DD228799A1 - PROCESS FOR PREPARING CORNECTIVE CARBON FOR THE PRODUCTION OF FLUORES FOR COLOR PICTURES - Google Patents

Abstract

The invention relates to a process for the preparation of grain activated carbon for phosphor production of colored picture tubes. The goal and task is to produce a grain activated carbon without much effort, which produce a green phosphor that fully meets the requirements allowed. According to the invention this is achieved in that charcoal, Fruchtschalenkokse, Steinobstschalenkokse and lignite Hochtemperaturkoks untreated or alkalized after prior combined alkali, acid and Wasserwaesche with potassium hydroxide or potassium carbonate and activated at 800 to 1 100C in known activation apparatus by gas activation. The active is optionally washed with acid and water, dried, broken and classified.

Description

Title of the invention

Process for the preparation of grain activated carbon for phosphor production for color picture tubes

Field of application of the invention;

The invention relates to a process for the production of activated carbon, which is used for the production of the green phosphor for color picture tubes.

Characteristic of the known technical solutions

Hach in the prior art, the green phosphor for color picture tubes made of zinc sulfide with the addition of other metal salts. The substances mentioned are given in a certain ratio in a crucible. On the mixture, a graphite shell, in which a deducted amount of activated carbon is placed. The crucible is closed with a lid and heated to 960 ⁰ C, lilach completion of the annealing process-the graphite shell is removed with the activated carbon in it and the phosphor substance ζ worked up. The activated carbon used is a granular activated carbon, which is distinguished from commercially available activated carbon in particular by a low ash content of about 1 % and a very low content of iron, copper and ITiekel. Thus the iron content is <i 65 ppm, the copper content -β 24 ppm and the nickel content <T 1 ppm.

The production of such activated carbons is associated with great expense, with selected raw materials, such. 3 Coconut schalenkok se, and expensive apparatus, which may not give off any metal compounds to the reaction mixture applied. Furthermore, working with the deashing of such activated carbons with purest substances.

Iron-free or low-carbon coals can be obtained by acid leaching or by treatment with gaseous or vaporous materials that form volatile compounds with iron in the heat. Hierau include halogens, halogen compounds or carbon monoxide (Kienle, H.v., Bäder, E. activated carbon and its industrial application, Enke Yerlag Stuttgart, 1980, p 168).

Object of the invention

The object of the invention is to produce a granular activated carbon without much effort, which produce a green fluorescent fully compliant with the requirements allowed.

Presentation of the essence of the invention

The object of the invention is, starting from known raw materials, to obtain this grain activated carbon by a gas activation process while maintaining conventional apparatuses.

According to the invention. This is achieved by pretreating charcoal, fruit peel coke, stone scotch coke and brown coal high temperature coke, or after prior combined. Alkali, acid and water alkalized with potassium hydroxide or potassium carbonate and activated at 800 ⁰ G to 1100 ⁰ C in known activation apparatus by gas activation.

The active is optionally washed with acid and water, dried, broken and classified

The applied amount of potassium hydroxide or potassium carbonate is 0.5 to 5 '%, preferably 1 to .2% _t based on the raw material used nevertheless "When washing herds preferably dilute potassium hydroxide solution and dilute hydrochloric acid used.

Ausführunssbeispiele

example 1

Beech charcoal mlrd is poured over with 5% potassium hydroxide solution and allowed to stand for 24 h, then it is rinsed with water. Subsequently, the beech charcoal is left to stand with 5% hydrochloric acid three times, each time for 24 hours. After the third acid wash, it is washed with running water until the effluent reaches a pH of β. The washed beech charcoal was sprayed with potassium hydroxide solution containing 1.5% of potassium hydroxide, based on the starting material used.

200 kg of this treated beechwood charcoal are in a 3 ώ long discontinuously operating rotary kiln, with direct Generatorgasfeuerung.bei 9QO ⁰ C with the addition of 400 ml of water / min, the sprayed with compressed air to the burning coal v? Ird, for 20 to 24 is activated h. The activity is broken and sieved. Fraction 2 to 5 nnn is used in the production of the green phosphor for color picture tubes. The obtained coal had the following analysis over the comparison coal:

compared coal

200 38C 2-5 2-5 8th 1 1400 1320 25 21

Vibration density / k * g / nr7 Grain / mm7 Ash content F "% J Iodine number / mg / ^ 7 Ue t hy 1 e iibl aut erer / ßlJ7

The quality of the green phosphor is characterized by the following values:

Vergleichakohle

relative brightness 106.7 106

Color location 0.999 0.999

mean particle size / 7 * m7 7.3 7.3

Example 2

, Kernschalen von.Sauererkirschkernen were coked in the laboratory rotary kiln at a Sndtemperatur of 65O ⁰ C. 250 g of this cup were at 920 ⁰ C in the laboratory rotary kiln with the addition of 12β ml of water / h in vapor form. ^ Activated for 90 min. Potassium hydroxide containing 2 % of potassium hydroxide, based on the amount of coke used, was added as activation aid. During the activation, 50 l of carbon dioxide / h and 340 l of stick / h were passed through the activation oven. The. AKTIVAT "Tsurde with 10% hydrochloric acid treated, then a water wash was joined. Hach drying at I50 ⁰ C ^ aurde classified. The fraction 2 to 5 nan ^ iurde employed in the preparation of the green Leuchtsotffes for color picture tubes»

The obtained granular coal had the following analysis values compared to the Tergleichskohle:

310 compared coal Bag density / kg / irr / 2-5 380 Grain / ~ βιπι_7 0.6 2-5 Ash content ~ J ~% J 1040 1 Iodine number / mg / g / 1320

Methylene blue titre / ~ ml7 14 21

The quality of the green phosphor was characterized by the following values:

compared coal

relative brightness / ^ M7 1 06 1 06 Parbort 0 , 998 0 999 middle grain size 7 2 , 7 3

Claims (4)

Invention sansprucb. 1. A process for the preparation of grain activated carbon for phosphor forth for color picture tubes, characterized in that charcoal, fruit schalenkoks, Steinobstschalenkoks and Braunkohlenho.chtemperaturkoks untreated or after previous combined alkali, acid and va asserwäsehe at 8CO to 1100 ⁰ G a Gas activation in known apparatuses in the presence of 0.5 to 5% activation auxiliaries, based on the raw material used, subjected ge and washed with acid and water in a known manner, dried, broken and classified -werden. 2. The method according to item 1, characterized ^ ^ daSmittel as Aktivie.rungshilf. Kaiiurnhydroxid or potassium carbonate in amounts of 1 to 2 % used ^ ird. Dilute potassium hydroxide solution and dilute hydrochloric acid are used ^r l aschproze SEN, .vorzugsvieise; d8n ._: 3 · The method of item 1 -and 2, characterized in that -in. 4. The method according to item 1 to 3 », characterized in that the active ingredient broken and classified without prior washing ^ i