RU2108996C1 - Method for producing phosphoric organo-mineral fertilizers - Google Patents

Abstract

FIELD: agriculture; organic chemistry. SUBSTANCE: phosphate flour or simple superphosphate are mixed with humic substances taken in amount 2-9 wt. -%, followed by drying mixture at 85-105 C. As humic substances, method employs product resulting from oxidative-hydrolytic decomposition of lignosulphonates. The latter are oxidized with air oxygen in alkaline medium, at 150-200 C and under pressure not more 2.5 MPa. Liquid phase is concentrated until its moisture content is brought down to 8-10%, followed by mixing it with mineral component. Method permits to expand range of phosphoric organo-mineral fertilizers and to improve environmental conditions due to using, as humic component, lignosulphonates constituting difficult-to-dispose wastes resulting from operation of pulp--and-paper-making plants. EFFECT: broadened range of phosphoric fertilizers for agriculture; improved environmental conditions. 4 tbl

Description

 The invention relates to the production of phosphoric organic-mineral fertilizers of improved quality with a high content of digestible phosphorus.

 A known method of producing special phosphorus fertilizers is that the phosphorus fertilizer is mixed with humic substances in the ratio phosphates: humic substances 4: 1 - 0.5: 1 and other nutrients and binders are added to ensure a slow release of nutrients. The mixture is granulated in a drum granulator and dried in air (application Germany No. 3101801, class C 05 G 1/100, decl. 21.01.81, publ. 19.08.82).

A known method of producing phosphogumus (Brazilian patent N 8304493, class C 05 F 11/02, 19.03.85), carried out by the reaction of natural phosphate with bone meal and humates of lignin or peat at 80 - 120 ^o C followed by fusion and granulation with CaSO ₄ .

The closest in technical essence and the achieved result is a method of producing organo-mineral fertilizers (A.S. USSR N 1608170, class C 05 F 11/00, 1990) based on phosphate rock and hydrolysis lignin, carried out by mixing phosphate rock and hydrolysis lignin in a ratio of 1: (1-1.2) in terms of absolute dry matter and subsequent grinding of ore. This treatment increases the degree of lignin activation, increases the number of hydroxyl groups in it, and its interaction with phosphate ore leads to an increase in the relative percentage of lemon-soluble P ₂ O ₅ to 64.9%. Such treatment of phosphate rock gives an increase in the yield of various crops.

 The objective of the invention is to expand the assortment of phosphorus organic-mineral fertilizers and improve the ecology of the environment through the use of lignosulfonates as a component of humate - waste pulp and paper plants.

 The technical result of the invention is to obtain phosphorus organic-mineral fertilizers with a higher relative percentage of digestible phosphorus, and therefore, increased agrochemical efficiency.

The problem is solved as follows. Organic and mineral phosphorus fertilizer is obtained by mixing phosphorite flour or simple superphosphate with humic substances taken in an amount of 2-9 wt.% Followed by drying of the mixture at 85 - 100 ^o C. Oxidative-hydrolytic destruction of lignosulfonates obtained is obtained as humic substances their oxidation with atmospheric oxygen in an alkaline medium at 150 - 200 ^o C and a pressure of not more than 2.5 MPa. The liquid phase thus obtained is concentrated to a moisture content of 8-10%.

 The raw materials for the production of humic substances are organo-containing waste from pulp and paper production - lignosulfonates. This is a multicomponent aromatic product containing up to 80% of organic matter (Sapotnitsky S. A. Use of sulfite liquors, Lesnaya prom., 1965). An important circumstance is the content in lignosulfonates of up to 7 - 9% of the total sulfur, which is approximately the same in the humic product after the oxidation of lignosulfonates. The presence of sulfur in humic substances enhances their value, since sulfur is part of the amino acids cystine and methionine, is of great importance in protein metabolism and redox processes, and is part of vitamins and vegetable oils. According to the Norsk Hydro survey (Fertilizers in Perspective, Sweden), sulfuric deficiency is observed due to the improvement of the ecological situation in the world. Humic preparations from lignosulfonates additionally help solve this problem.

 Upon receipt of humic substances, sodium hydroxide, potassium hydroxide or ammonium hydroxide can be used as an alkaline agent. Ammonium hydroxide is particularly preferred, since humic preparations contain up to 5-7% nitrogen, and with oxidative degradation of lignosulfonates in sodium or potassium hydroxide, the nitrogen content is not higher than 1 - 2%. Alkali in the process of oxidative degradation of organo-containing raw materials plays the role of a catalyst for the polycondensation reaction of oxygen-containing compounds, in particular phenols, resulting in their conversion to polyphenols and quinones with high physiological activity.

On the one hand, the solubility of oxygen depends on the temperature factor of the reaction of the oxidative degradation of lignosulfonates, and on the other hand, when the temperature rises, the yield of the target product decreases due to the accumulation of oxygen-containing compounds that are prone to self-condensation in an alkaline medium, while decreasing the carboxyl groups decreases and humic substance content. In addition, at high temperatures, desulfurization of the target product occurs, which reduces the sulfur content in the N-humates. Lowering the temperature below 150 ^o C increases the reaction time to 8 - 12 hours, this makes the process energetically unprofitable.

To achieve the technical result of increasing the digestible phosphorus in phosphorus-containing mineral fertilizers, the limits of the addition of humic substances of 2 - 9 wt.% Are taken. Above this limit, as can be seen in the table. 1, the CaO content is reduced, and it is known that most plants are able to assimilate phosphorus from phosphate fertilizers with a CaO: P ₂ O ₅ ratio in the ash above 1.3.

The temperature regime of drying the organo-mineral fertilizer of the mixture 85 - 105 ^o C is limited, on the one hand, by saving energy, since drying time increases at low temperature, on the other hand, the temperature 105 ^o C is a partial decomposition of the mineral component.

 The invention is illustrated by the following examples.

 Example 1

To obtain WMD, 617.3 g of phosphoric flour with a content of P ₂ O _{5 of} 30% and a moisture content of 16% are taken and mixed with powdered humic substances from lignosulfonates (4%) in an amount of 20 g. The mass is placed in a reactor and for 10-15 min thoroughly mixed. Then the mass is dried at 105 ^o C to constant weight.

Humic substances are prepared as follows: 15 ml of sodium hydroxide in the form of a 42% solution are added to 100 ml of lignosulfonates with a solids concentration of 20%. The suspension is oxidized at 200 ^° C., a pressure of 2.3 MPa, an air flow rate of 50 l / h, an oxidation time of 2 hours. The liquid phase is concentrated to a moisture content of 8-10%.

The resulting humic substances have the following characteristics:
active acidity (pH) - 9.4
organic matter content,% - 61.3
the content of N-humates,% - 47.5
sulfur content in N-humates,% - 4.13
The characteristic of the obtained WMD, the content%:
moisture - 2.09
P ₂ O _{5 total} - 24.2
P ₂ O _{5 assimilation} - 15.2
P ₂ O _{5 l / rust} - 17.4
CaO - 36.6
Example 2
To obtain WMD, 520 g of simple superphosphate with a moisture content of 4% is taken and mixed with 20 g of humic substances (2%), as in Example 1.

Humic substances are prepared as follows:
Download, as in example 1. Oxidation at 150 ^o C, pressure 18 MPa, the amount of air 50 l / h, the oxidation time of 6 hours. The liquid phase is concentrated to a moisture content of 8%.

The resulting humic substances have the following characteristics:
active acidity (pH) - 9.56
moisture content,% - 8
organic matter content,% - 56.4
the content of N-humates,% - 48.3
the sulfur content in R-humates,% - 5.83
The characteristic of the obtained WMD, the content%:
moisture - 1,60
P ₂ O _{5 total} - 13.5
P ₂ O _{5 assimilation} - 54.0
P ₂ O _{5 l / rust} - 16.8
CaO - 36.8
Other examples of the production of phosphorus organic-mineral fertilizers and their characteristics on two types of phosphate rock with a content of P ₂ O _{5 total} 25.7% and 30% and simple superphosphate are shown in table. 1.

The replenishment of phosphorus in the soil passes only through the use of phosphorus fertilizers, but the coefficient of phosphorus utilization from phosphorus fertilizers is low and amounts to less than 10-20% of mineral fertilizers. In the obtained according to the invention phosphoric fertilizers enriched in humates, the relative percentage of assimilable P ₂ O ₅ increases. As can be seen from the table. 1, when using powdered humates with phosphate rock with a total content of P ₂ O ₅ - 25.7% increase in the relative percentage of P ₂ O ₅ from 47.66 to 60.0%, i.e. by 13%, and with a content of 30% - from 52.14 to 66.5%, i.e. also ≈ 13.5%. WMDs based on simple superphosphate with humates show an increase in assimilable phosphorus from 42 to 56%, i.e. ≈ by 7%.

 When dry humates are added to phosphorite flour at a moisture content of 16%, the effect of mass dilution is obtained, the mixture acquires greater ductility at the same humidity of 16%.

In the table. 2 shows data on composting standard phosphoric flour, flour with the addition of humates and superphosphate with the addition of humates with sod-podzolic soil, characterized by acidic medium (pH _KCl 4.1) and low content of mobile phosphorus (5.9 mg / 100 g soil) .

 Composting time 95 days. As follows from the data in Table 2, three-month composting of both standard phosphate rock and WMD with humates did not reveal differences in the water-soluble form of phosphates. This extract of phosphates in a ratio of 1:10 gives an idea of the phosphorus level of soils, i.e. a decrease in the mobility of phosphates in the soil. The three-month composting of WMD enriched with humates increased the phosphate level of soils. Using the Kirsanov method, the content of mobile phosphorus was determined, which increased for 4–5.1% for phosphoric flour and superphosphate with humates. An increase in composting time leads to a more complete conversion of calcium triphosphates to monophosphates, and even more so to water-soluble phosphates.

 A technical analysis of the effect of various doses of phosphorite flour with the addition of humates on the growth and yield of flax flax varieties Belinn (table 3) showed that an increase in the mobile forms of phosphorus affects, in contrast to the action of standard phosphorite flour, the root mass and length of the main root, when In this, the larger the dose, the greater this increase, which affects the increase in grain yield. It should be noted that the application dose practically does not affect the height of the stem and, as a result of this, the straw yield. The increase in barley yield in this case is 3 - 6%.

 In the table. Figure 4 shows the effect of WMD based on simple superphosphate on the growth dynamics and productivity of barley c. Krinichny.

 Supplements to simple superphosphate produced significant grain increases compared to standard ones. Where the dose of humates is greater, the percentage of digestible phosphorus and, accordingly, the increase in barley yield in the range of 14-15% are higher.

 Thus, the proposed method for producing phosphorus organic-mineral fertilizers ensures the achievement of a technical result, namely, in terms of increasing the relative percentage of digestible phosphorus and, as a result of this, an increased agrochemical effect.

Claims (1)

A method of producing phosphoric organo-mineral fertilizers, comprising mixing a phosphorus-containing mineral component with humic substances, characterized in that phosphorite flour or simple superphosphate is used as a mineral component, and a product obtained as a result of oxidative-hydrolytic destruction of lignosulfonates by oxidizing them is used as humic substances air oxygen in an alkaline medium at a temperature of 150 - 200 ^o C and pressure less than 2.5 MPa, followed by concentration of the liquid phase to a moisture content 8 - 10%, and when mixed with flour or phosphate simple superphosphate take 2 - 9 wt% of said product, after which the mixture was dried at 85 -. 105 ^o C.

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