PhreeqcUsers Discussion Forum

Applications and Case Studies => Acid mine/rock drainage => Topic started by: Jeisonb on June 15, 2021, 10:19:32 PM

Title: neutralization
Post by: Jeisonb on June 15, 2021, 10:19:32 PM
Hi, I want to simulate the neutralization of an acidic water with a slag waste, previously I already carried out the water neutralization with CaCO3 and CAO, now the slag is composed of CAO, SiO2, FeO, Fe2O3 and MgO, can you help me with a prototype of template to be able to enter the values of the components of the slag ... Thank you.
Title: Re: neutralization
Post by: dlparkhurst on June 15, 2021, 10:49:16 PM
Seems like you are talking about two separate issues: (1) dissolution of slag by acidic water and (2) neutralization of acidic water with dissolved metals with CaCO3.

Part (1) would be difficult to estimate. You probably do not have well-defined phases with known solubilities, but some would be very soluble. NaO and KO are probably also present. I think the dissolution of the slag would need to be done by experiment to find out how much of each element dissolves within a given time period.

Part (2) could be modeled from a known solution composition after acid addition either by incremental addition of CaCO3 with REACTION or by including EQUILIBRIUM_PHASES. You would need to consider which mineral oxide and carbonate phases might precipitate during the addition of CaCO3. You also need to consider potential redox reactions between oxygen, and Fe(2) other redox elements.
Title: Re: neutralization
Post by: Jeisonb on June 15, 2021, 11:17:51 PM
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Resultados de traducción
I want to react acidic water with slag composed of CaO, SiO2, FeO and Fe2O3 I had planned to do it as a mixture of solutions as follows:
TITLE  Neutralización de agua acida
SOLUTION 1  Agua ácida
    temp         25
    pH           3.62   
    units        mg/L           
    density     1.01
    pe           12
    AL      36.9
    Ca      9.6
    Cl      4.0
    Cu      6.4
    Fe      74.4
    Mg      8.4
    Mn      2.2    
    K      3.4
    Na      2.6
    S(6)   52.5
    Zn      1.2
    O(0)       8.36
      -water    1       # kg
      end
  SOLUTION 2 ESCORIA DE ACERIA
    temp         25
    units        mg/L           
    density     13
   CaO   10
   SiO2  11
   FeO   25
   Fe2O3 0.5
end
MIX 1
1    0.5
2      0.5
 END


the idea is to see if the slag serves to neutralize that acidic water,
I don't know if this is possible.
Title: Re: neutralization
Post by: dlparkhurst on June 15, 2021, 11:33:11 PM
You can add the oxides with REACTION as shown below. REACTION must be defined in moles, so I added a USER_PRINT block to calculate moles from mg, and then wrote the REACTION data block. I did not take into account the 50/50 mix

Code: [Select]
SOLUTION 1  Agua ácida
    temp         25
    pH           3.62   
    units        mg/L           
    density     1.01
    pe           12
    Al      36.9
    Ca      9.6
    Cl      4.0
    Cu      6.4
    Fe      74.4
    Mg      8.4
    Mn      2.2   
    K      3.4
    Na      2.6
    S(6)   52.5
    Zn      1.2
    O(0)       8.36
    -water    1       # kg
USER_PRINT
10 PRINT "CaO, mol:   ", 1e-3*10/GFW("CaO")
20 PRINT "SiO2, mol:  ", 1e-3*11/GFW("SiO2")
30 PRINT "FeO, mol:   ", 1e-3*25/GFW("FeO")
40 PRINT "Fe2O3, mol: ", 1e-3*.5/GFW("Fe2O3")
END
USE solution 1
REACTION 1
CaO      1.7834e-04  # 10 mg
SiO2     1.8311e-04  # 11 mg
FeO      3.4799e-04  # 25 mg
Fe2O3    3.1313e-06  # 0.5 mg
1 mol
END