JPS59190217A - High purity magnesium hydroxide and high-density magnesia clinker having coarse crystal size, and their preparation thereof - Google Patents

Abstract

PURPOSE:To prepare magnesia clinker having high density and coarse crystal size, by treating sea water with an ion exchange resin capable of capturing boron-containing anion, and reacting with calcined dolomite thereby producing a specific composition. CONSTITUTION:Sea water, bittern, saline water, or its treated liquid to remove carbonic acid, is treated with an ion exchange resin capable of capturing boron- containing anion (e.g. a resin having polyhydric alcohol residue as pendant group), and if necessary, subjected to the removal of carbonic acid or inactive carbonate before or after the treatment with the ion exchange resin. The product is made to react with calcined dolomite, lime, or their hydrate to obtain a high-purity magnesium hydroxide composed of >=99.3% of MgO, <=0.3% CaO, <=0.2% of SiO2, <=0.05% of B2O3, and <=0.15% of the sum of Fe2O3 and Al2O3 (based on wt% after ignition). The magnesium hydroxide is compression molded and calcined to obtain the objective product. The bulk density of the product is >=3.40g/cm<3> and the average particle diameter of the periclase crystal is >=60mu.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-density coarse-grained magnia clinker and seven methods for producing the same, as well as a method for producing high-purity magnesium hydroxide and the like.

As steel manufacturing technology advances, the physical properties required for refractories are becoming increasingly strict. Historically, regarding the magnesia clinker used as a material for steelmaking furnaces, it was initially desired to develop a high-purity magnesia clinker with a high content of magnesium oxide. For example, a magnesia clinker with low porosity is desired, and recently there has been a desire to develop a magnesia clinker with large periphery 1/-z crystal grains.

Magnesium hydroxide derived from seawater, bittern or brine (hereinafter referred to as water-19 magnesium derived from seawater)
It inevitably contains persimmon impurities present in these sources, and therefore the amount of impurities directly affects the quality of the magnesia clinker (hereinafter referred to as seawater-derived magnesia clinker), which is a finished product. Affect. Such impurities are contained in magnesia linker derived from seawater in the form of boron oxide (B2O3), calcium oxide (CaO), and silicon dioxide (5iO2).

After the development of magnesia clinker with low impurity content reached a certain level, it gradually became clear that improving the purity alone was not enough to give the refractory the desired and sufficient properties.
・If B20° as an impurity is conveyed to the properties of 1 refractory 4 refractory using Magui shear liquor, it becomes clear that it has a strong influence on the hot physical properties, spalling resistance, or IIjJ slag property of the refractory, and B, 03 content as low as possible and editing density MAGNESI AC 1 non-car k IA
In recent years, methods have been proposed for providing the service.

There are two different methods for producing B2O3@Y" small magnesia clinker (hereinafter referred to as "magnesia clinker"). One method is hydration, which is the JJA material. This is a method of reducing the boron content of magnesium, and the method of grade 2 is a method of trying to make boron lose successively when firing magnesium hydroxide.T3iJ's method is, for example, adding Mg (01
1) Add 2 to convert the boronated @*J in seawater to Mg(Ol
i) Method of removing by letting 2 absorb 7B (Special Publication No. 45-5
(see Publication No. 3) or Zr in seawater (Oli l 2
In addition to f, γjσ underwater bow rope signal is Zr (OH
A method of adsorbing and removing it in the same way as +2
(See Publication No. 839). According to the description in Japanese Patent Publication No. 51-5839, Zr(OH)2 and Mg(OH)2 L
Zr (OI) also seems to exhibit cumulative adsorption ability, but
J) Even when using 2, for example the boron content 3
pp? In order to obtain Z water with a low boron content of 7L (as BzOg) (as BzOg), it is necessary to use 111, which is about 300 times more boron than the boron present in water. is loaded with 1 mi. , Z to 1st child
Since a small amount of Zr (Oli,) 2 remains in seawater, magnesium hydroxide containing l r (Q H) 2 is given by a method that is conveniently used as an adsorbent for r (Oli) 2. It turns out.

Furthermore, there is a method in which when seawater and lime are reacted, an excessive amount of lime is used to raise the pB to 11 or more in order to prevent boron from being adsorbed to the resulting magnesium hydroxide. This method, however, reduces B,03 to 0 on a scorching basis.
．． When the amount is reduced to 10%, CaO becomes '2. ．． If boron is increased to 49% by weight, and B20sYt is reduced by 0.04% (by weight), CaO increases to 5.06% by weight. Only magnesium oxide can be obtained (Tokuko Sho 57)
-31547, Table 1). For this reason, the special public
In the invention of No. 31547, the above-mentioned purified magnesium hydroxide is lightly fired at 700 to 1100°C, and then the entire amount of the obtained craft ware is poured into seawater to rehydrate it, thereby reducing the amount of calcium hydroxide. In-made magnesium hydroxide 'JJi9j, this, V-#, i'! The obtained magnesia cliquer contained a chemical composition of 0.011% by weight of hydroxide magnesia and B20 and had a corner density of 3.47 g/crrL30. The method disclosed in Japanese Patent Publication No. 57-31547 not only uses an excessive amount of lime but also requires four steps, resulting in large energy losses, so it cannot necessarily be said to be an advantageous method in terms of construction.

Baking, especially 8′ that combines boron! Method 2 tends to be approved in the United States, in which sodium salt of sodium carbonate, for example, is added to magnesium hydroxide, and boron is dispersed as Ha 2B 407 during firing.

Also, Yamamoto! 1. If the content of carunium hydroxide impurities in magnesium hydroxide is reduced, it will become a fired product (boron is easily volatilized as B2O3 and J,
It was revealed that a high-purity, high-density magnesia clinker with a low content of 1203 and 111: can be obtained by decarburization) 34? After separating magnesium hydroxide obtained by adding lime to seawater,
Iyaki (~, Hebi) Pour into seawater or water to rehydrate.
Calcium hydroxide, an impurity, is removed from one bale of magnesium hydroxide to produce magnesium hydroxide with a low calcium hydroxide concentration, and this is fired (~Mede, B2O
A4g099.63 assuming that there are no 3-loss slopes.
%, Ca0O, 24%, SiQ 2 0.14%, I
'e 2 Q g 0.04 '10, At2030
, 05 "High purity and high density red sea bream shear clinker with a composition of 0.008% In and B20, 1", 3.42.9 / c♂, fully strained (inflammable) f/J Volume 25 5480 1973, Tσ:ble in the marrow
8).

According to this document, the above-mentioned high-purity high-density magnesia clinker is obtained by processing magnesium hydroxide containing B2O3 (40,139 tonne weight %) on a scorching basis.

On the other hand, demand for carbon bricks has increased rapidly as the country has become more popular. Madanesia carbon brick (Madanesia carbon brick) is a permanent brick made by pressure molding a mixture of magnesia clinker and graphite. It has slag resistance.The reason is that graphite acts as a cushion ion for the magnesia clinker, so the graphite part is soaked by the slag, so there is no ri, and the magnesia clinker
It is believed that this is due to the gradual erosion of the slag. Recently, magnesia carbon l/
A magnesia clinker suitable for use in Mega is required to have large Periclese 11 crystal grains, and in fact, such magnesia clinker with large Periclese crystal grains is required.
It has also been demonstrated that magnesia carbon bricks using magnesia clinker have even better spalling resistance.

However, the above refractory material 25. @547 page 197
As described in Fig. 16 of 2003, the object of the present invention is to provide magnesia clinker which is conventionally derived from seawater and has large Vericlese crystal grains exceeding 50 microns.

The object of the present invention is to provide a high purity double water 111+ magnesium which is suitable for providing the above-mentioned magnesia clinker of the present invention and has a very low boron content as well as calcium.

Still another object of the present invention is to provide a method for producing the magnesium hydroxide and magnesia clinker of the present invention.
It is to provide i%.

Other objects and advantages of the invention will become apparent from the description below.

According to the present invention, in accordance with the above object 2 and advantages of the present invention, MqO 99.3% as oxidation 9% is
More than Ca, OO, 3' death or less 5in2 0.2% or less B 2
03 0.01% Wood GaFe
Total of 2O3 and At203 -420, 15% or less However,
MgO, Cab, 5in2, B201, Fe2O3
and the total fr'r of At203, f 100 intake%
It has the following composition, and the bulk (a) is 3.40 g/α3 or more, and the average particle size of magnesia delivered to Vericlaze is 60 microns or more as measured by the method defined later. A high-density magnesia clinker with high density crystal grains is provided.

The above-mentioned high density coarse grained magnesia clinker of the present invention (
cf, can be produced according to the method of the present invention described below. Hereinafter, the method of the present invention will be explained first. That is, according to the present invention, the magnesia clinker of the present invention can be prepared from seawater,
The distilled water or the decarboxylated solution thereof is treated with an ion exchange resin capable of capturing boron-containing anions, and if necessary, decarboxylation or no bathing is performed before or after the ion exchange resin treatment. By removing carbonic acid and reacting it with dolomite burnt material or lime or their hydrates, M'q O993% or more CaOO, 3% or less 5 in2 .2% or less B20
30.05% or less 1'e203 and At203 total it O,15
% or less (BL, MgO, Ca, 0.Si O2, B,,
03, Fe2O3,%"j and A1203 (D combination 1-Ht
eto.

It can be manufactured by producing high-purity magnesium hydroxide having a composition of %, followed by pressure molding and firing.

The magnesium-containing aqueous solution used in the method of the present invention may be seawater, bittern or brine, or a decarboxylated solution thereof.The decarboxylated solution may be seawater, bittern or brine, and may be treated with an alkaline compound such as calcium hydroxide according to a known method. or by adding a strong acid such as sulfuric acid.

The ion exchange resin used in the present method is one that is capable of trapping boron-containing anions.

As such an ionic grammar resin, one having, for example, polyhydric alcohol/14M as a pendant group as a trapping agent for a handful of boron-containing ions is preferably used. For example, as a pendant group, n is an integer of 1 to 4, R is 11 hydrocarbon groups, and 2 is a pentahydroxyhexyl group or a tetrahydroxypentyl group. An ion exchange resin containing a group represented by is shown in Example 4.

In the above formula, It is, for example, methyl, etinopeprobi/lz
, butyl, hexyl, octyl, lau IJ) pecyclohexyl, phenyl, benzyl JI3 @
-Valency 1) is a hydrocarbon group.

Pentahydroxyhexyl group representing Z (formula -C6H
8(0f-1), such as sorbityl, mannitil, and galactytil valley.

Also, tetrahydroxypentyl, I + ¥ ha formula C5 no a
It can be represented by (OH)4, such as arabicyl and ribicyl.

As such an ion exchange position, one in which N-methylglucamine is expressed by the following formula (%) is preferably used. The above-mentioned ionic resin used in the present invention is US Pat. No. 48i3,83
It is disclosed in Specification No. 8. 6 of this U.S. patent specification.
Own publication is incorporated by reference herein.

Conventionally, such boron-selective ion exchange resins were used as
Although there is no suggestion of the possibility of removing boron from rtrr water or reduced bittern [Interceram (lnt, erceraml, Nl<, 3.1973,
See pictures 212-218], such an exchange of girls
Magnesia clinker is produced from seawater treated with fat.
An example of producing high-altitude magnesium hydroxide is that by using an ion-exchange resin such as this one, magnesium oxide with the highest boron content can be produced. ') It is completely unknown whether it will happen.

According to this I6 light method, magnesium-containing water such as seawater/~L (preferably tL, <pH 8~1o) is preferably -
1-Ion Exchange" Back 4. Processed by passing through a column filled with YitI fat. It is appropriate that the processing speed of the magnesium 3m aqueous solution be approximately 0.1 to 0.6 m per minute per ion parent resin In3.The ion exchange resin is commercially available as an 8-acid addition salt, and when used, It is generally recommended to convert it into the free form with an alkali, such as Xun's sweat soda or ammonia, and use it.
According to the present invention, the ion exchange resin can be used as it is as an acid addition salt, such as hydrochloride or 41νIN #1 salt, and it is better to use it as a CaO-containing t4 It has been found that this method is rather preferable in obtaining extremely low amounts of magnesium fluoride. Ion exchange resins can be regenerated by treatment with a strong acid such as sulfuric acid or hydrochloric acid, but according to the present invention, a used ion exchange resin saturated with boric acid anions can be regenerated by treating it with a boron-containing anion. is a strong acid and has the advantage that it can be reused as it is for treating magnesium-containing bathing fluids of seawater without having to be treated with alkali after use.

According to the present invention, the aqueous magnesila solution can be optionally decarboxylated or freed from insoluble carbonates by C before or after treatment with the ion exchanger resin.

Decarburization (7 yen) can be carried out by blowing air into an aqueous solution containing magnesium and adding hot acid, etc. Filtration can be carried out, for example by sand filtration.

According to the present invention, if the red sea bream sium-containing bathing liquid is seawater, bittern or can water, decarboxylation treatment can be performed before or after ion exchange resin treatment, and decarboxylation treatment can be performed before or after treatment with an ion exchange resin. In the case of carbonated p + r- liquid, 'rtJ 9 of ion exchange resin treatment is later replaced with non-δ carbon t]
- salts can be removed from the decarboxylation process;

According to the present invention, the decarboxylated t2-treated liquid of seawater, bittern or canned water is preferably filtered, and the carbonate ion or insoluble carbonate in the filtrate/(1) is removed. Insoluble carbonates are removed by subjecting to ion-exchange resin treatment, or by treating city water, bittern or can water with ion-preparing resin, and then decarboxylating the resulting treated water or subjecting it to a 5-day treatment. As a result, it is possible to obtain water seeded magnesium containing not only B2O3 but also less CaO-containing texture.

Treated water treated with ion exchange resins contains boron at very low d-relative levels, e.g. 12-13 ppm in B2O3.
Y) B20. In total, it is possible to produce two prefectures of processing liquid with a concentration of 1 ppm or less.

According to the invention, this treated water is then reacted with dolomite burnt products or lime or hydrates according to the method published in the series itself, and is heated at a rate of 1%. According to 7, below, f・[↓Native MqO99,3
% or more Ca O0, 3% or less δ'io2 0.2% or less B2
O30.05% or less (preferably 0.03% or less) 1” Total amount of e20. and At203 0.15%
Produces commercially pure magnesium hydroxide which has the following properties:

This city j pure j saesui I “Magnesium dioxide! Samurai (CCa
The magnesia clinker of the present invention is characterized by containing very low levels of O, B, and O, and has high-density coarse crystal grains as will be explained in detail later. As mentioned above, high-purity magnesium hydroxide with extremely low impurity content has not been widely known as the water electrified magnesium of γ-Yakusuiki rM.

According to Book 71', the clear method of the present invention, the present invention's compact lW original large-grain magnetic force -Lf:,C(LOtoB2O3
k] and which always contains a low level of high purity magnesium hydroxide having the above composition can be produced by press molding and then firing. Pressure forming is usually carried out under a cutting edge pressure of 2 to 3 tons/- to give a compact with a density of about 1.5 to 1.7 jJ/cx3. -Delicious. In addition, firing is usually performed at a temperature of 1900 to 2100°C for about 15 minutes to 1 hour.
The contract will last for a period of time.

According to the present invention, the oxide is MgO99, 3% or more CaOO, 3% or less 5in2 0.2 °A or less B
2O30, 01% less, t) iId The sum of Fe203 and A l, 03 t + ta o
, ts% or less, and the bulk I skin is 3.40 M/crr
A: A high-density, coarse-grained magnesia clinker of the invention is provided, in which the particle size is L3 or more and the average grain size of magnesia perige one-nose crystals is 60 microns or more as measured by the method defined later.

One of the excellent solutions of the above-mentioned method of the present invention is to treat seawater, aquatic juice, canned water, or a decarboxylated liquid thereof with an ion-sparing resin capable of capturing boron-containing ions, and to obtain Ca0L.
- and BtOsf is to produce high purity magnesium hydroxide which has only 1% purity at very low levels; Not only does it have a bulk crystallinity of 3.401!/cr1 or more, but the average grain size of the slip phrase crystals is 60.
Extremely large madanesia cleaning force of microns or more
In the scorching Tachibana table, which is at the point of total production, CaO is less than 0.3% and B2O3
is 0.05 ilj amount%, a CaO-containing beak and B;
It was discovered for the first time by the present inventor that by firing high-purity magnesium hydroxide containing both O and Ni at low levels, a red sea bream clinker bearing coarse crystal grains as described above can be obtained. It's $ real.

In the high purity coarse quartz crystal grain magnesia clinker of the present invention, the average particle size of magnesia periclase crystals is preferably 7.
It is 0 microns or more, more preferably 80 microns or more, and most preferably 90 microns or more.

The high purity coarse grained magnesia clinker of the present invention preferably has a density of 3.42 H/bx3 or more, more preferably 3.43 Mlα3 or more.

In addition, the high-purity grained magnesia clinker of the present invention preferably contains, as an oxide, MgO99, 4% or more CaOO, 25% or less Sin, and 0.2% or less B.
2'jl
0. 0 1% less? +1r4Fe20. and At,03's total "rff, composition of 0.15% or less.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited in any way by the Examples.

In addition, various types of ``Musei Lun'' in Suimei Kinshu were measured/ζ by the following method.

Chemical 'i' composition Measured in accordance with the "JSPS Method 1 Chemical Analysis Method for Magnesia Clinker" (Refer to 1981 Edition Refractory Handbook) determined by the Test Methods Subcommittee of the 124th Committee of the Japan Society for the Promotion of Science. .

Sometimes B20. For the analysis of curcumin, which was adopted as the Gakushin method after consideration by the Anseikai (absorptiometric method)
This was done by

Bulk Density (Specific Gravity) Apparent porosity of magnesia clinker, apparent porosity of magnesia clinker, method for measuring specific gravity and oyster specific gravity determined by Japan Society for the Promotion of Science 124th Committee Examination, Ryo method subcommittee '(198
(Refer to the 1st Edition Refractory Notebook), the total value was calculated using the following formula.

W3-shiV2 Wl: Dried Tokyo loss of clinker <q> W2: One table amount in white kerosene of the sample 4-hydrated with white kerosene <1) W3: 1・ken*JL in white kerosene, Ta test 4,1 L no 1 weight <y) S: Specific gravity of white kerosene at measurement temperature (g/α
3) Considering the particle layer distribution of clinker 1:・3<L,,5~10
I randomly took out the sm4 early work and grinded it.
Observe the polished surface of the rooster using a reflection microscope. Photographs of three representative areas are taken at 20x magnification, enlarged to 3x and printed on photographic paper. 3. Select 50 periclase grains in the photo of 3. Select 50 of them with the largest maximum weight φ and measure their maximum particle diameter. do.

Example i'ji Dissolved carbonate ion in water (CO2 conversion a-jD18
0 pprn) by adding milk of lime to CO7 equivalent value 1
0ppm-J.

It was filtered using a trowel and a sand filter. This decarboxylation treatment solution contained boron in an amount of about 12 ppm as 113BO3. Furthermore, this solution was filled with an ion exchange resin (N-methylglucamine recontained, fDf salt type) 1007 capable of capturing boron-containing anions, and passed through an adsorption tower at a speed of 404/min. If, BO3 is adsorbed to the resin, H3
BOs content 0. 'loppm low boron content seawater was produced. This seawater and milk of lime are reacted at a reaction rate of 92%,
The produced* magnesium oxide precipitate is transferred to charcoal by furnace.
It was washed with treated tap water to produce magnesium chloride water with a high purity as shown in IK.

The numbers shown in Table 1 represent 1t% by weight, and IgL o
s s represents the amount lost during scorching heat.

Example 2 The magnesium hydroxide produced in Example 1 was dried in a dryer to a water content of 8% by weight, and then pressure molded at a molding pressure of 3 t/d, and then heated to 2000°C in an oxygen/pronok gas furnace. It was fired at high temperature. Table 2 shows the chemical composition, bulk density, and average particle size of periclase crystals of this magnesia clinker. A photograph of the periclase crystal is shown in Fig. 1.

Example 3 Decarburization I-shaped place J Hayabusa using the method of Example 1 and 2B? (The pond that changes the passing rate of 'l- through the absorption tower to 301/min is made by reacting with round milk at a reaction rate of 92%, and after separating the raw magnesium hydroxide, decarboxylation. Treatment 1 was washed with ice water to produce high purity water 1 clouded magnesium as shown in Table 3.

Example 4 Chemistry of magnesia clinker obtained by sintering the magnesium hydroxide produced in Example 3 in exactly the same manner as described in Example 2. The average single diameter of the periclase crystals is shown in Figure 4.

A photograph of the bericraze crystal is shown in Figure 2.

Comparative Example 1 Z 7 kl of seawater 1001, which had been decarboxylated by the same method as described in Example 1, was mixed with 7 Kl of 7 Kl of seawater using a FL machine. By licking and mixing with the light minutes? FIf≧Toy Hou Ito Seki defeat Fui ligase, 57
It was reduced to 5p p mli, B O, and distal. This r
Waterproofing and milk of lime were reacted at a reaction rate of 492%, and the produced magnesium oxide in water was cleaned with JjiL7ζ water to produce 2I2 magnesium hydroxide as shown in Table 5.

/ This purified magnesium hydroxide was sintered using the same method as described in Example 1. A photograph of Peril1]-su Shao crystal is shown in Figure 3.

[Brief explanation of the drawing]

Figures 1 and 2 of the accompanying drawings are sharp-edge photographs (at a magnification of about 150F) showing the periculate crystals of the magnesia clinker of the present invention. The 31st picture shows a comparative magnesia clinker Berik 1 nose Yuki'l cheek imitation - λ tool (approximately 150 times to 4 times)
It is. The minimum graduation of the scale shown in the photograph in Figure 1 is 10μ, as shown in Table 4. 1 other personFigure 1Figure 2Figure 3

Claims (1)

[Claims] 1. MgO99,3 as an oxide expressed in weight%
% or more CaOO, 3% or less 5in2 0.2% or less B, 0.
Less than 0.01%;;
lFe2O, and At203(7) total amount o, 15
% and has a high density of 3.40 g/m”
The above-described high-density IW coarse grained magnesia clinker-0 z characterized in that the average grain size of magnesia vericlaze crystals is 60 microns or more as measured by the method described in the main text, and the average grain size of nuclear periclase crystals. Magnesia clinker-0 according to claim 1, wherein the particle size is 70 microns or more; One magnesia clinker according to claim 1, wherein the average particle size of the magnesia clinker-04-ape'J craze mackerel crystals is 90 microns or more, and the bulk density is 3. 42 M/cm" or more, the magnesia clinker-96 according to any one of claims 1 to 4, and claim 1, wherein the bulk density is 3.43 fl/crr? or more. Magnesium ac linker according to any one of items 7 to 4. 7. Expressed by weight, the oxide and (-, MgO99,
4% or more CaOO, 25% or less 5in2 0.2% or less B2O
Less than 30,01% F e 203 and A l 20. total i4y
Claim 1: 0.15% or less
Mag stirrup clinker listed in any of items 6 to 6. 8 It is produced by the reaction of seawater, bittern or bittern water with dolomite burnt material or lime or their hydrates, expressed in weight%, with scorching heat group, Aig O99, 33 or more CaO0, 3% or less Sin, 0.2% or less B2
O30.05% or less p″e, total amount of 03 and At203 0.15%
High purity magnesium hydroxide characterized by having the following composition: 9, B20. When the content of is less than 0.03', 'n, the yoke of yoke [8:l water described in item 8] I) magnesium chloride. 10. Before or after decarboxylation or non-bath coal pouring hood] before or after deresin treatment of sea water, bittern or can water or their deresin treatment, remove the tray and react it with dolomite paste, fabric or lime or their hydrates. At least, expressed as i: Y knee + 1-%, on a scorching basis, 11g0 9
9.3% or more - Hi-CaOO, 3% or less 5in2 0.2% or less B, 0
3 o, os% or less Fe2O,
and At20. High-purity hydroxide with a composition of less than 0.15% - Gnesium, characterized in that it is then pressure-molded and sintered, expressed in weight %, oxide As AIgo 99.3 3 or more Ca
O0.3% or less Is' Z Q 2 0-2
% or less B21s O, 01% or less I' e ,, 03 and At20. Total amount of 0.15
% or less, and has a bulk density of 3.40 g/e
x3 or more, and the average grain size of magnesia vericley crystals is 60 microns or more as measured by the method specified in the main text. 11. Seawater, reed sap, kansui, or their decarboxylated liquids are treated with an ion exchange resin that captures boron-containing anions.
If necessary, decarboxylate or remove insoluble carbonates before or after the ion exchange (before or after burning), and mix this with dolomite burnt material or lime or their hydrates. Reacted and expressed in weight percent, based on scorching heat, MqO 99.3% or more, CaOO, 3% or less, 5in2 0.2% or less B2O.
3005% or less Fe2O3 and At20. eeTTlio, a method for producing high purity magnesium hydroxide having a composition of 15% or less. 1'2- Claims in which carbonate ions or insoluble carbonates in the decarboxylated liquid are removed by p-filtering the decarboxylated liquid of seawater, bittern, or can water, and then the ion exchange resin treatment is performed. The method according to paragraph 10 or paragraph 1311. 13. Treat seawater, bittern or bittern water with a 1-year old ion exchange resin, and then decarboxylate the resulting treated water or condition it to remove insoluble carbonates (II: after removing dolomite). or lime or a hydrate thereof. 14. The ion exchange resin has pendant polyhedral alcohol residues as a boron-containing anion trapping group. The method according to any one of Items 10 to 13 of the patent hI''l as a group.15 The ion exchange resin is expressed as a boron-containing anion trapping group by the following formula (% formula %). Patent containing a prestigious N-methylglucamine group'
Any one of Items 10 to 13 of the iJI request [method described.