Nothing Special   »   [go: up one dir, main page]

WO1995003251A1 - Method of making a pigment based on calcium carbonate and silicium dioxide usable as filler for paper - Google Patents

Method of making a pigment based on calcium carbonate and silicium dioxide usable as filler for paper Download PDF

Info

Publication number
WO1995003251A1
WO1995003251A1 PCT/FI1994/000329 FI9400329W WO9503251A1 WO 1995003251 A1 WO1995003251 A1 WO 1995003251A1 FI 9400329 W FI9400329 W FI 9400329W WO 9503251 A1 WO9503251 A1 WO 9503251A1
Authority
WO
WIPO (PCT)
Prior art keywords
mixture
calcium carbonate
carbon dioxide
paper
filler
Prior art date
Application number
PCT/FI1994/000329
Other languages
French (fr)
Inventor
Erkki VÄÄNÄNEN
Original Assignee
Vaeaenaenen Erkki
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from FI933270A external-priority patent/FI933270A0/en
Application filed by Vaeaenaenen Erkki filed Critical Vaeaenaenen Erkki
Priority to AU71270/94A priority Critical patent/AU7127094A/en
Publication of WO1995003251A1 publication Critical patent/WO1995003251A1/en

Links

Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
    • D21H17/63—Inorganic compounds
    • D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
    • D21H17/68—Water-insoluble compounds, e.g. fillers, pigments siliceous, e.g. clays
    • 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
    • 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
    • C09C1/0081—Composite particulate pigments or fillers, i.e. containing at least two solid phases, except those consisting of coated particles of one compound
    • C09C1/0093—Composite particulate pigments or fillers, i.e. containing at least two solid phases, except those consisting of coated particles of one compound whose phases only contain calcium ions, carbonate ions and silicate ions or silica
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
    • D21H17/63—Inorganic compounds
    • D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
    • D21H17/675—Oxides, hydroxides or carbonates
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
    • D21H17/63—Inorganic compounds
    • D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
    • D21H17/69—Water-insoluble compounds, e.g. fillers, pigments modified, e.g. by association with other compositions prior to incorporation in the pulp or paper
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/50—Agglomerated particles
    • 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
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/12—Surface area
    • 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
    • C01P2006/60—Optical properties, e.g. expressed in CIELAB-values

Definitions

  • the invention relates to a method for preparing a mixed pigment of calcium carbonate and silica, useful as a filler for paper.
  • precipitated calcium carbonate can be prepared on an industrial scale by reacting carbon dioxide C0 2 (from flue gases, for example) with lime milk Ca(OH) 2 to produce precipitated calcium carbonate, the crystal form of which can be regulated by varying t • ⁇ - reaction conditions, Thieme C, Aumann G., Precipitated Calcium Carbonate, Pigment Handbook, Lewis P.A. (ed.), 2nd edition, Volume 1, John Wiley & Sons, New York, 1987, pp. 97-109.
  • the reaction can be illustrated by the fol ⁇ lowing equation:
  • the resulting pigment is a filler employed by the paper industry to improve the opacity and brightness of paper. On account of the low cost of the raw mater ⁇ ials, it is also a relatively inexpensive filler.
  • precipitated silica is prepared on an industrial scale by precipitating silica from a dilute sodium silicate solution with sulphuric acid, and filtering it from the mother liquor, thus leaving sodium sulphate in the filtrate.
  • the reaction can be illustrated by the following equation:
  • silica has good properties as a filler for paper, particularly as a component controlling the striking in of printer's ink and improving the optics of the paper, the final cost of the pigment will be high, since the yield is only 55% of the raw materials and, furthermore, 40% of the produce is unnecessary sodium sulphate which has only limited demand in industry. Therefore, sodium sulphate must in many cases be issued into the waterways, which limits the use of the method.
  • Silica can also be precipitated with carbon dioxide, but in this case sodium carbonate remains in the mother liquor, and it is not feasible to use sodium carbonate as such for other purposes than in dried form to be employed as a raw material in the water glass pro ⁇ cess, Wason S.K., Precipitated Silica, Pigment Handbook, Lewis, P.A. (ed.), 2nd edition, Vol. 1, John Wiley & Sons, New York, 1987, pp. 139-159.
  • the reaction can be illustrated by the following equation:
  • the invention relates to a method for pre ⁇ paring a mixed pigment of calcium carbonate and silica, useful as a filler for paper.
  • the method is characterized by admixing lime milk and an aqueous sodium silicate solution and raising the temperature of the mixture to 55-170°C, and thereafter supplying carbon dioxide to the mixture until the pH of the mixture falls to 7 or below, thus precipitating a mixed pigment comprising calcium carbonate and silica.
  • the method of the invention produces no actual process waste.
  • the tail liquor is a dilute lye solution which, when evaporated, can be used in industry in which lye is becoming increasingly difficult to obtain as the use of chlorine is becoming more scarce.
  • Carbon dioxide can be obtained directly e.g. from the flue gases of steam boilers.
  • the amounts of the components in the reaction mixture should be selected so that calcium hydroxide precipitates all sodium oxide freed from silicate as calcium carbonate.
  • Sil: ⁇ te of a molar ratio of 3.3 was employed under the te ⁇ nditions, and thus the mixture ratio Ca0:Si0 2 was 1:3
  • the ratio of the ,s- ponents of the mixed pigment can be selected by varying the alkalinity of the silicate.
  • the reaction temperature must be between 55°C and 170°C.
  • a particularly preferred temperature is 55°C, as this gives a mixed pigment having an active surface area (BET) and a particle size specifically suitable for use as a filler for paper.
  • BET active surface area
  • the BET value should prefer ⁇ ably be below 100 m 2 /g, which yields a filterable pigment composition.
  • calcium carbonate also precipitates as calcite, which is desirable.
  • Carbon dioxide must be supplied to the reaction mixture with maximum efficiency and in minimum time, since this yields the most homogeneous mixed pigment. Under the test conditions, 20 minutes were sufficient for this purpose.
  • the pH of the reaction mixture falls to 7 or below, preferably to 6-7, during the supply of carbon dioxide.
  • the silicate solution should be diluted to a concentration of about 10% by weight in order that a filterable (non-gelatinous) precipitate may be obtained from the precipitation step.
  • the lime milk may be 20% by weight, even though under the test conditions a clear solution filtered from lime milk was employed to enable an accurate mass analysis.
  • the lime milk and silicate solution must be stirred prior to the supply of carbon dioxide.
  • the calcium carbonate should precipitate out as calcite and the silica in amorphous form.
  • the method of the invention may be carried out either in an on-site or in an off-site production plant. All other raw materials are utilized in the final product except sodium, which can be used in industry as a lye solution after evaporation or sold to the market.
  • the mixed pigment prepared by the method is ground to obtain an agglomerate size, preferably below 2 ⁇ m, having the best optical per- formance.
  • a sodium silicate solution Na 2 0'3,3Si0 2 and lime milk Ca(0H) 2 were employed as starting materials.
  • the exact molar ratio of the sodium silicate solution was 3.29 and the sodium silicate content 36.41% by weight.
  • the Si0 2 /Ca0 ratio of the starting materials was 3.6. 500 ml of lime milk were measured into a reactor and a suitable amount of sodium silicate was added to give a Si0 2 /Ca0 ratio of 3.6.
  • the reaction temperature was 95°C and the stirring rate 600 rpm.
  • the stirring rate was 100 rpm. After the temperature had risen to 95°C, supply of carbon dioxide was started. Carbon dioxide was supplied to the reactor at a rate of 10 1/min for 60 minutes. During carbon dioxide supply, the pH of the mixture dropped to 6-7. Thereafter the mixture was left to cool in the reactor for one day, and subsequently stirred at a rate of 100 rpm. The reaction product was filtered in a B ⁇ chner funnel attached to a suction flask onto a filter paper, and the filtrate was recovered. The reaction product precipitate was washed with water and dried at 105°C for one day.
  • a sodium silicate solution Na 2 0*3,3Si0 2 and lime milk Ca(0H) 2 were employed as starting materials.
  • the exact molar ratio of the sodium silicate solution was 3.29 and the sodium silicate content 36.41% by weight.
  • the Si0 2 /CaO ratio of the starting materials was 3.6. 500 ml -_- of lime milk were measured into a reactor and a suitable amount of sodium silicate was added to give a Si0 2 /Ca0 ratio of 3.6.
  • the reaction temperature was 170°C and the stirring rate 600 rpm.
  • a sodium silicate solution Na 2 0*3,3Si0 2 and lime milk Ca(0H) 2 were employed as starting materials.
  • the exact molar ratio of the sodium silicate solution was 3.29 and the sodium silicate content 36.41% by weight.
  • 273 g of sodium silicate solution were mixed in 2.5 dm 3 of water and heated to 55°C.
  • the Si0 2 /Ca0 ratio of the starting mater ⁇ ials was 3.6.
  • the heated solutions were added into a reactor, the stirring rate was adjusted to 1200 rpm, and supply of carbon dioxide was started.
  • Carbon dioxide was supplied to the reactor at a rate of 32 1/min for 20 minutes. During carbon dioxide supply, the pH of the mix ⁇ ture dropped to 6-7. The reaction product was filtered with a ceramic disc filter. The pigment was ground with a bead mill prior to laboratory sheet experiments.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Organic Chemistry (AREA)
  • Composite Materials (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Dispersion Chemistry (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
  • Paper (AREA)

Abstract

The invention relates to a method for preparing a mixed pigment of calcium carbonate and silica, useful as a filler for paper. In accordance with the method, lime milk and an aqueous sodium silicate solution are admixed and the temperature of the mixture is raised to 55-170 °C, and thereafter carbon dioxide is supplied to the mixture until the pH of the mixture falls to 7 or below, thus precipitating a mixed pigment comprising calcium carbonate and silica.

Description

METHOD OF MAKING A PIGMENT BASED ON CALCIUM CARBONATE AND SILICIUM DIOXIDE USABLE AS FILLER FOR PAPER.
The invention relates to a method for preparing a mixed pigment of calcium carbonate and silica, useful as a filler for paper.
It is known that precipitated calcium carbonate can be prepared on an industrial scale by reacting carbon dioxide C02 (from flue gases, for example) with lime milk Ca(OH)2 to produce precipitated calcium carbonate, the crystal form of which can be regulated by varying t •■- reaction conditions, Thieme C, Aumann G., Precipitated Calcium Carbonate, Pigment Handbook, Lewis P.A. (ed.), 2nd edition, Volume 1, John Wiley & Sons, New York, 1987, pp. 97-109. The reaction can be illustrated by the fol¬ lowing equation:
Ca(0H)2 + C02 -> CaC03 + H20
The resulting pigment is a filler employed by the paper industry to improve the opacity and brightness of paper. On account of the low cost of the raw mater¬ ials, it is also a relatively inexpensive filler.
In general, precipitated silica is prepared on an industrial scale by precipitating silica from a dilute sodium silicate solution with sulphuric acid, and filtering it from the mother liquor, thus leaving sodium sulphate in the filtrate. The reaction can be illustrated by the following equation:
Na20'xSi02 + H2S04 -> xSi02 + NaS04 + H20
Even though silica has good properties as a filler for paper, particularly as a component controlling the striking in of printer's ink and improving the optics of the paper, the final cost of the pigment will be high, since the yield is only 55% of the raw materials and, furthermore, 40% of the produce is unnecessary sodium sulphate which has only limited demand in industry. Therefore, sodium sulphate must in many cases be issued into the waterways, which limits the use of the method.
Silica can also be precipitated with carbon dioxide, but in this case sodium carbonate remains in the mother liquor, and it is not feasible to use sodium carbonate as such for other purposes than in dried form to be employed as a raw material in the water glass pro¬ cess, Wason S.K., Precipitated Silica, Pigment Handbook, Lewis, P.A. (ed.), 2nd edition, Vol. 1, John Wiley & Sons, New York, 1987, pp. 139-159. The reaction can be illustrated by the following equation:
Na20*xSi02 + C02 -> xSi02 + Na2C03
The process is costly and requires production plants having an extremely high capacity.
It has now been found that by treating a mixture of lime milk and sodium silicate solution with carbon di¬ oxide under given reaction conditions, a mixed pigment formed by calcium carbonate and silica with very good optical characteristics is produced, simultaneously avoiding production of process waste. The reaction can be illustrated by the following equation:
Ca(0H)2 + C02 + Na20*xSi02 -> CaC03 + xSi02 + 2 NaOH
Thus the invention relates to a method for pre¬ paring a mixed pigment of calcium carbonate and silica, useful as a filler for paper. The method is characterized by admixing lime milk and an aqueous sodium silicate solution and raising the temperature of the mixture to 55-170°C, and thereafter supplying carbon dioxide to the mixture until the pH of the mixture falls to 7 or below, thus precipitating a mixed pigment comprising calcium carbonate and silica. The method of the invention produces no actual process waste. The tail liquor is a dilute lye solution which, when evaporated, can be used in industry in which lye is becoming increasingly difficult to obtain as the use of chlorine is becoming more scarce. Carbon dioxide can be obtained directly e.g. from the flue gases of steam boilers.
The amounts of the components in the reaction mixture should be selected so that calcium hydroxide precipitates all sodium oxide freed from silicate as calcium carbonate. Sil: ~te of a molar ratio of 3.3 was employed under the teε nditions, and thus the mixture ratio Ca0:Si02 was 1:3 When a more alkaline silicate is used, a greater amount of lime milk is needed, and thus the resultant mixed pigment has a relatively h,"- >=r amount of calcium carbonate. Hence the ratio of the ,s- ponents of the mixed pigment can be selected by varying the alkalinity of the silicate.
The reaction temperature must be between 55°C and 170°C. A particularly preferred temperature is 55°C, as this gives a mixed pigment having an active surface area (BET) and a particle size specifically suitable for use as a filler for paper. The BET value should prefer¬ ably be below 100 m2/g, which yields a filterable pigment composition. Thus calcium carbonate also precipitates as calcite, which is desirable.
Carbon dioxide must be supplied to the reaction mixture with maximum efficiency and in minimum time, since this yields the most homogeneous mixed pigment. Under the test conditions, 20 minutes were sufficient for this purpose. The pH of the reaction mixture falls to 7 or below, preferably to 6-7, during the supply of carbon dioxide. The silicate solution should be diluted to a concentration of about 10% by weight in order that a filterable (non-gelatinous) precipitate may be obtained from the precipitation step. The lime milk may be 20% by weight, even though under the test conditions a clear solution filtered from lime milk was employed to enable an accurate mass analysis. The lime milk and silicate solution must be stirred prior to the supply of carbon dioxide. The calcium carbonate should precipitate out as calcite and the silica in amorphous form.
The method of the invention may be carried out either in an on-site or in an off-site production plant. All other raw materials are utilized in the final product except sodium, which can be used in industry as a lye solution after evaporation or sold to the market.
For purposes of use, the mixed pigment prepared by the method is ground to obtain an agglomerate size, preferably below 2 μm, having the best optical per- formance.
The tests performed show that replacing Ti02 with a mixed pigment prepared in accordance with the invention in a pigment composition comprising, besides SPS kaolin, 10 parts by weight of Ti02, does not impair the opacity or brightness in any way, even though the total amount of Ti02 were replaced. In fact, a distinct improvement is found in the brightness on account of the high specific brightness of the mixed pigment. This is also the case when SPS kaolin is replaced with the mixed pigment. Thus the method of the invention enables prepar¬ ation of a novel mixed pigment that can be used as a filler for paper to improve the opacity and brightness and to replace e.g. expensive titanium dioxide.
The following examples illustrate the invention. Example 1
A sodium silicate solution Na20'3,3Si02 and lime milk Ca(0H)2 were employed as starting materials. The exact molar ratio of the sodium silicate solution was 3.29 and the sodium silicate content 36.41% by weight. The lime milk was prepared from calcium oxide CaO (M = 56.08 g/mol) and water. The calcium oxide was mixed in water and the mixture was filtered. The calcium content of the filtered lime milk solution was analyzed. The Si02/Ca0 ratio of the starting materials was 3.6. 500 ml of lime milk were measured into a reactor and a suitable amount of sodium silicate was added to give a Si02/Ca0 ratio of 3.6. The reaction temperature was 95°C and the stirring rate 600 rpm. During raising of the temperature, the stirring rate was 100 rpm. After the temperature had risen to 95°C, supply of carbon dioxide was started. Carbon dioxide was supplied to the reactor at a rate of 10 1/min for 60 minutes. During carbon dioxide supply, the pH of the mixture dropped to 6-7. Thereafter the mixture was left to cool in the reactor for one day, and subsequently stirred at a rate of 100 rpm. The reaction product was filtered in a Bϋchner funnel attached to a suction flask onto a filter paper, and the filtrate was recovered. The reaction product precipitate was washed with water and dried at 105°C for one day.
Example 2
A sodium silicate solution Na20*3,3Si02 and lime milk Ca(0H)2 were employed as starting materials. The exact molar ratio of the sodium silicate solution was 3.29 and the sodium silicate content 36.41% by weight. The lime milk was prepared from calcium oxide CaO (M = 56.08 g/mol) and water. The calcium oxide was mixed in water and the mixture was filtered. The calcium content of the filtered lime milk solution was analyzed. The Si02/CaO ratio of the starting materials was 3.6. 500 ml -_- of lime milk were measured into a reactor and a suitable amount of sodium silicate was added to give a Si02/Ca0 ratio of 3.6. The reaction temperature was 170°C and the stirring rate 600 rpm. During raising of the temperature, the stirring rate was 100 rpm. After the temperature had risen to 170°C, supply of carbon dioxide was started. Carbon dioxide was supplied to the reactor at a rate of 28 1/min for 60 minutes. During carbon dioxide supply, the pH of the mixture dropped to 6-7. Thereafter the mixture was left to cool in the reactor "for one day, and subsequently stirred at a rate of 100 rpπw The reaction product was filtered_in_.a Bϋchner funnel attached to a suction flask onto a filter paper, and fche filtrate was recovered. The reaction' product precipitate was washed with water-and dried atτ!05°C for ,one day.sc:
Example 3 ' -~
A sodium silicate solution Na20*3,3Si02 and lime milk Ca(0H)2 were employed as starting materials. The exact molar ratio of the sodium silicate solution was 3.29 and the sodium silicate content 36.41% by weight. 273 g of sodium silicate solution were mixed in 2.5 dm3 of water and heated to 55°C. The lime milk was prepared from calcium oxide CaO (M = 56.08 g/mol) and water. 12 g of calcium oxide were mixed in 1.5 dm3 of water and heated to 55°C. The Si02/Ca0 ratio of the starting mater¬ ials was 3.6. The heated solutions were added into a reactor, the stirring rate was adjusted to 1200 rpm, and supply of carbon dioxide was started. Carbon dioxide was supplied to the reactor at a rate of 32 1/min for 20 minutes. During carbon dioxide supply, the pH of the mix¬ ture dropped to 6-7. The reaction product was filtered with a ceramic disc filter. The pigment was ground with a bead mill prior to laboratory sheet experiments.
The analysis results for Examples 1-3 are given in the table below. Table Example 1 2 3 Temperature °C 95 170 55 CaO/Si02 1:3.6 1:3.6 1:3.6
Reaction time min, 60 60 20 C02 supply 1/min. 10 28 32 Reaction product
CaC03 Calcite Calcite Calcite
Si02 Amorphous Amorphous Amorphous BET No 77 108
Part, size < 2 μm 95% 95% 95% after grinding

Claims

Claims:
1. A method for preparing a mixed pigment of calcium carbonate and silica, useful as a filler for paper, c h a r a c t e r i z e d by admixing lime milk and an aqueous sodium silicate solution and raising the temperature of the mixture to 55-170°C, and thereafter supplying carbon dioxide to the mixture until the pH of the mixture falls to 7 or below, thus precipitating a mixed pigment comprising calcium carbonate and silica.
2. A method as claimed in claim 1, c h a r a c ¬ t e r i z e d in that the ratio of lime milk and sodium silicate in the mixture is such that the CaO frees all Na20 from the silicate as sodium hydroxide.
3. A method as claimed in claim 2, c h a r ¬ a c t e r i z e d in that the molar ratio Ca0:Si02 is 1:3.6.
4. A method as claimed in any one of claims 1-3, c h a r a c t e r i z e d in that the concentration of the sodium silicate solution is below 10%.
5. A method as claimed in any one of claims 1-4, c h a r a c t e r i z e d in that the concentration of the lime milk is below 20%.
6. A method as claimed in any one of claims 1-5, c h a r a c t e r i z e d in that the temperature of the mixture is 95°C.
7. A method as claimed in any one of claims 1-6, c h a r a c t e r i z e d in that the pH of the mixture falls to 6-7 during the supply of carbon dioxide.
8. A method as claimed in any one of claims 1-7, c h a r a c t e r i z e d in that a sufficient amount to precipitate all CaO as calcium carbonate and silicate as Si02 is supplied to the mixture.
9. A method as claimed in claim 8, c h a r ¬ a c t e r i z e d in that carbon dioxide is supplied to the mixture for 20 minutes at most.
PCT/FI1994/000329 1993-07-20 1994-07-20 Method of making a pigment based on calcium carbonate and silicium dioxide usable as filler for paper WO1995003251A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU71270/94A AU7127094A (en) 1993-07-20 1994-07-20 Method of making a pigment based on calcium carbonate and silicium dioxide usable as filler for paper

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
FI933270 1993-07-20
FI933270A FI933270A0 (en) 1993-07-20 1993-07-20 FOERFARANDE FOER FRAMSTAELLNING AV ETT KALCIUMKARBONAT / KISELDIOXIDBLANDPIGMENT OCH ANVAENDNING AV BLANDPIGMENTET SOM FYLLMEDEL FOER PAPPER
FI941143 1994-03-10
FI941143A FI94058C (en) 1993-07-20 1994-03-10 Method for preparing a calcium carbonate / silica mixed pigment for use as a paper filler

Publications (1)

Publication Number Publication Date
WO1995003251A1 true WO1995003251A1 (en) 1995-02-02

Family

ID=26159548

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI1994/000329 WO1995003251A1 (en) 1993-07-20 1994-07-20 Method of making a pigment based on calcium carbonate and silicium dioxide usable as filler for paper

Country Status (3)

Country Link
AU (1) AU7127094A (en)
FI (1) FI94058C (en)
WO (1) WO1995003251A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1297074A1 (en) * 2000-06-01 2003-04-02 J.M. Huber Corporation Composite precipitated calcium carbonate/silicon compound pigment
WO2008049750A1 (en) * 2006-10-24 2008-05-02 Ciba Holding Inc. Process for preparing high strength paper
EP0954512B2 (en) † 1996-12-30 2010-07-21 Minerals Technologies Inc. The use of calcium carbonate in an acidic aqueous media
CN105377575A (en) * 2013-04-26 2016-03-02 太平洋纳米产品公司 Fibrous structured amorphous silica including precipitated calcium carbonate, compositions of matter made therewith, and methods of use thereof

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE221920C1 (en) * 1968-08-06

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE221920C1 (en) * 1968-08-06

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
DERWENT'S ABSTRACT, No. 61935C/35, Week 8035; & SU,A,709 536 (LENINSK ORE CHEM), 25 January 1980. *
DIALOG INFORMATION SERVICES, File 351, DERWENT WPI, Dialog Accession No. 003741742, WPI Accession No. 83-737942/33, TOYO DENKO KOGYO KK, "Mfg. Calcium Carbonate Filler of Excellent Dispersibility Includes Adding Water Glass or Silica Sol to Calcium Hydroxide Suspension and Introducing Carbon Dioxide *

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0954512B2 (en) † 1996-12-30 2010-07-21 Minerals Technologies Inc. The use of calcium carbonate in an acidic aqueous media
EP1297074A1 (en) * 2000-06-01 2003-04-02 J.M. Huber Corporation Composite precipitated calcium carbonate/silicon compound pigment
US6623555B1 (en) 2000-06-01 2003-09-23 Jukka P. Haverinen Composite precipitated calcium carbonate/silicon compound pigment and method of making same
EP1297074B1 (en) * 2000-06-01 2017-09-27 Omya International AG Composite precipitated calcium carbonate/silicon compound pigment
WO2008049750A1 (en) * 2006-10-24 2008-05-02 Ciba Holding Inc. Process for preparing high strength paper
CN105377575A (en) * 2013-04-26 2016-03-02 太平洋纳米产品公司 Fibrous structured amorphous silica including precipitated calcium carbonate, compositions of matter made therewith, and methods of use thereof
US9580867B2 (en) 2013-04-26 2017-02-28 Pacific Nano Products, Inc. Fibrous structured amorphous silica including precipitated calcium carbonate, compositions of matter made therewith, and methods of use thereof
US9637864B2 (en) 2013-04-26 2017-05-02 Pacific Nano Products, Inc. Fibrous structured amorphous silica including precipitated calcium carbonate, compositions of matter made therewith, and methods of use thereof
US9708770B2 (en) 2013-04-26 2017-07-18 Pacific Nano Products, Inc. Paper, paperboard, or label stock coated with fibrous structured amorphous silica including precipitated calcium carbonate
CN105377575B (en) * 2013-04-26 2017-12-08 太平洋纳米产品公司 Fibre structure amorphous silica including winnofil, the composition of matter being produced from it and its application method
US10077363B2 (en) 2013-04-26 2018-09-18 Pacific Nano Products, Inc. Fibrous structured amorphous silica including precipitated calcium carbonate and compositions of matter made therewith
US11447641B2 (en) 2013-04-26 2022-09-20 Pacific Nano Products, Inc. Fibrous structured amorphous silica including precipitated calcium carbonate and compositions of matter made therewith

Also Published As

Publication number Publication date
FI941143A (en) 1995-01-21
FI94058B (en) 1995-03-31
FI94058C (en) 1995-07-10
FI941143A0 (en) 1994-03-10
AU7127094A (en) 1995-02-20

Similar Documents

Publication Publication Date Title
JP2939659B2 (en) Precipitated calcium carbonate
KR101759765B1 (en) Production of high purity precipitated calcium carbonate
US6156286A (en) Seeding of aragonite calcium carbonate and the product thereof
US5939036A (en) Manufacture of precipitated calcium carbonate
US6132696A (en) Manufacture of precipitated calcium carbonate of improved color and stable crystalline form
FI109017B (en) Process for Preparation of High Opacity Precipitated Calcium Carbonate by Reacting Sodium Carbonate with Calcium Hydroxide
EP0480587B1 (en) Precipitated calcium carbonate
KR100671441B1 (en) Lime treatment
WO1995003251A1 (en) Method of making a pigment based on calcium carbonate and silicium dioxide usable as filler for paper
TW201708107A (en) High solids PCC with depolymerized carboxylated cellulose
KR20180014071A (en) How to increase the opacity of precipitated calcium carbonate
CN110563015B (en) Preparation method of light calcium carbonate for food
JP3860834B2 (en) Co-production method of calcium carbonate and sodium hydroxide
JP3674858B2 (en) Method for producing high specific surface area calcium hydroxide particles
JPS5926927A (en) Preparation of fusiform calcium carbonate crystal
EP1351882B1 (en) A process for the manufacture of zeolite-a useful as a detergent builder
JP2556699B2 (en) Method for producing aragonite crystalline calcium carbonate
JP2675465B2 (en) Hydrous calcium carbonate and method for producing the same
US2859100A (en) Process of extracting alumina from raw calcium aluminates
JP4813075B2 (en) Method for producing aragonite acicular calcium carbonate
SU1650589A1 (en) Method for obtaining chemically precipitated calcium carbonate
KR20110067091A (en) Aluminum hydroxide gel particles and process for production of same
JPH10292283A (en) Production of calcium carbonate
AU2003248412A1 (en) Calcium carbonate synthesis method and resulting product
JPS593019A (en) Manufacture of fine-grained a-type zeolite

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AM AT AU BB BG BR BY CA CH CN CZ DE DK ES FI GB GE HU JP KE KG KP KR KZ LK LT LU LV MD MG MN MW NL NO NZ PL PT RO RU SD SE SI SK TJ TT UA US UZ VN

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): KE MW SD AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

NENP Non-entry into the national phase

Ref country code: CA