Title of Invention

"ABSORBENT BODY COMPRISING POWDER OF INORGANIC MATERIAL"

Abstract

An absorbent body intended for absorbing liquids comprising a powder of an inorganic material characterized in that the inorganic material comprises at least one calcium compound, a dry residue of the distillation of an effluent mother liquor from an aqueous ammonia soda factory and is mixed with vegetable fibres wherein the said body comprises at least 5% by weight of vegetable fibres and more than 30% by weight of calcium compound.

Full Text

The present invention relates to Absorbent body comprising powder of inorganic material. The invention relates to absorbent bodies intended for absorbing liquids. Solid absorbent bodies find various applications in every day life and in industry. Absorbent bodies in the form of powders or of granules find in particular wide use in the manufacture of absorbent litter for animals, mainly domestic animals such as cats and rodents. The properties sought for these litters comprise in particular the absence of a repellent effect on the animals for which they are intended, good absorption of liquid animal excrements, without the formation of slurry, sufficient mechanical resistance to support the weight of the animal, a low apparent volume weight and a low tendency to adhere to the ground during use. Various categories of litters have been proposed, but none has all the desired optimum properties. A first category of litters consists of porous mineral rocks of volcanic origin. These known litters generally have the desired properties as regards the apparent volume weight and the adhesion to the ground. They are on the other hand very defective as regards the -absorption of liquid animal excrements;- which implies the disadvantage of a large consumption of litter and requires its frequent replacement. A second category of known litters consists of clays, such as bentonite, attapulgite and montmorillonite. These known litters generally have a low level of absorption of liquid animal excrements and tend to form slurries during use and to adhere to the ground, which complicates their evacuation after use. A third category of known litters comprises vegetable litters. The latter, which are used either for pets or for livestock, are generally manufactured from wood chips or from straw. They have the advantage of a low volume weight, but their efficiency in absorbing liquid animal excrements is low. They are moreover expensive. The invention aims to provide a solid absorbent body which combines all the advantageous properties of the known absorbent bodies described above, without having the disadvantages thereof. Consequently, the invention relates to an absorbent body comprising a powder of an inorganic material, which is characterized in that the inorganic material comprises at least one calcium compound and is mixed with vegetable fibers. In the absorbent body according to the invention, the inorganic material comprises at least one calcium compound. The expression calcium compound is understood to mean any compound of calcium which is substantially insoluble in the liquids for which the absorbent body is intended. A compound of calcium is preferably used which is substantially chemically inert toward said liquids. The choice of the calcium compound will therefore depend on the destination of the absorbent body, in particular on the liquids which it is intended to cause it to absorb. Calcium carbonate, calcium sulfate and calcium hydroxide are calcium compounds which are quite suitable in the majority of cases, in particular in the case where the inorganic body is intended for the absorption of liquid animal excrement, such as urine. Calcium carbonate and calcium sulfate are preferred, especially anhydrous calcium carbonate. Ground limestone is quite suitable. In addition to the calcium compound, the inorganic material may optionally contain other inorganic compounds, which are substantially free of calcium. These are preferably insoluble in the liquids for which the absorbent body is intended and are preferably chemically inert toward these liquids. The inorganic material advantageously contains clays, in addition to the calcium compound. The inorganic material is present in the form of a powder in the absorbent body. The optimum diameter of the powder results from a compromise between the search for a maximum liquid absorption capacity and ease of handling. In general, the optimum diameter of the powder will depend in particular on the calcium compound and, where appropriate, on the other inorganic compounds, in particular on their volume weight. In practice, it is desirable that the powder has a mean particle diameter of at least 0.10 urn, preferably of at least 1.00 urn. It is desirable that the mean diameter of the powder does not exceed 2 mm, preferably 100 urn. Mean diameters of 0.1 to 10 urn are usually quite suitable. In the present report, the mean particle diameter of the powder is determined by means of a Sedigraph 5100 X-ray granulometer (Micromeritics Inst Corp. USA). The calcium compound content by weight of the absorbent body will depend on the choice of calcium compound and on the destination of the absorbent body. In general, it is desirable that the absorbent body contains more than 30% (preferably at least 60%) by weight of calcium compound, contents which are greater than or equal to 65% being especially advantageous. It is preferable that the calcium compound content by weight of the absorbent body does not exceed 95%, preferably 90%. Contents of calcium compounds by weight of 65 to 95% are quite suitable, contents of 70 to 85% being preferred. In the present report, unless otherwise stated, the contents by weight are expressed in weight of dry matter. The choice of the vegetable fibers is not critical. They may for example comprise chopped straw, husks of cereals, cotton or flax fibers, or wood chips. In a preferred embodiment of the invention, the vegetable fibers are cellulose fibers. These may optionally comprise cellulose fibers recovered from the recycling of old paper or carton. As a variant, they may consist exclusively of cellulose recovered from the recycling of old paper or carton. The optimum vegetable fiber content of the absorbent body will depend on the nature of the vegetable fibers, their sizes, the calcium compound and the destination of the absorbent body. In general it is desirable that the absorbent body contains at least 5% (preferably at least 10%) by weight of vegetable fibers, contents greater than or equal to 15% being especially advantageous. It is preferable that the vegetable fiber content of the absorbent body does not exceed 50%, preferably 40%, values less than or equal to 35% being especially recommended. Vegetable fiber contents by weight of 5 to 35% are generally quite suitable, contents of 15 to 30% being especially advantageous. Absorbent bodies in accordance with the invention, comprising from 70 to 85% by weight of calcium compound and from 15 to 30% by weight of vegetable fibers are especially quite suitable for the absorption of liquid animal excrements. They are quite suitable for pets, in particular cats. In the present report, the expression animal excrements is understood to mean both feces and urine. In the case where the absorbent body contains clay, it is preferable that the latter does not exceed 5% by weight. Examples of compositions in accordance with the invention comprise from 60 to 90% by weight of calcium compound, from 5 to 351 by weight of vegetable fibers and from 0 to 5% by weight of clay. The absorbent mass according to the invention may optionally contain additives intended to confer on it particular additional properties, for example perfumes or antiseptic agents. In a particular embodiment of the absorbent body according to the invention, the inorganic material comprises a dry residue of the distillation of an effluent mother liquor from an aqueous ammonia soda factory. The expression dry residue of the distillation of a mother liquor from an aqueous ammonia soda factory is understood to mean an anhydrous solid residue which has been separated from an aqueous suspension obtained from a column for distillation of the mother liquor from the manufacture of sodium carbonate by the aqueous ammonia process. Examples of the composition of such an aqueous suspension are provided in the Te-Pang Hou treatise, "Manufacture of soda", second edition, Hafner Publishing Company 1969, page 237. Such dry residues comprise, as main constituents, calcium carbonate, calcium sulfate and calcium hydroxide. In addition to these constituents, they often contain magnesium compounds, iron oxides, alumina and silica. The contents of these various constituents depend on the origin of the raw materials used in the aqueous ammonia process for the manufacture of sodium carbonate, and on the operating parameters for this process. Dry residues which are quite suitable for this embodiment of the invention comprise at least 40% (preferably at least 45%) by weight of calcium carbonate, at least 1% (preferably at least 5%) by weight of calcium hydroxide and at least 1% (preferably at least 10%) by weight of calcium sulfate. Preferably, the maximum contents by weight of dry residue in these three constituents do not exceed respectively 90% (preferably 80%) in the case of calcium carbonate, 40% (preferably 30%) in the case of calcium hydroxide and 45% (preferably 40%) in the case of calcium sulfate. Dry residues which are especially recommended contain from 40 to 70% (advantageously from 50 to 60%) by weight of calcium carbonate, from 1 to 25% (advantageously from 5 to 15%) by weight of calcium hydroxide, from 1 to 40% (advantageously from 20 to 35%) by weight of calcium sulfate and, optionally, up to 10% (generally from 1 to 10%) by weight of silica. If necessary, it is possible to subject an industrial dry residue to an enrichment process in order to achieve these optimum contents. The absorbent bodies in accordance with this embodiment of the invention have a good capacity for absorbing acidic liquids, and they are especially quite suitable for the absorption of liquid animal excrements, especially those of livestock and pets. They moreover constitute a means of enhancing the value of an industrial waste, which constitutes an advantage which is both economic and environmental. The absorbent body according to the invention finds both applications in industry and domestic applications. In industry, it can in particular serve for cleaning industrial premises or for absorbing liquids accidentally spilled on the ground. An example of such an application is the absorption of a liquid accidentally spilled on a road following a road accident. The invention therefore also relates to the use of the absorbent body according to the invention for absorbing a liquid on the ground. The absorbent body according to the invention has proved especially suitable for the absorption of liquid animal excrements, mainly urines. The invention therefore also relates to a litter for animals, which comprises an absorbent body inj accordance with the invention. By comparison with the known litters described above, the litter according to the invention combines a combination of advantageous properties, among which are a low apparent volume weight, a high mechanical strength, sufficient to withstand crushing under the weight of an animal and a high capacity for absorbing liquid animal excrements, without forming slurry. Moreover, when they are made wet by animal excrements, they do not adhere to the ground, which constitutes an advantage for their evacuation after use. The litter according to the invention is suitable for livestock, poultry and pets. It is equally suitable for big livestock (bovines, horses), small livestock (ovines, porcines) and poultry (chickens, ducks, geese, turkeys, for example). The litter according to the invention is especially suitable for pets, especially cats and small rodents. The benefit of the •invention will appear during the following description of a few trials carried out with absorbent bodies. In the trials of which the description follows, a slurry obtained from the distillation of a mother liquor from the manufacture of sodium carbonate by the aqueous ammonia process was used. The composition of the slurry, after washing with water in order to remove the water-soluble materials therefrom, is mentioned in table 1 below. Table 1 (Table Removed) This slurry served for the manufacture of a few absorbent bodies, which are examined in the trials of which the description follows. First series of trials (in accordance with the invention) Two samples of the slurry obtained above were collected. To each sample, there were added dry cellulosic fibers (obtained from the removal of fiber from paper) , and water in a quantity adjusted so that the aqueous mixture obtained contains from 300 to 500 g of water per kg. It was treated in a mixer in order to obtain an extrudable homogeneous body. The composition of the two slurry samples, supplemented with fibers, is mentioned in table 2 below. Table 2 (Table Removed) On passing through an extruder, each sample was converted to a series of filaments, which were subjected to sufficient drying in order to remove all the water. The dry product recovered from the drying was subjected successively to grinding and to screening, from which an absorbent body in accordance with the invention was recovered. The apparent volume weight of the two absorbent bodies obtained was measured and they were additionally subjected to a water absorption test. In order to carry out the water absorption test, 10 g of water were introduced into a vertical cylindrical chamber having an inner diameter of 90 mm and the absorbent body was gradually poured therein until compete absorption of the water was obtained. The absorbent power of the absorbent body is defined by the formula: (Formula Removed) A denotes the absorbent power of the absorbent body, M denotes the quantity of water used, and P denotes the weight of the absorbent body. The volume weight and the results of the absorption test are reproduced in table 3 below. Table 3 (Table Removed) Second series of trials (not in accordance with the invention) Two other samples of the slurry described above were used. A first sample was treated as it was, as described in the first series of trials, but without adding fibers or other additives thereto. 14% of bentonite was added to the second sample. The compositions of the two samples (numbered 3 and 4) are presented in table 4 below. Table 4 (Table Removed) The apparent volume weight of the absorbent bodies obtained was measured and they were subjected to the water absorption test described above. The results are presented in table 5 below. Table 5 (Table Removed) Comparison of the results of table 3 (absorbent bodies in accordance with the invention) with those of table 5 (absorbent bodies not in accordance with the invention) shows the improvements provided by the invention as regards- the volume weight of the absorbent body and its water absorption capacity. claim: 1. An absorbent body intended for absorbing liquids comprising a powder of an inorganic material characterized in that the inorganic material comprises at least one calcium compound, a dry residue of the distillation of an effluent mother liquor from an aqueous ammonia soda factory and is mixed with vegetable fibres wherein the said body comprises at least 5% by weight of vegetable fibres and more than 30% by weight of calcium compound. 2. The absorbent body as claimed in claim 1, wherein the calcium compound essentially consists of ground limestone. 3. The absorbent body as claimed in any one of claims 1 and 2, which comprises from 70 to 85% by weight of the calcium compound and from 15 to 30% by weight of vegetable fibers. 4. The absorbent body as claimed in any one of claims 1 to 3, wherein the powder of inorganic material has a mean diameter of 0.1 to 10µm. 5. The absorbent body as claimed in any one of claims 1 to 4, wherein the powder of inorganic material optionally comprises a maximum of 5% by weight of clay. 6. The absorbent body as claimed in claim 5, which comprises from 60 to 90% by weight of calcium compound, from 5 to 35% by weight of vegetable fibers and from 0 to 5% by weight of clay. 7. An absorbent body as claimed in any one of claims 1 to 6 as and when used as a litter for animals.

Documents:

1376-DELNP-2003-Abstract-(05-12-2008).pdf

1376-DELNP-2003-Abstract-(18-12-2008).pdf

1376-delnp-2003-abstract.pdf

1376-DELNP-2003-Cancelled Claims-(05-12-2008).pdf

1376-DELNP-2003-Claims-(05-12-2008).pdf

1376-DELNP-2003-Claims-(18-12-2008).pdf

1376-delnp-2003-claims.pdf

1376-DELNP-2003-Correspondence-Others-(05-01-2009).pdf

1376-DELNP-2003-Correspondence-Others-(05-12-2008).pdf

1376-DELNP-2003-Correspondence-Others-(18-12-2008).pdf

1376-delnp-2003-correspondence-others.pdf

1376-DELNP-2003-Description (Complete)-(05-12-2008).pdf

1376-DELNP-2003-Description (Complete)-(18-12-2008).pdf

1376-delnp-2003-description (complete).pdf

1376-DELNP-2003-Form-1-(05-01-2009).pdf

1376-DELNP-2003-Form-1-(05-12-2008).pdf

1376-DELNP-2003-Form-1-(18-12-2008).pdf

1376-delnp-2003-form-1.pdf

1376-delnp-2003-form-13-(05-01-2009).pdf

1376-delnp-2003-form-18.pdf

1376-DELNP-2003-Form-2-(05-12-2008).pdf

1376-DELNP-2003-Form-2-(18-12-2008).pdf

1376-delnp-2003-form-2.pdf

1376-DELNP-2003-Form-3-(05-12-2008).pdf

1376-delnp-2003-form-3.pdf

1376-delnp-2003-form-5.pdf

1376-DELNP-2003-GPA-(05-12-2008).pdf

1376-delnp-2003-gpa.pdf

1376-delnp-2003-others-correspondence-others(18-12-2008).pdf

1376-delnp-2003-others-document(18-12-2008).pdf

1376-DELNP-2003-Others-Document-(05-12-2008).pdf

1376-delnp-2003-pct-101-(18-12-2008).pdf

1376-delnp-2003-pct-409.pdf

1376-DELNP-2003-Petition-137-(05-12-2008).pdf