CN105924222A - Attapulgite and biomass compound biological ceramsite and preparation method thereof - Google Patents

Abstract

The invention discloses attapulgite-biomass composite biological ceramsite. The biological ceramsite contains solid powder and liquid binder, wherein the solid powder contains the following components in mass percentage: 50% to 90% of attapulgite powder, 5% to 30% of biomass material, and 10% to 40% of auxiliary materials; wherein, the auxiliary material is first-grade fly ash, and the liquid binder is sodium bicarbonate solution or ammonium chloride solution, the amount of the liquid binder accounts for 15-35% of the mass of all solid powders, and the concentration range of the liquid binder is no more than 2%. The attapulgite and biomass composite biological ceramsite prepared by the present invention replace traditional binders, plasticizers and fluxes with fly ash and sodium bicarbonate solution, which saves raw material costs and improves the strength and Porosity makes ceramsite have the advantages of high porosity, large specific surface area, high strength and strong water resistance. The ceramsite of the present invention can be used as an adsorption material, a filler for a biofilter and a denitrification filter.

Description

A kind of attapulgite and biomass composite type biological ceramsite and preparation method thereof

technical field

The invention relates to a method for preparing ceramsite. In particular, it relates to a method for preparing ceramsite by reclaiming and reusing solid waste to make ceramsite.

Background technique

In recent years, the world's energy resources have become increasingly scarce, and the utilization of biomass materials has received more and more attention. my country is a large agricultural country, and rice production in my country accounts for about 1/2 of the country's total grain production. It is rich in biomass materials. The traditional biomass treatment method is to transport and incinerate the biomass in processing plants. This treatment method will cause damage to the atmospheric environment. Serious pollution will inevitably be eliminated under the current situation of deteriorating ecological environment. The country's policy of banning the burning of agricultural waste is the best proof. The way to properly handle biomass such as rice husk powder is to make people realize that biomass materials are resources and energy that can be processed and utilized. At present, domestic biomass processing methods mainly include making livestock and poultry feed, making biogas, and making organic fertilizer. . These methods are too low to the utilization rate of rice husk, and are difficult to popularize.

Patent document CN 102225870 A discloses attapulgite clay porous ceramsite and its preparation method and application. It uses attapulgite as the main raw material, and adds components such as biomass and binder to obtain it through a granulation and calcination process. The method mainly has the following deficiencies: (1) the required binder water glass itself is an industrial raw material, which is expensive and added in a large amount, which not only consumes resources, but also greatly increases the production cost, and its environmental protection effect is also greatly reduced. It is not suitable for the popularization and application of biomass ceramsite; (2) the sintering temperature is high, which greatly increases the energy cost, so it is not suitable for the popularization and application of biomass ceramsite.

Contents of the invention

Purpose of the invention: the purpose of the present invention is to overcome the deficiencies of the above technologies and propose a method for preparing a compound bio-ceramsite of attapulgite and biomass with low production cost, a simpler preparation method and a wide range of uses.

Technical solution: In order to realize the above-mentioned technical solution, the present invention proposes a kind of attapulgite and biomass composite bio-ceramic, the bio-ceramic contains solid powder and liquid binder, wherein the solid powder The material contains the following components in mass percentage: 50%-90% of attapulgite powder, 5%-30% of biomass material, and 10%-40% of auxiliary materials; wherein, the auxiliary materials are primary fly ash, and the The liquid binder is sodium bicarbonate solution or ammonium chloride solution, the amount of the liquid binder accounts for 15-35% of the mass of all solid powders, and the concentration range of the liquid binder is no more than 2%. More preferably, when ammonium chloride is selected as the liquid binder, its concentration does not exceed 1%.

Wherein, the biomass material is pulverized powder of agricultural plant waste.

Specifically, the agricultural waste material is any one of rice husk powder, walnut shell, chestnut shell, straw, wood chips and the like.

The first-class fly ash is commercially available first-class fly ash, and its component mass percent range is as follows: SiO ₂ 34.0%-60.0%, Al ₂ O ₃ 17.0%-35.0%, Fe ₂ O ₃ 2.0%-15.0% %, CaO 0.4% to 3%, MgO 0.7% to 2.9%, Na ₂ O 0.2% to 1.1%, and K ₂ O 0.7% to 2.9%.

The present invention further proposes a preparation method of the above-mentioned attapulgite and biomass composite bioceramsite, comprising the following steps:

(1) Preparation of raw materials:

a. The attapulgite is pulverized by a pulverizer, passed through a 200-mesh sieve, and dried in an oven for more than 2 hours to obtain attapulgite powder;

b. After passing the biomass material through an 80-mesh sieve, put it in an oven to dry for more than 2 hours to obtain a biomass material powder;

c. Pass the primary fly ash through a 200-mesh sieve and dry it in an oven for more than 2 hours to obtain the processed primary fly ash;

(2) stirring:

Mix the concave powder powder obtained in step (1), the biomass material powder and the first-grade fly ash according to the proportion, and stir them evenly through a mixer for more than 0.5h to obtain a mixed powder;

(3) Add water to granulate:

Add sodium bicarbonate solution to the mixed powder and stir evenly. The amount of liquid added is 15% to 35% of the mass of the mixed powder to make spherical particles of 3 to 5 mm, and then placed in an oven to dry at 100°C to 110°C. Dry for more than 2 hours to obtain unfired ceramsite with more voids;

(4) Calcination:

Place the unfired ceramsite in a muffle furnace, and calcinate at 500°C-700°C for 0.5-3 hours in air atmosphere to obtain high-strength, high-porosity attapulgite-biomass composite bio-ceramsite.

Wherein, the biomass material is pulverized powder of agricultural plant waste.

The agricultural waste material is any one of rice husk powder, walnut shell, chestnut shell, straw and sawdust.

Preferably, the first-class fly ash is commercially available first-class fly ash, and its component mass percent range is as follows: SiO ₂ 34.0%-60.0%, Al ₂ O ₃ 17.0%-35.0%, Fe ₂ O ₃ 2.0 %～15.0%, CaO 0.4%～3%, MgO 0.7%～2.9%, Na ₂ O 0.2%～1.1% and K ₂ O 0.7%～2.9%

Furthermore, the present invention proposes the application of the above-mentioned biological ceramsite in the denitrification biological filter as the biological carrier of the denitrification bacteria group.

Beneficial effect: Compared with the prior art, the beneficial effect of the present invention is reflected in:

(1) The attapulgite used in the present invention comes from natural ores, has a wide range of sources and is cheap, and expands the application of attapulgite.

(2) Both the biomass and the fly ash used in the present invention come from agricultural and industrial solid wastes, so that the solid wastes can be recycled, the environmental benefits can be maximized, and the production cost of ceramsite can be reduced simultaneously.

(3) Compared with the existing ceramsite invention technology, the sintering temperature of the present invention is lowered by more than 100°C, which saves sintering energy consumption, reduces production costs, and is beneficial to the popularization and application of attapulgite and biomass composite bio-ceramsite.

(4) The porosity of the ceramsite sold on the existing market is between 40%～50%. On the premise of reaching the compressive strength of 40N, the porosity is stable at 50%～55%, and the porosity has obtained 5%. An increase of ~10% is beneficial to biofilm formation, increasing the microbial biomass of particle film formation, and improving its effect.

Description of drawings

Fig. 1 is the SEM photo of attapulgite and biomass composite type biological ceramsite prepared by the present invention, wherein Fig. a and Fig. b are SEM photographs of the outer surface of ceramsite, and Fig. c and Fig. d are SEM photographs of the ceramsite cross-sectional surface , the ceramsite in the figure has dense voids and deep voids;

Fig. 2 is a photograph of attapulgite and biomass composite bio-ceramsite prepared in the present invention before and after calcination, the particles appear gray before calcination and brown after calcination.

detailed description

The present invention is further illustrated below by way of examples. Wherein, the chemical composition of the fly ash used in the following examples is shown in the table below:

Table 1-1 Chemical composition of fly ash

unit:%

Element SiO ₂ Al ₂ O _{3 Fe2O3 _} CaO MgO Na ₂ O K ₂ O percentage 48.6 28.6 6.2 3.5 2.5 0.8 2.0

Example 1:

(1) Preparation of raw materials:

a. The attapulgite is pulverized by a pulverizer, passed through a 200-mesh sieve, and dried in an oven for more than 2 hours to obtain attapulgite powder.

b. After passing the rice husk powder through an 80-mesh sieve, put it in an oven to dry for more than 2 hours to obtain the rice husk powder.

c. After passing the fly ash through a 200-mesh sieve, put it in an oven to dry for more than 2 hours to obtain fly ash.

(2) stirring:

The powder is mixed according to the mass percentage of attapulgite: rice husk powder: fly ash = 3:0:2, and stirred by a mixer for more than 1 hour to stir evenly.

(3) Add water to granulate:

Add deionized water to the mixed powder and stir evenly. The amount of water added is 25% of the mass of the mixed powder to make spherical particles of 3-5mm, and then placed in an oven and dried at 105°C for more than 2 hours.

(4) Calcination:

The dried ceramsite was placed in a muffle furnace, and calcined at 700°C for 1 hour in an air atmosphere to obtain attapulgite composite biomass material ceramsite. The average compressive strength of the prepared ceramsite is 149N, the average porosity is 32.6%, and the apparent density is 1.35g/cm ³ .

Example 2:

(1) Preparation of raw materials:

a. The attapulgite is pulverized by a pulverizer, passed through a 200-mesh sieve, and dried in an oven for more than 2 hours to obtain attapulgite powder.

b. After passing the sawdust powder through an 80-mesh sieve, put it in an oven to dry for more than 2 hours to obtain the sawdust powder.

c. After passing the fly ash through a 200-mesh sieve, put it in an oven to dry for more than 2 hours to obtain fly ash.

(2) stirring:

The powder is mixed according to the mass percentage of attapulgite: sawdust powder: fly ash = 7:1:2, and stirred by a mixer for more than 1 hour to stir evenly.

(3) Add water to granulate:

Add 1% by mass sodium bicarbonate solution to the mixed powder and stir evenly, add 25% of the mass of the mixed powder to make 3-5mm spherical particles, then place them in an oven and dry at 105°C More than 2 hours.

(4) Calcination:

The dried ceramsite was placed in a muffle furnace, and calcined at 600°C for 1.5 hours in an air atmosphere to obtain attapulgite composite biomass material ceramsite. The average compressive strength of the prepared ceramsite is 118N, the average porosity is 38.5%, and the apparent density is 1.27g/cm ³ .

Example 3:

(1) Preparation of raw materials:

a. Attapulgite is pulverized through a pulverizer, and after passing through a 200 mesh sieve, put it in an oven to dry for more than 2 hours to obtain attapulgite powder.

b. Pass the chestnut shell powder through an 80-mesh sieve, and put it in an oven to dry for more than 2 hours to obtain the chestnut shell powder.

c. After passing the fly ash through a 200-mesh sieve, put it in an oven to dry for more than 2 hours to obtain fly ash.

(2) stirring:

The powder is mixed according to the mass percentage of attapulgite: chestnut shell powder: fly ash = 18:7:5, and stirred by a mixer for more than 1 hour to stir evenly.

(3) Add water to granulate:

Add 1% by mass sodium bicarbonate solution to the mixed powder and stir evenly, add 25% of the mass of the mixed powder to make 3-5mm spherical particles, then place them in an oven and dry at 105°C More than 2 hours.

(4) Calcination:

The dried ceramsite was placed in a muffle furnace, and calcined at 500°C for 3 hours in an air atmosphere to obtain attapulgite composite biomass material ceramsite. The average compressive strength of the prepared ceramsite is 35.7N, the average porosity is 55%, and the apparent density is 1.15g/cm ³ .

Example 4:

(1) Preparation of raw materials:

a. The attapulgite is pulverized by a pulverizer, passed through a 200-mesh sieve, and dried in an oven for more than 2 hours to obtain attapulgite powder.

b. After passing the rice husk powder through an 80-mesh sieve, put it in an oven to dry for more than 2 hours to obtain the rice husk powder.

c. After passing the fly ash through a 200-mesh sieve, put it in an oven to dry for more than 2 hours to obtain fly ash.

(2) stirring:

The powder is mixed according to the mass percentage of attapulgite: rice husk powder: fly ash = 28:7:5, and stirred by a mixer for more than 1 hour to stir evenly.

(3) Add water to granulate:

Add 0.5% by mass of sodium bicarbonate solution to the mixed powder and stir evenly, add 25% of the mass of the mixed powder to make 3-5mm spherical particles, then place them in an oven and dry at 105°C More than 2 hours.

(4) Calcination:

The dried ceramsite was placed in a muffle furnace and calcined at 500°C for 2 hours in an air atmosphere to obtain attapulgite composite biomass material ceramsite. The average compressive strength of the prepared ceramsite is 42.3N, the average porosity is 53.0%, and the apparent density is 1.21g/cm ³ .

Example 5:

(1) Preparation of raw materials:

a. The attapulgite is pulverized by a pulverizer, passed through a 200-mesh sieve, and dried in an oven for more than 2 hours to obtain attapulgite powder.

b. After passing the rice husk powder through an 80-mesh sieve, put it in an oven to dry for more than 2 hours to obtain the rice husk powder.

c. After passing the fly ash through a 200-mesh sieve, put it in an oven to dry for more than 2 hours to obtain fly ash.

(2) stirring:

The powder is mixed according to the mass percentage of attapulgite: rice husk powder: fly ash = 28:7:5, and stirred by a mixer for more than 1 hour to stir evenly.

(3) Add water to granulate:

Add deionized water to the mixed powder and stir evenly. The amount of water added is 25% of the mass of the mixed powder to make spherical particles of 3-5mm, and then placed in an oven and dried at 105°C for more than 2 hours.

(4) Calcination:

The dried ceramsite was placed in a muffle furnace and calcined at 500°C for 2 hours in an air atmosphere to obtain attapulgite composite biomass material ceramsite. The average compressive strength of the prepared ceramsite is 45.3N, the average porosity is 50.3%, and the apparent density is 1.28g/cm ³ .

Embodiment 6:

(1) Preparation of raw materials:

a. The attapulgite is pulverized by a pulverizer, passed through a 200-mesh sieve, and dried in an oven for more than 2 hours to obtain attapulgite powder.

b. After passing the rice husk powder through an 80-mesh sieve, put it in an oven to dry for more than 2 hours to obtain the rice husk powder.

c. After passing the rice husk powder through a 200-mesh sieve, put it in an oven to dry for more than 2 hours to obtain fly ash.

(2) stirring:

The powder is mixed according to the mass percentage of attapulgite: rice husk powder: fly ash = 28:7:5, and stirred by a mixer for more than 1 hour to stir evenly.

(3) Add water to granulate:

Add ammonium chloride solution with a mass percentage of 0.1% to the mixed powder, stir evenly, add water at 25% of the mixed powder mass, make 3-5mm spherical particles, then place them in an oven, and dry them at 105°C More than 2 hours.

(4) Calcination:

The dried ceramsite was placed in a muffle furnace and calcined at 500°C for 2 hours in an air atmosphere to obtain attapulgite composite biomass material ceramsite. The average compressive strength of the prepared ceramsite is 41.2N, the average porosity is 52.7%, and the apparent density is 1.g/cm ³ .

Embodiment 7:

(1) Preparation of raw materials:

a. The attapulgite is pulverized by a pulverizer, passed through a 200-mesh sieve, and dried in an oven for more than 2 hours to obtain attapulgite powder.

b. After passing the rice husk powder through an 80-mesh sieve, put it in an oven to dry for more than 2 hours to obtain the rice husk powder.

c. After passing the rice husk powder through a 200-mesh sieve, put it in an oven to dry for more than 2 hours to obtain fly ash.

(2) stirring:

The powder is mixed according to the mass percentage of attapulgite: rice husk powder: fly ash = 28:6:6, and stirred by a mixer for more than 1 hour to stir evenly.

(3) Add water to granulate:

Add ammonium chloride solution with a mass percentage of 0.05% to the mixed powder, stir evenly, add water at 25% of the mass of the mixed powder, and make spherical particles of 3-5mm, then place them in an oven, and dry them at 105°C More than 2 hours.

(4) Calcination:

The dried ceramsite was placed in a muffle furnace and calcined at 500°C for 2 hours in an air atmosphere to obtain attapulgite composite biomass material ceramsite. The average compressive strength of the prepared ceramsite is 44.5N, the average porosity is 49.6%, and the apparent density is 1.31g/cm ³ .

Embodiment 8:

(1) Preparation of raw materials:

a. The attapulgite is pulverized by a pulverizer, passed through a 200-mesh sieve, and dried in an oven for more than 2 hours to obtain attapulgite powder.

b. After passing the rice husk powder through an 80-mesh sieve, put it in an oven to dry for more than 2 hours to obtain the rice husk powder.

c. After passing the rice husk powder through a 200-mesh sieve, put it in an oven to dry for more than 2 hours to obtain fly ash.

(2) stirring:

The powder is mixed according to the mass percentage of attapulgite: rice husk powder: fly ash = 4:1:0, and stirred by a mixer for more than 1 hour to stir evenly.

(3) Add water to granulate:

Add 1% by mass sodium bicarbonate solution to the mixed powder and stir evenly, add 25% of the mass of the mixed powder to make 3-5mm spherical particles, then place them in an oven and dry at 105°C More than 2 hours.

(4) Calcination:

The dried ceramsite was placed in a muffle furnace and calcined at 700°C for 3 hours in an air atmosphere to obtain attapulgite composite biomass material ceramsite. The average compressive strength of the prepared ceramsite is 36N, the average porosity is 58%, and the apparent density is 0.98g/cm ³ .

Embodiment 9:

Get the ceramsite prepared in Example 4 as the attapulgite and the biomass compound type biological ceramsite as the microbial carrier in the denitrification reactor No. 1, adopt a kind of ceramsite (porosity 40) produced in Changzhou City for sale %～45%) was used as the microbial carrier in denitrification reactor No. 2 as the control group. Investigate and compare the film-forming time of two kinds of ceramsite and the removal efficiency of NO ₃ ^- -N and NO ₂ ^- -N.

The test site is a sewage plant in Taicang City. The test adopts artificial inoculation, and the inoculation is taken from the improved A ² /O+SBR biochemical pool of the plant. The first stage of stuffy aeration: mix the raw water and inoculated sludge into the filter column according to the ratio of 7:3 to ensure that the water level above the filter material layer is 50mm, and continuously stuffy aeration with an aeration rate of 7000L/h for 24 hours. Half of the sewage in the filter column is discharged, and fresh sewage is injected again, and this stage runs for 8 days.

The second stage of continuous water intake: the filter column will be emptied, the aeration will be stopped, and 3mg/L sodium acetate will be added to the denitrification reactor at the same time as the tail water of the plant, and the two filter columns will be continuously fed at a filtration rate of 2.8m/h water. After No. 1 reactor continued for 12 days, the average sum of NO _{3 - -N and NO 2 - -N in the tail water was about 12 mg/L, and the average sum of NO 3} ^- _{-N and NO 2} ^- _-N ⁱⁿ _the ^reactor effluent was about 3.5 mg/L, the total removal rate of NO ₃ ^- -N and NO ₂ ^- -N by denitrification was stable at about 70.8%; after 14 consecutive days in No. 2 reactor, the tail water inflow was the same as that of No. The average sum of ₃ ^- -N and NO ₂ ^- -N is 4.5 mg/L, and the total removal rate of NO ₃ ^- -N and NO ₂ ^- -N is stable at about 62.5%, indicating that the microorganisms loaded in the present invention multiply rapidly, and According to the porosity is 8.3% higher than that of No. 2 reactor ceramsite, the denitrification effect and treatment efficiency are better.

Claims (9)

1. A kind of attapulgite and biomass compound biological ceramsite, it is characterized in that, described biological ceramsite comprises solid powder and liquid binder, and wherein, described solid powder comprises the following mass percentage Divided into: attapulgite powder 50%-90%, biomass material 5%-30%, auxiliary material 10%-40%; wherein, the auxiliary material is first-grade fly ash, and the liquid binder is carbonic acid Sodium hydrogen solution or ammonium chloride solution, the amount of the liquid binder accounts for 15-35% of the mass of all solid powders, and the concentration range of the liquid binder is no more than 2%. 2 . The attapulgite and biomass composite biological ceramsite according to claim 1 , wherein the biomass material is pulverized powder of agricultural plant waste. 3. The attapulgite and biomass composite biological ceramsite according to claim 2, wherein the agricultural waste material is any one of rice husk powder, walnut shell, chestnut shell, straw and sawdust kind. 4. attapulgite and biomass composite type biological ceramsite according to claim 1, is characterized in that, described primary fly ash is commercially available primary fly ash, and its component mass percent scope is as follows: SiO ₂ 34.0%～60.0%, Al ₂ O ₃ 17.0%～35.0%, Fe ₂ O ₃ 2.0%～15.0%, CaO 0.4%～3%, MgO 0.7%～2.9%, Na ₂ O 0.2%～1.1% and K ₂ O 0.7% to 2.9%. 5. the preparation method of attapulgite and biomass composite type biological ceramsite according to claim 1, is characterized in that, comprises the steps: (1) Preparation of raw materials: a. The attapulgite is pulverized by a pulverizer, passed through a 200-mesh sieve, and dried in an oven for more than 2 hours to obtain attapulgite powder; b. After passing the biomass material through an 80-mesh sieve, put it in an oven to dry for more than 2 hours to obtain a biomass material powder; c. Pass the primary fly ash through a 200-mesh sieve and dry it in an oven for more than 2 hours to obtain the processed primary fly ash; (2) stirring: Mix the concave powder powder obtained in step (1), the biomass material powder and the first-grade fly ash according to the proportion, and stir them evenly through a mixer for more than 0.5h to obtain a mixed powder; (3) Add water to granulate: Add sodium bicarbonate solution to the mixed powder and stir evenly. The amount of liquid added is 15% to 35% of the mass of the mixed powder to make spherical particles of 3 to 5 mm, and then placed in an oven to dry at 100°C to 110°C. Dry for more than 2 hours to obtain unfired ceramsite with more voids; (4) Calcination: Place the unfired ceramsite in a muffle furnace, and calcinate at 500°C-700°C for 0.5-3 hours in air atmosphere to obtain high-strength, high-porosity attapulgite-biomass composite bio-ceramsite. 6 . The attapulgite and biomass composite biological ceramsite according to claim 5 , wherein the biomass material is pulverized powder of agricultural plant waste. 7. The attapulgite and biomass composite biological ceramsite according to claim 5, wherein the agricultural waste material is any one of rice husk powder, walnut shell, chestnut shell, straw and sawdust kind. 8. attapulgite and biomass composite type biological ceramsite according to claim 5, is characterized in that, described primary fly ash is commercially available primary fly ash, and its component mass percent scope is as follows: SiO ₂ 34.0%～60.0%, Al ₂ O ₃ 17.0%～35.0%, Fe ₂ O ₃ 2.0%～15.0%, CaO 0.4%～3%, MgO 0.7%～2.9%, Na ₂ O 0.2%～1.1% and K ₂ O 0.7% to 2.9%. 9. the application of biological ceramsite as claimed in claim 1 in the biological carrier of denitrifying flora in the denitrification biofilter.