LT2010046A - Clinker ceramics and method for obtaining thereof - Google Patents

Abstract

The invention could be applied to the production of facade wall ceramics, particularly to brick those facades, which are operated by aggressive conditions (eg., coastal zone). The formation mix of ceramic samples was made from such components: clay,quartz sand and firestone. After formation, drying and burning of samples by appropriate regime (the maximum burning temperature was 1075 1090oC) obtained ceramic body, which forecast frost resistance is more than 1000 cycles (by forecasting methodology 1413.12 BS: 1998), the average compressive strength is 25 MPa, density - 2092 kg/m3, water absorption, which was determined in the normal conditions after 72 hours - 2.1 %, reserve of porous volume - 59,7 %.@

Description

1

The present invention relates to the field of clinker ceramic products and may be adapted to the production of finishing articles, such as bricks or tiles. These products have very low water absorption and high frost resistance and can therefore be used in aggressive environments (in the coastal zone) where wet cold winds prevail.

The ceramic composition of International Application PCT / RU2008 / 0060 is clay 75-81%, methyl methacrylate 1-3% and water. The prepared semi-finished products were burned at a maximum temperature of 800 ° C. The entire combustion process lasted 20 hours. The authors claim that the introduction of methyl methacrylate into the molding mass enabled them to reduce the combustion temperature to 120 ° C and obtain analogous ceramic properties. For example, the compression strength of such specimens is 30 MPa, but water absorption is about 19%.

The author of the patent RU2358943, J. A. Shchepochkina, used paper, sawdust, glass waste and ladder for the production of ceramic bricks. The samples were burned at 1000 ° C. The product has a compressive strength of 8-10 MPa. The same scientist patent RU2358947 contains ceramics composition: 43-48% clay, nickel production slag 36-38%, lead 8-10% and water 6-11%. Such a mass was burned at 900 ° C and ceramic frost resistance increased (220 cycles).

International Application W00021902 shows how to obtain sintered ceramics. Clay, ash and heavy metal oxides (40%) are used to prepare the composition of the molding mixture, and the combustion temperature is 1150-1200 ° C. The resulting ceramic density was 2.68-2.85 g / cm3. When steel slag is used, which is added 50% to the molding mass and combusted at 1200 ° C, the product density is up to 3 g / cm3 and the compressive strength reaches 6 MPa.

Highly resistant to cold ceramics is described in the patent SU1675275. Its frost resistance, determined by long-standing standards, reaches 2600 cycles, but water absorption is as high as 13%. The products of these characteristics were obtained using the following composition of the formulation mixture: clay minerals 21-30% quartz, 0.005-0.05 mm particle size and 0.05-1.25 mm particle size quartz sand.

Patents LT3792 include a mixture of cold-resistant ceramics (clay 66-86%, sand 10-20%, anthracite with a dispersion less than 0.005 mm 0.5-4% and calcite, or dolomite, or magnesite with less than 0.05 dispersion) -0.01 mm). In this patent, one of the forming masses can be considered as a prototype of our invention because it was obtained from 85% clay and 15% sand. Such a mass was formed by plastic, 2 dried semi-finished products were burned at 960 ° C. The samples are impregnated at 15% and the frost resistance at 350 cycles.

The method for producing clinker ceramics is described in RU2148564, and its water absorption is less than 2%. However, lime sludge 20-30% and nepheline-wallite 3-5% are introduced into the molding mass without clay and quartz sand. The samples were burned at 920-950 ° C.

An example of the invention is the patent RU2137731. Methods and characteristics of clinker bricks and floor tiles are described herein. Clinker bricks were obtained using clay 40-60% and granodiorite (field sponge) 40-60%. Such blanks were burned at 1210 ° C. Water absorption is 1.2-1.4%, but the cold resistance is only 60 cycles. The floor tile mass was 52.5-60% clay, 20-30% granodiorite and 17.5-20% kaolin. Samples of such mass were formed at 1150-1180 ° C. The resulting ceramic water is impregnated with 2.8-3.2%, compressive strength 34-36 MPa, and cold resistance of 40 cycles. The object of the invention is to provide a clinker-resistant (water-impregnation, determined after 72 hours is less than 3%) frost-resistant ceramics.

The proposed clinker pottery (water absorption after 72 hours is less than 3%) is a new component of its formulation composition, its amounts, dispersion and combustion conditions. Formulation mixture used: 76-84% clay, 12-18% quartz sand, 4-6% chamotte. In the production of clinker ceramics, combustion is carried out at a temperature of 1075-1090 ° C. The resulting clinker ceramics are different in additives and in their mineralogical composition. Ceramic minerals found are quartz, hematite, anortite, diopsid, mulitone, and quartz, mulit, crystallite and cordierite found. BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated by the drawings in which: FIG. clay x-ray (X-chlorite, K-kaolinite, I-ilite, Do-dolomite, C-calcite, Q-quartz); FIG. - Shamoto X-ray (M - mulitas, Kr - Cryobalite, Co - cordierite); FIG. - X-ray of the obtained clinker ceramic sample (Q-quartz, H-hematite, A - anortitis, D-diopsid, M-mulit).

The purpose of the work was achieved by using the following composition of the formulation mixture: 1) clay (sieved through a sieve with 0.63 mm mesh) 76-84% 2) quartz sand (sieved through a 0.63 mm mesh sieve) 12-18% 3) chamotte ( screened through a 1.25 mm mesh sieve) 4-6%

The chemical composition of clay is given in Table 1 and the granulometry composition is shown in Table 2. 3 Table 1. Average chemical composition of clay

Plants SiO2 AI2O3 + T1O2 Fe2C > 3 CaO MgO K20 Na20 Heat Dysnas 51.63 20.09 7.56 5.45 1.46 3.35 1.15 9.1 Table 2. Mean granulometric composition of clay

Pitching Sandy fraction content (particles larger than 0.05 mm),% Dust fraction (particles with a size of 0.05 to 0.005 mm),% Amount of clay fraction (particles less than 0.005 mm),% Dysnos 1.76 16.34 81.90

X-ray analysis of clay resulted in an X-ray (Fig. 1).

According to clay X-ray analysis (Fig. 1), the clay minerals are as follows: kaolinite K (0.716, 0.450, 0.356) nm, chlorite X (1.420, 0.716, 0.356) nm, quartz Q (0.426, 0.335, 0.246, 0.228, 0.224, 0.235, 0.235, 0.235 0.213.0.182.0.167) nm, dolomite Do (0.289.0.240.0.219) nm, calcite C (0.385, 0.304, 0.209, 0.191, 0.187) nm, ilite (0.998, 0.500,) and some field spatula F (0.324 nm ). Burning such clay from the original clay minerals results in: hematite F (Fe2O3), gelenite G (2Ca0-Al2O3-SiO2), anortite A (CaOl203-2SiO2), diopsid D (CaOMgO-2SiO2), cryobalite Kr (S1O2), mulitol ( 3Al203 * 2SiO2), glass phase.

The chemical composition of the quartz sand used is given in Table 3. Table 3. Average chemical composition of quartz sand

Chemical composition,% SiO2 Al2O3 Fe2C > 3 CaO MgO r2o Furnaces 88,16 3,85 0,75 3,20 0,49 1,4 2,15 2 fig. chamotte X-ray is provided. Chamotte X-ray shows that the dominant mineral is mulit (0.542, 0.378, 0.339, 0.290, 0.270, 0.256, 0.243, 0.234, 0.230.0, 211, 0.213, 0.209, 0.189, 0.185, 0.180, 0.172, 0.170, 0.161, 0.158, 0.153, 0.153 , 0.146, 0.145, 0.141) nm. Multifilament and crystallite (S1O2) are thermodynamically stable minerals, so the inclusion of a chamotte from such minerals should improve the final ceramic properties, especially the frost resistance. You also find a cordierite (2MgO 2AI2O3 5S1O2), which is sufficiently inert to the temperature development. 4

The resulting ceramic specimens were subjected to X-ray analysis and their phase composition with the diffractometer DRON-7 (X-ray shown in Fig. 3).

The following minerals were detected in all batches: quartz Q ((SiO 2) 0.154, 0.167, 0.182, 0.198, 0.213, 0.229, 0.246, 0.335, 0.424) nm), hematite H ((Fe 2 O 3) 0.157, 0.170, 0.184, 0.220, 0.251, 0.270 ) nm), anortitis A ((Ca0 [Al2Si2O8] or CaO-Al2O3-2SiO2) 0.251, 0.321.0.324, 0.370, 0.376, 0.406) nm), diopsid D ((CaO-MgO-2SiO2) 0.204, 0.289, 0.298) nm), Mulit M ((3Al203-2SiO2) 0.342.0.540 nm) (Fig. 3).

Method of obtaining clinker ceramics: 1) preparation of raw materials (crushing, sieving), 2) mixing of components, 3) wetting or drying of the mixture to a suitable moisture, 4) semi-finished products, 5) drying and burning in optimal time and temperature mode.

The main characteristics of clinker ceramics and prototype and analogues are presented in Table 4. In our research, the frost resistance was predicted according to the methodology of structural indicators (ManiojiaftTHC, P. 1997. MopoeoemoKoemb u domoeenHocmb mdenuu φαοαόΗού KepcmuKU. Vilnius: Technique, page 307) calibrated according to LST 1413.12: 1998 (Construction mortar. Test methods. and the determination of frost resistance of other finishes by one-way cooling). The resistance to frost, as a physical indicator of façade ceramics, can be described as being able to withstand the filling of defects in water due to migration processes.

In the case of an analogue, the frost resistance was determined by the volumetric method and the prototype according to GOST 7025-91 item 2. Volumetric method does not correspond to operating conditions and often results are unreliable because, in the case of directional freezing (as in operation), ceramics can decompose faster than in all directions, depending on the structure of the samples. Table 4. The main features and advantages of the invention

Average frost resistance, cycles 1067 350 09 40 Average water absorption,% 2.1 15.72 rn 2.8 Overall contraction 14.8 1 6.5 Composition of molding mixture Kaolin content,% 1 1 1 17.5-20 Grana - content of diorite,% 1 1 40-60 20-30 yen - Amount of chamotte,% 4-6 1 1 1 Quartz sand content,% 12-18 1-H 1 1 Clay content,% 76-84 00 40-60 52.5-60 Maximum Burning Temperature, ° C 1075-1090 960 1210 1180 Proposed Prototype Analogue 1 Analogue2 6

The resulting clinker pottery is a relatively large pool of porous space - 59.7% (while the prototype is only 21.4%), which is the main indicator of operational frost resistance. It shows how many pairs and capillaries are in which water penetrates very hard. Offering ceramics, the average density is 2092 kg / m3, and compression strength is also quite high - 25 MPa.

Clinker ceramics was obtained by using conventional raw materials and comparing to low analog combustion temperatures. The inventors of the invention have obtained clinker ceramics by burning samples at a maximum combustion temperature of 1210 ° C, and our clinker ceramics were obtained by burning samples at 1075-1090 ° C. This significantly reduces energy consumption. Another suggestion of clinker ceramics is the use of quartz sand and chamotte, which is fire resistant. In addition, all components were finely dispersed. Clay and quartz sand, at high temperatures, accompanied by a solid phase with the liquid phase caking. The motive force of this sintering was the tension of the melt surface, resulting in a negative pressure in the closed pair. At this pressure, the pores of the ceramic material were filled with a melt, and the grains converged. The more liquid phases are formed and the smaller the raw materials, the more intensively the diffusion process takes place in the sample. Due to this process, the grains regroup, the open pairs of irregular shapes are reduced, the smaller, smaller and more regular pores are formed. Water of this structure is hardly penetrated by water, and when weather conditions change, water is not able to change its state, migrate, causing internal stress and material degradation.

Claims (2)

7 DEFINITION OF DEFINITION 1. Clinker ceramics, the composition of which contains clay and sand, characterized in that the formulation mixture comprises the following components and amounts: clay 76-84%, quartz sand 12-18%, chamotte 4-6 %. A method for producing clinker ceramics comprising preparing the raw material, mixing the components, forming the semi-finished products, drying and burning, characterized in that the combustion takes place at 1075-1090 ° C.