DE931163C - Process for the recovery of the luminescent salts from glow body waste incurred in the manufacture of glow bodies - Google Patents

Description

Process for the recovery of the luminous salts from the incandescent body production incidental incandescent waste. The invention relates to a method for processing the silk residues from the manufacture of incandescent bodies. These are already impregnated with a luminous salt solution, which thorium, cerium and others for the Hardening and fixing of the incandescent body contains substances.

The recycling of these valuable chemicals has so far been made carried out in such a way that the silk waste is burned, incinerated and the resulting waste Oxides were re-unlocked. Then the components were separated from each other and the most valuable substances, thorium and cerium, obtained in pure form and made usable again for impregnation.

This known method is cumbersome and requires effort larger devices feasible. In contrast, there is the method according to the invention in that the incandescent body waste with ammonium carbonate solution with the addition of ammonia extracted and from the extraction solution by boiling the same Thoriumhy drocarbo @ nat and cerium hydrocarbonate are obtained. By dissolving the hydrocarbonates In nitric acid, a nitrate solution is formed, which becomes an impregnation lye (luminous salt solution) is processable.

Since the silk waste is often contaminated by heavy metals, it is necessary in this case, before boiling the extraction solution, the existing Eliminate heavy metals by adding ammonium sulfide.

In addition to heavy metal impurities, the impregnated mantle structure contains also certain Amounts of calcium, magnesium and alkalis Partly from the silk, partly from the additives, which in addition to thorium and cerium are used for hardening and fixing. In the presence of larger quantities of these substances, the resulting hydrocarbonate is dissolved in nitric acid and placed on it a mixture of luminous salt hydroxides is precipitated with ammonia. These can then be Dissolve again in nitric acid and thus result in an easily usable impregnation agent.

On an industrial scale, by using a continuous or stepwise countercurrent extraction, the respective washing water, which is necessary to wash out the silk and which otherwise unnecessarily increases the amount of filtrate which is boiled, can be used to make up a new ammonium carbonate solution. Example 400 g of silk are used with q. 1 of an i 2.5% ammonium carbonate solution after the addition of 500 ml of 25% ammonia was poured over it and left to stand for 90 minutes. Then the lye above the silk waste is separated from the silk by suction, washed with water and ammonium sulfide solution is added to the combined filtrates for the purpose of separating out heavy metals until the odor of the excess sulfide is clearly noticeable. After filtering, the clear solution is heated to 90 °. The precipitate, which settles out well, is decanted and washed twice with 500 ml of water each time. After thorough suction, the carbonate is dissolved in 100 ml of 35% nitric acid to about q. 1 filled up and the liquid sucked off. The precipitate is then washed twice with 21% water each time. The still moist hydroxide is dissolved in 60 ml of 35% nitric acid and, after filtering, the solution is evaporated to the required concentration.

According to the result of the analysis, the lye is easy to soak of silk knitted fabric to be used for incandescent bodies.

Claims (3)

PATENT CLAIMS: i. Process for the recovery of the luminous salts Waste generated during the manufacture of the incandescent body with the luminescent salts impregnated incandescent body made of knitted silk, characterized in that the Incandescent body waste extracted with ammonium carbonate solution with the addition of ammonia and from the extraction solution by boiling thorium or cerium hydrocarbonate is obtained, which by dissolving in nitric acid results in a nitrate solution, which to an impregnation solution for incandescent bodies can be processed. 2. The method according to claim i, characterized in that prior to the boiling of the extraction solution, if necessary existing heavy metals can be excreted by adding ammonium sulfide. 3. The method according to claim i or 2, characterized in that in the presence larger amounts of calcium, magnesium and alkalis, the resulting hydrocarbonates dissolved in nitric acid and precipitated a mixture of luminous salt hydroxides with ammonia which are dissolved in nitric acid. q .. Method according to one of the claims i to 3, characterized in that to save water on an industrial scale a countercurrent extraction of the silk is carried out.