Recycling sweeps and bullions

Coming from various sources such as incineration of rags/wipes, precious metal-bearing milled slags and metallic electronic scraps, sweeps and bullions actually close the loop of the pre-processing chain to achieve ultimate refining.

Other precious metal bearing residues, be it complex by-products from the PM-refiners, high grade solutions from PM-chemistry or PM-bearing wastes are also recovered.

A unique flowchart, strong sampling and assaying capabilities and metallurgical expertise in meticulous separation of a wide variety of impurities make Umicore Precious Metals Refining a natural home for sweeps, bullions and other precious metals containing residues.


Sweeps are defined as dry, free-flowing, inorganic powders consisting of fine particles, homogenized and bearing economically significant precious metal elements (sometimes resulting from an incinerating process).
Depending on their origin, sources of sweeps can be summarized as follows:

  • silver sweeps: ashes or residues, primarily from the photographic industry
  • jewelry sweeps: wipes, sweeps and grindings from jewelers
  • electronic scrap sweeps: ex e-scrap pre-processors yielding e.g. incinerated samples or fused boards, e-components, etc
  • GM-sweeps: ex production scrap, end-of-life treatment of car and industrial catalysts, ground scraps from the glass industry, by-product of a recovery operation, ground rich slags, etc.


Bullions originate mainly from smelting processes involving jewelry, dentistry and metallic production scraps containing economically viable amounts of recoverable elements, cast into ingots or blocks. Copper is one of the major non-ferrous elements along with precious and/or platinum group metals.

Other PM-bearing residues

Precious metal refining and specialized industrial down stream operations yield various types of process residues, e.g.:

  • wet materials like solutions, filtrates, sludges, cakes, etc
  • dry residues such as flue dusts, slags, etc
  • bricks and refractories from the glass and fiberglass industries.


In a genuine move towards environment protection, Umicore Precious Metals Refining with its truly regarded ability to separate precious metals from other associated elements will help you valorize your residues effectively.

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