Activated clay is acid-activated bentonite, known in the industry as activated clay or bleaching earth. Montmorillonite is the main mineral bentonite, its characteristics determine the basic properties of bentonite. The most important property of montmorillonite is cation exchangeability, that is, equivalent exchange between Na +, Ca2 +, K + ions adsorbed between layers and other ions in the solution can be carried out. Activated activated bentonite is the use of bentonite montmorillonite exchangeable between the layers of Na +, Ca2 + and other cations in strong acidic solution, H + partially or fully replaced by a larger specific surface area and more absorbent activated clay [ 1] . The current production process of activated clay is mainly wet production. It is the dispersed bentonite pulp into the reactor, adding a quantitative acid, with steam or other heating medium activation . The method is applicable to the production of activated clay with different qualities of bentonite, and the product quality is stable. It is currently the most widely used production process. Wet process disadvantage is due to heating caused by higher energy consumption, high requirements for equipment corrosion, in addition, greater use of pulp washing water. Wet process is:
Bentonite ※ Drying ※ Crushing sieving ※ Stirring pulping ※ Reaction activation (inorganic acid) ※ Drying ※ Crushing ※ Activated clay
The main purpose of activated clay is to decolorize oil and grease products. Therefore, the main sales targets of activated clay are oil refining and oil industry, which depollute and purify the products of lubricating oil and cooking oil to remove the impurities in the products.
1 Activated clay production and use
Refining companies use activated clay is the decolorization of lubricants. There are mainly two kinds of processes for decolorization of lubricating oil: one is hydrogenation to carry out chemical reaction to decolorize, and the hydrogenation process is used to produce large amount of manufacturers. Its disadvantage is that the product has poor stability, easy oxidation and the color of the product over time Prolongations will produce changes in the Qilu Petrochemical Victory Refinery and Dongying Shengli Oilfield refinery use. Another process is the use of activated clay bleaching, which is used in smaller or smaller refineries, which is characterized by a stable color after bleaching. Jinan Refinery lubricants workshop using activated clay, the use of relatively large, about 300t per month, with activated clay bleaching is the last process of the entire process, from the refining effect, bleaching process is: mixing, heating, evaporation ( Steam to water), filtered.
Activated clay used in the oil industry is mainly for the salad oil bleaching. Finished pure peanut oil without activated clay bleaching, but the filter is the product of refined oil, salad oil is refined from the filtered residual oil, the purification of this part of the need to use activated clay, after decolorization Made of peanut salad oil, peanut refined oil. Luhua Group mainly produces peanut oil, peanut oil refining is very small, so the amount of activated clay is very small, 9t per month, decolorization process: Add activated clay in the leaching oil, mixing, heating, filtration. Therefore, the use of activated clay in the oil industry is based on the production of salad oil plant-based oil plants, rather than like Luhua Group to produce pure peanut oil-based enterprises.
2 Activated clay in the production and use of the specific problems
The manufacturer, the main problems are the following. (1) The requirements of various industries on the quality indicators of activated clay are not uniform, and some require high decolorization rate, and some require high activity, and some see the production process simulation results. (2) The producers of activated clay have rich experience in production, but lack of understanding of the theoretical basis or activation mechanism for improving product quality or an indicator. Only by relying on experience in production.