JPH08208209A - Production of carbide - Google Patents

Abstract

PURPOSE: To obtain a carbide improved in yield by coating the surface of a starting material consisting of combustibles or a material containing the same with a film composed of inorganic binder and water-soluble saccharine followed by baking. CONSTITUTION: A material to be carbonized as a starting material consisting of combustible such as coffee grounds, rice hulls and/or sawdust or powder or granules of a material containing such combustibles is coated with an inorganic binder by kneading the starting material with a mixture of about 10-15vol.% of an inorganic binder such as bentonite or refractory clay, a specified amount of water-soluble saccharine such as sucrose or glucose, and water- absorbing inorganic aggregates such as blast furnace slag or perlite of <=65 (esp. <=150) mesh particle size, and, if needed, an appropriate amount of water. Subsequently, the kneaded product is baked at about 600-700 deg.C for 1-10min or so in e.g. a rotary kiln, thus obtaining the objective carbide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a carbide, and more particularly, to a method for producing a carbide by carbonizing a combustible waste such as coffee meal and rice husk.

[0002]

2. Description of the Related Art How to treat industrial waste is now a social problem. A large amount of sludge, residue, dregs, and organic waste such as kitchen waste discharged from food factories are used for compost, but most of them are burned. The organic waste inevitably contains water, and it is necessary to dry the water, which is a double cost. In addition, cardboard, newspaper, shredder waste paper, pulp mill waste pulp, mushroom cultivation waste sawdust, waste plastic, waste oil, waste coal, etc. , Most are burned purposelessly. In other words, all combustible materials are incinerated for no purpose, and the cost of combustion and air pollution are serious. The problem of disposal of industrial waste is best if it can be converted into useful products at low cost. This is the best solution if you can turn it into an economically useful one. The present inventor has previously made the following invention in this regard. The gist of the present invention is a method of wet-mixing flammable waste and bentonite, molding and firing, and a method of mixing water-soluble sugar with bentonite and molding and firing. According to this method, even if it is oxidized and burned in the air, it has a characteristic that it can be carbonized with almost no oxidative consumption, and it can carbonize from sludge to food waste, waste oil, and waste plastic. Further, the obtained carbide is extremely excellent in water absorption, and can be expected to have many uses as a water absorbing material.
However, in this invention, the molding step was essential. Since the purpose is the carbonization of combustible waste, it is desirable to have as few steps as possible, and in some cases molding is essentially unnecessary.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a new method for producing a carbide that can be carbonized as it is as a waste by omitting the molding step. Is.

[0004]

The above-described manufacturing method has the following configuration. That is, 1. A method for producing a carbide, characterized in that a combustible substance or a substance containing a combustible substance is used as a starting raw material, and the surface of the raw material is covered with an inorganic binder and fired. 2. A method for producing a carbide, which comprises using a combustible substance or a substance containing a combustible substance as a starting material, coating the surface of the raw material with a film of an inorganic binder and a water-soluble saccharide, and firing the coated material. 3. A method for producing a carbide, which comprises firing a powder of combustible material or a material containing the combustible material, the surface of which is coated with an inorganic binder, and a mixture of particles and the inorganic aggregate. 4. A method for producing a carbide characterized by comprising firing a powder of combustible material or a material containing the combustible material, the surface of which is coated with a film of an inorganic binder and a water-soluble saccharide, and a mixture of particles and an inorganic aggregate. 5. 5. The production method according to 1 to 4, wherein the inorganic binder is bentonite.

[0005]

[Action]

[Principle] Usually, in order to carbonize a combustible material, it is necessary to fire it in a reducing atmosphere. When a combustible material is burned in an oxidizing atmosphere, it burns to form ash, but in the present invention, even if it is baked in an oxidizing atmosphere, it burns and carbonizes. It is presumed that the inorganic binder is coated on the surface of the combustible material, and the combustible component is coated with the fine particles of the binder, whereby the oxidation is suppressed.
This effect of suppressing oxidation is exhibited when the inorganic binder is coated. When the inorganic binder is bentonite, the effect of suppressing oxidation is greatest. This effect is further improved when the inorganic binder and the water-soluble saccharide are simultaneously coated.

[Coating of Caking Agent] Even if a small amount of the caking agent of about 1% is added, the suppressing effect appears. Therefore, even if the coating is thin, it has a sufficient effect of suppressing oxidation. If the material to be carbonized contains water, such as coffee grounds, a film just enough to knead the material to be carbonized and the binder to cover the binder is sufficient without adding new water. Has an effect of suppressing oxidation. Of course, there is no problem even if new moisture is added to cover the layer thickly.
When it does not contain water like chaff, it is necessary to add water. The coating operation may be simply kneading. As for the coating of the water-soluble saccharide, at least the saccharide dissolved in water may be coated on the surface of the material to be carbonized. The sugar dissolved in water may be coated with the binder, or it may be coated separately. That is, first, a coating of sugar dissolved in water is formed, and a case where the binder is coated on this, and vice versa, and a mixture of the sugar dissolved in water and the binder is simultaneously obtained. It may be coated. The saccharides may be used after being dissolved in water in advance, or when the material to be carbonized contains water, a film of the saccharides dissolved in water may be formed only by kneading the powder of the saccharides.

[Combustible material] The combustible material in this specification means coal,
Wood, bamboo, plastics, grain husks (soba husks, rice husks, etc.), grains, foods, and processing residues thereof, and wastes using these as raw materials, in short, all solid burning materials. In particular, it is extremely effective for waste discharged as powder and granular solids such as coffee grounds, rice husks, sawdust, and grains. What contains a combustible substance is a mixture of a combustible substance and a non-combustible substance, and the non-combustible substance is glass, ceramics such as refractory, water, or the like. Waste is rarely emitted only in the state of pure combustible substances, and rather, it is often emitted in the state where combustible substances and non-combustible substances are mixed. In the present invention, combustible waste and waste containing combustible material are expressed by the term combustible waste. The combustible wastes referred to in the present invention are mainly as follows. Ordinary vegetables, fruits, meat, fish, soybean food, processing residues of fish (such as offal), waste paper, waste pulp, shells of husks (rice husks, rattles, etc.), food factory residues, lees, dehydrated sludge , Alcohol factory residue, wood, waste wood, bamboo, animal hair, chemical fiber, dietary fiber, cotton, feces, and so on. Although these wastes disappear when completely burned, they change into carbides when fired. In other words, the waste will be reborn as a functionalized carbide. Since the above-mentioned combustible waste often retains water by nature, the water content may be sufficient to cover the binder, as in the case of the coffee grounds described above. If the water content is insufficient (for example, in the case of rice husks), it is sufficient to replenish the water content. If the amount is too large, a water-absorbing material such as waste paper or waste wood powder (sawdust) may be mixed to absorb water. Alternatively, they may be used as a moisture source for a material lacking moisture.

[Water-soluble saccharides] When water-soluble saccharides coexist with the binder, the effect of suppressing the oxidation of combustibles is further improved.
It is not oxidized even if heated to 600 to 700 ° C for a short time. In addition, the degree of blackening of the fired product is increased. There are various kinds of saccharides such as polysaccharides, small saccharides, monosaccharides and the like depending on the molecular weight thereof, but in the present invention, saccharides soluble in water are preferable among the saccharides mentioned above. Especially, small sugars such as sucrose, maltose and glucose, and monosaccharides are preferable. In addition to the sugar itself, a sugar-containing substance such as scraps of waste confectionery or a residue generated during the sugar refining process may be added to the sugar.

[Inorganic binder] As the inorganic binder,
In particular, so-called clay-like binders such as refractory clay, bentonite, and special clay are preferable, and bentonite is particularly effective in suppressing oxidation. These binders may be added alone or in the form of a binder containing them as components. As described above, when the binder is added in a small amount of about 1% of the material to be carbonized, the effect of suppressing oxidation appears. If the addition amount is increased, the oxidative consumption will be reduced, but the cost will increase, so
Considering practicality, a maximum of about 10 to 15% is sufficient. By the way, if it is oxidized and baked in the air without adding a binder, about 80% of coffee grounds are consumed by oxidation. 55% of rice husks oxidize and disappear. Addition of 15% reduces the oxidative consumption of coffee grounds and chaff in less than 10%.

[Mixing of Inorganic Aggregate] When the material to be carbonized is oxidized and fired in the atmosphere, most of it is consumed by oxidation, and the remaining carbonized product is fine powder and extremely light so as to be scattered by the wind. For this reason, there is a large loss of scattering in the firing furnace and going out with smoke. Also, when something that has gone out of the furnace is sprayed on a field for the purpose of soil improvement, etc., it is scattered by the wind and scattered. The addition of the binder has the effect of increasing the weight of the carbonized powder and particles as well as suppressing the above-mentioned oxidative consumption, and as a result, the effect of preventing the carbonized powder and particles from scattering. The mixture of the inorganic aggregates similarly increases the weight of the carbonized powder and particles, and the effect of preventing scattering is remarkable. As the aggregate, fine particles of inorganic waste are preferable. Foundry sand, sludge sand, bricks,
Roof tiles, concrete grains, powder, iron blast furnace slag, casting slag, perlite, glass fiber, rock wool, waste clay,
Incinerator ash, slag metal rust, etc. Among these aggregates, water absorbing materials such as blast furnace slag and perlite are advantageous. The aggregate preferably has a particle size of 65 mesh or less, more preferably 150 mesh or less.

[Drying] Drying can be appropriately selected from non-drying to complete drying.

[Baking conditions] A baking temperature of about 700 is sufficient. The firing atmosphere may be either an oxidizing atmosphere or a reducing atmosphere. The greatest feature of the present invention is that it can be oxidized and fired. It is most economical to perform the firing by heating to a predetermined temperature in a short time of about 1 to 10 minutes using a rotary kiln, rapid firing, taking out into the atmosphere and cooling. In the present invention, the self-combustion also occurs to some extent due to the hydrocarbon component of the combustible material as described above, so that the fuel supply is small.

[Properties] The fired product obtained by the method of the present invention has good water absorption. The functions of the fired body are water absorption and water retention,
The carbonized portion is a porous body having a large surface area and can be used as a soil improving material or artificial soil by utilizing the storability of activated carbon function, microbial carrier, filtration material, air, water, fertilizer and the like. It can also be used as a heat insulating material for building, a moisture absorbing material, and a soundproofing material. Further, when copper and silver powder are mixed with the aggregate component, copper ions and silver ions are eluted to exhibit an antibacterial action. Further, this is not an aggregate, and the same effect can be obtained when the surface of the powder is sprinkled with powder of copper, silver or the like and carbonized.

[Shape] The obtained carbide does not become aggregated and is in a dry state, and the shape of each particle is almost the same as before the firing. Although it varies depending on the type of material to be carbonized, it becomes granular in coffee grounds and chaff.

[0015]

EXAMPLES The present invention will be described with reference to examples. In addition, all the compounding ratios of the examples are shown by volume ratio. The firing atmosphere is all oxidation firing. [Example 1] Material to be carbonized: Coffee meal Type of binder: Bentonite Clay A Clay B Amount of binder (%): 2,4,6,8,10,12 Knead of coffee meal and binder The mixture was kneaded in a machine for about 1 minute to uniformly coat the surface of the coffee grounds with a binder. For comparison, a material not coated with the binder was also prepared. Drying and firing The kneaded product was dried at 150 ° C in a drier, heated to 700 ° C in a rotary kiln for about 2 minutes, fired, immediately taken out, and allowed to cool in the air. In addition, those without kneading the binder were dried and fired under the same conditions. The baked ones were scattered without particles forming a dumpling, and almost remained the original shape of coffee grounds, and were carbonized black. When I put it in the water tank, it absorbed water in an instant. The water absorption was extremely excellent. Yield The yield of the obtained carbide is shown in FIG. Results As can be seen from FIG. 1, when the binder is not coated, the yield of carbides is 22%, that is, 78% is oxidized and disappears, but when coated, almost 90% can be recovered by adding 12%. That is, the oxidative consumption is about 10%. Regarding the binder, there is a significant difference between bentonite and clays A and B, and bentonite is the best. Next, the obtained carbide was sprayed on the field. No matter what amount of binder was used, it could be sprayed without fluttering in the wind and was familiar to the surface of the field. On the other hand, those that were not coated with the binder were fine powder, and were scattered by the wind. Incidentally, the one not coated with the binder had a bulk specific gravity of 0.07, while the one coated with 12% bentonite was 0.15. Regarding the state of smoke and ash at the time of firing, it was found that pollution control equipment is indispensable because a large amount of smoke and ash will be emitted if the binder is not covered. On the other hand, the present invention did not generate smoke or ash, and it was found that pollution equipment is unnecessary. It turned out to be a very useful method considering the economics.

Example 2 Bentonite with 10% sugar
7% of the mixture is mixed with coffee grounds and kneaded for 30 seconds,
It was calcined at 700 ° C. without being dried. The yield of the obtained carbonized product was 85%, which was slightly higher than that of the same amount of bentonite. It was confirmed that the saccharide coating was effective in suppressing oxidation. In addition, the carbonized product was pure black, and the degree of blackening was higher than that without sugar.

[Example 3] Material to be carbonized: Rice husk Kind of binder: Bentonite Clay A Amount of binder (%): 2,4,6,8,10,12 Kneader for kneading and binder Was kneaded for about 1 minute to uniformly coat the surface with the binder. For comparison, a material not coated with the binder was also prepared. Calcination Do not dry the kneaded product, directly in a rotary kiln 7
It was heated to 00 ° C. for about 2 minutes, baked, taken out immediately, and allowed to cool in the atmosphere. In addition, those without kneading the binder were fired under the same conditions. The fired product remained in its original shape and was carbonized black without forming particles in which the particles were stuck together. When I put it in the water tank, it absorbed water in an instant. The water absorption was extremely excellent. Yield The yield of the obtained carbide is shown in FIG. Results As can be seen from FIG. 2, when the binder is not coated, the yield of carbide is 45%, that is, 55% is oxidized and disappears, but when coated, almost 90% can be recovered by adding 12%. That is, the oxidative consumption is about 10%. Regarding the binder, there is a significant difference between bentonite and clay A, and bentonite is excellent.

[Example 4] Material to be carbonized: Pine ogre powder Type of binder: Bentonite Amount of binder (%): 2, 4, 6, 8, 10, 12 Pine ogre powder and bentonite kneader Was kneaded for about 1 minute to uniformly coat the surface with bentonite. Firing The kneaded mixture was not dried, but was heated in a rotary kiln as it was at 700 ° C. for about 3 minutes, fired, immediately taken out, and allowed to cool in the air. The fired product remained in its original shape and was carbonized black without forming particles in which the particles were stuck together. When I put it in the water tank, it absorbed water in an instant. The water absorption was extremely excellent. Yield The yield of the obtained carbide is shown in FIG. Results As can be seen from FIG. 3, almost 85% can be recovered by adding 12%. That is, the oxidative consumption is about 15%. The uncoated bentonite has a yield of 15%, that is, 8
5% burned and disappeared. Next, the obtained carbide was sprayed on the field. It could be sprayed without being scattered by the wind, and was familiar with the surface of the field. Those that did not cover the binder were fine powder and were scattered by the wind.

Example 5 Mushroom waste ogre powder 10 parts (water content 65%) Crushed stone dust 1 part Bentonite 0.7 part Dextrin 0.1 part The above ingredients were kneaded for 30 seconds with a kneader. Although the bentonite was uniformly coated on the surface of the ogre powder, it did not become agglomerates and was in a scattered state. When this was not dried and heated in a special rotary kiln for 3 minutes (700 ° C.), the shape of the ogre powder did not collapse, and heavy pulverized coal with a specific gravity was formed.

Example 6 Rice husk 10 parts Raw okara 8 parts Bentonite 1 part Sugar 0.2 parts Crushed stone dust 2 parts The above ingredients were kneaded for 30 seconds by a kneader. When this was not dried, but heated in a special rotary kiln for 3 minutes (700 ° C.), heavy pulverized coal with a specific gravity was formed.

[Example 7] Rice husk 10 parts Food sludge 8 parts Bentonite 1 part Dextrin 0.2 parts No. 8 silica sand 3 parts This is not dried but is kept for 3 minutes in a special rotary kiln (70
When heated (0 ° C.), heavy pulverized coal having a specific gravity was formed.

[Effects of the Invention] As described in detail above, the present invention is a method of carbonizing a combustible waste with good yield even if it is oxidatively burned, and currently treats coffee grounds, chaff, ogre powder, okara, sludge, etc. It has the feature that it can economically convert organic wastes that are in trouble to functionalized carbides, and makes a great contribution to the recycling of wastes.

[Brief description of drawings]

FIG. 1 is a diagram showing a yield of Example 1.

FIG. 2 is a diagram showing a yield of Example 3.

FIG. 3 is a diagram showing a yield of Example 4.

Claims (5)

[Claims] 1. A method for producing a carbide, characterized in that a combustible substance or a substance containing a combustible substance is used as a starting raw material, and the surface of the raw material is coated with an inorganic binder and fired. 2. A method for producing a carbide, which comprises using a combustible substance or a substance containing a combustible substance as a starting raw material, coating the surface of the raw material with a film of an inorganic binder and a water-soluble saccharide, and firing the raw material. 3. A method for producing a carbide, which comprises firing a mixture of powder or particles of an inflammable material or a material containing an inflammable material, the surface of which is coated with an inorganic binder, and an inorganic aggregate. 4. A powder of a combustible material or a material containing the combustible material, the surface of which is coated with an inorganic binder and a water-soluble saccharide, and a mixture of the particles and the inorganic aggregate is fired. Method for producing carbide. 5. The method according to claim 1, wherein the inorganic binder is bentonite.