RU2806883C1 - Method for obtaining blue pigment for ceramics - Google Patents

Abstract

FIELD: ceramic industry.

SUBSTANCE: method for producing a blue pigment for ceramics, including grinding the raw materials, mixing them, followed by heat treatment and grinding to the required dispersion, and porcelain scrap containing manganese oxide and vanadium production waste containing oxides of vanadium and manganese, mixing is carried out at a ratio of 1:2, then the resulting mixture is granulated to produce granules 2-4 mm in size, followed by heat treatment in a plasma reactor with a granular charge flow rate of 5 g/s, after cooling the resulting melt, dry grinding is carried out until passing through sieve 0056 to obtain a blue pigment containing the main coloring phase of spinel and manganese vanadate Mn₂V₂O₇.

EFFECT: use of industrial waste, accelerating the process of obtaining pigment, which reduces energy costs for the production of finished products and cheapens the final product.

1 cl, 3 tbl

Description

The invention relates to the production of pigments used in the ceramic industry.

There are a number of known methods for producing ceramic pigments, the disadvantages of which are the duration of the technological process and the use of expensive materials.

The closest to the proposed one in terms of technical essence and achieved result is the method for producing ceramic pigment, Maslennikova G.N., Pishch I.V. Ceramic pigments. 2nd ed. reworked and additional – M.: LLC RIF “Building Materials. 2009, (p. 181). – 224 pp., including averaging of components (manganese oxide, ferrous sulfate, zinc sulfate, potassium nitrate), their firing at 900-1400ºС, subsequent wet grinding for 6-48 hours, control of dispersion by the size of the residue on sieve No. 0056, centrifugation , washing in hot water at a temperature of 70-80 ºС for 2-5 hours and spinning the water.

The disadvantages of this method are the duration of the technological process for obtaining the pigment and the use of expensive components for its production.

The technical result of the proposed invention consists in the use of industrial waste, accelerating the process of obtaining pigment, which reduces energy costs for the production of finished products and makes the final product cheaper.

The technical result is achieved by the fact that the method of producing a blue pigment for ceramics, including grinding the raw materials, mixing them, followed by heat treatment and grinding to the required dispersion, and porcelain scrap containing manganese oxide and vanadium production waste containing oxides of vanadium and manganese, mixing is carried out at a ratio of 1:2, then the resulting mixture is granulated to produce granules 2-4 mm in size, followed by heat treatment in a plasma reactor with a granular charge flow rate of 5 g/s, after cooling the resulting melt, dry grinding is carried out until through sieve 0056 to obtain a blue pigment containing the main coloring phase of spinel and manganese vanadate Mn ₂ V ₂ O ₇ .

A comparative analysis of the known and proposed methods is presented in Table 1.

Table 1

A well-known method is Ceramic pigments, Maslennikova G.N., Pishch I.V. 2nd ed. reworked and additional – M.: LLC RIF “Building Materials. 2009, (p. 180). – 224 p.] Suggested method Grinding and averaging of components
(manganese oxide, ferrous sulfate, zinc sulfate, potassium nitrate)

Firing at 900-1400ºС
24 hours

Wet grinding 6-48 hours
Dispersion control
(sieve No. 0056)

Centrifugation

Washing in hot water (70-80ºС)

Water extraction Grinding and averaging of broken porcelain and vanadium production waste at a ratio of 1:2 parts by weight

Granulation of the charge

Heat treatment in a plasma reactor
with granular charge consumption
5g/s

Dry grinding for 0.5 hours

Dispersion control
(sieve No. 00560) 30 hours 1 hour

The proposed method differs from the prototype in that porcelain scrap containing manganese oxide and vanadium production waste containing vanadium and manganese oxides are used as raw materials, mixing is carried out at a ratio of 1:2, then the resulting mixture is granulated to produce granules of size 2-4 mm, followed by heat treatment in a plasma reactor with a granular charge flow rate of 5g/s, after cooling the resulting melt, dry grinding is carried out before passing through sieve 0056 to obtain a blue pigment containing the main coloring phase of spinel and manganese vanadate Mn ₂ V ₂ O ₇ .

In the proposed method, during heat treatment, partial melting and crystallization of coloring centers occurs, which include spinels and manganese vanadates of the composition Mn ₂ V ₂ O ₇ .

Vanadium waste contains manganese oxides and vanadium oxides, which have clearly developed chromophoric properties. Vanadium waste contains oxides of vanadium and manganese. Vanadium oxide has the following chromophoric properties. Compounds containing V ²⁺ ions have strong reducing properties and can be oxidized to V ³⁺ . The color changes from purple to green. The melting point of V ₂ O ₃ is 6700ºС. Color can vary from green to orange, blue-violet. The color of vanadium-containing pigments and minerals depends on the amount of V ³⁺ and V ²⁺ ions and their ratio [Optical spectra of spinels / Boginsky O.N., Grum-Grzhimailo S.V., Popova A.A. and others // Spectroscopy of crystals. – M.: Nauka, 1970. – 123 p.]. Manganese oxide contained in vanadium waste has the following chromophore properties. In the spectra of minerals containing manganese ions with an oxidation state of +2, there are three absorption bands in the visible region with maxima in the violet and green regions [Low W. Paramagnetic resonance in solids. – M.: Chemistry, 1966. – 25 p.]. The brightest colors are found in tetrahedral complexes, in which the complexing agent is represented by Mn ²⁺ ions. Complex compounds of Mn ³⁺ are colored purple with a wide absorption band at a wavelength of 20,000 cm ^- [Ballhausen K. Introduction to ligand field theory. – M.: Mir, 1964. – 592 p.]. The green color of manganese-containing compounds is associated with the formation of Mn ²⁺ ions from Mn ³⁺ and Mn ⁴⁺ ions. In this case, two colors are superimposed - yellow and pink, which, when mixed, form green [Platonov A.N. The nature of the color of minerals. – Kyiv: Naukova Dumka, 1976. – 263 p.].

The composition of finely dispersed porcelain scrap contains manganese oxide, which has pronounced chromophore properties. As a result of melting the mixture of porcelain scrap and vanadium production waste, calcium sulfate decomposes and calcium oxide transforms into a silicate melt due to the melting of the entire mixture. Melt from broken porcelain has a high crystallization ability. During the process of spontaneous rapid cooling in the silicate melt, coloring crystallization centers are formed due to the formation of chromophore crystalline phases evenly throughout the entire volume of the melt.

After cooling, the hardened granules are crushed until they pass through sieve No. 0056.

The optimal ratio of fine porcelain powder and vanadium production waste, obtained experimentally, is presented in Table 2.

table 2

Optimal ratio of components

No. Component ratio Amount of crystalline phase with coloring chromophore properties, wt. % Porcelain fight Vanadium production waste 2 1 58 1 1 69 1* 2* 88* 1 3 72 * – optimal option

Example

Vanadium production waste with the following chemical composition was taken as the starting components (Table 3).

Table 3

Chemical composition of vanadium production waste

Oxides content, % CaO SO _{3 Mn2O3 _} MgO _{SiO2 V2O5 _ Al2O3 _} PPP Other 36.93 33.03 17.39 5.03 3.22 2.81 0.41 1.13 0.06

We took broken porcelain, pre-crushed it in a laboratory jaw crusher and ground it in a ball mill for 0.5 hours.

Fine powders of scrap porcelain and vanadium production waste at a ratio of 1:2 parts by weight were averaged in a laboratory mixer and the mixture was granulated in a laboratory granulator to form charge granules of 2-4 mm.

The granulated mixture was placed in a powder feeder. From the powder feeder, the granules were fed into the UPU-8m plasma reactor with a GN-5R plasma burner with a productivity of 5 g/s. As productivity increases, the gas-air channels become stuck. The average mass temperature of the plasma jet was 8500K. The plasma-forming gas was argon, the flow rate of which was 30 l/min. Under the influence of high temperatures of the plasma jet, the charge granules melted to form a melt. Under the influence of the outgoing flow of plasma-forming gas - argon, molten drops were transported in a gas-air flow from the plasma reactor to the collection tank. During transportation, the melt crystallized and accumulated in the collection tank.

The amount of crystalline phase in the final product was controlled by X-ray phase analysis using an ART XTRA Thenno Fishen Scientific diffractometer in the angle range 2Ɵ=4-64ºС.

Powder diffraction patterns were interpreted using ASTM cards.

Parameters for shooting powder diffraction patterns: copper anode and K _α - radiation at 40 kW.

The amount of crystalline phase was 88%.

Claims (1)

A method for producing blue pigment for ceramics, including grinding raw materials, mixing them, followed by heat treatment and grinding to the required dispersion, characterized in that porcelain scrap containing manganese oxide and vanadium production waste containing vanadium oxides are used as raw materials. manganese, mixing is carried out at a ratio of 1:2, then the resulting mixture is granulated to produce granules of 2-4 mm in size, followed by heat treatment in a plasma reactor with a granular charge flow rate of 5 g/s, after cooling the resulting melt, dry grinding is carried out until passing through sieve 0056 to obtain a blue pigment containing the main coloring phase of spinel and manganese vanadate Mn ₂ V ₂ O ₇ .