2. ENVIRONMENTAL ChEMISTRy & TEChNOLOGy 2.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Environmental Chemistry & Technology
L07 hEAVy METALS IN SOLID IMMISIONS IN
ThE VICINITy OF IRON ORE MINING AND
PROCESSING PLANT IN NIŽNÁ SLANÁ
JOZEF HAnČUľáK, ERIKA FEDOROVá, OľGA
ŠESTInOVá, TOMISLAV ŠPALDOn, Ján BREHUV and
PAVeL SLAnČO
Institute of Geotechnics of the Slovak Academy of Sciences
Watsonova 45, 043 53 Košice, Slovak Republic,
hanculak@saske.sk
Introduction
The content of hazardous substances in atmospheric
deposition significantly contributes to the pollution of
environment. A lot of studies deals with the research of
atmospheric deposition, mostly using methods monitoring
wet deposition, wet and dry deposition (bulk deposition),
but also methods using fog and low cloud sampling 1 . The
solid emissions from the technologies of ores and industrial
minerals processing by their specific composition influence
constitution of atmospheric deposition, especially in the areas
of processing plants. The main emission source in the area
of nižná Slaná is iron-ore mining and processing plant. The
plant exploits the siderite ore. The run-off-mine ore is through
several technological centres processed into the blast furnace
pellets as a final product of the plant. The contribution deals
with the evaluation of results obtained from monitoring of
atmospheric deposition in the form of dust fallout (modified
method bulk deposition). The research was carried out by the
Institute of Geotechnics of the SAS in the area of the Siderite,
Ltd. from 2001 to 2007, predominantly from viewpoint
of heavy metals deposition (Fe, Mn, Zn, Pb, Cu, Cr, Cd, and
As).
Characteristics of the Plant
The plant is situated in the Slaná river valley in the Slovak
Republic. The valley has an orientation of north-south
and northwest-southeast, respectively. The wind circs are
influencing by an orography of given territory. Distribution
of wind directions and the occurrence of calm in the near-by
Rožňava town are shown in Table I.
Exploited deposit is located in the Revúca upland Mts.,
the Dobšiná foothill belt Mts. of the Slovak Ore Mts. Utility
mineral is siderite. The average content of iron and manganese
in ore is 33.5 % and 2.8 %, respectively. Manganese
is bonded isomorfically in the siderite lattice. There are also
unfavourable elements (As, S, Pb, Zn) that occur as, sulphides,
sulphates, sulphosalts and oxides. The most significant
unacceptable impurity is arsenic that is present in the form of
arsenopyrite. The average content of As in the run-off-mine
ore is approximately of 0.01–0.1 %. Ore processing consists
of crushing, magnetizing roasting, wet milling, magnetic
separation and pelletizing. Primarily, thermal technologies,
i.e. pelletizing and magnetizing roasting are responsible for
the amount of dust outlet. Flue gases are exhausted to the
environmental air through 120-meter high chimney after
s309
several stages of dedusting. Table II presents the average concentrations
of the selected elements in the dust outlet from
pelletizing plant and rotary furnaces. The emissions of solid
pollutants from 1998 to 2007 are shown in the Table III.
Material and Methods
The samples of dust fallout were taken in the 30 days
( ± 3 days) intervals from the seventeen sampling stations.
The cylindrical plastic sedimentation containers (inside diameter
– 12.5 cm), put in two support stands in the height of
2.5 to 3 m, were used for the sampling. The containers were
filled with 250 ml of pure water with addition of isopropanol.
After sampling, the content of containers was quantitatively
located to evaporating dishes and evaporated. The organic
mass was removed by annealing of dry matter at 450 °C. The
chosen temperature prevented carbonate degradation and in
such way enables to avoid the misinterpretation of dust fallout
gravimetry results. The samples were gravimetrically evaluated
before and after annealing, in the mass units recalculated
for the area and the respective time period. Inorganic
portion determined by annealing from twelve month period
was cumulated to the one sample and after mineralization it
was analysed using AAS (SpectrAA – 30 VARIAn). On the
basis of these chemical analyses and mass yield of the dust
fallout, the average annual depositions by observed heavy
metals were calculated for each of the seventeen sampling
points. The localization of sampling stations is illustrated in
Fig. 1.
Fig. 1. Sampling locations in the area of Nižná Slaná
Results and Discussion
The average year values of total deposition for whole
monitored period determined for individual sampling points