JP2007051016A - Porous composite ceramic using incineration residue powder of waste dry cell and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inexpensively manufacture a large quantity of a high quality porous composite ceramic using the incineration residue powder of waste dry cell as a raw material through steps of preparation/kneading/forming/drying/firing with a common extruder without using a clay outer frame or an expensive pressure molding apparatus. <P>SOLUTION: The manufacturing method is carried out by applying a 2 step preparation and forming method using the incineration residue powder of waste dry cell or the like as the raw material. That is, as a preparation 1st step, water and a forming assistant are added to the incineration residue powder of the waste dry cell, uniformly kneaded and aged and as a preparation 2nd step, a pore forming agent, a sintering assistant and water are added and kneaded thereto and finally, the mixture is formed, dried and fired. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to porous composite ceramics made from waste dry cell roasting residue powder (powder obtained by decomposing / disassembling waste dry cell and re-roasting roasted, crushed and magnetically selected zinc soot) and its It relates to a manufacturing method.

  As disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2004-292205), the present applicants have already proposed an invention relating to a ceramic for collecting exhaust gas using a waste battery roasting residue powder as a raw material and a method for producing the same. is doing.

  In this method, waste dry cell roasting residue powder, pore-forming agent and binder are kneaded and pressurized and filled into the outer frame of the clay, then molded and dried, and the filler and outer frame are sintered simultaneously to form the inside. A porous composite ceramic using a waste battery roasting residue powder is formed. The advantage of this method is that the waste dry battery roasting residue powder is a non-plastic and hardly sinterable powder composed of a complex oxide of manganese and zinc, and it is extremely difficult to maintain a certain shape by itself. In the sintering process, it is possible to form porous composite ceramics using waste battery roasting residue powder without using special molds by simultaneously sintering clay outer frame and waste battery roasting residue powder It was to become. However, the following problems existed.

(1) An outer frame that is sintered together with the waste dry battery roasting residue powder of raw material powder is required.
(2) The firing shrinkage rate of the outer frame and the raw material powder filled in the outer frame must be matched, and the formulation and moisture content of the outer frame must be adjusted accurately.
(3) A filling / pressurizing device is required to fill the outer frame of the clay with the raw material powder, and fine pressure adjustment is indispensable to obtain the desired porosity and pore diameter.
(4) Mass production of ceramic products is difficult because of the complicated multi-step process of outer frame preparation, desorption, raw material filling, pressurization, firing, and removal of the sintered body.
JP 2004-292205 A

  In view of the property of waste battery roasting residue powder that is difficult to form, the present inventors tried various methods and tests for the forming. In a general wet extrusion method in which all raw materials and binder (a kind of molding aid) are prepared at the same time in advance, how to change the waste dry cell roasting residue powder, pore former, binder and compounding composition ratio However, it was not possible to avoid problems such as cracking during molding and drying until the end of sintering.

  As a result of trial and error, the present inventors have found the present invention that can solve various problems as described above by dividing the raw material preparation process into two stages.

  That is, in the present invention, as a first stage of preparation, after adding a molding aid and water to the waste dry battery roasting residue powder and kneading and aging, as a second stage of preparation, a pore-forming agent, a sintering aid and Water is added and kneaded, formed by, for example, a wet extrusion method, sufficiently dried, and then fired. The composition ratio of the waste dry battery roasting residue powder and the pore-forming agent is preferably 30 to 90% and 10 to 60%.

  In the first stage of preparation, in addition to the molding aid and water, in addition to the molding aid and water, the calf bone-derived calcined apatite (calcium phosphate pulverized and calcined calf bone: HAp) is added to the waste dry battery roasting residue powder. By improving the microbial affinity of the porous composite ceramics using waste dry cell roasting residue powder, it exhibits excellent water purification characteristics and can be applied to a microbial carrier for water treatment.

  In the second stage of preparation, when agricultural products or wastes thereof, for example, cheap and easily available corn starch or wheat bran are used as pore forming agents, these are used in an oxidizing atmosphere firing furnace in the ceramic industry. By completely burning the pore-forming agent, the porous material using the waste dry battery roasting residue powder having a pore structure that retains the size and shape of the pore-forming agent without discharging harmful substances such as dioxin to the environment Composite ceramics can be designed.

  Porous composite ceramics produced by a wet extrusion method using waste dry cell roasting residue powder has a pore diameter of 1 to 500 μm and a porosity of 30 to 80 vol%, and is a commercially available water treatment microorganism carrier (pore diameter). : 5-70 μm, porosity: 50-70 vol%) and exhaust gas collection filters (pore diameter: 10-100 μm, porosity: 50-80 vol%) and the like.

  In the present invention, by using a general wet extrusion method without using an outer frame made of clay and without using pressure forming using a pressure device, and after sufficiently drying, by firing, A high-quality porous composite ceramic using a waste battery roasting residue powder as a raw material can be produced. Since a conventional general extrusion molding machine can be used, continuous molding is possible and mass production is easy.

FIG. 1 shows a manufacturing process (two-stage compounding method) of porous composite ceramics using waste dry battery roasting residue powder. In the first stage of preparation, the organic binder (1-2%) of the molding aid 2 and water 3 are added to the waste dry battery roasting residue powder 1 (50-70%) and kneaded uniformly. After the mixture 4 is aged for a predetermined time, as a second stage of preparation, the mixture 4 is mixed with a sintering aid 5 (2 to 10%), an agricultural product of a pore former 6 or agricultural waste (20 to 40%) and Add water 7 and knead. This kneaded clay 8 is put into an extrusion molding machine and formed into a desired shape. The total amount of water 3 and water 7 in the first and second stages of preparation is an amount suitable for molding.
In some cases, part of the waste dry battery roasting residue powder is replaced with calf bone-derived fired apatite in the first stage of preparation.

  The molded body 9 manufactured by the above method is dried and then fired according to a firing temperature curve shown in FIG. 2 as an example. By this firing step, the pore-forming agent and the like are completely burned without remaining as carbides, and the porous composite ceramic 10 having the desired pore structure is obtained.

  The present inventors produced porous composite ceramics by the following preparation, kneading, molding, drying, and firing processes. Table 1 shows the chemical composition of waste dry battery roasting residue powder (particle size of 60 mesh or less) used as a raw material.

  As the first stage of preparation, 1400 g of waste dry battery roasting residue powder, 30 g of methyl cellulose (MC) as a molding aid and 250 g of water were homogeneously kneaded and aged at room temperature for about 30 minutes. As the second stage of blending, 200 g of activated carbon sludge as a sintering aid, 400 g of pore forming agent (CS) and 300 g of water are added to the mixture prepared in the first stage of blending and kneaded, and then an extruder. And then molded. The shape of the compact using waste battery roasting residue powder was tried in various ways: prism, cylinder, cylinder. In any case, no dry crack was observed, and a good molded product was obtained.

  A molded body using waste dry battery roasting residue powder was prepared by the simultaneous blending molding method with the above-mentioned blended composition ratio, but dry cracks and breakage were observed in the molded body. In addition, various attempts were made by changing the composition ratio, but the same tendency was observed in all the molded bodies.

The reason why dry cracks and breakage occurred in molded bodies using all waste dry battery roasting residue powders produced by the simultaneous blending molding method is that the molding aid does not sufficiently exhibit its function. This is due to the large water absorption rate of the pore-forming agent, so that when the raw materials are mixed and kneaded at the same time, moisture is taken into the pore-forming agent and sufficient water is supplied to the molding aid to express its function. Because it is not done.
In order to solve this problem, the time required to add water to the forming aid and the pore-forming agent was divided so that the water necessary for the forming aid was sufficiently supplied. In addition, in order for the molding aid to exhibit its function, it is necessary to have enough time for the mixture of the waste dry battery roasting residue powder, the molding aid and water to be fully blended, and to allow time for this mixture to age. It was.

  For the reasons described above, the waste dry battery roasting residue powder, the molding aid and water are uniformly mixed and kneaded as the first stage of preparation, and after aging for a predetermined time, the mixture is then made into a pore-forming agent as the second stage of preparation. The present inventors have found a two-stage blending molding method in which a sintering aid and water are blended and kneaded.

  Table 2 shows the composition ratio of the molded body using the waste dry battery roasting residue powder obtained by the two-stage compounding method. The rod-like samples (molded bodies) produced by this method were dried and fired satisfactorily without any dry cracks or cracks.

In addition, the preparation composition ratio shown in Table 2 was determined from the following viewpoints.
The main raw material waste dry cell roasting residue powder is a waste, and the formulation composition ratio was determined from the balance with the pore-forming agent with the goal of making the composition ratio as large as possible from the viewpoint of effective utilization.

  Since calf bone-derived calcined apatite is effective in improving the affinity for microorganisms and improving sinterability, a part of the waste dry battery roasting residue powder of the main raw material is replaced with calf bone-derived calcined apatite, and its effect I grasped the degree of.

  In order to improve the moldability and sinterability, a molding aid and a sintering aid were used, and the optimum composition ratio was examined. Two types of organic binders were used as the molding aid, and activated carbon sludge was used as the sintering aid.

Wheat bran and corn starch were used as a pore-forming agent because they burned easily during the baking process, and in addition to obtaining the desired pore structure, they were available at low cost and in large quantities. This is because it has features such as no harmful gas emission.
For the reasons described above, wheat bran and corn starch were used as the pore-forming agent, and the composition ratio and particle size were examined according to the intended pore structure.

  As for the amount of water added, the composition ratio was determined in accordance with the amounts of waste dry battery roasting residue powder and molding aid in the first stage of preparation. In addition, in the second stage of preparation, the mixture prepared in the first stage of mixing, the sintering aid and the pore former are kneaded until they are hard enough to produce a molded body with an extruder. went.

  Among samples prepared according to the composition ratios shown in Table 2, for samples that may be applicable to exhaust gas collection filters or water treatment microorganism carriers, samples are prepared in a plate shape or hollow body shape, respectively. The suitability for each application was examined.

The water absorption, porosity, and bulk specific gravity of the plate-like and hollow body-shaped porous composite ceramics were measured. However, the firing temperature was about 1000 to 1200 ° C.
FIGS. 3A, 3B, and 3C show the appearance and dimensions (unit: mm) of the three types of porous composite ceramics that were prototyped.

Table 3 shows the measurement results of the plate-like sample fired at 1200 ° C. When used as an exhaust gas collecting filter, it is required to have a pore diameter of 10 to 100 μm, a porosity of 50 to 80 vol%, and continuous pores. In addition to satisfying these conditions for both the pore diameter and porosity, the sample prepared under these conditions has a gas permeability coefficient of about 1.1 × 10 ⁻¹¹ and has sufficient porous characteristics as an exhaust gas collection filter. It was confirmed that

  In Table 4, the measurement result of the hollow body sample baked at 1050-1200 degreeC is shown. When used as a microbial carrier for water treatment, it is required to have a pore diameter of 5 to 70 μm and a porosity of 50 to 70 vol%. It was confirmed that the sample prepared under these conditions satisfied these conditions and had sufficient porous characteristics as a microbial carrier for water treatment.

  The porous composite ceramics obtained by the present invention are expected to be applied to water treatment materials, exhaust gas collection materials, and the like. In order to investigate the superiority of porous composite ceramics using waste dry battery roasting residue powder to water treatment materials, the present inventors conducted a water purification microbe test and a water purification nitrification activity test.

<Test Example 1> Microbial activity test for water purification The effect of the porous composite ceramic according to the present invention on the removal activity of BOD (Biological Oxgen Demand) component was verified by the evaluation apparatus shown in FIG. . This porous composite ceramic is a hollow cylindrical porous body (outer diameter 13 mm × inner diameter 8 mm × height 15 mm) prepared by blending 20% of a cone starch as a pore-forming agent, and extruding and firing at 1150 ° C. for 4 hours. ) Was used.

  As a first test, mixed solution containing BOD components (peptone 100 mg / L, glucose 100 mg / L, nutrient buffer (phosphate buffer, magnesium sulfate solution, calcium chloride solution, iron (III) chloride solution)) In a carrier system using 100 mg / L of a microbial preparation (trade name: Hypolka S) and a waste dry cell baking residue powder, a total volume of 160 mL containing 4 porous composite ceramics is cultured at 20 ° C. with stirring with a stirrer for 3 days. did. On the other hand, in the system without carrier as a control sample, only the microorganism preparation was added to the BOD component-containing mixed solution, and stirring culture was performed in the same manner.

In the second microbial activity test, in the carrier system using waste dry cell roasting residue powder, the material surface of the porous composite ceramic after the first test is washed with distilled water and then put into a new mixed solution containing BOD components. The oxygen consumption for 3 days under stirring with a stirrer at 20 ° C. was measured. In the system without carrier, the culture solution after the first test was added in an amount equal to the porous composite ceramics input volume, and the oxygen consumption for 3 days was measured in the same manner. FIG. 5 is a graph showing the relationship between the second elapsed reaction time and the oxygen consumption. A large oxygen consumption at an early stage means high BOD removal activity.
In the third and subsequent tests, the test was continued in the same manner by adding and adding the porous composite ceramics or culture solution of the previous test.

  FIG. 6 is a graph showing the relationship between the elapsed time of the sixth reaction and the oxygen consumption. It was confirmed that when the porous composite ceramic according to the present invention was added, the oxygen consumption was larger, the decomposition of the BOD component proceeded faster, and the microbial activity increased.

Test Example 2 Nitrification Activity Test for Water Quality Purification The effect of porous composite ceramics on the oxidation (nitrification) activity of ammonia nitrogen was verified by a test as shown in FIG. Porous composite ceramics is a hollow cylindrical porous body (outer diameter 13 mm × inner diameter 8 mm × height 15 mm) prepared by blending 20% of a cone starch as a pore-forming agent, extruded and fired at 1150 ° C. for 4 hours. Was used.

In the test carrier system, the porous composite ceramics was introduced at a carrier volume ratio of 0.08 in a 2 L experimental tank in which a liquid medium for ammonia-oxidizing bacteria was added to a liquid medium for excrement of urine and cultured for 1 month at room temperature under aeration. . As a control sample, in a commercially available carrier system, a sponge carrier made of PVA (polyvinyl alcohol) (length 4 mm × width 4 mm × height 4 mm, average pore diameter 80 μm) was introduced with the same surface area as the test carrier and cultured in the same manner.
In each experimental tank of the test carrier system and the commercial carrier system, after culturing, artificial drainage (diammonium phosphate 0.96 g / L, inorganic nutrient salt solution (magnesium sulfate solution, calcium chloride solution, EDTA iron solution)) at room temperature Under aeration, water was passed through with a constant amount of water (1 L / d) (NH3-N concentration: 200 mg / L, volumetric load: 100 mg / L · d).
The ammonia, nitrite, and nitrate nitrogen concentrations of the treatment liquid discharged from the experimental tank side were measured, and the nitrification rate was calculated by the following formula.

  Nitrification rate = {(nitrite nitrogen concentration) + (nitrate nitrogen concentration)} / {(ammonia nitrogen concentration) + (nitrite nitrogen concentration) + (nitrate nitrogen concentration)}

  FIG. 8 is a graph showing the relationship between the elapsed reaction time and the nitrification rate. It was confirmed that the nitrification rate of the support system using the waste dry cell roasting residue powder was higher than that of the commercially available support system, and that the oxidation (nitrification) activity of ammonia nitrogen was improved by using porous composite ceramics.

It is an example of the manufacturing-process figure of the porous composite ceramics using the waste dry battery roasting residue powder made as an experiment by this invention. It is a graph which shows an example of the time transition of the calcination temperature in a baking process among the manufacturing-process diagrams of FIG. (A), (b), (c) is a figure which shows each external appearance and dimension of three types of porous composite ceramics made as an experiment. It is a schematic diagram of the microbial activity test for water purification | cleaning using the porous composite ceramics obtained by this invention. It is a graph which shows the relationship of the elapsed time of the 2nd time microbial decomposition reaction in the same test, and oxygen consumption. It is a graph which shows the relationship between the elapsed time of the 6th microbial decomposition reaction in the same test, and oxygen consumption. It is a schematic diagram of the nitrification activity test for water purification | cleaning using the porous composite ceramics obtained by this invention. It is a graph which shows the relationship between the elapsed time of the nitrification activity test for water quality purification, and a nitrification rate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Waste battery roasting residue powder 2 Molding aid 3 Water 4 Mixture 5 Sintering aid 6 Pore making agent 7 Water 8 Kneading clay 9 Molded body 10 Porous composite ceramics

Claims (10)

  A porous material characterized in that a molding aid and water are added to a waste dry battery roasting residue powder, kneaded and aged, then added with a pore-forming agent, a sintering aid and water, kneaded, molded, dried and fired. Composite ceramics.   2. The porous composite ceramics according to claim 1, wherein the composition ratio of the waste dry battery roasting residue powder and the pore former is 30 to 90% to 10 to 60%.   In addition to molding aid and water, calcined apatite derived from beef bone (calcium phosphate obtained by crushing and calcining beef bone: HAp) is added to the waste dry battery roasting residue powder, kneading and aging, followed by pore-forming agent and sintering aid And porous composite ceramics characterized by being added, kneaded, molded, dried and fired.   The porous composite ceramic according to claim 1, 2 or 3, wherein the pore-forming agent is an agricultural product or a waste product thereof.   5. The porous composite ceramic according to claim 1, wherein the pore diameter is 1 to 500 μm and the porosity is 30 to 80 vol%.   A porosity characterized by adding a molding aid and water to a waste battery roasting residue powder, kneading and aging, then adding a pore-forming agent, a sintering aid and water, kneading, molding, drying and firing. For producing conductive composite ceramics.   The method for producing a porous composite ceramic according to claim 6, wherein the composition ratio of the waste dry battery roasting residue powder and the pore-forming agent is 30 to 90% to 10 to 60%.   In addition to the molding aid and water, the calf bone-derived calcined apatite (HAp) is added to the waste dry battery roasting residue powder, and after kneading and aging, the pore former, the sintering aid and water are added and kneaded. A method for producing a porous composite ceramic, characterized by molding, drying and firing.   The method for producing porous composite ceramics according to claim 6, 7 or 8, wherein the pore-forming agent is an agricultural product or a waste product thereof.   10. The method for producing porous composite ceramics according to claim 9, wherein either or both of starch and wheat bran are used as the pore-forming agent.

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