the difference of melting temperature between them was decreased with the redu- cing of particle size.In addition,the sensitive extent of the melting temperature due to the particle size of simply mixed fluxes was larger than that of prefused fluxes. 2.4“Volume”Melting Characteristics With rcducing particle size the "point"fusion rate of the simply mixed fluxes was increased until the size was smaller than 100-150 mesh,especally at the tem- perature of higher than 1400Ct).But,for the "volume"fusion rate of simply mixed fluxes at 1550C,the flow-out weight of liquid flux per minute in the case when the particle size was in the grade of 75-100 mesh was a little more than that of mixed fluxes of particle size in the grade of 100-150 mesh (shown in Fig-6.). When CaF:,Na2COa and Fe2O3 was added in flux from 5%6 to 10%6,the primary experimental results showed that the effect of CaF2 was stronger than that of Na2CO3 and Fe2O3. The effect of particle size on the prefused granule type fiuxes was shown in Fig.7.With the increase of particle size,the flow-out weight of liquid flux per minute varied from 8.75g/min at particle size of 0.7-1.4mm to 12.8g/min at par- ticle size of 7-11,7mm. 120r- 1550℃ 100 00 60 515Dmc型 ino-Mold 40 20 12 Time:min 2 4 81012 Time,min Fig.6The“volume”melting beha- Fig.7 The realation between the viour of simply mixed powder melting characteristic and the fluxes for two grades of particle size of the commercial prefused granule type fluxes particle size at 1550C particle size:]11.8-7mm; 2.7-5mm:3.5-3mm;4.3-0.7 1111 A conclusion has becn madc that the fusion rate of prefused flus is larger than that of simply mixed flux.The melting rate of commercial prefused fluxes particle size of which was in the range of 0.7-11.8mm can be 8.75-12g/min. The melting rate of simply mixed flux with particle size of 75-150 mesh was 521· ， 笠 ，’ ” 万 “ ，， 一 ， “ 一 ， “ ’， ， 一 从 一 又 一 。 ， 。 、 一百 早百 ， ，。 。 · 手 · · ， 一 、 · · 。 一 。 一 。 。 助一火﹃‘ ﹁目石兰弓亏。琴助 忍左工 雏 军 “ 尹 国 户声尹 一 ， 才华之 尸 沪刁卢 扮产 产含 一 州 忿 又 ， 之二 ℃ 产 户乞 “ 少冷 生 一 庚名 少一 消多厂 臀 夕 卫二节子 一沁工考。 少 卜 “ ，， 、 己 ， 。 卜 飞 。 一 。 一 。 一 。 一 。 」 、 。 又 皿 扭 一 一 · 一