Product Assay Separation
Summary
Product Assay Separation calculates a mass-closed two-product separation from target component grades in concentrate and tail. It is intended for steady-state studies where product assays are available but component recoveries are not specified directly.
DPSIM model key: DPSIM.Concentration.ProductAssaySeparator
Category: Concentration
Subcategory: Separators
Display name: Product Assay Separation
Streams
| Port | Role |
|---|---|
| Feed | Solids and water entering the separation stage. |
| Concentrate | Product associated with the configured concentrate assays. |
| Tail | Complementary product that closes the component and total mass balances. |
Solution Method
For an anchor component with feed grade f, concentrate grade c and tail grade t, the common solids recovery to concentrate is:
R = (f - t) / (c - t)
For example, feed, concentrate and tail grades of 40%, 65% and 10% give a concentrate solids recovery of 54.55%. DPSIM then calculates the component recoveries required by that solids split while preserving every component mass.
Anchor Mode
The Anchor check box identifies the component whose complete feed-concentrate-tail assay balance determines the common solids recovery. Choose a component with reliable analyses and a clear difference between concentrate and tail grades. The anchor is a calculation reference; it is not automatically the most valuable component and it does not prescribe that component's recovery directly.
- Only components with both concentrate and tail targets enabled and with different target grades can be valid anchors.
- If no anchor is selected, DPSIM uses the first complete valid assay pair in project component order.
- If more than one anchor is selected, DPSIM uses the first valid selected component and reports the condition in the setup window.
- The Anchor selections are ignored in Reconciled mode.
Reconciled Mode
Reconciled mode obtains one common solids recovery from all complete enabled assay pairs by weighted least squares. Concentrate and tail weights express their relative confidence. Higher weights make the solution remain closer to the corresponding assay, but no single assay is guaranteed to be matched exactly.
After either solution, DPSIM calculates bounded component recoveries while enforcing total and component mass closure.
When assay targets are mutually inconsistent, calculated product grades may differ from their targets. The derived RMS, maximum and component residuals quantify those differences.
Parameters
| Parameter | Description |
|---|---|
| Solution mode | Choose anchor-component or reconciled weighted-assay solution. |
| Minimum/maximum solids recovery | Physical bounds applied to the concentrate solids recovery. |
| Water recovery to concentrate (%) | Fraction of feed water reporting to concentrate. |
| Fallback mode | Use configured component recoveries, retain the last valid solution, or preserve feed grades. |
| Component target grades and switches | Enable concentrate and tail assays independently for each project component. |
| Use as anchor component | Selects the component used to determine solids recovery in Anchor mode. |
| Component assay weights | Relative confidence used in reconciled mode. |
| Fallback component recovery | Recovery used when the configured fallback mode requires component-specific values. |
Recommended Workflow
- Enter concentrate and tail assays only where measured or deliberately specified.
- Enable both assay switches for every pair that should participate in the solution.
- Use Anchor mode for one trusted assay balance, or Reconciled mode when several measurements should contribute.
- Run the simulation and review calculated grades, residuals, recovery bounds and fallback status.
Status Codes
| Code | Meaning |
|---|---|
| 0 | Valid assay solution. |
| 1 | Valid solution limited by a configured recovery bound. |
| 10 | Component fallback recoveries applied. |
| 11 | Last valid solution retained. |
| 12 | Unchanged-grade fallback applied. |
| 20 | Feed solids flow is zero. |
Application And Limitations
The model is suitable for survey reconstruction, conceptual studies and specified-product scenarios. It is an empirical mass-balance model, not a mechanistic flotation or physical-separation model. Component recovery is independent of particle size, assays use a dry-solids basis, and water is split independently.
References
Wills, B. A., and Finch, J. A. (2016). Wills' Mineral Processing Technology, 8th ed. Butterworth-Heinemann.
Napier-Munn, T. J. (ed.) (1996). Mineral Comminution Circuits: Their Operation and Optimisation. Julius Kruttschnitt Mineral Research Centre.