• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Slaked lime composition having a content of Ca (OH) 2 particles of platelet crystalline morphology, called platelets, said platelets having a diameter D of a circle circumscribed to the wafer and a thickness, as well as a form factor consisting of the ratio between said circle diameter circumscribing the wafer and said thickness, having a platelet content of between 50 and 100% relative to the total of the Ca (OH) 2 particles and in that said form factor is between 10 and 300 and its manufacturing process.
    公开号:BE1018979A4
    申请号:E2009/0660
    申请日:2009-10-29
    公开日:2011-12-06
    发明作者:Lorgouilloux Marion Gross；Tierry Chopin；Gaetan Blandin
    申请人:Lhoist Rech Et Dev；
    IPC主号:
    专利说明:

    "OFF-LIME COMPOSITIONS AND METHOD FOR THEIR
    MANUFACTURING."
    The present invention relates to slaked lime compositions comprising Ca (OH) 2 particles of platelet crystalline morphology, called platelets, said platelets having a circle diameter circumscribed to the wafer and a thickness, as well as a form factor. consisting of the ratio between said circle diameter circumscribing the wafer and said thickness.
    The slaked lime consists of a set of solid particles, mainly calcium dihydroxide Ca (OH) 2, which is the industrial result of hydration or extinction of quicklime with water. It is also called hydrated lime. Subsequently, the calcium dihydroxide will be named simply "calcium hydroxide".
    Lime means a mineral solid material whose chemical composition is mainly calcium oxide CaO. Quicklime is commonly obtained by calcareous firing, mainly consisting of CaCO3. Quicklime contains impurities, that is, compounds such as magnesium oxide MgO, silica S102 or alumina Al2O3, etc., up to a few percent. It is understood that these impurities are expressed in the aforementioned forms but may actually appear in different phases. In addition, quicklime also contains sulfur compounds; sulfur is usually present in quicklime at 0.01% to 0.2% by weight.
    In a "dry" mode of extinction, the amount of water added is limited to that required for the quenching reaction, increased by that lost to water vapor due to the exothermic nature of the reaction; the product obtained is powdery.
    In a "wet" quench mode, the amount of water added is in substantial excess over the amount strictly necessary for the quenching reaction. A "lime milk" is thus obtained, namely an aqueous suspension of slaked lime particles.
    In a case intermediate to the two previous ones, the product obtained is pasty and one speaks of extinction "by pasty way" (Lime putty, in English).
    In general, the slaked lime obtained can obviously contain the impurities from lime, mentioned above.
    It is generally accepted that the hydration reaction is controlled by a CaO-reprecipitation mechanism of Ca (OH) 2, limited by the diffusion of water within the CaO solid material. At the first contact between quicklime and water, the lime particles dissolve at the surface, at the most active sites leading to the formation of Ca (OH) 2. This reaction is accompanied by an increase in volume and a release of heat. The quicklime particles are then placed under stress, crack, leaving wide access to the water of hydration to continue the reaction. The reaction stops when all the lime has been converted to calcium hydroxide or when all the water in the system has been consumed.
    The kinetics of the hydration reaction of quicklime is clearly dependent on the reactivity of the quicklime. Quicklime resulting from soft cooking will have a high porosity and will have a large contact area with extinguishing water. In this case, the hydration reaction is very fast, often called explosive. Locally, the temperature may rise above 100 ° C and lead to a vapor phase reaction. For lime more cooked or overcooked, the contact surface between lime and water is limited because the porosity of these lime is more closed and therefore the hydration reaction is slower. In all cases, the slaked lime is presented as a set of disordered agglomerates of Ca (OH) 2 crystals of very small size, having any morphology random and sometimes described as amorphous.
    Several phenomena are thus brought into play: the diffusion of water, the explosion of grains and a reaction in the heart of the grains. The observation, especially with the Scanning Electron Microscope (SEM), of the burned lime shows - very predominantly agglomerates of any morphology, nonuniform; - some hexagonal crystals testifying to a secondary and minor mechanism of dissolution of Ca (OH) 2-recrystallization of Ca (OH) 2.
    In order to provide particular properties or to improve the existing properties of calcium hydroxides, there is a need for calcium hydroxides, mainly composed of particles of defined morphology, in particular in the form of platelets, instead of agglomerates. of Ca (OH) 2 random morphology, usually encountered.
    Synthetic calcium hydroxides (portlandite) obtained from sodium hydroxide and calcium chloride whose crystals are in the form of platelets are known (see, for example, Yasue et al (Gypsum and Lime, 1984) and Yilmaz et al. Journal of Materials Science Letters, 1991)). These synthetic calcium hydroxide crystals lead to specific products that are not lime crystals. Among others, Yilmaz et al relates to a cement composition and the effect of the SMF superplasticizer on the morphology and crystallization of portlandite.
    It is also known to promote the production of hexagonal crystals either by modifying the hydration mechanisms of quicklime, or by maturation of already formed aqueous pastes or suspensions, via the dissolution of Ca (OH) 2-recrystallization of Ca ( OH) 2. Maturation however appears as a very slow and very limited phenomenon.
    Those skilled in the art could plan to modify the hydration mechanisms by slowing down the quenching reaction in order to control or modify the morphology of the Ca (OH) 2 particles. One well-known means for slower extinguishing is the use of quick lime. SEM observation, however, shows that such extinction does not lead to the formation of platelets or other particular morphologies.
    Moreover, it is possible to modify the mechanisms of the extinction reaction of quicklime by the use of additives, in particular to promote the dissolution mechanism of
    CaO / reprecipitation of Ca (OH) 2 by slowing down the kinetics of hydration.
    For example, EP 0152008 discloses an aqueous slurry in which there is calcium sulfate and an organic substance, particularly an oxycarbonic acid to retard the extinction of quicklime. In this document there is no mention of crystals in the form of platelets.
    Similarly, US 5,332,436 discloses extinguishing reaction modifying chemicals such as ethanolamine, ethylene glycol and derivatives thereof (see column 2, line 54 to column 3 line 5). There is also mention of the use of diethylene glycol (DEG). These chemical agents delay the quenching reaction. No mineral additives are added. In addition, crystallization in the form of platelets is disclosed in order to increase the specific surface area of the resulting slaked lime. The level of platelets with respect to agglomerates of any morphology is not specified; their thickness is not disclosed.
    BE 1017305 relates to particles of calcium hydroxide and / or magnesium with very high reactivity, characterized in that they have an X-ray diffraction line typical of slaked lime, of intensity less than 50%, preferably less than 20% (reduction of at least 75%) of the intensity of a traditional hydrated lime, a sign of low crystallization, an X-ray diffraction line being all the more intense as the crystallization is high. Indeed, preferably at least 50% by weight, advantageously at least 75% or 85% by weight of the particles is in the form of micelles very weakly crystallized. According to the document BE1017305, this slaked lime is prepared by simply reacting a ground quicklime with a quantity of water corresponding to a specific water / lime weight ratio of 0.60 / 1 and optionally comprises additives of the family. siloxanes or organic polymers having one or more ether and alcohol functional groups and mixtures thereof. According to an advantageous detail, this document mentions that at least 50% by weight of the particles is formed by platelets having a thickness of less than 150 μm, in particular less than 75 μm (see p.12.1, 24 to 26). ).
    The document KR 2002 0004916 discloses an extinction during which additives are added gradually and at a controlled temperature, in the presence of a co-solvent. The additives are extinguishing retardants and surfactants or dispersants, added in a significant amount, 1 to 3% relative to the extinguishing water, ie 3% to 15% relative to the mass of quicklime.
    BE 1006655 in the name of the applicant relates to a process for producing a lime milk highly concentrated in solid material (up to 60%) and low viscosity. This whitewash is prepared in the presence of a mineral anion (sulphate, sulphite or chloride) and a polyanion (polyacrylate, polymethacrylate, methacrylic acid ...). The inorganic anion is added independently of the organic polyanion, the inorganic compound being added from the beginning of the reaction while the polyanion is added at the beginning, during or at the end of the reaction and preferably during or at the end of the reaction. reaction, which is clearly related to their respective roles. The mineral anion is intended to slow the hydration of quicklime and lead to the formation of larger crystals of Ca (OH) 2, the polyanion playing a role of dispersant. The milk obtained by this method contains microfilms of Ca (OH) 2. These microfeuilles have a thickness of less than 0.5 μm, preferably of 0.3 μm, and may have a lower face and an upper face parallel to each other. the surface of said faces being less than 200 pm 2, preferably 100 pm 2.
    JP 60086066 discloses a use of a strong acid metal salt alone or in combination with a polyhydric alcohol for the purpose of obtaining slaked lime crystals in the form of platelets. The rate of these specific morphology crystals with respect to non-uniform Ca (OH) 2 particles is not reported. The temperature of the hydration reaction is kept below 50 ° C, in order to limit the speed of the hydration reaction.
    Various mechanisms are mentioned in the literature to explain the delayed effect that additives have on the hydration reaction of quicklime: blocking the most active sites of quicklime, in particular by adsorption of additives on the surface of particles of quicklime; the formation around the quicklime particles of a poorly soluble layer which delays the extinction reaction; adsorption of additives on the surface of Ca (OH) 2 seeds, preventing the growth of crystals; the formation of complexes between the additives and the Ca ++ ions in solution.
    The use of sulphates (sulphites and bisulphites also) is particularly envisaged, so as to slow the kinetics of hydration of quicklime. In particular, it has been shown that the use of sulfate contributes to the formation of platelet hexagonal crystals of calcium hydroxide. However, the level of hexagonal crystals remains reduced and the width of the platelets generally remains low in comparison with their thickness.
    The addition of sulphate as sole additive during extinction, for example according to JP 60086066, makes it possible to observe platelets with a SEM but of small size (diameter <5 μm) and thick with respect to their size (thickness: 1 - 5 pm).
    The use of DEG as the only additive at the time of extinction, for example according to US 5,332,436 or JP 60086066, makes it impossible to observe at MEB a significant proportion of platelets or the like, which remain marginal with respect to the whole particles.
    As noted above, there is however a need for calcium hydroxide compositions, the majority of the particles has a specific morphology.
    The aim of the invention is to overcome the drawbacks of the state of the art by providing slaked lime compositions which have a high content of Ca (OH) 2 particles having a defined morphology, unlike the documents of the prior art. for which the presence of platelets is fortuitous and / or uncontrolled and in all cases, the platelet morphology is a minority.
    To solve this problem, there is provided according to the invention, a slaked lime composition having a platelet content of between 50 and 100% relative to the total particles of Ca (OH) 2, and said form factor is included between 10 and 300
    Indeed, the composition according to the invention therefore has a majority of Ca (OH) 2 particles which are in the form of platelets and the formation of these platelets is controlled and reproducible, namely that the level of these particles of Ca ( OH) 2 of defined morphology is greater than 50%, relative to the total particles of Ca (OH) 2, including those of random morphology, usually encountered.
    In addition, in the composition according to the invention, said platelets have a face of characteristic dimension D, greater than the thickness e. The characteristic dimension D is the diameter of the circle circumscribing one face of the wafer.
    Indeed, it is appropriate that these three-dimensional crystals of Ca (OH) 2 of defined morphology (particles of platelet crystalline morphology) have a ratio D greater than or equal to 10.
    This ratio is called in the context of the present invention "form factor". In the aforementioned documents, slaked lime with such calcium hydroxide particles are not described.
    More particularly, the particles having a platelet crystalline morphology have a form factor D / e of between 10 and 300, preferably between 20 and 200, more preferably between 30 and 100, advantageously between 45 and 80.
    Advantageously, the particles of the slaked lime composition according to the invention have a substantially hexagonal platelet crystal morphology.
    By the term "substantially hexagonal platelet crystalline morphology" is meant crystallized particles of slaked lime in three dimensions, one of whose faces, when the crystallization is complete, an irregular hexagonal section, regular or truncated.
    Advantageously, the slaked lime composition has a platelet content of greater than 70%, more particularly greater than 80% and advantageously greater than 90%, relative to the total of Ca (OH) 2 particles, including those of random morphology, encountered. habitually.
    Advantageously, the dimension D is between 1 μm and 80 μm. Most of the particles having a platelet crystal morphology will, more particularly, have a dimension D of between 2 and 40 μm and preferably between 3 μm and 30 μm.
    Preferably, the thickness e is between 0.05 μm and 1 μm and preferably between 0.1 and 0.5 μm.
    Advantageously, the composition according to the invention is obtained by adding at least one inorganic compound having a sulfur content and an organic compound, namely diethylene glycol (DEG). Consequently, the composition according to the invention has a sulfur content, preferably between 0.01% and 1.5% relative to the weight of the composition. In addition, the composition according to the invention has, in a preferred form, a DEG content, preferably between 0.1% and 2% relative to the weight of the composition.
    In this way, the slaked lime composition according to the invention makes it possible to maintain a relatively high Ca (OH 2) 2 concentration and thus to obtain a composition of high purity.
    Preferably, the calcium hydroxide is present in an amount ranging from 80% to 98% by weight relative to the total weight of the composition, preferably in an amount of between 85% and 97%, more particularly between 90% and 96% and very advantageously between 92% and 95% by weight relative to the total weight of the composition.
    It is indeed particularly advantageous that the slaked lime composition according to the invention is of high purity, all morphologies combined.
    Preferably, the content of alkali metal (sodium or potassium in particular) of the composition according to the invention is less than 3% by weight, more particularly less than 2% and even less than 1% by weight, relative to the total weight of the composition.
    Other embodiments of the composition according to the invention are indicated in the appended claims.
    The invention also relates to a process for producing a slaked lime from a quicklime.
    This process is characterized in that it comprises: a mixture of quicklime, extinguishing water, a sulfur-containing mineral additive and DEG, an extinction of said quicklime by said extinguishing water, in the presence of said sulfur-containing mineral additive and DEG, Ca (OH) 2 platelet formation having a circle diameter circumscribed to the wafer and a thickness, and a form factor consisting of a ratio of said circle diameter circumscribed to the wafer at the thickness of between 10 and 300, at a platelet content of between 50 and 100% relative to the total of Ca (OH) 2 particles formed
    A slaked lime composition according to the invention can be prepared according to a method of slaking lime using a pair of additives, one being of mineral origin (sulfur mineral additive), the other organic (DEG). .
    Said sulfur-containing mineral additive and DEG can be added to either quicklime or extinguishing water, together or separately (one in quicklime, the other in water). In all cases, these two additives must be present when the water is brought into contact with the quicklime.
    In an advantageous embodiment, said sulfur mineral additive is added to the quicklime and the DEG is added to the quenching water.
    In a preferred embodiment, said sulfur mineral additive and DEG are added to the quenching water.
    As can be seen, the method according to the invention does not require more infrastructure than an infrastructure in which a current channel extinction is performed. The process is indeed particularly flexible since the additives are added to either quicklime or extinguishing water. However, it is advantageous that the combination of additive is added to the extinguishing water.
    Preferably, the sulfur-containing mineral additive is chosen from the group of sulfur-containing compounds, preferably from sulphates, sulphites, bisulfates and bisulphites of solubility (at 20 ° C.) of 1 g / dm 3, of their derivatives and of their mixtures. Said mineral additive is more particularly chosen from the group consisting of CaSO 4 (in the form of gypsum CaSO 4 .2H 2 O for example), MgSO 4, Na 2 SO 4, Na 2 SO 3, NaHSO 4 and NaHSO 3, their derivatives and their mixtures. The sulfur-containing mineral additive is, according to the invention, a salt, or the corresponding acid, chosen so that it is capable of forming a poorly soluble compound with calcium ions in solution at the moment of hydration reaction of quicklime. This poorly soluble compound preferably has a solubility in water of between 0.05 and 3 g / dm3 at 20 ° C.
    In a particularly advantageous manner, said sulfur-containing mineral additive is added in an amount of between 0.1% and 5%, in particular between 0.3% and 2.5% and preferably between 0.5% and 1.5% by weight. anhydrous additive weight based on the weight of quicklime.
    In this way, the total amount of sulfur, from quicklime and said sulfur mineral additive present in the medium before extinction, is between 0.03% and 1.75%.
    Part of the sulfur present in the medium before extinction can of course be removed by the excess water and it is estimated that the fraction of sulfur remaining in the composition according to the invention varies between 50% and 100% of the sulfur initially present in the medium. before extinction.
    In addition, the DEG is advantageously added in an amount ranging from 0.1% to 2.5% by weight relative to the weight of quicklime, more particularly from 0.2% to 1%, and particularly preferential from 0.3% to 0.6% by weight relative to the weight of quicklime.
    Advantageously, said water is added for quenching in a quicklime / water weight ratio of between 1 / 1.5 and 1/12. Preferably, quicklime is added to the water. The product is then obtained in the form of a paste or a milk of lime.
    In some embodiments, the reaction time is 1 to 5 hours, especially 2 hours. Particularly advantageously, the medium is stirred during part or all of the reaction time.
    The process does not require temperature control.
    A curing time of the aforesaid mixture, with or without stirring, of several hours, in particular from 12 h to 24 h can also be applied to the medium. A subsequent step of removing the water, possibly combined with deagglomeration or grinding, allows to harvest a powdery product.
    This method allows a control of the morphology, thanks to the aforementioned combination of additives.
    Other embodiments of the process according to the invention are indicated in the appended claims.
    Other features, details and advantages of the invention will emerge from the description given below, without limitation and with reference to the examples and figures.
    FIG. 1 is a scanning electron microscope view focused on a Ca (OH) 2 wafer obtained according to the invention.
    FIG. 2 is a scanning electron microscope view of a set of Ca (OH) 2 platelets of the composition according to the invention.
    FIG. 3 is another view by scanning electron microscope focused on a Ca (OH) 2 wafer of the composition according to the invention.
    Figure 4 is a graphic illustration of the incidence of the sulfur-containing mineral additive (gypsum) and DEG on the kinetics of the quicklime quenching reaction according to the invention.
    As can be seen in FIG. 1 and in FIG. 3, the composition according to the invention has particles of Ca (OH) 2 in the form of substantially hexagonal platelets having a high form factor (low thickness e and high diameter D). circumscribed circle). Figure 2 illustrates a set of obtained particles where the number of platelets is high.
    As can be seen, the particles have a platelet crystalline morphology (small thickness e and large diameter D) substantially hexagonal. This means that the crystallization tends to form regular or irregular hexagonal crystals and that this includes all the intermediate forms illustrated in FIG.
    FIG. 4 represents the evolution of the temperature as a function of the extinction time when 150 g of industrial quicklime are hydrated in 600 ml of water, initially at 20 ° C. Four situations are illustrated: 1. a control solution without additives; 2. extinction of quicklime with water containing 0.5% DEG; 3. slaking quicklime with water containing 1% gypsum and 4. quenching quicklime with water containing 1% gypsum and 0.5% DEG. The percentages of the aforementioned additives are expressed relative to the weight of quicklime.
    As can be seen from FIG. 4, the DEG alone hardly modifies the curve with respect to the control solution. Moreover, no platelet formation is observed (see in particular Comparative Example No. 2). On the other hand, gypsum alone can delay the reaction. The delay in hydration is represented by the value of teo, ie the time required to reach 60 ° C in the suspension of slaked lime, from a water at 20 ° C. Platelet morphology is observed but the form factor is low (see in particular Comparative Example No. 1).
    In the coupled use of gypsum and DEG, FIG. 4 shows a synergy between the two additives, the addition of DEG leading to a significant additional delay effect with respect to the addition of gypsum alone. A platelet morphology is observed which has a high form factor (see in particular example No. 1).
    These results suggest that the mineral additive with a sulfur content appears to have an effect on the control of morphology whereas the DEG appears to have an effect on the control of platelet thickness.
    The invention will now be described in more detail by way of non-limiting examples.
    EXAMPLES
    Examples 1 to 10
    All the tests are carried out using 150 g of industrial quicklime of the same origin, except for example 7. The mass of water used for a hydration reaction is calculated according to the mass ratio CaO / H20 chosen for this method. reaction, as shown in Table 1 below. For each reaction, the calculated mass of water, previously heated to 20 ° C, is introduced into a vessel equipped with a stirring system. The stirring system is chosen such that the diameter of the stirring blades corresponds to about 50% of the internal diameter of the isothermal vessel.
    The additives are added to the water, first the mineral and then the organic (DEG); the various additives used as well as the proportions in which they were added, are noted in Table 1 below. The proportions of additive are expressed in relation to the mass of quicklime.
    Stirring is maintained for a few minutes to ensure good homogeneity of the system. At the end of this period, the 150 g of quicklime are introduced into the water / additives mixture. This reaction medium is stirred for 2 hours, then the lime milk obtained by this method is left to stand for 1 night before being filtered on paper and dried at 105 ° C. The characterization of hydrated products is done by scanning electron microscopy (SEM).
    Table 1
    Ratio1 =% by weight of the anhydrous sulfur-containing mineral compound relative to the mass of CaO.
    Ratio2 =% by weight of DEG with respect to the mass of
    CaO.
    Ratio3 = weight ratio of the amount of quicklime to the quantity of water D in pm4 = diameter of platelets in pm = diameter of the circle circumscribed in the wafer in μm (if the face is not a regular polygon, the circumscribed circle is the smallest that can include the entire wafer face).
    e in pm5 = platelet thickness in μm P% 6 = proportion of particles with a platelet morphology to the total number of Ca (OH) 2 particles.
    Die7 = form factor = ratio of diameter (μm) to thickness (μm) of platelets
    Example 11
    Example 1 was repeated with 20 kg of quicklime. The product obtained under the conditions given with 20 kg of quicklime is similar to that obtained under the same experimental conditions with 150 g of quicklime. The proportion of platelets obtained was greater than 90%, the platelet diameter D was between 3 and 45 μm while the thickness e was 0.2 to 0.3 μm. The form factor was between 10 and 225.
    COMPARATIVE EXAMPLES Comparative Example 1
    Example 1 was repeated but without adding any organic compound. The mass of sulfur in the quicklime is 0.015 g while the mass of sulfur provided by the mineral additive is 0.353 g. The mass of the initial solid mixture is 151.5 g and the percentage of sulfur in the initial mixture is therefore 0.24. The results are shown in Table 2. As can be seen, many platelet crystalline morphology Ca (OH) 2 extinct particles are synthesized, but platelets are very small and the form factor is low.
    Comparative Example 2
    Example 1 was repeated but without adding any mineral additive. The results are shown in Table 2. As can be seen, platelet formation was not observed.
    Comparative Example 3
    Example 1 was repeated but the mineral additive is sodium sulfate and the proportion of quicklime in relation to the amount of water was 1 / 0.6. The results are shown in Table 2. As can be seen, platelet formation was not observed, which can probably be attributed to the fact that the proportion of quicklime in relation to the amount of water is too high .
    Comparative Example 4
    Example 2 was repeated but the mineral additive is magnesium nitrate hydrated six times. The results are shown in Table 2. As can be seen, platelet formation was not observed.
    Comparative Example 5
    Example 2 was repeated but the mineral additive is magnesium iodate hydrated four times. The results are shown in Table 2. As can be seen, the platelets are too small, they are too small and the form factor too low. Comparative Example 6
    Example 1 was repeated, but the mineral additive added at a level of 1% anhydrous mineral additive relative to the weight of quicklime is SrS04, a poorly soluble sulfur carrier (solubility in water at 20 ° C.). C = 0.14 g / dm3). The mass of sulfur in the quicklime is 0.015 g while the mass of sulfur provided by the mineral additive is 0.261 g. The mass of the initial solid mixture is 151.5 g and the percentage of sulfur in the initial mixture is therefore 0.18. The results are shown in Table 2. As can be seen, the formation of Ca (OH> 2) slaked lime particles of platelet crystalline morphology is very limited.
    Comparative Example 7
    Example 1 was repeated, but the mineral additive added at a level of 1% of anhydrous mineral additive relative to the weight of quicklime is five times hydrated Na2S203, a soluble sulfur carrier which forms with Ca ++ ions. in solution from quicklime a very soluble compound (solubility in water at 20 ° C of CaS203 very high). The mass of sulfur in the quicklime is 0.015 g while the mass of sulfur provided by the mineral additive is 0.608 g. The mass of the initial solid mixture is 151.5 g and the percentage of sulfur in the initial mixture is therefore 0.41. The results are shown in Table 2. As can be seen, platelet formation was not observed.
    Comparative Example 8
    Example 1 was repeated, but decreasing the proportion of water in the mixture. This time, 500 g of quicklime No. 1 was added in 500 g of demineralized water at 20 ° C which corresponds to a CaO / H 2 O ratio of 1/1 instead of 1/4 in Example 1. This case can be considered as hydration in pasty / dry way. Stirring was modified to obtain a homogeneous mixture. The mass of sulfur in the quicklime is 0.05 g while the mass of sulfur provided by the mineral additive is 1.176 g. The mass of the initial solid mixture is 505 g and the percentage of sulfur in the initial mixture is therefore 0.24. The results are shown in Table 2. As can be seen, no platelet formation is observed.
    Table 2 comparative examples
    Ratio1 =% by weight of the anhydrous compound relative to the mass of CaO.
    Ratio2 =% by weight of the organic additive relative to the mass of CaO.
    Ratio3 = weight ratio of the amount of quicklime to the quantity of water D in pm4 = diameter of platelets in pm = diameter of the circle circumscribed in the wafer in pm.
    e in pm5 = platelet thickness in μm.
    P% 6 = proportion of particles with platelet morphology relative to the number of Ca (OH) 2 particles.
    D / e7 = form factor = ratio of diameter (μm) to thickness (μm) of platelets.
    Comparative Example 9
    Example 1 was repeated, but the DEG which is the organic additive used in Example 1 is replaced by mono-ethylene glycol (MEG) at a level of 0.5% by weight of the quicklime. The mass of sulfur in the quicklime is 0.015 g while the mass of sulfur provided by the mineral additive is 0.353 g. The mass of the initial solid mixture is 151.5 g and the percentage of sulfur in the initial mixture is therefore 0.24. The results are shown in Table 3. As can be seen, the platelets obtained are small and their form factor is low. The Ca (OH) 2 quenched lime particles of platelet crystalline morphology obtained are similar to that obtained in Comparative Example 1 in the presence of only gypsum, indicating that MEG has no additional effect with respect to gypsum alone. Comparative Example 10
    Example 1 was repeated, but the DEG which is the organic additive used in Example 1 is replaced by tri-ethylene glycol (TEG) to 3% of the weight of the quicklime. The mass of sulfur in the quicklime is 0.015 g while the mass of sulfur provided by the mineral additive is 0.353 g. The mass of the initial solid mixture is 151.5 g and the percentage of sulfur in the initial mixture is therefore 0.24. The results are shown in Table 3. As can be seen, the platelets obtained are small and their form factor is low. The Ca (OH) 2 quenched lime particles of platelet crystalline morphology obtained are similar to that obtained in Comparative Example 1 in the presence of gypsum only, indicating that TEG has no additional effect with respect to gypsum alone.
    Comparative Example 11
    Example 1 was repeated, but DEG, which is the organic additive used in Example 1, is replaced by diethanolamine (DEA) at a level of 3% by weight of the quicklime. The mass of sulfur in the quicklime is 0.015 g while the mass of sulfur provided by the mineral additive is 0.353 g. The mass of the initial solid mixture is 151.5 g and the percentage of sulfur in the initial mixture is therefore 0.24. The results are shown in Table 3. As can be seen, the platelets obtained are small and their form factor is low. The Ca (OH) 2 quenched limestone particles of platelet crystalline morphology obtained are similar to that obtained in Comparative Example 1 in the presence of gypsum only, indicating that DEA has no additional effect with respect to gypsum alone.
    Table 3 comparative examples
    Ratio1 =% by weight of the anhydrous compound relative to the mass of CaO.
    Ratio2 =% by weight of the organic additive relative to the mass of CaO.
    Ratio3 = weight ratio of the amount of quicklime to the quantity of water D in pm4 = diameter of platelets in pm = diameter of the circle circumscribed in the wafer in pm.
    e in pm5 = platelet thickness in μm.
    P% 6 = proportion of particles with platelet morphology relative to the number of Ca (OH) 2 particles.
    Die7 = form factor = ratio of diameter (μm) to thickness (μm) of platelets.
    It should be understood that the present invention is in no way limited to the embodiments described above and that many modifications can be made without departing from the scope of the appended claims.
    权利要求:
    Claims (18)
    [1]
    A composition of slaked lime comprising Ca (OH) 2 particles of platelet crystalline morphology, called platelets, said platelets having a circle diameter D circumscribed to the wafer and a thickness e, and a form factor consisting of the ratio between said circle diameter circumscribed in the wafer and said thickness, characterized in that the composition has a platelet content of between 50 and 100% relative to the total of Ca (OH) 2 particles, and in that said form is between 10 and 300.
    [2]
    2. slaked lime composition according to claim 1, wherein said form factor D / e is between 20 and 200, more preferably between 30 and 100, advantageously between 45 and 80.
    [3]
    The slaked lime composition of claim 1 or claim 2, wherein said particles having platelet crystal morphology have a substantially hexagonal platelet crystal morphology.
    [4]
    4. slaked lime composition according to any one of claims 1 to 3, wherein said platelet content is greater than 70%, more particularly greater than 80% and advantageously greater than 90%, relative to the total particles of Ca (OH) 2.
    [5]
    The slaked lime composition according to any one of claims 1 to 4, wherein the dimension D is between 1 μm and 80 μm, more preferably between 2 and 40 μm, and preferably between 3 μm and 30 μm.
    [6]
    The slaked lime composition according to any one of claims 1 to 5, wherein said thickness e is between 0.05 μm and 1 μm and preferably between 0.1 and 0.5 μm.
    [7]
    7. slaked lime composition according to any one of claims 1 to 6, having a sulfur content, preferably between 0.01% and 1.5% relative to the weight of the composition.
    [8]
    8. slaked lime composition according to any one of claims 1 to 7, having a DEG content, preferably between 0.1% and 2% relative to the weight of the composition.
    [9]
    A composition according to any one of the preceding claims, wherein the calcium hydroxide is present in an amount of from 80% to 98% by weight based on the total weight of the composition, preferably in an amount of from % and 97%, more particularly between 90% and 96% and very advantageously between 92% and 95% by weight relative to the total weight of the composition.
    [10]
    10. A process for producing a slaked lime from a quicklime comprising: a mixture of quicklime, extinguishing water, a sulfur-containing mineral additive and DEG, an extinction of said quicklime; by said quenching water, in the presence of said sulfur-containing mineral additive and DEG, platelet formation of Ca (OH) 2 having a circle diameter circumscribed to the wafer and a thickness, and a form factor consisting of a ratio of said circle diameter circumscribed to the wafer to the thickness of between 10 and 300, at a platelet content of between 50 and 100% relative to the total of particles of Ca (OH) 2 formed.
    [11]
    The method of claim 10, wherein said sulfur mineral additive is added to the quicklime and the DEG is added to the quenching water.
    [12]
    The method of claim 10, wherein said sulfur mineral additive and DEG are added to the extinguishing water.
    [13]
    13. A method according to any one of claims 10 to 12, further comprising maturing the aforesaid mixture for 12 to 24 hours.
    [14]
    The process according to any of claims 10 to 13, wherein said sulfur mineral additive is selected from the group consisting of sulphates, sulphites, bisulphates and bisulphites, having a solubility at 20 ° C greater than or equal to 1 g / dm3. and is more particularly selected from the group consisting of CaSO 4, MgSO 4, Na 2 SO 4, Na 2 SO 3, NaHSO 4 and NaHSO 3 from their derivatives and mixtures thereof
    [15]
    The process according to any one of claims 10 to 14, wherein said sulfur mineral additive is added in an amount of between 0.1% and 5%, in particular between 0.3% and 2.5%, and preferably between 0.5% and 1.5% by weight of anhydrous additive based on the weight of quicklime.
    [16]
    The process according to any one of claims 10 to 15, wherein the DEG is added in an amount of from 0.1% to 2.5% by weight based on the weight of quicklime, more particularly 0.2 % to 1%, and particularly preferably from 0.3% to 0.6% by weight relative to the weight of quicklime.
    [17]
    17. Method according to any one of claims 10 to 16, wherein said water is added for extinction in a quicklime / water weight ratio between 1 / 1.5 and 1/12.
    [18]
    18. A method according to any one of claims 10 to 17, further comprising a removal of water, optionally combined with deagglomeration or grinding.
    类似技术:
    公开号 | 公开日 | 专利标题
    BE1018979A4|2011-12-06|DETACHED LIME COMPOSITIONS AND METHOD FOR MANUFACTURING SAME.
    CA2691686C|2015-10-20|Dual component system containing retarded aluminous cement with instantaneous initiation
    EP3046877B1|2019-02-06|Mineral composition based on a mixed solid phase of calcium and magnesium carbonates and process for preparing such a composition
    EP2895437B1|2018-06-13|High-finesse limewater composition
    BE1021199B1|2015-07-28|CALCO-MAGNESIAN HANDHELD SUSPENSION
    CA2533529C|2012-04-03|Calco-magnesian aqueous suspension and method for the production thereof
    WO1998002499A1|1998-01-22|Fluid comprising cellulose nanofibrils and its use for oil mining
    EP1999082B1|2009-09-23|Stabilization of milk of lime suspensions
    FR2647433A1|1990-11-30|PROCESS FOR THE AQUEOUS PREPARATION OF PURIFIED CALCIUM SULFATE
    FR2560607A1|1985-09-06|PROCESS FOR DELAYING THE CURING OF A GRINDING SUSPENSION FOR THE PRODUCTION OF BASIC PEARLS FOR DETERGENT COMPOSITIONS, SUSPENSIONS, BASE PEARLS AND DETERGENT COMPOSITION CONTAINING SAME
    FR3018518B1|2019-07-12|LIME MILK COMPOSITION
    CA2190295C|2003-09-16|Method for processing trihydrate alumina bauxite with a low reactive silica content
    FR2993267A1|2014-01-17|CALCIUM AND MAGNESIAN MIXED COMPOUND AND PROCESS FOR PRODUCING THE SAME
    FR2697830A1|1994-05-13|Process for the preparation of injectable grout
    EP0646099A1|1995-04-05|Method for preparing an aqueous calcium sulphate-based suspension
    EP0168281B1|1989-04-19|Process for the production of a sodium tripolyphosphate hexahydrate with a high absorbant capability, and tripolyphosphate prepared by this process
    BE1022069B1|2016-02-15|LIME MILK COMPOSITION
    BE1027914B1|2021-07-26|PROCESS FOR THE PRODUCTION OF AN ALKALINE AGGREGATE
    EP3166397B1|2020-10-07|Delayed reactivity quicklime, process for manufacturing same and use thereof
    EP0151890B1|1988-08-03|Accelerating compositions for the hydraulic setting of anhydrite, and processes for their use
    BE686798A|1967-03-13|
    BE516434A|
    WO2014053536A1|2014-04-10|Method for preparing an inorganic binding composition
    BE459118A|
    BE825529A|1975-05-29|PROCESS FOR PREPARING MIXTURES OF RAW MATERIALS FOR VITRIFIABLE COMPOSITIONS
    同族专利:
    公开号 | 公开日
    BRPI0919886A2|2016-02-16|
    WO2010049479A1|2010-05-06|
    EP3191424A1|2017-07-19|
    RU2519285C2|2014-06-10|
    US8440163B2|2013-05-14|
    RU2011121649A|2012-12-10|
    US20110219986A1|2011-09-15|
    BRPI0919886A8|2017-10-24|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    JPS58176124A|1982-04-10|1983-10-15|Agency Of Ind Science & Technol|Preparation of calcium hydroxide plate crystal|
    JPS6086066A|1983-10-18|1985-05-15|Okutama Kogyo Kk|Manufacture of plate-like calcium hydroxide|
    US5332436A|1990-11-21|1994-07-26|Chemical Lime Company|Method of increasing the surface area and plastic properties of hydrated lime|
    BE1006655A5|1992-01-31|1994-11-08|Lhoist Rech & Dev Sa|Milk lime and / or magnesium hydroxide.|
    WO1997039991A1|1996-04-24|1997-10-30|Yabashi Industries Co., Ltd.|Process for producing calcium hydroxide|
    KR20020004916A|2001-11-26|2002-01-16|김상봉|Manufacturing method of slaked lime|
    BE1017305A6|2007-10-19|2008-05-06|Lime Technology Consulting Spr|Hydroxide calcium and / or magnesium very high reactivity and its preparation.|
    WO1992009528A1|1990-11-21|1992-06-11|Lhoist Recherche Et Developpement S.A.|Method for preparing calcium and/or magnesium hydroxide, and use thereof|
    US5173279A|1990-11-21|1992-12-22|Lhoist Recherche Et Developpement S.A.|Method and composition for treating flue or exhaust gases utilizing modified calcium hydroxide|
    RU2166485C1|2000-03-20|2001-05-10|Хозин Вадим Григорьевич|Method of producing slaked lime and device for its embodiment|
    US7326400B2|2005-08-11|2008-02-05|Chemical Lime Company|Treatment of high sulfate containing quicklime|
    US20100196239A1|2007-10-19|2010-08-05|Lime Technology Consulting Sprl|Calcium and/or magnesium hydroxide with very high reactivity, and preparation thereof|
    US8440163B2|2008-10-30|2013-05-14|S.A. Lhoist Recherche Et Development|Slaked lime composition and its manufacturing process|US8440163B2|2008-10-30|2013-05-14|S.A. Lhoist Recherche Et Development|Slaked lime composition and its manufacturing process|
    WO2015135954A1|2014-03-11|2015-09-17|Lhoist Recherche Et Developpement Sa|Lime water composition|
    BE1022069B1|2014-03-11|2016-02-15|Lhoist Recherche Et Developpement Sa|LIME MILK COMPOSITION|
    CN110997593A|2017-07-17|2020-04-10|埃科莱布美国股份有限公司|Rheology modifier for slurries|
    CN108046617B|2017-12-25|2020-09-29|上海盛宝冶金科技有限公司|Method for preparing high-purity metallurgical lime|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    BE200800584|2008-10-30|
    BE200800584|2008-10-30|
    [返回顶部]