CS255142B1 - The method of purification of radioactive wastewater in uranium industry - Google Patents

Abstract

The essence of the method for treating radioactive wastewater from the uranium industry containing ammonia is that radioactive mine water containing suspended solid particles is treated with a mixture of acidic saline solutions from the underground leaching process of radioactive ores, especially uranium ores, with sulfuric acid, containing up to 100 kg.m of dissolved -3 substances, of which up to 50 kg.m of free sulfuric acid, up to 5 kg.m of aluminum Al, up to -3 + -3 3 kg.m of ammonium ions NH. and up to 80 kg.m 2_ * sulfate ions SO^ , the pH of which is lower than 3.5, lime milk with a dose of up to 50 kg of calcium oxide per 1 m* 3 of acidic saline solutions and a solution of hypochlorite of an alkali metal or alkaline earth metal with a content of 50 to 200 g of active chlorine per liter in an amount of up to 0.55 m3 of hypochlorite solution per 1 m3 of acidic saline solutions, this mixture being added to radioactive mine waters 3 3 in a ratio of up to 0.25 m per 1 m of radioactive mine waters. The method can be used in water purification wherever wastewater and solutions with an analogous composition are available, which can serve as a substitute for a coagulant, however, their use is limited by the content of ammonium ions in them.

Description

The present invention relates to a process for the purification of radioactive wastewater of the uranium industry.

Possibilities of treatment of radioactive wastewater of the uranium industry according to the author's certificate 233 902 are often limited by the content of ammonium ions in acid saline solutions from underground leaching of uranium ores with sulfuric acid, because these ions undergo the treatment process unchanged and their content on streams is strictly monitored.

Selective removal of ammonium ions is not possible due to the composition of the solutions in which they are contained.

These disadvantages are overcome by the method of purification of radioactive wastewater of the uranium industry according to the invention. It is based on the fact that radioactive mine water containing suspended solid particles is treated with a mixture of acidic saline solutions from the underground leaching process of radioactive ores, in particular uranium, with sulfuric acid

-3 -3 —3

100 kg.m of solutes, of which up to 50 kg.m free sulfuric acid, up to 5 kg.m aluminum

3+ -3 + -3 2A1, up to 3 kg.m of NH4 + and up to 80 kg of SO2. having a pH of less than 3,5, of lime milk in a dose of up to 50 kg of calcium oxide per 1 nm of acid saline solutions and of an alkali metal or alkaline earth metal hypochlorite solution containing 50 to 3 3

200 g of active chlorine per liter in quantities of up to 0,55 m of hypochlorite solution per 1 m of acid saline solutions, this mixture being added to radioactive mine waters in a proportion of up to 0,25 m ³ per m ^{3 of} radioactive mine water.

The process according to the invention enables the purification and thus the disposal of part of the excess of acidic saline solutions from the process of underground leaching of radioactive ores with ammonium-containing sulfuric acid, which would have to be cleaned by a separate complex technology, immediately and at minimal cost. By containing acidic saline solutions which act as a coagulating agent for clarifying radioactive mine water, they serve as a substitute for these coagulating agents, resulting in a significant reduction in the costs of purifying radioactive mine water. Both radioactive mine waters and acidic saline solutions from the underground leaching process of radioactive ores with sulfuric acid are cleaned together to a quality corresponding to the water management requirements for discharge into the public watercourse.

In the wastewater treatment process according to the invention, acidic saline solutions from the underground leaching process of radioactive ores with sulfuric acid, after mixing with lime and hypochlorite and radioactive mine water, are fed to a common sump where they are mixed together. From the sump, the suspension of the liquid phase and the resulting precipitate is discharged to a sedimentation tank where the precipitate is sedimented. The clarified water is discharged from the sedimentation tank to the public watercourse.

Due to the varying composition of radioactive mine waters, which are clarified using acidic saline solutions from the underground leaching process of radioactive ores with sulfuric acid, the optimum dose of a mixture of these acidic saline solutions with lime and hypochlorite should be determined.

Example

The optimum course of clarification of radioactive mine water by the method according to the invention was operated when the acidic saline solutions from the underground leaching process of the radioactive mine

-3—3 3+ ores of sulfuric acid containing 7 kg.m of dissolved substances, of which 0.5 kg.m.

0.15 kg.m Fe ^ ⁺ , 4.5 kg.mSO4, 0.12 kg.m NH3 and whose pH 2.7 at 60 m < 3 > were made alkaline with lime milk at 180 kg.h * of calcium hypochlorite containing 112 kg.m of active chlorine, and this month was treated with radioactive mine water flowing into the mixing well in an amount of 900 m ³ . h ^_1 .

SUBJECT OF THE INVENTION

Claims (2)

SUBJECT OF THE INVENTION Method for the purification of radioactive wastewater of the uranium industry, characterized in that radioactive mine water containing suspended solid particles is treated with a mixture of acidic saline solutions from the underground leaching process of radioactive ores, in particular uranium, -3-3 sulfuric acid containing up to 100 kg.m. of solutes, of which up to 50 kg.m. -3 3+ -3 + -3 sulfuric acid, up to 5 kg.m of aluminum Al, up to 3 kg.m of ammonium ions NH. and up to 80 kg.m 2 ^- * sulphate ions SO. Whose pH is below 3.5, the milk of lime at a dose of 50 kg of calcium 3 ^{3 4} 1 m salty acidic solution and an alkali metal hypochlorite or alkaline earth metal content of from 50 to 200 g active chlorine per liter in an amount to 0.55 m 3 of hypochlorite solution per 1 m of acidic saline solutions, this mixture being added to radio-3 active mine waters at a rate of up to 0.25 m per m of radioactive mine water.