Pot. Chlorate by electrolysis?

[TheGandalf]

Hello.

Is there anyone here who has experience in making Pot. Chlorate by electrolysis?

Where to find my electrodes? They must be purchased within the EU.

//TheGandalf

[TheGandalf]

Could I use those?

# http://www.goldn.co.uk/stainless-steel-electrode/

# http://www.goldn.co.uk/platinum-electrode/

[Mumbles]

You may want to start by reading the following thread. http://www.amateurpyro.com/forums/topic/1629-making-potassium-per-chlorate/

 

As far as electrodes, the steel one probably wont work, but the platinum will. The biggest thing is finding the right anode. Mixed metal oxide (MMO) is one of the most popular options. It's relatively inexpensive, and robust. Ebay can even be a source for them. A majority of people opt for plate anodes for electrolysis. They have higher surface area for one, and chemistry only really happens between the electrodes. Cylindrical electrodes would have a low useful area.

[Arthur]

Current thinking of mine which I think is shared, is to use CP1 or CP2 Titanium with MMO on titanium and the electrode pair for chlorate. To go to Perc you have to make chlorate first then electrolyse with a Ti electrode and either a Lead dioxide coated Ti electrode or a platinum electrode.

 

Do have a look at

http://www.amateurpyro.com/forums/topic/7729-the-bucket-cell-start-to-finish/?hl=%2Bbucket+%2Bcell

 

It's a practical guide to making and running a small cell (say 10 litres) in a disposable plastic bucket.

 

Posts by Swede have good chemistry and engineering, posts by WSM are gold dust.

 

Before you spend lots do please consider how much product you will use over a year! It's far too easy to have a small chemical plant that will make hundreds of kilos, or stand empty for long periods

[schroedinger]

If you just need pot Chlorate, electrolysis of KCl is the way to go.

Here you should use MMO or MnO2 anodes and Ti (Grade 1 or 2) cathodes. Graphite anodes work good too, require more processing and don't last as long as MMO.

[Arthur]

The electrolysis of KCl is OK but my findings are that KCl is less easily available that NaCl. To make the yield of the process worth the effort you do need to start with several kilos of KCl (which isn't easy to find in the UK) which you will need a retail source of in your country.

 

Lab grade KCl will be costly, agricultural grade may only be 90% but cheaper. The USA members can locate KCl for water softeners, which is clearly food grade but available cheaply in fair bulk.

Edited March 29, 2016 by Arthur

[schroedinger]

Well then try to find K-S 60-0-0 Pottasium Chloride. The bag i got is declared 98% pure and Works brilliant.

[Col]

aka, Yara MOP

[TheGandalf]

I only need to make chlorate. I have KCL, so it's no problem.

I just need a place to buy my cathodes and anodes.

Are there any places that sell within the EU?

//TheGandalf

[schroedinger]

Ebay lists some

[WindowLicka]

You may want to start by reading the following thread. http://www.amateurpyro.com/forums/topic/1629-making-potassium-per-chlorate/

 

As far as electrodes, the steel one probably wont work, but the platinum will. The biggest thing is finding the right anode. Mixed metal oxide (MMO) is one of the most popular options. It's relatively inexpensive, and robust. Ebay can even be a source for them. A majority of people opt for plate anodes for electrolysis. They have higher surface area for one, and chemistry only really happens between the electrodes. Cylindrical electrodes would have a low useful area.

 

Ok so what about using a stainless steel electrode for the cathode and an MMO mesh for the anode?

I'm well aware that titanium is the preferred electrode both for the cathode and the rod the MMO is spot welded to for the anode. I've read where people got by with an MMO anode and a stainless spoon cathode. Is that doable? What problems do you see coming from taking a SS spoon cathode shortcut? Extreme corrosion & contamination? Anything?

Or could it be done just fine for someone looking to cut corners on the titanium?

[WSM]

Ok so what about using a stainless steel electrode for the cathode and an MMO mesh for the anode?

I'm well aware that titanium is the preferred electrode both for the cathode and the rod the MMO is spot welded to for the anode. I've read where people got by with an MMO anode and a stainless spoon cathode. Is that doable? What problems do you see coming from taking a SS spoon cathode shortcut? Extreme corrosion & contamination? Anything?

Or could it be done just fine for someone looking to cut corners on the titanium?

 

The stainless steel cathode will work, BUT those who use stainless cathodes successfully often add some dichromate to the electrolyte for a couple different reasons:

• it helps prevent breakdown of the chlorate at the cathodes
• it protects the stainless steel

In a running cell the stainless steel is protected by the current flow (cathodic protection). When the current stops flowing, the stainless is attacked by the electrolyte. Even titanium cathodes are attacked by the electrolyte when the power is off; maybe not as much (ymmv).

 

I use CP titanium cathodes because:

• I can get the material and make them
• they work so well in my electrolysis
• they don't add unwanted ions to the electrolyte

CP titanium takes some work to find, but I think it's worth the effort.

 

WSM

[Mike]

Yes even mild steel aould work, but Ti is mucheasier to work with. You can make the electrodes yourself, Buy precut Grade1/2 Ti sheet and some strips or cut them (or even better use tubular leads). Thenthe cathodes are done. For the anode make a MnO2 anode or buy MMO.

[WindowLicka]

Cool, good to hear I can use stuff I have on hand.

 

The whole thing is I don't have any Ti, and no OTC sources come to mind so I was gonna just run it with SS. That is everywhere in California and the world over really. But I'm going to wait and set it up right.

I don't need to rush it just to get some chlorate.

Where would you say the best deals on Ti are to be found?At the end of a Google search.

 

The cell I got is smaller than my MMO mesh is what's the best way of cutting it without jacking up lasered's work? Would it be best to use the MMO mesh as the anode and epoxy it through the cells lid or does it need to be welded onto a Ti rod, bar, piece,ect?

 

If you got a connection for the CP Ti shoot me a link if you will.?

[WindowLicka]

Any OTC Ti sources like Home Depot or someplace like it?

[WSM]

Any OTC Ti sources like Home Depot or someplace like it?

Search for CP titanium on eBay.

 

WSM

[taiwanluthiers]

You are going to have to mail order the CP titanium. Titanium is just so special and exotic that no big box stores, metal dealers, or fabricators are going to have any on hand. Unless you somehow stumble on Mythbuster's M5 facility, and I doubt even they keep any titanium on hand either. In fact I'm finding that buying anything other than food or toiletries OTC is a challenge... I must mail order almost everything. Most people do not have hobbies like we do.

 

Oh and by some rare chance if you DO run into some titanium locally, 99.99% of the time it will be 6AL4V which will NOT work well as anode connection (strap or otherwise) or poorly as cathode. Which is another reason why you must mail order it.

Edited June 11, 2016 by taiwanluthiers

[Arthur]

Commercially Pure(CP1 or 2) titanium is available from specialist alloys sellers and works well for electrodes. ALL other alloys of titanium offer better specialist mechanical properties but inferior chemical resistance (which we want!).

[WindowLicka]

Since this is Ti coated w/MMO, can't I just cut a slot 1mm wide and 1" long and epoxy it in the cell w/marine epoxy? Or does mounting it onto yet another solid piece of Ti serve some function for my anode?

Where did the picture/file attachment go?

[WSM]

Since this is Ti coated w/MMO, can't I just cut a slot 1mm wide and 1" long and epoxy it in the cell w/marine epoxy? Or does mounting it onto yet another solid piece of Ti serve some function for my anode?

Where did the picture/file attachment go?

 

Mumbles mentioned reading in the (per)chlorate thread. I think that's excellent advice. It was easier when the thread was only 30 pages long, but who said anything worthwhile was easy?

 

Another excellent source is Swede's blog, "You'll put your eye out"; also here in APC.

 

There is a LOT of good material here, and definitely worth the investment of time and energy to read through; especially before you spend much money or effort on a system.

 

WSM

[WSM]

Commercially Pure(CP1 or 2) titanium is available from specialist alloys sellers and works well for electrodes. ALL other alloys of titanium offer better specialist mechanical properties but inferior chemical resistance (which we want!).

 

It's my understanding that any CP (commercially pure) grade of titanium will work for our needs. One CP grade that is sometimes offered (I can't recall the number, but it's not 1 through 4) contains a very small percentage of palladium or ruthenium, and is probably well suited to plating with other materials (LD, Pt, et cetera).

 

I've used grades 1-4 and they all seem to get the job done. If my understanding is correct, the purest form is CP 1, but the others seem to work just fine and cost a bit less. I usually use CP titanium sheet metal for cathodes. Grade 2 is usually offered by surplus dealers, but I think any CP grade will work in our chlor-alkali cells.

 

WSM

Edited June 11, 2016 by WSM

[WSM]

I did a quick Wikipedia search of CP titanium and found this list:

 

The ASTM International standard on titanium and titanium alloy seamless pipe references the following alloys, requiring the following treatment:

"Alloys may be supplied in the following conditions: Grades 5, 23, 24, 25, 29, 35, or 36 annealed or aged; Grades 9, 18, 28, or 38 cold-worked and stress-relieved or annealed; Grades 9, 18, 23, 28, or 29 transformed-beta condition; and Grades 19, 20, or 21 solution-treated or solution-treated and aged."

[4]

"Note 1—H grade material is identical to the corresponding numeric grade (that is, Grade 2H = Grade 2) except for the higher guaranteed minimum

UTS

, and may always be certified as meeting the requirements of its corresponding numeric grade. Grades 2H, 7H, 16H, and 26H are intended primarily for pressure vessel use."

[4]

"The H grades were added in response to a user association request based on its study of over 5200 commercial Grade 2, 7, 16, and 26 test reports, where over 99% met the 58 ksi minimum UTS."

[4]

• Grade 1 is the most ductile and softest titanium alloy. It is a good solution for cold forming and corrosive environments.ASTM/ ASME SB-265 provides the standards for commercially pure titanium sheet and plate.^[5]
• Grade 2 Unalloyed titanium, standard oxygen.
• Grade 2H Unalloyed titanium (Grade 2 with 58 ksi minimum UTS).
• Grade 3 Unalloyed titanium, medium oxygen.

Grades 1-4 are unalloyed and considered commercially pure or "CP". Generally the tensile and yield strength goes up with grade number for these "pure" grades. The difference in their physical properties is primarily due to the quantity of interstitial elements. They are used for corrosion resistance applications where cost, ease of fabrication, and welding are important.

• Grade 5, also known as Ti6Al4V, Ti-6Al-4V or Ti 6-4, is the most commonly used alloy. It has a chemical composition of 6% aluminum, 4% vanadium, 0.25% (maximum) iron, 0.2% (maximum) oxygen, and the remainder titanium.^[6] It is significantly stronger than commercially pure titanium while having the same stiffness and thermal properties (excluding thermal conductivity, which is about 60% lower in Grade 5 Ti than in CP Ti).^[7] Among its many advantages, it is heat treatable. This grade is an excellent combination of strength, corrosion resistance, weld and fabricability.

"This alpha-beta alloy is the workhorse alloy of the titanium industry. The alloy is fully heat treatable in section sizes up to 15 mm and is used up to approximately 400 °C (750 °F). Since it is the most commonly used alloy – over 70% of all alloy grades melted are a sub-grade of Ti6Al4V, its uses span many aerospace airframe and engine component uses and also major non-aerospace applications in the marine, offshore and power generation industries in particular."

[8]

"

Applications

: Blades, discs, rings, airframes, fasteners, components. Vessels, cases, hubs, forgings. Biomedical implants."

[6]

Generally, Ti-6Al-4V is used in applications up to 400 degrees Celsius. It has a density of roughly 4420 kg/m³, Young's modulus of 120 GPa, and tensile strengthof 1000 MPa.^[9] By comparison, annealed type 316 stainless steel has a density of 8000 kg/m³, modulus of 193 GPa, and tensile strength of 570 MPa.^[10]Tempered 6061 aluminium alloy has a density of 2700 kg/m³, modulus of 69 GPa, and tensile strength of 310 MPa, respectively.^[11] Ti-6Al-4V standard specifications include:^[12]

• UNS: R56400,
• AMS: 4911, 4920, 4928, 4934-4935, 4965, 4967, 6930-6931, T9046
• ASTM: B265, B348, B381 F136
• MIL: T9046-T9047
• MMS: 1217, 1233
• DMS: 1570, 1583, 1592, 2285, 2442 R-1
• BMS: 7-348

• Grade 6 contains 5% aluminium and 2.5% tin. It is also known as Ti-5Al-2.5Sn. This alloy is used in airframes and jet engines due to its good weldability, stability and strength at elevated temperatures.^{[citation needed]}
• Grade 7 contains 0.12 to 0.25% palladium. This grade is similar to Grade 2. The small quantity of palladium added gives it enhanced crevice corrosion resistance at low temperatures and high pH.^[13]
• Grade 7H is identical to Grade 7 with enhanced corrosion resistance.^[13]
• Grade 9 contains 3.0% aluminium and 2.5% vanadium. This grade is a compromise between the ease of welding and manufacturing of the "pure" grades and the high strength of Grade 5. It is commonly used in aircraft tubing for hydraulics and in athletic equipment.
• Grade 11 contains 0.12 to 0.25% palladium. This grade has enhanced corrosion resistance.^[14]
• Grade 12 contains 0.3% molybdenum and 0.8% nickel.^[14]
• Grades 13, 14, and 15 all contain 0.5% nickel and 0.05% ruthenium.
• Grade 16 contains 0.04 to 0.08% palladium. This grade has enhanced corrosion resistance.
• Grade 16H contains 0.04 to 0.08% palladium.
• Grade 17 contains 0.04 to 0.08% palladium. This grade has enhanced corrosion resistance.^{[citation needed]}
• Grade 18 contains 3% aluminium, 2.5% vanadium and 0.04 to 0.08% palladium. This grade is identical to Grade 9 in terms of mechanical characteristics. The added palladium gives it increased corrosion resistance.^{[citation needed]}
• Grade 19 contains 3% aluminium, 8% vanadium, 6% chromium, 4% zirconium, and 4% molybdenum.
• Grade 20 contains 3% aluminium, 8% vanadium, 6% chromium, 4% zirconium, 4% molybdenum and 0.04% to 0.08% palladium.
• Grade 21 contains 15% molybdenum, 3% aluminium, 2.7% niobium, and 0.25% silicon.
• Grade 23 contains 6% aluminium, 4% vanadium, 0.13% (maximum) Oxygen. Improved ductility and fracture toughness with some reduction in strength.^[14]
• Grade 24 contains 6% aluminium, 4% vanadium and 0.04% to 0.08% palladium.
• Grade 25 contains 6% aluminium, 4% vanadium and 0.3% to 0.8% nickel and 0.04% to 0.08% palladium.
• Grades 26, 26H, and 27 all contain 0.08 to 0.14% ruthenium.
• Grade 28 contains 3% aluminium, 2.5% vanadium and 0.08 to 0.14% ruthenium.
• Grade 29 contains 6% aluminium, 4% vanadium and 0.08 to 0.14% ruthenium.
• Grades 30 and 31 contain 0.3% cobalt and 0.05% palladium.
• Grade 32 contains 5% aluminium, 1% tin, 1% zirconium, 1% vanadium, and 0.8% molybdenum.
• Grades 33 and 34 contain 0.4% nickel, 0.015% palladium, 0.025% ruthenium, and 0.15% chromium .^{[citation needed]}
• Grade 35 contains 4.5% aluminium, 2% molybdenum, 1.6% vanadium, 0.5% iron, and 0.3% silicon.
• Grade 36 contains 45% niobium.
• Grade 37 contains 1.5% aluminium.
• Grade 38 contains 4% aluminium, 2.5% vanadium, and 1.5% iron. This grade was developed in the 1990s for use as an armor plating. The iron reduces the amount of Vanadium needed as a beta stabilizer. Its mechanical properties are very similar to Grade 5, but has good cold workability similar to grade 9.

 

This data should settle some of the questions about titanium and its alloys.

 

Enjoy!

 

WSM

[taiwanluthiers]

You want to attach it so you can clip a lead to it and make full use of the anode. I used a strap of titanium but I think WSM said that titanium has poor electrical conductivity so he would use a tube, and then fill it with copper. I initially used a bolt to attach the strap to the anode but the titanium bolt was grade 5, it turned into soup 5 minutes into the run. Nobody makes CP titanium bolt so you will have to machine one yourself. You don't always have to have a lathe to do this. You can use a rod, and a die (the kind that makes threads) to make a threaded rod. Then use a tap to make a "nut" out of a titanium plate.

[Arthur]

The "Titanium" fittings (nuts bolts etc ) found on ebay etc tend to be stronger alloys but have been found to vanish in electrolysis cells. CP1 and CP2 have so far been found to be resistant to the cell liquor. Other alloys certainly exist. Remember that this cell liquor has been suspected of etching some glasses.

[WSM]

You want to attach it so you can clip a lead to it and make full use of the anode. I used a strap of titanium but I think WSM said that titanium has poor electrical conductivity so he would use a tube, and then fill it with copper. I initially used a bolt to attach the strap to the anode but the titanium bolt was grade 5, it turned into soup 5 minutes into the run. Nobody makes CP titanium bolt so you will have to machine one yourself. You don't always have to have a lathe to do this. You can use a rod, and a die (the kind that makes threads) to make a threaded rod. Then use a tap to make a "nut" out of a titanium plate.

 

The low electrical and thermal conductivity of titanium and its alloys are physical facts. That said, all metals are electrically conductive; but to vastly different degrees. For example, If we assign copper a conductivity of 100, titanium has a conductivity of 3.1!

 

What does this mean? It means that copper is about 32 times as conductive as titanium. It also means titanium can get horrendously hot as an electrical conductor unless the conductivity is increased in some manner (power "wasted", is typically exhibited as heat). I've used a titanium tube filled with lead-free solder (about 95% tin which is five times more conductive than titanium) as an electrode lead, successfully.

 

In my latest experiment, I'm using a titanium tube with a solid copper rod inside, closely matching the ID of the tubular titanium leads. The electrical connection is by brass bolts threaded into the tube and firmly pressed against the copper rod. In those electrode leads (carrying about 45-50 amperes continuously) the heating exhibited are about 45^oC on the anode lead and about 35^oC on the cathode lead; which is within the tolerable limits of the Kynar compression fittings holding the leads in the lid of the cell.

 

For connecting the leads to the electrodes themselves, I prefer spot welding (resistance welding) for a permanent bond. Some practice is required to get a good bond by spot welding but it's not difficult to figure out. Titanium screws or other fixtures are only required if in contact with the electrolyte (as in the cell). Many means of attaching the electrodes to the leads have been tried and they all work reasonably well.

 

I'm impressed with one individual who cut small bits of titanium sheet metal into elongated triangles and "stitched" his parts together by bending the end of the rough "rivets" he made thereby. They weren't pretty, but they worked. You can't argue with success. There was some discussion about them, where even if they weren't tight, on the cathode particularly, there was probably some hydrogen conductivity between the parts while the chlorate cell was running.

 

Threading together with titanium wire has been discussed and tried. Some have gotten larger titanium wire ( 0.125" [3 mm] diameter) and, using a rivet setter, formed rivets to bind the electrodes to the straps for leads. Swede even used TIG welding on the assembly of some of his cathode arrangements (as seen in his blogs).

 

As for CP grade titanium bolts, nuts and (I suppose) washers; they are made, just very hard to find. When you do find them, be prepared to pay dearly for them. Fabricating your own may well be the least expensive option, depending on your machining skills and the quality of your tools. Don't let that deter you, if you're determined and have patience, anything is possible.

 

WSM