Self-foaming geopolymer composition containing aluminum dross

Abstract

The present invention relates to a self-foaming geopolymer composition comprising at least one hydraulic binder; at least one binder selected from latent hydraulic binders, pozzolanic binders, and mixtures thereof; at least one alkaline activator; and aluminum dross. It moreover relates to the use of that geopolymer composition for the production of geopolymer foams and/or foamed geopolymer products.

Claims

1. A self-foaming geopolymer composition comprising: at least one hydraulic binder, wherein the hydraulic binder is selected from portland cement, high alumina cement, calcium sulphoaluminate cement, portland composite cement according to classes CEM II to V, and mixtures thereof; at least one binder selected from latent hydraulic binders, pozzolanic binders, and mixtures thereof; at least one alkaline activator; and aluminum dross.

2. The composition of claim 1, wherein the latent hydraulic binder is selected from blast furnace slag, electrothermic phosphorus slag, steel slag, and mixtures thereof.

3. The composition of claim 1, wherein the latent hydraulic binder is blast furnace slag.

4. The composition of claim 1, wherein the pozzolanic binder is selected from amorphous silica, precipitated silica, pyrogenic silica, microsilica, ground glass, fly ash, brown-coal fly ash, mineral-coal fly ash, metakaolin, natural pozzolanas, tuff, trass, volcanic ash, natural zeolites, synthetic zeolites, and mixtures thereof.

5. The composition of claim 4, wherein the pozzolanic binder is selected from pyrogenic silica, microsilica, fly ash, metakaolin, and mixtures thereof.

6. The composition of claim 5, wherein the pozzolanic binder is metakaolin.

7. The composition of claim 1, wherein the alkaline activator is selected from alkali metal carbonates, alkali metal fluorides, alkali metal hydroxides, alkali metal aluminates, alkali metal silicates, and mixtures thereof.

8. The composition of claim 7, wherein the alkaline activator is selected from alkali metal hydroxides, alkali metal silicates, and mixtures thereof.

9. The composition of claim 8, wherein the alkali metal silicate is selected from compounds having the empirical formula in SiO.sub.2.n M.sub.2O, in which M is the alkali metal, Li, Na, K or a mixture thereof, and the molar ratio of m:n is 4.0.

10. The composition of claim 1, wherein the aluminum dross comprises 50 to 99.9% by weight oxides and/or nitrides, and 0.1 to 50% by weight metallic aluminum.

11. The composition of claim 10, wherein the aluminum dross comprises 75 to 99% by weight oxides and/or nitrides, and 1 to 25% by weight metallic aluminum.

12. The composition of claim 11, wherein the oxides comprise Al.sub.2O.sub.3 and SiO.sub.2.

13. The composition of claim 1, wherein the hydraulic binder is portland cement.

14. The composition of claim 1, further comprising a surfactant.

15. The composition of claim 14, wherein the surfactant is an alkyl polyglucoside.

16. The composition of claim 1, further comprising water.

17. The composition of claim 16, further comprising a gas phase comprising hydrogen gas.

18. The composition of claim 1, wherein the molar ratio of metallic aluminum to alkali metal (Al/M) is 0.3.

Description

EXAMPLES

(1) General Remarks:

(2) A typical composition of the aluminum dross type CAI-Alon B (Cast Aluminium Industries, Dubai, UAE) was as follows [% by weight]:

(3) TABLE-US-00001 Al (metallic) 13.7 N 4.3 Al.sub.2O.sub.3 73.0 SiO.sub.2 4.0 CaO 3.1 MgO 1.5 Fe.sub.2O.sub.3 0.4

(4) A typical composition of the aluminum dross type CAI-Alon S (Cast Aluminium Industries, Dubai, UAE) was as follows [% by weight]:

(5) TABLE-US-00002 Al (metallic) 10.9 N 4.3 Al.sub.2O.sub.3 75.0 SiO.sub.2 3.9 CaO 3.7 MgO 1.8 Fe.sub.2O.sub.3 0.4

(6) The basic formulation is a two component system where the liquid components and the solid components are mixed together. The shelf life of the separate components is thus very high. Percentages are given in percent by weight. The quantities shown hereinbelow are calculated for small sample specimens for compressive strength measurement. For preparation of plate specimens for lambda value measurements the quantities given below must be multiplied by the factor of 5.3.

(7) The lambda values are given in mW/(m*K). The Instrument for lambda value measurement was a Lambda-Meter EP500 according to EN 1946-2 from Lambda-Messtechnik GmbH, Dresden, Germany. The thickness of the test specimen was measured according to EN 823, and the heat conductivity measurement was performed according to ISO 8320/EN 12667 at a pressure of 1000 Pa.

(8) Compressive strength was measured on a MEGA 110-300DM1 instrument from FORM+TEST Seidner & Co. GmbH, Riedlingen. Values are given in N/mm.sup.2. The testing velocity was 1.5 N/mm.sup.2 per second.

Example 1a

(9) TABLE-US-00003 27.0 g Potassium waterglass K45M (Woellner GmbH&Co KG, 40.5% solids, mod. 1.0) 15.4 g Distilled water 0.5 g Triton CG 110 (Dow Chemicals, C.sub.8-10 alkyl polyglucoside surfactant, m = 1-5) 15.4 g Metakaolin (Argical 1200 S, AGS SA Clerac) 10.4 g Mineral Coal Fly Ash (L-10, Evonik Industries) 3.8 g Portland Cement (CEM I, Schwenk Zement KG, Mergelstetten) 1.9 g Tegostab B 8407 (Evonik Industries, silicone oil-based surfactant) 1.0 g Aerosil 200 (Evonik Industries, pyrogenic silica) 6.0 g CAI-Alon B (aluminum dross)
were blended. The pot-life was 10 min. Foaming completed after 35 min. A stable foam was obtained after curing for 24 h. After water removal (drying to weight constancy) the foam density was 302 g/l.

Example 1b (Comparative)

(10) TABLE-US-00004 27.0 g Potassium waterglass K45M (Woellner GmbH&Co KG, 40.5% solids, mod. 1.0) 15.4 g Distilled water 0.5 g Triton CG 110 (Dow Chemicals, alkyl polyglucoside surfactant) 15.4 g Metakaolin (Argical 1200 S, AGS SA Clerac) 10.4 g Mineral Coal Fly Ash (L-10, Evonik Industries) 0.0 g Portland Cement 1.9 g Tegostab B 8407 (Evonik Industries, silicone oil-based surfactant) 1.0 g Aerosil 200 (Evonik Industries, pyrogenic silica) 6.0 g CAI-Alon B (aluminum dross)
were blended. The pot-life was 10 min. Foaming completed after 18 minutes. After these 18 minutes the foam started immediately to collapse and collapse was completed after 30 min. After 24 h only powder is yielded, no hardened foam.

Example 2

(11) TABLE-US-00005 27.0 g Potassium waterglass K45M 15.4 g Distilled water 0.5 g Triton CG 110 (Dow Chemicals, alkyl polyglucoside surfactant) 15.4 g Metakaolin (Argical 1200 S, AGS SA Clerac) 10.4 g Mineral Coal Fly Ash (L-10, Evonik Industries) 3.8 g Portland Cement (CEM I, Schwenk Zement KG, Mergelstetten) 4.0 g Kieselgel 60, (0.04-0.063 mm, 230-400 mesh, Carl Roth GmbH + Co. KG) 6.0 g CAI-Alon B (aluminum dross)
were blended. The pot-life was 10 min. Foaming completed after 35 min.

Example 3

(12) TABLE-US-00006 27.0 g Potassium waterglass K45M 15.4 g Distilled water 0.5 g Triton CG 110 (Dow Chemicals, alkyl polyglucoside surfactant) 15.4 g Metakaolin (Argical 1200 S, AGS SA Clerac) 10.4 g Aluminosilicate hollow spheres (Fillite 106, OMYA GmbH) 3.8 g Portland Cement (CEM I, Schwenk Zement KG, Mergelstetten) 4.0 g Kieselgel 60 (0.04-0.063 mm, 230-400 mesh, Carl Roth GmbH + Co. KG) 4.0 g CAI-Alon B (aluminum dross)
were blended. The pot-life was 15 min. Foaming completed after 35 min.

Example 4

(13) TABLE-US-00007 27.0 g Potassium waterglass K45M 15.4 g Distilled water 0.5 g Triton CG 110 (Dow Chemicals, alkyl polyglucoside surfactant) 15.4 g Metakaolin (Argical 1200 S, AGS SA Clerac) 10.4 g Mineral Coal Fly Ash (L-10, Evonik Industries) 3.8 g Portland Cement (CEM I, Schwenk Zement KG, Mergelstetten) 1.9 g Tegostab B 8407 (Evonik Industries, silicone oil-based surfactant) 4.0 g Kieselgel 60 (0.04-0.063 mm, 230-400 mesh, Carl Roth GmbH + Co. KG) 6.0 g CAI-Alon S (aluminum dross)
were blended. The pot-life was 6 min. Foaming completed after 25 min.

Example 5

(14) TABLE-US-00008 27.0 g Sodium waterglass Betol 39T (Woellner GmbH&Co KG, calculated as solids) 15.4 g Distilled water 0.5 g Triton CG 110 (Dow Chemicals, alkyl polyglucoside surfactant) 15.4 g Metakaolin (Argical 1200 S, AGS SA Clerac) 10.4 g Mineral Coal Fly Ash (L-10, Evonik Industries) 3.8 g Portland Cement (CEM I, Schwenk Zement KG, Mergelstetten) 4.0 g Kieselgel 60 (0.04-0.063 mm; 230-400 mesh, Carl Roth GmbH + Co. KG) 4.0 g CAI-Alon B
were blended. The pot-life was 12 min. Foaming completed after 30 min.

Example 6

(15) TABLE-US-00009 27.0 g Potassium waterglass K45M 15.4 g Distilled water 0.5 g Triton CG 110 (Dow Chemicals, alkyl polyglucoside surfactant) 15.4 g Metakaolin (Argical 1200 S, AGS SA Clerac) 10.4 g Mineral Coal Fly Ash (L-10, Evonik Industries) 10.4 g Blast furnace slag (Heidelberger Httensand SLAG SH 20, HeidelbergCement AG) 3.8 g Portland Cement (CEM I, Schwenk Zement KG, Mergelstetten) 4.0 g Kieselgel 60 (0.04-0.063 mm, 230-400 mesh, Carl Roth GmbH + Co. KG) 4.0 g CAI-Alon B
were blended. The pot-life was 5 min. Foaming completed after 20 min.

Example 7

(16) TABLE-US-00010 27.0 g Potassium waterglass K45M 15.4 g Distilled water 0.5 g Triton CG 110 (Dow Chemicals, alkyl polyglucoside surfactant) 15.4 g Metakaolin (Argical 1200 S, AGS SA Clerac) 10.4 g Mineral Coal Fly Ash (L-10, Evonik Industries) 3.8 g Portland Cement (CEM I, Schwenk Zement KG, Mergelstetten) 4.0 g Hollow glass spheres S22 (OMYA) 4.0 g CAI-Alon B (aluminum dross)
were blended. The pot-life was 10 min. Foaming completed after 35 min.

Example 8

(17) TABLE-US-00011 27.0 g Sodium waterglass Betol 39T 15.4 g Distilled water 0.5 g Triton CG 110 (Dow Chemicals, alkyl polyglucoside surfactant) 15.4 g Metakaolin (Argical 1200 S, AGS SA Clerac) 10.4 g Mineral Coal Fly Ash (L-10, Evonik Industries) 3.8 g Portland Cement (CEM I, Schwenk Zement KG, Mergelstetten) 1.0 g Aerosil 200 (Evonik Industries, pyrogenic silica) 6.0 g CAI-Alon B
were blended. The pot-life was 10 min. Foaming completed after 30 min.

Example 9 (Comparative)

(18) TABLE-US-00012 27.0 g Potassium waterglass K45M (Woellner GmbH&Co KG, 40.5% solids, mod. 1.0) 15.4 g Distilled water 0.5 g Triton CG 110 (Dow Chemicals, alkyl polyglucoside surfactant) 15.4 g Metakaolin (Argical 1200 S, AGS SA Clerac) 10.4 g Mineral Coal Fly Ash (L-10, Evonik Industries) 3.8 g Portland Cement (CEM I, Schwenk Zement KG, Mergelstetten) 1.9 g Tegostab B 8407 (Evonik Industries, silicone oil-based surfactant) 1.0 g Aerosil 200 (Evonik Industries, pyrogenic silica) 720 mg Aluminum Powder (Sigma Aldrich, <5 micrometer) 5.28 g Al.sub.2O.sub.3 Powder (Sigma Aldrich, puriss.)
were blended. The pot-life was only 5 sec. Foaming completed after 5 min. No stable foamed material could be obtained.

(19) A comparison of the formulations of Examples 1a (inventive) and 1b (comparative) shows that without the presence of a hydraulic binder (here: Portland Cement) no hardened foam could be obtained. A comparison of the formulations of Examples 1a and 2 demonstrates that a certain foaming behavior and foaming degree could be achieved from different compounds via targeted formulation. The formulation of Example 3 demonstrates that fly ash could be replaced by a silicate based binder/filler (Fillite). The formulation of Example 4 demonstrates the robustness of the foaming process, i.e. the system was not sensitive towards slight changes in composition of the aluminum dross. The formulation of Example 5 shows that the use of sodium water glass instead of potassium water glass was also possible. The formulation of Example 6 demonstrates the versatility of applicable raw materials, e.g. fly ash could be replaced by blast furnace slag. The formulation of Example 7 shows that through the use of additional light weight filler components, such as hollow glass spheres, the thermal insulation property of the final material could be further improved (see Table 1 below).

(20) The comparative Example 9 demonstrates that aluminum must be present in the form of aluminum dross. Otherwise no useful pot-life and no stable foamed material is obtained.

Example 10

(21) A typical thermal insulation plate was prepared via the following procedure. First, the solid compounds containing the aluminum dross, the hydraulic binder, the geopolymer binder and solid additives and the liquid compounds containing water glass, surfactant and liquid additives were mixed together. Then, the mixture was poured into a mold. After a certain time period the mixture started to foam (pot-life). The foaming was completed after another time period (given in Examples 1-8) ending up with a wet inorganic foam. After the foaming was completed the plate was cured. The curing took place in a closed or opened mold between 0 C. and 100 C. in dry or 100% humid air. Depending on the curing conditions, the thermal insulation coefficient and compressive strength, the most important parameters characterizing the performance of the panel, varied. Typically, however, the mixture was covered after foaming with a plastic foil to reduce evaporation, the mixture was then allowed to stand for 24 h at room temperature, 24 h at 40 C., was heated in 10 C./4 h steps to 80 C., and was then removed from the mold. It was further stored 24 h at 80 C. for complete drying.

(22) Plates with the dimensions of 28028555 mm, which have been used for lambda-value measurements, and cubes with 30 mm dimension, which have been used for compressive strength measurements, were produced form the formulations of Examples 1-8. (In lager batches as used for plate production the temperature increased by about 10 C. due to exothermic reactions.) The properties of some formulations and specimens are given in Table 1 below.

(23) TABLE-US-00013 TABLE 1 Example: 1a 2 7 8 Density [kg/m.sup.3] 302 290 229 284 Lambda value [mW/(m * K)] 60 63 55 61 Compressive strength [kN/mm.sup.2] 0.2 0.2 0.3 0.4