Soda (Sodium Carbonate)

Soda ash (sodium carbonate, Na2CO3) is a white, odorless, water-soluble salt. It is a critical industrial chemical, historically obtained from the ashes of sodium-rich plants.

Description of what it is like

• Appearance: White powder or crystalline solid.
• Taste: Strongly alkaline (cooling taste).
• Solubility: Dissolves easily in water.

Origin and where to find it

• Environments: Saline lakes (natron deposits) or ashes of seashore plants (barilla, kelp).
• Signs: White crusts on dry lake beds.
• Natural: Occurs as the mineral natron.

Minimum processing required

• Leaching: Soaking plant ashes in water to dissolve the salts.
• Evaporation: Boiling the water to crystallize the soda.
• Calcination: Heating to remove water and bicarbonates.

Tools needed to work on it

• Pots/Kettles: For boiling and leaching.
• Furnace: For burning plants or calcining.

Common forms of use

• Flux: Lowers the melting point of silica for glass.
• Lye: Reacted with lime to make caustic soda for soap.
• Cleaner: Washing soda for laundry.

Possible substitutes

• Potash: Potassium carbonate from wood ashes (makes glass harder/less durable).

Limitations and common failures

• Humidity: Absorbs moisture from air and clumps.

Risks and safety

• Irritant: Dust irritates eyes and lungs. Solution is alkaline and can irritate skin.

Related materials

• Glass: Essential ingredient.
• Soap: Precursor ingredient.
• Ash: Source material.