DE893195C - Process for drying acid-activated fuller's earth - Google Patents

Description

Method for Drying Acid Activated Fuller's Earth The invention refers to the production of activated fuller's earth and other bleaching earths of the aluminum hydrosilicate type, 4. h. those prepared from montmorillonite clay are. Such bleaching earths are activated by treating them with dilute aqueous Treats, washes and dries mineral acids. They are mainly used for cleaning and removal of non-aqueous liquids such as animal, vegetable or oil of mineral origin, or of fats or waxes or as catalysts or used as a carrier for catalytically active agents.

The removal of the water remaining from the washing has been done so far by heating. It has already been proposed to use the loosely bound water to remove volatile water solvents and then to evaporate the solvent, giving the product greater bleaching power. For this procedure it is essential that the water by means of filtration or the like. Is replaced by a water solvent. This results in the difficulty of unnecessary losses of water solvents Prevent evaporation.

It has now been found that the removal of water from the wet or damp fuller's earth without separate replacement of the water can be accomplished by subjecting the fuller's earth to evaporative drying in the presence a water solvent and a third liquid slide, which are not mixes completely with the mixture of water and water solvent.

About the recovery of the water solvent and the third liquid To facilitate from the condensate can be added amounts of these liquids according to the Phasendiagl-amm of the three-liquid system is chosen in this way will; that the water / water solvent mixture differs from the third liquid water solvent - Mixture separates when standing. It is also possible to add water to the condensate, to divide it into two layers. It is not necessary that the third liquid and the water solvent alone are completely immiscible with each other.

Numerous liquids, such as. B. methanol, Ethanol, isopropanol or acetone can be used; are preferred below 100 ° boiling liquids. The third liquid must be completely or almost completely immiscible with water, preferably also with the mixture of water and water solvent, to facilitate the recovery of the third liquid and the water solvent. For this purpose, a liquid boiling at close to 100 ° is preferred, around high temperatures to go in the distillation. A light hydrocarbon is used as a third liquid, such as B. toluene, preferred. Also petroleum fractions boiling in the range from 65 to 120 ° can be used, as well as chlovated hydrocarbons with boiling points im same area.

The method according to the invention can be carried out in various ways will. For example, a still can be used under normal or low Pressure can be used with or without recirculation of a portion of the distillate. Any other drying device is also suitable, provided it is completely encapsulated is to recover the volatilized water solvent and the third liquid to enable.

The method is expedient for the wet filter cake applied, which is created by filtering the washing water from the bleaching earth, or even with a fuller's earth that is mild to a moisture content of not has been dried below 25%. It is also possible to add bleaching earth to the process to subject, which results from washing and from which most of the washing water by settling and stripping, by centrifugation, or in any other similar manner away.

The advantages of the method according to the invention over the simple one Treatment with a water solvent consist in making the substitution of the water is unnecessary by a water solvent in a filtering process. Consequently The water solvent and the third liquid can be wet or damp Fuller's earth is added to a vessel, from which it is distilled after Thoroughly removed the mixture. Furthermore, the amount to be used is reduced Amount of water solvent on a given amount of fuller's earth. The whole procedure or At least the last traces of liquid can be removed in a vacuum walk. Another major advantage is that the water solvent used contains no acids or salts, so that the recovery of the water solvent takes place under neutral conditions.

Furthermore, the degree of acidity of the finished soil can be determined in advance while washing as the subsequent treatment with the water solvent and the third liquid does not affect the acidity of the end product.

The invention is illustrated below using examples, the Numbers relate to parts by weight.

Example I Fuller's earth was activated by being in an open Vessel for 24 hours a mixture of 210 parts of earth, 70 parts of commercially available concentrated sulfuric acid and 420 parts of water boiled, whereupon the earth washed to remove the excess acid and to remove the superfluous Wash water has been filtered. Part of the filter cake with a content of II, 8 Parts of dry activated earth were mixed with 8 parts of methanol and 75 parts of toluene distilled in an apparatus used for liquid determination. The distillate divided into two layers, of which the upper class mainly consisted of continuous circulated toluene and the lower layer of a mixture of water and methanol. After all the water and methanol from the still had been removed, d. H. after the volume of the aqueous layer of the distillate no longer increased, the distillation was continued without toluene reflux until the Earth was dry. After the two layers separated, the distillate became this Toluene directly recovered while the aqueous layer making up 27.5 parts Contained 7.9 parts of methanol, which was recovered by distillation and reused became.

Example 2 As in Example I, Fuller's earth was activated, with water washed and filtered. One part of the filter cake with a content of 15 parts dry earth was mixed with 45 parts of methanol and 45 parts of a light petroleum fraction mixed with boiling points ranging from go to 1030.

The mixture was heated in a vessel and the vapors produced condenses until all the liquid is removed and the earth is completely dry was.

Example As in Example I, Fuller's earth was activated, with water washed and filtered. Part of the filter cake with a content of 18 parts dry earth was mixed with 50 parts of methanol and 20 parts of toluene. The mixture was heated in a vessel at negative pressure of 10 to 20 mm Hg until all the liquid removed and the earth was completely dry.

Example 4-As in Example I, Fuller's earth was activated, with water washed and filtered. EWn part of the Filter cake with a content 12 parts of dry earth were mixed with 10 parts of methanol and 70 parts of toluene. The mixture was heated in a vessel with a high speed stirrer and condenser. The heating and stirring were carried out until the earth was completely dry and was in the form of loose powder. To a complete separation of the toluene from to achieve the water-methanol mixture in the collected distillate small amounts of water were added to the distillate and the mixture was stirred until in the subsequent divorce the toluene volume no longer increased.

Example 5 Fuller's earth was activated by being in an open Vessel for 24 hours a mixture of 2I0 parts of earth, 75 parts of commercially available concentrated sulfuric acid and 420 parts of water boiled, whereupon the earth was washed to remove the excess acid by settling and stripping. The last sediment with the washed earth was in the form of a viscous suspension before. Part of this suspension containing 20 parts of dry earth was made mixed with 20 parts of methanol and 70 parts of toluene and the mixture heated under Circulate the toluene until all of the water and methanol were removed. In the end the Toluolüherschuß was distilled off without circulation until the earth was completely dry was.

Example 6 As in Example I, Fuller's earth was activated, with water washed and filtered. One part of the filter cake with a content of 3.2 parts dry earth was mixed with 10 parts of methanol and 1.5 parts of a light petroleum fraction mixed with boiling points ranging from 105 to I2IO.

The mixture was poured into a shallow evaporating dish and poured through Radiant heating elements arranged close to the liquid level are heated until the product was completely dry.

The dry earth produced in each of the above process examples easily crumbled into a loose powder that was neither ground nor sifted and had exactly the same degree of acidity as the earth that passed through simply drying the water-washed cake was gained. Your effectiveness as bleaching earth was determined by its use for decolorizing linseed oil. It Its decolorizing power turned out to be that of the same water-washed and by normal drying by heating water-free earth superior and equal The effectiveness of the earth was making up the water by replacing it with methanol had been removed.

Claims (6)

PATENT CLAIMS: I. Method for drying acid-activated, washed Fuller's earth of the aluminum hydrosilicate type, characterized in that the moist or wet fuller's earth evaporative drying in the presence of a water solvent and is subjected to a third liquid that does not or practically dissolves with water does not mix. 2. The method according to claim I, characterized in that the water solvent Methanol, ethanol, isopropanol or acetone can be used individually or in groups. 3. The method according to claim I or 2, characterized in that the third liquid is a light hydrocarbon or a mixture of these or one or more chlorinated hydrocarbons with boiling points in the range from 65 to I20 ° can be used. 4. The method according to claims 1 to 3, characterized in that that drying by distillation of the liquid mixture at atmospheric or negative pressure is effected. 5. The method according to claim 4, characterized in that the distillation the liquid mixture is effected with reflux of part of the distillate. 6. The method according to claims I to 5, characterized in that that the proportions of water solvent and third liquid are chosen so that the water-water-solvent mixture in the condensate differs from the third-party liquid-water solvent mixture part.