We don't have synonyms for pug mill yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are pugmill, per mill and gig mill.
(n) :
(construction, pottery) A kind of mill for grinding, mixing, and working clay, either for art or brickmaking. It consists essentially of an upright shaft armed with projecting knives, which is caused to revolve in a hollow cylinder, tub, or vat in which the clay is placed.
(n) :
(construction, pottery) A kind of mill for grinding, mixing, and working clay, either for art or brickmaking. It consists essentially of an upright shaft armed with projecting knives, which is caused to revolve in a hollow cylinder, tub, or vat in which the clay is placed.