JPS61162578A - Porous oil absorbing material - Google Patents

Abstract

PURPOSE:To obtain the titled material capable of effectively adsorb oils either floating on water surface or dispersing in water, by treatment, with lipophilicity- affording agent, of rigid foam having cell structure constituted by lamellar mineral. CONSTITUTION:Lamellar mineral (e.g. kaolin-contg. clay) powder is mixed with water by agitation. The resulting suspension is gasified into a wet foam, which is derived followed by calcination to make a rigid foam having cell structure (pref. with a porosity ca. 78-98%). This foam is then immersed in a lipophilicity-affording agent (e.g., cationic surfactant) followed by taking out then drying to provide said foam with lipophilicity, thus obtaining the objec tive oil-absorbing material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an oil-absorbing material that can effectively adsorb oils floating on the surface of water or dispersed in water.

[Technical background of the invention and its problems] Oil-containing wastewater, in which oil is finely dispersed in water, cannot be separated sufficiently by mere gravity separation, so an oil-absorbing material with high oil-absorbing capacity is desired. Further, it is preferable that the oil-absorbing material floats on the water surface after adsorbing the oil, in order to easily recover the oil.

Furthermore, oil absorbing materials are often not adopted unless they can be used repeatedly and have low processing costs.

Conventionally, inorganic oil-absorbing materials that separate the oil content from oil and water have been treated with lipophilic pearlite particles, lipophilic treated porous chamotte particles, sodium-montmorillonite clay, and organic dyes. Chinoku Special Publication No. 49-37033)
It has been known.

However, chamotte has a drawback in that its particles have low strength, and if it is subjected to incineration treatment after oil absorption for repeated use, the particles will break and cannot be reused.
Moreover, the pores of Barai 1- and Chamot 1- are connected, so when oil is absorbed, the pores become filled with oil and become heavy.
It sinks in water, making it difficult to recover the oil-absorbing material.

Next, while montmorillonite clay has oil absorption properties, it also has water absorption properties, and has poor water resistance, so montmorillonite clays that have absorbed oil are difficult to dehydrate sufficiently, and therefore solvents cannot be used. It has drawbacks such as difficulty in removing oil and incineration of oil.

Furthermore, since an aqueous solution prepared by mixing sodium-montmorillonite-based clay and an organic cationic agent in water is a solution type, it is difficult to reuse the separation agent. Furthermore, the oil absorption of this separation agent takes advantage of the structure of sodium montmorillonite, in which the length and thickness are several thousand values, so there are relatively many places where oil can adhere, but this naturally has its limits. , its oil absorption ability was not satisfactory.

"Objective of the Invention 1 The object of the present invention is to solve the above-mentioned problems of conventional oil-absorbing materials, especially oil-absorbing materials using layered minerals such as montmorillonite, which have good oil-absorbing properties and can be used repeatedly. Our objective is to provide oil-absorbing materials that are of the highest quality.

[Structure of the Invention] As a result of extensive research into this problem, the above object has been achieved by the structure of the present invention as detailed below.

That is, the porous oil-absorbing material of the present invention is characterized in that a hard foam having a cell structure made of a layered mineral is treated with a lipophilic treatment agent.

The most preferred embodiment of the porous oil-absorbing material of the present invention is:
The layered mineral is kaolin-containing clay, the porous oil-absorbing material has a porosity of 78 to 98%, and the lipophilic treatment agent is a cationic surfactant.

The hard foam having a cell structure made of layered minerals in the present invention is produced by stirring and mixing powder of layered minerals called phyllosilicate minerals with water, gasifying the suspension to form a wet foam, drying this, and then sintering it. This is a rigid foam with extremely high porosity and substantially closed pores.

Such a form and its manufacture are disclosed in Japanese Patent Application Laid-Open No. 58-2174.
No. 57@, the application of the rigid foam disclosed in that publication was related to thermal insulation and fire protection.

The layered minerals used in the present invention include layered minerals with a two-layer structure, a three-layer structure, or a multi-chain structure, such as kaolin-containing clay, montmorillonite, seviolite, and vermiculite. In addition, the density of the hard foam is 0405~0.5
g/cm3, the average cell diameter is 60 μm or less, all cell diameters are 150 μm or less, and at least 9 of the cells
0% has a cell structure with a diameter of 100 μm or less, and the porosity in that case is 78 to 98%.

The present invention is characterized in that a hard foam having a cellular structure made of the layered mineral described above is treated with a lipophilic treatment agent, and its use is made into a porous oil absorbing material. Examples of the lipophilic treatment agent include cationic surfactants, silicone resin emulsions, and paraffin emulsions. There are commercially available cationic surfactants such as Duomin T, Alucard 2 HT-75, Armac C, and Armac T (all brand names from Lion Akzo).
polonM F for silicone resin emulsion
There are commercially available products such as -40 and Po1onC (both trade names of Shin-Etsu Chemical Co., Ltd.). The treatment method with the lipophilic treatment agent is to form the treatment agent into a solution or emulsion with a concentration of 0.03% by weight or more, and 0.3 to 3.0% by weight with respect to the layered mineral, particularly preferably 0.0% with a cationic surfactant. .5-1.0
In the case of a silicone resin emulsion or a paraffin emulsion, it is preferable to use the coating amount in an amount of 1 to 3% by weight. Thus, in the present invention, the cationic surfactant has the advantage that it requires the least amount and has the best oil absorption.

[Example 1 of the invention] A wet floss made by adding a blowing agent to a kaolin-containing clay and gasifying it is dried, and the resulting dry prills are sintered at 1100°C to obtain a density of 0.06 (J/' (J3 hard (same as the hard foam in Example 1 of JP-A No. 58-217457).One part of this hard foam was 0.07%
The sample was immersed in 15 parts of a cationic surfactant aqueous solution for 30 minutes, taken out, and dried to perform lipophilic treatment to obtain an inorganic porous oil absorbent.

The oil absorption performance of this oil absorbing material was tested by the following method.
Add oil-absorbing material to a mixture of 50 ml of water, 50 ml of kerosene, and
After standing for 30 minutes, the oil-absorbing material was scooped out and the amount of remaining oil was measured to determine the amount of oil absorbed. As a result, the oil absorption amount of this oil-absorbing material was four times the weight of the oil-absorbing material itself.

Furthermore, this oil-absorbing material was fired at 700° C. for 1 hour, then regenerated by the above-mentioned lipophilic treatment, and an oil-absorption test was conducted. This operation was repeated four times, but there was no change in appearance or oil-absorption performance.

As a comparative example, an oil absorption test was conducted on an oil absorbing material made of porous material of Shisemot in the same manner as in the example, and the oil absorption amount was 1.1 times the weight of the oil absorbing material itself. Furthermore, as a result of the same reprocessing as in the example, the strength of the particles was low and the particles gradually broke down into powder.

[Effects of the Invention] The porous oil-absorbing material of the present invention has an extremely large specific surface area, with a porosity of 78% or more, which increases the contact area of oil and physically fills the pores with oil. and exhibits high oil absorption.

In addition, since the oil-absorbing material has a density of 0.05 to 0.5 g/c1 and is extremely lightweight, it does not sink in water even when it absorbs oil or water and can be easily recovered. The presence of independent pores is also a factor in improving the ability to float on water.

Moreover, since it has a specific cell structure, it has high strength and does not lose its shape even during recycling. That is, after oil absorption, the porous oil absorbing material is easily regenerated by incinerating the burnt tIC oil, then baking it at 700° C. for 30 minutes, and further performing the above-described lipophilic treatment and drying.

As described above, according to the present invention, the porosity of the oil absorbing material is high.
It has oil absorbency several times higher than conventional oil absorbing materials of this type, and by burning the oil and regenerating it, it provides an oil absorbing material that can be used several times over. The disadvantages of low oil absorption and inability to reuse have been completely resolved.

Claims (1)

[Scope of Claims] 1. A porous oil-absorbing material characterized in that a rigid foam having a cell structure made of a layered mineral is treated with a lipophilic treatment agent. 2. The porous oil-absorbing material according to claim 1, wherein the layered mineral is kaolin-containing clay. 3. The porous oil-absorbing material according to claim 1, wherein the porous oil-absorbing material has a porosity of 78 to 98%. 4. The porous oil-absorbing material according to claim 1, wherein the lipophilic treatment agent is a cationic surfactant.