Chemical and mineralogical characterisation of cutting process sludge
PETER VAN STRAATEN
Dr. Annita Colombo*, Dr. Annalisa Tunesi*, Dr. Valentina Barberini**,Dr. Lucia Galimberti*, Dr. Alessandro Cavallo* *Department ofGeological Sciences and Geotechnologies, University of Milan Bicocca -www.geo.unimib.it **Department of Earth Sciences Ardito Desio,University of Milan
ABSTRACT
The sludge produced through the sawing and working of stone is stillconsidered an inert waste product. Once it has satisfied the requiredcriteria for acceptance, it is given to authorised waste dumps (D.M.03/08/2005). The first fundamental step towards evaluating its possiblereutilisation is to find out its chemical and mineralogical compositionand assess any possible compositional variation in time. In order to dothis, and as part of the PIC INTERREG III A project, a systematicsampling was carried out with 11 firms (9 of which are located in theVerbano Cusio Ossola area and 2 in the Canton Ticino). 2 samples amonth were systematically collected for 6 – 8 months from each firm;the two samples from each month were then mixed in order to obtain onesample per firm to analyse every month. The chemical and mineralogicalcomposition of the sludge was then established; on the one hand therewere obvious connections between the make-up of the sludge and that ofthe stone from which it came; on the other hand, significantdifferences from the original rock were also highlighted. This wasfound to be due to the different type of processing carried out by eachfirm.