Investigation of re

The M

Abstract—The light brick, porous chamottelight brick with burn-out process were used insulation materials in furnaces of thermmetallurgical plants, mortar, cement and brMongolia. Each year 500000 thermal insulimported from Russia, China, Japan, Italy, Gethe Mongolian market.

This shows that there is necessity to improject with the purpose to develop porous based on local refractory clay (kaolinite) wrequirements of the international standards 1972 and DIN EN 1094. The main purpose is chamotte brick based on local refractory clay study their physical and mechanical propertithe technological processes.

The porous chamotte produced has a bug/cm3 and a crushing strength of 1,84 Мconductivity coefficient of the porous chamotte1000°С.

Keywords- porous chamotte, refractory clasoap

I. INTRODUCTION

The primary kaolinite of Tsogt ovoo depoand used for the experiments which have laboratory for the chemical technology andthe School of Materials science of the Monof Science and Technology and at the linstitute for ceramics, glass and constructioTU Mining academy Freiberg, Germany.

II. ANALYSIS OF THE RAW MAThe review of the geological reports o

refractory clay deposits shows that the pkaolinite of the Tsogt ovoo deposit has tAl2O3 content for the chamotte brick productresistant until 1745˚С [1].

That means that this kaolinite is suitable of high qualitative refractory materials. Akaolinite samples were analysed. (s.Table 1 a

fractory thermal insula

G.Saran Mongolian University of Science and Technology

School of Materials Science saran13@yahoo.de

e, porous diatomite, mostly as thermal

mal power plants, rick production in lation bricks were ermany and USA to

mplement research chamotte product

which fit technical such as ISO-2245-to produce porous of Mongolia and to ies and to optimize

ulk density of 0,47 МPа. The thermal e is 0,28 W/mК at

ay, technical liquid

osit was processed been done at the

d new materials of ngolian University laboratory of the n materials of the

ATERIALS of the Mongolian processed primary the most suitable tion and is the fire

for the production As next step the and Figure 1)

TABLE I. CHEM

Sample SiO2 Al2O3 Fe2O

Raw kaolin 65.4 19.2 0.72

Enriched kaolin 48.1 33.6 2.2

Figure 1.Raster electron m

Three refractory clay depogobi and Tsogt ovoo were ananalytical results of the chemictechnological properties showkaolinite is more suitable for tporous chamotte brick.

The primary kaolinite of tchamotte produced by this kaoraw material for the porous cha

The foam forming technicalof the company Zimmer-Schwaas foaming agent [3].

Paper and wood span wereTotal 18 foaming mass were pr

The experiments for the detbetween foaming agent and amount is for foaming agent mass and 50% for water. At highest. (s. Figure 2)

ation material

ICAL ANALYSES

O3 CaO MgO Na2O K2O

1.0 0.4 0.4 5.5

1.1 0.4 0.3 2.1

microscopic images of kaolin

osits such as Tavan tolgoi, Elgen nalysed more closely [2]. The cal composition and the ceramic

w that the enriched Tsogt ovoo the production of the refractory

the Tsogt ovoo deposit and the olinite was chosen as the main amotte brick production. l liquid soap С285 for ceramics arz from Germany was selected

e used as combustible additive. repared and analysed [4]. termination of the optimal ratio

water reveal that the optimal approximately 1% of the dry

t this condition the porosity is

978-1-4673-1773-3/12/$31.00 ©2013 IEEE

Figure 2. Temperature dependence of the bulk densi

III. TECHNOLOGICAL EXPERMENPOROUS CHAMOTTE

The technological parameters for the therthe porous chamotte were selected as follows

- 1 % foam forming technical liquiagent,

- Preparation of the foaming mass w- Drying with air circulation at 50˚С- Burning the chamotte at the temp

1100˚С, - Grinding the chamotte until

reaches 7000 - 9000 сm2/g, - Adding 50 - 60% chamotte to the - The temperature range of 110

chosen as suitable for burning. The porous chamotte produced has a bu

g/cm3 and a crushing strength of 1,84 МPа. (The thermal conductivity coefficient

chamotte is 0,28 W/mК at 1000°С. Thesethe porous chamotte produced with the kaolovoo deposit fits the thermal technical reqinternational standards. (s. Figure 5)

As result of the mathematical regressiopossible to produce a porous chamotte with athan 0,51 g/сm3 and a crushing strength morewe add 50-60% chamotte with 7000-800surface and 1% foam agent and burn atbetween 1100-1200˚С.

Figure 3. Temperature and grinding dependence o

ity of different masses

NTS ON THE

rmal processing of s: id soap as foaming

with 50% water, С, perature of 1000 -

specific surface

foaming mass, 00 - 1200˚С was

ulk density of 0,47 (s. Figure 3 and 4)

of the porous e results show that linite of the Tsogt quirements of the

on modeling it is a bulk density less e than 1,96 МPа if 00 сm2/g specific t the temperature

f the bulk density

Figure 4. Temperature and grinding

Figure 5. Thermal conductivity c

The x-ray diffraction analreveal strong lines for mullite2,69; 2,42; 2,29; 1,69А°); qcrystobalite (4,09 А°) and a 3,81А°). The decrease of crystothrough the new formation of th

The increasing the grindchamotte leads to a higher specenergy which increases the remullite formation.(s.Figure 7 an

Figure 6. Diffractograms of th

g dependence of the crushing strength

coefficient of the porous chamotte

lyses on the porous chamotte e (3,37; 5,40; 2,20; 2,88; 2,54; quartz (1,83 ;2,12 ;4,25 А°);

weak lines for feldspar (3,18; obalite amount can be explained he mullite. (s.Figure 6)

ding intensity of the additive cific surface and a lower surface eaction activity and enables the nd 8)

he porous chamotte with Dron-2

Figure 7. Diffractograms of the porous chamotte which was grinded to a

specific surface of 8200 сm2/g

Figure 8. Diffractograms of the porous chamotte which was grinded to a specific surface of 7500 сm2/g

The specific surface and the amount of additive chamotte were increased to reduce the shrinkage of the porous chamotte during the heating and burning processes and to keep the mass volume constantly. The result was the decreasing bulk density and decreasing thermal conductivity [6].

IV. CONCLUSIONS 1. As research result the optimal parameters were

determined for the production of porous chamotte brick with the bulk density of 0,5 g/cm3 and the crushing strength of more than 1,84 MPа and a thermal conductivity coefficient of 0,28 W/mК at 1000°С.

2. Three refractory clay deposits such as Tavan tolgoi, Elgen gobi and Tsogt ovoo were analysed more

closely. The analytical results of the chemical composition and the ceramic technological properties show that the enriched Tsogt ovoo kaolinite is more suitable for the production of the refractory porous chamotte brick.

3. The specific surface and the amount of additive chamotte were increased to reduce the shrinkage of the porous chamotte during the heating and burning processes and to keep the mass volume constantly. The result was the decreasing bulk density and decreasing thermal conductivity.

4. The increasing the grinding intensity of the additive chamotte leads to a higher specific surface and a lower surface energy which increases the reaction activity and enables the mullite formation.

5. It is experimentally proven that a refractory thermal insulation porous chamotte brick can be produced semi industrial which fits the technical requirements of the international standards ISO-2245-1972. For this purpose we took the processed kaolinite and their chamotte of Tsogt ovoo deposit which was grinded to a specific surface of 7500-8200 сm2/g, added it as 50% of mass and swell it with a 1% foam agent and finally burn it.

6. A feasibility study was calculated for the production unit of refractory porous chamotte brick based on Tsogt ovoo processed kaolinite. This feasibility study shows that the production unit can pay back its investment within 4 years.

REFERENCES [1] Manalow J.R., Karadjinow D.B.,"Report on prospecting for refractory

clay and tugrplovkoe porovedennyh cheese party number 5 Bulgarian geological expedition in some areas of the MPR in 1967/68 years,"Ulaanbaatar, 1969

[2] G.Saran, Ts. Jadambaa “Investigation of the raw materials for refractory brick”, Scientific Transactions of Mongolian University of Science and Technology, №4/66, p.64-67, Mongolia, 2004

[3] Juettner, T.; Moertel, H.; Svinka, V.: Patent EP2105421(A1), on 2009-09-30, porous ceramic

[4] Melzer, D.: Insulating brick, silicate technology, 34 (1983), S.131-133 [5] G.Saran, Ts. Jadambaa “Technological investigation of refractory

brick”, MUST, research magazine, №3/93, p.118-122, Mongolia, 2007