Electrolytes, copper-manufg., spent

Endpoint summary

Additional information

The UVCB substance is an inorganic, complex metal containing material.

 

Intermediate B12 - Electrolyte, Copper Manufacturing, Spent   “Spent electrolyte consisting of copper non-ferrous metal sulfates and sulfuric acid. It is produced as by-product during the electrolytic refining of copper, purified by physical treatment (demetalization) and prepared for re-use (closed circuit).”
EC Names	Substances covered /synonyms	EC number / EINECS No.	CASNo.
Electrolytes, copper-manufg., spent*	Spent electrolyte; bleed, white acid	273-752-2	69012-54-0
Electrolytes, copper-manufg., spent, demetalized*	Spent demetalized electrolyte; black acid	273-716-6	69012-16-4

 

At room temperature, the substance is a liquid.

The UVCB can be considered as containing mainly contain sulphuric acid ( typicallly across industry ca 20 to 30% w/w) and water. A detailed chemical analysis (ICP +iodometry) was performed on a representative sample (IUCLID 4.23).

The majority of the available data on physical and chemical properties of the UVCB is therefore read across from sulphuric acid data (as found in publicly available literature and reviews). Because a number of physical and chemical properties of the UVCB are highly influenced by the sulphuric acid content (water content) and the presence of the metal sulphates, additional testing were performed on a representative sample in view to address boiling temperature, vapour pressure and self ignition properties, etc of the material ( REACH Copper Consortium).

It is important to note that the UVCB is not stable, and precipitates of the metal suphates may be formed during transport.  

Explosive properties can be excluded in the absence of structural alerts. also sulphuric acid is not expected to possess explosive properties. Flammability testing in accordance with UN Transport Test N1 is not applicable to a liquid. Also pure Sulphuric acid is non-flammable. Experience of handling and use provide sufficient information to indicate the substance is not pyrophoric and investigation in accordance with UN Transport Test N3 is not required. Sulphuric acid does not meet the CLP criteria as an oxidizer. The UVCB is therefore not necessary to consider for classification as self-reactive substance. From sulphuric acid, it is known that the substance reacts with water, emitting SO2 (non-flammable gas).

  

The selection and collection of the representative UVCB samples was made based on expert knowledge and according to a standardized sampling protocol developed by the REACH Copper Consortium, an industry joint-venture regrouping major manufacturing and importing companies of the UVCB substance. Details on the sampling approach and the representative samples are reported as supporting information in IUCLID 1.4 and 4.1.

 

Sulphuric acid is known to have a high affinity for (and is miscible with) water. It dissociates in water to form sulphate and hydrogen (carbonium) ions. The dissolution and dissociation of sulphuric acid in water is strongly exothermic and occurs with a vigorous reaction. Sulphuric acid is a powerful acidic oxidiser that does however not meet the CLP criteria as an oxidizer (i.e. not causing ignition or explosion in contact with cellulose).

These properties do also apply to the UVCB, to a minor extent (due to lower content in H2SO4) and with the consequence that the high affinity to water induce more or less precipitation of non-ferrous metal salts to occur.

A number of the physical and chemical properties of sulphuric acid are highly influenced by its purity (water content). Waivers are proposed (based on the nature of the substance and its reactivity with water).