Elements and Performance Criteria
- Plan work for shift
- Review job requests to identify the samples, preparation methods required for each, and shift priorities
- Identify hazards, safety equipment/procedures associated with samples, preparation methods, reagents and equipment
- Plan parallel work sequences to optimise the throughput of multiple sets of samples during shift
- Assemble all required equipment, materials, reagents and check they are fit for purpose
- Check pots and cupels and discard those with faults and/or a record of high gold values
- Check that fusion and muffle furnaces are operating at the specified temperatures
- Prepare sample racks for fusion
- Check samples against accompanying documentation and record/report any discrepancies
- Conduct simple visual/chemical tests for each sample to assess the adequacy of prior sample preparation and possible presence of sulphides or other mineralogy
- Weigh out the recommended amount of sample and add specified identifier to maintain orientation, as necessary
- Weigh out flux components, mix thoroughly with the sample charge and transfer to recommended type and size of pot without loss of material
- Place pots in racks
- Record all required details of sample preparation to ensure traceability of samples
- Seek advice to deal with any situation beyond scope of responsibility or knowledge
- Obtain acceptable buttons and prills
- Maintain sequencing in order to track samples, buttons and prills throughout the recovery process
- Monitor furnace temperature/time to ensure complete sample fusion
- Remove fused samples from furnace and pour into moulds with minimal loss of material
- Recognise the need for repeat firings due to lead shotting and/or poor fusions
- Separate slag and button with minimal loss of collector
- Inspect buttons for matte, brittleness, size and malformed shape
- Place acceptable buttons in muffle furnace using cupels that have been previously loaded and preheated
- Regularly monitor furnace temperature/time/air flow to ensure efficient cupellation
- Recover prills, check identifiers and inspect for contamination, losses and evidence of other precious metals (e.g. high gold, Platinum and Palladium)
- Complete and collate sample records before presenting prills for analysis
- Troubleshoot and correct common recovery failures
- Monitor all stages of recovery for indicators of potential loss
- Recognise undesirable recovery conditions and decide whether the process requires correction
- Apply an established corrective action and restart the process
- Document any adjustments made to standard methods and re-sequencing of samples
- Seek advice when problems are beyond scope of responsibility or knowledge
- Perform daily maintenance of assay equipment
- Maintain a safe work environment