A METHOD OF PRODUCING A LIQUID-ABSORBING GRANULATE AND ALSO A LIQUID-ABSORBING GRANULATE MADE BY THE METHOD

Abstract: By the method of producing a liquid-absorbing granulate, the basic material which may be clay and/or diatomite is admixtured a fibre material such as cellulose filament. By this it has turned out that among other things till now unutilized clay deposits may be used for the purpose and also that you may omit to burn the granulate which otherwise is necessary as regards the well-known granulate of moler which contains no appreciable ashes. It has turned out that recycling paper may be used as a suitable and cheap fibre material. A liquid-absorbing granulate produced according to the invention consists of a basic material such as clay, under here moler, sepiolite, attapulgite, kaolin or mixtures of these or diatomite and a fibre material such as cellulose filament, e.g. wood fibre cellulose, straw cellulose fibres, hemp cellulose fibres, mineral wool fibres, ceramic fibres, plastic fibres, woolastonite fibers.

Description: A method of producing a liquid-absorbing granulate and also a liquid-absorbing granulate made by the method. The invention relates to a method of producing a liquid- absorbing granulate, especially used for cat litter and for shop floors to absorb oil, and also a liquid-absor¬ bing granulate produced according to the method. There exists knowledge of a granulate used as above which is based on moler under +19. In the moler deposits there are more than 200 ' ash layers in all, of which the 179 thickest and easiest recognizable ones are numbered from +140 to -39. The ash layers are irregularly distributed down through the 55-60 m of moler deposits. There is an ash section of approx. 20 in the upper part of the mo¬ ler, consisting of 118 tightlying ash layers (No. +1 to +118). At the very top there is 5-10 m moler with only 22 ash layers, viz. +119 to +140. The nethermost appr. 30 of deposits only have 39 very scattered ash layers, -1 to -39. The industies are only interested in that part of the moler which is poorest in ashes, meaning the part be¬ ing below the ash layer +19- The moler deposits above +19 have hitherto been without interest because of their large amount of ash layers. There is a well-known method of producing a granulate which is used for cat litter and floor litter and which is based on moler below +19. By that method the raw moler and re-cir¬ culated dust are led to a combined grinding and crushing a- chine where it is hacked to pills of a size of 0-13 mm, and next it is led to dehydration at 100 C- After dehydration a fractionation takes place, by which the granulate with a grain size of 2^—10 mm continues on to be burned in a rotary kiln. After that another fractionation takes place by which approx. 10% of dust appears as a residue. The final product next continues on to the packing or storing facilities. By the fractionation which is carried out after the dehrydration the grains with a grain size of more than 10 mm are conveyed to a crusher and from there back to the fractionation. Grains with a grain size under 2 mm are mixed into the moler as re-circulated dust. From the description of the Danish patent No. 127 410 there is a well-known method of producing an absorbing granulate of moler, but that method gives a large waste in the form of dust which cannot be reused. Furthermore the granulate made by that method does not possess quite a satisfactory hardness and it may also have a tendency of disintegrating i water. The granulate must fulf l.certain conditions as to the abili¬ ty to absorb, to strength, to set-off and to colour. The ab¬ sorbing ability for the given purpose must alltogether be as good as possible. It is also essential hat the grains pos¬ sess a certain compression strength so that they are able to bear the pressures which occur during storage and shipment and also when used as floor litter, so that it will not be crushed under a foot's load. As to set-off, this to some extent will depend on the colour, as a neutral colour as grey or golden allows for more set-off than does the characteristic reddish colour of moler. The purpose of the invention is to indicate a method of pro¬ ducing a granulate which fulfils the above conditions and which enables the use of another substance than moler under +19. In connection with the invention it has turned out that if the raw clay is mixed with a fibre substance such as cellu¬ lose filament, by way of example wood fibre cellulose, straw cellulose fibres, hemp cellulose fibres, mineral wool fibres. ceramic fibres, plastic fibres (polypropylene) , glass fi¬ bres, wollastonite, for the purpose you may use deposits of clay which have not yet been utilized and diatomite and still obtain a granulate with properties which are compar- able with those of a granulate made traditionally from mo¬ ler occurences under +19. Besides it appears that the well- known moler granulate will obtain materially better proper¬ ties when some fibre substance is mixed with it. Thus you may use thetill now un-utilized moler deposits above +19. Even other sorts of clay, such as sepiolite, attapulgite, kaolin, brick-clay etc. may be used together with diatomite. A cheap material available is recycling paper and cardboard. A method of producing a granulate going out from moler above +19 and recycling paper is that by which the recycling paper is split up in a paper mill. The split-up paper, the moler above +19 and sifted-out dust from the final product and al¬ so possible large grain sizes separated by the fractionation having passed an extruder are mixed in a kneading machine, from which the mixture is conveyed to the extruder, which makes pills out of the substance. After extrusion a fractio¬ nation may take place, as already mentioned. Next the pills are dried and the drying may prospectively take place in a rotary kiln, in a drying conveyor or by air-drying, of which the last-mentioned has proved to be the best method. As ear- lier mentioned a fractionation takes places after the drying and by that the dust is sifted out and brought to the mixer. After that the finished material will be taken to the pack¬ ing. Compared with the production of the well-known granulates it should be notified that the production according to the in¬ vention is energy-saving for that reason alone that easier accessible clay deposits may be utilized and - which is es¬ sential - that the burning of the pills may be omitted. Be- sides the method gives a larger profit, as the dust which is sifted out by the well-known method as a waste may be returned into the mixture. The procedure just described is not exclusively meant for producing the granulate based on moler above +19 and recycling paper, but it is also applic¬ able for other basic materials. As to admitting the fibres, this must be adapted to the material in speech; thus mine¬ ral wool fibres and ceramic; fibres are dispersed in water before they are admitted. On the following pages the invention will be illustrated more explicitly by some examples. Example 1 A granulate consisting of 90% moler below +19 and 10% split- up paper is produced. (The indicated percentages are based on dry weight) . The paper is split up by means of a stirring propeller in water. The paper pulp and the moler are mixed in a agitator mixer while anadequate amount of water is ad¬ ded, i.e. until the mixture is extrudable. The mixture is extruded and the granulate is dried at 110 C. The granulate made in this manner has the following charac¬ teristics: Density: 387 kg/m 3 estLnghouse oil 64.05% water: 99.65%, The Mop-test: before the test 99.86 g over 1.19 mm after the test 79.38 - - 1.19 - 79.49% granulate - 1.19 - after the test It should be observed that the granulate does not disinte- grate in water. "SURET Example 2 To enable a comparison we have made a granulate like the one in example 1, but without adding paper. The granulate produced by that has the following character- 5 istics: Density: 521 kg/m 3 estinghouse oil: 57.45% water 113.40% The Mop-test: Before the test 90.30 g over 1.19 mm 10 after the test 16.39 - - 1.19 - 18.13% granulate - 1.19 - after the test It should be observed that the granulate disintegrates in wa¬ ter. Example 3 15 A granulate consisting of 90% moler above +19 from which the ashes have been sifted out as indicated in the description of the Danish patent No. 127 410 and 10% split-up paper is produced. The production method is the same as for example 1. The granulate produced has the following characteristics: 3 20 Density: 451 kg/m Westinghouse oil: 51.95% water: 60.20% The Mop-test: Before the test 99.79 g over 1.19 mm after the test 58.93 g - 1.19 - 25 59.07% granulate - 1.19 - after the test. It should be observed that the granulate does not disinte¬ grate in water. Example 4 To enable a comparison we have made a granulate like the one in example 3, but without adding paper. The granulate produced by that has the following charac¬ teristics: 3 Density: 475 kg/m Westinghouse oil: 59.95% - water: 66.60% The Mop-test: Before the test 98.16 g over 1.19 mm after the test 1.26 - - 1.19 - 1.28% granulate - 1.19 - after the test. It should be observed that the granulate disintegrates in water. Example 5 A granulate of 90% moler above +19, without sifting out the ashes, and 10% split-up paper is produced. The production method is the same as for example 1. The granulate produced has the.following characteristics: 3 Density: 475 kg/m Westinghouse oil: 48.35% water: 55.15% The Mop-test: Before the test 98.31 g over 1.19 mm fc. after the test 45.95 - - 1.19 - 46.74% granulate - 1.19 - after the test. It should be observed that the granulate does not disinte- 5 grate in water. Example 6 For comparison a granulate of moler like that of example 5 is made, but no paper is added. The granulate is dried at 150-250°C in a rotary kiln. 10 The granulate produced has the following characteristics: 3 Density: 644 kg/m Westinghouse oil: 51.80% - water: 108.40% The Mop-test: Before the test 77.40 g over 1.19 mm 15 after the test 28.74 - - 1.19 - 37.13% granulate - 1.19 - after the . test. It should be observed that the granulate disintegrates slightly in water. 20 Example 7 A granulate like the one in example 3 is made, however, the paper is replaced by 10% straw cellulose. The material produced has the following characteristics: Density: 485 kg/m 3 Westinghouse oil: 55.81% 8 Westinghouse water: 67.00% The Mop-test: Before the test 99.52 g over 1.19 mm after the test 81.39 g - 1.19 - 81.78% granulate - 1.19 - after the test. It should be observed that the granulate does not disinte¬ grate in water. O PI

Claims: Claims 1. Method of producing a liquid-absorbing granulate which especially is used as cat litter and floor litter and c h a r a c t e r i z e d b y the material being admix- tured a fibre material such as cellulose filament, by way of example wood fibre cellulose, straw cellulose fibres, hemp cellulose fibres, mineral wool fibres, ceramic fibres, plastic fibres (polypropylene) , glass fibres, wollastonite fibres before the pulp is moulded into pills. 2. A method as claimed in Claim 1, c h a r a c t e r ¬ i z e d b y the fibre material being split up e*g. by being dispersed in water before it is mixed with the raw clay or the diatomite, and possible sifted-out dust from the end product and large grain sizes are admixtured during the production, after which the pulp is moulded into pills, which next are dried, e.g. in a rotary kiln of the co-cur¬ rent type, in a conveyor-drier or open-air drier, after which the material is packed, possibly after a preceding sifting-out of the dust. 3. A liquid-absorbing granulate, especially being used as cat litter and floor litter, c h a r a c t e r i z e d b y the fact that it consists of a material such as clay, under here moler, brick-clay, sepiolite, attapulgite, kao¬ lin or mixtures of these, or diatomite and a fibre material, such as cellulose filament, e.g. wood fibre cellulose, straw cellulose fibres, hemp cellulose fibres, mineral wool fibres, ceramic fibres, plastic fibres, glass fibres, wol¬ lastonitefibres. 4. A granulate according to Claim 3, c h a r a c t e r - i z e d b y the fact that the fibre material makes out a percentage by weight between 5 and 25.

Inventors: BOLL JOERGEN, JULH LEO FISCHER, BOLL, JOERGEN, JULH, LEO, FISCHER
Applicants: SKAMOL SKARREHAGE MOLERVERK AS, SKAMOL SKARREHAGE MOLERVAERK A/S
Application year: 1983
Main classification: C09K3
IPC codes: A01K1