LU83115A1 - METHOD FOR PRODUCING WHITE MASONRY OR VISIBLE STONES - Google Patents

Description

Kalsiton QrbH, 4100 Duldiurq 1 and KWK Kalkwerke Dctmap GftfaH, 5600 WiyperLal - Domap 'process for the production of white facing or exposed brick! The invention relates to a method for producing hydrothermally hardened, white facing stones or visible rubble stones from a mixture! consisting of 5 - 15 weight percent lime, 95 - 85 weight percent! . silicate aggregate, based on the dry matter, as well as 6 pieces of water required to achieve a sufficient compressibility of 6 pieces and the amount of water required for hydrating the

Lime required wasænienge.

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Processes for the production of hydrothermally hardened facing bricks j from freeze lime and silicate aggregates, e.g. quartz sand I are known. Pie stones are supplied in various formats as whole J stones with a smooth or broken-radii visible surface, in addition also with broken-broken visible surfaces as a saving brick or as straps. The aim is that the stones are pure white, but at least have a white basic color. In the rarest of cases, however, the quality of these facing stones is so satisfactory that they can compete with facing stones on a ceramic basis, so-called door cladding panels.

The most common cause of the complaints, depending on the type of sand and limestone used, is on the one hand a relatively unsightly fine color, on the other hand Ver - 2 - / / / Λ L - ^ __

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»» - 2 - »/ sdmttzungen and discolorations, which occur in particular under the influence of Wberungsbedingvngenn. By punctual repetition at repeated intervals or, in the worst case, by a covering coat, you can reduce the risk of contamination and discolouration, but these additional measures do not provide a real alternative to tan blending. By adding burned and shredded flint or flint stones to the calcification of sand and sand or by completely replacing the quartz sand with this fired and appropriately shredded flint or flint stone, a further brightening of the facing stones and a reduction in the risk of var soiling can be achieved .

For the prior art, cf. "2nd International Synposium for Dairpf-Hardened Calcium Silicate Building Materials" Hanover, March 25/28, 1969, Contract No. 77, are also known laboratory tests which aimed to determine the influence of pre-fired sand on the strength of sand-lime bricks. By pre-firing sand at 1400 ° C, the quartz was partly converted to cristalite, depending on the burning time J to different degrees and hardened hydrothermally. Examination of the hardened test specimens showed that, as the crystal balance increased, the cooking density and, at the same time, the compressive strength decreased, as expected, while the job tolerance increased.

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The invention is based on the object of specifying a method for producing hydrothermally hardened white facing or exposed masonry stones of the type mentioned at the beginning, by means of its pressure-resistant, in! their pure white color weather-resistant, in particular frost-resistant, stones can be produced, which give a special optical effect when exposed to light and which are easy to clean from fairytale residues ·! 'i i -

This object is achieved according to the invention in that the lime! Cristobalite is used as a silicate additive, whereby! up to 40 percent by weight of cristabalite is replaced by broken, pure white rock of calcitic or silicate nature

Preferably, the cristobalite in the commercially available form i with more than 98%, preferably with very than 99% SiO ^ as a pure white j

Powder in the cone size range from 0.1 to 0.6 mr used, that out! processed quartz sands is produced in a high temperature process. Since the given grain structure does not allow an optimal compaction in sand-lime brick presses, especially the very fine parts with a Kvg vcn less than 0.1 µm and the coarser parts with a grain size Vcn very much less than 0.6 µm, which are strength-enhancing, are missing · To increase the fine tantalum, it is preferred to add cristbalite flour. It is e.g. B. produced by iron-free grinding of crcbalite sand with more than 99 t SiO £ ·

Mixtures of commercial cristobalite tod cristobalite flour with 5 I to 15% lime, z. B. with approx. * 10% fine white lime and the amount of water required for stone production can be processed in sand-lime presses. -------- - 4 - v stone presses, but the reed stability is so low, Since transport and stacking the scrap rate is very high and production becomes uneconomical. A significant improvement in the stability of the ring is accordingly achieved in that the mixture in a ratio of about 80 to 20 to 70 to 30 of cristochalite or cristobalite flour is added individually with white calcite, with the camber egg 0-4 rxn, preferably 0-3 itm. The latter is u. won in Norway and offered in commercial grit. In the same way, the use of Taunus quartzite is given. The resistance to chips and the compressive strength of the stones increase significantly with this addition without the color changing significantly after the beard. «In particular with stones with a rough-roughened visible surface, there is an additional positive effect that occurs when you hit

Light, especially sunlight, in a glitter on the crystalline! »

Expressed areas of the added calcite.

The glitter effect becomes even clearer if, instead of calcite, the grain size O - 4 ran or O - 3fam is added teterially with a grain size of 2 to 8 µm, preferably 3 to 5 ran. The coarser grit has an even more positive effect on the compressive strength of the stones, however, the use of these kimonos is only useful for augmented reasons and rainy edge sharpness is only useful for facing stones with a rough-fractured visible surface.Otherwise, with the inventive stelnherefrgl 1 rag lime with a maximum of 0. 5%, preferably a maximum of 0.3%, coloring sweat metal codings used, - 5 - - 5 -

By adding colored aggregates of 3 to 8 mm, in particular 3 to 5 µm, of a Caldtlian or Sicilian nature, such as marroar chippings or diabase, but also by adding glassy amorphous granules to the Cristobalit-GrcnänrLschurig can be used for facing stones, especially with a rough surface , special cp table effects can be achieved. The prerequisite, however, is that the added grains are well screened, so that the grind of the stones is not impaired.

The visible surface of the broken facing stones is preferably already provided with a colorless surface protection in the factory, in order to reduce the risk of contamination during transport to the construction site and during processing of the stones. Stubborn dirt, in particular mortar residues, which cannot be removed by brushing or washing off, can be removed by treatment with dilute hydrochloric acid and subsequent watering without impairing the quality. The COD phases (CSH * = calcium silicate hydrate) present on the surface are destroyed, but their color differs only slightly from that of the additive Cristdbalit, so that the surface can no longer be objected to after the particles have been brushed off. As is known, normal lime sandstone facing stones cannot be treated in this way, since after acidifying, i.e. h, washing with dilute hydrochloric acid, the natural color of the aggregate quartz sand becomes visible, which changes depending on the occurrence! - 6 - / / _________ - 6 - j or less clearly stands out from the CSH phase,

Axis above shows that the use of crlstobalite as an additive in the manufacture of hydrothermally hardened white facing or exposed masonry bricks, which are pressure-resistant, weather-resistant, in particular frost-resistant and which produce a glitter effect when struck by light, is essential to the invention

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The advantages of the method according to the invention are particularly i i: the fact that the production of a white facing or j

Visible maxi stone is made possible, which is pressure-resistant, the pure white disc of which is resistant to the weather, in particular frost, and which is easy to clean. By the given white

Finally, the color of the stones and their color fastness make a protective coating of the masonry that is otherwise necessary at certain intervals unnecessary.

The procedure for manufacturing! 1 mg of the stones according to the invention is explained below using exemplary embodiments.

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example 1

In a compulsory mixer, a mixture of 960 kg Crsfanbal 1 tsand in a grain size of 0.1 to 0.6 µm, 300 kg Cristalbal i sand in a grain size of less than 0.2 ran, 540 kg of Norwegian white calcite in a grain size of less ! i 0.3 mn, 200 kg white fine lime and 200 leg water homogenized. ! i i

The mixture of approx. 86% cristbalite with calcite and approx. 10% lime, based in each case on the dry substance, was then in one; i

Reactor given, in which the burnt white lime was completely hydrated to hydrated lime. The dwell time in the beactor depends on the degree of firing and on the fineness of the quicklime. It was about 1.5 hours. The fully reacted mixture was compacted in a known manner in a sand-lime brick press at a specific pressure of about 16 N / mn to form full blocks of the standardized formats DF or NF. The hardening of these stones was carried out under the known hydrothermal conditions in an autoclave with saturated water vapor at IO to 16 atfi.

The ram weight of the solidified stones produced and hardened in the manner described was about 1.6 kg / dm3 and the compressive strength 26 * 5 10m2.

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t - 8 - lfech dam Breaking these solid bricks, they can be used as facing bricks with fractured face, either as a wall spar or a brick.

Example 2

In a compulsory shear, a sinew was made from 875 kg cristobalite sand in a grain size from 0 # 1 to 0.6 irm,> 5 “350 kg cristobalite flour in a grain size below 0.2 μm, 18

525 kg of Norwegian white calcite in a grain of 3 to 8 µm, \\ 1 195 kg of fine lime and! .C

195 kg water = 1945 i »j homogenized. ;

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The mixture consisting of approx. 90 S cristobalite with calcite and approx. 10% lime (in each case based on the dry substance) was processed in the same way as that in Example 1.

The bar weight of the stones produced and hardened in this way was approx. 1.60 kg / dm ^ and the compressive strength was 28 * 0 H / ώε? .

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Claims (7)

• ·! Werke · Κ Kalkwerke Dornap GftbH, 5600 'Wuppertal ~ Dornap ti 1. Process for producing hydrothermally hardened * white facing or exposed masonry from a mixture consisting of 5-15 percent by weight of lime, 95-85 percent by weight of silicic aggregate, based on the dry matter , as well as the amount of water required to achieve sufficient compressibility of the mixture and the amount of water required for hydrating the lime, characterized in that * iconic additive cristobalite is added to the lime as s 11, with up to 40 percent by weight of the cristobalite due to broken, pure white rock calcitic or silicate nature is replaced. 2. The method according to claim 1, characterized in that the additive cristobalite consists of more than 98%, preferably more than 99% of ShC ^. ! 3. The method according to claims 1 and 2, characterized in that the cristobalite in a mixture of cristobalites and with a grain size of 0.1 - 0.6 µm and from Cristdbalit flour with a grain size of less than 0.2 µm in a ratio of about 80 to 20 to 70 to 30 'is added. - 2 - / - 2 - «* 0 r ___ -. 4. The method according to claim 1, characterized in that the lime max. 0.5% preferably contains a maximum of 0.3% coloring heavy metal code. 5. The method according to claims 1 to. 4, characterized in that ’- to the lime 90 to 92 weight percent, based on the dry substance, cristobalite is added. * 6. i Method according to claim 1, characterized in that calcite, preferably Norwegian calcite or j läunus quartzite with a grain size of less than 4 µm, preferably less than 3 µm, is added as the pure white rock. 7. The method according to claim 1, characterized in that as a pure white rock up to 30% further in a grain size range vcn 2 to 8 ntn, preferably 3 to 5 µm is added, l {j \ W ti i> \ / \ / \ / \ X /