RU2708953C1 - Method of producing an aqueous suspension based on sulfur and peat - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: invention relates to the agriculture. Method of producing a stable aqueous suspension based on sulfur and peat for use in fertilizers is characterized by that it includes preparation of a mixture of elemental sulfur, natural drying peat with moisture content of 40–60 % and water, and dispersion of obtained mixture in dispersing devices, in form of rotary-pulse apparatus or static flow cavitators or ultrasonic flow-through cavitation units or hydropercussion assemblys of wet grinding to obtaining a stable finely dispersed suspension without using other chemical reagents. All components are taken at a certain ratio.

EFFECT: invention enables to develop an environmentally safe, explosion-fire-safe and low-cost method of producing a stable aqueous suspension based on sulfur and peat, intended for use in agriculture, veterinary science and technology of organic-mineral and mineral fertilizers.

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Description

The invention relates to agriculture, veterinary medicine and technology for the production of fertilizers and agricultural products and can be used to obtain aqueous suspensions based on sulfur and peat for use in crop production as soil conditioners (for long and soft acidification of the soil), sulfur-containing fertilizers, fungicides and acaricides; in veterinary medicine to combat various ticks (ixodidae, scabies, chicken), lice, bugs, fleas; in fertilizer technology as a hydrophobic additive for the processing of fertilizer granules and as a component containing sulfur and humic substances.

Sulfur and peat are non-toxic (hazard class 4) natural materials widely used in crop production, animal husbandry, pharmacology, technology of fertilizers and agricultural products [State catalog of pesticides and agrochemicals approved for use in the Russian Federation. M., 2010. - 840 p.]. The Russian Federation has huge reserves of both peat and sulfur. Of particular interest for processing is sulfur, which is formed as a waste of petrochemical production. The accumulation of unused petrochemical sulfur in the storage areas represents a certain environmental problem. Sulfur in its pure form is a fire hazardous substance, and in a finely dispersed state with an average median dust particle size of up to 70 microns it can form dusty explosive fire hazardous mixtures. At the same time, finely dispersed sulfur is of interest as fertilizers, since this substance does not dissolve in water, and the rate of transition of sulfur to the sulfate form available to plants directly depends on the degree of dispersion of the corresponding material. The search and development of new economically and environmentally sound explosive and fireproof methods for processing sulfur and peat into useful products is of great practical interest.

Currently, a large number of agrochemical preparations are being made on the basis of sulfur to protect plants from damage by phytopathogenic fungi and tick pests, as well as veterinary preparations. The main disadvantage of the corresponding drugs is the inclusion in their composition of surface-active additives that contribute to the production of stable aqueous suspensions. The content of technological additives in the preparations reaches 20%. Used additives lead to a significant increase in the cost of finished forms. In addition, colloidal sulfur with a particle size of less than 70 ÷ 75 microns is an explosive and flammable product, and the presence of synthetic surfactants and other additives in the agricultural product can have an adverse effect both on the grown plants and on the environment.

There is a known possibility of using sulfur as a cheap sulfur fertilizer, and the agrochemical efficiency of sulfur increases when it is included in complex fertilizers. However, the hydrophobic properties of sulfur significantly complicate the process of obtaining granular products based on sulfur and water-soluble salts, which limits its use in fertilizer technology.

It is known that sulfur can be used to create a hydrophobic layer on the surface of such readily soluble fertilizers as urea. Sulfur in the form of a coating on the surface of urea granules provides reduced caking of the granules, delayed dissolution of urea in the soil and, accordingly, a decrease in nitrogen loss due to leaching of urea by atmospheric precipitation or irrigation water. Sulfur on the surface of the fertilizer granules is usually applied in the form of a melt, which is associated with certain technological difficulties that can be overcome if an aqueous suspension of this element is used to create hydrophobic coatings.

From the existing level of technology there is known a method of obtaining a preparative form of water-soluble elemental sulfur, for use as a fungicide, acaricide in order to protect agricultural and forest plants from diseases and pests. The corresponding form of sulfur includes an aqueous solution of calcium polysulfides, water-soluble low molecular weight polyalcohols (as a stabilizer) and non-ionic water-soluble film-forming and surface-active polymers (as an additive of prolonged action) [Sangalov Yu.A., Massalimov IA, Krasulina N.A. ., Petukhova N.I., Antonova N.E., Chanyshev N.S., Turyanov R.A., Miftakhov A.A., Davletova A.R. The preparative form of water-soluble elemental sulfur to protect cultivated plants from pests // Patent RU 2142908 C1. IPC С01В 17/43, A01N 59/02, application No. 98117430/12, 09.21.1998, publ.: 20.12.1999]. The disadvantage of this technical solution is the high cost of the resulting preparation and the presence in the finished form of polyalcohols, surface-active and film-forming polymers obtained by chemical synthesis methods. These compounds are not inherent to nature and can have a negative impact on the environment.

A known method of producing a combined pesticidal preparation for combating plant diseases and pests, containing 27 ÷ 40% colloidal sulfur, copper chloride and a concentrate of sulphite-alcohol stillage (SSB) or sulphite-yeast mash as a dispersant [Tropin V.P., Overchuk V .AND. Combined pesticidal preparation and method for combating plant diseases and pests // Patent RU 2240002 C1. IPC A01N 59/20, A01N 59/20, A01N 59/02, A01N 25/30, A01N 25/24, A01N 25/04, application No. 2003115176/15, 05.23.2003, publ.: 20.11.2004 Bul. No. 32]. The disadvantage of this technical solution is the presence in the composition of the preparation of copper oxychloride, belonging to the 3rd hazard class and the relatively high cost of the finished product, the low stabilizing effect of sulfite-alcohol vinasse and the high consumption of dispersant. In addition, the formation of a dense polymer film on the surface of sulfur and copper chloride particles reduces the agrochemical effectiveness of the corresponding preparation.

A known method of producing a suspension of sulfur for use in agriculture in order to improve the soil, correct the alkaline balance of the soil, increase productivity [Shakenov B.K., Takbergenova M.M. Takbergenova A.T. A method of producing a suspension of sulfur // Patent KZ 31149. IPC С01В 17/00. Application No. 2014/1823.1 dated 12/09/2014, publ.: 05.16.2016 in Bull. No. 5]. The method involves coarse grinding of sulfur, followed by passing it through a dispersing grinder together with a stream of water. The disadvantage of this technical solution is the low stability of the aqueous suspension and its unsuitability for storage and transportation.

A known method of stabilizing a suspension of sulfur by introducing as hydrophilizing - stabilizing additives solutions of high molecular weight water-soluble polymer stabilizers (based on polyacrylonitrile and waste nitron) [Suleimenov Zh.T. Asanov A., Aidarova A.O., Asanov A.A. The method of stabilization of sulfur suspension // Patent KZ 14439. IPC B01J 13/00, С01В 17/10, application No. 2002/1050.1 of 08/07/2002, publ.: 08/15/2006 in Bull. No. 8]. The disadvantage of this technical solution is the presence in the finished suspension of products of chemical synthesis, which when decomposed in the environment lead to the formation of a number of toxic products. There is evidence that acrylonitrile causes cancer in animals and, according to some studies, in humans. Thus, the use of appropriate stabilizers to obtain stable aqueous sulfur suspensions leads to undesirable environmental pollution.

Closest to the claimed technical solution according to the technical essence and the technical result achieved is a method of stabilizing aqueous sulfur suspensions by introducing a stabilizing additive, which is used as wastewater obtained by cocoon winding containing silk glue sericin [Yunusov L.Yu., Saidov P., Khodzhimuratova D.S., Sakiev A.S., Akhmedov K.S., Khamraev A.Sh. The method of stabilization of sulfur // Patent SU 983036 A1. IPC С01В 17/10. Application No. 3311408, 07/06/1981, publ.: 23.12.1982]. Thus stabilized sulfur suspensions are intended for use in agriculture for pest control. The described method is the combination of essential features closest to the claimed invention, therefore, it is adopted as a prototype of the claimed invention. The method allows to obtain a sufficiently stable aqueous suspension of sulfur through the use of a natural stabilizer. The disadvantages of this technical solution are the limited resources and low availability of sericin, as well as contamination of the finished product with other wastes from the processing of silkworm cocoons, except for sericin, which limits the possibility of using the finished product.

The technical result of the invention is the development of an environmentally friendly, explosive and fireproof and low-cost method for producing a stable aqueous suspension based on sulfur and peat, intended for use in agriculture, veterinary medicine and technology of organic-mineral and mineral fertilizers.

The technical result is achieved through the use of a cyclic-periodic process of dispersing an aqueous suspension of ground sulfur and peat using dispersing devices of serial production. The stability of the resulting suspension is provided by natural surface-active substances of peat. The surface activity of peat is due to the presence in this material of a complex of aromatic biopolymers of humic and lignin nature, characterized by the presence of both a hydrophobic framework and hydrophilic structural elements (carboxyl, carbonyl, hydroxyl, amino, and other groups). The increase in the surface activity of peat is facilitated by mechanical activation that occurs during cavitation dispersion. It is known that mechanical activation makes it possible to transfer humic substances of peat to a soluble state, reduce molecular weight, reduce the particle size of the processed substance to 50 microns, increase reactivity due to partial destruction and oxidation of polymer structures contained in the starting material [Ivanov A.A. , Filatov D.A. The biological activity of humic acids of peat obtained by mechanical activation // Vestnik TSPU. 2011. No5. S. 131-134]. Enrichment of the suspension with soluble humic substances leads to a significant increase in the agrochemical value of the product, since humic substances exhibit high physiological activity, increase seed germination, stimulate plant development, bind heavy metals in soils to forms inaccessible to plants, and provide a bioprotective and anti-stress effect.

To obtain an aqueous suspension of peat and sulfur with a solids content of up to 40% of the mass, rotary-pulse apparatuses, static flow cavitators, ultrasonic flow cavitation units or any other dispersing device providing mechanical activation of peat and obtaining stable suspensions based on sulfur and peat can be used without the use of other chemicals.

To obtain an aqueous suspension of peat and sulfur with a solids content of up to 50% of the mass, a wet grinding wet knot can be used.

Moreover, in the first case, a mixture of elemental sulfur, peat of natural drying to a moisture content of 40 ÷ 60% and water in a proportion of 10 ÷ 30% of the mass of sulfur, 10 ÷ 30% of the mass of peat on a dry substance is prepared in a dissolver at a mixer speed of 1500 ÷ 3000 rpm and the rest is water. In the second case, a mixture of elemental sulfur, peat of natural drying to a moisture content of 40 ÷ 60% and water in a proportion of 10 ÷ 30% of the mass of sulfur, 10 ÷ 30% of the mass of peat on dry matter and the rest of the water is prepared in a dissolver. A homogeneous suspension with a screw pump from a dissolver tank sways on a rotary-pulse apparatus, a static (flowing) cavitator, an ultrasonic flowing apparatus or a wet-grinding wet percussion unit. The finished product is pumped into containers, for example, plastic barrels of any capacity and sent for packaging in consumer packaging.

Properties of the finished suspension.

The finished suspension is a non-combustible paste of dark brown (almost black) color with a slight smell of sulfur. The main active ingredients of the suspension are finely dispersed sulfur stabilized by the surface-active components of peat and a complex of humic substances that pass into solution during the cavitation treatment (mechanical activation) of peat. The suspension does not contain pathogenic microflora and is stable when stored at a temperature of 0 to 25 ° C for at least 1 year. During storage, a barely noticeable deposit of sulfur appears on the surface of the suspension, which does not affect the properties and activity of the finished product. The suspension is easily mixed with water in any ratio, which makes it possible to prepare working solutions of the required concentration and use these solutions for spraying plants or soil. The average particle size of sulfur after cavitation treatment is 50 microns, which ensures high efficiency of the suspension when it is used to protect plants from phytopathogenic fungi, ticks and insect pests, as well as uniform distribution and rapid oxidation of sulfur in soils.

The technical result provided by the given set of features is to obtain a new type of natural, stable and non-combustible aqueous suspension based on sulfur and peat containing a complex of humic substances formed during the technological processing of raw materials (dispersion). The appropriate aqueous suspension is intended for use in the following areas:

- crop production: as a soil conditioner (for long-term and mild acidification of the soil); sulfur-containing fertilizers with humates; fungicidal, acaricidal, insecticidal preparation for protecting plants from pathogenic fungi (phylloxera, powdery mildew, sferotek, etc.) and a complex of pests. In this case, the surface-active components of peat ensure good adhesion of sulfur to the treated plants, and humic substances prevent burns of the leaf surface of the treated plants with sulfuric acid (sulfuric acid is formed as a result of oxidation of sulfur in the environment under the influence of microorganisms), have an anti-stress effect on the plant after applying finely dispersed sulfur exhibit a stimulating effect on the development of plants, bind heavy metals in soils.

- livestock: as a substitute for feed sulfur in the composition of feed and medicinal mixtures for inclusion in the diets of cows and young cattle, goats, sheep, cats, dogs and birds. Humic substances that make up the suspension will contribute to a milder effect of sulfur and provide an additional effect of detoxification of the animal organism through adsorption of toxic compounds formed in the gastrointestinal tract.

- Veterinary medicine: to combat various ticks (ixodidae, scabies, chicken), lice, bugs, fleas;

- in fertilizer technology: as a hydrophobic additive for processing fertilizer granules in order to provide a prolonged effect, prevent caking, and also as a component containing sulfur and humic substances for inclusion in complex fertilizers.

Unlike the prototype, this technical solution has the following advantages:

- all the raw materials included in the suspension are readily available and have a low cost;

- finely dispersed state of sulfur provides the possibility of uniform application of the drug and the accuracy of dosing of the active substance, at the same time, finely dispersed sulfur in the composition of peat gel is an explosively non-fire hazardous product;

- for the production of slurry, in addition to the main raw materials (sulfur, peat, water), no other additives are used;

- through the use of peat, it is possible to obtain a highly concentrated suspension, which reduces the cost of transportation and storage of the finished product;

- the product obtained by the proposed technology can be used not only for pest control, but also in such areas as veterinary medicine, fertilizer technology, animal husbandry;

- the inclusion of peat in the suspension allows you to reduce the possible negative effect of sulfur on the treated plants and soil, as well as to increase the agrochemical effectiveness of the suspension by enriching it with humic substances;

- the production of an aqueous suspension based on sulfur and peat is characterized by low cost and can be organized at enterprises of any capacity;

- the proposed technical solution contributes to the expansion of the beneficial use of peat and waste sulfur;

- the production of an aqueous suspension based on sulfur and peat is waste-free and fully complies with the principles of green chemistry.

Claims (4)

A method of obtaining a stable aqueous suspension based on sulfur and peat for use in fertilizers, characterized in that it includes preparing a mixture of elemental sulfur, natural drying peat with a moisture content of 40-60% and water, and dispersing the resulting mixture in dispersing devices, which use rotary pulsed devices or static flow cavitators or ultrasonic flow cavitation units or wet-impact wet grinding units until a stable finely dispersed suspension is obtained without using other chemical reagents, while the starting components are used in the following ratio, wt. %: sulfur - 10-30, dry matter peat - 10-30, water is the rest.