Introduction

In this tutorial you will learn how manage the components you’ve added to your project and how add components that are currently not in the standard database. This includes creating arbitrary components that are not necessarily ‘real’. Here you will add a component ‘ore’ with a custom name, chemical formula and properties and then use this component in a reaction.

The exercise will demonstrate a method of modelling mineral liberation in Cycad Process. We will add a component called ore and this will "react" in the mill to form some pure components, which are regarded as liberated. Thus the degree of liberation is the same as the reaction conversion or extent.

You will go through the following steps in this tutorial:

  1. Draw the flowsheet
  2. Add user-defined components
  3. Add Components
  4. Add a liberation "reaction"
  5. Calculate and examine the results
  6. Extend the model to include size distributions
  7. Define the size classes for the overall distribution
  8. Define the size distribution for the feed
  9. Calculate and examine the results

Step 1: Draw the Flowsheet

The first step is to draw the flowsheet, which is shown in Figure 1.

Add an Autogeneous Mill to the page together with its feed and discharge streams.

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Figure 1. AG Mill flowsheet


Step 2: Add User-Defined Components

Launch the Manage Components Selection Form by pressing the "Manage Components" button on the Setup Balance process toolbar, shown in Figure 2.

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Figure 2. The Component Selection Form.

This will launch the Project component management page, shown in Figure 3.

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Figure 3. Project component management page.

From this form it is possible to edit components already added to the project, add new components from the database or create new components manually.

In this tutorial we will add a manually entered component. This component will be used to model a copper sulfide ore with silica gangue. Begin by clicking the “Add new user component” button, shown above in Figure 3. This will load the “Add a new Component” form, shown in Figure 4, below.

4a 4b

Figure 4. Adding a user-defined component.

Enter the following component information:

  • Component name: Ore
  • Component formula: SiO2:0.002CuS
  • Component description: Copper ore
  • Data source: user
  • Component state: (s)
  • Density: 2.7 t/m3

Step 3: Add Database Components

We have defined and added the component "Ore" to the project.

Now add the components SiO2 (s), CuS (s) and H2O (l) to the project.

This is done in the same manner that you added components to the project in previous tutorials. It can also be done from the Manage Components Form by clicking on the “Add new DB component” button.

Select the feed stream and set the flow of the Ore component in the feed stream to be 2 t/hr and set the flow of water in the feed stream to be 6 t/hr.


Step 4: Add a Liberation "Reaction"

Select the Mill and add the following parameters:

Mill reaction:

Ore (s) -> SiO2 (s) + 0.002 CuS (s)

Set the extent of liberation to be 90% by typing "ext = 0.9" in the "Expression" column.

Set the Model property for the Mill to Default.


Step 5: Calculate and Examine the Results

Press the "Run Cycad Project" button on the Calculate Process Toolbar.

The results are those displayed in Table 1:

Table 1. Results for the Mineral Liberation model

Stream Tag     100 200
Stream Description     MILL FEED MILL DISCHARGE
Component State Units    
Ore (s) t/hr 2.0000 0.2000
SiO2 (s) t/hr 0.0000 1.7943
CuS (s) t/hr 0.0000 0.0057
H2O (l) t/hr 6.0000 6.0000

These results indicate that 0.0057 t/hr of CuS is liberated in the mill, which represents 90% liberation of the material in the feed.

Note that because we added no thermochemical data to the component in project database when adding the Ore component, the net heat duty for this Process Unit has no meaning.


Step 6: Extend the Model to Include Size Distributions

It is worthwhile to extend the milling model to include the change in distribution with milling.

This means that the model describes the change in liberation and the change in size.

Select the mill and then change the properties in the Properties Viewer to those shown in Figure 5.

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Figure 5. Properties for the milling model.

Note that the mill load is set to 3.0 t!

Now select the Parameters property and click on the ellipsis (...) button.

This launches the form shown in Figure 6.

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Figure 6. Breakage and Selection functions for the mill.

Enter the properties shown in Figure 6.

In the next step we will add a size distribution to the ore.


Step 7: Define the Size Classes for the Overall Distribution

Select the “All Streams” tab from the Stream Manager and check the box opposite "Total Mass" in the PSD column.

This incorporates an overall size distribution for all the streams into the project.

This is shown in Figure 7.

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Figure 7. The overall size distribution check box.

Now select "View Distributions" from the Setup Balance tab, shown in Figure 8, below.

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Figure 8. Showing the project size distributions.

This will display a tab that shows the Size Distributions for the project – “DistributionSheetAndChart”.

Click the ellipsis button in the “Size” column in the “Overall” row.

This launches the form in which the classes for the size distribution are defined.

The form is shown in Figure 9.

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Figure 9. Define the size classes.

Enter the values shown in Figure 9.

Press "Apply" and then "OK".


Step 8: Define the Size Distribution for the Feed

In this step we define the size distribution coming into the mill.

In the Distributions tab of the Stream Manager, press the button in the column representing the feed stream (100)

This launches the particle size distribution form, which is shown in Figure 10.

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Figure 10. The Particle Size Distribution form.

Enter the values shown in Figure 10. Press "Apply" and then "OK".


Step 9: Calculate and Examine the Results

In this step, we calculate the results for the model.

Run the project. Once the calculations are complete, go back to the “Distributions” tab. From here, check the streams that you wish to see distributions for.

Figure 11 shows an example of the distribution.

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Figure 11. The two different size distributions for the feed and product from the mill.

The feed stream size distribution is the bottom line and the product stream is the top line.