A kind of under the potential of hydrogen alternation condition ion-exchange fixed tower put forward the uranium method
Technical field
The invention belongs to the uranium method of putting forward of using the ion-exchange fixed tower, be specifically related to a kind of under the solution acid alkalinity alternation condition ion-exchange fixed tower put forward the uranium method.
Background technology
Adopt ion exchange method from leach liquor, to extract uranium; for the zone that does not have the particular surroundings protection to require; it generally is the kind of selecting eluent according to the characteristic of ore leach liquor that ion exchange method is carried uranium; promptly from acid leaching solution, reclaim extraction uranium and adopt acid eluent, from neutrality or weakly alkaline solution, reclaim and extract uranium employing neutrality or weakly alkaline eluent.At present, China's uranium mill great majority adopt acid system to leach---anionite-exchange resin absorption---acid villaumite or acid nitrate drip washing---depositing technology.Wherein the single charging or the mode of charging down of going up adopted in the operation of ion exchange tower, is qualifying liquid when the uranium concentration of drip washing effluent liquid is higher can reach the subsequent technique service requirements time, is called a barren solution and two barren solutions when uranium concentration drops to certain value.
---the technical process of anionite-exchange resin absorption---acid villaumite or acid nitrate drip washing---precipitation product that the employing acid system leaches, adopted acid villaumite or acid nitrate to carry out desorb owing to carry the uranium resin, in the process water working cycle, can cause chlorine root or nitrate radical constantly to accumulate, influence the absorption of follow-up ion exchange resin, and adsorption tail liquid need efflux.Strict or do not have the zone of receiving water body for environmental protection requirement, this puies forward the relevant requirements that the uranium technical process can't reach national environmental protection.
If adopt carbonate that the ion exchange resin that extracts uranium from acid leaching solution is carried out drip washing, can realize the process water closed cycle, but at the drip washing initial stage, the acid-base neutralisation reaction can produce a large amount of CO
2Bubble is handled improperly in actual mechanical process, can cause damages such as pipeline, equipment, brings great potential safety hazard to production.
Summary of the invention
The object of the invention provides a kind of ion-exchange fixed tower under the potential of hydrogen alternation condition that improves elution efficiency, shortening elution volume and puies forward the method for uranium.
The technical solution adopted in the present invention is:
A kind of under the solution acid alkalinity alternation condition ion-exchange fixed tower put forward the uranium method, comprising: poor resin absorption uranium step and carry a uranium resin drip washing uranium step, wherein:
Carrying uranium resin drip washing uranium step comprises again successively:
The drip washing neutralization stage: use the spent acid in the alkaline eluent neutralization year uranium resin, feeding manner is following feed liquor;
The drip washing qualifying liquid stage: feeding manner is last feed liquor;
The one poor stage of drip washing: feeding manner is last feed liquor, and effluent liquid is a barren solution;
The two poor stages of drip washing: feeding manner is last feed liquor, and effluent liquid is two barren solutions.
Aforesaid a kind of under the solution acid alkalinity alternation condition ion-exchange fixed tower put forward the uranium method, wherein: described poor resin absorption uranium step adopts the ion-exchange fixed tower to reclaim uranium from acid leaching solution, feeding manner is following feed liquor, when effluent liquid uranium concentration and stoste uranium concentration difference during at 0~20mg/L, with solution emptying in the ion-exchange fixed tower, poor resin absorption uranium step finishes.
Aforesaid a kind of under the solution acid alkalinity alternation condition ion-exchange fixed tower put forward the uranium method, wherein: described poor resin absorption uranium step adopts the placed in-line mode of a plurality of ion-exchange fixed tower to carry out.
Aforesaid a kind of under the solution acid alkalinity alternation condition ion-exchange fixed tower put forward the uranium method, wherein: in the described two poor stages of drip washing, when drip washing effluent liquid uranium concentration during less than 0.2g/L, drip washing finishes, the solution in the emptying ion-exchange fixed tower.
Aforesaid a kind of under the solution acid alkalinity alternation condition ion-exchange fixed tower put forward the uranium method, wherein: in described drip washing neutralization stage, when the pH of effluent liquid value was in 2.5~8.0, the drip washing neutralization stage finished to enter the drip washing qualifying liquid stage.
Aforesaid a kind of under the solution acid alkalinity alternation condition ion-exchange fixed tower put forward the uranium method, wherein:, adopt to contain CO in the described drip washing qualifying liquid stage
3 2-Eluent or a barren solution of last tower make eluent and carry out drip washing carrying a uranium resin.
Aforesaid a kind of under the solution acid alkalinity alternation condition ion-exchange fixed tower put forward the uranium method, wherein: adopt in the one poor stage of described drip washing to contain CO
3 2-Eluent or two barren solutions of last tower make eluent and carry out drip washing carrying a uranium resin.
Aforesaid a kind of under the solution acid alkalinity alternation condition ion-exchange fixed tower put forward the uranium method, wherein: adopt in the two poor stages of described drip washing to contain CO
3 2-Eluent carry out drip washing to carrying a uranium resin.
Aforesaid a kind of under the solution acid alkalinity alternation condition ion-exchange fixed tower put forward the uranium method, wherein: in the described drip washing qualifying liquid stage, when the uranium concentration of effluent liquid was reduced to 1~10g/L, the described drip washing qualifying liquid stage finished, and enters the one poor stage of drip washing.
Aforesaid a kind of under the solution acid alkalinity alternation condition ion-exchange fixed tower put forward the uranium method, wherein: in the described one poor stage of drip washing, when the uranium concentration of effluent liquid was reduced to 0.5~1g/L, the one poor stage of described drip washing finished, and enters the two poor stages of drip washing.
The invention has the beneficial effects as follows:
1. the present invention is by dividing drip washing neutralization stage and drip washing qualifying liquid stage in carrying uranium resin drip washing uranium step, and feed liquor and last feed liquor mode are descended in employing respectively, help the unobstructed discharge of a large amount of gases of production in the ion exchange tower, can avoid in lessivation, producing " dead angle " owing to gas blocks up, and help to improve elution efficiency, shorten elution volume.
2. the present invention has improved the effect of adsorption uranium by adopting the placed in-line mode of multitower in poor resin absorption uranium step.
3. the present invention by distinguishing four-stage at specified range point, helps to improve elution efficiency in carrying uranium resin drip washing uranium step, shortens elution volume.
4. the present invention can effectively improve the efficient and the effect of ion-exchange by adopting a barren solution of last tower and two barren solutions to make eluent in drip washing qualifying liquid stage and one poor stage of drip washing.
Description of drawings
Fig. 1 be provided by the invention a kind of under the potential of hydrogen alternation condition ion-exchange fixed tower carry the schema of uranium method;
Fig. 2 is that ion-exchange ADSORPTION IN A FIXED BED and drip washing pipeline are arranged synoptic diagram;
Among Fig. 2: 1,2 ...., the 8th, the ion-exchange fixed tower; The 9th, following fluid inlet valve; The 10th, last fluid inlet valve; Dotted line is represented the string pipe, the shared pipe of line expression.
Embodiment
Below in conjunction with drawings and Examples a kind of method that the ion-exchange fixed tower is carried uranium under the potential of hydrogen alternation condition of the present invention is introduced:
As shown in Figure 1, a kind of method that the ion-exchange fixed tower is carried uranium under the potential of hydrogen alternation condition is divided following step:
(1) poor resin absorption uranium step: adopt the ion-exchange fixed tower from acid leaching solution, to reclaim uranium, the acid leaching solution feeding manner is following feed liquor, resin adsorbs the uranium in the acid leaching solution, in this process, when the stoste uranium concentration before effluent liquid uranium concentration after waiting to adsorb and the absorption is basic identical (both concentration differences are when 0~20mg/L), can think that ion exchange resin absorption is saturated, and with solution emptying in the ion exchange tower, in order to drip washing.
In the present embodiment, this step adopts 3 towers series connection absorption, with 1,2, No. 3 tower is the example narration: at first adsorb stoste (promptly being acid leaching solution) and enter the tower internal adsorption from No. 1 tower bottom, No. 1 tower adsorption tail liquid by adsorb shared pipe, absorption string tower pipe enters the tower internal adsorption from No. 2 tower bottoms, No. 2 tower adsorption tail liquids by adsorb shared pipe, absorption string tower pipe enters the tower internal adsorption from No. 3 tower bottoms, No. 3 adsorption tail liquid directly enters the outer comb of adsorption tail liquid by adsorbing shared pipe.Also can according to circumstances change the quantity of columns in series, get over for a long time when the quantity of columns in series, tail washings concentration is low more, and adsorption effect is good more.
(2) carry uranium resin drip washing uranium step:
1) drip washing neutralization stage:,, (contain CO with alkaline mother liquor of precipitation of ammonium at the drip washing initial stage owing to carry uranium resin (or being ion exchange resin) system for acid
3 2-Eluent with sodium hydroxide) resin is carried out drip washing, in and remaining spent acid in the resin, feeding manner is feed liquor down, makes the acid-base neutralisation reaction produce a large amount of CO
2Bubble helps effluxing (discharging from the vent valve of ion-exchange fixed tower cat head).Find that by the drip washing test neutralization stage in the lessivation is to the transition in qualifying liquid stage, the pH value of its effluent liquid can change (pH rises to 2.5~8.0), therefore is easier to control transformation point.
2) the drip washing qualifying liquid stage: after treating that the drip washing neutralization stage finishes, adopt to contain CO
3 2-Eluent carry out drip washing to carrying a uranium resin, feeding manner changes feed liquor into by original following feed liquor.The uranium concentration of effluent liquid is higher (to reach 10~30g/L), and CO
3 2-Concentration is lower (to be reached 20~30g/L) and is the drip washing qualifying liquid.
3) the one poor stage of drip washing: when the uranium concentration of effluent liquid is reduced to 1~10g/L, effluent liquid is a barren solution of current tower, and feeding manner is last feed liquor during drip washing; Employing contains CO
3 2-Eluent carry out drip washing to carrying a uranium resin.
4) the two poor stages of drip washing: when the uranium concentration of effluent liquid is reduced to 0.5~1g/L, adopt to contain CO
3 2-Eluent carry out drip washing to carrying a uranium resin, feeding manner is last feed liquor, effluent liquid is two barren solutions of current tower.Treat that drip washing effluent liquid uranium concentration reduces to below the 0.2g/L, drip washing finishes, and the solution in the emptying ion exchange tower, in order to absorption.
As shown in Figure 2, adopt the placed in-line mode of a plurality of ion-exchange fixed tower usually in carrying uranium resin drip washing uranium step, then in the drip washing qualifying liquid stage, back one tower can adopt a barren solution of last tower to make eluent; In the one poor stage of drip washing, back one tower can adopt two barren solutions of last tower to make eluent.
At first open the following fluid inlet valve 9 of each ion-exchange fixed tower, alkaline mother liquor of precipitation of ammonium is entered from tower bottom carry out acid-base neutralisation in the tower; The structure of described ion-exchange fixed tower is those skilled in the art's a common practise;
After the neutralization stage of each tower finishes, close down fluid inlet valve 9, meanwhile open and go up fluid inlet valve 10, one barren solution of last tower enters from cat head by the shared pipe of drip washing (line among Fig. 2) as eluent carries out drip washing to carrying the uranium resin, this stage is the drip washing qualifying liquid stage, because there is not its last tower in No. 1 tower, thereby the eluent that uses is the CO that contains of external world's adding
3 2-Eluent;
To any tower, when the uranium concentration of effluent liquid was reduced to 1~10g/L, this tower entered the one poor stage of drip washing, two barren solutions of using last tower are as eluent, feeding manner is last charging, because there is not its last tower in No. 1 tower, thereby the eluent that uses is the CO that contains of external world's adding
3 2-Eluent;
To any tower, when the uranium concentration of effluent liquid was reduced to 0.5~1g/L, this tower entered the two poor stages of drip washing, adopted to contain CO
3 2-Eluent carry out drip washing to carrying a uranium resin, feeding manner is last feed liquor;
When the effluent liquid uranium concentration is reduced to below the 0.2g/L, drip washing finishes, the solution in the emptying ion exchange tower.Certainly, those skilled in the art also can change the uranium concentration value of each weight break point according to the uranium concentration that will obtain.But above-mentioned value range can obtain bigger effluent liquid uranium concentration under shorter drip washing time and less elution volume.
The drip washing test has been carried out in following charging after the charging in single last charging, single charging down, the elder generation respectively, the results are shown in following table:
Table 1 drip washing test-results
From above result as can be known, adopt and go up charging, the back feed liquor mode of charging down earlier, use less accumulative total elution volume can make liquid uranium flow out (be that effluent liquid uranium peak value is big, end value is little) fast, help to improve elution efficiency, shorten the drip washing time and reduce elution volume.