Precious Metal Laboratory
With over 100 years of sampling and assaying experience, our customers are left assured their material is evaluated and paid based on accurate/transparent assays. Beyond utilizing Fire Assay and Wet Chemistry when assessing customer’s material, Electrum sends representative samples to certified independent laboratories. Why? – For Confirmation. We trust our processes, equipment, and techniques; however an independent analysis will confirm the assays are correct. “Trust but verify” is the Electrum motto.
Fire assays provide refiners with the most accurate method for determining Silver, Gold, Platinum, and Palladium content. The three step process is as followed:
- Preparation: Sample is ground, screened, and blended to produce a homogeneous sample.
- Collection: Sample is mixed with a proprietary flux compound which releases Lead to collect the precious metal. The crucible is poured to create a slag and “Lead button”.
- Separation: The lead bead button is put into a cupel and melted at 1562 degrees. The sample remains in the furnace until the Lead is volatilized and the non-precious metal is absorbed into the cupel. What remains is a “prill button” containing Gold, Silver, Platinum, or Palladium to be chemically separated.
Electrum uses Nitric Acid or Aqua Regia solution for digestion to identify Silver, Gold, Platinum, or Palladium content in a heterogeneous or homogenous sample.
Aqua Regia is a combination of Hydrochloric and Nitric Acids used to completely dissolve surface or embedded Gold, Platinum, Palladium, or multiple precious metals. The reaction is complete when all metals are dissolved and gassing ceases.
Nitric digestion is used to dissolve Silver bearing samples only. Nitric acid will digest the sample into a clean solution for analysis. Again, reaction is complete when all metals are dissolved and gassing ceases.