Transportation of soluble solids

A method of transporting solids that are soluble in a solvent comprising

• (A) placing in a a cylindrical horizontal tank of a railroad tank car a quantity of said solids that exceeds the amount that will dissolve when said tank is filled with said solvent, where said tank has a volume, a longitudinal axis, an intersecting vertical axis, and an agitator assembly mounted on its top, said agitator assembly comprising a shaft that enters said tank, a propeller fixed to the end of said shaft that is inside said tank, and means for rotating said shaft so that said propeller has an axial discharge velocity of flow of about 4.25 to about 4.75 m/sec with a flow equivalent of about 0.22 to about 0.26 tank volumes/minute, where said shaft is at an angle α to said longitudinal axis of said tank of between about 35 and about 45 degrees and at an angle β to said vertical axis of said tank of between about 35 and about 45 degrees;
• (B) transporting said railroad tank car to a location where said solids are to be removed therefrom;
• (C) adding said solvent to said railroad tank car around said propeller;
• (D) rotating said propeller at an angular velocity sufficient to provide a flow discharging axially from said propeller of about 4.25 to about 4.75 m/sec with a flow equivalent of about 0.22 to about 0.26 tank volumes/minute, whereby said solids dissolve in said solvent, forming a solution;
• (E) removing solution from the bottom of said railroad tank car;
• and
• (F) adding additional solvent to said tank and repeating steps (D) and (E).

A method of shipping chromic acid in a railroad tank car comprising

• (A) placing in the tank of a railroad tank car a quantity of solid chromic acid that exceeds the amount that can be dissolved when said railroad tank car is filled with water, where said tank is cylindrical and horizontal and has a volume, a longitudinal axis, an intersecting vertical axis, at least one nozzle on top that is not near the center of said tank, and an agitator assembly mounted over said nozzle, said agitator assembly comprising
• (1) an agitator which comprises
• (a) a shaft;
• (b) a propeller fixed to one end of said shaft;
• and
• (c) an electric motor capable of rotating said shaft in fluid in said tank with a flow discharging axially from said propeller of about 4.25 to about 4.75 m/sec with a flow equivalent of about 0.22 to about 0.26 tank volumes/minute;
• (2) means for mounting said agitator over said nozzle so that
• (a) said shaft enters said tank through said nozzle at an adjustable angle α to said longitudinal horizontal axis of said tank of between about 35 and about 45 degrees and at an adjustable angle β to the vertical axis of said tank of between about 35 and about 45 degrees;
• and
• (b) said propeller is about 0.2 to about 0.4 m from a side of said tank;
• (B) transporting said railroad tank car to a location where said chromic acid is to be removed therefrom;
• (C) adding water to said tank around said propeller;
• (D) rotating said propeller at an angular velocity sufficient to provide an axial discharge from said propeller of about 4.25 to about 4.75 m/sec with a flow equivalent of about 0.22 to about 0.26 tank volumes/minute, whereby said chromic acid dissolves in said water forming an aqueous solution of chromic acid;
• (E) removing said aqueous solution from the bottom of said tank;
• and
• (F) repeating steps (C), (D), and (E) until all of said chromic acid has been dissolved and removed from said tank.