1、发明的背景最近已经确定,空心微珠是粉煤灰里的一个较大的组分,它是一种化学上惰性的空心小球,直径近似地等于300微米,化学组成主要是氧化硅,氧化铝和氧化铁,在它的球形空腔内还有一些氮气。目前空心微珠已经商品化,但是由于它的分选成本较高,限制了在诸多方面的广泛应用。然而,空心微珠的成本仅仅只包括把它从粉煤灰中分选出来的费用,如果能采用一个 1. Background of the Invention It has recently been established that cenospheres are a larger component of fly ash, which is a chemically inert hollow sphere approximately equal to 300 microns in diameter and chemically composed primarily of silica. Alumina and iron oxide also have some nitrogen in their spherical cavity. At present, hollow microspheres have been commercialized, but due to its high cost of sorting, it has limited its wide application in many aspects. However, the cost of cenospheres only includes the cost of sorting it out of fly ash, if one can