JPH07102983B2 - How to neutralize slag - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for neutralizing alkaline slag, and more specifically, a method for neutralizing alkaline slag which can effectively neutralize alkaline slag without using synthetic organic acid or inorganic acid. I will provide a.

[0002]

2. Description of the Related Art Conventionally, in various steelworks and smelters,
A large amount of slag (slag) is generated during metal production and refining, and depending on the type, these slags are used as raw materials for manufacturing other useful articles such as ceramics and cement, or as a base material for construction sites, marshes and coasts. It is used for land reclamation of lowlands.

[0003]

[Problems to be solved by the invention] Among these slags, for example, many of them have high alkalinity based on oxides such as calcium oxide, and are stored in a place where iron or smelter is generated. during transport, when exposed to rain water during actual use such issues a large amount of strong Arukaru water 滲, environmental pollution, various problems occur such as phytotoxicity. Of course, for the above-mentioned alkaline neutralization, it is possible to neutralize easily and simply by using other chemicals (acids), but since the slag itself is extremely inexpensive, other neutralization is possible. It is economically difficult to use the agent, and conversely, problems such as environmental pollution due to the neutralizing agent and deterioration of slag quality occur. Therefore, it is an object of the present invention to provide a method capable of economically neutralizing alkaline slag without using a neutralizing agent for artificial substances and without causing environmental pollution or other chemical damage.

[0004]

The above object can be achieved by the present invention described below. That is, the present invention relates to alkaline slag and Rhodococcus erythropoles or Pseudomonas
Eggplant, Acinetobacter, Agrobacterium,
Enterobacter, Aureobacteria and Oe
At least one genus selected from the group consisting of the genus Ruscovia
A method for neutralizing slag, which comprises mixing a bacterium belonging thereto and / or a culture thereof and optionally a nutrient source .

[0005]

[Function] When alkaline-resistant microorganisms (the nutrients as needed) or cultures thereof (if necessary, the nutrients) are mixed in the alkaline slag, the organic substances are decomposed by the microorganisms and carbon dioxide gas is generated. It is generated and this carbon dioxide gas neutralizes the alkaline component in the slag. At this time, when a microorganism that produces a flocculant is used as the microorganism, a flocculant is also generated together with carbon dioxide, and the flocculation agent prevents the outflow of the microorganism and maintains an environment in which the microorganism proliferates well. It is also possible to prevent the colloidal fine particles from flowing out together.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the preferred embodiments. Although any slag may be used as the target of the neutralization method of the present invention, typical examples thereof include blast furnace slag, converter slag, electric furnace slag, desulfurization slag, and the like.

The microorganism used in the present invention may be any microorganism that is durable to strong alkalinity such as activated sludge that is widely used for treating microbial wastewater, and among them, it is a flocculant-producing bacterium. A certain Road Coccus
Erythropoleth is the preferred microorganism. Coagulant-producing bacteria other than Rhodococcus erythropoles include Pseudomonas spp., Acinetobacter spp., Agrobacterium spp.
Bacteria having a flocculant-producing ability belonging to at least one genus selected from the group consisting of Enterobacter, Aureobacteria, and Oerscovia. Further, the flocculant-producing bacteria belonging to these genera are the conventionally known Rhodococcus erythropoles KR-256-2 and FERM-P.
No. 3923 and Rhodococcus erythropoleth K
R-S-1, FERM-P No. As a microorganism that is a genus different from 3530, etc. and produces a novel bio-flocculant different from the bio-flocculant produced by Rhodococcus erythropoles, and producing an excellent flocculant, Pseudomonas sp., Acinetobacter sp., Agrobacterium sp. Umm,
Examples of the microorganisms include at least one genus selected from the group consisting of Enterobacter, Aureobacteria, and Oerscovia. These are referred to as R-3 in the present invention. 11333 (F
ERM P-11333), No. 11334 (FER)
MP-11334), No. 11335 (FERM
P-11335), No. 11336 (FERM P-
11336), No. 11337 (FERM P-11
337) and No. 11357 (FERM P-1135).
7) and No. 11358 (FERMP-11358).
Has been deposited as.

The mycological properties of the above flocculant-producing microorganisms are described in detail in Japanese Patent Application No. 3-87428, which has already been filed. In addition, regarding these mycological properties, Bergey's Manual of Systematic Bacte
riology Volume 1, 2), (1984), KY
The M-1 strain was identical to Pseudomonas fluorescens described on page 165 of the same book, and the KYM-1 strain was identified as Pseudomonas fluorescens, and was deposited by the Institute of Microtechnology Deposit No. 11
Deposited as No. 333 (FERM P-11333). The KYM-2 strain is appropriate when considered to be Pseudomonas cepacia described on page 175 of the same document, and is deposited by the Institute of Microscopy, No. 1
Deposited as 1334 (FERM P-11334). The KYM-3 strain coincides with the bacterium of the genus Acinetobacter described on page 303 of the same document, and has been deposited as Micromachine Research Deposit No. 11335 (FERM P-11335).
Although the description of KYM-4 strain is almost the same as Agrobacterium reideobacter described on page 254 of the same book, it is taxonomically considered to be a related species because it is slightly different in details such as sugar assimilation. It is valid, and this bacterium is the 11th deposit
Deposited as 336 (FERM P-11336). The KYM-5 strain is completely in genus level with the bacteria of the genus Enterobacter described on page 465 of the same document, and has been deposited as Microindustrial Research Deposit No. 11337 (FERM P-11337). The KYM-6 strain is a bacterium of the genus Aureobacterium described on page 1323 of the same book, and the KYM-7 strain is 1489 of the same book.
The description at the genus level is the same as that of the genus Oerscovia described on the page. The KYM-6 strain has been deposited as the Japan Institute of Mechanical Engineering deposit No. 11357 (FERM P-11357), and the KYM-7 strain has been deposited as the Japan Institute of Mechanical Engineering deposit No. 11358 (FERM P-11358).

[0009] is a known bacteria following Russia Dokokkasu-Erisuroporesu KR-S-1 (FERM- P No.353
0) One example of a method for culturing (S-1 bacterium) and R-3 bacterium (the physical properties of the aggregating agent produced by culturing R-3 bacterium are described in Japanese Patent Application No. 3-87428). Culture method (1) S-1 bacterium 3 liters of the following production medium was placed in a 5 liter jar fermenter equipped with a temperature, DO and pH meter, and sterilized by autoclave. The culture solution was inoculated with 2% (V / V) of the culture solution, the temperature was 28 to 30 ° C., and the air amount was 1.5 liter / mi.
n. The cells were cultured for 1 week under the conditions of stirring intensity of 200 rpm. Composition of liquid medium Carbon source (monosaccharide) 10 g / liter K ₂ HPO ₄ 5 g / liter KH ₂ PO ₄ 2 g / liter MgSO ₄ 0.2 g / liter (NH ₄ ) ₂ SO ₄ 0.5 g / liter NaCl 0.1 g / Liter yeast extract 0.5 g / liter (2) R-3 bacterium 3 liters of the following production medium was placed in a 5 liter jar fermenter equipped with a temperature, DO and pH meter and autoclaved. The culture solution was inoculated with 2% (V / V) of this, the temperature was 25 to 27 ° C., and the air amount was 3 liters / mi.
n. The cells were cultured for 1 week under the conditions of stirring intensity of 200 rpm.
However, since the viscosity of the culture solution increased from the second day of culture, the stirring intensity was increased to 400 rpm. Liquid medium composition Carbon source (polysaccharide) 10 g / liter K ₂ HPO ₄ 5 g / liter KH ₂ PO ₄ 2 g / liter MgSO ₄ 0.2 g / liter (NH ₄ ) ₂ SO ₄ 0.5 g / liter NaCl 0.1 g / Liter Yeast extract 0.5g / liter

The neutralization method of the present invention is characterized by mixing the above-mentioned slag with the above-mentioned microorganism or a culture thereof. As a method for mixing the two, a temperature at which the slag powder does not affect the survival of microorganisms (usually 50 ° C or lower)
If the mix after drops, may be Ikana Ru method, also methods such as impregnated from the surface of these slags by spraying the liquid or the culture containing microorganisms from the surface of the slag deposit This is the preferred method. The microorganism to be used may be any of the microorganism itself (however, the nutrient source of the microorganism is also used in combination), its culture, culture-treated product, culture solution itself, its concentrate, filtrate, its filtration residue, their dried product, etc. It may be in the form. The amount of microorganisms used cannot be unconditionally specified because it varies depending on the type of the alkaline slag that is the object to be treated, but for example, in the case of iron-making slag, a range of about 50 to 100 g in a dry state per ton is a preferable range. is there.

[0011]

EXAMPLES Next, the present invention will be described more specifically by way of examples. Example 1 (Example of using S-1 bacterium) About 3 liters of the culture solution of the S-1 bacterium was sprayed onto a blast furnace slag to allow it to soak, and the wet slag was divided into 3 parts to supply a nutrient source (monosaccharide). Was added at a concentration of 30% by weight, 15% by weight and 7.5% by weight, and the three kinds of liquids were uniformly sprayed on separate slags to be impregnated with the liquids. Three hours after that, about 15 liters of each slag was filled in a 20 liter open container having a mesh-like bottom and solidified, and left for one week.
Then, 2 liters of tap water was sprinkled on the surface of each slag for about 30 seconds, and 1 minute after sprinkling water, water leaked from the bottom of the container was collected and the pH thereof was measured. This operation was performed 5 times in total for 100 days. The result is shown in FIG. In Comparative Example (BK), the same operation as described above was performed except that the microorganism culture solution was not used. Example 2 (Example of using R-3 bacterium) About 3 liters of the culture solution of the R-3 bacterium was sprayed on a blast furnace slag to allow it to soak, and the wet slag was divided into 3 parts to supply a nutrient source (polysaccharide). Was added at a concentration of 30% by weight, 15% by weight and 7.5% by weight, and the three kinds of liquids were uniformly sprayed on separate slags to be impregnated with the liquids. Three hours after that, about 15 liters of each slag was filled in a 20 liter open container having a mesh-like bottom and solidified, and left for one week.
Then, 2 liters of tap water was sprinkled on the surface of each slag for about 30 seconds, and 1 minute after sprinkling water, water leaked from the bottom of the container was collected and the pH thereof was measured. This operation was performed 5 times in total for 100 days. The result is shown in FIG. In Comparative Example (BK), the same operation as described above was performed except that the microorganism culture solution was not used. Example 3 (Example of using activated sludge bacteria) About 2 liters of the activated sludge culture solution was sprayed on a blast furnace slag to allow it to soak, the wet slag was divided into two, and nutrient sources (monosaccharides and polysaccharides) were divided into 15 parts. The two kinds of liquids added at the concentrations of 7% by weight and 7.5% by weight were evenly spread on separate slags and impregnated with them. Three hours later, each slag was placed in an open container of 20 liters with a mesh-like bottom and about 1
After filling 5 liters and hardening, it was left for 1 week. Thereafter, 2 liters of tap water was sprinkled on the surface of each slag for about 30 seconds, and 1 minute after sprinkling water, water leaked from the bottom of the container was collected and the pH thereof was measured. This operation totals 5 in 100 days
I went there. The result is shown in FIG. Comparative example (BK)
Is the same as the above except that the microbial culture is not used.

[0012]

[Effect] According to the present invention as described above, when an alkali-resistant microorganism (the nutrient as necessary) or a culture thereof (the nutrient as necessary) is mixed in the alkaline slag, the microorganism is mixed. As a result, organic matter is decomposed to generate carbon dioxide gas, and the carbon dioxide gas neutralizes the alkaline component in the slag. At this time, when a microorganism that produces a flocculant is used as the microorganism, a flocculant is also generated together with carbon dioxide, and the flocculation agent prevents the outflow of the microorganism and maintains an environment in which the microorganism proliferates well. It is also possible to prevent the colloidal fine particles from flowing out together.

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the pH of slag permeated water and the number of days elapsed.

FIG. 2 is a diagram showing the relationship between the pH of slag-permeated water and the number of days elapsed.

FIG. 3 is a diagram showing the relationship between the pH of slag-permeated water and the number of days elapsed.

[Explanation of symbols]

 None

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideaki Matsuyama 1-5-7 Kajimachi, Chiyoda-ku, Tokyo Inside Environmental Engineering Co., Ltd. (72) Ichiro Yamamoto 1-5-7 Kajimachi, Chiyoda-ku, Tokyo Hitoshi Amano, Examiner, Environmental Engineering Co., Ltd.

Claims (3)

[Claims] 1. Alkaline slag and Rhodococcus et al.
Lithropoles or Pseudomonas sp., Acinetobacter
-Genus, Agrobacterium, Enterobacter, Oh
-Group consisting of Rheobacterium and Oerscovia
A method for neutralizing slag, which comprises mixing a bacterium belonging to at least one genus selected from the above and / or a culture thereof and optionally a nutrient source . 2. The microbial strain is KR-S-1 strain (FERM
P-3530), KYM1 strain (FERM P-113
33), KYM2 strain (FERM P-11334), K
YM3 strain (FERM P-11335), KYM4 strain (FERM P-11336), KYM5 strain (FERM
P-11337), KYM6 strain (FERM P-11
357) and KYM7 strain (FERM P-11358).
The method for neutralizing slag according to claim 1, which is a bacterium belonging to at least one strain selected from the group consisting of: 3. The method for treating slag according to claim 1, wherein the slag is a slag generated from a steel mill or a smelter.