FR2691979A1 - Detoxification process of combustion residues by extraction of mobile toxic compounds and fixation - concentration of these same compounds from treatment solutions. - Google Patents

Abstract

The invention relates to a method for stabilizing slag by removal of solubilizable metal fractions. It comprises leaching said slag with an aqueous leaching solution containing exchangeable elements in the form of chlorides with the cations of heavy metals present in said slag. The leaching solution is a dilute hydrochloric acid solution for the basic slag, or an alkali or alkali-earth metal chloride solution for neutral slag.

Description

METHOD FOR DETOXING COMBUSTION RESIDUES BY
EXTRACTION OF MOBILE TOXIC COMPOUNDS AND FIXATION
CONCENTRATION OF THESE COMPOUNDS FROM
TREATMENT SOLUTIONS
Slags are non-volatile solid residues extracted from combustion fires at industrial sites. Evacuated generally by a hydraulic flush towards a reception pit and then containing from 3 to 30% of water, they have the appearance of black solids more or less divided and very heterogeneous.

 In the context of the present description, the expression "slag" must therefore be understood in the widest possible sense. It will concern all products and combustion residues, for example machefers, likely to contain heavy metals more or less elutable by runoff or meteoric water.

They may still consist of fly ash from, for example, the incineration of urban waste.

 The slag is often characterized by a silico-aluminous gangue containing metal oxides, mainly ferric oxides and at lower levels, chromium oxides, copper, nickel, zinc or even cobalt and lead (Table 1). .

Their compositions can naturally vary considerably from one site to another.

 This can be observed, for example in the analysis of Table 1 which follows. I1 presents the results given by way of examples of multi-elemental slag analysis obtained at three different industrial sites in Strasbourg (ST 1), Salaise, in the department of Isère (S II), and in Saint-Vulbas. , in the department of Ain (SV 1).

Table 1: Multi-elemental analysis of Tredi Strasbourg (ST 1) slag from
Tredi Salaise II (S II) and Tredi St. Vulbas (SV 1).

<Tb>

Major <SEP> Elements <SEP> in <SEP> Slag <SEP> ST <SEP> 1 <SEP> Slag <SEP> S <SEP> II <SEP> Slag <SEP> SV <SEP> 1
<tb> percentage <SEP> of oxide:
<tb> SiO2 <SEP> 28.89 <SEP> 23.9 <SEP> 23.58
<tb> A1203 <SEP> 9.70 <SEP>. <SEP> 8.46 <SEP> 23.12
<tb> Fe203 <SEP> 33.95 <SEP> | <SEP> 23.8 <SEP> 18.91
<tb> MnO2 <SEP> 1.86 <SEP> 1.44 <SEP> 0.13
<tb> MgO <SEP> 1.89 <SEP> | <SEP> 0.87 <SEP> 1.01
<tb> CaO <SEP> 5.84 <SEP>. <SEP> 9.51 <SEP> 8.58
<tb> Na2O <SEP> 3.70 <SEP>. <SEP> 1.45 <SEP> 0.75
<tb> K2O <SEP> 0.87 <SEP> | <SEP> 1.29 <SEP> 0.75
<tb> TiO2 <SEP> 5.85 <SEP> 2.93 <SEP> 0.98
<tb> P205 <SEP> 1.22 <SEP>. <SEP> 9.61 <SEP> 7.85
<tb> Sulfur * <SEP> 0.04 <SEP>. <SEP> 1.42 <SEP> 0.16
<tb> * Results in basic form
Trace elements (contents expressed in elemental form in ppm):

<tb> Barium <SEP> 11500 <SEP><SEP><SEP> 2429 <SEP> | <SEP> 2200
<tb> Berylium <SEP> 3,4 <SEP> 0.6 <SEP> 1
<tb> Cobalt <SEP> 6800 <SEQ> 94.5 <SEP> 51
<tb> Chrome <SEP> 20800 <SEP> | <SEP> 1090 <SEP> 1205
<tb> Copper <SEP> 4800 <SEP> | <SEP> 13874 <SEP> 8800
<tb> Galium <SEP> 58 <SEP> | <SEP> 5.0 <SEP> 21
<tb> Niobium <SEP> 124 <SEP> 10.1 <SEP> 11
<tb> Nickel <SEP> 5800 <SEQ> 1468 <SEP> 784
<tb> Rubidium <SEP> 24 <SEP> | <SEP> 17 <SEP> 16
<tb> Scandium <SEP> 6.4 <SEP> 7.9 <SEP> 6
<tb> Strontium <SEP> 402 <SEP> | <SEP> 171 <SEP> 290
<tb> Thorium <SEP> 5 <SEP> | <SEP> 5 <SEP> 5
<tb> Vanadium <SEP> 484 <SEP> | <SEP> 115 <SEP> 105
<tb> Yttrium <SEP> 6 <SEP> | <SEP> 10 <SEP> 7
<tb> Zinc <SEP> 1900 <SEP> | <SEP> 893 <SEP> 620
<tb> Zirconium <SEP> 282 <SEP> | <SEP> 112 <SEP> 98
<tb> Tin <SEP> 48 <SEP> | <SEP> 105 <SEP> 360
<tb> Cadmium <SEP> 0.3 <SEP> 3.2 <SEP> 1.3
<tb> Mercury <SEP> 0.04 <SEP> 0.1 <SEP> 3.8
<tb> Arsenic <SEP> 6.2 <SEP> 14.5 <SEP> 50
<tb> Lead <SEP> 186 <SEP>#<SEP><SEP> 324.1 <SEP> 190
<Tb>
Slag from incineration of industrial waste should normally be stored in landfills or landfill sites.

 These slags can indeed present risks, especially when their contents of heavy metals, toxic, in easily elutable forms, are still high. These heavy metals are concentrated in the slag according to various physicochemical mechanisms, and according to their natures, form various associations little or not known. This is the reason why these risks are the subject of evaluations, with consequent referrals to C.E.T. which can be distinguished according to their respective capacities to authorize these burials under conditions each time meeting standards - when they have been defined - of appropriate security.

 The selective extraction methods, used in soil science (soil science), make it possible to distinguish certain associations or specific constitutions (speciations) and provide information on the chemical forms and on the possible conditions for the solubilization of metals. Knowledge of these data is important to evaluate the possibility of a decontamination treatment.

 The metals present in the slag may be water-soluble, exchangeable, associated with amorphous or crystalline oxides and hydroxides, or in the form of precipitates, such as carbonates or sulphides. Often the important pollutions to which the slag can give rise, result from the extraction of these metals by solubilization in meteoric water or runoff. The "isotopically" exchangeable cations will be exchanged more rapidly if the electrostatic forces on negatively charged sites are low.

 More generally, these findings have led specialists to define the mobility of an element, that is to say the ability of this element to pass into compartments of the environment where it is less and less energetically retained, the ultimate compartment being represented by the liquid phase (solution).

Various standards exist for correlating the risk presented by the slag treated with the contents (or solubilizable amounts) of dissolved metals in the leachate or eluates obtained. For these standardized tests, these slags are leached by aqueous solutions simulating the action of meteoric waters. These leaching tests, carried out in the laboratory, allow an evaluation of the real risks incurred during the controlled disposal of slag. They can specify the conditions under which some machefers can be valued in public works (circular machefers of 8/04/92, see table 2 below). For example in
France, the AFNOR standard study protocol (X31210, 1988) recommended by the Ministry of Environment aims to extract soluble substances contained in crushed slag (diameter <4 mm).

Other types of standards are being studied by the competent services of the European Economic Community (EEC).

In the different leachate categories, analyzes of soluble toxic metals make it possible to locate the measured concentrations in relation to thresholds set by French and European standards. This referencing will depend on the recovery authorizations (Table 2) or landfill
This ad hoc, depending on whether the treated products obtained will be classified, for example, as "hazardous waste" (Class I CET), "non-hazardous waste" (Class II Class II), or "inert waste" (see table 3 following).

The procedure of the standardized study protocol
AFNOR (X31210, 1988) is the following
a demineralised water saturated with air and with CO 2 at pH 4.5 and with a resistivity of between 0.2 and 0.4 Nn.cm is mixed with 100 g of slag for 16 hours at room temperature under rotary stirring.

 the first leachate is obtained by filtration of the supernatant after centrifugation of the mixture (2000 g for 15 minutes). The color, odor, conductivity and pH are then measured. The solid is then taken up for 2 new extractions with the result of obtaining two additional leachates (or eluates). At the end of these operations, the chemical oxygen demand (COD), the total organic carbon (TOC) and a mineral analysis are performed on the 3 eluates.

 Similar trials have been developed in other countries or in C.E.E.

 They helped define standards, as shown in Table 3, but subject to change. The values presented define various "elution thresholds" corresponding to the sum of the maximum solubilizable amounts of each of the metals or other pollutant constituents (eg soluble chlorides and cyanides) that can be tolerated, with respect to each of the categories or classes of wastes. in question.

 For polluting metal elements, chlorides and cyanides, the French and European standards (non-hazardous waste) also require that the quantities of each of the elements leached during the three successive extractions go decreasing.

In the opposite case, that is to say the one where one would observe "increasing solubilizations" of certain metals in at least two leachates or successive eluates, one could not conclude to the stabilization of slag in time. One could indeed always fear risks of pollution resulting from renewed exchanges between buried slag and runoff.

 The following tables 4, 5 and 6 make it possible to assess what are the main polluting characteristics of the slags, ST 1, SII and SV 1 considered as examples.

Table 2: Valorisation of incineration machefers
of garbage in public works
threshold concentrations given by the
leachable fraction obtained by the test
standardized AFNOR (x 31-210).

* * * * * * * * * * * * * * * * * * * * * * **
* unburned <5% *
* soluble fraction <3% *
* Hg <0.2 mg / kg of dry matter *
* Pb <4 mg / kg of dry matter *
* cd <1 mg / kg of dry matter *
* Cu <20 mg / kg of dry matter *
* As <2 mg / kg of dry matter *
* CeVI <1 mg / kg dry matter *
* Sulfates <4000 mg / kg of dry matter *
* Chlorides <2800 mg / kg dry matter *
* TOC <1000 mg / kg dry matter *
* * * * * * * * * * * * * * * * * * * * * * **
If the leachable fractions meet the above thresholds, the machefers are considered to have a low leachable fraction. The corresponding production is then valorisable in public works.

Reference: Circular machefers, Service des
clean technologies and waste from
Ministry of the Environment, project of the
8.4.92.

Table 3: Comparison of European and French standards on landfilling
waste. Threshold concentrations given for the leachable fraction obtained by
German test for European standards (100g of dry waste / 11 of water) and by the
afnor standardized test for French standards (1OOg of raw waste / 11 of water). The
results are expressed in amounts solubilizable in mglkg.

<Tb>

<SEP> Waste <SEP> Standards <SEP> Waste <SEP> no <SEP> Standards
<tb><SEP> dangerous <SEP> French <SEP> dangerous <SEP> French <SEP> Waste
<tb><SEP> nuns <SEP> EEC <SEP> class <SEP> I <SEP> standards <SEP> EEC <SEP> class <SEP> II <SEP> inert
<tb><SEP> mg / kg (1) <SEP> (slag) <SEP> mg / kg (1) <SEP> (ash <SEP> standards <SEP> EEC
<tb><SEP> mg / kg (2) <SEP> flying) <SEP> mg / kg (1)
<tb><SEP> mg / kg (2)
<tb> pH <SEP> 4-13 <SEP> 5-13 <SEP> 4-13 <SEP> - <SEP> 4-13
<tb> DCO <SEP> - <SEP><5000<SEP> - <SEP> - <SEP>
<tb> Loss <SEP> at <SEP> Fire <SEP> - <SEP><5%<SEP> - <SEP> - <SEP>
<tb><SEP> TOC <SEP> 400-2000 <SEP> - <SEP> 400-2000 <SEP><400<SEP><2000
<tb><SEP> arsenic <SEP> III <SEP> 2-10 <SEP><10<SEP> 1-2 <SEP><2<SEP><1
<tb><SEP> lead <SEP> 4-20 <SEP><100<SEP><4<SEP><30<SEP> the <SEP> total
<tb><SEP> cadmium <SEP> 1-5 <SEP><50<SEP><1<SEP><5<SEP> of
<tb><SEP> chromium <SEP> IV <SEP> 1-5 <SEP><100<SEP><1<SEP> - <SEP> these
<tb><SEP> copper <SEP> 20-100 <SEP> - <SEP><20<SEP><20<SEP> elements
<tb> nickel <SEP> 4-20 <SEP><100<SEP><4<SEP> - <SEP> must
<tb><SEP> mercury <SEP> 0.2-1 <SEP><10<SEP><0.2<SEP><0.2<SEP> be
<tb><SEP> zinc <SEP> 20-100 <SEP><500<SEP><20<SEP> - <SEP><50mg / kg
<tb> mercury 0.2-1 zinc 20-100
(1) in mg / kg of dry waste
(2) in mg / kg of raw waste
REFERENCES
- Draft European Directive on the landfill of waste.

 - Draft Ministerial Order on the landfilling of special industrial waste (Class 1). Text of the Ministry of the Environment, ref DEPR / SEI / SDO / AN Feb-31, 14 May 1991.

- Circular on the landfilling of solid residues from the purification of smoke from factories
Incineration of urban residues (Class 11). Text of the Ministry of the Environment, ref
DEPR / SEI / SM / STPD / APR / MBr, 12 June 1991.

TABLE 4: STANDARD LIXIVIATION TEST (WITNESS)
Slag from Strasbourg (ST 1)
Analytical follow-up of extractions

<tb><SEP> Quantity <SEP> Standards <SEP> Standards
<tb><SEP> Parameter <SEP> 1st <SEP> 2nd <SEP> 3rd <SEP> total <SEP> retrieved <SEP> valuation <SEP> in
<tb> Class <SEP> I (1)
<tb><SEP> controlled <SEP> Extraction <SEP> Extraction <SEP> Extraction <SEP> of <SEP> Waste <SEP> Jobs <SEP> Pub.
<tb> Class <SEP> II (2)
<tb><SEP> crude <SEP> (mg / kg) <SEP> (mg / kg <SEP> MS)
<tb> (mg / Kg)
<tb><SEP> Odor <SEP> Odorless <SEP> Odorless <SEP> Odorless <SEP> - <SEP> - <SEP>
<tb><SEP> Color <SEP> Colorless <SEP> Colorless <SEP> Colorless <SEP> - <SEP> - <SEP>
<tb><SEP> pH <SEP> 7.0 <SEP> 6.4 <SEP> 6.0 <SEP> - <SEP> - <SEP>
<tb><SEP> Resistivity <SEP> (Ohm.cm) <SEP> 4000 <SEP> 24000 <SEP> 45000 <SEP> - <SEP> - <SEP>
<tb><SEP> COD <SEP> mg <SEP> O2 / 1 <SEP> 24 <SEP> 0 <SEP> 0 <SEP> 240 <SEP><5000 (1) <SEP>
<SEP> TOC <SEP> mg / l <SEP>#<SEP><SEP>#<SEP>#<SEP>#<SEP><400 (2) <SEP><1000
<tb><SEP> Concentration <SEP> Concentration <SEP> Concentration <SEP> Q. <SEP> tot. <SEP> Extr. <SEP> Standards <SEP> Standards <SEP> Standards
<tb><SEP><SEP><SEP> Elements <SEP> First <SEP><SEP> Third <SEP><SEP> Third <SEP> Waste <SEP> Class <SEP> I <SEP> Class <SEP> II * <SEP> TP (MS)
<tb><SEP> extract <SEP> (mg / l) <SEP> extract <SEP> (mg / l) <SEP> extract <SEP> (mg / l) <SEP> crude <SEP> (mg / kg) ) <SEP> (mg / kg) <SEP> (mg / kg) <SEP> (mg / kg)
<tb><SEP> Lead <SEP> 0.107 <SEP> 0.045 <SEP> 0.004 <SEP> 1.56 <SEP><100<SEP><30<SEP><4
<tb><SEP> Cadmium <SEP> ND <SEP> ND <SEP>, <SEP><SEP><50<SEP><5<SEP><1
<tb><SEP> Zinc <SEP> 0.358 <SEP> 0.095 <SEP> 0.264 <SEP> 7.17 <SEP><500<SEP> - <SEP>
<tb><SEP> Copper <SEP> 2.274 <SEP> 0.611 <SEP> 0.056 <SEP> 29.41 <SEP> - <SEP><20<SEP><20
<tb><SEP> Nickel <SEP> 0.051 <SEP> 0.04 <SEP> 0.068 <SEP> 1.59 <SEP><100<SEP> - <SEP>
<tb><SEP> Chrome <SEP> 0.060 <SEP> 0.000 <SEP> 0.000 <SEP> 0.60 <SEP><100<SEP> - <SEP><1
<tb><SEP> Mercury <SEP><0.003<SEP><0.003<SEP><0.003<SEP><0.03<SEP><10<SEP><0.2<SEP><0.2
<tb><SEP> Cyanides <SEP> NS <SEP> NS <SEP> ND <SEP> - <SEP><10<SEP> - <SEP>
<SEP> Arsenic <SEP> 0.0043 <SEP> 0.0009 <SEP><0.0008<SEP> 0.052 <SEP><10<SEP><2<SEP><2
<tb><SEP> Chloride <SEP> 1.61 <SEP> 1.39 <SEP> 1.96 <SEP> 49.6 <SEP> - <SEP><10000<SEP><2800
<tb><SEP> Sulfates <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP><4000
<tb> * for fly ash from urban waste incineration ND: non-dosable, MS: dry matter
Behavior with solubilization

<tb><SEP> Behavior <SEP><SEP><SEP><SEP> Solubilizable <SEP> Quantities in
<tb><SEP> mg <SEP> by <SEP> Kg <SEP> of <SEP> Waste <SEP> crude
<tb><SEP> Elts <SEP> Dissolu- <SEP> Solubili- <SEP> Solubili- <SEP> Solubili- <SEP> | <SEP> In <SEP> the <SEP> Potentially
<tb><SEP> tion <SEP> total <SEP> sation <SEP> sation <SEP> sation <SEP> solubilizable <SEP> conditions
<tb><SEP> decreasing <SEP> stagnant <SEP> increasing <SEP> of <SEP> test <SEP> (conc.dechet)
<tb> Lead <SEP> X <SEP> 1.56 <SEP> 186
<tb> Zinc <SEP> X <SEP> 7.17 <SEP> 1900
<tb><SEP> Copper <SEP> X <SEP> 29.41 <SEP> 4800
<tb><SEP> Nickel <SEP> X <SEP> 1.59 <SEP> 5800
<tb><SEP> Chrome <SEP> X <SEP> 0.60 <SEP> 20800
<tb><SEP> Arsenic <SEP> x <SEP> 0.052 <SEP> 6.2
<tb><SEP> Chloride <SEP> X <SEP> 49.6 <SEP> 3990
<tb> Sulfates <SEP> - <SEP>
TABLE 5: STANDARD LIXIVIATION TEST (WITNESS)
Slag slag (S II)
Analytical follow-up of extractions

<tb><SEP> Quantity <SEP> Standards <SEP> Standards
<tb><SEP> Parameter <SEP> 1st <SEP> 2nd <SEP> 3rd <SEP> total <SEP> retrieved <SEP> valuation <SEP> in
<tb> Class <SEP> I (1)
<tb><SEP> controlled <SEP> Extraction <SEP> Extraction <SEP> Extraction <SEP> of <SEP> Waste <SEP> Jobs <SEP> Pub.
<tb> Class <SEP> II (2)
<tb> crude <SEP> (mg / kg) <SEP> (mg / kg <SEP> MS)
<tb> (mg / Kg)
<tb><SEP> Odor <SEP> Odorless <SEP> Odorless <SEP> Odorless <SEP> - <SEP> - <SEP>
<tb><SEP> Color <SEP> Yellowish <SEP> Colorless <SEP> Colorless <SEP> - <SEP> - <SEP>
<tb><SEP> pH <SEP> 6.8 <SEP> 7.1 <SEP> 7.6 <SEP> - <SEP> - <SEP>
<tb><SEP> Resistivity <SEP> (Ohm.cm) <SEP> 0 <SEP> 900 <SEP> 3500 <SEP> - <SEP> - <SEP>
<tb><SEP> COD <SEP> mg <SEP> O2 / l <SEP> 84 <SEP> 36 <SEP> 0 <SEP> 1200 <SEP><5000 (1) <SEP>
<SEP> COT <SEP> mg / l <SEP>#<SEP>#<SEP>#<SEP>#<SEP><SEP><400 (2) <SEP><1000
<tb><SEP> Concentration <SEP> Concentration <SEP> Concentration <SEP> Q. <SEP> tot. <SEP> Extr. <SEP> Standards <SEP> Standards <SEP> Standards
<tb><SEP><SEP><SEP> Elements <SEP> First <SEP><SEP> Third <SEP><SEP> Third <SEP> Waste <SEP> Class <SEP> I <SEP> Class <SEP> II * <SEP> TP (MS)
<tb><SEP> extract <SEP> (mg / l) <SEP> extract <SEP> (mg / l) <SEP> extract <SEP> (mg / l) <SEP> crude (mg / kg) <SEP > (mg / kg) <SEP> (mg / kg) <SEP> (mg / kg)
<tb><SEP> Lead <SEP> 0.443 <SEP> 0.116 <SEP> 0.052 <SEP> 6.11 <SEP><100<SEP><30<SEP><4
<tb><SEP> Cadmium <SEP> | <SEP> 0.058 <SEP> 0.015 <SEP> 0.005 <SEP> 0.78 <SEP><50<SEP><5<SEP><1
<tb><SEP> Zinc <SEP> 0.093 <SEP> 0.029 <SEP> 0.028 <SEP> 1.50 <SEP><500<SEP> - <SEP>
<tb><SEP> Copper <SEP> 0.088 <SEP> 0.066 <SEP> 0.034 <SEP> 1.88 <SEP> - <SEP><20<SEP><20<SEP>
<tb><SEP> Nickel <SEP> 0.338 <SEP> 0.085 <SEP> 0.031 <SEP> 4.54 <SEP><100<SEP> - <SEP>
<tb><SEP> Chrome <SEP> 0.100 <SEP> 0.000 <SEP> 0000 <SEP> 1.00 <SEP> L <SEP><SEP><100<SEP> 1 <SEP><1
<tb><SEP> Mercury <SEP><0.003<SEP><0.003<SEP><0.003<SEP><0.03<SEP><10<SEP><0.2<SEP><0.2
<tb><SEP> Cyanides <SEP> NS <SEP> NS <SEP> ND <SEP> - <SEP><10<SEP> - <SEP>
<tb><SEP> Arsenic <SEP><0.0008<SEP><0.0008<SEP><0.0008<SEP><0.008<SEP><10<SEP><2<SEP><2
<tb><SEP> Chloride <SEP> 338.3 <SEP> 85.6 <SEP> 9.5 <SEP> 4333 <SEP> - <SEP><10000<SEP><2800
<tb><SEP> Sulfates <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP><4000
<tb> * for fly ash from incineration of urban waste.

ND: non-dosable, MS: dry matter
Behavior with solubilization

<tb><SEP> Behavior <SEP><SEP> solubilizable <SEP> quantities in
<tb><SEP> mg <SEP> by <SEP> Kg <SEP> of <SEP> waste <SEP> gross <SEP>
<tb><SEP> Elts <SEP> Dissolu- <SEP> Solubili- <SEP> Solubili- <SEP> Solubili- <SEP> In <SEP> the <SEP> Potentially
<tb><SEP> tion <SEP> total <SEP> sation <SEP> sation <SEP> sation <SEP> solubilizable <SEP> conditions
<tb><SEP> decreasing <SEP> stagnant <SEP> increasing <SEP> of <SEP> test <SEP> (conc.dechet)
<tb> Lead <SEP> x <SEP> 6,11 <SEP> 343
<tb> Cadmium <SEP> X <SEP> 0.78 <SEP> 3.4
<tb> Zinc <SEP> X <SEP> 1.50 <SEQ> 948
<tb> Copper <SEP> x <SEP> 1.88 <SEP> 14150
<tb> Nickel <SEP><SEP> 4.54 <SEP> 1523
<tb> Chrome <SEP> X <SEP> 1.00 <SEP> 1092
<tb> Chloride <SEP> X <SEP> 4333 <SEP> 20500
<tb> Sulfates <SEP> - <SEP>
TABLE 6: NORMALIZED LIXIVIATION TEST (WITNESS)
Slag from Saint Vulbas (SV I)
Analytical follow-up of extractions

<tb><SEP> Quantity <SEP> Standards <SEP> Standards
<tb><SEP> Parameter <SEP> 1st <SEP> 2nd <SEP> 3rd <SEP> total <SEP> retrieved <SEP> recovery <SEP> in
<tb> Class <SEP> I (1)
<tb><SEP> controlled <SEP> Extraction <SEP> Extraction <SEP> Extraction <SEP> of <SEP> Waste <SEP> Jobs <SEP> Pub.
<tb> Class <SEP> II (2)
<tb><SEP> crude <SEP> (mg / kg) <SEP> (mg / Kg) <SEP> (mg / kg <SEP> MS)
<tb> Odor <SEP> Odorless <SEP> Odorless <SEP> Odorless <SEP> - <SEP> - <SEP>
<tb><SEP> Color <SEP> Colorless <SEP> Colorless <SEP> Colorless <SEP> - <SEP> - <SEP>
<tb> H <SEP> 9.64 <SEP> ss <SEP> 9.36 <SEP> 8.5 <SEP><SEP> - <SEP> - <SEP> - <SEP>
<tb><SEP> Resistivity <SEP> (Ohm.cm) <SEP> 2222 <SEP> 5435 <SEP> 8695 <SEP> - <SEP> - <SEP>
<tb><SEP> COD <SEP> mg <SEP> O2 / l <SEP> 4 <SEP> 0 <SEP> 0 <SEP> 40 <SEP><5000 (1) <SEP>
<SEQ> COT <SEP> mg / l <SEP> NS <SEP> 1 <SEP> ND <SEP> 10 <SEP><400 (2) <SEP><1000
<tb><SEP> Concentration <SEP> Concentration <SEP> Concentration <SEP> Q. <SEP> tot. <SEP> Extr. <SEP> Standards <SEP> Standards <SEP> Standards
<tb><SEP><SEP><SEP> Elements <SEP> First <SEP><SEP> Third <SEP><SEP> Third <SEP> Waste <SEP> Class <SEP> I <SEP> Hunting <SEP> II * <SEP> TP (MS)
<tb><SEP> extract <SEP> (mg / l) <SEP> extract <SEP> (mg / l) <SEP> extract <SEP> (mg / l) <SEP> crude <SEP> (mg / kg) ) <SEP> (mg / kg) <SEP> (mg / kg) <SEP> (mg / kg)
<tb><SEP> Lead <SEP> 0.086 <SEP> 0.031 <SEP> 0.018 <SEP> 1.35 <SEP><100<SEP><30<SEP><4
<tb><SEP> Cadmium <SEP> 0.008 <SEP> 0.0028 <SEP> 0.0027 <SEP> 0.135 <SEP><50<SEP><5<SEP><1
<tb><SEP> Zinc <SEP> 0.010 <SEP> 0.003 <SEP> 0.0014 <SEP> 0.144 <SEP><500<SEP> - <SEP>
<tb><SEP> Copper <SEP> 0.0024 <SEP> 0.0010 <SEP> 0.0007 <SEP> 0.041 <SEP> - <SEP><20<SEP><20
<tb><SEP> Nickel <SEP> 0.018 <SEP> 0.0084 <SEP> 0.0048 <SEP> 0.312 <SEP><100<SEP> - <SEP>
<tb><SEP> Chromium <SEP> 0.027 <SEP> 0.0096 <SEP> 0.0077 <SEP> 0.443 <SEP><100<SEP> - <SEP><1
<tb><SEP> Mercury <SEP><0.003<SEP><0.003<SEP><0.003<SEP><0.03<SEP><10<SEP><0.2<SEP><0.2
<tb><SEP> Cyanides <SEP> NS <SEP> NS <SEP> ND <SEP> - <SEP><10<SEP> - <SEP>
<tb><SEP> Arsenic <SEP><0.0008<SEP><0.0008<SEP><0.0008<SEP><0.008<SEP><10<SEP><2<SEP><2
<tb><SEP> Chloride <SEP> 54.6 <SEP> 11.9 <SEP> 4.0 <SEP> 705 <SEP> - <SEP><10000<SEP><2800
<tb><SEP> Sulfates <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP><4000
<tb> * for fly ash from incineration of urban waste.

ND: non-dosable, MS: dry matter
Behavior with solubilization

<tb><SEP> Behavior <SEP><SEP> solubilizable <SEP> quantities in
<tb><SEP> mg <SEP> by <SEP> Kg <SEP> of <SEP> Waste <SEP> crude
<tb><SEP> Elts <SEP> Dissolu- <SEP> Solubili- <SEP> Solubili- <SEP> Solubili- <SEP> In <SEP> the <SEP> Potentially
<tb><SEP> tion <SEP> total <SEP> sation <SEP> sation <SEP> sation <SEP> solubilizable <SEP> conditions
<tb><SEP> decreasing <SEP> stagnant <SEP> increasing <SEP> of <SEP> test <SEP> (conc.dechet)
<tb> Lead <SEP> X <SEP> 1.35 <SEP> 190
<tb> Cadmium <SEP> x <SEP> 0.135 <SEP> 1.3
<tb> Zinc <SEP> X <SEP> 0.144 <SEP> 620
<tb> Copper <SEP> X <SEP> 0.041 <SEP> 8800
<tb> Nickel <SEP> X <SEP> 0.312 <SEP> 784
<tb> Chrome <SEP> X <SEP> 0.443 <SEP> 1205
<tb> Chloride <SEP> X <SEP> 705 <SEP>
<tb> Sulfates <SEP> - <SEP>
Tables 4, 5, and 6 are easier to read when the following notes are taken into account, with respect to the four right-hand columns of the middle sub-tables and the lower sub-tables showing that
the "total quantity extracted from the raw waste" in "mg per kg" corresponds for each element to 10 times the sum of the quantities extracted by the three extraction solutions (or extractants) used to treat 100 g of the same waste.

- these numbers are to be compared to the standards in the three right-hand columns of the median sub-tables (which correspond to the values indicated in the columns "French standards class I", "French standards class II" of table 3 and "Standards
Valorisation in Public Works "of Table 2).

 these same numbers are, in the lower sub-tables, compared with the concentrations of the corresponding elements "potentially solubilizable", which are none other than the values corresponding to the same slag and contents taken from Table 1.

 From the examination of Tables 4, 5 and 6, it is therefore possible to draw the following observations as to the possible polluting character of the slags examined as examples. Samples ST 1, SII and SV 1 lead to colorless and odorless leachates. The chemical oxygen demand (COD), mineral and organic pollution index, is 240 mg / l for ST 1, 1200 mg / l for SII and 40 mg / l for SV 1.

 The soluble fraction of the ST 1 slag (Table 4) is likely to induce a pollution constituted by copper (total quantity extracted in mg / kg higher than the class II norm and not in conformity with a valuation in public works), zinc, nickel and chlorides (increasing solubilizations in successive eluates).

 For SII slag leachates (Table 5), all the elements measured show decreasing solubilizations. But they have an elution threshold higher than the European standards for non-hazardous waste for lead (8.72 mg / kg of dry waste), cadmium (1.11 mg / kg of dry waste), chromium ( 1.42 mg / kg of dry waste) and nickel (6.48 mg / kg of dry waste). In addition, these leachates are not in conformity with the legislation which provides for a valuation of the machefers in public works (the lead, the cadmium, the chromium and the chlorides have threshold concentrations too high).

Leachate nevertheless complies with French class II standards.

 The leachates obtained from dried SV 1 slag comply with the aforementioned standards (Table 5).

 It follows from the foregoing that some of these slags belong to a decontamination treatment before any storage, burial or recovery. It should be the same for slag SV 1, even if they already meet the standards tolerated to date, but may not be so in the future.

 The object of the invention is precisely the development of a method allowing the preservation of the environment while limiting the expensive storage of slag, especially in class I discharge. More particularly, it relates to a process for the stabilization of residues. of combustion, whatever its origin, by extraction of the solubilizable metal fraction.

The invention more particularly aims, with reference to the French and European standards in force, to obtain in a particularly simple manner the detoxification or "inerting" of the slag to the point that they can then be stored in class II landfills at as non-hazardous or even recycled waste.

According to a first essential provision of the invention, it consists in first making one or more slag lixiviations, if necessary previously milled to sufficiently small particle sizes, especially at values of less than 50 mm, to allow sufficient contact. between the combustion residues and an aqueous solution or leach liquor, having a sufficient concentration of cations (K +, Na +, Ca2 +) or exchangeable protons in the form of chlorides with the heavy metal cations present in these residues.This leaching must be sufficient to ensure the transformation of at least a portion of the determined metals, especially heavy metals contained in these slags, into soluble chlorides extractable by this leach liquor, and their effective extraction in sufficient proportions for
on the one hand, a standardized elution test subsequently applied to the slag thus treated attests to the decrease of the successively solubilized quantities of each of these metals determined during the repeated extraction tests carried out with a standardized solution of leaching or elution according to this test and,
on the other hand, the sum of the amounts solubilized in the eluates resulting from the extractions with the above-mentioned standardized solution is at values corresponding to concentrations lower than the threshold concentrations also predetermined by the above-mentioned standardized test for each of these metals.

For clarity of language, it has been done in the foregoing and will be done also in the following, a distinction between
"leaching solutions", that is to say extraction solutions containing the aforesaid exchangeable cations or protons and
the "standard elution solutions" corresponding to the solutions implemented in the above-mentioned standardized tests.

 The number of successive elution tests and concentration thresholds (at least for those metals already subject to special standards) are determined by existing or future standard protocols. The standard study protocol used in the present study corresponds to the AFNOR standard (X31210, 1988), the detailed implementation of which was recalled above.

 In this case, the repeated elution tests with the standard solution are then 3 and the standard solution is itself constituted by a demineralized water saturated with air and CO 2 at pH 4.5 and with a resistivity of between 0.2 and 0.4 Nn.cm.

 The elution tests with the standard solution are then carried out by mixing with the treated slag (for example used at a rate of 100 g) for 16 hours and with stirring.

 The exchangeable cations or protons in the form of chlorides of the liquor used for the initial leaching of the slag can be provided in any form to achieve the goal to be accomplished. The leaching solution may consist of dilute hydrochloric acid, more particularly for the treatment of basic slag, for example slag which, when suspended in water for a sufficient time, have the effect to bring the pH to values of the order of 9 to 10.

For neutral slags under the same conditions, it is preferred to use solutions of alkali metal or alkaline earth metal chlorides, rather than hydrochloric acid. Experience shows that hydrochloric acid, even in the diluted state, sometimes tends to attack, more than it should, the matrix or gangue of neutral slag.

It will immediately be apparent to those skilled in the art that the concentrations of exchangeable cation solutions in the form of chlorides, or even the nature of the cation used, (preferably potassium, calcium or other alkali or alkaline earth metal) will most often have to be adjusted. depending on the slag processed, the nature of heavy metals mobilizable.

 In general, the hydrochloric acid concentrations of the acidic solutions applicable to the treatment according to the invention, will have molar concentrations most often in intervals of 0.01 M to 1 M, while concentrations of metal chloride. The alkali or alkaline earth solutions of the corresponding leaching solutions will most often be in the range 0.05 M to 5 M.

 As observed during experiments carried out on various types of slag, a solution of 0.1 N hydrochloric acid is a reagent particularly suitable for the treatment of basic slag, whereas a solution of potassium chloride I M or calcium chloride 0.01 to 2 M, in particular 0.15 M, will allow the extraction of mobilizable metals contained in slags with low acidity.

This static or dynamic leaching (slag / extractant ratio 1.1) will be followed by leachate drainage to a storage pond. They can also be treated themselves as discussed below.

Example:
The slag from the Strasbourg incineration plant (ST 1) was crushed, crushed and then divided to reconstitute a homogeneous average sample size of 0 to 2 mm. The slag from Saint Vulbas (SV 1) was previously dried before being combined into an average sample. Slag slag (SII) was treated as is. Samples of
Strasbourg (ST 1), Salaise II (SII) and Saint-Vulbas (SV 1) have a pH of 10.0, 7.6 and 8.2, respectively.

Experimental set: extraction of exchangeable metals:
The extraction tests are carried out by bottleneck leaching tests or by dynamic lixiviation (with stirring) on 100 g of slag. The reagents used (100 ml per 100 g of slag) are 0.1 N hydrochloric acid, 1 M potassium chloride or 0.15 M calcium chloride. They are left in contact for 2 to 24 hours with slag and can undergo 2 recycling operations (ie at least 3 times 24 hours of slag / extraction liquid contact). The pH, the conductivity and the chemical composition are determined on the leachates obtained. The slag sample is then rinsed with not more than twice 100 ml of distilled water and then the standardized lixiviation test is applied.

Results
The extractants used in the mobility tests form with the slag elements soluble metal chlorides whose formation rate is a function of their solubility constant.

 By way of example, 1M potassium chloride leads to a significant solubilization of calcium and copper in the ST slag. Potassium (excess reagent) and sodium, which are not measured in these tests, have been found, in the assays , be matrix elements having a negative impact on the analyzes (yellow emission in the plasma). The solubilized trace elements are shown in Table 7. In the SII slag, the most mobilizable elements are manganese and magnesium for the major elements, the trace elements being solubilized in variable proportions (Table 7). The analytical disturbance, due to massive solubilization of alkaline earth elements is also noticed in these solutions from SII slag.

 Hydrochloric acid mobilizes metals more efficiently, in particular copper in ST 1 slag.

The dissolution of the alkaline earths by this reagent causes a disruption of the calcium dosage, whereas the yellow emission of the plasma is synonymous with a strong presence of sodium (Table 7).

Table 7: Determination of the mobility of 9 major elements and 7 trace metals
during column leaching engorged with 100g slag per 100
ml of extractant (3 successive passages). Leachate analysis obtained by
determination of the metallic elements in solution with the spectrophotometer
plasma emission. Results expressed in percentage by weight of the contents
initials.

<Tb>

<SEP> Elements <SEP> extracts <SEP> (in <SEP>%) <SEP> by <SEP> || <SEP> Elements <SEP> extracts <SEP> (in <SEP>%) <SEP> by
<tb><SEP><SEP> chloride <SEP> of <SEP> potassium <SEP> 1M <SEP> acid <SEP> hydrochloric acid <SEP> 0.1 <SEP> N
<tb> SEP <SEP> Search <SEP> Scones <SEP> ST <SEP> 1 <SEP> Slag <SEP> S <SEP><SEP> Slag <SEP> ST <SEP> 1 <SEP> Slag <SEP > S <SEP> II <SEP>
<tb> Aluminum <SEP> 0.00 <SEP> 0.00 <SEP> 0.33 <SEP> 0.01
<tb> Calcium <SEP> 0.05 <SEP> 0.00 <SEP> No <SEP> Dosable <SEP> No <SEP> Dosable
<tb> Manganese <SEP> 0.00 <SEP> 0.14 <SEP> 0.41 <SEP> 0.60
<tb> Magnesium <SEP> 0.01 <SEP> 1.05 <SEP> 0.64 <SEP> 5.45
<tb> Iron <SEP> 0.00 <SEP> 0.00 <SEP> 0.17 <SEP> 0.00
<tb> Silicon <SEP> 0.00 <SEP> 0.00 <SEP> 0.19 <SEP> 0.01
<tb> Potassium <SEP> No <SEP> Dosable <SEP> No <SEP> Dosable <SEP> No <SEP> Assayed <SEP> No <SEP> Assayed
<tb> Sodium <SEP> No <SEP> Assay <SEP> No <SEP> Assay <SEP> No <SEP> Assay <SEP> No <SEP> Assayed
<tb> Phosphorus <SEP> No <SEP> Assay <SEP> No <SEP> Assay <SEP> No <SEP> Assay <SEP> No <SEP> Assayed
<tb> Cobalt <SEP> 0.00 <SEP> 0.19 <SEP> 0.02 <SEP> 0.59
<tb> Chromium <SEP> 0.00 <SEP> 0.03 <SEP> 0.00 <SEP> 0.04
<tb> Copper <SEP> 0.02 <SEP> 0.00 <SEP> 10.10 <SEP> 0.00
<tb> Nickel <SEP> 0.00 <SEP> 0.04 <SEP> 0.08 <SEP> 0.32
<tb> Zinc <SEP> 0.00 <SEP> 0.01 <SEP> 0.13 <SEP> 0.04
<tb> Cadmium <SEP> 0.00 <SEP> 0.00 <SEP> 0.00 <SEP> 0.00
<tb> Lead <SEP> ~ <SEP><SEP> 0.00 <SEP> ~ <SEP> 0.18 <SEP> ~ <SEP> 0.49 <SEP> 0.23
<Tb>
Table 8: Determination of the mobility of 9 major elements and 7 trace metals
during the rinsing (2 times 100 ml of distilled water) congested columns
100 g of slag after treatment with 100 ml of extractant. Analysis of
water obtained by metering the metal elements in solution
plasma emission spectrophotometer. Results expressed as a percentage
weight of the initial contents.

<Tb>

<SEP> Elements <SEP> extracts <SEP> (in <SEP>%) <SEP> by <SEP> Elements <SEP> extracts <SEP> (in <SEP>%) <SEP> by
<tb><SEP><SEP> chloride <SEP> of <SEP> potassium <SEP> 1M <SEP> acid <SEP> hydrochloric acid <SEP> 0.1 <SEP> N
<tb> SEP <SEP>SEPs> Slag <SEP> ST <SEP> 1 <SEP> Slag <SEP> S <SEP> II <SEP> Slag <SEP> ST <SEP> 1 <SEP> Slag <SEP > S <SEP> II
<tb> Aluminum <SEP> 0.00 <SEP> 0.00 <SEP> 0.01 <SEP> 0.00
<tb> Calcium <SEP> 0.00 <SEP> 0.00 <SEP> 0.01 <SEP> No <SEP> Dosable
<tb> Manganese <SEP> 0.00 <SEP> 0.02 <SEP> 0.01 <SEP> 0.23
<tb> Magnesium <SEP> 0.00 <SEP> 0.05 <SEP> 0.64 <SEP> 0.51
<tb> Iron <SEP> 0.00 <SEP> 0.00 <SEP> 0.00 <SEP> 0.00
<tb> Silicon <SEP> 0.00 <SEP> 0.01 <SEP> 0.01 <SEP> 0.01
<tb> Potassium <SEP> No <SEP> Dosable <SEP> No <SEP> Dosable <SEP> No <SEP> Assayed <SEP> No <SEP> Assayed
<tb> Sodium <SEP> No <SEP> Assay <SEP> No <SEP> Assay <SEP> No <SEP> Assay <SEP> No <SEP> Assayed
<tb> Phosphorus <SEP> No <SEP> Assay <SEP> No <SEP> Assay <SEP> No <SEP> Assay <SEP> No <SEP> Assayed
<tb> Cobalt <SEP> No <SEP> Assay <SEP> No <SEP> Assay <SEP> No <SEP> Assay <SEP> No <SEP> Assayed
<tb> Chromium <SEP> No <SEP> Assay <SEP> No <SEP> Assay <SEP> No <SEP> Assay <SEP> No <SEP> Assayed
<tb> Copper <SEP> 0.00 <SEP> 0.00 <SEP> 0.59 <SEP> 0.00
<tb> Nickel <SEP> 0.00 <SEP> 0.01 <SEP> 0.01 <SEP> 0.11
<tb> Zinc <SEP> 0.00 <SEP> 0.01 <SEP> 0.07 <SEP> 0.02
<tb> Cadmium <SEP> 0.00 <SEP> 0.00 <SEP> 0.00 <SEP> 0.00
<tb> Lead <SEP> 0.04 <SEP> 0.14 <SEP> 0.07 <SEP> 0.19
<Tb>
The rinsing water is intended to eliminate excess reagents before the implementation of the standardized lixiviation test. During this operation, a low mobility of the elements is to be noted whatever the extractant and slag considered (table 8).

 The percentage of metals that can be mobilized from the slag could not be precisely assessed, but the partial analyzes carried out during the successive passes of the reagents suggested that only a contact between 2 and 24 hours slag / extractant and a single rinsing would be necessary to obtain a stabilization. effective of this waste. This simplification by limiting the number of operations initially planned demonstrates the interest of a single leaching and is an optimization of this process.

Standardized leaching test
Given the objectives set in these examples, the leaching tests must comply with French class II standards and European standards for non-hazardous waste or standards for the valuation of machefers in public works.

 At the end of the two treatments applied on the Strasbourg slag (ST 1) and Salaise II (SII), the standardized lixiviation tests lead to the formation of leachates having a higher resistivity compared to the controls, thus to less effluents. loaded with mineral elements (Figures 1 and 2).

 The reduction in the chemical oxygen demand (COD) is 23% after treatment with potassium chloride on slag of Salaise II (SII), it is 100% for all other treatments and whatever the slag considered ( Figure 3).

It is noted that in Figures 1 and 2 relating to the standardized slag leaching test respectively of Strasbourg (ST 1) and Salaise II (SII), the variation of the resistivity of the leachates before and after treatment with the lixiviation liquor, by showing what were the resistivities expressed in ohm / cm on the y-axes after application of the standardized test (standard
AFNOR X31210, 1988),
- directly on the slag in question (TN),
- slag pre-treated with potassium chloride solution (KCl), and
- slag treated beforehand with hydrochloric acid solution (HCl).

In FIG. 3, the COD abatements (COD% on the y-axis) are also illustrated as a result of the treatment applied to slags of
Strasbourg (ST 1) and Salaise II (SII).

For polluting metallic elements, chlorides and cyanides, the standards require their decreasing solubilization and / or an elution threshold. The determination of these parameters for strongly basic Strasbourg slag (ST 1) shows the following results
the treatment with the potassium chloride solution is manifested by strong extraction of polluting metals; but it is observed that several metals (lead, copper and chromium) as well as chlorides give rise to increasing solubilizations (Table 9),
- On the other hand, treatment with hydrochloric acid (Table 10) increases the solubility of the polluting elements, but the elution threshold imposed with decreasing solubilization remains in accordance with French standards and European standards on non-hazardous waste. corresponding production of machefers would also be worthy of public works.

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

TABLE 9: NORMALIZED LIXIVIATION TEST AFTER KCL TREATMENT
Slag from Strasbourg (ST I)
Analytical follow-up of extra: donations

<tb><SEP> Quantity <SEP> Standards <SEP> Standards
<tb><SEP> Parameter <SEP> 1st <SEP> 2nd <SEP> 3rd <SEP> total <SEP> retrieved <SEP> valuation <SEP> in
<tb> Class <SEP> I (1)
<tb><SEP> controlled <SEP> Extraction <SEP> Extraction <SEP> Extraction <SEP> of <SEP> Waste <SEP> Jobs <SEP> Pub.
<tb> Class <SEP> II (2)
<tb><SEP> crude <SEP> (mg / kg) <SEP> (mg / kg <SEP> MS)
<tb> (mg / Kg)
<tb><SEP> Odor <SEP> Odorless <SEP> Odorless <SEP> Odorless <SEP> - <SEP> - <SEP>
<tb> Color <SEP> Colorless <SEP> Colorless <SEP> Colorless <SEP> - <SEP> - <SEP>
<tb> H <SEP> H <SEP> 7.0 <SEP> 6.4 <SEP> 6.0 <SEP> - <SEP> - <SEP>
<tb><SEP> Resistivity <SEP> (Ohm.cm) <SEP> 30000 <SEP> 45000 <SEP> 60000 <SEP> - <SEP> - <SEP>
<tb><SEP> COD <SEP> mg <SEP> O2 / l <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP><5000 (1) <SEP>
<SEP> COT <SEP> mg / l <SEP>#<SEP><SEP>#<SEP><SEP>#<SEP><SEP>#<SEP><SEP><400<SEP> (2) <SEP><1000
<tb><SEP> Concentration <SEP> Concentration <SEP> Concentration <SEP> Q. <SEP> tot. <SEP> Extr. <SEP> Standards <SEP> Standards <SEP> Standards
<tb><SEP><SEP><SEP> First <SEP> Elements of <SEP> Second <SEP> of <SEP> Third <SEP> of <SEP> Waste <SEP> Class <SEP> I <SEP> Class <SEP> II * <SEP> TP (MS)
<tb><SEP> estrase <SEP> (mg / l) <SEP> extract <SEP> (mg / l) <SEP> extract <SEP> (mg / l) <SEP> crude <SEP> (mg / kg) ) <SEP> (mg / kg) <SEP> (mg / kg) <SEP> (mg / kg)
<tb><SEP> Lead <SEP> 0.044 <SEP> 0.001 <SEP> 0.014 <SEP> 0.59 <SEP><100<SEP><30<SEP><4
<tb> Cadmium <SEP> NS <SEP> NS <SEP> ND <SEP> - <SEP><50<SEP><5<SEP><1
<tb><SEP> Zinc <SEP> 0.282 <SEP> 0.293 <SEP> 0.278 <SEP> 8.53 <SEP><500<SEP> - <SEP>
<tb><SEP> Copper <SEP> 0.676 <SEP> 0.150 <SEP> 0.239 <SEP> 10.65 <SEP> - <SEP><20<SEP><20
<tb><SEP> Nickel <SEP> 0.052 <SEP> 0.031 <SEP> 0.031 <SEP> 1.14 <SEP><100<SEP> - <SEP>
<tb><SEP> Chrome <SEP> 0.060 <SEP> 0.000 <SEP> 0.000 <SEP><SEP> 0.60 <SEP><SEP><100<SEP> - <SEP><1
<tb><SEP> Mercury <SEP><0.003<SEP><0.003<SEP><0M003<SEP><SEP><Q, 03 <SEP><SEP><10<SEP><0.2<SEP> | <SEP><0.2
<tb><SEP> Cyanides <SEP> NS <SEP> NS <SEP> ND <SEP> - <SEP><10<SEP> - <SEP>
<tb><SEP> Arsenic <SEP> 0.0009 <SEP><0.0008<SEP><0.0008<SEP> 0.009 <SEP><10<SEP><2<SEP><2<SEP>
<tb><SEP> Chloride <SEP> 0.8 <SEP> 2.33 <SEP> 0.62 <SEP> 37.5 <SEP> - <SEP><10000<SEP><2800
<tb><SEP> Sulfates <SEP> 1,4 <SEP> 2,2 <SEP><1,0<SEP> 36,0 <SEP> t <SEP> - <SEP><4000
<tb> * relating to fly ash from the inci @ tion of urban waste.

ND: non-dosable, MS: dry matter
Behavior with solubilization

<tb><SEP> Behavior <SEP><SEP> solubilizable <SEP> quantities in
<tb><SEP> mg <SEP> by <SEP> Kg <SEP> of <SEP> Waste <SEP> crude
<tb><SEP> Elts <SEP> Dissolu- <SEP> | <SEP> Solubili- <SEP> Solubili- <SEP> | <SEP> Solubili- <SEP> In <SEP> the <SEP> Potentially
<tb><SEP> tion <SEP> total <SEP> sation <SEP> sation <SEP> sation <SEP> solubilizable <SEP> conditions
<tb><SEP> decreasing <SEP> stagnant <SEP> increasing <SEP> of <SEP> test <SEP> (SEP) <SEP>
<tb> Lead <SEP> x <SEP> 0.59 <SEP> 186
<tb> Zinc <SEP> X <SEP> 8.53 <SEP> 1900
<tb> Copper <SEP> X <SEP> 10.65 <SEP> 4800
<tb> Nickel <SEP> X <SEP> 0.312 <SEP> 5800
<tb> Chrome <SEP> X <SEP> 0.60 <SEP> 20800
<tb> Arsenic <SEP> X <SEP> 0.009 <SEP> 6.2
<tb> Chloride <SEP> x <SEP> 37.5 <SEP> 3990
<tb><SEP> Sulfates <SEP> x <SEP> X <SEP> 36.0 <SEP>
TABLE 10: NORMALIZED LIXIVIATION TEST AFTER TREATMENT IN IICL #
Slag from Strasbourg (ST I)
Analytical follow-up of extractions

<tb><SEP> Quantity <SEP> Standards <SEP> Standards
<tb><SEP> Parameter <SEP> 1st <SEP> 2nd <SEP> 3rd <SEP> total <SEP> retrieved <SEP> valuation <SEP> in
<tb> Class <SEP> I (1)
<tb><SEP> controlled <SEP> Extraction <SEP> Extraction <SEP> Extraction <SEP> of <SEP> Waste <SEP> Jobs <SEP> Pub.
<tb> Class <SEP> II (2)
<tb><SEP> crude <SEP> (mg / kg) <SEP> (mg / kg <SEP> MS)
<tb> (mg / Kg)
<tb> Odor <SEP> Odorless <SEP> Odorless <SEP> Odorless <SEP> - <SEP> - <SEP>
<tb><SEP> Color <SEP> Colorless <SEP> Colorless <SEP> Colorless <SEP><SEP> I <SEP>
<tb><SEP> pH <SEP> 7.0 <SEP> 6.4 <SEP> 6.0 <SEP> - <SEP> - <SEP>
<tb><SEP> Resistivity <SEP> (Ohm.cm) <SEP> 70000 <SEP> 80000 <SEP> 90000 <SEP> - <SEP> - <SEP>
<tb><SEP> COD <SEP> mg <SEP> O2 / l <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP><5000 (1) <SEP>
<tb><SEP> TOC <SEP> mg / l <SEP>#<SEP><SEP>#<SEP>#<SEP>#<SEP><400 (2) <SEP><1000
<tb><SEP> Concentration <SEP> Concentration <SEP> Concentration <SEP> Q. <SEP> tot. <SEP> Extr. <SEP> Standards <SEP> Standards <SEP> Standards
<tb><SEP><SEP><SEP> Elements <SEP> First <SEP><SEP> Third <SEP><SEP> Third <SEP> Waste <SEP> Class <SEP> I <SEP> Class <SEP> II * <SEP> TP (MS)
<tb><SEP> extract <SEP> (mg / l) <SEP> extract <SEP> (mg / l) <SEP> extract <SEP> (mg / l) <SEP> crude <SEP> (mg / kg) ) <SEP> (mg / kg) <SEP> (mg / kg) <SEP> (mg / kg)
<tb><SEP> Lead <SEP> 0.075 <SEP> 0.029 <SEP> 0.015 <SEP> 1.19 <SEP><100<SEP><30<SEP><4
<tb><SEP> Cadmium <SEP> ND <SEP> NS <SEP> ND <SEP> - <SEP><50<SEP><5<SEP><1
<tb><SEP> Zinc <SEP> 0.132 <SEP> 0.070 <SEP> 0.048 <SEP> 2.50 <SEP><500<SEP> - <SEP>
<tb><SEP> Copper <SEP> 0.723 <SEP> 0.295 <SEP> 0.197 <SEP> 12.15 <SEP> - <SEP><20<SEP><20
<tb><SEP> Nickel <SEP> 0.064 <SEP> 0.045 <SEP> 0.041 <SEP> 1.50 <SEP><100<SEP> - <SEP>
<tb><SEP> Chrome <SEP> 0.040 <SEP> 0.000 <SEP> 0.000 <SEP> 0.04 <SEP><100<SEP> - <SEP><1
<tb><SEP> Mercury <SEP><0.003<SEP><0.003<SEP><0.003<SEP><0.03<SEP><10<SEP><0.2<SEP><0.2
<tb><SEP> Cyanides <SEP> NS <SEP> NS <SEP> ND <SEP> - <SEP><10<SEP> - <SEP>
<SEP> Arsenic <SEP> 0.0071 <SEP> Q0025 <SEP><0, OQ08 <SEP><SEP> 0.096 <SEP><10<SEP><2<SEP><2
<tb><SEP> Chloride <SEP> 5.92 <SEP> 1.05 <SEP> 1.00 <SEP> 79.7 <SEP> - <SEP><10000<SEP><2800
<tb><SEP> Sulfates <SEP> 24 <SEP> 2,4 <SEP> 1,2 <SEP> 276 <SEP> - <SEP> - <SEP><4000
<tb> * for fly ash from urban waste incineration @ND: non-dosable, MS: dry matter
Behavior with solubilization

<tb><SEP> Behavior <SEP><SEP> solubilizable <SEP> quantities in
<tb><SEP> mg <SEP> by <SEP> Kg <SEP> of <SEP> Waste <SEP> crude
<tb><SEP> Elts <SEP> | <SEP> Dissolu- <SEP> 0 <SEP><SEP> Solubili- <SEP>: <SEP> Solubili- <SEP> Solubili- <SEP> In <SEP> the <SEP> Potentially <SEP>
<tb><SEP> tion <SEP> total <SEP> sation <SEP> sation <SEP> sation <SEP> solubilizable <SEP> conditions
<tb><SEP> decreasing <SEP> stagnant <SEP> increasing <SEP> of <SEP> test <SEP> (conc.dechet)
<tb> Lead <SEP> x <SEP> 1.19 <SEP> 186
<tb> Zinc <SEP> X <SEP> 2.50 <SEP> 1900
<tb> Copper <SEP> X <SEP> 12.15 <SEP> 4800
<tb> Nickel <SEP> x <SEP> X <SEP> 1.50 <SEP> D <SEP><SEP> 5800
<tb> Chrome <SEP> x <SEP> 0.04 <SEP> 20800
<tb> Arsenic <SEP> X <SEP> 0.096 <SEP> 6.2
<tb> chlorides <SEP> x <SEP> X <SEP> 79.7 <SEP> 3990
<tb> Sulfates <SEP> x <SEP> 276 <SEP>
TABLE 11: NORMALIZED LIXIVIATION TEST AFTER KCL TREATMENT
Slag slag (S II)
Analytical follow-up of extractions

<tb><SEP> Quantity <SEP> Standards <SEP> Standards
<tb><SEP> Parameter <SEP> 1st <SEP> 2nd <SEP> 3rd <SEP> total <SEP> retrieved <SEP> valuation <SEP> in
<tb>Cl; asse <SEP> I (1)
<tb><SEP> controlled <SEP> Extraction <SEP> Extraction <SEP> Extraction <SEP> of <SEP> Waste <SEP> Jobs <SEP> Pub.
<tb> Class <SEP> II (2)
<tb> crude <SEP> (mg / kg) <SEP> (mg / kg <SEP> MS)
<tb> (mg / Kg)
<tb> Odor <SEP> Odorless <SEP> Odorless <SEP> Odorless <SEP> - <SEP> - <SEP>
<tb><SEP> Color <SEP> Colorless <SEP> Colorless <SEP> Colorless <SEP> - <SEP> - <SEP>
<tb> pH <SEP> 7.1 <SEP> 7.1 <SEP> 7.2 <SEP> - <SEP> - <SEP>
<tb><SEP> Resistivity <SEP> (Ohm.cm) <SEP> 800 <SEP> 2600 <SEP> 6000 <SEP> - <SEP> - <SEP>
<tb> COD <SEP> mg <SEP> O2 / l <SEP> 20 <SEP> 8 <SEP> 0 <SEP> 280 <SEP><5000 (1) <SEP>
<SEP> COT <SEP> mg / l <SEP>#<SEP>#<SEP>#<SEP><SEP>#<SEP><400 (2) <SEP><1000
<tb><SEP> Concentration <SEP> Concentration <SEP> Concentration <SEP> Q. <SEP> tot. <SEP> Extr. <SEP> Standards <SEP> Standards <SEP> Standards
<tb><SEP><SEP><SEP> Elements <SEP> First <SEP><SEP> Third <SEP><SEP> Third <SEP> Waste <SEP> Class <SEP> I <SEP> Class <SEP> II * <SEP> TP (MS)
<tb><SEP> extract <SEP> (mg / l) <SEP> extract <SEP> (mg / l) <SEP> extract <SEP> (mg / l) <SEP> crude <SEP> (mg / kg) ) <SEP> (mg / kg) <SEP> (mg / kg) <SEP> (mg / kg)
<tb><SEP> Lead <SEP> 0.181 <SEP> 0.06 <SEP> 0.024 <SEP> 2.65 <SEP><100<SEP><30<SEP><4
<tb><SEP> Cadmium <SEP> 0.023 <SEP> 0.008 <SEP> 0.004 <SEP> 0.35 <SEP><50<SEP><5<SEP><1
<tb><SEP> Zinc <SEP> 0.037 <SEP> 0.017 <SEP> 0.011 <SEP> 0.65 <SEP><500<SEP> - <SEP> - <SEP>
<tb><SEP> Copper <SEP> 0.045 <SEP> 0.036 <SEP> 0.014 <SEP> 0.95 <SEP><SEP> t <SEP><20<SEP><20<SEP>
<tb><SEP> Nickel <SEP> 0.139 <SEP> 0.053 <SEP> 0.028 <SEP> 2.20 <SEP><100<SEP> - <SEP>
<tb><SEP> Chrome <SEP> 0.060 <SEP> 0.000 <SEP> 0.000 <SEP> 0.60 <SEP><100<SEP> - <SEP><1
<tb><SEP> Mercury <SEP><0.003<SEP><0.003<SEP><0.003<SEP><0.03<SEP><10<SEP><0.2<SEP><0.2
<tb><SEP> Cyanides <SEP> NS <SEP> NS <SEP> ND <SEP> - <SEP><10<SEP> - <SEP>
<tb><SEP> IArsenic <SEP><0.0008<SEP><0.0008<SEP> E <SEP><0.0008<SEP><0.008<SEP> | <SEP><10<SEP><2<SEP> D <SEP><2
<tb><SEP> Chloride <SEP> 127.0 <SEP> 17.0 <SEP> | <SEP> 3.2 <SEQ> 1472 <SEP>, <SEP><SEP><10000<SEP><280Q<SEP>
<tb><SEP> Sulfates <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP><4000
<tb> * for fly ash from incineration of urban waste.

ND: non-dosable, MS: dry matter
Behavior with solubilization

<tb><SEP> Behavior <SEP><SEP> solubilizable <SEP> quantities in
<tb><SEP> mg <SEP> by <SEP> Kg <SEP> of <SEP> Waste <SEP> crude
<tb><SEP> Elts <SEP> Dissolu- <SEP> Solubili- <SEP> Solubili- <SEP> Solubili- <SEP> In <SEP> the <SEP> Potentially
<tb><SEP> tion <SEP> to <SEP> sation <SEP> sation <SEP> sation <SEP><SEP> solubilizable <SEP> conditions
<tb><SEP> decreasing <SEP> stagnant <SEP> increasing <SEP> of <SEP> test <SEP> (conc.dechet)
<tb> Lead <SEP> X <SEP> 2.65 <SEP> 343
<tb> Cadmium <SEP> X <SEP> 0.35 <SEP> 3.4 <SEP>
<tb> Zinc <SEP> X <SEP> 0.65 <SEQ> 948
<tb> Copper <SEP> x <SEP> 0.95 <SEP> 1450
<tb> Nickel <SEP> X <SEP> 2.20 <SEP> 1523
<tb> Chrome <SEP> 1 <SEP> 0.60 <SEP> | <SEP> 1092
<tb> Chloride <SEP> X <SEP> 1472 <SEP> 20500
<tb> Sulphates <SEP>
<Tb>
TABLE 12: STANDARD LIXIVIATION TEST AFTER HCL TREATMENT
Slag slag (S II)
Analytical follow-up of extractions

<tb><SEP> Quantity <SEP> Standards <SEP> Standards
<tb><SEP> Parameter <SEP> l <SEP> 2nd <SEP> 3rd <SEP> total <SEP> retrieved <SEP> recovery <SEP> in
<tb> Class <SEP> I (1)
<tb><SEP> controlled <SEP> Extraction <SEP> Extraction <SEP> Extraction <SEP> of <SEP> Waste <SEP> Jobs <SEP> Pub.
<tb> Class <SEP> II (2)
<tb><SEP> crude <SEP> (mg / kg) <SEP> (mg / kg <SEP> MS)
<tb> (mg / Kg)
<tb> Odor <SEP> Odorless <SEP> Odorless <SEP> Odorless <SEP> - <SEP> - <SEP>
<tb><SEP> Color <SEP> Colorless <SEP> Colorless <SEP> Colorless <SEP> - <SEP> - <SEP>
<tb><SEP> pH <SEP> 6.8 <SEP> 6.6 <SEP> 6 <SEP> 6 <SEP>
<tb> Resistivity <SEP> (Ohm.cm) <SEP> 1000 <SEP> 3000 <SEP> 6000 <SEP> - <SEP> - <SEP>
<tb><SEP> COD <SEP> mg <SEP> O2 / l <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 280 <SEP><5000 (1) <SEP>
<SEP> COT <SEP> mg / l <SEP>#<SEP><SEP>#<SEP><SEP>#<SEP>#<SEP><SEP><400 (2) <SEP><1000
<tb><SEP> Concentration <SEP> Concentration <SEP> Concentration <SEP> Q. <SEP> tot. <SEP> Extr. <SEP> Standards <SEP> Standards <SEP> Standards
<tb><SEP><SEP><SEP> Elements <SEP> First <SEP><SEP> Third <SEP><SEP> Third <SEP> Waste <SEP> Class <SEP> I <SEP> Class <SEP> II * <SEP> TP (MS)
<tb><SEP> extract <SEP> (mg / l) <SEP> extract <SEP> (mg / l) <SEP> extract <SEP> (mg / l) <SEP> crude <SEP> (mg / kg) ) <SEP> (mg / kg) <SEP> (mg / kg) <SEP> (mg / kg)
<tb><SEP> Lead <SEP> 0.421 <SEP> 0.156 <SEP> 0.058 <SEP> 6.35 <SEP><100<SEP><30<SEP><4
<tb><SEP> Cadmium <SEP> 0.056 <SEP> 0.020 <SEP> 0.007 <SEP> 0.83 <SEP><50<SEP><5<SEP><1
<tb><SEP> Zinc <SEP> 0.118 <SEP> 0.044 <SEP> 0.038 <SEP> 2.00 <SEP><500<SEP> - <SEP>
<tb><SEP> Copper <SEP> 0.071 <SEP> 0.048 <SEP> 0.023 <SEP> 1.42 <SEP> - <SEP><20<SEP><20
<tb><SEP> Nickel <SEP> 0.913 <SEP> 0.259 <SEP> 0.122 <SEP> 12.94 <SEP><100<SEP> - <SEP>
<tb><SEP> Chromium <SEP> 0.020 <SEP> 0.010 <SEP> 0.000 <SEP> 0.30 <SEP><100<SEP> - <SEP><1
<tb><SEP> Mercury <SEP><0.003<SEP><0.003<SEP><0.003<SEP><0.03<SEP><10<SEP><0.2<SEP><0.2
<tb><SEP> Cyanides <SEP> NS <SEP> NS <SEP> ND <SEP> - <SEP><10<SEP> - <SEP>
<tb><SEP> Arsenic <SEP><0.0008<SEP><0.0008<SEP><0.0008<SEP><0.008<SEP><10<SEP><2<SEP><2
<tb><SEP> Chloride <SEP> 33.3 <SEP> 17.2 <SEP> 7.8 <SEP> 583 <SEP> - <SEP><10000<SEP><2800
<tb><SEP> Sulfates <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP><4000
<tb> * for fly ash from urban waste incineration @ND: non-dosable, MS: dry matter
Behavior with solubilization

<tb><SEP> Behavior <SEP><SEP> solubilizable <SEP> quantities in
<tb><SEP> mg <SEP> by <SEP> Kg <SEP> of <SEP> Waste <SEP> crude
<tb><SEP> Elts <SEP> Dissolu- <SEP> Solubili- <SEP> Solubili- <SEP> Solubili- <SEP> In <SEP> the <SEP> Potentially
<tb><SEP> tion <SEP> total <SEP> sation <SEP> sation <SEP> sation <SEP> solubilizable <SEP> conditions
<tb><SEP> Decreasing <SEP> Increasing <SEP> Increasing <SEP> of <SEP> Testing <SEP> (SEP) <SEP>
<tb> Lead <SEP> X <SEP> 6.35 <SEP> 343
<tb> Cadmium <SEP> X <SEP><SEP> 0.83 <SEP> 3.4
<tb> Zinc <SEP> x <SEP> 2.00 <SEP> 948
<tb><SEP> Copper <SEP> X <SEP> 1.42 <SEP> 1450
<tb> Nickel <SEP> X <SEP> 0.30 <SEP> 1523
<tb> Chrome <SEP> x <SEP> o, 60 <SEP> 1092
<tb> Chloride <SEP> X <SEP><SEP> 583 <SEP> 20500
<tb> Sulphates
<Tb>
CONCLUSIONS:
Depending on the leaching tests carried out on the slag and on their foreseeable Class II storage or recycling, the following conclusions (Table 13) can be drawn from the previous experiments, after application to the treated or "inertised" slag, of the study according to the aforementioned AFNOR standard
- Strasbourg slag (ST I) without prior treatment generate eluates whose toxicity thresholds are higher than the French class II standards, in addition to European standards. These eluates are, moreover, not in conformity with the legislation which provides for a valuation of the slag in public works. After the slag has been pretreated with hydrochloric acid, the eluates produced comply with the French class II standards, the European standards on non-hazardous waste, the treated slag may also be recycled in public works.

 - Slag II slag (S II) without prior treatment generates eluates whose toxicity thresholds are lower than the French class II standards but higher than the European standards for non-hazardous waste and the valuation standards in public works. After treatment with potassium chloride, the eluates produced comply with European standards and recycling standards of machefers.

Table 13: Summary of the results obtained during slag treatment. Comparison of the results of their leaching with the European and French standards on the landfill of waste. Limit concentrations given for the leachable fraction obtained by the German test for European standards (100g of dry waste / 1l of water) and by the afnor standardized test for French standards (100g of raw waste / 1l of water). The results are expressed in amounts that can be solubilized in mg / kg.

Waste <SEP> Standards <SEP> Waste <SEP> no <SEP> Standards <SEP> Standards <SEP> Slag <SEP> SII4
<tb> hazardous <SEP> English <SEP> hazardous <SEP> English <SEP> Waste <SEP> recovery <SEP> Slag <SEP> STI3 <SEP> Slag <SEP> STI3 <SEP> Slag <SEP> SII4 <SEP > after <SEP> Slag <SEP> SV <SEP> 1
<tb> standards <SEP> EEC <SEP> class <SEP> I <SEP> standards <SEP> CEE <SEP> class <SEP> II <SEP> inert <SEP> in <SEP> work <SEP> without <SEP > after <SEP> without <SEP> treatment <SEP> 5 <SEP> dried <SEP> without
<tb> mg / kg (1) <SEP> (slag) <SEP> mg / kg (1) <SEP> (ash <SEP> standards <SEP> EEC <SEP> public <SEP> treatment <SEP> treatment <MS> treatment <SEP> KCl <SEP> treatment
<tb> mg / kg (2) <SEP> flies) <SEP> mg / kg (1) <SEP> mg / kg (1) <SEP> mg / kg (2) <SEP> HCl <SEP> mg / kg kg (2) <SEP> mg / kg (2) <SEP> mg / kg (1)
<tb> mg / kg (2) <SEP> mg / kg (2) <SEP> (mg / kg (1)) <SEP> (mg / kg (1))
<tb> pH <SEP> 4-13 <SEP> 5-13 <SEP> 4-13 <SEP> - <SEP> 4-13 <SEP> - <SEP> 6.5 <SEP> 7 <SEP> 7 , 1 <SEP> 7.1 <SEP> 9.6
<tb> COD <SEP> - <SEP><5000<SEP> - <SEP> - <SEP> - <SEP> - <SEP> 240 <SEP> 0 <SEP> 1200 <SEQ> 280 <SEP> 40
<tb> Loss <SEP> at <SEP> Fire <SEP> - <SEP><5%<SEP> - <SEP> - <SEP> - <SEP><5%<SEP>#<SEP>#<SEP> 13.36 <SEP> - <SEP> 12.68
<tb> TOC <SEP> 400-2000 <SEP> - <SEP> 400-2000 <SEP><400<SEP><2000<SEP><1000<SEP>#<SEP>#<SEP>#<SEP>#<SEP> 10
<tb> arsenic <SEP> III <SEP> 2-10 <SEP><10<SEP> 1-2 <SEP><2<SEP><1<SEP><2<SEP> 0.052 <SEP> 0.096 <SEP ><0.008<SEP><0.008<SEP><0.008
<tb> Lead <SEP> 4-20 <SEP><100<SEP><4<SEP><30<SEP> The <SEP> Total <SEP><4<SEP> 1.56 <SEP> 1.19 <SEP> 6.11 <SEP> (8.72) <SEP> 2.65 <SE> (3.78) <SEP> 1.350
<tb> cadmium <SEP> 1-5 <SEP><50<SEP><1<SEP><5<SEP> of <SEP><1<SEP> 0.00 <SEP> 0.00 <SEP> 0 , 78 <SEP> (1,11) <SEP> 0.35 <SEP> (0.50) <SEP> 0.135
<tb> chromium <SEP> IV <SEP> 1-5 <SEP><100<SEP><1<SEP> - <SEP> these <SEP><1<SE<0.60<SEP> 0.04 <MS> 1.00 <SEP> (1.42) <SEP> 0.60 <SEP> (0.85) <SEP> 0.443
<tb> copper <SEP> 20-100 <SEP> - <SEP><20<SEP><20<SEP> elements <SEP><20<SEP> 29.41 <SEP> 12.15 <SEP> 1, 88 <SEP> (2.68) <SEP> 0.95 <SEP> (1.35) <SEP> 0.041
<tb> nickel <SEP> 4-20 <SEP><100<SEP><4<SEP> - <SEP> must <SEP> - <SEP> 1.59 <SEP> 1.50 <SEP> 4.54 <SEP> (6.48) <SEP> 2.20 <SEP> (3.14) <SEP> 0.312
<tb> mercury <SEP> 0.2-1 <SEP><10<SEP><0.2<SEP><0.2<SEP> be <SEP><0.2<SEP><0.03<MS><0.03<SEP><0.03<SEP>(<0.03)<SEP> 0.03 <SEP>(<0.03)<SEP><0.03
<tb> zinc <SEP> 20-100 <SEP><500<SEP><20<SEP> - <SEP><50mg / kg <SEP> - <SEP> 7.17 <SEP> 2.50 <SEP> 1.50 <SEP> (2.14) <SEP> 0.65 <SEP> (0.92) <SEP> 0.144
<tb> phenols <SEP> 200-1000 <SEP> - <SEP> 100-200 <SEP> - <SEP><100<SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <MS> fluorine <SEP> 100-500 <SEP> - <SEP> 50-100 <SEP> - <SEP><50<SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP > ammonium <SEP> 2-10 <SEP> - <SEP>? <SEP> - <SEP><500<SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> chlorides <SEP> 12000-60000 <SEP> - <SEP> 5000-12000 <MS><10000<SEP><5000<SEP><2800<SEP> 49.6 <SEP> 79.7 <SEP> 4333 <SEP> (6190) <SEP> 1472 <SEP> (2102) <SEP> 705
<tb> cyanide <SEP> 2-10 <SEP> - <SEP> 1-2 <SEP> - <SEP><1<SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> sulphates <SEP> 2000-10000 <SEP> - <SEP> 2000-10000 <SEP> - <SEP><10000<SEP><4000<SEP> - <SEP> 276 <SEP> - <SEP> - <SEP> nitrites <SEP> 60-300 <SEP> - <SEP> 30-60 <SEP> - <SEP><30<SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP >
AOX <SEP> 6-30 <SEP> - <SEP> 3-6 <SEP> - <SEP><3<SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> solvents <SEP> Cl <SEP> 0.2-1 <SEP> - <SEP> 0.1-0.2 <SEP> - <SEP><0.1<SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> pesticides <SEP> Cl <SEP> 0.01-0.05 <SEP> - <SEP> 0.005-0.01 <SEP> - <SEP><0.005<SEP> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> sub <SEP> lipophilic <SEP> 4-20 <SEP> - <SEP> 4-10 <SEP> - <SEP><10<MS> - <SEP> - <SEP> - <SEP> - <SEP> - <SEP> (1) in mg / kg of dry waste 3,5 moisture content <1% (2) in mg / kg of gross waste 4 moisture content # 30%
The leachates resulting from the application of the leaching process contain salts of metal chlorides and an excess of extractant.The average composition of leachates and rinsing water, all treatments combined, obtained during our experiments on 100 g of slag, is given in Table 14.

 However, and according to a further preferred embodiment of the invention, these metals are biosorbed out of these leachates. Indeed, these metals are in a form very accessible to a number of biosorbents. In other words, the process according to the invention is advantageously completed by an additional step of biosorption of the leached metals out of the treated slag, as described above.

Table 14: Chemical analysis of leachates and rinsing waters.

Average composition obtained from different
treatments carried out on Strasbourg slag (ST 1) and
Salaise II (S II).

<Tb>

<SEP> LIXIVIATS <SEP> WATERS <SEP> FROM <SEP> RINSE
<tb> pH <SEP> | <SEP> 1.86 <SEP> to <SEP> 9.37 <SEP> 4.30 <SEP> to <SEP> 8.94
<tb><SEP> Concentration <SEP> in <SEP> mg / l <SEP> Concentration <SEP> in <SEP> m <SEP>
<tb> Aluminum <SEP> 0.4 <SEP> to <SEP> 170 <SEP> 0.09 <SEP> to <SEP> 3.06
<tb> Iron <SEP> 0.5 <SEP> to <SEP> 415 <SEP> 0.06 <SEP> to <SEP> 10.78
<tb> Magnesium <SEP> 1.4 <SEP> to <SEP> 288 <SEP> 0.12 <SEP> to <SEP> 27.76
<tb> Manganese <SEP> 0.02 <SEP> to <SEP> 60 <SEP> 0.03 <SEP> to <SEP> 20.52
<tb> Silicon <SEP> 2.6 <SEP> to <SEP> 256 <SEP>?
<tb> Calcium <SEP>? <SEP>?
<tb> Sodium <SEP>? <SEP>?
<tb> Copper <SEP> 0.1 <SEP> to <SEP> 484 <SEP> 0.08 <SEP> to <SEP> 28.44
<tb> Zinc <SEP> 0.04 <SEP> to <SEP> 2.4 <SEP> 0.05 <SEP> to <SEP> 1.26
<tb> Lead <SEP> 0.6 <SEP> to <SEP> 0.9 <SEP> 0.07 <SEP> to <SEP> 0.60
<tb> Nickel <SEP> 0.6 <SEP> to <SEP> 4.7 <SEP> 0.02 <SEP> to <SEP> 1.56
<tb> Chrome <SEP> 0.3 <SEP> to <SEP> 0.5
<tb> Cobalt <SEP> 0.18 <SEP> to <SEP> 1.21
<tb> Cadmium <SEP> 0 <SEP> 0
<Tb>
In this respect, it is recalled that biosorption is the sequestration of metal ions by a solid material of natural origin. This general term includes a wide variety of mechanisms: particle ingestion, active ion transport, complexation, adsorption and inorganic precipitation on the biosorbent.

 A biosorbent whose use seems particularly advantageous is chitosan.

 Chitosan is the main derivative of chitin (poly N-acetyl D-glucosamine). It is a saccharide polymer consisting of a long linear polymer chain with glucosamine units, linked by ss (1-4) glucosidic bridges.

 Little present in nature, chitosan is obtained by deacetylation of chitin, itself extracted from the exoskeleton of crustaceans, myriapods and other arthropods or even microorganisms, fungi.

 From the diversity of sources of chitin, there is a great variety of potential qualities of chitosan.

 The deacetylation rate ranging from 80 to 100% and the average molecular weight of 5,000 to 1,000,000 result in the possibility of fixing the turbidity, viscosity and solubility of the solutions. This solubility of chitosan, with a low degree of N-acetylation, is obtained only in dilute acid medium in the pH range <6.

It is related to the presence of amine functions on the C-2 glucosidic units, conferring on this polymer a low polybase behavior.

Several authors admit that the use of chitosan in water treatment is indeed a way forward. A product seems to be currently developed in Europe in this sense, it is PRO FLOCTM (Protan). Its characteristics are the following flakes / powder; free amine form (-NH2), medium purity. In Japan, chitosan (chitosan beads, Fujibo
Inc., Shizuoka) is used in domestic and industrial water treatment. Another form of usable chitosan (which has been used in the preliminary tests reported hereinafter) is SIGMAR chitosan (ref: C.0792). But other biosorbents can be used in place of chitosan. For example, some of the biosorbents identified below may be used. Their biosorption characteristics do not always coincide with those of chitosan. The choice of the most appropriate biosorbent will often result from the leachate contents obtained by applying the first part of the process according to the invention to the slags that were to be treated.

Preliminary tests were carried out with different biosorbents able to fix metals: chitin
SigmaR (ref: C.3387), chitosan SigmaR (ref: C.0792), fungal biomass with chitosan walls (Rhizopus arrhizus), bacterial biomass (Zoogloea ramigera) and feather meal.

Methodology:
In 250 ml plasma flasks, we introduce 100 ml of a saline solution (Cobalt: Co (NO3) 2 or
Chromium: Cr (NO3) 2, 9H2O or Copper: CuSO4, 5H20 or Zinc
ZnSO 4, 5H 2 O or Cadmium: 3CdSO 4, 8H 2 O or lead (Pb (NO 3) 2 at 100 mg / l adjusted to pH 4.0 and 100 mg of biosorbents (ie 1 g / l) as is or ground.

 The incubation is carried out at 25 ° C. with gentle agitation, The samples are taken after 3, 6, 12, 24, 48 and 72 hours of contact.

 The analysis of the elements in solution is carried out by plasma emission spectrophotometry.

 Figures 4 to 9 provide relative curves, adsorption kinetics respectively of lead, copper, chromium, cobalt, zinc and cadmium on different biosorbents.

The following salts were respectively used
- lead nitrate (Figure 4),
- copper sulphate (Figure 5),
chromium nitrate (FIG. 6),
cobalt nitrate (FIG. 7),
- zinc sulphate (FIG. 8),
- cadmium sulphate (Figure 9).

 The figures are representative of the respective variations of the absorbed metal (in% of the initial content on the ordinate axis) as a function of time (in hours tH) on the abscissa axis.

Results:
By choosing initial conditions that were unfavorable for biosorption (initial pH 4.0), the various metals tested at a salt / biosorbant weight ratio of 0.1 gave the following results:
- the lead is quickly fixed by Zoogloea will barge at a rate of 75% in 5 hours; chitin and feather flour accumulate up to 30% and the fixation stops for further kinetics. R.arrhizus regularly fixed this metal to reach 80% after 72 hours.

 Chitosan does not appear to immobilize lead under the conditions of the experiment (Figure 4).

 copper has a very similar behavior with regard to chitin, fungal and bacterial biomasses and feather flours; its immobilization is close to 10% and remains practically constant. Chitosan is the best copper adsorbent and takes a colored hue in its presence, 50% of copper sulfate is chelated in 72 hours (Figure 5).

 chromium alone has an affinity for chitosan and its adsorption reaches 6% in 72 hours of incubation (FIG. 6).

 cobalt has an alternating adsorption and desorption profile for all the biosorbents tested. The fixed percentage varies between 2 and 8% (Figure 7).

 zinc has a good affinity for Rhjzoous arrhizus and chitosan (10% adsorbed in 72 hours of incubation). The other polymers do not chelate zinc either at the chosen concentrations or at the fixed parameters (FIG. 8).

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

 it follows from the comparative examination of the above-mentioned curves that one can, by the choice of the biosorbents used in these preliminary tests, deal with the treatment of all the leachates obtained resulting from the treatment of slag by a solution containing chloride ions, whatever may be their respective levels of polluting metals.

 It can also be noted that some of the biosorbents used may be slightly active under certain conditions, but the fate in others. This is the case, for example, for chitosan with respect to lead and copper.

 Some of the biosorbents are of particular interest, especially when they can be regenerated.

In this respect, chitosan is of particular effectiveness. The tests briefly reported below demonstrate the ability of chitosan to be regenerated by treatment with an exchange reagent or an acid.

 Another parameter may in particular reside in the bringing of greater amounts of biosorbents vis-à-vis the element to extract. This is also the case for lead and zinc. Under the conditions of the experiment carried out as indicated below, the amount of lead absorbed can increase considerably when the relative proportion of the biosorbent increases with respect to the concentration of metal to be adsorbed.

methodologies:
In 250 ml flasks, 100 ml of saline solution (metals tested: CuSO 4, 5H 2 O, ZnSO 4, 5H 2 O, CdSO 4, 8H 2 O, Pb (NO 3) 2, NitO 4, 6H 2 O) are introduced, on the one hand, to pH4.0 (with the acid corresponding to the conjugate base), is left at its own pH, and secondly, respectively 100, 200, 400 and 800 mg of chitosan. After incubation for 24 hours at 25 ° C. with gentle stirring, the preparation is centrifuged and 20 ml of the supernatant are taken for assay using a plasma emission spectrophotometer.The "800 mg" pellet is stored to measure the desorption.

 On this, 20 ml of distilled water are added and then the whole is stirred for 1 hour before being centrifuged. The supernatant is analyzed and the pellet taken up in a solution of 0.1M ammonium sulphate and / or 1N hydrochloric acid. After further stirring, the analysis of the supernatant is repeated.

Results:
Copper is the element that has the best affinity for chitosan; with a salt / biosorbent ratio of 0.8 the chelation of the metal is practically complete in 24 hours of contact. the value of the initial pH does not seem to affect the fixing capacities of the biosorbant, however its basic power tends to orient the pH of the medium towards values close to 7 where the competition for the protons becomes less.

 The desorption using ammonium sulphate is weak, thus proving that the fixed metal is difficult to exchange. The modification of the pH by addition of hydrochloric acid tends to ionize the intervening groups and lead to the release of the chelated metal. Not taking into account the losses during the experiment, the recovery percentage is around 80 t. In addition, the hydrochloric acid used to shift the equilibrium of the reaction appears to alter the structure of chitosan because a slight disintegration of the product has been observed. According to the literature data, sulfuric acid could be effective in displacing the chemical equilibrium of the reaction without solubilizing chitosan.

 Zinc, another element tested, has a lower affinity compared to copper and its percentage of fixation reaches 60% in 24 hours for a salt / biosorbant ratio of 0.8. The pH of the medium evolves identically to the experiments with copper.

 Water desorption appears to be a wash rather than an active desorption. Zinc is slightly exchangeable but mobilization becomes effective by addition of acid.

 Among the elements tested, cadmium behaves similar to zinc, its degree of fixation reaches 60% in 24 hours for an identical salt / biosorbent ratio.

 With the exchange reagent, cadmium is strongly desorbed; its desorption becomes total by adding hydrochloric acid. The use of acid as the sole desorption reagent does not seem sufficient to extract all of the fixed metal.

 Lead is adsorbed at 91% for a salt / biosorbent ratio of 0.8. This metal is weakly exchangeable, it is partly mobilized by adding hydrochloric acid.

 Nickel has a lower affinity for chitosan, its fixation percentage reaches 60% in 24 hours for a salt / biosorbent ratio of 0.8. Its desorption is effective (78%) following the displacement of the reaction equilibrium by addition of hydrochloric acid.

 The results obtained make it possible to envisage the industrialization of the biosorption stage of the pollutant metals contained in the leachates obtained at the end of the "initialization" stages of the initial slags.

 Figure 10 is a block diagram of an industrial device that can be envisaged for this purpose.

The leachates will be directed to a reactor containing the chitosan or to a mixed device comprising in a separate reactor or in a mixture another biosorbent (e.g., stabilized biomass). This will be equipped with a recycling loop in order to obtain a complete purification of the waters. These metals-free waters may be discharged into the river or possibly recycled as slag rinsing water.

 By analogy with ion exchange resins, the chitosan will be regenerated by desorption of the metals using an acid eluent, possibly followed by a repackaging of the biosorbent by adding sodium hydroxide.

Regeneration will be performed alternately on one of the treatment chains (lane I or II). The acid eluate will be directed to a storage tank before ultimate solidification but recovery of metals and recycling of water may be considered later.

 It follows from the foregoing that the process according to the invention leads to combustion residues which, after treatment, comply with the definition of European inert waste and / or comply with the values leading to a product that can be used in public works.

 On the other hand, the mobile fraction of heavy metals initially contained in the residues was concentrated in a mass very much lower than the initial mass of slag.

 Finally the treatment does not lead to a pollution transfer in the natural environment.

Claims (12)

 on the other hand, the sum of the amounts solubilized in the eluates resulting from the extractions with the above-mentioned standardized solution is at values corresponding to concentrations lower than the equally predetermined threshold concentrations for each of these metals and for the other fixed parameters. by the standards.  on the one hand, a standardized elution test subsequently applied to the slag thus treated attests to the decrease of the successively solubilized quantities of each of these metals determined during the repeated extraction tests carried out with a standardized elution solution in accordance with this test and,  1. A method for stabilizing combustion residues, especially slag from any source, and particularly by extraction of solubilizable metal fractions, characterized by carrying out one or more slag leachings, previously if necessary, ground to sufficiently small particle sizes, especially at values less than 50 mm, to allow sufficient contact between the combustion residues and an aqueous solution or leach liquor, having a sufficient concentration of elements, either cations (K +, Na +, Ca2 +), or exchangeable protons in the form of chlorides with the heavy metal cations present in these residues, this leaching being sufficient to ensure the transformation of at least a part of the determined metals, especially heavy metals contained in the combustion residues, into soluble chlorides and which are extractable by this leach liquor, and their extraction effectively in sufficient proportions to ensure that  2. Method according to claim 1, characterized in that the aforesaid standard elution test comprises three extraction tests carried out with a standard solution itself consisting of demineralized water saturated with air and CO2 at pH 4.5 and resistivity between 0.2 and 0.4 Mn.cm.  3. Method according to claim 1 or claim 2, characterized in that the leaching solution or treatment consists of a dilute hydrochloric acid solution, more particularly for the treatment of basic slag.  4. Method according to claim 3, characterized in that the hydrochloric acid concentration of the slag lixiviation solution has a molar concentration in the range of 0.01 M to 1 M, in particular of the order of 0.1. Mr.  5. Method according to claim 1 or claim 2, characterized in that the leaching solution or treatment consists of a solution of alkali metal or alkaline earth metal chloride, more particularly for the treatment of neutral slag.  6. Method according to claim 5, characterized in that the leaching solution or treatment consists of a solution of potassium chloride.  7. Process according to claim 6, characterized in that the concentration of alkali metal or alkaline-earth metal chloride of the leaching or treatment solution is in the range 0.05 M to 5 M.  8. Method according to claim 7, characterized in that the alkali metal chloride is potassium chloride, and that its concentration is of the order of 1 M.  9. Method according to claim 7, characterized in that the alkali metal chloride is calcium chloride, and that its concentration is in the range of 0.05 to 5 M, in particular is of the order of 0.15. Mr.  10. Process according to any one of claims 1 to 9, characterized in that the leaching solutions collected from the treated slag are biosorbed with biosorbents capable of sequestering at least a large part of the metal ions. heavy metals extracted from these slags.  11. Process according to claim 10, characterized in that the biosorbent is based on chitosan.  12. Process according to claim 10, characterized in that the biosorbents are biomasses, in particular fungi or bacteria, derived from biological cultures or fermentations.