The answer to this question involves more speculation than fact. Your 10 MT is assumed to mean 10 metric tons, not 10 million tons (which is ridiculous).  At that mass, I get a volume of approximately 2,600 gal (10 cubic meters).  That volume will fit in a 96-inch (2.5 m)  diameter by 96-inch (2.5 m) tall vessel.
 
A 40-inch (1.0 m) diameter pitched-blade turbine running at 100 rpm (1.67 rps) should be able to suspend about 10wt% (a guess about the application), 5/8-inch particles with a 1.15 sp.gr. in hot water, assuming the particles are fairly round and do not stick together. The mixer will require a 15 hp (11.4 KW) motor and a gear reducer capable of 9,500 in-lbs (1.000 NM) torque.
 
Far more information is needed to accurately size a mixer. This information is only a budget estimate.  The mechanical design is another consideration entirely.  Tank baffles, mixer mounting, shaft diameter, and impeller blades all must be designed for strength.  The shaft must be designed for critical speed, which could be a serious problem.  The mechanical limits of this design have not been considered in this general information.  A competent equipment manufacturer or mixing consultant is needed for a more detailed design based on complete information about the application.