He Temperature,℃ Eig,1 Change of sample height of mold flux with furnace 妞 temperature Fig,2 Schematic of the apparatus used for measuring the "volu- In fact,the melting of fluxes is me"melting behavlour of flux completed in three-dimensional space 1.flux; 2.corubin tube; 3.coil 4.Al2O3 crucibler in practical utilization,that is,a tempe- 5.Al203 packing;6.graphite base; rature gradient exists in the vertical 7.corubin tuber 8.supporty 9.Pt/Rh themocouples direction of flux layer. 10,corubin crucible, The graphite base heated by induction was used for finding the "volume" melting characterislics of flux.The mold flux whose weight was 140g was set in the furnace and whose temperature had been rised to 1550C and kept stable. Absorbed heat in horizontal direction,the molten flux flowed out from the cen- tral hole of the graphite base.The weight of flowout liquid flux were measured at regular intervals,the observation of the tendency to forming glass phase and the homogenization of samples after it was melted as well. 2 Experimental Results The difference of the melting characteristics between prefused fluxes and simply mixed fluxes with variation of their principal flux systems,additives and particle size has been studied. 2.1 Melting Curves of Principal Composition of Flux Systems Bascd on the SiO,-CaO-Al2Oa flux system,the prefused type powder flux and simply mixed type powder flux were compounded separately according to the ingredients of fluxcs of type I in Table l.The experimental results of the me- Iting characteristics measured with drip-mcthod in the case of same particle size are shown in Fig.3. 518一 飞 梦笼‘沈 ‘ 脸队卜 几 忿 ， ℃ 卜 矛 氮到臻热 、 留， 丫， 翔 逻 硕 、 、 盯 的 钟 马 夔 二 电 ，，，， 尸凿 。 ， 一 。 ， ， 一 “ 们 一 卜 一 。 ， 。 ， ， ， 。 ， 。 ， “ ，， 从队入乳 · 尹 ， 一 ， 、、 · ， 。 。 一 一 一 一 了 ， 。 几 一 。 一 ‘ 一 一 一 一