Patent ID: 8217215

Claim:
A plant for the transformation of dangerous wastes containing chromium six into non dangerous wastes, wherein said plant includes: a milling area, where a waste material is transported through dump trucks to a milling area inlet; a vibration hopper feeding a jaw crusher that reduces the granulometry of the waste to pieces no larger than 2.54 cm (one inch); a conveyor belt taking the material coming from the crusher to a second milling step; a ball mill that reduces the granulometry, in order to expose all the chromium six derivatives to the extraction and reduction process; a storage silo where the milled material is sent by means of a bucket elevator; a chemical reaction area where three 20,000-liter stainless steel reactors are used, each equipped with stirring devices, steam jacket heating, gas extraction and washing an injection pipe supplying a sulfurous anhydride gas stream; a temperature control; dosing pumps to add a diluted sulfuric acid and eventually an additional reducing agent used; a carbon steel tank, minimum capacity 20,000 liters, for sulfuric acid storage; a carbon steel tank, minimum capacity 20,000 liters, for alternative auxiliary reducing agents storage; a series of four 1,000-Kg liquid sulfurous anhydride cylinders; and optionally a connection through adequate piping to a plant generating continuously an 8% sulfurous anhydride stream in air; and a tailings dam-type deposit for the storage of a treated waste material material or dangerous waste transformed into non dangerous waste, where the separation of solutions resulting from the transformation of dangerous wastes and a solid to be stored is conducted.