1. An excellent nitrogen fertilizer (commonly known as field powder), which is suitable for general soil and crops, can make branches and leaves grow healthily, improve fruit quality and yield, and enhance crop resistance to disasters. It can be used as base fertilizer, topdressing fertilizer and seed fertilizer. It can react with salt to produce ammonium chloride, with aluminum sulfate to produce ammonium alum, and with boric acid to make refractories. Adding to the plating solution can increase the conductivity. It is also a catalyst for the color of food soy sauce, a nitrogen source for cultivating yeast in the production of fresh yeast, a dyeing auxiliary for acid dyes and a leather ashing agent. In addition, it is also used in beer brewing, chemical reagents and battery production. Another important role is to mine rare earth, use ammonium sulfate as raw material, exchange rare earth elements in ores by means of ion exchange, and then collect leachate to remove impurities, precipitate, press, and burn rare earth raw ores. For each ton of rare earth raw ores mined and produced, ammonium sulfate needs about 5 tons.
2. There are many biological uses, most of which are used in the protein purification process. Because ammonium sulfate is an inert substance, it is not easy to react with other bioactive substances, and it can maximize the protection of protein activity in the purification process. In addition, ammonium sulfate has excellent solubility, can form a high salt environment, and is used for protein precipitation and subsequent high salt purification preparation. The solubility of ammonium sulfate at room temperature of 0 ° C and 25 ° C varies greatly. The following are the molar concentrations of ammonium sulfate at different saturations at two temperatures.