PROCESS FOR MANUFACTURING A MATERIAL WITH A HIGH SPECIFIC SURFACE AREA

Abstract

A process for manufacturing a material with a high specific surface area, including a step of spraying a liquid composition based on liquid residues derived from a chemical extraction of clinker, to a material based on clinker residues having a high specific surface area ranging from 200 m.sup.2.Math.g.sup.1 to 900 m.sup.2.Math.g.sup.1 and also by a mesopore size ranging from 2 nm to 50 nm, and to the use of materials for the absorption of pollutants species.

Claims

1-17. (canceled)

18. A process for manufacturing a material with a high specific surface area, comprising a step of spraying of a liquid composition based on liquid residues derived from a chemical extraction of clinker.

19. The manufacturing process as claimed in claim 18, comprising a preliminary step of preparing said liquid composition.

20. The manufacturing process as claimed in claim 19, wherein the composition is prepared by mixing the liquid residues derived from a chemical extraction of clinker and a structuring agent.

21. The manufacturing process as claimed in claim 20, wherein the liquid residues derived from a chemical extraction of clinker are obtained by solid/liquid extraction of clinker.

22. The manufacturing process as claimed in claim 21, wherein the solid/liquid extraction is performed with an acidic and/or oxidizing solution.

23. The manufacturing process as claimed in claim 22, wherein the acidic and/or oxidizing solution is at least one of a hydrochloric acid (HCl), sulfuric acid (H.sub.2SO.sub.4), hydrofluoric acid (HF), sodium oxide (Na.sub.2O) or potassium oxide (K.sub.2O) solution.

24. The manufacturing process as claimed in claim 20, wherein the structuring agent is at least one of surfactants, polymers, cellulose-based compounds, and mineral salts.

25. The manufacturing process as claimed in claim 18, wherein the composition based on liquid residues derived from the chemical extraction of clinker also comprises a precursor.

26. The manufacturing process as claimed in claim 25, wherein the matrix precursor is at least one of silicic acid, silicon alkoxides, silicate, colloidal silica, and silicon tetrachloride.

27. The manufacturing process as claimed in claim 20, comprising, after said spraying step, a step of removing the structuring agent.

28. The manufacturing process as claimed in claim 27, wherein the step of removing the structuring agent is a calcination step.

29. The manufacturing process as claimed in claim 28, wherein the calcination is performed at a temperature of from 400 C. to 600 C.

30. The manufacturing process as claimed in claim 28, wherein the calcination step is performed for a time of 1 hour to 3 hours.

31. The manufacturing process as claimed in claim 28, wherein it also comprises, after said calcination step, a step of washing and drying.

32. A material based on clinker residues, said material having a high specific surface area, determined by nitrogen adsorption in accordance with the standard ASTM D 3663-78 established from the Brunauer-Emmett-Teller method, ranging from 200 m.sup.2.Math.g.sup.1 to 900 m.sup.2.Math.g.sup.1, and also by a mesopore size, determined by transmission electron microscopy, ranging from 2 nm to 50 nm.

33. The material based on clinker residues as claimed in claim 32, having a particle size, determined by transmission electron microscopy, ranging from 0.3 to 100 m.

34. An adsorption support as obtained according to the process of claim 18.

Description

EXAMPLES

Example 1

Production of the Liquid Residues Derived from a Chemical Extraction of Clinker

[0087] The clinker leachate is obtained from 1 kg of dried and ground clinker screened to less than 100 m, to which are added, in a fume cupboard, 1.18 kg of hydrochloric acid at 37% by mass, portionwise so as to limit the exothermic reaction.

[0088] Once the hydrochloric acid addition is complete (the change from a pasty state to a liquid state is very rapid; on obtaining the liquid state the exothermic reaction stops), 2 kg of mains water are added with stirring for 10 minutes. This addition makes it possible notably to make the preparation filterable. The mixture is then filtered through a funnel with filter paper of 10 m porosity.

Example 2

Manufacture a Material with a High Specific Surface Area.

[0089] Several mesostructured materials with a high specific surface area were manufactured according to the process of the invention from liquid residues derived from a chemical extraction of clinker and by varying the nature of the structuring agent(s) and of the precursor and the amount of structuring agent(s).

[0090] For each of the manufactures, the spraying is performed with a Bchi B-290 spray-dryer and the particles have a diameter of between 0.5 and 10 m (diameter determined by scanning electron microscopy). [0091] a) Mesostructured material with a micron-sized high specific surface area based on leachate from the washing of clinker, TEOS and Brij 58 (molar composition: 1 leachate dry extract: 1 TEOS: 0.12 Brij 58).

[0092] The following compounds are added in order and with magnetic stirring (500 revolutions.Math.min.sup.1) to a 500 mL beaker: 25 mL of leachate from the washing of clinker with HCl (37% by mass), 200 mL of osmosed water and 20.49 g of Brij 58.

[0093] The solution is then stirred at 60 C. until the Brij 58 has fully dissolved. After dissolution of the surfactant and cooling of the solution to 25 C., 31.62 g of tetraethoxysilane (TEOS) are added to the solution dropwise using a Pasteur pipette.

[0094] The solution is then stirred at 25 C. for 1 to 2 hours until a clear solution is obtained.

[0095] The solution is then sprayed as micrometer-sized droplets in a stream of hot gas (air) using a mono-nozzle with an aperture diameter of 0.7 mm.

[0096] The circulation flow rate of the solution was set at 0.36 L.Math.h.sup.1. The flow rate of compressed air for the spraying was set at 670 L.Math.h.sup.1. The circulation of air for the suction of the sprayed droplets was set at 34 m.sup.3/h. The nominal sprayer inlet temperature was set at 170-180 C. so that the outlet temperature observed was about 90 C.

[0097] The particles thus synthesized and recovered in the recovery tank are then hermetically stored in a polypropylene flask at room temperature, to be subsequently calcined at 450 C. in an oven (ramp of 3 C./min and steady stage of 2 hours at 450 C.).

[0098] The material obtained is in powder form and has a BET specific surface area of 505 m.sup.2/g. [0099] b) Mesostructured material with a micron-sized high specific surface area based on leachate from the washing of clinker, TEOS and Brij 58 (molar composition: 1 leachate dry extract: 1 TEOS: 0.20 Brij 58).

[0100] The following compounds are added in order and with magnetic stirring (500 revolutions.Math.min.sup.1) to a 500 mL beaker: 25 mL of leachate from the washing of clinker with HCl (37% by mass), 200 mL of osmosed water and 34.15 g of Brij 58.

[0101] The solution is then stirred at 60 C. until the Brij 58 has fully dissolved. After dissolution of the surfactant and cooling of the solution to 25 C., 31.62 g of tetraethoxysilane (TEOS) are added to the solution dropwise using a Pasteur pipette.

[0102] The solution is then stirred at 25 C. for 1 to 2 hours until a clear solution is obtained.

[0103] The solution is then sprayed as micrometer-sized droplets in a stream of hot gas (air) using a mono-nozzle with an aperture diameter of 0.7 mm.

[0104] The circulation flow rate of the solution was set at 0.36 L.Math.h.sup.1. The flow rate of compressed air for the spraying was set at 670 L.Math.h.sup.1. The circulation of air for the suction of the sprayed droplets was set at 34 m.sup.3/h. The nominal sprayer inlet temperature was set at 170-180 C. so that the outlet temperature observed was about 90 C. The particles thus synthesized and recovered in the recovery tank are then hermetically stored in a polypropylene flask at room temperature, to be subsequently calcined at 450 C. in an oven (ramp of 3 C./min and steady stage of 2 hours at 450 C.).

[0105] The material obtained is in powder form and has a BET specific surface area of 410 m.sup.2/g. [0106] c) Mesostructured material with a micron-sized high specific surface area based on leachate from the washing of clinker, TEOS, MTEOS and Brij 58 (molar composition: 1 leachate dry extract: 0.95 TEOS: 0.05 MTEOS: 0.12 Brij 58).

[0107] The following compounds are added in order and with magnetic stirring (500 revolutions.Math.min.sup.1) to a 500 mL beaker: 40 mL of leachate from the washing of clinker with HCl (37% by mass), 100 mL of osmosed water and 24.14 g of Brij 58.

[0108] The solution is then stirred at 60 C. until the Brij 58 has fully dissolved. After dissolution of the surfactant and cooling of the solution to 25 C., 29.99 g of tetraethoxysilane (TEOS) and 0.64 g of methyltriethoxysilane (MTEOS) are added to the solution dropwise using a Pasteur pipette.

[0109] The solution is then stirred at 25 C. for 1 to 2 hours until a clear solution is obtained. The solution is then sprayed as micrometer-sized droplets in a stream of hot gas (air) using a mono-nozzle with an aperture diameter of 0.7 mm.

[0110] The circulation flow rate of the solution was set at 0.36 L.Math.h.sup.1. The flow rate of compressed air for the spraying was set at 670 L.Math.h.sup.1. The circulation of air for the suction of the sprayed droplets was set at 34 m.sup.3/h.

[0111] The nominal sprayer inlet temperature was set at 170-180 C. so that the outlet temperature observed was about 90 C.

[0112] The particles thus synthesized and recovered in the recovery tank are then hermetically stored in a polypropylene flask at room temperature, to be subsequently calcined at 350 C. in an oven (ramp of 3 C./min and steady stage of 2 hours at 350 C.).

[0113] The material obtained is in powder form and has a BET specific surface area of 440 m.sup.2/g. [0114] d) Mesostructured material with a micron-sized high specific surface area based on leachate from the washing of clinker, SiCl.sub.4 produced and Brij 58 (molar composition: 1 leachate dry extract: 1 SiCl.sub.4: 0.12 Brij 58).

[0115] The following compounds are added in order and with magnetic stirring (500 revolutions.Math.min.sup.1) to a 300 mL beaker: 12.5 mL of leachate from the washing of clinker with HCl (37% by mass), 100 mL of osmosed water and 10.24 g of Brij 58.

[0116] The solution is then stirred at 60 C. until the Brij 58 has fully dissolved.

[0117] In a second 500 mL beaker, 12.9 g of SiCl.sub.4 stored at 4 C. are added dropwise to 22.15 mL of absolute ethanol stored at 4 C. Since the reaction is exothermic and highly reactive, this mixing takes place in an ice bath with vigorous stirring (1000 revolutions.Math.min.sup.1).

[0118] After dissolution of the surfactant and cooling of the leachate/Brij 58 solution to 25 C., this solution is added to the SiCl.sub.4/ethanol solution dropwise using a Pasteur pipette and with vigorous stirring (1000-1200 revolutions.Math.min.sup.1).

[0119] The solution obtained is then stirred at 25 C. for 1 to 2 hours until a clear solution is obtained, and is then sprayed as micrometer-sized droplets in a stream of hot gas (air) using a mono-nozzle with an aperture diameter of 0.7 mm.

[0120] The circulation flow rate of the solution was set at 0.36 L.Math.h.sup.1. The flow rate of compressed air for the spraying was set at 670 L.Math.h.sup.1. The circulation of air for the suction of the sprayed droplets was set at 34 m.sup.3/h. The nominal sprayer inlet temperature was set at 170-180 C. so that the outlet temperature observed was about 90 C.

[0121] The particles thus synthesized and recovered in the recovery tank are then hermetically stored in a polypropylene flask at room temperature, to be subsequently calcined at 450 C. in an oven (ramp of 3 C./min and steady stage of 2 hours at 450 C.). The material obtained is in powder form and has a BET specific surface area of 560 m.sup.2/g. [0122] e) Mesostructured material with a micron-sized high specific surface area based on leachate from the washing of clinker, SiCl.sub.4, MTEOS and Brij 58 (molar composition: 1 leachate dry extract: 0.95 SiCl.sub.4: 0.05 MTEOS: 0.12 Brij 58).

[0123] The following compounds are added in order and with magnetic stirring (500 revolutions.Math.min.sup.1) to a 200 mL beaker: 12.5 mL of leachate from the washing of clinker with HCl (37% by mass), 100 mL of osmosed water and 10.24 g of Brij 58.

[0124] The solution is then stirred at 60 C. until the Brij 58 has fully dissolved.

[0125] In a second 500 mL beaker, 12.27 g of SiCl.sub.4 stored at 4 C. are added dropwise (Pasteur pipette) to 21.04 mL of absolute ethanol stored at 4 C. Since the reaction is exothermic and highly reactive, this mixing takes place in an ice bath with vigorous stirring (1000 revolutions.Math.min.sup.1). The 0.51 g of methyltriethoxysilane (MTEOS) is added dropwise (Pasteur pipette) to the SiCl.sub.4/ethanol solution.

[0126] After dissolution of the surfactant and cooling of the leachate/Brij 58 solution to 25 C., this solution is added to the SiCl.sub.4/ethanol/MTEOS solution dropwise using a Pasteur pipette and with vigorous stirring (1000-1200 revolutions.Math.min.sup.1).

[0127] The solution obtained is then stirred at 25 C. for 1 to 2 hours until a clear solution is obtained. The solution is then sprayed as micrometer-sized droplets in a stream of hot gas (air) using a mono-nozzle with an aperture diameter of 0.7 mm. The circulation flow rate of the solution was set at 0.36 L.Math.h.sup.1. The flow rate of compressed air for the spraying was set at 670 L.Math.h.sup.1. The circulation of air for the suction of the sprayed droplets was set at 34 m.sup.3/h. The nominal sprayer inlet temperature was set at 170-180 C. so that the outlet temperature observed was about 90 C.

[0128] The particles thus synthesized and recovered in the recovery tank are then hermetically stored in a polypropylene flask at room temperature, to be subsequently calcined at 350 C. in an oven (ramp of 3 C./min and steady stage of 2 hours at 350 C.). The material obtained is in powder form and has a BET specific surface area of 620 m.sup.2/g. [0129] f) Mesostructured material with a micron-sized high specific surface area based on leachate from the washing of clinker, SiCl.sub.4, MTEOS and Brij 58 (molar composition: 1 leachate dry extract: 0.85 SiCl.sub.4: 0.15 MTEOS: 0.12 Brij 58).

[0130] The following compounds are added in order and with magnetic stirring (500 revolutions.Math.min.sup.1) to a 200 mL beaker: 12.5 mL of leachate from the washing of clinker with HCl (37% by mass), 100 mL of osmosed water and 10.24 g of Brij 58. The solution is then stirred at 60 C. until the Brij 58 has fully dissolved.

[0131] In a second 500 mL beaker, 11.63 g of SiCl.sub.4 stored at 4 C. are added dropwise (Pasteur pipette) to 20.26 mL of absolute ethanol stored at 4 C. Since the reaction is exothermic and highly reactive, this mixing takes place in an ice bath with vigorous stirring (1000 revolutions.Math.min.sup.1). The 1.03 g of methyltriethoxysilane (MTEOS) are added dropwise (Pasteur pipette) to the SiCl.sub.4/ethanol solution.

[0132] After dissolution of the surfactant and cooling of the leachate/Brij 58 solution to 25 C., this solution is added to the SiCl.sub.4/ethanol/MTEOS solution dropwise using a Pasteur pipette and with vigorous stirring (1000-1200 revolutions.Math.min.sup.1).

[0133] The solution obtained is then stirred at 25 C. for 1 to 2 hours until a clear solution is obtained. The solution is then sprayed as micrometer-sized droplets in a stream of hot gas (air) using a mono-nozzle with an aperture diameter of 0.7 mm. The circulation flow rate of the solution was set at 0.36 L.Math.h.sup.1. The flow rate of compressed air for the spraying was set at 670 L.Math.h.sup.1. The circulation of air for the suction of the sprayed droplets was set at 34 m.sup.3/h. The nominal sprayer inlet temperature was set at 170-180 C. so that the outlet temperature observed was about 90 C.

[0134] The particles thus synthesized and recovered in the recovery tank are then hermetically stored in a polypropylene flask at room temperature, to be subsequently calcined at 350 C. in an oven (ramp of 3 C./min and steady stage of 2 hours at 350 C.). The material obtained is in powder form and has a BET specific surface area of 625 m.sup.2/g. [0135] g) Mesostructured material with a micron-sized high specific surface area based on leachate from the washing of clinker, SiCl.sub.4, PTEOS and Brij 58 (molar composition: 1 leachate dry extract: 0.95 SiCl.sub.4: 0.05 PTEOS: 0.12 Brij 58).

[0136] The following compounds are added in order and with magnetic stirring (500 revolutions.Math.min.sup.1) to a 200 mL beaker: 12.5 mL of leachate from the washing of clinker with HCl (37% by mass), 100 mL of osmosed water and 10.24 g of Brij 58. The solution is then stirred at 60 C. until the Brij 58 has fully dissolved.

[0137] In a second 500 mL beaker, 12.27 g of SiCl.sub.4 stored at 4 C. are added dropwise (Pasteur pipette) to 21.04 mL of absolute ethanol stored at 4 C. Since the reaction is exothermic and highly reactive, this mixing takes place in an ice bath with vigorous stirring (1000 revolutions.Math.min.sup.1). The 0.91 g of phenyltriethoxysilane (PTEOS) is added dropwise (Pasteur pipette) to the SiCl.sub.4/ethanol solution.

[0138] After dissolution of the surfactant and cooling of the leachate/Brij 58 solution to 25 C., this solution is added to the SiCl.sub.4/ethanol/PTEOS solution dropwise using a Pasteur pipette and with vigorous stirring (1000-1200 revolutions.Math.min.sup.1).

[0139] The solution obtained is then stirred at 25 C. for 1 to 2 hours until a clear solution is obtained. The solution is then sprayed as micrometer-sized droplets in a stream of hot gas (air) using a mono-nozzle with an aperture diameter of 0.7 mm. The circulation flow rate of the solution was set at 0.36 L.Math.h.sup.1. The flow rate of compressed air for the spraying was set at 670 L.Math.h.sup.1. The circulation of air for the suction of the sprayed droplets was set at 34 m.sup.3/h. The nominal sprayer inlet temperature was set at 170-180 C. so that the outlet temperature observed was about 90 C.

[0140] The particles thus synthesized and recovered in the recovery tank are then hermetically stored in a polypropylene flask at room temperature, to be subsequently calcined at 350 C. in an oven (ramp of 3 C./min and steady stage of 2 hours at 350 C.). The material obtained is in powder form and has a BET specific surface area of 695 m.sup.2/g. [0141] h) Mesostructured material with a micron-sized high specific surface area based on leachate from the washing of clinker, SiCl.sub.4, APTES and Brij 58 (molar composition: 1 leachate dry extract: 0.95 SiCl.sub.4: 0.05 APTES: 0.12 Brij 58).

[0142] The following compounds are added in order and with magnetic stirring (500 revolutions.Math.min.sup.1) to a 200 mL beaker: 12.5 mL of leachate from the washing of clinker with HCl (37% by mass), 100 mL of osmosed water and 10.25 g of Brij 58. The solution is then stirred at 60 C. until the Brij 58 has fully dissolved.

[0143] In a second 500 mL beaker, 12.27 g of SiCl.sub.4 stored at 4 C. are added dropwise (Pasteur pipette) to 21.04 mL of absolute ethanol stored at 4 C. Since the reaction is exothermic and highly reactive, this mixing takes place in an ice bath with vigorous stirring (1000 revolutions.Math.min.sup.1). The 0.84 g of aminopropyltriethoxysilane (APTES) is added dropwise (Pasteur pipette) to the SiCl.sub.4/ethanol solution. After dissolution of the surfactant and cooling of the leachate/Brij 58 solution to 25 C., this solution is added to the SiCl.sub.4/ethanol/APTES solution dropwise using a Pasteur pipette and with vigorous stirring (1000-1200 revolutions.Math.min.sup.1).

[0144] The solution obtained is then stirred at 25 C. for 1 to 2 hours until a clear solution is obtained. The solution is then sprayed as micrometer-sized droplets in a stream of hot gas (air) using a mono-nozzle with an aperture diameter of 0.7 mm. The circulation flow rate of the solution was set at 0.36 L.Math.h.sup.1. The flow rate of compressed air for the spraying was set at 670 L.Math.h.sup.1. The circulation of air for the suction of the sprayed droplets was set at 34 m.sup.3/h. The nominal sprayer inlet temperature was set at 170-180 C. so that the outlet temperature observed was about 90 C.

[0145] The particles thus synthesized and recovered in the recovery tank are then hermetically stored in a polypropylene flask at room temperature, to be subsequently calcined at 350 C. in an oven (ramp of 3 C./min and steady stage of 2 hours at 350 C.). The material obtained is in powder form and has a BET specific surface area of 410 m.sup.2/g. [0146] i) Mesostructured material with a micron-sized high specific surface area based on leachate from the washing of clinker, TEOS and CTAB (molar composition: 1 leachate dry extract: 1 TEOS: 0.28 CTAB).

[0147] The following compounds are added in order and with magnetic stirring (500 revolutions.Math.min.sup.1) to a 500 mL beaker: 25 mL of leachate from the washing of clinker with HCl (37% by mass), 200 mL of osmosed water and 15.49 g of CTAB. The solution is then stirred until the CTAB has fully dissolved.

[0148] After dissolution of the surfactant, 31.62 g of tetraethoxysilane (TEOS) are added to the solution dropwise using a Pasteur pipette. The solution is then stirred at 25 C. for 1 to 2 hours until a clear solution is obtained.

[0149] The solution is then sprayed as micrometer-sized droplets in a stream of hot gas (air) using a mono-nozzle with an aperture diameter of 0.7 mm. The circulation flow rate of the solution was set at 0.36 L.Math.h.sup.1. The flow rate of compressed air for the spraying was set at 670 L.Math.h.sup.1. The circulation of air for the suction of the sprayed droplets was set at 34 m.sup.3/h. The nominal sprayer inlet temperature was set at 170-180 C. so that the outlet temperature observed was about 90 C.

[0150] The particles thus synthesized and recovered in the recovery tank are then hermetically stored in a polypropylene flask at room temperature, to be subsequently calcined at 450 C. in an oven (ramp of 3 C./min and steady stage of 2 hours at 450 C.). The material obtained is in powder form and has a BET specific surface area of 485 m.sup.2/g.