AP663A - Calcium carbonate precipitation method. - Google Patents
Calcium carbonate precipitation method. Download PDFInfo
- Publication number
- AP663A AP663A APAP/P/1997/001063A AP9701063A AP663A AP 663 A AP663 A AP 663A AP 9701063 A AP9701063 A AP 9701063A AP 663 A AP663 A AP 663A
- Authority
- AP
- ARIPO
- Prior art keywords
- solution
- nitrate
- ammonium
- calcium carbonate
- mother liquor
- Prior art date
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- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 title claims abstract description 57
- 238000000034 method Methods 0.000 title claims abstract description 25
- 229910000019 calcium carbonate Inorganic materials 0.000 title claims abstract description 21
- 238000001556 precipitation Methods 0.000 title claims abstract description 8
- ZCCIPPOKBCJFDN-UHFFFAOYSA-N calcium nitrate Chemical compound [Ca+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O ZCCIPPOKBCJFDN-UHFFFAOYSA-N 0.000 claims abstract description 42
- 239000000243 solution Substances 0.000 claims abstract description 39
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 26
- 239000012452 mother liquor Substances 0.000 claims abstract description 17
- 239000007864 aqueous solution Substances 0.000 claims abstract description 14
- 229940088417 precipitated calcium carbonate Drugs 0.000 claims abstract description 13
- PAWQVTBBRAZDMG-UHFFFAOYSA-N 2-(3-bromo-2-fluorophenyl)acetic acid Chemical compound OC(=O)CC1=CC=CC(Br)=C1F PAWQVTBBRAZDMG-UHFFFAOYSA-N 0.000 claims abstract description 12
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 claims abstract description 12
- 239000001099 ammonium carbonate Substances 0.000 claims abstract description 12
- 235000012501 ammonium carbonate Nutrition 0.000 claims abstract description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 12
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims abstract description 11
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims abstract description 10
- 238000004519 manufacturing process Methods 0.000 claims abstract description 9
- 239000000908 ammonium hydroxide Substances 0.000 claims abstract description 7
- 229910002651 NO3 Inorganic materials 0.000 claims abstract description 6
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 claims abstract description 6
- 229910002092 carbon dioxide Inorganic materials 0.000 claims abstract description 6
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 claims abstract description 5
- 239000000706 filtrate Substances 0.000 claims abstract description 5
- 238000010438 heat treatment Methods 0.000 claims abstract description 5
- 239000007787 solid Substances 0.000 claims abstract description 5
- 239000001569 carbon dioxide Substances 0.000 claims abstract description 4
- 238000001914 filtration Methods 0.000 claims abstract description 4
- 239000011369 resultant mixture Substances 0.000 claims abstract description 4
- 239000013078 crystal Substances 0.000 claims description 26
- 239000011575 calcium Substances 0.000 claims description 14
- 238000006243 chemical reaction Methods 0.000 claims description 13
- 238000009826 distribution Methods 0.000 claims description 8
- 239000002245 particle Substances 0.000 claims description 8
- 239000003153 chemical reaction reagent Substances 0.000 claims description 7
- 230000015572 biosynthetic process Effects 0.000 claims description 5
- 239000007795 chemical reaction product Substances 0.000 claims description 5
- 239000000203 mixture Substances 0.000 claims description 4
- 229910021529 ammonia Inorganic materials 0.000 claims 1
- 239000000047 product Substances 0.000 description 9
- 229910052791 calcium Inorganic materials 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 239000011550 stock solution Substances 0.000 description 4
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 3
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 3
- 235000011941 Tilia x europaea Nutrition 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 239000004571 lime Substances 0.000 description 3
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- 229910052681 coesite Inorganic materials 0.000 description 2
- 229910052906 cristobalite Inorganic materials 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 229910052682 stishovite Inorganic materials 0.000 description 2
- 229910052905 tridymite Inorganic materials 0.000 description 2
- 229910021532 Calcite Inorganic materials 0.000 description 1
- 235000019738 Limestone Nutrition 0.000 description 1
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000013065 commercial product Substances 0.000 description 1
- 239000002178 crystalline material Substances 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 239000012527 feed solution Substances 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- GEYXPJBPASPPLI-UHFFFAOYSA-N manganese(III) oxide Inorganic materials O=[Mn]O[Mn]=O GEYXPJBPASPPLI-UHFFFAOYSA-N 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 239000000825 pharmaceutical preparation Substances 0.000 description 1
- 229940127557 pharmaceutical product Drugs 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000012066 reaction slurry Substances 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 229940034610 toothpaste Drugs 0.000 description 1
- 239000000606 toothpaste Substances 0.000 description 1
Classifications
-
- 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
- C01F11/181—Preparation of calcium carbonate by carbonation of aqueous solutions and characterised by control of the carbonation conditions
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/51—Particles with a specific particle size distribution
- C01P2004/52—Particles with a specific particle size distribution highly monodisperse size distribution
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Gas Separation By Absorption (AREA)
- Treating Waste Gases (AREA)
Abstract
A method for producing precipitated calcium carbonate by reacting an aqueous solution of calcium nitrate [ca(no3)2]with an aqueous solution of ammonium carbonate [(nh4)2c03]and allowing calcium carbonate to precipitate fron the resultant mixture containing nitrate [nh4no3]in the mother liquor, the process being characterised in that: (i)the calcium nitrate [ca(n03)2)] solution utilised in the processes is prepared by slaking lime [cao]in water in the presence of ammonium nitrate [nh4no3]to form calcium nitrate [ca(no3)2]and ammonium hydroxide [nh4oh]in solution, filtering the solution to render it solids free, and heating the filtrate to dissociate the ammonium hydroxide [nh4oh]and to drive ammonia gas [nh3]from the solution; (ii)the ammonium carbonate (nh4)2co3 solution utilised is prepared by absorbing ammonia gas [nh3]and carbon dioxide gas [c02]in water, the ammonia gas preferably being derived from the step in (i)above in which the ca(n03)2 solution is heated; and (iii)the ammonium nitrate used is derived from the precipitation phase during which calcium carbonate is precipitated from the mother liquor containing ammonium nitrate.
Description
HARARE
ZIMBABWE
A method for producing precipitated calcium carbonate by reacting an aqueous solution of calcium nitrate [CafNOjh] with an aqueous solution of ammonium carbonate [(NHahCOs] and allowing calcium carbonate to precipitate from the resultant mixture containing nitrate [NH4NO3] in the mother liquor, the process being characterised in thac (i) the calcium nitrate [CafNCbri)] solution utilised in the processes is prepared by slaking lime [CaO] in water in the presence of ammonium nitrate [NH4NO3] to form calcium nitrate [CafNCriJi] and ammonium hydroxide [NHaOH] in solution, filtering the solution to render it solids free, and heating the filtrate to dissociate the 'mmonium hydroxide [NHaOH] and to drive ammonia gas [NH3] from the solution; (ii) the ammonium carbonate (NJDaCOj solution .ilised is prepared by absorbing ammonia gas [NH3] and carbon dioxide gas [COr] in water, the ammonia gas preferably being derived from the step in (i) above in which the Ca(NOj)2 solution is heated; and (iii) the ammonium nitrate used is derived from the precipitation phase during which calcium carbonate is precipitated from the mother liquor containing ammonium nitrate.
Documents Cited: EP 0499666 A
WO 79 00931 A
WO 96 26902
AP.00663
CALCIUM CARBONATE PRECIPITATION METHOD
HELD OF INVENTION
THIS invention relates to methods for producing crystalline materials by precipitation. According to one aspect of the invention it relates to the production of precipitated calcium carbonate. The invention thus relates particularly, but not exclusively, to the production of high purity calcium carbonate from relatively impure calcium source material.
BACKGROUND TO THE INVENTION 10 Calcium carbonate is a natural carbonate which is present in large quantities particularly in calcitic and dolomitic limestone. In raw impure form these products are used in various industries including the mining and cement industries. In purified crystalline form calcium carbonate is used in the production of paint, in toothpaste, paper coating and sizing and as an acid neutraliser or as a filler in pharmaceutical products, amongst other applications.
Despite the natural abundance of calcium carbonate as such pure calcium carbonate is a relatively expensive product due to the difficulties and expenses associated with conventional purification methods.
OBJECT OF THE INVENTION
It is an object of the present invention to provide a new method for producing precipitated calcium carbonate from a natural source material containing calcium values.
AP/P/ 9 7 / 0 1 0 6 3 ςι iR<rnn ftp cucct /di ii c ->g\
- 1 AP.00663
SUMMARY OR TREE INVENTION
According to the invention there is provided a method for producing precipitated calcium carbonate by reacting an aqueous solution of calcium nitrate [Ca(NO3)2] with an aqueous solution of ammonium carbonate [(NH4)2COJ and allowing calcium carbonate to precipitate from the resultant mixture containing nitrate [NH4NO?] in the mother liquor, the process being characterised in that [i] the calcium nitrate [Ca(NO3)J solution utilised in the processes is prepared by slaking lime [CaO] in water in the presence of ammonium nitrate [NH4N0,] to form calcium nitrate [CafNOJJ and ammonium hydroxide [ΝΗ,ΟΗ] in solution, filtering the solution to render it solids free, and heating the filtrate to dissociate the ammonium hydroxide [NH4OH] and to drive ammonia gas [NHJ from the solution;
[ii] the ammonium carbonate (NH4),COj solution utilised is prepared by absorbing ammonia gas [NHJ and carbon dioxide gas in water, the ammonia gas preferably being derived from the step in [i] above in which the Ca(NO3), solution is heated; and [iii] the ammonium nitrate used is derived from the precipitation phase during which calcium carbonate is precipitated from the mother liauor containing ammonium nitrate.
The precipitation reaction between the two reagent solutions which react to form the precipitated CaCO3 is preferably performed by feeding the
- 2 AP/P/ 9 7 / 0 1 0 6 3
SUBSTITUTE SHEET (RULE 26) solutions into intimate contact with one another in a contact zone of a reactor arrangement and immediately displacing the mixture from the contact zone, and allowing the resultant crystalline reaction product to precipitate from its mother liquor and separating the precipitated crystals from the mother liquor.
In a preferred form of the invention the reagent solutions are introduced into a reactor arrangement which is in the form of an elongated tubular conduit into which the reagent solutions are fed under a pressure of between 1 and 5 bar gauge pressure. It has been found that- the application of feed pressure in this range results in a decrease in crystal particle size.
In one application of this aspect of the invention there is thus provided a method for selectively producing precipitated calcium carbonate crystals in which a preferred crystal size distribution predominates, the method comprising the steps of intimately contacting an aqueous solution of Ca(NO3)2 with an aqueous solution of (NH4)2CO3 whilst controlling the pressure of the reaction to remain within a range at which the formation of the required particle size and distribution of the CaCO3 crystals is favoured, allowing the resultant crystalline reaction product to precipitate from its mother liquor and separating the precipitated crystals from the. mother liquor.
AP/P/ 97/01063
- 3 SUBSTITUTE SHEET (RULE 26)
AP.00663
The method may be used to produce precipitated calcium carbonate which is predominantly of the vaterite crystalline form which has been found to be the default crystalline form when the temperature was kept between 15°C and 75°C. The reaction is for this purpose most preferably carried out at between 34°C and 40°C.
With residence in slurry form the vaterite crystal form has been found to convert into calcite and is known in the art.
»
TO According to a further aspectof the present invention there is provided a method for producing precipitated calcium carbonate crystals of a selected crystal size comprising the steps of reacting an aqueous solution of calcium nitrate with an aqueous solution of ammonium carbonate and controlling the crystal size of the precipitated calcium carbonate by providing at least one of the reagent solutions at a concentration favouring the formation of the desired crystal size, allowing the resultant crystalline reaction product to precipitate from its mother liquor and separating the precipitated crystals from the mother liquor.
Such concentration control for influencing crystal size may of course be combined with reaction pressure control as described above.
In one embodiment of this aspect of the invention it has been found that by reacting a 20% [by mass] solution of Ca(NO2)2 with a stoichiometric equivalent quantity of (NH<)2CO3 it is possible to produce calcium
- 4 AP/P/ 9 7 / 0 1 0 6 3
SUBSTITUTE SHEET (RULE 26)
A ZX ** Λ Λ W
Ar. υ υ ο ο o carbonate crystals having a dJ0 value of less than 6 microns, and that an increase in the concentration of the Ca(NOj)2 leads to the formation of finer crystals.
The various aspects of the invention will now be illustrated with reference to the accompanying examples:
EXAMPLES OF THE INVENTION
EXAMPLE!
Selective preparation of different CaCO, crystalline forms [a] Preparation of stock solutions
Kg NH<NOj was dissolved in 120 litres water with stirring, to which was added 17,5 Kg lime sourced from Lime Acres in South Africa. 100 ml of triethanolamine was added to the dissolved NH^NOj before the addition of the lime. The mixture was filtered to remove undissolved solids. The clear Ca(NOj)2/NH4OH filtrate was transferred to a separate vessel and heated to a temperature of 80°C and held at 80°C for 30 minutes to drive off ammonia gas. [Care must be taken to ensure the pH of the Ca(NOj)2‘ solution remains above 9.5].
AP/P/ 97/01063
- 5 SUBSTITUTE SHEET (RULE 26)
AP.00663
A solution of approximately 10% (NHJ2CO3 was prepared in 100 litres of water by absorbing NH3 [released by heating the filtered
Ca(NO3)2/NH«OH solution as described above] and pure CO2 gas in the water in an absorbtion column.
The stock solutions of Ca(NO3)2 and (NH4)2CO3 as prepared above were used to demonstrate the invention.
It will be appreciated that the ammonium carbonate solution may in the alternative have been prepared by feeding ammonia gas from another source with CO2 gas into a scrubber arrangement to absorb such gases in water thereby to render a solution of ammonium carbonate.
[b] Influence of reaction pressure
The stock solutions prepared as described above were fed by means of constant displacement pumps at various pressures into an elongated reaction chamber of about 5 m in length. It was found that the pressure in the reaction chamber, which was controlled by means of a valve at the outlet end thereof, had a marked influence on the size of the crystals of CaCO3 formed by the- reaction between the concentrated stock solutions. Reaction temperatures were measured by determining the temperature of the final reaction slurry at the end of the reaction chamber. The results of
- 6 £9010/26 /d/dV
SUBSTITUTE SHEETfRULE 26)
AP.00663 typical pressure and temperature influences on crystal size are summarised in Table 1, the crystal size values being the dJ0 values in microns.
TABLE 1
Effect of Pressure:
| GAUGE PRESSURE [BAR] | |||
| REACTION TEMPERATURE | 0 | 3 | 5 |
| 17°C | ND | 2.44 | 1.86 |
| 50°C | 7.27 | 2.38 | 2.38 |
It will be seen that changes in reaction pressure affects particle size and distribution specifically, pressure above zero bar reduces particle size and narrows distribution.
AP/P/ 97 / 0 1 0 6 3
The tightening or narrowing effect of the present invention on particle size distribution is graphically illustrated in Figure 1.
In Figure 1 Graph A represents the particle* size distribution and composition ranges for a commercially available ground calcium carbonate.
- 7 SUBSTITUTE SHEET (RULE 26)
AP.00663
Graph B represents the same for a precipitated calcium carbonate produced by the method of the invention at 5C°C and 3 bar pressure.
It will be seen that the product of the method of the invention displays 5 a sharper gaussian distribution of crystal sizes than the commercial product.
[c] Influence of concentration of feed solutions
It has been found that increased concentration from 20% Ca(NOj)2 to 30% Ca(NOj)2 typically results in a decrease in mean particle size, e.g. d50 6 μτη to dJ0 2 μτη.
EXAMPLE 2
The purity of the product produced by the method as described in Example l[a] and [b] is extremely high and is in many respects comparable with the industry spectrographic standard for CaCO3 marketed by Johnson Matthey. In Table 2 below the relative values for various impurities are compared against the Johnson Matthey standard [taking the quantities of impurities in such standard as being 1] and against two commercially available products identified as A and B.
AP/P/ 97 / 01063
- 8 SUBSTITUTE SHEET (RULE 26)
AP · Ο Ο 6 6 3
TABLE 2
| JM | A | B | Product of Invention | |
| SiO2 | 1 | 2,8 | 2,7 | 0,61 |
| ΑΙ,Ο, | 1 | 1,1 | 2,5 | 0,67 |
| Fe^ | 1 | 2,2 | 3,5 | 0,83 |
| Mn2O3 | 1 | 1,16 | 1,37 | 1,08 |
| MgO | 1 | 19,8 | 17,7 | 1,03 |
| P2O5 | 1 | 1,15 | 0,47 | 1,09 |
| SO3 | 1 | 0,97 | 0,89 | 2,65 |
| cr | 1 | 1,17 | 1,15 | 1,41 |
| K2O | 1 | 1,33 | 1,76 | 1,93 |
| Nm2O | 1 | 1,12 | 0,61 | 1,06 |
From the above table it will be seen that the product of the invention contains only 61% of the quantity of SiO2 present in spectro graphic grade CaCOj while other products in the market contain almost three times such amounts. For many of the other impurities similar observations may be made.
If one bears in mind that the process by which the product of this purity is achieved startsfrom very impure CaO, this achievement is remarkable.
Many variations of the invention are possible without departing from the spirit of the invention.
Claims (7)
1. A method for producing precipitated calcium carbonate by reacting an aqueous solution of calcium nitrate [CafNOJJ with an aqueous solution of ammonium carbonate [(NH4)2CO3] and allowing
5 calcium carbonate to precipitate from the resultant mixture containing nitrate [NH4NOj] in the mother liquor, the process being characterised in that [i] the calcium nitrate [Ca(NO3)2] solution utilised in the
10 processes is prepared by slaking lime [CaO] in water in the presence of ammonium nitrate [ΜΉ4ΝΟ3] to form calcium nitrate [Ca(NO,)J and ammonium hydroxide [NH4OH] in solution, filtering the solution to render it solids free, and heating the filtrate to dissociate the ammonium hydroxide
15 [NH4OH] and to drive ammonia gas [NH,] from the solution;
[ii] the ammonium carbonate (NH4)2CO3 solution utilised is prepared by absorbing ammonia gas [NH3] and carbon dioxide gas [COJ in water, the ammonia gas- preferably
20 being derived from the step in [i] above in which the
Ca(NO3)2 solution is heated; and
AP/P/ 9 7 / 0 1 0 6 3
- 10 SUBSTITUTE SHEET (RULE 26)
AP.00663 [iii] the ammonium nitrate used is derived from the precipitation phase during which calcium carbonate is precipitated from the mother liquor containing ammonium nitrate.
5
2. The method of claim 1 wherein the Ca(NO)j and the (NH<)2COj are fed into intimate contact with one another in a contact zone of a reactor arrangement and immediately displacing the mixture from the contact zone, and wherein the resultant crystalline reaction product is allowed to precipitate from its mother liquor
10 and the precipitated crystals are thereafter separated from the mother liquor.
3. The method of claim 2 wherein the reagent solutions are introduced into a reactor arrangement which is in the form of an
15 elongated tubular conduit into which the reagent solutions are fed under a pressure of between 1 and 5 bar gauge pressure.
4. The method of claim 3 wherein the pressure of the reaction is controlled to remain within a range at which the formation of the
20 required particle size and distribution of the CaCOj crystals is favoured.
AP/P/ 9 7 / 0 1 0 6 3
- 11 cIHRernTIJTT SHFFTfRin P
AP.00663
5. The method of claim 1 comprising the steps of reacting an aqueous solution of calcium nitrate with an aqueous solution of ammonium carbonate and controlling the crystal size of the precipitated calcium carbonate by providing at least one of the reagent
5 solutions at a concentration favouring the formation of the desired crystal size, allowing the resultant crystalline reaction product to precipitate from its mother liquor and separating the precipitated crystals from the mother liquor.
10 6. The method of claim 5 wherein a 20% [by mass] solution of
Ca(NO3)2 is reacted with a stoichiometric equivalent quantity of (NH4)2CO3 to produce calcium carbonate crystals having a d50 value of less than 6 microns.
15 7. A method of producing pure precipitated calcium carbonate crystals substantially as herein described with reference to the accompanying examples.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ZA951727 | 1995-03-02 | ||
| PCT/GB1996/000488 WO1996026902A1 (en) | 1995-03-02 | 1996-03-01 | Calcium carbonate precipitation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AP9701063A0 AP9701063A0 (en) | 1997-10-31 |
| AP663A true AP663A (en) | 1998-08-19 |
Family
ID=25584884
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| APAP/P/1997/001063A AP663A (en) | 1995-03-02 | 1996-03-01 | Calcium carbonate precipitation method. |
Country Status (14)
| Country | Link |
|---|---|
| US (1) | US6036933A (en) |
| EP (1) | EP0812300B1 (en) |
| JP (1) | JPH11500998A (en) |
| AP (1) | AP663A (en) |
| AT (1) | ATE174007T1 (en) |
| AU (1) | AU709774B2 (en) |
| BR (1) | BR9607683A (en) |
| CA (1) | CA2214132A1 (en) |
| DE (1) | DE69601082T2 (en) |
| DK (1) | DK0812300T3 (en) |
| ES (1) | ES2128161T3 (en) |
| NO (1) | NO311668B1 (en) |
| PL (1) | PL185259B1 (en) |
| WO (1) | WO1996026902A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI116573B (en) * | 2001-11-28 | 2005-12-30 | M Real Oyj | Filler for making thin base paper and method for making base paper |
| RU2205153C1 (en) * | 2002-07-03 | 2003-05-27 | Федеральное государственное унитарное предприятие "Комбинат "Электрохимприбор" | Calcium carbonate production process |
| US7604787B2 (en) * | 2003-05-02 | 2009-10-20 | The Penn State Research Foundation | Process for sequestering carbon dioxide and sulfur dioxide |
| US7198653B2 (en) | 2003-07-31 | 2007-04-03 | Delavau Llc | Calcium carbonate granulation |
| US20050089466A1 (en) * | 2003-10-27 | 2005-04-28 | Degenova Mark G. | Methods and apparatus for producing precipitated calcium carbonate |
| CN100418885C (en) * | 2004-07-09 | 2008-09-17 | 胡志彤 | High-purity medicinal calcium carbonate and its manufacturing method |
| EP1838618A1 (en) * | 2004-12-15 | 2007-10-03 | FUJIFILM Corporation | Method for producing carbonates |
| US9138414B1 (en) | 2006-09-15 | 2015-09-22 | Delavau Llc | Calcium supplement having enhanced absorption |
| US8159956B2 (en) * | 2008-07-01 | 2012-04-17 | Finisar Corporation | Diagnostics for serial communication busses |
| US8114214B2 (en) * | 2009-12-31 | 2012-02-14 | Calera Corporation | Methods and compositions using calcium carbonate |
| US8906156B2 (en) | 2009-12-31 | 2014-12-09 | Calera Corporation | Cement and concrete with reinforced material |
| MX356682B (en) * | 2013-03-19 | 2018-06-08 | Colgate Palmolive Co | Two-phase dentifrices. |
| US20150367577A1 (en) * | 2014-06-19 | 2015-12-24 | Materialise N.V. | Use of multiple beam spot sizes for obtaining improved performance in optical additive manufacturing techniques |
| CN104817101A (en) * | 2015-04-08 | 2015-08-05 | 常熟市宏宇钙化物有限公司 | Calcium oxide powder preparation method |
| JP7705661B2 (en) * | 2019-07-21 | 2025-07-10 | アレラク， インコーポレイテッド | Method and system for utilizing calcium compounds derived from calcined limestone |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2535999A (en) * | 1945-05-12 | 1950-12-26 | Sylvania Electric Prod | Method for producing cathode coating compositions |
| WO1979000931A1 (en) * | 1978-04-14 | 1979-11-15 | A Andersson | Preparation of white liquor |
| EP0499666A1 (en) * | 1989-11-29 | 1992-08-26 | Chemische Fabrik Kalk GmbH | Process for the preparation of very pure calcium carbonate powder |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1011861B (en) * | 1956-01-20 | 1957-07-11 | Basf Ag | Process for the production of ammonium nitrate and calcium carbonate |
| SU1594140A1 (en) * | 1988-04-15 | 1990-09-23 | Новгородское Производственное Объединение "Азот" Им.50-Летия Великого Октября | Method of producing calcium carbonate |
| CN1055718A (en) * | 1991-06-06 | 1991-10-30 | 邹凤祥 | The production method of magnesium oxide and lime carbonate |
| CA2090088C (en) * | 1992-02-26 | 1995-07-25 | Pierre Marc Fouche | Production of purified calcium carbonate |
| CA2213750A1 (en) * | 1995-02-27 | 1996-09-06 | Aeci Limited | Production of precipitated calcium carbonate |
-
1996
- 1996-03-01 AT AT96904933T patent/ATE174007T1/en not_active IP Right Cessation
- 1996-03-01 DE DE69601082T patent/DE69601082T2/en not_active Expired - Fee Related
- 1996-03-01 US US08/894,881 patent/US6036933A/en not_active Expired - Fee Related
- 1996-03-01 DK DK96904933T patent/DK0812300T3/en active
- 1996-03-01 PL PL96322089A patent/PL185259B1/en unknown
- 1996-03-01 AU AU48849/96A patent/AU709774B2/en not_active Ceased
- 1996-03-01 JP JP8526110A patent/JPH11500998A/en active Pending
- 1996-03-01 AP APAP/P/1997/001063A patent/AP663A/en active
- 1996-03-01 ES ES96904933T patent/ES2128161T3/en not_active Expired - Lifetime
- 1996-03-01 EP EP96904933A patent/EP0812300B1/en not_active Expired - Lifetime
- 1996-03-01 WO PCT/GB1996/000488 patent/WO1996026902A1/en active IP Right Grant
- 1996-03-01 CA CA002214132A patent/CA2214132A1/en not_active Abandoned
- 1996-03-01 BR BR9607683-6A patent/BR9607683A/en not_active IP Right Cessation
-
1997
- 1997-09-01 NO NO19973998A patent/NO311668B1/en not_active IP Right Cessation
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2535999A (en) * | 1945-05-12 | 1950-12-26 | Sylvania Electric Prod | Method for producing cathode coating compositions |
| WO1979000931A1 (en) * | 1978-04-14 | 1979-11-15 | A Andersson | Preparation of white liquor |
| EP0499666A1 (en) * | 1989-11-29 | 1992-08-26 | Chemische Fabrik Kalk GmbH | Process for the preparation of very pure calcium carbonate powder |
Also Published As
| Publication number | Publication date |
|---|---|
| NO973998L (en) | 1997-09-01 |
| DE69601082D1 (en) | 1999-01-14 |
| ATE174007T1 (en) | 1998-12-15 |
| NO311668B1 (en) | 2002-01-02 |
| DE69601082T2 (en) | 1999-07-29 |
| ES2128161T3 (en) | 1999-05-01 |
| EP0812300B1 (en) | 1998-12-02 |
| AU4884996A (en) | 1996-09-18 |
| AP9701063A0 (en) | 1997-10-31 |
| EP0812300A1 (en) | 1997-12-17 |
| BR9607683A (en) | 1999-11-30 |
| CA2214132A1 (en) | 1996-09-06 |
| PL322089A1 (en) | 1998-01-05 |
| AU709774B2 (en) | 1999-09-09 |
| US6036933A (en) | 2000-03-14 |
| DK0812300T3 (en) | 1999-08-16 |
| WO1996026902A1 (en) | 1996-09-06 |
| JPH11500998A (en) | 1999-01-26 |
| PL185259B1 (en) | 2003-04-30 |
| NO973998D0 (en) | 1997-09-01 |
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