Novara Environmental Statement 2007 English MEMC-NO ...

The plan to adopt cutting technologyconsisting of a steel wire soakedin an abrasive suspensionfor cutting silicon bars in a singlestep was implemented for all barcutting operations in 2007. Thismeasure has made it possible toconsiderably limit the consumptionof acetic acid and potassiumhydroxide used in the ungluingstage to remove residuesof glue used to stick the siliconbar to the base prior to cutting.The following graphs illustratethe strong downward trend in thechemical substances listed, bothin specifi c and absolute terms,precisely because the ungluingstage no longer contributes tothe factory’s total consumption ofsaid substances.Consumption of chemical sustances: Potassium hydroxide KOHAnnual consumption (t)1201008060402002000 2001 2002 2003 2004 2005 2006 2007YEARConsumption of chemical sustances: Acetic acid CH 3COOH18Annual consumption (t)16141210862001 2002 2003 2004 2005 2006 2007YEAR0,50,40,30,20,100,100,080,060,040,020,00Specifi c consumption (t/MSIE)Specifi c consumption (t/MSIE)Finally they highlight a situationderiving from the upkeep of animprovement action, strengthenedover the years, that continuesto offer excellent results in termsof environmental performance:that is to say a reduction in theconsumption of hexavalent chrome,a chemical substance, thecompounds of which are classified as carcinogenic by inhalationand are therefore particularlyhazardous. Said reduction hasbeen achieved thanks to a decreasein the number of productdefect tests performed requiringapplication of the chromic etchingprocess and the application of aprocess foreseeing multiple useof the etching bath.Consumption of chemical sustances: Chromium VI70605040302010-2000 2001 2002 2003 2004 2005 2006 2007YEARTotal annual consumptionSpecifi c consumptionAnnual consumption (kg)Consumption ofHexavalent ChromiumTotalCons.Spec.Cons.Year kg kg/MSIE 2000=1002000 40 0,23 1002001 32 0,23 1002002 46 0,27 1162003 61 0,32 1382004 34 0,15 662005 8 0,04 152006 7 0,03 112007 4 0,02 70,20-%Specifi c consumption (kg/MSIE)22