Sodium Chlorate


Sodium Chlorate is the Chlorate that is mass produced by industry in tonnage quantities.
Its main use is in the making of ClO2 (Chlorine Dioxide gas) for bleaching in the paper industry and others. Industrial setup's use a continuous method of making Chlorate as opposed to a batch process. The amateur will usually use a batch process.
The starting material is NaCl (Sodium Chloride or common salt). About 330 grams NaCl per liter of water is the starting solution. A saturated solution is OK, which can be made by heating the water and adding excess salt. When no more salt is dissolving, cool, and you will then have a saturated solution. Getting the NaCl to dissolve can be difficult but heating helps, not because the solubility of NaCl increased much with increase in temperature, but rather the heating stirs the solution. There is some information on Chloride solutions here.
The wanted product, Sodium Chlorate, is very soluble.

Exactly what procedure you follow when making Sodium Chlorate is up to you. It depends on the Anode materials that you have available and on what Chlorate (or Perchlorate) salt that you ultimately want.
If you are ultimately going to make Sodium Perchlorate you may decide to separate the Chlorate and Perchlorate steps by separating out the Sodium Chlorate and then using this Chlorate in another cell to make Perchlorate. You may decide not to separate the Chlorate and Perchlorate stages (labour saving) and simply keep running your cell without separating out the Chlorate as per US patent 3,493,478 (see the Sodium Perchlorate section). You need a Lead Dioxide Anode to run from Chloride all the way to Perchlorate as wear rates ($$$) on Platinum may be too high. Graphite or Manganese Dioxide will not work. Magnetite may work if you run the cell long enough and it may not reduce the Chlorate to a low level.
If you have enough evaporation from the cell you can run a continous process by adding NaCl solution to the cell. The Na Chlorate will crystallize out when the concentration gets high enough.

If you are making Potassium Chlorate (from the Sodium Chlorate) you can simply run your cell for the required run time and take out a crop of Potassium Chlorate by adding KCl and start running the cell again.

Removal of product.
Collection of graphs and tables for Na Chlorate and Chloride.
Cost of making Sodium Chlorate.
Article from Encyclopedia of electro chemistry regarding Chlorate making