JP2006218386A - Ceramic-coated bamboo charcoal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ceramic-coated bamboo charcoal material, which has high adsorption and good water decontamination properties, the original properties of bamboo charcoal, and is free from problems which lower the marketability of bamboo charcoal as an industrial material, such that: conventional bamboo charcoal materials lack quality stability due to its varied production methods and float in water at the initial stage due to their porosity; bamboo charcoal sections have charcoal powders adhering to it, which are dispersed to cause water to look black; and conventional bamboo charcoal materials pollute water similarly when the materials come into contact and collide with each other so as to be powdered, because such materials are more brittle than white charcoal. <P>SOLUTION: These problems are solved by coating bamboo charcoal sections with hard ceramic having active force, so as to increase the mass of bamboo charcoal. Bamboo charcoal sections are coated with ceramic that is made of zeolite powders with active force containing bentonite as a main component and 1 type of or a mixture of 2 types of bamboo charcoal powders. Subsequently the coated bamboo charcoal sections are sintered at high temperature under a carbon dioxide atmosphere. The thus produced bamboo charcoal is activated and has higher adsorption power. Furthermore, the thus produced bamboo charcoal has highly stabilized quality, because the bamboo charcoal is produced through the heat treatment step for activation with the use of carbon dioxide gas. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  By covering the bamboo charcoal pieces with ceramic, the adsorption characteristics of bamboo charcoal are further enhanced, and at the same time, by coating with a highly active ceramic, for example, a composite material having a high water purifying ability can be replaced. In the case of a single piece, when it was introduced into water because of its high porosity, it had to float for a long period of time, and bamboo charcoal powder adhering to the bamboo charcoal piece would disperse in water and stain the water black, making it necessary to consider handling. The present invention has been completed by examining the above technical problems in detail, and relates to a new purification material.

Good bamboo charcoal has high adsorptive power and purification ability, and its marketability is gradually increasing.
However, there are some problems to be widely used as a purification material as an industrial material. Many are carbonized at low temperature, and the adsorptive power and altitude are poor. For this reason, high-temperature carbonization and stabilization of characteristics with hard bamboo charcoal, removing powder adhering to the bamboo charcoal to prevent the water from becoming black, and long-term floating due to high porosity when put in water It is inevitable and, in use, the charcoal comes into contact with each other, rubs and powders to cause secondary contamination.

The present invention was devised to make bamboo charcoal that can be used industrially as a purification material, and succeeded in overcoming the problem by coating the surface of the bamboo charcoal with ceramic.
Make a muddy liquid with purified water or divalent iron salt aqueous solution as a binder in mixed powder in which bentonite powder is the main component and zeolite powder or bamboo charcoal powder is mixed or dispersed, and put bamboo charcoal pieces into this By dispersing and stirring, a mud is coated. The coated bamboo charcoal pieces are dried and then sintered at 850 to 950 ° C. for 2 to 3 hours in a carbon dioxide atmosphere furnace. The ceramic-coated bamboo charcoal made by the above manufacturing method is coated with hard ceramic, which can eliminate the disadvantages of the bamboo charcoal piece alone, and at the same time, it can be replaced with activated ceramic by adding deolite and bamboo charcoal powder. I understood. Furthermore, it has been found that the ceramic is more activated when a divalent and trivalent iron salt aqueous solution is used as a binder.

  Bamboo charcoal is classified into cutting charcoal, pulverized coarse grain, small grain, fine powder charcoal, etc., depending on the intended use. Of these various products, used for water purification, such as water purifiers for home use, charcoal for rice cooking, etc., should be thoroughly washed with brushing so that powder is not produced as much as possible during use. The actual situation is processing. However, there are cases in which the contact wear between charcoal leads to generation of powder and fine particles, and there are also complaints from users. In addition, as described above, charcoal itself has a high porosity and may float in water for a long period of time, and a reduction in water contact area also causes a loss of purification efficiency. The present invention has problems such as blackening of water by charcoal powder adhering to bamboo charcoal, eliminating contact wear of charcoal during use, and charcoal sinking in a short time and improving purification efficiency.

  As a means of sinking bamboo charcoal, it can be easily submerged by putting bamboo charcoal and stones in the net, but all the problems cannot be solved. The present invention has found a solution by coating ceramic as a means for increasing the mass of bamboo charcoal. In addition to simply increasing the mass, it has just been finished into a new composite material by coating active ceramics.

Using mixed powder of bentonite powder as a main component and active zeolite powder and bamboo charcoal powder, or mixed with one or two kinds of bamboo charcoal powder, using purified water or divalent iron salt aqueous solution as binder, It was found that bamboo charcoal powder adhering to the bamboo charcoal piece was absorbed and absorbed into the mud and easily integrated when the bamboo charcoal piece was put into this.
It was also found that the bamboo charcoal pieces and the muddy liquid were well-familiar and could be coated uniformly. By drying after coating and sintering in a carbon dioxide atmosphere, it was confirmed that the bamboo charcoal was a composite composed of a hard ceramic layer, and the mass increased compared to the bamboo charcoal itself. It has been confirmed that it is a high ceramic layer and a means for solving it has been found.

One kind or two kinds of zeolite powder and bamboo charcoal powder are mixed with bentonite powder. Zeolite is a molecular sieve and has excellent adsorption effect on nitrogen-based processed material. Bamboo charcoal fine powder is finer than bamboo charcoal piece and adsorbing effect. It is effective to further increase The effect increases if the blending amount is increased, but if it exceeds 50% by weight, the coating strength of the ceramic layer decreases and becomes brittle, and the adhesion strength is also inferior. Moreover, the binder used can be obtained with purified water with sufficiently high activity. However, the use of a divalent and trivalent iron salt aqueous solution increases the activity of the main component bentonite and can suppress the generation of anaerobic bacteria. is there.

  Furthermore, when carbon dioxide gas was used during sintering, it was confirmed that the bamboo charcoal pieces were activated and the adsorption area of the bamboo charcoal was improved by 3 to 4 times compared to general bamboo charcoal. Nitrogen gas may be used as the sintering atmosphere gas, but both bamboo charcoal and ceramics have the potential to adsorb nitrogen, and carbon compound gas is used because of a reduction in nitrogen compound adsorption capacity during water purification.

  The sintering temperature was set to 850 to 950 ° C. because the quality stability due to insufficient strength of the ceramic is inferior at 850 ° C. or less, and if it is higher than 950 ° C., a part of the ceramic component is melted and the adsorption power is reduced. Limited temperature range.

  As a result of detailed studies to solve various problems in water purification of bamboo charcoal fragments, the present invention is not only a solution to problems in use, but also a ceramic coating layer of bamboo charcoal that has a high activity and is hard. Was formed. This resulted in a material with a much higher purification capacity than the conventional one made of a single bamboo charcoal. In water purification, it can be expected to be effective in adsorbing and decomposing chlorides and nitrogen compounds, and suppressing anaerobic bacteria. It is considered to be applied to water purifiers for household use as well as materials for advanced treatment in water purification facilities. ing.

  It consists of a step of putting bamboo charcoal pieces in a muddy liquid composed of a main component of betonite and coating it, and taking out and drying it, followed by a step of sintering in a carbon dioxide atmosphere furnace. Moreover, activation with carbon dioxide gas is similar to the activated carbon production process, and can be provided as a high-quality purification material at low cost by mass production. Advanced treatment of purified water can be expected by passing the water after sand filtration through the treatment tank filled with this material in the water purification facility. In this case, the bamboo charcoal grains can be easily adjusted compared to the activated carbon, which is convenient for handling. Although the present invention is limited to bamboo charcoal, it can also be applied to charcoal and other carbonized materials.

After mixing 1 kg of zeolite powder with 5 kg of bentonite powder, 10 liters of purified water was added and stirred to make a mud. A bamboo charcoal piece with 20 kg of bamboo charcoal was put into this and a bamboo charcoal piece coated with a mud liquid was prepared by stirring with a rotary inclined kneader, taken out and dried with hot air, and then sintered at 870 ° C. for 2 hours in a carbon dioxide atmosphere electric furnace. Manufactured. The finished product was covered with hard ceramic on the surface of bamboo charcoal, and foamed when poured into water. This is a phenomenon that is not observed with a single piece of bamboo charcoal, and it can be said that the adsorption area increased due to activation. Moreover, about 0.8 liters of tap water was put in 1 liter of PET bottles, 8 g of the product was put in this, lightly covered, and left in a cool and dark place for 24 hours.
It was found that it foamed and floated immediately after putting the product, but it would sink in 2 to 3 hours when the firing stopped. After 24 hours, the water was transparent, free of turbidity due to bamboo charcoal powder, and free of odor.

  After mixing 1 kg of bamboo charcoal powder with 5 kg of bentonate powder, 15 liters of a commercially available pie water source water diluted 800 times was added as a divalent and trivalent iron salt aqueous solution and stirred to form a mud liquid. 20 kg of bamboo charcoal pieces were put into this and stirred with a kneader, the coated bamboo charcoal pieces were taken out, dried, and sintered in a carbon dioxide atmosphere electric furnace at 930 ° C. for 2 hours to produce ceramic coated bamboo charcoal. When 10 g of this product was put into 1 liter of a plastic bottle, about 0.8 liter of rainwater collected from a bag was added and lightly shaken to encourage firing, it settled easily in 0.5 to 1 hour. At this time, there was no turbidity due to bamboo charcoal powder. When the rainwater was examined after 24 hours, the pH value changed from 5.2 to 7.5, and potassium changed from 0.3 mg / liter to 14.5 mg / liter. In the E. coli test, the initial value was detected but not detected.

  After 5 kg of bentonite powder was mixed with 1 kg of bamboo charcoal powder and 1.5 kg of zeolite powder, 10 liters of purified water was added to make bamboo charcoal powder and zeolite powder-containing mud. 20 kg of small finger-sized bamboo charcoal particles were added thereto and stirred with a kneader. The coated bamboo charcoal particles were taken out, dried, and sintered in a carbon dioxide atmosphere electric furnace at 900 ° C. for 2 hours to produce ceramic-coated bamboo charcoal particles. 15 g of this product was placed in a 1 liter beaker, about 0.5 liter of tap water was added and stirred for 3 hours. Although the products collided with each other by stirring, there was no water contamination due to the generation of bamboo charcoal powder, and the transparent state could be maintained. Moreover, firing was promoted by stirring, and the product settled in about 10 minutes.

  Bamboo charcoal has been on the market for less than 20 years, but it is still low as an industrial material. The main reasons for this are thought to be quality stability and small production scale.

  In the present invention, taking into account these problems, taking advantage of the adsorption performance of bamboo charcoal, and detailed examination in consideration of ease of use as an industrial material, it was possible to develop a ceramic-coated bamboo charcoal with excellent characteristics that has never been seen before.

The raw materials used in the present invention are bamboo and clay mineral betonite. Bamboo is inexhaustible as far as the present desolated bamboo forests are seen, and the same applies to clay minerals. Furthermore, the product of the present invention is stable in quality because it is heat-treated and sintered at a high temperature in the final stage of production, and can be expected to surpass activated carbon by mass production. Therefore, the possibility of wide use such as for advanced treatment of water purification facilities, for rainwater purification facilities, and aquaculture facilities is high. In addition, the ceramic-coated bamboo charcoal of the present invention has a gas adsorbing power. For example, nitrogen compounds and sulfur compounds in combustion exhaust gas can be adsorbed, and a trap using this material can be installed in the flue to purify the exhaust gas. Can also be used.

Claims (3)

A mixture of bamboo charcoal powder or zeolite powder mixed with bentonite powder is mixed with purified water or a divalent iron salt aqueous solution as a binder. Ceramic coated bamboo charcoal formed by adhering and forming the liquid on bamboo charcoal, then drying and sintering in a carbon dioxide atmosphere furnace at 850-950 ° C. for 2-3 hours Ceramic-coated bamboo charcoal characterized in that when the bamboo charcoal powder and zeolite powder added to the bentonite powder are mixed individually, the mixing amount does not exceed 5 to 50% by weight. Ceramic coated bamboo charcoal characterized in that the total amount of both substances does not exceed 50% weight when adding bamboo charcoal powder and zeolite powder to bentonite powder, respectively