NFTN - collective approach towards green foundries in South Africa
“A collective approach towardsgreen foundries in South Africa” Moving towards green foundries in South Africa MCTS Colloquium 2011 27 October 2011, Johannesburg Adrie El Mohamadi Project Leader
1. Setting the contextFoundry waste sand NOT WASTE NOT USED RATHER Spent foundry sand
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
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 Assessmentof Waste for Landfill Disposal, and the National Standard for the Disposal of Waste to Landfill, These are all currently in draft form.
Regulatory context - continuedCurrent bottleneckis that foundry sand is classified as hazardous waste according to the Minimum Requirements for the Handling, Classification and Disposal of Hazardous Waste “Minimum Requirements”
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 listThese macro elements would leach from inorganic materials under the acidicconditions of the TCLP test.On this basis, many materials are classified incorrectly as hazardousEven virgin garden soil was demonstrated to be hazardous in a test casesubmitted by concerned academicsThese elements are highly abundant in natural soils and are very importantsince they produce oxides.Only under extremely low pH conditions do they present a phytotoxicity issueIn the US comparisons are made between foundry sand and soils.
Cost to foundriesIn 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 aboutR250=$34.00 per tonneProblem is not only the cost but the inconsistencyof applying this regulation
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”
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
German Recycling of spent sands, dust and slags in Road construction Cement production Landfill liner Backfilling
Recycling of spent sands, dust and slagsRecycling of used Foundry Foundry sand I sand IIsands and slags pH value >9 >6Road 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]
Recycling of spent sands, dust and slagsRecycling of used sandsand quartz dust LimitCement 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
Recycling of spent sands, dust and slagsLandfill: road Landfill Landfill Landfill Landfillconstruction, Cat. 0 Cat. I Cat. II Cat. IIIlandfill liner,(limit values in Loss of ignition [%] <3 <3 <5 <10Germany) 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]
Recycling of spent sands, Limit value dust and slags TOC [mg/kg] <6Recycling of dust PAH [mg/kg] 20and used sands Metals, e.g. 600Backfilling 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
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
Adrie El MohamadiProject LeaderNFTN012 841 2127082 902 email@example.com
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