US 2020/0048147 A1 · METHOD FOR PREPARING CERAMSITE BY USING MUNICIPAL SLUDGE AS RAW MATERIAL

Abstract

A method for preparing ceramsite by using municipal sludge as raw material, including the following specific steps: drying; preparing ingredients including raw sludge, fly ash, kaolinite, steelmaking slag, zeolite, hematite, calcareous shale, waste incineration fly ash, Fe2O3, waste glass, calcium carbonate, sodium lauryl sulfate, and sodium benzoate; mixing and stirring uniformly, and putting the stirred materials into a granulating machine for granulation; drying and preheating the material pellets after granulation, and then quickly transferring to a sintering device for first sintering at a low temperature and then sintering at a high temperature; crushing large chunks of the cooled materials; and separating and screening the crushed materials. The method of the present invention reduces the generation of the large chunks of the cooled materials in the obtained ceramsite, thereby reducing the subsequent crushing work and saving energy consumption accordingly.

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Claims8

Dependent claims

A method for preparing ceramsite by using municipal sludge as a raw material, comprising:

(1) drying:
concentrating, digesting, mechanically dehydrating and drying the municipal sludge to obtain a raw sludge;
wherein the step of the digesting comprises:
removing a biodegradable organic matter in the municipal sludge by a common anaerobic process;
(2) preparing ingredients:
taking the ingredients according to the following parts by weight:
80-120 parts of the raw sludge, 10-20 parts of fly ash, 1-5 parts of kaolinite, 10-20 parts of steelmaking slag, 5-15 parts of zeolite, 1-5 parts of hematite, 5-15 parts of calcareous shale, 5-20 parts of waste incineration fly ash, 0.5-2 parts of Fe2O3, 1-4 parts of waste glass, 0.1-2 parts of calcium carbonate, 0.1-2 parts of sodium lauryl sulfate, and 0.1-1.5 parts of sodium benzoate;
(3) mixing and stirring the ingredients uniformly to obtain stirred materials, pouring the stirred materials into a granulating machine for a granulation to obtain material pellets, and controlling a particle size of the material pellets to range from 15 mm to 20 mm;
(4) drying the material pellets after the granulation at 90-110° C. for 1-2 hours to obtain dried material pellets, then preheating the dried material pellets at 220-280° C. for 10-20 minutes to obtain preheated material pellets, then transferring the preheated material pellets to a sintering device for a sintering to obtain sintered material pellets, and then cooling the sintered material pellets to obtain cooled materials;
(5) discharging the cooled materials, and crushing large chunks of the cooled materials into crushed materials with a maximum particle size of 20-26 mm;
and
(6) separating and screening the crushed materials to obtain a first ceramsite having a particle size of 5-15 mm, a second ceramsite having a particle size of 15-26 mm, a ceramic sand having a particle size of 0.5-5 mm, and a fine powder having a particle size of less than 0.5 mm.

9 more elements

A method for preparing ceramsite by using municipal sludge as a raw material, comprising:

(1) drying:
concentrating, digesting, mechanically dehydrating and drying the municipal sludge to obtain a raw sludge;
wherein the step of the digesting comprises:
removing a biodegradable organic matter in the municipal sludge by a common anaerobic process;
(2) preparing ingredients:
taking the ingredients according to the following parts by weight:
80-120 parts of the raw sludge, 10-20 parts of fly ash, 1-5 parts of kaolinite, 10-20 parts of steelmaking slag, 5-15 parts of zeolite, 1-5 parts of hematite, 5-15 parts of calcareous shale, 5-20 parts of waste incineration fly ash, 0.5-2 parts of Fe2O3, 1-4 parts of waste glass, 0.1-2 parts of calcium carbonate, 0.1-2 parts of sodium lauryl sulfate, 0.1-1.5 parts of sodium benzoate, 0.1-0.5 part of nano zirconia, 1-5 parts of kaolinite porcelain clay;
2-4 parts of silicon nitride;
and 1-4 parts of calcium oxide;
(3) mixing and stirring the ingredients uniformly to obtain stirred materials, putting the stirred materials into a granulating machine for a granulation to obtain material pellets, and controlling a particle size of the material pellets to range from 15 mm to 20 mm;
(4) drying the material pellets after the granulation at 90-110° C. for 1-2 hours to obtain dried material pellets, then preheating the dried material pellets at 220-280° C. for 10-20 minutes to obtain preheated material pellets, then transferring the preheated material pellets to a sintering device for a sintering to obtain sintered material pellets, and then cooling the sintered material pellets to obtain cooled materials;
(5) discharging the cooled materials, and crushing large chunks of the cooled materials into crushed materials with a maximum particle size of 20-26 mm;
and
(6) separating and screening the crushed materials to obtain a first ceramsite having a particle size of 5-15 mm, a second ceramsite having a particle size of 15-26 mm, a ceramic sand having a particle size of 0.5-5 mm, and a fine powder having a particle size of less than 0.5 mm.

11 more elements

Dependencies are inferred from the claim text.

Description5,529 words

Summary1,651 words

#The present invention belongs to the field of ceramsite preparation, and more specifically relates to a method for preparing ceramsite by using municipal sludge as a raw material.

#In recent years, with the rapid development of Chinese cities and the increase of population in China, a significantly increasing amount of municipal sludge is being produced in the cities of China. The conventional methods for treating the municipal sludge are composting, incineration, and land reclamation. Whereas the pollution, caused by a large amount of harmful microorganisms, heavy metals and leachates in the municipal sludge, has raised many people's concerns. The recent environmental regulations have imposed strict regulations on municipal sludge disposal. For example, a few years ago, the municipal sludge could be used directly as agricultural fertilizer. Nowadays, the municipal sludge has been banned as a fertilizer due to a high content of heavy metals in the sludge.

#One of the most effective methods for treating the municipal sludge is to use the municipal sludge to produce ceramsite. The production of ceramsite will effectively solve the problem of the municipal sludge accumulation, avoiding secondary pollution to the environment caused by improper discharge. Moreover, the ceramsite, as a lightweight aggregate, can be used in basic buildings, and also alleviates the resource crisis of building materials such as sand, stone, etc. This method complies with the current national policy in China on the resource utilization of solid wastes.

Detailed description3,878 words

#The present invention is further illustrated by the following embodiments.

#A method for preparing ceramsite by using a municipal sludge taken from a sewage treatment plant in Qingdao as a raw material include the following specific steps.

#(1) Drying: the municipal sludge is concentrated, digested, mechanically dehydrated and dried to obtain a raw sludge with a water content of about 23%.

Method for preparing ceramsite by using municipal sludge as raw material

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Method for preparing ceramsite by using municipal sludge as raw material

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Abstract

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Claims8

Description5,529 words

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Description5,529 words