DE102009021159A1 - Waste dump, waste heap or contaminated land sealing method, involves supplying mixture of components such as rock clay, water sludge and/or sewage sludge, bonding agent, water glass and water, to waste dump, waste heap or contaminated land - Google Patents

Abstract

The method involves supplying a mixture of components such as rock clay, water sludge and/or sewage sludge, bonding agent, water glass and water, to a waste dump, a waste heap or a contaminated land with an inclination angle of more than 30 degree. The mixture of components is sprayed on a surface to be sealed, where the waste dump, a waste heap or a contaminated land contains water soluble salts. The mixture is conveyed to an edge of a high position of the waste dump by a conveyor belt.

Description

The The invention relates to a method for sealing the surface of landfills, dumps and / or contaminated sites, and preferably of Potash and salt dumps through a watertight sealing system.

At the Mining of rock salt and potash fall large amounts of overburden. This spoil contains predominantly Proportions of water-soluble salts, their further work-up but not worth it. The overburden is on huge, often several hundred Meter high waste dumps stored. Rainwater turns it Salt washed out by consuming and from view of the Environmental protection questionable measures prevented must be to get into the groundwater. A possible Method for sealing waste dumps is that one Sealing sheets of plastic deposited on the heap and with a Mounted by earth and gravel, or huge amounts of earth as Apply protection and reclamation layer. These measures However, they are very expensive and not possible with all heaps. For this one needs a feed which is not possible due to lack of space or lack of floor masses. On the other hand, some heaps have so steep flanks that one Do not build a classic seal due to the shear forces leaves.

• • EP-A 125 680 ,
• • EP-A 702 110 ,
• • EP-A 1 116 526
• • DE-A 101 17 902

beschrieben.Methods for sealing landfills are z. In the patent publications

• • EP-A 125 680 .
• • EP-A 702 110 .
• • EP-A 1 116 526
• • DE-A 101 17 902

described.

there are various mixtures, the sand, clays, blast furnace slag, Foundry sand, seaweed, may contain used, which partially even waterglass to improve the tightness was added. However, it has been shown that in landfills with a slope of more than 35 ° the known Mixtures are not sufficiently free-flowing, so that They only with great difficulty and with high costs exclusively with cable-guided devices can be applied.

Of the Invention was therefore the object of a simple and effective Method for sealing landfills, dumps or contaminated sites with an angle of inclination of more than 30 °, in particular of 35 to 45 °, which provide high shear forces Stands up for salt, garbage and other landfills is resistant.

• A. Tonschiefer,
• B. Gewässerschlamm und/oder Klärschlamm
• C. Bindemittel
• D. Wasserglas
• E. Wasser, sowie
• F. gegebenenfalls weiteren Zuschlagstoffen

This object is achieved in that applying to the landfill or heap a mixture of:

• A. slate,
• B. sewage sludge and / or sewage sludge
• C. Binders
• D. Water glass
• E. Water, as well
• F. optionally further additives

there is a homogeneous mixture of the components A, B, C, D, E and possibly made F, so that depending on the application method a free-flowing, viscous silty or preferably a pumpable, liquid mass is formed.

• • Paddelmischer mit Dosiereinrichtung
• • Kaltmischanlagen mit Vorlagesilos und mehreren Mischschnecken
• • Trommelmischer mit Dosiereinrichtung.

Suitable mixing units are, for example:

• • Paddle mixer with dosing device
• • Cold mixing plants with storage silos and several mixing screws
• • Drum mixer with dosing device.

• • Klassische Auftragung mit Muldenfahrzeugen und Raupen
• • Aufbringung nach dem Abrieselverfahren
• • Vorzugsweise Aufbringung durch Pump-/Spritzverfahren

The newly developed organic-mineral seal can generally be applied in three processes:

• • Classic application with dump trucks and caterpillars
• • Application by the trickling process
• • Preferably applied by pumping / spraying

Pumping / injection method

at this process is a technology known per se, which has not yet been used in landfill construction. At this preferred embodiment is the homogeneous mixture on the surface to be sealed by means of a mobile applicator sprayed in the form of a concrete pump until one of the given Requirements according thick sealing layer is applied. The application is preferably carried out in 2 to 4 layers of 10-15 each cm strength.

First, the components A, B, C, optionally a minor part of D and possibly F are mixed homogeneously in one of the described mixing plants, wherein so much water E is added that a pumpable mass is formed. This is transported in special transport containers with counter-rotating mixer coils, which prevent segregation of the mass, to the mobile concrete pumps or feed pumps. Since the conventional mobile concrete pumps with a telescopic or articulated mast have only a limited interpretation and thus not necessarily reach a complete flank height of a heap, it is preferable to use an improved technology:
Delivery pumps transport the sealant into Pipelines to the desired head of the heap. From these points, the sealant is taken in a rope when necessary, provided with a crawler landing gear applicator, with which the mass is then applied to the heap.

So that the sealant adheres to the steep heap, the component D or its predominant part is added to initialize the adhesion and the hydraulic curing by means of a metering device. To avoid voids in the sealant, the water glass must be added before the mass exits the applicator. This metering is preferably carried out on the spray head of the applicator. For short conveyor lines, the water glass can be added to the applicator also shortly before spraying. By a chemical reaction of the water glass, a gel is formed, which causes the solidification of the sealant. There is a total of so much water glass added that the water-impermeable sealing layer a Kf value (measure of the tightness), measured according to DIN 18130 of preferably at least 5 × 10 high minus 9 m / s. The sealing layer is then sufficiently waterproof, flexible and strong so that it is walkable.

Abrieselverfahren

The pourable mixture is by means of a conveyor belt transported to the edge of the highest point of the landfill. The conveyor belt is now in a circle segment of z. B. 15 ° back and forth and leaves at the same time you trickle the mixture down the slope sideways. On reason Its consistency is slow to trickle down and comes after a few Meters to a standstill. The next batch trickles over it and come to rest further down, and so on. If This has formed a 20 to 60 cm thick layer, is the conveyor belt laterally continued and the whole process is repeated until all around the landfill has formed the 20 to 60 cm thick layer.

On This layer forms then - supported in this case from rain or artificial irrigation - through the described chemical reaction the gel, which the solidification the layer causes. So that the flowability guaranteed may, may be due to an additional addition of water be waived.

Classic application with Dump trucks and caterpillars

This Method is known and need not be described specifically. Here you go preferably from a viscous sullen mixture.

reclamation

about the water-impermeable, formed in all three before described methods Layer, a reclamation layer can be applied, the also about 20 to 60 cm thick. This layer is for example from soil, sludge and / or sewage sludge, Slate and at most small amount of water glass. she can be greened.

slate

The Component A is a special natural clay shale, about 10 to 25 wt.% Swellable and non-swellable Clay minerals, preferably illite, kaolite and chlorite. The quartz content is preferably less than 25 wt.%, The Lime content less than 10% by weight.

water sludge

in this connection For example, it is port silt from the Hamburg Port that arises there, because the port and the navigation channels at certain intervals to the respective water depth have to be adjusted. In the mud are next to one certain percentage of fine sands and quartz also about 8% organic Materials included. By the deposit in the water and the permanent Inflow of silt, the organic material is rotted. Especially preferred is the so-called METHA silt. Due to its organic Structure changes the water content of the METHA silt not essential in periods of drought or rainfall. The formation of cracks feared by dehydration in seal construction Volume loss is prevented by the use of METHA silt.

The Preventing cracking is caused by the organic, in particular fibrous constituents from which absorptively bound Water is released slowly and as a buffer of the formation of Counteracts shrinkage cracks. The fibrous ingredients still have the further advantage that they are felt-like interwoven with each other and thereby like a "steel mesh mat" on train and Pressure react and thus an extremely flexible basic structure the sealant yield.

When Component C is preferably used water sludge, In addition, sewage sludge can also be used.

sewage sludge

Sewage sludge comes from municipal bio logical wastewater treatment plants, in compliance with the applicable limits of the Sewage Sludge Ordinance. In this case, only sewage sludge should be used, which are polymer or iron oxide conditioned. Due to its organic structure with many fibers, sewage sludge does not react in dry periods or in rainfall due to changes in the water content. The sewage sludge also prevents cracking.

binder

The Component C is preferably conventional cement. This one supports especially in pumping / spraying a solidification by hydraulic Setting. This component should have a high sulphate resistance (PCHS) The content of tricalcium aluminate should be less than 3% by weight. It is also due to a low heat of hydration and a low tendency to shrink.

water glass

The Component E is water glass, an alkali silicate. By admission of Carbon dioxide from the air and / or rain, especially in the acidic region (responsible for the above all the clay content in the slate is) forms from water glass a gel, whereby silicic acid precipitates, which condenses into silica gel, which is the mixture penetrates completely and solidifies and waterproofs them. Water glass is preferably in liquid form as aqueous, It uses about 28 to 30% solution, but it can also be added as a powder. It has been shown that the commercial product LEGASIL 39, a sodium silicate of the Woellner works, is most suitable.

aggregates

Possibly the mixture can still further additives, such. As lead coatings, waste incineration slag or foundry sands be added. Foundry sand increases the binding power the components; the bentonite contained therein increases the Water impermeability of the sealing layer. simultaneously The shear strength is due to the coarse-grained, stable structure clearly increased. Slag also works in the same direction from the waste incineration.

mixture

• A. 10 bis 40, insbesondere 12 bis 25 Gewichtsteile Tonschiefer,
• B. 5 bis 30, insbesondere 8 bis 20 Gewichtsteile Gewässerschlamm und/oder Klärschlamm, vorzugsweise METHA-Schlick
• C. 5 bis 15 Gewichtsteile Bindemittel, vorzugsweise Zement
• D. 2 bis 10, insbesondere 3 bis 6 Gewichtsteile Wasserglas
• E. 5 bis 30, insbesondere 8 bis 20 Gewichtsteile Wasser
• F. 0 bis 30, insbesondere 8 bis 20 Gewichtsteile Zuschlagstoffe,

wobei die Gewichtsteile sich auf 100 addieren.Preferably, the mixture contains:

• A. 10 to 40, in particular 12 to 25 parts by weight of slate,
• B. 5 to 30, especially 8 to 20 parts by weight of water sludge and / or sewage sludge, preferably METHA silt
• C. 5 to 15 parts by weight of binder, preferably cement
• D. 2 to 10, in particular 3 to 6 parts by weight of water glass
• E. 5 to 30, especially 8 to 20 parts by weight of water
• F. 0 to 30, in particular 8 to 20 parts by weight of additives,

where the parts by weight add up to 100.

at Water glass refers to the indication of the parts by weight on the dry substance. If water glass is used as an aqueous solution If their water content appears in component D.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 125680 A [0003]
• - EP 702110 A [0003]
• - EP 1116526 A [0003]
• - DE 10117902 A [0003]

Cited non-patent literature

• - DIN 18130 [0012]

Claims (7)

A method for sealing landfills, dumps or contaminated sites by a water-impermeable sealing system, characterized in that applying to a water-soluble salts landfill, dump or contaminated site with an inclination angle of more than 30 ° a mixture of the components A. Tonschiefer B. waterslide and / or sewage sludge C. binder D. water glass E. water, and F. optionally further additives Method according to claim 1, characterized in that First, the mixture of A, B, C, D, E and optionally F and this mixture by means of classical Application method, with dump trucks and caterpillars applies. Method according to claim 1, characterized in that that you first made a free-flowing mixture A, B, C, D, E and optionally F produces this mixture by means of a conveyor belt to the edge of the highest point transported the landfill and let it trickle slowly from there. Method according to claim 1, characterized in that that the mixture of A, B, C, D, E and optionally F on the surface to be sealed is sprayed on. Method according to claim 2, 3 or 4, characterized that you apply the mixture until a 30 to 60 cm thick layer has emerged. Method according to claim 4, characterized in that that a homogeneous mixture of the components A, B, C and if applicable, F and at most one subordinate part of D, this component adds as much component E as that pumpable mass arises, this mass in a applicator transferred in the form of a concrete pump, there component Add D and spray the mass onto the landfill. Method according to claim 1, characterized in that that the mixture A. 10 to 40 parts by weight slate B. 5 to 30 parts by weight of sewage sludge and / or sewage sludge, preferably METHA silt C. 5 to 15 parts by weight of binder, preferably cement D. 2 to 10 parts by weight of water glass E. 5 to 30 parts by weight of water, as well F. 0 to 30 parts by weight of others Aggregates, such as waste incineration slag, foundry sands or lead coatings containing the Gew.teile on Add 100.