite powder, although it is a bit expensive

It is right down the bottom on the last page http://www.ejwinter.com.au/catalogue/ejw-materials-8-08.pdf

And this mob sell Sodium Ferro Cyanide although probably only in bulk lots.. http://www.quantumchemicals.com.au/PageId/pg745366919edoras

Ouch! $38.50 for 100 grams (about a quarter pound)! Last time I bought Harris Quick Hard was last summer and it was about $30 for a one pound container.

For those interested in the MSDS for this and similar compounds see:

http://www.harrisproductsgroup.com/pdf/MSDS/Quick_Hard.pdf

This or similar compounds used with common sense, good ventilation and as in the instructions should pose little problem.

You might try welding supply houses or black smith supply. That is where I get the Harris product.

cheers, Graham

bob ward
04-16-2009, 10:43 PM
That doesn't necessarily extend to high temperatures, which could concievably free the cynaides from the metal (sodium) bonds, but sodium ferrocyanide is also a common component in welding rods, so that seems counter-intuitive.

As you say lazlo, there is sodium ferrocyanate in both arc welding rod coatings and in Kasenit, both emit undesirable high temp decompostion products, but one is OK the other is banned.

I suspect that WHS here may like to ban both, but the arc welding industry, and I include suppliers and welders here, is just too big and is found in every corner of industry, it simply can't be banned, its too pervasive. Just use good ventilation guys!

But in house case hardening can be banned without little disruption or outcry because the hardening can go to the properly set up professionals. WHS score because they can point to their illogical ban, which most people don't know is illogical, as an achievement in their on going struggle for workshop safety.

The small shops still have their tin of Kasenit hidden away of course and it still gets used.

.RC.
04-16-2009, 10:59 PM
But is Kasenit banned in Australia bob???

I cannot find any info where it is...

bob ward
04-16-2009, 11:28 PM
Ringer, Kasenite itself is not banned AFIK, but it has disappeared from the shelves because the small shops can't use it any more.

Sodium ferrocyanide even has its own web page, and what can't it do!
1. Pigment production
2. Anti-caking additive in conventional salts and street (snow removal) salts
3. Precipitation of trace metallic ions (for separation in chemical processes)
4. Cleaning agents
5. Corrosion inhibitors (for continuous processes in contact with soft steel)
6. Steel surface treatment
7. Galvanization (silver and pewter)
8. Photographic development processes
9. Fermentation of Citric Acid and Ascorbic Acid, etc
http://www.sodium-ferrocyanide.com/

I've looked through my notes and can't find the guys that sold the carbon based hardening powders. But it was an odd bod in their main range of products, which I think may have been lubricants, maybe Fuchs.

Evan
04-17-2009, 02:12 AM
Ironically, sodium ferrocyanide is used in dry chemical fire extinguishers to prevent caking of the agent. It is also used in air dropped fire control agents.

bob ward
04-17-2009, 01:15 PM
Ringer, the charcoal based case hardening powder is available from Fuchs Australia, it is listed half way down this page.

http://www.fuchs.com.au/categories.asp?cID=22

As an aside, I had no idea of the level of sophistication of quenching oils, Fuchs list 6 different quenching oils on the page.

GrahamC
04-17-2009, 02:19 PM
And to take the discussion of sodium ferrocyanide a bit further, potassium ferricyanide K3Fe(CN)6 and potassium ferrocyanide K4Fe(CN)6·3H2O are similar and can also be used for case hardening.

Potassium ferricyanide is commonly used in photo processing (among other uses) as a bleaching agent. It is still available from Kodak in 1 lb containers (if you can find it) and also in small quantities as part A of a product called Farmers Reducer.

Potassium salts are generally prefered to sodium as they tend to work better however where price is an issue sodium wins out. That is why your "heart healthy" grocery products with "reduced sodium" have replaced some of the sodium chloride (salt) with potassium chloride and have upped the price.

Tread lightly and carefully if experimenting "outside the box". Your best bet is always to get a commercial off the shelf product and follow the instructions. This way you will save yourself a lot of time and grief.


cheers, Graham

Mike Hunter
04-17-2009, 03:26 PM
Case hardening is quite simple, it’ s been around for centuries. To do simple, but effective case hardening all you really need is something that gives off carbon (in the form of Carbon Monoxide, Carbon dioxide) when heated.
This can be raw bone meal that you get from the local garden center, leather, bone char, horse hoof, I’ve also seen recipes that used sugar. I have done simple case hardening with raw bone meal, leather, and charred bone, they all work
Put this compound with the part that you want to case harden , in an air tight container and heat to 1450 for a period of time then quench ….Simple.
Although, the stench that comes from raw leather & raw bone is something not easily forgotten. I highly recommend charring those outside first before using.
I have tried both barium carbonate and calcium carbonate in the mixes, didn’t see any difference with the addition of either.
No way am I trying anything with Cyanide in its name
The really hard part is case hardening for colors, and trying to match the specific colors and patterns that the individual companies attained back in the day.

Evan
04-17-2009, 03:42 PM
We are talking about two different processes here. Using carbon based hardening agents such as charcoal or other carbon containing compounds is known as carburizing. On the other hand, Sodium ferrocycanide is known as a carbonitriding agent since it contains large amounts of carbon and nitrogen and produces a high carbon case with a shallower nitride case as well. Using plain carbon such as charcoal will not produce the same results.



No way am I trying anything with Cyanide in its name


Don't be silly. Would you consider eating anything that is made up of 50% chlorine? You know, the same thing they used to kill people in WW1?

lazlo
04-17-2009, 05:13 PM
We are talking about two different processes here. Using carbon based hardening agents such as charcoal or other carbon containing compounds is known as carburizing. On the other hand, Sodium ferrocycanide is known as a carbonitriding agent since it contains large amounts of carbon and nitrogen and produces a high carbon case with a shallower nitride case as well. Using plain carbon such as charcoal will not produce the same results.

Oh dear Lord, not again.

Kasenit is a common carburizing compound. Like all carburizing processes, Kasenit must be applied above the austentizing temperature: 1500 - 1800F.

Nitriding is a specialty process that uses ammonia gas to create hardened nitrides in chromium rich nitriding alloys like Nitralloy. Nitriding is done at much lower temperatures (around 900F), so there's no warping of the workpiece, which is the primary reason it's used.

If Kasenit had any nitriding properties, you'd see a substantial increase in hardness if it's applied at 900F, and believe me, it doesn't.

Kasenit is a little Mom and Pop operation in upstate New York. Feel free to call and ask him :)

Kasenit Co
13 Park Ave
Highland Mills, NY 10930
845-928-9595

Evan
04-17-2009, 06:38 PM
Oh dear Lord, not again.

Kasenit is a common carburizing compound. Like all carburizing processes, Kasenit must be applied above the austentizing temperature: 1500 - 1800F.

Nitriding is a specialty process that uses ammonia gas to create hardened nitrides in chromium rich nitriding alloys like Nitralloy. Nitriding is done at much lower temperatures (around 900F), so there's no warping of the workpiece, which is the primary reason it's used.

If Kasenit had any nitriding properties, you'd see a substantial increase in hardness if it's applied at 900F, and believe me, it doesn't.

Kasenit is a little Mom and Pop operation in upstate New York. Feel free to call and ask him


What does who sells Kasenit have to do with the process?

It's called salt bath carbonitriding and relies on Sodium ferrocyanide as the major constituent of the molten salts. It will not produce any appreciable effect at 900F since the salt must be heated to at least 1000 to 1100F for diffusion to occur.


Case Hardening : A unique feature of salt bath nitrocarburized layers is the monophase _-Fe_N compound layer, with a nitrogen content of 6-9% and a carbon content of around 1%. Compared with double phase nitride layers which have lower nitrogen concentrations, the monophase _-Fe_N layer is more ductile and gives better wear and corrosion resistance by improvement with case hardening. In metallographic analysis the compound layer is clearly definable fron the diffusion layer as a lightly etched layer. A porous area develops in the outer zone of the compound layer. The case hardness of the compound layer measured on a cross-section is around 700 HV for unalloyed steels and up to about 1600 HV on high chromium steels. Treatment durations of 1-2 hours usually yield compound layers about 10-20 _m thick (0.0004 - 0.0008"). The higher the alloy content, the thinner the layer for the same treatment cycle. Fig. 2 shows the relationship of layer thickness to treatment time with nitrocarburizing temperature of 580�C (1057�F).


See here: http://www.burlingtoneng.com/case_hardening.html

lazlo
04-17-2009, 06:50 PM
What does who sells Kasenit have to do with the process?

So you won't believe the guys who sell Kasenit when they tell you it's ordinary carburizing compound?


See here: http://www.burlingtoneng.com/case_hardening.html

Fig. 2 shows the relationship of layer thickness to treatment time with nitrocarburizing temperature of 580�C (1057�F).

So Evan, heat your workpiece up to 1057F, which is well below steel's austentizing temperature. Coat it will Kasenit as per the instructions, and quench it. It won't change hardness a bit. There's absolutely no nitriding going on, because Kasenit is just plain, ordinary carburizing compound.

Evan
04-17-2009, 07:06 PM
So you won't believe the guys who sell Kasenit when they tell you it's ordinary carburizing compound?


Oddly enough the rest of the industry thinks differently. I'm not talking about gas nitriding. I'm talking about ferrocyanide salt carbonitriding. See the link I provided above. I think they may know more about it than the "mom and pop" operation.

lazlo
04-17-2009, 07:18 PM
Oddly enough the rest of the industry thinks differently. I'm not talking about gas nitriding. I'm talking about ferrocyanide salt carbonitriding. See the link I provided above.

Nowhere in that article, or even the entire site, does it indicate that they're using Sodium ferrocyanide (the active ingredient in Kasenit) for carbonitriding. In fact, there's not a single mention of "cyanide" anywhere on their web page -- they state that they use "salt baths" but don't indicate which chemical.

Google:
? cyanide site:http://www.burlingtoneng.com/

Your search - cyanide site:http://www.burlingtoneng.com/ - did not match any documents.

Mike Hunter
04-17-2009, 07:21 PM
Evan.

Have no problem with chlorine at the 5% level; don’t like chlorine gas or anything above 7%.

50% Chlorine…You’re e not talking about table salt are you? Sodium CHLORIDE?

There is a difference between Chlorine and Chloride. Chlorine is an element, it is a strong oxidizer, Chloride ions are essentially non-reactive.

And the fact that a certain product is found in foods,…. Doesn’t convince me as being safe. Read several DOD reports about aspartame (Equal, NutraSweet) breaking down into some very nasty compounds when heated.

So who here can tell me what Sodium the break down components are of Sodium ferrocyanide when heated to 1500 deg F?

lazlo
04-17-2009, 07:26 PM
Kasenit is a common carburizing compound. Like all carburizing processes, Kasenit must be applied above the austentizing temperature: 1500 - 1800F.

Case Hardening
http://en.wikipedia.org/wiki/Case_hardening

Modern use

The term case hardening is derived from the practicalities of the carburization process itself, which is essentially the same as the ancient process. The steel work piece is placed inside a case packed tight with a carbon-based case hardening compound. This is collectively known as a carburizing pack. The pack is put inside a hot furnace for a variable length of time. Time and temperature determines how deep into the surface the hardening extends. However, the depth of hardening is ultimately limited by the inability of carbon to diffuse deeply into solid steel, and a typical depth of surface hardening with this method is up to 1.5 mm. Other techniques are also used in modern carburizing, such as heating in a carbon rich atmosphere. Small items may be case hardened by repeated heating with a torch and quenching in a carbon rich medium, such as the commercial products Kasenit / Casenite or "Cherry Red". Older formulations of these compounds contain potentially toxic cyanide compounds, such as ferrocyanide compounds, while the more recent types such as Cherry Red do not.[1][2]

Evan
04-17-2009, 08:13 PM
CASE-HARDENING MATERIALS-carbonitriding-nitrocarburizing
Materials for adding carbon and/or other elements to the surface of low-carbon or medium-carbon steels or to iron so that upon quenching a hardened case is obtained, with the center of the steel remaining soft and ductile. The material may be plain charcoal, raw bone, or mixtures marketed as carburizing compounds. A common mixture is about 60% charcoal and 40 barium carbonate. The latter decomposes, giving carbon dioxide, which is reduced to carbon monoxide in contact with the hot charcoal. If charcoal is used alone, action is slow and spotty. Coal or coke can be used, but action is slow, and the sulfur in these materials is detrimental. Salt is sometimes added to aid the carburizing action. By proper selection of the carburizing material, the carbon content may be varied in the steel from 0.80 to 1.20%. The carburizing temperature for carbon steels typically ranges from 1550 to 1750°F (850 to 950°C) but may be as low as 1450°F (790°C) or as high as 2000°F (1095°C). The articles to be car-burized for case hardening are packed in metallic boxes for heating in a furnace, and the process is called pack hardening, as distinct from the older method of burying the red-hot metal in charcoal.


Steels are also case-hardened by the diffusion of carbon and nitrogen, called carbonitriding, or nitrogen alone, called nitriding. Carbonitriding, also known as dry cyaniding, gas cyaniding, liquid cyaniding, nicarbing, and nitrocarburizing, involves the diffusion of carbon and nitrogen into the case. Nitriding also may be done by gas or liquid methods. In carbonitriding, the steel may be exposed to a carrier gas containing carbon and as much as 10% ammonia, the nitrogen source, or a molten cyanide salt, which provides both elements. Ammonia, from gaseous or liquid salts, is also the nitrogen source for nitriding. Although low- and medium-carbon steels are commonly used for carburizing and carbonitriding, nitrid-ing is usually applied only to alloy steels containing nitride-forming elements, such as aluminum, chromium, molybdenum, and vanadium. In ion nitriding, or glow-discharge nitriding, electric current is used to ionize low-pressure nitrogen gas. The ions are accelerated to the workpiece by the electric potential, and the work-piece is heated by the impinging ions, obviating an additional heat source. All three principal case-hardening methods provide a hard, wear-resistant case. Carburizing, however, which gives the greater case depth, provides the best contact-load capacity. Nitriding provides the best dimensional control, and carbonitriding is intermediate in this respect.
The principal liquid-carburizing material is sodium cyanide, which is melted in a pot that the articles are dipped in, or the cyanide is rubbed on the hot steel. Cyanide hardening gives an extremely hard but superficial case. Nitrogen as well as carbon is added to the steel by this process. Gases rich in carbon, such as methane, may also be used for carburizing, by passing the gas through the box in the furnace. When ammonia gas is used to impart nitrogen to the steel, the process is not called carburizing but is referred to as nitriding. Tufftriding, of Degussa AG of Germany, is a nitriding process using molten potassium cyanate with a small amount of sodium ferro-cyanide in titanium-lined melting pots.Case-hardening compounds are marketed under a wide variety of trade names. These may have a base of hardwood charcoal or of charred bone, with sodium carbonate, barium carbonate, or calcium carbonate. Char is a carburizing material in which the particles of coal-tar carbon are surrounded by an activator and covered with a carbon coating. Accelerated Salt WS, of Du Pont, for heat-treating baths, has a content of 66% sodium cyanide, with graphite to minimize fuming and radiation losses. For selective case hardening on steel parts, a stiff paste of carburizing material may be applied to the surfaces where a carbon impregnation is desired. Carburit is a car-burizing paste of this kind. Aerocarb and Aerocase, of American Cyanamid Co., are mixtures of sodium and potassium nitrates and nitrides for use in carburizing baths at a temperature up to 1850°F (1010°C).


Sodium cyanide is used in most industrial carbonitriding because it is cheaper than sodium ferrocyanide. Either salt has the same action since they both contain nitrogen. Sodium cyanide is NaCN and Sodium ferrocyanide is Na4Fe(CN)6.


http://dictionary.mechanicalengineering.tv/CASE-HARDENING_MATERIALS-carbonitriding-nitrocarburizing.html

Evan
04-17-2009, 08:34 PM
There is a difference between Chlorine and Chloride. Chlorine is an element, it is a strong oxidizer, Chloride ions are essentially non-reactive.



No there isn't any difference other than the fact it is reacted with another element, the same as the Carbon and Nitrogen in a cyanide. It's the carbon-nitrogen bond that makes a cyanide a cyanide regardless of whatever else it is combined with. The chlorine in salt is elemental chlorine and can easily be released by electrolysis of salt water during derusting for example.

When the CN is also bonded with iron it is inert enough to eat, which you do if you consume commercial table salt. Sodium cyanide is a food grade additive used to prevent table salt from caking.

lazlo
04-18-2009, 12:55 AM
Sodium cyanide is used in most industrial carbonitriding because it is cheaper than sodium ferrocyanide.

Sodium cyanide, (http://en.wikipedia.org/wiki/Sodium_cyanide) NaCN, which is used in molten salt baths for carburizing, is a completely different chemical than sodium ferrocyanide (http://en.wikipedia.org/wiki/Sodium_ferrocyanide), Na4Fe(CN)6, which is the active ingredient in Kasenit.

Sodium cyanide is highly toxic.

Sodium ferrocyanide is complete inert, and used as a food grade anti-caking agent, and is the pigment in Prussian Blue.



Sodium cyanide is the inorganic compound with the formula NaCN. This highly toxic colourless salt is used mainly in gold mining but has other niche applications. It is the conjugate base of the weak acid hydrogen cyanide.

Sodium ferrocyanide, is a coordination compound of formula Na4Fe(CN)6 which forms semi-transparent yellow crystals at room temperature, and which decomposes at its boiling point. Despite the presence of the cyanide ligands, sodium ferrocyanide is not especially toxic because the cyanides are tightly bound to the metal, although it can react with acid or photodecompose to release hydrogen cyanide gas.

As yellow prussiate of soda, it is added to road and food grade salt as an anticaking agent. When combined with iron, it converts to a deep blue pigment which is the main component of Prussian blue. In photography it is used for bleaching, toning and fixing. It is used as a stabilizer for the coating on welding rods. In the petroleum industry it is used for removal of mercaptans.

Evan
04-18-2009, 01:30 AM
Everything you wrote and quoted is true at room temperature.

So what?

You obviously aren't even reading what I have posted. Good night Robert.

Ropetangler
03-26-2018, 07:26 PM
Sodium cyanide is a food grade additive used to prevent table salt from caking.
I very much doubt it, certainly not in Australia. Perhaps the KGB used it long ago, now it seems they use nerve agents according to newspaper reports.
Rob.

MichaelP
03-26-2018, 08:56 PM
I very much doubt it, certainly not in Australia. Perhaps the KGB used it long ago, now it seems they use nerve agents according to newspaper reports.
Rob.

Yellow prussiate of soda (a.k.a. sodium ferrocyanide) is the anti-caking agent added to table salt.

Mcgyver
03-26-2018, 09:23 PM
someone please contact Evan so this can go on for 500 posts :rolleyes:

dave_r
03-27-2018, 02:29 AM
Yellow prussiate of soda (a.k.a. sodium ferrocyanide) is the anti-caking agent added to table salt.

Fortunately, that is slightly different from "Sodium cyanide".

DennisCA
03-27-2018, 07:37 AM
I believe this is the stuff you want for case hardening at any rate:
https://www.ebay.de/sch/i.html?_from=R40&_sacat=0&_nkw=Kaliumhexacyanoferrat

A source for those in europe. Known as "blood lye salt" in swedish.

CCWKen
03-27-2018, 11:58 AM
I still have a can of the old Kasenit. Must be worth a couple of Bit Coins by now. :D

Yondering
03-27-2018, 01:30 PM
People, look at the dates before posting. This thread is 9 years old.

J Tiers
03-27-2018, 02:06 PM
People, look at the dates before posting. This thread is 9 years old.

It WAS 9 years old.....

cameron
03-27-2018, 02:57 PM
People, look at the dates before posting. This thread is 9 years old.

Look at the dates, but don't let the date keep you from posting.

There's still a bit of 2009 home shop technology that's not completely obsolete yet.

engineerd3d
03-27-2018, 03:09 PM
Clickspring did a primitive case hardening. It may be worth a look. He uses charcoal he made from leather.

https://youtu.be/V_Mp1fNzIT8