Drying-free processing method for granular fertilizer

Abstract

The invention aims to design a drying-free processing method for a granular fertilizer, the granular fertilizer is granulated by a method of high temperature melting and cooling curing or a method of hot air drying, dehydration and curing of a granulated wet material. Heating is needed in the process, environmental pollution is caused by coal-fired heating, cost and energy consumption are increased by oil, gas and electric heating, according to the drying-free processing method, 3-15% by mass of calcined magnesium-carbonate-containing ore is added, main component magnesium oxide is used as a curing agent, a curing reinforcer accounted for 15-20% of the mass of the curing agent is added, the curing agent can fast react to form crystals when meeting water in the presence of the curing reinforcer, large quantity of water is absorbed in the reaction process, material temperature is improved, water evaporation in the granulation material is promoted, the crystals are formed by curing in the air, and the crystals have a certain strength to ensure the particles are not broken.

Description

technical field [0001] The invention relates to a process for processing, molding and granulating fertilizers, which belongs to the field of fertilizers. Background technique [0002] Usually, the molding method of granular fertilizer is to use high temperature melting to form liquid solidification molding, such as urea, sulfur spraying or high tower granulation; the other is to add adhesive to bond the particles to form a certain strength. Method one using high-temperature melting has problems such as high cost, no energy saving, and no environmental protection. Commonly used in compound fertilizers, not suitable for organic fertilizers. The second method is to add an adhesive, which is expensive, and some adhesives degrade slowly and remain in the soil. This method is commonly used in compound fertilizer coatings, and is also used in organic fertilizers. However, it is usually dried in a hot air stove, and energy consumption increases at the same time For PM2.5, as envir...

AI Technical Summary

Problems solved by technology

Invention patent 21110271217.2 proposes a coated fertilizer, which adopts a self-curing process and mainly uses calcium-containing powders including calcium oxide and calcium sulfate. The test found that the strength of this material is low, and the particle sealing performance needs to be improved in actual use.

The problem that this invention exists has following three aspects, the first reaction time is long, magnesia and water just coagulate after 40 minutes, and this is unacceptable in fertilizer processing, must bag immediately after fertilizer granulation, just can finish whole process. Assembly line production

The second strength is low. Magnesium hydroxide reacts with water to form magnesium hydroxide, which basically has no strength. It is difficult to withstand the pressure that fertilizers must bear when they are stacked, and they are pulverized during the stacking process.