analysis of preparation technology of high performance lightweight aggregate -尊龙登录

1 preface
ceramsite is a kind of light aggregate produced by foaming in kiln. it has a spherical shape, hard surface and honeycomb inside. ceramsite has excellent properties, such as low density, high compressive strength, high porosity, high softening coefficient, good frost resistance and alkali resistant aggregate reaction. in particular, because of its small density, porous interior, uniform shape and composition, and certain strength and firmness, it has the characteristics of light weight, corrosion resistance, frost resistance, earthquake resistance and good isolation.
and the production of ceramsite can use a large number of solid waste, widely used in sludge, tailings, coal gangue, fly ash, red mud, industrial waste, fly ash and other waste disposal. "treating waste with waste" will eventually produce a green product with high added value - ceramsite.
2. ceramsite is widely used
ceramsite, as a kind of high-performance lightweight aggregate, can be used in prefabricated building components, lightweight aggregate concrete, sponge city construction, sewage filter material, ecological wetland construction, etc., with high added value and broad application prospect (figure 1).

figure 1 application scope of ceramsite

using ceramsite instead of sand and stone aggregate to prepare concrete in commercial concrete can effectively reduce the weight of buildings, and has the advantages of good heat preservation performance, strong impermeability and fire resistance. fabricated building structural parts, high-rise building insulation blocks, large-span concrete components, foundation backfilling and pouring can be widely used.
sponge city seepage water storage. ceramsite has many pores and strong adsorption. it is an ideal sponge material for the construction of sponge city. it can be used in building green roof soilless cultivation, permeable pavement laying, etc. ceramsite can absorb and lock up a lot of rainwater and eliminate urban waterlogging. when the weather is hot, the water evaporates, reducing the urban heat island effect.
used as filter material for sewage treatment. ceramsite filter material is light in quality, high in porosity, large in surface area, strong in mechanical strength and adsorption, stable in chemical properties, and cheaper than activated carbon. it is suitable for decolorization and other treatment, and can also be used as industrial filter material.
wetland floating bed green planting. because of the uniform distribution of pores, strong permeability and water absorption, ultra light through-hole ceramsite can be used for cultivation of microorganisms and green plants. it can be used in floating bed ecosystem, wetland ecosystem and so on, which is beneficial to plant root growth and can purify various water systems. it is an ideal way to deal with eutrophication water.

3 preparation technology of super high strength solid waste ceramsite

hengyuanli waste co., ltd. introduced fall type rotary kiln of rtal company of uk in 2012, and cooperated with chinese academy of sciences to develop the technology of "collaborative treatment of industrial solid waste calcined ceramsite".
the method of "low temperature drying high temperature roasting" is adopted to produce ceramsite. the whole production line adopts a unique set of ceramsite forming patent technology (patent no.: 201310564630.7). after the sludge and the solid wastes of si al system are mixed and granulated, they are dried at 200 ℃ and then directly put into the kiln for roasting at 1100 ℃. this method can greatly improve the yield of ceramsite, and the temperature of drying and baking section avoids the producing area of dioxin. during the roasting process, the organic matter of sludge is all combustion supporting, the solid wastes of silicon aluminum system are melted and recombined at high temperature, the heavy metal elements are solidified into the lattice, and finally the resource product ceramsite is formed.
the core roasting equipment waterfall rotary kiln is originated from england. the unique three leaf arc-shaped section heat exchange efficiency is high, which is twice as high as the traditional rotary kiln, realizing the purpose of low consumption and high yield. the length of the kiln is only 1 / 4 of that of the traditional rotary kiln, and the pelletizing process outside the kiln is adopted. the whole production line occupies a small area and has a high utilization rate of space, which greatly reduces the investment in civil engineering. the supporting waste heat recycling system can recycle the heat of kiln tail gas, and then use it in dehydration and drying, which meets the development requirements of green energy saving.
the production workshop is completely closed, and the negative pressure is used to treat the flue gas and odor, so as to achieve no secondary pollution. the whole production line integrates sludge drying, aging, molding, sintering and cooling, and is equipped with a cleaning treatment system. the whole process of ceramsite production is automated, and the whole workshop is almost unmanned. in the high-temperature roasting section of the core link, through the flame automatic control system matched with high-definition camera monitoring in the kiln, precise temperature adjustment can be realized to ensure the high quality of ceramsite products.
the technology has six characteristics, such as large amount of sludge, high yield and low energy consumption, electric control automation, waste heat reuse, flue gas odor treatment, small investment and so on. it represents the advanced level of domestic ceramsite production industry.
3.1 utilization of various solid wastes with high content
it can be widely used in the complete treatment of tailings, coal gangue, fly ash, red mud, sludge, sludge, engineering waste soil and industrial waste residue. the content of fly ash and tailings can reach more than 90%, and the content of sludge can reach more than 30%.
3.2 environmental protection and no pollution of production line
the flue gas can be controlled to stay for more than 2 seconds at 850 ℃ in the combustion chamber, so that the dioxin can be completely decomposed. the system of flue gas recovery, odor disposal, air pollutant treatment, etc. is adopted to make the pollutant discharge meet the environmental protection requirements.
3.3 low efficiency, high energy consumption of roasting equipment
the core equipment of the production line - waterfall rotary kiln (patent no.: zl201310564729.7) (fig. 2, fig. 3), is developed in cooperation with rtal (huantai) co., ltd. in the uk. the unique three leaf structure in the kiln has high heat exchange rate, low energy consumption and small land occupation. fully automatic flame monitoring, automatic temperature control in the kiln, dual channel burner can realize instant fuel switching, saving 30% energy than traditional kiln.

 figure 2 waterfall rotary kiln       3 waterfall rotary kiln and wireless temperature collection and monitoring

the kiln can run stably above 1200 ℃, the high temperature environment can effectively kill the pathogens and parasites in the solid waste, and solidify and stabilize the toxic and harmful substances such as heavy metals in the finished products. the production line can realize full airtight production. odor pipeline is set for sludge comprehensive utilization project to collect odor and conduct environmental protection treatment in a unified way, without odor. the whole process temperature of the kiln is controlled above 850 ℃, which can effectively prevent the generation of dioxins.

3.4 high efficiency of mixing equipment
vertical turbulent mixer (patent no.: zl201010201175.0) (fig. 4, fig. 5) overcomes the problem of uneven mixing of viscous materials, and makes the uniformity of viscous materials reach 99.8% in 90 seconds. the rotating cylinder and the unique mixing device make full use of the counter current and cross flow to improve the mixing effect. alloy high-strength wear-resistant blade, with military special coating, effectively prolong the service life of the equipment. the production capacity is customized according to the customer's needs, and the rotating speed is adjustable, which can meet the needs of mixing, granulation and other different needs.

fig. 4 vertical turbulence mixer                                                              fig. 5 actual mixing scene of vertical turbulence mixer

3.5 waste heat reuse of production line
a heat exchanger (fig. 6) is set at the kiln tail to use the clean air after heat exchange for drying the raw meal ball. the drying section does not need to set external heat source to reduce energy consumption.

fig. 6 waste heat recycling device

3.6 automatic control of production line
automatic operation of production line, online monitoring and alarm system are set, and automatic sequence start and stop of production process is realized through automatic control system. conduct real-time monitoring on production process and equipment operation status to ensure equipment operation safety and alarm prompt in case of abnormal conditions.
3.7 high quality ceramsite products
the technology of "low temperature drying and high temperature roasting" is adopted to solve the problem of low strength and easy crushing of raw meal balls. the strength of ceramsite products is high, and the cylinder pressure strength can reach more than 15mpa.
3.8 wide range of product application
high strength ceramsite has a wide range of applications, which can be used as a substitute of natural sand aggregate for commercial concrete and prefabricated components; can be used to produce ceramsite aerated concrete as load-bearing materials for retaining structures; can be used to produce ceramsite blocks, eps ceramsite insulation wall panels; can be used to produce sponge city permeable blocks; can be used as sewage treatment and filtration materials.
4 conclusion
hengyuan waste is committed to the development of circular economy and the comprehensive utilization of bulk solid waste. it has core technologies such as solid waste preparation of ceramsite, solid waste preparation of aerated concrete, solid waste preparation of autoclaved brick, zero diffusion dredging of heavy metal sediment, tailings concentration and dry drainage, mine filling, etc.
after more than ten years of development, hengyuan has achieved fruitful results in the field of comprehensive utilization of large amount of solid wastes. up to now, the company has undertaken and completed more than 600 comprehensive utilization projects of industrial solid wastes, which can achieve an annual total of over 120 million tons of various industrial solid wastes.
after more than 600 projects, the company has trained a high-quality team with customer service as the center, solid professional skills and quick response, including many professional talents in material analysis, process design, electrical design, mechanical design, project management, etc., with the ability to deliver projects on time, quality and quantity, and can undertake sampling and testing engineering design, equipment manufacturing, installation and commissioning integrated epc project.