A physical form of iron sulfide known as pyrophoric iron sulfide, is often present in solid iron sulfide scales in refinery units. Regardless of their form—pyrite, troilite, marcasite, or pyrrhotite—pyrophoric iron sulfides can ignite spontaneously when they are dried and exposed to atmospheric oxygen. The resulting fires frequently damage equipment and endanger lives.

Distillation columns in crude and vacuum distillation units are most susceptible to these fires. Fortunately, with the use of the Zyme-Flow^SM Process, accidents due to pyrophoric iron oxidation are entirely avoidable.

The oxidizing action of Zyme-Flow^® 657 neutralizes iron sulfides on contact while they are still in place, converting all surface sulfides to either elemental sulfur or soluble sulfates. All surface iron is oxidized to the ferric condition (Fe⁺³).