Study On Modificatory Molding Of Kaolin And Its Product Exchange Capacity

Nitrogen and phosphorus compounds are very essential nutrient elements for all forms of life as a basic building block of plant and animal proteins. However, too much of it can lead eutrophication. Ever since a long time ago, there is a defect of the higher operation costs, although the removal efficiency of organic contaminators such as ammonia has been enhanced from large range along with the great improvement of the wastewater treatment technology, related to existent problems on the reclaimed water reuse. Therefore how to reduce the removal costs had been a new problem in the reclaimed water treatment technology.This paper studies spherical grains taking on exchange capacity for ammonia nitrogen, which is made from Fujian Longyan original kaolin by using modification molding equipment. Extrusion balling method employed here is a popular molding technique both home and abroad. Some important parameters are studied during modification process through experiment, including relations between molding equipment parameter and water amount and molding rate; the effects of modifier amount, calcinations temperature on modification; relations between factors such as pore forming agents amount, calcinations temperature, calcinations time and grain fragmentation, specific surface are and porosity. The results show: on the basis of good control over main parameters of the modification molding machine and the material humidity, final products are good in all aspects when calcined for 3h under 500℃, pore forming agents amount10～20%,NaOH15%.On this basis final product performances are researched further, such as the effects of kaolin dosage, water's pH and temperature on the remove capacity of the products, the results show: the remove rate of ammonia nitrogen grows with more kaolin, but exchange amount per unit reduces, the effects of water's pH, and temperature is weak, it can be substituted by natural water. At last, dispel mechanism of NH4+ is analyzed by energy spectrum analysis and absorption spectrum analysis of modifying process and its molding products.