Lye Purification Information
Contents
Basics
So basically I was doing some work to document, and/or plan out how to make biodiesel. I realized then that most reactions use sodium or potassium hydroxides (Lye). I remembered a past instructable on making lye via wood ash leaching. Thus I made the Open Source Bases Construction Set. So later I was planing how to purify the crude lye into actual pure (or at least as close as we can get) potassium hydroxide. I made the Open Source Lye Purification Apparatus page but intend for that to be an automated device likable to the Open Source Lye Production Apparatus. Thus I am now here. I determined that repeated recrystilizations should yeild a relitively pure product. Due to the washing after each recrystilization of everything it seemed more simple to just do this with a chemist, some basic lab equipment, and a whole lot of time.
Lab Equipment Needed
- Open Source Ball Mill
- Open Source Lye Production Apparatus
- Open Source Round Botomed Flask
- Open Source Heating Mantle
- Open Source Chilled Labratory Bath (If you are fancy, otherwise use a bowl/sink filled with ice water)
- Pick one of these
- Open Source Evaporative Dish
- Pick One of These
- Open Source Dessicator
- Open Source Vacuum Dessicator
- Open Source Drying Oven
- Basic Saftey Gear (Gloves, Glasses/Goggles/Facesheild/mix of these, Lab Apron Etc) (Also see Open Source Saftey Construction Set)
- Open Source Glass Stir Rod
- Device for scraping out the flask and drying dish
Materials/Consumables
- Distilled Water
- Wood Ashes
- Filter Paper
Procedure
- Begin by gathering materials
- Leach the ashes
- Filter The Liquid
- Dry the powder you get
- Pour this powder into the bottom of a round bottomed flask
- Add a magnetic stir rod
- Add Xml of Distilled Water (Note that this is exothermic so cool as needed) (also heat may help the reaction get staarted but is otherwise not needed much at this point
- Once dissolved start slowly drying the liquid via heat to begin the recrystilization
- Once crystal growth has peaked, remove from heat and filter as soon as possible
- Once dissolved start slowly drying the liquid via heat to begin the recrystilization
- Dry the powder you get
- Filter The Liquid
- Leach the ashes
Now loop steps 3-7 untill desired purity is reached. Then clean up all materials and store the powder in a dry place