A mixing tank arrangement , comprising: a tank , the tank comprising at least one feed opening for feeding at least a first and a second material into the tank , wherein the at least one feed opening is coupled with a feeding system for controlling feeding of the at least first and the second material into the tank ; and a recirculation system having a first inlet and a first outlet for recirculating and mixing the first and the second material in the tank , wherein the first inlet comprises a body pipe in an upper side of the tank (FS), having a plurality of feeding pipes extending to a lower side of the tank (SS) configured to jet the at least first and the second material to the upper side of the tank (FS), characterized in that the tank is a horizontal tank having a first end (FE), a second end (SE) and a curved side wall (CS) between the ends, the body pipe extends in a longitudinal direction of the tank , and the recirculation system is configured to provide a pressure for jetting the at least first and second material through the feeding pipes from the lower side (SS) to the upper side (FS) of the tank such that the first and the second material hit a curved side wall of the tank (CS) in the upper side (FS) and wherein curved shape of side the wall (CS) in the upper side (FS) is configured to divide the at least first and the second materials to at least two streams that flow on the opposite sides of the tank following the curved shape of the side wall (CS) to the lower side of the tank (SS) and collide in the lower side of the tank (SS). at least one feed opening for feeding at least a first and a second material into the tank , wherein the at least one feed opening is coupled with a feeding system for controlling feeding of the at least first and the second material into the tank ; and a recirculation system having a first inlet and a first outlet for recirculating and mixing the first and the second material in the tank , wherein the first inlet comprises a body pipe in an upper side of the tank (FS), having a plurality of feeding pipes extending to a lower side of the tank (SS) configured to jet the at least first and the second material to the upper side of the tank (FS), characterized in that the tank is a horizontal tank having a first end (FE), a second end (SE) and a curved side wall (CS) between the ends, the body pipe extends in a longitudinal direction of the tank , and the recirculation system is configured to provide a pressure for jetting the at least first and second material through the feeding pipes from the lower side (SS) to the upper side (FS) of the tank such that the first and the second material hit a curved side wall of the tank (CS) in the upper side (FS) and wherein curved shape of side the wall (CS) in the upper side (FS) is configured to divide the at least first and the second materials to at least two streams that flow on the opposite sides of the tank following the curved shape of the side wall (CS) to the lower side of the tank (SS) and collide in the lower side of the tank (SS). characterized in that the tank is a horizontal tank having a first end (FE), a second end (SE) and a curved side wall (CS) between the ends, the body pipe extends in a longitudinal direction of the tank , and the recirculation system is configured to provide a pressure for jetting the at least first and second material through the feeding pipes from the lower side (SS) to the upper side (FS) of the tank such that the first and the second material hit a curved side wall of the tank (CS) in the upper side (FS) and wherein curved shape of side the wall (CS) in the upper side (FS) is configured to divide the at least first and the second materials to at least two streams that flow on the opposite sides of the tank following the curved shape of the side wall (CS) to the lower side of the tank (SS) and collide in the lower side of the tank (SS). <EOS>