GB2360034A - Precipitating aragonite calcium carbonate - Google Patents
Precipitating aragonite calcium carbonate Download PDFInfo
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- GB2360034A GB2360034A GB0105274A GB0105274A GB2360034A GB 2360034 A GB2360034 A GB 2360034A GB 0105274 A GB0105274 A GB 0105274A GB 0105274 A GB0105274 A GB 0105274A GB 2360034 A GB2360034 A GB 2360034A
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- aragonite
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/02—Compounds of alkaline earth metals or magnesium
- C09C1/021—Calcium carbonates
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F11/00—Compounds of calcium, strontium, or barium
- C01F11/18—Carbonates
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F11/00—Compounds of calcium, strontium, or barium
- C01F11/18—Carbonates
- C01F11/182—Preparation of calcium carbonate by carbonation of aqueous solutions and characterised by an additive other than CaCO3-seeds
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F11/00—Compounds of calcium, strontium, or barium
- C01F11/18—Carbonates
- C01F11/182—Preparation of calcium carbonate by carbonation of aqueous solutions and characterised by an additive other than CaCO3-seeds
- C01F11/183—Preparation of calcium carbonate by carbonation of aqueous solutions and characterised by an additive other than CaCO3-seeds the additive being an organic compound
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/03—Particle morphology depicted by an image obtained by SEM
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/10—Solid density
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/22—Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability
Abstract
A process for producing a particulate precipitated aragonite calcium carbonate, comprises reacting an aqueous calcium hydroxide slurry with a carbon dioxide or a gas containing it, wherein the parameters of said process, including at least one preselected active agent, mode of operation, operating concentrations of raw materials, operating temperature, operating mixer speed and operating pH, are such that (A) the specific gravity of the product after drying for 12 hours at 120{C is <2.5 g/cm<SP>3</SP>; and (B) the specific gravity of this dry product after ignition for eight hours at 500{C is <2.5 g/cm<SP>3</SP>. The active agent may be carboxylic acid of the formula CH<SB>3</SB>(CH<SB>2</SB>)<SB>n</SB> COOH where n = 7-10 or a salt, anhydride ester or acyl halide thereof or a ketene CH<SB>3</SB>(CH<SB>2</SB>)<SB>n</SB> C=C=O (n=7-10).
Description
2360034 PRECIPITATED ARAGONITE AND A PROCESS FOR PRODUCING IT
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to a novel form of precipitated aragonite and to a novel process for producing it.
Various routes are known for the production of calcium carbonate, which finds use as a thickening material, as a filler, as an extender, and most of all as a pigment, in a variety of industries such as pharmaceuticals, plastics, adhesives, printing, coating (paint), paper, rubber and in filtration. For such purposes, there may be used ground calcium carbonate (GCC) or precipitated calcium carbonate.(PCC). PCC in general possesses advantages over GCC, in that it is economical to produce and its precise composition, or purity, can be more strictly controlled.
The most frequently used chemical process for producing PCC is based on the carbonation of aqueous suspensions of calcium hydroxide (also known as "milk of lime" or "slaked lime") with carbon dioxide gas, or with a carbon dioxide containing gas. This process gives rise to relatively pure precipitated calcium carbonate and is a preferred process, because there are no serious problems of contamination of the product with undesired salts, and moreover it can be controlled in order to adjust the properties of the final product. Thus, the process is based essentially on four stages: firstly, calcination of raw limestone to produce calcium oxide or "quicklime" and carbon dioxide gas or a carbon dioxide containing gas; secondly, "slaking" of the quicklime with water to produce an aqueous suspension of calcium hydroxide; thirdly, carbonation of the calcium hydroxide with carbon dioxide gas or a carbon dioxide containing gas; and finally, downstream operations such as dewatering, drying, deagglomeration, grinding, surface treatment, surface coating, mixing with other minerals (e.g. titanium dioxide, talc, kaolin, GCC, PCC - including aragonite PCC) and dyeing, which allow optimization of the properties of the precipitated calcium carbonate particles in order to be adapted to their intended uses.
Calcium carbonate can be precipitated from aqueous calcium hydroxide slurries or solutions in three different crystal lographic forms (polymorphs): the vaterite form which is thermodynamically unstable, the aragonite form which is metastable under normal ambient 1 conditions of temperature and pressure, and the calcite form which is the most stable and the most abundant in nature. These forms of calcium carbonate can be prepared by carbonation of slaked lime by suitable variations of the process conditions.
The calcite form is easy to produce on industrial scales, as precipitated calcium carbonate particles. It exists in several different shapes, of which the most common are the rhombohedral shape and the scalenoliedral shape.
Aragonite forms crystals having a length/width ratio (hereinafter "aspect ratio") in the range between > 1: 1 and 100: 1 of which a typical aspect ratio is 10, in which case the aragonite forms long, thin needles, Therefore, aragonite having a high aspect ratio may be denoted hereinafter - "acicular aragonite" or "needle-shaped aragonite". The production of aragonite is a slow process and is very difficult to control on an industrial scale.
PCC particles are used as thickening materials, fillers, extenders and, most of all, as inexpensive pigments. The latter use implies that a particularly desirable property of this material is its light scattering characteristics, in order to be able to impart opacity and brightness to the products containing it. Such characteristics are optimized, when the pigment particles are very effectively dispersed and are apart by an average distance in the range between 0.2gin and 0.4im in their final products, and their size distribution is in the range between 0.2Vtin and 0.4tm, namely, in the range of half a wavelength of the visible light. That means that either the production of the PCC should be adjusted to produce small particles in order to avoid expensive downstream particle size reduction operations and to cope with the expensive problems of dewatering and drying the product, or, alternatively, the process should be adjusted to produce large particles, and subsequently effect the downstream dewatering and grinding operations. In both cases, the production costs of precipitated calcium carbonate of pigment grades may be doubled or tripled just because of these unavoidable downstream steps.
High light scattering pigments currently available to the above-mentioned industries include titanium dioxide particles, which are very effective to scatter the light due to their relatively high refractive index (2.76; for the rutile form) and their meticulously controlled particle size distribution of which median is in the range between 0.2tm and 0.4gm. However, this product is of a high specific gravity (-4.0g/cm 3), of a high surface area due 2 to its small particles, and most of all, is quite expensive. Fine kaolin particles are also being used as pigments, but this product, which has a much lower refractive index (1.56), is of limited whiteness and is still relatively expensive. Particulate calcium carbonate is the ideal least expensive pigment and could replace much more of the titanium dioxide and kaolin pigments in their respective present applications, if it could be prepared in a form having improved light scattering properties.
Calcium carbonate pigments are produced in part by grinding coarse natural rocks and in part by precipitation processes. Of the precipitated calcium carbonate particles, a particulate precipitated aragonite is considered to be the most effective light scattering calcium carbonate pigment, of which refractive indices are 1.530, 1.681 and 1.685, depending on its crystallographic surfaces, its specific gravity is above 2.5 g/CM3, and is the most suitable for same applications. However, its production rate is characteristically very slow and its production conditions are very difficult to control, industrially.
While the majority of references, cited hereinafter, relate to the technology for producing a particulate precipitated aragonite, some of the references are included in order to better present the state of the art for the production of PCC more generally, including the downstream operations, which may be common to all these processes and also to the present invention.
1. U.S. Patent No. 2,081,112 (N. Statham et al.) describes a process for producing precipitated calcium carbonate by carbonating milk of lime with carbon dioxide containing gas, where the temperature in the gas absorber is maintained at 50-600C, preferably around 550C. It is recognized that the more violent the agitation in the gas absorber, the finer will be the product; the aim being to create a fine mist of calcium hydroxide slurry.
2. U.S. Patent No. 2,964,382 (G. E. Hall, Jr.) describes production of precipitated calcium carbonate by various chemical routes, in which calcium ions are contacted with carbonate ions in a precipitation zone, the process including also carbonation of milk of lime with carbon dioxide gas. A high shear stator/rotor agitator is used to provide turbulence by rotating at a peripheral speed of at least 1160 feet per minute (589 cm per second) in the precipitation zone. Also, this patent teaches that it is desirable to operate the process at pH values of at least 8.5 and that at temperatures above 600C, needle-shaped 3 precipitated aragonite particles are formed, which however produce an adverse flow property effect.
3. U.S. Patent No. 3,320,026 (W. F. Waldeck) describes the production of various forms of precipitated calcium carbonate.
4. GB Patent No. 941,900 (assigned to Kaiser Aluminium & Chemical corporation) describes the production of precipitated aragonite particles, for use as a filter aid, by reacting continuously sodium carbonate solution and aqueous calcium hydroxide slurry at temperatures higher than 600C in a multistage system. The product and the solution are withdrawn at the third stage from the bottom of the reactor, the product is then separated from the solution and part of the crystals are recycled to the various stages of the process as seeds for further precipitation of the precipitated aragonite particles.
5. U.S. Patent No. 3,669,620 (M. C. Bennett et al.) describes a continuous process for the production of a particulate precipitated aragonite by carbonating aqueous calcium hydroxide slurry in sucrose solutions. However, due to the cost of the sucrose, the solution had to be recycled and detrimental materials had to be removed by anion exchange resin. The preferred temperature range was between 600C and 90OC; the pH values were in the range between 7 and 9; and the concentration of the calcium hydroxide was quite low - in the range between one-half and onetwentieth molar.
6. U.S. Patent No. 4,018,877 (R. D. A. Woode) describes carbonation of calcium hydroxide slurry, wherein a complexing agent for Ca' is added to the suspension in the gas absorber, after the calcium carbonate primary nucleation stage and before completion of the carbonation step, the complexing agent being e.g. citric acid, ethylenediarnine tetraacetic acid (EDTA), aminotriacetic acid, aminodiacetic acid or a hydroxy polycarboxylic acid. Optionally, long-chain fatty acids or their salts can be added, preferably, after the final carbonation stage.
7. U.S. Patent No. 4,157,379 (J. Arika et al.) describes the production of a chainstructured precipitated calcium carbonate by the carbonation of calcium hydroxide suspended in water in the presence of chelating agents, such as aliphatic carboxylic acids, and water-soluble metal salts.
4 8. U.S. Patent No. 4,244,933 (H. Shibazaki et al.) describes a multistage production process for producing a particulate precipitated aragonite, using aqueous calcium hydroxide slurry and carbon dioxide gas or a carbon dioxide containing gas, in the presence of phosphoric acids and water-soluble salts thereof.
9. U.S. Patent No. 4,420,341(T. H. Ferrigno) describes inorganic fillers (including calcium carbonate) surface modified with carboxylic acids, antioxidants and high-boiling non-reactive liquid agents.
10. JP Patent Publication No. 63260815 (H. Shibata et al.) describes the production of a particulate precipitated aragonite, by reacting carbon dioxide gas with an aqueous calcium hydroxide slurry in presence of phosphoric acid, a phosphoric acid compound, a barium compound and a strontium compound.
11. JP Patent No. 1261225 (H. Shibata et al.) describes reacting carbon dioxide gas with an aqueous calcium hydroxide slurry, in order to produce a particulate precipitated aragonite, which is stated to have improved properties compared with particulate precipitated calcite.
12. U.S. Patent No. 4,824,654 (Y. Ota et al.) describes a process for producing precipitated needle-shaped (5-100 gm) particulate precipitated aragonite, in which a relatively dilute aqueous calcium hydroxide solution (0.04-0.17 wt.%) and carbon dioxide gas or a carbon dioxide- containing gas are reacted together at a temperature of not less than 600C, in a continuous or semi-continuous (intermittent) manner.
13. U.S. Patent No. 5,043,017 (J. D. Passaratti) describes a process for producing acidstabilized precipitated calcium carbonate particles.
14. U.S. Patent No. 5,164,172 (H. Katayama et al.) describes a process for producing a particulate precipitated aragonite, in which a mixture of aqueous calcium hydroxide slurry, aragonite calcium carbonate particles and a water-soluble phosphoric acid compound are premixed prior to the addition of carbon dioxide gas.
15. U.S. Patent No. 5,342,600 (1. S. Bleakley et al.) describe a process of producing particulate precipitated calcium carbonate, in which aqueous calcium hydroxide slurries of varying concentrations are reacted with carbon dioxide-containing gas under a controlled mixing speed. It is recommended therein to prepare the aqueous calcium hydroxide suspension under high shear mixing and subsequently to lower the energy and shear agitation in the reaction mixture in which the precipitated calcium carbonate particles are formed.
16. U. S. Patent No. 5,3 76,343 (P. M. Fouche) describes a process for producing various forms of particulate PCC. In the case of aragonite, a mixture of quite dilute aqueous calcium hydroxide solution and a watersoluble source of specific anions (e.g. ammonium nitrate) are premixed prior to additionOf C02gas.
17. U.S. Patent No. 5,380,361 (R. A. Gill) describes inter alia calcium carbonate particles coated with Cl 2-C22 fatty acids salts.
18. U.S. Patent No. 5,593,489 (K-T. Wu) describes a process for producing acidresistant calcium carbonate particles for making neutral to weakly acid paper. 19. U.S. Patent No. 5,833,747 (1. S. Bleakley et al.) describes a process for producing a particulate precipitated aragonite, in which an aqueous calcium hydroxide slurry (148g Ca(OH)2 per liter of suspension) is reacted with carbon dioxide gas at an exceptionally slow rate of 0.0026 moles per minute per mole of Ca(OH)2 in a batch operation.
Claims (3)
1. The particulate precipitated aragonite calcium carbonate of the present invention (PCC-Aragonite) can be used to produce paints without a substantial prior size reduction, except that effected by the mixing system of the production of the paint, which is anyway being used in this art to thoroughly disperse the pigments in the various formulations.
2.
features:
(a) said at least one active agent is selected from the group consisting of carboxylle acids of formula CH3(CH,,COOH, where n is7-10 their carboxylate salts, their acid 7 anhydrides, their esters, their acyl halides and ketenes of the formula CH3(CH2),-IC=C=Q where n is 7-9; (b) said concentration of the at least one active agent is within the range between 0.2 wt.% and 10 wt.%, calculated as CH3(CH2),1COOH and based on the weight of calcium carbonate; (c) said slurry contains calcium hydroxide in a concentration within the range of from 3 to 30 wt.%; (d) said pH is within the range of from 8 to 11 (c) said temperature is in the range between 60oC and the boiling temperature of the reaction mixture-, (f) said mode of operation is selected from a continuous and a semicontinuous (intermittent) mode of operation; (g) said mixer peripheral speed (tip-speed) is above 5 m/sec; (h) said at least one active agent is added in a manner selected from introduction into the carbonation reactor and premixing ith said calcium hydroxide slurry prior to reaction with said gas.
A process according to claim 1, which is further characterized by the following C-7
2. Though the particulate precipitated aragonite calcium carbonate of the present invention (PCC-Aragonite) is not yet optimized for its use in the production of paints and though the formulations used are by no means optimized, still this product is able to substitute over 50% of the expensive titanium oxide pigment without any deterioration of the resulting paint, as it manifested by the hiding power measured.
3. As the coatings (paints) are being sold and used by volume, and not by weight, the additional saving resulting from using the particulate precipitated aragonite calcium carbonate of the present invention (PCCAragonite) can surpass 10% on all the constituents of the coating, including the titanium oxide.
4. For simplicity in formulating the above mentioned paints, dry samples of The particulate precipitated aragonite calcium carbonate of the present invention (PCCAragonite), were used. However, wet filter cakes that contaiweven more water than 20% wt.%, based on wet CaC03 cake, can be used, provided that this water is being taken in account. However, on an industrial scale, dry PCC-Aragonite will be rarely used, due to the economy of using the wet product.
While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made.
56 CLAIMS 1 A process for producing a particulate precipitated aragonite calcium carbonate, which comprises reacting an aqueous calcium hydroxide slurry with a gas selected from the group consisting of carbon dioxide and a gas containing it, wherein the parameters of said process, including at least one preselected active agent, mode of operation, operating concentrations of raw materials, operating temperature, operating mixer speed and operating pH, are such that (A) the specific gravity of the product after drying for 12 hours at 1200C is <2.5 g/CM3; and (B) the specific gravity of this dry product after ignition for eight hours at 5000C is <2.5 g/CM3.
A process according to claim 1, which is further characterized by the following 2. features: (a) said at least one active agent is selected from the group consisting of carboxylic acids of formula C113(CH2)nCOOH, where n is 7-9, their carboxylate salts, their acid anhydrides, their esters, their acyl halides and ketenes of the formula CH3(CH2),-IC=C=Q where n is 7-9; (b) said concentration of the at least one active agent is within the range between 0.2 wt.% and 10 wt.%, calculated as CHACH211COOH and based on the weight of calcium carbonate; (c) said slurry contains calcium hydroxide in a concentration within the range of ftoin 3 to 30 wt.%; (d) said pH is within the range of from 8 to 11; (e) said temperature is in the range between 600C and the boiling temperature of the reaction mixture; (f) said mode of operation is selected from a continuous and a semi- continuous (intermittent) mode of operation; (g) said mixer peripheral speed (tip-speed) is above 5 m/sec; (h) said at least one active agent is added in a manner selected from introduction into the carbonation reactor and premixing with said calcium hydroxide slurry prior to reaction with said gas.
57 1
3. A process according to claim 2, which is further characterized by at least one of the following features: (a) said at least one active agent is selected from the group consisting of carboxylic acids of formula CH3(CH2)nCOOH, where n is 7-9, and the calcium salts thereof; (b) said concentration of the at least one active agent is within the range between 0.3 wt.% and 5 wt.%, calculated as the CHACH2),C00H and based on the weight of calcium carbonate; (c) said slurry contains calcium hydroxide in a concentration within the range of from 4 to 20 wt.%; (d) said pH is within the range of from 9 to 10; (c) said temperature is in the range between 800C and the boiling temperature of the reaction mixture; (f) said mode of operation is a continuous mode of operation.
4. A process according to claim 3, which is further characterized by at least one of the following features, namely: said active agent is selected from the group consisting of decanoic acid and the calcium salts thereof, said concentration of said at least one active agent is within the range between 0.4 wt.% and 31 wt.%, calculated as the CH3(CH2)nCOOH and based on the weight of calcium carbonate, said temperature is in the range between 900C and the boiling temperature of the reaction mixture, and said slurry contains calcium hydroxide in a concentration within the range of from 5 to 15 wt.%.
5. A process according to claim 1, which is conducted as a flotation process in a flotation cell.
58 6. A process according to claim 5, and substantially as hereinbefore described with reference to Figure 3 of the attached drawings.
7. A particulate precipitated aragonite produced by the process of claim 1.
8. A particulate precipitated aragonite according to claim 7, which is characterized by at least one of the following features:
(a) it contains at least one calcium salt of carboxylic acids selected from those of the general formula: C1-13(CH2),,C0011, where n = 7, 8, and 9, in an amount between 0.2 and 10 M%, calculated as CHACH2)nCOOH and based on the weight of calcium carbonate; (b) it has an XRD spectrum substantially in accordance with Figure 5 of the attached drawings.
9. A particulate precipitated aragonite according to claim 7, having a specific gravity <2.3 g/cm 3 after drying at 1200C for twelve hours, and a specific gravity <2.3 g/CM3 after ignition for eight hours at 5000C.
10. A particulate precipitated aragonite according to claim 9, having a specific gravity <2.0 g/CM3 after drying at 1200C for twelve hours.
11. A particulate precipitated aragonite according to claim 9, having a specific gravity < 1. 8 g/cm 3 after drying at 1200C for twelve hours.
12. A modification of the process according to any one of claims 2 to 6, wherein n is 710.
13. A particulate precipitated aragonite produced by the process of claim 12, which is characterized by at least one of the following features:
(a) it contains at least one calcium salt of carboxylic acids selected from those of the general formula: CHACH21,C001-1, where n = 7, 8, 9 and 10, in an amount between 0.2 59 and 10 wt.%, calculated as CHACH2WOOH and based on the weight of calcium carbonate; (b) it has an XRD spectrum substantially in accordance with Figure 5 of the attached drawings.
14. A particulate precipitated aragonite which has (A) a specific gravity <2.5 g/CM3 after drying for 12 hours at 1200C, and (B) a specific gravity <2.5 g/CM3 after ignition for eight hours at 5000C of the product dried in (A).
15. A particulate precipitated aragonite which has (A) a specific gravity <2.3 g/CM3 after drying at 120 OC, and (B) a specific gravity <2.3 g/CM3 after ignition for eight hours at 5000C of the product dried in (A).
16. A particulate precipitated aragonite which has a specific gravity <2. 5 g/cm. 3 after ignition for eight hours at 5000C.
17. A particulate precipitated aragonite which has a specific gravity <2. 3 g/CM3 after ignition for eight hours at 5000C.
18. A particulate precipitated aragonite which has (A) a specific gravity <2.0 g/cm 3 after drying at 120 OC, and (B) a specific gravity <2.3 g/CM3 after ignition for eight hours at 5000C of the product dried in (A).
19. A particulate precipitated aragonite which has (A) a specific gravity <1.8 g/cm' after drying at 120 OC, and (B) a specific gravity <2.3 g/CM3 after ignition for eight hours at 5000C of the product dried in (A).
20. A particulate precipitated aragonite according to claim 14, which is further characterized by at least one of the following features:
(a) it contains at least one calcium salt of carboxylic acids selected from those of the general formula: CH3(C1-12)nCOOH, where n = 7, 8, and 9, in an amount between 0.2 and 10 wt.%, calculated as CH3(C1-12),C001-1 and based on the weight of calcium carbonate; (b) it has an XRD spectrum substantially in accordance with Figure 5 of the attached drawings.
21. A particulate precipitated aragonite according to claim 14, which is further characterized by at least one of the following features:
(a) it contains at least one calcium salt of carboxylic acids selected from those of the general formula: CH3(CH2)nCOOH, where n = 7, 8, 9 and 10, in an amount between 0.2 and 10 wt.%, calculated as CHACH2),C001-1 and based on the weight of calcium carbonate; (b) it has an XRD spectrum substantially drawings.
in accordance with Figure 5 of the attached 22. A particulate precipitated aragonite according to any one of claims 7 to 11 and 14 to 2 1, of crystallographic purity (aragonite/(aragonite + calcite)) at least 90%.
23. A particulate precipitated aragonite according any one of claims 7 to 11 and 14 to 2 1, of crystallographic purity (aragonite/(aragonite + calcite)) <90%.
24. A process according to any one of claims 1 to 6, wherein said specific gravity is determined substantially as described in Example 14 (E).
25. A process according to claim 12, wherein said specific gravity is determined substantially as described in Example 14 (E).
26. A particulate precipitated aragonite according to any one of claims 7 to 11 and 14 to 19, wherein said specific gravity is determined substantially as described in Example 14 (E).
61 27. A particulate precipitated aragonite according to claim 13, wherein said specific gravity is determined substantially as described in Example 14 (E).
28. A particulate precipitated aragonite according to claim 20, wherein said specific gravity is determined substantially as described in Example 14 (E).
29. A particulate precipitated aragonite according to claim 21, wherein said specific.gravity is determined substantially as described in Example 14 (E).
D 30. A coating composition which comprises a particulate, precipitated aragonite as defined in any one of claims 7 to 11 and 14 to 2 1.
31. A coating composition according to claim 30, which comprises substantially dry particulate precipitated aragonite.
32. A coating composition according to claim 30, which comprises particulate precipitated aragonite in aqueous dispersion.
33. A paper composition which comprises a particulate, precipitated aragonite as defined in any one of claims 7 to 11 and 14 to 2 1.
34. A paper composition according to claim 33, which comprises substantially dry particulate precipitated aragonite.
35. A paper composition according to claim 33, which corn rises particulate, 3 p precipitated aragonite in aqueous dispersion.
36. A plastics composition which comprises a particulate precipitated aragonite as defined in any one of claims 7 to 11 and 14 to 2 1.
62 37. A plastics composition according to claim 36, which comprises substantially dry particulate, precipitated aragonite.
38. A rubber composition which comprises a particulate precipitated aragonite as defined in any one of claims 7 to 11 and 14 to 2 1.
39. A rubber composition according to claim 38, which comprises substantially dry particulate precipitated aragonite.
40. An adsorbent composition which comprises a particulate precipitated aragonite as defined in any one of claims 7 to 11 and 14 to 2 1.
41. An adsorbent composition according to claim 40, which comprises substantially dry particulate precipitated aragonite.
42. A powder detergent composition which comprises a particulate precipitated aragonite as defined in any one of claims 7 to 11 and 14 to 2 1.
43. A powder detergent composition according to claim 42, which comprises substantially dry particulate, precipitated aragonite.
44. A pharmaceutical composition which comprises a particulate precipitated aragonite as defined in any one of claims 7 to 11 and 14 to 2 1.
45. A pharmaceutical composition according to claim 44, which comprises substantially dry particulate precipitated aragonite.
46. A pharmaceutical composition according to claim 44, which comprises particulate precipitated aragonite in aqueous dispersion.
63 47. An agrochemical composition which comprises a particulate precipitated aragonite as defined in any one of claims 7 to 11 and 14 to 21.
48. An agrochemical composition according to claim 47, which comprises substantially dry particulate precipitated aragonite.
49. An agrochemical composition according to claim 47, which comprises particulate precipitated aragonite in aqueous dispersion.
50. A flavor composition which comprises a particulate precipitated aragonite as defined in any one of claims 7 to 11 and 14 to 21.
51. A flavor composition according to claim 50, which comprises substantially dry particulate, precipitated aragonite.
52. A flavor composition according to claim 50, which comprises particulate precipitated aragonite in aqueous dispersion.
3. A fragrance composition which comprises a particulate precipitated aragonite as defined in any one of claims 7 to 11 and 14 to 2 1.
54. A fragrance composition according to claim 53, which comprises substantially dry particulate precipitated aragonite.
55. A fragrance composition according to claim 53, which comprises particulate precipitated aragonite in aqueous dispersion.
56. A food composition which comprises a particulate precipitated aragonite as defined in any one of claims 7 to 11 and 14 to 2 1.
64 57. A food composition according to claim 56, which comprises substantially dry particulate precipitated aragonite.
58. A food composition according to claim 56, which comprises particulate precipitated aragonite in aqueous dispersion.
59. A feed composition which comprises a particulate precipitated aragonite as defined in any one of claims 7 to 11 and 14 to 21.
60. A feed composition according to claim 59, which comprises substantially dry particulate precipitated aragonite.
61. A feed composition according to claim 59, which comprises particulate precipitated aragonite in aqueous dispersion.
62. A sunscreen composition which comprises a particulate precipitated aragonite as defined in any one of claims 7 to 11 and 14 to 2 1.
63. A sunscreen composition according to claim 62, which comprises substantially dry particulate, precipitated aragonite 64. A sunscreen composition according to claim 62, which comprises particulate precipitated aragonite in aqueous dispersion.
65. A conductive powder composition which comprises a particulate precipitated aragonite as defined in any one of claims 7 to 11 and 14 to 2 1.
66. A conductive powder composition according to claim 65, which comprises substantially dry particulate precipitated aragonite.
6. A process according to claim 5, and substantially as hereinbefore described with reference to Figure 3 of the attached drawings.
7. A particulate precipitated aragonite produced by the process of claim 1 - 8. A particulate precipitated aragonite according to claim 7, which is characterized by at least one of the followinc, features:
(a) it contains at least one calcium salt of carboxylic acids selected from those of the aeneral formula: CH3(CHi),COOH, where n or 10 in an amount between 0.2 and wt.%, calculated as CH3(CH2)nCOOH and based on the welaht of calcium carbonate; (b) it has an XRD spectrum substantially in accordance with Figure 5 of the attached drawinas.
0 9. A particulate precipitated aragonite according to claim 7, having a specific gravity <2.3 g/cm 3 -> 3 j g after drying at 1200C for twelve hours, and a specific gravity <2.3 g/cm after ignition for eight hours at 5000C.
10. A particulate precipitated aragonite according to claim 9, having a specific gravity W ::9-.0 c,,/cm3 after drying at 120oC for twelve hours.
11. A particulate precipitated aragonite according to claim 9, having a specific gravity <1.8 C/CM 3 after drying at 1200C for twelve hours.
0 C> 12. A process according to any of claims 2 to 6, wherein n is 7-9.
0 A particulate precipitated aragonite produced by the process of claim 1.2 which is characterized by at least one of the following features:
(a) it contains at least one calcium salt of carboxylic acids selected from those of the -general formula: CH3(CH2),COOH, where n = 7, 8, 9 and 10, in an amount between 0.2 1.7 GG Amendments to the claims have been filed as follows CLAIMS 1 A process for producing a particulate precipitated aragonite calcium carbonate, which comprises reacting an aqueous calcium hydroxide slurry with a gas selected. from the _group consisting of carbon dioxide and a gas containing it, wherein the parameters of said W process, including at least one preselected active agent, mode of operation, operating concentrations of raw materials, operating temperature, operating mixer speed and operating pH, are such that (A) the specific gravity of the product after drying for 12 hours at 120()C is <2.5 a/CM3; and (B) the specific gravity of this dry product after ignition for n cio,ht hours at 5000C is <2.5 /CM3.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB0005364A GB2360033A (en) | 2000-03-06 | 2000-03-06 | Precipitating aragonite calcium carbonate |
Publications (4)
Publication Number | Publication Date |
---|---|
GB0105274D0 GB0105274D0 (en) | 2001-04-18 |
GB2360034A true GB2360034A (en) | 2001-09-12 |
GB2360034A8 GB2360034A8 (en) | 2001-10-17 |
GB2360034B GB2360034B (en) | 2002-01-23 |
Family
ID=9887057
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB0005364A Withdrawn GB2360033A (en) | 2000-03-06 | 2000-03-06 | Precipitating aragonite calcium carbonate |
GB0105274A Expired - Fee Related GB2360034B (en) | 2000-03-06 | 2001-03-02 | Precipitated aragonite and a process for producing it |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
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GB0005364A Withdrawn GB2360033A (en) | 2000-03-06 | 2000-03-06 | Precipitating aragonite calcium carbonate |
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GB (2) | GB2360033A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2390280A1 (en) * | 2010-05-28 | 2011-11-30 | Omya Development AG | Treated mineral filler products, process for the preparation thereof and uses of same |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030161894A1 (en) * | 2001-09-05 | 2003-08-28 | 3P Technologies Ltd. | Precipitated aragonite and a process for producing it |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2145074A (en) * | 1983-06-16 | 1985-03-20 | Shiraishi Central Lab Co Ltd | Calcium carbonate |
WO1998052870A1 (en) * | 1997-05-21 | 1998-11-26 | Ecc International Inc. | Seeding of aragonite calcium carbonate and the product thereof |
US6022517A (en) * | 1996-09-05 | 2000-02-08 | Minerals Technologies Inc. | Acicular calcite and aragonite calcium carbonate |
-
2000
- 2000-03-06 GB GB0005364A patent/GB2360033A/en not_active Withdrawn
-
2001
- 2001-03-02 GB GB0105274A patent/GB2360034B/en not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2145074A (en) * | 1983-06-16 | 1985-03-20 | Shiraishi Central Lab Co Ltd | Calcium carbonate |
US6022517A (en) * | 1996-09-05 | 2000-02-08 | Minerals Technologies Inc. | Acicular calcite and aragonite calcium carbonate |
WO1998052870A1 (en) * | 1997-05-21 | 1998-11-26 | Ecc International Inc. | Seeding of aragonite calcium carbonate and the product thereof |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2390280A1 (en) * | 2010-05-28 | 2011-11-30 | Omya Development AG | Treated mineral filler products, process for the preparation thereof and uses of same |
WO2011147778A1 (en) * | 2010-05-28 | 2011-12-01 | Omya Development Ag | Treated mineral filler products, process for the preparation thereof and uses of same |
CN102933642A (en) * | 2010-05-28 | 2013-02-13 | Omya发展股份公司 | Treated mineral filler products, process for the preparation thereof and uses of same |
RU2540628C2 (en) * | 2010-05-28 | 2015-02-10 | Омиа Интернэшнл Аг | Processed products of mineral fillers, methods of their obtaining and application |
EP2390280B1 (en) | 2010-05-28 | 2015-03-04 | Omya International AG | Treated mineral filler products, process for the preparation thereof and uses of same |
US9238727B2 (en) | 2010-05-28 | 2016-01-19 | Omya International Ag | Treated mineral filler products, process for the preparation thereof and uses of same |
JP2016014143A (en) * | 2010-05-28 | 2016-01-28 | オムヤ インターナショナル アーゲー | Processed product of mineral filler, method of preparing the same and use of the same |
CN102933642B (en) * | 2010-05-28 | 2016-04-13 | Omya国际股份公司 | The mineral filler product, the Its Preparation Method And Use that processed |
EP2576669B1 (en) | 2010-05-28 | 2016-07-20 | Omya International AG | Treated mineral filler products, process for the preparation thereof and uses of same |
EP3112400A1 (en) * | 2010-05-28 | 2017-01-04 | Omya International AG | Treated mineral filler products, process for the preparation thereof and uses of same |
Also Published As
Publication number | Publication date |
---|---|
GB0005364D0 (en) | 2000-04-26 |
GB2360034B (en) | 2002-01-23 |
GB0105274D0 (en) | 2001-04-18 |
GB2360034A8 (en) | 2001-10-17 |
GB2360033A (en) | 2001-09-12 |
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PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20060302 |