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The preparation technology of molecular sieve

2014-12-22

Molecular sieve is a kind of silicon aluminate compound with cubic lattice, meet dozens of varieties. Molecular sieve production process is divided into two stages: one is the synthesis of the molecular sieve powder; Another is the molding molecular sieve. Molecular sieve is made of silicon compounds (such as silica sol, sodium silicate, etc.), aluminum compounds (for example, the activated alumina, aluminum salts, etc.), alkali (such as sodium hydroxide, etc.) as well as the template agent under the condition of hydrothermal synthesis, the preparation of products known as molecular sieve powder, is a kind of extremely tiny silicon aluminium acid salt crystal materials, crystal at about 100 nanometers in diameter, cannot be directly used in industrial production process, and must be processed into certain shape and size of particles is the practical value.
Molecular sieve according to their use need to be processed into different shapes, different forming methods and a lot of more phyletic, each have its characteristics. At present, the industry there are three kinds of commonly used molecular sieve shape: strip, globular and micro spheres. The strip and spherical molecular sieve is the most common and widely used as adsorbent and fixed bed acid catalyst.
Traditional molecular sieve system mostly adopts the rotational molding process, with the ball machine. Mainly through the molecular sieve catalyst powder powder and a moderate amount of water (or adhesive) to turn the pot body of the container, the pot body clockwise rotation, artificial add powder and water the material inside the pot body back, sliding, friction and abrasive, through continuous rolling effect, wetting material clung to each other, gradually formed for spherical particles. The traditional processing model is only suitable for some easy into the ball material processing, but also need to have a certain strength of materials and shape retention. For Cui Hua agent, the dosage of the glue and regulation is important, moreover raw water and supply water, there is a certain balance relationship between complex and not easy to adjust. It thus is suitable for rotational molding in one-component material, or the proportion of relevant multicomponent materials forming. For multicomponent materials related to larger proportion, differences between the proportion of each component can be caused when the rotational centrifugal force difference, so difficult to get uniform consisting of a small ball.
In the process of ball, artificial control of material inventory between poor reproducibility, easy to cause the finished product batch to lower order after drying process efficiency, manual labor intensity. The ball forming process by the operating personnel according to the experience and technology to control and judgment, therefore the technology level of operating workers have higher requirements, and second because the objective of artificial factors limiting the quality and performance of products, often cause the finished product range ball size differences, sphere uneven density, surface compressive strength is not high wear-resisting, low product quality and performance. And in the process of rolling, dust pollution is bigger, has damage to the operation of the workers' health, is not conducive to environmental protection. In a competitive market, the quality of product and performance high demands, high degree of automation of continuous production and environmental protection in today's modern production, the traditional ball equipment to highlight deficiencies, unable to meet the needs of modern production.
In the modern production, connect equipment and auxiliary equipment in accordance with the process sequence, automatic completion of all or part of the product manufacturing process of the automatic production line, play an important role in the industrial production, not only can make the management of the production workshop organized, improve labor productivity, stability and improve product quality, and improve the working conditions, reduce production costs, while ensuring production balance has obvious economic benefits.
From the early stages of the molecular sieve powder, mixture, silica sol, purifying water mixture, the forming system of the ball, to the later period, such as drying process can also be made to complete automated production line equipment. The whole production line a high degree of automation, implementation "steady, accurate, fast" continuity of production, greatly improve productivity, reduce the labor force, improve the production environment. These functions respectively by mixing equipment, refining equipment, ball equipment, screening equipment, drying equipment, and improve linkage, transport and other equipment.