Slags, nickel smelting

Additional information on environmental fate and behaviour

Administrative data

Endpoint:

additional information on environmental fate and behaviour

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study performed to OECD guidline

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD 29, 2001, Guidance on transformation /dissolution of metals and metal compounds in aqueous media

Deviations:

yes

Remarks:

mesocosm pond water used instead of standard media

Principles of method if other than guideline:

Transformation/dissolution behavior of copper slag was assessed through an experimental design that follows recommendations of the OECD 29 guidance document on transformation/dissolution (T/D) (OECD , 2001)
Release study was conducted on 5 different slag materials in 4 loadings for 7 days, stirring rate (100rpm).
As the study aim at “bridging” the results from the slag mesocosm study to other slag, copper smelting materials, the conditions of the copper slag mesocosm study (AUR-001/4-52) were adapted concerning water quality (mesocosm pond water, pH 8), and presence of basalt material.
Three basalt controls with the highest loading of 12500 mg/L were run additionally to two mesocosm water controls. All loadings of all slag materials were added by control basalt fines to a total loading of 12500 mg/L.
This test protocol is based on an experimental procedure of agitating various quantities of different slag crushed fines in control mesocosm water, and sampling and analyzing the solutions after filtration at specific time intervals to determine the concentrations of dissolved metal ions in the water.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Slag, copper smelting

IUPAC Name:

Slag, copper smelting

Details on test material:

This test protocol is based on an experimental procedure of agitating various quantities of different slag crushed fines in control mesocosm water, and sampling and analyzing the solutions after filtration at specific time intervals to determine the concentrations of dissolved metal ions in the water.
Test materials were tested in bulk (original particle size) or crushed/sieved to 1-2 mm (massive materials) as follows;
3512 (bulk)
2987(bulk)
3821 (bulk)
5244 (1-2 mm, mesocosm reference sample)
3181 (1-2mm)
The materials were selected based on the following criteria, applied to the hazard characterisation of the various slags:
-Selection of different material types produced by the industry (granules, stones, fines)
-Selection of materials produced during primary and secondary copper productions
-Selection of materials with relative high measured metal releases during 7 days transformation/dissolution tests, carried out at pH 6 and a loading of 100 mg/l , standard media (Rodriges et al, 2010)

Results and discussion

Any other information on results incl. tables

Table 1: Metals released from test materials under mesocosm-like conditions (water, basalt control) after 7d, corrected by subtraction of basalt control concentrations (ECI-001/7-80)

ECI-001/7-80 / 7 d		3512 Bulk				2987 Bulk				3821 Bulk				5244 1-2mm*				3181 1-2mm
test item	mg/2L	6250	3012	1504	750	3012	1501	750	377	12497	6253	3017	1503	25005	12504	6255	3012	12499	6254	3015	1506
Basalt fine	mg/2L	18752	21984	23499	24247	21990	23495	24246	24622	12495	18745	21981	23496	0	12501	18746	21988	12495	18747	21986	23498
sum	mg/2L	25002	24996	25003	24997	25002	24996	24996	24999	24992	24998	24998	24999	25005	25005	25001	25000	24994	25001	25001	25004
level in ecotox test		4	3	2	1	4	3	2	1	4	3	2	1	4	3	2	1	4	3	2	1	LOD	LOQ
Al	µg/L	19.3	17.8	10.9	8.4	6.6	9.2	8.2	7.6	bLD	bLD	6.1	9.5	bLD	bLD	bLD	bLD	86.1	31.4	4.8	7.8	3.5	11.5
Cd	µg/L	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	0.7	2.3
Co	µg/L	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	2.0	6.5
Cr	µg/L	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	1.4	4.5
Cu	µg/L	30.9	14.3	3.5	bLD	77.2	44.4	27.5	13.4	15.0	5.6	3.2	bLD	223	107	48.9	26.5	83.5	44.3	23.5	13.5	2.2	7.3
Fe	µg/L	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	7.9	26.2
Mn	µg/L	1.1	bLD	bLD	bLD	1.8	bLD	bLD	bLD	bLD	bLD	bLD	bLD	2.4	1.2	bLD	bLD	8.5	3.8	1.5	bLD	0.9	2.9
Mo	µg/L	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	1.2	3.9
Ni	µg/L	bLD	bLD	bLD	bLD	8.0	4.6	3.0	bLD	2.3	bLD	bLD	bLD	7.1	3.8	bLD	bLD	6.7	4.6	bLD	bLD	1.9	6.4
Pb	µg/L	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	8.9	bLD	bLD	bLD	15.5	bLD	bLD	bLD	8.6	bLD	bLD	bLD	5.9	19.6
Sb	µg/L	bLD	bLD	bLD	bLD	3.3	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	2.6	8.6
V	µg/L	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	bLD	3.2	10.8
Zn	µg/L	3.7	bLD	bLD	bLD	29.6	12.3	4.7	bLD	212.3	66.3	29.1	9.5	119	33.0	10.2	bLD	23.5	10.0	4.5	bLD	2.3	7.5

yellowvalues marked are below the limit of quantification (see last column); bLD= values below the limit of detection. *batch as used in study AUR-001/4-52.

Table2:  Data Summary of table 4. Average metal releases from slag, copper smelting materials after 7 days transformation/dissolution tests under mesocosm-like conditions (water, basalt control), corrected by subtraction of basalt control concentrations (ECI-001/7-80). The metal releases are expressed per gram slag material. 

Sample number	Mean Cu release (µg/g)	Mean Zn release (µg/g)	Mean Pb release (µg/g)	Mean Ni release (µg/g)
1	8.01	1.2	BDL	BDL
2	63.071	16.2	BDL	6.5
3	2.1	21.8	1.4	0.4
4	17.05	6	1.2	0.6
5	15.26	3.3	1.3	1.4

                                                                           

Applicant's summary and conclusion

Conclusions:

The data are of good quality and critical for extrapolation from slag used in mesocosm study to other slags

Executive summary:

Transformation/dissolution test (7 days, 4 loadings, pH around 8) was carried out using a range of slags exposed to the water used for a meosocosm ecotoxicity study on one slag material.

The following metal releases (µg/g slag material) were observed corrected by subtraction of basalt control concentrations The metal releases are expressed per gram slag material. 

Cu 2.1 – 63.07 µg/g

Zn 1.2 – 21.8 µg/g

Pb 1.2 – 1.3 µg/g

Ni 0.6 – 6.5 µg/g

 

The data indicate usually lower release rates from the slags then the ones observed during the classic T/D tests at pH6 (Rodriguze et al., 2010). The difference in solubility could not be entirely explained by differences in pH. Other differences, such as slag-specific characteristics (eg particle sizes and crystalline structure) and medium-specific characteristics (eg DOC) may be responsible for the observed differences among materials and test media.