US20220153602A9 - Method of producing magnesium hydroxide - Google Patents

Method of producing magnesium hydroxide Download PDF

Info

Publication number
US20220153602A9
US20220153602A9 US17/259,247 US201917259247A US2022153602A9 US 20220153602 A9 US20220153602 A9 US 20220153602A9 US 201917259247 A US201917259247 A US 201917259247A US 2022153602 A9 US2022153602 A9 US 2022153602A9
Authority
US
United States
Prior art keywords
containing material
magnesium hydroxide
magnesium
less
hydration
Prior art date
Legal status (The legal status 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 status listed.)
Pending
Application number
US17/259,247
Other languages
English (en)
Other versions
US20210300775A1 (en
Inventor
Konstantinos G. Gatos
Pantelis Baxevanidis-Taros
Filippos Boukas
Emmanouel Tsontakis
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Terna Mag SA
Original Assignee
Terna Mag SA
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
Application filed by Terna Mag SA filed Critical Terna Mag SA
Publication of US20210300775A1 publication Critical patent/US20210300775A1/en
Publication of US20220153602A9 publication Critical patent/US20220153602A9/en
Pending legal-status Critical Current

Links

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
    • C01F5/00—Compounds of magnesium
    • C01F5/14—Magnesium hydroxide
    • C01F5/16—Magnesium hydroxide by treating magnesia, e.g. calcined dolomite, with water or solutions of salts not containing magnesium
    • 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
    • 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
    • C01P2004/60—Particles characterised by their size
    • C01P2004/62—Submicrometer sized, i.e. from 0.1-1 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
    • C01P2006/80—Compositional purity

Definitions

  • Current invention relates to a process for producing magnesium hydroxide.
  • this invention is directed to a method of producing magnesium hydroxide suitable for mixing with polymers.
  • Said magnesium hydroxide is especially appropriate for inducing flame retardant properties in polymeric compounds being at the same time an environmental friendly filler.
  • EP 0 599 085 discloses a process for producing magnesium hydroxide by wet-pulverizing a light burned magnesia followed by its hydration in presence of an alkaline aqueous medium at a temperature of not less than 70° C. and preferably below 120° C.
  • the pH of the reaction is not less than 11.
  • light burned magnesia bears increased porosity and on the other hand, the extended wet-pulverizing during hydration may create further uneven particle surfaces putting at stake desirable flame retardant crystal structures.
  • EP 0 568 488 presents a particulate magnesium hydroxide with specific surface (BET) of 13-30 m 2 /gr and average particle size 0.3-1.0 ⁇ m. These flame retardant have been produced by the calcination of a magnesium feedstock, which has a specific surface of 3-10 m 2 /gr, followed by its hydration and milling for achieving the desirable particle size.
  • BET specific surface
  • magnesium hydroxide with BET values above 13 m 2 /gr is expected to induce difficulties in mixing with polymers increasing the viscosity of the compound.
  • CA 2 032 470 presents a magnesium hydroxide of average grain size less than 10 ⁇ m and low content of impurities within the magnesia suitable for flame retardant applications.
  • the claimed process is energy intensive involving apart from leaching with strong acids, spray roasting of a magnesium chloride solution, as well as, subsequent post-washes.
  • U.S. Pat. No. 4,098,762 refers to magnesium hydroxide particles coated with an anionic surface active agent. These particles have a specific surface of less than 20 m 2 /gr. Said magnesium hydroxide has been produced by hydrothermal treatment at elevated temperature and pressure of basic magnesium chloride or magnesium nitrate in an aqueous medium. Besides the prerequisite of a coating agent for producing said particles, above method involves extended retention time of the solution within the autoclave in order to bring the properties at the desired level.
  • U.S. Pat. No. 5,843,389 describes a process for producing magnesium hydroxide of low particle size and specific surface from solution by precipitation. Said process includes subsequent stages of leaching a magnesium-containing ore, purification, filtration and hydrothermal treatment in an autoclave. Special care has been taken for the handling and recycling of the chemical by-products formed due to leaching.
  • GR 20080100407 discloses the production of magnesium hydroxide from hard burned magnesia. Said process involves at least two stages of hydration at a temperature of 50-100° C. for 15-24 hours each, in order to obtain the desired properties for flame retardant applications. Apart from the long lasting hydration process, said method demands the presence of magnesium salts.
  • Prior art relates either to energy-intensive procedures and time-consuming methods or to necessary additives and by-product handling concerns, which all complicate magnesium hydroxide production, raise environmental issues and increase cost.
  • the object of the present invention is to overcome the problems mentioned above.
  • a method of producing magnesium hydroxide comprising hydrating a magnesium oxide containing material at high temperatures and pressures, resulting in a magnesium hydroxide containing material.
  • the magnesium oxide containing material has a specific surface of more than 0.1 m 2 /gr and lower than 25 m 2 /gr.
  • the method comprising the steps of (i) hydrating a magnesium oxide containing material at high temperatures and pressures, resulting in a magnesium hydroxide containing material, (ii) drying the magnesium hydroxide containing material, and (iii) milling.
  • hydration is taking place at a temperature between 120° C. and 350° C. and a pressure between 2 bar and 165 bar.
  • the magnesium hydroxide containing material comprising particles, wherein said particles present a specific surface of more than 1 m 2 /gr and less than 20 m 2 /gr.
  • the magnesium hydroxide comprising particles of d 50 of more than 0.5 ⁇ m and less than 20 ⁇ m.
  • the magnesium hydroxide containing material is suitable for mixing with polymers and presents flame retardant properties.
  • the magnesium containing material which will be used for receiving the magnesium oxide containing material of the present invention is any available magnesium source.
  • said magnesium containing material is any mineral known in the art such as magnesium carbonate, periclase, brucite and the like.
  • the initial magnesium containing material is a mixture of various chemical structures.
  • the magnesium containing material is a natural ore such as magnesite, serpentine, brucite and the like.
  • the magnesium oxide containing material of said invention has been produced by agglomerating, pelletizing or briquetting mixtures of powders of magnesium containing materials with known means in the art.
  • the magnesium oxide content in the magnesium oxide containing material is more than 80% (loss-free—XRF analysis) or more than 85%, preferably more than 90% most preferably more than 92% such as 94%, 97%, 95% and the like.
  • the magnesium oxide containing material used for the present invention can be produced by known means in the art such as muffle furnace, multiple-hearth furnace, rotary kiln, electro-fusion, shaft kiln, and the like.
  • the magnesium oxide containing material used for the present invention has been produced by calcining said magnesium containing material at a temperature higher than 700° C. and lower than 2000° C.
  • the temperature was higher than 900° C. and lower than 1900° C. and most preferably the temperature was higher than 1100° C. and lower than 1800° C.
  • the calcination temperature was higher than 1300° C. or higher than 1500° C.
  • the magnesium oxide used for the present invention has not been produced by hydro-pyrolysis, magnesium chloride or magnesium nitrate sources.
  • the magnesium oxide crystal is increased. Furthermore, its specific surface and reactivity are decreased, accordingly. More specifically, the specific surface as measured by BET method, is more than 0.1 m 2 /gr and less than 25 m 2 /gr, such as 15 m 2 /gr, 19 m 2 /gr, 22 m 2 /gr, 12 m 2 /gr, 4 m 2 /gr, 9 m 2 /gr and the like. Preferably specific surface is more than 0.2 m 2 /gr and less than 10 m 2 /gr.
  • the specific surface is more than 0.2 m 2 /gr and less than 7.5 m 2 /gr, preferably more than 0.2 m 2 /gr and less than 5 m 2 /gr. In special embodiments the specific surface is more than 0.3 m 2 /gr and less than 3 m 2 /gr. It is not obvious for someone ordinary skilled in the art to use hard burned magnesium oxide of low specific surface for hydration due to the fact that it would increase considerably the hydration time, would deliver low productivity and would require additives for improving process.
  • the BET value of magnesium oxide used for hydration in the present invention is lower than 2.9 m 2 /gr such as 2.0 m 2 /gr, 0.5 m 2 /gr, 1.5 m 2 /gr and the like.
  • the magnesium oxide containing material of the present invention presents 0-10 mm particle size distribution.
  • said magnesium oxide containing material has a 0-5 mm particle size distribution, preferably 0-2 mm, more preferably 0-1.5 mm, most preferably 0-1 mm.
  • said magnesium oxide containing material presents 0-0.8 mm particle size distribution and most specifically 0-0.5 mm particle size distribution.
  • said magnesium oxide containing material has d 50 less than 300 ⁇ m, such as 100 ⁇ m, 200 ⁇ m, 75 ⁇ m, 150 ⁇ m, 25 ⁇ m, 35 ⁇ m and the like.
  • said particles pass through a 120 mesh screen.
  • the magnesium oxide containing material of the present invention has d 10 more than 0.5 ⁇ m, preferably more than 1 ⁇ m.
  • said d 10 is more than 3 ⁇ m or more than 5 ⁇ m.
  • said magnesium oxide containing material has d 50 more than 10 ⁇ m, preferably more than 15 ⁇ m.
  • said magnesium oxide containing material has d 50 more than 20 ⁇ m.
  • current invention works also with coarse particles without special limitations on particle size distribution or need of surfactants. Current invention does not require slurry stabilization. In the art, specific and well-defined viscosity ranges are usually required for the suspension, which is going to be processed. In many cases, said suspensions proposed in the art require surfactants for achieving processing. In these cases, wet milling has been suggested for stabilizing the slurry.
  • the hydration of said magnesium oxide is taking place preferably at high temperatures and pressures. It is preferred a temperature of more than 110° C. and less than 350° C., preferably more than 130° C. and less than 330° C. or even 320° C., preferably more than 140° C. and less than 300° C. and most preferably more than 150° C. and less than 290° C. In preferred embodiments the hydration temperature is more than 160° C. and less than 280° C. or even 270° C. In special embodiments the hydration temperature is more than 170° C. or more than 180° C. and less than 260° C. The pressure is regulated by the water vapor, accordingly.
  • pressure is more than 2 bar, preferably more than 5 bar, most preferably more than 11 bar.
  • the pressure in the reactor is further increased by external methods such as pressurized gas. Hydration pressure is preferably lower than 165 bar such as 90 bar, 30 bar, 60 bar and the like. In special cases the internal pressure is increased by the use of suitable solvents.
  • the in weight content of the magnesium oxide containing material in the aqueous solution is more than 1% and less than 100%.
  • said solid content is more than 2% and less than 70% in weight, more preferably more than 5% and less than 50% in weight, such as 25%, 40% and the like.
  • the required time of hydration within the reactor is less than 12 h, preferably less than 8 h, preferably less than 6 h, preferably less than 4 h, more preferably less than 3 h, most preferably less than 2 h such as 30 min, 1 h, 15 min, 5 min and the like. Hydration is taking place either in batch reactor or at continuous process. In special cases, hydration is taking place in combinations thereof.
  • Hydration at high temperature and pressure compared to atmospheric conditions for a magnesium oxide containing material assist the finalization of the hydration within a reasonable timeframe. Surprisingly, the increased temperature and pressure assist the production of magnesium hydroxides of low BET values without the absolute need of additives during hydration.
  • Current invention does not require presence of chloride ions.
  • chlorine ions are lower than 0.02 wt. % of the dry magnesium oxide containing material such as 0.01 wt %, 0.001 wt.%, 0.005 wt. % and the like.
  • Chloride ions are known to be corrosive.
  • hydration of a magnesium containing solution in an autoclave requires extended time for creating adequate magnesium hydroxide material particles of low BET values suitable for mixing with polymers.
  • Current invention solves this issue by hydrating a magnesium oxide containing material particles, which initially have low BET value and transform them to a magnesium hydroxide of low BET value in suspension.
  • the magnesia of the present invention when hydrated in an autoclave produces magnesium hydroxide, which succeeds low BET values and particle sizes.
  • magnesia with BET values higher than 25 m 2 /gr even when hydrated in reactor does not produce the magnesium hydroxide with the desired characteristics described in current invention.
  • the hydration of the magnesium oxide of the present invention does not require any hydrating agent.
  • said hydration can be performed in presence of hydrating agents such as hydrochloric acid, nitric acid, acetic acid, citric acid, formic acid, magnesium nitrate, magnesium chloride, ammonium chloride, magnesium acetate, sodium acetate and the like.
  • hydrating agents such as hydrochloric acid, nitric acid, acetic acid, citric acid, formic acid, magnesium nitrate, magnesium chloride, ammonium chloride, magnesium acetate, sodium acetate and the like.
  • present invention does not exploit sodium hydroxide during hydration.
  • current invention does not require the presence of ammonium chloride.
  • the process of the present invention involves drying by any mean that does not increase the specific surface of the magnesium hydroxide by more than 40%, not more than 30%, preferably not more than 20%, preferably not more than 10%. in preferred embodiments, drying does not increase the specific surface of the magnesium hydroxide.
  • the initial reference specific surface of the magnesium hydroxide is measured by taking part of the precipitated suspension after hydration and drying it in an oven at 120° C. under static conditions. It has been disclosed that drying in a long gap mill increased the BET value of the magnesium hydroxide up to 40% compared to the initial BET value in the slurry.
  • the drying process can be performed by any mean in the art and combinations thereof, such as vacuum filter, pressure filter, spray dryer, paddle dryer, drum dryer, freeze dryer, fluidized-bed dryers and the like. In preferred cases, drying does not include crushing or milling at the same time. In specific embodiments, current invention does not involve drying in a long gap mill.
  • the magnesium hydroxide containing material, which is directed to drying can be in slurry or cake form.
  • the drying process of the present invention does not involve spray drying of the magnesium hydroxide slurry. This latter drying method performs low-yield and it is energy-intensive. Present invention has advantages over prior art as it does not require the use of dispersing agents and well-defined range of particle size distribution in the slurry.
  • the magnesium hydroxide containing material of the present invention holds the majority of the impurities of the magnesium oxide containing material.
  • the process of the present invention does not require filtering for removing impurities.
  • Impurities are mostly encapsulated in the magnesium hydroxide containing material without affecting adversely the hydration process.
  • Impurities are less than 20% and more than 0.5% (loss-free—XRF analysis), preferably less than 10% and more than 1%, such as 8%, 4%, 6%, 2% and the like.
  • optional conventional beneficiation processes are combined with present invention if purity increase is required.
  • present invention does not include complex formers during hydration for improving purity.
  • Additives such as hydroxylamine, ammonium salts, ethylenediaminetetraacetic acids or nitryltriacetic acids are not required for current invention.
  • other methods presented in prior art, which involve leaching must include plenty of post washes, purifications and filtering to remove the dissolved impurities and the by-products in order to produce a magnesium hydroxide suitable for mixing with polymers. It is obvious that all these steps burden the environment with chemical waste management. Current invention successfully overcomes these problems.
  • the process of the present invention involves milling by any mean that does not increase the specific surface of the magnesium containing material by more than 100%, 50%, 40% or 30%, preferably not more than 20%, preferably not more than 10%.
  • Each reference specific surface value of the magnesium containing material is measured each time by taking part of the dried magnesium containing material before each fine milling step.
  • the magnesium containing material can be magnesium oxide, magnesium carbonate, magnesium hydroxide and the like.
  • the process of the present invention involves milling by any mean that does not increase the specific surface of the magnesium hydroxide by more than 40%, not more than 30%, preferably not more than 20%, preferably not more than 10%. Preferably, milling does not increase the specific surface of the magnesium hydroxide.
  • the specific surface of the grinded magnesium hydroxide is lower than prior its milling. Drying and milling in a long gap mill as presented in WO 2008/146089 increased the BET value of the magnesium hydroxide up to 40% compared to the initial BET value in the slurry.
  • the milling can be performed in wet or dry conditions, exploiting equipment such as ball mill, agitated bead mil, jet mill, long gap mill, pin mill, pendulum roller mill, disk mill and the like.
  • milling is performed at the dried magnesium hydroxide containing material. In other embodiments, milling is performed at the wet magnesium hydroxide containing material.
  • milling is performed at both the wet and the dry magnesium hydroxide containing material.
  • current invention does not involve milling in a long gap mill.
  • the extended milling time which is applied in order to reduce the particle size, induces a considerable increase of the specific surface of the mineral.
  • current invention exploits short time for milling with enhanced particle-to-particle attrition, thus balancing the specific surface increase of the mineral.
  • milling is performed at the magnesium oxide containing material prior to hydration.
  • milling is performed both at the magnesium oxide containing material prior to hydration and the magnesium hydroxide containing material after hydration.
  • the particle size reduction that is taking place during hydration in reactor is likely due to crystal transformation, shearing and platelet exfoliation.
  • hydro-cyclones, screening, sieving, air-cyclones, sorters, classifiers and the like are equipment that can be combined with current invention.
  • a method of producing magnesium hydroxide comprising the steps of (i) hydrating a magnesium oxide containing material at a temperature between 120° C. and 350° C. resulting in magnesium hydroxide containing material, (ii) drying the magnesium hydroxide containing material, (iii) milling the magnesium containing material.
  • the steps of the invention are not necessarily executed in that particular order.
  • the dried magnesium hydroxide containing material has particles with d 90 of more than 1.5 and less than 50 ⁇ m, preferably more than 2.0 ⁇ m and less than 30 ⁇ m, preferably more than 2.2 ⁇ m and less than 20 ⁇ m. In special embodiments d 90 is less than 10 ⁇ m, less than 8.0 ⁇ m or less than 6.0 ⁇ m.
  • the dried magnesium hydroxide containing material of present invention has particles with d 50 of more than 0.5 and less than 20 ⁇ m, preferably more than 1.0 ⁇ m and less than 15 ⁇ m, most preferably more than 1.1 ⁇ m and less than 10 ⁇ m or even 8 ⁇ m.
  • d 50 is more than 1.3 ⁇ m or more than 1.5 ⁇ m and less than 5.0 ⁇ m or less than 3.5 ⁇ m.
  • particles with d 50 of more than 10 ⁇ m are produced such as 20 ⁇ m, 30 ⁇ m, 25 ⁇ m, 18 ⁇ m, 35 ⁇ m and the like.
  • the average particle size of said dried magnesium hydroxide containing material is more than 1.5 ⁇ m and less than 20 ⁇ m.
  • a low average particle size is required for mixing with polymers.
  • a great presence of fines lower than 1.0 ⁇ m makes harder the compounding with polymers as the viscosity during melt mixing increases.
  • the d 10 of the magnesium hydroxide containing material of the present invention as measured by laser diffraction in suspension (Malvern Mastersizer equipment) is more than 0.3 ⁇ m and less than 5.0 ⁇ m, preferably more than 0.5 ⁇ m and less than 3.0 ⁇ m. In specific embodiments, d 10 is more than 0.7 ⁇ m, such as 1.1 ⁇ m, 0.9 ⁇ m, 1.0 ⁇ m and the like. It is an advantage of the current invention compared to other methods in the art that produces a low amount of fines.
  • the magnesium hydroxide containing material of the present invention has a narrow particle size distribution suitable for mixing with polymers.
  • the dried magnesium hydroxide containing material comprising particles presenting a specific surface (BET) of more than 0.5 m 2 /gr and less than 20 m 2 /gr, preferably more than 1 m 2 /gr and less than 18 m 2 /gr, preferably more than 2 m 2 /gr and less than 15 m 2 /gr, more preferably more than 3 m 2 /gr and less than 13 m 2 /gr.
  • BET specific surface
  • said specific surface is less than 12.9 m 2 /gr, such as 5 m 2 /gr, 10 m 2 /gr, 12 m 2 /gr, 12.5 m 2 /gr, 4 m 2 /gr, 7.5 m 2 /gr and the like.
  • a low BET value of said dried magnesium hydroxide containing material is appropriate for mixing with polymers enabling better dispersion and high filler loadings.
  • the degree of conversion of magnesium oxide containing material to magnesium hydroxide containing material should be appropriately adequate for each application.
  • the degree of conversion should be more than 70%, preferably more than 80%, such as 85%, 91%, 88%, 96% and the like. Most preferably the degree of conversion is more than 90%.
  • the degree of conversion is calculated as the percentage of the MgO (measured in XRF) in the magnesium oxide containing material that has been converted to magnesium hydroxide.
  • the magnesium hydroxide containing material according to the present invention can be coated with surface modifiers such as fatty acids, amino-, alkyl- or vinyl- silanes, siloxanes, stearates, titanate or zirconate coupling agents, maleic anhydrite grafted polymers and the like.
  • the coating can be applied in wet or dry conditions by any method known in the art.
  • the BET value of the magnesium hydroxide can be further reduced compared to the uncoated material due to the presence of surface modifiers.
  • the magnesium hydroxide containing material of the present invention is suitable for mixing with polymers.
  • said magnesium hydroxide containing material contains already a high amount of magnesium hydroxide (e.g. degree of conversion more than 70%, preferably more than 85%, most preferably more than 90%) prior its mixing with the polymers.
  • the range of polymers includes both synthetic and natural ones involving thermoplastics, thermosets and elastomers.
  • Such polymers involve polyethylenes, polypropylenes, a-olefins, ethylene-acrylate copolymers, ethylene-vinyl acetate copolymers, polyvinyl chlorides, polyamides, epoxy resins, polyester resins, natural rubber, butyl rubber, ethylene-propylene rubber, acrylic rubber, nitrile rubber, and the like.
  • the magnesium hydroxide containing material of the present invention is suitable for mixing with polymers and various polymer blends thereof.
  • the magnesium hydroxide containing material according to the present invention induces flame retardant properties in the polymer compound. Beneficial on said properties is purity and high degree of conversion. Present invention exploits a broad spectrum of purities, while is able to achieve a high degree of conversion. Said magnesium hydroxide is a halogen-free flame retardant mineral.
  • a magnesium oxide containing material with 91% purity which was dry grinded at d 50 of 300 ⁇ m and presenting a BET value of 2.2 m 2 /gr, was hydrated in distilled water at 10 wt. % solid content in reactor at 190° C. for 2 h.
  • a magnesium oxide containing material with 93% purity which was grinded at d 50 of 28 ⁇ m and presenting a BET value of 0.7 m 2 /gr, was hydrated in distilled water at 10 wt. % solid content in reactor at 190° C. for 2 h.
  • a magnesium oxide containing material with 96% purity which was dry grinded at d 50 of 55 ⁇ m and presenting a BET value of 0.8 m 2 /gr, was hydrated in distilled water at 10 wt. % solid content in reactor at 190° C. for 2 h.
  • a magnesium oxide containing material with 96% purity which was dry grinded at 0-1 mm particle size distribution and presenting a BET value of 11.7 m 2 /gr, was hydrated in distilled water at 10 wt. % solid content in reactor at 190° C. for 2 h.
  • a magnesium oxide containing material with 96% purity which was dry grinded at d 50 of 75 ⁇ m and presenting a BET value of 7.5 m 2 /gr, was hydrated in distilled water at 10 wt. % solid content at 80° C. for 24 h.
  • a magnesium oxide containing material with 96% purity which was dry grinded at d 50 of 4.5 ⁇ m and presenting a BET value of 31.7 m 2 /gr, was hydrated in distilled water at 10 wt. % solid content in reactor at 190° C. for 2 h.

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)
US17/259,247 2018-07-12 2019-07-04 Method of producing magnesium hydroxide Pending US20220153602A9 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GR20180100313 2018-07-12
GR20180100313A GR20180100313A (el) 2018-07-12 2018-07-12 Μεθοδος παραγωγης υδροξειδιου του μαγνησιου
PCT/GR2019/000047 WO2020012202A1 (en) 2018-07-12 2019-07-04 Method of producing magnesium hydroxide

Publications (2)

Publication Number Publication Date
US20210300775A1 US20210300775A1 (en) 2021-09-30
US20220153602A9 true US20220153602A9 (en) 2022-05-19

Family

ID=67515023

Family Applications (1)

Application Number Title Priority Date Filing Date
US17/259,247 Pending US20220153602A9 (en) 2018-07-12 2019-07-04 Method of producing magnesium hydroxide

Country Status (6)

Country Link
US (1) US20220153602A9 (el)
EP (1) EP3820819A1 (el)
AU (1) AU2019300376B2 (el)
BR (1) BR112021000481A2 (el)
GR (1) GR20180100313A (el)
WO (1) WO2020012202A1 (el)

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2898194A (en) * 1955-12-23 1959-08-04 Basic Inc Beneficiation of magnesite ores
SU559899A1 (ru) * 1975-05-04 1977-05-30 Институт общей и неорганической химии АН Белорусской ССР Способ получени гидроокиси магни
GB1514081A (en) 1975-05-30 1978-06-14 Kyowa Chem Ind Co Ltd Particulate magnesium hydroxide
JPH0248414A (ja) * 1988-08-09 1990-02-19 Mitsubishi Mining & Cement Co Ltd 水酸化マグネシウムの製造方法
AT392774B (de) * 1989-05-05 1991-06-10 Veitscher Magnesitwerke Ag Feinpulveriges magnesiumhydroxid und verfahren zu dessen herstellung
IE921328A1 (en) * 1992-04-23 1993-11-03 Defped Ltd Particulate magnesium hydroxide
US5662881A (en) 1992-10-29 1997-09-02 Daicel Abosisangyo Co. Apparatus and method for the production of active magnesium hydroxide
IL112385A (en) 1994-01-21 1998-08-16 Flamemag International Gie Process for preparing magnesium hydroxide for extinguishing flames
EP0791559B1 (de) * 1996-02-20 2000-09-13 MAGNIFIN, Magnesiaprodukte Gesellschaft mbH Verfahren zur Herstellung eines kristallinen Magnesiumhydroxids
EP0958243A1 (en) * 1997-01-31 1999-11-24 Solutia Inc. Hydration of alkaline earth metal oxide to produce alkaline earth metal hydroxide
JP5350232B2 (ja) 2006-06-21 2013-11-27 マルテインスベルク・ゲゼルシヤフト・ミツト・ベシユレンクテル・ハフツング 水酸化アルミニウムの製造方法
GB0812714D0 (en) * 2008-07-10 2008-08-20 Imerys Minerals Ltd Magnesium hydroxide

Also Published As

Publication number Publication date
AU2019300376B2 (en) 2024-07-11
AU2019300376A1 (en) 2021-02-04
GR1009717B (el) 2020-03-06
GR20180100313A (el) 2020-03-18
US20210300775A1 (en) 2021-09-30
WO2020012202A1 (en) 2020-01-16
EP3820819A1 (en) 2021-05-19
BR112021000481A2 (pt) 2021-04-06

Similar Documents

Publication Publication Date Title
TWI401307B (zh) Preparation of cerium - based abrasive
RU2414427C2 (ru) Состав для полировки стекла на основе двуокиси церия и процесс для его изготовления
TWI461364B (zh) Method for producing boehmite particles and method for producing aluminum particles
CN111547750B (zh) 一种粒度可控、六角片状氢氧化镁阻燃剂的制备方法
JP2638890B2 (ja) 易解砕性アルミナの製造方法
EP1768928B1 (en) Process for complete utilisation of olivine constituents
KR20060043550A (ko) α―알루미나 입자의 제조 방법
CA2939493C (en) Method for producing nickel powder
CN112408439B (zh) 以氢氧化镁粗粉为原料制备阻燃剂用超细氢氧化镁的方法
KR20070013213A (ko) 미립 α 알루미나
KR100482912B1 (ko) 산화인듐-산화주석분말,이의 제조방법 및 산화인듐-산화주석 소결체의 제조방법
EP3067320B1 (en) Method for producing aqueous zirconium chloride solution
JP2008156146A (ja) αアルミナスラリー
JP2008214174A (ja) 難燃剤用水酸化マグネシウム粒子及びその製造方法並びに表面処理方法
AU2019300376B2 (en) Method of producing magnesium hydroxide
KR20190131724A (ko) 고순도 알루미나의 제조방법
JP2869287B2 (ja) 板状ベーマイト粒子の製造方法
EP0536381B1 (en) Process for preparing sub-micron alumina particles
KR101440473B1 (ko) 판상 알루미나의 제조방법
KR100894872B1 (ko) 난연제용 분산성이 우수한 수산화마그네슘의 제조방법
JP3089110B2 (ja) 炭酸カルシウム微粒子分散体の製造方法
JP2007186379A (ja) αアルミナ粒子の製造方法
JP2007161560A (ja) 微粒αアルミナの製造方法
KR20150060188A (ko) 바륨티타닐옥살레이트의 제조방법 및 티탄산바륨의 제조방법
JPS62230615A (ja) アルミナ粉末の製造法

Legal Events

Date Code Title Description
STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: NOTICE OF ALLOWANCE MAILED -- APPLICATION RECEIVED IN OFFICE OF PUBLICATIONS