Slags, steelmaking, converter

Additional information on environmental fate and behaviour

Administrative data

Endpoint:

additional information on environmental fate and behaviour

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study well documented. Study meets generally accepted scientific principles. Study acceptable for assessment

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1998

Materials and methods

Principles of method if other than guideline:

Assessment done by Larm of the Niedersaechsisches Landesamt fuer Oekologie (Lower Saxonian State Agency for Ecology). Assessment of environmental properties by comparison of leachate concentrations of with concentration limit values of the TVO (Trinkwasser-Verodnung = German Federal Drinking Water Regulation) and the Pruefwert (test value) of LAWA (= Bund/Laender-Arbeitsgemeinschaft Wasser = German Federal and Federal States Working Group on Water).

GLP compliance:

not specified

Type of study / information:

Environmental assessment

Test material

Test material information

Constituent 1

Reference substance name:

Slags, ferrous metal, blast furnace

EC Number:

266-002-0

EC Name:

Slags, ferrous metal, blast furnace

Cas Number:

65996-69-2

Molecular formula:

~ Al(n)Ca(m)Mg(o)Si(p)O(3n/2+m+o+2p)

IUPAC Name:

Aluminium-Calcium-Magnesium-Silicium oxide equivalent

Details on test material:

Analytical information (elemental and mineralogical data) is presented in Chapter 1.4 of the IUCLID

Results and discussion

Any other information on results incl. tables

Table 1. Analytical information on slags (analytical information is derived from elemental analysis according to DIN 52100 (part 2, 6.1) and is given in the oxides notation. The use of the oxides notation does not indicte that the slag is a mixture of these oxides. Therefore neither CAS No. nor EG No. are specified)

	ABS/GBS		BOS		EAF
% w/w	Mean	Maximum	Mean	Maximum	Mean	Maximum
SiO2	36.7	40	18	14	13	18.5
Al2O3	10.2	12	2.0	5.0	6	9.5
CaO	39.5	43	49	53	26	36
CaO frei	n.d.	n.d.	6	9.5	0.4	0.8
MgO	9.4	16	2.5	6.0	5	7.5
Na2O	0.4	0.8	n.d.	n.d.	n.d.	n.d.
K2O	0.5	0.9	n.d.	n.d.	n.d.	n.d.
TiO2	1.1	2.5	n.d.	n.d.	n.d.	n.d.
P2O5	n.d.	n.d.	1.5	2.7	0.6	1.0
MnO2	0.6	1.3	4.2	6.0	6.1	9.8
Feges.	0.4	0.7	18	22	26	30
Sges.	1.5	1.9	0.1	0.2	0.2	0.4
Cr2O3	n.d.	n.d.	0.3	0.5	2	3.0
Trace elements (mg/kg)
As	<1	<1	<1	<1	3	13
Cd	<1	<1	<1	<1	5	30
Cr	20	40	s.o.	s.o	s.o	s.o
Co	4	8	7	10	6	10
Cu	5	10	30	50	140	300
Hg	<1	<1	<1	<1	<1	<1
Mo	<2	<2	20	80	90	200
Ni	<2	<2	4	9	20	70
Pb	5	<21	6	8	20	90
Se	2	2	<1	<1	<1	<1
Tl	<1	<1	<1	2	1	1
V	30	50	300	600	800	2500
Zn	<100	<100	60	150	300	900
Anions (mg/kg)
F	600	<900	2200	3800	800	1800
CNges	n.d.	n.d.	n.d.	<10	n.d.	<10

Leachate concentrations reported in the assessment by Larm

Analytical information on slag leachates (DIN 38 414. S4. Analytical methods FGSV-Papier 28/1)
	ABS Grain size 8 -11 mm		GBS Grain size 0 - 5 mm		BOS Grain size 8 -11 mm		EAF Grain size 8 -11 mm
	Mean	Maximum	Mean	Max.-wert	Mean	Maximum	Mean	Maximum
pH	11	11.4	11	11.5	12.1	12.7	11.6	12.3
ConductivitymS/m	82	126	46	100	269	765	77	198
CODmg/l	78	182	<20	<20	2.4	7	5	20
	Dimension mg/L:
Al	1.3	2.9	0.07	1.1	1.7	7.0	9.5	40
As	0.002	0.005	0.001	0.003	<0.001	<0.001	0.001	0.003
Cd	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001
Co	<0.002	<0.002	<0.002	<0.002	<0.002	<0.002	<0.002	<0.002
Cr	0.001	0.002	0.001	0.001	0.001	0.04	0.026	0.08
Cr^6+	<0.01	<0.01	<0.01	<0.01	0.01	0.02	0.016	0.04
Cu	<0.001	<0.001	<0.001	<0.001	0.001	0.002	0.001	0.002
Hg	<0.0005	<0.0005	<0.0005	<0.0005	0.0006	0.001	<0.0005	0.0005
Mo	<0.01	<0.01	<0.01	<0.01	0.01	0.02	0.01	0.03
Ni	<0.002	<0.002	<0.002	<0.002	<0.002	<0.002	<0.002	0.002
Pb	<0.001	0.001	<0.001	0.001	0.001	0.002	0.002	0.006
Se	0.006	0.009	0.0009	0.002	0.0005	0.0005	0.0005	0.002
Tl	<0.0005	<0.0005	<0.0005	<0.0005	<0.0005	<0.0005	<0.0005	<0.0005
V	0.01	0.02	0.005	0.01	0.02	0.05	0.06	0.38
Zn	0.01	0.02	0.01	0.01	0.01	0.01	0.01	0.02
Anions
F	0.5	1.0	<0.2	<0.2	2.0	8	0.5	1.5
Cl	5	10	<5	<5	5	20	1	7
SO4^2-	288	598	34	106	22	45	15	18
CN total	<0.01	<0.01	<0.01	<0.01	0.01	0.02	<0.01	0.01
CN soluble	<0.01	<0.01	<0.01	<0.01	<0.01	<0.01	<0.01	<0.01

Results of leachate assessment of Larm (Niedersaechsisches Landesamt fuer Oekologie = Lower Saxonian State Agency for Ecology)

LAWA = Bund/Laender-Arbeitsgemeinschaft Wasser (German Federal and Federal States Working Group on Water)

TVO = Trinkwasserverordnung (German Federal Regulation on Drinking Water)

	Element detected only in levels similar to geologic background	Concentration in leachate exceeds limit values of TVO	Concentration in leachate exceeds limit value of LAWA	continuous monitoring nessessary
Al	yes; <background	no	no limit value available	no
As	yes	no	no	no
Cd	yes (exceeded only in EAF)	no	no	no
Co	yes; <background	no	no	no
Cr	yes (exceeded significantly in EAF)	no; exceptionally exceeded	no; exceptionally exceeded	yes, if marketed
Cu	yes	no	no	no
Hg	yes	no	no	no
Mn	yes for ABS and GBS (exceeded significantly in BOS and EAF)		no limit value available	no
Mo	Not consistantly below background		no	no
Ni	yes	no	no	no
Pb	yes (exceeded by some EAF)	no	no	no
Se	yes		no	no
Tl	yes		no
V	no, exceeding		yes; significantly exceeding	yes
Zn	no(exceeded by some EAF)	no	no	no
CN^-		no	no	no
SO4^2-		yes		yes
F^-		yes (occasionally)	yes (occasionally)	yes

Applicant's summary and conclusion

Conclusions:

The elemental composition of slags, the type of chemical incorporation of these elements into the mineral matrix of the slag as well as its leaching properties are important for the assessment of the environmental long-term behaviour of slags. Monitoring is only necessary in regard to Cr (if slag is marketed) and V, as well as SO4 and F.

Executive summary:

The mineralogical and elemental composition of slag was determined for ABS/GBS (and 2 similar slags, BOS and EAF). The elemental composition of the solid material did not correlate with the leachates obtained by the S4 leaching method which had the highest reproducibility. The S4 leaching method yielded comparable results on leaching of grain sizes 8 -11 mm and 0 -32 mm. The following parameters of the leachates were assessed by comparison to standards for environmental and human health protection (limit values of TVO (German Federal Drinking Water Regulation) and LAWA Pruefwerte (test values) as far as available): pH, conductivity, COD, Al, As, Cd, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Se, Tl, V, Zn, CN, SO₄, F. Only 2 elements have to be continuously monitored: Cr only in case of marketing (use) of the slag, and V. SO₄ is to be monitored because fresh ABS exceeds the German "Zuordnungswerte" (TR Bauschutt (Technical guidance for demolishion rubble) limit values for general use), F because of limits for drinking water.