After uemuras summer break he is submitting two methods for the preparation of two valuable salts. This method shows how to make Potassium chlorate from OTC chemicals. KClO3 can be used for preparation of KMnO4, which is explained in onther thread.
Introduction:
KClO3 has been used in explosives. This is the main reason why it's watched and not sold to private persons. It is a strong oxidiser. It must kept very clean, it must be kept away from any organic substances as well from most other chemicals. ALL SUCH CHLORATE BASED MIXTURES ARE SENSITIVE TO FRICTION, AND SHOCK, AND THESE BETTER BE AVOIDED. The following two procedures are from the internet. Pyrotechnical de-tours have been removed to keep them nice and tidy.
Mol: 123 g/mol
Preparation (Procedure 1, using bleach powder)
Required Chemicals:
1200 g H.T.H (calcium hypochlorite 65%)
220g Potassiumchlorid
Procedure 1:
In this reaction the H.T.H. (calcium hypo-chlorate CaC10) is mixed with water and heated with potassium chloride (salt substitute). The potasium chloride if prefered over sodium chlorite due to the easy crystallization of the potassium chlorate. This mixture will need to be boiled to ensure complete reaction of the ingredients.
In a large pyrex glass or enameled steel container place 1200 g H.T.H. and 220 g potassium chloride. Add enough boiling water to dissolve the powder and boil this solution. A chalky substance (calcium hydroxide?) will be formed. When the formation of this chalky substance is no longer formed the solution is filtered while boiling hot. The potassium chlorate will drop out or crystalize as the clear liquid left after filtering cools. These crystals are filtered out when the solution reaches room temperature. The KClO3 can be easily recristallised from hot water. This will lead to a very pure product because of the high solubility of KClO3 in boiling water.
Preparation (Procedure 2, Electrolytical method from the Internet)
Required Chemicals:
454 G sodium chloride [1]
some muriatic acid
7g sodium dichromate [2]
9g barium chloride [3]
Procedure 2:
The major part of the manufacture of this explosive from rock salt is the cell reaction where D.C. current changes the sodium chloride to chlorate by adding oxygen by electrolysis of a saturated brine solution. The reaction takes place as follows:
NaCl + 3H2O ----> NaClO3 + 3H2
In this reaction the sodium chloride (NaCl) takes the waters' oxygen and releases its hydrogen as a gas. This explosive gas must be vented away as sparks or open flame may very well cause a tremendous explosion. This type of process or reaction is called a 'cell' reaction. The cell should be constructed of concrete or stainless steel. I won't give any definite sizes on the cell's construction because the size is relative to the power source. This cell would have to be large enough to allow the brine to circulate throughout the cell to insure as uniform a temperature as possible.
The speed of the reaction depends on two variables. Current density is a very important factor in the speed of the reaction. The advantages of high current densities are a faster and more efficient reaction. The disadvantages are that cooling is needed to carry away excess heat and the more powerful power sources are very expensive. For small operations, a battery charger can be used (automotive). This is the example I will use to explain the cell's setup and operation (10 amp 12 volt). The current density at the anode (+) and cathode (-) are critical. This density should be 50 amps per square foot at the cathode and 30 amps per square foot at the anode. For a 10 amp battery charger power source this would figure out to be 5 5/16" by 5 5/16" for the cathode. The anode would be 6 15/16" by 6 5/16". The anode is made of graphite or pressed charcoal and the cathode is made of steel plate (1/4"). These would need to be spaced relatively close together. This spacing is done with some type of nonconducting material such as glass rods. This spacing can be used to control the temperature to some extent. The closer together they are, the higher the temperature. These can be placed either horizontally or vertically although vertical placement of the anode and cathode would probably be the ideal set up as it would allow the hydrogen to escape more readily. The anode would be placed at the bottom if placed horizontally in the cell so that the chlorine released could readily mix with the sodium hydroxide formed at the cathode above it. As the current passes through, the cell chlorine is released at the anode and mixes with the sodium hydroxide formed at the cathode. Hydrogen is released at the cathode which should bubble out of the brine. This gas is explosive when mixed with air and proper precautions should be taken. PROPER VENTILATION MUST BE USED WITH THIS OPERATION TO AVOID EXPLOSION.
Temperature control is left up to the builder of the cell. The temperature of the cell should be maintained at 56 degrees C during the reaction. This can be done by the circulation of water though the cell in pipes. But the easiest way would be to get an adjustable thermostatic switch adjusted to shut the power source off until the cell cools off. This temperature range could be from 59 degree shut off to a 53 degree start up. An hour meter would be used on the power source to measure the amount of time the current passes through the cell. If the water cooling coil design appeals to the manufacturer and an easily obtained cheap source of cool or cold water is available, this would be the quickest design to use. Again a thermostatic type arrangement would be used to meter the cold cooling water through the cell. The cooling coils would best be made of stainless steel to overcome the corrosiveness of the salts although this is not entirely necessary. A thermostatic valve would be set to open when the brine electrolyte was heated above approximately 58 degrees C. Again this would be the best and most efficient method and the waste heat could be used relatively easily.
To run the cell, after the cell has been constructed and the concrete has been sealed and has set and cured for several weeks, is very simple. First to seal the concrete I suggest Cactus Paint's C P 200 series, two component epoxy paint, or an equivalent product. To fill the cell place 454 G sodium chloride in the cell (rock salt is excellent here). Place four liters of distilled water into the cell with the salt. The liquid should cover the anode and the cathode completely with room to spare. Remember that some of the water will be used in the reaction. Thirty three grams of muriatic acid (hydrochloric), which should be available at swimming pool supply stores or hardware stores, is then added to the liquid in the cell. Be careful when handling ANY acid!!! Then seven grams of sodium dichromate and nine grams of barium chloride is added. The cell is then ready to run if the plates are connected to their respective cables. These cables are best made of stainless steel (the most corrosion resistant available). The power supply is then hooked up and the cell is in operation. The power is best hooked up remotely to lessen the chance of explosion. Any time the cell runs it will be making hydrogen gas.
THIS GAS IS EXPLOSIVE WHEN MIXED WITH AIR AND ALL SPARKS, FLAME, AND ANY SOURCE OF IGNITION SHOULD BE KEPT WELL AWAY FROM THE CELL AND THIS CELL SHOULD ONLY BE RUN WITH VERY GOOD VENTILATION.
The steel plate cathode should be hooked to the negative side of the power source and the anode hooked to the positive side. Again these are hooked to the power supply via stainless steel cables. This cell is then run at the proper temperature until 1800 amp hours pass through (amount per pound of sodium chloride) the electrolyte. The liquid in the cell is then removed and placed in an enameled steel container and boiled until crystals form on liquid. It is cooled and filtered, the crystals collected being saved. This is done twice and the remaining liquid saved for the next cell run. The process will become easier as each run is made. It is a good idea to keep records on yields and varying methods to find out exactly the best process and yield. To purify these crystals place 200 grams in 100 ml distilled water. Boil the solution until crystals are seen on the surface. Let cool and filter as before. Save this liquid for the next cell run. These purified crystals are placed in a pyrex dish and placed in the oven at 50 degrees C for two hours to drive off all remaining water.
[1] The equivalent amount of Potassium chloride could be used as well.
[2] [3] These two are added to protect the electrodes. Should work without them.
Carpe Diem
