НОВЫЕ ПУТИ ПОЛУЧЕНИЯ NP-УДОБРЕНИЙ ИЗ НИЗКОСОРТНЫХ ФОСФОРИТОВ УКРАИНЫ

Научная статья
Выпуск: № 3 (22), 2014
Опубликована:
2014/04/08
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Вецнер Ю.И.1, Савенков А.С.2, Белогур И.С.3

1Преподаватель-стажер, Национальный технический университет «Харьковский политехнический институт»;

2Доктор технических наук, Национальный технический университет «Харьковский политехнический институт»;

3Кандидат технических наук, Национальный технический университет «Харьковский политехнический институт»

НОВЫЕ ПУТИ ПОЛУЧЕНИЯ NP-УДОБРЕНИЙ ИЗ НИЗКОСОРТНЫХ ФОСФОРИТОВ УКРАИНЫ

Аннотация

В статье описаны – новые пути получения NP-удобрений в результате взаимодействия продуктов азотнокислотного разложения низкосортного фосфорита с карбамидом методом высаливания по безотходной технологии.

Ключевые слова: фосфорит, карбамид, промышленность, удобрения.

Vetsner Yu.I.1, Savenkov A.S.2, Belogur I.S.3

1 Lecturer- probationer, National Technical University "Kharkov Polytechnic Institute";

2 Doctor of Technical Sciences, National Technical University "Kharkov Polytechnic Institute";

3 Candidate of Technical Sciences, National Technical University "Kharkov Polytechnic Institute"

NEW WAYS OF RECEIPT NP-FERTILIZERS FROM LOW-GRADE PHOSPHATES OF UKRAINE

Abstract

This article describes new ways to receipt NP-fertilizers as a result interaction products nitrate decomposition low-grade phosphates with urea by method salting-out on waste less technology.

Keywords: phosphate, urea, industry, fertilizer.

Modern tendency of industry’s development foresee maximum utilization of all reagents and salvaging by-products and waste were formed in technology. In phosphorous industry treatment, on the whole, high-quality phosphates ores and their concentrates with strictly regulate chemical-mineralogical composition. Supplies of such ores in Ukraine are absent. Deposits of phosphate raw materials with content of  P2O5 8 - 13% and a high content of calcium oxide and silicon - up to 30 % were located in Ukraine and on their base it is necessary create the raw material base of phosphorus fertilizers [1]. Special interest represents the development of new methods for NP-fertilizers. One of the direction is the crystallization.

Crystallization as process is used for a long time and in different branches of industry. Especially it concerns to crystallization from solutions that form the basis of many technological operations [2, 3, 4].

We are researched to receipt of fertilizers from products nitrate decomposition low-grade phosphate Novo-Amvrosievskogo deposit with urea. As a method of manufacturing NP- fertilizer had chosen isothermal, comprising the formation of a supersaturated solution by salting-out. The mechanism of found of solid crystalline phase conditioned to change of the solubility of calcium nitrate by the influence of urea. The advantage of utilize of urea in its influence to removal of the fullness calcium nitrate from nitrate solution (NS), which receipt by the decomposition low-grade phosphate Novo-Amvrosievskogo deposit by 56-58 % nitric acid.

Initial substances were used NS, % mass.: [HNO3] – 4-6, [H3PO4] – 11-12, [Ca(NO3)2] – 40-46,  [H2O] – 41-45,  [Fe(NO3)3] – 3-5  [Al(NO3)3] –  3-5 [Mg(NO3)2] – 1-3  [NaNO3] – 0,02-0,05,  [KNO3] – 1-3,  [H2SiF6] – 0,5-0,7 and urea (mass fraction of nitrogen on the dry substance,%, not less than 46,2-46,3; biuret mass fraction,%, not more than 0.6-1.4).

Models were prepared with mixing the initial substances in a molar ratio R = solid phase: liquid phase = (0,5 ÷ 5) : 1 in a thermostat equipped with a mechanical stirrer at 25-50 °C. The mixing time ranged from 30 to 90 minutes, after which the resulting mixture was sent on filtration to separate a crystalline solid from the uterine liquor. Then the solid phase was sent to drying at 80-100 °C, and the uterine liquor was sent for further processing into complex liquid fertilizers. Ready fertilizer was analyzed with physicochemical methods according to all-Union State Standard of Ukraine, the data presented in Table 1.

 

Table 1 - Analysis of X-ray diffraction studies of fertilizer

R Products
(0,5 ÷ 3) : 1 Ca(H2PO4)2∙H2O, Ca(H2PO4)2, CaHPO4, CaHPO4∙2H2O,   CO(NH2)2∙HNO3
(4 ÷ 5) : 1 Ca(NO3)2∙4CO(NH2)2, Ca(H2PO4)2, Ca(H2PO4)2∙H2O, CaHPO4,          CO(NH2)2∙H3PO4, CO(NH2)2∙HNO3
 

According to facts were received with increasing the ratio R in the final product observed the emergence and increase of Ca(NO3)2∙4CO(NH2)2, which is a valuable fertilizer in agriculture.

Further researches were associated with a decrease in the amount of calcium nitrate in NS, the facts were presented in Table 2.

Table 2 - Changes in the amount of calcium nitrate in NS

    Cа(NО3)2, % NS R
0,5 : 1 1 : 1 2 : 1 3 : 1 4 : 1 5 : 1
45,95 45,83 45,45 45,04 41,79 36,05 34,82
 

In this way, the incorporation of urea into the nitrate solution leads firstly to obtain a solid phase consisting mainly of water-soluble calcium compounds, and, secondly, to reduce the content of calcium nitrate in the uterine liquor from 0.26% to 24.22 %, enabling further processing of the uterine liquor in the NP-fertilizers.

References

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