CN-118084531-B - Preparation technical method of sludge-based light composite ceramsite

Abstract

The invention discloses a technical method for preparing sludge-based light composite ceramsite, which comprises the steps of uniformly mixing dewatered sludge of a sewage plant with construction waste powder, an expanding agent, a regulator and a fluxing agent, adding a composite binder, adjusting the water content of the mixed material, preparing a circular ceramsite blank, coating enamel layer materials on the outer surface of the circular ceramsite blank, naturally airing for 24-48 hours, sintering the dried ceramsite blank at 1030-1180 ℃ for 15-40 min, and naturally cooling to obtain the sludge-based light composite ceramsite. The invention realizes the synergistic treatment and resource utilization of the sludge of sewage plants, the iron-containing dust sludge, the crop straw and other multiple solid wastes, and the prepared lightweight ceramsite has developed internal closed pores, low stacking density and high compressive strength, and can be widely applied to the fields of landscaping, heat preservation/heat insulation building materials and the like.

Inventors

• CHEN GUOLEI
• LIU SHUGEN
• PENG YUXIN
• TIAN SENLIN
• ZHAO QUN
• SHI JIANWU

Assignees

• 昆明理工大学

Dates

Publication Date

20260508

Application Date

20240301

Claims (5)

1. 1. The technical method for preparing the sludge-based light composite ceramsite is characterized by comprising the following steps of: (1) Mixing dehydrated sludge of a sewage plant and construction waste to obtain Tao Jiti materials, sequentially adding an expanding agent, a regulator, a fluxing agent and a composite binder, regulating the water content of the mixed materials, stirring and mixing uniformly to prepare a round ceramsite blank, wherein the mass ratio of the dehydrated sludge of the sewage plant to the construction waste is 10:1-2, the construction waste comprises powdery waste bricks and mortar with the mass ratio of 8:3-5, the particle size of the powdery waste bricks in the construction waste is 0.18-0.45 mm, the composite binder consists of a solid binder and a liquid binder, the addition amount of the solid binder is 35-40% of the mass ratio of Tao Jiti materials, the solid binder consists of bentonite and coal gangue according to the mass ratio of 10:2-4, the liquid binder is a polyacrylamide solution, the concentration of the mother solution is 1.5-2.5 g/L, and the liquid binder mother solution is added into Tao Jiti materials per 1: 1 kg; (2) Coating the outer surface of the obtained ceramsite blank with enamel layer materials of 0.6-1.5 mm, and naturally airing for 24-48 hours, wherein the enamel layer materials consist of 0-5% of ferric oxide, 0-15% of manganese oxide, 35-50% of anorthite mineral powder and 40-55% of bentonite in percentage by mass; (3) And (3) carrying out high-temperature sintering treatment on the dried ceramic aggregate blank, and naturally cooling to obtain the sludge-based light composite ceramic aggregate, wherein the high-temperature sintering temperature of the ceramic aggregate blank is 1030-1180 ℃ and the sintering time is 15-40 min.
2. 2. The technical method for preparing the sludge-based light composite ceramsite, which is characterized in that the step (1) is characterized in that an expanding agent is added according to the mass of Tao Jiti-14%, wherein the expanding agent consists of two or more of iron-containing dust sludge, fe 2 O 3 and red mud, and the Fe 2 O 3 component is required to be contained and accounts for 20-35% of the mass of the expanding agent.
3. 3. The technical method for preparing the sludge-based light composite ceramsite, which is characterized in that in the step (1), agricultural and forestry biomass waste is added according to the mass of Tao Jiti to 12 percent of the mass of the material to serve as a regulator, wherein the regulator comprises sawdust, peanut shell powder and corn cob powder, and the proportion of the sawdust to the mass of the regulator is 45 to 65 percent.
4. 4. The technical method for preparing the sludge-based light composite ceramsite, which is characterized in that in the step (1), a fluxing agent is added according to the mass ratio of Tao Jiti mass percent of materials, wherein the fluxing agent consists of CaO and MgO, and the mass ratio of the fluxing agent is 1:0.8-1.2.
5. 5. The technical method for preparing the sludge-based light composite ceramsite is characterized in that the moisture content of the ceramsite blank is 64% -72%, and the moisture content of the air-dried ceramsite blank is 12% -20%.

Description

Preparation technical method of sludge-based light composite ceramsite Technical Field The invention belongs to the technical field of solid waste treatment and resource utilization, and particularly relates to a technical method for preparing sludge-based light composite ceramsite. Background With the increasing importance of countries and society for environmental protection, solid waste is becoming a misplaced resource, and its disposal and recycling are becoming a great concern. The sludge is organic matter solid waste produced in the urban sewage treatment process, has complex components, often contains pathogenic microorganisms, parasitic ova, toxic and harmful heavy metals and a large amount of refractory substances, and is extremely easy to cause secondary pollution to the environment if the sludge is improperly treated. At present, the recycling of the sludge mainly comprises the steps of recovering heat energy by cement kiln collaborative incineration, extracting protein or releasing carbon sources in the sludge, producing building materials, preparing RDF fuel, utilizing the land after composting and the like. The sludge building material utilization is an effective sludge reduction and resource utilization means. The basic approach of sludge as building material can be divided into two types according to the different pretreatment modes of sludge, wherein one type is that the sludge is directly used for building material manufacture after dehydration and drying, and the other type is that the sludge is used for building material manufacture after treatment characterized by chemical composition conversion, and the typical treatment mode is incineration and melting. At present, sludge building material utilization has been regarded as a sustainable sludge disposal mode that is rapidly developing in japan and european countries and regions. The prior patent CN108002859A discloses a process for preparing lightweight porous ceramsite by using sludge, which comprises the steps of drying the sludge at a temperature of more than 100 ℃, grinding the sludge, kaolin, an expanding agent and CaF 2 into mixed powder, extruding and granulating to prepare ceramsite raw materials, preheating and baking at a high temperature for a long time, and calcining at a high temperature of 1300 ℃ to be approximately 1 h. The invention can produce high-quality ceramsite, but the technological process is complex, the firing time of the ceramsite is long, and the energy consumption is high. Patent CN112010668a discloses a method for preparing haydite from sludge without drying and preheating, which comprises mixing dewatered sludge and clay uniformly according to a given proportion, making into haydite blank, air drying under natural condition, and sintering in a high temperature furnace. The invention simplifies the process flow and saves the cost, but the amount of the consumed sludge is very small when the haydite is prepared, the proportion of the clay in the raw materials reaches more than 50 percent, the clay belongs to non-renewable resources, and the application of the clay haydite is forbidden in the recent years. How to develop a novel technology for preparing sludge-based ceramsite according to local conditions and specific conditions, a large amount of sludge in a sewage plant is consumed, and the energy consumption of the ceramsite preparation technology is obviously reduced, so that technical innovation and breakthrough are urgently needed. Disclosure of Invention The invention provides a technical method for preparing a sludge-based light composite ceramsite, which comprises the steps of taking dewatered sludge of a sewage plant and powdery construction waste as Tao Jiti materials, sequentially adding an expanding agent, a regulator, a fluxing agent and a composite binder, preparing a ceramsite blank, coating enamel layer materials on the outside of the ceramsite blank, performing high-temperature sintering treatment after natural air drying, and naturally cooling to obtain the sludge-based light composite ceramsite. The prepared ceramsite has good porosity, the stacking density is generally 350-480 kg/m 3, and the compressive strength is 1.3-1.8 MPa, and is widely applied to the fields of garden flowers, heat preservation/insulation, ventilation and drainage, building backfill and the like. The implementation steps of the invention are as follows (1) Mixing dehydrated sludge of a sewage plant and crushed construction waste to obtain Tao Jiti materials, sequentially adding an expanding agent, a regulator and a fluxing agent to realize that the ceramsite prepared under the condition of lower temperature has a good closed pore structure, adding a solid and liquid composite binder, adjusting the water content of the materials, stirring and mixing uniformly to prepare a round ceramsite blank with uniform texture; (2) Coating enamel layer materials on the outer surface of the obtained ceramsite blank for 0.6-1.5 mm,