PDV Pure Dried Vacuum Salt Sodium Chloride NaCl White Powder Cas 7647-14-5

Pure Dried Vacuum Salt (often abbreviated as PDV Salt) refers to a high-purity grade of sodium chloride (NaCl) that is manufactured using a specific vacuum evaporation process.

What is Pure Dried Vacuum Salt?

It is one of the purest forms of salt available commercially, typically containing 99.9% or more sodium chloride. It is called "vacuum salt" because it is produced by evaporating purified brine (a saltwater solution) under a vacuum, which allows for gentle heating and superior purity.

Manufacturing Process

The production involves several key steps:

1. Solution Mining/Dissolution:​ Underground rock salt deposits are dissolved using water to create a concentrated brine solution.

2. Purification:​ The brine is treated to remove impurities like magnesium, calcium, and sulfate ions.

3. Vacuum Evaporation:​ The purified brine is fed into large evaporator vessels. By reducing the pressure inside these vessels (creating a vacuum), the boiling point of the water is significantly lowered (to around 70-80°C / 158-176°F). This allows the water to evaporate gently without causing thermal decomposition or incorporating impurities into the salt crystals.

4. Crystallization & Harvesting:​ As the water evaporates, pure sodium chloride crystals form and grow. These crystals are then harvested, washed, and dried.