阅读说明：本技术 一种利用洗砂污泥和市政污泥制作的陶粒及其制作方法 (Ceramsite prepared from sand washing sludge and municipal sludge and preparation method thereof ) 是由 张宪芝 刘松 何汇洲 于 2019-11-20 设计创作，主要内容包括：一种利用洗砂污泥和市政污泥制作的陶粒,其特征在于,由以下重量百分比的原料混合均匀后通过至少两条并行的陶粒烧制生产线烧制而成：市政污泥55％-60％、洗砂污泥30.5％-36.5％、外加剂8％-14％,所述洗砂污泥的含水率为8.5％～9.5％,所述的市政污泥的含水率为60-70％,所述的外加剂为高岭土、铝矾土或飞灰；本发明的有益效果：能耗低,城市固废利用率较高。(The ceramsite prepared from the sand washing sludge and the municipal sludge is characterized by being prepared by uniformly mixing the following raw materials in percentage by weight and firing the mixture through at least two parallel ceramsite firing production lines: 55-60% of municipal sludge, 30.5-36.5% of sand washing sludge and 8-14% of an additive, wherein the water content of the sand washing sludge is 8.5-9.5%, the water content of the municipal sludge is 60-70%, and the additive is kaolin, bauxite or fly ash; the invention has the beneficial effects that: low energy consumption and high utilization rate of urban solid wastes.)

1. The ceramsite prepared from the sand washing sludge and the municipal sludge is characterized by being prepared by uniformly mixing the following raw materials in percentage by weight and firing the mixture through at least two parallel ceramsite firing production lines: 55-60% of municipal sludge, 30.5-36.5% of sand washing sludge and 8-14% of an additive, wherein the water content of the sand washing sludge is 8.5-9.5%, the water content of the municipal sludge is 60-70%, and the additive is kaolin, bauxite or fly ash.

2. The ceramsite prepared from the sand washing sludge and the municipal sludge according to claim 1, is prepared by the following method:

(1) taking materials, namely taking municipal sludge, sand washing sludge and an additive as raw materials according to a proportion;

(2) pretreating raw materials, namely crushing the sand washing sludge obtained in the step (1) into powdery particles with the particle size of less than or equal to 0.3 mm;

(3) mixing, namely feeding the taken municipal sludge and the sand washing sludge pretreated in the step (2) into a double-stick mixer, and adding an additive into the double-stick mixer to be uniformly mixed;

(4) aging, namely feeding the mixed raw materials into an aging warehouse for aging treatment, wherein the aging treatment time is 2-3 d;

(5) granulating, namely feeding the raw material treated in the step (4) into a double-roller granulator for granulation so as to prepare material balls from the raw material treated in the step (4);

(6) screening, namely screening the material balls prepared in the step (5) by using a screening machine, and taking the material balls with the particle size of more than or equal to 1mm as qualified material balls for later use;

(7) roasting, namely feeding the qualified pellets obtained in the step (6) into a rotary kiln for roasting, wherein the roasting temperature in the rotary kiln is 900-1200 ℃, the roasting time is 40-60min, and high-temperature ceramsite is obtained after roasting; the flue gas generated in the roasting process passes through a belt type dust remover and a spray tower and then is discharged after reaching the standard;

(8) cooling, namely feeding the high-temperature ceramsite obtained in the step (7) into a cooler to be cooled to the temperature of less than 60 ℃ to obtain cooled ceramsite;

(9) and (4) screening, namely feeding the cooled ceramsite obtained in the step (8) into a screening machine for screening, selecting the cooled ceramsite with the particle size of more than or equal to 1mm as a finished product, and returning the rest cooled ceramsite to the double-roller stirrer for mixing.

3. The ceramsite prepared from sand washing sludge and municipal sludge according to claim 2, wherein the fuel used in the roasting process in step (7) is natural gas or biomass fuel.

4. The ceramsite prepared from the sand washing sludge and the municipal sludge according to claim 2, wherein the heat recovered by the cooler during cooling the high-temperature ceramsite in the step (8) is returned to the step (7) for recycling.

5. The ceramsite prepared from the sand washing sludge and the municipal sludge is characterized by being prepared by uniformly mixing the following raw materials in percentage by weight and firing the mixture through at least two parallel ceramsite firing production lines: 60% of municipal sludge, 30% of sand washing sludge and 10% of additive, wherein the water content of the sand washing sludge is 8.5% -9.5%, the water content of the municipal sludge is 65%, and the additive is kaolin, bauxite or fly ash.

6. The ceramsite prepared from the sand washing sludge and the municipal sludge according to claim 5, which is prepared by the following steps,

a. taking materials, namely taking municipal sludge, sand washing sludge and an additive as raw materials according to a proportion;

b. mixing, namely uniformly mixing the weighed raw materials by a wheel mill;

c. drying, namely drying the uniformly mixed raw materials to ensure that the water content in the dried raw materials is less than or equal to 45 percent;

d. stirring and mixing, namely feeding the dried raw materials into a double-stick stirrer for further uniformly mixing;

e. aging, namely feeding the mixed raw materials into an aging warehouse for aging treatment, wherein the aging treatment time is 2-3 d;

f. granulating, namely feeding the raw material treated in the step (4) into a double-roller granulator for granulation so as to prepare material balls from the raw material treated in the step (4);

g. screening, namely screening the material balls prepared in the step (5) by using a screening machine, and taking the material balls with the particle size of more than or equal to 1mm as qualified material balls for later use;

h. roasting, namely feeding the qualified pellets obtained in the step (6) into a rotary kiln for roasting, wherein the roasting temperature in the rotary kiln is 900-1200 ℃, the roasting time is 40-60min, and high-temperature ceramsite is obtained after roasting; the flue gas generated in the roasting process passes through a belt type dust remover and a spray tower and then is discharged after reaching the standard;

i. cooling, namely feeding the high-temperature ceramsite obtained in the step (7) into a cooler to be cooled to the temperature of less than 60 ℃ to obtain cooled ceramsite;

j. and (4) screening, namely feeding the cooled ceramsite obtained in the step (8) into a screening machine for screening, selecting the cooled ceramsite with the particle size of more than or equal to 1mm as a finished product, and returning the rest cooled ceramsite to the double-roller stirrer for mixing.

7. The ceramsite of claim 6, wherein the drying temperature in step c is 200 ℃.

8. The ceramsite prepared from sand washing sludge and municipal sludge according to claim 6, wherein the water content in the dried raw material in step c is preferably 30-40%.

9. The ceramsite prepared from sand washing sludge and municipal sludge according to claim 6, wherein the fuel used in the roasting process in step h is natural gas or biomass fuel.

10. The ceramsite according to claim 6, wherein the heat recovered by the cooler during cooling the high-temperature ceramsite in step j is recycled in step h.

Technical Field

The invention relates to a method for manufacturing ceramsite, in particular to a method for manufacturing ceramsite by utilizing sand washing sludge and municipal sludge.

Background

The urban domestic sewage and the industrial wastewater can be discharged only after being treated by a sewage treatment plant and reaching the national sewage discharge standard, which is an essential environmental engineering measure for urban ecological environment construction. The sludge is an accessory after sewage treatment, is a very complex heterogeneous body consisting of organic matters, nitrogen, phosphorus, heavy metals, pathogens, ash and other components, is a waste with great harmfulness, and can cause serious secondary pollution to the environment if not thoroughly treated and controlled.

The amount of sludge is usually 0.3-0.5% by volume of the amount of sewage, and if advanced sewage treatment is used, the amount of sludge is increased by 0.5-1 times. At present, domestic sludge treatment methods mainly comprise landfill, incineration and composting, but the methods have obvious defects. The waste of land resources is large by sludge landfill, and the leachate of the landfill site easily pollutes underground water sources. Sludge incineration can reduce the volume and the amount to the maximum extent, but has the problems of high treatment cost, difficult treatment of residues after incineration and the like. The sludge compost has the advantages of low energy consumption, capability of recycling nutrients in sludge and the like, but has potential risks of pathogenic bacteria diffusion and heavy metal pollution. In view of the above, the search for a new sludge treatment method which is economical and reasonable and is compatible with the environmental development is a research focus of current sludge treatment, and one of the focuses is to use sludge to manufacture ceramsite.

The ceramsite is a light aggregate, has the advantages of small density, high strength, good heat preservation and heat insulation performance and the like, is a novel building base material with excellent performance, and has great market demand. The traditional porcelain granules are made of clay minerals, and the production cost is higher due to the influence of the price of the clay minerals, so that the yield of the clay porcelain granules is limited, and the vigorous development of related industries is also restricted. The sludge is used as a raw material to prepare the ceramsite, organic matters in the sludge can be used as a gas product to enable the ceramsite to form a porous structure, the consumption of other fuels is reduced, inorganic components in the sludge can be utilized, toxic heavy metals in the sludge can be solidified at high temperature, pathogens can be inactivated, and the environment, economic and social benefits are remarkable. But SiO in the sludge₂The content of the clay ceramsite is low, the loss on ignition is large, and the clay ceramsite has no burning expansion performance, so that a certain amount of auxiliary materials and additives are required to be added when the sludge is prepared, and the components of the prepared ceramsite reach the component standard for preparing the clay ceramsite.

The existing method for preparing ceramsite from sludge mainly comprises the steps of drying wet sludge in a dryer to form semi-dry sludge, uniformly mixing the semi-dry sludge with other materials (clay and coal ash), preparing the mixture into pellets in a granulator, feeding the pellets into a roasting kiln for roasting, and feeding the high-temperature ceramsite roasted in the roasting kiln into a cooling cylinder for cooling. The hot air generated in the cooling process is used as combustion-supporting air of a combustor and secondary air of a burning section, and the flue gas generated at the tail part of the roasting kiln is exhausted by a chimney through a draught fan after passing through a dust remover, a sludge dryer and a purification tower. And (3) sorting the cooled ceramsite discharged from the cooling cylinder by a screening machine, selecting the ceramsite with the granularity of more than 1 millimeter (mm) as aggregate, and sending the ceramsite with the granularity of less than 1mm back to the stirring machine.

However, the existing method for preparing ceramsite from sludge needs a large amount of clay, which causes certain damage to the environment, and equipment of the existing method is easy to break down, so that the whole production line is forced to stop production. In view of the above, there is a need to provide a new method for producing ceramsite from sludge to solve the above problems.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides ceramsite prepared from sand washing sludge and municipal sludge and a preparation method thereof.

The invention is realized by the following technical scheme,

the ceramsite prepared from the sand washing sludge and the municipal sludge is prepared by uniformly mixing the following raw materials in percentage by weight and firing the mixture through at least two parallel ceramsite firing production lines: 55-60% of municipal sludge, 30.5-36.5% of sand washing sludge and 8-14% of additive; the water content of the sand washing sludge is 8.5-9.5%, the water content of the municipal sludge is 60-70%, and the additive is kaolin, bauxite or fly ash.

A ceramsite prepared from sand washing sludge and municipal sludge is prepared by the following method:

(1) taking materials, namely taking municipal sludge, sand washing sludge and an additive as raw materials according to a proportion;

(2) pretreating raw materials, namely crushing the sand washing sludge obtained in the step (1) into powdery particles with the particle size of less than or equal to 0.3 mm;

(3) mixing, namely feeding the taken municipal sludge and the sand washing sludge pretreated in the step (2) into a double-stick mixer, and adding an additive into the double-stick mixer to be uniformly mixed;

(4) aging, namely feeding the mixed raw materials into an aging warehouse for aging treatment, wherein the aging treatment time is 2-3 d;

(5) granulating, namely feeding the raw material treated in the step (4) into a double-roller granulator for granulation so as to prepare material balls from the raw material treated in the step (4);

(6) screening, namely screening the material balls prepared in the step (5) by using a screening machine, and taking the material balls with the particle size of more than or equal to 1mm as qualified material balls for later use;

(7) roasting, namely feeding the qualified pellets obtained in the step (6) into a rotary kiln for roasting, wherein the roasting temperature in the rotary kiln is 900-1200 ℃, the roasting time is 40-60min, and high-temperature ceramsite is obtained after roasting; the flue gas generated in the roasting process passes through a belt type dust remover and a spray tower and then is discharged after reaching the standard;

(8) cooling, namely feeding the high-temperature ceramsite obtained in the step (7) into a cooler to be cooled to the temperature of less than 60 ℃ to obtain cooled ceramsite;

(9) and (4) screening, namely feeding the cooled ceramsite obtained in the step (8) into a screening machine for screening, selecting the cooled ceramsite with the particle size of more than or equal to 1mm as a finished product, and returning the rest cooled ceramsite to the double-roller stirrer for mixing.

Preferably, the fuel used in the roasting process in step (7) is natural gas or biomass fuel.

Preferably, the heat recovered by the cooler when the high-temperature ceramsite is cooled in the step (8) is returned to the step (7) for recycling.

The ceramsite prepared from the sand washing sludge and the municipal sludge is prepared by uniformly mixing the following raw materials in percentage by weight and firing the mixture through at least two parallel ceramsite firing production lines: 60% of municipal sludge, 30% of sand washing sludge and 10% of additive, wherein the water content of the sand washing sludge is 8.5% -9.5%, the water content of the municipal sludge is 65%, and the additive is kaolin, bauxite or fly ash.

A haydite made of sand washing sludge and municipal sludge is prepared by the following steps,

a. taking materials, namely taking municipal sludge, sand washing sludge and an additive as raw materials according to a proportion;

b. mixing, namely uniformly mixing the weighed raw materials by a wheel mill;

c. drying, namely drying the uniformly mixed raw materials to ensure that the water content in the dried raw materials is less than or equal to 45 percent;

d. stirring and mixing, namely feeding the dried raw materials into a double-stick stirrer for further uniformly mixing;

e. aging, namely feeding the mixed raw materials into an aging warehouse for aging treatment, wherein the aging treatment time is 2-3 d;

f. granulating, namely feeding the raw material treated in the step (4) into a double-roller granulator for granulation so as to prepare material balls from the raw material treated in the step (4);

g. screening, namely screening the material balls prepared in the step (5) by using a screening machine, and taking the material balls with the particle size of more than or equal to 1mm as qualified material balls for later use;

h. roasting, namely feeding the qualified pellets obtained in the step (6) into a rotary kiln for roasting, wherein the roasting temperature in the rotary kiln is 900-1200 ℃, the roasting time is 40-60min, and high-temperature ceramsite is obtained after roasting; the flue gas generated in the roasting process passes through a belt type dust remover and a spray tower and then is discharged after reaching the standard;

i. cooling, namely feeding the high-temperature ceramsite obtained in the step (7) into a cooler to be cooled to 5-15 ℃ to obtain cooled ceramsite;

j. and (4) screening, namely feeding the cooled ceramsite obtained in the step (8) into a screening machine for screening, selecting the cooled ceramsite with the particle size of more than or equal to 1mm as a finished product, and returning the rest cooled ceramsite to the double-roller stirrer for mixing.

Preferably, the drying temperature in step c is 200 ℃.

Preferably, the water content of the dried raw material in the step c is preferably 30-40%.

Preferably, the fuel used in the roasting process in step h is natural gas or biomass fuel.

Preferably, the heat recovered by the cooler when the high-temperature ceramsite is cooled in the step j is returned to the step h for recycling.

Compared with the prior art, the invention has the following beneficial effects: 1. the method for preparing the ceramsite does not need to dry the sludge to prepare the half-dry sludge, and then mix the half-dry sludge with other raw materials, so that the proportion of the sludge in the raw materials is improved, the reutilization of the sludge is realized, the problem of sludge direction is solved, and the secondary pollution of the sludge to the environment is avoided; 2. the invention adopts the sand washing sludge to replace clay, thereby not only solving the recycling of the urban waste soil and the phenomenon that a large amount of urban waste soil is disorderly dumped, but also avoiding the problem that cultivated land is damaged due to the exploitation of clay, protecting the farmland and saving resources; 3. according to the invention, the water content of the mixed raw materials is quantized, the raw materials which do not meet the water content requirement are dried, and the heat source required by drying adopts the waste heat generated when the ceramsite is roasted and cooled, so that the energy consumption is reduced, and the energy conservation is realized; 4. the method for manufacturing the ceramsite adopts at least two parallel ceramsite firing production lines to produce the ceramsite, can greatly improve the production capacity of the ceramsite, can still continue to produce when one ceramsite firing production line fails and needs to be overhauled, and can transfer the raw materials conveyed to the failed ceramsite firing production line to a normal ceramsite firing production line for production, so that the reliability of the whole system is greatly improved.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.