273 lines
14 KiB
Plaintext
273 lines
14 KiB
Plaintext
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Making chlorate and perchlorate
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This file has two parts... the first is predominantly about
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KClO4, and the second about KClO3. Both were taken from the
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net, original sources unknown.
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MAKING POTASSIUM PERCHLORATE
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This proceedure is a "tried and true" method. Unlike
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some rec.pyro postings, which are informational, or just
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plain speculative, this proceedure WORKS. I have used it
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myself to make my own supply of perchlorate - until I
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decided to quit because I was making it far too fast to use.
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This proceedure works well to make chlorates as well. The
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proceedure can be modified easily to make only chlorates.
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When using this proceedure to make perchlorate, it produces
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significant amounts of chlorate as a by-product. This is
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because carbon rods are not highly efficient in converting
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chlorate to perchlorate. Other anodes work better, but this
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proceedure was designed using easily available common
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materials and supplies.
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--- Author
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Carbon Rods
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Get some carbon rods from the welding shop. They are made by
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"arcair", and are 3/8" diameter by 12" long, and cost between
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40 to 60 cents(US) each. They are copper plated, and they are used
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for a welding proceedure known as "gouging".
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Cut off the top of a plastic 1 gallon milk jug. This is a
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good cheap source of containers for using in this proceedure.
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Dissolve 1/2 cup of salt in 2 liters of warm water. Put this
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in a small plastic container. Cut out a piece of coffee can,
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roughly 4" by 4" with a tab extending up to connect a wire to.
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The dimensions are not critical. With a 6 volt battery charger,
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connect the minus (-) connector to the piece of coffee can.
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Wrap some aluminum foil on the end of the carbon rod, to improve
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the electrical connection, and connect the plus (+) connector
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of the charger to it.
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Turn on the charger, and let it run for about 20 minutes. The
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copper will be removed from the rod. If some still remains,
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run it for a little longer till it is free of copper.
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Discard the salt water used to remove the copper.
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<p>You can probably use a 12V charger, but the current may get too
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high, so you may need to reduce how much of the rod is being
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etched at one time.
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Electrolyte solution
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Make a mixture of salt and potassium chloride solutions.
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Dissolve roughly 2 ounces (60 grams) of salt, and 8 ounces
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(240 grams) of potassium chloride in 2 liters (just a bit
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more than 2 quarts) of hot water. There is much room for
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inaccuracy here, because the exact mixture is not absolutely
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critical.
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At this point, it is good to add between 2 to 10 grams of
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either potassium chromate or dichromate. While this is not
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absolutely necessary, it helps improve how much perchlorate
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is finally produced. The process will work without it, but
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not quite as well.
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NOTE: Potassium chloride can be obtained as several commonly
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available products, such as: dietary salt substitute,
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ice melter (look at label for actual contents), and
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"muriate of potash" from farm and garden supply shops.
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Hagenow Laboratories carries potassium dichromate.
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The reason a mixture of salt and KCl is used, is two fold.
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First, salt is more easily electrolyzed than KCl, but after
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it converts to chlorate (and perchlorate), it will tend form
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the potassium salt instead of the sodium salt. The electrolysis
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tends to work on the sodium salt, while the final potassium
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perchlorate forms, and due to it's poor solubility, tends to
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crystalize out of solution. Secondly, the concentration of
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KCl is chosen to help prevent chlorate from crystalizing out,
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while being too high for the perchlorate to remain in solution,
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which causes it to crystalize out as it is created. These
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concentrations may be varied, to compensate for different
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operating temperatures. It was designed to operate at 40C, and
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will work fine above that temp, but below it, you might get
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some chlorate crysatlizing out, in which case you might need to
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reduce the amount of KCl just a little.
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I have been using a little salt in my mixture, but someone could
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exclusively electrolyze KCl, without the addition of salt. The
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purpose of the salt is to provide a sodium salt which is more
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easily electrolyzed than the potassium salt. It is NOT necessary,
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and will probably work well with only KCl.
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****** (Chlorate note) ******
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BTW, chlorates are produced here as an intermediate chemical
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product. Chlorates tend to be the predominant component around
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1 1/2 to 2 days of operation. Chlorate could be caused to
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crystalize out during electrolysis if the concentration of KCl
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in the starting electrolyte solution is increased to nearly
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saturation (about 21 ounces KCl/ with 2 ounces of salt). Although
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I have not concentrated on chlorate production, I would expect that
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you could actually run it for more than 2 days - possibly up to
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4 or 5 days, and keep building up a layer of largely chlorate
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crystals on the bottom. In that case, I would _GUESS_ that you could
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get around 2 pounds of chlorate after 5 days of operation.
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Electrolysis
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Using a coffee can for a source of steel, cut it out to form
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an inverted U shaped trough. Insert it in the mixture of salt
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and KCl dissolved in water. The (-) connector is connected to
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the steel. The steel U trough (similar to a rain gutter, except
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upside down) is setting at an angle to increase the amount of
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surface area in contact with the liquid. The carbon rod has
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some aluminum foil wrapped around the end of the rod, and the (+)
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connector is connected to it. The rod is positioned within the
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U shaped trough - under it, without touching. The charger is
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turned on, and he position & depth of the rod is adjusted to
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get 8 to 12 amps of current.
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NOTE: A setup with the electrodes running electricity through
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an electrolyte is called a "Cell". This setup is commonly
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refered to as a cell throughout this description.
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Let the liquid electrolyze for about 5 days continuously.
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Add water to make up for water lost during the process, and
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try to keep it roughly constant.
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A couple times a day, you will need to check the current level,
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and adjust the rod position to keep the current in the 8-12amp
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range. Mine has been running between 40 - 50C, but commercial
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proceedures keep the temp just below 40C to reduce carbon rod
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errosion. The rods will gradually errode away, but if you use
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a 6V charger, one rod will probably last for the full 5 days.
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You can also use higher voltage chargers, but you will probably
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need to connect several electrolytic cells together to keep
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the voltage accross ONE cell to be about 6 volts. If you use
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a 12 V charger, you will need 2 cells ( 12V/(6V per cell) = 2cells).
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If you connect more than 1 cell in series, you may need to use
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a voltmeter to check the actual voltage accross each cell - because
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it will change depending upon the resistance differences between
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the cells, which can be adjusted by re-positioning the rods.
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The purpose for the U shaped trough cathode (-) electrode, is to
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cause the gas bubbles formed to generate a convection flow up
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through the trough. This causes the chemical products produced
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at each electrode to mix and react efficiently. Other electrode
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geometries will work, some better, and others worse. The key
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is to cause the two electrodes to be very close to each other,
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and cause the chemical products to mix well to help form chlorate
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and perchlorates. The WORST case situation is where the electrodes
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are on opposite sides of the cell, causing the chlorine gas
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produced at the anode (+) to tend to bubble and escape
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out of solution into the air.
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Crystalization
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The potassium perchlorate crystalizes out
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as it electrolyzes. When you're done, you have a mixture of
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black carbon, perchlorate, and some chlorate after you drain
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off the liquid. I generally get a layer of perchlorate
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crystals about 1 inch (2.5cm) thick on the bottom, which tends
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to be about 1 pound.
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Cool the liquid in a freezer to help increase the amount of
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perchlorate that is crystalized out, before draining the electrolyte
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liquid. When draining the electrolyte, save it if you want to
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re-electrolyze it to make even more perchlorate again.
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Load the crystals into a filter, and use boiling water to
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dissolve the perchlorate out. As it filters, the perchlorate forms
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nice flat rhombic shaped (almost square) flakes that float out of
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solution. You watch it as it cools, and watch for chlorate crystals,
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which tend to look like clusters of cactus needles. When they
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start to form (well after the perchlorate has largely
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crystalized out), you drain the liquid, and add some room
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temp water which is to be about 2 - 3 times the volume of the
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crystals you have in the container. Shake them, and let it
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stand overnight to dissolve any chlorate crystals. Then
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drain, wash (with ice cold water), and dry the crystals.
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NOTE: Coffee filters generally aren't good enough to filter out
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the black carbon particles. You can load a coffee filter
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with a good layer of diatomaceous earth, and then use it
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to filter the liquid. Diatomaceous earth is used to filter
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swimming pool water, and a 10 pound bag can be obtained
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for less than US$10.00.
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You can purify them again by weighing the dried crystals,
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and adding enough water to dissolve the whole mass as if it
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was pure chlorate (i.e. 7g/100ml water)*. Use hot water, and
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then cool it down to room temp. You might even need to cool
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get the perchlorate to begin to crystalize (it seems to
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super saturate commonly). You might be able to get it
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started by adding a small amount of perchlorate dust as
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crystal seeds - if you have some to start with.. Then wash
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your crystals (with ICE COLD water), and dry them. That will
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help produce a higher purity product of perchlorate. If you
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want to make a chlorate-free batch of perchlorate, repeat this
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process again. It will be essentailly free of chlorate if you
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double crystalize it, and make certain you wash the crystals
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several times with cold water.
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Example: 100 grams of crystals would require
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100grams/(7gm/100ml) = 14.3 (100 ml), or 1430 ml of water,
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or about 48 ounces.
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NOTE: When harvesting the crystals, a cotton cloth makes a
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good filter. I wear rubber gloves, and squeeze the excess liquid
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from the crystals before & during washing them. Squeezing
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helps remove additional contaminants which are dissolved
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in the liquid that wouldn't otherwise be removed by
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simple gravity filtering. While this method loses very
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small crystaline particles, the loss tends to be very small
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in comparison to the amount of crystals harvested.
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Perchlorate is very easy to make, but it takes a little
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work. The hardest ingredient to get is patience.
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WARNINGS
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This proceedure generates small amounts of chlorine gas, as well
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as hydrogen gas. It should be conducted outdoors, or in a well
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ventilated building which is NOT used for living quarters! Hydrogen
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can accumulate in non-ventilated and sealed rooms to form potentially
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explosive mixtures with air!! Chlorine generally is more of a
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irritant, but can be poisonous at high concentrations. There are
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also other (?) chlorine oxides and/or ozone produced which should
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also be avoided.
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Chlorates and perchlorates are NOT chemicals for playing!! They
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are serious oxidizing agents which can be used to make VERY DANGEROUS
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pyrotechnic mixtures - _ESPECIALLY CHLORATES_ !!! Be certain to
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read up on all litterature describing the use and dangers of these
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compounds! It is VERY EASY to forget the safety hazards associated
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with these oxidizers in a time of haste - and lose a limb or your
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life as a result of your forgetfulness! Be careful to clean up
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any oxidizer which is spilled on carpets, or solutions which have
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spilled or splashed on any form of flamable material, including
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clothes, wood, paper, etc.
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CHLORATES ARE ESPECIALLY FRICTION AND SHOCK SENSITIVE!
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PERCHLORATES CAN ALSO PRESENT THE SAME HAZARDS, BUT NOT AS
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BADLY AS CHLORATES!
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ALSO, AVOID THE DISASTEROUS MIXTURE OF CHLORATE WITH SULFUR.
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NEVER MIX EITHER OF THESE WITH ANY FORM OF PHOSPHORUS, AS IT
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CAN IGNITE OR EXPLODE BY THE FRICTION OF SIMPLY MIXING THEM!!!!!
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Also, chlorates must be kept from any form of acids, especially
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sulfuric. Even small traces of acids (from the presence of sulfur,
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etc) can cause what "appeared" to be a stable mixture, to ignite at
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some unknown time later!
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