SK11694A3 - Method of detoxification of combustion residues by removing of movable toxic compounds by binding and concentrating these compounds and method of their obtaining of treatment solutions - Google Patents

Abstract

By the method wastes are decontaminated by the extraction of the soluble metal fractions where the extraction is carried out by chloride-containing aqueous solutions. The solution to be extractes consists of diluted solution of hydrochloric acid for treatment of residues of base character or from a solution of a chloride of alkaline or alkali-earth metal for the treatment of residues of neutral character.

Description

Technical field

The invention relates to a method for detoxifying combustion residues by extracting and moving the toxic components.

The state of the art

Slags are solid, non-vaporised residues obtained from incinerators in industrial areas. Usually discharged by means of hydraulic troughs to the receiving tank and containing 3 to 30% of water, they appear to be black. more or less divided and very heterogeneous.

In the context of this description, the term slag must be understood in the broadest sense of the word. It will cover all products and combustion residues, such as clinker, which could contain heavy metals more or less elutable (washable) by leakage or precipitation. They may also consist of fly ash, for example from the incineration of urban residues.

Slags are often characterized by tailings containing silicon and aluminum and metal oxides, mainly iron oxides and to a lesser extent chromium, copper, nickel, zinc, even cobalt and lead oxides (Table 1). Of course, their composition may vary considerably depending on the area.

This is what can be observed, for example, when analyzing Table no. 1, which follows. It shows the results obtained from examples of multi-elemental slag analyzes from three different industrial areas, namely Strasbourg (ST I), with Salaise in Isése (S II) and Saint-Vulbas in Ain (SV 1).

Table 1: Multielemental analysis Strasbourg (ST 1), from Tredi Tredi Saint-Vulbas (SV 1).

debris from Tredi

Salaise (S II) and Others

main % components in oxide: debris ST 1 debris Force ruins SV1 Si ° ₂ 28.89 23.9 23.58 ai _{2 3 3} 9.70 8.46 23,12 ^Fe 2 ° 3 33.95 23.8 18.91 MnO ₂ 1.86 1.44 0.13 MgO 1.89 0.87 1.01 CaO 5.84 9.51 8.58 Na? O 3.70 1.45 0.75 k ₂ 0 0.87 1.29 0.75 TiO 5.85 2.93 0.98 ^P 2 ° 5 1.22 9.61 7.85 sira ^x 0.04 1.42 0.16

^x results in elementary form

Trace elements (contents expressed in elemental form in ppm):

barium 115000 2429 2200 beryllium 3.4 0.6 1 cobalt 6800 94.5 51 chrome 20800 1090 1205 copper 4800 13874 8800 gallium 58 5.0 21 niobium 124 10.1 11 nickel 5800 1468 784 rubidium 24 17 16 scandium 6.4 7.9 6 strontium 402 171 290 thorium 5 5 5 vanadium 484 115 105 yttrium 6 10 7 zinc 1900 893 620 zirconium 282 112 98 tin 48 105 360 cadmium 0.3 3.2 1.3 mercury 0.04 0.1 3.8 arsenic 6.2 14.5 50 lead 186 324.1 190

Slags resulting from the incineration of industrial waste must normally be stored in landfills or in technical underground landfills (C.E.T.).

In fact, these debris can present various dangers, especially if their heavy metals, toxic substances, in easily washable forms are high. These heavy metals are concentrated in debris on the basis of various physico-chemical mechanisms and, by their nature, form various associations that are little known or completely unknown. That is why these hazards are subject to different assessments for the needs of C.E.T., which can be differentiated on the basis of their ability to permit such landfills underground under conditions which in any case must comply with the relevant standards - when these are defined - of adequate safety.

The selective extraction methods used in soil science make it possible to distinguish between some associations and some specific constitutions (specialties) and provide information on chemical forms and possible metal dissolution conditions. Knowledge of these data is important to consider the possibility of decontamination processing.

The metals present in the debris may be dissolved in water, interchangeable, associated with oxides and amorphous or crystallized hydroxides, or may be in the form of precipitates, such as carbonates or sulfides. The extensive contamination that can be caused by debris is often caused by the extraction of these metals by dissolution in precipitation or leakage. The isotopically exchangeable cations will be exchanged faster, the weaker the electrostatic forces in the areas charged negatively.

More generally, these findings have led experts to define the mobility of the element, i.e., the ability of the element to pass into different parts of the environment where they will become less and less energy retention, the last part being the liquid phase (solution).

There are different standards to relate the hazards of processed slag to the contents (or soluble quantities) of metals dissolved in the lyes or eluates obtained. In these standardized tests, these slags are leached with aqueous solutions simulating the effects of precipitation. These leaching experiments carried out in the laboratory make it possible to estimate the real risks arising from the controlled storage of debris. They can specify the conditions under which certain types of clinker can be used in public works (circular clinker dated 8 April 1992, see Table 2 below). In France, for example, the standardized AFNOR study protocol (X31210, 1988) recommended by the Ministry of the Environment aims to extract soluble substances contained in the ground slag (diameter below 4mm).

Other types of standards are currently being examined by the competent authorities of the European Economic Community (EEC).

In the individual leachate categories, the analysis of soluble toxic metals makes it possible to locate the measured concentrations in relation to the thresholds set by French and European standards. Depending on these results, the use permit (Table 2) or storage on CET will also depend on which the processed products will be classified, for example, as hazardous waste (CET Type I), harmless waste (CET Type II), or inert waste (see table). 3, which follows).

The procedure for the AFNOR standardized study protocol (X31210, 1988) is as follows:

- demineralized water saturated with air and C0 ₂ at pH 4.5 and a resistivity ranging between 0.2 and 0.4 MO.cm is mixed with 100 grams of slag for 16 hours at room temperature and with constant rotary motion.

- the first extract is obtained by filtration of the surnagent (the substance floating on the surface) after centrifugation of the mixture (2000 grams in 15 minutes). Color, odor, conductivity and pH are measured. The solid is then subjected to two further extractions resulting in two leaches (or eluates). At the end of these operations, a chemical test for oxygen content (DCO), total organic carbon (COT) and mineral analysis is performed on three eluates.

Similar tests have been carried out in other countries or within the EEC.

They allowed to define standards as illustrated in Table 3, but these can still be modified. The values presented define different washing thresholds, corresponding to the sum of the maximum soluble amounts of each of the metals or other pollutants (for example, chlorides and soluble cyanides) that can be permitted with respect to each of the relevant categories or classes of waste concerned.

As regards the polluting metal elements, chlorides and cyanides, the French and European standards (harmless waste) also require that the quantities of each of the leached elements gradually decrease over three consecutive extractions.

Otherwise, that is, if increasing dissolution of some metals in at least two leachates or successive eluates is found, it would not be possible to stabilize the slags over time. Basically, there was still the threat of pollution that would be the result of repeated exchanges between buried debris and leaks.

Tables 4,5 and 6, which follow, make it possible to evaluate the basic properties in connection with pollution of the slag, ST 1, S II and SV 1, which are given as examples.

Table 2: Application of Clearances from the Incineration of Household Waste for Public Works; concentration thresholds given in relation to the leachable component obtained by the standardized AFNOR test (X 31-210).

unburned soluble part

hg < Pb < CD < Cu < and < CrVI < sulphates < chlorides < COT <

<5%

0,2 mg / kg dry weight mg / kg dry weight mg / kg dry weight mg / kg dry weight mg / kg dry weight mg / kg dry weight

4000 mg / kg dry matter

2800 mg / kg dry matter

1000 mg / kg dry matter

Where the leachable parts comply with the above thresholds, the slag is considered to have a low leachable component content. The production concerned can then be used for public works.

Note: See Škvar Circular, Department of Technology and Waste of the Ministry of the Environment, project of 8.4.1992.

Table 3: Comparison of European and French waste storage standards. Reported concentration thresholds for the leachable component obtained by the German test for European standards (100 g dry waste / 1 liter of water) and by the standardized afnor test for French standards (100 g gross waste / 1 liter of water). The results are expressed in soluble amounts in mg / kg.

hazardous waste - EEC standards mg / kg French standards-class I (debris) harmless waste - EEC standards mg / kg M French standards class II (fly ash) inert waste - EEC standards mg / kg ( ¹ pH 4-13 5-13 4-13 4-13 DCO - below 5000 - - - The loss on ignition - pod 5í - - - TOC 400-2000 - 400-2000 below 400 under 2000 arsenic III 2-10 under 10 1-2 under 2 under 1 lead 4-20 under 100 under 4 under 30 sum cadmium 1-5 under 50 under 1 under 5 these ' chrome 1-5 under 100 under 1 - elements copper 10-100 - under 20 under 20 it has to be nickel 4-20 under 100 under 4 - smaller than mercury 0,2-1 under 10 below 0.2 below 0.2 50 mg / kg zinc 10-100 below 500 under 20 -

mg / kg of dry matter waste in mg / kg of gross waste

references:

- a proposal for a European directive on the storage of waste

- a draft ministerial decision on the storage of special industrial waste (Class I). Text of the Ministry of Environment, stamp. DEPR / SEI / SDO / AN Feb.-31, 14 May 1991

- Circular on the storage of solid residues from the cleaning of smoke from municipal waste incineration plants (Class II). Text of the Ministry of the Environment, no.

DEPR / SEI / SM / STPD / APR / MBR. 12.6.1991.

TABLE 4: STANDARD BALKING TEST (STANDARD) Slags from Strasbourg (ST 1) Analytical monitoring of extraction

controlled parameter first extraction second extraction third extraction Total amount of coarse waste extracted (mg / kg) class I 'J standards of class H (Mg / kg) standards of application in public works (mg / kg H.S.) fragrance without smell odorless · without smell ... - - color without color without color without color - - - PH 7.0 6.4 6.0 - - - resistivity 4000 24000 45000 - - - DCOmg 0 ₂ / l 24 0 0 240 below 5000I ¹ ) - C.O.T. mg / 1 ε e ε ε below 400 ^ 2) below 1000

I

elements concentration of the first extract (rag / l) concentration of the second extract concentration of the third extract total extr. Q gross. by. (mg / kg) standards class II standards tr.Il ' standards class III lead 0,107 0,045 0,004 1056 <100 <30 <4 cadmium ND ° ND ND - <50 <5 <1 zinc 0,358 0,095 0,164 7.17 <500 - - honey 2,274 0,611 0,056 29,41 - <20 <20 nickel 0,051 0.04 0,068 1.59 <100 - - chrome 0,060 0,000 0,000 0.60 <100 - <1 mercury below 0.03 below 0.003 below 0.003 below 0.03 <10 <0.2 <0.2 cyanides ND ' ND ND - <10 - - arsenic 0.0043 0.0009 below 0.0008 0,052 ..... <10 <2 <2 chlorides 4.61 1.39 1.96 49.6 - <10000 <2800 sulphates 44 5 1 500 - - <4000

concerns fly ash from municipal waste incineration ° ND: not reported, MS: dry matter

Dissolution behavior

elements behavior Soluble quantities in mg / kg of gross waste complete solution decreasing dissolution stagnant dissolution increasing dissolution v podo. test with possible. dissolution lead x x 1.56 186 zinc x 7.17 1900 copper x 19.41 4800 nickel x 1.59 5800 chrome x 0.60 20800 arsenic x 0,052 6.2 chlorides x 49.6 3990 sulphates x 500 300

TABLE 5: BALKING TEST (NORMALIZED, STANDARD) Slags from Salaise (S II)

Analytical monitoring of extractions

controlled parameter first extraction second extraction third extraction Total amount of coarse waste extracted (mg / kg) class I standards class II (mg / kg) standards of application in public works (mg / kg H.S.) fragrance without smell without smell without smell - - - color nažitlá without color without color - - - P » 6.8 7.1 7.6 - - - resistivity 0 900 3500 - - - D.C.O.mg (^ / l 84 36 0 1200 below 5000 ⁽¹ ) - C.O.T. mg / 1 E e ε ε below 400 < ² ) below 1000

elements concentration of the first extract (mg / l) concentration of the second extract concentration of the third extract total extr. Q. gross. by. (ug / kg) standards class II standards tr.Il ' standards class III lead 0,443 0,116 0,052 6.11 <100 <30 <4 cadmium 0,058 0,015 0,005  0.78 <50 <5 <1 zinc 0,093 0,029 0,028 1.57 <500 - - copper 0,088 0,066 0,344 1,881 - <20 <20 nickel 0,338 0,085 0,031 4.54 <100 - • chrome 0,100 0,000 0,000 1.00 <100 - <1 mercury below 0.003 below 0.003 below 0.003 0.03 <10 <0.2 <0.2 cyanides ND * ND ND - <10 - - arsenic below 0.0008 0.0008 0.0008 0.0008 <10 <2 <2 chlorides 338.3 85.6 9.56 4333 - <10000 <2800 sulphates 1650 250 68 19680 - - <4000

concerns fly ash from urban waste incineration; ° ND: non-recent, MS: dry matter

Dissolution behavior

elements behavior Soluble quantities in mg / kg of gross waste complete solution decreasing dissolution stagnant dissolution increasing dissolution in the soil. test with possible. dissolution lead x 6.11 343 cadmium x 0.78 3.4 zinc x 1.50 948 copper x 1.88 14150 nickel x 4.54 1523 chrome x 1.00 10920 chlorides x 4333 20500 sulphates x 19680 18200

TABLE 6: BREATHING TEST (NORMALIZED, STANDARD) Debris from Saint-Vulbas (SV1)

Analytical monitoring of extractions

checked parameter first extraction second extraction third extraction Total amount of coarse waste extracted (mg / kg) class I standards class II (Mg / kg) standards of application in public works (mg / kg H.S.) fragrance without smell without smell without smell - - color without color without color without color - - - PH. .9,64 ..... 9.36 6.0 - - - resistivity 2222 54350 86950 • - - O2 / I 4 0 0 40 below 5000 ^) - C.O.T. mg / 1 ND ° 1 ND ° 10 below 400i ² ) below 1000

elements concentration of the first extract (mg / l) concentration of the second extract concentration of the third extract total extr. 0 gross by. (mg / kg) standards class II tr.Il ’standards standards class III lead 0,086 0,031 0,018 1:35 <100 <30 <4 cadmium 0,008 0.0028 0.0027 0,135 <50 <5 <1 zinc 0,010 0,003 0.0014 0,144 <500 - - Raed 0.0014 0.0010 0,007 0,041 - <20 <20 nickel 0,018 0,084 0.0048 0,312 <100 - chrome 0,027 0.0096 0.0077 0,443 <100 - <1 mercury below 0.03 below 0.003 below 0.003 below 0.03 <10 <0.2 <0.2 cyanides ND ' ND ND - <10 - - arsenic below 0.0008 below 0.0008 below 0.0008 below 0.0008 <10 <2 <2 chlorides 54.6 11.9 4.06 7056 - <10000 <2800 sulphates - - - - - - <4000

- 13 concerns fly ash from urban waste incineration ° ND: not reported, MS: dry matter

Dissolution behavior

elements behavior Soluble quantities in mg / kg of gross waste complete falling stagnant increasing v podm. with possible. solution solution dissolution dissolution test dissolution lead x 1.35 190 cadmium X 0,135 1.3 zinc x 0,144 620 honey x 0,041 8800 nickel x 0,132 7843 chrome x 0,443 12050 chlorides x 7053 -

The reading of Tables 4, 5 and 6 is facilitated by the use of the following notes in respect of the four boxes to the right, the intermediate and lower tables:

the total extracted quantity of coarse waste in mg / kg corresponds, for each element, to ten times the sum of the quantities extracted for the three extraction solutions (or extracts) used in the treatment of 100 grams of the same waste.

These figures should be compared to the standards that appear in the three columns to the right of the intermediate sub-tables (and which correspond to the values given in the columns French Standard Class I, French Standard Class II of Table 3 and standards for public works Table 2).

the same numbers are compared in the lower sub-tables14 with the concentrations of the relevant dissolution elements that do not differ from the respective values of the same debris and contents of Table 1.

Examination of Tables 4, 5, and 6 thus provides the following information as to the possible polluting nature of the debris examined as examples. The samples ST1, Force and SV1 lead to colorless leaching results which have no odor. The chemical oxygen content (DCO), the mineral and organic contamination index, is 240 mg / kg at ST 1, 1200 mg / kg at Sil and 40 mg / kg at SV 1.

The soluble slag component of ST 1 (Table 4) could lead to copper pollution (total extracted quantity in mg / kg higher than the Class II standard and not in compliance with public works conditions), zinc, nickel and chlorides ( increasing dissolution indicators in successive eluates).

For the slag leaching results of the Force (Table 5), all the dosed elements exhibit decreasing dissolution. However, they have an elution threshold higher than the European standards for harmless waste in lead (8.72 mg / kg dry waste), cadmium (1.11 mg / kg dry waste), chromium (1.42 mg / kg dry waste) waste and nickel (6.48 mg / kg dry waste). In addition, these leaching results are not in line with the legislation envisaging the use of scrap in public works (lead, cadmium, chromium and chlorides have too high concentration thresholds). However, the leaching results are in accordance with French Class II standards.

The leaching results obtained in the case of slag SV 1 of the dried type comply with the above standards (Table 5).

It follows from the foregoing that some of these types of debris are associated with decontamination treatment before each storage, burial or use. In addition, the same should apply to SV 1 wreckage, even if it already complies with the standards currently in force, but may not be so in the future.

It is an object of the present invention to provide a process which would preserve the state of the environment while at the same time limiting the costly storage of slag, particularly in class I landfills. extracting the soluble metal component. In addition, the present invention aims, in the light of the French and European standards currently in force, to obtain, in a particularly simple manner, the detoxification or disposal of debris so that they can later be stored in Class II landfills as harmless waste or recycled.

SUMMARY OF THE INVENTION

According to the first basic claim, the essence of the present invention is one or more slag leaching and, if necessary, the slag should first be crushed so as to achieve a sufficiently low grain size, in particular with values below 50 mm, to allow sufficient contact between the slag. combustion residues and aqueous or liquid leaching solutions, with a concentration of sufficient cations (K ⁺ , Na ⁺ , Ca ⁴⁺ ) or exchangeable protons in the form of chlorides with heavy metal cations present in these residues.

This leaching must be sufficient to ensure that at least a portion of the specified metals, in particular the heavy metals contained in these debris, are transformed into soluble chlorides extractable by the leaching liquid and are effectively extracted to a sufficient extent such that:

- on the one hand, a standardized washing test subsequently applied to the debris thus treated confirmed a decrease in the sequentially dissolved amounts of each of these metals, determined during repeated extraction tests, carried out using a standardized leach solution or elution solution in accordance with that test, and

- on the other hand, the sum of the soluble amounts dissolved in the eluates resulted from the extractions using the above standard solution and ranged around values corresponding to concentrations below the concentration thresholds also determined by the above standard text for each of these metals.

For the sake of clarity, in the previous sections, as in the following sections, a distinction was made between:

- leaching solutions, i.e. extraction solutions containing the aforementioned cations or exchangeable protons and standardized elution (elution) solutions corresponding to those used in the above standardized tests.

The number of consecutive elution tests and concentration thresholds (at least for those metals which have already been the subject of special standards) is determined using existing or future standardized protocols. The standardized study protocol used in this study corresponds to the AFNOR standard (X31210, 1988), the detailed application of which has been mentioned above.

In the case of repeated elution tests using a standardized solution, three of these tests must be taken into account and the standardized solution itself consists of saturated water, free of minerals and enriched in air and CO2 with a pH of 4,5 and with a resistivity of between 0,2 and 0,4 Mfi .cm.

Elution (elution) tests using a standardized solution are thus carried out using a mixture of processed slags (for example, used in an amount of about 100 g) for 16 hours and with constant stirring.

The exchangeable cations or protons in the form of chloride of the liquid used in the initial leaching of the slag can be added in any form to achieve the goal we have set. The leaching solution may consist of dilute hydrochloric acid, and especially in the treatment of slags of a basic nature, for example slags, which, when they form a suspension with water for a certain period of time, subsequently change the pH to about 9-10.

For neutral type debris under these conditions, it is recommended to use solutions of alkaline or alkaline-earth chloride rather than hydrochloric acid. Experience has shown that hydrochloric acid, even in its diluted state, can sometimes attack, more than necessary, a neutral-type slag matrix or slag. The skilled artisan immediately knows that the concentrations of exchangeable cation solutions in the form of chlorides, and even the type of cation used (preferably potassium, calcium or other alkali or alkaline earth metal), must most often be adjusted depending on the debris treated, the nature of the heavy mobilizable metals.

In general, the hydrochloric acid concentrations of the acid solutions used in the treatment according to the research will have molar concentrations often in the range of 0.01 M, in particular 0.05 M to 5 M.

As we have noticed on the occasion of experiments carried out on various types of slag, a 0.1 N hydrochloric acid solution is particularly suitable for the treatment of basic slag, whereas a potassium chloride solution of 1 M or a calcium chloride of 0.01 to 2 M, in particular 0 , 09 M and 0.015 M allow the extraction of the mobilizable metals contained in the debris with low acidity. This static or dynamic leaching (slag / extractant ratio of 1.1) passes into the drainage (drainage) of the leaching results towards the storage tank. They will be able to be processed as mentioned later.

BRIEF DESCRIPTION OF THE DRAWINGS

Figures 1, 2 and 3 show graphically the results of the comparative tests. Figures 4 to 9 show relative curves with the adsorption kinetics of the elements for individual biosorbants. In FIG. 10 is a basic diagram of an industrial plant for implementing the method of the invention. In FIG. 11 shows the results of the treatment of extracts with fungicidal biomass; FIG. 12 shows schematically the treatment of leachate and FIG. 13 is a schematic diagram of the application of one of the preferred methods of the invention.

Examples of a particular embodiment

The slags from the combustion center in Strasbourg (ST 1) were crushed, ground and then split to produce an average homogeneous granulometric sample with a grain size ranging from 0 to 2 mm. Slags from Saint Vulbas (SV 1) were previously dried and then combined into an average sample. The debris from Salaise (Force) was processed in its original condition. Samples from Strasbourg (ST 1), Salaise II (S II) and Saint-Vulbas (SV 1) were sequentially at pH values of 10.0, 7.6 and 8.2.

Experimental Equipment: Extractable Metal Extraction:

Extraction tests are performed by leaching tests in a packed column or by dynamic leaching (with stirring) at 100 grams of slag. The reagents used (100 ml per 100 g slag) are 0.1 N hydrochloric acid, 1 M potassium chloride or 0.09 M calcium chloride and 0.015 M. They are allowed to interact for 2 to 24 hours while in contact with the debris and may undergo two recycles (which is at least three times 24 hours of contact between the slag and the extraction fluid). The pH, conductivity and chemical composition are determined in the extracts obtained. The slag sample is then rinsed with at least twice 100 ml of distilled water and then a standardized leaching test is performed.

The results:

In the mobility tests, the extraction agents used together with the slag elements form soluble metal chlorides, the rate of formation of which depends on their solubility constant.

For example, potassium chloride 1 M causes extensive dissolution of calcium and copper in ST 1 debris. Potassium (excess reagent) and sodium that are not dosed in these tests have proven to be essential dosing elements with negative effects on analyzes (yellow emission to plasma). The dissolved trace elements are listed in Table 7. In the debris force, the elements with the greatest mobility are manganese and magnesium for the major elements, the trace elements being dissolved according to varying proportions (Table 7). An analytical disturbance caused by the massive dissolution of the alkaline-earth elements is also observed in these slag-derived solutions

III.

Hydrochloric acid mobilizes metals, especially copper, more efficiently in ST1 debris. Dissolution of alkaline-earth substances with a reactant leads to calcium dosing disturbance, while yellow plasma plasma is synonymous with a strong sodium presence (Table 7).

Table 7: Determination of the mobility of 9 major elements and 7 trace metals during leaching in a clogged column of 100 g slag per 100 ml extractant (3 consecutive cycles). Analysis of leaches obtained by dosing of metal elements in solution with plasma emission spectrophotometer. Results expressed as a percentage of the starting weight.

elements extracted with potassium chloride 1 M (s) elements extracted with hydrochloric acid 0,1 N searching elements debris ST 1 debris S II debris ST 1 debris S II aluminum 0.00 0.00 0.33 0.01 calcium 0.05 0.00 nedávkovatelné nedávkovatelné manganese 0.00 0.14 0.41 0.60 magnesium 0.01 1.05 0.64 5.45 iron 0.00 0.00 0.17 0.00 silicon 0.00 0.00 0.19 0.01 potassium nedávkovatefný nedávkovatelný nedávkovatelný nedávkovatelný sodium nedávkovatelný nedávkovatelný nedávkovatelný nedávkovatelný phosphorus nedávkovatefný nedávkovatefný nedávkovatefný nedávkovatelný cobalt 0.00 0.19 0.02 0.59 chrome 0.00 0.03 0.00 0.04 med ¹ 0.02 0.00 10.10 0.00 nickel 0.00 0.04 00:08 0.32 zinc 0.00 0.01 0.13 0.04 cadmium 0.00 0.00 0.00 0.00 lead 0.00 0.18 0.49 0.23

Table 8: Determination of the mobility of 9 main elements and 7 trace metals during rinsing (2 times 100 ml distilled water) of 100 g slag clogged columns after treatment with 100 ml extractant. Analysis of water obtained by dosing metal elements in solution with a spectrophotometer for plasma emission. Results expressed as a percentage of the starting weight.

elements extracted with potassium chloride 1 M (s) elements extracted with hydrochloric acid searching elements debris ST 1 debris S II debris ST 1 debris S II aluminum 0.00 0.00 0.01 0.00 calcium 0.00 0.00 0.01 nedávkovatelné manganese 0.00 0.02 0.01 0.23 magnesium 0.00 0.05 0.64 0.51 iron 0.00 0.00 0.00 0.00 silicon 0.00 0.01 0.01 0.01 potassium nedávkovatelný nedávkovatelný nedávkovatelný nedávkovatelný sodium nedávkovatelný nedávkovatelný nedávkovatelný nedávkovatelný phosphorus nedávkovatelný nedávkovatelný nedávkovatelný nedávkovatelný cobalt nedávkovatelný nedávkovatelný nedávkovatelný nedávkovatelný chrome nedávkovatelný nedávkovatelný nedávkovatelný nedávkovatelný copper 0.00 0.00 0.59 0.00 nickel 0.00 0.01 0.01 0.11 zinc 0.00 0.01 0.07 0.02 cadmium 0.00 0.00 0.00 0.00 lead 0.04 0.14 0.07 0.19

The rinse water is intended to remove excess reactant using a standardized leaching test. During this operation, the low mobility of the elements, be it the extractant or the respective debris, should be noted (Table 8).

The percentage of slag mobilisable metals could not be detected accurately, but partial analyzes performed over the sequential use of the reactants indicated that 2 to 24 hours contact time between the slag and the extractant and a single rinse would be required to obtain effective stabilization of these wastes. This simplification by limiting the number of original planned operations shows the need for a single leaching and represents an optimization of this process.

Standardized leaching test

In view of the objectives set out in these examples, the leaching tests must comply with French Class II standards and European standards on the disposal of waste or on the use of scrap in public works.

After two treatments applied to the debris of Strasbourg (ST 1) and Salaise II (Force), standardized leaching tests lead to the formation of leaches that have a higher resistance than the reference (standard solutions, ie effluents containing less mineral elements) (Figures 1 and 2). ).

The decrease in chemical oxygen demand (DCO) is 23% after the treatment of slag from Salaise II (Sil) with potassium chloride; It represents 100% for all other treatments irrespective of the relevant slag species (Figure 3).

It has been found that Figures 1 and 2, relating to a standardized leaching test on the debris of Strasbourg (ST 1) and Salaise II (Silo), showed a change in the resistivity of the extracts before and after treatment with the leaching fluid, resistances expressed in Ω / cm on the coordinate axes after application of a standardized test (AFNOR standard X31210, 1988),

- directly on the relevant debris (TN),

- on previously prepared debris treated with potassium chloride solution (KCl), and

- on debris treated previously with a hydrochloric acid (HCl) solution.

Figure 3 also shows DCO decreases (DCO% on the coordinate axis) when processing debris coming from

Strasbourg (ST 1) and Salais II (Force).

For polluting metal elements, chlorides and cyanides, standards require their increasing tendency to dissolve and / or washout thresholds. The determination of these parameters for strongly alkaline debris from Strasbourg (ST 1) shows the following results:

- Potassium chloride solution treatment results in a strong extraction of contaminating metals; But we observe that some metals (lead, copper and chromium) as well as chlorides lead to an increasing tendency to dissolve (Table 9),

- on the other hand, hydrochloric acid treatment (Table 10) increases the dissolution of the pollutants, but the elution threshold due to decreasing solubility remains in line with French and European standards on harmless waste. The corresponding scrap production would be equally favorable in public works.

Tables 11 and 12 illustrate the results obtained under similar conditions in standardized leaching tests after treatment of the slag with potassium chloride (Table 11) and hydrochloric acid (Table 12).

TABLE 9: NORMALIZED BALKING TEST AFTER KCL PROCESSING

Wreckage of Strasbourg (ST I)

Monitoring of extractions

checked parameter first extraction second extraction third extraction Total amount of coarse waste extracted (mg / kg) class I standards class II (mg / kg) standards of application in public works (mg / kg H.S.) fragrance without smell without smell without smell - color without color without color without color - - PH 7.0 6.4 6.0 - - resistivity 30000 45000 60000 - - O2 / I 0 0 0 0 below 5000I ¹ ) C.O.T. mg / 1 e ε ε ε below 400 ^) below 1000

elements concentration of the first extract (mg / l) concentration of the second extract concentration of the third extract total extr. Q gross. by. (mg / kg) standards class II standards class II * standards class III lead 0,044 0,001 0,014 0.59 <100 <30 <4 cadmium ND ' ND ND - <50 <5 <1 zinc 0,282 0,293 0,278 8.53 - <500 - - med ¹ 0,678 0,150 0,239 10.65 - <20 <20 nickel 0,052 0,031 0,031 1.14 <100 - - chrome 0,060 0,000 0,000 0.60 <100 - <1 mercury below 0.003 below 0.003 below 0.003 below 0.03 <10 <0.2 <0.2 cyanides ND ' ND ND - <10 - arsenic 0.0009 below 0.0008 below 0.0008 below 0.009 <10 <2 <2 chlorides 0.8 2.33 0.62 37.5 - <10000 <2800 sulphates 1.4 2.2 below 1.0 36.0 - - <4000

* refers to fly ash from incineration of municipal waste ° ND: not reported, MS: dry matter

Dissolution behavior

elements behavior Soluble quantities in tng / kg gross waste complete solution decreasing dissolution stagnant dissolution increasing dissolution in the test with possible dissolution lead x 0.59 186 zinc x 8.53 1900 copper x 10.65 4800 nickel x 0,312 5800 chrome x 0.60 20800 arsenic x 0,009 6.2 chlorides x 37.5 3990 sulphates x 36.0 300

TABLE 10: NORMALIZED BALKING TEST AFTER HCL PROCESSING

Wreckage of Strasbourg (ST 1)

Monitoring of extractions

checked parameter first extraction second extraction third extraction Total amount of coarse waste extracted (mg / kg) standards Class I class 11 (2) (Mg / kg) standards of application in public works (mg / kg H.S.) fragrance without smell without smell without smell - color without color without color without color - - PH 7.0 6.4 6.0 - - resistivity 70000 80000 90000 - - DCOmg 0 ₂ / l 0 0 0 0 below 5000 ^ ¹ ) C.O.T. UJG / 1 ε ε ε ε below 400 ^ 2) below 1000

elements concentration of the first extract (mg / l) concentration of the second extract concentration of the third extract total extr. Q gross. by. (®g / kg) standards class II standards class II * standards class III lead 0,075 0,029 0,015 1.19 <100 <30 <4 cadmium ND ' ND ND - <50 <5 <1 zinc 0,132 0,070 0,048 2.50 <500 - - med ¹ 0,723 0,295 0,197 12.15 - <20 <20 nickel 0,064 0,045 0,041 1.54 <100 - - chrome 0,040 0,000 0,000 0.04 <100 - <1 mercury below 0.003 below 0.003 below 0.003 below 0.03 <10 <0.2 <0.2 cyanides ND * ND ND - <10 - - arsenic 0.0071 0.0025 0.0008 0,096 <10 <2 <2 chlorides 5.92 1.05 1.00 79.7 - <10000 <2800 sulphates 244 2.4 1.2 276 - - <4000

* refers to fly ash from incineration of municipal waste ° ND: not reported, MS: dry matter

Dissolution behavior

elements behavior Soluble quantities in mg / kg of gross waste complete solution decreasing dissolution stagnant dissolution increasing dissolution in soil test with possible. dissolution lead x 1.19 186 zinc x 2.50 1900 copper x 12.15 4800 nickel x 1.50 5800 chrome x 0.04 20800 arsenic x 0,096 6.2 chlorides x 79.7 3990 sulphates x 276 300

TABLE 11: NORMALIZED BALKING TEST AFTER KCL PROCESSING

Ruins of Salaise (S II)

Analytical monitoring of extractions

controlled parameter first extraction second extraction third extraction Total amount of coarse waste extracted (mg / kg) class 1 standards class II (Mg / kg) standards of application in public works (mg / kg H.S.) fragrance without smell without smell without smell - - * color without color without color without color - - - P » 7.1 7.1 7.2 - - - resistivity 800 2600 6000 - - - O2 / I 20 8 0 280 below 5000 ( ¹ ) - C.O.T. IDG / 1 e e e . e below 400 (2) below 1000

elements concentration of the first extract (mg / l) concentration of the second extract concentration of the third extract total extr. Q gross. by. (kg / kg) standards class II standards tr.Il ' standards class II lead 0,181 0,061 0,024 2.65 <100 <30 <4 cadmium 0,023 0,008 0,004 0.35 <50 <5 <1 zinc 0,037 0,017 0.0114 0.65 <500 - - honey 0,0454 0,036 0,014 0.95 - <20 <20 nickel 0,139 0,053 0,028 2,202 <100 - - chrome 0,060 0,000 0,000 0.60 <100 - <1 mercury below 0.003 below 0.003 below 0.003 below 0.03 <10 <0.2 <0.2 cyanides ND ND ND - <10 - - arsenic below 0.0008 below 0.0008 below 0.0008 below 0.0008 <10 <2nd <2 chlorides 127.0 17.0 3.26 1472 - <10000 <2800 sulphates - - - - - - <4000

* refers to fly ash from incineration of municipal waste ° ND: not reported, MS: dry matter

Dissolution behavior

elements behavior Soluble quantities in mg / kg of gross waste complete dissolution decreasing dissolution stagnant dissolution increasing dissolution v podm. test with possible dissolution lead x 2.65 343 cadmium x 0.35 3.4 zinc x 0.65 948 copper x 0.95 1450 nickel x 2.20 1523 chrome x 0.60 10920 chlorides x 1472 20500

TABLE 12: NORMALIZED BALKING TEST AFTER HCL PROCESSING

Ruins of Salíise (S II)

Analytical monitoring of extractions

controlled parameter first extraction second extraction third extraction Total amount of coarse waste extracted (mg / kg) IM Class II standards ( ² ) (mg / kg) standards of application in public works (mg / kg M.S.) fragrance without smell without smell without smell - - color without color without color without color - - - PH 6.8 6.6 7.0 - - - resistivity 1000 3000 6000 - - - DCOmg 0 ₂ / l 0 0 0 0 below 5000 ^) - C.O.T. mg / 1 e € ε e below 40q ( ² ) below 1000

elements concentration of the first extract (mg / l) concentration. second extract concentration of the third extract total extr. Q gross. by. (mg / kg) standards class II standards tr.Il ' standards class III lead 0,421 0,156 0,058 6.35 <100 <30 <4 cadmium 0,056 0,020 0,007 0.83 <50 <5 <1 zinc 0,118 0,044 0,038 2.00 <500 - - med ¹ 0,071 0,048 0,023 1.42 - <20 <20 nickel 0,913 0,259 0,122 12.94 <100 - - chrome 0,020 0,010 0,000 0.30 <100 - <1 mercury below 0.003 below 0.003 below 0.003 below 0.03 <10 <0.2 <0.2 cyanides ND ' ND ND - <10 - - arsenic below 0.0008 below 0.0008 below 0.0008 below 0.0008 <10 <2 <2 chlorides 33.3 17.2 7.8 583 - <10000 <2800 sulphates - - - - - - <4000

concerns fly ash from municipal waste incineration ° ND: not reported, MS: dry matter

Dissolution behavior

elements behavior Soluble quantities in mg / kg of gross waste complete solution decreasing dissolution stagnant dissolution increasing dissolution v podm. test s ffiožn. dissolution lead x 6.35 343 cadmium x 0.83 3.4 zinc x 2.00 948 copper x 1.42 1450 nickel x 0.30 1523 chrome x 0.60 10920 chlorides x 583 20500

conclusions:

Based on the leaching tests carried out on the debris and expected to be stored in class II or recycled, the following conclusions (Table 13) can be drawn from previous experiments, following the application of the AFNOR study protocol to processed or disposed debris:

Strasbourg (ST I) debris, without prior treatment, produces eluates whose toxicity thresholds are higher than the French standards. Moreover, these eluates are not in line with the legislation which envisages both Class II and European legislation, and are not consistent with the use of debris in public works. After the pretreatment of the slag with hydrochloric acid, the eluates produced are in accordance with French class II standards, the European standards for harmless waste, and the treated slag can also be recycled in public works.

The slags from Salaise II (Force) without prior treatment produce eluates whose toxicity thresholds are lower than those laid down in European standards for harmless waste and standards for the use of debris in public works. After treatment with potassium chloride, the eluates produced comply with European and scrap recycling standards.

Table 13: Recapitulation of slag processing results. Comparison of the results of their leaching with European and French waste storage standards. Concentrations of the extractable fraction obtained by means of the German test for European standards (100 g of dry waste per 1 l of water) and the standardized AFNOR test for French standards (100 g of gross waste for 1 liter of water). Results are expressed in soluble amounts of water in mg / kg.

hazardous wastes EEC standard ing / kgi ¹ ) frane, tr. I (debris) ing / kg ( ² ) harmless wastes of the EEC standard mg / kg ^ f early standards tr. (Flying ash) ^ 2) inert wastes of EEC standard mg / kg ^ standards of use in ver. work mg / kgW Ρ » 4-13 5-13 4-13 4-13 DCO - <5000 - - - - The loss on ignition - <556 - - - <556 COT 400-2000 - 400-2000 <400 <2000 <1000 arsenic III 2-10 <10 1-2 <2 <1 <2 lead 4-20 <100 <4 <30 everything <4 cadmium 1-5 <50 <1 <5 <1 chrome VI 1-5 <100 <1 - <1 copper 20-100 - <20 <20 <20 nickel 4-20 <100 <40 - - mercury 0,2-1 <10 <0.2 <0.2 <0.2 zinc 20-100 <500 <20 - <50 - phenols 200-1000 100-200 • <100 - fluoro 100-500 50-100 - <50 - ammonium 2-10 ? - <500 - chlorides 1200-60000 5000-12000 <1000 <5000 <2800 cyanides 2-10 1-2 - <1 - sulphates 2000-10000 2000-10000 - <10000 <4000 nitrites 60-300 30-60 - <30000 AOX 6-30 3-6 - <3 C1 solvents 0,2-1 0.1-0.2 - <0.1 pestiády C1 0.01-0.05 0.005-0.01 - <0.005 sub lipophiles 4-20 4-10 - <10

33a

Continuation of Table 13

slag ST I ³ without processing. mg / kg ( ¹ ) slag ST I ³ spracθ processed. HCl mg / kg ¹ ) debris Force ⁴ without process. nig / kg ( ¹ ) (mg / kg ^) Slag ⁴ after processing KC1 mg / kg ² ) (mg / kg ¹ )) Slags SV ¹⁵ dried unprocessed, mg / kg ( ¹ ) PH 6.5 7 7.1 7.1 9.6 DCO 240 0 1200 280 40 The loss on ignition e e 13.36 - 12.68 COT e e ε E 10 arsenic III 0,052 0,096 <0.0008 <0.008 <0.008 lead 1.56 1.19 6.11 (8.72) 2.65 (3.78) 1,350 cadmium 0.00 0.00 0.78 (1.11) 0.35 (0.50) 0,135 chrome VI 0.60 0.04 1.00 (1.42) 0.60 (0.85) 0,443 copper 29,41 12.15 1.88 (2.68) 0.95 (1.35) 0,041 nickel 1.59 1.50 4.54 (6.48) 2.20 (3.14) 0,312 mercury <0,03 <0,03 <0,03 <0,03 <0,03 zinc 7.17 2.50 1.50 (2.14) 0.65 (0.92) 0,144 phenols - - - - - fluoro - - - - - amóniura - - - - - chlorides 49.6 79.7 4333 (6191) 1472 (2103) 705 cyanides - - - sulphates 500 276 19680 nitrites - - - AOX - - - C1 solvents - - - pestiády C1 - - - sub lipophiles - - - - -

(1) in mg / kg dry waste 3.5 humidity <1% in mg / kg gross waste 4 humidity = 30%

As a result of the leaching process, the extracts contain metal chloride salts as well as an excess of the extractant. The average composition of leaches and rinsing water, all treatments performed in our 100 g slag experiments, are shown in Table 14.

Table 14: Chemical analysis of leaches and rinse water. Average composition obtained from the treatment of Strasbourg debris (ST 1) and Salais II (Force).

leachate rinse water PH 1.86 - 9.37 4.30 to 8.94

concentration in mg / l concentration in mg / l aluminum 0.4 to 170 0.09 to 3.06 iron 0.5 to 415 0.06 to 10.78 magnesium 1.4 to 288 0.12 to 27.76 manganese 0.02 to 60 0.03 to 20.52 silicon 2.62 to 256 ? calcium 2.6 to 256 ? sodium ? ? copper 0.1 to 484 0.08 to 28.44 zinc 0.04 to 2.4 0.05 to 1.264 lead 0.06 to 0.9 0.07 to 0.60 nickel 0.06 to 4.7 - chrome 0.3 to 0.5 - cobalt 0.18 to 1.21 - cadmium 0 0

The leaching has been extended to other reactants under various conditions.

The transformation of slags into inert gravel substances, under the influence of cations or exchangeable protons, has investigated the use of salt waste and acids in combustion centers for reaction purposes.

Experimental extraction equipment

The leaching was carried out (dynamic leaching in 2 liter flasks in the presence of a maximum of 1 liter of extractant and 100 g of slag. Incubation lasted for 2 hours at ambient temperature after processing. Separation of the solid from the liquid is accomplished by centrifugation at 2000 g. Filtration was performed on Millipore membranes with a diameter of 0.45 m for analytical purposes.

Treatment of debris with salt wastes, from the incineration of chlorine wastes

Dynamic Slag Leaching Force; leaches and water

The leaching was carried out on silo debris using Rhône effluents originating from the TREDI Saint-Vulbas center (Ain), this extraction reagent corresponding to a sample taken in January 1992 at the exit of the cleaning element (Table 15).

The slags were also subjected to extraction using a calcium effluent (calcium chloride 10 g / l, which corresponds to a molar concentration of 0.09 M). In addition, they were leached with 1 M potassium chloride.

The results

The use of salt wastes in accordance with the regulations as a reactant leads to a significant reduction of the washing thresholds compared to the standard test (Table 16). This dynamic leaching largely mobilizes nickel. Chromium, despite its rich content and representation in waste, remains insoluble. DCO remains unchanged while COT decreases by 50%, which is related to the adsorption of organic matter in the slag (Table 17).

The use of a calcium effluent leads to similar results under the same conditions (Table 18).

Potassium chloride treatment results in little nickel extraction but more effective copper mobilization (Table 19).

Rinse water for all treatments resulted in the elimination of residual dissolved elements and removal of excess reactant (Tables 17-19).

Verification of debris stability

Slags from Salaise II with saline waste have a soluble component that is reduced to match the possibility of use in public works. The leaching DCO will be reduced, as will the dissolution of chlorides, while the sulphate content will reach a concentration below the thresholds of the public works standard (modified in 1992). Decreasing nickel solubility, see Tables 20 and 21.

As in the case of sulphates, the slags from Salaise II leached with KCl 1 M are suitable for public works (Table 22).

In all cases, the treatment of the slags by leaching, due to the extraction of the polluting component, leads to a significant increase in the leaching resistance in the standardized test.

Previous tests have shown that both potassium chloride and calcium chloride allow a significant movement of heavy metals out of the debris, although the amounts found vary. In all cases, it is within the skill of the art to select salt for successive leaching according to the content and extractability of the various heavy cations from each type of slag where disposal is sought. It is noteworthy that chlorides

In addition, calcium often allows stabilization of the treated slag.

With various processed debris, especially silos debris, it has been found that the amount of exchanged calcium is greater than the experimentally calculated cation exchange capacity, which amount exceeds the heavy metal content extracted during successive leaching.

Processed slags, 18 months after collection (Table 20), improve their solubility quality, the solubility of nickel, chlorides and sulphates.

This test repeated 3 months after this treatment on stored slags at ambient temperature shows that these slags, under the effect of calcium chloride treatment, stabilized (decrease of soluble component, and in particular, the chloride and sulphate wash thresholds (Table 23)).

In addition, no destabilization of the slag base occurred. This stability phenomenon could be explained as follows.

Mineral Slag Analysis A force carried out under the same conditions on the standard solution and on the treated residue 3 months after leaching showed the enrichment of calcium treated slag to carbonate.

Such standard slags contain 1.83% carbon in the form of carbonates, while the treated slags have a concentration of 2.38%, which represents an increase in the carbonate content of 30%.

Calcium exchanged in leaching with heavy metals should therefore allow the natural uptake of carbon dioxide in the debris to be accelerated to provide better stability. Such an outcome is of particular importance, for example in the case of scrap from household waste incineration plants when the scrap is stored in the open for a longer period of time.

Table 15: Study of the composition of e.fluent-Rhône waste from the center

TREDI in Saint-Vulbas. Analysis performed on

13.1.1992 by plasma emission spectroscopy and atomic absorption.

parameters efluent-waste Rhône ph 7.6 resistivity (O.cm) - DCO mg 0 ₂ / l 750 C.O.T. mg / 1 13

elements concentration mg / 1 * lead below 0.010 (0.000) cadmium below 0.010 (0.000) zinc 0,120 copper 0,180 nickel 0,120 chrome below 0.010 (0.003) calcium 2030 chlorides 3540

* detection limits and (gross values)

Ruins of Salais (Force)

physical property waste the results standards tr.ľ standards tr.Il application in public. works soluble component 4.5i below 10% pod 5í pod 3í burn (at 550 ° C) - below 5 i - pod 5í dry) C.O.T. (dry) - - - - pH - 4 <pH <13 - - dry - over 35% - -

on standards for slags before stabilization ** on fly ash from the incineration of oily wastes

Analytical monitoring of extractions

monitored parameters for leaching first extraction second extraction third extraction Total amount of coarse waste extracted (mg / kg) class I standards class II (mg / kg) total ext. Q dry waste (mg / kg) norm. TP of dry waste (mg / kg) fragrance without smell without smell without smell - color nažitia without color without color - - - - PH 6.8 7.11 7.6 - - - - rezistivi ta 0 900 3500 - - - - D.C.O.mg (^ / l 84 36 0 1200 below 5000 ^) 1630 - C.O.T. mg / 1 under 1 under 1 under 1 under 30 under 1θ ⁴ ( ¹ ) / 4θθ ( ² ) under 41 below 1500 volume 1000 1000 1000 - - -

elements concentration of the first extract (mg / l) concentration second extract concentration of the third extract total extr. Q gross. by. (mg / kg) standards class II standards class II tot. Q rec. standards TP at PM lead 0,443 0,116 0,052 6.11 <100 <30 8.30 <15 cadmium 0,058 0,015 <0.010 0.73 to 0.83 <50 <5 0.99-1.13 <1 zinc 0,093 <0.050 <0.050 0.93 to 1.93 <500 - 1.26 to 2.62 - honey 0,088 0,066 <0.050 1.54 to 2.04 - <20 2.10 to 2.77 - nickel 0,338 0,085 <0.050 4.23 to 4.73 <100 - 5.74 to 6.42 - chrome 0,100 <0.010 <0.010 1.00-1.20 <100 - 1.36-1.63 <1 mercury <0.001 <0.001 <0.001 <0,03 <10 <0.2 <0,04 <0.2 cyanides ND ¹ ND ND - <10 - - - arsenic <0.010 <0.010 <0.010 <0,30 <10 <2 <00:40 <2 chlorides 3383 86 9 4330 - 10000 5883 - sulphates 1650 250 68 19680 - - 26739 <7000

° ND: non-detectable

Dissolution behavior

behavior Soluble quantities in mg / kg of gross waste elements complete falling 'stagnant increasing in lodges. with possible. breakdown fuse breakdown Itano test dissolution lead x - 6.11 343 cadmium x - 0.73 to 0.83 3 zinc x - 0.93 to 1.93 948 honey x - 1.54 to 2.04 14500 nickel x - 4.23 to 4.73 1523 chrome x - 1.00-1.20 1092 chlorides x - 4330 20500 sulphates x - 19680 18200

Table 17: Monitoring of leaches and rinse water during processing of slag from Salaise II (Force) using Rhône waste effluent.

parameters leachate rinse water PH 7.5 7.1 resistivity (O.cm) 94 925 D.C.O. mg O2 / l 414 0 C.O.T. mg / 1 6 7

elements concentration mg / 1 * concentration mg / 1 * lead <0.010 (0.000) <0.010 (0.000) cadmium 0,012 <0.010 (0.000) zinc 0,060 <0.050 (-) copper 0,200 <0.050 (-) nickel 0,850 <0.120 chrome <0.010 (0.000) <0.010 (0.000) calcium 1930 150 chlorides 3940 250

detection limits and (gross values).

Table 18: Monitoring of rinse water leaches during slag treatment from Salaise II (Force) with CaCl 2 at a ratio of 10g / L.

parameters leachate rinse water pH 7.2 7.5 resistivity (fi.cm) 86 1030 D.C.O. mg O2 / l 407 35 C.O.T. mg / 1 5 6

elements concentration mg / 1 * concentration mg / 1 * lead <0.010 (0.008) <0.010 (0.001) cadmium 0.011 <0.010 (0.000) zinc 0.060 <0.050 (0.010) copper 0.150 <0.050 (0.030) nickel 0.710 <0.110 (0.000) chrome <0.010 (0.002) <0.010 (0.000) calcium 2580 171 chlorides 4925 300

detection limits and (gross values).

Table 19: Monitoring of leaching and rinse water results during slag processing from Salaise II (Force) using KC1 IM.

parameters leachate rinse water PH 7.8 7.4 resistivity (O.cm) saturated 107 DCO mg 0 ₂ / l 3934 171 C.O.T. mg / 1 4 3

elements concentration mg / 1 * concentration mg / 1 * lead 0,014 <0.010 (0.002) cadmium 0,032 <0.010 (0.000) zinc <0.050 (0.030) <0.050 (0.010) copper 0,210 <0.050 (0.010) nickel 0,390 <0.100 (0.080) chrome <0.010 (0.002) <0.010 (0.002) calcium 173 15 chlorides 25400 1770

detection limits and (gross values).

Table 20: Normalized leaching test after treatment with effluent Rhône waste on the move

Ruins of Salaise II (Force)

physical property waste the results standards class II * standards tr.Il application in public. works soluble component 1,936 below 10% below 5% below 3% burn (at 550 ’C - below 5% - below 5% dry) C.O.T. (dry) - - - - - PH 8.5 4 <pH <13 - - dry 63.9 over 35% - -

on standards for slags before stabilization ** on fly ash from the incineration of oily wastes

Analytical monitoring of extractions

monitored parameters for leaching first extraction second extraction the third extraction Total amount of coarse waste extracted (mg / kg) class I standards class II (mg / kg) total ext. Q dry waste (mg / kg) norm. TP of dry waste (> g / kg) fragrance without smell without smell without smell - - - - color without color without color without color - - - - PH 6.9 7.3 7.7 - - - - resistivity 1110 3540 6130 - - - - DCOmg 0 ₂ / l 0 0 0 0 below 5000 ^ ¹ ) 0 - C.O.T. mg / 1 11 WITH 5 218 below 10 ^^ / 400 ^ ² ) 341 below 1500 volume 1000 1000 1000 - - - -

elements concentration of the first extract (mg / l) concentration of the second extract concentration of the third extract total extr, Q gross. by. (mg / kg) standards class II standards tr.U tot. Q rec. TP standards in the amount of lead <0.010 <0.010 <0.010 <0,30 <100 <30 <00:47 <15 cadmium <0.010 <0.010 <0.010 <0,30 <50 <5 <00:47 <1 zinc <0.050 <0.050 <0.050 <1,50 <500 - <2:35 - med ¹ 0,060 <0.050 <0.050 0.60 to 1.60 - <20 0.94-2.50 - nickel 0,160 <0.050 <0.050 1.60 to 2.60 <100 - 2:50 to 4:00 - chrome <0.010 <0.010 <0.010 <0,30 <100 - <00:47 <1 mercury <0.001 <0.001 <0.001 <0,03 <10 <0.2 <00:04 <0.2 cyanides ND ° ND ND - <10 - - - arsenic <0.010 <0.010 <0.010 <0,30 <10 <2 <00:47 <2 chlorides 59 9 4 720 <10000 1127 - - sulphates 326 81 38 4450 - - 69689 <7000

° ND: non-detectable

Dissolution behavior

behavior Soluble quantities in rag / kg gross waste elements complete falling stagnant increasing v podm. with possible. solution solution dissolution dissolution test dissolution med ¹ - X - - 0.60 to 1.60 13874 nickel - x - - 1.60 to 2.60 1468 chlorides - x - - 720 20500 sulphates - x - - 4450 18200

Table 21: Normalized caustic penalty after effluent treatment (CaCl2 at 10g / l) during movement. Ruins of Salais (Force)

4 physical property waste the results standards tr. I ’ standards the market" application in public. works soluble component 1,4% pod 10í pod 5í pod 3í burn (at 550 ’C - below 5I - pod 5í dry) C.O.T. (dry) - - - pH 7.8% 4 <pH <13 - - dry 66.7 nad 35í - -

on standards for slags before stabilization ** on fly ash from the incineration of oily wastes

Analytical monitoring of extractions

monitored parameters for leaching first extraction second extraction third extraction Total amount of coarse waste extracted (mg / kg) class I standards class II ( ² ) (mg / kg) total ext. Q dry waste (mg / kg) norm. TP of dry waste (mg / kg) fragrance without smell without smell without smell - - - color nažitia without color without color - - - - PH 6.8 7.3 7.8 - - - - resistivity 1190 3420 6210 - - - - DCOmg 0 ₂ / l 0 7 0 70 below 5000I ¹ ) 105 - C.O.T. IAG / 1 9 5 4 180 below 10 µ / 400 µ 270 below 1500 volume 1000 1000 1000 - - - -

elements concentration of the first extract (mg / l) concentration of the second extract concentration of the third extract total extr. Q gross. by. (mg / kg) standards class II standards class II tot. Q rec. standards TP at PM lead <0.010 <0.010 <0.010 <0,30 <100 <30 <0:45. <15 cadmium <0.010 <0.010 <0.010 <0,30 <50 <5 <00:45 <1 zinc <0.050 <0.050 <0.050 <1,50 <500 - <2/25 - copper <0.050 <0.050 <0.050 <1,50 - <20 <2/25 - nickel 0,150 0,060 <0.050 2.10-2.60 <100 - 3.14-3.90 - chrome <0.010 <0.010 <0.010 <0,30 <100 - <00:45 <1 mercury <0.001 <0.001 <0,00.1 <0,03 <10 <0.2 <00:04 <0.2 cyanides ND ' ND ND - <10 - - - arsenic <0.010 <0.010 <0.010 <0,30 <10 <2 <00:45 <2 chlorides 101 13 5 1190 - <10000 1783 - sulphates 290 82 39 4110 - - 61599 <7000

° ND: non-detectable

Dissolution behavior

behavior Soluble quantities in rog / kg of coarse waste elements complete falling stagnant increasing v podm. with possible. solution solution dissolution dissolution test dissolution nickel - x - 2.10-2.60 1468 chlorides - X - - 1190 20500 sulphates - x - - 41100 18200

Table 22: Normalized leaching test after KCl treatment

M while moving.

Ruins of Salais (Force)

physical property waste the results standards tr.ľ standards tr.Il " application in public. works soluble component 1,556 below 10% below 5% below 3% burn (at 550 ° C) - below 5% - below 5% dry) C.O.T. (dry) - - - - pH 7.8% 4 <pH <13 - - dry 68,2% over 35% - -

on standards for slags before stabilization ** on fly ash derived from the incineration of oily wastes »Analytical monitoring of extractions

monitored parameters for leaching first extraction second extraction third extraction Total amount of coarse waste extracted (mg / kg) class I standards class II (rag / kg) total ext. Q dry waste (mg / kg) norm. TP of dry waste (mg / kg) fragrance without smell without smell without smell - - color without color without color yellowish - - - - PH 7.45 7.4 7.3 - - - - resistivity 783 2990 5460 - - - DCOmg 0 _2/1 54 7 41 1020 below 500o (l) 1469 - C.O.T. mg / 1 6 4 3 130 Under 10 ^) / 400 ( ² ) 190 below 1500 volume 1000 1000 1000 - - - -

elements concentration of the first extract (mg / l) concentration of the second extract concentration of the third extract total extr. Q gross. by. (mg / kg) standards class II standards class II tot. Q rec. TP standards in the amount of lead <0.010 <0.010 <0.010 <0,30 <100 <30 <0.44. <15 cadmium <0.010 <0.010 <0.010 <0,30 <50 <5 <0,44 <1 zinc <0.050 <0.050 <0.050 <1,50 <500 - <2.20 - med ¹ <0, 050 <0.050 <0.050 <1,50 - <20 <2.20 - nickel 0,070 <0.050 <0.050 0.70-1.70 <100 - 1.02 to 2.49 - chrome <0.010 <0.010 <0.010 <0,30 <100 - <0,30 <1 mercury <0.001 <0.001 <0.001 <0,03 <10 <0.2 <0,04 <0.2 cyanides ND * ND ND - <10 - - - arsenic <0.010 <0.010 <0.010 <0,30 <10 <2 <0,44 <2 chlorides 165 25 7 1970 - <10000 2888 - sulphates 126 51 30 2070 - -  3033 <7000

° ND: non-detectable

Dissolution behavior

behavior Soluble quantities in mg / kg of gross waste elements complete falling stagnant increasing v podm. with possible. solution solution dissolution dissolution test dissolution nickel - x - - 0.70-1.70 1468 chlorides - x - - 1970 20500 sulphates - x - - 2070 18200

Table 23: Normalized leaching test after effluent treatment - stability study

Ruins of Salais (Force)

• physical property waste the results standards tr.ľ standards tr.Il " application in public. works soluble component 0,9% below 10% below 5% below 3% burn (at 550 ° C) - below 5% - below 5% dry) C.O.T. (dry) - - - - pH 7,5% 4 <pH <13 - - dry 95% over 35% - -

on standards for slags before stabilization ** on fly ash from the incineration of oily wastes

Analytical monitoring of extractions

monitored parameters for leaching first extraction second extraction third extraction Total amount of coarse waste extracted (mg / kg) class I ( ¹ ) class II standards (mg / kg) total ext. Q dry waste (mg / kg) norm. TP of dry waste (mg / kg) fragrance without smell without smell without smell - - - color without color without color without color - - - - PH 7.5 7.4 7.6 - - - - resistivity 1277 3663 5555 - - - - D.C.O.rag C ^ / 1 48 8 8 640 below 5000 ^) 673 - C.O.T. mg / 1 5 3 3 110 below 10 ^{4 (l} ) / 400 ( ² ) 116 below 1500 volume 1000 1000 1000 - - -

elements concentration of the first extract (lDg / 1) concentration second extract concentration of the third extract total extr. Q gross. by. (mg / kg) standards class II standards tr.ll tot. Q rec. standards TP at PM lead <0.010 <0.010 <0.010 <0,30 <100 <30 <0,31 <15 cadmium <0.010 <0.010 <0.010 <0,30 <50 <5 <0,31 <1 zinc <0.050 <0.050 <0.050 <1,50 <500 - <1,58 - copper <0.050 <0.050 <0.050 <1,50 - <20 <1,58 - nickel 0,130 0,070 0,050 2.30 <100 - 2.42 - chrome <0.010 <0.010 <0.010 <0,30 <100 - <0,31 <1 mercury <0.001 <0.001 <0.001 <0,03 <10 <0.2 <0,03 <0.2 cyanides ND ¹ ND ND - <10 - - - arsenic <0.010 <0.010 <0.010 <0,30 <10 <2 <00:31 <2 chlorides 51 9 4 640 - <10000 673 - sulphates 240 68 38 3460 - - 3642 <7000

° ND: non-detectable

Dissolution behavior

behavior Soluble quantities in mg / kg of gross waste elements complete falling stagnant increasing v podm. s roožn. solution solution dissolution dissolution test dissolution nickel - x - - 2.30 1468 chlorides - x - - 6400 20500 sulphates - x - - 3460 18200

In accordance with another provision, biosorption is carried out in these metals outside the leachate. Basically, these metals are present in a form that is readily accessible to a certain amount of biosorbants. In other words, the process is complemented by the next stage of biosorption of the leached metals outside the treated debris, as described above.

It should be remembered that biosorption is the sequestration of metal ions by means of a solid material of natural origin. This general concept includes a very diverse mechanism: particle uptake, active ion transport, assembly, adsorption, and inorganic precipitation on the biosorbate.

The biosorbant, the use of which appears to be particularly advantageous, is chitosan. Chitosan is a basic derivative of chitin (poly N-acetyl D-glucosamine). It is a long chain carbohydrate polymer of a linear polymer with glucosamine units linked by beta (1-4) glucose bridges.

Chitosan, which is rarely present in nature, is obtained by the de-acetylation of chitin, extracted from an exoskeleton of crustaceans, centipedes and other arthropods or microorganisms, fungi.

The diversity of chitin sources shows a great variety of possible properties of chitosan.

A range of de-acetylation ranging from 80 to 100% and an average molecular weight of 5,000 to 1,000,000 results in the ability to determine the turbidity, viscosity and solubility of the solutions. This solubility of chitosan with a low degree of N-acetylation is only achieved in a dilute acid medium at pH < 6. It is associated with the presence of amine function in C-2 glucose units, causing this polymer to behave as a weak polyvalent base.

Some authors admit that the use of chitosan in water treatment is a method of the future. It seems that a similar 'TT'Xf product is currently being developed in Europe, going from PRO FLOC ⁱⁿ (Protan). Its properties are as follows: flakes / powder; free amine form (-NH 2), average purity. In Japan, chitosan (chitosan beads, Fujibo Inc. Shizuoka) is used in domestic and industrial water treatment. Another useful form of chitosan (which has been used in previous experiments discussed below) is chitosan SIGMA ^R (No. C.0792). However, other biosorbents may be used instead of chitosan. For example, some of the biosorbants listed below may be used. Their biosorbent properties do not always correspond to those of chitosan. The choice of this most suitable biosorbant will often be based on the content of leaches obtained by applying the first part of the process to the debris to be treated.

Previous experiments were performed using various metal-fixed biosorbants: chitin Sigma ^R (# 3387), chitosan Sigma ^R (# C.0792), fungal biomass on chitosan (Rhizopus arrhizus.) Walls, bacterial biomass (Zoogloea ramigera) ) and meal biomass.

methodology:

To flasks containing 250 ml add 100 ml of brine (Cobalt: Co (NO ₃ ) ₂ or chromium: Cr (No ₃ ) ₂ , 9H ₂ 0 or copper: CuSo ₄ , 5H ₂ 0 or zinc: ZnSO ₄ , 5H ₂ 0 or cadmium:

3CdSO ₄ , 8H ₂ O or lead: (Pb (NOj) ₂ - 100 mg / l with pH 4.0 and 100 mg biosorbants (which is 1 g / l) in their original state or ground.

Incubate at 25 ° C with gentle agitation; sampling is performed after 3, 6, 12, 24, 48 and 72 hours of contact.

Analysis of the elements in solution is done by plasma emission spectrophotometry.

Figures 4 to 9 show the relative curves with the adsorption kinetics of lead, copper, chromium, cobalt, zinc and cadmium for individual biosorbants.

The following salts will be used depending on the element:

- lead nitrate (Figure 4)

- copper sulphate (Figure 5)

- chromium nitrate (Figure 6)

- cobalt nitrate (Figure 7)

- Zinc sulphate (Figure 8)

cadmium sulphate (Figure 9).

The figures represent changes in absorbed metal (in percent of initial content on the coordinate axis) versus time (in hours (H)) on the lines.

x

Výsladky:

When selecting initial conditions that are not favorable to biosorption (pH at baseline: 4.0), the individual metals tested for the salt / biosorbant ratio give the following results:

- the lead is quickly fixed: with 75% of Zoogloea ramegera in 5 hours; chitin and meal accumulate it up to 30% and then fixation stops. As a rule, R. arrhizus fixes this metal so that the result is 80% after 72 hours.

Chitosan does not appear to stabilize lead under experimental conditions (Figure 4).

- Copper behaves very similarly to chitin, fungal biomass and bacterial biomass and meal; its fixation is approximately 10% and practically remains constant. Chitosan is the best copper adsorbant and will stain in the presence of copper, chelating with 50% copper sulfate in 72 hours (Figure 5).

- only chromium shows affinity for chitosan and its adsorption reaches 6% in 72 hours of incubation (Figure 6).

- cobalt has an adsorption profile and an alternate desorption profile for all biosorbants tested. The fixed percentage is between 2 and 8% (Figure 7).

- Zinc has a good affinity for Rhizopus arrhizus and chitosan (10% adsorbed in 72 hours incubation). Other polymers do not form chelates either from zinc or from selected concentrations or at specified parameters (Figure 8).

cadmium is fixed to 20% by chitosan after 72 hours of incubation. Other biosorbents do not accumulate this metal (Figure 9).

A comparative test of the above curves shows that the selection of the biosorbants used in these previous tests can counter the treatment of all the leaches obtained as a result of the treatment of the slag with a solution containing chloride ions, regardless of their contaminating metal content.

In addition, it may be noted that some of the biosorbents used may have little activity under certain conditions, but vice versa. This is the case, for example, with chitosan and lead and copper.

Some biosorbents are of particular interest, especially when they can be regenerated. In this case, chitosan has a particular activity. The briefly described assays (see below) show the ability of chitosan to regenerate by the action of an exchange reagent or acid.

Another parameter may consist mainly in the presence of very large amounts of biosorbants for the element to be extracted. This is also the case with lead and zinc. Under experimental conditions, as you will see below, the amount of lead absorbed can increase considerably as the biosorbant ratio increases relative to the concentration of metal to be adsorbed.

methodology:

In flasks containing 250 ml, add 100 ml of saline (test metals: CuSO ₄ , 5? 0; ZnSO ₄ , 5? 0; CdSO ₄ , 81? 0; PbNO ₄ ; N ₂ SO ₄ , 6H ₉ 0) at pH 4, 0 (with the acid corresponding to the associated base), or at the original pH, a.100, 200, 400 or 800 mg of chitosan. After 24 hours of incubation at 25 ° C with gentle mixing, the preparation is centrifuged and 20 ml of surnagent (floating substance) is collected for dosing into a plasma emission spectrophotometer. The 800 mg pellet is left to measure desorption.

To this was added 20 ml of distilled water and then the whole contents were stirred for 1 hour and then centrifuged. The surgagent is analyzed and the resulting pellet is added to a solution of 0.1 M ammonium sulfate and / or 1 N hydrochloric acid. After re-mixing, the surnagent is analyzed again.

The results:

Copper is the element that shows the best affinity for chitosan; at a salt / biosorbant ratio of 0.8, the chelation of the metal is virtually completed within 24 hours of contact. The initial pH does not appear to affect the fixation capacity of the biosorbant, but its alkalinity tends to orient the pH of the environment to around 7, where proton contamination decreases.

Desorption with ammonium sulfate is poor, indicating that the fixed metal is difficult to replace. Modification of the pH by the addition of hydrochloric acid leads to ionization of the action groups and to the chelating of the chelated metal. Excluding losses during the experiment, the recovery rate is approximately 80%. In addition, the hydrochloric acid used to replace the equilibrium of the reaction apparently changes the structure of chitosan, since less disaggregation of the product has been found.

Based on literature data, sulfuric acid could be effective in replacing the chemical equilibrium of the reaction without dissolving chitosan.

Zinc, another test element, appears to have a lower affinity when compared to copper and has a fixation percentage of 60% in 24 hours at a salt / biosorbant ratio of 0.8. PH environment develops in the same way as in copper experiments.

Desorption with water is a washing rather than an active desorption. Zinc is readily exchangeable, but mobilization becomes effective upon addition of acid.

Among the elements tested, cadmium has a zinc-like behavior, with a degree of fixation of 60% in 24 hours at the same salt / biosorbant ratio.

In the exchange reagent, cadmium is strongly desorbed; its desorption is completed by the addition of hydrochloric acid. The use of an acid as the only desorption reactant seems to be insufficient to extract the entire amount of fixed metal.

Lead is adsorbed to 91% at a salt / biosorbant ratio of 0.8. This metal is poorly exchangeable, on the other hand, it is mobilized by the addition of hydrochloric acid.

Nickel shows less affinity for chitosan, its percentage fixation reaches 60% in 24 hours at a salt / biosorbant ratio of 0.8. Its desorption is effective (78%) after replacing the reaction equilibrium after addition of hydrochloric acid.

The results obtained allow industrialization in the biosorption stage of the polluting metals contained in the extracts obtained under the conditions of the initial slag inerting stages.

Figure 10 is a basic diagram of an industrial plant that can be used for this purpose. The leaches will be directed to a chitosan-containing reactor or to a mixed plant containing an additional biosorbant (e.g. stabilized biomass) in a separate reactor or mixed plant. This will be equipped with a recycling loop to obtain a complete water purification. This metal-free water will be able to be discharged into the river or possibly recycled, similar to the rinsing water at the slag.

Analogous to ion-exchange resins, chitosan will be regenerated by metal desorption using an acidic eluant, which operation may be followed by treatment of the biosorbant with sodium carbonate. The regeneration will be carried out alternately on one of the processing lines (lane I or II). The acidic eluate will be directed to the storage vessel before final solidification, but metal recovery and water recycling may be scheduled for later.

Very similar results can be obtained with other biosorbants, for example fungic biomasses (particularly effective in the treatment of lime extracts).

Treatment of leachates using fungicidal biomass

Working conditions

Biosorption tests are performed with stirring for 2 hours at 25 ° C and without pH control. 100 ml of effluent of a similar composition to leach extracts are added to 50, 100 or 250 mg of biomass (Rhizopus arrhizus) grown in the laboratory. The mineral elements are then dosed on solutions obtained after filtration on millipore membranes with a diameter of 3 μπι and then 0.45 μπι.

The results

The results presented in Table 24 and Figure 11 show that Rhizopus arrhizus is particularly effective in eliminating the trace metal lime matrix (matrix).

Treatment of leachates (Figure 12)

In practice, the effluents or leachate may be processed continuously in a bath-containing device that is mixed and supplied with effluents and biomass and in a decanting vessel for separating the solid and liquid components. Liquid surnagents are eliminated and the solids (biomass) are either recycled at supply if they have not yet been saturated with metals, or are sent for purification if saturated. They are then concentrated (final waste) and possibly destroyed, for example by incineration, or solidified, for example by conversion into glass for storage.

Table 24 shows the results obtained. Figure 11 provides a picture of the test results at three different concentrations of Rhizopus arrhizus (study of individual metal adsorption contained in effluents. Calculation of elimination percent and confidence interval of 5% after a contact time of 2 hours with stirring in the presence of Rhizopus arrhizus).

Table 24: Heavy metal biosorption. Study of the composition of effluents before and after processing on fungal biomass. Three replicates per test, concentration in gg / l and confidence interval of 5%.

Rhizopus Rhizopus (50mg) (100mg) (250mg)

parameters initial final final final concentration lead 15 15 ± 5 3 ± 2 2 ± 1 cadmium 40 32 ± 0 20 ± l 14 ± 13 zinc 615 210 ± 0 100 ± 0 50 ± 0 copper 40 10 ± 0 20 ± 0 20 ± 0 nickel 115 30 ± 0 30 ± 0 20 ± 0 chrome 15 - - - calcium 2.70 2.78 2.73 2.71 COT (mg / l) 7.8 1.4 13.7 ± 1.9 19.7 ± 3.9 32.8 ± 3.8

Debugging threshold in pg / l for dosed mineral elements: lead below 25, cadmium below 10, zinc below 50, copper below 50, nickel below 100, chromium below 10

All of these results indicate the high efficiency of the whole process. A schematic diagram of one of the preferred uses is shown in Figure 13.

It follows that the process leads to incineration residues which, after treatment, comply with the definition of inert European waste and / or comply with the values for use of the product in public works.

On the other hand, the movable heavy metal component contained initially in the residues was concentrated to a very small mass compared to the initial slag mass.

Finally, treatment does not lead to the transfer of pollution to the natural environment.

Claims (13)

PATENT CLAIMS 1. A method for stabilizing combustion residues, in particular slags, irrespective of their origin, and in particular for extracting soluble metal components, characterized in that one or more slag leaches which have previously been crushed, if necessary, to a sufficiently low granulometry are carried out. , in particular below 50 mm, to allow sufficient contact between the combustion residues and the aqueous solution or leaching liquid, with a concentration of elements of sufficient level, either cations (K ⁺ , Na ⁺ , O I Ca), either of the protons exchangeable in the form of chlorides for the cations of heavy metals present in these residues, the leaching being sufficient to transform at least a portion of the metals concerned, in particular the heavy metals contained in the combustion residues, into soluble chlorides extractable by the leaching fluid , and their effective extraction in sufficient proportion to: - on the one hand, a standardized elution test carried out later on slags treated in this way confirmed a decrease in the quantities of each of these metals, determined during repeated extraction tests using a standardized solution in accordance with that test, and on the other hand, the sum of the soluble amounts in the eluates resulting from the extractions with the said standardized solution was around values corresponding to concentrations below the threshold concentrations also predetermined for each of these metals and other parameters set by the standards. Method according to claim 1, characterized in that the aforementioned standardized test comprises three extraction tests, carried out with the aid of a standardized solution consisting of mineralized water, saturated with air and CO2 with a pH of 4,5 and a resistance of between 0,2 and 0.4 Mn.cm. ? Ι / Method according to claim 1 or 2, characterized in that the leach solution or treatment solution consists of a (dilute) hydrochloric acid solution, in particular in the treatment of slags with a basic character. The method according to claim 3, characterized in that the concentration of hydrochloric acid of the slag leaching solution has a molar concentration ranging from 0.01 M to 1 M, in particular about 0.1 M. Method according to claim 1 or 2, characterized in that the leaching or treatment solution consists of an alkali or alkaline earth metal chloride solution, especially in the treatment of neutral type slag.) Method according to claim 5, characterized in that the leaching solution consists of a potassium chloride solution. Method according to claim 6, characterized in that the concentration of the alkali or alkaline earth metal chloride of the leach solution or the treatment solution is in the range of about 0.01 M, in particular between 0.05 M and 5 M. The method of claim 7, wherein the alkali metal chloride is potassium chloride and its concentration is about 1 M. Method according to claim 7, characterized in that the alkali metal chloride is calcium chloride and that its concentration is in the range of 0.01 M, in particular about 0.05 to 5 M, in particular between 0.09 M and 0 M, 15 M. The method of claim 7, wherein the alkali-earth metal chloride is calcium chloride and its concentration is about 0.09 M. Method according to any one of claims 1 to 10, characterized in that the leaching solutions obtained from the treated slags are subject to biosorption by means of biosorbants capable of trapping at least a major part of the metallic heavy metal ions extracted from the slags. The method of claim 11, wherein the biosorbant is chitosan-based. Method according to claim 11, characterized in that the biosorbants are biomasses, in particular fungi or bacteria, derived from cultures or biological fermentations.