The method of extraction of molybdenum from acidic solutions
(57) Abstract:The invention relates to hydrometallurgy rare metals, extraction of molybdenum from acidic sulphate-nitrate solutions and clear of impurities. The method of extraction of molybdenum from acidic solutions includes multi-stage extraction with an organic extractant and a multistage reextraction sulfate-ammonium solution. When this extraction is carried out at a saturation of the extractant molybdenum on 90-95% of theoretical with the subsequent two-stage washing of the extract and reextraction are at an equilibrium pH of 4-6, regulated by filing extragent parts in the several stages of Stripping. Extract molybdenum washed successively with a solution of sulfuric acid of a concentration of 0.3-0.5 mol/l and sulfate-ammonium solution to create in equilibrium leaching solution pH 1-2. After Stripping rinse extractant, for example, a sulfuric acid solution with a concentration of 0.3 to 0.5 mol/l, which is then channelled to the washing of the extract. The method allows to increase the extraction of Maboutwhen the extraction of up to 99.5% and the degree of purification from impurities. 2 C.p. f-crystals, 1 Il., 3 table. The invention relates to the field of hydrometallurgy rare metal is of molybdenum core of tungsten spirals.A known method of producing paramolybdate ammonium from organic extracts containing molybdenum (ed. St. USSR 633811, IPC C 01 G 39/00, publ. 25.11.78, BI 43).The original aqueous solution containing sulfuric acid, molybdenum, iron, calcium, phosphorus, and others, were treated with a 15% solution polyalkylacrylate acid (PARRC) in hydrocarbon (extraction), resulting in a residual content of molybdenum in the aqueous solution decreased to 0.005 g/lThe extract obtained was treated with an aqueous solution of ammonia containing 5% ammonium sulfate, at an equilibrium pH of 6.5-8.5 and a volume ratio of organic and aqueous phases is from 3:1 to 1:3 (reextracted); the pH of the solution was regulated by changing the concentration of ammonia, the ratio of the phases was regulated by circulating the aqueous phase.In the process of Stripping was not formed traderstewie emulsion improved the quality of the final product.However, the known method, possessing certain advantages, it has several drawbacks that prevent its practical use, namely:
- when selected (appointed) high pH values of 6.5-8.5 restraint used acidic extractants di-2-ethylhexylphthalate acid (D2EGFK), the second organic phase, that eliminates the possibility of conducting the process in a continuous mode;
- change conditions Stripping causes the need to carry out quite complex technological operation is to change the composition of the extractant (in ammonia) directly during operation.Known methods closest to the claimed technical essence and the achieved result is a method for extracting molybdenum from acidic solutions, including multi-stage extraction with an organic extractant and a multistage reextraction ammoniagenesis solution (RJ Chemistry, M., VINITI, 1972, summary 13L P).The disadvantage of this known method is the low degree of extraction of molybdenum from the original solution in the extraction step (94,5%) and the lack of conditions for the further purification of the extract molybdenum from impurities.These deficiencies indicate a lack of efficiency of this method.These shortcomings deprived offer applicants the method of extraction of molybdenum from acidic solutions, the implementation of which will reach the desired technical result - increasing the depth of extraction of molybdenum when extra the traction molybdenum.The inventive method of extraction of molybdenum from acidic solutions, as prototype method includes multistage extraction with an organic extractant and a multistage reextraction ammoniagenesis solution.Proposed by applicants method differs from the prototype method the fact that the extraction is carried out at a saturation of the extractant molybdenum on 90-95% of theoretical with the subsequent two-stage washing of the extract and reextraction lead sulphate-ammonium solution at equilibrium pH 4-6, regulated by filing extragent parts in the several stages of Stripping.In addition, the new method is that the lead leaching sulfuric acid solution with a concentration of 0.3 to 0.5 mol/l, and reextraction sulfate-ammonium solution to create in the washing solution pH 1-2. After Stripping rinse extractant solution of sulfuric acid with a concentration of 0.3 to 0.5 mol/l, which is then channelled to the washing of the extract.The claimed method meets all the criteria of patentability.He has novelty, as currently, the applicants did not find any famous of world-class technology solutions, harakterizuyu the ptx2">The method involves an inventive step, because the applicant has not identified solutions that have the signs consistent with its hallmarks.The proposed method solves a very challenging task, as a result of its industrial implementation is to obtain the pure desired products: reextract molybdenum, which is used to obtain paramolybdate ammonium, and the raffinate mixture of sulfuric and nitric acids.Given the significant volumes of raw materials, the creation of the present invention is a timely and necessary.The inventive method is industrially applicable, as it is characterized by the list and sequence of specific actions and operations.Each operation of the method separately there is no doubt in reproducibility.The whole set of essential features and each feature individually is not inconsistent use in the implementation of the method in an industrial environment.The whole set of essential features and each feature individually aimed at the achievement of the expected technical, as well as the economic result is to extract molybdenum from a mixture of sulphuric and nitric acids, and to cleanse it from assalaya to use it to produce paramolybdate ammonium.Confirmation of the foregoing are the results of the extraction and Stripping of molybdenum on the proposed method.As initial solution used was a mixture of acids of molybdenum under the terms of ICU. 670308.026 THAT, having the following structure.The concentration of acid, g/l (mol/l):
Sulfuric - 304 (3,1)
Nitrogen - 145 (2,3)
The molybdenum content, g/l - 33,8
Impurities, g/l (wt.% the molybdenum):
Iron - 7,6 (22)
Aluminum - 0,17 (0,5)
Nickel - 0,13 (0,4)
Tungsten - 0,13 (0,4)
Silicon - 0,02 (0,06)
Manganese - 0,017 (0,05)
Magnesium is 0.01 (0.03 in)
Calcium - 0,02 (0,06)
Sodium - Not determined
As a solvent (organic phase) was applied 15% vol. the solution PAGING (analog PARRC) in normal paraffins with carbon number of atoms of C12-C15.The extraction was performed by successive five-contacting the starting solution with an extractant in the organic and aqueous phase A:B=1:1.The results of extraction of the distribution of molybdenum in stages and the distribution coefficient of molybdenum between organic and aqueous phases are given in table. 1.From the above table. 1 data shows that the population exceeded 100.Extract with a molybdenum content of about 30 g/l (saturation 90-95% of theoretical, obtained by additional contact with the initial solution) was washed with respect to the organic and aqueous phase a:=5:1, first on one level with a solution of 0.5 mol/l sulfuric acid with the purpose of further purification of molybdenum from impurities, then the same degree of sulfate-ammonium solution with a pH of 5-8 to create in equilibrium leaching solution pH 1-2 with a view to creating favourable conditions for carrying out the process of Stripping of molybdenum.Then spent reextraction molybdenum in counter-current mode according to the scheme of Alders on four stages with respect to the organic and aqueous phase a:=5:1.As restraint was applied a solution containing 3 wt.% ammonia and 5 wt.% ammonium sulfate (pH 12).No less effective for carrying out the process of Stripping the solution containing 1 wt.% ammonia and 9 wt.% carbamide.For comparison, two experiments were carried out by Stripping. The first is a conventional circuit with one input extragent. Second, in accordance with the proposed method, additionally injected restraint in the third degree (fractional reextracted), experiments on Stripping are shown in table. 2.From the above table. 2 data shows that traditional counterflow (experiment 1) after the second stage was increased acidity of the aqueous phase (pH 1 in steps 3 and 4) and, as a consequence, the termination of further extraction of molybdenum.With additional input extragent in the third degree (experiment 2) was stable optimal acidity in all reextraction levels (pH 4-6), which resulted in an increase in the completeness of Stripping up to 75% (four steps).To assess the degree of purification of molybdenum and suitability of the obtained product (reextract molybdenum) to produce paramolybdate ammonium, reextract with the concentration of molybdenum 42 g/l (stage 4 in experiment 2) spectral method determined the content of impurities. The composition of reextract compared with the composition of the initial solution on the content of impurities, as well as to limit their content in paramolybdate ammonium GOST 2677-78.The results of this mapping and the collection efficiencies of molybdenum impurities on the proposed retrieval method is shown in table. 3.As shown, after a four-stage countercurrent Stripping was provided by van to get paramolybdate ammonium, since the concentration of impurities therein is lower than allowed according to GOST 2677-78.The proposed method for the extraction of molybdenum from acidic solutions can be implemented by setting, principal hardware technological scheme is applied to the processing of molybdenum-containing mixtures of acids under the terms of ICU. 670308.026 THE one shown in the drawing.The direction of movement of the organic and aqueous phases are marked by arrows:
> organic phase; ---> water phase.The number of steps taken during the organic phase.The method is as follows.On extraction, in step 5, served the original solution is a mixture of sulfuric and nitric acids, containing 30 g/l of molybdenum and impurities of iron, aluminum, Nickel, tungsten, silicon, magnesium, manganese and others (aqueous phase).The extractant - 15 vol.% the solution PAGING in normal paraffins (organic phase) is introduced in stage 1.Extraction is carried out at steps 1-5 when the flux ratio of organic and aqueous phase A:B=1:1, which provides, respectively, removing more than 99% of molybdenum (residual content in the raffinate less than 0.05 g/l) and the concentration of molybdenum in the extras is C extraction stage 1 and sent for further use, for example, for underground leaching of metals in the development of mineral resources.The extract is washed molybdenum at levels 6 and 7 and is supplied to reextraction in step 1.Reextracted molybdenum is held on the steps 1-10 aqueous solution containing 3 wt.% ammonia and 5 wt.% ammonium sulphate (restraint), which is dosed parts in five stages (the fractional reextraction) in order to achieve in the area of Stripping the optimal equilibrium pH 4-6.The reextract of molybdenum from the molybdenum content of about 40 g/l issued from reextraction stage 1 and sent to the receiving paramolybdate ammonium.After Stripping, cleaning of the extractant on two levels with a solution of 0.5 mol/l sulfuric acid.The sulfuric acid solution after leaching of the extractant and the intermediate reextract of reextraction stage 9 with a concentration of 1-3 g/l of molybdenum and pH 5-8 are used consistently as a washing solution for washing the extract, which results in correspondingly additional purification of molybdenum from impurities and creates favorable conditions (washing to pH 1-2 equilibrium leaching solution) for process rechtstaat liquid waste. Both produced product is used according to its purpose in other processes: the raffinate for underground leaching of metals in the mining and reextract molybdenum for receiving paramolybdate ammonium.Thus, the inventive method allows to achieve a high degree of extraction and purification of molybdenum from impurities.To implement the proposed method does not require solving complex technical problems. It is carried out using standard chemical equipment and with the use of known, produced by domestic industry of the extractant. The list of supplies during the process, in addition to compensate for minor natural losses of extractant, is limited to sulfuric acid and ammonia solution. 1. The method of extraction of molybdenum from acidic solutions, including multi-stage extraction with an organic extractant and a multistage reextraction ammoniagenesis solution, characterized in that the extraction is carried out at a saturation of the extractant molybdenum on 90-95% of theoretical with the subsequent two-stage washing of the extract and reextraction lead sulfate-ammo the Stripping.2. The method of extraction of molybdenum under item 1, characterized in that the washing of lead-sulfuric acid solution with a concentration of 0.3 to 0.5 mol/l, and reextraction - sulfate-ammonium solution to create in equilibrium leaching solution pH 1-2.3. The method of extraction of molybdenum under item 1 or 2, characterized in that after Stripping rinse extractant solution of sulfuric acid with a concentration of 0.3 to 0.5 mol/l, which is then channelled to the washing of the extract.
FIELD: metallurgy of rare and dispersed metals, chemical technology.
SUBSTANCE: invention relates to a method for extraction separation of tantalum and niobium. Method involves extraction separation of tantalum from niobium with organic solvent. As an organic solvent method involves using a mixture of methyl isobutyl ketone taken in the amount 40-80 vol.% with aliphatic (C7-C9)-alcohol taken in the amount 20-60 vol.%. At the extraction process tantalum transfers into organic phase and niobium - into aqueous phase. Then organic and aqueous phases are separated. Invention provides enhancing the extraction degree of tantalum into organic phase and to enhance the separation degree of tantalum and niobium in extraction.
EFFECT: improved separating method.
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