Industrial Application of the Flushing Process to High Purification of Natural Raw Materials

为了从陶瓷原料中高效地分离出细小的杂质颗粒，作者开发了洗涤工艺。在这一复杂的过程中，用煤油提取悬浮在原始矿浆中的1微米以下的超细矿物颗粒。本文利用商用液-液连续萃取器对天然无定形石墨和一些绢云母粘土进行了实验处理，以揭示该工艺在工业应用中的实用价值。选择已在中国中浓缩的无定形石墨进一步去除粘性杂质。台湾产的绢云母粘土有时需要降低化妆品中的砷和铅的含量。产于冈山的低品位绢云母中含有丰富的黄铁矿，工业上需要对其进行黄铁矿的分离。这些原料在…中以一定的微米级进行了分级在冲洗操作之前进行更多操作。在柠檬酸、EDTA、次亚硫酸钠的存在下，将水泥浆在pH 4.3的条件下进行处理，以增强所需物质的疏水性。此外，还确定了操作条件，如进料速度、叶轮摆动次数、料浆密度、含油率等。岛崎工业萃取器由于其圆柱形叶轮，可以产生高剪应力的细小油滴，有利于疏水固体颗粒的收集，并将组成颗粒释放到单个颗粒中，因此对固体颗粒具有良好的提油作用。通过加入非离子表面活性剂和碳酸钠，将提取到油相中的石墨颗粒恢复到原来的水分散状态，并用离心机进行回收。2um样品的灰分含量显著降低到1.8质量%，脱色率为88.5%。此外，废油用硫酸洗涤再生，黄铁矿与绢云母粘土的分离效果良好。台湾绢云母中砷、铅含量可降低至化妆品标准值以下。对于冈山绢云母，原矿氧化后除铅效率降低，实验结果表明，冲洗法对天然原料的工艺提纯具有很大的优势。较少

The flushing process was developed by the author for the purpose of highly efficient separation of fine impurity particles from ceramic raw materials. In this sophisticated process, ultrafine mineral particles of under 1mum size suspended in raw ore slurries are extracted with kerosene.In this report, a natural amorphous graphite and some sericite clays were treated experimentally using a commercial liquid-liquid continuous extraction apparatus to reveal the practical value of the flushing process in industrial application.The amorphous graphite which was already concentrated in China was selected for the further elimination of clayy impurities. The sericite clay occurring at Taiwan is sometimes required to lower the contents of As and Pb for the use in cosmetics. The low grade sericite occurring at Okayama contains abundant pyrite for which the separation of pyrite is necessary for its industrial application.These raw materials were classified at a certain size of micrometer order in … More prior to the flushing operation. The aqueous slurries were conditioned at pH 4.3 in the presence of citric acid, EDTA,sodium dithionite to enhance the hydrophobicity of desired substance for oil-extraction. Besides operational conditions were determined such as feed rate, numbers of oscillating motion of impeller, slurry density, hold-up fraction.The commercial extractor made by Shimasaki Manufacturing Co.showed excellent function for the oil-extraction of solid particles owing to its cylinder-shaped impeller by which high shearing stress fine oil droplets are created available for the collection of the hydrophobic solid particles, together with the release of the constituent particles to individual particles. The graphite particles extracted into the oil phase were returned to its original aqueous dispersions by the addition of nonionic surfactant and sodium carbonate and were recovered using centrifuge. The ash content of the 2mum sample was significantly lowered to 1.8mass% with the removed ratio of 88.5%. In addition, the waste oil was regenerated by washing with sulfuric acid.Separation of pyrite from the sericite clays was well performed. The content of As and Pb in Taiwan sericite could be lowered under the values of criterion for cosmetics. As to Okayama sericite, the efficiency of eliminating Pb was decreased when the raw ore had been oxidized.In conclusion, the experimental results suggest that the flushing process is very advantage for technical purification of natural raw materials. Less