An idiots guide to making Chlorate's and Perchlorate's By WarezWally
1. Introduction 1.1. Aim of guide 2. Materials 2.1. Starting Salts 2.2. Anodes 2.3. Cathodes 2.4. Other 2.5. Power Supply 3. Cell Design 3.1. Materials 3.2. Design 4. Operation 4.1. Cell run start 4.2. Electrolyte processing 5. Miscellaneous 5.1. Material sources 5.2. Glossary
1. Introduction
1.1. Aim of guide The aim and purpose of this guide is to allow a home hobbyist to manufacture both chlorate's and perchlorate's in their own home. Some of the information out there is difficult to understand at the best of time and this guide will serve as a definitive source. There are many reasons why you may with to make your own chlorate's and perchlorate's, from rising commercial prices, experimentation or complete lack of supplies in various countries. With this guide you will be able to make: sodium chlorate sodium perchlorate potassium chlorate potassium perchlorate ammonium perchlorate While there are many other chlorate's and perchlorate's out there the above are the most commonly used by hobbyists and are the essayist to make. *WARNING* Making chlorate's and perchlorate's can be dangerous, you will be dealing with various toxic salts and dangerous processes which could result in serious injury or loss of life. Proceed with caution and common sense.
2. Materials
1.1. Starting Salts This section of the guide will cover the various salts you can start with and their uses. Sodium Chloride (NaCl) - This is the basic and best salt to start with if you intend to make chlorate's or perchlorate's. It is highly soluble in water and is easily obtainable sold just about everywhere as Table Salt. It is cheap and for all intensive purposes non-toxic. This is the starting salt I recommend as its easy to go from either sodium chlorate or perchlorate to potassium chlorate or perchlorate.
Potassium Chloride (KCl) - Probably the most important salt you will need, while you can start your cell with a potassium chloride electrolyte when it turns from potassium chloride to potassium chlorate it becomes very insoluble making to trip from potassium chlorate to potassium perchlorate very hard as you will need a huge quantity of water to dissolve all of the potassium chlorate in. This isn't a problem if you just want potassium chlorate as all you would need to do is to filter they crystals but this may be a issue depending on your anode selection. The best way around this problem is to go from sodium chloride > sodium chlorate and then perform a double decomposition reaction with potassium chloride to form potassium chlorate. The process is the same with sodium perchlorate. More on this later.
Ammonium Chloride (NH4Cl) - *WARNING* Never use this as a starting salt as it will turn into ammonium chlorate which is highly unstable. I cannot stress the importance of this enough. Ammonium chloride does play a role later in the production of ammonium perchlorate.
2.2. Anodes If anything gives you trouble getting set up it will be related to the anode. Unfortunately you are limited in what you van use for a anode in your cell. Same anodes can only make chlorate's. I will go into the various types below and how to make or source them.
Chlorate specific: Graphite: Graphite is the most easy anode to find. Graphite is a black dense solid which has a wide variety of uses which makes getting some much easier than some of the materials below. Graphite can be used in any shape but rod or block form is preferred, it should be at least 1/4" thick. While carbon will also work it will deteriorate much faster and is not recommended. The best graphite to use is the dense form used in EDM machines, it is very dense and when not abused will corrode very little. Graphite anodes should not be used when the electrolyte temperature is above 35c degrees and the current density should be around 35mA per square cm. Anything higher and it will corrode at a accelerated rate.
Magnetite: Magnetite anodes are made by melting and casting black iron oxide (Iron(III) oxide, Fe203) into a anode. A suitable mold is made out of iron and the powder is pressed into the mold and then is melted with a suitable heat source (1200c+). The easiest heat source is a oxy-acetylene flame used for welding. First the top side is melted with the flame, then carefully the semi-formed anode is flipped over so the un-melted powder on the other side can be melted. After that is done the anode must be annealed to prevent cracking as it cools, this can be achieved with a oven on the hottest setting and you gradually lower the temperature over a few hours. Magnetite anodes are poor conductors and efficiency will suffer, current density's are in the range of 50mA per square cm.
MMO (mixed metal oxide): This can be regarded as the best anode material out there for chlorate production. It is a mixture of valve metal oxides baked on a substrate (titanium). It will not erode and will work at very high current loads. Unfortunately they are not that easy to come by but they are sold as pool chlorinators for around $150. I was fortunate enough to find a seller who sells chlorate specific anodes for around $40.
I recommend you look around and try get a MMO anode, it will make the whole process so much easier.
Perchlorate specific: Lead dioxide: Lead dioxide is the perfect anode, it will not corrode unless badly abused and will make chlorate's and perchlorate's. It is cheap and will last a long time. This anode can go all the way from chloride to perchlorate and unlike platinum will not erode. The only major difficulty is obtaining one. The only real way to get one is to make one yourself but recently I may have located a supplier who operates out of India, see Suppliers section for more. I will discuss one way of making a suitable anode here. You will need: Lead nitrate Distilled water Lead oxide / carbonate (or any soluble lead salt) Copper (thicker pipe works best) Suitable container (glass is best) Adjustable power supply Nitric acid (*optional* Copper nitrate (*optional*) Aquarium heater (*optional* Plating bath setup 1. Dissolve 600g of lead nitrate in 1000ml of distilled water 2. Add the lead nitrate solution to your suitable container and carefully place the water heater to the side. Heat the solution to approximately 40c 3. *optional step* Add a few drops of 70% nitric acid and 3g of copper nitrate 4. Insert your copper cathodes and the material you with to plate into your plating bath. 5. Connect the cathode to the negative terminal and the substrate to the positive terminal. Adjust the voltage so the current is approximately 4-10mA, leave it like this for a f ew hours until a layer have been deposited on your substrate. After this you can adjust the voltage and raise the current to 50-80mA. 6. As more lead dioxide is plated onto your substrate you will need to replenish your lead levels so as the the layer grows dissolve some of your lead salt in the plating bath. This method will yield a lead dioxide platen anode, depending on your substrate and other factors it may last from a few hours to months. It should hold up well and will not erode as long as the cell temperature is kept below 60 degrees Celsius.
Platinum: Platinum is a very good anode material to use, the only downside is its very high cost (approximately $1440 per ounce). This limits people to platinum plater anodes, I personally dislike platinum plated anodes as the coating is very very thin (2-5um) and when your talking about such a thin layer it erodes very quickly if the conditions are not perfect. You will face increased erosion if you try to go from chloride to perchlorate as the anode erodes at a accelerated level when the chloride level drops too low. In order for you to avoid this problem you have to eliminate as much chloride as possible. The best way to do this is to use a chlorate specific anode to make the chlorate and then switch to t he platinum anode to go to perchlorate. This makes for extra work and can be a hassle depending on what anode you use. I list several sources of platinum anodes in the supplies section at the end of the guide. It is by far the most easy way to get a perchlorate capable anode but there are better and cheaper options out there. From what I can see you can run a large cell straight from chloride > perchlorate but by the end your anode will be wrecked but you should still end up with a few kilos of perchlorate.
2.3. Cathodes Fortunately getting a good cathode is much easier than getting a anode. You have a few options and the best option is quite easy to get. Your cathode should have a similar surface area to your anode although this isn't critical. Titanium: Titanium is the best cathode to use, it doesn't erode at all and will last forever no matter the conditions. The best grade to get is grade 1 through to 4 which are pure titanium. You can use some of the other alloys but its recommended to stick with the pure product. Both rod and sheet are easy to come by but its much easier to buy a rod as cutting titanium can be quite difficult. Once again, see the supplies section of the guide for a list of sources.
Stainless Steel: This is the next best thing to use but it is not recommended if you are using a lead dioxide anode. The best grade by far is 316, this is a fairl y common grade and like titanium will last a long time and will take a lot of abuse. It is much easier to shape compared to titanium.
While you can use other metals as your cathode (mild steel, iron) they may corrode and contaminate your product. Never use copper or brass as copper acts as a sensitizer.
2.4. Other This section covers other items that while are non essential will make your life much easier and will yield a better product. All of the items here are relatively easy to get a hold of. Glassware: I personally think getting good glassware is vital if you want good product. Some items can be easily substituted with things around the house while other you will have to buy. Below is a list of items you should get; 1. Beakers - 1000ml minimum, buy at least two or more. 2. Filter funnel - 70mm should be the minimum, you really only need one but a spare is always nice to have. 3. Filter paper - Coffee filters are a cheap option and work quite well but filter paper is cheap and you will get a much better product - paper and filtrate wise. Plus it will fit your filter funnel, you will need to improvise with a coffee filter to hold it securely. 4. Conical flask - Optional as a 2 liter soft drink bottle works just as well and costs next to nothing.
Other equipment: There are a few other things which are needed: 1. Heat source - A cheap butane camping stove as pictured above is great, its cheap, no need for expensive and large gas cylinders, its portable so it can be used outside. A electric hotplate works just as well but its less portable and more expensive. My model cost $20 and a 5 pack of gas was $8 2. Scales - A must have, a cheap set of digital scales will always come in handy. Can be purchased for $15 3. Multimeter - Another must have, you will need to know the voltage and current going into your cell. You can pick these up for $5 if you look around. You only need to measure voltage and current.
2.5. Power Supply Getting a suitable power supply is very easy and cheap, forget expensive battery chargers and lab supplies. Simply with pull apart a old computer and remove the ATX power supply or go to a computer store and ask for a old one. Chances are they will have a old one kicking around and will let you have it for $10. If not new ones are very cheap and there are plenty of second hand ones floating around. When you get your power supply it will be a jumble of wires, don't worr y we are only interested in a few. A ATX power supply is great because it supplies many voltages with plenty of capacity (current). The first thing you will have to do is to hot-wire your power supply. This is a simple procedure which is best explained by the picture below.
You should a connector like this. All you have to do is to connect the green wire (pin 14) to the black wire (pin 15) next to it and the power supply with turn on. This is completely safe.
Now that that is done we can get down to business. The only voltages we are interested in are the 5v rail and 7v rail. All of the black wires are the same, they are all negative (-), the red wires are 5v and the yellow wire are 12v. Below I will show you which wire to connect to to get what voltage you want.
So now we have a supply capable of multiple voltages, while we wont be using the 12v I left it there as its very useful for running 12v appliances (fans etc).
This is what a ATX power supply looks like, you can see the main connector used for hotwiring the power supply and the various colored wire which can be used.
3. Cell Design
3.1. Materials Many people give little thought to the design of the cell and simply whack a anode, a cathode in and away they go. Little do they know that that their makeshift cell is breaking apart and contaminating their product. There are a few materials which are perfectly suited for use as in a electrolytic cell, these are: Glass Polycarbonate Polyinylchloride The easiest cell material to use is glass, I find the perfect container to be a canning or pickling jar. They have a lid with a rubber seal which keeps them airtight at all times.
You may have to do a bit of searching to find one with a plastic lid but they are out there, while it is possible to drill through glass I do not recommend it (It can be done with a masonry bit). Another cheap option involves making your own container out of PVC plumbing parts. You can make it to your specifications and it is relatively cheap. The only downside is that it wont be clear and you wont be able to easil y see whats going on inside. PVC in the form of plumbing supplies should be available in nearly every hardware store.
3.2. Design Before drilling any holes you will need to work out the distances between your anode and cathode as this determines the current that will flow through your cell. The closer your anode and cathode is the higher the current will be. You will need to work all of this out before you go drilling and holes. After you have drilled or cut holes for your anode, cathode and vent hole you then need to seal around them so nothing can wick up and out which can destroy your electrical connections and cause havoc. Silicone can be used but I prefer hot melt glue, it works just as well and is cheaper. Simply go around where the anode, cathode and vent hole enters the cell with glue and make sure its a good seal. If hot melt glue doesn't work to well then I suggest epoxy glue.
4. Operation
4.1. Cell start run For our first cell run we will want to keep things simple, most people want to make potassium chlorate so we will start there. I am assuming you are using a MMO or platinum anode, if not you should be able to make the necessary adjustments as you go along. 1. Start by making a saturated solution of potassium chloride, simply take a large bucked and dump a large amount of your salt into it. Next add hot water until most of the potassium chloride dissolves. Let this cool to room temperature and you should have a bucket with a decent amount of crystals on the bottom and with a large amount of liquid on top. This is your starting electrolyte. 2. Pour as much saturated solution into your cell container making sure to fill it up as much as possible. 3. Dissolve a small amount of sodium of potassium hydroxide into your electrolyte, this will raise the pH and ensure that minimal chlorine escapes your cell. Ideally just keep adding until the pH is around 10 but if you don't have the materials to do that (pH pager, indicator solution) you can add a few grams, if you go over it wont hurt (and you can always add some HCl to counter it) 4. Insert anode(s) and cathode(s) into your cell making sure that they are covered by as much solution as possible. 5. Connect power supply leads, positive to the anode and negative to the cathode. Make sure you get this right. 5v is recommended. 6. Power up the cell and monitor the temperature, if it gets to hot then you will have to adjust the spacing between the anode and cathode. 7. Monitor the cell and top up with fresh solution as required.
