Hydrothermal synthesis of alumino-silicate from coal ash

粉煤灰水热合成硅铝酸盐

基本信息

批准号：
07555324
负责人：
MATSUOKA Isao
金额：
$ 2.11万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

The present project have been aimed at purification (flotation, magnetic separation) of fly ash and its hydrothermal treatment for synthesis of alumino-silicate as kaolinite.Flotation Carbon removal of fly ash by flotation have been investigated with the aid of kerosene bridging between bubble and the carbonaceous particles. The results were discussed in relation with the results of zeta potential measurement or water/oil extraction on the fly ash particles. Effects of pH adjustment, comminution of feed and surfactant addition on the results were examined. Zeta potential measurements revealed that electrostatic interaction among carbonaceous or inorganic particles was found to be very small. Water/oil extraction indicated it was liophobicity of inorganic surface rather than of carbonaceous one that should be affected by pH : in alkaline condition metallic cations on the surface of fly ash should increase consumption of oil by inorganic particles.Magnetic separation. Iron component in fly ash was removed in amount from 3.7% to 0.1% by dry magnetic separation. Analysis of separated samples with XRD and SEM-EDX indicated the magnetic components (mainly magnetite) should be conbined with carbonaceous materials. Indeed, purification was substantially improved when flotation was performed after magnetic separation.Hydrothermal treatment. Synthesis of kaolinite was found to be facilitated by alkaline pretreatment for decomposition of quartz included in fly ash. There were little effect of temperature (up to 300ﾟC), pressure or pulp condition on growth of kaolinite. Ionic impurities of fly ash (Ca, Mg, K,Na) did not seem to hinder the reaction. Only pH was found to have some relationship with the productivity. The synthesized kaolinite had low crystalinity and large specific surface area. One of the present problem is low brightness of the product, caused by iron impurity.

本项目的目的是针对粉煤灰的纯化（浮选，磁分离）及其水热处理，用于合成铝硅酸盐作为高岭石。借助煤油在气泡和碳质颗粒之间填充了煤油桥梁，通过浮选进行了研究。与狂热颗粒上的Zeta电位测量或水/油提取的结果讨论了结果。检查了pH调节，饲料佣金和添加表面活性剂对结果的影响。 Zeta电位测量表明，发现碳质或无机颗粒之间的静电相互作用非常小。水/油的提取表明，应受pH值的影响是无机表面的苦味性，而不是碳质表面的含量：在葡萄酒表面上的酒精条件下，金属阳离子应通过无机颗粒来增加油的消耗。通过干磁分离，将粉煤灰中的铁分量从3.7％到0.1％去除。用XRD和SEM-EDX分析样品的分析表明，应将磁成分（主要是磁铁矿）与碳质材料结合。实际上，当磁分离后进行浮选时，纯化得到了显着改善。发现高岭石的合成是通过饮酒预处理制备的，以使粉煤灰中的石英分解。温度几乎没有影响（最多300 c），压力或纸浆条件对高岭石的生长。粉煤灰（CA，MG，K，NA）的离子杂质似乎并没有阻碍反应。发现只有pH与该产品有一定的关系。合成的高岭石具有低结晶度和较大的特定表面积。目前的问题之一是产品杂质引起的产品的亮度低。