Pump for molten materials with suspended solids

A molten material pump includes an impeller housed within a base member of the pump. A plurality of grooves are defined in a peripheral sidewall of the impeller for either drawing a molten material into the base member's chamber or pushing molten material out of the base member's chamber. The impeller is rotated by a rotatable shaft connected to an upper surface of the impeller. The rotatable shaft includes a non-circular shaped lower end dimensioned to be received within a cooperating opening in the impeller. The molten material pump further includes a connecting assembly for interconnecting components of the molten material pump. The connecting assembly includes a first mounting member attached to a first pump component that is dimensioned to be fitted within a cooperating recess of a second mounting member attached to a second pump component. In another embodiment of the invention, a stub shaft connects an upper shaft portion of the shaft to the impeller. The stub shaft includes a universal joint that is not rigidly connected to the upper shaft portion. In addition, the universal shaft is configured to allow the stub shaft and impeller to pivot. A floating deflector block weighs on an upper sealing block of the pump for enhancing the seal at the pump's bearing surfaces.