JPS59195579A - Manufacture of magnesia clinker with increased density - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides one advantage in the production of magnesia clinker with increased density If.

With the progress of steel manufacturing technology, the demand for refractories has become increasingly severe. Looking at the magnesia clinker used in steelmaking and as a P material, magnesia clinker with a high density of 11 and large periclase/combined crystal grains (211 shots) is desired.

One of the reasons why the price is 1 yen and 7 is probably due to the rapid increase in demand for magnesia carbon bricks in recent years. Magnesia-carbon brick is an unfired brick made by side-pressure molding (a mixture of mag-purified shea clinker and graphite), and is much more arrogant than the magnesia brick used in Toyo I. tC+1 slag 1g
Z: have. The reason for this is thought to be that Gelaphalt, as a material for magnesia clinker shoes/yong, has a poor t-shape due to its high power or slag size. Since the carbon brick wears out mechanism, the graphite part is likely to be contaminated by the slag, so it's a good idea to use a magnetic linker;'r! It is thought that the S content is due to erosion by slag (inujing tools).High purity; Lenka says that by using such a magnetic screw connector, the wear and tear will be slowed down by 7".

How to produce magnesia clinker with increased η4.1 and 7G? It is to provide a.

Another object of the present invention is to provide a method for constructing a mag-neutral container with improved strength in a simple worker.An object of the Zara Kitl of the present invention is to Along with Ji 1 Me Σ, we have developed a mag-clean shear clinker with low micropores inside the crystal and large Vericlese crystal grains.
l,! The goal is to provide a way to leave behind a legacy.

The further objectives 2 and 3 of this statement will become clear from the following explanation.

According to the book '76, 1:V, this invention's part 11':J
The 11th point Hd, decarbonated water of seawater, bittern or brine, and water-soluble iron compound → 2/l. k
7Q to produce a precipitate mainly consisting of magnesium hydroxide, and then calcining the precipitated precipitate.
The eaves are sealed using the Madanesian clinker-fi method.

In the method of the present invention, demineralization of magnesium from water, bittern or water,
・Me water 1f kneemata. Such decarboxylated aqueous solution can be prepared by adding an alkalinizing agent such as lime or calcium hydroxide to seawater, bittern or brine using known methods, or by adding an alkalinizing agent such as lime or calcium hydroxide, or by adding an alkalinizing agent such as lime or calcium hydroxide. It can be obtained by cooling.

It is well known that magnesium hydroxide is precipitated by adding an alkaline compound ψ1, or calcium aqueous to the aqueous decalcifying acid solution, but in the uninvented method, lime is added to the decarbonated water solution. It is important to add all the water bath ferruginated substances before adding the alkalinizing substances such as. When a water-bathable iron compound is added after adding an alkalinizing additive such as lime, magnesia clinker having the specified seven-fold concentration, which is the object of the present invention, can be produced. This is at least very controversial.

Conventionally, j1σ water 1 [monme of magnesium hydroxide with iodide 9]
A field of shame? It is known that A is used as a sintering wound to promote the sintering of Madanosium monomonomer. However, this method does not allow the formation of iron compounds during calcination.
e 203 as an impurity in the magnesium hydroxide source of seawater.
2O3 and calcium ferrite (2CaO-Fe, 03
1 and BuO-:l-5ite (4Ca O-A1203
・By forming a low-grade compound (hereinafter referred to as a low-melting compound) such as Fe, 03), and forming a low-melting phase during firing, This method promotes sintering of magnesium oxide. With this method, it is therefore not possible to produce magnesia clinker of high density and various purity, and it is not possible to produce large periclase crystals.

According to the method of the present invention in which water-soluble outer iron compound' + tJ'f adds an alkaline compound such as lime, etc., ni'l K is added. The density is better than that by the conventional method of drawing later! The reason why a magnesia clinker with a hole is rented is not necessarily clear, but according to the method of the present invention, in the water bath 1+-, lime etc. are added to the decarbonated water bath solution containing ferrous adducts. Iron hydroxide particles are produced, and then magnesium hydroxide is produced as a result of these particles, and the iron hydroxide that can be used in the water reforming bath has a commercial effect on producing precipitation of magnesium hydroxide. On the other hand, this is thought to be due to the fact that there are few φ groups that produce low-melting compounds during firing.

The water-soluble iron compound may be either an inorganic acid salt or an organic acid salt of iron or trivalent iron. Mineral acid salts as well as inorganic acid salts are preferred ferrites. Such water-soluble iron compounds include agglomerated iron, (pfn iron,
Nitric acid method, phosphorous iron inorganic acid salt or acetate salt, benzoic acid salt, 7)-) luenesulfonate salt method can be used. In step 7, bath ironization@rotation is performed using magnesia clinker as F e t Os charcoal thfRj, for example, 0.
It can be used in an amount of 2 to 1.0%, preferably 0.3 to 07%.

Decarburizing the water-shaving iron 1-' compound! 3. Addition of alkaline compounds such as lime to water bathing and water bathing
i is about 10.8 or more to produce magnesium hydroxide, preferably dpi 111-12
It is done so that pH of water, 6 liquid - 10
If it exceeds 8, alkaline compounds will be added; By doing so, it is possible to produce water containing less boron (magnesium dioxide), and therefore it is also possible to produce less boron-containing water; Magnesium Acrylic Sword - h::, i can be presented. 7] If H is 11 to 12, then (as I said above, this anti-Y1'-1, 'I, l-) Since the alkaline compounds of the re-liming are somewhat concentrated, the reaction solution should be treated with seawater, bittern or It is preferable to react with decarbonated water solution of brine to remove excess alkaline compounds such as lime. A precipitate can be obtained.

According to the method of the present invention, the produced mainly submerged red sea bream
The precipitate containing sium is separated using, for example, a Schizner Kona, washed with water if necessary, and after being pressure-molded, it is fired.

Firing, arc, ]m normal 1900-2100℃ (7) 711
It will be held from about 15 minutes to 1 o'clock. Pressure production is preferably about 1.5 to 1.5 tons/day under pressure of 2 to 3 tons/d.
The molded body was scraped to give a molded body with a causticity of 7 μ/d. According to the present invention, before calcination, the magnesium hydroxide precipitate is subjected to S 0 on the basis of the mag shear clinker.

? It is preferable to extricate the A calculation value at 0.5 jjLy failure% or less. By drying, a magnesia clinker with a more cylindrical retention is obtained.

In order to make it easier to understand the method of the present invention, we will explain a practical example 1 leading to the formation of magnesium hydroxide precipitation in the present invention.
The f and Q aspects are as follows.

For example, add an aqueous solution of erosive acid to one volume of carbonated seawater, then add lime to prepare a reaction solution with p#11.2 to 11.8.・Neck ratio CaO
/ Kg Q 2~4, B2O3/Mq00.05~0
．． 1 and Fe203/MgO0,3-0,8 to form a precipitate mainly consisting of magnesium hydroxide, and before separating this precipitate from the reaction solution, the reaction system is injected with, for example, a decarbonated water waste solution of seawater. Ete p jf 9.8~10
．． 8 and the weight ratio as a functionalized product Ca O / Mg 0
1.8-3.0, B, 03/MgO0, 05-0.1, F'e203/ivigo 0.3-0.8 produces a precipitate mainly from magnesium hydroxide, and If necessary, the weight ratio Ca as an oxide is
O/Mg O1,4-1,8, B20. / klg
O0,08~0.12P and Fe 20. / Mg 0
A total precipitate consisting of 0.3-0.8% magnesium III-hydride is formed.

Thus, according to the A-determining method, it is preferable to
Expressed as a percentage, as an eye Hhi1 course, ノS4gQ
97.0% or more, Ca O1,2-1. s%, 5LO20.25-0.6%, F'e20. 0.3-0.8%, Al 20
30-1 s% or less, B20. 0.1%
Hereinafter, a magnesia clinker having the composition and having a narrowed pore is provided. Further, according to the method of the present invention, it is possible to provide a magnesia crinkle at a high density level having a bulk density of 3.48 g/2 or more, for example, and σ
Moreover, it is possible to provide a coarse crystal magnesia clinker in which the bericraze crystal grains are approximately 100 μm or more in size and the number of micropores inside the crystals is reduced.

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, all physical property values in this specification were measured by the following method.

Chemical Composition 0 Gakushin Method 1 Chemical Analysis Method of Magnesia Clinker determined by the Test Methods Subcommittee of Japan Society for the Promotion of Science Kinsha 124 (1981 Edition 1111 Person Notebook Reference IVC
Measured according to the same method.

First, the analysis of B2O3 was carried out using the curcumin method (absorption light method), which was adopted by the same committee as the 1-pod Kyoto University method.

Basin Mitsuha (Degree of Umbrella) H Honjijutsu) Tatsukokai 124th Membership Examination, Ash Law Subcommittee, Tk Definition Temperature Image Method 2 Missed Porosity of Magnesia Clinker, Apparent is the method for measuring specific gravity and bulk specific gravity” (z
According to lsl "Raw version 11" 1 fire, 11 dragons), it was iced from the 8 year old calculation formula below.

W, -W2 W,: dry weight of clinker (,V) W, car front (jA) of sample saturated with white kerosene in white kerosene (jA W2: dry weight (&) S: C measurement of sample saturated with white kerosene White kerosene ladyship (17cm) in 1Fra iL
) Average particle size of periclase crystals Considering the particle size distribution of the clinker, particles having a particle size of about 5 to 10 am are randomly taken out. This is ground and polished, and the polished surface is examined with a reflective inkstone. Photographs of three representative areas are taken at 50x magnification, enlarged to 3x, and printed on photographic paper. The particle diameters of all the periclase particles in the three photographs are measured, and the average value is taken as the average particle diameter of the periclase crystals.

In addition, in order to show the distribution of crystal grain size, the ratio of particles of 100 μm or more and the ratio of particles of 125 μm or more were determined as the ratio of crystals.

Examples 1 to 3 Milk of lime is cooled in seawater, and dissolved carbonate ions (C
o, calculated value of 80 ppm) was reduced to 10 ppm, calculated value of co, H. This decarboxylated mixed water 11.8 j? The water-soluble FtrSO solution is added to the final product, approximately 0.3% by weight as Fe, O8 content in the clinker, 0.
．． Lime milk (CαO yield rate 1 2 M7 1 0 0 me
) e2 5 8m side opening p H11M 11.3
Magnesium hydroxide was produced under conditions of ~11.5.

Next, the upper sodage was separated, and the decarboxylated seawater was added to the shrunk magnesium hydroxide slurry by 660 kg.
Re-reaction was carried out under the conditions of HHIO20-10.4. I repeated this operation a total of 20 times. Like this vc%,,
The finally produced magnesium hydroxide was purified with tap water treated with decarburized wire, and the crucible containing lagego was rated at 97.5% on a scorching heat basis.
It was possible to obtain magnesium hydroxide containing more than 1.5% of iron compounds. Table 1 shows the chemical composition of this magnesium hydroxide (numbers are % by weight).

Water glass was added to each of the magnesium hydroxides shown in Table 1 in an amount of about 0.4% by weight based on scorching heat, and then dried until the water content was 8% by weight. The dried product was pressure molded at a pressure of 3 t/cd, and fired at 2000°C in an acid purple propane gas furnace.

The chemical composition, bulk density, and average grain size and distribution of periclase crystals of the borrowed sintered bodies are shown in Table 2.

Note that FIG. 1 of the attached drawings shows the sintered body of Example 3.
A mirror photo was shown.

Example 4 The water-1 modified magnesium containing the iron compound obtained in Example 3 was dried and tasted in a trench with a moisture content of 18% by weight, without adding water glass. 3t/cr of the dried food
Pressure molded at a pressure of 200 liters and fired at 2000°C in a gas furnace. The chemical composition, bulk density, and average particle size and distribution of periclase crystals of the obtained sintered body are shown in the third column. In addition, a microscopic photograph of the sintered body is shown in Figure ¥2 of the drawing with the bucket.

Comparative Example 1 Seawater 11, 8 decarboxylated in the same manner as Examples 1 to 3
258 ml of milk of lime (CaO yield 2.@/100 mJ) was added to No. 7, and magnesium hydroxide was produced under the conditions of pHHI 3↓3-115. Next, the supernatant layer was separated, and 660 kg of decarboxylated seawater was added to the concentrated magnesium hydroxide slurry to give a pli value of 100 to 10.4.
The reaction was carried out again under the following conditions. This operation was repeated 20 times in total. The magnesium hydroxide finally produced in this way was depurified with decarboxylated tap water, and M
Magnesium hydroxide with a gO content of 97 and 5% or more could be obtained.

After adding water glass to this magnesium hydroxide to a concentration of about 0.4% by weight on a scorching basis, it is dried until the moisture content is 8%. /c
Pressure molded at a pressure of d and heated in an oxygen/pronokun furnace to
It was fired at 0°C. Table 4 shows the chemical composition, bulk density, and average particle size and distribution of periclase crystals of the obtained sintered body.

FIG. 3 of the accompanying drawings shows a photograph of a sintered body in comparison example 2. Water glass and iron sulfate were added to the magnesium hydroxide obtained in comparative example 1 by 0.4% by weight and 0.4% by weight, respectively. After adjusting the addition so that the amount was 45% by weight, it was dried with reeds to have a moisture content of 8% by weight. The dried product was press-molded at a pressure of 3 t/c-i and fired at 2000° C. in an acid-prone furnace. Table 5 shows the chemical composition, bulk density, and average grain size and distribution of periclase crystals of the sintered body. FIG. 4 of the attached drawings shows a microscopic photograph of the sintered body.

[Brief explanation of the drawing]

FIGS. 1 and 2 of the accompanying drawings are microscopic photographs of magnesia clinker produced by the method of the present invention. Figures 3 and 4 are photographs of magnesia clinker manufactured by a method to be compared with the method of the present invention.To Patent Patent Patent Patent Patent: Ube Chemical Industry Co., Ltd. Mine 1 Figure 2

Claims (1)

[Claims] 1. Decarburization of seawater, bittern or brine 1. After adding a water-soluble iron compound to an aqueous solution, 45% of dolomite or lime or a hydrate thereof is added to produce mainly magnesium hydroxide. 1. A method for producing magnesia clinker with increased density, characterized in that a precipitate consisting of is formed, and then the precipitate obtained is calcined. 2 A water-soluble iron compound is converted into Fe with a magnesia clinker group.
, 03iA calculation (If: 1.) How many companies add decarbonated water to the liquid at an electric rate of 0.2 to 1.0%?Claim 1
The method described in section. 3. Water-soluble iron compounds are F based on magnesia clinker standards.
The method according to claim 1, wherein the e2O3 peak value is added to the reconstituted acid water bath in an amount of 0.3 to 0.7% by weight. 4. Claims in which the water-soluble iodide is an iron ore salt>
M'y The method according to any one of items 1 to M and 4. 5. Forming magnesia clinker with the obtained precipitate 1
Before carrying out the second formation, a silicon-containing compound 1. I
2! Sin, exchange 'J,
As a ¥ value, add 0.5% or less → + of permission request
++ The method described in any of the encirclement clauses 1 to 44. 6. Range 1 to 16 of the invention, which generates a precipitate mainly consisting of magnesium hydroxide in the reaction solution adjusted to pH 11 to 12 by adding dolomite, limestone, or their hydrates. The method according to any of paragraph 5. 7. Before separating the precipitate mainly consisting of magnesium hydroxide from the above reaction solution having a pH of 11 to 12, p.
Reaction of the above reaction solution of fti ~ 12 with l condensate, bittern or brine and carbonated water overflow.
The method described in section.