DE621854C - Process for the production of cadmium paints - Google Patents

Description

Process for producing cachnium colors Cadmium colors, such as cadmium yellow or cadmium red, as is well known, can be produced in such a way that mixtures of cadmium carbonate and sulfur with or without the addition of selenium for certain, does not burn too high temperatures.

It has now been found that the quality of the products produced in this way can be improved Cadmium paints can improve significantly if the mixture to be burned is alumina hydrate contains. The products obtained in this way are much stronger in color and brighter than the colors produced in the known way without the addition of alumina.

When carrying out the new procedure, one can find the one to be burned Add certain amounts of alumina hydrate to the mixture. But you can also do this proceed that one in the production of the cadmium carbonate by precipitating cadmium salt solutions with alkali carbonates the alumina hydrate precipitates together with the cadmium carbonate, by z. B. the cadmium salt solution adds alumina salts.

It was also found that in the production of blends Cadmium colors by burning cadmium carbonate with sulfur or selenium with added of barium sulfate the simultaneous presence of alumina hydrate in the to be burned Mixing has a beneficial effect on the quality of the fired product.

A mixture of cadmium carbonate, blanc, suitable for the firing process Fixe and clay can be used for. B. obtained when using a solution of cadmium sulfate falls with the corresponding amount of chlorobarium. Without filtering, you put the Solution to the appropriate amount of an alumina salt and now falls with alkali carbonate. The resulting precipitate is filtered off, washed and, after drying, with Burned sulfur or sulfur and selenium.

To get a greenish yellow, add the mixture to be burned varying amounts of zinc sulfide too.

It is known to produce cadmium colors by burning cadmium carbonate with sulfur or sulfur and selenium with the addition of substrates such as Barium sulfate and the like. It has also already been suggested for the felling add zinc compounds to the cadmium salts with barite sulfide and add the mixture to burn and quench to get .green tones.

However, the present proceedings are not one Substrate effect of the clay, as can already be seen from it, @daB known substrates, such as barium sulfate, must be added if there is a substrate effect it is asked for. Rather, the clay shows a specific substrate effect opposite effect by deepening the hue and increasing the luminosity. Embodiments i. Zoo g of cadmium carbonate were intimately mixed with 37 g of sulfur and 10 g of alumina hydrate and calcined the mixture for 2 hours at about 500 ° C.

2 .. 1 1 Cadmium sulfate solution with Z85,5 g Cd SO, was mixed with a solution of 70 g of potassium alum in zoo ml of water. The mixture was stirred with 1.381 soda solution containing 38 g of Nag C 03, and the precipitate was washed out and dried.

Ioo g: of the precipitation product were once with 37 g of sulfur, the other times mixed with 13 g sulfur and 8 g selenium and 1/2 hour at about Annealed at 500 ° C.

3. 1 1 cadmium sulfate solution containing 1855 g of Cd S 04, was treated with a solution of potash alum in 7o g Zoo cc of water; 207 g of blanc fixe or barite were also added. The mixture was then stirred with 4381 soda solution containing 138 g of Nag C 03.

100 g of the washed-out, dry precipitation product were used once mixed with 15 g of sulfur, the other time with 7.3 g of sulfur and 3.6 g of selenium and the mixture calcined at about 500 ° C. for 11/2 hours.

I 1 CadmiumsulfatlQSurig, containing i85.5 - Cd S04, was exposed to a solution of 70 g of I <: alia lauride in 100% water. The solution was then mixed with 217 g of Ba C12 # "2 H2 O; the calcium sulfate was precipitated with 2, Z71 of a barium chloride solution, and the mixture obtained was stirred with 1.381 soda solution containing 138 g of Nag CO".

Zoo g. Of the washed-out, dry precipitation product were once mixed with 15 g of sulfur, the other time with 7.3 g of sulfur and 3.6 g of selenium and the mixture was calcined for 1 1/2 hours at about 500.degree.

Claims (3)

PATENT CLAIMS: i. Process for the production of cadmium sulphide paints by annealing cadmium carbonate in a mixture with sulfur or with sulfur and Selenium and optionally with the addition of barium sulfate as an extender, thereby characterized in that alumina hydrate is added to the mixture to be fired. 2. Verfaliren according to claim i. Characterized .gekisiert that cadmium carbonate with Alumina hydrate from solutions containing cadmium and alumina by means of alkali or Ammonium carbonates = is precipitated at the same time. 3. The method according to claim i and 2, characterized in that the precipitation of cadmium carbonate and alumina hydrate according to claim 2 in the presence of "barric sulfate" produced by precipitation containing S. suspension takes place. "q .. Method according to claim i -to 3, ', characterized' by adding zinc sulfide, which is known per se.