Melamine is a basic organic chemical intermediate product with a wide range of uses. Condensed with formaldehyde can be made into amino resin, which has excellent properties such as heat resistance, water resistance, aging resistance, chemical resistance, arc resistance, high gloss, and high hardness.
Application
Melamine powder is widely used in wood processing, coatings, textiles, electrical appliances manufacturing, papermaking, plastic products, national defense and transportation and other industrial sectors. It is an important organic chemical raw material.
The production method of melamine is divided into dicyandiamide method and urea method according to raw materials. The dicyandiamide method has been gradually eliminated due to high energy consumption and difficult raw material sources. At present, the production of melamine generally uses urea as raw material, and is divided into high pressure method (above 8.0 MPa), low pressure method (0.5 to 1.0 MPa), and normal pressure method (0.05 to 0.10 MPa) according to operating pressure.
Today, Huafu Chemicals (the manufacturer of melamine and MMC) will introduce the Productive Process of Melamine in Normal Pressure for you.
Process flow diagram of melamine production in normal pressure
1.1 Reactor
The main raw material for the reaction is urea. The reactor is equipped with a certain amount of catalyst, which is fluidized under the action of circulating carrier gas.
1.2 Cooling filtration
The gas leaving the reactor contains a certain amount of by-products and fine catalyst powder. It first enters the hot gas cooler for cooling, and then enters the filter, where the by-products and catalyst fine powder are filtered through the filter tube.
1.3 Crystal separation
The filtered process gas enters the crystallizer and mixes with the cold gas from the liquid urine scrubber in reverse, so that the melamine gas in it is cooled and condensed to form melamine crystals, and enters the separator together with the gas to separate the gas from the solid, and the solid is the finished product to be packaged.
1.4 Liquid urine washing
In the liquid urine scrubbing tower, the liquid urine and the tail gas from the cyclone separator co-currently contact the triamine particles carried in the tail gas, wash and cool, and purify the process gas.
1.5 Exhaust gas absorption
The tail gas from the liquid urine scrubber passes through two scrubbers for scrubbing and absorption to generate ammonium bicarbonate liquid.
