FR2809028A1 - Recuperation of solid phase from heterogeneous mixture by vibro-fluidization comprises continuous vibration after mixing with extracting substance - Google Patents

Abstract

Treating a mixture of at least two phases, one a liquid, solid or paste containing chemical pollutants to be extracted, another being of solids that are homogeneous or heterogeneous in nature or size, and a possible third phase essentially of gas containing volatile chemical components, comprises solubilization/extraction with the aid of a third substance such as gas-oil or water. The mixture is dissolved in the extracting substance and agitated by continuous vibration to separate the solid components in it. Part of the extracting substance can be drawn off and recycled by spraying over or injecting into the solid components. The extracted solids can be dried with a circulating fluid heated to ca. 450[deg]C. The process can be carried out in an extraction plant with a feeder ramp (1) and extractors (2, 8) with vibration generators (15) operating at a frequency of 20-50 Hz and an amplitude of 0.1-10 mm.

Description

<B> "Process for recovering a solid phase from a heterogeneous mixture by vibro-fluidization" The present invention relates to a physicochemical treatment method of a heterogeneous mixture comprising at least two phases P1 and P2 solubilization / extraction of at least one chemical component extract in at least one third extractant body (TCE).

Phase P1 is in liquid, pasty solid form and includes the chemical components to be extracted.

The P2 phase is essentially solid and, in particular, comprises solid components that are homogeneous and / or heterogeneous in size and / or in nature. These components must be cleared of the chemical components of the P1 phase.

The mixture may also comprise a substantially gaseous third phase comprising volatile chemical compounds. These compounds can also be extracted by mixing (N) with at least one third extractant body (TCE).

As in any operation for separating chemical constituents, the "chemical" reactions to be carried out are well known to those skilled in the art and involve, for example, solubilization, dissolution or reactions between solids and liquids (adsorption, desorption).

However, the implementation of processes that allow these reactions are complex and are specific to the industrial processes concerned.

It will be seen that because of its simplicity, the invention can be implemented on a very broad spectrum of products to be treated. This is particularly the case in the field of waste where separations are made difficult because of the great heterogeneity of the products to be separated; this heterogeneity of the mixture being, at one and the same time, related to the physical state of the constituents (solid, liquid, pasty) but also to the dimension of the components.

Indeed, we may have to treat a mixture of pebbles, water, oil, organic constituents of various origin, tools from handling, work clothes, falling within the definition of waste from tide black.

It may still be necessary to treat a mixture of pebbles, water and organic solvents defining polluted land.

A mixture of pebbles, organic residues, water, debris constituting the sludge, or a mixture of ash, salts, glasses, scrap, falling within the definition of residues of incineration, waste or more generally a mixture consisting of a first solid phase to be recovered, optionally for the purpose of recovering it, and a second phase in the liquid, pasty solid form may also have to be treated.

Although the invention is particularly intended for heterogeneous mixtures, industrial applications involving separation between a solid phase, granular liquid, solid or pasty (optionally a gaseous phase resulting from the reaction) will greatly facilitate the invention.

The processes that currently exist, generally implement two distinct steps. The first is to put the mixture to be treated, consisting of at least two phases, contact with an extractant medium.

The second consists of separating the two phases and then recovering the solid phase.

Unfortunately, such methods often have the disadvantage of not providing a clean and efficient separation of each group of components. Moreover, in such processes, the frequent fouling of the machines prevents the realization of a treatment with chain, and consequently fast, as well as the regular pumping of the mixture to be treated to convey it in the various structures constituting the installation treatment.

There is also a need for a separation treatment method, mixtures of components, liquid and possibly gaseous solids, of very heterogeneous chemical nature, making it possible to achieve rapid separation that is easy to implement and effective for each main group of components. The subject of the invention is therefore a method for the physicochemical treatment of a heterogeneous mixture (N) comprising at least two phases (P1 and P2) by solubilization / extraction in at least one third aqueous organic extractant (TCE), said phase (P1) being liquid, solid or pasty comprising said polluting chemical components to extract said phase (P2) being essentially solid and comprising in particular solid components homogeneous or heterogeneous in size and / or in kind, a third phase (P3) essentially gaseous and comprising volatile chemical compounds that may be derived from a chemical reaction between the TCE mixture, said method comprising a) contacting the mixture (N) with at least a first third extracting body (TCE) so as to obtain a mixture ( N + 1) b) stirring the mixture (N + 1) so as to solubilize and / or dissolve in the first TCE the chemical components to be extracted from said mixture (N + 1), c) solubilizing / extracting the chemical phase components (P1) optionally from the phase (P3), characterized in that stirring of the mixture (N + 1) carried out continuous vibration, and in that solubilization / extraction is carried out by vibration continues to separately separate said solid components present in the mixture (N + 1), said solid components being able to be contacted again with at least second organic or aqueous so as to obtain a mixture (N + 2) before to be stirred with the second TCE and then recovered from said mixture (N + 2) to be optionally further processed, the process steps being reproduced at least once and successively.

Part of the second third extractant body can be withdrawn from the mixture (N + 2) and then recycled into the process by being incorporated directly into the mixture (N + 1) and / or by being sprayed onto the solid components recovered mixture (N + 1) ).

The third body used in the process of the invention may be chosen from the group of organic solvents and aqueous, acidic or basic solutions, known to those skilled in the art, as representing a liquid medium in which the product to be extract, has a high solubility.

The method according to the invention has the advantage of being of simpler design and implementation than those already existing.

Indeed, it allows the continuous feed mixture (N) comprising the starting products to be treated without any interruption in the processing chain, and therefore it makes it possible to handle the starting materials easier. It also has the advantage of ensuring effective contact between the mixture to be treated and TCE, of consuming electrical energy, of regulating the quantity of virgin TCE to be added, or of the amount of TCE. recycle, and allow simultaneous vibration and fluidization processing.

The virgin TCE may be the one that has never been in contact with the mixture (N), the mixture (N + 1) or the mixture (N + 2). Therefore it does not include any molecule of organic origin, or mineral, dissolved, and which could come from said mixtures (N), (N + 1) or (N + 2).

Finally, such a method allows a very efficient continuous recovery, within minutes, of the solid components of the P1 phase present in the mixture (N), (N + 1) or (N + 2) to be treated.

The TCE reaching its saturation threshold can be extracted from the mixture (N + 1). The TCE can be chosen from the virgin TCEs in chemical components to be extracted, and from the mixture of virgin TCE and TCE already recycled a first time.

After extracting the mixture (N + 1) and / or the mixture (N + 2), the solid components may be drained on a sieve optionally integrated with the extractor, and / or may be dried by insufflation of a gaseous fluid. having a temperature between 100 C and 700 C, means of a device that can also be integrated in the extractor.

The gaseous fluid may be selected from air, superheated steam, or an acid gas for neutralizing the reaction medium.

According to a second variant, after recovering the mixture (N + 1) and / or the mixture (N + 2), the solid components may be drained on a sieve, and may then be dried by placing in contact with a heating table in which circulates , in a double jacket, a heat-transfer fluid having a temperature ranging from approximately 100 ° C. to 450 ° C.

The coolant is selected from those known to those skilled in the art.

The set of steps of the process of the invention is preferably carried out in a total time ranging from about 1 to 60 minutes.

The solubilization or dissolution of the chemical component (s) to be extracted is carried out at a lower threshold than that of its saturation concentration (s) in the TCE so as to optimize the process for separating the constituents of the mixture.

The TCE comprising a high concentration of chemical component (s) to be extracted, close to its saturation threshold (s) in the TCE, can be regularly withdrawn, in part or in whole, from the process, directly in the process. the mixture (N + 1) so as to maintain a medium that is effective in its extraction properties of the chemical component (s) to be extracted.

Virgin TCE may be added regularly in the process of choice directly into the mixture (N + 1) and / or into the mixture (N + 2) and / or sprayed onto the solid components recovered by vibration of the mixture (N + 1) and / or the mixture (N + 2) solid particles resulting from the process steps can be rinsed with TCE before a subsequent treatment or storage step.

The chemical, liquid, solid or pasty organic nature components are preferably chosen from products and by-products from all industries such as the chemical industry, the metallurgical industry, the surface treatment industry and the petrochemical industry. , such as hydrocarbon waste (fuel oil, heavy fuel oil, oil). The liquid, solid or pasty mineral chemical components are preferably ordinary and / or special components, and may be chosen from by-products and / or industrial by-products from the same industries as above, and may be chosen among salt compounds, metallic or not.

Phase P2 may include slags, sands, pebbles and sludge.

The third body (TCE) used in the process of the invention may be chosen from the group of organic solvents and aqueous, acidic or basic solutions known to those skilled in the art, as representing a liquid medium in which the product to be extracted, has a high solubility.

TCE is used in the process of the invention to solubilize the components to be extracted, to allow the separation of the unsolubilized solid phase in the TCE by vibro-fluidization.

The organic TCE used in the process of the invention is preferably selected from gas oil, gasoline, acetone and alcohols and mixtures thereof.

The inorganic TCE used in the process may be selected from water, aqueous salt solutions, aqueous acidic or basic solutions or mixtures thereof.

The invention will now be described with the aid of the figures which follow and which are only given by way of illustration.

FIG. 1 represents a schematic view from above of the elements of an installation allowing the implementation of the process of the invention, and FIG. 2 represents a schematic side view of the elements of an installation allowing the implementation of the method of the invention.

As can be seen in Figures 1 and 2, the mixture (N) to be treated, consisting of petroleum residues mixed with pebbles and sand arrives regularly through an access ramp 1 in a first extractor 2 having substantially the shape of a trough. The virgin organic TCE consisting essentially of gas oil is incorporated at the beginning of the process into the extractor 2 via a pipe 3. The virgin diesel does not include any dissolved petroleum component.

together consisting of petroleum residues and diesel forms the mixture (N + 1). This mixture (N + 1) is continuously stirred by a vibro-fluidization technique, in the lower part of the extractor 2.

As shown in FIG. 2, the lateral ramp 4 of the extractor 2 is equipped, on each lateral flank, with a system 15 for generating vibrations, designed to make it vibrate continuously at a frequency that may range from at 50 Hz and over an amplitude ranging from 0.1 to 10 mm displacement.

This lateral ramp 4 forms an angle A with the vertical part 5 of the extractor 2. The angle A is preferably between 1 and 20.

The permanent vibration of the ramp 4 allows gradually recovering the mixture (N + 1) of solid particles 6 (pebbles, sands), partially freed of oil which engulfed them.

After reaching the terminal end 7 ramp 4, the recovered particles leave the first extractor 2, and fall into a second extractor designated by general reference 8, identical to the first, and already comprising diesel. The assembly consisting of this TCE and solid particles 6 recovered from the extractor 2 forms the mixture (N + 2).

The second extractor 8 operates identically to the first.

After having undergone a vibro-fluidization in the bottom of the extractor 8, the particles 6 also rise along the ramp 9 and are then completely freed of the oil which still remained partially present at the end of the previous processing steps carried out in the first extractor 2.

The cleaned particles recovered are then withdrawn and are either stored or for further processing.

Preferably, the two extractors comprise a cover covering at least the step of mixing by vibration, firstly to limit the release of more or less smelly gases and / or volatile organic compounds (VOCs) to the outside of the membrane. installation, and secondly, to avoid splattering of dirty diesel, outward extractors.

The TCE (gas oil) may be either already present in each extractor 2, before the arrival of the mixture N or particles 6 partially free of the product (s) to be extracted, or be incorporated simultaneously to the mixture to be treated.

According to an alternative embodiment, the diesel fuel that is lightly loaded with petroleum can be taken from the lower part 8a of the extractor 8, where the extraction is carried out, and then recycled to the extractor 2.

The sampling of the gas oil in the extractor 8 is preferably carried out in the central part of the surface of the stirring bath, so as to leave in the bath all the fine particles mixed with the foam present on the surface and resulting from the forced stirring.

The diesel / oil mixture withdrawn from the mixture (N + 2) is conveyed via a pipe 10 to the inlet of the extractor 2. The pipe 10 can also supply a nozzle manifold 11 arranged parallel to the ramp 4. The spraying of diesel fuel with little oil, through the nozzles 11, refines the cleaning of the particles 6 by an additional rinse.

According to another variant, the diesel fuel can arrive directly at the end end of the ramp 9 of the extractor 8 via a pipe 12 and flow continuously or semi-continuously along said ramp 9.

This arrival of diesel on the ramp 9 through the pipe 12, further refines the cleaning of the particles before their final withdrawal of the installation.

Throughout the realization of the recovery process, the diesel in which the oil is close to its saturation threshold, is regularly withdrawn and then removed from the installation. The amount of TCE is regulated, either with an overflow disposed within each extractor 2.8, or with a pump (not shown).

The particles 6, from the extractors 2.8, can be drained on a sieve 14 disposed on the upper part of the ramp 4.9, before being dried, so as to eliminate the maximum TCE.

The drying can be carried out by blowing a heat-transfer fluid (gas or vapor) having a temperature which may be between 100 and 700 C. The heat-transfer fluid sent forcibly into a pipe is blown in a known manner towards the upper part of the pipe. the ramp, 9, for the purpose of drying the particles 6 present on the ramp.

Claims (3)

1. Physicochemical treatment process of a heterogeneous mixture (N) comprising at least two phases (P1 P2) by solubilization / extraction in at least one third organic or aqueous extracting body (TCE), said phase) being liquid, solid or pasty and comprising said polluting chemical components to extract, said phase) being essentially solid and comprising in particular solid components homogeneous or heterogeneous in size and / or in kind, a third phase (P3) essentially gaseous comprising volatile chemical compounds, which may be derived from a chemical reaction between the mixture (N) and said process comprising a) contacting the mixture (N) with at least a first third extracting body (TCE) so as to obtain a mixture (N + 1), b) stirring the mixture (N + 1) so as to solubilize and / or dissolve in the first TCE the chemical components to be extracted from said mixture (N + 1), c) to solubilize / extract the chemical components of the phase (P1) optionally of the phase (P3), characterized in that the stirring of the mixture (N + 1) is carried out continuously, and in that the solubilization / extraction is carried out by continuous vibration so as to recover separately, said solid components present in the mixture (N + 1), said solid components being able to be brought into contact again with at least a second organic or aqueous TCE so as to obtain a mixture (N + 2) before being mixed with the second TCE and then recovered from said mixture (N + 2) to be optionally further processed, the process steps being reproduced at least once and successively. 2. Method according to claim 1, characterized in that part of the second third extractant body is withdrawn from the mixture (N + 2 to be recycled in the process by being sprayed on the solid components extracted from the mixture (N + 1) or injected into this mixture. 3 Process according to claim 1, characterized in that the arriving at its saturation threshold is extracted mixture (N + 1). Process according to Claim 1, characterized in that it is chosen from virgin TCE in chemical components to be extracted and, among the mixture of virgin TCE and TCE already recycled a first time. Process according to claim 1, characterized in that after recovering the mixture (N + 1) and / or the mixture (N + 2) the solid components are drained on a sieve, and / or are dried by blowing with a gaseous fluid having a temperature between about 100 ° C. and 700 ° C. 6. Process according to claim 1, characterized in that after recovering the mixture (N + 1) and / or the mixture (N + 2), the solid components are drained on a sieve, and then dried by contact with a heating table in which circulates a heat transfer fluid having a temperature ranging from about 100 C to 450 C. 7. Process according to claim 1, characterized in that steps a), b) and c) have a total duration ranging from about 1 to 60 minutes. 8. Method according to claim 1, characterized in that the chemical components, heterogeneous, solid, liquid or pasty organic nature are selected from all industries, such as the chemical industry, the metallurgical industry, the processing industry. surface the petrochemical industry. 9. Method according to claim 1, characterized in that the chemical components, heterogeneous, liquid, pasty solid mineral nature are commonplace and / or special components selected from co-products and / or industrial by-products from all sources. industries, such as the chemical industry, the metallurgical industry, the surface treatment industry and the petrochemical industry. 10. The method of claim 1, characterized in that the TCE used and selected from the set of organic solvents and aqueous solutions, acidic or basic as representing a liquid medium in which the product to be extracted, has a high solubility.