A pump system (204, 804, 1004, 1204) for a metal furnace, the pump system (204, 804, 1004, 1204) comprising: a tank (206, 806, 1006, 1206) comprising a tank chamber (214, 814, 1014) configured to receive a molten material; and a magnetic stirrer (208, 808, 1008) comprising a rotating permanent magnet, wherein the tank (206, 806, 1006, 1206) is positioned above magnetic stirrer (208, 808, 1008) and such that the magnetic stirrer (208, 808, 1008) is outside of the tank chamber (214, 814, 1014), and wherein the magnetic stirrer (208, 808, 1008) is configured to generate a moving magnetic field in the molten material in the tank chamber (214, 814, 1014) to induce movement in the molten material, an inlet (222, 822, 1022, 1222) in fluid communication with the tank chamber (214, 814, 1014) and defining a flow path to the tank chamber (214, 814, 1014) for molten material entering the tank chamber (214, 814, 1014); and an outlet (224, 824, 1024, 1224) in fluid communication with the tank chamber (214, 814, 1014) and defining a flow path from the tank chamber (214, 814, 1014) for molten material exiting the tank chamber (214, 814, 1014), wherein a transverse dimension of the tank chamber (214, 814, 1014) proximate to the inlet (222, 822, 1022, 1222) is different from the transverse dimension of the tank chamber (214, 814, 1014) proximate to the outlet, wherein the transverse dimension of the tank chamber (214, 814, 1014) is the dimension across a widest portion of the tank chamber (214, 814, 1014), wherein a surface of the tank chamber (214, 814, 1014) comprises a non-linear curve between the inlet (222, 822, 1022, 1222) and the outlet (224, 824, 1024, 1224), characterized in that the pump system further comprises a mixer (112, 212, 1012), selectively positionable within and removable from the tank chamber, wherein the mixer (212, 1012) comprises a body, and wherein the body comprises one or more fins along an edge of the body, wherein the mixer (112, 212, 1012) is movable between a lowered position and a raised position, wherein in the lowered position, the mixer is positioned at least partially within the tank chamber (114, 214, 814, 1014) and/or at least partially within the molten material within the tank chamber (114, 214, 814, 1014), and, in the raised position, the mixer is positioned above the molten material within the tank chamber (114, 214, 814, 1014) and/or outside of the tank chamber (114, 214, 814, 1014). a tank (206, 806, 1006, 1206) comprising a tank chamber (214, 814, 1014) configured to receive a molten material; and a magnetic stirrer (208, 808, 1008) comprising a rotating permanent magnet, wherein the tank (206, 806, 1006, 1206) is positioned above magnetic stirrer (208, 808, 1008) and such that the magnetic stirrer (208, 808, 1008) is outside of the tank chamber (214, 814, 1014), and wherein the magnetic stirrer (208, 808, 1008) is configured to generate a moving magnetic field in the molten material in the tank chamber (214, 814, 1014) to induce movement in the molten material, an inlet (222, 822, 1022, 1222) in fluid communication with the tank chamber (214, 814, 1014) and defining a flow path to the tank chamber (214, 814, 1014) for molten material entering the tank chamber (214, 814, 1014); and an outlet (224, 824, 1024, 1224) in fluid communication with the tank chamber (214, 814, 1014) and defining a flow path from the tank chamber (214, 814, 1014) for molten material exiting the tank chamber (214, 814, 1014), wherein a transverse dimension of the tank chamber (214, 814, 1014) proximate to the inlet (222, 822, 1022, 1222) is different from the transverse dimension of the tank chamber (214, 814, 1014) proximate to the outlet, wherein the transverse dimension of the tank chamber (214, 814, 1014) is the dimension across a widest portion of the tank chamber (214, 814, 1014), wherein a surface of the tank chamber (214, 814, 1014) comprises a non-linear curve between the inlet (222, 822, 1022, 1222) and the outlet (224, 824, 1024, 1224), characterized in that the pump system further comprises a mixer (112, 212, 1012), selectively positionable within and removable from the tank chamber, wherein the mixer (212, 1012) comprises a body, and wherein the body comprises one or more fins along an edge of the body, wherein the mixer (112, 212, 1012) is movable between a lowered position and a raised position, wherein in the lowered position, the mixer is positioned at least partially within the tank chamber (114, 214, 814, 1014) and/or at least partially within the molten material within the tank chamber (114, 214, 814, 1014), and, in the raised position, the mixer is positioned above the molten material within the tank chamber (114, 214, 814, 1014) and/or outside of the tank chamber (114, 214, 814, 1014).