Technical field

The invention belongs to the field of feed additives, based on highly active ZnO and inorganic compounds and minerals and organic compounds, which has exceptional antimicrobial properties and shows an exceptional effect against diarrhea primarily caused by E.coli. This product also has exceptional nutritional properties as a source of zinc, as well as the possibility to adsorb polar mycotoxins, depending on the type of applied carrier particles. The present invention relates to the ultrasonic low-temperature synthesis and application of highly active zinc oxide which is simultaneously synthesized and firmly bound to the surface, or zinc oxide is synthesized and subsequently firmly attached to the surface of micrometer and/or submicrometer carrier particles based on natural and synthetic minerals and compounds such as zeolites (natural and synthetic), sepiolites, atapulte/ palygorskites, calcium carbonates and chalks, magnesium carbonates, dolomites, smectites (bentonites, montmorillonite, saponites) and other clays, diatoms, modified and unmodified cellulose and carbohydrates, already widely used and permitted for use as additive for animal feed in the EU and the PRC. These carrier particles are micrometer and/or submicrometer in size, which prevents the dispersion of active synthesized ZnO particles into the air, and also prevents the agglomeration of active ZnO particles and thus allows greater availability of active ZnO, as well as easy mixing into animal feed. The invention also belongs to the field of chemical technology and materials in a broader sense because it includes both the application and the production process for its production.

Technical problem

The technical problem solved by the present invention is the process of ultrasonic low- temperature synthesis and production of a new antibacterial and multifunctional additive for animal feed, based on highly active zinc oxide synthesized and firmly bound to the surface of micrometer and/or submicrometer-sized carrier particles: zeolite (natural and synthetic), sepiolite, attapulgite/paligorskite, calcium carbonate and chalk, magnesium carbonate, dolomites, smectite (bentonite, montmorillonite and saponite) and other clays, diatomaceous earth, modified and unmodified cellulose and carbohydrates, which are permitted for animal feed in the EU and PRC. This is achieved by production technology based on the synthesis of zinc oxide on the surface of the particles of these compounds and minerals, or the previous synthesis of zinc oxide and binding of those particles to the surface of the mentioned compounds and minerals, by dissolving compounds containing Zn ion (as a source of zinc can be used Zn-acetate, Zn-nitrate, Zn-chloride, Zn-sulfate) in demineralized water, at temperatures below 90°C, by dispersing the carrier particles in Zn solution at different ranges of carrier particle concentrations and zinc source compounds, which results in ion exchange and adsorption of Zn ions on the particle surface, adjusting slightly basic conditions (pH between 7 and 9) by adding base (ammonium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate can be used as the base source), and by applying an ultrasonic field at frequencies equal to or greater than 20kHz using ultrasonic horns with power between 500 and 3000 W in ultrasonic flow reactors connected in series (in row) from 1 to 4 or more pieces, in a time from 2 to 60 minutes, which synthesizes a well-dispersed zinc oxide, simultaneously synthesizing at low temperatures and firmly bound to the surface of the carrier particles, or by dissolving compounds containing the Zn ion (Zn-acetate, Zn-nitrate, Zn- chloride, Zn-sulfate can be used as a source of zinc) in demineralized water, at temperatures below 90°C, using ultrasound and setting slightly basic conditions (pH between 7 and 9) by the addition of a base (ammonium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate can be used as a base source), and the application of an ultrasonic field at frequencies equal to or greater than 20 kHz using ultrasonic probes with a power between 500 and 3000 W in ultrasonic flow reactors connected in series (in row) from 1 to 4 or more pieces, for a time of 2 to 60 minutes, whereby zinc oxide is synthesized and subsequent addition and dispersion of carrier particles at different concentration ranges of carrier particles and zinc oxide and by the additional application of an ultrasonic field at frequencies equal to or greater than 20kHz by the use of ultrasonic probes with power between 500 and 3000 W in ultrasonic flow reactors connected in series (in row) from 1 to 4 or more pieces, in the time from 2 to 60 minutes, by which the ZnO particles are firmly attached to the carrier particles, thus preventing the dispersion of active synthesized ZnO particles into the air, whereby a product with extremely high antimicrobial activity is obtained, which can be applied at maximum permissible zinc concentrations of 150 mg zinc per kilogram of feed in the EU, where the product shows excellent antimicrobial properties and a reduction in the occurrence of diarrhea, exceptional nutritional properties as a source of zinc microelements, the possibility of polar mycotoxins (alphatoxins) adsorption depending on the type of applied carrier particles, with prevented agglomeration of active ZnO particles enabling greater availability of active ZnO, as well as easy mixing with animal feed. Background art

Zinc oxide is an additive used in animal nutrition, especially piglets in the prestarter and starter phase, in order to reduce the occurrence of diarrhea that occurs when stopping milk and switching to solid foods, resulting in immature intestinal mucosal barrier of piglets, lack of immune responses due to the disappearance of maternal antibodies and the action of pathogenic bacteria, primarily E.coli. The appearance of diarrhea results in slow growth and slow weight gain, and very often the death of piglets, which all together reflects on the economy of production and breeding of pigs. According to the European Commission (Commission implementing decision of 26 June 2017 - Directive 2001/82 / EC) which has been in force since 26 June 2022, the content of zinc in the diet is limited to 150 mg / kg of complete feed in animal nutrition (to a maximum permissible content of about 186 mg ZnO/kg of food), which is significantly lower than the previously allowed therapeutic concentration of 3000 mg ZnO/kg of complete animal feed, while the use of this product obtained by the present invention achieves the same antimicrobial effect. In the PRC, this limit is a maximum of 110 mg Zn/kg of feed. Therefore, in order to overcome the difference in effectiveness from the therapeutic dose of 3000 mg of zinc-oxide and the allowed dose, it is necessary to produce far more active zinc oxide which will show antimicrobial effect in doses lower than allowed and prevent diarrhea, primarily caused by bacteria E.coli, and if possible have exceptional nutritional properties as a source of the trace element zinc, as well as the possibility to adsorb polar mycotoxins.

To obtain active powders to reduce the use of zinc oxide, various physical and chemical synthesis processes of nano zinc oxide, porous ZnO, microencapsulated ZnO, enteric coated ZnO are used. Scientific papers and patents indicate that it is possible to synthesize active nanoparticles of ZnO that show high antibacterial activity that reduces diarrhea in piglets and improves growth performance, but on the other hand there is always a potentially negative effect of free nanoparticles of zinc oxide on human health (dusting of nano-particles during the manipulation of workers in production), as well as the potential impact of nano-particles on the environment.

A detailed review of the ESPACENT patent database and scientific papers dealing with this topic, found the following solutions to presented technical problem in the form of synthesis and properties of feed additives based on zinc oxide, nano zinc oxide, zinc oxide on inorganic carriers and for methods of ultrasonic synthesis of nano zinc oxide: CN113080316A, CN103549162A, CN108975384A, CN101218959A, CN109511786A, CN102335196A, KR20160100038A, US10370789B2. Some of the scientific papers and patents are described and analyzed in more detail below:

Lina Long et al, in their scientific paper “Comparison of porous and nano zinc oxide for replacing high-dose dietary regular zinc oxide in weaning piglets” (PLOS ONE, https://doi.org/10.1371/joumal.pone.0182550, August 8, 2017) examined the effect of nano and porous zinc oxide in piglet nutrition. Nano zinc oxide has shown that its use can have a positive effect on reducing the occurrence of diarrhea, as well as better utilization of zinc as a trace element, with improved growth performance, intestinal morphology, reduced diarrhea and intestinal inflammation, such as high doses of commercial zinc -oxide. The same authors also state that similar results are obtained by using porous zinc oxide. However, it should be noted that these positive effects were obtained when using doses of 500 mg of nano and porous zinc oxide per kilogram of animal feed, which exceeds the permitted limits in the EU and the People's Republic of China.

CN113080316A (Preparation method of antibiotic substitute nano zinc oxide) - This patent document describes a method of preparing a replacement antibiotic, nano zinc oxide, and the method includes the following steps: adding surfactant to zinc source solution, uniform mixing, continuous addition of alkaline solution, mixing, the solution is then placed in a high pressure reaction vessel (autoclave) at a preset temperature and time, where after completion of the reaction, the dispersion is filtered, washed with deionized water and dried to give nano zinc oxide. Surfactants can be polymeric organic salts of weak acids and silicates, used as a protective agent, so that the prepared nano zinc oxide is not easily hydrolyzed in the stomachs of animals. According to the present invention, nano zinc oxide is slowly dissolved to obtain nanoparticles to provide an antibacterial effect, the reagent used has high biosafety, the prepared finished product is of good quality, and nano zinc oxide is added to animal feed as substitute for antibiotics to fill the gap in the product after the antibiotic was banned and promote the advancement of the livestock industry.

CN103549162 A (Novel feed additive and preparation method thereof) - This patent document discloses a new feed additive and a process for preparing a new feed additive. The additive consists of an enterically coated nano zinc oxide particle, the particle containing a grain of nano zinc oxide core, a coating layer passing through the small intestine, a middle layer of nano zinc oxide layer and a coating layer passing through the abdomen from the inside to the outside. The additive is prepared from two coatings, using nano zinc oxide and coating materials: maltodextrin, hydroxypropylmethylcellulose, ethylcellulose, acrylic resin, croscarmellose and hypromellose. The finished product is used as a feed additive for livestock and poultry to prevent diarrhea in livestock and poultry and accelerate their growth. The additive absorbs nanozinc oxide - the usable amount of nano zinc oxide is less than the usual amount of zinc oxide, and the effects in preventing diarrhea and accelerating growth are better than commonly used zinc oxide due to the specific surface effect and special ionic effect of nano zinc oxide.

CN108975384A (Nanometer zinc oxide and low-temperature preparation method thereof) - This patent document discloses nanometer zinc oxide and the process of its synthesis at low temperatures: 4 to 6 parts of potassium salt, 3 to 4 parts of lithium salt and 2 to 3 parts are mixed sodium salts, at a temperature of 200 to 500°C, where melting occurs. After the reaction has taken place, 1 to 7 parts of zinc salt are added at a temperature of 200 to 500°C, then stirred for a longer period of time. The obtained solid melt was cleaned and dried several times, after which a small nanometer zinc oxide was obtained. Potassium salt, lithium salt and sodium salt have advantages in that the solubility is better, salts can be easily dissolved in water, the melting point is low, so that the prepared liquid molten salt can be easily and evenly mixed. Liquidly fused salt can improve the fluidity of the reactants, and solidly formed fused salt can also be well separated to avoid agglomeration. The method of preparation according to the invention can be carried out under conditions of low temperature, the zinc salt growing directly by nucleation in low- temperature fused salt into nanometer zinc oxide. Calcination at high temperature is not necessary, so the process is simple. Nanometer zinc oxide prepared by this type of synthesis has a high degree of crystallinity, is uniform in size and has a large specific surface area. However, this patent was obtained at higher temperatures up to 500°C.

CN101218959A (Application of nano-zinc oxide as animal feed additives) - This patent proposes a new use of nanometer zinc oxide as a feed additive. As a source of zinc, nanometer zinc oxide has the advantages of high bioavailability, low doses of additives and difficult to react with other components. As a food supplement, nanometer zinc oxide can effectively meet the demand of animals for zinc sources, promote healthy animal growth, improve food efficiency, and effectively reduce the occurrence of diarrhea in piglets. With a low usable dose, the invention reduces environmental contamination caused by animal feces. Nanometer zinc oxide stimulates growth, improves the efficiency of food intake, replaces antibiotics, eliminates antibiotic residues in animal products, reduces environmental pollution. Although this patent indicates that its application reduces the contamination of the environment caused by animal feces, it does not indicate the possibility of endangering human health by possible inhalation of nanoparticles during application, nor the possibility of environmental impact during product handling. There is also no indication of solving the problem of nanoparticle agglomeration and interference in animal feed.

CN109511786A (Feed additive containing zinc oxide and preparation method of feed additive) - This patent describes a feed additive containing zinc oxide and a process for preparing feed additives. The additive is prepared from components in weight parts: 400-820 parts of zinc oxide, 100-400 parts of carrier dispersed in water and 80-200 parts of coating grease. Zinc oxide is uniformly sprayed onto a water-soluble dispersible carrier and then coated with enteric coating grease. When a food additive is prepared, the dispersible carrier of the prescribed dose is heated and dissolved, then zinc oxide powder is added, then sufficiently mixed, allowing the zinc oxide to disperse evenly on the dispersible carrier, then cooled and then pellets or particles are prepared containing zinc oxide. The prepared pellets or zinc oxide particles are introduced into the coating equipment, the melted fat in the coating equipment is sprayed to perform the enteric coating, after which an animal feed additive is obtained. For food additives that contain zinc oxide, the price of raw materials is low, the capacity of zinc oxide intake is high, the effect of absorption in the stomach is good, and the release in the intestines is satisfactory.

CN102335196A (Use of supported nano zinc oxide as an anti-diarrhea agent for weaned pigs and using method) - This patent discloses the use of supported nano zinc oxide as an anti-diarrhea agent for pigs and a method of use. Supported zinc oxide used as a diarrhea preventative agent for supernatants is a composite material to support nano zinc oxide using kaolin or montmorillonite or attapulgite or sepiolite or zeolite as a carrier. Zinc oxide makes up 10 to 50 weight percent of the composite material used as the nano zinc oxide carrier. Methods of using supported nano-zinc oxide to prevent diarrhea in pigs include adding 160 to 800 mg/kg of supported zinc in the form of zinc-oxide to pig feed. Supported nano zinc oxide can significantly reduce the incidence of diarrhea in weaned pigs, improve daily gain, improve the shape of the intestinal mucosa and protect the intestinal mucosal barrier. Pig skin is red and light, and the effect of supported zinc oxide exceeds the effect of using high-dose commercial zinc oxide, thus significantly reducing zinc oxide consumption, as well as zinc excretion and environmental pollution. However, the author states that this product contains nano ZnO where the content of applied zinc oxide is in the range of 10-50%, and that it is added to food to have anti-aging properties in doses of 160 to 800 mg Zn/kg of food, represent whose concentrations exceed the permitted values in the EU and the People's Republic of China. Also, each of the nano ZnO syntheses cited by the author in his patent are the syntheses of other authors, which involve subsequent high-temperature treatment at temperatures up to 500°C. The author states that the particles are uniformly deposited on the supports, that agglomeration and stability are prevented, but does not mention that the particles are firmly bound to the surface, which can result in dispersal of ZnO nanoparticles into the environment during manipulation, and thus affect workers' health and the environment.

KR20160100038A (Method for preparing zinc oxide nanoparticle having porous shell and hollow core by using ultrasonic irradiation) - This patent relates to a process for the preparation of zinc oxide nanoparticles, comprising the steps of: to obtain a zinc precursor solution and (b) subjecting the zinc precursor solution obtained from step (a) to ultrasonic radiation to obtain zinc oxide nanoparticles. The method uses water that is safe for the human body and an environmentally friendly solvent, DMSO, and involves a simple process of ultrasonic radiation in a vessel. With this method, it is possible to obtain zinc oxide nanoparticles with a large surface area in a highly cost-effective way that does not require a separate cooling system, heating unit and post-treatment process. In addition, the resulting zinc oxide nanoparticles have a porous-hollow structure, including many surface pores and a large hollow core, and therefore have an area of 30 m ² /g, significantly improved compared to the surface area of 10 m ² /g of zinc oxides nanoparticles obtained by a related technique. This is the reason for their application in various industrial fields, such as photovoltaic material for solar cells or as a cosmetic material. Thus, the author of the patent does not mention the use as an additive in animal feed, nor as an antimicrobial additive, nor as a source of Zn.

US10370789B2 (Sonochemical coating of textiles with metal oxide nanoparticles for antimicrobial fabrics) - This patent relates to a system for the preparation of antimicrobial surfaces, coated with metal oxide nanoparticles using a new sonochemical method. These antibacterial surfaces are widely used in medical and other applications. The deposition of metal oxides that are known to have antimicrobial action, ZnO, MgO and CuO, can significantly expand the use of textile fabrics, medical devices and other items and significantly extend the period of their use. Using the new sonochemical method discovered here, uniform deposition of metal oxide nanoparticles is simply achieved. The inventors base this patent on their previous research published in scientific papers such as: The Preparation of Metal-Polymer Composite Materials using Ultrasound Radiation, S. Wizel, R. Prozorov, Y. Cohen, D. Aurbach, S. Margel, A. Gedanken. J. Mater. Res. 13, (1998) 211; Preparation of amorphous magnetite nanoparticles embedded in polyvinylalcohol using ultrasound radiation ”. R. Vijaykumar, Y. Mastai, A. Gedanken, Y. S. Cohen, Yair Cohen, D. Aurbach, J. Mater. Chem. 10 (2000) 1125; Sonochemical Deposition of Silver Nanoparticles on Silica Spheres V. G. Pol, D. Srivastava, O. Palchik, V. Palchik, M. A. Slifkin, A. M. Weiss. A. Gedanken, Langmuir, 18, (2002) 3352; Synthesis and Characterization of Zinc Oxide -PVA Nanocomposite by Ultrasound Irradiation and the Effect of Crystal Growth of Zinc Oxide ”R. Vijayakumar, R. Elgamiel, O. Palchik, A. Gedanken, J . Crystal Growth and Design, 250 (2003) 409; Sonochemical Deposition of Silver Nanoparticles on Wool Fibers. L. Hadad, N. Perkas, Y. Gofer, J. Calderon-Moreno, A. Ghule, A. Gedanken. J. Appl. Polym. Sci. 104 (2007) 1732. Although these papers and patents study the deposition of different nanoparticles on different substrates by the ultrasonic-sonochemical method, they do not consider obtaining either antimicrobial feed additives or sources of zinc or mycotoxin adsorbents, nor do they consider zinc deposition oxides on the mentioned particles on the basis of natural and synthetic minerals and compounds, such as: zeolites (natural and synthetic), sepiolites, attapulgites/paligorskites, calcium carbonates and chalks, magnesium carbonates, dolomites, smectites (bentonites, montmorillonite, saponite) and other clays, diatomites, modified and unmodified cellulose and carbohydrates, which are already widely used and which are permitted for use as feed additives.

Disclosure of invention

European legislation on animal feed, according to the European Directive (Commission implementing decision of 26 June 2017 - Directive 2001/82 / EC) limits the total dietary Zn to a maximum concentration of 150 mg/kg of complete feed - is limited to 186 mg/kg of zinc oxide per kilogram of feed, which is well below the therapeutic dose of 3000 mg/kg of feed used as feed additive.

The present invention relates in part to a multifunctional feed additive based on highly active zinc oxide synthesized and firmly bound to the surface of particles based on natural and synthetic minerals and compounds such as: zeolites (natural and synthetic), sepiolites, attapulgites/palygorskites, calcium carbonates and chalks, magnesium carbonates, dolomites, smectites (bentonites, montmorillonite, saponites) and other clays, diatomites, modified and unmodified cellulose and carbohydrates, already widely used and permitted for use as additive for animal feed, which shows excellent antimicrobial properties against E.coli and as well as the property of preventing diarrhea in piglets, and is also an additive that shows nutritional properties as a source of zinc, and the possibility of adsorption of polar mycotoxins, such as alphatoxins, depending on the type of applied carrier particles. In the second part, the present invention relates to the technology of production of highly active zinc oxide which is realized by the technology of production based on ultrasonic or sonochemical low-temperature synthesis of zinc oxide on the surface of particles of mentioned compounds and minerals, or the synthesis of highly active zinc oxide and its binding to the surface of the carrier particles.

The disadvantages of applying the known solutions indicated in the state of the art are the fact that zinc oxide nanoparticles are used, which are either synthesized at high temperatures or used in concentrations higher than 160 mg Zn per kilogram of feed, which exceeds the EU and PRC values. Also, the indicated patent solutions do not show multifunctional properties, as well as some do not indicate the prevention of possible dispersion of ZnO nanoparticles into the environment during product manipulation, and thus the impact on workers' health by inhalation and environmental impact. Furthermore, some patent solutions do not indicate the solution of agglomeration of nanoparticles and the possibility of mixing ZnO nanoparticles in animal feed, and that some solutions do not show the possibility of use as an additive in animal feed but use in photocatalysis, photovoltaic systems or antimicrobial properties in textiles.

Advantage of the present invention over those known from the prior art:

- The application of the ultrasonic field or sonochemical procedure enables the simultaneous or successive synthesis of highly active zinc oxide and its firm binding to the surface of the carrier particle;

- Application of ultrasonic field and sonochemical reaction enables low temperature of Zn oxide synthesis at temperatures below 90°C,

- Carrier particles are already used in animal feed production and approved for use on which ZnO is synthecized,

- Micrometer and/or submicrometer-sized carrier particles prevent the dispersion of active synthesized ZnO particles into the air,

- The agglomeration of active ZnO particles is prevented and thus greater availability of active ZnO is enabled,

- Easily mixing of this highly-active ZnO additive into animal feed

- The product produced in this way shows excellent antimicrobial properties and reduction of diarrhea in the maximum permitted concentrations of 150 mg Zn per kg of feed in the EU, exceptional nutritional properties as a source of zinc trace elements, as well as the possibility of adsorption of polar mycotoxins (alphatoxins) depending on the type of applied carrier particles.

Best Mode for Carrying Out of the Invention

The present invention describes a technology for the production of higly-active zinc oxide which is achieved by production technology based on ultrasonic or sonochemical low-temperature synthesis of zinc oxide on the surface of particles of natural and synthetic minerals and compounds, or to the previous synthesis of zinc oxide and its binding to the surface of carrier particles of the mentioned compounds and minerals, such as zeolites (natural and synthetic), sepiolites, attapulgites/paligorskites, calcium carbonates and chalks, magnesium carbonates, dolomites, smectites (bentonites, montmorillonite, saponites) and other clays, diatomites, modified and unmodified cellulose and carbohydrates and carbohydrates already used for use as feed additives. The synthesis itself consists of dissolving with mixing compounds containing Zn ion, where as a source of zinc can be used Zn-acetate, Zn-nitrate, Zn-chloride, Zn-sulfate, in demineralized water preheated to temperatures from 30 to 90°C. Then, with stirring, a certain amount of carrier particle is added to the Zn solution, and the dispersion is stirred from 30 seconds to 60 minutes to perform ion exchange in the crystal lattice or adsorption of zinc ions on the surface of the carrier particles, using different concentration ranges of carrier particles and zinc source compounds. The dispersion-solution is then passed through an ultrasonic field for better homogenization for 2 to 30 minutes. The base is then added with stirring for up to 5 minutes until slightly basic pH conditions between 7 and 9 are reached, where ammonium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate can be used as the base source. The solutiondispersion is then pumped through ultrasonic flow reactors with horns where the use of an ultrasonic field at frequencies equal to or greater than 20kHz power between 500 and 3000 W connected in series (in row) from 1 to 4 or more pieces, in 2 to 60 minutes. Under these conditions excellent dispersed zinc oxide, firmly bound to the surfaces of the carrier particles are synthesized.

The synthesis can also take place in another way, by dissolving and mixing compounds containing the Zn ion, where Zn-acetate, Zn-nitrate, Zn-chloride, Zn-sulfate can be used as a source of zinc, in demineralized water preheated to temperatures of 30 up to 90°C. The solution is then passed through an ultrasonic field for better homogenization from 2 to 30 minutes. Then, with mixing, a base is added for up to 5 minutes until slightly basic pH conditions between 7 and 9 are reached, where ammonium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate can be used as a base source. Then the solution is pumped through ultrasonic flow reactors with probes, where by applying an ultrasonic field at frequencies equal to or greater than 20kHz power between 500 and 3000 W, connected in series (in row) from 1 to 4 or more pieces, in a time of 2 to 60 minutes, it is synthesized excellently dispersed zinc oxide. Then, with stirring, a certain amount of carrier particles is added to the Zn solution, and the dispersion is mixed from 30 seconds to 60 minutes, using different concentration ranges of carrier particles and synthesized zinc oxide. Then this dispersion is additionally treated by applying an ultrasonic field at frequencies equal to or greater than 20kHz using ultrasonic probes with a power between 500 and 3000 W in ultrasonic flow reactors connected in series (in row) from 1 to 4 or more pieces, in a time from 2 to 60 minutes, whereby the particles ZnO binds tightly to the carrier particles.

After ultrasonic treatment, the dispersion can be separated from the liquid phase and dried in several ways: - by passing through a filter press, washing with demineralized water and after removing the filter cake, the filter cake is dried in an dryer and then deagglomerated in different types of mills; - filtration through band or drum vacuum filters where the solid phase is separated and washed with demineralized water, and then dried on flash-dryer where the product is dried and deaglomerated at the same time; - spraying in spray dryers, where the product is dried and granulated at the same time.

In this way, a product is obtained which prevents the dispersion of active synthesized ZnO particles into the air, with extremely high antimicrobial activity, which can be used at maximum permissible zinc concentrations of 150 mg of zinc per kilogram of feed in the EU. The product shows excellent antimicrobial properties and reduces diarrhea, exceptional nutritional properties as a source of the trace element zinc, which shows the possibility to adsorb polar mycotoxins (alpha toxins) depending on the type of applied carrier particles, and which prevents agglomeration of ZnO particles greater availability of active ZnO, as well as easy mixing in animal feed.

The invention is illustrated, but not limited to, by the following examples, which should not be construed as limiting by those skilled in the art.

Example 1.

In 100 ml of demineralized water, heated to 60°C, 0.5 g of Zn-acetate dihydrate was dissolved with stirring and then 5 g of natural zeolite (with over 70% clinoptilolite mineral content and particle size below 40 micrometers) was added for 5 minutes. The solution-dispersion was then exposed to an ultrasonic field (20kHz, 100W/cm ² ) for 5 minutes. After that, about 0.15 ml of ammonium hydroxide (concentration 25-30%) was added until slightly basic conditions of pH 8.5 were reached. The dispersion was re-treated with an ultrasound probe for 5 minutes. The dispersion is then filtered, washed with deionized water, and the filter cake is then dried at 100 to 150°C for one hour and lightly crushed in a mortar to obtain a highly active ZnO powder deposited and firmly bound to natural zeolite particles.

Example 2.

In 100 ml of demineralized water, heated to 60°C, 0.5 g of Zn-acetate dihydrate was dissolved with stirring and then 5 g of natural sepiolite clay was added (with about 40 to 50% sepiolite mineral and 20 to 30% smectite mineral and particle size below 40 micrometers) for 5 minutes. The solution-dispersion was then exposed to an ultrasonic field (20kHz, 100W/cm ² ) for 5 minutes. After that, ammonium hydroxide (concentration 25-30%) was added until slightly basic conditions of pH 8.5 were reached. The dispersion was re-treated with an ultrasound probe for 5 minutes. The dispersion was then filtered, washed with deionized water, and the filter cake was then dried at 100 to 150°C for one hour and lightly crushed in a mortar to obtain a highly active ZnO powder deposited and firmly bound to sepiolytic clay particles.

Example 3.

In a reactor of 1501 with stirring and heating was poured 100 1 of demineralized water, heated to 60°C, 500 g of Zn-acetate dihydrate with stirring were dissolved and then 5 kg of natural zeolite (with over 70% clinoptilolite mineral content and particle size below 40 micrometers) were added and stirred for 5 minutes. The solution-dispersion was then exposed to an ultrasonic field with two series-connected flow ultrasonic probes (20kHz and 1000W each) in an ultrasonic reactor for 10 minutes. After that, about 180 ml of ammonium hydroxide (concentration 25-30%) was added until slightly basic conditions of pH 8 were reached with stirring for 2 minutes. The dispersion was re-treated with ultrasound probes for 20 minutes. The dispersion is then filtered through a laboratory filter press, the filter cake is washed with deionized water in a filter press, and the filter cake is then dried at 100 to 150°C for two hours and lightly crushed in a mortar to obtain a highly active ZnO powder deposited and firmly bound to natural zeolite particles. Example 4.

In 200 ml of demineralized water, heated to 60°C, 2 g of Zn-acetate dihydrate were dissolved with stirring and then 10 g of CaCCh (Omya GCC with a particle size below 4 micrometers) was added with stirring for 5 minutes. The solution-dispersion was then exposed to an ultrasonic field (20kHz, 100W/cm ² ) for 5 minutes. After that, ammonium hydroxide was added (concentration 25-30%) until slightly basic conditions of pH 8 were reached. The dispersion was re-treated with an ultrasonic probe for 5 minutes. The dispersion was then filtered, washed with deionized water, and the filter cake was then dried at 100 to 150°C for one hour and lightly crushed in a mortar to give a highly active ZnO powder deposited and firmly bound to CaCOs particles.

Example 5.

In 200 ml of demineralized water, heated to 60°C, 7.2 g of Zn-acetate dihydrate were dissolved with stirring and then 15 g of natural zeolite (with over 70% clinoptilolite mineral content and particle size below 40 micrometers) was added with stirring for 5 minutes. The dispersion solution was then exposed to an ultrasonic field (20kHz, 100W/cm ² ) for 3 minutes. After that, about 4 ml of ammonium hydroxide (concentration 25-30%) was added until slightly basic conditions of pH 8.5 were reached. The dispersion was re-treated with an ultrasound probe for 5 minutes. The dispersion is then filtered, washed with deionized water, and the filter cake is then dried at 100 to 150°C for one hour and lightly crushed in a mortar to obtain a more concentrated highly active ZnO powder deposited and firmly bound to natural zeolite particles.

Example 6.

In 100 ml of demineralized water, heated to 60°C, 7.2 g of Zn-acetate dihydrate were dissolved with stirring and then 15 g of synthetic zeolite 4A (Alumina BiH with a particle size below 4 micrometers) was added with stirring for 5 minutes. The dispersion solution was then exposed to an ultrasonic field (20kHz, 100W/cm ² ) for 3 minutes. After that, ammonium hydroxide (concentration 25-30%) was added until slightly basic conditions of pH 7.5 were reached. The dispersion was re-treated with an ultrasound probe for 5 minutes. The dispersion was then filtered, washed with deionized water, and the filter cake was then dried at 100 to 150°C for one hour and lightly crushed in a mortar to give a more concentrated highly active ZnO powder deposited and firmly bound to synthetic zeolite 4A particles. Example 7.

In a reactor of 20 1 with stirring was poured 10 1 of demineralized water, heated to 60°C, 1456 g of Zn-acetate dihydrate with stirring were dissolved and then 3 kg of synthetic zeolite 4A (Alumina BiH with a particle size below 4 micrometers) were added and stirred for 10 minutes. The solutiondispersion was then exposed to an ultrasonic field with two series-connected flow ultrasonic probes (20kHz and 1000W each) in an ultrasonic reactor for 10 minutes. After that, ammonium hydroxide (concentration 25-30%) was added until slightly basic conditions of pH 8 were reached with stirring for 2 minutes. The dispersion was re-treated with ultrasound probes for 10 minutes. The dispersion is then filtered through a laboratory filter press, the filter cake is washed with deionized water in a filter press, and the filter cake is then dried at 100 to 150°C for two hours and lightly crushed in a mortar to obtain a concentrated highly active ZnO powder deposited and tightly bound to synthetic zeolite 4A particles.

Example 8.

In a reactor of 100 1 with stirring was poured 50 1 of demineralized water, heated to 60°C, 675 g of Zn-acetate dihydrate was dissolved with stirring for 5 minutes. The solution was then exposed to an ultrasonic field in an ultrasonic probe (20kHz and power 1000W) in an ultrasonic reactor for 5 minutes. After that, ammonium hydroxide (concentration 25-30%) was added until slightly basic conditions of pH 8 were reached with stirring for 2 minutes. The dispersion was again treated with an ultrasonic probe for 40 minutes. A 3 kg of natural zeolite was then added to the dispersion, with mixing with a mechanical mixer, and then the dispersion was again treated with an ultrasonic probe for 15 minutes. The dispersion was then filtered through a laboratory filter press, the filter cake was washed with deionized water in the filter press, and the filter cake was then dried at temperatures from 100 to 150°C for two hours and gently deagglomerated in a mill, whereby a concentrated highly active ZnO powder deposited and tightly bound on natural zeolite particles.

Example 9.

In a reactor of 1001 with stirring was poured 45 1 of demineralized water heated to 60°C, 880 g of Zn-acetate dihydrate was dissolved with stirring for 5 minutes. The solution was then exposed to an ultrasonic field in an ultrasonic probe (20kHz and power 1000W each) in an ultrasonic reactor for 5 minutes. After that, ammonium hydroxide (concentration 25-30%) was added until slightly basic conditions of pH 8 were reached with stirring for 2 minutes. The dispersion was again treated with an ultrasonic probe for 40 minutes. A 2.2 kg of CaCCb was then added to the dispersion, while stirring with a mechanical stirrer, and then the dispersion was again treated with an ultrasonic probe for 10 minutes. The dispersion was then filtered through a laboratory filter press, the filter cake was washed with deionized water in the filter press, and the filter cake was then dried at temperatures from 100 to 150°C for two hours and gently deagglomerated in a mill, whereby a concentrated highly active ZnO powder deposited and tightly bound on CaCCh particles.

Industrial applicability

As described according to the invention, the process for preparing a multifunctional additive based on highly active zinc oxide deposited on inorganic and organic compounds and minerals by low temperature ultrasonic synthesis and its application to feed production is relatively simple and affordable for production and industrial use. A product with exceptional multifunctional properties is obtained, which is easily mixed into animal feed, which is an advantage in mass feed production.