EP1888458A1

EP1888458A1 - Mineral materials containing carbonate with reduced emission of combustible fossil carbonaceous gas on decomposition thereof and method for production and use thereof

Info

Publication number: EP1888458A1
Application number: EP06744734A
Authority: EP
Inventors: Matthias Buri; Thoralf Gliese
Original assignee: Omya Development AG
Current assignee: Omya Development AG
Priority date: 2005-05-20
Filing date: 2006-05-11
Publication date: 2008-02-20
Also published as: NO20076393L; CA2607053A1; IL187232A0; US20090211493A1; KR101278819B1; WO2006123235A1; MY142008A; RU2407702C2; MX2007014303A; FR2885900B1; WO2006123235B1; KR20080021662A; AR055955A1; BRPI0610346A2; TW200706491A; US20120073473A1; RU2007147468A; FR2885900A1; UY29541A1; AU2006248714A1

Abstract

The invention relates to a novel synthetic mineral material containing carbonate the decomposition of which reduces the level of emission of combustible fossil carbonaceous fuel. The invention further relates to batch, batch/continuous or continuous production thereof, and the uses thereof in pharmaceuticals, animal or human foodstuffs, or the paper industry, in particular for the production of paper, bulking, coating or any other paper surface treatment and aqueous or non-aqueous paints, plastic materials such as breathable polyethylene films or printing inks.

Description

MINERAL MATERIALS CONTAINING CARBONATE WITH GAS EMISSION

REDUCED FOSSIL FUEL FUEL AT THEIR DECOMPOSITIONS AND THEIR SYNTHESIS PROCESS AND THEIR

USES

The present invention relates to the field of inorganic materials (fillers and / or inorganic pigments) containing carbonate and their areas of application.

In these sectors of application, which are the pharmaceutical field including products such as drugs, the field of food or feed, or the paper industry including paper making, mass or coating or even any other surface treatment of paper as well as the fields of aqueous or non-aqueous paints as well as the field of plastics such as in particular the charges for breathable polyethylene film or the field of printing inks, it is common to use before, during or after the production of these various products, natural or synthetic mineral materials (fillers and / or pigments) containing carbonate.

With a view to respecting the environment and the fight against the greenhouse effect, and in the framework of the Convention on Climate Change of our planet, a protocol on the emission of carbon dioxide in the atmosphere has been signed at Kyoto on December 11, 1997 to reduce the amount of these carbon dioxide emissions into the atmosphere.

With the aim of reducing these carbon dioxide emissions, of which approximately 80% are from the combustion of coal, oil or natural gas and 43% of which result from global emissions from the industrial sector, the Applicant has found, after much research, on the one hand, new mineral substances (fillers and / or pigments) which emit only small amounts of fossil fuel carbon dioxide during their decomposition and, on the other hand, their synthesis process. At this stage, it should be noted that carbon dioxide fossil fuel, the Applicant hears carbon dioxide mainly from the combustion of fossil fuels such as coal, oil or natural gas or calcination of minerals.

Thus, the invention relates to a new synthetic mineral material containing carbonate whose decomposition reduces the rate of emission of carbon dioxide fossil fuel.

It also relates to the manufacture of this new mineral material batch, cascades still said continuously or batch-continuous mixing and its uses in the various fields that are the pharmaceutical field, the field of food or feed, or the paper industry, in particular the manufacture of paper, mass or coating, or any other surface treatment of paper as well as the fields of aqueous or non-aqueous paints, as well as the field of plastics such as in particular that of polyethylene films. breathable or the field of printing inks.

The problem that arises therefore to those skilled in the art, namely to comply with the Kyoto protocol in terms of the emission of carbon dioxide into the atmosphere, has found no satisfactory solution in the prior art known to date by the Applicant.

Indeed, to date, the Applicant knows more than 100 patents relating to the synthesis of synthetic calcium carbonate also called precipitated calcium carbonate, commonly called "PCC". These patents essentially describe either synthetic calcium carbonate synthesis processes, based on the calcination of natural calcium carbonate and the reuse of carbon dioxide released, or processes based on the reaction of lime and carbon dioxide, the source of which is coal, oil or natural gas. In addition, a large majority indicate that the source of carbon dioxide has no influence on the final product obtained. Thus, the Applicant may, among these numerous patents, mention the US Pat. Nos. 6,251,366, 6,666,953, 6,594,910, 6,540,870, 6,540,878, 6,445,459, 6440,209 and 6,221,146. , US Pat. No. 6,416,727 or else the documents WO 01/17905, EP 0 799 797, EP 1 222 146 or JP 08/252595 which disclose the synthesis of PCC by the implementation of carbon dioxide originating from the combustion of fossil energy without speaking of carbon 14 ( ¹⁴ C).

On the other hand a study carried out on the reduction of carbon dioxide emissions (Possibilities of reducing CO2 Emissions in the Finnish Forest Industry, S. Siitonen & P. Ahtila, Otaniemi 2002 published by Finnish Forest, Industries Federation, Helsinki 9/2002) leads the skilled person to consider using carbon dioxide from lime kilns to manufacture the PCC and reduce the amount of carbon dioxide emitted.

Thus, a person skilled in the art who must find a solution to reduce the emission of carbon dioxide from the combustion of fossil energy had not so far satisfactory solution.

In view of this problem, the Applicant has unexpectedly found that synthetic mineral materials containing carbonate having a high carbon 14 ( ¹⁴ C) content make it possible to comply with the Kyoto protocol by reducing the emission of combustible carbon dioxide. fossil.

Thus, the first object of the invention is a new synthetic mineral material containing carbonate having a high level of carbon 14 ( ¹⁴ C).

Another object of the invention is a method of manufacturing synthetic mineral materials containing carbonate having a high level of carbon 14 ( ¹⁴ C).

A further object of the invention is the use of synthetic mineral materials according to the invention in the aforementioned fields.

Throughout the present application, it should be noted that by mineral material, the Applicant intends mineral pigment and / or mineral filler. Thus, the synthetic mineral material containing carbonate having a high level of ¹⁴ C according to the invention is characterized in that it has a nuclear conversion rate of carbon of ¹⁴ C at ¹² C of at least 450 transformations per hour and per gram, preferably between 700 and 890 transformations per hour and per gram, very preferably between 850 and 890 transformations per hour and per gram.

Throughout the present application and in the claims, the carbon conversion rate in carbon from ¹⁴ C to ¹² C of the synthetic mineral material is carried out according to a method of determining the rate of nuclear transformation whose originality lies in the stage sample preparation.

Indeed, the conventional methods for analyzing the nuclear conversion rate in carbon from ¹⁴ C to ¹² C known to date are based on a preparation step consisting of a thermal decomposition at high temperature (approximately 1000 ⁰ C) by combustion or calcination of the sample to be analyzed and then of the collection of carbon dioxide released and trapped at a low temperature before its reduction, by catalytic hydrogenation, to an elemental carbon atom whose composition is isotope ¹³ C / ¹² C and ¹⁵ N / ¹⁴ N and ¹⁴ C is measured by a mass spectrophotometer.

However, it turns out that these methods based on the thermal decomposition of the sample to be analyzed do not make it possible to differentiate the sources of the carbon dioxide, that is to say do not make it possible to differentiate the carbon coming from the organic phases and inorganic or mineral phases.

Also, the Applicant has developed a method for determining the rate of nuclear transformation characterized by a step of preparation of the sample by means of an H ₃ O ⁺ donor, such as in particular hydrochloric acid, or of other donors of H ₃ O ⁺ stronger than carbonic acid such as phosphoric acid, and which allows to dose only the carbon from the inorganic or mineral phase of the sample to be analyzed. This method for determining the ¹⁴ C nuclear conversion rate at ¹² C of the synthetic mineral material containing the carbonate according to the invention is characterized in that it comprises: a) a step of preparing the sample consisting of an attack of the sample by an H ₃ O ⁺ donor, preferably hydrochloric acid or any H ₃ O ⁺ donor, stronger than carbonic acid such as 'Phosphoric acid,

b) a step of collecting the carbon dioxide evolved in a trap at the temperature of the liquid nitrogen,

c) a step of reducing the carbon dioxide, by hydrogenation on an iron catalyst, to an elemental carbon atom ( ^I3 C / ¹² C / ¹⁴ C)

(d) then the radiological analysis, in particular by mass spectroscopy, of the ¹³ C / ¹² C and ¹⁵ N / ^I4 N and ¹⁴ C isotope composition compared to an international reference standard for determining the nuclear transformation per hour and per gram.

A preferred variant of the process for determining the degree of nuclear conversion is characterized in that an additional trap having a temperature of 20 ° C. is added between the acid etching step and the carbon dioxide recovery stage. ° C at 30 ° C above the trap of step b), to avoid contamination with other volatile compounds from the sample.

The Applicant emphasizes that the nuclear conversion rates of 450 transformations per hour and per gram, preferably between 700 and 890 transformations per hour and per gram, very preferably between 850 and 890 transformations per hour and per gram, and which are the essential characteristic of the product object of the invention, may nevertheless be determined by any other appropriate method.

The sample to be analyzed according to the invention consists of the mineral material containing carbonate according to the invention, and can be a sheet of paper containing the mineral material, a calcium carbonate treated with organic compounds, a composition of polyvinyl (PVC), a calcium carbonate having organic impurities or any other sample. In particular, the inorganic materials according to the invention are characterized in that the carbonate is chosen from carbonates of monovalent and / or bivalent and / or trivalent cations or their mixtures.

More particularly, these inorganic materials according to the invention are characterized in that said monovalent and / or bivalent and / or trivalent cations are chosen from the cations of the first or second main group of the periodic table of Mendeleiev.

In a very particular way, said cations are chosen from lithium, sodium, potassium, magnesium, calcium, strontium or their mixtures.

The synthetic mineral material containing a carbonate according to the invention is preferably characterized in that it is a calcium carbonate having a crystalline structure of the calcite or aragonite or vaterite type or in that it is a mixture of a carbonate of calcic type structure calcium with a calcium carbonate of aragonite type structure and / or a calcium carbonate of vaterite-type structure, and more preferably in that it is a mixture of calcite-type structure and aragonite type.

In particular, said calcium carbonate according to the invention with the aforementioned crystalline structure is characterized in that it has a degree of whiteness greater than 80%, preferably greater than 90%, very preferably greater than 93% TAPPI determined according to the TAPPI standard. T452 ISO 2470.

In another variant of the invention, the synthetic mineral material containing carbonate according to the invention is characterized in that it is a mixture and / or a co-structure of the abovementioned carbonates with other mineral materials chosen from silicas. natural and / or synthetic, silicates such as in particular clay, talc, mica, or else chosen from aluminum hydroxides, sulphates, satin whites, phosphates such as brushites, octa-calcium phosphates or hydroxyapatites, or mixtures thereof. The process for manufacturing the mineral materials according to the invention is characterized in that it uses carbon dioxide resulting from aerobic or anaerobic fermentation, preferably anaerobic and more particularly derived from the fermentation of sugars or the combustion of alcohol. from the fermentation of organic compounds.

In the remainder of the present application, the Applicant states that carbon dioxide resulting from aerobic or anaerobic fermentation, or the fermentation of sugars or the combustion of alcohol from the fermentation of organic compounds will be called fresh carbon dioxide. inverse fossil fuel carbon dioxide resulting from the combustion of fossil fuels such as coal, oil or natural gas, or carbon dioxide from the calcination of natural calcium carbonate which will be called old carbon dioxide.

Particularly the fresh carbon dioxide is derived from the fermentation of sugars or the combustion of alcohol, in particular ethanol, methanol, or alkanes such as methane, ethane, or any other alkane, originating from the fermentation of organic compounds such as fruit, fruit alcohols or waste from landfills or is the result of fermentation or thermal decomposition or oxidative degradation of waste from supercritical pressure landfills.

Another particular way is that the fresh carbon dioxide used in the process according to the invention is a mixture of fresh carbon dioxide from the fermentation of sugars with fresh carbon dioxide from the combustion of organic compounds.

Another variant of the process according to the invention is characterized in that it implements a mixture of carbon dioxide resulting from aerobic or anaerobic fermentation, preferably anaerobic and more particularly derived from the fermentation of sugars or the combustion of alcohol. from the fermentation of organic compounds, with old carbon dioxide. According to this variant, the process according to the invention is characterized in that the mixture uses less than 50% by weight of old carbon dioxide.

More particularly, the method of manufacturing synthetic mineral material containing carbonate according to the invention is characterized in that the implementation of carbon dioxide is carried out at a temperature between 5 ° C and 100 ° C, preferably between 20 ^° C. and 30 ° C.

This process according to the invention is characterized in that it is a process in batch, in cascades still said continuous or in continuous-batch mixing.

By batch process, the Applicant hears a manufacturing process in which the reaction takes place in a single tank where all the reagents are introduced.

According to the still-continuous cascading method, the Applicant understands a manufacturing process in which the fresh carbon dioxide used is introduced into a cascade of n reactors installed in series and / or in parallel whose assembly in series is illustrated by the drawing n ° 1.

In this drawing No. 1, the Applicant denotes by "n" the number of cascaded reactors in which carbon dioxide and / or any other additive are introduced continuously, this number n ranging from 1 to 50, preferably from 1 to 10, very preferably from 1 to 5.

By continuous-batch mixing process, the Applicant intends a continuous synthesis process followed by one or more steps in batch, this or these last steps may be the addition of carbon dioxide storage or addition of various additives or still a physical treatment step (such as grinding, centrifugation, thermal concentration, mechanical concentration) or a chemical treatment step such as treatment with sodium silicate followed by addition of an acid such as acid citric acid or phosphoric acid or optionally at least one step of introducing a dispersant. In drawing No. 2 illustrating this batch-batch mixing process, the Applicant designates by "m" the number of physical or chemical treatment mentioned above, this or these treatments which can be in particular a treatment by mechanical concentration by implementing a centrifuge.

This number "m" varies from 1 to 5, preferably from 1 to 2.

Similarly in this drawing No. 2, the Applicant indicates by "o" the number of steps corresponding to a possible addition of dispersant, this dispersant being any type of dispersant known to those skilled in the art whose choice is adapted so obvious to those skilled in the art depending on the intended application. This number "o" varies from 0 to 3, preferably from 0 to 1.

The method according to the invention is finally characterized in that it optionally comprises at least one dispersion step and / or at least one step of grinding in a dry medium or in a humid medium, in the presence of optionally at least one dispersing agent and / or at least one grinding aid agent. Those skilled in the art will be able to adapt the choice of its possible dispersing agents and / or grinding aid agents according to the intended final application.

Finally, the inorganic materials according to the invention are used in the pharmaceutical field with products such as drugs, the field of food or feed, or the paper industry such as papermaking, mass and / or coating on a paper or plastic medium or any other surface treatment of paper and / or plastic, the plastic being preferably chosen from polyolefins of the polyethylene or polypropylene type and their derivatives, as well as the fields of aqueous paints or non-aqueous as well as the field of plastics or the field of printing inks.

The use of mineral materials in the coating of paper is preferably done during blade coating operations, film transfer, water curtain or by "size-press". The use of inorganic materials as paper mass filler is preferably done by adding the mineral material according to the invention to different locations before and / or during the formation of the sheet.

The inorganic materials according to the invention used in the field of printing inks are used in inks for inkjet printing, offset printing and / or rotogravure printing.

The scope and interest of the invention will be better understood by the following examples, which can not be limiting.

Example 1

This example illustrates various processes of the prior art using an old carbon dioxide.

Test n ° 1

This test, which illustrates the prior art, relates to a process for producing calcium carbonate precipitated by reacting lime with old carbon dioxide from the combustion of fossil energy such as butane.

To do this, after having produced calcium oxide CaO by calcining a crushed natural calcium carbonate (Omyapure ™ from Omya SAS) in a muffle furnace for 6 hours at 900 ° C., the suspension is suspended. Calcium oxide CaO in a container containing water without carbon dioxide to form a Ca (OH) ₂ calcium hydroxide suspension.

Once this suspension of lime formed with a weight concentration of dry matter equal to 10%, is introduced at room temperature (22 ° C ± 2 ⁰ C) old carbon dioxide, from the combustion of butane by means of a camping burner gas, until the pH drops from a strongly alkaline value of the order of 13 up to a value between 8.0 and 8.5. The product obtained, which is a precipitated calcium carbonate of the prior art, is then dried at 140 ^° C.

Test n ° 2

This test, which illustrates the prior art, relates to a process for producing calcium carbonate precipitated by reacting lime with old carbon dioxide from the calcination of natural calcium carbonate.

To do this, with the same material and the same procedure as in the previous test, old carbon dioxide gas from calcination is reacted in a muffle furnace at 900 ° C. with a ground natural calcium carbonate ( Omyapure ™ from Omya SAS), with a suspension of lime at 10% by weight of dry matter.

The product obtained, which is a precipitated calcium carbonate of the prior art, is then dried at 140 ^° C.

Test n ° 3

This test, which illustrates the prior art, relates to a process for producing strontium carbonate by reaction of strontium hydroxide with old carbon dioxide from the calcination of natural calcium carbonate.

To do this, the Sr (OH) ₂ x 8 (H ₂ O) strontium hydroxide (Lot 9329 A from Riedel-de Haën) is suspended in a container containing water without carbon dioxide for forming a suspension of strontium hydroxide at a solids concentration of 10% by weight.

Once this suspension has been formed, old carbon dioxide, obtained from calcination in a muffle furnace at 900 ^° C. of a ground natural calcium carbonate (Omyapure ™), is introduced at ambient temperature (22 ° C. ± 20 ^° C.). from Omya SAS), until the pH drops to a value between 8.0 and 8.5. The product obtained, which is a strontium carbonate of the prior art, is then dried at 140 ° C.

Example 2

This example illustrates the process according to the invention using fresh carbon dioxide.

Test n ° 4

This test, which illustrates the invention, relates to a process for producing calcium carbonate precipitated by reacting lime with fresh carbon dioxide from the combustion of ethanol from the fermentation of an organic compound such as kirsch.

At the same time, a kirsch alcohol bought in supermarkets was distilled from 37% by volume to 65% by volume and then treated with sodium sulphate to absorb the rest of the water and obtain a concentration of 97% by volume. ethanol.

Once this suspension of lime formed and this alcohol obtained, is introduced into the slurry of lime and at room temperature (22 ° C ± 2 ° C) the fresh carbon dioxide, resulting from the combustion of the aforementioned ethanol by means of a methanol burner until the pH drops to a value between 8.0 and 8.5.

The product obtained, which is a precipitated calcium carbonate according to the invention, is then dried at 140 ^° C. Test n ° 5

This test, which illustrates the invention, relates to a process for producing strontium carbonate by reaction of strontium hydroxide with fresh carbon dioxide from the combustion of ethanol from the fermentation of an organic compound such as kirsch .

To do this, is suspended strontium hydroxide Sr (OH) ₂ x 8 (H ₂ O) ₅ (lot 9329A of from Riedel-de Hae ^'n), in a container containing water without carbon dioxide to form a suspension of strontium hydroxide at a dry matter concentration of 10% by weight.

Once this suspension of strontium hydroxide Sr (OH) ₂ × 8 (H ₂ O) formed and this alcohol obtained is introduced into the suspension of strontium hydroxide and at ambient temperature (22 ^° C. ± 20 ^° C.) the fresh carbon dioxide from the combustion of the aforementioned ethanol by means of a methanol burner until the pH drops to a value between 8.0 and 8.5.

The product obtained, which is a strontium carbonate according to the invention, is then dried at 140 ^° C.

Test n ° 6

This test, which illustrates the invention, relates to a batch manufacturing process of precipitated calcium carbonate by reacting lime with fresh carbon dioxide from the fermentation of a sugar.

To do this, after having produced calcium oxide CaO by calcining a crushed natural calcium carbonate (Omyapure ™ from Omya SAS) in a muffle furnace for 6 hours at 900 ° C., 30 g of calcium oxide CaO are suspended in a beaker containing 200 g of water without carbon dioxide to form a suspension of calcium hydroxide Ca (OH) ₂ .

On the other hand, 1 kg of refined household sugar (C ₁₂ H ₂₃ On) is introduced into a 5-liter container and dissolved in 4 liters of distilled water to which 7 g of baker's yeast are added. to allow the release of carbon dioxide from the fermentation of sugar.

This fresh carbon dioxide which is created and which is continuously formed during 21 days by the fermentation of the sugar is then introduced into the suspension of lime during these 21 days at ambient temperature (22 ° C ± 2 ° C) until the pH drops to a value of about 7 ± 0.3.

This introduction of fresh carbon dioxide into the lime slurry is effected by means of a washing vessel with distilled water which collects any volatilised ethanol.

The product obtained, which is a precipitated calcium carbonate according to the invention, is then dried at 140 ° C.

Test n ° 7

This test, which illustrates the invention, relates to a continuous manufacturing process of precipitated calcium carbonate by reacting lime with fresh carbon dioxide from the fermentation of a sugar.

To do this, in a cascade of 4 reactors filled with distilled water and installed in series, as shown in drawing No. 1, an aqueous slurry of lime and fresh carbon dioxide from the fermentation of a mixture of 500 g of sucrose and 42 g of baker's yeast (saccharomyces cerevisiae) in 4 liters of water. Thus, an aqueous suspension of lime is first prepared by suspending 1000 g of calcium hydroxide in a vessel containing 50 liters of water without carbon dioxide and stirred by a mechanical stirrer. 4 closed bottles of 5 liters are then placed, in each of which a mixture of 500 grams of refined household sugar (C ₁₂ H ₂₃ O ₁₁ ) and 42 grams of baker's yeast is dissolved in 4 liters of distilled water to allow the release of carbon dioxide from the sugar fermentation for 5 days.

Once these operations have been carried out, the introduction of the carbon dioxide gas previously formed into each of the flasks is started simultaneously and the suspension of lime contained in the stirred vessel is continuously pumped by a mechanical stirrer into the 4 reactors equipped with a lid. and interconnected by means of a pipe.

The rate of introduction of the slurry of lime corresponds to an introduction of 7.35 g in dry weight of lime per hour until 45 of the 50 liters of suspension of lime are passed through the 4 carbonation reactors.

Thus the fresh carbon dioxide, which is created and which is continuously formed during 5 days by the fermentation of the sugar, is introduced into the 4 agitated reactors at 400 revolutions per minute and at a temperature equal to 25 ° C. ± 3 ° C. during the 5 days.

The pH in the fourth reactor has a value between 6.7 and 7.3.

The product obtained, recovered in a final reservoir is a precipitated calcium carbonate according to the invention, which is then dried at 140 ^° C.

This precipitated calcium carbonate obtained is a pure calcite as shown by the infrared spectrum and has the following particle size distribution, expressed as a percentage by weight of the particles and measured with a Sedigraph ™ 5100 type granulometer: 77% have a diameter <2 μm, 44% have a diameter <1 μm, 6% have a diameter <0.2 μm.

Test n ° 8

This test, which illustrates the invention, relates to a process for the continuous production of a precipitated calcium carbonate obtained by reacting lime with fresh carbon dioxide resulting from the fermentation of a sugar, and then treated in a fifth reactor by sodium silicate.

To do this, we have a cascade of 5 reactors arranged in series as illustrated in drawing n ° 2.

In the cascade of the first 4 reactors, the product obtained with the same procedure as the preceding test is a precipitated calcium carbonate according to the invention, which is then treated in the fifth reactor with sodium silicate (Inosil 4237 from Van Berle), diluted in water at 1% by weight, in an amount equivalent to 4% by dry weight relative to the dry weight of calcium carbonate formed. The dosage was set at 0.22 g of sodium silicate per hour, corresponding to 22 ml per hour of a 1% by weight solution.

The pH is then 10.8 ± 0.1 in the fifth reactor at the end of the test.

Test n ° 9

This test, which illustrates the invention, relates to a continuous production process of a precipitated calcium carbonate obtained by reacting lime with fresh carbon dioxide from the fermentation of a sugar, and then treated in the front-end. last reactor by a sodium silicate and in the last reactor by an addition of citric acid.

To do this, we have a cascade of 6 reactors arranged in series as shown in drawing No. 2. In the cascade of the first 4 reactors, the product obtained with the same procedure as the preceding test is a precipitated calcium carbonate according to the invention, which is then treated in the fifth reactor with sodium silicate (Inosil 4237 from Van Berle) in an amount equivalent to 4% by dry weight relative to the dry weight of calcium carbonate formed. The pH is then 10.8 ± 0.1.

In the sixth reactor which allows pH control and adjustment, the necessary amount of citric acid is continuously added to obtain a pH of 8.5 ± 0.3. It should be noted in this example, that the addition in this sixth reactor could, in an equivalent way, be carried out in batch.

Test n ° 10

This test, which illustrates the invention, relates to a process for the batch production of sodium carbonate by reacting sodium hydroxide with fresh carbon dioxide resulting from the fermentation of a sugar, and then producing a precipitated calcium carbonate. by reaction of the sodium carbonate formed according to the invention with a calcium chloride.

To do this, first dissolve 30 g of sodium hydroxide for analysis sold by Riedel-de Haën in 120 g of water without carbon dioxide gas and then, in a 2.5 liter container, 500 g of refined household sugar (C ₁₂ H ₂₃ Oi ₁ ) which is dissolved in 2 liters of distilled water to which are added 21 g of fresh baker's yeast corresponding to 7 g of baker's yeast to allow the release of carbon dioxide derived from the fermentation of sugar.

This fresh carbon dioxide which is created and which is continuously formed during 21 days by the fermentation of the sugar is then introduced into the soda solution during these 21 days at ambient temperature (22 ° C. ± 2 ° C.) until the pH reaches a value between 8.0 and 8.5.

This introduction of the fresh carbon dioxide into the sodium hydroxide solution is carried out by means of a washing vessel with distilled water which collects any volatilised ethanol. Part of the solution of the sodium carbonate obtained is then filtered using a 0.45 μm filter to separate the insoluble components and obtain a filtrate which is then dried at 140 ° C. to obtain the sodium carbonate according to US Pat. 'invention. In a second step, the sodium carbonate according to the invention is mixed at room temperature (22 ^° C. ± 2 ° C.) with a stoichiometric amount of calcium chloride in order to obtain a precipitated calcium carbonate whose insolubles are filtered as previously. and whose filtrate is dried at 140 ° C.

Test n ° 11

This test, which illustrates the invention, relates to a dry mixture of precipitated calcium carbonate obtained by mixing a dry calcium carbonate according to the invention (test No. 4) with a dry calcium carbonate of the prior art (Test No. 2) in a weight ratio 55/45.

Test n ° 12

This test, which illustrates the invention, relates to a dry mixture of precipitated calcium carbonate obtained by drying a mixture of a suspension of calcium carbonate according to the invention (test No. 4) with a suspension of calcium carbonate. calcium of the prior art (test No. 2) in a weight ratio 51/49.

Example 3

This example illustrates the process according to the invention for determining the ¹⁴ C nuclear conversion rate at ¹² C of a medicinal formulation consisting essentially of calcium carbonate.

Test No. 13 This test, which illustrates the prior art, uses a dry drug formulation consisting of a crushed natural calcium carbonate powder marketed by Omya SAS under the name of Omyapure ™. To do this, 30 mg of the test sample are placed in a 7 ml ampoule equipped with 2 consecutive 14.7 ml reactors at a pressure of 250 mbar, thus forming 2 consecutive traps, the last of which is a trap. liquid nitrogen and the first is cooled to a temperature of 20 ^° C to 30 ° C above the second to avoid contamination with other volatile compounds from the sample.

About 0.4 ml of hydrochloric acid are then poured into this ampoule, which will react with the drug formulation and release carbon dioxide which will be trapped in the successive traps.

The carbon dioxide thus trapped is then reduced by hydrogenation on a cobalt powder catalyst to an elemental carbon atom ( ¹³ C / ¹² C / ¹⁴ C).

The ¹³ C / ¹² C and ¹⁵ N / ¹⁴ N isotope composition of the graphite thus obtained as well as that of ¹⁴ C compared to an international reference standard is then determined by the so-called "AMS" technique for mass-accelerating mass spectrometry.

"Accelerator Mass Spectrometry" using a spectrophotometer commonly used by those skilled in the art.

The nuclear conversion rate per hour and per gram of the synthetic mineral material to be analyzed is then determined by the ratio between the measured ¹⁴ C value and the value of the internationally recognized reference standard referenced in the ¹⁴ C dating methods.

Test n ° 14

This test, which illustrates the invention, implements, with the same procedure and the same material as the previous test, a dry drug formulation consisting of a calcium carbonate according to test No. 4.

Example 4

This example illustrates the use of the inorganic materials according to the invention in the paper industry as well as the method according to the invention for determining the nuclear transformation of ¹⁴ C in ¹² C of a formulation in the paper industry, and more particularly in the field of offset ink.

Test n ° 15

This test illustrates the prior art and uses, in an "offset" ink application, the precipitated calcium carbonate of test No. 1.

To do this, by means of a HSM 100-H type vibratory disk mill marketed by the company Herzog equipped with a tungsten carbide grinding chamber with an internal diameter of 95 mm filled with a grinding body of 60 mm in diameter, 20 g of the precipitated calcium carbonate of test No. 1 are milled dry to a fineness whose particle size characteristics determined by measurement using a Sedigraph ™ 5100 granulometer of Micromeritics ™ are :

an average diameter of approximately 1.8 μm,

91.9% by weight of the particles have a diameter of less than 5 μm,

56.8% by weight of the particles have a diameter of less than 2 μm,

25.9% by weight of the particles have a diameter of less than 1 μm, - 9.7% by weight of the particles have a diameter of less than 0.5 μm,

4.0% by weight of the particles have a diameter of less than 0.2 μm.

Then using a mortar equipped with a "pistil", we add and dispersed these 20 g of precipitated calcium carbonate crushed in 200 g of an "offset" ink marketed by the Schaffher GF AG (Switzerland) under the name of Skinex Cyan 4X800.

The composition then produced is used to print an IKONOFIX ™ paper, 150 g / m ² , from M-Real ™ Zanders GmbH, Bergisch-Glattbach (Germany) using a marketed "offset" printing machine. by the company SeGan (Great Britain) under the name of Ink / Surface Interaction Tester.

This test, called Ink Surface Interaction Test (ISIT), which represents the ink detachment force as a function of time, is a three-phase curve: an ascending phase with a certain climb gradient, a maximum value, then a descending phase with a certain slope of descent, and is based on a printing installation provided with a device for creating and measuring the force necessary to separate a release disc, a printing ink film. This installation constituted on the one hand by this device for creating and measuring force and on the other hand by an ink disk rotating above the sheet of paper to be tested is marketed under the name "Ink Surface Interaction Tester" by the company SeGan Ltd.

To do this, first prepare the different sheets of paper to be tested by applying the different coating colors to be tested on these sheets of paper using the Erichsen ™ Model 624 laboratory coater from Erichsen ™ GmbH + Co. KG (Germany) equipped with exchangeable rolling blades.

The paper thus coated has a value determined in g / m ² . It is fixed on a roll equipped with a double-sided adhesive tape. The application of an offset ink is performed by contacting the ink disk with a width of 25 mm during a rotation of 180 °. The print speed and pressure are adjustable and are of the order of 0.5 m / s and 50 kg respectively. The ink volume is under standard conditions of 0.3 cm ³ thus resulting in a thickness of about 1 g / m ² of ink on the paper sheet to be tested.

The printing process is followed by a sequence of repeated measurements of the peeling force, at pre-selected time intervals dependent on this time set to separate this peel disc (of the same size as the printing disc) of the ink film.

An offset printing quality nitrile rubber coating is usually used for the release disc but any equivalent material can be used.

The contact force between the release disc and the ink is measured by a system generating an electromagnetic force. The amplitude and duration of the peeling force are adjusted to achieve uniform adhesion between the film surface and the peel disc after 3 seconds. Slow rotation of the paper sheet during the application of the electromagnetic force makes it possible to ensure intimate contact and continuity of the ink film. Upon stopping the magnetic force, the peel disc retracts from the printed film by the force of a tensioned spring, sufficient force to separate the disc from the ink film. A strain gauge, secured between the release disc and the spring, generates a signal that is recorded as the peel force.

The sequence is automatically repeated for 13 cycles.

At the first and thirteenth cycles the print densities are measured using a Gretag D 186 densitometer.

This measurement being carried out, the determination of the ¹⁴ C nuclear conversion rate at ¹² C of the paper sample thus printed by installing 150 mg of the printed paper sample loaded at 20% in a 7 ml ampoule. equipped with 2 consecutive reactors of 14.7 ml at a pressure of 250 mbar, thus forming 2 consecutive traps, the last of which is a liquid nitrogen trap and the first is cooled to a temperature of 20 to 30 ⁰ C above the second to avoid contamination by other volatile compounds from the sample.

About 0.4 ml of hydrochloric acid are then poured into this ampoule, which will react with the printed paper sheet and release carbon dioxide which will be trapped in the successive traps.

The carbon dioxide thus entrapped is then reduced by hydrogenation on a cobalt powder catalyst to an elemental carbon atom ( ¹³ C / ¹² C / ¹⁴ C).

The isotope composition ^I3 C / ¹² C and ¹⁵ N / ¹⁴ N of the graphite thus obtained and that of ¹⁴ C are then determined in comparison with an international reference standard by the so-called "AMS" technique for mass accelerometric mass spectrometry. Accelerator Mass Spectrometry "using a spectrophotometer commonly used by those skilled in the art.

The rate of nuclear conversion per hour and per gram of the synthetic mineral material to be analyzed is then determined by the ratio between the measured ¹⁴ C value. and the value of the reference standard internationally recognized and referenced in dating methods by ¹⁴ C.

Test n ° 16

This test illustrates the invention and uses, in an "offset" ink application, the precipitated calcium carbonate of test No. 4.

To do this, by means of a HSM 100-H type vibratory disk mill marketed by the company Herzog equipped with a tungsten carbide grinding chamber with an internal diameter of 95 mm filled with a grinding body of 60 mm in diameter, 20 g of the precipitated calcium carbonate of test No. 4 are milled dry to a fineness whose particle size characteristics determined by measurement using a Sedigraph ™ 5100 granulometer of Micromeritics ™ are :

an average diameter of approximately 1.7 μm,

93.2% by weight of the particles have a diameter of less than 5 μm, 58.5% by weight of the particles have a diameter of less than 2 μm,

- 26.8% by weight of the particles have a diameter of less than 1 μm, - 10.1% by weight of the particles have a diameter of less than 0.5 μm,

4.2% by weight of the particles have a diameter of less than 0.2 μm.

The composition then produced is used to print a paper type IKONOFIX ™, 150 g / m ² , from M-Real ™ Zanders GmbH, Bergisch-Glattbach (Germany) using a laboratory offset printing machine. marketed by the company SeGan ™ (Great Britain) under the name of Ink / Surface Interaction Tester, under the same conditions as those of the previous trial. The results obtained appear on curve 1 which represents the detachment force of the ink as a function of time. This curve is represented in drawing No. 3. Curve 1 shows that the offset printing of the ink, loaded with the calcium carbonate according to the invention of test No. 16 (product B of the curve 1) is identical to the offset printing of the ink, loaded with calcium carbonate according to the prior art of test No. 15 (product A of curve 1).

Example 5

This example illustrates the use of the inorganic materials according to the invention in the field of polymeric plastics, and in particular their use for the preparation of filled thermoplastic compositions such as, in particular, filled polyvinyl chloride (PVC) compositions.

Test n ° 17

This test illustrates the prior art and uses the precipitated calcium carbonate of test No. 1.

The charged PVC composition is produced by mixing the uncharged PVC resin and the calcium carbonate to be dispersed in a Colling ™ mill equipped with two rolls of diameter equal to 150 mm and length equal to 400 mm so as to obtain a content of pigment of about 20% by weight.

In all the tests of the example, the formulation of the filled PVC composition is as follows:

Corvic ™ S 704 100 parts

DIDP (diisodecyl phthalate) 55 parts Bâropan E-292 4 parts

Carbonate to disperse 40 parts

The exact content of calcium carbonate equal to 19.7% by weight was determined by calcination for 2 hours at 65O ⁰ C. Test n ° 18

This test illustrates the invention and uses the precipitated calcium carbonate of Test No. 4 using the same procedure and equipment as the previous test.

^• The exact content of calcium carbonate equal to 19.5% by weight was determined by calcination for 2 hours at 65O ⁰ C.

Test n ° 19

This test illustrates the invention and uses a mixture of 50% by weight of precipitated calcium carbonate of Test No. 4 and 50% by weight of precipitated calcium carbonate of Test No. 5 using as a coating. a polypropylene support.

5 g of precipitated calcium carbonate of test No. 4 and 5 g of precipitated calcium carbonate of test No. 5 were mixed and dispersed in 40 g of water with 0.1% by weight relative to dry weight of the fillers of a sodium polyacrylate (with a molecular weight Mw equal to 3500 Daltons and a polydispersity index of 2.7) as dispersant. 2 g of a latex of the Acronal ™ S 360 D type, BASF ™ (50% by mass of active product), were used as binder.

Various amounts per m ² of this coating were coated on a polypropylene film, white, semi-transparent, Synteape ™ type, Fischer Papier ™, St.

Gallen-Rotkreuz (Switzerland). Whiteness and opacity have been determined.

The opacity is measured according to DIN 53146 and the implementation of an Elrepho 2000 spectrophotometer from Datacolor ™ AG (Switzerland).

The so-called whiteness Tappi R 457 whiteness is determined according to TAPPI T452 ISO 247.

The results are shown in Table 2.

Table 2: layer weight and opacity and whiteness values TAPPI R 457 measured respectively according to DIN 53146 and TAPPI T452 ISO 247

The net values determined at a given layer weight correspond to the difference between the raw value measured for this layer weight and the raw value measured at a layer weight of 0 g / m ² . These results show that we gain more than 1.5 points in whiteness with a layer weight equal to 1.7 g / m ² .

We gain more than 1.5 points in whiteness and opacity with a layer weight equal to 4 g / m ² . With a layer weight of 20 g / m ² one gains more than 4 points in opacity.

Test n ° 20

From the calcium carbonate of test No. 10, a suspension of said carbonate in water at a content of 10% by weight of dry matter is carried out, in the presence of 1% by weight of sodium polyacrylate by relative to the dry weight of calcium carbonate as dispersant. After 5 minutes of mechanical stirring the suspension was heated to 65 ° C with stirring and introduced 25% by weight of phosphoric acid relative to the dry weight of calcium carbonate. Phosphoric acid was assayed for 20 minutes as a 10% active solution. The temperature during the reaction was 65 ° C ± 5 ° C. After the assay, the reaction continued for 5 hours. The final pH measured at 23 ° C was 7.6.

The microscopic structures of the products obtained before and after treatment with phosphoric acid were photographed by means of an electron microscope, and appear respectively in the drawings No. 4 and No. 5.

The product finally obtained has a BET specific surface area equal to 52 m 2 / g.

This BET specific surface area measurement is determined according to the BET method of the ISO 9277 standard, namely that the measurement is carried out under cooling with liquid nitrogen and under a stream of nitrogen on the dried sample until constant weight and constant temperature. at

250 ° C for one hour under a nitrogen atmosphere.

Finally, the nuclear conversion rates from ¹⁴ C to ¹² C were determined for each of the mineral materials exemplified above.

To do this, the same method and material as used in Example 3 are used, except for one of the two UPM ™ Paper Comparative Tests.

Schongau, for which there is only one trap, the one with liquid nitrogen.

The results obtained for the various products were collated in Table 2 below, which also includes the results of comparative tests carried out with pigments well known to those skilled in the art.

These comparative tests use the Socal ™ P2 PCC marketed by Solvay ™, the Type A PCC marketed by Schaefer ™, the Unikristall ™ Syncarb ™ F0474-GO PCC and UPM ™ Schongau paper.

Table n ° 2

* with a method with a single liquid nitrogen trap ** with a method implementing both traps

Example 6

Test n ° 21

This test, which illustrates the invention, relates to a continuous process for producing precipitated calcium carbonate by reacting lime with fresh carbon dioxide, said gas being derived from the decomposition of organic carbon source under supercritical condition.

In addition, this test illustrates the use of one or more chemical and / or physical treatments in the manufacture of precipitated calcium carbonate according to the invention.

To do this, an aqueous suspension is prepared having a concentration equal to 15% by dry weight of lime, stirred by means of a mechanical stirrer.

This suspension was pumped at 238 kg / h continuously, passing two heat exchangers in a first part of the tube reactor, with a diameter of 10 to 12 mm and a second part of the tube reactor with a diameter of 6 to 8 mm.

In the first homeland of the reactor, a flow rate of 29.0 kg / h of oxygen was used. In the second part of the reactor, a flow rate of 11.0 kg / h of oxygen and 12.4 kg / h of rapeseed oil was used as a source of fresh organic carbon. The reactor used for the test is marketed by the company "Supercritical Fluid Technology Sweden AB" (Karlskoga, Sweden).

After the supercritical and cooling phase, 500 ppm active formamidinesulfinic acid (CAS 1758-73-2), in 10% aqueous suspension, relative to the calcium carbonate were introduced into the product at 90 ° C.

Procedure parameters: Suspension feed rate Ca (OH) ₂ : 238 kg / h

Temperature / pressure in the feed tray 20 ° C / 1 bar

Temperature / pressure in heat exchangers 255-367 ⁰ C / 237 bar Temperature / pressure in the first part of the reactor 473-569 ° C / 235 bar

Temperature / pressure in the second part of the reactor 534-567 ° C / 231 bar

Temperature / pressure in the heat exchangers 364-380 ° C / 229 bar Temperature / pressure at the outlet of the heat exchangers 1,271 ° C / 229 bar Temperature / pressure at the outlet of the heat exchangers 2 59 ⁰ C / 226 bar

The Applicant indicates that the device actually has 2 heat exchangers, denoted 1 and 2.

The product was then cooled to 16 ° C and the pressure reduced to atmospheric pressure. The product obtained, recovered in a final reservoir, is a precipitated calcium carbonate according to the invention, whose nuclear conversion rate of ¹⁴ C carbon at ¹² C is greater than 850 transformations per hour and per gram.

Part of this product is then dried at 120 ^° C. for analysis. The precipitated calcium carbonate obtained is of pure calcite structure, after infrared and XRD analysis.

Drawing No. 6 corresponds to a photograph taken by scanning electron microscope of the product obtained.

A second sample portion in aqueous suspension form was treated with a permanent magnetic magnet covered with Teflon.

After 5 minutes of magnetic separation treatment, the magnet was covered with black and colored magnetic and / or paramagnetic impurities, visible on the surface. Drawing No. 7 corresponds to a photograph taken by scanning electron microscope of the magnet after the 5 minutes of treatment.

A third part of the sample was ground in an aqueous medium at a concentration of 18% by dry weight of calcium carbonate, without dispersant, with zirconium oxide beads for 1 hour. The product obtained was then dispersed by means of sodium polyacrylate, and its particle size distribution was determined from a Sedigraph ™ 5100 type apparatus: 62% by weight of the particles had a diameter of less than 2 μm and 31% by weight of the particles had a diameter of less than 1 μm.

Claims

1- Synthetic mineral material containing carbonate, characterized in that it has a carbon conversion rate of carbon at ¹⁴ C at ¹² C of at least 450 transformations per hour and per gram, preferably between 700 and 890 transformations per hour and per gram, very preferably between 850 and 890 transformations per hour and per gram.

2- synthetic mineral material containing carbonate according to claim 1, characterized in that the carbonate is selected from monovalent cation carbonates and / or bivalent and / or trivalent or mixtures thereof.

3- synthetic mineral material containing carbonate according to claim 2, characterized in that said monovalent and / or bivalent and / or trivalent cations are selected from the cations of the first or second or third main group of the periodic table Mendeleyev.

4- synthetic mineral material containing carbonate according to claim 3, characterized in that said cations are selected from lithium, sodium, potassium, magnesium, calcium, strontium or mixtures thereof.

5- synthetic mineral material containing carbonate according to any one of claims 1 to 4, characterized in that the carbonate is a calcium carbonate having a crystalline structure of the calcite or aragonite or vaterite type or in that the carbonate is a mixture a calcium carbonate of calcium-type structure with a calcium carbonate of aragonite-type structure and / or a calcium carbonate of vaterite type structure, and more preferably in that it is a mixture of calcium carbonate of calcite type structure and aragonite type structure.

6- synthetic mineral material containing carbonate according to one of claims 1 to 5, characterized in that the carbonate has a degree of whiteness greater than 80%, preferably greater than 90%, very preferably greater than 93% TAPPI determined according to TAPPI standard T452 ISO 2470.

7- synthetic mineral material containing carbonate according to any one of claims 1 to 6, characterized in that it is a mixture and / or a co-structure with other inorganic materials selected from natural and / or synthetic silicas silicates such as clay, talc, mica, or else chosen from aluminum hydroxides, sulphates, satin whites, phosphates such as brushites, octa-calcium phosphates or hydroxyapatites, or their mixtures.

8- A method of manufacturing synthetic mineral material containing carbonate characterized in that it implements carbon dioxide from aerobic or anaerobic and preferably anaerobic fermentation.

9- A method of manufacturing synthetic mineral material containing carbonate characterized in that it implements a mixture of carbon dioxide from the aerobic or anaerobic fermentation, with carbon dioxide from another source, preferably old, very preferably thermal decomposition of calcium carbonate.

10- A method of manufacturing synthetic mineral material according to claim 9, characterized in that the mixture uses less than 50% by weight of old carbon dioxide.

11- A method of manufacturing synthetic mineral material containing carbonate according to one of claims 8 to 10, characterized in that the fresh carbon dioxide is derived from the fermentation of sugars or the combustion of alcohol, in particular ethanol , methanol, or alkanes such as methane, ethane, or any other alkane, derived from the fermentation of organic compounds such as fruits, alcohols, fruit or waste from landfills.

12- A method of manufacturing synthetic mineral material containing carbonate according to one of claims 8 to 10, characterized in that the fresh carbon dioxide is a mixture of fresh carbon dioxide from the fermentation of sugars with fresh carbon dioxide from the combustion of organic compounds, or in that it comes from the fermentation of waste from supercritical pressure discharges.

13- A method of manufacturing synthetic mineral material containing carbonate, characterized in that it implements fresh carbon dioxide from the thermal decomposition or oxidative degradation of waste supercritical pressure discharges.

14- A method of manufacturing synthetic mineral material containing carbonate according to one of claims 8 to 13, characterized in that the implementation of carbon dioxide is carried out at a temperature between 5 ⁰ C and 100 ⁰ C, preferably between 20 ⁰ C and 30 ⁰ C.

15- A method of manufacturing synthetic mineral material containing carbonate according to any one of claims 8 to 14, characterized in that it is a batch process, in cascades still said continuous or batch-continuous mixing.

16- A method of manufacturing synthetic mineral material containing carbonate according to claim 15, characterized in that it is a continuous process, preferably with one or more chemical treatment steps such as treatment with sodium silicate or treatment with sodium silicate followed by an addition of acid, such as citric acid, or phosphoric acid or other H ₃ O ⁺ donors, the chemical treatments occurring very preferably continuously after the acid treatment carbonic. 17- A method of manufacturing synthetic mineral material containing carbonate according to claim 15, characterized in that the batch process is a process in which the reaction takes place in a single tank where all the reagents are introduced.

18- A method of manufacturing synthetic mineral material containing carbonate according to claim 15, characterized in that the continuous process is a process in which the fresh carbon dioxide implemented or the mixture of fresh carbon dioxide with the old carbon dioxide put implemented is introduced in a cascade of n reactors installed in series and / or in parallel, n denoting a number ranging from 1 to 50, preferably 1 to 10, very preferably 1 to 5.

19- A method of manufacturing synthetic mineral material containing carbonate according to claim 15, characterized in that the continuous-batch mixing process is a continuous synthesis process followed by a number m of steps in batch, said steps being the addition of carbon dioxide to the storage or a physical treatment step or a chemical treatment step such as treatment with sodium silicate followed by the addition of an acid such as citric acid or phosphoric acid or o steps corresponding to the introduction of a dispersant, m denoting a number varying from 1 to 5, and preferably from 1 to 2, and o denoting a number varying from 0 to 3, preferably from 0 to 1.

20- A method of manufacturing synthetic mineral material containing carbonate according to one of claims 8 to 19, characterized in that said method optionally comprises at least one dispersion step and / or at least one grinding step, optionally in the presence of at least one dispersing agent and / or at least one grinding aid agent.

21- Use of mineral materials according to any one of claims 1 to 7 in the pharmaceutical field with products such as drugs, the field of food or feed, or the paper industry such as paper making, mass and / or coating on a paper or plastic medium or any other surface treatment of paper and / or plastic, the plastic being preferentially chosen from polyolefins of the polyethylene or polypropylene type and their derivatives, as well as the fields of aqueous or non-aqueous paints as well as the field of plastics or the field of printing inks.