Environmental hot spot – landfill for industrial waste "HIV Veles" mineralogical, geochemical and radiochemical research

Jancev, Mitko (2022) Environmental hot spot – landfill for industrial waste "HIV Veles" mineralogical, geochemical and radiochemical research. Doctoral thesis, University Goce Delcev - Stip.

Text Doktorska - Mitko Jancev komplet_kor.pdf - Accepted Version Download (78MB)

Abstract

The work of the factory for the production of fertilizers in the area of Veles (the
Republic of Macedonia) resulted in a residual amount of about 3.4 million tons of
phosphogypsum that was deposited at the dump adjacent to the plant in the period
from 1980 to 2003.
So far, there no remediation of the phosphogypsum dump has been performed.
This paper presents the results obtained from representative samples taken from the
phosphogypsum dump by applying the following methods: analytical methods (ICP�MS, FUS-ICP-MS), mineralogical methods, X-ray powder diffraction (powder-XRD),
electron microscopy (SEM-EDS), and high-resolution γ-ray spectrometry.
The samples contain crystalline gypsum (Ca sulphate), Fe hydroxide, Ba
sulphate, Ca fluorite, Si-oxy-hydroxide and zirkon.
The gross alpha specific activities varied between 820 Bq/kg and 1090 Bq/kg
with an average 950±104 Bq/kg, while the gross beta specific activities ranged from
1380 Bq/kg to 1980 Bq/kg with an average of 1694±220 Bq/kg.
Phosphogypsum is obtained in the process of obtaining phosphoric acid by
treating phosphate rock (phosphorites) with sulfuric acid (Al-Hwaiti et al., 2015; Al�Masri et al., 2004; Cánovas et al, 2017; Degirmenci, et al., 2007).
The Fertilizer Plant "Chemical Industry Veles" (abbreviated as "HIV") is a factory
for the production of fertilizers near the village of Zgropolci, in the central part of
Macedonia, in the immediate vicinity of the river Vardar. The factory is located about
12 km southeast of the city of Veles, or about 15 km from the lead and zinc smelter
"MHK Zletovo".
The plant for phosphoric acid within the "Chemical Industry Veles" was first
opened in 1979. In February next year the production of mono-ammonium
phosphate (МАР) began, and the plant for the production of fertilizers was opened in
May 1980. The factory ceased operations in June 2003.
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The factory was primarily built to use the sulfuric acid obtained in the
metallurgical complex of the Lead and Zinc Smelter "MHK Zletovo" near Veles. The
main production of the plant was the production of phosphoric acid, the production of
monoammonium phosphate, and the production of fertilizers.
The capacity for the production of phosphoric acid was projected at 50,000 tons
with a dihydrate procedure, and the maximum realized capacity was 33,000 tons per
year.
The factory represents an ecological hot spot in the surrounding area, due to the
unorganized acid waste water discharge and the gypsum dump, which was used
since the plant started operation in 1979 until its closure in 2003. There are 3.7
million tons of gypsum on the gypsum dump and it covers 70.000 m². The gypsum
dump is located about 1.5 km southwest of the factory complex, in a small valley
between hills.
The gypsum dump was filled by a pipeline, whereby the solid waste materials
were transported in the form of a phosphogypsum suspension. Beside this dump, the
factory also completely polluted the river Vardar through the discharge of waste
water.
The detailed investigations of the chemical, geochemical, mineralogical and
radiological composition of the phosphogypsum from the of HIV Veles dump show
that it is a chemically, geochemically, mineralogically, and radiologically relatively
uniform material. The mineral composition is simple and dominated by gypsum, and
there is very little presence of accessory minerals (quartz, Ba sulphate, Sr sulphate,
fluorite, zircon, mica). The high representation of elements of the rare-earth elements
group (REE) in an amount that in some cases reaches 300 ppm points to the fact
that this material is a serious raw material with a high proportion of elements from
the group of rare-earth elements and that it is an economically interesting raw
material.
Based on radiological testing, the following conclusions ca be made:
- The total alpha and beta specific activities in the dump are higher compared
to their values in soils from Veles and the surrounding area;
- The specific activities of 40K, as well as of the radioisotopes from the 232Th
array were below the detection level. The presence of 238U and 226Ra with
activities higher than the activities in soils has been identified;
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- The arithmetic mean value of the specific activity of 226Ra of this study is lower
in relation to the values published in such studies conducted in other
countries;

Item Type:	Thesis (Doctoral)
Subjects:	Natural sciences > Earth and related environmental sciences
Divisions:	Faculty of Natural and Technical Sciences
Depositing User:	Ivan Boev
Date Deposited:	15 Feb 2022 19:12
Last Modified:	15 Feb 2022 19:12
URI:	https://eprints.ugd.edu.mk/id/eprint/29483

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