CS9100899A2 - Method of substrate production for plants - Google Patents

Abstract

Disclosed is a process for the production of a porous granulated ceramic material with a pore size greater than 1 mm, in which clay is mixed with calcite, quartz sand, dolomite, feldspar, fireclay, kieselgur and/or sepiolite as aggregate material, with water, with a fluidizer and with a surface-active agent and foamed in the usual way. The foamed mixture is subsequently moulded, if required, to form clay mouldings, the mouldings dried at a temperature between room temperature and 200 DEG C, the dried mouldings crushed and sieved, if required, the sieving fines being returned to the starting mixture, and finally the mouldings or crushed mouldings within a given particle-size range roasted at a temperature above 600 DEG C. The porous material thus produced is intended for use as a plant substrate. The starting materials are added to the mixture in given proportions and the mouldings or crushed mouldings with a residual moisture content of 5-25 % are placed in a preheated oven and roasted at a given temperature in the range between 750 and 1050 DEG C. This invention also includes the subsequently manufactured plant substrate, as well as the new use for this product.

Description

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Technical field

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BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a plant substrate comprising clay, in particular a porous ceramic granulate having a pore size of less than 1 mm such that clay, limestone, quartz, dolomite, feldspar, lignite, infusion clay and / or piolite are mixed. an additive, further water, a liquefying agent and a wetting agent, and this mixture is foamed in a dispersing device at a pressure of at least n 0.03 MPa of supplied air under pressure and at room temperature to 95 ° C, maintaining up to the exit of the nozzle and optionally adding an agent to prevent the liquefying agent from effecting the production of a highly viscous, thixotropic and stable foamed suspension, whereupon the mixture, if desired, is foamed into clay moldings which are dried at a temperature of room temperature to 200 UC, the dried molding bodies are optionally crushed, with a fine fraction being introduced after sifting into the outlet mixture, whereupon the clay bodies or the comminuted shaped clay moldings are chosen size of the particles fired at a product temperature inside alespoň600 DEG C. The invention also relates to the use of these materials as substrates spring plants and these substrates as such.

DE 37 05 204 discloses a process for the production of similar products in which a ceramic granulate is obtained which is suitable as a substrate for growing plants. This material has very good physical and chemical properties. Despite these advantageous properties. it would further be desirable to further improve the material, particularly in terms of its internal purity.

SUMMARY OF THE INVENTION It is an object of the present invention to further develop the known process in order to further improve the porous structure of the ceramic granulate so that it is even more suitable for use as a plant growing substrate. 2

SUMMARY OF THE INVENTION

According to the invention, this object is achieved by using 25 to 45% by weight of clay, dx > 40% by weight of limestone, quartz sand, dolomite, feldspar, fireclay, diatomaceous earth and / or sepiolite, 20 to 55% by weight of water, 0.1 to 1% by weight. 0% by weight and 0.1 to 1.0% by weight of wetting agent and clay moldings, optionally crushed, with a water content of from 2 to 25%, are fed to a preheated oven at a predetermined internal product temperature of 750 to 1050 ° C.

In a preferred embodiment of the process of the invention, an indirectly heated cylindrical rotary kiln is used in the firing process.

In addition, it is particularly advantageous to transfer the fired product immediately after firing from the kiln to a cooling drum into which, in addition to indirect air cooling, the spray is supplied directly.

The invention also relates to a plant growing substrate obtained by the process of the invention and to the use of this product as a depot carrier for nutrients, fertilizers and / or pesticides.

Surprisingly, it is possible to substantially improve the internal porous structure, as can be demonstrated by uniform distribution of pores with a stable structure and an optimum capillary effect, which is higher than that of products made in a known manner, by precisely selected amounts of starting materials and clay firing conditions of the present invention. From the viewpoint of ceramic processes, this improvement can be expected, in particular it is surprising that improvements in product properties can be achieved by some combination of starting material, water residue in clay mold bodies before firing and choice of baking temperature. A preferred, controlled, rapid cooling of the fired clay bodies by direct spraying of water in the cooling drum to cool the product from 1000 to 60 ° C within a few minutes is to be considered extreme for this ceramic material, so it is wondering that this rapid cooling, which is economically advantageous, has no negative effect on the properties of the final product. Example 400 kg of clay (Uestcruald) with U% of remaining water is placed in a blender together with 200 kg of water and 460 kg of resin containing 5% of water, 4.5 kg of sodium dodecylsulfonate and 2 kg are added sodium polyphosphate, the mixture was stirred for 5 minutes, and the resulting high thixotropic clay slurry was processed into 1 cm diameter strands in the respective apparatus and transferred to a seven-dryer. After the desired residual water content had been reached, the foamed clay material was transferred to a cylindrical mortar to be crushed. The crushed particles of foamed clay are transferred to a sifter and the fraction with a particle size in the range of 1.0 to 5.0 mm is fed to a baking oven and the fraction with particles smaller than 1.0 mm is discharged back to the starting material. The particles in the kiln are heated in a preheated furnace to 750 to 5050 ° C. The fired ceramic product is immediately transferred from the kiln to a cooling drum in which it is cooled indirectly by air and simultaneously sprayed with water. After a few minutes, the cooled product can be fed to the packaging machine.

The materials obtained as described above have the following parameters:

pH value: 7.3 - 7.5 water absorption capacity: 150 - 190% by weight internal surface: 100 - 200 m ^ / g pore diameter: less than 0.0 mm.

The invention has been described on the basis of a preferred embodiment.

It will be appreciated, however, that other combinations of features of the invention may be used as set forth in the specification and claims without departing from the spirit of the invention.

Claims (5)

1. A method for producing a substrate for clay-based plants, in particular a porous ceramic granulate having a pore size of less than 1 mm, such as: the clay, the limestone, the quartz sand, the dolomite, the feldspar, the self-infusing clay and / or the non-epithelium admixtures, the water, the wetting agent and the wetting agent, and the mixture is dispersed in the dispersing device at a pressure of at least 0.03 MPa of air supplied by the vacuum room temperature to 95 ° C, wherein the pressure is maintained until the exit of the nozzle is added and, if desired, an agent preventing the effect of the liquefaction agent is added in the manufacture of the highly viscous, thixotropic and stable foaming suspension, whereupon the mixture or foamed material is processed to dry the shaped bodies which are dried at a temperature of up to 200 DEG C., the dried shaped bodies are optionally crushed, the fines being recycled after sieving to the initial mixture, whereupon the clay shaped bodies or crushed clay shaped bodies with the selected particle size are fired at an internal product temperature of 600 to 1500 ° C to form a material for use as a plant substrate, characterized in that 25 to 45% by weight of clay, 40% by weight of limestone, quartz sand, dolomite, feldspar, fireclay, diatomaceous earth and / or seululite, 20-55% by weight of water, 0.1-1.0% by weight of liquefying agent and 0.1-1.0% by weight of wetting agent and clay moldings, optionally crushed clay shaped bodies with residual content water of 5 to 25 µl is stored in a preheated kiln and fired at a predetermined internal product temperature in the range of 750 to 1050 ° C. 2. A method according to claim 1, characterized in that the combustion process is carried out in an indirectly heated cylindrical baking oven. 6 Method according to claim 1 or 2, characterized in that the fired product is transferred immediately after firing from the kiln to the cooling drum, where it co-cools indirectly through the air and, in addition, is directly sprayed with water. 4. A substrate for growing plants, characterized in that it is produced by the method described in claims 1 to 3. Use of a plant growing substrate according to claim 4, as a depot carrier for nutrients, fertilizers and / or non-pesticides.