Talk:Sodium chlorate

From PyroGuide

+++++PROFMAD: Now that sodium chlorate is no longer available in the UK, as of this year, I feel it OK to detail how it could be purified from the weed killer. It was present as 53% NaClO3, the rest fire depressant. Using relative solubility, the mixture was dissolved until approximately half of the weed killer had dissolve in boiling water and then filtered rapidly. NaClO3 has a solubility of ~200g/100ml @100deg.C; the filtrate is then cooled to 0 deg. The residue is discarded. After a few hours, crystals of relatively pure NaCl03 crystallise out (solubility: ~80g/100ml @0deg. C). The crystals are then washed with a little ice cold water, then dried (as quickly as possible, due to its hygroscopic nature), then re-crystallised if greater purity is required. All filtrate is kept. From the filtrate KCl03 is made by adding a stoichiometric quantity of hot KCl to the filtrate, and again left to cool at O deg. C. KCl03 has a solubility of ~3.3g/100mls @)0 deg. C. As the filtrate is at a concentration of approximately 80g/100ml less the volume of KCl solution, a great deal of KCl03 will ppt. The total yield of Cl03- as Na+ & K+ can be as high as 90% This ppt of KClO3 is then washed with ice cold water and dried at room temperature, or re-crystallised for greater purity. PROFMAD+++++