Doubleview Gold Corp. V.DBG

fyi

[seveneleven711]

... NH4F solution is used to strip Sc from the organic phase, and Sc is then recovered as (NH4)3ScF6 by crystallization. This intermediate product can be calcined at temperatures between 340 and 350 °C to obtain ScF3 [23]. ScF3 can be used for the direct production of scandium metal and Sc–Al alloys by metallothermic reduction [24]. This processing route is favorable from sustainability and economic perspectives since it eliminates the direct use of HF acid in the production of ScF3 and calcination of the intermediate product, (NH4)3ScF6, is accomplished at lower temperatures, hence at low-energy and with low-cost benefits. In addition, the processing route has fewer steps since fluoride salts can be directly crystallized from solution. For antisolvent crystallization, the high quantities of the antisolvent required can be offset by the fact that the antisolvent can be recovered in a separate distillation process and reused in the precipitation stage...