| 摘要 |
Process for the treatment of a uraniferous ore, carried out continuously with one or more alkaline lyes based on sodium carbonate and bicarbonate. This process comprises the following stages: - siderite is introduced before the digestion, in a quantity such that during the process it supplies carbonate ions in sufficient quantity to form the sodium carbonate and the sodium bicarbonate which are necessary for the digestion of the uraniferous ore, - at the end of the digestion stage the liquor obtained after separation of the ore, which contains uranium and bicarbonate ions, is divided into two parts to obtain a recycle liquor and an output liquor, - the output liquor is subjected to decarbonation with the aid of an acid and then to the precipitation of uranium with the aid of sodium hydroxide, - and the recycle liquor is subjected directly to the action of sodium hydroxide, to precipitate directly at least approximately 85 % of the uranium present in the recycle liquor and to convert the sodium bicarbonate completely to sodium carbonate, - the quantity of sodium hydroxide employed in the recycle liquor being such that it provides the quantity of sodium ions which is sufficient to form during the process the sodium carbonates and sodium bicarbonates which are needed for the digestion of the uraniferous ore. o
|
