The Research On The Application Of Multi-effective Evaporation In The Production Of Ammonium Sulfate By Using Filtrate Of Iron Oxide Black

Ammonium sulfate, a kind of white or light gray to yellow granules, is widely applied in industry. It is prone to dissolve in water, but can't dissolve in ethanol, acetone and ammonia. It is easily to get wetted in air. It's mainly used as fertilizers applied to a variety of soil and crops as well as textile, leather, pharmaceutical etc. Edible ammonium sulfate is made from industrial ammonium sulfate by adding distilled water, and then added in some reagent to get rid of arsenic and heavy metals, and by processes of purification, filtration, evaporation, cooling and crystallization, centrifugal separation, dryness.Multiple-effect evaporation has a variety of application in many industrial areas. However, it's seldom applied in the production of ammonium sulfate. Using multiple-effect evaporation can take full advantage of heat energy, because the steam consumption is greatly reduced by reuse the second evaporation during the evaporation process. In total, the economic performance of the whole evaporation installations can be greatly enhanced. In the production of ferric oxide in Panzhihua Asian Pigment Co. Ltd in Sichuan Province, a large amount of ferrous ammonium sulfate is inevitablely formative in waste liquid or washing-up water. The iron, vitriol, and ammonium are recycled by a series of processes including purification, filtration, evaporation, cooling and crystallization, centrifugal separation, dryness. Finally, ammonium sulfate is obtained.Firstly, we research into the multiple-effect evaporation theory, and know many multiple-effect evaporation applications home and abroad. The comparisons between multiple-effect evaporation and other forms of evaporation were done. The results show that multiple-effect evaporation is more economical than other forms of evaporation. Meanwhile, the feasibility analysis of ammonium sulfate production using multiple-effect evaporation was worked out. Many factors which influence the performance of multiple-effect evaporation were considered, and the best effect number was chosen.In addition, thermodynamics performance of a multiple-effect evaporation system were designed and calculated, and it's programmed in C-language. The select between multi-effect paratactic flow evaporation systems and multi-effect counter flow ones were done. Also, the comparisons research between four-effect paratactic flow evaporation system and three-effect paratactic flow evaporation system were finished.Finally, combining with the real conditions of production of filtrate of iron oxide black process of Panzhihua Asian Pigment Co. Ltd in Sichuan Province, and combining with the characteristics of the multiple-effect evaporation process, the multiple-effect evaporation was applied in recycling ammonium sulfate of iron oxide black. On the basic of sufficiently considering the measure of saving energy, we has discussed how to select the multiple-effect evaporation system and ameliorate the system. The select and application of vacuum pump in multiple-effect evaporation were also discussed. In addition, the drying process of the crystal of ammonium sulfate were presented. In the end, comprehensive analysis on the economic benefits and social benefits of recycling ferrous ammonium sulfate during the production of iron oxide black was completed.