DE2725687A1 - Gypsum granules for absorption on liquids - used to absorb oils, fats, water e.g. animal excrement, as supports for chemicals e.g. agriculture and as soil conditioning agents - Google Patents

Abstract

Method comprises mixing water and calcium sulphate hemi-hydrate plaster in predetermined proportions to form wet mixt. and hydrate the plaster to form calcium sulphate dihydrate b) drying the wet mixture, and c) grinding and sieving the dried material to form granules of the desired size. The granules are used for absorption of oils and fats, or after liqs. e.g. on floors of factories and shops for absorption of animal waste e.g. in cat boxes as supports for chemicals used in horticulture and agriculture e.g. pesticides (insecticides), fungicides and herbicides, as soil conditioning agents and as light, decorative coverings for soil which may be coloured by pigments if desired. Compared with natural clays which are presently used as absorbants the present granules are made from material which is readily available in most parts of the world and transport costs of the product to the site where they are used can be minimised, their size may be easily controlled to give a product suitable for the use envisaged and their cost of prodn. compares favourably. It is also much easier to produce a standard product, with hardness, absorption properties, apparent density and stability.

Description

Description:

The present invention relates to absorbent granules made from naturally occurring, absorbent minerals are made and so far consisted almost entirely of absorbent clay granules. For these granules there are various possible uses in industry and abroad; for example these granules can be used to absorb oils and fats and the like from floors and in any other place where these materials present a risk of accident; Furthermore, these granules can be used as litter and absorbent in animal toilets be used, for example at a sleeping place for a sentence; Farther these granules can be used as carriers for other chemical agents, such as pesticides, animal bicides and the like are used and in the field of agriculture and horticulture be used; Finally, these granules can be used as flooring with their original natural coloring can be used.

With this invention a method is provided to as The basic material for these granules is to use hydrated plaster of paris. Plaster of paris in the mold the naturally occurring mineral, or the powdered form made from it Plaster of paris, such as stucco, is useful as a moisture absorbing material such as absorbent sound, not suitable; leave under controlled process conditions However, absorbent granules can be produced from it, their properties are essentially equivalent to the properties of granules made of absorbent dom Volume.

In particular, the present invention provides a method, in which the standardized, commercially available plaster, which is also known as the blown USlter Gypsum or lime gypsum is called, and in powder form from the natural existing plaster of paris can be used. This baked plaster of paris is mixed with water or with water and other materials under certain conditions Conditions to obtain a mixture. Changes to these conditions lead to changes the characteristic properties of the end product, especially with regard to on the bulk density, the absorption capacity for moisture, the hardness, as well the resistance in water or other liquids.

With regard to the production conditions, the inventive, absorbent granules have consistent properties from batch to batch, whereby only it is assumed that from approach to approach the the same plaster of paris is used; this belluh'c on the fact that plaster of paris is known can have different properties. The characteristic properties of gypsum can be determined before starting the manufacturing process, so that appropriate modifications of the procedure can be made, to compensate for undesired changes in properties. Such uniformity The product can be used in the manufacture of absorbent granules from natural occurring absorbent minerals such as absorbent clays cannot be achieved.

The late thirties as well as the early forties are natural occurring absorbent minerals, such as clay, also known as "Fuller's earth" is known, and which already have a porous structure in their natural state, for the first time as an absorbent for oils, fats, water and other undesirable Substances on the floors of factories, workshops, filling stations and the like been used. Before that, "i'uller-earth" was mainly used for refining Oils are used. Because of the low bulk density of this material in the order of magnitude from 0.40 to 0.88 g / cm) as well as because of its porosity and its absorption properties further application possibilities have been developed. Granules from "Fuller's earth" have a considerable share of the market as litter material in the pet toilets found for hsustierc, especially in cats, as well as a carrier for chemical Active ingredients in the IJDll (lwj.rtschaft} as stated above; was.

The following materials fall into the specified density range referred to as lightweight materials.

The naturally occurring, absorbent or absorbent mineral clays are mined, dried or burned, crushed and sifted to a specific sorting, which suits the respective purpose is adapted.

For example, the usual particle size of such granules corresponds to used as an absorbent for oil and fats, as well as litter for cats are, a sieve number from 6 to 60; that is, such a particle size that a sieve with a mesh size of 3.3 mm passed and a sieve with a clear mesh size of 0.25mm is retained. The granules can however, have different particle sizes for each application. For example Sieve numbers from 10 to 60 (particle sizes between 1.6 and 0.25 mm), sieve numbers from 6 to 16 (particle sizes from 3.3 to 1.0 mm) and sieve numbers from 6 to 24 (particle sizes from 3.3 to 0.2 mm); all of these particle sizes are commercially available at Products. For one or the other iall of the above Possible applications are also very coarse particles with sieve sizes from 4 to 10 particle sizes from 4.7 to 1.6 mm) have been used. For absorption media For oils and fats, efforts are still being made to ensure that the granulate grains against comminution and sticking to the floor persists when the grain is stepped on, or is driven over it with a device such as a hand truck.

Regarding the particle size, the size can be for either of the above Granules vary widely; in addition, there are also much larger ones Particles with a diameter of approximately 25 to 50 mm in decorative floor coverings been used.

Unless granules of absorbent mineral clay as Carriers for insecticides, pesticides or herbicides have been applied, are right tight specifications required. The usual particle sizes here are sieve numbers from 8 to 16 (particle size 2.4 to 1.0 mm) with sieve numbers from 16 to 30 (particle size 1.0 to 0.54 mm), with sieve numbers from 30 to 60 (particle size 0.54 to 0.25 mm) and with sieve numbers from 24 to 48 (particle sizes from 0.70 to 0.30 mm); here there are special tolerances with regard to the particle size for each particle size range and the bulk density provided. A relevant specification for one Product demands that the bulk density according to the well-known Ohaus bulk density method " is determined and in this determination the bulk density of the nterials between 0.50 and 0.56 g / cm3. Ilinsichtli.ch is the fluctuation range of the particle sizes provided that a maximum of 2 wt .-% 'of the granules are larger than 0.83 mm and no particles are larger than 1.65 mm. The proportion of particles that are smaller than 0.25 mm must not make up more than 1.5 to 2% by weight of the material.

As far as sieve numbers are mentioned in this context, refer relate this to the Tyler Siebt & Belle and concern the number of stitches per Customs. In addition, for this product it has been required that 5 to 8 million Granulate particles come to 450 g of absorbed active ingredient.

There is an important requirement for these chemical agent carriers in that the material is dust-free. It is also important that the specified Properties of absorbent clay granules from shipload to shipload are constant, otherwise the distribution of the different chemical Active ingredients using these granules require careful monitoring would.

From the above specified special properties that are common to these materials are usually required, it follows with all clarity that the processing from naturally occurring minerals, such as absorbent Toning requires a considerable amount of supervision and control so that meet the requirements for the numerous purposes for which these granules are used will. With the exception of a careful selection of what is intended for processing Tones, however, such a control is not possible. The particle size can vary the measures for size reduction and screening are varied; can continue the hardness and resistance of the granules to water due to the conditions changed to burn the absorbent mineral; however, this represents essentially the limits for regulating the characteristic properties of absorbent granules, which are made from naturally occurring mineral substances how to make clay. There is practically no way of the bulk density or to change the absorption capacity of these clays.

The lack of uniform bulk density in such clays that come from different mines and / or worked up according to different processes continues to lead to packaging difficulties. If the bulk density c is relatively high in terms of the norm for a certain size packaging, a given amount, such as 2.5 or 25 kg, fills a sack or package with a given size only partially. On the other hand, if the bulk density is too low, or it yourself it is a very light tone, so i'iin on the other hand, the intended packaging; t'üi the required weight of granules not enough.

The usefulness and effectiveness of absorbent granules Tone for the purposes specified above can continue to fluctuate, which can be attributed to the origin of different clays in different areas is.

In addition to the difficulties already listed, there is another problem, that absorbent clay, which is the main absorbent mineral for represents the stated uses, only in limited areas of the United States of America as well as in some other countries of the world; moreover, this material is in the most industrialized areas not found on earth. As a result, the transportation costs make up for transportation from the place of discovery to the areas of application a considerable proportion of the sales price the end. In fact, it exists in the United States of America and even stronger in Europe the situation that absorbent clay with the desired properties, which is suitable for the purposes described, only in such In limited areas, the cost of transportation is a significant percentage the selling price for this powdery Represent product.

With the constant expansion of the possible uses for absorbent GromllatlcörlJer, such as clay granules, and.

in view of the limited areas where such clays are available There is widespread industry research for new sources for the necessary raw materials. However, they are essentially no new occurrences of absorbent minerals have been found which can be used for the purpose of absorbent clays; Furthermore no equivalent naturally occurring absorbent materials are determined which are manufactured and sold under economical conditions can. As a result, synthetic substitutes have been considered; until however, no product is acceptable for developing the product according to the invention Properties have been developed that can be manufactured at competitive prices and for which the occurrences are so widespread that the transport costs on a Minimum can be decreased.

Keeping in mind that there is a worldwide need for such absorbents exists and that the greatest need in industrial, agricultural and urban Areas located mostly from the natural sites for absorbent If minerals such as absorbent clays are far away, then it becomes clear that all the trouble with this naturally occurring Product have become a hurdle that industry will overcome got to.

The object of the present invention is to provide an essentially Inorganic, synthetic absorbent as a substitute for the naturally occurring ones from. -ptable minerals to provide that up to a desired Particle size can be crushed so that it is suitable for the following applications is suitable, namely (1) for the absorption of liquids on the floors of Factories, shops and the like where water, oil and fat can accumulate and thus represents a security risk; (2) as an absorbent litter for stalls and beds for pets, in particular cats; (3) as a carrier and chemical agent dispensing agents for agricultural use; (4) as a means of improving the quality of the soil; and (5) as a floor covering of light weight colored with an aimed color pigment.

Another object of this invention is to provide a method to indicate the production of granular absorbent, which with a Material works that can be found in many parts of the world, so that easy available sources for the production of the granular, synthetic, absorbent are available relatively close to the points of sale, so that the transport costs of the produced product are significantly reduced in comparison to the production costs for the absorbent granules currently in use.

Another object of this invention is to provide a method for the production of absorbent granules, with the characteristic Properties and the particle size of the end product to a relatively narrow range of fluctuation Can be adjusted so that the product does not only serve the intended purpose fulfilled, but that, moreover, the properties of the product from approach to Approach to manufacture remain the same.

Yet another object of this invention is to provide a manufactured or to provide synthetic absorbent that is versus natural occurring absorbents are manufactured and sold at competitive costs can be.

The main feature of this invention is that that an absorbable granulate bercitgctell and a process for its production is specified, the product being used for essentially the same purposes is suitable as the absorbent granules made of naturally occurring absorbent mineral substances, although the starting material is plentiful in numerous Areas of the world. The synthetic, absorbent granules can under economic conditions and compliance with the required specifications guaranteed; furthermore, the transport costs for numerous markets are reduced compared with the cost of transporting granules made from naturally occurring absorbent Minerals.

Stucco plaster or plaster of paris, as this material is also called, is made from gypsum extracted by mining or quarrying, which is chemically described as calcium sulfate dihydrate (CaS04 2H20). In the preparation of of plaster of paris, the raw plaster of paris is heated and loses water, thereby forming Calcium sulphate hemihydrate (CaS041 / 2H20) or plaster of paris. The manufacture of Plaster of paris is well known and facilities for making it are in many places spread over the whole earth.

The processing of plaster of paris or calcium sulfate hemihydrate is in accordance with the invention intended; to the invention provided procedural step the mixing of plaster of paris with water in specified quantities, in order to obtain a slurry or a paste, what from the proportions of water relative to the plaster volume. As a result of this treatment stage, the fired Gypsum is essentially converted into gypsum (CaS04 2H20).

The slurry or paste is then placed in a mold or molded to set and cure. After setting, Curing and drying, the material is ground or crushed and thereupon the granules are sieved to produce particles of a certain particle size distribution to obtain. Alternatively, the material can be in a given shape, for example in the form of granules. For this purpose, the mixture is in a Pelletizing device or placed in an extruder or similar device, which the material directly into granules with the desired for the finished product Shape processed.

The process can be carried out with easily accessible mixing equipment, Chopping and sieving are carried out; thus the process can be economical Way anywhere with a minimum of fuss and a minimum at the cost of setting up new production facilities.

The finished absorbent granules are lightweight on, as well as pores and spaces for the absorption of liquids; on top of that the particles retain their physical granularity to a sufficient extent in use Structure and are chemically resistant for the specified uses.

Thus, according to one aspect of this invention, there is a method for the production of synthetic, liquid-absorbing granulates from burnt-off Plaster of paris indicated; this procedure includes the following measures: a) Water and plaster of paris such as calcium sulfate hemihydrate are used in specified quantities mixed in a mixing device; b) the mixing of water and spirits Plaster of paris in the mixing device is carried out under such conditions that a moist Mixture of burned plaster of paris and water is obtained and thereby the burned plaster of paris hydrated and again converted to calcium sulfate dihydrate during the course of mixing and is thereafter in a state that can be dried; c) the damp Mixture is dried; d) the dried material will be so long crushed until it is in the form of granules; and e) the granules are sieved by means of sieving devices to remove granules of a selected particle size range after which the granules are ready for use as a liquid absorbent granules.

According to another aspect of this invention, a Process for the production of synthetic, liquid-absorbing granules of dry, baked plaster of paris, with the following for the method Measures include: (a) Dry calcined plaster of paris powder and water are put in predetermined amounts mixed with one another in a mixing device; (b) mixing of dry, baked plaster of paris and water in the mixing device takes place under conditions such that a mixture of the plaster of paris and water is obtained the plaster of paris is moistened and hydrated in the process, as well as in the course the mixing process is converted back into calcium sulfate dihydrate; (c) granules or w. Granules shaped, their shape and size is adapted to the intended use of the end product, with possible applications for this include: the absorption of unwanted accumulations of oil and fat; the usage as litter for pets, for example in pet toilets; as a carrier for chemical agents such as pesticides, herbicides and the like in agriculture or in horticulture; (d) these granules are dried; and (e) the dried ones Granulate particles are sieved in order to obtain them according to the above-mentioned application possibilities to sort and select.

The invention is described below with reference to an exemplary one Embodiment described; a sheet of illustrations also serves as an explanation a single drawing, which is a schematic representation of the process stages reproduces the method according to the invention.

To carry out the method according to the invention is customary in the trade accessible, baked plaster in a mixer brought. Dom powder enough water is added to sell the mixing process Paste or a slurry. The Itor.m of the slurry or. the The shape of the paste in turn determines the density that can ultimately be achieved in the end product.

If the mixture is in the form of a slurry, it will usually be Poured into molds for setting and curing.

If the mixture is in the form of a paste, it will either spread out in the form of a layer, or it is placed in a suitable device into pellets, for example in the form of cylinders or polygons, or in the form brought by bullets. The special particular shape to which the pasty Material is processed has such a size and shape that a light subsequent handling including shredding using accessible facilities is guaranteed. Provided that an absorbent litter is made for cats is to be, the paste can directly into granulate particles of the desired shape can be processed which, without further comminution, is the desired for the end product Have shape.

The material is then allowed to set and harden; the required Time to set and harden is due to the use of well-known special plasters, Affects retarding or accelerating the mixing.

Regardless of the shape, shape and size of the material for the steps of setting and hardening, the material is allowed to set and harden and dry afterwards. Alternatively, the material can be dried in a dryer be dried, it must be ensured in each case that the temperature the dehydration temperature in the dryer or in the drying environment of gypsum, which is approximately 120 to 150 0G, is not exceeded. in the Following the drying, the material is crushed and then sieved to the desired particle size of the granulate particles for the intended use to obtain.

For some drying facilities, such as drying in Fluid bed dryer it can be aimed to shred the material first, then to dry and then to sieve the dried granulate particles.

This alternative is not shown in the figure.

As can be seen from the figure, the purpose of sieving is to the synthetic, absorbent granular particles with the desired particle size separate them in order to pack them and then sell them. Provided If there are granulate particles with a particle size that is too large, they are comminuted again or granulated and then sieved again. The too small particles, namely that so-called finely divided material can in turn in the lIers tel lui'sverfairen to be returned; in detail, the finely divided material In turn, up to a proportion of 30% by weight of the used gypsum the Mi Scheinriehtung fed and mixed with the remaining ingredients. baked plaster of paris and the finely divided material is then mixed with water, to obtain a slurry or paste, depending on the amount of water added depends, and then carried out the method steps explained above.

This re-use of finely divided material, which in the course the implementation of the method according to the invention is an essential one This is an advantage. There is no possibility in the course of the comminution to prevent the accumulation of finely divided material; within the scope of the invention Process, however, this finely divided material can be completely reused. with only minor additional costs.

In contrast, when shredding and sorting the natural, mineral absorbents such as absorbent clay are commonly used in the industry incapable of handling the dust produced during the shredding and sorting and returning the fines to the process. For this reason are such fines in an additional pelletizing step pelletized, such as that in U.S. Patent Application 510,502 is described. An alternative option is to simply use the clay fines to camp on Hilde or otherwise to be deposited.

In the preferred embodiment described above, the both properties, namely the bulk density and the ability to absorb moisture of the finished product regulated by the fact that the water content is relative to the proportion is changed on baked plaster of paris. It is still possible to use these properties adjust by using different additives iii different proportions will. The water content is adjusted in connection with the additive. Such additives are lightweight materials with natural absorbency, such as For example paper pulp, or finely divided paper, or sawdust, or peat dust, or light weight clay dust.

Usually such additives are added to the mixture in proportions of 1 to 20%, based on the weight of the plaster of paris, added.

Examples: To carry out the preferred embodiment of the invention Procedure in Holland, the following approaches were carried out and thereby the relative amounts of burned Changed plaster of paris and water; at The properties listed below were determined for the products obtained. The plaster of paris used in all approaches was one that was commercially available in Amsterdam accessible material labeled SBA 10FM ".

Approach: baked plaster of paris water bulk density water- setting absorption time g / cm³% (min.) 1 85 15 0.809 22 8 2 82 18 0.830 19 8 3 78 22 0.774 24.7 11 4 75 25 0.658 27.4 13 5 73 27 0.621 34 14 6 70 30 0.620 33 14 7 68 32 0.59 39.6 15 8 66 34 0.530 47 17 9 63 37 0.503 54.7 20 10 62 38 0.479 61.3 23 11 60 40 0.458 69.6 27 12 58 42 0.423 78 34 Each of these twelve approaches was in a total weight from 450 to 675 g, including plaster of paris and water in the above percentages were used. Each of these approaches was made prepared by hand in a bowl, the mixing is carried out in the bowl, and then spread the mixture to a thickness of approximately 6 on a plastic sheet After setting, the tied piece was sufficiently durable to be erect Position to be air dried. After this drying, it was approximated to One-third of each piece in granular particles with an approximate particle size of 5 mm broken and these granules for final drying with hot Air heated to 110 ° C.

From the above approaches, approach 7 appears to be the best granule particles to have surrendered. This approach was therefore repeated on a larger scale. To this Purpose were 50 kg of quick lime and water for 10 minutes in a usual Concrete mixer mixed. In detail, 68% by weight of 'calcined plaster of paris with 32% by weight' Water mixed. The obtained mixture was approximated from the mixer in the form of a 30.5 mm thick layer poured; after a setting time of approximately 3 hours the material was hard and had a moisture content of 2.3%. Roof the layer was broken down into small granules with sieve numbers from approximately 4 to 10 (particle sizes from 4.7 to 1.6 mm) broken.

Approximately 3 kg of these small granules were deposited on a fatty Concrete floor spread out to the absorbency these particles for oil and fat to be determined.

After a period of approximately two hours there was oil and fat absorbed by these granules; the following day, these became granular particles simply removed by bending with a broom. After that the ground was dry and clean. The absorption effect was as good or better as that of natural occurring absorbent sound used for the same corner.

Over a longer period of time, 22 kg of this sample was used as Litter and absorbent material used in various cat toilets; here the granulate material absorbs the moisture and diminishes the odor in the corresponding toilet or basket is just as satisfactory for the cat, as do the absorbent clay particles that are currently commercially available are.

The inventive method was also carried out with plaster of paris, the available in Chicago, Illinois; this plaster of paris is known as "U.S. Plaster no. 1 "known; for each approach this plaster of paris and water were converted into a commercially available electric kitchen mixer and a bowl. For each approach, 450 up to 675 g of mixture produced. After mixing, the material was each on poured or given a plastic wrap; then the material was left Set and cure for an hour. Then each layer was broken into small ones Bit broken and these before a hot air formation with air of 3800 dried for three hours.

The broken pieces were then manually operated using a Next, granulate the granulate particles obtained both with a sieve the number of sieves 6 (clear mesh size 3.3 mm) as with a sieve with the number of sieves 16 mm mesh size 1.0 nm) sieved. I) like granules that the sieve with the sieve number 6 had passed, were then on the sieve with the sieve number 16 given. Then those particles were that last called sieve, separated from those who did not pass through the sieve had; thereafter three different types of particles were obtained, namely (1) Particles which had not passed the sieve with the sieve number 6; (2) particles that had passed the sieve with the number 16 sieves; and (3) particles that the sieve has with the sieve number 6 had passed, but were held back by the sieve with the number 16 sieve became.

Those particles that do not pass the sieve with the number 6 sieve were crushed again until they passed this sieve. To this comminution corresponded the granulated material has the number of sieves 6 to 1C; while the smaller material (particle size below 1.0 mm) as finely divided Material has been classified and not investigated further. In other words, like that in the industry for the production of granular particles for the absorption of Liquids are common, those granules that also have the the finest sieve and therefore not suitable for a specific sales purpose are referred to as finely divided material.

The material corresponding to the sieve numbers 6 to 16 (particle size between 3.3 and 1.0 mm) was then in terms of its bulk density, his Investigated absorption capacity for liquid and its absorption capacity for oil. The tests were carried out according to the information for granulate particles, such as see them in Federal Specification Bulletin P-A-1056, Absorbent Material, Oil and Water (For Floors and Decks) (available from General Services Administration). The respective approaches and the results obtained are shown below listed: Approach: baked gypsum water bulk density water-oil absorption sorption%% g / cm3%% 13 70 30 0.769 52 34 14 62 38 0.618 50 50 15 59 41 0.609 66 16 56 44 0.569 70 66 17 50 50 0.529 88 74 From the above information it can be seen that the granules obtained from these approaches have such properties, e e the properties of commercially available and accepted absorbents from granulated clay correspond; the latter have the following properties on: Schiitt oil and water sieve number d.

dense absorption particles g / cm Commercially available products 0.320-0.881 20-110 6 to 60 Granules according to the invention from batches 13 to 17 0.529-0.769 30-88 6 to 16 With dela already mentioned above, in Holland acquired braised plaster for 10FM "a mixture was also made, there. contained another addition; used newsprint was added to the mixture added to allow the bulk density and absorbency of the finished synthetic To change granules. The used newspaper was mixed with water and from it into an electric mixer that runs at high speed made a slurry or pulp; then it became excess Squeezed out water so that the mixture had a paper: water ratio of 1:15 exhibited; in this form the paper / water Brci was made with the baked plaster of paris and vermiscit the water.

The proportions of added used newsprint in relation to each other The table below shows the proportions of plaster of paris and water remove; furthermore there are the density and the water absorption capacity for the granules from each batch are listed. For each run, it was approximated to 450 processed up to 675 g; the raw materials were mixed by hand, off removed from the shell, left to set, hardened and dried; afterward the dry material was crushed as described above is.

Approach: burned plaster of paris paper water bulk water setting density absorption time%%% g / cm3% (mine.) 18 69.6 0.9 29.5 0.540 44.6 16 19 66.7 1.7 31.6 0.522 51.2 19 20 64.5 1.6 33.9 0.472 58 20 21 64 2.4 33.6 0.4-50 73 24 22 61.5 3.1 35.4 0.412 81 30 23 59.3 3.7 37.0 0.391 111 31 Note: The percentage of paper refers to the weight of the dry paper.

Approaches 20 and 21 were repeated on a larger scale and out the granulate obtained 10 kg over a longer period of time as litter material in a cat toilet used; here the synthetic, absorbent ones turned out to be Granules from each batch as completely satisfactory.

The characteristic properties of plaster of paris can be derived from be different for numerous reasons; this includes differences that affect the Deposit and nature of the naturally occurring, mined gypsum as well as the results of the following Bebajilung for firing the natural plaster it. To the characteristic properties of the synthetic, absorbable green sheet particles for a given fired To determine plaster of paris, simple experiments can be carried out correspond to one or more of the approaches 1 to 17 mentioned above. For every attempt the water content results from the desired bulk density and the absorption properties. After the desired properties have been obtained, it follows from the the respective test conditions, the water content required for the production of the granulate particles from that particular baked plaster of paris is required. From the various examples it becomes clear that a simple experiment is sufficient to determine the water content, which is required for any calcined plaster of paris to allow the granulate particles have the special required properties.

Unless additives, such as paper pulp or other materials with natural Absorbance and low weight are used, result from the exemplary approaches 18 to 23 further investigation methods to the combination check of plaster of paris with each of these absorbent materials in order to select those manufacturing conditions that have the desired properties of the finished granules.

In some cases it may be desirable to have colored synthetic granules to obtain; according to a further aspect of the invention it is therefore provided the mixture of plaster of paris and water in the mixing device with a pigment to add the desired color.

The entire approach including the colored pigment is then followed Treated the above process steps, crushed the material obtained and sieved as indicated.

As stated above, the process according to the invention can be used Synthetic production of liquid-absorbing granules, the equivalent or have better properties than the granulate particles from naturally occurring, liquid-absorbing minerals such as "Fuller's earth"; Furthermore can determine the essential properties of the final product there for a given composition and for a particular particular use in a manner and an extent adjusted and regulated, which is not the case with the naturally occurring product is possible.

L e r s e i t e

Claims (23)

Synthetic, liquid-absorbing granules, a process for its production and its use claims: 1. Synthetic, liquids absorbent granules, characterized in that the granules essentially consists of calcium sulfate dihydrate CaSO4.2H2O) and has a particle size such that that it passes a sieve with a mesh size of 3.3 mm and of a ' Sieve with a clear one Mesh @@ eite of 0.25 mm is retained. 2. Granules according to claim 1, d a d u r c h g e k e n n z e i c h n e t that it contains an additive made of a lightweight material, which affects the bulk density of the granules. 3. Granules according to claim 2, d a d u r c h g e k e n n z e i c h n e t that it contains used newsprint as an additive. 4. Process for the production of synthetic, liquid absorbent Granulate according to claims 1 to 3, characterized by the following process steps: a) Burnt gypsum in the form of calcium sulfate shark hydrate (CaSO4. 1 / 2H2O) is mixed with Water mixed in given amounts to obtain a moist mixture; b) in the course of mixing, calcium sulfate dihydrate (CaSO4.2H2O) is formed; c) the resulting mixture is dried; d) the dried mixture is comminuted; and c) the granules obtained are sieved with respect to sorted by their particle size. 5. The method according to claim 4, d a d u r c h g e k e n n z e i c h n e t that, in addition, a material of light weight and of course absorbency is used, and this is mixed with water and plaster of paris. 6. The method according to claim 5, d a d u r c h g e k e n n z e i c h n e t that paper pulp, finely divided paper, sawdust, Peat dust and / or loam, clay or brick flour or dust is used. 7. The method according to claim 5, d a d u r c h g e k e n n z e i c h n e t that used newsprint is used as an additive and this through Mixing with water is brought into the form of a slurry or pulp and put in this state is mixed with plaster of paris and water. 8. The method according to any one of claims 4 to, d a d u r c h g e k It is noted that the calcium sulfate hemihydrate is in the form of dry powder is used. 9. The method according to one of claims 4 to 8, d a d u r c h g e it is not stated that a pourable paste is formed from the constituents is converted into a flat, layered form and in this Condition is brought to set, hardened and dried. 10. The method according to any one of claims 4 to 9, d a d u r c h g e it is not noted that essentially 15 to 50% water with 85 to 50% baked plaster of paris. 11..Verfahrcn according to one of claims 4 to 10, d a d u r c h g e it is not stated that several sieves with different lights can be used to screen Mesh size used, and the resulting granules of different Particle size can be used for various purposes. 12. The method according to claim 11, characterized in that the granules for the various purposes of use, particle sizes between 4.7 and 0.25 mm exhibit. 13. The method according to claims 11 or 12, characterized in that that the excess material remaining after sieving is renewed crushed and then sieved again. 14. The method according to any one of claims 11 or 12, characterized in that that the resulting from sieving, too finely divided for the intended uses Material fed back into the process in specified proportions and by means of is mixed with the burnt plaster. 15. The method according to claim 14, characterized in that the finely divided Material in a proportion of approximately up to 30%, based on the used Amount of plaster of paris to be returned to the process. 16. Use of the granules according to claims 1 to 15 for agricultural Purposes including the granules with an insecticide, herbicide, or fungicide are mixed, and this mixture is used to spread the active ingredients. 17. Use of the granules according to claims 1 to 15, for recording of oils or fats from surfaces, including the granules on the with oil or Fat-covered surface can be spread and after the absorption of oil and / or Fat can be removed again. 18. Use of the granulate according to Änspiüchcn 1 to 15, as a litter and recording material for the body exudates of acousticren. 19. Use according to hnslruch 18, d a d u r c h e k e n n n z e i c It does not mean that an odor-absorbing substance is added to the granules. 20. Delivery according to claims 18 or 19, d a d u r c h g e k Note that the granules were used as litter for cats will. 21. Use of the granulate according to claims 1 to 15, as a floor covering, for which the granules are grazed with a colored pigment. 22. Use of the granules according to claims 1 to 15, as a means to improve the quality of the soil, for which purpose the granules are introduced into the ground will. 23. Use according to one of claims 16 to 22, d a d u r c h g It is not noted that such a particle size is used for the granules it is provided that the granules are a sieve with a clear mesh size from 3.3 mm pass and from one Sicb with a clear mesh size be retained by 0.25 mm.