JPS58210846A - Method for producing moisture absorbent and adsorbent from slag or slag and coal ash, shale or calcium silicate - Google Patents

Abstract

PURPOSE:To produce a moisture absorbent and adsorbent from industrial waste, by gelling a raw material consisting essentially of slag with addition of inorg. acids and further adding a basic raw material to make the gel alkaline in pH and subjecting the resulted sediment to filtering, washing and drying. CONSTITUTION:Industrial waste such as blast furnace slag or electric furnace slag alone or under addition of coal ash, shale, calcium silicate, etc. is pulverized. Inorg. acid such as hydrochloric acid, sulfuric acid, nitric acid or the like is added to the same to form a gel. A basic raw material such as an aq. alkaline soln. obtd. by eluting the slag produced when molten iron or the like is desulfurized with soda ash or an aq. NaOH soln. is added to the gel under stirring to regulate the pH to 8.5-10.0. The sediment deposited in this stage is filtered and washed and is then dried, whereby a moisture absorbent and adsorbent is produced.

Description

[Detailed description of the invention] This invention relates to the production of moisture absorption and adsorption agents by effectively utilizing shale and calcium silicate plates.
slowly cooled slag), converter slag, WL air furnace slag (oxidation stage,
During the reduction stage), slag alone such as agglomerated slag or slag added with coal ash, shale, or calcium silicate is dissolved (gelled) in an inorganic acid aqueous solution, and an alkaline aqueous solution (mainly Na ions) eluted from the soda ash desulfurization slag is created. Stow, pigeon OH
, containing S ions) or a basic substance such as sodium hydroxide solution, and adjust the pH to approximately 8.5 to 10.0.
The precipitate is filtered, washed with water, and dried to absorb moisture and synthesize an adsorbent.

A huge amount of slag is generated from steelworks, and blast furnace slag is roughly divided into water slag (quenched slag) and slowly cooled slag (field slag).The former is mainly glass and has latent hydraulic properties, so it cannot be mixed with blast furnace cement. The latter is mainly composed of melilite and has almost no latent hydraulic properties, so it is used for roadbed materials and aggregates, but there are also many unused materials and artificial sands that are used as landfill materials.

In addition, converter slag generated during the steelmaking process is γ-2Cso・S.
in,, F@CaO (free lime) as the main component, 2caO,F
e, 03.4CaO"A%0.-Fe, O,, F, Mg
Since it contains 0 (free magne, shea), it has expansion and disintegration properties, so it cannot be used effectively for roadbed materials, etc. unless it is modified, and only a small portion is used as silica fertilizer and cement raw material. Parts are being disposed of in landfills.

Similarly, the oxidation stage slag generated from the electric furnace is 2CaO・A
z, o,, sio,, 2Ca O* F 62 o,,
4CaO-A40. - Mainly Fe, O8 and r-2CaO
＠SiO,, F-Coo is small A+7) Most of it is used as roadbed material, but the rest is disposed of in landfills.

The reduction stage slag is 2CaO・S*02 or 3CaO・
2 S * OH mainly causes dusting during the cooling process, and almost all of it disintegrates and is disposed of in a landfill.

Like the reduction stage slag, the agglomerated slag also contains γ-2CaO・Si.
n.

Since it is mainly rich in p'@cao, it often causes dusting and collapses during the cooling process, so it is disposed of in landfills.

Coal ash is fly ash from coal-fired power plants.

It occurs under the name Bottom 7 Tsushiyu, Cinder Ash,
Most fly assemblies are used as cement admixtures, but research is being conducted on the effective use of bottom ash as fertilizer, light aggregate, roadbed material, etc., but most of it is disposed of in landfills. .

Shale is an unused resource that exists widely throughout Japan and contains clay minerals such as kaolinite and montmorillonite.

The calcium silicate plate used as the calcium silicate raw material in the present invention is manufactured by crushing and blending silica stone and lime and treating it in an autoclave.However, it is a rejected product that was damaged during the manufacturing process and the main minerals are zonolite, This is industrial waste consisting of Tobel i-light and other materials.

Note that soda ash desulfurization slag does not require adding soda carbonate to remove the 8% content in the hot metal.

The slag is rich in Nano (Nat
Sometimes unreacted Naff1C
Since it also contains OB, when it comes into contact with water, it produces Nm ions as well as Sin.

A/, 0. , S ions, etc. are eluted and the pH is high, making it difficult to treat the tailings after metal recovery.

At SoC, we researched the effective use of slag, coal ash 1 shale, and calcium silicate plates, and succeeded in producing a moisture absorbent and adsorbent.

Blast furnace slag (water slag), electric furnace slag (reduction stage) 1. t
Sin, ,Cab, At, 0. etc., and gels when treated with an alkaline solution at about 60 to 100°C for 6 to 6 hours, but other cooled blast furnace slag, converter slag, agglomerated slag, oxidation stage slag, coal ash 1 shale, calcium silicate plate It is hard and does not gel even if treated with alkaline solution for a long time)
.

The above-mentioned slag is crushed to a size of about 2 or less (dusting slag and blast furnace water slag are left as is), subjected to magnetic separation treatment, and the tailings are further crushed to a size of about 1 or less and treated with hydrochloric acid, sulfuric acid, nitric acid, etc. When 89 acid-free is added, blast furnace water slag and electric furnace slag (in the reduction stage) react violently while generating Co and gas, instantaneously gel and swell, reaching a temperature of about 100°C and a pH of about 1 to 2.
becomes.

In addition, since the above reaction hardly occurs with other slags, coal ash, shale, and calcium silicate plates, 10% or more of blast furnace water slag or reduction phase slag is used as a reaction accelerator. When an acid is added, it reacts violently and instantaneously gels and swells, reaching approximately 100°C and a pH of approximately 1 to 2.

The eluate from the soda ash desulfurization slag (Nail solution may also be used) is added to these with stirring to adjust the pH to approximately 85-10.
The resulting precipitate is temporarily washed with water and dried to produce blast furnace slag.

White hygroscopic and adsorbent substances are produced from reduction phase slag, agglomeration slag, coal ash, shale, and calcium silicate substances, and dark brown moisture absorption and adsorption agents are produced from converter slag and acid death phase slag.

Tests conducted to confirm the effects of the present method and their results are shown below.

<Test method> Converter slag, oxidation stage slag, blast furnace slow cooling slag.

The agglomerated slag was coarsely crushed to about 2!1 m or less and subjected to magnetic separation treatment, and only the tailings were crushed to about 1 m or less.

Blast furnace water slag and reduction phase slag were subjected to magnetic separation treatment using the grain layer as they were, and only the tailings were pulverized to a size of approximately 1 m or less.

Coal ash, shale, calcium silicate ($1! Rejected calcium silicate plates that were damaged during the manufacturing process) are 1-
It was pulverized and used as a sample.

In addition, the soda ash theory sulfur slag is subjected to a coarse crusher magnetic separation treatment to reduce the sulfur slag to about 2 - or less, and 1 tailings are eluted at a bulb concentration of 509. To the eluted water obtained, new tailings are added to the bulb concentration of 50 S as much as possible and eluted. This was repeated three times and used for neutralization. The chemical analysis values of the slag, coal ash, shale, and calcium silicate used are shown in Table 11, the properties are shown in Table 2, and the leached water of the soda ash theory sulfur slag is shown in Table 3.

The slag sample mentioned above was placed in a 2000CC beaker.
Weigh out f, add 300 cc of pure water, and add 250-300 cc of HCt (309 concentration), E, 8 while stirring.
04 (1: 1) to 200-250cc or HN
When 250 cc of O, (1:1) is added, heat is generated while generating carbon dioxide gas, and the temperature reaches about 100° C., which instantly gels and swells, and the pH becomes about 1 to 2.

Add about 50% of the solution eluted from the soda ash desulfurization slag to this solution.
When approximately 500 cc of sodium hydroxide solution (AN) is added, a white precipitate is formed, which is filtered together with the gel, washed with water, and dried in a constant temperature dryer (105-110°C).
When dried, it becomes a lightweight powder.

In this case, as mentioned above, converter slag, oxidation stage slag, agglomeration slag, shale, coal ash, and calcium silicate plates do not gel instantly even if they are treated with acid alone, but blast furnace water is a reaction accelerator. When 10 or more slags or reducing stage slags are mixed and treated with acid, they instantly gel.

In addition, the basic substance used may be, for example, NaOH solution, but as mentioned above, the eluted water of soda ash desulfurization slag is N
The weight of l ions is Sin, , Al40. Ions are also eluted and it also contains a kind of water glass, so Na1L
The invention recited in claim 2 is more effective because a larger amount of product is produced than when a solution is used, and industrial waste can be used more effectively.

In addition, elution water from soda ash desulfurization slag, NaOH solution,
When the concentration of HC/-%H, 804, HNO3 solution is high, a small amount is required, and when the concentration is low, a large amount needs to be used.

Table 4 shows the raw materials used, mineral acids and alkali solutions used, and the product l, and Table 5 shows the properties of the product.

The product produced by this treatment method is different from synthetic zeolite in that it is amorphous and no crystalline mineral peaks appear in X-ray diffraction.

In addition, the specific surface area is very large, the same as or slightly larger than that of synthetic zeolite type 4A, and the moisture absorption capacity (llmN of the hygroscopic material relative to the weight of the material) is also equal to or slightly larger than that of synthetic zeolite type 4A. Some of the results are shown in Table 6.

Further, Table 7 shows chemical analyzes of several examples of products obtained by treating slag and the like with mineral acids and then treating them with alkaline solutions.

Table 5 As stated above, moisture absorbents and tiering agents can be easily manufactured using raw materials such as slag, coal ash, shale, and calcium silicate, which are currently still unused resources or industrial waste. The product can be widely used as a substitute for 1 synthetic zeolite, for example as an adsorbent or moisture absorbent for soap raw materials, etc.

Patent applicant: Japan Magnetic Separation Co., Ltd. 231 Yoshi Kyo Haru who has a background

Claims (1)

[Claims] 1. Adding a basic substance to a gel-like substance obtained by gelling slag or a mixture of slag with coal ash, shale, and calcium silicate with an aqueous inorganic acid solution in an amount that makes the gel-like substance alkaline. A method for producing a moisture absorbent and adsorbent from slag or a mixture of coal ash, shale, and calcium silicate, characterized by adding the precipitate at this time, filtering and washing with water, and then drying. 2. Moisture absorption from slag or a mixture of slag and coal ash, shale, and calcium silicate, characterized in that the basic substance is an alkaline solution eluted from soda ash desulfurization slag in the method described in claim 1. , a method of producing an adsorbent.