MXPA97005933A - Procedure for the production of briquetted and pressed granulates and its - Google Patents

Abstract

The present invention relates to a process for the production of pressed or briquetted granules of carbon black pigments with auxiliary substances, characterized in that: a) one or more pigments of carbon black are mixed with one or more processability promoting adjuvants , b) this mixture is subjected to a pressing or briquetting step, c) this pressed or briquetted product is crushed, d) the crushed product is separated into two or more fractions, e) the fraction in which at least 85% of the particles is greater than 80 um, preferably greater than 100 um, or is between 80 and 2,000 um, preferably between 100 um and 1,000 um, is extracted as a product and, if necessary, is rounded off in another stage; fraction or fractions are excluded from the process or recycled

Description

Procedure for the production of pressed and pressed granules and their use DESCRIPTION OF THE INVENTION The present invention relates to a process for the production of pressed and pressed granules and to their use in the dyeing of construction materials such as concrete and asphalt and of organic media such as lacquer systems, plastics and coloring pastes. The processing of pigment granules for the achievement of optimum color printing requires grinding of the pigments into primary particles. The ground materials originated with it raise a lot of dust and due to the fineness of its particles tend to adhesion and sticking in the dosing devices. Therefore, for toxicologically hazardous substances, measures must be found in the processing to avoid a threat to man or the environment due to the dust that originates. But also for harmless inert substances, such as iron oxide pigments, the avoidance of dust contamination is increasingly desired by the market. The avoidance of dust and the improved dosage due to the best flow properties, for the achievement of a qualitatively homogeneous color printing in the use in building materials and organic media is, therefore, the objective in the handling of pigments. This objective is achieved to a greater or lesser extent by applying granulation procedures to the pigments. This generally indicates granulation processes by agglomeration or spraying. Compaction processes are less suitable to date because of the limited dispersibility of the granules originated therewith. In the use of pigment granules, two opposite properties are basically required of the market pigments: mechanical stability of the granulate and good dispersibility properties. The mechanical stability is responsible for the good transport properties both in the transport from the manufacturer to the user as well as in the good dosage and flow properties in the use of the pigments. It is favored by high shear stresses and depends, for example, on the amount of binder or, also, on the pressure of the press in the molding. On the other hand, the dispersibility is influenced by a good milling before the granulation (wet and dry milling), the mechanical energy in the incorporation (shear stresses) and the dispersion aids, which immediately reduce the adhesive forces in the granulate dry by incorporation into a medium. In any case, the application of large quantities of dispersion aids to pigments is limited due to the additive / pigment cost ratio. In addition, a higher proportion of additive favors a respective decrease in the coloring power or the behavior in the dispersion. Since the oscillations of the coloring power are generally below ± 5%, the use of additives is also limited, even when they act simultaneously as adhesion promoters and dispersion aids. The additives must also not adversely modify the properties of use of the final product, such as construction materials, plastics and lacquers, for example the mechanical stability or the setting behavior in the concrete or the resistance to compression or abrasion resistance. in the asphalt, the mechanical stability or the resistance in plastics and the elastic properties in elastomers (polymers). According to the state of the art, granulation by spraying (spray drying on a disk or nozzle) and granulation by agglomeration (mixer, fluidized bed granulator, plate granulator or granulator) are considered as production methods for pigment granules. drum). The granulation of spray drying starts from suspensions of pigments using binders. The corresponding procedures are described in various patents. In them water-soluble binders are used. A) Yes, DE-A 3619363, EP-A 0268645 and EP-A 0 365 046, are based on organic substances such as, for example, lignin sulphonates, condensates of formaldehyde, gluconic acids, sulphated polyglycol ether, whereas according to DE-A 3 918 694 and US-A-5 215 583 are based on inorganic salts, such as, for example, silicates and phosphates. A combination of granulation by spraying and agglomeration has also been described in EP-A 0507046. In DE-A 3 619 363 (column 3, lines 44-47) and EP-A 0 268 645 (column 7, lines 18,19) the application of a compaction procedure is excluded. In this process, by applying pressure, a strong cohesion of the particles is achieved, so that a good transportability is certainly favored, but at the same time also decreased dispereability properties. EP-A 0 257 423 and DE-A 3 841 848 disclose the spray granulation using polyorganosiloxanes as lipophilic, hydrophobic additives. The subsequent hydrophobicizing treatment leads, in spray-granulated products, to a granulate with very good fluidity, but extraordinarily dusty which, moreover, is poorly wettable with water. EP-A 0 424 896 discloses the production of fine powdery fine granules, in a process for obtaining them in known intensive kneaders. In this, a lower content of waxes in combination with emulsifiers and wetting agents is indicated by application of an aqueous dispersion. With this, water contents of 20 to more than 50% are obtained in general. These granules must be dried first and the over- and infrared particles separated. DE-A 31 32 303 discloses granules of inorganic pigments capable of flowing poor in powder, which are mixed with fluidizable binders by the action of heat and granulated by a sieving process with application of sieving aids (pressure). With this, between 10 and 20%, approximately, of the production is presented as a fine component (<0.1 mm). From document EP-A 0 144 940 pigment granules poor in powder form arise, which from filtration sludge with 50% water, approximately, by the addition of 0.5-10% surfactants and, in addition, oil mineral or fluidizing waxes, they are mixed between 50 and 2002C up to the point of lubrication. The process is carried out in intensive kneaders, but eventually it is subsequently granulated and then dried. Water is present in the final product in an amount of 10 to 15%, which is disadvantageous for incorporation into plastics. Other procedures are also limited in their application. The spray granulation, due to the formation of drops, requires the use of suspensions of good aptitude to flow, that is, little viscous. Therefore, in the drying process it is necessary to evaporate a larger amount of water than in a fluidized bed drying which can often be used from highly pressed pigment filter pastes. This leads to higher energy costs. In the pigments previously obtained by calcination, the spray granulation means an additional step of the process with high energy costs. In addition, a more or less large fraction of fine material appears in the spray granulation in the dust filter, which must be recycled back into production. Granulation by agglomeration also often exhibits disadvantages. It can be carried out from pigment powder (in mixers under high turbulence, in fluidized bed processes or also by plate or drum granulation). To all these processes it is common that the requirement of binder is high, most of the time water, so they must be followed by drying as an additional stage of the process. Granules of various sizes are also obtained with this, especially if sufficient binder is not made available for the amount of powder or the current distribution is not optimal. Then, a known fraction of the granulate may become too large while, on the other hand, fractions that are too small and, therefore, still dusty are present. That is why a classification of the granules originated with a recycling of over- and under-dimensioned particles is necessary. The granulation in the dish leads to a wide spectrum of particle sizes of the granulates. Where this is undesirable because of the poor dispersibility of the oversized particles, the granulation process must be followed by intensive personal supervision of the granulation process and the production of the granulate should be optimized by manually controlling the amount of germs. In this, a classification is also usually carried out with recycling of over- and under-dimensioned particles. The processes of extrusion from pastes lead in the drying to relatively solid granulates that because of their size do not guarantee any optimal dispersibility either. DE-A 42 14 195 discloses a process for dyeing asphalt with granules of inorganic pigments in which oils are used as binders. In this, it is a simple granulation process. In DE-A 4 336 613 and DE-A 4 336 612 granules of inorganic pigments are obtained from pigments by mixing with binders, compaction, grinding and granulation. These granules thus obtained are poorly pneumatically driven; there is a lot of dust in the feed, which is undesirable. The purpose of the present patent application was, therefore, to develop a method which avoids the present disadvantages of spray granulation, extrusion granulation or granulation by agglomeration, in its application to inorganic pigments, especially to pigments. of carbon black, and put in place granulates sufficiently stable, dosable, poor in powder, of better dispersibility, as homogeneous as possible, than that of the powders used to date. It was now found that this task can be solved by a combination in several stages of the steps of mixing, compacting, separating and, if necessary, rounded. The object of the invention is a process for the production of pressed or briquetted granules of carbon black pigments with adjuvants, which is characterized in that a) One or more pigments of carbon black are mixed with one or more promoting substances. of the processability, b) This mixture is subjected to a pressing or briquetting step, c) This pressed or briquetted product is crushed, d) The crushed product is separated into two or more fractions, e) The fraction in which at least 85% of the particles are greater than 80 μm, preferably greater than 100 μm, or are between 80 and 2,000 μm, preferably between 100 μm and 1,000 μm, extracted as a product and, if necessary, rounded off in another stage; the other fraction or fractions are excluded from the process or recycled. Prior to step c) the pressed or briquetted product can preferably be separated into two fractions (intermediate stage x), then crushed in step c) the coarse fraction in which at least 85% of the particles are larger than 500 μm , preferably 600 μm, and separate the other fraction, the fine, in step d) separately, or together with, the product of step c), again in two or more fractions. Preferably, the fine fraction of the intermediate stage x) is simply separated into two or more fractions in step d), while the coarse fraction of the intermediate stage x) is ground in step c) and then discharged from the process as product. The intermediate stage x) can preferably be carried out by classification or sieving (mechanical separation). Preferably, screening machines are used. With special preference, the crushed product is separated into two fractions in d), the fine fraction, less than 80 μm, being discharged or recycled to the process, and the coarse fraction, greater than 80 μm, being rounded off, if necessary in another stage. The crushed product can also be separated preferably into three fractions in step d), the fine fraction and the coarse fraction being discharged or recycled to the process, and the intermediate fraction between 80 and 2,000 μm being rounded off, if necessary in another step. special preference between 100 and 1,000 μm, with very special preference between 100 and 500 μm. The granulates preferably exhibit a residual water content of less than 4% by weight, particularly preferably less than 2% by weight. This can be obtained, if necessary, by subsequent drying. The rounded stage in e) is preferably carried out with separation of the pulverulent fraction. The product originated after rounded in step e) can also be coated, preferably, with adjuvants. If a rounded step is carried out in e), then a thick fraction with particle sizes > 1,500 μm and, if necessary, recycled to the process. The carbon black granules preferably have particle size densities of 0.1 to 2.5 g / cm. Adjuvant substances which can be used are inorganic as well as organic substances. Preferably used as adjuvants are water, salts of the group of phosphates, carbonates, nitrates, sulfates, chlorides, silicates, aluminates and borates, formates, oxalates, citrates and tartrates, polysaccharides, cellulose derivatives, such as, for example, cellulose ethers, cellulose esters, phosphonocarboxylic acids, modified silanes, silicone oils, biological culture oils (for example rapeseed oil, soybean oil, corn germ oil, olive oil, coconut oil, sunflower oil), refined paraffinic and / or naphthenic base oils, synthetically obtained oils, alkylphenols, glycols, polyethers, polyglycols, polyglycol derivatives, albumin-fatty acid condensation products, alky1benzenesulfonates, alkylnaphidene sulfonates, lignin sulphonates, sulphated polyglycol ethers, melamine-formaldehyde condensates, condensates naphthalene formaldehyde, gluconic acid, polyhydroxy compounds or aqueous solutions of them. In addition, emulsifiers, wetting agents and dispersants can be used in the mixtures in a proportion of 0.01 to 5% by weight, preferably 0.01 to 3% by weight, based on the weight of the pigments used. Emulsifiers which are particularly suitable are emulsifiers with HLBs of from 7 to 40, in particular from 8 to 18, for use in construction materials with aqueous systems, such as concrete, composed of alkyl and acrylic residues and groups hydrophilic intermediates and terminals such as, for example, amido, amino, ether, hydroxyl, carboxylate, sulfate, sulfonate, phosphate, amine salt, polyether, polyamide, polyphosphate. According to their HLB index, the substances can be used individually or in combination. Particularly suitable wetting agents are alkyl benzene sulphonates, fatty alcohol sulfates, fatty alcohol ethersulphates, fatty alcohol ethoxylates, alkylphenol ethoxylates, alkanesulfonates, olefin sulfonates. The dispersing aids used are preferably melamine sulfonates, naphthalene sulfonates, metal soaps, polyvinyl alcohols, polyvinyl sulfates, polyacrylamides, fatty acid sulfates. In order to increase the stability or as a coadjuvant in the processing of the granulates, it can be advantageous to coat the granules with a final additional layer. This layer can be originated by applying inorganic salts in solution of polyols, oils or waxes or polyethers, polycarboxylates or cellulose derivatives, preferably carboxymethylcellulose. It is also possible to add preservatives to the granules in the mixture in a concentration of 0.01 to 1% by weight, based on the pigment weight. Dissociative compounds of formaldehyde, phenolic compounds or isothiazolinone preparations are to be mentioned as examples. Surprisingly, as adjuvants for pressed and briquetted granules, especially if they are intended for incorporation into aqueous construction systems such as cement or concrete mortar, not only water-soluble substances can be used, but also water-insoluble substances, such as for example, oils. The adjuvants are preferably used in amounts of 0.001 to 10% by weight, particularly preferably 0.01 to 5% by weight, very particularly preferably 0.1 to 3% by weight, based on the pigment used .

The adjuvants can preferably be used in conjunction with other additives, such as, for example, emulsifying agents, wetting agents, metal soaps, and the like. The pressing or briquetting step b) is preferably carried out on a roller press or a hydraulic press and, preferably, with linear forces of 0.1 to 50 kN / cm, preferably 0.1 to 20 kN / cm . In pressing or briquetting (compaction, step b)), an important parameter is the pressing force (kN) per cm of roll width (linear force). In roller compaction, a linear transmission of the pressing force is used, since a pressing surface can not be defined and, therefore, a pressure (kN / cm2) is not calculable. The compaction is preferably carried out at small linear forces. The applied linear forces are generally, preferably in the lowest range of commercially available apparatuses, between 0.1 and 50 kN / cm. With very special preference, the linear forces are from 0.1 to 20 kN / cm. Commercially available devices are, for example, the Pharmapaktor 200/50 from Bepex GmbH, Leingarten (Germany). The additional separation stage x) is preferably carried out with sieving machines, such as, for example, drum sifters, oscillating sifters and vibration sieves. The crushing can be carried out in all commercial crushing equipment, such as crushers, toothed rollers, rollers with friction devices and granulators-sieves. The grinding step c) is preferably carried out with granulators-sieves or sieve mills, in which the material is pressed through a chopper screen with a mesh opening of 0.5 to 4 mm, particularly preferably 0. , 5 to 2 mm, with very special preference of 1 to 2 mm (called crusher). The rotors move, as is generally known, in rotating or oscillating form, with a rotation speed of 0.05 m / s at 10 m / s, preferably from 0.3 to 5 m / s. The separation between rotor and sieve or perforated disk is 0.1 to 15 mm, preferably 0.1 to 5 mm, particularly preferably 1 to 2 mm. As a grinding apparatus, for example, the Flake Crusher from Frewitt, Friborg (Switzerland) can be used. After grinding, the fine fraction, less than 80 μm, is separated. Preferably, the amount of this fine fraction is from 10 to 50% by weight, particularly preferably from 10 to 30% by weight. Preferably, the fine fraction is recycled to step b). The residual fraction is loose, dosable, stable, poor in powder and well dispersible. Another optimization can be obtained by additional rounding. The rounding step in e) is preferably carried out on a turntable, in a rotating drum or dripping drum, in sieve drums or similar apparatuses or in a fluidized bed or fluid bed or in a screening plant. For this, the powder fraction can be sucked in vacuum or discharged with air into the fluidized bed. The process according to DE-A 43 36 613 or DE-A 43 36 612, by granulation by agglomeration on the turntable leads to certainly round particles which, however, are heterogeneous. They are composed of a compact core and a layer or outer layers (s) agglomerate (s), which can erode. Therefore, these products are powdery, especially in the pneumatic drive, and the fluidity is not especially good. The products obtained by the process according to the invention do not have these disadvantages, since they are composed of homogenously compacted particles of unit density and stability. The granules obtained by the process according to the invention are used for the dyeing of building materials such as, for example, concrete, cement mortar and plaster and for the dyeing of organic media such as lacquers, plastics and dye pastes and for obtaining them of dispersion dyes and grouts.

The granules obtained according to the invention are particularly suitable for incorporation into dry cement mortar mixtures and in plaster. In the multi-stage process according to the invention, it is essential that in the first stage a sufficiently cohesive homogeneous material is produced by the addition of the auxiliary substance in a mixer. In the second stage the briquetting or pressing is then carried out. Another object of the invention is a method for dyeing building materials such as concrete with pigments of carbon black, which is characterized in that briquetted or pressed granules of carbon black pigments and auxiliary substances that were obtained by the process are mixed. according to the invention with the construction material, in a proportion of 0.1 to % by weight, preferably 1 to 5% by weight, based on the cement. The granules obtained according to the invention can also be used preferably in dispersion and slurry dyes. Another object of the invention is a process for the dyeing of organic media such as lacquer systems, plastics and dye pastes with carbon black pigments, which is characterized by the briquetting or pressing granules of carbon black pigments, which were obtained by the process according to the invention, it is mixed with the organic medium in a proportion of 0.1 to 10% by weight, based on the organic medium. The test of the dispersibility for building materials is carried out in cement mortar, by measuring the coloring power in prisms obtained with white cement: Cement-sand ratio of quartz 1: 4; water-cement index 0.35; 1.2% pigmentation height, referred to cement; kneader employee of RK Toni Technik, Berlin, mixing tank of 5 1, construction 1551, number of revolutions 140 rpm; addition of 500 g of cement. After 100 s, 3 samples of mixture are extracted (300 g) and samples are obtained (5 x 10 x 2, 5 cm) under pressure (300 bar). Hardening of the specimens: 24 hours at 30 ° C and 95% relative humidity with subsequent drying of 4 hours at 60 ° C. Measurement of color data on Dataflash 2000 Datacolor International, Kóln; 4 points of measurement by paving stone, by mixing pigments 12 measuring points. The average values obtained are compared with the values of a reference specimen. The Eac color difference and the coloring power (reference specimen = 100%) are evaluated (DIN 5033, DIN 6174 standards). The dispersibility is designated as good for a dye power difference of up to 5% with respect to the reference specimen, as a rule for a difference of up to 10%. The flow behavior test is carried out by evaluating the behavior in the pouring from a 100 ml volume funnel with a 6 mm opening, according to the ASTM D 1200-88 test. The flow behavior is designated as good when the material is poured freely. If no material flow occurs or flow only under pressure, the flow behavior is considered insufficient. The determination of the fine fraction as screening residue is carried out on a VA sieve according to DIN 4188, with 80 μm mesh opening, on an Alpine 200 LS air jet screening machine. 20 g of the sample to be tested are used. The fine material is sucked for a time of 5 minutes and the amount of the coarse fraction is rocked again on the screen. The test of the dispersibility in plastics is carried out according to a recipe approximated to DIN 53 775; part 7: "Test of coloring agents in molded polyvinyl chloride (PCV-P) masses containing plasticizer, determination of the dispersion hardness through rollers": The pigment to be tested is dispersed in PVC at 160 ± 52C on a mixer roller. The obtained rolled product is divided and one of the halves is then exposed to high shear stresses by calendering at room temperature. As a measure of dispersibility they serve, for color pigments the color difference? E according to CIELAB (DIN 5033, 6174 standards) between the hot and cold calendered PVC rolled products or, in white pigments, the difference of the normal color value Y (DIN standard) 5033) between hot and cold calendered PVC rolled products. A well-dispersible pigment is already dispersed at small shear stresses, while for the dispersion of a hard dispersible pigment high shear stresses in calendering at high temperature are necessary. Therefore it is valid: the smaller the color difference? E or the difference of the normal color value Y, the better the dispersion is the pigment. Especially in granulates, the dispersibility is of great importance since, firstly, the particles of granules which have to be dispersed in the plastic must be crushed. In granulates, the dispersibility is as good as that of the corresponding powder pigment, so that the characteristic parameters E or Y must not differ essentially for the powder and the granulate. The measurement of the fine powder for the determination of granular stability is carried out in accordance with DIN 55 992. The pulverulent properties of the granulate can be measured with the Heubach "powder meter". The discharge of fine dust from a rotating drum through which a defined force air stream flows is determined gravimetrically on a glass fiber filter. By means of measurements at various loading times, the course of dust production can also be shown as a function of mechanical stress. The present invention will be explained in more detail below by virtue of examples, without limitation being considered in these examples. Example 1 500 g of carbon black Corasol C30 (commercial product of Degussa) or 500 g of Monarch 800 carbon black (commercial product of Cabot Corp.) were mixed with ammonium lignin sulfonate and oil for machinery V 100 in various quantities, in a mixer for 18 minutes. The mixture was pressed into a type of WP50N compactor (Alend erk firm, Remscheid) with various linear forces and, after this, it was ground in a fine granulator RFG (Alexanderwerk firm, Remscheid) with a mesh screen. 1.5 mm. The crushed product was separated into two fractions on a sieve with a mesh size of 250 μm. The fraction of more than 250 μm was tested and showed good fluidity (the respective powder had poor fluidity). The remaining data of the fraction as well as the starting powder can be extracted from table 1. The relative coloring power in concrete was measured against the corresponding starting powder. In addition, the relative coloring power in concrete was converted to the pigment content of the granulate (theoretical value). Example 2 500 g of carbon black Corasol C30 (commercial product of Degussa) was mixed with 8% ammonium lignin sulfonate and 1% oil for machinery V 100, in a mixer for 18 minutes. The mixture was pressed in a type of P50N compactor (Alexanderwerk firm, Remscheid) with 7 kN / cm and, after this, it was crushed in a fine granulator RFG (Alexanderwerk firm, Remscheid) with a sieve with a mesh size of 1.5 mm.

A part of the crushed product was separated into two fractions on a sieve with a mesh opening of 250 um. The fraction of more than 250 μm (60% of the amount) was tested and showed good fluids (the corresponding powder had poor fluidity). The other part of the crushed product (about 150 g) including the fine fraction was granulated in a drum of 15 cm diameter at 60 revolutions per minute, for 5 minutes. With this the fine fraction was granulated up to 100%. This product also showed good fluidity and sufficient dispersibility. The behavior of the dust in the powder meter according to Heubach was, in any case, clearly different for the two products. The compacted, crushed and granulated material subsequently showed 1328 mg of powder, while the compacted, crushed, sieved and non-granulated material subsequently produced only 548 mg of powder in the test. The starting powder Corasol C 30 produced 2,669 mg of powder in the powder meter. the l LS - Ammonium ligninsulfonate. Oil - Oil for machinery V 100.

It is noted that, in relation to this date, the best method known to the applicant to carry out the aforementioned invention is that which is clear from the present description of the invention. Having described the invention as above, property is claimed as contained in the following:

Claims (14)

1. CLAIMS 1. Process for the production of pressed or briquetted granules of carbon black pigments with coadjuvant substances, characterized in that: a) One or more pigments of carbon black are mixed with one or more processability promoting adjuvants, b) This mixture is subjected to a pressing or briquetting step, c) This pressed or briquetted product is crushed, d) The crushed product is separated into two or more fractions, e) The fraction in which at least 85% of the particles is greater than 80 μm, preferably greater than 100 μm, or is between 80 and 2,000 μm, preferably between 100 μm and 1,000 μm, is extracted as a product and, if necessary, is rounded off in another step; the other fraction or fractions are excluded from the process or recycled. Method according to claim 1, characterized in that, before step c), the pressed or briquetted product of b) is separated into two fractions; the coarse fraction in which at least 85% of the particles are greater than 500 μm, preferably 600 μm, is fed to stage c) and crushed and the fine fraction is fed to stage d), to be separated into step d) separately from, or together with, the product of step c). Process according to claim 1, characterized in that the crushed product is separated in step d) into two fractions, the fine fraction of less than 80 μm being excluded or recycled to the process and the coarse fraction being rounded off, if necessary at a later stage. , greater than 80 μm. Process according to claim 1 characterized in that the crushed product is separated into three fractions in step d), excluding or recycling the fine fraction and the coarse fraction and rounding, if necessary at a later stage, the intermediate fraction from 80 to 2,000 um. Process according to one or more of claims 1 to 4, characterized in that the rounded step in e) is carried out with separation of the pulverulent fraction. Process according to one or more of claims 1 to 5, characterized in that the product obtained after stage d) or, if appropriate, the product originated after rounding in stage e), is coated with auxiliary substances. Process according to one or more of claims 1 to 6, characterized in that water, salts of the group of phosphates, silicates, aluminates, borates, polysaccharides and cellulose derivatives, organic crop oils, base petroleum refined are used as adjuvants. paraffinic and / or naphthenic, synthetically obtained oils, alkylphenols, glycols, polyethers, polyglycols, polyglycol derivatives, condensation products to 1 fatty acids, alkylbenzene sulfonates, alkylnaphthalenesulfonates, ligninsulphonates, sulphated polyglycol ethers, melamine-formaldehyde condensates, condensates naphthalene formaldehyde, gluconic acid, polyhydroxy compounds or aqueous solutions thereof. Method according to one or more of claims 1 to 7, characterized in that the adjuvants are used in amounts of 0.001 to 10% by weight, based on the pigments used. Method according to one or more of claims 1 to 8, characterized in that step b) of pressing or briquetting is carried out on a roller press or hydraulic press and at linear forces of 0.1 to 50 kN / cm, preferably 0 , 1 to 20 kN / cm. Method according to one or more of claims 1 to 9, characterized in that the grinding step c) is carried out by sieving through a chopper screen with a mesh opening of 0.5 to 4 mm, preferably 0.5 to 2.5 mm, particularly preferably 1 to 2 mm. Method according to one or more of claims 1 to 10, characterized in that the rounding step in e) is carried out on a turntable, in a rotating drum, in a sieving plant or in a fluidized bed. 12. Use of the granules obtained according to the process according to claims 1 to 11 for the dyeing of building materials such as, for example, concrete, cement mortar and plaster and for the dyeing of organic media such as, for example, lacquers, plastics and coloring pastes, and to obtain dispersion and grouts dyes. 13. Method for dyeing building materials with carbon black pigments, characterized in that briquetted or pressed granules obtained according to claims 1 to 11 are mixed with the building materials, in an amount between 0.1 and 10% by weight, referred to cement. 14. Process for dyeing organic media with carbon black pigments, characterized in that briquetted or pressed granules obtained according to claims 1 to 11 are mixed with the organic media, in an amount comprised between 0.1 and 10% by weight, referred to the organic medium.