DE2027658A1 - Recovering refractory metal compounds - from a concentrate containing these com- - Google Patents

Abstract

The concentrate contg. the refractory metal compsn. is mixed with a composition of sulphur and alkaline metal. The mixture is heated sufficiently to melt it, and long enough to form a water-soluble reaction product of thio-refractory metal and alkaline metal, and a residue which is non-soluble in water. The refractory metal is recovered from the water-soluble reaction product of thio-refractory metal and alkaline metal.

Description

Method of selective separation and recovery of difficult-to-melt Metals from concentrates.

The present invention relates to a method of recovering difficult to melt Metals by selective separation of those metals from concentrates that are difficult to melt and other metals contained; according to the method of the invention, the concentrate mixed with an alkali metal sulfur compound and the mixture heated to a melting temperature heated and the water-soluble alkali metal thio compound thus obtained as a reaction product of the difficult-to-melt metal is selectively dissolved using an aqueous lye.

The invention particularly relates to the separation and recovery of Difficult-to-melt metals molybdenum and vanadium from ore concentrates with a sufficient amount of an alkali metal sulfur compound to form a water soluble one Alkali metal thio compound of the refractory metal, the mixture on a high enough temperature is heated to melt it and become water soluble Form compound and melt the reaction product with an aqueous alkali solution is treated to make the water-soluble alkali metal thio compound of the difficult to melt Selectively dissolve metal and remove it from the water-insoluble metals and concentrate residue to separate. The insoluble concentrate residue is from the caustic solution that the contains water-soluble alkali metal thio compound of the difficult-to-melt metal, separated.

The designation refractory metal is supposed to be molybdenum, vanadium and / or other metallic components.

There can be a sufficient amount of a mineral acid to lower it the pH to below 8.5 should be added to the difficult-to-melt metal as to precipitate a water-insoluble hydrogen metal-sulfur compound. The sulfur compound The refractory metal can be heated to a sufficiently high temperature to decompose them into a difficult-to-melt metal oxide. The metal oxide and sulfur can be obtained.

The invention particularly relates to selective separation and recovery of ore concentrates containing molybdenum and vanadium from these metals, which also other metals such as iron, copper, lead and zinc as well as silicon dioxide and gangue contain; according to the method of the invention, the concentrate becomes sufficient Amount of an alkali metal sulfide and / or sulfate at the same time as a reducing one Means optionally added in a non-oxidizing atmosphere to a to form water-soluble alkali metal thomolybdate and / or vanadate; the mixture L melting is heated to a sufficiently high temperature> to selectively the To convert molybdenum and vanadium into water-soluble compounds, while iron, Copper, lead and zinc remains and / or in water-insoluble sulfur compounds The water-soluble alkali metal thiomplybate and vanadate are to be transferred selectively dissolved and from the molten reaction product by means of an aqueous The caustic solution leached out practically the entire amount of what was originally in the Concentrate of molybdenum and vanadium present in the form of the water-soluble alkali metal thiomolybate and vanadate-containing lye solution is separated from the insoluble residue, in the form of the water-insoluble sulfides, practically the entire amount of the ur originally the iron present in the concentrate contains copper> lead and zinc.

They are methods of recovering the shear fusible metals molyb- @ ar Danish and vanadium from these metals and various / impurities, such as iron, copper, Lead and zinc and ores containing sodium or potassium silicates are known.

Molybdenum, for example, is extracted according to a process known to me from ores in such a way that the molybdenum is concentrated in the ore, the molybdenum oxidized in the concentrate to obtain a molybdenum oxide concentrate which concentrated Molybdenum oxide volatilizes and it is reduced to metallic molybdenum.

A main source of molybdenum is the mineral molybdenite MoS2. the Commercially available ores contain about 0.2-1.0% by weight of molybdenite, proportionally large amounts of silicon dioxide, smaller amounts of impurities such as FeS, chalcopyrite, CuFeS2 and depending on the source of the ore different amounts of zinc and lead as Impurities.

For the known processes for the extraction of molybdenum it is characteristic, that the amount of impurities decreased and before the oxidation and volatilization the starting material brought to a content of molybdenite, MoS2, of 85 - 97% must become. The processing methods are known; to go through the processing Obtaining a concentrate with 80-97% by weight molybdenite requires considerable losses of available molybdenum must be accepted.

Depending on the querlle of the ore, this amounts to e.g. for a copper mold Loss of lybdenum ore, based on the molybdenum present, / to 40-60% by weight and, based on the molybdenum present in the ore to 10-3Q% by weight of molybdenum ore, and in the case of a molybdenum ore to 10-30% by weight of the molybdenum present in the ore.

The MoS2 concentrate is separated off by drying it and in molybdenum trioxide, MoO3, by roasting at about 600 - 650 ° C with development transferred from SO2 and So3.

Since MoO3 is very volatile at 7600C, precise setting of the Temperature to avoid excessive volatilization losses Tas Accruing MoO3 concentrate is then through a sublimation that also leads to considerable losses of Mo molybdenum, processed. In the case of sublimation the MoO concentrate is used as a thin layer in a stove operated at about 1200 C. Furnace fed. The MoO3 obtained by sublimation is of high purity, but the yields are only about 70-90%. The obtained MoO3 can be converted into a metallic mole dan.

The present invention is based on the object of the difficult-to-melt Metals molybdenum and vanadium from ores or ore concentrates in a simple way selectively to win; according to the known method, the difficult to melt Molybdenum or

Vanadium compounds made from iron, copper, lead and / or zinc sulfides containing ore concentrates are not obtained with high yield and high purity, because, for example, the losses in terms of molybdenum are of the order of 10 - 60% by weight of the molybdenum present, and the losses especially in the case of copper-molybdenum ores are very high. The process of the present invention is based on the object to overcome the disadvantages of the known methods.

According to the method of the invention, the selective separation takes place in.

the way that the concentrate with an alkali metal sulfide and / or Sulphate in the presence of a reducing agent or in a non-oxidizing atmosphere mixes and reacts at a temperature at which melting occurs and this forms a water-soluble alkali metal thiomolybate and vanadate. the Melting and reaction temperatures are critical, if the temperature is too low the water-soluble alkali metal thioverg bond of the poorly soluble metal not educated.

Depending on the particular type of concentrate and the one used Amounts of alkali metal sulfide and / or sulfate can carry out the reaction at temperatures from more than 700-1600 ° C, preferably from 850-1250 ° C and particularly preferred take place at temperatures of 950 - 110,000. The becoming fluid, melting and ae implementation are partly dependent on the reaction temperature and this process can be 5 minutes to 2 hours, preferably 10 minutes to 90 minutes and especially preferably 15 .i for about 15 to 30 minutes.

It becomes a sufficient amount of an alkali metal sulfur compound to react with the difficult-to-melt metal sulfide to form the water-soluble ones Alkali metal thio compound of the difficult-to-melt metal was added. This implementation is special in that it contains iron, copper, lead and zinc impurities no corresponding water-soluble alkali metal thio compounds are difficult to melt Forming metal.

The amount of the difficult-to-melt metal sulfide in the concentrate and the alkali metal sulfur compound are with regard to the formation of the water-soluble Alkali metal thio compounds of the refractory metal are critical. The required Amount of sulfur can be supplied entirely through alkali metal sulfide compounds will; in this case the melt reaction can take place in a non-oxidizing atmosphere occur. If necessary, all or part of the amount required can be used Sulfur can be supplied through alkali metal sulfate compounds; in this case a sufficient amount of a reducing agent such as coke or coal is added, to reduce the alkali metal sulfate to alkali metal sulfide. In practice it will it is preferred to carry out the melt reaction using an alkali metal sulfate such as Carry out coke or coal.

It has also been found that the addition of alkali metal sulfate or chloride in excess of the amount required to carry out the particular melting reaction is required, leads to a lowering of the melt reaction temperature.

Sufficient reducing agent is added to produce a sufficient amount of the alkali metal sulfate to reduce to sulfide and so the Implementation to make the water-soluble alkali metal thio compound of the difficult-to-melt metal.

Since it is a water-soluble alkali metal thio compound of the difficult soluble metals, these metals can be selectively removed from the water-insoluble, Iron, copper, lead and zinc oxide present as impurities through a simple aqueous leaching can be separated. For the method of the invention used Ore concentrates can be at least 5% by weight difficult to melt Contain metal sulfides or oxides. As for molybdenum, the ore concentrates can can be obtained by the known processing and flotation processes. A The main starting material for the process of the invention may be a by-product obtained in the extraction of other metals, such as copper, from copper-molybdenum orex will. Depending on the particular main product that is extracted, e.g. copper, kanndats By-product used as a starting material for. the method of the invention serves that Molybdenum sulphide are contained in approximately the same amounts as ore concentrates, which can be used for the method of the invention. If the by-product is a contains less weight of hard-to-melt metal sulfide than desired, this by-product can of course be worked up and / or in the customary manner subjected to flotation to reduce the amount of difficult-to-melt metal sulfide increase before melting.

The ratio of alkali metal sulfide that forms during melting the amount of heavy metal sulfide present in the concentrate is critical. if If an insufficient amount of alkali metal sulfide is used, no more will be formed soluble alkali metal thio compound of the refractory metal and the reaction product is not soluble in water.

The molar ratio of the alkali metal sulfide to the difficult to melt Metal amounts to at least 2.0: 1, preferably 2.0. 1 to 15: 1 and a ratio of 8: 1 to 13: 1 is particularly preferred.

If a reducing agent is used, it will be in excess to the amount used which is stoichiometric for the reduction of the alkali metal sulfate to sulfide is required. This is generally true at a molar ratio of e.g., carbon to alkali metal sulfate from 40: 1 to 230: 1, preferably 35: 1 to 2: 1 and particularly preferably at 30: 1 to 2: 1.

It is believed that the following chemical reactions take place in the process of the invention3 and the resulting water-soluble compound has the following formula: (1) 2MoS2 + Na2SO11 + 16C enamel a Na6Mo2S7 + Na2S + 16 CO The water-insoluble molybdenum sulfide or vanadium compound is converted into a water-soluble alkali metal thio heavy metal compound; The insoluble iron, copper, lead and zinc sulfides present as impurities are not converted and remain insoluble.

Ore concentrates can also be used in the method of the invention which the metals molybdenum and vanadium are not in the form of sulfides but as oxides, provided that the metals are first converted into sulfides or a sufficient close of an alkali metal sulfur compound before Melting reaction is added to the formation of the water-soluble alkali metal thio heavy metal compounds required sulfur and and the water-insoluble iron, copper, lead and Form zinc sulfides. For this purpose, i.e. to convert the heavy metal oxides and metal oxides present as impurities in sulfides must be an additional one Amount of sulfur and / or alkali 'metal sulfur compounds and / or reducing agents Be used beyond the amount that is required to make the water soluble Alkali metal thio heavy metal compound to form and the oxide of iron etc. in to transfer the sulphides.

After melting, the molten reaction mass is brought to room temperature cooled and ground to a suitable size and subjected to aqueous leaching.

The ground material that contains the water-soluble Al.kaJlmetallthio-5 heavy metal compound and the unreacted, water-insoluble sulfides of the als Containing impurities present elements is made with an aqueous solution leached to the alkali metal thio compounds of the difficult to melt metals Solubilize, with the water-insoluble iron, copper, lead and zinc sulfides remains as an insoluble residue It is also possible that to simultaneously cool and leach molten reaction mass in water.

The aqueous lye solution can have a pH of 9 during the leaching process - 12 and preferably 10-12. The weight ratio of the aqueous to solids Lye solution / depends on the amount present in the molten reaction product Alkali metal thio compound of the refractory metal, and this ratio can range from 10: 1 to 1: 1, preferably 8. 1 to 2: 1 and especially preferably to 4: 1 to 2: 1.

The concentration of the water-soluble alkali metal thio compound des difficult-to-melt metal, measured as metal, in the caustic solution can be 5 g / l up to the amount of a saturated solution, preferably 5 - 40 g / l and especially preferably 10-20 g / l.

The leaching is usually carried out at slightly elevated temperatures performed to increase the solubility of the alkali metal thio compound; the Lye temperature can, however, be 0-1000C, preferably 30-900C and especially preferably 30-60 ° C.

The alkali solution containing practically the entire amount of the soluble alkali metal thio compound of the hard-to-melt metal is contained in the insoluble metal sulfides, Dike rock and unreacted carbon in a suitable way, e.g. by filtering, Centrifuge or decant separately.

The leaching is carried out for a sufficient period of time leads to virtually the entire amount of the water-soluble alkali metal thio compound of the difficult-to-melt metal. Leaching can take 15 minutes to 3 hours5 preferably 30 minutes to 2 hours and particularly preferably 30 to 60 minutes last.

(According to one embodiment of the present invention, the aqueous caustic solution acidified to a certain pH value by adding a mineral acid to selectively to precipitate molybdenum and vanadium as water-insoluble sulfide compounds. as Mineral acids, hydrochloric acid and sulfuric acid can be used. The acidification takes place at about room temperature.

The acidification pH is critical up to the selective precipitation of the desired refractory metals and varies to some extent with the certain precipitated refractory metal.

Sufficient mineral acid is added to maintain pH in the range of about 8-1 and preferably 8-2. The specific pH depends on the difficult-to-melt metal to be deposited. the different metals that are difficult to melt and fall at different pH ranges, / what allows selective separation when there is more than one difficult-to-melt metal is present.

Sulfuric acid is preferred as a mineral acid because it is a recovery and recycling of the alkali metal sulfate for use in the smelting process enables.

It is believed that during precipitation, e.g. of alkali metal thiomolybdate, the following reactions occur: (2) Na6MoS7 + 3H2SO4 H6Mo2S7 + 3 Na2SO (2a) 2NA3VS4 + 3H2S04 2H3VS4 + 3NA2S ° 4 The exact formulas of the molybdenum and vanadium sulfur compounds are not known. When using excess alkali metal sulfate in the melting process the precipitated molybdenum acid sulphide contains excess sulphide and during the precipitation evolves H2S.

The precipitated sulfides are removed from the lye solution, e.g. by centrifugation, Filter or decant, separately.

The metal thiosultides can be obtained with a high yield of more than 99% and a purity of more than 98.5-99.0% by weight can be obtained.

The product can be chemically treated or oxidized in the usual way to convert the thiosulphide into a metal sulphide with a lower sulphide content or to be converted into metal oxide.

According to one embodiment of the invention, the precipitated sulfides are oxidized, and to obtain the metal oxides.

Metal thiosulfide is placed in a suitable oven and in the presence roasted by air at a temperature of 260 - 6000C.

The developed SO2 or SO3 can be obtained and used in a known manner be converted into sulfuric acid.

When roasting molybdenum hydrogen sulfide, molybdenum trioxide is obtained, which is sold as such or reduced to metallic molybdenum in a known manner can be.

According to the method of the invention, compounds of difficult to melt Metals in high purity and in high yield w * relatively inferior Concentrates are obtained as they are in known flotation processing plants attack. The process of the present invention results in virtually pure heavy metal salts obtained from concentrates that contain larger amounts of impurities than they could be worked up so far.

The previously processed concentrates of difficult-to-melt metals, e.g. molybdenum sulfide concentrates, contain 85% by weight; and generally 90-97% by weight MoS2. It turns out that concentrates with such high concentrations can be worked up Loss of about 10 - 60% of metal, i.e. molybdenum sulfide, which is actually used for extraction is available.

An advantage of the method of the present invention is the increase the amount of hard-to-melt metal material, e.g. molybdenum, that will be recovered can, in comparison with the amount that is to be extracted in the ore to be processed is available and in relation to the size of the flotation concentration. What As far as Moiybdänerze is concerned, 10 the increase amounts to 10 - 30 ew .-% and as far as copper-molybdenum ores are concerned applies to 40-60% by weight.

According to the process of the present invention, higher yields are obtained with a higher purity when using simpler work-up methods and less Flotation stages achieved and ajich at lower cost compared to the known Procedure.

The present invention relates to quantitative complete separation practically all metals that are difficult to melt, e.g. molybdenum from practically all metals Copper, iron, lead and zinc, which are present as impurities, by means of a simple and effective process.

The completeness of the separation allows manufacture either of molybdenum sulfide or molybdenum oxide with a purity of 99.9g and more percent by weight.

The invention enables considerable savings in terms of work-up as well as the concentration, since concentrates with such a good mind as 20% molybdenum sulfide is effective and useful in place of the previously required Concentrates containing 85-97% molybdenum sulfide can be used.

Another advantage of Erfinuu .-. G is that the separation of the Sulphides of the refractory metals from those in an ore concentrate as an impurity present metal sulfides very quickly and easily with few process steps and can be done at low cost.

The drawing shows a flow diagram of the method of the invention.

According to the method of the invention, ores can be processed, those of the difficult-to-melt metals molybdenum and vanadium and also as impurities Contains iron, swabs, lead, manganese and zinc.

The mainly available ore concentrates that are processed contain the difficult to melt metals and iron, copper, lead and zinc in the form of water-insoluble sulfur compounds. The sul- fide compounds of the hard Meltable metals can be obtained by known reconditioning and flotation processes brought to the desired concentration.

The mineral molybdenite, MoS2, is the main source of molybdenum, The mineral is generally used in ores in amounts of 0.2-1% by weight of the ore found. The impurities associated with molybdenite are proportionate large amounts of S102, pyrite, Feß, chalcopyrite, CuFeS2 and smaller amounts of lead, and zinc sulfidesO Another source of molybdenum is the by-product, which is obtained from the processing of copper molybdenum ores for copper.

A commercially available molybdenum ore concentrate containing about 58% by weight molybdenite MoS2e, and a commercial copper-molybdenum ore concentrate - by-product that Contains about 70% by weight of molybdenum sulphide have the following composition: MoS2 ore Cu-MoS2 by-product wt% wt% MoS2 58.1 Fe 5.3 6.0 Pb 0.85 0.20 Cu o.46 8.0 Insolubles 20.5 6.0 A major source of vanadium sulfide is the mineral Bartonite, V2S3 .; Cartridge ores contain about 1% vanadium0 One containing vanadium Concentrate, which is a by-product, is known as ferrophosphorus, an alloy that is produced in the manufacture of elementary heavy goods.

Another source is concentrates containing vanadium. Such concentrates can in addition to considerable amounts of radium oxide, silicon dioxide, iron and Contain minor amounts of oxides of other metals.

Used to form the water-soluble alkali metal thiometal The alkali metal sulfur compound can be obtained from any commercially available source originate.

It can be alkali metal sulfides, polysulfides, sulfates, sulfites and hydrosulfides be used. Specific examples are sodium, potassium and lithium sulfides and -sulphates. The preferred compounds are After K2S, Na2S04 and K2S04; because of the For cost and availability, Na2SO4 and K2SO4 are preferred.

Salts used with advantage to reduce the melting temperature are preferably KC1, K2S04, NaCl and Ila2SO4.

It can be used as a reducing agent by any agent which reduces the alkali metal sulfates to the corresponding alkali metal sulfides will. These include hydrogen, methane, ethane, liquid hydrocarbons, Coke, coal and carbon.

The preferred reducing agents are coal and coke.

A non-oxidizing atmosphere -a, n with nitrogen or helium will form.

To acidify the aqueous lye solution, a suitable mineral acid, such as hydrochloric acid or sulfuric acid are used; Sulfuric acid is preferred.

Melting can be done in any known furnace, and that Melting can be done continuously or intermittently.

The molten reaction product is generally prior to leaching cooled down; the quench cooling and leaching can occur simultaneously.

Known devices and devices can be used in the leaching process in which the molten reaction product is leached with an aqueous solution can be.

The lye solution can be treated with a mineral acid to make a To precipitate metal hydrogen sulfide in a known device without the precipitated Sulphide is contaminated.

An embodiment of the invention is described below with reference to the drawing in which Illustrated is a flow sheet of the process of the invention.

It is the extraction of molybdenum from a molybdenum sulfide containing Ore described A 70 wt .-% molybdenum sulfide concentrate, which in a known manner has been processed by grinding and flotation, serves as a feed. This in MoS2 contained in the concentrate is insoluble in water0 The concentrate also contains relatively larger amounts of impurities, including those that are insoluble in water Iron, copper, zinc and lead sulfides in various amounts.

The concentrate is mixed with sodium sulphate, potassium sulphate and ground coke as a reducing agent in a molecular ratio of 3 Na2SO4: 0.6 K2SO4: 8 C: 1 MoS2, and the mixture is fed to a Sehmelarekator 1, in which it is heated to a temperature of 850- 950 ° C is heated for 15-30 minutes to turn the reactants into a Blüssi maturity to melt and to bring the alkali metal sulfur compounds to react with the molybdenum sulfide to form a water-soluble alkali thiomolybdate compound. The molten mass is removed from the reactor, allowed to cool to a temperature of about 20-80 ° C. and then fed to the aqueous liquor zone 2. An aqueous caustic solution is added to the molten reaction product in a weight ratio of about 4: 1 to 2: 1. The pH of the caustic solution is 10 = 12 during the leaching process. Leaching is carried out for 30-60 minutes and the temperature of the liquor is kept at 30-60 ° C.

During the leaching process, practically all of the water soluble becomes Alkali metal thiomolybdate dissolved in the caustic solution, However not the iron, copper, zinc and lead sulfides, which remain as an insoluble residue.

After leaching, the leach solution and the undissolved residue become the Filtratlonszone 5 fed, in which the liquors; solution of the unsolved he residue remaining impurities, unreacted coke and gangue rock is separated.

The lye solution contains 40 - 60 g / l of molybdenum, i.e. practically the entire amount of available molybdenum is fed to the precipitation zone 4. A ## mineral acid, preferably 3ehwefeXäure is slowly used to gradually lower the pH of the Lye solution added. As the pH drops from about 8 to about 2, will some H2S develops and molybdenum hydrogen sulfide precipitates, which are absorbed can. At a pH of around 2.5, practically all of the is in the caustic solution the molybdenum present. The precipitated acidic molybdenum sulfide is acidified by the Lye solution separated.

After removing the precipitated acidic molybdenum sulfide, the filtrate is practically saturated with Na SO and K2S04. These sulfates can be used in an easy way recovered and recycled to the furnace in a simple manner thereby that one leads the filtrate from zone 5 to zone 6 and evaporates the solution, which leads to the crystallization of Na2304 and K2S04. The crystallized sulfates are dried in zone 7 and returned to melt reaction zone 1.

Example 1 1,810 kg of molybdenite - MoS2 - ore concentrate, which according to known Process obtained by work-up and flotation served as the starting material. The molybdenite concentrate essentially had the following components:% by weight MoS2 70.0 CuS 6, o ZnS 2.5 FeS 5.0 PbS 1.5 acid insoluble 15.0 That Ore concentrate was mixed with 4,530 kg of water-treated sodium sulfate, 1,216 kg of anhydrous Potassium sulfate and 1 090 ground coke mixed ge. These quantities correspond to one molecular ratio of the constituents of about 2.8 Na2S04D, 7 K2S04: 8C: 1 MoS2. The mixture was fed to an oven and heated to 850-950 ° C for about 50 minutes heated; at this temperature the mixture melted and the liquid mass was poured and let cool.

The chilled mass weighed about 3,810 kg; so it was a loss of about 50% by weight mainly of CO2 occurred; the cooled mass was on a Milled particle size less than 10 mesh and placed in a caustic tank. The ground reaction product was with an aqueous alkali solution in proportion of about 3: 1 parts by weight and about 1 hour at about 55 0C in motion held to practically the entire amount of the water-soluble alkali metal thiomolybdate to extract.

The caustic solution was separated from the water-insoluble residue; the residue was washed and the washing water was added to the lye solution. the combined liquid had a pH of about 10-12 and contained, based on molybdenum, about 60 g / l water-soluble alkali metal thiomolybdate and practically no PbSn Cu3, Zn or FeS.

The water-insoluble residue contained practically the entire amount PbS, CuS, ZnS and FeS, the unreacted carbon and the remaining duct rockO The residue can be dried and worked up to recover copper, lead and / or zinc will.

The aqueous alkali solution was mixed with a sufficient amount of sulfuric acid acidified to lower the pH to about 2.5.

As the pH lowers, starting at a pH of about 5, a water-insoluble molybdenum hydrogen sulfide was formed and started off the solution to precipitate. At a pH of 2.5, practically all of the amount was molybdenum sulfide pleases; the precipitate was washed, dried and in an inert atmosphere heated to a temperature of 600 ° C to remove excess sulfur as elementary Expel sulfur. An analysis of the solid residue resulted 99.5 wt% MoS2.

The MoS2 can be sold as such or be oxidized by roasting to extract MoO3, SO2 and / or SO3 in a known manner.

Example 2 Una the selective one obtained by the process of the invention To illustrate separation, a molybdenum sulfide flotation concentrate was used that as a by-product of a common copper sulphide flotation treatment accrues; this sulfide had the following composition: Ingredient% by weight MoS2 88.5 GuS 1.3 ZnS 0.21 PbS 0.21 reS 0.53 A 50g sample of the concentrate was with 200g sodium sulfate and 70g bituminous coal mixed and the mixture was on heated to a temperature of approximately 9800C for 60 minutes. The reaction mixture melted and a liquid mass was produced, which was poured, cooled, and weighed; it there was a loss of about 50% of the feed; the loss was essentially on attributed to the formation of and development of CO2.

A 155g sample of the cooled material was washed with an aqueous Leach solution leached and filtered at 25-35 ° C for 60 minutes; the filter cake was thorough washed; it weighed 25g after drying.

An analysis of the lye solution showed that about 99.4% of the in the.

Concentrate present molybdenum leached and dissolved in the lye solution was present as water-soluble sodium thiomolybdate.

An analysis of the lye residue showed that it was practically all Contained copper, zinc, lead and iron as water-insoluble sulfides.

Example 5 As described in Example 2, a lye solution was used obtained containing about 26.85 g / L molybdenum as water-soluble sodium thiomolybdate and had an AR of 10-12; the caustic solution was 37% ider H61 up to one pH 1.0 acidified. During acidification, a brown material fell out of solution that was separated from the lye solution, washed thoroughly and dried.

Analysis of the dried precipitated material indicated an acidic one Molybdenum polysulfide of the following compositions: wt Mo 53.65 S 64.48 Na 0.99 Die The excess amount of sulfide in the precipitated material varies with the amount of the sulphide present in the solution at the onset of precipitation.

The precipitated material was in an inert atmosphere at a temperature heated below 60 ° C and the sulfur distilled. The temperature then rose gradually increased from about 315 to 540 ° C. over 40 minutes and no further sulfur evaporated. The residue was found to be MoS2 and an analysis showed a content of sulfur of 40% by weight.

The residue was heated to 650 ° C. in air, SO2 was evolved and a solid residue, namely MoO3, is obtained.

Example 4 A caustic solution was made as in the preceding Examples described, produced containing about 12.8 g / L molybdenum as sodium thiomolybdate and had an initial pH of 12.0; the caustic solution was made using sulfuric acid gradually acidified to a pH of 1.0.

The sulfuric acid became various hydrogen ion concentrations with constant stirring admitted. Samples of the sludge were extracted and at the indicated hydrogen ion concentrations filtered. The filtrate was analyzed for its molybdenum content and the following Results obtained: Effect of pH on the solubility of molybdenum in a sodium thiomolybdate-sodium sulfide-sodium sulfate-potassium sulfate system Sludge analysis for molybdenum in the pH filtrate g / l 12.0 12.80 4.0 1.63 3.5 0.77 3.0 0.52 2.5 0.0012 2.0 0.0009 1.0 0.0005 An analysis of the dried precipitate resulted in the following: Element Mo 3), 7 5 64.5 Na 0.1 The ratio of molybdenum to sulfur indicates that an acidic molybdenum polysulfide was obtained as a precipitate.

Example 5 Experiments were / at temperatures of 700-9000C below Use of sodium sulfate to form what is necessary for the melting reaction Sodium sulfide and carbon.

The molybdenum sulfide concentrate used for this example was originated from a conventional molybdenum sulphide flotation; it had the following composition: molybdenum sulfide concentrate % By weight MoS2 90.0 Cu3 0.1 ZnS 01 PbS 0.2 FeS 1.4 The melting time was see for these attempts to 60 minutes.

The molten product was cooled and leached with water; sulfide, sodium sulfate, carbon and potassium sulfate were used for the experiments; the test results are given in the following table: Melt MoS2 Na2SO4 carbon Na2SO4: MoS2 K2SO4 pH of the temperature g g material weight g Caustic solution ratio of solution obtained ~~~~ ~~~~~ ~~~~~~~~~~~ ~~~~~~ No 700 ° C 10 30.0 8 3.4: 1 5 - no dirt reaction 800 ° C 10 30.0 8 3.4: 1 5 11.9 99.7 900 ° C 10 38.1 10 4.3: 1 5 9.9 99.0 The above figures clearly show: that the melting temperature is critical, namely a temperature above 700 ° C is required in order to be water-soluble Behave alkali metal thiomolybdate.

Example 6 Several experiments were carried out in which sodium chloride, Potassium chloride and potassium sulfate in the reaction mixture to lower the melting temperature were admitted. The melting reaction was carried out at temperatures of 750-8000C in a inert atmosphere carried out for one hour. In these attempts was does not reduce the sodium sulfate to Na2S. The melted mass was granulated and leached with an aqueous alkali solution and the alkali solution and the residue analyzed to determine the amount of dissolved molybdenum. The molybdenum sulfide concentrate came from a common molybdenum sulfide flotation process; it had the example 5 specified composition.

The test results are given in the following table: Melting Melting MoS Na 2 KC1 Na2S04 NaCl in the caustic soldering temperature 2 2 KCl Molybdenum obtained in the wet solution in% by weight 750 ° C 1 hour 8 8 8 8 8 99 750 ° C 1 hour 8 8 8 0 8 68 7500C 1 hour 8 8 0 b 8 48 750 C 1 hour @ 8 8 0 0 8 3.5 800 ° C 1 hour 5 5 5 - 5 5 98 8000C 1 hour 9 5 5 5 5 98 8000C 1 hour 5 - 5 0 5 5 95 800 ° C 1 hour 3 5 5 0 5 94 800 ° C 1 hour 5 5 0 0 10 28 The test results show that adding a salt, such as potassium chloride or excess sodium sulfate #, the temperature at which the melting reaction to form the water-soluble Alkali metal thiomolybdate takes place, decreased, and / or the amount of molybdenum increased, which can be obtained at a certain reaction temperature.

Example 7 A laboratory test was carried out to determine the To illustrate the utility of the process of the invention for the recovery of vanadium. A mixture of the following composition was melted at 900 ° C. for 1 hour.

Component g NH4VO3 22.8 Na2SO4 40.0 C 12> 0 K2SO4 10.0 The melted The mass was cooled and leached with water at room temperature for about 1 hour, whereupon the water-insoluble residue was separated off by filtration. + The lye solution was diluted to 1.42 g / l V and divided into 5 different samples. To achieve sulfuric acid was added to the desired hydrogen ion concentration Solution was removed by filtration and the filtrate analyzed for vanadium, to determine the effectiveness of the precipitation. The test results are in the the following table indicated: precipitation analysis of the filtrate effectiveness of the pH g / l V Precipitation 7.9 1.42 0 5.4 0.32 77.4 4.5 0.07 95.3 3.5 0.24 83.1 2.3 1.42 0 From the Experimental results follow that the vanadium is precipitated at a pH of 4.5.

The precipitates were oxidized with hydrogen peroxide, filtered and washed with water. The insoluble residue was treated with carbon disulfide Extraction, elemental sulfur leached and found that elemental sulfur Template.

M 74/8 + The lye solution contained 99.6% of the vanadium example 8 The solubility of vanadium was determined in a test facility. The analysis of the concentrate containing vanadium was as follows: Component V205 21.41 SiO2 19s52.

MnO 2.62 Cr2O3 2.87 AL 5,) 0 CaO 0.84 MgO 0.99 TiO2 5.78 total Fe 29.32 P205 0.028 The concentrate containing vanadium, sodium sulfate and carbon were mixed in a ratio of 10: 50: 6 and the mixture was placed in a furnace fed.

1. 630kg of the mixture, which contained 5.08% V2O5 (83 kg v205), melted at 1100 ° C; the dwell time in the furnace was about 15 minutes, whereupon the molten mass was fed to a quench liquor tank in which the dissolution of the vanadium takes place. The solid was removed by means of a drum filter and the filter cake is leached again with a sufficient amount of water to remove the dissolved vanadium compounds.

An analysis of the re-leached filter cake, which is a dry weight of 50.8 kg had the following: Components V2O5 0.50 Mn 1.65 Fe 17.2 the Experimental results show that 96.9% of the vanadium fed to the furnace is in a purified solution is obtained which contains only vanadium, sulfur and Contains sodium as constituents, and requires further processing for purification can be subjected.

Example 9 To remove the contamination of the dissolved after melting To influence vanadium by silicon oxide, the reaction mixture can before Melts either calcium carbonate or aluminum oxide are added.

The concentrate given in Example 8 was used and both Calcium carbonate as well as aluminum oxide separated with the vanadium concentrate, sodium sulfate and coke mixed before melting at 900 ° C for 1 hour. The molten mixture was cooled, leached, and analyzed for vanadium solubility to be determined taking into account the SiO2 / V2O5 ratio in the solution. It it was found that aluminum oxide is compared to calcium carbonate in terms of vanadium solubility is superior. Less calcium carbonate could probably be used, since the SiO2 / VS05 ratio with one part of CaCO3 was very low, as is from the following table results: Mixture for the melting experiment Vanadium con- Na2S04 coke additive to influence the solubility of SiO2 content in% 1 1o 30 4 0 85.9 2 10 30 4 1 CaCO3 67.4 3 10 30 4 2 CaCO3 68.0 4 10 30 4 5 CaCO 60.1 5 5 10 30 4 A1205 97.9 6 10 30 4 2 Al2O3 95> 1 7 10 30 4 3 Al2O3 claims

Claims (1)

P a t e n t a n s p r u c h e 1. Method for selective cutting and recovering refractory metal compounds from such compounds and material containing impurities, characterized in that the Material mixed with an alkali metal sulfur compound, the mixture by heating melts to a sufficiently high temperature and during a sufficiently heated for a long period of time to form a water-soluble alkali metal thio compound elusive metal and to form a water-insoluble residue, and the refractory metal from the water-soluble alkali metal thio compound of the refractory metal wins. 2. The method according to claim 1, characterized in that the reaction product obtained on melting cools and therein with an aqueous lye solution and finally the insoluble ones containing practically all impurities The residue separates from the caustic solution, which peractically contains the entire amount of the water-soluble Contains alkali metal thiometal product, and the heavy metal salt from the caustic solution wins. 5. The method according to claim 2, characterized in that one of the Alkaline solution adds a mineral acid to achieve a certain pH value, wherein the refractory metal as a water-insoluble sulfur compound pleases and separates this compound from the lye solution. 4. The method according to claim 3, characterized in that the Metal sulfur compound in a non-oxidizing atmosphere to a sufficient level high temperature and heated for a sufficiently long period of time to remove excess Volatilize sulfur and a sulfide compound of the difficult-to-melt metal and to gain sulfur. 5. The method according to claim 3, characterized in that the sulfide compound of the refractory metal in an atmosphere containing oxygen a sufficiently high temperature and for a sufficiently long period of time heated to obtain an oxide of the refractory metal and 302 gas. 6. The method according to any one of claims 1-5 or combinations thereof, characterized in that at least 5 wt. molybdenum and / or vanadium Containing concentrate is used, which in the form of these difficult-to-melt metals of compounds that contain at least 1 of the elements iron, Copper, zinc and lead, and the mixture of the concentrate and an alkali metal sulfur compound heated to a temperature of at least 700 ° C. 7. The method according to claim 6, characterized in that the alkali metal sulfur compound having an alkali metal sulfide and one the melting reaction in a non-oxidizing Atmosphere. 8. The method according to claim 6, characterized in that the alkali metal sulfur compound having an alkali metal sulfate and one beines the melting reaction in the presence Performing reducing agent. 9. The method according to claim 7, characterized in that the alkali metal heavy compound Has alkali metal sulfite and the reaction in the presence of a reducing agent performs. 10. The method according to claim 6, characterized in that the alkali metal sulfur compound having an alkali metal hydride and one the reaction in the presence of a reducing agent performs. 11. The method according to claim 8, characterized in that the reducing agent comprises a carbonaceous material. 12. Method of selectively separating and recovering difficult to melt Metal compounds from concentrates which contain at least 5% by weight of sulfur and / or oxide compounds the difficult-to-melt metals molybdenum and / or vanadium and as impurities contain at least 1 of the elements, iron, copper, zinc and lead, characterized that the concentrate with an alkali metal sulfur compound such as sodium sulfide, Sodium sulfate, potassium sulfide, potassium sulfate, lithium sulfide, L thium sulfate or mixtures this mixes, the mixture is heated to a temperature at least above 750 ° C, to melt them, and heated for a long enough time to make them water-soluble Alkali metal thiomolybdate and * iovanadate and a water-soluble residue as Reaction product heated, the molten reaction product cooled, the cooled Reaction product treated with an aqueous lye solution and selectively the water-soluble ones Alkali metal thiomolybdate and vanadate compounds in the lye dissolve that practically containing all impurities such as iron, copper, lead or zinc as sulphides The residue separates from the caustic solution, which is practically the entire amount of water-soluble Contains alkali metal thiomolybdate and vanadate compounds, and the molybdenum and Vanadium wins from the separated liquor. 15. The method according to claim 12, characterized in> that one a mineral acid such as sulfuric acid or hydrochloric acid is added to the alkali solution to maintain a certain pH value between 8 and 1 and thereby become insoluble in water To precipitate molybdenum and vanadium sulfide compounds and remove them from the lye solution separates. 14. The method according to claim 13, characterized in that the Sulfur compound of the refractory metal in an inert atmosphere a sufficiently high temperature and for a sufficiently long period of time heated to volatilize excess sulfur - and sulfur compounds the difficult-to-melt metals molybdenum and vanadium. to win. 15. Verrahren according to claim 14, characterized in that the Sulphide of the refractory metal to a sufficiently high temperature in a oxygen-containing atmosphere heated long enough to create a difficult-to-melt Metal oxide and 502 gas. 16. Process for the selective separation and extraction of molybdenum or Vanadium sulfur compounds from a concentrate containing at least 5% by weight thereof Compounds and as impurities at least one of the following elements, iron, Copper, zinc and lead, as sulfide + t, characterized in that one has the Concentrate with an alkali metal sulfur compound, the sodium sulfide, sodium sulfate, Contains potassium sulfide, potassium sulfate and mixtures of these, mixes up the mixture heated to a temperature at least above 750 ° C in order to melt the mixture and carrying out the heating for a time long enough to become water-soluble Alkali metal thiomolybdate or vanadate and to form a water-insoluble residue, the molten one Reaction product cools and the cooled product with an aqueous lye solution treats and selectively the water-soluble alkali metal molybdate or vanadate compounds in the lye to dissolve the insoluble residue, which is practically the entire amount of all impurities at least one of the elements iron, copper, lead -and'- Zinc. -as containing sulfides, separates from the caustic solution, which practically all of it Contains the amount of water-soluble alkali metal thiomolybdate or vanadate compounds, a mineral acid, such as sulfuric acid or hydrochloric acid der .laugenl-. solution is added to achieve a certain PH between 8 and 1 and around the molybdenum or vanadium as water-insoluble molybdenum or vanadium sulfide compounds to precipitate and the precipitated sulfide from the caustic solution separates the molybdenum and V. anadium sulfide compounds in an inert atmosphere to a sufficient level height Temperature and heated for a sufficiently long period of time to remove excess Volatilize sulfur and a sulfide compound of a hard-to-melt metal to harvest and the absorbed metal sulfide in an oxygen-containing atmosphere heated to a sufficiently high temperature for a sufficient period of time, to obtain a hard-to-melt metal oxide and SO2 gas. 17. Process for the selective separation and recovery of vanadium from a concentrate containing vanadium and impurities, characterized in that heating the concentrate with an alkali metal sulfur compound; the mixture heated to a temperature high enough to melt the mixture, and heated for a time sufficient to produce a water soluble alkali metal vanadate reaction product and to form a water-insoluble residue, the reaction product cools and then treated with an aqueous lye solution to produce selectively water-soluble alkali metal vanadate in which to dissolve the caustic solution, the caustic solution, which is practically the entire amount of water-soluble alkali metal vanadate, of which practically all impurities containing residue separates and from the separated alkali solution alkali metal vanadate records. 18. The method according to claim 17, characterized in that one of the Lye solution adds a mineral acid in order to achieve a certain pH value and thereby precipitating the vanadium as a water-insoluble vanadium-sulfur compound and then separates it from the lye solution. 19. Process for the selective separation and recovery of molybdenum from a concentrate containing molybdenum and impurities, characterized in that that the concentrate containing olybdenum is mixed with an alkali metal compound, heating the mixture to a temperature high enough to melt the mixture and carrying out the heating for sufficient time to produce a water-soluble alkali metal thiomolybdate as a reaction product and to form a water-insoluble residue; the melted Reaction product is cooled and then treated with an aqueous alkali solution; around selectively the water-soluble alkali metal molybdate compound in the alkali to dissolve practically the entire amount of the water-soluble alkali metal molybdate containing liquor separated from the residue, which practically all impurities contains, and the molybdenum wins from the separated liquor. 20. The method according to claim 19, characterized in that one Mineral acid is added to the lye solution up to a certain pH and the precipitated Molybdenum as a water-insoluble sulfur compound falls off and from the caustic solution separates.