DD201649A5 - PROCESS FOR THE DAMAGED DEPONING OF WASTE MATERIALS - Google Patents

Abstract

The invention relates to a method for the harmless dumping of solid or in aqueous media contained waste, wherein the waste is treated with alkaline substances and a solid product is obtained. The aim of the invention is to transfer in a simple and economical way toxic waste or Produktionsrueckstaende in solid landfillable products. According to the invention, the solid or in aqueous media dissolved or suspended waste with lignite ash, optionally with the addition of water to obtain a mushy to flowable consistency, homogeneously mixed and adjusted the Mengenverhaeltnisse with the proviso that the mixture product erhhaertet to a virtually wasserundurchlaessigen mass. The masses are used for the integration of waste materials, such as dural acids. They can be used to seal above-ground and underground landfills.

Description

2 3 4 80 6 0 ^Β © ^Γΐ1η * ^the 19.4.1982

AP B 09 B / 234 805/0 ή 60 .051 / 18

Method for the harmless disposal of waste materials Field of application of the invention

The invention relates to a method for the harmless dumping of solid or dissolved in aqueous media waste materials using lignite ash.

Characteristic of the known technical solutions

It is known to treat dusty or schlatnmförmige residues containing metal compounds with z .. B. »burned lime under agglomeration and convert it into a solid., Can be deposited on heaps granulated product (DE-AS 26 52 107), The previously known granulated Due to their large surface area and residual porosity as well as their loose fill, products and products left on stockpiles can not prevent the washing out of the pollutants contained therein. According to another known method, viscous, reactive chlorine- and sulfur-containing production residues obtained in the production of crop protection agents have also been mixed with alkaline powdery substances and, after addition of water, converted into solid, giant-shaped products. Irish prior art method lignite ash is not used (DE-AS 26 38 224).

According to the process known from DE-AS 29 25 882 method sulphate-containing brown coal ash is converted before its tilting by adding water into a paste with the _t hardens after tilting. In the mixture of the prior art process additional waste materials are not introduced.

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Object of the invention

The aim of the invention is to provide a simple and economical process, in which waste can be disposed of in such a way that it does not pollute the environment.

Explanation of the essence of the invention

The invention is based on the object toxic waste substances or · Produktionsruckständev which may be dissolved in solid form or in aqueous media: or slurried,

to convert into solid, landfillable products in the simplest and most economical way.

To solve this problem, the invention is based on a process for the harmless dumping of solid or aqueous media containing waste products, wherein the waste is treated with substances which react alkaline and a solid. Product is obtained In a. · Process: of the kind mentioned consists., The invention; in. ,, that the solid. , or in Abfall.Medien lössten.oder suspended waste .-- with lignite ash, optionally with the addition of water to achieve, from mushy to free-flowing consistency ,, homogeneous, mixed, and. the proportions set with: the-proviso; be that the mixture: product to: one, virtually impermeable to water. Mass hardens .. ... _. .... '... ·. "... · :. -, ..-..._. ^: . .-; · · ·.

In. the. invention. Method: A-IS: Alkaline: Reactive material is used .Brack coal power plant ash, which accumulates in large quantities and also causes problems: when dumping, because, their sulphate constituents in; inadmissibly large amount into the ground-

For the inventive. Method is suitable, both dusty, non-humidified .. Ashes ,. as. in the bunkers of. Power plants, accumulates _: as. also, moistened power plant before marriage ,. as they z. B. .. in the open-pit mining of lignite areas tilts- .. arrived. .. ". '.'

This power plant lake is made up of the mineral. Substance of pure coal and. from the coal and coal extracted during the mining of the coal. The largest part of this' ashes consists of. very fine-grained electro-filter ash, the smaller one from coarse grained, sand-rich cauldron ash; '. "· -. · -." '..'. , '

For the chemical and physical behavior of the lignite

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Kraftwerksasche their content of calcium is crucial. It is present as calcium oxide, ferrite and sulfate. The high reactivity is further enhanced by the fine grain of the ash and its large internal surface area.

In the method according to the invention, a wide variety of waste materials can be integrated and removed from the environment. These waste materials can be present as solid substances, as aqueous suspensions or sludges, or as aqueous solutions. Such waste materials are, for example, with catalyst poisons, such as soluble arsenic: en enriched solid iron oxide catalysts, also filter dusts from foundries and Hüttenbetrleben, slags and residuals, - blast furnace gas and. Galvanic sludges and other wastes containing water-soluble heavy metal compounds or other pollutants. As a rule, lignite ash can be admixed with up to 50% by weight of solid substance without adversely affecting its binding behavior. Solid waste materials are generally present in powdery or granular form, sometimes also in particulate form, and are advantageously dried with. the brown coal power plant ash mixed homogeneously and then added the required amount of water. This is generally from 20 to 40 wt .-% based on lignite ash. Further, in the process according to the invention in an advantageous manner einbindbare waste materials are waste acids, which occur in many chemical processes, eg. B. in the ore leaching and Metairbeizung with sulfuric acid solutions or. In the production of organic color pigments. These waste acids have a relatively low acid concentration and contain more or less impurities in the form of salts.

According to a preferred embodiment of the method according to the invention, waste acid is incorporated as waste, which is obtained in the digestion of titanium-containing ores for the production of titanium dioxide pigments. To achieve a firm,

- <+ -

It is necessary to homogenize the dilute acid with brown coal power plant ash in a certain weight ratio. mix and stir to obtain a mushy consistency. , At an average CaCO content of lignite ash of about 10% by weight and a H 2 SO 4 concentration of the dilute acid of on average about 12%. Mixing ratio, of, 100 parts by weight of ash to 50 to 75, preferably 60 to 65 parts by weight of dilute acid as. advantageous' proven. Lower CaO contents of the ash or higher acid or iron sulphate concentrations of the dilute acid make a dilution with water: necessary, since in each case a mushy consistency of the mixture must arise.

The mushy mixture resulting from lignite ash and dilute acid, which are further compressed by mechanical action (e.g., shaking, driving, with caterpillars or rollers), can be cemented, after a short time, due to. chemical. Reactions, those under warming; in front of you, go.,;

'To bind the contained in the Dünnsäure-. Heavy metal salts, the mixture, are compounded so that they show basic reaction and become compact. Mass solidified. On. Dissolving the heavy metal salts is thereby virtually prevented, so. that a threat to the groundwater can be excluded. ,

By the invention, problems of joint disposal of several waste materials are solved: by the harmless. Do not just deposit from ζ. As waste acids such as waste acid, but also of. Lignite power plant ash in a common process step, is made possible. Due to the achieved practical waterproofness of the solidified compact mixture of lignite power plant ash and dilute acid, the lignite ash sulphates of rain or groundwater can no longer be leached out. The heavy metals contained in the waste acid are in the solid, granular

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pacts product either like or sorted not washable included.

When mixing z. B. waste acid and lignite power plant as before, i. of two fundamentally different waste products which are not suitable for the landfill, the process according to the invention thus produces a single solid landfill product which, owing to its dense and compact nature, is no longer water-repellent and particularly suitable for disposal on organized landfills suitable. is.

A hitherto usual chemical further processing of the waste acid ,, which is connected to high investment costs, a considerable expenditure of energy and special measures for the Beseitigung- the resulting .Sondermülls- ¹ ,, ---- is he that-- s invention according to process e dispensable. The unloading of the dilute acid on open sea (so-called dumping) as also so far-applied problem solution, '' becomes in the future for reasons.des. strengthened environmental protection. also prohibit, so that with the method according to the invention an equally einfach.wie. economic way in an unexpected way.

The large-scale application, can thereby-.-Make sure that the lignite power plant ash via conveyors and the waste acid are transported separately via pipes. These two components are combined in a mixing plant in the required quantities directly on site, that is, the landfill of the resulting inert compact product .. Supply, mixing and discharging can be carried out continuously. The mixing plant can be advantageously mounted on a movable spreader.

According to a further embodiment of the invention, the "mixing of the method according to the invention for sealing" waste disposal landfills can be used.

L. + J * 4 UUUU _ δ _

HER-waste materials ,. at the deposit of which a definite danger of groundwater in the area of the landfill is to be feared, either with pure clay, sealed or in exploited clay pits, at which at the base and at. the Seitenflächen.noch pending several meters of clay in natural storage, landfilled .. For lack of clay or on abandoned clay pits it is largely also for use, passed from welded plastic films as lining material. Such operations are unnecessary by the method according to the invention.

Waste disposal sites are so effectively sealed, on the sole and on the flanks, in the required thickness, in accordance with the method of the invention, to prevent infiltration of contaminated leachate into the subsoil Thus practically impossible, on the basis of the landfills, accumulating waters can be collected by drainage and without damage be discharged.

If necessary, the surface of the landfill can also be sealed with the material according to the method of the invention in order to prevent precipitation water from entering the landfill.

In civil engineering and hydraulic engineering, can. Inflows of groundwaters and / or surface waters are dammed. Pits ,. Road cuts, - Canal buildings, etc. are protected against inflowing water. .

The thickness, the layer of insulation to be applied for the various fields of application, and the strength and number of individual layers. Depending on the type of waste material to be deposited or on the required insulation measures and on the local hydrological conditions.

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The mixture of the method according to the invention is also advantageously used for filling underground natural or mined cavities. It has proven to be expedient to add to the mixture of lignite power plant ash and waste a proportion of water in such an amount and at such a time that the resulting mixture for transport on site, ie at .Einsatzort, is flowable. With such a higher water addition, which leads over the mushy consistency out to a flowable G-emisch.dicht, or the waterproofing against water inflows in the rinsing process can be made, which also solidified, compact and dense mass is virtually impermeable to water.-

In the case of underground landfills, in which pollutants packed in containers are stored, such as nuclear or chemical wastes, a backfilling and sealing of the remaining cavities can be carried out according to the method according to the invention and additional protection can be ensured.

In mining, the method according to the invention, for example, can be applied underground during offsetting operations by mixing the tailings material with the flowable mixture of brown coal power plant ash and water. The otherwise remaining cavities when introducing the tailings material are largely filled, so that the settlement amount can be decisively 'reduced' and thus also the entering on the surface subsidence.

In the same way, sections of decommissioned lines can be filled in order to provide a barrier against incoming waters. The sumping measures for the lines in operation can thereby be substantially reduced.

Also the locations intended for the application of tailings material, be it on the surface or in abandoned

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Pits can be sealed by the process according to the invention in an economical way * This prevents the resulting weathering of the mountains sulfates, chlorides and other pollutants get into the groundwater. By laying drainage on the surface of the compacted layer produced by the process according to the invention, the accumulated polluted leachate can be removed and disposed of without damage *

In fissured rock * z. 8, in limestone quarries ,, it is also expedient to incorporate the mixture prepared by the process according to the invention in free-flowing form in order to effect the deepest possible filling of gaps, fractures and layer joints. The thus achieved complete seal can not be achieved with the methods previously used in the waste management »With the erfindungsgeraäßen method thus quiescent quarries'cost favorable for the harmless landfilling of waste materials can be used»

The advantages of the invention can be seen in the fact that by means of the method according to the invention waste materials, which in particular pollute the water industry harmful to the environment, are converted into a compact solidified, practically impermeable mass. From this composition are the pollutants contained therein, as Schvverme.talle no longer be eluted with water, so that this mass orderly on ^each: Neten landfill can be deposited. In addition, landfills can be safely sealed against groundwater and surface water with such masses. The landfills can

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finally covered with natural material, so that the newly obtained surfaces will be available again for any "use", "". "

EXAMPLES

The invention will be explained in more detail and by way of example with reference to the examples which follow. '...

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Example 1 A)

a) There were mixtures of brown coal Kraftwerksasche and 12% acidity in the ratio of 100 to 60 bis

65 parts by weight.

b) Mixtures of lignite Kraftwerksasche and 15 to .20 % H ₂ SO ^ containing, resulting in the production of organic color pigments in the ratio of'.100 to 70 parts by weight were also prepared.

The mixtures prepared under a) and b) were filled into 100 ml steel cylinders whose underside was closed by plastic caps and compacted by shaking. After a few days, the samples were tested for water permeability (K ^ apparatus according to K.E.Wit, differential pressure about 10 mm water column)

 The results are included in Table 1.

Table 1: Water permeability (K ^ in m / s) of test specimens from lignite ash and dilute acid

a) from the titanium dioxide production in a weight ratio.

100 : 60 5.4. 10 " ^a 9.3. 10 " ⁸ 4.6. 10 " ⁸ 3.9. ΙΟ " ⁸ 3.2. 10 " ⁸ 2.3. 10 " ⁸ 2.8 .- ΙΟ " ⁸ 1.6 .. 10 " ⁸

100 : 65 9.1. 1Ό " ⁸ 7.2. 10 ~ ⁸ 2 .. 5. .10 " ⁸ 4.9 .- , 10 ~ ^s 4.5 .. ΙΟ " ⁸ 4.4. 10 " ⁸ 2-5 ' .. 10 ~ ⁸ 1.6. ΙΟ ' ⁸

b) from the production of organic color pigments in a weight ratio of 100: 70

3.6. 10 ~ ⁸ 1.8. 10 ~ ⁸ 7.9. "ο " ⁸ 8 .. 5. 10 " ⁸ 8.2. 10 " ⁸ 1.4., 10 ~ ⁸ 7.2. ., 10 ~ ⁸

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B) To determine the substances which can be eluted from the product according to the invention, in particular with regard to the heavy metals contained in the dilute acid, leaching tests were carried out in accordance with current guidelines. For this purpose, 300 g specimens were treated with 10 times the amount of distilled water for 24 hours, with constant circulation of water. The evaporated residue of the clear filtrate was then analyzed. The result is shown in Table 2. Accordingly, the concentrations determined by X-ray fluorescence analysis for all investigated heavy metals are below the permissible values even for drinking water. It should be particularly noted that the eluates of the process according to the invention, im. With respect to the environmental impact of rendered harmless from both the titania production and, from the dye production have no significant differences.

The organic constituents considered to be particularly problematic in the dilute acid from dye production (see Table 2) are also largely bound. While the dilute acid contained 1 % (10,000 ppm) of benzene, naphthalene and anthraquinone sulfonic acids and 10 ppm of organohalogens, only 11 ppm of DOC (diluted inorganic carbon) were found in the eluate of the test specimens of ash and dilute acid. and <O, 6 ppm EOCL (extractable organic chlorine).

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Tab. 2: Elution of test specimens from lignite ash and dilute acid

a) from titanium dioxide production

Vanadium. - <0.03 ppm

Chrome. - <0.03 ppm.

Nickel. ".: <0.03 ppm

Copper. - <0.03 ppm

Zinc -sr.0j.03 ppm

Lead -S = 0.03 ppm

b) from the dye production

Vanadium - = s 0.04 ppm

Chromium 0. 04 · p-pm

Nickel - 0.04 ppm

Copper - * = - 0.04 ppm

Zinc 0.05 ppm

Lead. '- * =; 0.04 ppm

Arsenic "* = t; 0.04-.ppm.-

. ' DOC T1, 0 ppm

(diluted organic carbon)

EOCL. <Q ', Ö6 ppm

(extractable organic chlorine)

Tab. 3: Average analysis of dilute acids except dye production:

H ₂ SO ₄ 15 - 20 %

Benzene-,. Naphthalene and anthraquinone sulfonic acids, 1 %

Fe. 100 'ppm

Cr 20 ppm

Cu, Zn T - 10 ppm

Ni, V, Pb, Hg x 0.1-1 ppm

As, Cd, Ag - <C 0.1 ppm

Organohalogens 10 ppm

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Tab. 4: Average analyzes of dilute acids of different origin from the digestion of ilmenite (a, b) or Sorel slag (c) '

(A)

(B)

(C)

PH value under 1 under 1 9 g 0 _2/1 under 1 0 " CS ^B about 7 g 0 _2/1 approximately 12- about 5 go ₂ / i 3 " H ₂ SO ₄ , free about 12 % approx. ' 0 8 % approximately 23 % 2 " TiOSO ₄ approx. 1.0% approximately 0 % Not called 0.2 » MgSO _4. about 2.0 % approximately O ₅ 07 % ti H 0.03 » MnSO ₄ about 0.1% approximately ⁰ ' Z ..% tt 11 A1 ₂ (S0 ₄ ) ₃ not known Max. 0 03 % tt tt Na ₂ SO ₄ H tt Max. 0 07 % tt tt CaSO ₄ ti ti Max. 65 .. 000 mg / 1 tt tt iron Max. 50,000 mg / l approximately 110 " Max. 2.1 % vanadium Max. 350 " approximately 200 " Max. 0.05 % chrome Max. 200 " Max. 40 » Max. 0.03 % zinc Max. 20 " Max. 2 " max. 80 · mg / 1 lead Max. 2 " Max. , 15 ». Max. 1 nickel ,not known approximately  + • 1.5 ". Max. copper Max. ₊ 1.5mg / l Max. Max. cadmium N. N. N. N. ++ 4 Max. " mercury ^η · ^η · ₊₊₊ N. N. Max. arsenic N. N. N. N. N. N.

= undetectable above the limit of detection: detection limit 0.1 mg / 1 'detection limit 0.01 "detection limit 0.1"

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Example 2

This example illustrates the incorporation of a solid waste into a brine-coal ash-water mixture. The solid waste is a spent iron oxide catalyst such as that found in the petrochemical industry. Such spent catalyst has such a high proportion of water-soluble arsenic that it may only be deposited in a landfill for hazardous waste. The catalyst used consisted of compacts up to centimeters in size. An elution experiment in which this material in the ratio 1: 10 with distilled. Water was treated with continuous circulation for 24 hours, gave in the filtrate an arsenic content of 1.3 mg / 1. -.

A mixture of 30 parts by weight of waste catalyst, 100 parts by weight of lignite ash and 20 to 50 parts by weight of water gave a compact, dense, exceptionally hard specimen,:, for which a value for ^v is water permeability K 1

- 10 ' ^x

An appropriate elution test resulted in an arsenic content which was below the Machweis limit of 0.03 mg / l and thus also below the permissible limit value for drinking water of .05 mg / l. l.

Claims (13)

1. A method for the harmless dumping of solid or contained in aqueous media Abfallstoffen-, wherein the waste material treated with alkaline substances and a solid product is obtained, characterized in that the solid or dissolved in aqueous media or suspended waste with lignite ash * optionally with the addition of water to obtain a mushy to free-flowing consistency, mixed homogeneously and the proportions are set with the proviso that the mixture product hardens to a practically water-impermeable mass, 2. The method according to item 1, characterized in that basic brown coal power plant ash is used, 3. Method according to points 1 to 2, characterized in that waste acids are used as waste materials dissolved in water, 4 80 6 ö 19.4.1982 AP B 09 B / 234 806/0 - .60 051/18 4. The method according to the items 1 to 3, characterized in that as.Abfallsäure is used from titanium dioxide production, 4 8 0 6 0 19.4.1982 AP B 09 B / 234 806/0 - 15 - 60 051/18 Erfinduncjsanspruch 5. The method according to points 1 to 3, characterized in that as waste acid, the resulting in the production of organic color pigments waste acid is used. 80 6 0 19.4.1982 AP B 09 3/234 806/0 - 16 .- ♦ 60 051/18 6 ». Process according to items 1 to 4, characterized in that the mixture in the ratio of about 100 parts by weight lignite Kraftwerksasche with. About 50 to 75, preferably 60 to 65, parts by weight of thin acid are used. 7 «Method according to points 1 to 2> characterized in that solid waste is mixed homogeneously with the brown coal power plant ash prior to the addition of water», 8 * A method according to points 1 to 4 * characterized in that 3raunkohlen-Kraftwerksasohe is mixed in such an amount with the waste acid, "that the mixture has under binding of S contained in the Oünnsäure _c hwermetalle basic reaction" 9. Method according to items 1 to 8 * characterized in that the mixture is used for sealing waste landfills. 10. The method according to points 1 to 8, characterized in that the mixture for damaging inflows of groundwater and / or surface water in civil engineering, hydraulic engineering or 3ergbau is used. 11 · Procedure according to points 1 to 8 ,. characterized in that the mixture is used for filling underground natural or mined cavities. 12 »method according to the points 1 to 11, characterized in that the mixture such a VVasseranteii is added in quantity and time, that the resulting mixture for transport on site is flowable. 13. The method according to points 1 to 12, characterized in that the mixture is compacted by mechanical action.