Treatment and Destruction of Inorganic Fibers Wastes Like Asbestos by Sodium Polyphosphate

Abstract

The removal and destruction of ceramic fibers wastes are presently an important problem for the society health. Among these, the asbestos, which are silicates, is the more dangerous. Usually their destruction is obtained by a melting way, but this needs high temperature (about 1500-1600•Ž) and presents an expensive treatment. In this paper we show that the sodium polyphosphate addition to different asbestos (chrysotile, amosite and crocidolite) permits to obtain the fiber's destruction at a temperature below than 900•‹C. This process may be applied to composite materials containing a few part of asbestos, like carpet tiles or building plaster. This process of waste's treatment can open a new and a large market for sodium polyphosphate.

Qualitative and Quantitative Analysis of the Inorganic Materials Changes with Time in the Stages of the Wastewater Treatment Plant

“…In research field, many workers in literature gave their attention to find out economical and environmental methods to remove these inorganic materials. Furthermore, the phosphate compounds, and particularly the polyphosphates, were proposed as good removals to the inorganic wastes [7]. Chemical oxidants such as ozone, chlorine, chlorine dioxide, and chloramines, besides their disinfection role, were also used since a number of organic and inorganic compounds can go reactions with these oxidants [8][9][10][11][12][13][14][15][16].…”

“…On heating, these polyphosphates will react with the particles through oxoacidity reaction [7]. One cheap industrial salt commercially used is sodium polyphosphate, known as Graham or hexametaphosphate salt.…”

“…One cheap industrial salt commercially used is sodium polyphosphate, known as Graham or hexametaphosphate salt. Comparatively to other uses of these phosphates, their usage in waste treatment-particularly in inorganic wastes-has become a minor compared to other uses; one is the treatment of nuclear wastes [7].…”

Thermal decomposition of asbestos-containing materials

“…There are different ways of disposing of these wastes. Dissolution in acids or bases [8][9][10][11][12], hydrothermal [13] or mechanochemical treatment [14,15] as well as fibre melting with further vitrification [16,17] are methods that have been described in the technical literature. One of these methods could also be thermal treatment [18][19][20][21].…”