Influence of the setting activators on the physical mechanical properties of phosphoanhydrite
Phosphoanhydrite was obtained by processing dihydrate phosphogypsum generated during phosphoric acid production at Joint Stock Company (JSC) Lifosa (Lithuania). The influence on the properties of phosphoanhydrite of the treament process’ parameters was determined, including the conditions o...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Association of the Chemical Engineers of Serbia
2014-01-01
|
| Series: | Chemical Industry and Chemical Engineering Quarterly |
| Subjects: | |
| Online Access: | http://www.doiserbia.nb.rs/img/doi/1451-9372/2014/1451-93721300004L.pdf |
| Summary: | Phosphoanhydrite was obtained by processing dihydrate phosphogypsum generated
during phosphoric acid production at Joint Stock Company (JSC) Lifosa
(Lithuania). The influence on the properties of phosphoanhydrite of the
treament process’ parameters was determined, including the conditions of
phosphogypsum neutralisation in the lime suspension; temperature and duration
of calcination of neutralized phosphogypsum to phosphoanhydrite; fineness of
ground anhydrite; selection of additives activating the hydration of
anhydrite and their amounts. Upon adding activators of anhydrite hydration,
K2SO4 or Na2SO4, the data of XRD and IR spectral analysis show that the
specimens after 1 day of phosphoanhydrite hydration with additives contain
complex salts - syngenite upon using K2SO4 additive and glauberite in the
case of Na2SO4 additive. These additives act as crystallization centers and
accelerate hydration. It has been determined that the specimens of
phosphoanhydrite calcined at a temperature of 900 º C with 2 % K2SO4 additive
have the best physical and mechanical properties. Already after 1 day of
hardening the specimens acquired a compressive strength of 21.18 MPa, and
after 28 days of hardening they had a compressive strength of 58.5 MPa (dry
specimens). |
|---|---|
| ISSN: | 1451-9372 2217-7434 |