Salt purity is defined by the level of sodium chloride in the final crystal. The higher it is, the lower the level of impurities. Especially in membrane electrolysis the level of impurities greatly determines the efficiency of the process and quality of the products. For example impurities like Ca, Mg, Sr, Al, Fe, Ba, sulfate and iodide have a detrimental effect on the membrane and/or electrodes and lead to a lower current efficiency or increased voltage, greatly increasing the energy costs. Other impurities like Br and K end up in the chlorine / chlorate or caustic soda, respectively, affecting the value of these end-products.
It is precisely the purity that gives vacuum salt the edge over solar and rock salt. AkzoNobel vacuum salt has an extremely high purity and does not require additional purification steps. In contrast, lower salt qualities like solar or rock salt need primary brine purification adding complexity, investments, chemicals, manpower, waste management challenges and risks to the total supply chain. But even then, the quality of vacuum salt cannot be matched due the lack of a vacuum crystallization step. That is why high purity AkzoNobel vacuum salt ensures better cost control across the total process.
We are happy to discuss the many benefits of high purity vacuum salt for your particular operations and help you select the optimal anti-caking agent.