Electrophoretic Deposition and Fixing of Functional Mineral Fine Powder-Examination of the Technique to Prepare a Throw-in Type Environmental Cleaning Module -

环境污染在当今社会仍然是一个严重的问题。一些天然矿物有可能用于清洁环境，因为它们具有较大的比表面积，可以吸附各种化学物质和/或具有良好的离子交换能力。为了高效地去除环境中的有害物质，研究了将各种功能矿物粉末电沉积并固定在多孔衬底上的方法，制备了一种可快速暴露于大量受污染的天然水中的投入型环境清洁剂。我们研究了(1)用固液化学反应固定天然沸石(日本秋田县生产的斜发沸石)细粉的方法，(2)反应原料的化学成分对反应的影响(1)，以及(3)用常规的EPD工艺很难沉积的蛋白石-CT微粉的EPD。在实验中，使用了矿物粉，用行星钾磨机在&lt；1μm周围进行了精细粉碎。研究结果表明：(1)利用Na_2O-Al_2O_3-SiO_2-H_2O反应原料，在90℃下反应24小时以上，可使天然沸石(斜发沸石)细小颗粒生长并相互固定；(2)通过改变反应原料的组成(主要是SiO_2/Al_2O_3的比例)，使斜发沸石颗粒转变为各种沸石。(3)与易被EPD沉积的大颗粒钠钙玻璃粉共沉积，可在电极上沉积出超细的蛋白石-CT粉。如上所述，本研究论证了利用天然矿物制备高性能吸附材料的可能性。

Environmental pollution is still a serious problem in the society in these days. There is a possibility that some natural minerals can be used to clean the environment because they have large surface area for adsorbing various chemicals and/or superior ion-exchange ability. In order to remove harmful materials from the environment with high efficiency, the electrophoretic deposition (EPD) and fixing of various functional mineral powders on porous substrate to prepare a throw-in type environmental cleaner was investigated ; such deposited materials can be exposed to a large amount of polluted natural water rapidly. We studied : (1)the fixing of a natural zeolite (clinoptilolite, yielded in Akita prefecture, Japan) ~fine powder by a solid-liquid chemical reaction, (2)the effect of the chemical composition of reacting materials with the natural zeolite in the reaction (1), and (3)the EPD of opal-CT fine powder, which is difficult to be deposited by a normal EPD process. In the experiments, mineral powders finely ground with a planetary potmill around <1μm were used. As a result of the studies, the following results have been cleared : (1)the natural zeolite (clinoptilolite) fine particles can be grew and fixed each other by a solid-liquid chemical reaction using Na_2O-Al_2O_3-SiO_2-H_2O reacting materials in the reaction at 90℃ for longer than 24 h, (2)the clinoptilolite particle was changed into various zeolite by changing the composition (mainly in the ratio SiO_2/Al_2O_3) of the reacting material, and (3)very fine opal-CT powder can be deposited on an electrode by the co-deposition with a soda-lime glass powder with larger particle size which can be deposited easily by the EPD. As stated above, the the possibility of the preparation of a high-performance adsorbing material prepared from natural minerals was proved in this study.