Russian Journal of Applied Chemistry, 2013, Vol. 86, No. 4, pp. 463−468.
Pleiades Publishing, Ltd., 2013.
Original Russian Text © E.P. Lokshin, O.A. Tareeva, I.R. Elizarova, 2013, published in Zhurnal Prikladnoi Khimii, 2013, Vol. 86, No. 4, pp. 497−502.
AND INDUSTRIAL INORGANIC CHEMISTRY
On Integrated Processing of Phosphogypsum
E. P. Lokshin, O. A. Tareeva, and I. R. Elizarova
Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Resources,
Kola Scientiﬁ c Center, Russian Academy of Sciences, Murmansk oblast, Russia
Received February 1, 2013
Abstract—It is shown that phosphogypsums obtained from the Khibiny apatite concentrate can be puriﬁ ed by
percolation leaching with low-concentration sulfuric acid solutions to remove admixtures of ﬂ uorides, phosphates,
and water-soluble compounds of sodium, with simultaneous transfer of rare-earth element sulﬁ des into solution.
The achievable degree of impurity extraction enables use of the puriﬁ ed material as a gypsum raw material for
manufacture of gypsum binders and cement. The method is applicable to processing of both currently produced
phosphodihydrate, phosphohemihydrate, and mixtures of these and those long stored in dumps.
In Russia, sulfuric acid technologies are used to
annually process about 4.3 million tons of the Khibiny
apatite concentrate (AC), with about 3.15 million tons
of phosphodihydrate (PDH) and 3.35 million tons of
phosphohemihydrate (PHH), rather rapidly transformed
into PDH in storage, formed as a technological waste. The
manufacture of phosphogypsum in Russia is many times
that of other similar technological wastes: titanogypsum
(processing of ilmenite), sulfogypsum (puriﬁ cation
of efﬂ uent gases from fuel-burning power plants),
ﬂ uorogypsum (processing of ﬂ uorspar), and borogypsum
(processing of borates). Hundreds of millions of tons of
phosphogypsum produced from AC are accumulated in
dumps occupying large areas of land. The water-soluble
impurities contained in phosphogypsum, and primarily
ﬂ uorides and phosphates, are leached in storage under
the inﬂ uence of atmospheric precipitates and ﬁ nd their
way into surface water basins and underground water.
Phosphogypsum can be used in agriculture, road
building, and manufacture of sulfuric acid, cement,
gypsum binders, ammonium sulﬁ de, and calcium oxide
or carbonate [1–3]. In the USSR, about 3 million tons of
phosphogypsum served for melioration of alkaline soils,
whereas Russia’s use of phosphogypsum in agriculture
is only slight . In contrast to a number of foreign
countries, and primarily to Japan, phosphogypsum and
other forms of technogenic gypsum are hardly used in
Russia for manufacture of construction materials.
To provide manufacture of cement and gypsum
construction materials, Russia annually mines 5–6
million tons of natural gypsum with steadily decreasing
quality . The consumption of gypsum by the cement
industry will be many times larger if it is used not only
to control the cement setting rate, but also to produce
Certain achievements were made in application
of phosphogypsum instead of natural gypsum in
manufacture of gypsum construction materials [4, 5].
However, the gypsum binder production technology
employed at Voskresensk Minudobrenie OAO became
outdated and was terminated . Gypsum of G-2
and G-3 brands is produced from phosphodihydrate
on the experimental-industrial scale by Volkhovgips
Use of phosphogypsum in manufacture of cement
and gypsum construction materials is primarily hindered
by the high content of ﬂ uorides, phosphates, and water-
soluble sodium compounds, which substantially exceeds
the values required by regulations (Table 1) established
for gypsum raw materials by the leading manufacturer