Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28C—PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28C1/00—Apparatus or methods for obtaining or processing clay
  • B28C1/003—Plant; Methods
  • B28C1/006—Methods
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28C—PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28C1/00—Apparatus or methods for obtaining or processing clay
  • B28C1/02—Apparatus or methods for obtaining or processing clay for producing or processing clay suspensions, e.g. slip
  • B28C1/06—Processing suspensions, i.e. after mixing
  • B28C1/08—Separating suspensions, e.g. for obtaining clay, for removing stones; Cleaning clay slurries
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28C—PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28C1/00—Apparatus or methods for obtaining or processing clay
  • B28C1/10—Apparatus or methods for obtaining or processing clay for processing clay-containing substances in non-fluid condition ; Plants
  • B28C1/14—Apparatus or methods for obtaining or processing clay for processing clay-containing substances in non-fluid condition ; Plants specially adapted for homogenising, comminuting or conditioning clay in non-fluid condition or for separating undesired admixtures therefrom
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28C—PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28C7/00—Controlling the operation of apparatus for producing mixtures of clay or cement with other substances; Supplying or proportioning the ingredients for mixing clay or cement with other substances; Discharging the mixture
  • B28C7/02—Controlling the operation of the mixing
  • B28C7/022—Controlling the operation of the mixing by measuring the consistency or composition of the mixture, e.g. with supply of a missing component
  • B28C7/024—Controlling the operation of the mixing by measuring the consistency or composition of the mixture, e.g. with supply of a missing component by measuring properties of the mixture, e.g. moisture, electrical resistivity, density
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P40/00—Technologies relating to the processing of minerals
  • Y02P40/60—Production of ceramic materials or ceramic elements, e.g. substitution of clay or shale by alternative raw materials, e.g. ashes

Definitions

• the present invention relates in general and more particularly to a method for producing a working mass for heavy clay products, in particular clinker, masonry, roof tiles
• Main components form are there usually mined in the open pit. Special aggregate clays and other additives required to produce the operating mass from which the final products are formed can be transported from greater distances to the production facility.
• the mined raw materials are stored in layers on large heaps of raw materials (up to 300,000 m 3 ). These heaps are then broken down again perpendicular to the course of the storage layers to better mix the raw material and to compensate for compositional variations.
• the raw material warehouses also serve as buffers in order to ensure uniform production regardless of weather and seasons.
• the preparation and compilation of raw materials represents the core process in which the
• shaping is enriched with water or steam in order to obtain a plastically mouldable mass.
• the material then takes on its final form.
• coarse ceramics predominantly extruders or extruders, possibly with upstream mixers, are used for this purpose.
• the final press moisture is adjusted by means of water or steam.
• the operating mass is stiffened by applying vacuum, compacted by means of screw shafts and finally extruded through a mouthpiece.
• the optimum moisture content (percentage of water in the working mass) is between 19% and 24% ana.
• the extruded clay strand is cut into moldings and these are possibly in a further pressing process in its final form (eg in the production of roof tiles).
• the moisture is reduced to a value between 1% and 3%, so that they are not destroyed in the subsequent firing process.
• the moldings are heated at process temperatures of up to 130 ° C and dried.
• the so-called green compacts are heated at a temperature between 900 ° C (large block brick) and max. 1200 ° C (clinker) fired.
• the tunnel kilns used are operated continuously and operate on the principle of a countercurrent heat exchanger.
• the kiln undergoes a defined increase in temperature from the heating zone (kiln inlet) to the maximum temperature in the firing zone and a temperature drop to the ambient temperature in the cooling zone (kiln exit).
• This so-called firing curve - characterized by the heating and cooling rate, the firing temperature and the holding time - is decisive for the product properties. It is determined empirically depending on the respective raw material composition and the properties of the operating mass. Therefore, the processing of the operating mass, which defines the raw material composition, is a core process to ensure consistent product characteristics and to minimize quality losses caused by variations in composition of the operating mass.
• metering box feeders are usually used with a large-volume filling box, which are filled with the various raw and aggregates. From the stuffing box, the material passes onto a conveyor belt which presses the material against a reel or a slider. The speed of the belt, the position of the slider and / or the speed of the reel thereby determine the amount of raw material which is dropped onto a central collecting conveyor belt.
• Different box feeders are required for different main raw materials.
• Other dry, free-flowing raw materials and aggregates can also be metered with the aid of compressed air or via screw conveyors. be guided. This resulting mixture of operations is formed from the supplied proportions of different task devices.
• the production mixture must first be comminuted.
• the roller principle uses two counter-rotating rollers, one with a smooth surface (smoothing roller) and one with a thread (screening roller).
• the thread peels larger foreign bodies out of the raw material conveyed through the nip and carries them out via the thread grooves (screw thread). Smaller foreign objects are drawn into the nip and further crushed there.
• the raw material is forced through sieves with screws. So a clay cleaner presses it with a screw, the raw material through a rotating screen basket with a slot perforation and thereby promotes foreign matter, which can not pass the slot perforation, always on to the top of the conical sieve and carries it there at the Sieb- or Schneckenspitze by a Opening off.
• the production mixture is processed in continuous mixers (single-shaft or twin-shaft mixers) to a homogeneous molding compound, which has as far as possible a constant chemical composition and uniform physical properties. Uneven properties may cause undesirable stresses or even cracks on drying and firing.
• the method of moisturization outlined above reaches its limits very quickly, especially when raw materials with a high moisture content (moisture content from 21% ana, depending on the type of product)
• Raw material should be processed.
• Such over-moist raw materials are very sticky and can no longer be precisely and continuously metered via the usual box feeders, since the discharge particles only convey in bulk and agglomerating caking at the transfer of conveyor belts clogs the chutes. Also, the usual methods and devices for crushing such as roll crushers and edge mills no longer work.
• the continuous metering is also very difficult because it comes to dome formation in the box loader bodies.
• the discharge belts running underneath go through, if necessary, empty.
• the raw material dome breaks down.
• the material gets impact- trough or bangs on the discharge conveyor and can not be precisely metered.
• the raw material composition fluctuates and the subsequent process engineering processes have to be adapted to different operating mixtures.
• Very moist raw material also causes problems in particular if it is to be frozen in areas with cold and long winters and processed as iced raw material.
• the conventional box feeders are not suitable for "dry" icy clay chunks (blockage, wear, operational damage, machine breakage) and, on the other hand, high raw material losses can occur if iced agglomerations are separated out as stones.
• the present invention provides a method for producing a bulk material for heavy clay products, in particular clinker, masonry and roof tiles, comprising: giving raw materials for the operating mass in a ball mill, processing the raw materials in the ball mill, providing and processing the Operating mass in a stirred tank, drying and storing the operating mass in a drying storage system, discharging the stored in the drying storage system operating mass by means of a mechanical conveyor and supplying the operating mass to a molding plant.
• Another aspect relates to a drying storage plant (Sprühmaukturm), which is designed as a spray tower device with a drying zone and a storage zone. Further aspects and features of the present invention will become apparent from the dependent claims, the accompanying drawings and the following description of preferred embodiments.
• FIG. 2 is a schematic representation of a drying storage system according to the invention
• FIG. 3 is a schematic representation of an alternative discharge device for the system according to FIG. 2.
• FIG. 1 illustrates an embodiment of the method according to the invention.
• the inventive method for producing a working mass for heavy clay products is characterized by the fact that instead of the usual process for processing (especially dry and wet processing) here a special wet treatment process comes into effect, in which also high moisture content (higher 21%, in particular higher 25% ana) can be processed.
• the raw materials are poured into a ball mill and there wet treated with the addition of water and plasticizers, depending on the initial moisture of the added Grubentone (eg 30%) is added so much water that a slip or Tonbrei (suspension of solids and water ) is formed (about 40% moisture content ana), the solid constituents of which is comminuted continuously or discontinuously by the grinding media in the ball mill.
• Grubentone eg 30%
• Tonbrei suspension of solids and water
• ball mill also drum mill
• the term ball mill here includes crushing machines aut hi- a rotating grinding drum usually with a horizontally mounted, cylindrical or cylindrical-conical grinding chamber.
• the material is circulated or toppled together with the Mahlkörpem.
• the Zcrminin ceremoniess- or Mahlrial arises by the collision of the grinding media with the intermediate Mahlgut or by their shearing motion against each other during the rotation of the drum.
• metallic grinding media made of steel, chilled cast iron or hard metal alloys. Undesirable iron abrasion can then be separated, if necessary, magnetically or chemically (by leaching).
• Other synthetic grinding media may also be formed of ceramic such as hard porcelain or sintered aluminum oxide.
• the millbase suspension is drawn off and sieved to the desired maximum particle size ( ⁇ 0.4 mm). Larger residual or waste particles (e.g., rock debris, organic contaminants such as wood or roots, etc.) either remain in the ball mill, are further comminuted, or are discarded as the slurry is discharged, or optionally removed upon replacement of the baffles or during cleaning of the ball mill.
• Larger residual or waste particles e.g., rock debris, organic contaminants such as wood or roots, etc.
• the withdrawn Schiicker is provided in one or more stirred tank (s) and further processed.
• additional additives are added to the slurry as needed and the exact moisture content is set.
• Existing pollutants may optionally be precipitated by means of suitable starting materials. Wet spirals can be used to separate certain precipitate products or to specify the particle size distribution.
• the so precisely defined operating mass suspension (slurry) is then reduced in a drying storage system in a spray drying process to an initial moisture content of between 15% and 18% ana (this is about 3% below the optimum press moisture of the respective operating mass).
• the operating mass thus adjusted to the desired humidity is temporarily stored in the drying storage system.
• the thus prepared operating mass is then discharged by means of a mechanical conveyor from the drying storage system and fed to a molding plant.
• the operating mass is dried in the drying storage system in a drying zone and stored in a storage zone.
• the operating mass passes directly into an external storage zone (for example, a swamp shed) where intermediate storage takes place.
• the residual moisture content of the operating mass of the stored operating mass is between 9% and 23%, preferably between 15% and 18% (in each case ana). This initial moisture is particularly suitable for subsequent shaping.
• a mechanical conveying device is provided at the bottom of the storage zone, which discharges the operating mass from the storage zone and supplies it to the shaping installation.
• the arrangement on the ground allows a uniform from promoting the already partially compressed operating mass with the desired properties.
• the overlying storage zone serves as an operating mass buffer that can be assembled and disassembled during operation (e.g., interrupting the drying process with a change in slurry feed from different stirred tanks) without interrupting the continuous supply of operating material to the forming operation.
• this mechanical conveyor is designed as a discharge screw, as a collection plate and / or as a collection tape. These facilities allow a precisely metered continuous discharge of the operating mass from the drying storage system.
• stirred tank can be endeert in the drying storage system, and filled another stirred tank and the operating mass suspension contained therein (slurry) are processed.
• the drying storage system comprises a spray tower device which sprays the suspension into a drying zone, which passes dried into a storage zone arranged therebelow.
• the desired drying and intermediate storage can be realized in a particularly simple manner.
• the illustrated method comprises a number of sub-processes, some of which run in batch mode, that is to say batchwise (area A), and those which run continuously, ie in flow mode (area B).
• the raw materials 1 and 2 additives are filled with wheel loaders 3 in feeder 4.
• Raw materials 1 are different clay blends and sand.
• Additives 2 are e.g. water-soluble additives such as e.g. Manganese granules, which serve to make color changes or product-specific adjustments of the operating mass.
• the proportions by weight of the individual raw materials and additives 1, 2 are determined by means of scales (weighing bridges) so that the components filled in the feeder 4 form the correct mixture in proportion and quantity.
• additives 2 which are obtained in smaller quantities, via other metering devices (for example screw conveyors).
• At least two feeders 4 are provided, which are filled alternately.
• the raw material mixture 5 present in the feeder 4 is conveyed by means of a hydraulic pusher or else by other suitable means, such as e.g. through snails,
• the actual wet processing begins.
• the raw material mixture 5 with a water content or moisture content of more than 20% is additionally added to water 7, which is used to improve the process. It can also be heated. Hot water 7 is added in particular when very cold or partially frozen raw materials 1 are to be processed in the wet ball mill 6.
• the filled raw materials and additives 1, 2 are mixed with the water 7 and comminuted by the grinding media (eg balls), so that a slurry suspension is formed, which has a water content of 30 to 60% and the essential process components to the desired Grit size spectrum ( ⁇ 0.4 mm) are crushed.
• the slurry suspension in the wet ball mill 6 can be supplemented with further additives such as flux 9 (plasticizers) and organic fuels 10, which later also serve as a porosity agent.
• the slip suspension 5 is filled via a sieve device 11 into a stirred tank 12.
• organic impurities such as wood and uncrushed raw material components 14 are deposited and removed.
• the raw material components 14 can be filled again for further comminution in the wet ball mill 6 and processed there with a further mixture of raw materials 5.
• the slip suspension 5 is further processed and defined. Firstly, by removing further undesired constituents (for example precipitation by means of suitable starting materials). And second, by adding more chemical additives and constituents 16. The exact quantities required for this purpose can be precisely determined by analyzes of the slip suspension 5.
• two stirred tank 12 are provided, which are alternately fed from the wet ball mill 6. In this way, initially different raw material mixtures 5 in the respective stirred tank by adding appropriate additives (water 7, organic fuels 10, chemical additives 15, 16 Tontscher) are accurately mixed. Likewise, batchwise different impurities occurring depending on the composition of the slurry slurry 5 can be deposited.
• the slip suspension 5 is pumped out of the stirred tank 12 into a drying device, which is designed here as a drying storage system 17 (spray tower tower).
• the drying storage system 17 also serves to convert the previously batch process into a continuous process (flow process).
• the slip suspension 5 is subjected to a spray-drying process in the upper region (drying zone 20). It is atomised in a hot gas stream 24, which extracts a certain amount of water from the individual droplets of the slurry, which, together with the warm air, is removed via a hot air stream. deduction of Annex 17 is withdrawn.
• the partially dried slurry particles fall under gravity into a storage area (storage zone 40) where the operating mass 50 is accumulated and increasingly compressed.
• This Sprühmaukturm 17 combines the functions of a spray tower and a so-called. Swamp House.
• the operating mass 50 is continuously discharged and conveyed into a likewise continuously operating mixer 18, where the mass 50 is finally processed, in the water 7 or steam and other additives 2, 9, 10, 15, 16 can be added. From the mixer then passes the finally processed operating mass 50 in the extruder 19 for shaping.
• Fig. 2 shows an embodiment of a suitable drying storage system 17, which as
• Sprühmaukturm is formed. It has a drying zone 20 in its upper area and a storage zone 40 in the lower area.
• the slip is supplied via a ring line 21 extending at the edge of the system in the drying zone 20, at which a plurality of spray nozzles 22 are arranged, through which the slurry slurry 5 is sprayed upwards and inwards into the drying zone 20 at a pressure of approximately 20 bar.
• a hot gas supply 23 which blows a hot gas stream 24 cyclonic into the drying zone 20.
• the hot gas stream 24 can be composed of furnace exhaust air and, if appropriate, also of combustion exhaust gases, or be produced by suitable heating units.
• the present in the hot gas stream 24 Schlickertröpfchen moisture is removed in the desired manner and enriched with particles of the operating mass hot gas (hot air / gas stream 240) is withdrawn in the lower part of the drying zone 20 under a baffle hood 25 and out of the drying zone 20. There, the gas stream 240 in a cyclone 26, the operating mass particles 55 are withdrawn, which can be used and possibly the operating mass 50 are fed again.
• the dried-on slurry droplets or granule parts fall from the drying zone 20 into the storage zone 40, which has approximately the same or greater diameter (eg, conically widened downwards) as the drying zone 20.
• a Radiomassenstock 50 whose density increases towards the bottom. Since the residual moisture (15% -18%) is relatively high, forms at the bottom of the storage zone 40 (the bottom of the drying storage device 17) is a relatively compact and homogeneous operating mass layer 51, which additionally supports the moisture balance and the homogenization.
• FIG. 3 shows an alternative discharge device 143, which can discharge the operating mass layer 51 in the sole of the storage zone 40 over the entire cross section of the drying storage system 17.
• the operating mass 50 rests on a support plate 143a, over which one or more conveyor belts 143b run.
• lateral slots 145 the operating mass 50 then passes from the bottom of the operating mass layer 51 from the storage zone 40 and can be further processed.
• the discharge can also take place via a rotating disk, optionally with conveying grooves or ribs

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• Chemical & Material Sciences (AREA)
• Dispersion Chemistry (AREA)
• Preparation Of Clay, And Manufacture Of Mixtures Containing Clay Or Cement (AREA)

Applications Claiming Priority (2)

Publications (1)

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Cited By (3)

Citations (2)

Family Cites Families (3)

• 2012
  • 2012-02-15 DE DE102012101202A patent/DE102012101202A1/de not_active Ceased
• 2013
  • 2013-02-14 WO PCT/EP2013/052923 patent/WO2013120925A1/fr not_active Ceased

Patent Citations (2)

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