RESUMEN
The purpose of the present study is to develop a process to regenerate the polish liquid used in Chemical and Mechanical Polishing (CMP), called "slurry", and more specifically Silicon CMP slurry. Physico-chemical analyses show a considerable dilution of slurry through washing waters used in polishing. Thus, this effluent has been characterised for a better identification of the deviations from the slurry of reference (Point Of Use). Hence, the principle is to regenerate this effluent by membrane processes. The ultrafiltration results obtained at laboratory scale have led to the development of an industrial prototype. An optimal utilisation of this treatment allows completing a two-step process: the reconcentration by ultrafiltration and a chemical adjustment by addition of concentrated slurry. A stable behaviour of the slurry at the different steps of the process has been observed. Polishing results are similar with retreated and POU slurries. Furthermore, the functioning at industrial scale permits to maintain the performances obtained on the laboratory pilot.
Asunto(s)
Membranas Artificiales , Silicio/químicaRESUMEN
Anterior open-bites may be skeletal, alveolar or mixed. The infra-alveolae is always due to a postural or functional muscular cause and the clinical examination plays an important part in the diagnosis. Delaire's cephalometric analysis can define the type of infra-alveolae. In view of their aetiology, the infra-alveolae require functional re-education, although glossectomy and multiple bands therapy may also be useful.