JPH0425060B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a liquid adsorbent that can absorb liquid or retain the absorbed liquid.

[Prior art and its problems]

Hundreds of types of adsorbents are available, ranging from liquid adsorbents whose main materials are synthetic resins and polymeric water-absorbing resins to liquid adsorbents whose main materials are ash, straw waste, and the like. The former is said to be a luxury product and has a water absorption rate of 10 times or more. The latter belongs to the category of low-grade products and has a low water absorption rate.

However, the above liquid adsorbent has the following drawbacks. That is, those belonging to the class of luxury products have good water absorption capacity, but are expensive. Low-grade products have low water absorption capacity and are inconvenient to handle, such as being easily blown away by the wind and easily becoming dirty. Furthermore, some liquid adsorbents mainly composed of synthetic resins pose problems in terms of pollution control when disposing of them after adsorbing organic substances. For example, there was a problem that harmful gases were generated during the combustion process.

By the way, the importance of coal as an energy alternative to oil is currently being reconsidered, and the construction of large-capacity coal-fired power plants is being promoted, and it is expected that a large amount of coal ash will be generated in the future. Since the treatment of this large amount of coal ash is a major problem, the development of technology for its effective use is becoming important.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a liquid adsorbent that can effectively utilize coal ash, can be easily disposed of after adsorption, can reduce costs, and is suitable for a variety of uses. It is.

[Means and actions to solve the problem]

The present invention forms a liquid adsorbent by granulating coal ash and paper fibers as main materials, mixing a hardening agent and water, and curing the granulated product to advance hydration of the hardening agent and harden it. This is what I did.

This allows liquid to be absorbed through the synergistic effect of the pore structure of the coal ash itself and the porous tubes formed between the paper fibers, and furthermore, the absorbed liquid can be retained. Furthermore, it is possible to avoid the use of materials that cause the generation of toxic gases during post-processing.

[Embodiments of the invention]

The paper fiber used is a material that does not generate toxic gases during disposal or combustion.
In this embodiment, newspaper was used as waste paper in consideration of the above points and in order to further reduce costs. The newspaper is first stirred in water at high speed to break it up into fibers, and then drained using a dehydrator. This draining should be done to the extent that the water does not drip. The paper fibers in this state are mixed with coal ash, which is mainly composed of silicon dioxide collected from the flue of a coal-fired power plant, and is spherical and has voids inside itself. The proportion of contamination varies depending on the intended use of the product. For example, for treating waste from livestock, dogs, cats, etc., 300% paper fiber is added to coal ash.
Approximately %. In this case, it is mainly necessary to increase the water absorption capacity. In addition, for seedbeds for germination of plants where water retention capacity is important, the paper fiber content should be about 1% based on the coal ash. In this way, the mixing ratio of the two is appropriately set depending on the type of product. Cement or the like is added as a hardening agent along with water and stirred to form a uniform mixture. after that,
The granules are granulated to a size that matches the desired product, and the granules are cured. In this example, steam curing was performed as follows.

The granules were steam cured at a humidity of 100% and a temperature of 65° C. for 8 hours. As a result, sufficient strength as a liquid adsorbent was obtained. Furthermore, the strength will increase if the material is left at a high temperature after that, but as mentioned above, sufficient strength has already been obtained, so there is no need to do so.

In addition, under high temperature and high pressure (pressure 10kgf/cm ² , temperature 180℃)
You may also use autoclave curing, which is saturated steam curing in which the material is left for several hours. This is preferably used when particularly high strength is required. Specifically, the temperature is raised from room temperature to 180°C over 3 hours, the pressure is increased from normal pressure to 10 kgf/cm ² over about 10 minutes, the high temperature and high pressure state is held for 3 hours, and then,
The temperature and pressure were lowered over about 1 minute to normal pressure and about 3 hours to normal temperature.

Test results regarding the water retention rate of the liquid adsorbent produced as described above will be explained below. The water retention rate was determined as follows.

(1) Put the liquid adsorbent into the pot and fill it with water. The amount of water should be at least the height of the liquid adsorbent.

(2) After 1 minute, place the pot upside down on top of the net and drain the water. The wet state of the liquid adsorbent was determined when the gap between water drops was 10 seconds or longer, and the wet state was calculated using the following formula.

Water retention rate = Total weight in wet state - Total weight in dry state / Total weight in dry state. Shown in the figure. The mixing proportion of hardener is 20% of the total weight of coal ash and paper. As the mixing ratio of newspaper to coal ash increases, the water retention rate increases linearly. Therefore, it is possible to easily select a mixing ratio of the two suitable for the water retention rate of the target product from this diagram.

FIG. 2 is a diagram showing the relationship between the mixing ratio of newspaper to coal ash and specific gravity. Since it changes linearly, the weight, or specific gravity, of the target product can be selected from this.

〔Effect of the invention〕

According to the present invention, the liquid adsorbent is formed by granulating coal ash and paper fibers by mixing a curing agent and water as main materials, and curing the granules, so that the effective use of coal ash can be achieved. In addition, by appropriately changing the mixing ratio of coal ash and paper fibers, it can be adapted for a variety of uses, from blotting papers to plant nurseries. Furthermore, since waste paper such as newspaper can be used as the paper fiber, costs can be reduced by effectively utilizing coal ash. Furthermore, it is possible to avoid the use of materials that produce harmful components through post-treatment, so for example, burning oil after adsorption does not pose a pollution control problem, or after adsorbing excreta, , it can also be used directly as fertilizer.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the water retention rate of the liquid adsorbent according to the present invention, and FIG. 2 is a diagram showing the relationship between the mixing ratio of newspaper to coal ash and specific gravity.

Claims (1)

[Claims] 1. A liquid adsorbent characterized by granulating coal ash and paper fibers by mixing them with a hardening agent and water, and curing the granulated product by promoting hydration of the hardening agent to harden it.