MX2008002390A

MX2008002390A - Stevensite- and/or cerolite-containing adsorbents for binding interfering substances during the manufacturing of paper.

Info

Publication number: MX2008002390A
Application number: MX2008002390A
Authority: MX
Inventors: Ulrich Sohling; Friedrich Ruf
Original assignee: Sued Chemie Ag
Priority date: 2005-08-23
Filing date: 2006-08-21
Publication date: 2008-03-18
Also published as: CA2620089A1; EP1920111A1; DE102005039850A1; WO2007022942A1; BRPI0614883A2; ZA200802224B; JP2009506224A

Abstract

The invention relates to a method for binding interfering substance during the manufacturing of paper, comprising the following steps: (a) preparing at least one stevensite- and/or cerolite-containing constituent; (b) preparing a paper pulp or fibrous material; (c) adding the at least one stevensite- and/or cerolite-containing constituent to the paper pulp or fibrous material, and; (d) enabling the binding of interfering substance to the at least one stevensite- and/or cerolite-containing constituent in the paper pulp or fibrous material suspension.

Description

ADSORBENTS CONTAINING ESTEVENSITE AND / OR KEROLITE TO LINK INTERFERING SUBSTANCES IN PAPER PRODUCTION FIELD OF THE INVENTION The present invention relates to the use of materials containing stevensite and / or querolite to bind or eliminate interfering substances in the production of paper. BACKGROUND OF THE INVENTION The elimination or binding of interfering substances in the production of paper is increasingly important. The problem is also due to the fact that the water generated during the production of paper is handled in a circulating way, with which the interfering substances accumulate little by little. These interfering substances can thus cause the most diverse alterations of the product, such as, for example, causing the formation of deposits on the cylinders of the paper machine, clogging the sieves, etc. These effects cause interruptions in paper production. To minimize the number of production stoppages it is desirable to bind the interfering substances that are generated in the water circuit, introducing polymers or adsorbents already in the preparation. Most of the interfering substances that are relevant have a negative charge. It is, for example, humic acids, colloids of tree resins, REF: 189781 derivatives of lignin, lignin sulphonates that are introduced by the fibers into the paper circuit. To this must be added interfering substances that are introduced into the paper machine through a recycling of waste paper. This waste paper is typically re-dispersed and fed into the paper machine. Due to this the substances and auxiliary means that it contains are completely returned to the circuit. By this additionally, for example, carboxymethylcelluloses, polyacrylates, polyphosphonates and silicates are introduced. Other interfering charged substances are the lattices that are used in the impregnation of paper. These can tend strongly to the agglomeration with what the agglomerates are deposited on the paper machine as sticky white residues (mixture of fats and waste is known as white pitch in English). In the state of the art the discharge of sticky substances (known as "stickys" in English) is already widely described by the use of talc. Thus, according to P. Biza, E. Gaksch and P. Kaiser "Verbesserter Austrag von Stickys durch den Einsatz von Talkum", papermaking weekly 11/12 (2002) page 759 et seq. Was documented no later than Early last century the effect of talcum to reduce sticky stools. Almost all known natural and synthetic sticky substances are hydrophobic. Talc is excellently suited for bonding these glutinosities in that it has a hydrophobic surface by nature that allows it to be easily adsorbed to adhesive surfaces and by wrapping makes them less sticky. In addition, for example, US Pat. No. 5,368,962 describes the use of montmorillonites, such as bentonite, for the control of interfering substances in paper pulp. It also indicates as a possibility the alkaline treatment of bentonites. In US 4,964,955 there is also described a method for reducing interfering substances in paper production. In this, for the binding of the interfering substances, a particulate composition containing (a) a water-soluble cationic polymer that is applied to (b) a particulate substrate substantially insoluble in water is described. The polymer must be sufficiently electropositive, so that the particulate composition has a zeta potential of at least about +30 mV. In the case of the polymer, it is preferably a poly (dialkyldiallylammonium halide). In the case of the substrate, it is, for example, a phyllosilicate mineral. Similarly, EP 0 760 406 A2 refers to a combination of a poly (dadmac / acrylamide) and a bentonite in the binding of interfering substances.

GB 2 297 334 A again reveals the use of a smectite clay for the control of interfering substances, whereby the smectite clay is modified as follows: interchangeable monovalent cations are present in the range of 0.20 to 0.60 in a equivalent ion portion; a first type of interchangeable divalent cations is present in the range of 0.40 to 0.80 in an equivalent portion of ions; and a second type of interchangeable divalent cations is present in the range of 0.00 to 0.20 in an equivalent ion portion, wherein the first type of interchangeable bivalent cations comprises calcium and the second type of interchangeable bivalent cations comprises magnesium. Many of the means used in the state of the art to bind interfering substances are extremely expensive and are not optimally suitable for certain compositions of interfering substances. Accordingly, there is a continuing need for means to bind interfering substances in the production of paper. BRIEF DESCRIPTION OF THE INVENTION Therefore, it is the object of the present invention to provide an improved method for the binding of interfering substances in the production of paper which avoids the disadvantages of the state of the art. Also, it is an object to allow the use of an easy and economical means of producing, and to provide a high proportion of binding of interfering substances, also of hydrophobic fractions. This problem is solved by the method according to claim 1. Thus, within the framework of the present invention it was unexpectedly discovered that by means of the use of components containing stevensite and / or querolite, an excellent binding or elimination of interfering substances is possible. a process for the production of paper. The components containing stevensite and / or querolite bind or respectively sorbate interfering substances, including their hydrophobic moieties in a surprisingly high proportion. Therefore these components can also be considered as sorbents or respectively ad- and ab-sorbents, being that in this document these concepts are handled with the same meaning for reasons of simplicity. Interfering substances are understood in the context of the present invention both sticky substances, which in the literature are also referred to as "adhesives" or "stickies", as well as the so-called "pitch", that is to say, first of all components of tree resin. Here it is possible to refer to what was exposed about interfering substances in the introduction of the description. A detailed listing of the components of "pitch" and "stickies" is found, for example, in WO 01/09424 on pages 1 and 2, and this disclosure is expressly incorporated by reference in the present description. A particularly preferred aspect relates to the use of at least one component containing stevensite and / or querolite to bind or respectively eliminate hydrophobic interfering substances in a process for the production of paper. According to a first aspect according to the invention, the component used contains stevensite or a stevensite phase respectively. The expert is familiar with what is meant by estevensita. A more detailed characterization of stevensite is found, for example, in JL Martin de Vidales et al., Clay Minerals (1991) 26, pages 329-342, and GB Brindley et al., Mineralogical Magazine, 1977, Vol. 41 , pages 443-452, to which you can expressly refer. The determination of stevensite can be carried out as described therein. Characteristic is the grid distance diffraction peak (basal distance) of 10 Á, whose position shows a clear displacement at different humidities. In other words, according to a first aspect of the invention, estevensite or the component containing stevensite is considered to be a material having the characteristic diffraction peak at a distance from the grid (basal distance) of 10 A according to Brindley et al ( as indicated in the preceding), and preferably also the displacement of this peak at different humidities or a treatment with ethylene glycol (see below) that is described there. Characteristic is also the distance close to 17 Á in the treatment with ethylene glycol. At this point, it is expressly referred to the X-ray powder diffractograms for estevensite indicated in Figure 2 in G.B. Brindley et al. (in the indicated site) and the corresponding text parts. Therefore, in accordance with the invention, in the stevensites used in the mycotoxin adsorbent or in the stevensite-containing component, it typically varies the position of the grating distance diffraction peak of approximately 10 A at different humidity or with different humidity. a treatment with ethylene glycol according to Fig. 2 of the bibliographic site Brindley et al. (in the indicated site). By this the estevensita used also differs, for example, from the pure querolite. For reasons of simplification, the expression "estevensite" should in this document also include the components that contain stevensite. The term "component containing stevensite" should express that in the composition according to the invention it is also possible to use components that in addition to stevensite include other additional components. For example, many commercially available stevensite products contain in addition to stevensite different amounts of mineral impurities. Furthermore, mixtures of stevensite with other components are conceivable, such as, for example, other mineral components, in particular layered silicates. According to one embodiment according to the invention at least one component including stevensite and / or querolite is used, which is substantially or completely composed of stevensite or at least one component containing stevensite. According to another aspect according to the invention, the component used contains querolite or a querolite phase. What is understood by querolite is known to the expert in the field and it is not necessary to explain it in more detail in this document. For example, it is also possible to refer here to Brindley et al. (in the indicated site). The identification of the querolite can be carried out as described there. The chemical analysis of querolite results in a composition close to R3Si4O? O (OH) 2 • nH20, where R is mainly Mg and n is approximately 0.8 to 1.2. Characteristic is the diffraction peak in the grid interval (basal interval) of 10 Á, whose position does not show expansion at different humidities and does not show thermal contraction up to 500 ° C. Here, it is expressly referred to X-ray diffractograms of powder for querolite indicated in figure 2 and to the corresponding text sites in G.B. Brindley et al. (in the indicated site). According to a possible embodiment according to the invention, in the composition according to the invention the stevensite or the minimum of a component containing stevensite is partially or completely replaced with querolite or at least one component containing querolite. For reasons of simplification, the term "querolite" should in this document also include components containing querolite. The concept "component containing querolite" should express that according to the invention it is also possible to use components that besides querolite contain other components. For example, many commercially available querolite products contain in addition to querolite different amounts of mineral impurities. In addition, mixtures of querolite with other components are also possible, such as, for example, other mineral components, in particular sheet silicates. According to one embodiment according to the invention at least one component containing stevensite and / or querolite is used, which is substantially constituted or completely of querolite or at least one component that contains querolite. According to another aspect according to the invention, the component used contains both stevensite or a phase of stevensite as well as querolite or respectively a phase of querolite. It was found that this type of components containing stevensite and querolite show binding properties of particularly good interfering substances. In accordance with a preferred modality, the used component containing stevensite and / or querolite contains at least 10% by weight, preferably at least 50% by weight, in particular at least 75% by weight, particularly preferably at least 90% by weight, most preferably at less 95% by weight of stevensite and / or querolite. It was unexpectedly discovered that a particularly good binding of interfering substances results if stevensite and / or querolite constitutes the main mineralogical phase in the components that are used according to the invention. Within the framework of the present invention it was further discovered that those components containing stevensite and / or querolite comprising a magnesium oxide content of at least 15% by weight, in particular of at least 17% by weight, are particularly suitable. most preferred way at least 20% by weight. The corresponding materials are obtained commercially. It is further preferred that the content of magnesium oxide of the components used here containing stevensite and / or querolite, in particular of the stevensite component or containing stevensite, does not exceed 40% by weight, in particular not to exceed 35% by weight , in many cases more preferably it does not exceed 32% by weight. The content of magnesium oxide is also determinant for the exact configuration of the laminar structure of the material. It is assumed, without limiting the invention to the truth of this assumption, that the laminar structure of the material used in accordance with the invention, in particular of stevensite, provides a particularly favorable porosimetry and particularly efficient surfaces for the adsorption of a multitude of substances different interferers. According to an embodiment according to the invention, in particular in the case of components with a high proportion of stevensite, the BET surface (measured according to DIN 66131, see part related to the method) is at least 60 m2 / g , in particular at least 80 m2 / g, in particular at least 100 m2 / g. These high BET surfaces apparently allow even more efficient adsorption for some interfering substances. It was further discovered that those materials having a cation exchange capacity (CEC = Cation Exchange Capacity) of less than 40 meq / 100 g, in particular less than 35 meq / 100 g, give particularly good results. very preferably less than 30 meq / 100 g. The CEC can be determined as indicated in the following part related to the method. According to another preferred embodiment, those components containing stevensite and / or querolite whose CEC is at least 2 meq / 100 g, preferably at least 5 meq / 100 g, in particular at least 10 meq / 100 g, are used. most preferred way at least 15 meq / 100 g. '"Cation exchange capacity" (CEC) means the sum of all interchangeable cations, indicated in mVal / 100 g, and determined according to the CEC analysis method as explained below in the section of examples (determination of cation exchange capacity). That is, the cation exchange capacity comprises, for example, the sum of all interchangeable bivalent and monovalent cations, such as calcium, magnesium, sodium, lithium and potassium ions. To determine the cation exchange capacity, the component containing stevensite and / or querolite is treated with a solution of ammonium chloride. Due to the high affinity of the ammonium ions to the component containing stevensite and / or querolite virtually all exchangeable cations are exchanged for ammonium ions. After separating and 1 washing the nitrogen content of the components containing stevensite and / or querolite is determined and from this the content of ammonium ions is calculated. As discussed above, the stevensite and / or querolite-containing components used in accordance with the invention surprisingly have a substantially better effect for binding or eliminating interfering substances than conventionally used products, such as, for example, talc. Compared with other agents, such as conventional bentonites, another advantage lies in the fact that components containing stevensite and / or querolite can usually be processed to obtain slurries or suspensions (aqueous) with a content of solids much higher without a too high viscosity of the slurry or suspension adversely affecting processing and dosing. Thus, in many paper mills, the raw materials are practically dosed in liquid form, including the agents and components used to bind the interfering substances. The higher the solids content of the slurry or metered suspension, the smaller the quantity to be metered or prepared and transported. Within the framework of the present invention it was also unexpectedly discovered that it is possible to further increase the binding effect of interfering substances of the components containing stevensite and / or querolite if these are activated. In particular in the components containing stevensite a good effect of the activation is shown. According to the invention, in this document, activation means an at least partial exchange of the cations of the intermediate layer, in particular of the bi-or polyvalent cations of the intermediate layer of stevensite in the component containing stevensite by monovalent cations. . In the case of the exchanged monovalent cations, it is possible in particular to treat H + or one or more alkali cations. The preferred forms of activation are activations with the use of acid or alkali. A preferred, non-limiting example of an alkaline activation is activation with soda. For this purpose, for example, the wet clay of the mine, which usually has water contents between 25 and 40% by weight of moisture with up to 5% by weight, in particular up to 4% by weight of soda, potassium carbonate, is mixed. or other alkali metal salts such as, for example, phosphates or citrates with respect to the anhydrous clay, and optionally still extruded. Then dry and grind. An acid activation of the component containing stevensite can be carried out in general by a treatment with one or more acids. For this purpose the component is brought into contact with at least one inorganic and / or organic acid. In principle it is possible to use any method known to the skilled artisan for the activation of clays with acid. According to a possible embodiment according to the invention it is not necessary to wash the surplus acid and salts that are generated during the activation. Rather, a washing step is not carried out after addition of the acid as is usual in acid activation, but the treated component is dried and optionally milled to the desired grain size. The activation with acid can be carried out, for example, with acids in solid form or with an acid solution. Thus, in one embodiment the activation of the component is carried out in aqueous phase. For this purpose the acid is brought into contact as an aqueous solution with the component containing stevensite. One can proceed so that, for example, the stevensite-containing component, which is preferably provided in the form of a powder, is first suspended in water. The acid is then added, for example, in concentrated form. However, the component containing stevensite can also be suspended directly in an aqueous solution of the acid, or the aqueous solution of the acid added to the component containing stevensite. According to a favorable embodiment it is possible, for example, that the aqueous acid solution is sprayed onto a component containing crushed stevensite or in powder form, the amount of water preferably being kept as low as possible. For example, a concentrated acid or concentrated acid solution is used here. If small amounts of acid are sprayed, often only surface activation occurs, also referred to as "surface modification". The amount of acid can preferably be selected between 1 and 10% by weight, particularly preferably between 2 and 6% by weight of a strong acid, in particular a mineral acid such as sulfuric acid with respect to the component containing water-free stevensite (atro) As necessary, it is possible that the surplus water is removed by evaporation and that the component containing optionally activated stevensite is ground to the desired fineness. As already mentioned in the foregoing, according to one embodiment, the method according to the invention does not require a washing step. After adding the aqueous acid solution, it is only dried, as necessary, until reaching the desired degree of humidity. Most often the water content of the obtained activated stevensite-containing component is adjusted to a fraction of less than 20% by weight, preferably less than 10% by weight. For the activation described above with an aqueous solution of an acid or a concentrated acid it is possible to choose any acid at will. It is possible to use both mineral acids as well as organic acids or mixtures of the preceding acids. It is possible to use conventional mineral acids such as hydrochloric acid, phosphoric acid or sulfuric acid, with sulfuric acid being preferred. It is possible to use concentrated or diluted acids or acid solutions. As organic acids it is possible to use, for example, citric acid or oxalic acid. According to a particularly preferred embodiment according to the invention, the component containing stevensite and / or querolite comprises, in relation to the cation exchange capacity, a fraction of at least 50%, in particular of at least 80% of monovalent cations such as H +, Na +, K +, and / or Li +. This fraction can be reached or increased, for example, by activation of the component with acid or an alkaline salt (for example, soda). Particularly preferred are at least 90% in particular about 100% monovalent cations relative to the cation exchange capacity of the component containing stevensite and / or querolite. The method according to the invention using the stevensite and / or querolite-containing components described in this document can be used in general in all processes for the production of paper or paperboard.

Correspondingly, the terms pulp of paper and fibrous pulp suspension should generally comprise all compositions or streams containing interfering substances that are used in the production of paper, cardboard, other fibrous pulps or the like. For the rest, the expert is familiar with the terms "pulp (paper)" and "suspension of fibrous pulps" and it is not necessary to explain them in more detail in this document. According to a preferred embodiment according to the invention, in the case of the pulp or the fibrous pulp suspension, it is a suspension containing (fine) wood pulp. In the case of wood pulp it is generally finely disintegrated, finely ground wood (most of the time without further chemical or thermal treatment). The wood pulp suspension is used either directly after the grinding or subjected to a decolorization with peroxide, and then the so-called peroxide-bleached wood pulp is produced. It was unexpectedly found that the stevensite and / or querolite-containing components used according to the invention show particularly good results in paper grades containing wood pulp or wood pulp treated with peroxide. But the method according to the invention can also be favorably used in other kinds of paper. Thus, for example, the pulp or pulp suspension can also contain highly purified fractions of fiber (in addition to paper pulp), as is the case, for example, in so-called newsprint (News Print Paper as know in English). The invention also provides very good results in the so-called "de-inked pulp" (DIP paste). It is a paper pulp that is produced from old paper. There, in particular, hydrophobic glutinosities of the magazine and newspaper adhesive are produced. Also, these can be bonded well in the final product with the components containing stevensite and / or querolite which are used in accordance with the invention. Other so-called paper pulps in which it is possible to use favorably the components containing stevensite and / or querolite according to the invention comprise substance TMP (Mechanical Thermo Pulp), sulphate cellulose, sulphite cellulose as well as mixtures of different celluloses. Depending on the type of paper and the location of the paper mill, these celluloses are mixed in different proportions and adapted to the material requirements of the final product. According to a favorable embodiment according to the invention, the pulp fraction that is preferred in the paper pulp or the fibrous pulp suspension is at least 10% by weight; in particular at least 30% by weight, in each case in relation to the dry weight of the whole pulp or suspension. The minimum of a component containing stevensite and / or querolite in the method according to the invention probably acts, without the invention being limited to the truth of this assumption by binding the interfering substances or interacting with them and thus Counteracts aggregation and deposition on the parts of the paper machine, such as cylinders. The concentration of interfering substances in paper production is typically determined in sifting water by the three processes of current use, cation need (cationic charge requirement), turbidity measurement and chemical oxygen requirement. In the case of the need for cations, it is assumed that the interfering substances are all negatively charged and the sifting water is filtered in short chain cationic polyelectrolytes. Spending is converted to the so-called need for cations. In the turbidity measurement, it is assumed that the interfering substances are partly present in colloidal form and that their concentration can be determined by the extinction caused by the turbidity. In the need for chemical oxygen, the existing fraction of organic compounds is tested by means of an oxidation medium. Although these methods are widespread in the paper industry, more recent investigations have demonstrated that these average on all the impurities in the sifted water and only detect partially the particularly critical interfering substances. This results, for example, because the so-called wood resin colloids, which in part are composed of hydrophobic compounds, can only bear reduced surface charges and therefore contribute little to the need for cations. On the other hand, lignins have a great need for cations; when they are present in the sifting water they only bother very little in the production of paper. The most recent investigations also show that the correlation between turbidity measurement and the concentration of colloidal interfering substances does not always occur. By virtue of this new experience with the methods commonly used for the determination of the interfering substances, the effects of the components containing stevensite and / or querolite according to the invention were further characterized by new methods. This is, for example, an analysis by gas chromatography of the sifting water according to the method of F. Orsa and B. Holmbom "A Convenient Method for the Determination of Wood Excipients in Papermaking Process Waters and Effluents" , Journal of Pulp and Paper Science, Vol. 20 No. 12 December 1994, pages J361. In the production of a paper containing wood pulp, the concentration of the individual components of tree resin is determined by a gas chromatography method. In this aspect, it is a complete quantitative analysis, while the standard determination methods such as turbidity, cation needs and chemical oxygen need can only be assessed at best as semiquantitative. In addition, L. Váhásalo et al. (at the indicated site), see "Flowcytometrische Analyze des Siebwassers" below) showed that the so-called flow-through flow cytometry is very suitable for determining the number of colloidal interfering substances in paper sifting waters. For this reason this new method was also used in the present invention to show the reducing effect of interfering substances of the components containing stevensite and / or querolite according to the invention. The addition of the minimum of a component containing stevensite and / or querolite which is used according to the invention to the pulp or its fibrous pulp function can be carried out at any suitable time at discretion during the production of paper. It is also recommended in particular the direct addition to the pulper former, since there is the possibility of a long contact time with the pulp and there is the likelihood of a considerable interferent substance bond. Other feeding sites are found throughout the area called coarse substance. Also, an addition for the "dissolved air flotation" (as it is known in English) for the purification of water is imaginable. In many cases there will be an existing feed site for additives in the paper making devices in each case, for example in the form of a dosing device or dosing pump which can be used for feeding the component (s) containing stevensite and / or querolite which is used according to the invention. The components containing stevensite and / or querolite can be used in the form of a powder as well as in the form of a suspension or slurry. The suspension or slurry will allow in many cases a better dosage and can be automated more easily in large-scale industrial processes that are developed continuously. It was also found that the effect of the stevensite and / or querolite-containing components that are used according to the invention is particularly positive if a certain particle size is respected. Thus, according to a particularly preferred embodiment of the invention, the particle size of the components containing stevensite and / or querolite is chosen such that the wet sifting residue above 45 μm is less than 2% by weight. , preferably in less than 1% by weight, in particular in less than 0.5% by weight. The determination of the wet sifting residue is still explained in more detail before the examples. The preferred particle size can also be determined according to the light scattering method (Malver). According to a particularly preferred embodiment according to the invention, the average particle size (D50) is (relative to the test volume) between 0.5 and 10 μm, in particular between 2 to 8 μm, particularly preferably between 3 and 6 μm. Within the framework of the present invention it was also unexpectedly discovered that the use of the stevensite and / or querolite-containing components used in accordance with the invention leads to a particularly good interferent substance bond if the use of talc is dispensed with in the process. With the aid of the stevensite and / or querolite-containing components used according to the invention, it is also possible to reduce or even completely omit the use according to the state of the art of cationic polymers, such as, for example, poly (dadmac) or polyacrylamide. The amounts of use of the components containing stevensite and / or querolite in the method according to the invention can be determined routinely by the skilled person by means of empirical tests. In most cases, use quantities between 0.5 and 12 kg / t of paper pulp or fibrous pulp suspension will be favorable, preferably between 1 and 8 kg / t, in particular between 1.5 and 7 kg / t, in each case in relation to the pulp / anhydrous suspension (dry weight). Also, it was surprisingly found within the framework of the present invention that the method according to the invention not only allows a very good binding of anionic interfering substances fractions, such as fatty acids, but also an excellent binding or elimination of fractions of substances hydrophobic interferers such as sterols, sterilyesters and triglycerides. The results obtained with this unexpectedly surpass both those obtained with conventional bentonites and those of talcum. A further aspect of the present invention relates to the use of at least one component containing stevensite and / or querolite as described herein for the binding of interfering substances in the production of paper. As mentioned above, the minimum of a component containing stevensite and / or querolite is preferably used in a paper pulp or fibrous pulp suspension containing pulp fractions. However, the present use comprises all kinds of paper and pulps. Particularly preferred are the types of paper mentioned above as paper types containing wood pulp or wood pulp treated with peroxide, those which (in addition to wood pulp) also contain highly purified fiber fractions as is the case, For example, in so-called Newsprint Paper, the so-called "de-inked pulp" (DIP substance), thermo-mechanical pulp (TMP), sulfate cellulose , sulphite cellulose and mixtures of different celluloses. Methods section: as soon as it is not indicated otherwise, the analysis processes indicated below were used: 1. Determination of cation exchange capacity (CEC analysis) and cation fractions Principle: clay (the component containing stevensite and / or querolite) is treated with a large excess of aqueous NH 4 Cl solution, washed and the amount of NH 4 + remaining on the clay is determined according to Kjeldahl. Me + (clay) "+ NH4 + NH4 + (clay)" + Me + (Me + = H +, Na +, 1/2 Ca2 +, 1/2 Mg2 + ...) Apparatus: Strainer, 63 μm; frosted flask Erlenmeyer, 300 ml; analytical balance; membrane filter for vacuum, 400 ml; cellulose nitrate filter, 0.15 μm (Cia. Sartorius); drying cabinet; reflux cooler; hot iron; distillation unit, VAPODEST-5 (Cia. Gerhardt, No. 6550); graduated flask, 250 ml; Flame AAS.

Chemical products: 2N NHC1 solution, Nessler reagent (Cia.Merck, Art. No. 9028); boric acid solution, 2%; sodium hydroxide, 32%; 0.1 N hydrochloric acid; 0.1% NaCl solution; 0.1% KCl solution. Execution: 5 g of clay are sifted through a 63 μm sieve and dried at 110 ° C. After this, Erlenmeyer flush flasks are placed in the exact 2 g heavy weights on the analytical balance by means of differential weighing, and they are mixed with 100 ml of 2N NH 4 Cl solution. The suspension is boiled for one hour at reflux. In the case of clays with a high content of CaCO3, ammonia may develop. In these cases it is necessary to add NH4C1 solution for a long time until the ammonia odor can no longer be seen. It is possible to carry out additional control with a wet indicator paper. After a period of rest of approximately 16 h, the NH4 + bentonite is filtered through a vacuum membrane filter and washed with completely desalinated water (approximately 800 ml) until it is considerably free of ions. The verification of the ion freedom of the washing water is carried out on NH4 + ions with the Nessler reagent which is sensitive to these. The washing time can vary between 30 minutes and 3 days depending on the type of clay. The washed NH + clay is removed from the filter, dried for 2 h at 110 ° C, milled, hovered (sieve 63 μm) and dried again for 2 h at 110 ° C. After this the NH4 + content of the clay according to Kjeldahl is determined. Calculation of the CEC: the CEC (abbreviation in English for the Capacity of Exchange of Cations) of the clay is the content of NH4 + of the clay NH4 + determined according to Kjeldahl (for the CEC of some clay minerals see annex). The data are provided in mval / 100 g of clay (meq / 100 g). Example: Nitrogen content = 0.93%; Molecular weight: N = 14.0067 g / mol 0.93 x 1000 CEC = = 66.4 mVal / 100 g 14.0067 CEC = 66.4 meq / 100 g of bentonite NH4 + Cations exchanged and their fractions: The cations released by the exchange are found in the water washing (sifting). The fraction and type of monovalent cations ("interchangeable cations") was determined in the sieve according to DIN 38406, part 22, spectroscopically. For example, for the determination of AAS, the washing water (sifting) is concentrated, transferred to a 250 ml graduated flask and filled with completely desalinated water to the level mark. The appropriate measurement conditions for FAAS are derived from the following tables.

Calculation of the cations: Value Me (mg / l) x 100 x dilution Me = = mval / 100 g 4 x weight (in g) x molar mass (g / mol) Molar masses (g / mol): Ca = 20,040; K = 39,096; Li = 6.94; Mg = 12156; Na = 22,990; Al = 8,994; Fe = 18,616 In over-activated bentonite calls (components containing stevensite and / or querolite), that is, those that were activated with an amount of, for example, greater than stoichiometric soda, it is possible that the sum of the determined amounts of monovalent cations exceeds the CEC determined as indicated in the preceding. In these cases, the total content of monovalent cations (Li, K, Na) is considered as 100% of the CEC. 2. Determination of the BET surface: The determination was carried out in accordance with DIN 66131 (determination of several points). 3. Determination of wet sifting residue: In the case of the use of pigments and additives, it is important to know if and how many thick parts contain the material to be investigated, which differ from the normal particles by their grain size. These parts are determined by sifting an aqueous suspension with water as the washing liquid. As a wet sifting residue the determined residue is valid under pre-established conditions.

Apparatus: analysis scales, plastic cup, Pendraulik LD 50; sieve: 200 mm in diameter, mesh width 0.025 (25 μm), 0.045 mm (45 μm), 0.053 mm (53 μm) or 0.063 mm (63 μm); ultrasonic bath. First there was a 5% suspension of the component to be analyzed (component containing stevensite and / or querolite) (another, that is, after drying at 110 ° C) in 2000 g of water. For this purpose the component is intermixed- stirring at 930 rpm in about 5 minutes. After a stirring time of 15 additional minutes at 1865 rpm the suspension is poured into the clean and dry sieve (45 μm mesh width) and washed with tap tap water for such a long time until the wash water comes out transparent. After washing the residue of the sieve with water from the tap, the sieve is placed for 5 minutes in an ultrasonic bath to sieve the remaining fine parts. Care must be taken that when the sieve is inserted in the ultrasonic bath no air remains between the water surface and the bottom of the sieve. After the ultrasonic treatment, wash again briefly with tap water. After this the sieve is removed and the water in the ultrasonic bath is renewed. The operation in the ultrasonic bath is repeated until it is no longer possible to recognize dirt in the water. The sieve with the remaining residue is dried at constant weight (another) in the circulating air drying cabinet. After cooling the residue is transferred with a brush to a tray. Evaluation: wet sifting residue (NSR) in (%) by weighing. 4. Determination of particle size according to Malvern: This is a conventional procedure. A Mastersizer (size master determinator) was used from the Cia. Malvern Instruments Ltd, United Kingdom, according to the manufacturer's instructions. The measurements were carried out in air with the provided test chamber ("dry powder feeder"), and the values referred to the test volume were determined. 5. Investigation of the link of interfering substances: In the investigation of the link of impurities, we proceeded as follows: a) Pulp and filtration production: Experiments with peroxide bleached wood pulp The selected pulp (wood pulp bleached with peroxide) can be obtained either directly from the paper mill or stored in the refrigerator before use. The pulp was then diluted to 1% with hot deionized water in a well stirred 2000 ml cup at 10 g atro. While stirring at 150 rpm the pulp preparation was heated with the aid of a hot plate at 40 ° C. When the temperature is reached, the amount to be tested for adsorbent is added to the pulp preparation with the help of a Pasteur pipette. The adsorption time in the paste preparation is then established in 30 minutes at 40 ° C, and the mixture is stirred during this time at 150 rpm. For the production of sifting water the water of 1000 g of this preparation of diluted paste (1% by weight of solid fraction) is separated during 420 seconds in the apparatus of separation of water and retention (Mütek DF3 03 of the Cia. Mütek , DE) (sieve 170 μm, stirring speed 700 rpm). Sifting water tests were examined analytically (see examples). Experiments with DIP The pulp of old paper ("DIP") was diluted to a solids content of 1% with hot water at 40 ° C and homogenized 30 seconds in stage II with a stirring rod ("ESGE-Zauberstab", ESGE / Switzerland) with the use of the so-called impact plate. After this it was stirred at 150 rpm, the adsorbent (component containing stevensite or querolite) was added and then stirred another 30 minutes with a magnetic stirrer. Finally the water was removed as in the wood pulp experiments (see last paragraph). The sifting water was analyzed by flow cytometry. b) Flow cytometric analysis of sifting water: In this case, the so-called pass cytometry was used, as described in Váhásalo et al., "Use of Flow Cytometry in Wet End Research", Paper Technology, 44 (1), page 45, February 2003, and in addition in "Effects of pH and calcium chloride on pitch in peroxide- bleached mechanical pulp suspensions ", 7. European workshop on lignocelluloses and pulp, August 26-29, 2002, Abo / Finland, as well as in" Flow Cytometry of Bacteria and Wood Resin Particles in Paper Proction ", Nordic Pulp and Paper Research Journal, Vol. 19 No. 4/2004, page 450. In these, briefly, a method of scattering light combined with a fluorescence label to count the particles is used. To stain the hydrophobic particles in the sifting water of the old paper pulp and the resin particles in the sifting water of the wood pulp for flow cytometry with fluorescent dye, the Nile Red dye from Molecular Probes / invitrogen was used Detection Technologies (Invitrogen Corporation, 1600 Faraday Avenue, PO Box 6482 Carlsbad, California 92008 USA) as indicated in the preceding Article. c) Analysis by gas chromatography of the sifting water: In this case the method of F. Orsa and B. Holmbom "A Convenient Method for the Determination of Wood Extractions in Papermaking Process Waters and Effluents" was applied (A Convenient Method for the Determination of Wood Extract in Water and Effluents from Paper Manufacturing Process), Journal of Pulp and Paper Science, Vol. 20 No. 12, December 1994, pages J361. BRIEF DESCRIPTION OF THE FIGURES Fig. 1 shows a graphic display of the hydrophobic particles in the sifting water at different dosages of the additives sorb 1 and sorb 2 according to the invention as well as cationized talc as a comparative additive. Fig. 2 shows the graphical exposure of resin particles in the sifting water at different dosages of the sorb 1 and sorb 2 additives according to the invention as well as cationized talc as a comparative additive. It was measured by flow cytometry. Fig. 3 shows the graphic display of the concentration of the extraction substances in the sifting water at different dosages of the additives sorb 1 and sorb 2 according to the invention as well as cationized talc as a comparative additive. Extraction substances were measured by gas chromatography. DETAILED DESCRIPTION OF THE INVENTION The invention is now further explained by the following examples which are not limiting.

Example 1: The following materials were analyzed for the binding of interfering substances. For the investigations the following two materials containing stevensite were used in each case as ground crude clays, both raw clays being milled at a conventional particle size for paper applications. For this purpose a wet sifting residue was adjusted by grinding < 1% by weight on 45 μm. The average particle sizes (D50, relative to volume) were between 2 and 8 μm. The water content of the tests was 10 ± 4%. The stevencite as the main phase was confirmed according to Brindley et al. (in the indicated site) and Martin de Vidales et al. (in the indicated site). In both materials sorb 1 and sorb 2 used also could be checked a fraction of querolite. As indicated in the two previous bibliographical sites, the stevencite can be delimited against the querolite and other lamellae smectites, among other things by means of powder X-ray diffractograms and the displacement of the diffraction pattern after the treatment with ethylene glycol, after heating and different humidity. In order to characterize the materials according to the invention, the magnesium oxide content and the CEC can also be used.

The analytical data on the materials used according to the invention are compiled in the following tables 1 to 3. Table 1: Analytical data Table 2: Mineral impurities Mineral impurities (from X-ray diffractometry) Sorb 1 2-3% quartz, 2-3% feldspar, 0.5-1% calcite Sorb 2 1-2% quartz, 2% feldspar, 0.5-1% calcite Table 3: Silicate analysis Example 2: According to the preceding description, a filtration experiment with a very heavy old paper pulp was carried out. To this paper pulp the additives according to the invention (components containing stevensite and / or querolite) were added before filtration in a dosage of 3 kg / t and 6 kg / t, in each case in relation to the dry weight of the paper pulp. In the reference filtration tests it was also filtered without the addition of the additives. In addition, cationized talc was used in a dosage of 3 kg / t and 6 kg / t as a comparative system. The sifting water was characterized by flow cytometry (see the preceding) in relation to the concentration of hydrophobic particles. The results are shown graphically in Figure 1. Figure 1 shows that the additives according to the invention markedly reduce the concentration of the hydrophobic particles in the sifting water, while the cationized talc used as a comparative does not show significant effects to the same concentrations of use. Example 3: Filtration tests analogous to those of Example 2 were carried out with a pulp bleached with peroxide. The additives according to the invention were dosed again at a concentration of 3 kg / t and 6 kg / t with respect to the dry weight of the pulp. As an additional additive according to the invention, the sorb was added 2 in activated form with alkali (= sorb 3). This material was produced by kneading the wet sorb 2 material with 3% anhydrous soda and subsequent drying and grinding (wet sifting residue less than 1% by weight, average particle size (D50) between 1 and 6 μm). The sifting waters are analyzed both with the aid of flow cytometry and with the gas chromatography method according to Orsa and Holmbom (see the preceding). Figure 2 shows the results of flow cytometry. Also in this paper pulp the two sorb additives 1 and sorb 2 according to the invention led to a remarkable reduction in the number of resin particles in the sifting water. The comparative material (cationized talc) again did not show a significant effect, even with a dosage of 9 kg / t. Figure 3 shows the characterization of the sifting water by gas chromatography. The results found here correlate very well with those of flow cytometry. The data obtained according to the two research methods further demonstrate that an alkaline activation of the sorb material 2 according to the invention leads to a considerable improvement of the binding of interfering substances in the pulp and to an additional reduction of the substances interfering in sifting water (see sorb 3). It is assumed that this effect is caused by an exchange of Ca2 + ions by Na + ions (100% of the CEC) in the stevensite phase. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims

CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. Method for linking interfering substances in the production of paper, characterized in that it comprises the following steps: a) providing at least one component that contains estevensita and / or querolite; b) providing a paper pulp or pulp of fibrous material; c) adding the minimum of a component containing stevensite and / or querolite to the pulp of paper or the pulp of fibrous material; d) allowing the binding of interfering substances to the minimum of a component containing stevensite and / or querolite in the paper pulp or fibrous pulp suspension. Method according to claim 1, characterized in that the component containing stevensite and / or querolite contains both stevensite and also querolite. Method according to any of the preceding claims, characterized in that in the case of the component containing stevensite and / or querolite it is an acid or alkali activated component. Method according to any of the preceding claims, characterized in that the component containing stevensite and / or querolite is used in the form of a particle with an average particle size of between 0.5 and 10 μm, in particular between 2 and 8 μm, and particularly preferably between 3 and 6 μm with respect to volume. Method according to any of the preceding claims, characterized in that the component containing stevensite and / or querolite has a fraction of at least 50%, in particular at least 80%, preferably at least about 90% of monovalent cations such as, for example, H +, Na +, K + and / or Li +, in relation to the cation exchange capacity. Method according to any of the preceding claims, characterized in that the component containing stevensite and / or querolite is used in the form of particles with a wet sifting residue of less than 1% by weight of 45 μm. Method according to any of the preceding claims, characterized in that the addition of the component containing stevensite and / or querolite is carried out in the absence of talc. 8. Method according to any of the preceding claims, characterized in that approximately between 0.5 and 10 kg / t of dry weight of paper pulp or fiber pulp suspension is used, in particular between 1 and 7 kg of pulp or slurry. fiber paste. Method according to any of the preceding claims, characterized in that the paper pulp or the fiber pulp suspension contains fractions of wood pulp. Method according to any of the preceding claims, characterized in that the fraction of wood pulp in the paper pulp or the pulp suspension is at least 10% by weight, in particular at least 30% by weight. weight in relation to the dry weight of the whole pulp or suspension of fiber pulp. 11. Use of a component containing stevensite and / or querolite to bind or eliminate interfering substances in the production of paper. 12. Use according to the preceding claim, wherein the use is made in a pulp of paper or suspension of fiber pulp with fractions of wood pulp. 13 Use according to any of the preceding claims, wherein the paper pulp or fiber pulp suspension contains fractions of hydrophobic interfering substance. 14 Use according to any of the preceding claims, wherein to the pulp of paper or suspension of fiber pulp are added, in addition to the minimum of a component containing stevensite and / or querolite, additional components such as retention agents, other means to eliminate interfering substances, such as talc or bentonite.