JPS60827A - Manufacture of air purifying agent - Google Patents

Abstract

PURPOSE:To manufacture an air purifying agent having excellent water resistance, strength, and air pollutant removing efficiency by adding water to potassium permanganate, zeolite, slaked lime, and colloidal silica, kneading, molding, and drying. CONSTITUTION:3-30pts.wt. potassium permanganate, 10-70pts.wt. zeolite, and 6-70pts.wt. slaked lime and colloidal silica are blended to obtain 100pts.wt. total solids. Then 10-100pts.wt. water is added to the 100pts.wt. total solids, and the mixture is kneaded, molded, and then dried at 50-150 deg.C. In that case, slaked lime and colloidal silica are blended in 0.5-10mol ratio of CaO/SiO2. The air purifying agent thus obtained exhibits a high absorbing and adsorbing performance of harmful gases such as NOx, SOx, and gaseous NH3, and does not disintegrate even in water. The agent, having water resistance and high particle strength, without generating dust, and easy to handle, can be utilized industrially.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air purifying agent, and more particularly to a method for producing an improved air purifying agent having improved water resistance, strength, and air pollutant removal rate.

The inventors have already filed a patent application! 3-610t11. No. (JP-A-5II-/!r2/, b/) proposes a method for removing air pollutants using a kneaded molded product containing potassium permanganate, bentonite, and zeolite as active ingredients. Although the removal efficiency of air pollutants by this method is good, the kneaded molded product used here disintegrates when placed in water or comes into contact with a large amount of water droplets, and has no water resistance, and also has low particle strength. Dust is generated during transportation, filling, etc., which poses a problem in handling.

In view of the above, the inventors of the present invention have conducted intensive research on a method for producing an improved air purifying agent. As a result, water resistance can be obtained by kneading and molding a mixture of potassium permanganate and zeolite with slaked lime and colloidal silica, and drying the mixture. The present invention was completed based on the finding that the particle strength is increased and the removal rate of air pollutants is also improved, so that the performance as an air purifying agent can be exhibited most effectively and appropriately.

That is, the present invention is a method for producing an air purifying agent, which includes adding potassium permanganate, zeolite, slaked lime, and colloidal silica water, cross-molding, and then drying.

In the present invention, KMnO, which is the main material used as a material for removing air pollutants, has an excellent purifying effect on NoX and Sox gases. In particular, KMnO is a hard-to-adsorb No.
It has the effect of oxidizing the gas to form No2 gas and removing it.

Furthermore, due to this oxidizing action, it also has the effect of deodorizing by reacting with the malodorous gases of organic sulfur compounds such as H2S gas, amines, mercaptans, and alkyl sulfides. On the other hand, zeolite, which is another material, adsorbs and removes NH3 gas which cannot be removed by the above-mentioned materials, and also promotes the interaction between colloidal silica and slaked lime, which will be described later. The zeolite used in the present invention may be either a synthetic product or a natural product, and may be an H-type heptaolide obtained by treating tf, ni, t-lite with an acid or ammonium chloride. Naturally produced mordenite is particularly suitable for the purposes of the present invention.

By the way, N is generally produced by the oxidizing action of KMnO4.

It is well known that zeolites can be removed by converting them into gas, and that zeolites have the effect of adsorbing ammonia, but in the former case, they are generally used as a solution in a highly reactive state to remove highly concentrated gases. , On the other hand, the removal of ammonia by zebulite is well known as the adsorption removal of NH4+ in waste liquid.

However, as in the present invention, using each material as a solid air purifying agent to simultaneously and substantially remove harmful gases in a short period of time involves completely different difficulties.

That is, in many cases, the characteristics of each material against harmful gases cannot be directly exhibited by mixing and molding.

This also varies greatly depending on the selection of a binder for cross-molding the materials of each active ingredient.

For this reason, the present inventors have conducted numerous experiments to find that K
It has been recognized that a combination of MnO4 and zeolite materials can not only effectively exhibit the characteristics of each material without inhibiting them, but also work synergistically.

The colloidal silica used in the present invention is a silica component with an average particle size of 30 mμ or less as a colloidal silica sol.
In, 5 to 50% by weight, usually 10 to 30% by weight, is colloidally dispersed in water. Known commercial products of such colloidal silica aqueous solutions include the Snowtex series manufactured by Nissan Chemical Industries, Ltd. and the Cataloid series manufactured by Catalysts Kasei Co., Ltd. Further, as the slaked lime, both reagent and industrial products can be used, but one with fine particle size is preferred because it has good reactivity with colloidal silica.

For example, industrial slaked lime special issue (JISRi (7/)) etc. are mentioned.

In the present invention, colloidal silica and slaked lime react with each other, depending on their reaction molar ratio, resulting in either amorphous calcium silicate, which does not have a very strong bonding force, or a fibrous, strip-like, or plate-like crystalline calcium silicate, which has a strong bonding force. It forms calcium silicate, which acts to bind potassium permanganate and zeolite, and it also has the ability to absorb or adsorb air pollutants and absorb moisture, so it absorbs moisture from the atmosphere and binds potassium permanganate. It also exhibits a dissolving action.

The air purifying agent of the present invention is prepared by adding 10 to 100 parts by weight of water to the total solid content of the above-mentioned raw materials and thoroughly kneading it to form a mud or slurry. It is molded into granules or crushed shapes and then dried. The amount of water here varies depending on the type and amount of raw materials, mixer, molding machine, etc., but in any case, if it is less than 10 parts by weight, kneading and molding will not be sufficient, and if more than 100 parts by weight of water is used, it will be dried after molding. Therefore, it is usually uneconomical in terms of heat management.

In addition, when producing the air purifying agent of the present invention, in addition to the above-mentioned raw materials, porous inorganic adsorptive materials that do not react with potassium permanganate and have a small bulk specific gravity and a relatively large specific surface area and pore volume, such as silicic acid, are used. It is more preferable to add calcium, magnesium silicate, finely powdered silicic acid, activated alumina, silica alumina, etc. as auxiliaries.

Further, depending on the target gas to be removed, one or more of Mg(OH)22Mg01 talc, white clay, diatomaceous earth, clay, kaolin, right front, etc. can be blended as necessary.

The mixing ratio of each raw material is determined by the type and composition of the air pollutants to be treated, the water resistance and strength of the resulting air purifying agent, and the ability to treat air pollutants, but basically all A suitable range of 100 parts by weight of solid content is 3 to 30 parts by weight of potassium permanganate, 10 to 70 parts by weight of zeolite, and 6 to 0 parts by weight of slaked lime and colloidal silica. Especially for slaked lime and colloidal silica, it is 0 to 35 parts by weight and C! aO/S
i Ot molar ratio 0. ! ; It is preferable to mix it so that it falls within the range of -10.

If the mixing ratio of potassium permanganate is less than 3 parts by weight, the ability to treat air pollutants will not be sufficient, and if it exceeds 30 parts by weight, it will precipitate on the surface of the air purifying agent, causing powdering and reducing the strength. Lower the sleeve direction. Regarding zeolite, if the amount used is less than 10 parts by weight, not only will the removal performance of ammonia in particular deteriorate, but also the water absorption capacity of the air purifying agent will be low. reduces the strength of the air purifying agent itself.

For slaked lime and colloidal silica, the blending ratio, O
If both the aO/SiOt molar ratios are outside the above ranges, the air purifying agent will not have sufficient strength and water resistance, and the binder effect of potassium permanganate and zeolite will not be fully exhibited.

Next, regarding the drying process of the present invention, in this process, slaked lime and colloidal silica are reacted to form amorphous calcium silicate or crystalline calcium silicate, and potassium permanganate and zeolite are used to improve the ability to treat air pollutants. This is an essential step for bonding without damage. It is generally known, particularly in the technical field related to building materials, that slaked lime and colloidal silica react to produce various forms of calcium silicate. In the manufacturing method, the calcium silicate immediately after production is used not only as a binder but also as a treatment agent for air pollutants, and a part of the zeolite is used as a catalyst for the reaction, regardless of the predetermined molar ratio. It is the result of studies by the present inventors that it was discovered that a suitable air purifying agent can be produced by combining zeolite and KMnO. Slaked lime and colloidal silica form various forms of calcium silicate at various molar ratios from low to high temperatures.
It is preferred to carry out the reaction and dry at a temperature range of . If the drying temperature is below 130°C, the strength of the air purifying agent will not only decrease, but also the drying time will be long, making it unsuitable for industrial use.It is best to avoid drying temperatures above 130°C as much as possible from the viewpoint of decomposition of KMnO4. The drying time varies depending on the type of raw materials, blending ratio, other drying conditions, physical properties of the air purifying agent, etc., but within the above drying temperature range, the moisture content of the target air purifying agent is 70%. It is best to dry it until it reaches about 100 lbs. This is because within the above range, the water resistance, strength, and air pollutant removal rate of the air purifying agent are greatly improved.

In this way, the air purifying agent according to the present invention can be produced, but the combination of zeolite, slaked lime, and colloidal silica of the present invention can be combined with other third substances to produce an ozone remover, an acidic gas remover, a freshness-preserving agent, and a dehydrator. It can also be applied to the production of other water-resistant molded products such as moisturizers.

Since the air purifying agent according to the present invention has a large pore volume, it exhibits highly effective absorption and adsorption performance against harmful gases such as NOx, SOx, and NH gas, and
It is industrially useful because it has the characteristics of so-called water resistance that does not disintegrate even in water, and high single grain strength that does not generate dust and is easy to handle.

Further, the air purifying agent of the present invention has the property of oxidizing and decomposing odor components as described above due to the strong oxidizing power of KMnO, and at the same time, a sufficient deodorizing effect can be expected.

When using the air purifying agent according to the present invention, it can be used by filling it into a suitable container.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

First, each powder of KMnO, fine powder crystal, inorganic adsorptive substance (e.g. calcium silicate), naturally produced zeolite, and slaked lime was added.
After taking the specified amount in the table and mixing well, add the specified amount of Sin,
The mixture was thoroughly kneaded with a 20% colloidal silica aqueous solution and water, formed into a cylindrical shape with a diameter of 3 m using an extrusion molding machine, and dried at a predetermined temperature for a predetermined time to produce each air purifying agent.

The water resistance of each of the above air purifying agents was measured when they were left in water overnight, and the strength of each tablet was measured using a tablet breaking strength measuring device (n=10, one upper and lower one was cut, and the average of three pieces). The pore volume was calculated from the volume of cc't impregnated by immersing the sample in carbon tetrachloride (001,) for 21 hours.

\ \1, ゛＼ \ \ Oak/Sin of Examples/~g and Comparative Example/-2.

Figure 1 shows the relationship between molar ratio and single grain strength. The temperatures shown in the figure are drying temperatures. In the figure, data of Examples 1 to Example g and Comparative Example/-J are plotted sequentially from the vertical axis side. Oa
The points above O/El iO2 molar ratio 0 and ioo are comparative examples.

Examples 9 to 13 and Comparative Examples 3 to S In order to examine the relationship between the blending ratio of slaked lime and colloidal silica per total solid content and the physical properties of the air purifying agent, the same procedure as in Example 1 was carried out using the blending ratios shown in Table 2. Each air purifying agent was manufactured and its physical properties were measured and summarized in the same table.

゛・１、 ′・、 \、 ゛＼ 〜・、 \ Shown below. The temperature in the figure is the drying temperature.

, O, and Ma] are comparative examples.

Example/II-/g and Comparative Example 6 In order to examine the relationship between the amount of inorganic adsorptive substances and water and physical properties during the production of air purifying agents, each sample was prepared in the same manner as in Example 1 using the combinations shown in Table 3. An air purifying agent was manufactured and its physical properties were measured and summarized in the same table. The H and S removal performance of each air purifying agent is also summarized in the same table.

＼、 ＼＼ ＼ ＼ゝ、 〜゛・、 〜 Table 3 Note l) Water resistance (-after being left overnight) 0 = does not collapse, × = collapses.

2) Comparative Example 6 is a conventional product manufactured by JP-A-5E-IS Colo 6/3) The conditions for the H,8 removal test are as follows.

Humidity so~AO'ly, room temperature, H, S concentration 20pp
m.

H2E+ was absorbed under the following conditions (sv test example 1 Example/S air purifier: room velocity, NO gas concentration ti, sppm and Bv/: 1
When NO gas was absorbed under the conditions of 000, the NO removal rate was 92% after bo minutes.

Test Example λ Regarding the air purifying agent of Example 10, humidity is SO, temperature is 2.
3℃, SO2 gas concentration u, Oppm, eV /200
When SO gas was absorbed under conditions of 0, the SO removal rate was 99% after 60 minutes.

Test Example 3 Regarding the air purifying agent of Example DA, humidity qo%, temperature 20°C
When NH gas was absorbed under the conditions of NH3 gas concentration of 200 ppm% BV120θO, the klH removal rate was 93% after 60 minutes.

Test Example V Regarding the air purifying agent of Example 9, humidity 50-60 degrees, room temperature, trimethylamine (CH3)3N gas concentration 20 pp
When N was absorbed under the conditions of (OH8) and EVlooooo (CH3), the 3N removal rate was 9g after 60 minutes.
%Met.

Test example! Regarding the air purifying agent of Example 3, humidity bo%, room temperature, triethylamine (C2HI+) 11N gas concentration 10 pp
m, (C2H1+)3 under the condition of SV / 0000
When N was absorbed (0, H,), the N removal rate was 95% after 60 minutes.

Test Example 6 Regarding the air purifying agent of Example 1, humidity sro%, room temperature, methyl mercaptan 0H3SH gas concentration 5θppm,
Under the condition of 8V/0000, the removal rate of all 3SH of CH3SH was 99% after 60 minutes.

[Brief explanation of the drawing]

Figure 1 shows the Oa of the purifying agents of Example/-g and Comparative Examples/--.
Figure 2 showing the relationship between k/Sin, molar ratio and single grain strength
The figures show Examples 9 to 13 and Comparative Examples 3 to 3. Patent applicant: Nippon Chemical Industry Co., Ltd.

Claims (1)

[Claims] 1. A method for producing an air purifying agent, which comprises adding water to potassium permanganate, zeolite, slaked lime, and colloidal silica, kneading and molding the mixture, and then drying the mixture. Total solid content ioo weight part Potassium permanganate 3~
30 parts by weight of zeolite, 10 to 70 parts by weight of slaked lime and colloidal silica, and 6 to 0 parts by weight of slaked lime and colloidal silica. 3 10 to io per 100 parts by weight of total solids. The method for producing an air purifying agent according to claim 1 or 2, wherein parts by weight of water are added. DA Claim 1, in which slaked lime and colloidal silica are mixed in an Oak/Sin molar ratio in the range of O, S to IO.
A method for producing an air purifying agent according to any one of Items 3 to 3. ! The method for producing an air purifying agent according to any one of claims 1 to v, wherein the air purifying agent is dried in a temperature range of rSO°C to /30°C.