Preparation of Molecular Sieve

Preparation of Molecular Sieve

Fulong molecular sieve

Molecular sieve is a kind of aluminosilicate compound with cubic lattice, which has dozens of varieties.

The production process of molecular sieve is divided into two stages: one is the synthesis of molecular sieve raw powder; the other is the molding of molecular sieve.

Molecular sieve is synthesized by using silicon compounds (such as silica sol, sodium silicate, etc.), aluminum compounds (such as activated alumina, aluminum salt, etc.), alkali (such as sodium hydroxide, etc.) and template agent under hydrothermal conditions. The prepared product is called molecular sieve raw powder, which is an extremely fine aluminosilicate crystal material with a crystal diameter of about 100 nanometers and cannot be directly used in industrial production processes, particles must be processed into a certain shape and size to have practical value.

Molecular sieves need to be processed into different shapes according to their different uses, and there are many methods and types of molding, each with its own characteristics.

At present, there are three shapes of molecular sieves commonly used in industry: strip, spherical and microspherical. Striped and spherical molecular sieves are the most common and are widely used as adsorbents and fixed-bed acid catalysts.

The traditional molecular sieve ball is the use of rotary molding process, with rolling ball machining. Mainly through the molecular sieve powder or catalyst powder and the appropriate amount of water (or adhesive) to the rotating pot container, the pot body clockwise rotation, artificial powder and water to make the material in the pot body tumbling, sliding, friction and grinding, through continuous rolling action, wetting materials adhere to each other, gradually formed into spherical particles.

This traditional processing mode is only suitable for the processing of some materials that are easy to form balls, and the materials need to have a certain strength and shape retention.

For the Cui agent, the amount and adjustment of the binder is very important. In addition, there is a certain balance between the water contained in the raw material and the supplied water, which is complicated and difficult to adjust. Therefore, the rotational molding method is suitable for the molding of single-component materials or multi-component materials with similar specific gravity. For multi-component materials with a large specific gravity correlation, the difference in the specific gravity of each component during rotation will cause a difference in centrifugal force, so it is difficult to obtain pellets of uniform composition. In the process of rolling ball, manual control of the amount of material input is easy to cause poor reproducibility between finished batches, so that the subsequent drying process efficiency is reduced, manual labor intensity is large.

The whole ball making process is controlled and judged by the operators according to their experience and technical level, so there are higher requirements for the technical level of the operators. Secondly, due to objective human factors, the quality and performance of the finished products are limited, which often results in different sizes of the finished products, uneven ball density, low surface compressive and wear resistance, and low product quality and performance. And in the process of rolling, the dust pollution is large, which is harmful to the health of the operators and is not conducive to environmental protection. In today's modern production with strong market competitiveness, high requirements for product quality and performance, high degree of continuous production automation and environmental protection, this traditional ball rolling equipment highlights the shortcomings and cannot meet the needs of modern production.

In modern production, the automatic production line that connects equipment and auxiliary equipment in accordance with the process sequence to automatically complete all or part of the manufacturing process of the product plays an important role in industrial production, not only can the production management of the workshop be organized, Improve labor productivity, stabilize and improve product quality, but also improve labor conditions and reduce production costs, it has significant economic benefits in ensuring production balance.

Starting from the mixing of raw powder, mixture, silica sol and purified water in the early stage of molecular sieve, to the molding of balls, and then to the later drying process, etc., can also be completed by using the equipment of the automatic production line. The whole production line has a high degree of automation, which realizes the continuous production of "stable, accurate and fast" process, greatly improves productivity, reduces labor force and improves the production environment. These functions are composed of mixing equipment, refining equipment, ball making equipment, screening equipment, drying equipment and lifting, transmission and other equipment linkage.