Process for extracting and purifying naturally occurring zeolite

Abstract

A process for extracting and purifying naturally occurring zeolite from ores in the presence of other mineral phases by using mechanical dispersion and differential suspension to remove a majority of the clay content of the ore. The process continues by removal of contaminants with a higher mass to surface area ratio than that of the desired zeolite product by employing the properties of demineralized water in combination with a countercurrent flow separation column. No chemical flocculating or flotation agents need be employed in the process.

1 - 55 . (canceled)  
   
   
       56 . A method for classification of a particulate mineral compound comprising: 
 injecting demineralized water into one or more countercurrent classifying columns comprising an aqueous slurry of the particulate mineral compound to form an ascending demineralized water stream sufficient to amplify differences in particle settling velocity.    
   
   
       57 . The method of  claim 56 , wherein the one or more classifying columns each have one or more stages, a feed injection port at about the midpoint of said classifying column, a demineralized water injection port below said feed injection port, a cap at such column's topmost edge, and an overflow port below said cap.  
   
   
       58 . The method of  claim 56 , wherein the number, size and/or configuration of the one or more countercurrent classifying columns is tailored to a desired particle size and/or mineral phase.  
   
   
       59 . The method of  claim 56 , wherein the aqueous slurry in the countercurrent classifying column has a slurry density of about 5% to about 40%.  
   
   
       60 . The method of  claim 56 , wherein the particulate mineral compound comprises particles possessing an electrical double layer when hydrated in low electrolyte medium and having a range of particle sizes.  
   
   
       61 . The method of  claim 56 , wherein said particulate mineral compound is a compound comprising particles of a desired range of sizes from a lower portion of a secondary separation column.  
   
   
       62 . The method of  claim 56 , wherein the particulate mineral compound is a zeolite compound.  
   
   
       63 . The method of  claim 56 , wherein the aqueous slurry has a slurry density of 10% to 20%.  
   
   
       64 . The method of  claim 56 , wherein the demineralized water has a low electrolyte content.  
   
   
       65 . The method of  claim 56 , wherein the demineralized water has an electrolyte content of less than about 500 ppm.  
   
   
       66 . The method of  claim 56 , wherein the demineralized water has an electrolyte content of less than about 100 ppm.  
   
   
       67 . The method of  claim 56 , wherein the demineralized water has an electrolyte content of less than about 50 ppm.  
   
   
       68 . The method of  claim 56 , wherein the demineralized water has an electrolyte content of less than about 10 ppm.  
   
   
       69 . A method for classification of a particulate mineral compound comprising: 
 introducing an aqueous slurry of said particulate mineral compound slurry into a countercurrent classifying column, said classifying column having one or more stages, a feed injection port at about the midpoint of said classifying column, a demineralized water injection port below said feed injection port, a cap at such column's topmost edge, and an overflow port below said cap;    injecting demineralized water into said countercurrent classifying column at said demineralized water injection port so as to form an ascending demineralized water stream sufficient to amplify differences in particle settling velocity;    separating said particulate compound using the separation effect of said electrical double layer; and    extracting an overflow stream through said overflow port.    
   
   
       70 . The method of  claim 69 , wherein said particulate mineral compound is a compound comprising particles of a desired range of sizes from a lower portion of a secondary separation column.  
   
   
       71 . The method of  claim 69 , wherein the particulate mineral compound is a zeolite compound.  
   
   
       72 . The method of  claim 69 , wherein the aqueous slurry in the countercurrent classifying column has a slurry density of about 5% to about 40%.  
   
   
       73 . The method of  claim 69 , wherein the aqueous slurry in the countercurrent classifying column has a slurry density of about 10% to about 20%.  
   
   
       74 . The method of  claim 69 , wherein the demineralized water has a low electrolyte content.  
   
   
       75 . The method of  claim 69 , wherein the demineralized water has an electrolyte content of less than about 500 ppm.  
   
   
       76 . The method of  claim 69 , wherein the demineralized water has an electrolyte content of less than about 100 ppm.  
   
   
       77 . The method of  claim 70 , wherein the demineralized water has an electrolyte content of less than about 50 ppm.  
   
   
       78 . The method of  claim 71 , wherein the demineralized water has an electrolyte content of less than about 10 ppm.  
   
   
       79 . A method for classification of a particulate mineral compound comprising: 
 injecting a slurried process stream into a multistage countercurrent primary separation column at about the midpoint of said primary separation column, said primary separation column having upper, lower and mid-stages;    injecting demineralized water into said lower stage of said primary separation column;    extracting an overflow stream of suspended particulate mineral compound from said upper stage of said primary separation column; and    controlling the injection rate of said slurried process stream and said demineralized water into said primary separation column and the extraction rate of said suspended particulate mineral compound such that said demineralized water flows upward at a rate sufficient to suspend said particulate compound and such that higher density components of said slurried process stream, having a net settling velocity, flow downward to said lower stage of said primary separation column.    
   
   
       80 . The method of  claim 79 , additionally comprising: 
 injecting said suspended particulate mineral compound from said primary separation column into a secondary separation column, said secondary separation column having upper and lower portions;    injecting demineralized water into said secondary separation column near said lower portion;    extracting a fine particle overflow stream from said upper portion;    controlling the injection rates of said suspended particulate mineral compound and said demineralized water into said secondary separation column and the extraction rate of said fine particle overflow stream such that a countercurrent flow is established and that particles of said particulate mineral compound of a desired range of sizes are not carried into said countercurrent flow; and    removing said particles of a desired range of sizes from said lower portion of said secondary separation column.    
   
   
       81 - 93 . (canceled)