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To obtain of ceramic pigments different waste as chromophore component were used: slime which was received from shops on processing tanning raw material of OC "Merolla Pelle", the waste cobalt and vanadium catalysts.
The dried waste is a powder of grey color with a weak violet shade of the following structure (% of weights.): Cr (III) - 20,4 (in recalculation on Cr2O3 - 29,80), Na - 8,7, Cl - 12,7, Mg - 2,7, Ca - 2,1, Si - 0,6, SO4 - 6,5.
The waste cobalt catalyst is a powder of dark blue color of the following structure (% of weights.): Al2O3 - 68,9; CoO - 5,02; Fe2O3 - 0,24; Na2O - 0,037; MoO3 - 12,30.
The waste vanadium catalyst VK-58 represents granules in diameter 3-5 mm of the following structure (% of weights.): V2O5 - 6–8, oxides alkalen metals - 17-21.
Other initial components for obtaining of ceramic pigments on the basis of cordierite are magnesium and aluminium oxides, pure quartz sand. A boric acid and zinc oxide were used as mineralizers. Mineralizers are necessary for acceleration of process of sintering.
Pigments of the following structures have been chosen for an experiment:
- 2MgO•0,5Cr2O3•1,5Al2O3•5SiO2
- 2MgO•Cr2O3•Al2O3•5SiO2
- 2MgO•1,5Cr2O3•0,5Al2O3•5SiO2
- 2MgO•2Cr2O3•5SiO2
- 2MgO•Cî2O3•Al2O3•5SiO2.
- 2MgO•1,5Cî2O3•0,5Al2O3•5SiO2
- 2MgO•2Cî2O3•5SiO2
- 2MgO•V2O5•Al2O3•5SiO2
- 2MgO•1,5V2O5•0,5Al2O3•5SiO2
- 2MgO•2V2O5•5SiO2
For preparation of mixture initial components have been weighed on analytical weights, then crushed before passage through a sieve 02 and mixed in the ratio corresponding to the composition of pigments. Then mixture has been placed in a corundum bowl and burned at the chosen temperature: 1100oC - for the pigments containing waste of tanning manufacture and the cobalt catalyst; 950o - for the pigments containing a waste of the vanadium catalyst.
The product received at the given temperatures was well sintered.
The received pigment was used for colouring of colorless fritted glaze. A pigment was added in quantity of 10 %, colorless frit – 90 %. Also 5 % (over 100 %) of white refractory clay was added. A pigment was applied on burnt non-glazed tile by an irrigation method. Firing of the covered tiles was carried out at 1000oÑ.
For definition of color the color card RAL was used . The composition and color of dyed fritted glaze are given in table 1.
Table 1 –Color of colourless fritted glaze
| Composition of pigment |
Color |
2MgO•0,5Cr2O3•1,5Al2O3•5SiO2
(mineralizer H3BO3) |
olive yellow
RAL 1020
|
2MgO•Cr2O3•Al2O3•5SiO2
(mineralizer H3BO3) |
yellow grey
RAL 7034 |
2MgO•Cr2O3•Al2O3•5SiO2
(mineralizer ZnO) |
olive grey
RAL 7002
|
2MgO•1,5Cr2O3•0,5Al2O3•5SiO2
(mineralizer H3BO3) |
moss grey
RAL 7003
|
2MgO•Co2O3•Al2O3•5SiO2
(mineralizer H3BO3) |
pigeon blue
RAL 5014
|
2MgO•1,5Co2O3•0,5Al2O3•5SiO2
(mineralizer H3BO3) |
telegrey1
RAL 7045
|
2MgO•1,5Co2O3•0,5Al2O3•5SiO2
(mineralizer ZnO) |
violet grey
RAL 7040
|
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