Analyte Definitions

An analyte is a specific substance or chemical constituent that is being analysed or measured in a sample. For example, analytes measured to assess the quality of coal may include calorific value, moisture, ash, and sulphur content. For copper concentrates, analytes are copper, sulphur, iron, gold, silver and other elements.

Analytes can also be grouped into order-dependent analyte groups.

Types of Analytes

MineMarket has the following analyte types.

  • Aggregable—Can be numerically added or subtracted, or used in weighted-average calculations. The unit for the analyte can only be selected from the Proportion unit category. When analytical results for aggregable analytes are entered for transaction samples, the resulting quality of the destination stockpile is calculated by using the Weighted Average aggregate formula. This considers the quality and mass of the stockpile before the transaction and the quality and mass of the material being added. The proportion of analyte is based upon whether it is a top-level analyte, or a nested analyte.
  • Numeric—Contains a numeric value. The unit for the analyte can be selected from any unit category. Example: pH.
  • Text—Contains a text value.
  • ListItem—Used when the analyte value is to be selected from a predefined drop-down list, known as a text list.
  • Calculated—Used when the analyte value is to be calculated with a formula defined in a script in the Analyte Formula (script editor). Example: Fe:MgO.

You cannot change the value type after you have saved the analyte definition.

Calculated Analytes

Calculated analytes:

  • Must be associated with an analyte formula.
  • Can only be top-level analytes (that is, they cannot be nested under other analytes, nor have any nested analytes).
  • Cannot be added to a survey, sample or the analyte list of a process flow.

This means that calculated analytes are purely calculated from their source analyte values, and they cannot be overridden by surveys or samples.

Whenever the State Engine is calculating the quality of a stock balance (such as a stockpile state or a transaction state), it:

  1. Calculates the base quality (for example, assume source).
  2. Applies any sample or survey quality overrides.
  3. Calculates the analyte values using the analyte formula.

The State Engine attempts to get the value for all calculated analytes in the system. For each calculated analyte, if a non-null result is returned from the calculated analyte’s script, then the analyte and its calculated value are automatically be added to the balance. Calculated analytes do not need to be explicitly specified for a stockpile or process flow. All available calculated analytes are included.

Example: Calculation of Fe:MgO across WAG Stockpile Transactions

For this example, the following assumptions have been made:

  • Fe and MgO are As Received analytes.
  • WAG Stockpile B has no material before the first transaction.

WAG Stockpile A is surveyed as having 100 t with 15% Fe and 8% MgO.

Fe:MgO = 15 / 8 = 1.875

Transaction 1 is from WAG Stockpile A to WAG Stockpile B. The transaction is 10 t and the sample results are 10% Fe and 4% MgO.

Fe:MgO = 10 / 4 = 2.5

Transaction 2 is also from WAG Stockpile A to WAG Stockpile B. The transaction is 12 t and the sample results are 11% Fe and 5% MgO.

Fe:MgO = 11 / 5 = 2.2

WAG Stockpile B now has 22 t. The analyte values for Fe and MgO are calculated as weighted averages, and the Fe:MgO is calculated based on those Fe and MgO values.

Fe = ( 10 * 10 + 12 * 11 ) / 22 = 10.5454%
MgO = ( 10 * 4 + 12 * 5 ) / 22 = 4.5454%
Fe:MgO = 10.5454 / 4.5454 = 2.32

Analyte Measurement Basis

The basis upon which the quality of an analyte is measured can be nominated to be either As Received or on a Dry Basis. This is not applicable to the Moisture analyte. See also Analyte Measurement Basis.

Moisture Analyte

In MineMarket, there is only one analyte definition for moisture. This is a special analyte definition used to calculate dry mass from wet mass. Therefore, it must be used for recording the moisture within a material. The Basis, Append Basis Symbol To Name, Show Content Basis and Content UOM cannot be defined for the Moisture analyte.

The Moisture analyte definition cannot be deleted, although it can be renamed; for example, H2O or TM.

Nested Analytes

When analytical results for aggregable analytes are entered for samples taken during various processes, the resulting quality of the destination stockpile is calculated by using the weighted average aggregate formula. This considers the quality of the stockpile before the transaction and the quality of the stock being added. The proportion of analyte is based upon whether it is a top-level analyte, or a nested analyte.

In the following example, Analyte A1, Analyte A2 and Analyte A3 are nested under Analyte A. If Analyte A has a quality measurement of 30%, then Analyte A1, Analyte A2 and Analyte A3 have a combined quality measurement of 30%. Likewise, Analyte A2-1 and Analyte A2-2 are nested under Analyte A2. Therefore, Analyte A2-1 and Analyte A2-2 would have a combined quality measurement that is the proportion Analyte A2 is of Analyte A.

  • Analyte A
    • Analyte A1
    • Analyte A2
      • Analyte A2-1
      • Analyte A2-2
    • Analyte A3

Analyte Groups

Analytes can be grouped based upon a logical commonality between the different analytes. The analytes in an analyte group can be placed in a specific order that is preserved when the analyte group is used. Analyte groups are primarily used for reporting purposes or for defining analytes for specification templates.

If the reporting is based upon the group order, just the order in the group needs to be changed for it to be changed in the report; the report itself does not have to be modified.

Analyte groups can also be used to specify the analytes in products, brands, sampling templates, surveys and contributor groups.

An analyte can exist as a member of multiple analyte groups.