Patent ID: 11873541
Assignee: JIANGXI UNIVERSITY OF SCIENCE AND TECHNOLOGY
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  G  Y | IPC C  G

Claim 0:
1. A method for determining a source sink term in an ionic type rare earth ore leaching process, comprising the following steps:
step one: determining a rare earth grade of a rare earth ore sample:
performing a balance tube leaching test for repeatedly leaching the ionic type rare earth ore sample by an ore leaching agent, testing a total mass of leached rare earth ions, and calculating the rare earth grade η of the rare earth ore sample by a relational expression (1):, η
          =
          
            
              
                m
                RE
              
              ⁢
              
                M
                REO
              
            
            
              
                m
                s
              
              ⁢
              
                M
                RE
              
            
          
        
        ,
      
    
    
      
        (
        1
        )
      
    
  

wherein in the relational expression (1), η is the rare earth grade; mRE is the total mass of the leached rare earth ions; ms is a mass of the rare earth ore sample; and MREO and MRE are respectively molar masses of a rare earth oxide and the rare earth ions;
step two: determining an ion exchange selection coefficient K of the rare earth ore sample:
performing a balance tube leaching test for leaching the ionic type rare earth ore sample by the ore leaching agent at a concentration of 1.0 to 20.0 g/L, testing a concentration of the rare earth ions in leachate to obtain a relationship curve of a concentration of an ore leaching agent solution and the concentration of the rare earth ions in the leachate, taking the ion exchange selection coefficient as a basic unknown, fitting the relationship curve of the concentration of the ore leaching agent and the concentration of the rare earth ions in the leachate with an ion exchange model, and determining the ion exchange selection coefficient of the rare earth ore sample;
step three: building a source sink term model of the ore leaching process:
setting, ⁢
        
          
            a
            =
            
              α
              
                NH
                4
              
              3
            
          
          ,
        
      
    
    
      
        (
        12
        )
      
    
  
  
    
      
        
          
        
        ⁢
        
          
            b
            =
            
              3
              ⁢
              
                
                  α
                  
                    NH
                    4
                  
                  2
                
                ⁡
                
                  (
                  
                    
                      
                        
                          M
                          RE
                        
                        
                          3
                          ⁢
                          
                            M
                            
                              NH
                              4
                            
                          
                        
                      
                      ⁢
                      
                        C
                        
                          lq
                          ⁢
                          
                            
                          
                          ⁢
                          0
                        
                        
                          NH
                          4
                        
                      
                    
                    +
                    
                      C
                      
                        lq
                        ⁢
                        
                          
                        
                        ⁢
                        0
                      
                      RE
                    
                    -
                    
                      C
                      lq
                      RE
                    
                  
                  )
                
              
            
          
          ,
        
      
    
    
      
        (
        13
        )
      
    
  
  
    
      
        
          c
          =
          
            
              3
              ⁢
              
                
                  
                    α
                    
                      NH
                      4
                    
                  
                  ⁡
                  
                    (
                    
                      
                        
                          
                            M
                            RE
                          
                          
                            3
                            ⁢
                            
                              M
                              
                                NH
                                4
                              
                            
                          
                        
                        ⁢
                        
                          C
                          
                            lq
                            ⁢
                            
                              
                            
                            ⁢
                            0
                          
                          
                            NH
                            4
                          
                        
                      
                      +
                      
                        C
                        
                          lq
                          ⁢
                          
                            
                          
                          ⁢
                          0
                        
                        RE
                      
                      -
                      
                        C
                        lq
                        RE
                      
                    
                    )
                  
                
                2
              
            
            +
            
              
                
                  
                    (
                    
                      
                        
                          
                            M
                            RE
                          
                          
                            3
                            ⁢
                            
                              M
                              
                                NH
                                4
                              
                            
                          
                        
                        ⁢
                        
                          C
                          
                            s
                            ⁢
                            
                              
                            
                            ⁢
                            0
                          
                          
                            NH
                            4
                          
                        
                      
                      -
                      
                        
                          
                            V
                            L
                          
                          
                            m
                            s
                          
                        
                        ⁢
                        
                          C
                          
                            lq
                            ⁢
                            
                              
                            
                            ⁢
                            0
                          
                          RE
                        
                      
                      +
                      
                        
                          
                            V
                            L
                          
                          
                            m
                            s
                          
                        
                        ⁢
                        
                          C
                          lq
                          RE
                        
                      
                    
                    )
                  
                  3
                
                
                  K
                  ⁡
                  
                    (
                    
                      
                        C
                        
                          s
                          ⁢
                          
                            
                          
                          ⁢
                          0
                        
                        RE
                      
                      +
                      
                        
                          
                            V
                            L
                          
                          
                            m
                            s
                          
                        
                        ⁢
                        
                          C
                          
                            lq
                            ⁢
                            
                              
                            
                            ⁢
                            0
                          
                          RE
                        
                      
                      -
                      
                        
                          
                            V
                            L
                          
                          
                            m
                            s
                          
                        
                        ⁢
                        
                          C
                          lq
                          RE
                        
                      
                    
                    )
                  
                
              
              ⁢
              
                α
                RE
              
            
          
        
        ,
      
    
    
      
        (
        14
        )
      
    
  
  
    
      
        
          e
          =
          
            
              
                (
                
                  
                    
                      
                        M
                        RE
                      
                      
                        3
                        ⁢
                        
                          M
                          
                            NH
                            4
                          
                        
                      
                    
                    ⁢
                    
                      C
                      
                        lq
                        ⁢
                        
                          
                        
                        ⁢
                        0
                      
                      
                        NH
                        4
                      
                    
                  
                  +
                  
                    C
                    
                      lq
                      ⁢
                      
                        
                      
                      ⁢
                      0
                    
                    RE
                  
                  -
                  
                    C
                    lq
                    RE
                  
                
                )
              
              3
            
            -
            
              
                
                  
                    (
                    
                      
                        
                          
                            M
                            RE
                          
                          
                            3
                            ⁢
                            
                              M
                              
                                NH
                                4
                              
                            
                          
                        
                        ⁢
                        
                          C
                          
                            s
                            ⁢
                            
                              
                            
                            ⁢
                            0
                          
                          
                            NH
                            4
                          
                        
                      
                      -
                      
                        
                          
                            V
                            L
                          
                          
                            m
                            s
                          
                        
                        ⁢
                        
                          C
                          
                            lq
                            ⁢
                            
                              
                            
                            ⁢
                            0
                          
                          RE
                        
                      
                      +
                      
                        
                          
                            V
                            L
                          
                          
                            m
                            s
                          
                        
                        ⁢
                        
                          C
                          lq
                          RE
                        
                      
                    
                    )
                  
                  3
                
                
                  K
                  ⁡
                  
                    (
                    
                      
                        C
                        
                          s
                          ⁢
                          
                            
                          
                          ⁢
                          0
                        
                        RE
                      
                      +
                      
                        
                          
                            V
                            L
                          
                          
                            m
                            s
                          
                        
                        ⁢
                        
                          C
                          
                            lq
                            ⁢
                            
                              
                            
                            ⁢
                            0
                          
                          RE
                        
                      
                      -
                      
                        
                          
                            V
                            L
                          
                          
                            m
                            s
                          
                        
                        ⁢
                        
                          C
                          lq
                          RE
                        
                      
                    
                    )
                  
                
              
              ⁢
              
                C
                lq
                RE
              
            
          
        
        ,
      
    
    
      
        (
        15
        )
      
    
  

wherein a, b, c and e are all temporary variables; αNH4 and αRE are parameters related to diffusion coefficients of ammonium ions and the rare earth ions in a diffusion layer, respectively; MNH4 is a molar mass of the ammonium ions; Clq0NH4 and Clq0RE are concentrations of cations and the rare earth ions in the added ore leaching agent, respectively; ClqRE is the concentration of the rare earth ions in the leachate after the ore leaching is balanced; Cs0NH4 and Cs0RE are concentrations of the ammonium ions and the rare earth ions which are adsorbed on the rare earth ore sample before the ore leaching, respectively, Cs0RE=ηMRE/MREO; K is the ion exchange selection coefficient; VL is a volume of the added ore leaching agent solution;
performing a leaching kinetics test on the rare earth ore sample to test the concentrations of the rare earth ions in the leachate at different reaction time, determining a generating rate of the rare earth ions in an external solution, and obtaining test data of the rate of change over time of the concentration of the rare earth ions adsorbed on the surfaces of rare earth ore sample particles through a relational expression (16):, dC
              s
              RE
            
            dt
          
          =
          
            
              -
              
                
                  V
                  L
                
                
                  m
                  s
                
              
            
            ⁢
            
              
                dC
                lq
                RE
              
              dt
            
          
        
        ,
      
    
    
      
        (
        16
        )
      
    
  

wherein in the relational expression (16), CsRE is the concentration of the rare earth ions adsorbed on the surfaces of the rare earth ore sample particles; ClqRE is the concentration of the rare earth ions in the external solution; t is the time; d is the derivative symbol; ms is the mass of the rare earth ore sample; VL is the volume of the external solution;
the process that the ammonium ions and the rare earth ions pass through the diffusion layer is described by the Fick law; an ion exchange process is described by a mass-action model; in consideration of the non-shrinkage of the ore sample particles and the reversibility of ion exchange in the ore leaching process, the source sink term model of the ionic type rare earth ore leaching process is obtained, and a result is as shown in a relational expression (9):, dC
              s
              RE
            
            dt
          
          =
          
            
              
                
                  -
                  
                    q
                    2
                  
                
                +
                
                  
                    
                      
                        (
                        
                          q
                          2
                        
                        )
                      
                      2
                    
                    +
                    
                      
                        (
                        
                          p
                          3
                        
                        )
                      
                      3
                    
                  
                
              
              3
            
            -
            
              
                
                  q
                  2
                
                +
                
                  
                    
                      
                        (
                        
                          q
                          2
                        
                        )
                      
                      2
                    
                    +
                    
                      
                        (
                        
                          p
                          3
                        
                        )
                      
                      3
                    
                  
                
              
              3
            
            -
            
              b
              
                3
                ⁢
                a
              
            
          
        
        ,
      
    
    
      
        (
        9
        )
      
    
  

wherein in the relational expression (9), t is the time; d is the derivative symbol; p and q are respectively calculated with a relational expression (10) and a relational expression (11):, p
          =
          
            
              
                3
                ⁢
                ac
              
              -
              
                b
                2
              
            
            
              3
              ⁢
              
                a
                2
              
            
          
        
        ,
      
    
    
      
        (
        10
        )
      
    
  
  
    
      
        
          q
          =
          
            
              
                27
                ⁢
                
                  a
                  2
                
                ⁢
                e
              
              -
              
                9
                ⁢
                abc
              
              +
              
                2
                ⁢
                
                  b
                  3
                
              
            
            
              27
              ⁢
              
                a
                3
              
            
          
        
        ,
      
    
    
      
        (
        11
        )
      
    
  

wherein αNH4 and αRE are taken as basic unknowns, and the test data of the rate of change over time of the concentration of the rare earth ions adsorbed on the rare earth ore sample is fitted with the relational expression (9), thus determining the parameters πNH4 and αRE in the source sink term of the rare earth ore leaching process;
the determined parameters aNH4 and αRE in the source sink term are substituted into the relational expression (9) to determine the source sink term of the rare earth ore sample.