Make your own pyramid salt crystals
  > But I did find a study published in the World Salt Symposium where researchers successfully grew pyramid salt from waste salt water in large, steel crystallizers.

Wow, I never knew that there was an entire symposium dedicated to salt.From https://www.bolton-menk.com/salt-symposium/:  This event celebrates the optimization of salt use to improve community sustainability and protect vital freshwater systems and infrastructure.
  The Salt Symposium brings together leaders from diverse economic sectors to learn about the impacts of chloride and reduction methods. Professionals from across the world will share their expertise on current research initiatives including water softening, wastewater, fertilizer, snow and ice management, and more.