Many users engaged in charcoal production are very familiar with pulverized coal or charcoal molding. The pulverized coal molding is an important link in the production of high-quality coal and charcoal briquettes. Pulverized coal and charcoal briquette machine is the main equipment for molding. There are several important factors in the pulverized coal and charcoal molding process that we should pay attention to.
1.Molding characteristics of raw materials
The forming characteristics of raw materials such as coal and charcoal are the most critical internal factors that affect the pulverized coal and charcoal forming process, especially the elasticity and plasticity of coal and charcoal. The higher the plasticity of pulverized coal and charcoal, the better its forming characteristics.
Peat, lignite, charcoal powder, and other raw materials are rich in high plastic asphaltene and humic acid materials, so their molding is good, molding effect is ideal. Generally, most of the coal powder and charcoal powder before pressing molding need to add a binder to increase its plasticity before molding.
2.The molding pressure
When the forming force is less than the crushing force, the mechanical strength of the charcoal briquettes extruding machine increases with the increase of the forming pressure. Different types of coal and charcoal have different crushing forces. The optimum molding pressure is closely related to the type of coal charcoal briquettes, the composition of moisture and particle size of the materials, and the type and quantity of binder.
3.The moisture content of the raw materials
The role of moisture in the material in the molding process mainly includes:
The proper amount of water content can act as a lubricant, reducing the internal friction of forming system and improve the mechanical strength of the charcoal extruder machine. If there is too much water, the water layer on the surface of the material will become thicker, which will affect the full density of materials among each other and reduce the mechanical strength of the charcoal briquette machine. In addition, the excessive moisture content will easily crack when the charcoal briquettes are dried, so that the charcoal or coal briquettes are prone to fracture;
If a hydrophilic binder is used for molding, an appropriate amount of water will wet the surface of materials in advance, so as to facilitate the bonding between materials. If too much water, the effect of the binder will become worse. The suitable molding moisture is generally 10% ~ 15%.
If the use of hydrophobic binder molding, water will reduce the effect of the binder, so the general control of the water content of the material below 4%. In a word, the moisture of materials should be controlled flexibly according to the actual situation and controlled in an optimal range.
Because most of the coal and charcoal molding performance is poor, so the use of binder molding process is more common. At this point, the amount of binder is not only the key factor affecting the briquette strength but also has a very important impact on the briquette production cost. From the situation of binder consolidation, increasing the amount of binder is beneficial to improve the briquette strength.
However, from the perspective of the molding process, increasing the amount of binder is not conducive to improving the molding pressure and briquette strength: from the perspective of the stability of molding, increasing the amount of binder is not conducive to improving briquette strength. Therefore, it is necessary to determine the optimal amount of binder through experiments.