Converting Alumina 1 to Alumina3

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Navigation: Alumina Models -> Converting Alumina Project

Related Links: Alumina 1 vs Alumina 3, Upgrading Projects, Upgrade to SysCAD 9.2, Upgrading_Builds

IMPORTANT NOTE: Alumina1 models are not distributed and supported with SysCAD 9.3. SysCAD 9.3 version of Alumina1 is available on request for project conversion purposes.

Detailed Bayer Species Model are documented in these two linked pages. Alumina1 and Alumina3. Please refer to these pages for full explanation of correlations, limitation and description of variables used.

The sections below only highlight the difference in the two models and also give some pointers to user wanting to convert existing Alumina1 project to Alumina 3.

Alumina Properties Model Comparison

The comparison of the two Alumina property models is detailed in page: Alumina 1 vs Alumina 3.

Project Conversion Work Flow

Step 1: Preparing the Alumina 1 Project

  1. Make sure this project is fully solved
  2. Create a series of reports to aid the conversion process, suggested reports to create are
    • Stream reports - be sure to include all variables used in the Bayer Calculator, this can make data entry into the new Alumina 3 project a lot easier.
    • Reaction reports
    • PID reports
    • Total Mass Balance, Impurity Balances etc
    • Precipitator settings report (if used)
  3. If Alumina 1 Precipitator models were used in the project, it will be necessary to remove all of these precipitation models before opening the project in Alumina 3. HINT: you can keep all the graphics symbols and reuse them. Use the Explode command to remove the precipitator mathematical models and leave only the graphics, then use the Construct command to attach new models to the graphics.

Step 2: Create the Alumina 3 Project

  1. Create copy of the project, including its Cfgfiles folder in a new location. Eg, ...\Alumina3 Projects\xxxx.spf
  2. Edit the Species Database (in the Alumina3 project location) to include the required Alumina3 species; also recommend changing all liquid components (excluding water) from (l) to (aq).
  3. Edit the configuration file (in the Alumina3 project location)
    1. During Step 1, select sort by DLL, un-tick the Alumina1.dll to remove the Bayer species model and Precipitator Model, tick the Alumina3.dll to add Bayer3 species model and Precipitator(3) model.
      Alumina3Convertion1.png
    2. During Step 2,
      • Configuration Tab - Change Default Species Model to Bayer3
      • Species Tab - Add the new Alumina 3 required species, fix and phase change (l) to (aq) issues
      • Calculations Tab - Add any user defined ratio if required, can be done at a later stage
      • Sieve Series Tab (if used) - remain unchanged
      • Size Distribution Tab (if used) - Change the Size Distribution Species to be Al[OH]3
      • Measurements Tab (if used) - remain unchanged

NOTE: The final cfg file should NOT have Alumina1 and Alumina3 DLLs selected. Mixing these requires a mixture of species and models to be present which easily leads to errors. A project should use one or the other. However, with care, it can be convenient to temporarily include both Alumina1 and Alumina3 in the cfg file during some of the conversion steps.

Step 3: Correct Flowsheets

If the Precipitator1 model was used in the old project, it will be necessary to re-do the precipitation area using the new Precipitator3 model. If Alumina1 precipitator model was removed using the Explode, then use the Construct Graphics Commands to recreate the graphics page. If Alumina1 and Alumina3 are temporarily both included in the cfg file, then in Build 134 the Change Unit command can be used to change these.

Use the reports created in step 1 to reconfigure the precipitators.

Step 4: Correct Reaction Files

Reactions that will need to be reviewed include:

  1. Gibbsite dissolution
  2. Boehmite dissolution
  3. Kaolin Dissolution / Reactive Silica to DSP formation reactions
  4. Quartz attack
  5. Reversion reactions in Washing Circuit
  6. Hydrate Precipitation reactions (if using the Precipitator 3 model, this will be built in, but any other areas where there is Gibbsite precipitation will need to be checked)

The heat of reaction should also be checked. Eg, if user has specified HOR based on kJ/kg Al2O3(l) in Alumina1, then in Alumina3, it will have to be corrected to be based on kJ/kg NaAl[OH]4. The correction factor to use (based on Molecular weight ratio) is 0.432. There are reference papers on heat of dissolution for Gibbsite and Boehmite on the SysCAD website at https://www.syscad.net/login/

NB If you are editing the RCT files - it is important to check that the reaction order or sequence have not been changed during the editing. If the order has been changed, then any external controllers which refer to reactions by number may now refer to the wrong reaction. The reaction editor has facilities to control order and sequence and the reaction order should be compared between versions. See Reaction Options.

Step 5: Correct Referenced Tags

Load the project in the Alumina 3 project location with the new configuration file. SysCAD message window would provide information on any errors/warnings encountered, use this window to debug the project.

HINT: Do not save the project until the PGM load errors are resolved because you may lose the state (values) of the PGM fields. Just close and project (without saving) and reload the project after all the PGM files have been corrected.

Reference tags that need to be changed would include:

  • PGM files - Hint: can use Notepad++ - Replace in Files function to correct tags in multiple files.
  • PID controllers - Hint: if a PID controller report was created in Step 1, this report can be turned into a SetTag report, and the new tags can be changed and set into SysCAD via Excel.
  • Reports - Hint: can use search and replace to correct tags

Step 6: Setting up Feed information

Use the reports created in Step 1 to set up a new report to input feed data into the new project. Important streams to check are:

  • Bauxite Feed - make sure the Gibbsite and Boehmite compositions are entered correctly
  • Spent Liquor to Mills and digestion - It maybe necessary to break some cross page connections and bring in user defined Bayer liquor into the circuit first. The easiest way to manually define the spent liquor streams would be to use the Bayer calculator. May use the stream information report created in Step 1 to set up a Feed Composition SetTag report.
  • Strong Liquor / Pregnant Liquor to White Side
  • Seed Charge streams to Precipitation

NOTE: When using the DefineLiquor Calculator, care must be taken when defining oxalate concentration. In Alumina 1, oxalate concentration is entered as g/L Oxalate expressed as Na2CO3, whereas in Alumina 3, oxalate concentration is entered as g/L oxalate.

Step 7: Check Global Methods and Constants

Make sure the global methods selected are the same (for comparison purposes).

Step 8: Solve and Debug project

  1. Start solving the project and use the excel reports (create similar reports to step 1 but for Alumina3 project), compare the reports to help debug the project.
  2. Work through the project in the direction of material flow. Re-connect any "broken" cross page connectors when flows are getting reasonable.
  3. Ensure that only Alumina3 is selected in the cfg file, and not Alumina1. Ensure that none of the unused Alumina1 species are included in the cfg file and therefor are not seen in streams, etc in the project.

Hints and Comments

  1. Do not save the project until the PGM load errors are resolved because you may lose the state (values) of the PGM fields. Just close the project (without saving) and reload the project after all the PGM files have been corrected.
  2. It maybe easier to do this page by page, disable cross page connectors will be very helpful to have the page running in a "controlled" manner.
  3. Users with a stand alone license may open two copies of SysCAD on the same machine and they can be different versions of SysCAD - this will allow you compare the OLD with NEW side by side.
  4. Users using single network license cannot open two copies of SysCAD, in this case, create more detailed reports and use the reports to debug.
  5. You may find that the first attempt at conversion turns into a mess - usually you can work out why easily enough and it is usually easier to take a clean copy and try again rather than attempt to fix up a project that has gone wrong. So if you need to save the project, save to a new project so you can always start from the beginning again if necessary.
  6. NOTE: Do not select Alumina1 and Alumina3 properties models in your final project cfg file. This can be convenient during conversion process, but can lead to significant issues in ongoing project use. For example, selecting both of these forces a mixture of Alumina1 species and Alumina3 species to be included leading to incorrect results when the "unexpected" Alumina1 species are non-zero when using Alumina3!