CN106518150B - A kind of composite haydite of clean water sludge and diatomite preparation - Google Patents

Abstract

The invention relates to a composite ceramsite prepared by using water purification sludge and diatomite and a method thereof, belonging to the field of inorganic non-metallic materials. The composite ceramsite is calculated according to the weight ratio, and the raw materials include: 60-90 parts of water purification sludge; 20-30 parts of diatomite; 10-20 parts of calcium oxide. The preparation steps of the composite ceramsite include mixing, pelletizing, drying, preheating and roasting. The invention uses the water purification sludge produced in the production process of the water supply plant and the waste diatomite produced for filter aid in the brewery as raw materials, which can effectively solve the problem of the treatment and disposal of these two solid wastes, and achieve "Treating waste with waste".

Description

Composite ceramsite prepared from water purification sludge and diatomite

technical field

The invention belongs to the field of inorganic non-metallic materials, and in particular relates to a composite ceramsite for sewage treatment prepared from water purification sludge and diatomite.

Background technique

Water purification sludge is a by-product produced in the process of purifying raw water in waterworks. It mainly comes from the backwash drainage of filters, sludge discharge from sedimentation tanks or clarification tanks. Since coagulants and softening agents are added during the raw water precipitation process, the sludge will contain corresponding oxides and hydroxides, such as Fe ₂ O ₃ , SiO ₂ , CaO, Mg(OH) ₂ , etc. Mud contains almost all the elements and compounds in the surface layer through which raw water flows, mainly inorganic components, and less organic components such as humus. At present, the water purification sludge is mainly used as waste for landfill treatment, which not only increases the production cost of the waterworks, but also occupies a large amount of land resources. If the water purification sludge is not properly disposed of, there will be "secondary impact on the environment pollution” risk. Since the main components of water purification sludge are similar to conventional clay, water purification sludge can be used instead of clay for the preparation of ceramsite, which has positive significance for sludge reduction, harmlessness, and resource utilization.

Diatomite is a porous biological siliceous rock. Its main component is SiO ₂ , and it also contains a small amount of metal oxides such as iron, calcium, magnesium, and aluminum. Usually, the higher the SiO ₂ content, the better the performance of diatomite. There are a large number of micropores arranged in an orderly manner on the diatomite shell, so diatomite has a large pore volume and specific surface area, a small bulk density, and strong adsorption and filtration capabilities. It is often used in industrial sewage Dealing with adsorbents, brewery filter aids, catalyst supports and more.

At present, there is no strict definition of ceramsite. Ceramsite belongs to a kind of light aggregate. Referring to the definition of artificial light aggregate: ceramsite is a kind of aggregate density less than 1100kg/m ³ , with a particle size of 5~20mm. It is a light aggregate with a certain compressive strength and a shell of ceramic or enamel on the surface. From the point of view of use function, ceramsite is mainly divided into building ceramsite and water treatment ceramsite. At present, my country's ceramsite is mainly clay ceramsite and shale ceramsite. Clay materials are made from cultivated land, and shale materials need to be mined from mountains, which will lead to increased tension in land resources and damage to the ecological environment. Therefore, combined with solid waste resources It is of great practical significance to develop new ceramsite materials through chemical utilization.

There are some invention patents that utilize sludge or diatomite to prepare ceramsite: CN101148348A discloses a method for sintering ceramsite from urban domestic sewage sludge, using more than 70% of urban sludge as the main raw material, and fly ash Clay is used as an auxiliary material, dried, pulverized and mixed, and then mixed, pressurized, preheated, roasted and other processes to obtain ceramsite products. CN102757255A discloses a method for preparing lightweight ceramsite from water purification sludge and sewage sludge, which is made by sintering technology using water purification sludge and sewage sludge as main raw materials. CN102491729A provides a method for preparing boiling water feedwater sludge ceramsite used for pretreatment of slightly polluted water. The ceramsite is composed of a certain proportion of dewatered sludge from a water supply plant, modified zeolite powder and foaming agent in a mass ratio of 50 to 60 %, 35%~49%, 1%~5% are uniformly mixed on the granulator to form balls, the raw materials are dried and then roasted to obtain ceramsite, which is cooled to room temperature and sieved to obtain the finished ceramsite. CN102775120A discloses a preparation method of diatomite porous ceramsite, the method first mixes sodium hydroxide, water glass and water according to 4:17:1:5 to prepare aging agent; according to mass percentage 45%~55% silicon Algae earth, 10%~18% bentonite, 35%~38% water are uniformly mixed, pressed into spherical particles; according to the mass percentage, 20%~30% fly ash, 20%~30% diatomite, 50% aging Prepare the outer shell powder by mixing the agent evenly; put the prepared spherical particles and the outer shell powder into the glutinous rice ball machine according to the mass ratio of 3:1 and roll to obtain ceramsite. CN104785203A discloses a production method of diatomite water purification ceramsite, which is made of diatomite and bentonite according to the mass ratio of 10:1 through batching, mud making, granulation, drying, roasting and other processes. The obtained ceramsite has a transparent texture, has adsorption and filter properties, and is beneficial to the attachment and reproduction of microorganisms.

Contents of the invention

The purpose of the present invention is to solve the problem of secondary pollution to the environment caused by the water purification sludge of the water supply plant, and at the same time combine the waste diatomite produced by the brewery for solid waste resource utilization, and develop a water purification sewage Composite ceramsite prepared from mud and diatomaceous earth. From the perspective of the composition of the sludge, the organic matter and heat content of the sludge are high, which can meet the basic requirements of firing, but the content of SiO ₂ and Al ₂ O ₃ in the sludge is low, and the use of sludge alone for firing Ceramsite cannot form balls, so diatomite with _SiO2 as the main component can be added, and a small amount of calcium oxide can be added as a binder.

Technical solution: The invention discloses a composite ceramsite prepared from water purification sludge and diatomite, which includes the following features: the raw materials used are water purification sludge, diatomite, and calcium oxide, mixed according to a certain proportion, and formed into balls , drying, preheating at 400°C for 25 minutes, and roasting at 900~1200°C for 30 minutes.

The composite ceramsite prepared from a kind of water purification sludge and diatomite is characterized in that: the raw materials used are water purification sludge, diatomite and calcium oxide, and the ratio is by weight: water purification sludge 60 ~90 parts; diatomaceous earth 20~30 parts; calcium oxide 10~20 parts.

Further, the composite ceramsite prepared from water purification sludge and diatomite is characterized in that: the diatomite is waste diatomite or ordinary diatomite recovered from breweries for filter aid One or more kinds of raw materials. When the raw materials are recycled waste diatom earth for filter aid in breweries, it is necessary to carry out hydrothermal pretreatment on the waste diatom earth: the heating temperature is 160°C, and the heating time is 6h to obtain Diatomaceous earth raw material with impurities.

The present invention has following beneficial effect:

1. The blending amount of sludge is as high as more than 60%, and the melting point of sludge is low. The improvement of sludge composition can significantly reduce the melting point of the mixture, and reduce the energy consumption of firing; it can treat and dispose of water purification sludge on a large scale, and realize the The resource utilization of mud can effectively solve the secondary pollution problem existing in the traditional landfill disposal of water purification sludge from water supply plants.

2. Using diatomite as an auxiliary material provides a new way of resource utilization for the waste diatomite produced by filter aids in breweries, and realizes the purpose of "treating waste with waste".

3. The prepared composite ceramsite product has good strength, well-developed pore structure, high water absorption rate and good adsorption performance, and is suitable as a water treatment material.

4. The method is practical and advanced, with simple operation, low cost, no secondary pollution, and can organically unify social benefits, ecological benefits and economic benefits.

Description of drawings

Figure 1 is a sample of composite ceramsite prepared by sintering water purification sludge and diatomite at 1100 °C.

Detailed ways

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

Example 1:

This embodiment provides a kind of composite ceramsite prepared from water purification sludge and diatomite, calculated by weight ratio, its raw materials include:

80 parts of water purification sludge;

20 parts of diatomaceous earth;

10 parts of calcium oxide.

(1) Raw material preparation

Dry the purified water sludge at a temperature of 110°C.

If the diatomite is the waste diatomite recovered from the brewery for filter aid, hydrothermal treatment of the waste diatomite: mix the diatomite with water evenly, put it in the reaction kettle, and put the reaction kettle at a constant temperature Heating in a blast drying oven for 6 h at a temperature of 160 °C, taking out the diatomite after the reaction was completed, and cooling to room temperature naturally. The organic matter in it can be carbonized by hydrothermal method, and the organic matter can be condensed into small spherical particles, so that the spent diatomite can be reactivated.

According to the above weight ratio, the pretreated water purification sludge, diatomaceous earth and calcium oxide are added with water and stirred and mixed uniformly to obtain a mixture.

(2) Prepared into balls

Process the mixture into spheres, the diameter of which ranges from 2cm to 5cm, place the spheres in an electric constant temperature dryer and heat up to 105°C for drying to obtain a dried material.

(3) Preheating treatment

Place the dried material in a box-type electric furnace for preheating treatment: set the heating rate to 10°C/min, raise the temperature in the electric furnace from room temperature to 400°C, and preheat at 400°C for 25 minutes. Preheating the drying material can effectively avoid the rupture caused by the sudden entry of the mixed sphere into a high-temperature environment, and at the same time reduce the energy consumption of the later roasting.

(4) Roasting spheres

The preheated spheres were fired in a box-type electric furnace with a heating rate of 10°C/min, a firing temperature of 1000°C, and a firing time of 30 minutes, and then cooled naturally to room temperature to become finished composite ceramsite.

Example 2:

This embodiment provides a kind of composite ceramsite prepared from water purification sludge and diatomite, calculated by weight ratio, its raw materials include:

80 parts of water purification sludge;

20 parts of diatomaceous earth;

10 parts of calcium oxide.

Preparation steps:

(1) Raw material preparation

Dry the purified water sludge at a temperature of 110°C.

Diatomite is the waste diatomite recovered from the brewery for filter aid, and the waste diatomite is treated with hydrothermal method: the diatomite and water are evenly mixed, placed in the reactor, and the reactor is placed in a constant temperature drum Heat in an air drying oven for 6 h at a temperature of 160 °C. After the reaction is complete, take out the diatomite and let it cool down to room temperature naturally.

According to the above weight ratio, the pretreated water purification sludge, diatomaceous earth and calcium oxide are added with water and stirred and mixed uniformly to obtain a mixture.

(2) Prepared into balls

Knead the mixture by hand into a sphere with a diameter ranging from 2cm to 5cm, place the sphere in an electric constant temperature dryer and heat up to 105°C to dry to obtain a dried material.

(3) Preheating treatment

Place the dried material in a box-type electric furnace for preheating treatment: set the heating rate to 10°C/min, raise the temperature in the electric furnace from room temperature to 400°C, and preheat at 400°C for 25 minutes. Preheating the drying material can effectively avoid the rupture caused by the sudden entry of the mixed sphere into a high-temperature environment, and at the same time reduce the energy consumption of the later roasting.

(4) Roasting spheres

The preheated spheres were fired in a box-type electric furnace with a heating rate of 10°C/min, a firing temperature of 1100°C, and a firing time of 30 minutes, and then cooled naturally to room temperature to become finished composite ceramsite. See Figure 1 for the photo of the ceramsite sample, showing the luster of the enamel surface.

Example 3:

This embodiment provides a kind of composite ceramsite prepared from water purification sludge and diatomite, calculated by weight ratio, its raw materials include:

90 parts of water purification sludge;

20 parts of diatomaceous earth;

15 parts of calcium oxide.

Preparation steps:

(1) Raw material preparation

Dry the purified water sludge at a temperature of 110°C.

Diatomite is the waste diatomite recovered from the brewery for filter aid, and the waste diatomite is treated with hydrothermal method: the diatomite and water are evenly mixed, placed in the reactor, and the reactor is placed in a constant temperature drum Heat in an air drying oven for 6 h at a temperature of 160 °C. After the reaction is complete, take out the diatomite and let it cool down to room temperature naturally.

According to the above weight ratio, the pretreated water purification sludge, diatomaceous earth and calcium oxide are added with water and stirred and mixed uniformly to obtain a mixture.

(2) Prepared into balls

Knead the mixture by hand into a sphere with a diameter ranging from 2cm to 5cm, place the sphere in an electric constant temperature dryer and heat up to 105°C to dry to obtain a dried material.

(3) Preheating treatment

Place the dried material in a box-type electric furnace for preheating treatment: set the heating rate to 10°C/min, raise the temperature in the electric furnace from room temperature to 400°C, and preheat at 400°C for 25 minutes. Preheating the drying material can effectively avoid the rupture caused by the sudden entry of the mixed sphere into a high-temperature environment, and at the same time reduce the energy consumption of the later roasting.

(4) Roasting spheres

The preheated spheres were fired in a box-type electric furnace with a heating rate of 10°C/min, a firing temperature of 1100°C, and a firing time of 30 minutes, and then cooled naturally to room temperature to become finished composite ceramsite.

Example 4:

This embodiment provides a kind of composite ceramsite prepared from water purification sludge and diatomite, calculated by weight ratio, its raw materials include:

80 parts of water purification sludge;

20 parts of diatomaceous earth;

15 parts of calcium oxide.

Preparation steps:

(1) Raw material preparation

Dry the purified water sludge at a temperature of 110°C.

Diatomite is the waste diatomite recovered from the brewery for filter aid, and the waste diatomite is treated with hydrothermal method: the diatomite and water are evenly mixed, placed in the reactor, and the reactor is placed in a constant temperature drum Heat in an air drying oven for 6 h at a temperature of 160 °C. After the reaction is complete, take out the diatomite and let it cool down to room temperature naturally.

According to the above weight ratio, the pretreated water purification sludge, diatomaceous earth and calcium oxide are added with water and stirred and mixed uniformly to obtain a mixture.

(2) Prepared into balls

Knead the mixture by hand into a sphere with a diameter ranging from 2cm to 5cm, place the sphere in an electric constant temperature dryer and heat up to 105°C to dry to obtain a dried material.

(3) Preheating treatment

Place the dried material in a box-type electric furnace for preheating treatment: set the heating rate to 10°C/min, raise the temperature in the electric furnace from room temperature to 400°C, and preheat at 400°C for 25 minutes. Preheating the drying material can effectively avoid the rupture caused by the sudden entry of the mixed sphere into a high-temperature environment, and at the same time reduce the energy consumption of the later roasting.

(4) Roasting spheres

The preheated spheres were fired in a box-type electric furnace with a heating rate of 10°C/min, a firing temperature of 1000°C, and a firing time of 30 minutes, and then cooled naturally to room temperature to become finished composite ceramsite.

The above descriptions are only preferred implementation cases of the present invention, and are not intended to limit the present invention. Any modifications, replacements, improvements, etc. made outside the core and principles of the present invention should be included in the protection scope of the present invention. Inside.

Claims (1)

1. A composite ceramsite prepared from water purification sludge and diatomite, characterized in that: the raw materials used are water purification sludge, diatomaceous earth, calcium oxide, mixed according to a certain proportion, pelletized, dried, and heated at 400°C Preheated for 25 minutes, roasted at 900~1200℃ for 30 minutes; including 60~90 parts of water purification sludge; 20~30 parts of diatomaceous earth; 10~20 parts of calcium oxide; The diatomaceous earth is recycled waste diatomite used for filter aid in breweries, and the waste diatomite needs to be pretreated by hydrothermal method: the heating temperature is 160°C and the heating time is 6h to obtain diatomite with impurities removed. Soil raw materials.