Synthesis Of Zeolite Y With Waste Slag From FCC Catalyst Preparation

A large amount of waste slag are produced in the course of FCC catalyst production. Up to now, a reasonable way to reuse the slag has not been found. The slag are usually abandoned directly,which leads to a series of problems, such as resource squander and environment pollution. In this paper, activated FCC catalyst slag was used as raw materials with silicon source and NaY zeolite structure directing agent(SDA) to synthesis NaY zeolite by in-situ hydrothermal crystallization method. A novel method was found for recycling the FCC catalyst waste slag, which aims to achieve the FCC catalyst “green production” and the resource efficiently recycling.Only after activation the waste slag could be used as raw materials to synthesis NaY zeolite. Compared with other activation methods, Alkali fusion activation after pretreatment was the optimal method. Different activation conditions were investigated. The result showed that the alkali addition, calcinations temperature and calcinations time all had obvious effect on the synthesis of NaY zeolite.Using activated waste slag in Na Y zeolite synthesis, SDA addition, alkalinity, Si-Al ratio, water addition, crystallization temperature and crystallization time were investigated in the synthesis. The structure and properties of the sample were characterized by N itrogen adsorption-desorption, X-ray diffraction(XRD), scanning electron microscope(SEM) and temperature programmed desorption(N H3-TPD). The yield of the products was also investigated. It is found that with the FCC waste slag as raw materials via in-situ synthesis, ultrafine NaY zeolite with high relative crystallinity and surface area can be synthesized whose surface area is 600m2 / g and Si-Al ratio is 4.6. The results also showed that the alkalinity and water addition of the reaction system have a great influence on the crystallinity of the synthesized zeolite Y. And the crystallization time was the main factor to affect the yield of the products. The synthesis conditions were optimized by orthogonal experiment. The results also indicated that the the Si-Al ratio of raw materials was the main factor to influence the relative crystallinity of the zeolite.The thermal stability and hydrothermal stability of as-synthesised Y zeolite were investigated. FCC catalysts were prepared with the synthesized zeolite Y as the active component to investigate its catalytic performance. The results showed that compared with industry Y zeolite, the as-synthesised Y zeolite had a good thermal and hydrothermal stability whose skeleton structure was collapsed after 800 ℃. Evaluation results showed that compared with the industrial catalyst,the as-synthesised zeolite Y as the active component of FCC catalyst had higher light oil yield and conversion rate. The result also showed that the conversion rate and coke yield were decreased and the selectivity of light oil was increased with the Si-Al ratio of zeolite increased.