JPH11104422A - Metallic silicon sintered filter medium and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To purify effectively domestic wastewater and seawater by enabling to remove contained harmful pollutant by catching by adsorbing powerfully in a metallic silicon pore when contaminated liquid passes in contact by a method wherein a formed product provided by sintering the metallic silicon in an interconnected pore state, is used as an adsorption catching means for the harmful pollutant. SOLUTION: A formed product provided wherein metallic silicon contained in a waste semiconductor chip and a silicon wafer broken material obtained as a byproduct from a semiconductor chip manufacturing plant is sintered in an interconnected pore state, is used as a filter medium. Thereby a contained pollutant is removed by catching by adsorbing powerfully when contaminated liquid passes in contact. Further, the filter medium is manufactured by a method wherein a carbon powder is mixed into a metallic silicon powder, kneaded in a clay state, the clay state material is formed in a required shape, which is fired in a firing furnace while the carbon powder is sublimated by combusion, and cooled slowly. An adosrption catching function against impurities and a harmful pollutant are developed over a long period of time thereby, and a high performance metallic silicon sintered filter medium capable of purifying the contaminated liquid at a low cost, is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoch-making filter material for purifying a contaminated liquid, and more particularly, to a method of continuously adsorbing metallic silicon to increase adsorption and trapping performance and contaminate river water, lake water or the like. The present invention relates to a high-performance metallic silicon sintered filter which can be used for purification of domestic wastewater and even for purification of seawater, and an economical production method thereof.

[0002]

2. Description of the Related Art As is well known, conventionally, when purifying a liquid (especially water) mixed with impurities and harmful substances, a porous medium such as activated carbon, zeolite and activated alumina, an ion exchange resin, and an ion exchange membrane are used. Such a porous polymer compound is used as a filter medium and the liquid is brought into contact therewith, and impurities and harmful substances are trapped in the voids of the filter medium to purify the liquid.

[0003] However, all of the above-mentioned conventional filter media have a bias in the performance of capturing and adsorbing impurities and harmful substances.
Simply using zeolite, activated alumina, or an ion-exchange polymer compound alone cannot capture all impurities and harmful substances in all rounds, so multiple types must be used in combination, resulting in cost reduction. In addition to being expensive, the volume is increased and the size of the filtration device is increased. In addition, ion-exchange polymer compounds have good trapping performance of impurities and harmful substances, but they are not efficient because both cation exchange resin and anion exchange resin must be used sequentially. Moreover, it is not suitable for treating a large amount of contaminated water such as when purifying river water or lake water.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the conventional filter media. Even if a plurality of types of filter media are not combined, harmful substances, microorganisms, It is a technical object to provide a high-performance filter medium capable of efficiently purifying a liquid (for example, polluted river water or lake water) mixed with an organic substance, and a method for producing the same.

Another technical problem of the present invention is to improve the adsorption performance by skillfully and continuously foaming metallic silicon contained in discarded semiconductor chips and broken silicon wafers obtained as a by-product from a semiconductor chip manufacturing plant. It is an object of the present invention to provide an epoch-making filter medium capable of efficiently purifying a large amount of contaminated water such as polluted river water, lake water, and seawater, and an industrial production method thereof.

Further, another technical object of the present invention is to provide a high-performance and inexpensive metallic material capable of inexpensively purifying a contaminated liquid by exerting a function of adsorbing and trapping impurities and harmful substances over a long period of time. An object of the present invention is to provide a silicon sintered filter medium and a method capable of economically mass-producing the sintered filter medium.

[0007]

In order to solve the above-mentioned technical problems, the present invention employs means for adsorbing and trapping harmful pollutants on a compact formed by sintering metallic silicon into a continuous pore state. This is characterized in that the contaminant contained in the metallic silicon pores can be strongly adsorbed and captured and removed when the contaminated liquid passes through the contact.

[0008] The present invention also provides a means for solving the above technical problem in a method, in which a kneading step of mixing carbon powder into metal silicon powder and kneading the mixture into a clay-like form is provided. A forming step of forming the obtained clay-like material into a required shape, and a firing step of firing and sublimating the charcoal powder in a firing furnace, firing the formed clay-like material in a firing furnace, and gradually cooling. Accordingly, an epoch-making method capable of efficiently and economically mass-producing the metallic silicon sintered filtration material is realized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The specific contents of the present invention will be described below with reference to embodiments.

The qualitative analysis of the embodiment product obtained by specifically applying the present invention at the Fukui Industrial Technology Center resulted in the following results. In addition, in the same technical center, in accordance with JIS Z 8830, the measurement was performed using a proportional surface area / pore distribution device (Nippon Bell Co., Ltd .: BELSORP 28SA) with a fluorescent X-ray analyzer (Rigaku Corporation: 3070E). . Measurement conditions are as follows: temperature 300 ° C, pressure 10 ^-1 m
While applying 5 hours under reduced pressure of mHg or less, the measurement method of the adsorbate and the adsorption amount is performed by "nitrogen, constant volume method", and
The amount of sample collected was 0.3476 g.

[0011] 1. Qualitative analysis results (1) Si 82.00 wt% (9) Mn 0.078wt% (2) Na 5.4 wt% (10) Mg 0.070wt% (3) Al 4.0 wt% (11) P 0.046wt% (4) Ti 2.5 wt% (12) S 0.026wt% (5) Ag 2.3 wt% (13) Cl 0.022wt% (6) Zn 1.8 wt% (14) Ca 0.021wt% (7) Fe 1.5 wt% (15) Sr trace ( 8) K 0.098wt% (16) Zr trace 2. Specific surface area 0.000 m ² / g

Lake Biwa lake water (June 16, 1997: collected at Lake Biwa) was used as a test object, and a comparative test of the COD reduction degree of these filter media using the product of the present embodiment and coconut shell activated carbon (granular) was conducted. Commissioned to the Fukui Prefectural Institute of Public Health. The COD of the lake water itself is 6.5 mg / l.
Met. a. This embodiment product (79 g solid) 3.0 mg / l b. Coconut shell activated carbon (about 39 g) 4.2 mg / l (In this comparative test, in accordance with the factory drainage test method <JIS K0102>
After the immersion of the samples (a) and (b), the COD was measured after stirring for 6 hours with a stirrer and then left for 3 days and nights.

The COD reduction rate of the product a of the present embodiment is 1.2 mg / l as compared with the coconut shell activated carbon, but it has been commented that this difference is surprising as it greatly breaks the conventional level. Received.

Next, a description will be given of a process of manufacturing the above-mentioned example product. Mix the general size (granularity: 10-150mm) of metallic silicon (JIS G 2312 MSi2) and bamboo charcoal powder with 90 parts by weight of the former and 10 parts by weight of the latter, add water and knead until clay-like. After that, this is 10cm in diameter, 2.5cm in thickness
This was placed in a pottery kiln and fired by burning bamboo charcoal. The firing temperature was increased by 720 ° C. in 2 hours after the burning, and then increased to 720 ° C. in 1 hour.
Over 4 hours, the heating power was gradually reduced to about 200 ° C., and then the air was cooled in a carbon dioxide atmosphere in the ceramic kiln for about 116 hours, and the fired product was taken out. This calcined product is the product of the above embodiment (Si 82.00 wt%, Na 5.4 wt%, Al 4.0
wt%, Ti 2.5 wt%, Ag 2.3 wt%, Zn 1.8 wt%, Fe 1.5 wt
%, K 0.098 wt%, Mn 0.078 wt%, Mg 0.070 wt%, P 0.
046 wt%, S 0.026 wt%, Cl 0.022 wt%, Ca 0.021 wt%,
Others were Sr and Zr).

Although the embodiments specifically illustrated in the present specification and the manufacturing steps thereof are generally as described above, the present invention is by no means limited to the above-described embodiments.
Various changes are possible within the scope of the claims.

In the above-described example of the manufacturing process, bamboo charcoal was used as a heating fuel for the pottery kiln. However, black straw ash made by carbonizing rice straw was stored in the pottery kiln in advance, and bincho charcoal was put on top of it. It may be burned, and if it does, the silicon component contained in the rice straw ash is transferred to the fired product, and a good quality metallic silicon sintered filter medium is obtained.

Also, in the above-described example of the manufacturing process, the cooling rate in the firing furnace (ceramic kiln) was 24 hours. However, even about 18 hours, there was no problem. A satisfactory product can be obtained even for 48 hours.

[0018]

As described above with reference to the embodiments, the metallic silicon sintered filter material of the present invention provides a molded body obtained by sintering metallic silicon in a continuous pore state as a means for adsorbing and trapping harmful pollutants. Adopted, it is possible to purify liquids containing harmful substances, microbes and organic substances very efficiently, and the function of adsorbing and trapping such contaminants is maintained for a long time. So
It is also very useful for cost reduction of environmental purification.

Further, the metallic silicon sintered filter material of the present invention utilizes metallic silicon contained in waste semiconductor chips or broken silicon wafers obtained as a by-product from a semiconductor chip manufacturing plant as a raw material, as if firing ceramics. Since it can be fired efficiently using a cheap coal fuel in a simple firing furnace, the production cost is very economical.

As described above, the present invention can almost completely eliminate the difficulties of the conventional filter media.
Its industrial utility value is very large.

Claims (5)

[Claims] 1. A metallic silicon body formed by sintering metallic silicon in a continuous pore state, wherein a metallic contaminant is strongly adsorbed and trapped to remove contaminants when the contaminant liquid passes through the metallic silicon. Sintered filter media. 2. Si is 82.00 wt%, Na is 5.4 wt%, and Al is 4.0 wt%.
%, 2.5 wt% Ti, 2.3 wt% Ag, 1.8 wt% Zn, 1.5 wt% Fe
The metallic silicon sintered filter material according to claim 1, wherein% and the balance are impurities. 3. Mixing carbon powder into metallic silicon powder and kneading it into a clay-like material, forming the clay-like material into a required shape, and burning and sublimating the coal powder in a firing furnace. (4) A method for producing a sintered metallic silicon filter material, characterized by firing and slow cooling. 4. A kneaded product of metallic silicon powder and charcoal powder is fired in a firing furnace at a temperature of 700 to 800 ° C. for 3 to 4 hours, and thereafter, while heating power is reduced, about 200 ° C. for 18 to 24 hours. The method for producing a metallic silicon sintered filter material according to claim 3, wherein the temperature is lowered until the temperature falls, and then, the fire is dropped and air-cooled in the furnace filled with carbon dioxide gas for 48 hours or more. 5. The method for producing a metallic silicon sintered filter according to claim 3, wherein bamboo charcoal is used as a heating fuel for the firing furnace.