Hydrostatic pressure assisted autoclave system for hydrometallurgical processing

Abstract

The hydrostatic pressure differential existing in a column of fluent material conveyed through an excavated passage possessing a downward entrance run and upward return run facilitates hydrometallugical processing including metals recovery and treatment of ores. Conveyance of the fluent material through the passage is facilitated by appropriate means including a difference in elevation between the inlet and outlet and/or gaseous expansion applied proximate the bottom of the return run. Cooling of effluent proximate the outlet may be utilized consequent to application of heat during processing as in roasting ore. The passage is excavated through rock filly capable of containing the pressures anticipated and has an interior casing which seals the rock porosity. Iron reinforced concrete is recommended in appropriate wall thicknesses. Location of appropriate pipe lines for pressurized fluid additives including compressed gas and liquid chemical reagents and the location of electrical lines if utilized within this interior casing is also recommended. Continuous operation autoclaving of hydrometallurgical processes in a safe and economical manner is facilitated.

It is emphasized that the foregoing is intended to provide one skilled in the art with what is considered the best manner of making and utilizing a system in accordance with the principles relating to the present invention and is not to be construed in any manner as restrictive of the scope of said invention nor of the rights and privileges obtained by Letters Patent for which we claim:  
     
         1 . An autoclave system for conducting various processes in which fluent material, inclusive of solids, liquids, and gases, is subjected to pressure elevated from ambient, said system comprising: 
 an excavated passage, flow inducing means, and fluid addition means;    said excavated passage possessing an entrance run with an inlet and a return run with an outlet, each said run possessing an inclination from horizontal and extending downward through rock, both said runs possessing communication with each other at a predetermined depth with respect to said inlet and said outlet, said entrance run and said return run each possessing a fully encompassing continuous casing sealing surrounding rock porosity;    said flow inducing means being capable of inducing flow of fluent material introduced through said inlet through said excavated passage, including autoclave areas in which elevated pressure is naturally created and maintained by a hydrostatic column of fluent material, and out said outlet;    said fluid addition means being capable of adding at least one fluid reagent to at least one location inside said passage at a pressure exceeding the hydrostatic pressure existing at that location in the passage when said passage is filled with fluent material;    whereby flow of fluent material introduced through said inlet is induced downward through said entrance run and the addition of fluid reagent under pressure into, and the pressure maintained hydrostatically in, said flow of fluent facilitates hydrometallurgical processing of said fluent material under elevated pressure resulting in processed effluent outflow through said outlet.    
     
     
         2 . The system of  claim 1  wherein said entrance run possesses a volume exceeding the volume of said return run.  
     
     
         3 . The system of  claim 2  wherein said entrance run possesses a substantially uniform cross sectional area which exceeds in size a substantially uniform cross sectional area possessed by said return run.  
     
     
         4 . The system of  claim 1  wherein said entrance run and said return run both occupy a single excavated shaft.  
     
     
         5 . The system of  claim 1  wherein said entrance run and said return run each occupy a separate excavated shaft.  
     
     
         6 . The system of  claim 5  wherein said entrance run and said return run are connected by a connecting run.  
     
     
         7 . The system of  claim 1  wherein said continuous casing sealing surrounding rock porosity is primarily constructed in ferro-reinforced concrete.  
     
     
         8 . The system of  claim 7  wherein said fluid addition means is inclusive of addition lines run through said ferro-reinforced concrete.  
     
     
         9 . The system of  claim 7  wherein said continuous casing possesses a ceramic lining.  
     
     
         10 . The system of  claim 1  further possessing means of adding heat to an area in said entrance run.  
     
     
         11 . The system of  claim 10  further including a heat exchanger located in said return run.  
     
     
         12 . The system of  claim 10  wherein said means of adding heat is comprised of an electric heating element.  
     
     
         13 . The system of  claim 10  wherein said means of adding heat is comprised of the burning gaseous fuel supply burned in elevation of temperature of the fluent material in a roast chamber.  
     
     
         14 . The system of  claim 13  further including a condensation chamber below said roast chamber in which addition of water is made by said fluid addition means.  
     
     
         15 . The system of  claim 1  wherein said fluid addition means is capable of adding liquid reagent.  
     
     
         16 . The system of  claim 1  wherein said fluid addition means is capable of adding gaseous reagent.  
     
     
         17 . The system of  claim 1  wherein said flow inducing means includes an elevational head resulting hypsometricaly from said inlet possessing a superior elevation than said outlet.  
     
     
         18 . The system of  claim 17  wherein said effluent flows out said outlet at ambient pressure.  
     
     
         19 . The system of  claim 1  wherein said flow inducing means includes use of compressed air release within said return run as a flow inducing means lifting fluent material upward through said return run.  
     
     
         20 . The system of  claim 19  wherein said compressed air release is located proximate a bottom of said return run.  
     
     
         21 . The system of  claim 20  wherein said return run above said compressed air release possesses a substantially vertical orientation.  
     
     
         22 . The system of  claim 1  wherein a pump is utilized for pressurized introduction of said fluent material.  
     
     
         23 . The system of  claim 22  wherein said processed effluent outflow through said outlet is at ambient pressure.  
     
     
         24 . The system of  claim 22  wherein said processed effluent outflow through said outlet is at a pressure elevated from ambient.