助熔剂对型煤灰熔融特征温度的影响

Effects of Fluxes on Fusibility Temperature of Briquette Ash

研究了高灰熔点型煤灰成分与灰熔融特性的关系,考察了Fe2O3,MgO,CaO和固体水玻璃助熔剂对型煤灰熔融温度的影响.结果表明,碱性氧化物与灰中所含矿物质在高温下易形成低共熔混合物,能有效降低型煤灰熔融温度.加入等量(11%,ω)的MgO,CaO及固体水玻璃、Fe2O3,流动温度分别下降了22.0,58.8,81.2和91.9℃.通过三元相图及XRD分析揭示了物相组成变化和矿物晶体的存在形式.CaO,固体水玻璃和Fe2O3适宜的添加量分别为11%,9%和9%.CaO和固体水玻璃对型煤还具有粘结和促进气化作用,更适合作为助熔剂.

The additive of Fe2O3, MgO, CaO or solid water glass was blended with briquette ash at different proportions, respectively, as flux. The briquette ash fusibility temperature was studied under the condition of weak reduction atmosphere to lower its melting temperature. The results show that its fusibility temperature can be lowered by blending with alkaline oxides efficiently due to the fact that mineral matters react with alkaline oxides and produce low melting eutectic matters. The decrease of ash fusibility temperatures by adding the same amount （11%, o9） of flux follows the sequence of MgO, CaO, solid water glass and Fe2O3, and the flow temperature is lowered by 22.0, 58.8, 81.2 and 91.9 ℃ respectively. Ternary phase diagram and XRD analysis were used to examine the effects of each flux on briquette ash fusibility temperature, verify the existence of mineral crystals, which is well coincided with the experiment results. The suitable adding quantity of CaO, solid water glass and Fe203 flux is 11%, 9% and 9% respectively, and CaO and solid water glass with both adhesive and accelerating gasification properties are found to be better fluxes of briquette ash.