Abstract: Foundry apparatus for mixing sand with binder ingredients to produce a composite mixture suitable for foundry molds includes a first premixing chamber enclosing a first bladed shaft mounted for rotation about a substantially horizontal first axis operable for conveying and commingling sand with a first binder ingredient to produce a first sand/binder ingredient mixture. A second premixing chamber, separate from the first premixing chamber, encloses a second bladed shaft mounted for counterrotation about a second axis, substantially parallel to the first axis, for conveying and commingling sand with a second binder ingredient to produce a second sand/binder ingredient mixture. A final mixing chamber includes agitators for receiving the sand/binder ingredient mixtures and blending them into a composite mixture while simultaneously transporting the composite mixture to a final discharge station.