How to make red bricks in china?
The production process of sintered bricks is generally composed of four parts: raw material preparation, blank body forming, wet blank drying, and finished product firing.After raw materials are excavated, some can be processed by adding water, stirring and grinding equipment,while others will not work.Raw materials,such as mountain soil, coal gangue and shale,are to be broken and finely chopped, then followed by water mixing and grinding.The choice and preparation of raw materials directly affect the quality of the finished product.As the saying goes, raw materials are fundamental to making sintered bricks,showing the importance of the raw materials preparation and raw materials.
After the selected brick raw materials are processed, they enter the molding workshop for molding.Blank forming method basically uses plastic extrusion molding in China.There are three methods for plastic extrusion. That is plastic extrusion molding,semi-hard plastic extrusion molding and hard plastic extrusion molding.
These three extrusion methods are based on the difference in the moisture content of the molding.When the moisture content more than 16%,wet billet molding is plastic extrusion molding. When the moisture content equals 14-16%, it’s semi-hard plastic extrusion molding. When the moisture content equals 12-14% ,it’s hard plastic extrusion molding.Blank forming includes: feeding material , mixing,adding water and grinding equipment processing before raw materials entering the molding shop not brick extruding machine.After passing through the molding brick machine, the qualified mud and wet billet are formed.Forming process should fulfill the requirement of the shape and structure.Forming is the foundation of the brick making process.The quality of the formed body is directly related to the appearance quality of the finished tile.
After the wet billets formed from the molding plant, they need to be dried by dehydration.In the production process of sintered bricks, there are two ways of drying wet blank: natural drying and artificial drying.
The natural drying is to place the wet billet on the billet stalk in the natural drying place,manually invert the code and use the atmosphere to wet the cold billet into a dry billet.Artificial drying is to use equipped artificial drying chamber to dry wet billet.The artificial drying room is divided into three types: large-section tunnel drying room, small-section tunnel drying room and chamber drying room.Whichever type is adopted, it is manually or mechanically placing wet billet on a drying truck,then put it into drying chamber.The heat medium in the drying chamber generally comes from the waste heat of the sintering kiln or the hot blast stove.Whichever drying method is adopted, it must be ensured that the blank will not be deformed or chapped during the drying process.If the wet billet can’t guarantee the appearance quality of the product during drying, it will cause high reject rate, falling output,increasing cost of the finished brick, which are definitely harmful to company economic efficiency.This shows the importance of drying wet billet in brick making process.
If the residual moisture rate after drying is less than 6%,the wet billet could be fired in the baking kiln.Hoffman kiln and tunnel kiln are normally used for roasting.When using Hoffman kiln, the brick code is manually placed in the kiln and the fire is roasted in the kiln.When using tunnel kiln,the brick code is manually or mechanically placed in the kiln cart.The kiln car enters kiln head and exits from the kiln tail. The brick blanks on the kiln car are roasted into bricks.The roasting flame in the kiln doesn’t move just the kiln cart.Whether using Hoffman kiln or tunnel kiln,this two conditions must be followed:1.never use underfire to produce unburnt brick.2.never use big fire to produce coke brick.It is often said that roasting is the key of the brick making process,which explains the importance of roasting in the brick making process.
Sintered brick process is composed of four parts.To sum up,it is said that the raw material is fundamental,molding is the basis,drying is ensure and roasting is the key. These four parts are interdependent.