| The main sources of molybdenum acid waste liquid are:the molybdenum acid waste liquid which are product during the productive process of ammonium molybdate; tungsten molybdenum beneficiation wastewater and molybdenum copper smelting waste acid and etc.Currently, extracting molybdenum from the molybdenum waster liquid has become an important part of the resources recovery on molybdenum.However, in accordance with the pH value,impurity content,type and the concentration of molybdenum which contains in the waste liquid and some other factors,we vary the technology methods when recovery the molybdenum.The methods we generally adopted present are the solvent extraction method and the ion exchange method, however,each of this has its limiting condition.For the solvent extraction method, the advantages are:large capacity of recovery; high selectiveness; fast reaction rate; high acid and alkali resistance.Relatively, it is more apply to recovery the molybdenum from acid waste liquid.While the disadvantage is the enrichment degree is relatively low,especially when disposing molybdenum waste with low concentration. As for ion exchange method,the main advantages are: good at processing low concentration molybdenum waste liquid;high enrichment degree; strong selective adsorption,especially for some solution with complicated composition.The disadvantages is the acid and alkaline resistance of ion exchange resin is low,most of its usage are at pH1-14.The law material in this research is rhenium extraction residue from the Arsenic Acid Workshop,Jiangxi Copper Corporation,at sulfuric acid concentration1.6mol/L,which has high acidity, at molybdenum0.09g/L,which is relatively low,and various mental impurities such as arsenic、ooper、iron、nickel.The main objective of this experiment is to purify and gathering molybdenum from this solution.And we can see from the analysis of the raw material,using the solvent extraction method and the ion exchange method can neither reach the target of recovery.For this situation,I used both of this method. First, I adopted the solvent extraction to purify the molybdenum waste liquid preliminary.And I turned the molybdenum oxide cations into the root anionic ammonium molybdate under strong acid solution,and after it was purified, I then gather it through ion exchange.Aimed at various influencing factors of the extraction and ion exchange,this project about extracting molybdenum is to test in following aspects:1.Ascertain the organic phase composition,which N235as extraction agent,2-octanol as modifier,sulfonated kerosene as diluent,and the results of the concentration of N235,the concentration of2-octanolO/A,shacking time and some other aspects impacts on the extraction of molybdenum..And we can conclude that the best condition to extract molybdenum is:30%N235 +10%2-octanol+60%sulfonated kerosene,O/A=2:1;7min for shaking time under normal temperature; ingle-stage extraction for molybdenum reach about93.8%.Through simulation on3-stage countercurrent we can make the total extraction rate of molybdenum be above99%,and the single stage extraction rate of the impurities of arsenic be6.43%, and the other impurities not be extracted.the separation effect is relatively good.2.Have a theoretical discussion on the extraction of molybdenum and arsenic and have a thermodynamic analysis on the process of the extraction of molybdenum.And have proved that under such system, using N235to extract molybdenum is a slight-heat release-process.3.As for loaded organic phrase, we take0.01mol/L dilute sulfuric acid as eluent, O/A=1:1,5min shaking time under normal temperature.After the abstersion of3-degree-cross-flow,the washout rate of the impurity arsenic can be99.2%, and the wastage on the washout of the molybdenum is lesser.4.Take ammonia water as stripping agent to survey the concentration of ammonia water O/A,shaking time and other aspects impact on the extraction of molybdenum.Take5mol/L ammonia water,O/A=5:1,7min for shaking time under normal temperature,the one-stage percentage stripping of molybdenum reached95.2%.Through extraction of2-stage-cross-flow, almost all of the molybdenum which are loaded on the organic phrase stripping into the water phase.5.determine201×7Model anion exchange resin is used as the extraction of molybdenum from the stripping liquid resin was investigated to obtain the optimal conditions for adsorbed:at a pH adjusted to the neutral range, the adsorption solution60ml, molybdenum concentration of about0.2g/L, corresponding to201×7models Dry based resin0.15g was added that the resin quality (quality/g):is adsorbed amount of solution (volume/ml)=1:400, if converted into the resin is added to the mass of the molybdenum in the amount of solution.ratio compared to12.5or so, the adsorption temperature was room temperature20℃adsorption equilibrium time was stirred for2hours, the better the adsorption effect of the resin, the adsorption rate reached96%, and the higher the working capacity of the resin to76.8mg/g.6.Saturated with molybdenum resin using0.5mol/L solution of ammonium chloride as the analysis liquid parsing experiments, at a temperature of20℃, the resin mass (g)/analytic solution volume (ml)=1:20, stirring parsing and50minutes to reach equilibrium, the resinthe analysis was96%, and the analytical solution of molybdenum concentration of3.69g/L, are high, the resolution rate and the analytic concentration obtained under this condition, the experiment better. |
PDF Full Text Request