Process for Producing a Binder

Abstract

The invention relates to a method of producing a binder comprising the steps of preparing (20) a residual material comprising amorphous alumina-rich and/or aluminium hydroxide-rich constituents, heating (30) the residual material to produce a fired material, the heating (30) of the residual material being at a temperature of >800° C.

Claims

1-20. (canceled)

21. A method for producing a binder comprising: Processing of a residual material comprising amorphous alumina-rich and/or aluminium hydroxide-rich components, Heating the residue to produce a fired material, wherein the heating of the residual material takes place at a temperature of >800° C.

22. The method of claim 21, wherein the residual material is formed at least partially in the form of water treatment residues.

23. The method according to claim 21, wherein the residual material has an X-ray amorphous content of more than 80 wt. %.

24. The method according to claim 21, wherein the processing of the residual material comprises the removal of water, the removal of water preferably being carried out at least via a heating or a mechanical dewatering process.

25. The method according to claim 21, wherein the processing of the residual material comprises comminution, the residual material preferably being shredded to a particle size of less than 100 μm.

26. The method according to claim 21, wherein the processing of the residual material takes place in such a way that a residual content of organic material remains in the residual material as a fuel source.

27. The method according to claim 21, wherein in addition, a source of calcium ions is added before the residual material is heated in order to produce a mixture of materials.

28. The method according to claim 21, wherein a source of sulphate ions is additionally added before the residual material is heated in order to produce a mixture of materials.

29. The method according to claim 21, wherein the substances 1) of a residual material, 2) the calcium ion source, and 3) the sulfate ion source in the following weight ratios: Component 1 at 10.0-100.0 wt. %, component 2 at 0.0-90.0 wt. % and component 3 at 0.0-90.0 wt. % based on the dry content of the sum of the weight of components 1, 2 and 3.

30. The method according to claim 21, wherein at least prior to heating of the residual material or prior to heating of the material mixture, an addition of water takes place for the formation of intermediate products containing hydrate phases.

31. The method according to claim 21, wherein additionally a processing of the hydrate phase-containing intermediate products is provided, the processing preferably comprising at least a drying or shredding.

32. The method according to claim 21, wherein a compacting of at least the residual material or of the material mixture or of the intermediate products containing hydrate phases is provided for minimizing the proportion of fine material, the compacting preferably comprising at least a briquetting for the production of briquettes or a pelletizing for the production of pellets or a granulating for the production of granules or a pressing for the production of pressed bodies.

33. The method according to claim 21, wherein at least the heating of the residual material or of the mixture of materials or of the prepared hydrate phase-containing intermediate products takes place at a temperature of >800° C.

34. The method of claim 33, wherein the heating takes place at least in a rotary (tubular) kiln or in a melting furnace or in an electric arc furnace or in a tub shaft kiln or in a fluid bed thermal calciner.

35. The method according to claim 21, wherein a preparation of the fired material is provided, wherein the preparation of the fired material comprises shredding, wherein the fired material is preferably shredded to a particle size of less than 100 μm.

36. The method according to claim 21, wherein the preparation of the fired material comprises the addition of additives at least such as grinding aids, ageing inhibitors or anti-dusting agents.

37. A binder, wherein the binder comprises at least aluminates or calcium aluminates or calcium sulfoaluminates.

38. The binder according to claim 35, wherein the calcium aluminate comprises at least CA or CA2 or C3A or C12A7 or the calcium sulfoaluminates comprise CSA.

39. A use of a binder comprising at least aluminates and/or calcium aluminates and/or calcium sulfoaluminates, for the manufacture of a construction chemical product, preferably a screed, a filling compound, a tile adhesive, a levelling compound, a mortar, a grout or a plaster.

40. A construction chemical product comprising a binder comprising at least aluminates and/or calcium aluminates and/or calcium sulfoaluminates, wherein the binder is present in the construction chemical product at a level of 0.1 wt. %-80 wt. %, wherein the construction chemical product additionally comprises at least fillers or additives.

Description

[0065] It shows:

[0066] FIG. 1 a schematic representation of a phase diagram of exemplary phases of a calcium aluminate cement,

[0067] FIG. 2a a schematic representation of the individual steps of a process according to the invention for producing a binder according to a first embodiment,

[0068] FIG. 2b a schematic representation of the individual steps of a method according to the invention for producing a binder according to a second embodiment,

[0069] FIG. 2c a schematic representation of the individual steps of a process according to the invention for producing a binder according to a third embodiment,

[0070] FIG. 3 a schematic representation of various heat calorimetric measurements a to f.

[0071] FIG. 1 shows a schematic representation of a phase diagram of exemplary phases of a calcium aluminate cement. For the production of calcium aluminate cements, the raw materials used must be brought to temperatures close to the necessary solid/liquid phase transition, which, as can be seen from FIG. 1, are generally at least >1700 K (>1430° C.). By using the method according to the invention, not only can residual materials be sensibly reused, but also the necessary production temperature for the production of aluminate-containing binders can be significantly reduced. According to the findings of the invention, this is due in particular to the upstream formation of hydrates, which significantly reduces the firing temperature required to produce the binder according to the invention, in contrast to known firing temperatures.

[0072] FIG. 2a shows a schematic representation of the individual steps of a method according to the invention for producing a binder according to a first embodiment.

[0073] In this regard, the method according to the first embodiment of the invention may be particularly referred to as the calcium aluminate route and comprises the steps of preparing 20 an amorphous alumina-containing and/or aluminum hydroxide-containing residual material, adding 22 a calcium ion source, and adding 26 water to form a hydrate phase-containing intermediate. Further, according to the first embodiment, the method comprises preparing 28 the hydrate phase-containing intermediate and heating 30 the material to produce a firing material, wherein the heating of the feed material is at >800° C.

[0074] Subsequently, in the method according to the first embodiment, the heated material is further processed 32 to obtain binders before the binder can be used 34 to produce a construction chemical product and the construction chemical product can be used 36 as a screed, filling compound, tile adhesive, levelling compound or mortar.

[0075] FIG. 2b shows a schematic representation of the individual steps of a method according to the invention for producing a binder according to a second embodiment.

[0076] The process according to the second embodiment, referred to herein as the calcium sulfoaluminate route, differs from the process according to the first embodiment only in that, in addition to an addition 22 of a calcium ion source, there is an addition 24 of a sulfate ion source prior to an addition 26 of water to form a hydrate phase-containing intermediate.

[0077] FIG. 2c shows a schematic representation of the individual steps of a method according to the invention for producing a binder according to a third embodiment.

[0078] The process according to the third embodiment proceeds without addition of water and, in contrast to the embodiment according to FIGS. 2a and b, comprises only the steps of preparing 20 an amorphous alumina-containing and/or aluminum hydroxide-containing residual material, adding 22 a calcium ion source, and heating 30 the material to produce a firing material, wherein the heating of the feed material is carried out at >800° C.

[0079] FIG. 3 shows a schematic representation of various heat calorimetric measurements a) to f).

[0080] These heat calorimetric measurements show the heat development of various construction chemical products, each of which contains different binders produced according to the invention in a proportion of 20 wt. %. Two different hydrate phase-containing intermediates were used for the binder production. For the preparation of the hydrate phase-containing intermediates, according to the invention, the following were available: [0081] 1) a processed amorphous alumina-containing and/or alumina-hydroxide-containing residual material [0082] 2) a source of calcium ions [0083] 3) a source of sulphate ion source (not used here)

[0084] For (a, b, c), a molar mixing ratio of 50% 1 (based on aluminum content) and 50% 2 (based on calcium ion content) was used. These resulting binders were internally referred to as CA binders. For (d, e, f), a molar mixing ratio of 66.6% 1 (based on the aluminum content) and 33.3% 2 (based on the calcium ion content) was used. These resulting binders were internally referred to as CA2 binders. Varying firing temperatures were used in the preparation of the binders. For (a, d), 180° C. was used. For (b, e) 800° C. was used and for (c, f) 980° C. was used.

[0085] The measurements of the heat development provide indirect information about the setting behaviour of the respective binder-containing building chemical product. A fast and strong heat development (measured here in the form of the voltage in mV) corresponds to a fast setting of the binder-containing constructing chemical product.

[0086] As can be seen from the plot in FIG. 3, the construction chemical products were measured calorimetrically for 2 hours after the addition of water. As can be seen from FIG. 3, the main reaction peak, i.e. the heat generated during the setting of the building chemical products, shifts to later times the higher the firing temperature of the respective binder used.

[0087] For example, the construction chemical products (a, d), whose binders were fired at a temperature of 180° C., show a strong heat development directly after the addition of water. Such construction chemical products are difficult to use because they set and harden too quickly and do not allow the user sufficient time to bring the construction chemical product into a desired shape.

[0088] The construction chemical products containing binders fired at a firing temperature of 800° C. (b, e) show a rapid but controllable heat development. After about 5 to 10 min, a sharp peak is observed, which then flattens out considerably.

[0089] The construction chemical products containing binders fired at 980° C. (c, f), in turn, have a very practicable processing time.

[0090] The absolute maximum of the heat development, which represents a parameter that is easy to determine and yet meaningful for determining the processing time of a construction chemical product, is above 60 minutes for both construction chemical products with binders with a firing temperature of 980° C. (c, f).

[0091] At firing temperatures >800° C., it is thus possible to produce binders tailored to the firing temperature for a wide range of construction chemical products (fast-setting and slow-setting products).

[0092] Examples of Embodiments:

[0093] For the preparation of a binder according to the invention, it is first provided that, in addition to a prepared amorphous residual material containing aluminium oxide and/or aluminium hydroxide, optionally additionally a calcium ion source and/or optionally additionally a sulphate ion source is added. The optional addition of the calcium ion source and/or the sulfate ion source is thereby preferably carried out before the optional addition of water, which can advantageously be added to form hydrate phase-containing intermediates, so that before the optional addition of the water a mixture of: [0094] 1) Processed amorphous alumina-containing and/or aluminium hydroxide-containing residual material [0095] 2) if necessary, additionally a calcium ion source [0096] 3) if necessary, additionally a sulphate ion source.

[0097] By marking the addition of water to form hydrate phase-containing intermediate products as an optional step, it is understood that the subsequent. Examples of embodiments can also be produced without the addition of water, for example merely by the addition of prepared amorphous residual material containing aluminium oxide and/or aluminium hydroxide and subsequent heating at a temperature of >800° C. or by the addition of prepared amorphous residual material containing aluminium oxide and/or aluminium hydroxide, a calcium ion source and/or a sulphate ion source and subsequent heating at a temperature of >800° C.

[0098] After carrying out the method steps provided according to the invention, the possible resulting binders have, among other things, the mineral phases CA and/or CA.sub.2 and/or CA.sub.3 and/or C.sub.12A.sub.7 and/or CSA in various concentrations, depending on the raw material used. A particular advantage of the present invention is that the main mineral phases of the resulting binder can be easily and flexibly adjusted by the mixing ratio of the three components 1, 2 and 3.

[0099] Some exemplary formulations for these mixtures are given below. The ratios given are to be understood as molar ratios, based on the aluminium content in the prepared amorphous alumina-containing and/or aluminium hydroxide-containing residue (1), on the calcium content in the calcium ion source (2) and on the sulphate content in the sulphate ion source (3).

[0100] Binder Mixture 1 (CA Mixture): [0101] 1) 76.2% [0102] 2) 23.8% [0103] 3) 0.0%

[0104] Binder Mixture 2 (CA.sub.2 Mixture): [0105] 1) 85.4% [0106] 2) 14.6% [0107] 3) 0.0%

[0108] Binder Mixture 3 (C.sub.12A.sub.7 Mixture): [0109] 1) 66.1% [0110] 2) 33.9% [0111] 3) 0.0%

[0112] Binder Mixture 4 (CSA Mixture): [0113] 1) 53.3% [0114] 2) 20.0% [0115] 3) 26.7%

[0116] Binder Mixture 5 (Pure Aluminate-Containing Binder): [0117] 1) 100% [0118] 2) 0% [0119] 3) 0%

[0120] In particular, the binders according to the invention can be prepared according to a method according to the invention by providing components (1) or mixtures of components 1, 2 and 3, optionally adding water to these components or mixtures to form hydrates, preparing these hydrates, and heating the prepared hydrates to a temperature of >800° C.

[0121] As described above, the binders of the invention can also be prepared without the addition of water to form hydrate phase intermediates.

[0122] The versatile, different binders according to the invention which can be produced by means of the mixtures listed in the embodiments are not only versatile in use and can be produced simply and inexpensively, but also at the same time make a contribution to sustainable construction, which is provided in particular by the fact that resources are conserved for the production of the hydraulic binders by using residual or waste materials for the production of the binders, which would otherwise have to be disposed of in a complex and cost-intensive manner.

LIST OF REFERENCE SIGNS

[0123] 1 Residual component

[0124] 2 Calcium ion source component

[0125] 3 Sulphate ion source component

[0126] 20 Preparation of an amorphous residual material rich in aluminium oxide and/or aluminium hydroxide

[0127] 22 Adding a calcium ion source

[0128] 24 Adding a sulfate ion source

[0129] 26 Addition of water to form hydrate phase intermediates

[0130] 28 Preparation of the intermediate products containing hydrate phases

[0131] 30 Heating of the residual material/mixture of materials/prepared intermediate products containing hydrate phases

[0132] 32 Preparation of the fired material

[0133] 34 Use of the binder for the manufacture of a construction chemical product,

[0134] 36 Use of the construction chemical product

[0135] U Voltage

[0136] mV Millivolt

[0137] T Time

[0138] h Hours

[0139] K Kelvin

[0140] C CaO

[0141] A Al.sub.2O.sub.3

[0142] S SO.sub.3

[0143] a construction chemical product containing 20 wt. % of a raw material based binder, internally designated as “CA”, produced at 180° C.

[0144] b construction chemical product containing 20 wt. % of a raw material based binder, internally designated “CA”, prepared at 800° C.

[0145] c Construction chemical product containing 20 wt. % of a raw material based binder, internally designated “CA”, prepared at 980° C.

[0146] d construction chemical product containing 20 wt. %of a raw material based binder, internally designated “CA.sub.2”, prepared at 180° C.

[0147] e construction chemical product containing 20 wt. % of a raw material based binder, internally designated as “CA.sub.2”, produced at 800° C. construction chemical product containing 20 wt. % of a raw material based binder, internally designated “CA.sub.2”, prepared at 980° C.