CS254336B2 - Method of watertight pit production for dumping ground - Google Patents

Abstract

1. A process for the production for a water-impermeable container for waste disposals by introducing a water-impermeable layer in to a prepared terrain formation, characterized in that fly ashes from coalfired power stations having a content of at least 3% of an alkaline initiator is mixed with water to form an earth-moist material and after Proctor-densification is applied to a thickness of at least 0.3 m.

Description

254336 3 4

BACKGROUND OF THE INVENTION The present invention relates to a method for producing a watertight pit for deposition by depositing a watertight layer into a prepared terrain formation.

A number of materials for depositing and also de-storable have the disadvantage that, at least in longer atmospheric influences, they cause the groundwater to contaminate and also change its mechanical properties in addition to permanent washing. This is the case, for example, with high gypsum products, whereby not only does they pollute the water by intensive scrubbing but also lose their mechanical resistance. Other depositable substances are fly ash and sludge from coal power plants and flue gas cleaning, even when they have a high heavy metal content. Therefore, it is desirable to deposit these materials only in depots having a waterproof layer. Further, it may be desirable to seal the tub after being fully filled. According to the prior art, only a viscous material, for example clay or clay-clay soil, which can be deposited and compacted in the appropriate thickness layer, is suitable for sealing. Another possibility of sealing would be to use welded plastic sheets in principle. However, this is not only associated with very high costs, but there is also the risk that the plastic film will tear with appropriate stresses and aging, and then the components of the deposited products will nevertheless reach the groundwater, as described, for example, in the journal. BRIEF DESCRIPTION OF THE INVENTION It is an object of the present invention to provide a method for producing a watertight pit for deposition by depositing a watertight layer in a ready-made field formation that will lead simply, cost-effectively and safely to the desired success. chu. The object is solved by the method according to the invention, which consists in the ash of the main power plants, with a content of at least 1% by weight. alkaline activator is mixed with water and applied at a thickness of at least 0.3 meters. Particularly suitable alkaline activators are Portland cement, calcium hydroxide and calcium oxide or mixtures thereof. All fly ash from coal-fired power plants is generally considered as fly ash, because all of them are combined with alkaline activators into sufficiently stable and watertight materials, which are suitable as waterproof tubs or sinks. The ashes contain already a certain amount of alkaline activators.

One particularly simple and cost-effective embodiment of the process according to the invention is that a dry, powdery fly ash derivative containing calcium oxide containing at least 4 wt. calcium hydroxide. Such a derivative can be obtained, for example, by reacting calcium hydroxide fly ash with at least 3% free oxide calcium oxide with excess water, said excess, but not extinguishing, the amount of water required to completely extinguish the extinguishing heat. and led. This method is described in detail in DE-OS 33 47 375.7 entitled " Method and apparatus for the production of fly ash derivatives and their use ". Calcium oxide-containing fly ash of at least 3% by weight. in particular, the free calcium oxide is formed during the dry desulfurization of flue gases according to the dry additive method. Such oxalate-containing fly ash is very aggressive and presents considerable problems in further processing. However, they have been converted according to the aforementioned method into a dry, powdery derivative, mixed with water in an excellent manner, without additional additives, to be used for the production of a waterproof tub or a sink for deposition. Of course, a waterproof cover layer can be formed from the material after filling the deposit, so that the tray is finally disposed as a closed tank. Of course, they can also be mixed with water and use of fly ash containing at least 1 percent by weight of the present invention. calcium oxide, optionally with addition of Portland cement, calcium hydroxide and / or calcium oxide.

The water content depends on the fineness of the composition varies between 15 and 45% by weight, which corresponds to a water / solid content of 0.5 to 0.45. The ash may have a fineness of between 2,500 and 5,000 cm 2 / g according to Blaine, i. fineness according to the form of excretion.

Cement may be added as a binder in an amount of 1 to 8% by weight. Thus, the proportion of binders is generally 1 to 8% by weight, but can be up to 35% by weight when using a dry, powdery calcium oxide-containing fly ash. It is desirable to admix granular components such as sand or slag into the mixtures. Furthermore, it is also possible to admix a sealing material such as bentonite or clay materials in an amount of up to 10% by weight to improve theological properties and performance. Further, the theological properties can be optionally improved by the addition of 0.1 to 1.5 wt. fluid material, in particular melamine resins, lignin sulphates and naphthalenesulphonates,

The process of the invention is further illustrated by the following examples. Example 1

The dry, powdery derivative obtained by expelling fly ash containing about 20% free calcium oxide, which is derived from brown coal boilers heated by a dry method, is reacted with water at a ratio of 1: 1.5 and immediately afterwards. extinguishing is mixed with additional water in a ratio of 1: 0.25. The earth-moist material is transported to the prepared terrain formation and sieved in a layer thickness of 0.5 to 1 m.

Claims (5)

254336 5 6 The material of the tub obtained has the following properties: 7.7 kg / dm33.5 MPa 11.5 MPa2 x 10-in in / n density in compression after 7 days compression strength after 28 days permeability coefficient after 56 days longer intense irrigation does not leach or mechanically change. Jeproto suitable as a waterproof bathtub for de-ponies. Example 2 The following mixtures were stored after Pr-octora compaction and yielded the following values for useful properties: Permeability coefficient MPa Modulpo · 56 days after> 28 days 90 T 180 T 3.60 T elasticity dn / s MPa after 90 days mixture 1 (1% calcium hydroxide, 90% fly ash) 8.6 x 10 ~ 9 1.8 2.2 2.4 2.8 3,800 mixture 2 (5% calcium hydroxide, 95% fly ash) mix 3 5 , 6 x 10 ~ ® 2,2 2,8 2,4 2,8 4,200 (10% calcium hydroxide, 90% fly ash) mixture 4 3,2 x ΙΟ "9 2,4 4,3 4,6 5.4 4,800 (20% calcium hydroxide, 80% fly ash) mixture 5 3, '2 x 10' 10 4.2 10.5 13.8 14.2 6,900 (5% calcium hydroxide, 3% cement , 92% fly ash) mixture 6 7 x 10-9 6.8 10.2 16.5 18.4 12.500 (as a mixture of 2 but 0.5% of a fluid material (modifi- cate 8.4 x 10 ~ 10 3 , 8 6.4 6.8 9.2 6 800 forged melamine resin] pRedmEt CLAIMS 1. A method for producing a waterproof well by deposition of a waterproof layer into a prepared field formation, characterized in that the coal power plant fly ash comprises 1 wt. % to 35 wt. the alkaline activator is mixed with water and applied at a thickness of at least 0.3 m. 2. The process of claim 1 wherein the alkali activator content is at least 3% by weight. 3. The process of clauses 1 and 2 wherein the alkaline activator is Portland cement, calcium hydroxide, calcium oxide or mixtures thereof. VYNALEZU 4. A process according to claim 1, wherein the dry, powdery fly ash is a calcium oxide containing at least 4% calcium hydroxide. 5. A process as claimed in claim 1, wherein a sealing material, for example bentonite or clay materials, is added to the mixture in an amount up to 10% by weight, and / or a nonfluidic material, for example modified elamine resin, lignin sulfates and naphthalene sulfates in an amount up to 1.5 wt.