What materials are suitable for use in the roller press granulator to make particles?
Essentially all of the granulated dry process can be granulated by a roller press granulator. In particular, the raw material powder has a size of less than 2 mm, preferably less than 1 mm, and is very suitable for extrusion granulation. Raw materials such as gravel, powder, crystal, granules and pellets are suitable. For example, for potassium chloride, lower cost standard grades and by-products or "waste materials" (because they are too fine to be blended) are suitable for extrusion. Although the urea of the pellet is available, a small-sized powder or crystalline urea is more suitable.
In some cases, the particle size of the feedstock differs too much, with large particles being broken first, resulting in a more uniform nutrient distribution of the product.
The smaller the particle size of the raw material, the detachment of the components in the extruded large block does not occur during the pulverization process. The purpose of the granulation of the roll extrusion granulator is to obtain fertilizer particles having a highly uniform nutrient element.
There are two ways to break:
Method 1: The raw material of the fertilizer is broken before the compounding, and the problem may be that during the forming process, the fluidity of the raw material after the crushing is poor, which may cause bridging and reduce the quasi-decision of the metering.
Method 2: The composite mixture is comminuted in a pulverizer prior to the addition of the feedstock (the feed size is generally lower than required) to provide a uniform particle size and distribution of the feedstock mixture prior to extrusion granulation. A possible problem with this method is that a higher density of the sheet is required because the raw material mixture contains air and requires a higher forming pressure. In particular, in the case where urea is one of the raw materials of the composite fertilizer, the heat softens the low-melting raw material, which makes the flow of the material difficult.
Although the above two methods each have disadvantages and have their own advantages under certain conditions, they are selected according to actual conditions and process conditions. Zhengzhou Huaqiang Heavy Industry has been working on the NPK fertilizer production granulation production line without drying and rolling granulator for nearly 20 years. It has rich practical experience and advanced granulation technology. Welcome to buy.