A method of obtaining a pigment containing chromium oxide

 

(57) Abstract:

The invention relates to the technology of production of pigments containing. the chromium oxide. The invention consists in thermal decomposition of chromium trioxide in the presence of modifying additives, which use lake Il - sapropel in the amount of 10-1000 % by weight chromic anhydride. The invention allows to obtain a pigment with high anti-corrosive properties. table 2.

The invention relates to the technology of production of pigments containing chromium oxide.

A method of obtaining pigment containing chromium oxide, including thermal decomposition of chromium trioxide in the presence of sodium oxalate in an amount of 0.1-1% by weight chromic anhydride [1].

However, the pigment does not have anti-corrosive properties.

Closest to the present invention is a method of obtaining a pigment containing chromium oxide, including thermal decomposition of chromium trioxide in the presence of water in amounts of 10-25% by weight chromic anhydride [2].

However, the pigment does not have anti-corrosive properties.

The objective of the invention is to obtain the anti-Christ., containing chromium oxide, including thermal decomposition of chromium trioxide in the presence of lacustrine silt - sapropel in the amount of 10-1000% by weight chromic anhydride.

As sapropel use any of the sapropel (they were described in table. 1).

The method is as follows. Prepare a mixture by mixing chromium trioxide with suspension, paste sapropel or dry sapropel. Calcined mixture at a temperature of 850-1000oC for 30-60 min, the resulting product is cooled and pulverized.

In the resulting pigment:

The chromium content in terms of Cr2O3, wt.% - 15 - 90

The content of Ca in terms of CaO, wt.% the 0.1 - 70

Example 1.

Mix 100 g of chromic anhydride with 100 g of a 20% suspension of organo-clay sapropel. The resulting mixture was calcined for 1 h at 850oC. the resulting product is cooled and pulverized to 40 microns.

In manufactured pigment:

The chromium content in terms of Cr2O3, wt.% - 70

The calcium content in terms of CaO, wt.% - 2

The resulting pigment is injected into the natural drying oil and check the currents and corrosion resistance to 3% NaCl. (The test results is given in tab. 2).

In manufactured pigment:

The chromium content in terms of Cr2O3, wt.% - 30

The calcium content in terms of CaO, wt.% - 16

The resulting pigment is injected into the natural drying oil and check the currents and corrosion resistance of the coating to the action of 3% NaCl. (The test results is given in tab. 2).

Example 3.

Mix 100 g of chromic anhydride with 100 g of dry calcareous sapropel. The mixture was calcined at 1000oC for 30 minutes the resulting product is cooled and pulverized to 80 μm.

In manufactured pigment:

The chromium content in terms of Cr2O3, wt.% - 45

The calcium content in terms of CaO, wt.% - 30

The pigment is injected into the natural drying oil and check the currents and corrosion resistance of the coating to the action of 3% NaCl. (The test results is given in tab. 2).

As can be seen from the table, compared with the prototype made the pigment has a high anti-corrosion properties.

A method of obtaining a pigment containing chromium oxide, including thermal decomposition of chromium trioxide in the presence of the modifying additive, characterized in that the of Idrija.

 

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1 tbl, 6 ex

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