Umicore
 

INDUSTRIAL BYPRODUCTS

Umicore Precious Metals Refining is one of the world's major processors of by-products from the non-ferrous industry. Among others, these industrial by-products include:

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Tankhouse slimes or anode slimes

Tankhouse slimes or anode slimes are generated in electrolytic refineries. The name refers to the refining process itself, which is performed in a succession of rectangular cells or tanks. These contain a solution in which a plate of impure metal (the anode) is immersed. When we apply electrical power to the anode, the impure metal dissolves and transits via the solution, right through the cell, to a second plate (the cathode), where it precipitates as a pure metal. The non-soluble impurities, settle on the bottom of the cell in the form of sludge (anode slime), together with the precious metals. This sludge can contain up to 7 or 8 precious metals (if secondary PGMs are present), diluted by the base metals lead, copper, etc. and their associated secondary metals: selenium, tellurium, tin, antimony, arsenic, bismuth, etc. In total, anode slimes can contain more than 20 different metals, making it one of the most complex products in the industry.
Umicore Precious Metals Refining is able to extract all the valuable metals that are present in all tankhouse slimes productions worldwide. This is a major advantage compared to other precious metals plants, especially to those plants that are integrated within a base metal refinery. Such operations are often limited to the processing of a few precious metals from anode slimes of a well-known and stable composition.
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Dross, matte and speiss

Dross is a solid phase that appears on top of a molten bath of impure metal. It results from the segregation of a second metal with a higher melting point. A classical example is copper dross, produced on top of a liquid lead bullion. This dross is a complex material as the copper in the dross is accompanied by other metals like nickel, iron etc. The separation with lead is far from complete. Typical lead contents in the dross still range up to 75%. Also, precious metals are present, more particularly PGMs, that are more active in copper than in lead. As a result, lead smelters are not keen on copper and associated metals.
With its lead/copper flowsheet, Umicore Precious Metals Refining is ideally suited for dross processing. Not only does it pay for the precious metals and other valuable metals, it also pays for the lead and copper contents present in this material.
Matte is the metallurgical name for a phase that typically associates any base metal with sulfur. Similarly, speiss results from the combination of base metals with arsenic or antimony. Both phases are alternative by-products for dross and are processed by Umicore Precious Metals Refining with equal success and good results.
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Zinc industry

In the zinc refining industry, lead is segregated as sulfate and, these days, is increasingly removed in leach products. Again, both materials have their own specific challenging characteristics for further processing, more particularly high moisture and sulfur contents. Umicore Precious Metals Refining is able to deal with such difficult by-products. We can insure optimal recovery of lead and accompanying precious and secondary metals. In doing so, we follow strict environmental regulations and are in agreement with the authorities.

In nature, precious metals are often linked to base metals, mainly copper, lead, zinc and nickel. They represent substantial values in primary mining concentrates that are processed by the base metals industry. In some instances, they can even exceed the value of the base metals themselves. The same goes for secondary scrap metals that are generated by the recycling industry. When we consider this, we see that we must not only look at separating the base and precious metals - we must also pay attention to the processing of the precious metals that need to be recovered.

During the refining process of base metals, the precious metals are collected in typical by-products, together with many other metals and impurities. These metals and/or impurities, such as arsenic, chlorine, fluorine, etc ..., which have little or no market value are carefully treated and collected, so that we can be sure they pose no negative effects to nature.

Umicore Precious Metals Refining is one of few global specialists that has expertise in extracting and refining all valuable and non-valuable metals and impurities within industrial by-products. Doing this in a safe and environmentally friendly way is one of our key values that we never lose track of.

CONTACT:

Sybolt Brouwer
T: +32 3 821 62 35
F: +32 3 821 78 07
E: sybolt.brouwer@umicore.com

Guy Daelman
T: +32 3 821 79 78
F: +32 3 821 78 07
E: guy.daelman@umicore.com

Els De Winter
T: +32 3 821 75 12
F: +32 3 821 78 07
E: els.dewinter@umicore.com

Kris Van Rompaey
T: +32 3 821 72 10
F: +32 3 821 78 07
E: kris.vanrompaey@umicore.com