Spanish to English Tech/Engineering Materials (Plastics, Ceramics, etc.) Refractive materials for an ironworks company

XX contratará a XX los suministros de masas refractarias de:
Masas de gunitados, feetling, y masas o arenas de piqueras para el Horno

I really have a problem with this entire sentence... masas, gunitados, feetling, piqueras...

For "masas refractarias" can I just say refractories?
"masas de gunitados" = just gunite, or gunning materials?
I have found the word "feetling" nowhere... Google keeps wanting to change it to feeling, could it be feeding perhaps?
piqueras, I have found ore chute, tapping bar, hole...
Thank you very very much for any help with this... Mary Bauer