High Volume Fly Ash Cement: An Economical Approach for Reducing the Pollution Impact of the Thermal Power Plant

1. HIGH VOLUME FLY ASH CEMENT AN ECONOMICAL APROACH FOR REDUCING THE POLLUTION IMPACT OF THE THERMAL POWER PLANT BY- PRODUCTS IN THE OHRID AREA Arjan Korpa; Kledi Xhaxhiu; Altin Mele; Bujar Seiti; Erjon Spahiu Vth International Scientific Conference on Water, Climate and Environment BALWOIS 2012 - Ohrid, Republic of Macedonia - 28 May, 2 June 2012

2. By-products of coal burning

3. Coal fly ash - FA Worldwide FA production estimated at around 600 million TPA. FA production in Macedonia more than 2.5 million TPA. Total FA generated since 1970 more than 50 million tons. Almost all of the fly ash produced is disposed of in landfills at significant cost. Fly ash creates massive pollution to the environment! As fly ash piles up, the challenge for safe disposal rises! Location of the two coal power plants in Macedonia

4. Fly ash generation and utilization - Europe FGD – Flue gas desulphurization product SDA – Semi dry absorption product FBC – Fluidized bed combustion product Source: ECOBA – European Coal Combustion Products Association

5. Hazardous waste - fly ash According to the US Environmental Protection Agency (USEPA): Hazardous waste - materials containing specific heavy elements which exceed regulated concentration levels. Heavy elements are extremely toxic - they present danger to the whole ecosystem. Dump sites/pond fly ash - can leak their toxic cargo into rivers or public water systems by leaching and migrationup to hundred kilometers. A number of incidences have been reported in the past, where leachate had contaminated the groundwater!

6. Dumped coal fly ash Production in Macedonia more than 2.5 million TPA.

7. Macedonian fly ashes – Toxic elements Trace elements enriched in waste products Bitola FA Nb, Mn, P, Mo, Ti Oslomej FA Nb, Sb, Hg, Y, Ti, Zr, Sc, Cu, Mn, V, Zn, Th, Ni, Ga, Co, Pb exceeds Clarke concentration by more than two times*! Some of these elements may contribute to environmental and health problems in the area!

8. Fly ash radioactivity/Macedonianfly ash where CTh, CRa and CKare the activity concentrations of 232Th, 226Ra and 40K in the final product, expressed in Bq/kg. European Commission: Radiation Protection Report (RP-112, EC), Luxembourg, (1999). *- Concentration in the final product

9. Fly ash can be upgraded to a valuable raw material with proper quality control Fly ash Cement

10. High Volume Fly Ash (HVFA) cement Current practice: Silicious fly ash in cement can be used up to 30% New approach: Silicious fly ash in cement up to 50% (a real challenge!)

11. Physical properties of the HVFA cements

12. Investment required for industrial production of HVFA through ball mills Air Slide Mill Inlet Silo Truck Unloading Cement Mill Vertical Screw Weigh Feeder

13. Economic Evaluation – Cost of New Mix Designs/HVFA Cost savings for 1.3 million TPA cement = 1.64 x 1 300 000 = 2 132 000 euro * Variable cost of fly ash comprises also the transport cost within 200 km distance

14. Conclusions • What is considered ”waste” for a human activity sector appears to be • a highly valuable raw material for another activity. • The economical solution to waste handling - incorporation into • construction products. • Materials bonded with cement tend to have significantly lower leaching • abilities. • Hence there is no significant influence of hazardous elements on the • surrounding waters due to leaching.

15. Thank You for your attention!