The aerated block equipment uses industrial wastes such as fly ash to produce concrete thermal insulation blocks, which can not only control pollution, save sewage funds, protect environment and cultivated land, but also reuse industrial wastes such as fly ash as resources, creating very considerable economic benefits for enterprises. Based on the annual output of 20000 cubic meters of foamed concrete blocks, 15000 tons of fly ash can be treated every year, saving 750000 yuan of sewage discharge funds for the power plant and creating 3 million yuan of economic benefits; Compared with the same amount of solid clay brick, it can save more than 3800 tons of standard coal and protect more than 100 mu of cultivated land. Obviously, if the aerated block equipment is used to produce concrete blocks, the social benefits will be huge, which will far exceed the economic benefits of the enterprise.

 

Concrete block is a new building energy-saving and thermal insulation technology, which has many excellent characteristics:

 

1. Low thermal conductivity, heat transfer coefficient, light body, high strength, fire prevention, acid and alkali resistance, sound insulation, environmental protection and simple construction. It is an ideal product to replace the traditional external wall insulation and aerated concrete blocks. However, the equipment investment is only one tenth of the traditional steam curing aerated concrete project.

 

2. The product uses fly ash, fine river sand and cement as raw materials, adds foaming agent, activator, inorganic composite minerals and other raw materials, modifies the materials through scientific formula, increases hardness and reduces water absorption, and produces high-quality lightweight thermal insulation material block products, which can not only meet thermal insulation and energy saving, but also have certain strength, The excellent thermal insulation effect will be integrated into the wall while building the wall, which meets the requirements of energy conservation and thermal insulation advocated by the state.

 

3. During the research and development of this product, our company successively applied to the State Intellectual Property Office for five inventions to realize the enterprise's protection of independent intellectual property rights. The products have been tested by the National Construction Engineering Quality Supervision Center and the testing station of Henan Academy of Building Sciences.

 

4. The products have been put into operation in Henan, Shanxi and Mongolia, and have achieved good economic benefits.

 

Resources and environment are increasingly becoming the primary issue of human survival and sustainable development. China's per capita resource shortage, low level of resource development and utilization, serious pollution to the environment, and facing greater pressure on resources and environment than other countries. It is a long-term strategic policy for China's sustainable economic development to improve the utilization rate of resources, develop new technologies for resource utilization and realize an environmentally friendly model.

Before World War II, autoclaved aerated concrete was mainly concentrated in the Nordic countries: Sweden, Norway and Finland. The Second World War seriously hindered the development of autoclaved aerated concrete and stagnated the new industry with good development momentum. Until the end of the Second World War, autoclaved aerated concrete with energy-saving advantages was developed again due to the global energy shortage.

 

In the 1950s, Western Europe, Eastern Europe and the former Soviet Union successively introduced the production technology of autoclaved aerated concrete, improved the production process, and emerged a number of patented technologies.

 

Around the world, more than 60 countries have set up factories to produce autoclaved aerated concrete, which are distributed in cold zone, temperate zone and tropical zone. The main technologies include YTONG technology and siporex technology in Sweden, Hebel technology in Germany, Unipol technology in Poland and durox technology in the Netherlands Technology and Denmark's stema technology.

 

Germany has become the technical center of autoclaved aerated concrete. The production of autoclaved aerated concrete around the world is mainly concentrated in the factories owned by haibol company and Yitong company.

 

At present, Wehrhahn, Masa, hess-stoke and aircrete of the Netherlands have innovated their own technical equipment on the basis of the above technologies and introduced them to the Chinese market.

 

Because autoclaved aerated concrete has excellent thermal insulation and energy-saving characteristics, its advantages are very obvious in cold areas. Therefore, the countries that used autoclaved aerated concrete as thermal insulation building materials earlier in the world are mainly concentrated in northern Europe, Eastern Europe and Western Europe, and later developed in Asia and other regions represented by Japan and the former Soviet Union. Poland is a severe cold region, with a higher latitude than Heilongjiang in China, and the requirements for building energy conservation are higher than Beijing. Therefore, more than 50% of the walls use autoclaved aerated concrete; Germany uses autoclaved aerated concrete to produce light blocks to build double-layer walls with air layer, so as to meet the requirements of thermal insulation and energy saving. At the same time, it is also widely used in firewall boards; Since the 1950s, autoclaved aerated concrete has developed rapidly in Japan, and now it is gradually becoming the main position of wall materials. 72% ~ 76% of the external walls of Japanese buildings use autoclaved aerated concrete strips, of which residential buildings use more, accounting for 51% ~ 56% of the total. Because autoclaved aerated concrete has alkaline environment, the United States also uses it as a retaining wall behind the target in the weapon shooting range, Reducing the pollution of lead to Groundwater provides environmental protection materials for military training in the United States.

 

Quicklime is one of the indispensable raw materials in the production of autoclaved aerated concrete. Quicklime provides an important calcareous material for the production of autoclaved aerated concrete. Therefore, the performance of quicklime is an important factor to ensure the stability of production process and product quality.

 

Next, Bona will give you a detailed introduction to the specific requirements for quicklime in the autoclaved aerated plate production line and autoclaved aerated block production line

 

Quicklime is generated by calcining limestone, dolomite or shell at high temperature. Quicklime used in autoclaved aerated concrete and plate production is mainly obtained by calcining limestone and dolomite.

 

Limestone and quicklime are described in detail below through the requirements of the standard.

 

1、 Requirements for limestone

 

The limestone for calcined lime is divided into ordinary limestone and magnesia limestone, and its chemical composition indexes are Cao, MgO, SiO2, P and s. The quality of limestone is mainly related to the quality of limestone, the particle size of lime stone, the temperature in the kiln and the firing time.

 

2、 Quicklime requirements

 

The chemical composition of lime is mainly Cao, and also contains a small amount of MgO, Fe2O3 and SiO2. Due to incomplete decomposition of CaCO3 during calcination, lime contains undissolved CaCO3 and other compounds. Therefore, the composition of lime includes two parts: one is the inactive part, including undissolved CaCO3, which does not participate in the hydrothermal synthesis reaction, so do not use total calcium in calculating the calcium silicon ratio; The second is the active part, which is the free CaO decomposed from CaCO3. It is the active part used in the production of aerated concrete blocks, including effective calcium oxide and free calcium oxide.

 

The role of quicklime in the production of aerated concrete blocks mainly includes two aspects:

 

First, provide calcium. The effective calcium oxide in quicklime reacts with SiO2 and Al2O3 in siliceous materials under hydrothermal conditions to form crystalline or colloidal hydrated calcium silicate and calcium aluminosilicate products;

 

Second, adjust the gas generation and thickening speed of slurry in the production process. On the one hand, improve the alkalinity of the slurry to make the aluminum powder gas; On the other hand, the heat released by digestion accelerates the gasification, thickening and hardening of slurry.

 

Reference standard for requirements of quicklime for autoclaved aerated concrete: JC / T 621-2009 lime for silicate building products, as shown in the table above.

 

1. A (CaO + MgO) mass fraction

 

Available calcium oxide and magnesium oxide are the main effective components in quicklime. They can react with SiO2 to produce silicate under hydrothermal conditions. The quality of quicklime is determined by its content.

 

If the content of effective calcium oxide and magnesium oxide is low, the amount of quicklime can be appropriately increased. The method in the appendix of JC / T 621-2009 standard is used for analysis. Since this analysis method detects the total amount of both, it is generally suitable for the analysis of calcareous lime. The analysis method of effective calcium oxide is carried out according to standard {JC / T 478-2013, test method for Building lime}.

 

2. MgO mass fraction

 

According to the MgO content, it can be divided into: ① calcareous lime: the MgO content is not more than 5%, which is obtained by calcining limestone; ② Magnesia lime: the MgO content is greater than 5%. Magnesia lime is obtained by calcining dolomite, or limestone will also lead to high MgO content when it is not fully burned. Calcareous lime is generally used in production, because most of MgO in lime is in overburned state, which will lead to expansion and cracking of green body after entering the kettle; If plates are produced, magnesia lime with appropriate MgO content can be used.

 

3. SiO2 mass fraction

 

SiO2 in quicklime comes from limestone. Generally, on the premise that the total amount of effective calcium meets the requirements, the total amount of SiO2 can be relaxed slightly, because it can participate in the reaction in the hydrothermal synthesis process, not harmful substances.

 

4. CO2 mass fraction

 

The mass fraction of CO2 is mainly determined by the amount of uncooked CaCO3 in lime, which can reflect the quickness of lime to a certain extent. The high mass fraction of CO2 indicates that there are more quicklime. Due to the complexity of measuring CO2 content, when the test conditions are not available, it can be roughly replaced by loss on ignition.

 

5. Digestion speed

 

The standard requires that the lime digestion speed of aerated concrete is 5 min ~ 15 min. for production, the lime of 5 min is generally too fast, resulting in insufficient afterforce of lime and affecting the hardening of green body; At the same time, the fineness of lime has an effect on the digestion rate.

 

6. Digestion temperature

 

The standard requires that the lime digestion temperature for aerated concrete is 60 ℃ ~ 90 ℃, and the temperature rise curve of lime for production is preferably flat.

 

7. Mass fraction of undigested residue

 

The main components of undigested residue are quicklime and superheated lime. Too high content will affect the quality of lime and the instability of process.

 

8. Fineness

 

The fineness of lime will affect the reaction speed. If it is too coarse, it is easy to produce white spots. Generally, the residue of 180 mesh sieve is controlled at 10% ~ 20%. The fast ash can be coarser and the slow ash can be finer.

What details should we pay attention to when using the AAC block?

 

The following requirements must be followed when using the AAC block products, otherwise errors may occur.

 

The detailed requirements are as follows:

 

First, when building with the AAC block, please remember to follow the relevant national standards and strictly follow the relevant national regulations. In addition, remember to reasonably arrange the construction period of the building aerated block equipment. You must not rush the work blindly in pursuit of progress. If possible, you should try to avoid the rainy season.

 

Second, when masonry the mortar, you must remember to select the special mortar with good viscosity. The strength of the special mortar must not be lower than M5, and also ensure that this special mortar product has good water retention performance. Of course, if possible, you can choose the special mortar for dry powder.

 

Third, in order to ensure that there will be no cracks between the wall and the main structure due to temperature changes, remember to bury reinforcement at the junction of the wall and the block.

 

Fourth, if the height of the wall is too large or the span is too large, beams and columns should be built in the middle of the wall. Fifth, the junction between the window front and the windowsill should also be paid attention to, because this junction is the part with the most concentrated stress, which is easy to produce cracks. Therefore, the Xiaobian suggests that you should build some concrete on the windowsill to prevent deformation.

 

Sixth, the AAC block added with concrete cannot be built together because of different density and strength grade. In addition, pay attention to the moisture content during masonry.

 

Seventh, after the wall is built, we must remember to do a good job of rain and sun protection. The above is the knowledge of aerating block equipment introduced by Xiaobian. After reading it, you should know something about aerating block equipment.

 

(1) The empty car shall be assembled on the kettle inlet track for trial operation, and the operation shall be stable.

 

(2) The bearing shall be cleaned and changed once every two months, and the lubricating grease shall be No. 1 colloidal graphite grease.

 

(3) There is also the maintenance of vulnerable parts of steam curing vehicle. If the vulnerable parts are damaged in production, they should be replaced at the first time!

 

The steam curing trolley is mainly composed of the following parts:

 

Frame: it is mainly composed of section steel, with good rigidity and simple structure. The upper part is equipped with a bottom plate guide device, which makes the bottom plate fast and convenient to place.

 

Wheel assembly: it is mainly composed of wheel, shaft and bearing. The surface of the wheel is quenched and durable. The internal structure is specially designed to ensure that the bearing can still roll sensitively and operate reliably after high-temperature and high-pressure steam curing in autoclave.

 

  

The advocacy of energy conservation and environmental protection policies has strengthened the government's control over the building materials industry, increased the use tax rate of clay bricks, and prohibited the opening of cave clay bricks; On the other hand, relax the production conditions of new building materials, provide subsidies and encourage the development of new building materials industry.

 

The production technology of aerated block equipment came into being and complied with the inevitable product of the development of the times. It is a widely used building wall material in recent years. It is light and porous and can float on the water; Good thermal insulation, heat insulation and sound insulation performance; Due to its special technology, it has certain seismic performance, can alleviate the earthquake intensity, and can protect the nature in a sense; These are needed for the current social development; The better performance is that it can well ensure the energy-saving and environmental protection policies: save land resources, save coal resources, reduce the greenhouse effect and protect the natural performance of the environment.

 

The raw materials for the production of aerated block equipment are fly ash, lime, cement, gypsum and sand, which are prepared according to a certain scientific proportion; The raw materials are mostly some wastes with a wide range of sources. The wastes left by thermal power plants and mining plants are the sources of raw materials, which greatly reduces the price of raw materials and reduces some investment. Equipment pouring section: the mixing center system is mainly used for mixing the slurry, so that the materials do not precipitate and the water and special materials are evenly dissolved, so as to lay a good foundation for good foaming of the embryo. Submerged slurry pump: mainly used for slurry transportation. Three sets are required for 200000 production line. One is used to transport the slurry to the drum screen; One is used to transport the mixed slurry to the pouring machine for pouring; One set is used to transport the waste cut by the cutting machine to the mixing tank after pulping. The waste slurry storage tank is mainly used for storing and re pulping the waste cut by the cutting machine, which is the effective utilization of raw materials to achieve energy-saving effect. Drum screen is mainly used for slurry filtration. Screen out the blocks and sundries that are not scattered to ensure the quality of blocks.

 

At present, the aerated block equipment produced by Zhengzhou Bona uses very few resources of raw materials, and there is basically no pollution in the production process. In the future, the long-term development of the equipment must be based on saving resources and protecting the environment, so we have a good grasp of the sustainable development of the aerated block equipment, Aerated block equipment is a new type of environmental protection equipment vigorously promoted and used in the modern market, not only because it is the product of advanced science and technology, but also an ideal building material production equipment to realize energy conservation, waste utilization, energy conservation and environmental protection. Aerated block equipment is one of the mainstream building material brick production equipment today.

 

With the continuous development of Zhengzhou bona, many enterprises lack the ability of independent innovation, so after the rapid development period. It began to stop, so we need to break through the development crisis with technological innovation, so as to make our gas filling block equipment better developed. Moreover, the raw materials used by our aerating block equipment are relatively cheap, which can not only control environmental pollution, but also save land resources and effectively protect the cultivated land area. At the same time, it responds to the national policy services and contributes to environmental protection. It will bring better returns to users in the development of building materials industry in China.

 

The numerous performance advantages of the aerating block equipment drive the industry to be active in various fields. While continuously strengthening the process innovation of the equipment, the maintenance of the equipment can not be ignored. Improve the manufacturing level of aerating block equipment and greatly improve its product quality.

 

(1) Accuracy and verification of measurement: the regular symmetrical measurement system shall be verified with weights to check whether each blanking valve is sealed without defect. In case of abnormal shaking of blanking height and unit weight, it shall be rechecked immediately to ensure the correctness of the measurement of aerated concrete according to the proportion.

 

(2) Secondly, uniform mixing and mixer maintenance: clean the mixer regularly, do a good job in the maintenance and protection of the mixer, timely replace the worn mixing blades, ensure that the mixing paddle and its accessories are intact, and the normal application functions of the mixing system, so as to ensure the cooperative operation of all bodies.

 

(3) Thirdly, the accuracy of cutting scale and the maintenance of cutting machine: cutting machine makes aerated concrete not only form in large volume, but also have sensitive and diverse shape and scale, high precision, and complete its large-scale mechanized production. The operation condition of the cutting machine directly affects the cutting scale accuracy. Therefore, the maintenance of the transmission equipment and steel wire positioning of the cutting machine should be strengthened, and the imperfections should be found and corrected in time.

 

(4) Stability and track maintenance of green body operation process: the strength of aerated concrete green body without autoclave protection is low, so it is necessary to ensure the smooth operation of transportation in the production process, reduce the damage to green body structure in the transportation process, and then reduce the impact on product quality.

 

(5) The continuity of the production process and the protection of other aerated block equipment are undoubtedly the key: the continuity and periodicity of the production technology of aerated concrete blocks require the continuous operation of the equipment in the production process, in which the failure of any equipment may cause the invalidation of the products and have a great impact on the production. Therefore, while maintaining the above equipment, other equipment such as ball mill, slurry pump, gas supply station and inductor also need to be inspected and maintained as scheduled, so as to reduce the number of false shutdown and strengthen its production power.