SU1692975A1 - Method for obtaining complex fertilizer - Google Patents

Abstract

The invention relates to the production of complex fertilizers and can be used in agriculture. The aim of the invention is to increase the absorption of macro-and micronutrients while reducing hygroscopicity and caking of the finished product. This goal is achieved by the fact that in the method of obtaining a complex fertilizer by treating perlite with a solution of potassium alkali, followed by decomposition of the insoluble residue with a solution of nitric acid and drying, the treatment is carried out with an alkali solution with a concentration of 40-300 g / l at a temperature of 80-160 ° C and the decomposition of the insoluble residue is carried out with concentrated nitric and / or phosphoric acids, followed by granulation and drying of the product. 1 hp f-ly, 2 tab.

Description

The invention relates to the production of complex fertilizers and can be used in agriculture.

The purpose of the invention is to increase the uptake of macro and microelements and the yield of the finished product while reducing hygroscopicity and caking.

Example 1. 2500 g of perlite rock (composition 1 given in the table is treated with 20 l of potassium hydroxide with a concentration of 40 g / l KOH at 80 ° C for 4 h. Liquid glass is removed from the reaction mass and water is added to the undissolved precipitate 500 ml of concentrated (56%) nitric acid. A 0.5% cellulose solution is introduced into the gel-like mass, granulated and dried at 250 ° C.

Example 2. 5000 g of perlite rock (composition 2 given in the table is treated in 25 l of potassium alkali with a concentration of 300 g / l KOH at 120 ° C for 2 h. The liquid mass is removed from the reaction mixture and the remaining sludge is mixed 2000 ml of 20% phosphoric acid is added before decomposition of the precipitate and to obtain a gelatinous mass. A solution of a polyvinyl acetate emulsion is introduced into the resulting mass, granulated and dried at 280 ° C.

Example 3. 2000 g of perlite rock (composition 3, shown in Table 1) are treated and heated by heating to 160 ° C in a potassium hydroxide solution with a concentration of 150 g / l KOH for 1 hour. The reaction mass is decanted and the liquid phase is drained. Then, 2000 ml of concentrated nitric acid is added to the obtained precipitate, the mixture is stirred until oO is obtained.

h

N

n

Is- With

second mass. To the resulting suspension, 600 ml of 20% phosphoric acid is added and homogenized again, resulting in a gel-like mass into which the binder solution is injected to obtain a soft, pasty mass, then granulated and dried at 265 ° C.

In tab. 2 shows data on the effect of alkali concentration (40-300 g / l) of the treatment temperature 80-160 ° C, the concentration of the acids used and their type on the process indicators.

From the analysis of table. 2 it follows that when using concentrated nitric and / or 20% phosphoric acid with decomposition of the insoluble residue in the following ranges of alkali concentrations (40-300 g / l) and decomposition temperature (80-160 ° С) (examples 1 -3) A total content of macro- and microelements of 65-67.3% is achieved with a hygroscopicity coefficient of 2.8 mol / kg.h and a caking rate of 0.026 MPa. When the concentration of the KOH solution in the exposed materials changes, the quality indicators of the complex fertilizer deteriorate — hygroscopicity and caking increase, and the content of trace elements in an assimilable form decreases. For example, when the concentration of KOH solution is less than 40 g / l (example 8), the properties of the fertilizer deteriorate — the hygroscopicity coefficient rises to 4.3 mol / kg hh, the caking at 1% humidity reaches 0.031 MPa and the amount of macro- and microelemento form is 59.8%.,

With an exorbitant concentration of KOH in an alkaline solution over 300 g / l, i.e. 320 g / l, fertilizer quality indicators deteriorate - hygroscopicity coefficient 8.5 mol / kg h, caking at 1% humidity 0.065 MPa, amount

macro - and micronutrients in an unassimilable form of 45%. When the temperature values leave at intervals, the quality of the fertilizer deteriorates (example 6): at 70 ° C - the hygroscopicity coefficient is 4.2 mol / kg, h, caking at 1% humidity of 0.033 MPa, the amount of nutrients is 60.0%; at 170 ° С - the hygroscopicity coefficient is 4.2 mol / kg.h, the caking is 0.048 MPa, the amount of nutrients is 61.8%.

Changes in the concentration of the acting mineral acid worsen the conditions of interaction with the undissolved aluminosilicate residue, the fertilizer is obtained with a polymorphic structure, which leads to a decrease in the quality indicators of the complex fertilizer (Table 2, Examples 9 and 10).

The economic efficiency of the proposed method allows to improve the quality of the fertilizer by increasing the further digestible macro and microelements and to obtain a fertilizer characterized by a low coefficient of hygroscopicity and caking.

Claims (1)

Invention Formula A method of obtaining a complex fertilizer, which involves treating perlite with an alkali solution followed by decomposition of the insoluble residue with a solution of nitric acid and drying, in order to increase the digestibility of macro- and microelements while reducing the hygroscopicity and caking of the finished product, the treatment is carried out with an alkali concentration solution 40-300 g / l at a temperature of 80-160 ° C, and the insoluble residue is decomposed by concentrated nitric and / or 20% phosphoric acid, followed by granulation of products that НгО, F, Clj, N Ñ С0г SOZ, СНд Trace elements (S, CrjOj, Vz05S.MuO, 2, CoO, UOj, SnO, CuO, ZnO, SbO, CdO, Au, Prg05)