Abstract:
The paper provides information about phosphogypsum waste from various enterprises and how
it can be used in the production of slow-release fertilizer mixtures. Such fertilizer mixes can
potentially be used with different types of soil, including acidified soils. Experiments were conducted
on phosphogypsum samples from the old and new dumpsites under the Taraz branch of Kazphosphate
LLP. All representative samples underwent chemical, mineralogical, thermal gravimetric
and differential thermal analyses, as well as Fourier-Transform Infrared (FTIR) spectroscopy and
polarized optical microscopy (POM). No significant differences were found in the content of the
samples. Phosphogypsum from the old dumpsite contained 87.93% gypsum (CaSO4
· 2H2
O), 9.10%
quartz (SiO2), 17.55% calcium (Ca), 0.13% potassium (K), 0.35% phosphorus (P), and 0.80% phosphorus
pentoxide (P2O5). Phosphogypsum from the new dumpsite contained 85.04% gypsum, 10.58% quartz
(SiO2), 19.42% calcium (Ca), 0.14% potassium (K), 0.30% phosphorus (P), and 0.69% phosphorus
pentoxide (P2O5). The current paper also offers a technological scheme for making a slow-release
fertilizer mixture with phosphogypsum.
