In terms of past history, sintered bricks are probably thousands of years old. Back in ancient times more than two thousand years ago. People have now learned to sinter into bricks. It is enough to see the great wisdom of the ancients.
Sintered bricks will have some of their own advantages through the inheritance of the moment, so modern people in China are very mature in this skill. Speaking of this, maybe we are not new to sintered bricks, but the following introduction to sintered bricks may make you better understand this skill.
First, the material of sintered brick
The main materials of general clay bricks are silty or sandy clay, whose main chemical components are SiO2, Al2O3 and Fe2O3 and crystal water. Because of different geological conditions, they may also contain a small number of alkali metals and alkaline earth metal oxides. The production process of clay bricks mainly includes soil extraction, mud refining, blank making, boring, roasting and so on.
In addition to clay, shale, coal gangue, fly ash, etc. can be used as materials to make, because their chemical composition is similar to clay. However, because their plasticity is not as good as that of clay, bricks often need to participate in a certain amount of clay in order to meet the plasticity requirements of billet making.
In addition, coal gangue and fly ash in the brick billet are combustible industrial wastes, which contain unburned carbon. The firing of tunnel bricks is also incinerated in the billet, thus saving a lot of external investment coal for roasting. This type of brick is also called internal combustion brick or semi-internal combustion brick.
The content of impurities in the material also greatly affects the firing temperature of the clay brick and the color of the finished product.
Production process of sintered brick
Roasting is a key part of the brick making process. Generally, the firing temperature is controlled between 900 and 1100 ° C, so that the brick is sintered until it is partially melted.
If the firing temperature is too high or the time is too long, fire bricks are liable to occur. Overfire bricks feature deep color, crisp percussion, and deformed headlights. If the firing temperature is too low or the time is insufficient, underfire bricks are liable to occur.
(Light fire brick, light percussion, low strength, high water absorption, poor durability)
When firing in a brick kiln, it is an oxidizing atmosphere, and the brick becomes red due to the formation of ferric oxide and becomes a red brick.
If it is fired in an oxidizing atmosphere and then sintered in a reducing atmosphere, the red iron oxide will be reduced to blue-grey ferrous oxide and become a green brick.
So what's the difference between blue brick and red brick?
Blue bricks are generally denser, more alkali-resistant, and more durable than red bricks, but because of their high price, they have fewer production applications. In addition, in the production, industrial waste such as coal slag and high carbon content fly ash can be put into the soil of the billet to make internal combustion bricks. When the bricks are fired to a certain temperature, the carbon in the waste residue is also incinerated in the dry body, which can save a lot of fuel and 5% to 10% of the clay material. Internal combustion bricks are uniformly incinerated, have a small apparent density, low thermal conductivity, and the strength can be improved by about 20%.
Third, the difference between cement brick, permeable brick, sintered brick.
1. Cement brick should be the cheapest. It is used for the same purpose as sintered brick. Cement brick is mainly composed of stone powder and some fine stones plus cement.
2. The permeable brick is used for paving the ground. Rainwater can quickly enter the ground through the permeable brick to prevent water from accumulating on the ground. The permeable brick is composed of cement and fine stones and a small amount of sand. The surface layer of the permeable brick also needs quartz sand. (Different from ordinary river sand) and cement, so the cost is relatively high, and the price will be more expensive than ordinary pavement tiles.
Rainwater permeability is blocked because of impervious concrete pavement, asphalt pavement, and the interception surfaces of various houses and constructions. In addition, due to long-term excessive development and drought in various cities, urban groundwater resources are declining year by year, causing urban groundwater levels. Dropped significantly……
3. Sintered brick is a clay component. The demand for clay produced by sintered bricks is relatively large, which will cause serious damage to the soil. Cement bricks and other environmentally friendly bricks are substitutes for sintered bricks.
In addition, many manufacturers on the Internet now use the banner of "vacuum extrusion" products to scam consumers. The price of vacuum extrusion products is higher, and the products also have high pressure resistance, strong freeze-thaw resistance, good brick durability, no fading, stable colors, environmental protection, no radiation, etc. I hope we don't blindly purchase when buying. So as not to be deceived.
Although sintered bricks have a long history, they can still be used today, but the harm to the national environment is really great. Therefore, the new type of environmentally friendly bricks for wall materials introduced in China is a substitute. Many people have doubts about green bricks.
In fact, environmentally friendly bricks use shale on the mountain and construction waste as materials, which not only plays a role in environmental protection, but also the quality of the bricks far exceeds the traditional old solid bricks, and also has the function of heat insulation. In a hollow brick house, the summer is significantly cooler by 2 or 3 degrees than in an old brick house.
Although the price of environmentally friendly bricks is higher than that of solid bricks, the country is now strongly recommending the use of environmentally friendly bricks. According to the preferential policies of different regions, trust will be more advantageous than the price of solid bricks.
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