Ceramic products in the production process, the raw material processing consumes a large proportion of energy consumption. At the same time the quality of raw materials processing also determines the quality of the product. Therefore, the research of raw material processing technology should focus on reducing energy consumption and improving the quality of slurry and powder.
Talk about the preparation of ceramic slurry. At present, the preparation process of ceramic slurry is widely used as: one-time pulping method for wet grinding of ceramic raw material by ball mill. The method of dispersion of raw materials is uniform, but the efficiency of grinding is not high. Ceramic industry ceramic raw materials are mostly natural minerals, raw materials, feed the size of about one centimeter, grinding ball diameter is usually 4-10 cm, the specific surface area is small. When the ball mill is working, at least twice the weight of the cylinder and the liner are rotated together. The weight of the raw material processed by the ball mill is in the tens to hundreds of tons, which consumes a lot of energy. Mill speed in each minute more than ten to several tens, turn on the ball by the free fall of raw materials will be smashed coarse particles. The initial particle size of the raw material is large, and the initial crushing is carried out by the impact of the grinding ball. With the decrease of the particle size of the raw material, the impact crushing effect will decrease rapidly. The efficiency after the grinding depends on the specific surface area of the grinding ball and the ratio between the grinding ball and the raw material Relative friction. Ball mill grinding ball diameter, low speed, making the ball between the ball and the relative friction between the low frequency, and ultimately lead to low grinding efficiency. There are also using ceramic raw materials by Raymond machine grinding, add water, mixing pulp or granulation method. This method requires all the raw materials to be pre-processed, due to impurities and mixed uniformity is not good, the current industry rarely use this method on a large scale.
Stirring mill is a new type of fine grinding equipment, more used in inkjet ink and nano-powder grinding processing. The grinding wheel is very small, about 0.2-10mm; grinding wheel in the mill high-speed rotation (up to several hundred turn), driving the grinding ball and material relative friction; in the high-speed Under the action of centrifugal force, coarse grain material and grinding ball adhere to the operation, fine particles concentrated in the middle of the mill was discharged, will not produce excessive crushing, so grinding efficiency is extremely high. At present it is in the traditional ceramic industry billet grinding has not yet used, one of the reasons is that a large number of impurities containing natural minerals can not be used directly.
The use of ball mill and mixing mill in combination with the method, that is, the completion of pre-grinding milling, grinding mill to complete the late grinding, will make the traditional ceramic raw materials processing efficiency to produce a qualitative leap.
Let’s talk about the preparation of ceramic powder. The most commonly used dry pressing molding process is: ceramic raw materials by wet grinding, atomization drying granulation method. The powder obtained was hollow spherical body, powder flow is good, brick consistency is better, deformation and cracking defects less. But there are still product deformation, large-scale flat products need to edging, scratching. The other is dry grinding, add dry water into the ball granulation, and then drying the milling method. Dry powder to solve the wet grinding water is high, the late drying energy consumption of the shortcomings of the dry granulation as a solid ball, forming the density of the green body, the subsequent drying, burning shrinkage small. But it still exists raw material mixing uniformity is poor; due to the solid particle hardness, forming the body between the particles there is a small gap between the defects; difficult to adapt to individual products, the process is generally poor applicability, only for sanitary ware or glazed tile blank use, So has not been a large number of popularization and application.
The hollow particles obtained by atomization drying granulation and granulation by dry method can obtain solid spherical powder with uniform composition and good water content, and if the part is atomized and dried Powder effect will be better. The drying, firing deformation and shrinkage of the molded body will be greatly reduced, the quality of the product will be significantly improved, and the energy consumption of the later grinding will be reduced.
In addition, the slurry and pigment powder mixture; slurry vacuum deaeration technology is also affecting the quality of dry products and grouting products, an important part of the concern. Foreign in the process and equipment, the study than we are deep, do better than we are, because they really used the mind, sink down, it is worthy of our industry to reflect on, study hard.