DE1792675A1 - Process for the flotation of ion exchangers - Google Patents

Description

Wintershall Aktiengesellschaft, Celle; Kassel, August-Rosterg-Haus

"Process for the flotation of ion exchangers"

The state of the art, which has not been previously published, includes a method for the flotation of ion exchangers, which is characterized by is that an amphiphilic substance of opposite charge 'adsorbed on the exchanger to be floated and that the adsorbate is foamed in an aqueous dispersion by blowing in a gas, in particular air.

This process is further characterized in that anion exchangers with quaternary nitrogen based on polystyrene, divinyl, benzene at a pH value not below 3-4, especially at pH 5-, with fatty acids or their soaps, or alkali sulfates or sulfonates the fatty acids are floated in water or in dilute aqueous solution, and furthermore, this means that cation exchangers with negative charge, such as with SO -, - active groups, at pH values of 1-8 with primary or secondary amines or quaternary ammonium compounds in water or aqueous Solutions are floated. ·

The previously known method relates to the flotation νοΆ ion exchangers from solutions. There is technical interest in this process especially when the filtration of these high molecular weight substances causes difficulties. . .

In technology, however, there is still the task of ion exchangers to separate from turbines that contain, for example, gait, so after the flotative separation of the charged ion exchangers the remaining solids of the pulp from the solution e.g. by filtration can be separated.

During the "acid leaching" of uranium ores such as Autunit or Chalcolite, a turbidity occurs, which is next to a uranium-containing solution with a pH value of around 2, there is still a lot of gait and very fine suspended matter Distribution contains. It is common practice to extract the uranium from this

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Carry out solution after clarification and subsequent passage through ion exchanger. The clarification before the uranium separation is one. the difficult and costly stages in the processing of uranium ores.

It is possible to use the so-called "resin-in-pulp" process, also unexplained Prepare lye. The ion exchanger is coarse in wire baskets in a horizontal stream of unclarified caustic solution moved vertically back and forth. Avoid deposits of suspended solids on the resin. This procedure is 1st difficult to handle and the full capture of the uranium in the Lye is not guaranteed. In addition, because of the necessity, to use very large exchanger granules, exchange speed and exchange capacity greatly reduced. These difficulties can be avoided by the method of the invention.

The technical implementation of the method of the invention in further development of the method according to the patent application P I7 67 260.Ö explained by the following exemplary embodiment:

1 kg of ground uranium-containing mineral with a content of 1.5 % uranium (17.6 g U-zOg) is digested with 10 1 diluted sulfuric acid (approx. 8 g / l H ₂ SO ^) with gentle heating until all of the uranium has gone into solution. After the pulp has cooled to room temperature, it has a pH value of about jj · The pH value is then adjusted to 5 with sodium hydroxide solution, which requires about 20 ml of 1 normal NaOH. Then about 500 g of anion exchanger in the sulfate form, namely the commercial product Dowex-2 sulfate, are stirred into the pulp and the exchanger is loaded _{with uranium in the form of the UO 2} (SO ^) _{2 ion with constant mixing with a slow-speed stirrer.} Cationic impurities are not absorbed by the exchanger, so that a very high selectivity with regard to the uranium is achieved. The loading of the exchanger is about 0.25 milliliters per gram.

After a full load, which is reached in about 10-15 minutes, the pulp is transferred to a floating machine, 0.25 g Na oleate added and the exchange resin flowed out completely through ventilation.

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animals. The uranium is made from the resin, which is available as a concentrate a weakly acidic NaCl solution. That from this eluate Uranium precipitated as uranium is very pure. The separated exchange resin becomes part of the process after it has been converted into the sulphate form returned for reuse.

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Claims (4)

Patent claims 1. A method for the flotation of ion exchangers as a further development of the method according to patent application P'17 6j 360.8, characterized in that during the flotation of ion exchangers from pulp on the exchanger to be floated, an amphiphilic substance of opposite charge is adsorbed and the adsorbate is adsorbed by blowing in a gas, in particular Air, foamed in an aqueous dispersion and thereby separated from the slurry » 2. The method according to claim 1, characterized in that anion exchanger with quaternary nitrogen on polystyrene, Dlvinyl, benzene base at a pH value not below 3 - 4, especially at pH 5 - 7, with fatty acids, or their soaps, or alkali sulfates or sulfonates of fatty acids In water or in dilute aqueous solution to be floated. ■ 3 · Process according to claims 1 and 2, characterized in that that cation exchangers with negative charge, such as with SO, active groups, at pH values of 1-8 with primary or secondary amines or quaternary ammonium compounds be floated in water or aqueous solutions. 4. The method according to claims 1 to 3 »characterized in that that the adsorbed ions are detached from the exchange resin in a known manner, the exchange resin in the salt form as converted into the sulfate form and into the Process is returned to re-adsorption. • December 27, 1968
FD-JH / schp 0098A5 / 1S12 BAD original