DE102004008019A1 - Clay mineral-based round granules, used as a litter absorbing liquid animal wastes, comprise clay mineral core coated with a powdery clay mineral absorbent - Google Patents

Abstract

Use is claimed of a clay mineral-based round granulate as an absorbent substance, especially for liquid animal wastes. An independent claim is included for the production of the granules by mixing a clay mineral starting granulate of predetermined size (preferably 0.1-10, especially 0.5-2, mm) with a powdery clay mineral absorbent, optionally with liquid addition, followed by drying to form a round granulate with a core of the starting granulate and a coating shell (preferably 0.1-3, especially 0.1-2, mm thick) of the absorbent.

Description

The The invention relates to a round granulate on clay mineral Base.

Such round granules are known in practice and are exemplified in the DE 690 10 535 T2 or the DE 43 28 285 C2 described. In the latter case, an animal litter is used, which has at least one moisture-absorbing organic material as a particle core, wherein the particle core is completely surrounded by a particle shell, which consists of a mineral material. The mineral material may be mica or vermiculite.

In addition, a method for producing a particular liquid animal waste absorbent bedding agent for pets by the U.S. Patent 4,591,581 known. At this point, the procedure is that individual mineral grains are dried with a grain size below 2 mm substantially and then mixed with water. Subsequently, this mixture is compacted and crushed into individual particles of desired size. Mineral minerals are used as mineral raw materials.

Moreover, it is well known to use water-swellable sodium bentonite thitonite in conjunction with an animal waste absorbing composition, as disclosed in US Pat EP 0 378 421 B1 is described. In doing so, liquid animal waste can be selectively removed from a garbage can because it produces an agglomerated mass that includes the absorbent composition and liquid animal waste. This agglomerated mass is of sufficient size and coherence force to be removed from the trash box.

The known procedures have basically proven, what the fluid absorbency of the clay mineral used and its agglomeration, to single lumps from an associated To remove waste box. However, lets the scattering behavior of the known granules to be desired. That's essentially what it's all about attributed that despite the fact that they are made in the production of a variety of different Particles of different sizes is present and by the way the individual grains over naturally given Break edges have. Here The invention aims to provide a total remedy.

Of the Invention is the technical problem underlying a suitable Specify substance that is beneficial as animal litter and on a favorable Has scattering behavior.

to solution This technical problem is the subject of the invention the use of a round granules on a clay mineral basis as in particular liquid Animal waste absorbing substance. In the context of the invention comes the Round granulate so primary the function too, liquid Animal waste, although of course also solid animal waste can be absorbed within certain limits.

To This is the purpose of the current innovation a preferably clay mineral starting granules predetermined granulation back, which mixed with a likewise clay mineral absorbent becomes. In this context, a liquid can be added, which is regularly water. Subsequently The mixture is dried, giving a total of round granules a core of the starting granulate and an enveloping one Coat arising from the absorbent coating.

there the absorbent coating is obligatory as a clay mineral before or is made on such a basis. On the other hand that likes the starting granules forming the core basically have any consistency, does not necessarily have to be of clay mineral origin. So can usual (mineral) Granules such as perlite, expanded glass, Pumice etc. are used. It is crucial that through the mixing process of the starting granulate with the powdery clay mineral absorbent - whether this now dry or with liquid addition done - round granules produced become. These feature in their core about the starting granules and in their mantle over the absorbent, being characterized by the mixing process and the associated stirring movements the spherical shape of the finished grains established.

In In this context, the theory of the invention usually attacks a mixer back at which rotates a granulating plate in opposite directions compared to agitator wings. This leads to a particularly intensive mixing of the Starting granules with the absorbent. That can for example done in an Eirich mixer or in a Lödige mixer.

Usually, the granules of the starting granules are sprayed during or after drying to improve the abrasion resistance of the absorbent coating by means of a binder, which may be a concrete based. However, if the abrasion resistance is already given from the outset and proves to be sufficient, may of course be dispensed with such a spraying. This also applies to a final sieving process, with the aid of which the coated grains of the starting granules (the round granules produced) are sieved after drying and optionally spraying. Because even this classification process is to be regarded as an option.

in the Thus, the scope of the invention is no longer obtained by sieving Clay mineral of certain grain structure used as a scattering agent for receiving in particular liquid animal waste, but rather a round granules whose round granules with a core of the (clay mineral) starting granules are equipped and over an enveloping one Sheath of the clay mineral absorbent coating feature. there the absorbent coating is in a layer thickness of regularly 0.1 to 3 mm, in particular 0.1 to 2 mm before. The grains of the starting granulate like in Original condition a grain of 0.1 to 10 mm, in particular 0.1 to 5 mm, preferably 0.2 to 2 mm have.

there likes the starting granules on a clay-mineral basis as phyllosilicate, such as a smectite or vermiculite. To increase the fluid intake can the starting granules or sheet silicate in question with, for example Be activated sodium or even calcium. That way you can the charge density distribution in the intermediate layers for liquid absorption targeted and influence positively. Because, as known, the intracrystalline swelling depends of three-layer minerals, which are most likely to be used by the Hydration of interlayer cations.

there likes the activation of the starting granules either before the mixing process or during that occur. Of course it is also within the scope of the invention, both alternatives simultaneously recourse. When the activation of the starting granulate is done during the mixing process it is necessary that activating material, for example sodium, Add the mixture components. This can take the form of soda respectively sodium carbonate happen. Alternatively or additionally, too Work with calcium carbonate to replace calcium ions of sodium ions or in addition to install these in the intermediate layers.

Basically, any clay mineral absorbents find use with the grains from the starting granules in the manner described a Are able to make contact. There are absorbents Based on three-layer clay minerals proved to be particularly favorable. Because such clay minerals have - as described - not only over an extremely pronounced swelling capacity, the liquid animal waste is able to absorb. But the achieved according to the invention Round granules agglomerate into easily handled lumps that flawlessly an associated one Litter box can be removed. The properties are therefore comparable to those of conventional spreading materials to disposal be put.

there is the fluidity and handling of the round granules according to the invention clearly across from previous embodiments improved. That leaves on the almost spherical shape return after production. It can both different than same clay minerals for one hand, the starting granulate and on the other hand the absorbent is used. In the simplest Case montmorillonite is used, which is the main ingredient commercially available Bentonite represents. In this case, for example, calcium bentonite for Use come, a natural one Sodium bentonite or technically activated sodium bentonite.

In all these make the starting granules are placed in a mixer and with the absorbent mixed. The absorbent may be present as a powder and consist of the same material as the starting granulate. By the addition of liquid, For example, water leads the subsequent one Mixing process that the initially powdered absorbent as a coating in the sense of an enveloping coat around the individual Starting granules sets. In this way, the grains produced are in the form of round granules, ie Grains with almost spherical Shape. As a result, the trickle behavior improves expressly and the handling is improved. If, in addition, the starting granules is present in a particular grain spectrum is through this process further ensures that the grain size of the produced round granules no size Has variation width.

In fact, it is in fact achieved by the mixing process that different sizes of the starting granules are equalized by a correspondingly thick or thin coating from the absorbent, so that even with a grain size of the starting material of 0.1 to 10 mm after the subsequent mixing round granules with a grain be present only 3 to 7 mm, so the range of variation in the mixing process to about half or even less decreases. - It should be emphasized that the liquid addition is optional, not so is mandatory. That is, of course, dry mixtures are also covered by the spirit of the invention.

the Absorbent or clay mineral or bentonite may additionally optical brightener attached become. This optical brightener is preferred Titanium dioxide, which is also used in paper production as a brightener Use finds. The binder for increasing the abrasion resistance of Absorbent coating is usually methylcellulose or also water glass, which - like the soda additive - the two main mixing components in the form of the starting granules and the absorbent during the mixture (and / or before) is added. Bentonite can also be used as a binder as described Find.

There the starting clay granules generally in any case via a Water content of about 10 wt .-%, can be an additional liquid addition omitted. However, if this is provided, with a water addition from 10 to 20 wt .-% based on the mixture worked. That is, the Weight fraction of the water in the mixture is at most 30 wt .-%. The starting granulate is used to 20 to 40 wt .-% in the mixture, while the Absorbent the rest, ie about 60 to 80 wt .-%, makes up. Soda is about 3 to 8 wt .-%, in particular 4 to 5 wt .-%, based on the proportion of clay mineral starting granules, added.

in the Result, a novel bedding remover will be provided for pets, which in particular liquid Animal waste is able to absorb. In this context, convinced the scattering means described in particular by the fact that conditionally by the mixing process of the starting granules with the absorbent Round granules produced with almost the same grain size that are easy to handle.

It has been shown that the realized by the absorbent layer thickness of about 0.1 to 3 mm of the absorbent coating sufficient to absorb the liquid animal waste properly. In fact, water uptake rates of well over 100% by weight are achieved which even exceed the indicated values in the U.S. Patent 4,591,581 for conventional spreading materials. Because the water absorption (according to Westinghouse) is over 300 wt .-%, in particular even over 400 wt .-%. Within the framework of the teaching of the invention, therefore, almost exclusively the outer layers of the respective round grain participate in the liquid absorption, whereas the inner core is used only to a limited extent for the liquid absorption. Because before it has already come to the desired lump formation.

First, will a clay mineral starting granules brought to a certain starting grain size. This can be done by appropriate grinding operations, with a particle size distribution of about 0.1 mm to 10 mm is achieved.

in the Following this, the particle size distribution can be further enhanced Seven are limited, but this is not mandatory. The thus obtained Starting granulate, which is exemplified by montmorillonite or bentonite is, with an absorbent (also Montmorillonite or bentonite) in a mixer. It lies the absorbent in powder form and is in terms of weight in about two to five times, in particular two to three times, the mass of the starting granules. This mixture is now added to water, depending on Moisture content of the starting granulate. A proportion of water has proven useful in the mixture of up to 30% by weight.

The Mixture will follow mixed together, wherein the powdered absorbent, at which is also montmorillonite in the example, as Absorbent coating around the respective starting granulate core sets. As a result, there is a round granulate after a mixing process lasting several minutes to disposal, its grain size spectrum is clearly limited compared to the starting granulate and in a grain from about 3 mm to 7 mm.

The Mixture will follow dried and optionally screened, if still a more extensive Limitation of the grain size spectrum is desired. Now is the round granules according to the invention for the Further processing or direct use finished.

Claims (10)

Use of round granules on clay mineral Base as especially liquid Animal waste absorbing substance. Use according to claim 1, characterized in that a preferably clay mineral starting granules of predetermined grain size with a powdered clay mineral absorbent - optionally with liquid addition - mixed and then dried, so that the resulting round granules with a core of the starting granules and an enveloping sheath of the Absorptionsmittelbeschich equipped. Use according to claim 1 or 2, characterized that the grains of the starting granulate during or after drying to improve the abrasion resistance of the Absorbent coating are sprayed by means of a binder. Use according to one of Claims 1 to 3, characterized that the coated grains of the starting granulate (the round granules produced) be screened drying and optionally spraying. Use according to one of Claims 1 to 4, characterized that the starting granules in a grain size of 0.1 to 10 mm, in particular 0.1 to 5 mm, preferably 0.5 to 2 mm, used as starting material becomes. Use according to one of claims 1 to 5, characterized that as starting granules on a clay mineral basis phyllosilicates such as smectites or vermiculites are used, which preferably to increase their fluid intake activated with, for example, sodium or calcium. Use according to one of claims 1 to 6, characterized that the layer thickness of the absorbent coating 0.1 to 3 mm, in particular 0.1 to 2 mm. Use according to one of claims 1 to 7, characterized that it is in the clay mineral starting granules and / or the clay mineral absorbent with montmorillonite as its main constituent commercially available Bentonite trades. Use according to one of claims 1 to 8, characterized that an optical brightener is added to the absorbent. Use according to one of claims 1 to 9, characterized that it is the liquid for the Mixing process is about water, possibly soda in a Amount of 3 to 10 wt .-%, in particular 4 to 5 wt .-%, based is added to the clay mineral starting granules.