NFTN - collective approach towards green foundries in South Africa

1. “A collective approach towards
green foundries in South Africa”
Moving towards green foundries in South Africa
MCTS Colloquium 2011
27 October 2011, Johannesburg
Adrie El Mohamadi
Project Leader

2. 1. Setting the context
Foundry waste sand
NOT WASTE
NOT USED
RATHER
Spent foundry sand

3. Colloquium 2009:
Major joint problem raised by companies was the irregular
manner in which foundry spent sand is regulated in SA -
 Exorbitant costs to dispose of spent foundry sand
 No facility to assist with process
 Industry not willing to unite to deal with the problem

4. Regulatory context
Waste management in South Africa is regulated under
the National Environmental
Management: Waste Act 2008.
The Waste Act is supported by
the National Waste Classification and Management
Regulations, the Standard for Assessment
of Waste for Landfill Disposal, and the National Standard
for the Disposal of Waste to Landfill,
These are all currently in draft form.

5. Regulatory context - continued
Current bottleneck
is that foundry sand is classified as hazardous waste according
to the
Minimum Requirements for the Handling, Classification
and
Disposal of Hazardous Waste
“Minimum Requirements”

6. South Africa is applying the leaching test: Toxicity
Characteristic Leaching Procedure (TCLP), however the
problem is that other than the international standards
SA included elements Al, Fe and Mn to the list
These macro elements would leach from inorganic materials under the acidic
conditions of the TCLP test.
On this basis, many materials are classified incorrectly as hazardous
Even virgin garden soil was demonstrated to be hazardous in a test case
submitted by concerned academics
These elements are highly abundant in natural soils and are very important
since they produce oxides.
Only under extremely low pH conditions do they present a phytotoxicity issue
In the US comparisons are made between foundry sand and soils.

7. Cost to foundries
In the United Kingdom foundry waste sand,
qualifies under the lower rate tax, which is £2.50
=$4.10 per tonne (FTJ, 2011)
In South Africa general waste disposal is about
R250=$34.00 per tonne
Problem is not only the cost but the inconsistency
of applying this regulation

8. 2. Taking action
 February 2011; a Foundry Waste management
working group was initiated
 April 2011; an external consultant was appointed to
do tests on 4 green sand foundries spent sand
 Chemical Analysis
 Interpretation of the analysis
 Documents for submission at Department of
Environment
 Sept 2011; received results of the above, stating that
“Overall, spent foundry
sand should be regarded as inert, rather than
low-risk waste”

9. 3. Way forward
 Give feedback to 4 foundries; on the results of their
sand
 Next few weeks; set up a meeting with Department
of Environment
 Influence regulation; engage America and Germany in
this
 Start working on alternative uses of spent foundry
sand

10. German Recycling of spent sands, dust and
slags in
 Road construction
 Cement production
 Landfill liner
 Backfilling

11. Recycling of spent sands, dust and slags
Recycling of used Foundry Foundry
sand I sand II
sands and slags
pH value >9 >6
Road construction,
(limit values in Germany) Conductivity 1,500 2,700
[microS/cm]
Fluoride 9 80
[mg/l]
DOC [mg/l] 30 200
Metals, e.g. 115 120
Chromium
[microg/l]

12. Recycling of spent sands, dust and slags
Recycling of used sands
and quartz dust
Limit
Cement production,
value
(limit values of the cement industry)
Phenole 40
[mg/kg]
PAH [mg/kg] 20
Metals, e.g. 400
Chromium
[mg/kg]
Nickel [mg/kg] 250

13. Recycling of spent sands, dust and slags
Landfill: road Landfill Landfill Landfill Landfill
construction, Cat. 0 Cat. I Cat. II Cat. III
landfill liner,
(limit values in Loss of ignition [%] <3 <3 <5 <10
Germany) pH value 5.5-13 5.5-13 5.5-13 4-13
Fluoride <1 <5 <15 <50
[mg/l]
DOC [mg/l] <50 <50 <80 <100
Metals, e.g. Chromium <0,05 <0,3 <1 <7
[mg/l]
Only landfill liner: < 1* 10-10 < 1* 10-10 < 1* 10-10 < 1* 10-10
Permeability [m/s]

14. Recycling of spent sands, Limit value
dust and slags
TOC [mg/kg] <6
Recycling of dust PAH [mg/kg] 20
and used sands Metals, e.g. 600
Backfilling in mines, Chromium
(Limit values (not regarding salt [mg/kg]
mines) in Germany)
Nickel [mg/kg] 600
•
Naphtaline (PAK) 2
[mg/l]
Metals, e.g. 50
Chromium
[mg/l]
Nickel [mg/l] 50

15. 3. Summary
 These has been progress since 2009
 Bottleneck – legislation
 Draw on international experience
 Develop a reliable publicly owned testing facility
 Start working on alternative uses for spent foundry sand
 Government, Academia, Industry and Research to joint
hands

16. Adrie El Mohamadi
Project Leader
NFTN
012 841 2127
082 902 4083
adrie.elmohamadi@nftn.co.za
www.nftn.co.za