KR960004748B1 - Material and method for fixation of waste - Google Patents

Abstract

The fixation agent is prepared by mixing 12-94wt% limestone powder coated with surfactant, 3-10wt% silicate, 2-10wt% gypsum, and 1-68wt% mixture of magnesium oxide, fine slag dust and aqueous polymeric material containing carboxyl and hydroxy groups. The surfactant used is stearic acid, palmitic acid, alkylsulfite, alkylarylsulfonate, alkylsulfonate, carbonic acid salt, soap, ethersulfite, nonylphenyl polyglycolether, or fatty alcohol polyglycolether. For practical use the fixation agent is mixed with industrial waste in the ratio of 1:1, while water is added by 30-40wt% with respect to the weight of waste.

Description

Immobilization treatment agent of industrial waste and its treatment method

The present invention relates to an immobilization treatment agent of industrial waste which can be treated as a stable waste by immobilizing heavy metals such as oil, polychlorinated biphenyl and / or cadmium, mercury and chromium contained in industrial waste and It relates to a treatment method.

In general, industrial wastes discharged from chemical plants, food factories, machine repair factories, steel mills, etc., waste oil and various oils used during the production process are mixed. There was a problem that causes contamination or destruction.

Therefore, in the past, various industrial wastes have been incinerated to volatilize or completely burn oil. In addition, when heavy metals are contained in industrial wastes, it is proposed to first incinerate the oil in the industrial wastes, and then to incorporate the solidified materials such as cement to solidify the wastes and to dispose of the solids.

However, incorporating a solidifying agent such as cement into the industrial waste solidifies the heavy metals, even if it is landfilled, so that when left for a long time, heavy metals slowly elute, causing environmental pollution.

In addition, incineration of industrial wastes such as plating liquids, vehicle waste lubricating oils, and condensate waste oils generates toxic dioxin, which requires chemical or physical treatment to separate them from solids and liquids without incineration. In this case, a separate processing device and a process are required, and a problem of cost increase occurs.

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an immobilization treatment agent and a method for treating industrial wastes containing oil and / or heavy metals which can be treated at a relatively low cost with little leaching of heavy metals from the treated materials. do. The present invention is an immobilization treatment agent composed of quicklime, silicate, gypsum and slag fine dust, which are uniformly spray-coated with an ionic surfactant on a surface of an industrial waste containing oil and / or heavy metals. After the addition of water, quicklime and water are mixed slowly to cause exothermic reaction to raise the temperature of the mixture, and react with silicate to form a gel of calcium silicate to fix the heated oil and heavy metals.

As the ionic surfactant used in the immobilization treatment agent of the present invention, anionic, cationic, or nonionic materials can be used, and in the presence of a surfactant, quick lime is pulverized uniformly or is a low viscosity liquid. It can be achieved by impregnation with a solution of the surfactant, and is obtained by placing the quicklime into a mixing dram and spraying with stirring.

Instead of the pretreated quicklime, it is also possible to use a treatment agent in which high fatty acids are mixed with quicklime. In the present invention, it is preferable to use sodium silicate (Na ₂ SiO ₃ ) as the silicate.

In the method for treating the industrial waste immobilization treatment agent of the present invention, the industrial waste containing oil, heavy metals, PCB (polychlorinated biphenyl), etc. is added and mixed with quicklime, silicate, surface treated with a surfactant, and then mixed with water and stirred. In the present invention, the mixing ratio of the industrial waste and the immobilization treatment agent is 1: 1, and 30 wt% to 40 wt% of water is mixed with respect to the amount of waste. It is preferable to add-3 times and make water 30 to 40 weight% of a processing agent.

By the above treatment, the following chemical reactions occur. That is, quicklime and water undergo a hydration reaction, and the mixture is exothermic at 50 to 140 ° C. and reacts with the injected silicate to produce a gel of calcium silicate.

Since the gel silicate gel has an extremely large surface area and a high porosity, the oil having heated thereon and having increased fluidity adsorbs and bonds and is immobilized. If the industrial waste contains heavy metals such as mercury, cadmium and chromium, or compounds thereof, for example, in the case of divalent metal ions (M ²⁺ ), these and silicates are separated by the following chemical reaction: Reactions with each other produce heavy metal silicates that do not dissolve in water to immobilize heavy metals.

The silicates of these heavy metals are matrix-structured, and heavy metals are surrounded by oxygen and are inactivated. Therefore, it is possible to firmly fix the heavy metals.

In addition, quicklime sprayed with a surfactant applied to the surface portion does not exothermic reaction with water, so the handling is easy and the reaction may be delayed. Hydrophobic wastes are also well absorbed when they are in aqueous polyphase systems. The quicklime which absorbs organic wastes by the water contained in or added to the aqueous polyphase system gradually becomes calcium hydroxide, and the organic matter is adsorbed extremely finely and uniformly during the reaction of reacting with silicate to become calcium silicate.

At this time, as the surfactant, anionic and cationic or nonionic surfactants are used, and fatty acids such as stearic acid and palmitic acid, alkylsulfites, alkylarylsulfonates, alkylsulfonates, salts of carboxylic acids, soaps, and ethereals. Pite, nonylphenyl polyglycol ether, fatty alcohol polyglycol ether, or sulfur oxides thereof are used, and petroleum oil such as paraffin oil is also suitable, and the addition amount is 1 to 5% by weight, preferably 1 to 3% by weight. In addition, magnesium oxide (MgO), gypsum (CaSO ₄ ), a water-soluble polymer (CMC), and the like are used as a substance to contribute to insolubilization and to delay the reaction.

As the water-soluble high molecular material, PVA, methoxy cellulose, hydroxy cellulose, CMC, ether cellulose, alginsa soda, gelatin, casein, etc., which contain a lot of carboxyl groups and hydroxyl groups, contribute to insolubilization. In addition, slag dust has the activity of silicate and contributes to insolubilization, and contains roughly the following components. That is, in the case of slag of slag produced in metal refining business as slag dust, its constituents are 33.07% of silicon oxide (SiO ₂ ), 13.93% of activated alumina (Al ₂ O ₃ ), 42.16% of quicklime (CaO), Magnesium oxide (MgO) 6.94%, titanium oxide (TiO) 1.26%, and other 2.64%.

The composition of the industrial waste treatment agent of the present invention is not particularly limited, but can be carried out in the following composition.

The invention is illustrated in more detail by the following examples.

Example 1

First, the industrial waste treatment agent of the following composition is prepared, and high viscosity waste oil (including tetrachloroethylene, cyan and PCB) containing harmful substances is added to a mixer, and the prepared treatment agent is added twice with respect to the waste oil while stirring and mixed well. And water was added to the amount corresponding to 35% by weight of the treatment to stand to obtain a fixed product.

The concentrations of the heavy metals contained in the waste oil before the treatment and the concentrations of the heavy metals in the water from which the fixed matter was removed after the treatment were measured and the results are shown in Table 1.

Treatment agent composition

90% by weight of powdered quicklime sprayed and coated with a surfactant

Silicate 7% by weight

Gypsum 2% by weight

Magnesium Oxide 1% by weight

Example 2

The waste was treated in the same manner as in Example 1 except that the industrial waste containing oil and heavy metals was mixed, and the mixing ratio of the industrial waste and the treatment agent was 1: 1. A satisfactory effect was obtained as a result of the treatment test.

EXAMPLES 3-4

The same procedure was followed as in Examples 1 and 2 except that the treatment agent composition was changed as follows, and a satisfactory effect was obtained as a result of the treatment test.

Treatment agent composition

50% by weight of powdered quicklime applied by spraying the surface part with a surfactant

8% by weight silicate

Slag fine dust 30% by weight

Magnesium oxide 2% by weight

Gypsum 7% by weight

3% by weight of water-soluble polymer (CMC)

As can be seen from the test results, solidified wastes do not elute heavy metals or PCBs, and oil and / or heavy metals contained in industrial wastes are immobilized. Thus, industrial wastes treated according to the present invention may be harmless, so they are buried in the ground. Even if it is disposed of, it does not cause any pollution problem, and large-scale facilities are unnecessary, so that waste can be disposed of at low cost.

Claims (5)

12 to 94% by weight of powdered quicklime coated with a surfactant, 3 to 10% by weight of silicate, 2 to 10% by weight of gypsum and magnesium oxide, slag fine dust and water-soluble high molecular weight Industrial waste fixation agent. A fatty acid such as stearic acid or palmitic acid as the surfactant, or an alkylsulfite, alkylarylsulfonate, alkylsulfonate, carbonate, soap, ethersulfite, nonylphenyl polyglycol ether, fatty alcohol poly Industrial waste immobilization treatment agent characterized in that the glycol ether or sulfur oxides thereof. The industrial waste fixation agent according to claim 1, wherein the water-soluble high molecular material contains a carboxyl group and a hydroxyl group. To industrial wastes containing oil and / or heavy metals, a quick-dispersion agent containing a mixture of quick-lime lime and silicate, gypsum, and slag fine dust, which are dispersed evenly on the surface of a surfactant, is added, and the quick-lime reaction of quick-lime and water is carried out by mixing water. Raising the temperature of the mixture and reacting with silicate to form a gel of calcium silicate to immobilize oil and heavy metals in the waste. 5. The method for treating industrial waste according to claim 4, wherein the mixing ratio of the industrial waste and the immobilization treatment agent is 1: 1 and water is mixed in an amount of 30 to 40% by weight based on the amount of waste.