pavanpec30

I was planning to setup a system to see what phases form at equilibrium when Fly Ash reacts with water with the database that I had sent you. The system consists of Fly Ash minerals (SiO2, Lime, Mullite, Hematite, Anhydrite). The aim of the system was to model the the interaction of fly ash minerals with H2O at a pH 10-14. I was particularly interested in the formation of phases such as Ettringite and C-S-H at equilibrium. As I wasn't able to move forward without the input of O2 conc, I had to use O2(aq) in the system (I do not actually need O2). If I use the mineral as Kinetic minerals, REACT prompts for the individual elemental concentration of the mineral to be given as an input in the basis pane (for. e.g. If I use Anhydride as a kinetic mineral, I get an error asking me to include SO4 2- in the basis pane). If I include the concentration of SO4 2- ions in the basis pane, I do not understand the need to Anhydrite as a kinetic mineral in the first place. I went through the Reaction modeling guide and I understand that equilibrium is first achieved by reacting all the phases in the pane and then, this is reacted with the mineral in the reactants pane (kinetic minerals) to produce the final output. Please correct me if I'm wrong. I'm trying to draft a model that works to study my system. Please let me know if you need more information on this. Thanks, Pavan Akula

Hi, I'm trying to study the formation of Ettringite and Calcium Silicate Hydrate (CSH) in a Fly Ash system. Fly Ash consists of Mullite, Hematite, Lime , SiO2(amorphous) and Anhydrite-CaSO4. The main objective is to vary the constituents of the Fly Ash mix to see its effect of Ettringite and CSH phase formation. When I modeled the above mentioned system in Geochemist's workbench, the system doesn't seem to converge. Is this because of High ionic strength or is there a solution to this problem. It would be great if you could advice me to model this system. I have attached the React file and also sent the database via email. Thanks and Regards, Pavan Akula 1_Fly Ash model.rea

Thank you. I have sent the database to support@gwb.com. Thanks and Regards, Pavan Akula

Hi, The size of the database is too big to attach it here. I can share it via google docs if you can provide me with an email id. Thanks, Pavan Akula

Hi, Thank you for the reply. I have been trying to come up with a stability/phase diagram for Na-Montmorillonite (refer attached file). I have not had any luck in generating a phase diagram that includes quartz and Na-Montomorillonite in the same diagram. My query is as follows 1. Can I produce a Phase diagram using Act 2 for the attached file which includes Si compounds (e.g. Quartz) and Al Compounds (e.g Gibbsite) in one diagram. I was able to generate one phase diagram with Al+++ as the diagram species and another one with Quartz as the diagram species. I would like to combine both species as stated above. Please let me know if there is a work around. Thanks, Pavan Akula 8_Volcay_MgNa_H4SiO4vsAl_Alcompounds.ac2

Hi, Thank you for the reply. I have been trying to run a speciation reaction for Na-Montmorillonite(MgCa) in my React module and I end up with a high residual error. The data for the input is an exact replica of the thermodynamic database which was already added to TData. For e.g. If I input the molar concentration (the coefficients of phases in the reaction - refer to attached file: 1_Montmorillonite_database) from the database Al+++ = 1.66 mol/l Ca++ = 0.17 mol/l Mg++ = 0.34 mol/l etc., I end with a high residual error. My question is why does the above mentioned reaction does not show that Na-Montmorillonite (MgCa) is not being favored at equilibrium? Also, how will I be able to see the Minerals that will form at equilibrium through Gtplot. Thanks, Pavan Akula 1_Volclay_Model.rea

I have been trying to model the reaction of Sulfonated oils (which consists of 99.8% H2SO4) with Na-Montorillonite. I have added Na-Montmorillonite to the database and I have been having difficulty to find the database parameters for H2SO4. Do you have any recommendations on where to get H2SO4 parameters that I can use in my database?.

Hi, I'm quite new to Geochemist's workbench and I have been trying to model Smectite and Kaolinite dissolution in the presence of H2SO4. The aim of my modelling is as follows 1) Phase diagram with different Smectite minerals that can form (pH on the X-axis and Activity of H2SO4 on the Y axis). 2) Time dependent dissolution of Smectite and Kaolinite when a fixed amount of H2SO4 is added to a soil sample containing Smectite and Kaolinite minerals. I have had little success in trying to model the above mentioned using Act2 and GSS respectively. It would be great if someone could help me a walk-through on how to model the above mentioned. Thanks, Pavan Akula