Summary of the invention
Purpose of the present invention aims to provide removes micro-tungsten a kind of the separation from the magnanimity molybdenum, and effective, and technology is simple, and is reliable and stable, a kind of method that deep purifying is removed micro-tungsten from high-concentration molybdenate solution that can not pollute
The objective of the invention is to realize by following manner:
Method of the present invention is: (1) pre-treatment: molybdate solution is added mineral acid, adjust pH value of solution value to 7.0~8.5, and deposited 5-12 hour; (2) will be through pretreated molybdate solution at the uniform velocity by the adsorption bed of anionite-exchange resin be housed, remove tungsten adsorption process duration of contact in the molybdate solution between 30~120min, continuously feeding is to WO
3Leakage is the absorption terminal point.
Molybdenum content range in the molybdate solution is 50~250g/l, and the mass ratio of tungstic oxide and molybdenum is 5 * 10
-4~2 * 10
-2
The preferred macroporous type weak base anion-exchange resin of described anionite-exchange resin is Cl when resin uses
-Type.
Negative tungsten resin is resolved with basic solution, and the sodium salt system is resolved with 1~2mol/lNaOH solution, and the ammonium salt system is resolved with the ammoniacal liquor of 5~6mol/l.
Resin after the parsing, the HCl solution regeneration with 4~6%, and water washing is used for next round absorption to fluid pH=3~5.
Its specific implementation process of technology of the present invention is:
1, the pre-treatment of solution: molybdate solution slowly adds mineral acid under agitation condition, adjust pH value of solution value to 7.0~8.5, make wolframate radical be condensed into isopoly-acid root heavy ion, and molybdenum is still existed with the unit molecule form, general sodium molybdate solution can be used hydrochloric acid, ammonium molybdate solution can be used nitric acid, and the molybdate solution that the pH value is adjusted to the right place was deposited 5-12 hour or heated a little to shorten the shelf-time.
2, anionite-exchange resin after the pre-treatment, changes into Cl routinely
-Type, transformation process should carry out in exchange column.The resin that is used to exchange except that tungsten is the macroporous type weak base anion-exchange resin, washes with water to fluid pH3~5 stand-by with the resin of 4-6%HCl after transition.
3, absorption removes tungsten: through the good molybdate solution of pre-treatment, at the uniform velocity pass through to load Cl with certain flow velocity
-The exchange bed of type macroporous weakly basic anion exchange resin, (Q is L/min) by the resin volume (V that exchanges cot loading for the absorption flow velocity
R, L) and absorption duration of contact (T, min) determine i.e. Q=V
R/ T removes tungsten adsorption process scope duration of contact between 30~120min from the molybdate solution of the low tungsten of high molybdenum, continuously feeding is to WO
3Leakage is the absorption terminal point, and liquid leaks to wear to press to purify and requires and decide for purify removing the tungsten qualifying liquid after the friendship of collection, looks the concentration and the scavenging solution WO of tungsten in the feed liquid
3/ Mo (mass ratio) controls requirement, and each exchanging operation can be handled the feed liquid of 10~30 times of resin bed volumes.
4, the desorb of tungsten (molybdenum): very easily from loaded resin, tungsten is resolved fully with basic solution, the sodium salt system is resolved agent with 1~2mol/lNaOH solution, the ammonium salt system is resolved with the ammoniacal liquor of 5~6mol/l, and the molybdenum that is adsorbed with tungsten loses (recyclable).For dropping into below 4% of total molybdenum amount
Resin regeneration; Resin after the parsing is washed with water to fluid pH=3~5 subsequently and is used for next round absorption with the HCl solution regeneration of the 4-6% of about 3 times of resin volumes.
It is ion exchange process that the present invention studies successful technology.In the tungstenic molybdate solution, impurity tungsten and magnanimity molybdenum generate the minute differences of isopoly-acid salt condition and select suitable ion exchange resin, and the tungsten preferentially adsorbed has obtained the effect of degree of depth separating tungsten.Tungstenic reaches 1% molybdate solution of the mass ratio of molybdenum (tungsten with) is after the degree of depth is separated, and tungsten is many ammonium molybdates of making of technology routinely, and W content can be reduced to below 0.02%.
The present invention is by means of making the tungsten polymerization generate the isopoly-acid radical ion under weak base and neutral medium condition, and molybdenum still exists with single molybdenum acid ion form basically, select suitable anionite-exchange resin, the many tungstate ions of energy preferentially adsorbed reach the isolating purpose of molybdenum tungsten under the situation that a large amount of molybdenums exist.This technology is suitable for separating tungsten from ammonium molybdate that contains a small amount of tungsten or sodium molybdate solution, and the molybdenum content range in the solution is 50~250g/l, and the mass ratio of tungstic oxide and molybdenum is 5 * 10
-4~2 * 10
-2,
The advantage of this technology is:
1, technology is simple, need not special reagent, reduced investment.
2, compare with inorganic adsorbent absorption tungsten, this technology is not introduced the chemical reagent that contains harmful impurity element, can not cause the pollution to the molybdenum the finished product because of the adding that removes the tungsten operation.
3, the convenient use, the different many ammonium molybdates manufacturer of raw material different process all is easy to use, and inserts before many ammonium molybdates of precipitated crystal operation and removes the tungsten exchanging operation just, and former technology can not done any change.
4, effective, reliable and stable except that tungsten, reach 1% ammonium molybdate solution as handling tungsten and molybdenum mass ratio, the tungsten ratio of an exchange process scavenging solution can be reduced to below 0.04%, and co-adsorption molybdenum amount belongs to recyclable loss below 4%.
Embodiment
Be described further from molybdate solution, purifying the exchange process that removes tungsten below in conjunction with embodiment.
Embodiment 1
Raw material is that molybdenum glance calcining ammonia leaching solution is through (NH
4)
2Ammonium molybdate solution behind the S purification and impurity removal behind concentrated nitric acid adjustment pH to 8.0, contains molybdenum 121.73g/l in the solution, tungstic oxide 1.379g/l, polymeric adsorbent are macroporous weakly basic anion exchange resin (numbering S
18), adsorbing on the post, exchange column Φ 20 * 250mm by liquid after the friendship after 8 times of resin bed volume feed liquids, contains molybdenum 121.73g/l 80 minutes duration of contact, tungstic oxide 0.101g/l, this moment, the clearance of tungstic oxide was 92.5%.
Embodiment 2
Stock liquid is with embodiment 1, and pH=7.5 contains molybdenum 120.71g/l in the liquid before handing over, and tungstic oxide 1.371g/l, polymeric adsorbent are macroporous weakly basic anion exchange resin (numbering 8
63), adsorb exchange column Φ 20 * 250mm on the post, 60 minutes duration of contact, preceding ten times of resin bed volume flow fluid tungstic oxide mean concnss are 0.054g/l, and the clearance of tungstic oxide can reach 96%, by the ammonium molybdate crystallization that this mixed solution acid settles out, W content is 0.0156%.
Embodiment 3
Ammonium molybdate crystal with ammonia solvent after, adjust pH value of solution value to 7.2, ammonium molybdate solution (molybdenum 120.7g/l, tungstic oxide 0.174g/l,) adsorb except that tungsten, adsorption column and resin are with embodiment 2, and be 40 minutes the duration of contact of absorption, preceding 21 times of resin bed volume flow fluid tungstic oxide mean concnss are 0.016g/l, and the tungstic oxide clearance is 90.8%.