The W.E. Mowrey Refining Company refines gold, platinum, palladium, and silver onsite. Our analytic and process capabilities allow us to analyze the precious metal content of scrap in any form and assign a value for purchase.
Incoming precious metal is purchased in one of two ways:
Small quantities: We do a visual grading and touch stone acid test
• Visual Grading: Smaller quantities of material can be purchased by identifying a mark (i.e. 18K, 14K, 10K, Sterling silver, etc.) A stone acid test is then used to verify the mark.
• Touch Stone Acid Test: The item being tested is scratched across a stone. A standard (known) karat is scratched alongside, and then acid is used to compare the reaction time it takes to disappear.
Larger volumes from professionals are purchased on a melt and assay basis:
1. The first step in the process is to weigh and record the incoming material.
2. The material is melted with flux to separate metallics from non-metallic elements (i.e. stones, dirt, etc).
3. Bar is cleaned then weighed.
4. From this bar a sample is taken and assayed to give us the precise gold, palladium, silver, and in some cases a platinum content.
5. Once the assay is complete and the bar is ready to be purchased; the value assigned and the price is settled on a current or forward market.
The Process of purification. We use a wet chemical process to recycle scrap metal back to pure form. The metals are dissolved in an aqua regia solution; from which we selectively precipitate each element of interest. Further processing is then required to remove trace elements before the precious metal is used in our line of dental product.
What happens next?
Ounce the scrap job is settled it is placed in a refining lot and moves through our batch refining process.
The first step of the refining is to flake the refining lot in water to increase the surfaced area.
The flaked gold alloy is then dissolved in aqua regia, an acid solution containing the precious metal ions.
From here each element is selectively precipitated, then additional steps are taken to purify the metal before it is used in our line of casting gold and palladium alloys.
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W.E. Mowrey Refining
Manufacturing and Refining since 1899