Molecular Sieve Production Process

I. Production Equipment

l Mixer Blender

l Oscillating granulator

l Enamel Machine

l Conveyer drying machine

l Roasting Kiln

l Sieve

II. Procedure                                             

Raw material mixing-----granulation-----sieve-----drying-----roasting----packaging

1. Raw material mixture

Pour the kaolin and 4A/3A/5A/13X zeolite raw powder into the cone mixer in a certain proportion, turn on the mixer and stir for about 90 minutes. The more uniform the mixing, the better.

2. Granulation

Put the uniformly stirred raw powder into the rocking granulator in batches, turn on the rocking granulator, and add the sodium tripolyphosphate solution while stirring (the concentration of the sodium tripolyphosphate solution is water: sodium tripolyphosphate = 20: 1). The very small crystal grains can be screened out. This step is required for the first granulation, as long as the production is not stopped in the future, this step is no longer needed for the granulation.

Turn on the enamel machine. Pour the obtained crystal grains into it, and slowly spray the prepared sodium tripolyphosphate solution. When the particles are wet, sprinkle the mixed raw materials in. After a period of time, the crystal grains will gradually increase. This process is called granulation. .

3. Sieving

When the particle size in the iridium enamel machine increases to a certain extent, it is taken out and sieved on a flat screen. Generally, it is sieved on a molecular sieve of 1.0-1.4mm, and the sieved particles of three particle sizes (ie <1.0mm, 1.0-1.4mm, >1.4mm) are put into different iridium enamel machines for granulation. Such cyclic operation is granulation. When the particle size reaches the required requirement, stop spraying the solution, and no more raw powder is added. This process is called exposure. After half an hour of exposure, the pan can be taken out.

The molecular sieve that will be out of the pot has to be tested for strength in the laboratory first, and only after its strength meets the standard can it be out of the pot, otherwise it is a substandard product, and it can be crushed as raw powder or used for other treatments.

4. Dry

The process of putting the molecular sieve out of the pot into a belt dryer for drying; the belt dryer is divided into 4 heating zones, and the temperature is set as follows: Zone 1 50℃, Zone 2 70℃, Zone 3 80℃, Zone 4 60 ℃. The lower the speed that the belt dryer pushes forward, the better the drying effect.

5. Roasting

Put the dried molecular sieve into a roasting furnace for calcination to obtain the finished molecular sieve. The roaster needs to be preheated for two days when it is used for the first time. After a period of time, it needs to be preheated for one day. The roasting furnace is divided into 9 heating zones, and the optimal heating temperature of molecular sieves of different particle sizes is different. The temperature is too high or too low, it will cause the strength and water absorption to deteriorate; the temperature difference between the laboratory muffle furnace and the industrial roasting furnace is about 100 ℃, the molecular sieve can be tested in the laboratory to measure the best temperature, and add 100 ℃ The best calcining temperature of the calciner can be obtained. The currently known calcination temperatures of different particle sizes are:

When the particle size is <1.6mm, the set temperature of each area of the roaster is 459, 450, 500, 550, 600, 650, 700, 750, 750, 600, and the flow rate V=35g/s.

When the particle size is <1.6-2.4mm, the set temperature of each area of the roasting furnace is 450, 450, 500, 550, 600, 700, 750, 750, 600, and the flow rate V=35g/s.

When the particle size is less than 2.5-3.0mm, the set temperature of each zone of the roasting furnace is 450, 450, 500, 550, 600, 650, 750, 600, and the flow rate V=35g/s.

The calcined molecular sieve must be tested for its strength and static water adsorption capacity. Products with different particle diameters must meet the required strength and static water adsorption capacity of the corresponding standards. Those that meet the standards are the finished products.

6. Packaging

The molecular sieve should pay attention to the tightness and try to avoid exposure to the air. Because the temperature of the product just coming out of the roasting furnace is relatively high, the molecular sieve is usually packed in a sealed iron drum.

7. Matters needing attention

A. Molecular sieves are afraid of oil and freezing, so when producing molecular sieves in winter, pay attention to anti-freezing. Each time the granulation is completed, it must be tested in the laboratory to ensure that it is a qualified product. After the molecular sieve is frozen, it is easy to explode after being calcined in the roaster.

B. When calcining in the roasting furnace, ensure that the moisture inside is discharged in time.

C. The ratio between raw powder and kaolin is different according to needs. Raw powder: Kaolin can be 5:5, 6:4, 7:3, etc. When mixing, try to ensure that the mixing is even./If there is too much raw powder, The most prone situation is dusting, which is a problem that should be considered when increasing the amount of raw powder.