ISO/PWI 10378

Copper, lead and zinc sulfide concentrates — Determination of gold and silver — Fire assay gravimetric and flame atomic absorption spectrometric method

Scope

This revision includes guidelines on

a) management of gold assay data when coarse particulate gold is present and
b) a method to validate the accuracy of the method as applied in a laboratory.

a) Guideline for Managing Gold Fire Assay data when Coarse Particulate Gold is Present.
Provide background and theory on the impact that coarse particulate gold has on the precision of gold analysis of a concentrate and the level of error associated with each reported mean value. Include guidance of how to manage high flying values and how to add annotations on Certificates of Analysis to communicate the error information. Provide additional guidance on how parties should cooperate when settling on values for a shipment containing coarse particulate gold.

b) Guideline for Establishing Performance Specifications for the Application of a Fire Assay Method within a Laboratory.
Using the principles outlined in ISO 5725 Accuracy (trueness and precision) of measurement methods and results — Parts 1 to 6 and other published information, provide a working template for establishing the precision and trueness of a fire assay method as applied in a Laboratory. Provide a list of suitable reference materials and worked examples of the Certified Reference Material and Recovery validation methods.