Method for Producing Solid Particles, Solid Particles, and the Use Thereof

Abstract

The invention relates to a method for producing solid particles from an inorganic solid containing at least one alkali metal and/or alkaline earth metal, comprising at least the following steps: a) providing the inorganic solid containing at least one alkali metal and/or alkaline earth metal; b) extracting the at least one alkali metal and/or alkaline earth metal from the inorganic solid containing alkali metal and/or alkaline earth metal to obtain an extract containing the alkali metal and/or alkaline earth metal and an alkali metal-depleted and/or alkaline earth metal-depleted residue; c) separating the extract from the residue; d) processing the residue to obtain the solid particles, wherein at least one of the processing steps is selected from a group comprising transporting, filling, packaging, washing, drying, adjusting the pH value, separating according to a mean grain size and/or mass and/or density, adjusting a mean grain size, magnetic separating, calcining, thermal rounding and surface coating.

Claims

1-15. (canceled)

16. A method for producing solid particles from an inorganic solid containing at least one alkali metal and/or alkaline earth metal, comprising at least the following steps: a) providing the inorganic solid containing at least one alkali metal and/or alkaline earth metal; b) extracting the at least one alkali metal and/or alkaline earth metal from the inorganic solid containing alkali metal and/or alkaline earth metal to obtain an extract containing the alkali metal and/or alkaline earth metal and an alkali metal-depleted and/or alkaline earth metal-depleted residue; c) separating the extract from the residue; d) processing the residue to obtain the solid particles, wherein at least one processing step is selected from a group comprising transporting, filling, packaging, washing, drying, adjusting the pH value, separating according to a mean grain size and/or mass and/or density, adjusting a mean grain size, magnetic separating, calcining, thermal rounding and surface coating.

17. The method according to claim 16, wherein the residue is a lithium-depleted and/or magnesium-depleted residue, the residue comprising less than 7 mass % of the extracted alkali metal and/or alkaline earth metal.

18. The method according to claim 16, wherein the residue is a lithium-depleted and/or magnesium-depleted residue, the residue comprising less than 1.5 mass % of the extracted alkali metal and/or alkaline earth metal.

19. The method according to claim 16, wherein step d) comprises at least two of the processing steps mentioned.

20. The method according to claim 19, wherein the processing steps take place separately from one another in space and/or time.

21. The method according to claim 16, wherein the solid particles have a whiteness determined according to R 457 of >50%, and/or a brightness value (L* value) determined according to EN ISO 11664-4 of >60.

22. The method according to claim 16, wherein the solid particles have a whiteness determined according to R 457 of >80%, and/or a brightness value (L* value) determined according to EN ISO 11664-4 of >80.

23. The method according to claim 16, wherein the solid particles have a specific surface area (BET) in a range from 0.01 m.sup.2/g to 300 m.sup.2/g.

24. The method according to claim 16, wherein step d) comprises at least four of the processing steps mentioned.

25. The method according to claim 16, wherein the solid particles have a mean grain size (d50, Sedigraph) in a range between 0.1 μm-5 mm.

26. The method according to claim 24, wherein the processing steps take place separately from one another in space and/or time.

27. The method according to claim 16, the solid particles have a silicate component, an aluminum silicate component, or both.

28. Solid particles obtained from a residue of an alkali metal and/or alkaline earth metal extraction from an inorganic solid containing at least one alkali metal and/or alkaline earth metal, wherein the solid particles are a residue that is transported, filled, packaged, washed, dried, pH value-adjusted, separated according to a mean grain size, mass and/or density, adjusted based on a mean grain size, magnetically separated, calcined, thermally rounded, surface-coated, or combinations thereof.

29. The solid particles according to claim 28, wherein the solid particles comprise at least two of the properties listed.

30. The solid particles according to claim 28, wherein the solid particles have a surface coating.

31. The solid particles according to claim 28, wherein the solid particles have a specific surface area (BET) in a range from 0.1 m.sup.2/g to 250 m.sup.2/g.

32. The solid particles according to claim 28, wherein the solid particles have a mean grain size (d50, Sedigraph) in a range between 0.1 μm-5 mm.

33. The solid particles according to claim 28, wherein the solid particles have a whiteness determined according to R 457 of >70% and/or a brightness value (L* value) determined according to EN ISO 11664-4 of >70.

34. The solid particles according to claim 28, wherein the solid particles have a silicate component, an aluminum silicate component, or both.

35. A product comprising the solid particles of claim 28, wherein the product is selected from the group consisting of: fillers, paints, varnishes, polymers, paper, paper fillers, release agents, free-flow agents, refractory materials, casting additives, adsorbers, absorbers, carriers, filtration additives, medical and/or agricultural products, composite materials, rubber and tyres.

Description

[0098] The invention is explained in greater detail below with reference to the following drawings. In the drawings:

[0099] FIG. 1a, b shows a morphology of solid particles from a lithium-depleted residue (example TLR 5.0);

[0100] FIG. 2a, b shows a morphology of solid particles from a lithium-depleted residue (example TLR 7.0).

[0101] In FIGS. 1a and 1b, SEM images of particles of a lithium-depleted residue are shown. The particles correspond to the sample TLR 5.0 and were imaged after calcination and extraction.

[0102] In FIGS. 2a and 2b, SEM images of particles of a lithium-depleted residue are shown. The particles correspond to the sample TLR 7.0 and were imaged after calcination and extraction.

[0103] The particles of the samples TLR 5.0 and TLR 7.0 each show a splintery and irregular grain shape. In addition, pores, gaps and crevices resulting from the chemical treatment before and during the extraction can be seen, which are more pronounced with TLR 7.0 than with TLR 5.0.

EXAMPLES

[0104] Two mineral concentrates or concentrates (the inorganic solid containing at least one alkali metal and/or alkaline earth metal) which originate from lithium extraction and substantially consist of spodumene, comprising a) 5.0 mass % of Li.sub.2O and b) 7.0 mass % of Li.sub.2O, were subjected to a calcination and leaching process (extraction) on a laboratory scale under the following conditions:

[0105] Roasting temperature: 1100° C.

[0106] Roasting time: 1 h

[0107] Baking temperature: 250° C.

[0108] Baking time: 1 h

[0109] H.sub.2SO.sub.4/spodumene: 0.3

[0110] Water/spodumene: 3:1

[0111] Washing solution/spodumene: 1:1

[0112] Extraction temperature: 90° C.

[0113] Extraction time: 1 h

[0114] After the above extraction or leaching, two lithium-depleted residues and therefrom the solid particles according to the invention were obtained, which are referred to below as TLR 5.0 and TLR 7.0 (TLR=test leach residue). The following chemical, physical and mineralogical properties were determined from TLR 5.0 and TLR 7.0, which are shown in Table 1.

TABLE-US-00001 TABLE 1 Physical properties and chemical composition of samples TLR 5.0 and TLR 7.0. Measurement Properties method TLR 5.0 TLR 7.0 Mean particle size Sedigraph 6.2 5.0 d.sub.10 [μm] Mean particle size Sedigraph 80 11 d.sub.50 [μm] Mean particle size Sedigraph 440 60 d.sub.90 [μm] Whiteness [%] R 457 92.9 92.7 Yellow value [%] EN ISO 1.9 2.5 11664-4 L* (LAB colour space) 97.8 97.8 a* (LAB colour space) 0.02 0.24 b* (LAB colour space) 1.0 1.2 Y (XYZ colour space) 94.3 94.4 x (XYZ colour space) 0.3156 0.3162 y (XYZ colour space) 0.3328 0.3331 Specific surface area 4.8 11.2 BET [m.sup.2/g] Oil absorption value 28 46 (pigments/dyes) [g/100 g] Bulk density [kg/dm.sup.3] 0.645 0.315 Density [g/cm.sup.3] 2.62 2.44 (pycnometer, H.sub.2O) pH value (soil) 3.1 4.1 Lithium oxide [mg/kg] 1100 9300 Rubidium oxide [mg/kg] 790 270 Chapelle test 1100 920 [mg Ca(OH).sub.2/g] (measure- ment on a fraction <63 μm) SiO.sub.2 [mass %] 77.5 67.5 Al.sub.2O.sub.3 [mass %] 18.1 26.4 Fe.sub.2O.sub.3 [mass %] 0.06 0.09 TiO.sub.2 [mass %] 0.01 0.03 K.sub.2O [mass %] 0.55 0.16 Na.sub.2O [mass %] 0.19 0.03 CaO [mass %] <0.01 <0.01 MgO [mass %] <0.01 <0.01 PbO [mass %] <0.01 <0.01 BaO [mass %] <0.01 <0.01 SO.sub.3 [mass %] <0.01 <0.01 MnO [mass %] 0.04 0.06 P.sub.2O.sub.5 [mass %] 0.03 0.06 ZrO [mass %] <0.01 0.01 GV (1025° C.) [mass %] 3.2 4.5

[0115] The mean particle size (d.sub.50, Sedigraph) of TLR 7.0 at 11 μm is significantly finer than TLR 5.0 at 80 μm due to the processing.

[0116] The degree of whiteness (measured according to ISO, R 457) is 92% for TLR 5.0 and TLR 7.0, which is higher than, for example, kaolin calcinates at +/−90%.

[0117] The yellow value of 1.9% for TLR 5.0 and 2.5% for TLR 7.0 is very low compared to calcinates with a yellow value of approx. 3-5%.

[0118] The specific surface area (BET) increases with the fineness and, in the case of TLR 7.0, at 11.2 m.sup.2/g is lower than calcinates at about 2-3 m.sup.2/g.

[0119] The oil absorption value also increases with the fineness, with the oil absorption value of TLR 7.0 being 46 g/100 g.

[0120] The pH value is slightly acidic with pH 3.1 for TLR 5.0 and 4.1 for TLR 7.0.

[0121] TLR 5.0 and TLR 7.0 are hydraulically active and, according to the Chapelle test, at the level of medium metakaolin.

[0122] The chemical compositions of TLR 5.0 and TLR 7.0 show the remaining Al-silicate structure (Al—Si—O structure), which comes from the spodumene.

[0123] The iron content is very low at <0.1 mass % for TLR 5.0 and TLR 7.0.

[0124] The higher Li content of the concentrate of TLR 7.0 was also found in the residue; just under 1.0 mass % in TLR 7.0.

[0125] The grain size distribution of TLR 5.0 and TLR 7.0 was also determined. The values are shown in Table 2.

TABLE-US-00002 TABLE 2 Grain size distribution of TLR 5.0 and TLR 7.0 Grain TLR 5.0 TLR 7.0 size [μm] [wt.- %] [wt.- %] 720 100 100 630 98.8 100 500 92.7 100 400 82.1 100 315 66.9 100 200 57.1 99.9 100 51.6 98.9 63 46.5 92.4 50 37.9 72.4 40 37.6 71.9 30 37.5 70.1 25 37.3 68.3 20 36.3 64.9 15 32.8 57.8 10 22.4 39.0 8.0 15.2 27.3 6.0 8.2 15.7 5.0 5.3 10.4 4.0 3.2 6.6 3.0 2.0 3.9 2.0 1.0 2.1 1.5 0.9 1.7 1.0 0.4 0.7 0.8 0 0.1

[0126] The samples TLR 5.0 and TLR 7.0 were also examined by means of X-ray diffractometry (powder). It was found that both samples contain hydrogen aluminium silicate as a crystalline phase.

[0127] Furthermore, according to the X-ray structure analysis, both samples comprise quartz.

[0128] The physical properties and the chemical composition of the samples TLR 5.0 and TLR 7.0 differ. It is conceivable that the different properties are attributable to the different Li.sub.2O contents or the associated different processing before and/or during the extraction or are attributable to an initially different chemical composition of the obtained samples TLR 5.0 and TLR 7.0.

[0129] The solid particles TLR 5.0 and TLR 7.0 were then subjected to further processing steps.

[0130] The solid particles TLR 5.0 were cleaned of magnetic components by wet and subsequent dry magnetic separation. The wet magnetic separation was carried out by means of a magnetic separator (from the company Eriez) in an aqueous suspension over a stainless steel grid matrix (approx. 1 mm mesh size) with a magnetic field strength of approx. 2 Tesla. The cleaned material was dried. The removed magnetic component was dried and then additionally cleaned using a tape magnetic separator (from the company Eriez).

[0131] The solid particles TLR 7.0 were cleaned of magnetic components by wet and subsequent dry magnetic separation. The wet magnetic separation was carried out by means of a magnetic separator (from the company Eriez) in an aqueous suspension over a stainless steel grid matrix (approx. 1 mm mesh size) with a magnetic field strength of approx. 2 Tesla.

[0132] After the magnetic separation and before the application-specific test, both dried solid particles TLR 5.0 and TLR 7.0 were sieved at 40 μm. With this procedure, the grain size classification is simulated using an air separator.

[0133] Finally, the following filler tests for use in emulsion paint in comparison to other products on the market (market product; MP) were carried out on the fraction <40 μm from the sieving of the solid particles TLR 5.0 and TLR 7.0.

[0134] The solid particles TLR 5.0 and TLR 7.0 and all other investigated materials/fillers MP 1-7 were introduced into a binder-additive mixture as the sole inorganic component (filler). No other fillers or pigments were included. The results of the filler test are summarised in Table 3.

TABLE-US-00003 TABLE 3 Physical properties and results of the filler test. Kaolin type calcined calcined calcined calcined calcined calcined calcined Product MP 1 MP 2 MP 3 MP 4 MP 5 MP 6 MP 7 TLR 5.0 TLR 7.0 Sedi [μm] mass % mass % mass % mass % mass % mass % mass % mass % mass % 30-45 0.1 0.6 2.0 0.0 0.5 1.1 0.3 0.1 2.4 20-30 1.0 2.4 10.7 0.3 4.4 8.9 0.7 8.8 16.2 10-20 3.6 12.2 46.1 4.5 16.6 21.1 3.8 48.3 47.5  6-10 7.0 21.5 24.8 11.8 12.2 14.0 7.0 28.7 21.1  4-6 7.8 26.4 8.7 18.2 8.8 12.1 11.2 8.5 7.2  2-4 17.1 30.0 5.9 34.1 17.0 20.0 29.8 1.6 1.4  0-2 63.4 6.9 1.8 31.1 40.5 22.0 47.2 4.0 4.2 d50 [μm] 1.3 5.0 13.0 2.9 2.7 5.2 2.1 11 12.8 <2 μm L 97.11 97.68 97.03 97.34 96.08 97.40 97.02 98.10 98.29 a −0.28 −0.19 −0.13 −0.20 −0.39 0.15 −0.22 −0.04 0.08 b 2.94 2.68 2.89 2.25 2.38 2.68 2.30 0.91 1.06 Yellowness 5.28 4.84 5.30 4.07 4.21 4.89 4.16 1.68 2 Density (g/L) TDS 2.60 2.45 2.25 2.67 2.58 2.58 2.60 2.60 2.45 Whiteness 89.0 90.7 88.9 90.4 87.0 85.0 89.5 94 94.2 Oil absorption value 51 50 55 66 52 25 53 48 46 (g/100 mL) Specific surface area 6.8 3.0 2.0 5.4 5.2 3.2 8.0 CPVC calculated from the oil 48 49 49 41 47 65 47 49 52 absorption value Density BM Wet abrasion according to DIN ∅ wet abrasion [μm] PVC 50 4.6 6.4 5.6 6.2 2.8 2.5 4.5 15.4 15.7 PVC 80 59 70 52 68 47 13 58 n/a n/a Wet abrasion class PVC 50 1 2 2 2 1 1 1 2 2 PVC 80 3 3 3 3 3 2 3 4-5 4-5 Hiding power PVC 50-150 μm 89.35 75.62 67.85 80.83 79.58 30.45 75.12 37.05 38.24 PVC 80-150 μm 97.41 90.93 84.54 93.68 96.29 82.41 94.86 69.43 66.13 PVC 50-250 μm 94.12 86.32 81.54 91.25 89.51 40.75 87.42 53.27 53.55 PVC 80-250 μm 98.88 95.19 91.29 97.64 98.58 89.78 98.21 79.7 77.39 PVC 50-350 μm 96.34 90.31 86.62 93.97 93.81 47.09 92.08 61.92 63.29 PVC 80-350 μm 99.50 97.40 94.50 98.81 99.73 93.58 98.96 85.78 84.38 Layer thickness [m] at 350 μm PVC 50 0.000106 0.000121 0.000123 0.000124 0.000107 0.000106 0.000109 0.000121 0.000126 PVC 80 0.000132 0.000152 0.000143 0.000143 0.000134 0.000107 0.000113 0.000125 0.00013 Spreading rate [m.sup.2/l] PVC 50 for class 1 1.74 1.27 0.61 2.21 2.20 −7.22 1.59 −4 −3.5 PVC 80 for class 1 4.57 2.67 1.75 3.80 4.50 1.75 4.25 0.2 0.7 PVC 50 for class 2 2.39 1.60 0.87 2.65 2.55 −7.01 1.93 −3.8 −3.3 PVC 80 for class 2 6.66 3.43 2.24 5.01 6.04 2.11 5.44 0.5 1 Gloss on contrast cards 305 μm PVC 50 at 60° 2.6 2.9 2.8 2.7 2.3 2.2 2.5 1.9 1.8 PVC 80 at 60° 2.9 3.4 3.3 3.1 2.7 2.4 2.9 2.4 2.3 PVC 50 at 85° 4.0 1.3 0.7 2.4 1.2 0.6 2.5 0.5 0.5 PVC 80 at 85° 9.6 4.2 1.4 7.5 3.5 0.9 6.9 0.8 0.6 Gloss behaviour Gloss at 85° starting value PVC 50-start 4.1 1.4 0.8 2.7 1.1 0.5 2.5 0.6 0.5 PVC 80-start 9.5 3.5 1.4 7.8 2.9 0.7 6.0 0.8 0.7 Gloss at 85° final value (20 cycles) PVC 50-end 17.4 3.1 2.5 6.7 3.3 1.5 5.9 2.7 2.2 PVC 80-end 30.3 8.4 2.6 21.6 9.1 1.8 17.0 2.5 1.9 Difference PVC 50 −13.3 −1.7 −1.7 −4.0 −2.1 −1.0 −3.4 −2.1 −1.7 PVC 80 −20.8 −4.9 −1.1 −13.8 −6.2 −1.1 −11.0 −1.7 −1.2 Rheology at 25° C. (P/P) Viscosity at 6.2 s.sup.−1 P/P PVC 50 2097 1488 1700 1482 1845 1571 1929 1498 1500 PVC 80 2748 2662 2766 2524 2720 1877 2658 2111 2303 Shear stress at 1200 s.sup.−1 [Pa] PVC 50 432 331 347 354 409 297 348 319 395 PVC 80 463 518 527 608 464 360 444 453 440 Colour location PVC 50 L 95.04 94.98 94.42 94.81 92.58 90.29 93.92 93.59 93.62 a −0.47 −0.50 −0.53 −0.34 −0.54 −1.11 −0.45 −0.83 −0.83 b 3.93 2.50 2.56 2.83 3.88 8.96 3.60 2.77 2.81 Standard colour 87.72 87.57 86.25 87.18 82.02 76.92 85.08 84.32 84.39 value Y Yellow value 7.09 4.39 4.50 5.14 7.08 16.34 6.55 4.7 4.77 PVC 80 L 96.70 96.49 95.56 96.47 95.22 93.28 96.33 94.78 94.74 a −0.27 −0.29 −0.32 −0.18 −0.33 −0.27 −0.21 −0.45 −0.44 b 2.75 1.78 1.84 2.03 2.46 5.03 2.11 1.58 1.64 Standard colour 91.70 91.19 88.96 91.14 8.15 83.60 90.81 87.09 87 value Y Yellow value 4.95 3.14 3.26 3.69 4.43 9.41 3.83 2.69 2.81 indicates data missing or illegible when filed

[0135] The mean particle size d.sub.50 of the solid particles TLR 5.0 and TLR 7.0 in the mixture is 11 μm and 13 μm, respectively.

[0136] The grain size distribution of the solid particles TLR 5.0 and TLR 7.0 in the mixture is comparable with the market products (MP).

[0137] The whiteness according to R 457 of the solid particles TLR 5.0 and TLR 7.0 in the mixture is approx. 94%.

[0138] The solid particles TLR 5.0 and TLR 7.0 in the mixture have an oil absorption value of 48 and 46, respectively.

[0139] The viscosity of the mixture with the solid particles TLR 5.0 and TLR 7.0 is comparatively high. This can be attributed to the particle shape or morphology.

[0140] The hiding power of the mixture with the solid particles TLR 5.0 and TLR 7.0 is low. This suggests a high colour strength in tinted formulations and better transparency in varnishes.

[0141] The matting of the mixtures with the solid particles TLR 5.0 and TLR 7.0 is high and comparable to that of the market products (MP).

[0142] Furthermore, an application-specific test (AST) was carried out. Finished paints were prepared that comprise other additives (such as additional fillers, pigments, defoamers, etc.). The only difference between the paint compositions was the fillers used, with the solid particles TLR 7.0 and other market products (MP) being used. The recipes or compositions used for the various paint compositions are summarised in Table 4. The results of the application-specific test performed are shown in Table 5.

TABLE-US-00004 TABLE 4 Recipes of the paint compositions produced. MP 1 MP 4 MP 2 MP 3 MP 6 MP 5 MP 7 TLR 7.0 Water 30.2 30.2 30.2 30.2 30.2 30.2 30.2 30.2 Thickener 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Dispersants 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Defoamer 1 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Pigment 12.5 12.5 12.5 12.5 12.5 12.5 12.5 12.5 Filler 1 15.0 15.0 15.0 15.0 15.0 15.0 15.0 15.0 Filler 2 12.5 12.5 12.5 12.5 12.5 12.5 12.5 12.5 MP 2 16.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 MP 11 0.0 16.5 0.0 0.0 0.0 0.0 0.0 0.0 MP 7 0.0 0.0 16.5 0.0 0.0 0.0 0.0 0.0 MP 8 0.0 0.0 0.0 16.5 0.0 0.0 0.0 0.0 MP 16 0.0 0.0 0.0 0.0 16.5 0.0 0.0 0.0 MP 14 0.0 0.0 0.0 0.0 0.0 16.5 0.0 0.0 MP 18 0.0 0.0 0.0 0.0 0.0 0.0 16.5 0.0 TLR 7.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 16.5 Defoamer 2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Binder (BM) 12.0 12.0 12.0 12.0 12.0 12.0 12.0 12.0 Sum 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Sum of fillers 44.0 44.0 44.0 44.0 44.0 44.0 44.0 44.0 Ratio of filler to BM 6.9 6.9 6.9 6.9 6.9 6.9 6.9 6.9 w (solid) 63.5% 635% 63.5% 63.5% 63.5% 63.5% 63.5% 63.5%

TABLE-US-00005 TABLE 5 Results of the application-specific test. MP 1 MP 4 MP 2 MP 3 MP 6 MP 5 MP 7 TLR 7.0 Density [g/cm.sup.3] 1.608 1.603 1.587 1.566 1.609 1.605 1.583 1.593 Rheology Shear stress at 1200 s.sup.−1 551 531 505 456 394 492 467 437 [Pa] after 1 d Viscosity at 6.2 s.sup.−1 2945 3190 3038 2714 2326 2886 2792 2635 P/P after 1 d Colour location L 97.04 96.90 96.92 96.63 96.11 96.38 96.85 96.40 a −0.38 −0.38 −0.40 −0.43 −0.38 −0.41 −0.35 −0.47 b 2.38 2.21 2.23 2.19 2.58 2.18 2.20 2.25 Y 92.55 92.20 92.24 91.54 90.27 90.92 92.06 90.97 Yellow value 4.17 3.87 3.88 3.80 4.58 3.81 3.88 3.88 Appearance OK OK OK OK OK OK OK OK EN13300 Spreading rate m.sup.2/l 6.9 6.4 5.6 5.4 5.1 6.7 6.0 4.3 Spreading rate class 1 1 1 1 1 1 1 1 Wet abrasion resistance 27 29 15 7 4 11 16 7 Wet abrasion class 3 3 2 2 1 2 2 2 Gloss 60° 2.6 2.6 2.5 2.4 2.5 2.6 2.7 2.3 Gloss 85° 9.0 5.4 3.0 1.4 2.0 4.8 7.4 0.8

[0143] The application-specific test (AST) shows that paint compositions comprising the fillers produced from the solid particles TLR 7.0 have substantially similar properties to comparable products on the market. It can be seen from this that the solid particles which come from a processed residue of an alkali and/or earth alkali extraction offer properties similar to those produced on the market for this purpose.

[0144] The applicant reserves the right to claim all the features disclosed in the application documents as essential to the invention, provided that these are novel individually or in combination over the prior art. It is also noted that features which in themselves can be advantageous have also been described in the individual drawings, tables and/or images. A person skilled in the art will immediately recognise that a particular feature described in one drawing, table and/or image can also be advantageous without adopting further features from said drawing, table and/or image. A person skilled in the art will also recognise that advantages can also result from a combination of a plurality of features shown in individual or in different drawings, tables and/or images.