Metal Recycling, Scrap Processing & Salvage worked example

Supplier Grade Variance with highest assayed grade reading across loads of 4 value: a worked example

Suppose highest assayed grade reading across loads falls to 4 value. This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimate supplier grade variance for metal recycling, scrap processing and salvage using production-ready inputs so teams can compare measurements against the expected process or specification window.

The inputs for this scenario

  • Highest assayed grade reading across loads: 4 value (the input this scenario stresses; the baseline uses 8)
  • Lowest assayed grade reading across loads: 12 value (held at the documented default)
  • Nominal contracted grade target: 10 value (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Supplier grade variance range = highest supplier grade variance reading - lowest supplier grade variance reading.
  • Supplier grade variance variation works out to 80 units at these inputs, and this is the headline figure for the scenario.
  • Spread works out to 8 value at these inputs.
  • Minimum works out to 4 value at these inputs.
  • Maximum works out to 12 value at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where highest assayed grade reading across loads sits at 8 value and the headline result is 40 units, this scenario comes in 100% above the baseline at 80 units.
  • It computes the range between the highest and lowest assayed grade readings and the delta between the midpoint of those readings and your nominal contracted grade. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • Supplier grade variance variation: 80 units (headline result)
  • Spread: 8 value
  • Minimum: 4 value
  • Maximum: 12 value

Run it with your numbers

  • To rerun this with your own numbers, open the live Supplier Grade Variance calculator, set highest assayed grade reading across loads to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.