Master student Amirbekov
A.B., Candidate of Technical
Sciences Kocherov Ye.N., Candidate of Technical Sciences, professor RAS
Kolesnikov A. S.
South-Kazakhstan State University names after M.Auezov,
Republic of Kazakhstan, Shymkent city
The high cost of chemicals, the exhaustion and non-renewable reserves of
phosphate raw materials of the country for the production of fertilizers,
especially metabolism of nitrogen compounds in plants, soil and water
environments, actualize problems in the most effective application of mineral
fertilizers and reduce their downtime..
Therefore there is a need to develop
a highly effective fertilizer containing macro - and microelements in easily
accessible form, allowing for joint use with other chemicals without reducing
their effect, can enhance the flow in plants of mineral nutrients from the
soil, not containing harmful and ballast substances. In patents [1-3]
proposed to use for preparation of fertilizers sludge from wastewater with the
use of plasticizing additives and fillers.
Physico-chemical and instrumental
methods of research explored the possibility of obtaining production of
NPK-fertilizers of the prolonged action containing humectant vermiculite. The
result worked out the basic optimal technological parameters of the process of
obtaining mineral fertilizer, which is characterized by the following optimal
performance (in %): phosphorus deposits Chulaktau – 75-85; vermiculite
deposits, Zhilandi – 7-12; brown coal deposits Karazhyra – 5-10; 40% aqueous
solution К2СО3.
Structural features and phase composition of the obtained NPK fertilizer
was investigated x-ray diffraction and IR-spectroscopic methods.
In the study of IR absorption
spectra of samples of NPK fertilizers in the region 4000-600∙10-2m-1
(figure 1) found that the interaction of the particles of the fertilizer with
the active functional groups of brown coal.
Figure 1. The IR spectra of
NPK-fertilizers prolonged action
It may also be noted that when the interaction range is undergoing
significant changes in the study area. The Association observed absorption band
at 1080∙10-2m-1 (C–C) and 1245∙10-2m-1
(SN), and form one broad absorption band 1080-1480∙10-2m-1.
Apparently, this is due to the interaction between active functional groups of
brown coal and fertilizers. This band can be attributed to the stretching
vibrations of the C=C.
There are also absorption bands in the region from 2700-3300∙10-2m-1,
apparently, the interaction of the particles of vermiculite with the active
centers of NPK fertilizers.
The result of differential thermal and thermogravimetric study was to
determine the thermal behavior of the sample and identify its composition
(figure 3). Thermochemical parameters of the studied samples in the first
approximation has identified a number of correspondences of its composition and
the thermochemical properties are found in fertilizers.
Figure 3. All NPK-fertilizers
Molecular and hydroxyl water for the most part (~90%) introduced in the
result of hydration of the original components of the charge, and only a small
fraction of hydrate (<10%) included in the components of the substance being
studied as elements of their structures. The most revealing factor in the
presence of water fills in the mass of the sample are clearly expressed
endothermic peaks in the DTA and DTG curves of the sample, detected at 90 and
400°C, which are associated with the emissions, respectively Δm1=1,75(H2O) and Δm3=0,2(HE)%.
In other ranges of temperatures of these lines provide very weak information about the presence of any water. Only
thermogravimetric (TG) curve in the intervals 220-375 and 430-575°C noted mild
decrease in the weight corresponding to the changes in the mass Δm2=0.4 a(HE) and Δm4=1/2·0,5 (HE)%.
Electron microscopic analyses NPK fertilizers was to withdraw with a
scanning electron microscope JEOL JSM-6390 (Japan) and obtained a structural
image of the samples in sizes 10, 100 and 500 µm (figure 2).
The resulting data was the following: particle size from 20 to 400 µm;
the structure of the particles is porous; the composition of the major
elements, wt.%: the oxygen of 44.86; calcium – 9,02; sodium - 0,62, aluminum –
1,11, magnesium – 1,79, sulfur – 4,24, silicon – 20,42 and R – of 6.46.
а – 100 µm, б – 500 µm
Figure 2. Electron
microscopic image of particles of NPK fertilizers
The results of the physico-chemical and instrumental researches has
allowed to develop technology of obtaining complex NPK-fertilizers of the
prolonged action, which contains in its structure the phosphorus, humates,
potassium, brown coal and water-holding substance, on the basis of exfoliated
vermiculite.
Literature
1. Ershov V. A. Problem of complex processing of phosphorites of Karatau //
Phosphate industry. 1972, Vol. 3(8 ). - p. 16-19.
2. The Geology of phosphorite deposits, methods of forecasting and
prospecting, M.: Nedra, 1980.-247 p.
3. Blaskowski V. 3. Material composition and obogatimost phosphorite ores. M.:
Nedra, 1983.- 200 p.