FR2754747A1 - Treatment of solid waste from incineration of domestic wastes - Google Patents

Abstract

Cinders and smoke from the combustion of domestic waste are collected and identified. Any pollutants from the residues are removed or neutralised. This neutralisation takes place in a vessel (1) with walls of filter material where cinders and smoke waste are held. Water (which may be heated) is pumped (3) from nozzles (2) over the waste and is collected in a vessel (4) below, from where it may be recycled or drawn off. Electrolysis may be carried out by electrodes (8) in the vessel.

Description

RESIDUE TREATMENT PROCESS
OF HOUSEHOLD GARBAGE INCINERATION AND
IMPLEMENTATION DEVICE
The invention relates to the technical sector of processing
household waste.

The legislation currently in force requires dealing with
household waste incineration fumes, to avoid pollution
of all kinds that they entail. To date, incineration residues
household waste is subjected to different treatments capable of
render inert and then be landfilled. It therefore appears that these
residues which are rendered inert are not reused and cannot be
rest, not be reused for various applications.

We also know that waste incineration waste
housewives are of variable compositions according to their origin and
incineration processes implemented. Especially the mints
incineration of household waste and smoke residues
household waste incineration are characterized by the parameters
following:
- granulometric and sedimentometric composition
- chemical and mineralogical composition,
- state of the metals (soluble solid or ionic phase, oxidized or not, bound or not ...)
- the state of toxic compounds (identification, chemical stability, solubility, molar mass, particle size, etc.)
From this state of the art, the problem that arises
to solve the invention is to avoid the mass landfill of
waste or residues and get an increasing amount of ultimate waste
more reduced and which would tend to become zero with the objective of
be able to recover this waste for various applications.

To solve such a problem, it was designed and developed a
household waste incineration residue treatment process,
remarkable for the following essential stages, according to which:
- the household waste incineration clinkers and the residues of household waste incineration fumes are identified,
- extract and / or neutralize any polluting element contained
in said machefers and / or said residues.

Depending on the nature and composition of the chews
incineration and residues of incineration fumes, we proceed to
any one, or any combination, of the phases of
following treatment:
- hydration and carbonation of lime to obtain an insoluble calcium carbonate,
- heavy metal extraction,
- destruction or extraction of toxic chemical compounds.

Given the technical solution used, namely
extraction or neutralization of polluting elements, we proceed
then to a compaction of the minces and fines, separately or
together, which we can then landfill with the residues,
according to their legal classification.

In an advantageous form of application, the mass is used
non-polluting mineral for making building materials.

To solve the problem of ensuring the extraction and / or the
neutralization of polluting elements contained in particular in
smoke residues but also in the machefers, we proceed
as following:
- we have the household waste incineration minces
and / or the residues from the incineration fumes of household waste in a filter tank,
- we water them continuously,
- the filtering water is collected in order to sprinkle said machefers and / or said residues again,
- the filtering water is drained,
- operations are repeated until the sample no longer presents any polluting material other than in legally permissible proportions.

 According to another characteristic, for the oxidation of certain toxic compounds as well as for the hydration and carbonation of lime, there are the household waste incineration minces and / or the residues of the incineration fumes of household waste in a tank in the presence of water, inside which a gaseous bubbling is caused by injection of air and / or ozone and / or carbon dioxide resulting from the combustion of the garbage after dedusting, the temperature is optionally raised of the bath at a temperature of about 70 "C to 110 C.

 For the extraction of heavy metals, the household waste incineration minces or the residues of the smoke from the incineration of household waste are subjected to an electrolysis operation.

 In the case where the machefers contain very little pollutants from the start, the machefers are crushed and screened to the desired particle size, which is preceded by a heat treatment at a temperature of about 80 "C 1200C in an atmosphere saturated with humidity for a variable time from 1 to 4 hours.

For the implementation of the method as described, a device has been designed and developed which essentially comprises:
- at least one tank equipped with a filtration system and receiving the household waste incineration bottom ash and / or the residues of household waste incineration fumes,
- at least one watering boom supplied by at least one
pump in communication with the tank,
- at least one container in the form of a tank mounted in
communication with the filter tank and connected to the pump or pumps,
- one or more sampling tanks connected to the tank (s),
- means for emptying the tank (s).

 To solve the problem posed of activating the chemical reactions if necessary, at least one heating ramp is mounted in combination with the filter tank and / or the tank.

 According to one characteristic, electrodes supplied by a direct current source are immersed in the tank.

The invention is set out below in more detail with the aid of the appended drawings in which:
Figure 1 is a block diagram showing the main steps of the process in the case of recovery of inert minerals and pollutant residues.

 FIG. 2 represents purely schematically a diagram of an exemplary embodiment of a device for the implementation of the treatment method.

 According to the invention, as indicated, one of the main problems which the invention proposes to solve is to transform the incineration residues of household waste into raw materials capable of being used in numerous applications, among which may be mentioned advantageously but not limited to, the manufacture of construction materials.

 For this purpose and according to a characteristic on the basis of the process according to the invention, one proceeds to a filtering of the bottom ash and the incineration residues. The purpose of this filtering is either to extract from the mass all the soluble pollutants and then treat the water collected, or to transform the pollutants in the mass in order to make them insoluble and / or harmless.

 This first phase of extraction and or neutralization of pollutants can advantageously be followed by a second phase of recovery of inert minerals and a third phase of recovery of pollutant residues. We refer to the block diagram of Figure 1, which shows the main steps of this complete treatment process.

 Household waste incineration bottom ash (A) and / or residues from household waste incineration film (B) are subjected to a pollutant extraction and / or neutralization process (step (C)) which constitutes the first phase of the process.

 This step (C) is followed by a step (D) which corresponds to the recovery of the inert minerals constituting the second phase of the process. Step (D) is itself followed by a step (E) corresponding to the recovery of pollutant residues constituting the third phase of the process.

 After extraction and neutralization of the pollutants, recoverable matured bottom ash (F) and / or recoverable fines (G) and / or pollutant residues (H). The recoverable bottom ash (F) and the recoverable fines (G) are compacted then, after approval (step (J)) possibly put in legal discharge (step (K)). Pollutant residues (H) can also be landfilled.

 With regard to the recovery of inert minerals, corresponding to a second phase of the process, the recoverable cured machefers (F) or the recoverable fines (G) or both at the same time, are subjected to operations capable of allowing the development of building materials step (L). After approval (step (M)), construction materials can be marketed (step M ').

 Regarding the third phase of recovery of polluting residues, we selectively treat them (step (N)) to obtain either marketable raw materials (step (O)) or minimized final waste ((step (P)), which can be landfilled in step (Q).

 Illustrated in Figure 2, by way of non-limiting example, an embodiment of a device capable of ensuring the extraction and / or neutralization of pollutants which constitute one of the essential characteristics at the base of the process.

 The residues from the incineration fumes of household waste (B) or the incineration mashers of household waste (A) are placed inside a tank (1) equipped with any known and appropriate filtration system. One or more ramps (2) ensure continuous watering of the products (A) or (B), placed in the tank (1). This or these ramps (2) are supplied by a pumping system (3) connected to a tank (4).

The filtering water is collected in the tank (4) either by natural gravity or by any suitable mechanical means. The bottom of the tank (4) is in communication with sampling tanks (5) shaped to test the content of various pollutants. These sampling tanks (5) are connected to the pumping system (3) to again introduce the filtering water into the tank (1) via the ramp (s) (2), if necessary.

 The volume of water and the duration of the cycle thus described depend on the origin and the nature of the residues and incineration films of household waste.

 The sampling tanks (5) are connected to a drainage system (6). After draining, a second filtering cycle is carried out with clean water. A number of other cycles are carried out until the sample detects no presence of pollutants. In this case, a last cycle is carried out with the addition of a chemical neutralizer to obtain a pH close to 7.

 Depending on the objective chosen, that is to say the applications envisaged, the water used for the various filtering cycles can be added with selective agents facilitating the solubility of the pollutants, their oxidation, their flocculation, their precipitation. ....

 It is also planned to heat the tank (1) and / or the tank (4) by means of a heating ramp (7) in order to activate the chemical reaction if necessary.

 The filter extraction and / or neutralization system can be completed by an electrolysis operation. For this purpose, electrodes (8) are immersed in the tank (5), these electrodes being supplied by a generator of direct electric current (9).

 To carry out the extraction of pollutants contained in the residues of household waste incineration fumes, an electro-chemical process can be used. In this case, the residues are placed inside electrolytic tanks, the liquid medium and the electrodes of which are selected to obtain any oxidation-reduction reaction of pollutants, either by electrolysing effect, or by galvanic cell effect, or by effect. of concentration stacks ...

 The free lime contained in the residues of the incineration fumes of household waste can be subjected to a carbonation operation during the filtering operation, by causing a gaseous bubbling inside the filtration tank (1) and / or the receiving tank (4). This gas bubbling can be obtained by injection of natural air, and / or ozone and / or carbon dioxide from the combustion of the garbage after dedusting. This operation promotes the condensation of heavy metals and possibly allows the pH to be rebalanced. The temperature of the injected gas is optimized for the desired application.

 As a result, after extraction and / or neutralization of the pollutants, under the conditions indicated above, the residues of the incineration fumes of household waste and the incineration flue gases of household waste are free of pollutants likely to be entrained by leaching, at least in proportions likely to be acceptable by the legislation in force.

 The filtering or electrolysis water is treated by any physical and / or chemical or electro-chemical process perfectly known by a person skilled in the art, in order to make this water reusable in a filtering cycle, or to be discharged into a public collector .

 With regard to the preparation of mortars and concretes, which constitutes one of the advantageous applications resulting from the implementation process, after de-ironing by any known means, and extraction of non-ferrous metals, the mash is treated under the conditions indicated above.

 When this clinker meets the criteria authorizing its classification in a recoverable category, it is crushed and screened to a particle size of 0 to 3 mm approximately, in the case of an application of mortars and of 0 to 10 mm approximately, in the case of an application to concrete.

 In the case where the incineration ash from household waste contains very little pollutants and they are classified as recoverable from the start, the only treatment to be applied before screening is accelerated ripening. The present process avoids long term storage areas which would be necessary for natural ripening. This generated ripening is carried out by heat treatment at a temperature of approximately 80 ° C. to 1200 ° C. in an atmosphere saturated with humidity, for a time which may vary from 1 to 4 hours approximately.

 The treatment enclosure can be an autoclave tank equipped with a mixing cylinder or else this enclosure can be constituted directly by the tank of a crusher.

 To cause oxidation and carbonation, natural air and / or ozone and / or combustion gases from the incinerator can be injected into the treatment enclosure.

 The recoverable fines (G) and the recoverable ripened chews (F) are introduced wet into a mixer by any known means. After an intimate mixing, the pH is readjusted according to the binder intended for them and then dried in the case of bituminous binder, or non-aqueous polymers. The mixture is then introduced into a mixer containing the binder according to its nature and its usual mode of implementation.

 As indicated, after preparation of the mortars or concretes under the conditions indicated (step I), it is possible to develop different types of building elements and materials, such as building bricks, concrete blocks, reconstituted stones ... as well as various elements of urban objects, such as self-blocking pavers, curbs, bollards, beacons, benches, bins ...

 Depending on the destination of the elements and the mechanical or physical qualities required, one or more curative treatments can be applied to the elements produced after molding. Mention may be made of the bricks obtained from a mortar resulting from the combination of recoverable fines, recoverable machefers and cements, placed for a few days in a water bath with the addition of sodium silicate. The product obtained becomes very resistant mechanically and to water.

 The advantages are apparent from the description.

Claims (1)

CLAIMS according to their classification. fines separately or together and they are landfilled with the residues characterized in that after extraction, the chews and the compacts are compacted according to any of claims 1 and 2, - destruction or extraction of the toxic chemical compounds, - extraction of heavy metals, - hydration and carbonation of lime to obtain an insoluble calcium carbonate, or in any combination, of the following treatment phases: residues and incineration fumes, any one is carried out, depending on the nature and composition of the incineration machefers -2- A method according to claim 1, characterized in that in said machefers and / or said residues - extracts and / or neutralizes any polluting element contained - identifies the household waste incineration clinkers and the residues of household and household waste incineration fumes, characterized in that:  -1 Process for treating waste from incineration of garbage  construction.  uses the non-polluting mineral mass to make materials for  -4- The method of claim 1, characterized in that  - operations are repeated until the sample no longer presents any polluting material.  - the filtering water is drained,  - the filtering water is collected in order to sprinkle said machefers and / or said residues again,  - we water them continuously,  filtered,  and / or the residues of household waste incineration fumes in a  - we have the household waste incineration minces  extraction:  -5- The method of claim 4, characterized in that for  -6- The method of claim 2, characterized in that to neutralize certain toxic products as well as for the hydration and carbonation of lime, there are the incineration minces of household waste and / or the residues of smoke from incineration of household waste in a tank in the presence of water, inside which a gaseous bubbling is caused by injection of air and / or ozone and / or carbon dioxide from the combustion of the waste and after dedusting , the temperature of the bath is optionally brought to a temperature of about 70 "C to 110 C.  -7- The method of claim 2, characterized in that for the extraction of heavy metals, subjecting the household waste incineration minces or the residues of the incineration fumes of household waste to an electrolysis operation .  -8- The method of claim 2, characterized in that for the destruction or extraction of toxic chemical compounds, one proceeds to a filtration.  - means for emptying the tank (s) (4).  - one or more sampling tanks (5) connected to the tank (s) (4),  communication with the filter tank (1) and connected to the pump (s) (3),  - at least one container (4) in the form of a tank mounted in  pump (3) in communication with the tank (1),  - at least one watering boom (2) supplied by at least one  - at least one tank (1) equipped with a filtration system and receiving the household waste incineration minces and / or the residues of the smoke from the incineration of household waste,  -9- Device for implementing the method, characterized in that it comprises:  -10- Device according to claim 9, characterized in that at least one heating ramp is mounted in combination with the filter tank (1) and / or the tank (4).  -11- Device according to claim 9, characterized in that electrodes (8) are immersed in the tank (4) and are supplied by an energy source (9).