Classifications

• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G39/00—Compounds of molybdenum
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G31/00—Compounds of vanadium
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
  • C01G41/00—Compounds of tungsten
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B34/00—Obtaining refractory metals
  • C22B34/20—Obtaining niobium, tantalum or vanadium
  • C22B34/22—Obtaining vanadium
  • C22B34/225—Obtaining vanadium from spent catalysts
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B34/00—Obtaining refractory metals
  • C22B34/30—Obtaining chromium, molybdenum or tungsten
  • C22B34/34—Obtaining molybdenum
  • C22B34/345—Obtaining molybdenum from spent catalysts
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B34/00—Obtaining refractory metals
  • C22B34/30—Obtaining chromium, molybdenum or tungsten
  • C22B34/36—Obtaining tungsten
  • C22B34/365—Obtaining tungsten from spent catalysts
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
  • C22B7/006—Wet processes
  • C22B7/008—Wet processes by an alkaline or ammoniacal leaching
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
  • C22B7/009—General processes for recovering metals or metallic compounds from spent catalysts
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P10/00—Technologies related to metal processing
  • Y02P10/20—Recycling

Definitions

• the present invention relates to a process for the preparation of calcium salts, in particular calcium molybdate (CaMoO 4 ), calcium tungstate (CaWO 4 ) and calcium vanadate (CaV 2 O 6 ), alone or as a mixture, from used catalysts from, among others, the petroleum industry
• alloy steels that is to say steels comprising one or more metals which provide the steel with particular desired properties, such as, for example, resistance to temperature, resistance corrosion, or a high mechanical strength, etc. for applications in different industries, such as automotive manufacturing, aeronautics, cutting tools or machining, or transport.
• metals used in the manufacture of alloy steels stainless steel, refractory, special or fast, we find molybdenum, tungsten or vanadium.
• ferroalloys such as FeMo, FeV 1 FeW or oxide briquettes, for example MOO3, V 2 O 5 and WO 3 .
• the ferroalloys or oxides mentioned above are expensive and constitute an important part of the cost of production of stainless steel or fast steel mentioned above.
• ferroalloys or oxide briquettes is not entirely satisfactory because it requires the supply of CaO, usually made by adding quicklime.
• the hygroscopic nature of the lime can generate defects, such as pits, blowholes or gas bubbles, which are the cause of scrap metal finished products.
• molybdenum, tungsten and vanadium are themselves expensive metals. These metals are for example used in the composition of catalysts, in particular catalysts used in the petroleum industry, for example for hydrotreatment, hydrodesulfurization and hydrocracking operations.
• the Applicant has discovered a particular process for producing calcium salts, in particular calcium molybdate, calcium tungstate and calcium vanadate, which are particularly pure, alone or as a mixture, from used catalysts comprising molybdenum tungsten and / or vanadium.
• pure calcium salts calcium salts substantially free of undesirable pollutants such as arsenic (As) and phosphorus (P), including calcium salts whose respective content of arsenic and phosphorus is strictly less than 200 ppm.
• These calcium salts can then be advantageously used in the production of ferroalloys or as an enrichment material in molybdenum, tungsten and / or vanadium in the manufacture of ferrous or non-ferrous alloys, in particular in substitution for ferroalloys FeMo , FeV and FeW or oxide briquettes of MoO 3 , V 2 O 5 and WO 3 .
• An object of the invention is a process for the preparation of calcium salts included in the group consisting of calcium molybdate, calcium vanadate, calcium tungstate and mixtures thereof, characterized in that it comprises the following steps: - a °) there are used catalysts comprising a metal or a combination of metals, selected from molybdenum, vanadium, tungsten and mixtures thereof,
• the aqueous leaching solution obtained in c °) and comprising the elements included in the group consisting of molybdenum, tungsten, vanadium and their mixtures, is purified by treatment at neutral pH at about 90 ° C., in the purified aqueous leaching solution obtained in d °), the calcium salts included in the group consisting of calcium molybdate, calcium vanadate, calcium tungstate and mixtures thereof are precipitated; by calcium compounds.
• the process according to the invention makes it possible both to recover precious metals in a directly usable form and to produce either pure or combined ferroalloys or enrichment materials made of these metals which are particularly easy to use in the steel industry and in foundry.
• the calcium salts produced according to the process of the invention can be used in the manufacture of alloy steels without the addition of quicklime: such a use has the advantage of limiting the risks of pitting, blow-molding and gas bubbles. often observed when using quicklime.
• the calcium salts obtained according to the process of the invention are practically free of particularly undesirable pollutants such as arsenic (As) and phosphorus (P).
• the process according to the invention makes it possible to produce calcium salts at a reduced economic cost and to limit damage to the environment by allowing the recycling of valuable raw materials such as molybdenum, tungsten and vanadium contained in end of life products.
• the process according to the invention makes it possible to recycle used catalysts in a simple, fast and inexpensive manner and to produce either ferroalloys or enrichment molybdenum, tungsten and / or vanadium directly usable in the iron and steel industry and in foundries.
• starting materials are combined in the form of used catalysts comprising a metal or a combination of metals, generally supported by the catalyst, chosen from molybdenum, vanadium, tungsten and their mixtures.
• the catalyst are generally used in the chemical, gas treatment or petroleum industry, in particular in the cracking and refining processes, for example to desulphurize the distillation products.
• the metal or combination of metals may be selected from Ni-Mo, Co-Mo, Ni-Co-Mo, Ni-Mo-V, Bi-Co-Mo, Ni-W, V- W.
• the support of these used catalysts is generally chosen from alumina, silica, titanium oxide and mixtures thereof.
• the metal or combination of metals is present in the minor catalyst, preferably at a content ranging from 5 to 30%, more preferably from 15 to 30% by weight, based on the weight of the used catalyst.
• the support is present in the used catalyst at a content ranging from 65 to 90%, more preferably from 70 to 85%, by weight, relative to the weight of the used catalyst.
• These catalysts may also include sulfur.
• the sulfur may be present in the spent catalyst at a level of from 3 to 25%, more preferably from 8 to 12%, by weight, based on the weight of the catalyst.
• These spent catalysts also generally include hydrocarbons and carbon from the distillation products that these catalysts have been used to desulphurize or gas treatment for example during the cracking of nitrogen oxides to limit emissions of greenhouse gases.
• These spent catalysts thus comprise mainly, in whole or in part, oxidized or sulfur compounds of molybdenum (Mo), nickel (Ni), cobalt (Co), tungsten (W), vanadium (V), bismuth (Bi), aluminum (AI), titanium (Ti) and silicon (Si), sulfur (S), carbon (C), hydrocarbons (HC) and residual metals of the arsenic type (As ), phosphorus (P).
• these used catalysts are grid at a temperature ranging from 700 to 1100 ° C., in excess of air, to obtain grilled catalysts and dust.
• the used catalysts are selectively grilled and by campaign in a controlled and oxidizing atmosphere.
• a grid makes it possible to extract used catalysts sulfur (S), carbon (C), hydrocarbons (HC) and arsenic (As).
• used catalysts are burned at a temperature ranging from 800 to 1000 ° C.
• a temperature ranging from 800 to 1000 ° C.
• the formation of alumina-metal oxide spinels is thus limited, which then allows a better leaching during heating. subsequent step of the process.
• a temperature makes it possible to sublimate a pollutant such as arsenic (As) that goes through the dust.
• a temperature also makes it possible to pass the sulphides in the form of oxides.
• the metal or combination of metals included in the group consisting of molybdenum, tungsten, vanadium and mixtures thereof is partially sublimed.
• molybdenum is sublimated during its oxidation as MoO 3 .
• this MoO 3 is recovered at the first stage of a bag filter.
• the oxidized compounds of the elements Al, As, P, V and W accompany the dust.
• these MoO 3 rich dusts also include A 2 O 3 , P 2 O 5 and I 1 As 2 O 3 .
• the deep roasting makes it possible to sublimate up to 70% of the quantity of metal or of the combination of metals included in the group consisting of molybdenum, tungsten, vanadium and their mixtures, initially present in the spent catalyst: the content of metal or combination of metals included in the group consisting of molybdenum, tungsten, vanadium and their mixtures, in used catalysts is greatly reduced.
• the carbon content (C) in spent catalysts is preferably less than or equal to 5% by weight, relative to the weight of used catalysts.
• the sulfur content (S) in the used catalysts is preferably less than or equal to 3% by weight, relative to the weight of used catalysts.
• the content of metal or combination of metals included in the group consisting of molybdenum, tungsten, vanadium and their mixtures, in used catalysts is preferably less than or equal to 6% by weight, relative to the weight of used catalysts.
• the gaseous effluents from the roasting can pass through an afterburner chamber after leaving the roasting furnace and can be burned at more than
• these gaseous effluents are treated with basic salts so as to neutralize and capture in the form of a stable compound SO 2 sulfur dioxide generated by roasting.
• the basic salts employed are calcium hydroxide Ca (OH) 2 or preferentially sodium bicarbonate as for example described in application EP
• step c ° leaching of the grilled catalysts and / or dusts obtained in b °) is carried out using a basic solution.
• the leaching may be carried out with sodium hydroxide NaOH, ammonia NH 3 or sodium carbonate Na 2 CO 3 in aqueous solution.
• Soda ash leaching involves the following reactions:
• the used catalysts are leached with sodium hydroxide NaOH or sodium carbonate Na 2 CO 3 .
• ammonia is less aggressive than soda or sodium carbonate towards alumina, it dissolves the elements Co, Ni, Mo and V.
• the leaching of used catalysts is carried out with a mixture of sodium hydroxide (NaOH) and sodium carbonate Na 2 CO 3, doped with hydrogen peroxide (H 2 O 2 ).
• NaOH sodium hydroxide
• Na 2 CO 3 sodium carbonate
• H 2 O 2 hydrogen peroxide
• the leaching parameters are adapted according to the catalyst so as to avoid excessive dissolution of the alumina.
• the sodium hydroxide is present in excess, for example
• the leaching step can generally last from 30 to 200 minutes.
• the leaching is generally carried out at a moderate temperature ranging from 50 to 100 ° C., preferably ranging from 70 to 90 ° C., preferably continuously and countercurrently in a series of at least 2 trays, for example 3 12 or more bins per percolation.
• the leach solution obtained at the end of this step comprises the elements included in the group consisting of molybdenum, tungsten, vanadium and their mixtures as well as impurities such as P, As, Al and optionally Ni and Co.
• impurities such as P, As, Al and optionally Ni and Co.
• the Ni and Co possibly present in the used starting catalysts are not dissolved and remain on the supports of said catalysts.
• aqueous leaching solution obtained in c °) and comprising the elements included in the group consisting of molybdenum, tungsten and vanadium is purified. and their mixtures.
• the leaching solution is purified by treatment at neutral pH. This makes it possible to eliminate by precipitation the elements P, As 1 Al, and the traces of Ni and Co almost completely. The traces of Fe and Si can also be eliminated with very high yields.
• the respective content of each of the elements As, Al, P, Ni, Co, Fe and Si in the leaching solution is preferably less than 2 mg / l.
• the mineral acids H 3 PO 4 , HNO 3 , HCl and H 2 SO 4 can be used for this precipitation by acid neutralization.
• the leaching solution is brought to a neutral pH by addition of an acid selected from H 3 PO 4 , HNO 3 , HCl, H 2 SO 4 and mixtures thereof.
• the acid is H 2 SO 4 .
• the treatment at neutral pH or neutralization of the purification step is carried out at about 9O 0 C.
• Such a temperature makes it possible to improve the precipitation of P 1 As, Fe and Si and simultaneously limits the possible and undesired precipitation of molybdenum and / or vanadium. Thanks to the process of the invention, it is therefore possible to separate unwanted pollutants such as arsenic and phosphorus from the leach solution.
• the calcium salts obtained at the end of the process are thus practically free of these pollutants.
• a fifth step of the process according to the invention is carried out, namely according to step e °), a precipitation of the calcium salts included in the group consisting of calcium molybdate and calcium vanadate. calcium tungstate and mixtures thereof with calcium compounds.
• the purified leach solution is precipitated by addition of calcium chloride (CaCl 2 ) or lime milk to obtain calcium salts of the metals of the group consisting of molybdenum, vanadium, tungsten and their mixtures.
• CaCl 2 calcium chloride
• lime milk to obtain calcium salts of the metals of the group consisting of molybdenum, vanadium, tungsten and their mixtures.
• nonselective precipitation of vanadium and molybdenum is achieved; the purified leaching solution is then, for example, acidified to a pH ranging from 4 to 5 by addition of hydrochloric acid HCl or nitric acid HNO 3 .
• CaCl 2 is then added to precipitate the molybdenum contained in solution.
• the reactions involved are the following:
• a selective precipitation of vanadium and molybdenum is carried out; the leaching solution is then, for example, first neutralized to a pH of between 7 and 8 by addition of ammonium chloride NH 4 Cl.
• Vanadium is precipitated in the form of sodium metavanadate NH 4 VO 3 according to the reaction:
• milk of lime can also be used.
• a solid / liquid separation using a filter press for example, makes it possible to expell the solution of the calcium molybdate crystals with or without the calcium vanadates and calcium tungstates in a mixture.
• These crystals can be dried or calcined before conditioning.
• the precipitation of molybdenum can be pushed up to 80% of molybdenum precipitated relative to to the total amount of molybdenum present in the leach solution.
• the solution is filtered and precipitated again with production of a calcium molybdate, with or without the calcium vanadates and calcium tungstates in mixture, and containing sulfur in particular.
• the calcium molybdate (CaMoO 4 ) obtained can either be sold as is or put back in the lead of the leaching process.
• the salts obtained in the fifth stage namely calcium molybdate (CaMoO 4 ), calcium tungstate (CaWO 4 ), are optionally dried and / or calcined.
• the process according to the invention makes it possible to recover precious metals in a directly usable form to produce pure or combined ferroalloys or to produce enrichment materials made of these precious metals that are particularly simple to use in the iron and steel industry and in foundries.
• the calcium salts produced according to the process of the invention are particularly pure and can be used in the manufacture of alloy steels without the addition of quicklime: such a use has the advantage of reduce the risk of punctures, blisters and gas bubbles that are usually observed when using quicklime.
• the process according to the invention makes it possible in particular to obtain calcium salts which are practically free of undesirable pollutants such as arsenic and phosphorus.
• the present invention further relates to the use of calcium salts selected from calcium molybdate (CaMoO 4 ), calcium vanadate (CaV 2 O 6 ), calcium tungstate (CaWO 4 ) and mixtures thereof, obtained according to the above method for making alloy steels.
• CaMoO 4 calcium molybdate
• CaV 2 O 6 calcium vanadate
• CaWO 4 calcium tungstate
• used catalysts are available from the hydrotreating of petroleum fractions, having the following composition:
• Table 2 Chemical composition of used hydrotreating catalyst of petroleum cuts (renormalization of the contents after removal of carbon and sulfur) Toasting:
• these catalysts are roasted in excess of air at a temperature ranging from 700 to 800 ° C. Used burnt catalysts and dust rich in oxides of molybdenum, tungsten and / or vanadium are recovered.
• the used grilled catalysts obtained in the preceding step are leached with sodium hydroxide.
• the leaching yields of Mo, V and Al are respectively 86%, 65% and 3%.
• the leaching solution obtained in the preceding step is purified by treating this solution at neutral pH.
• the precipitation is carried out at 90 ° C.
• a volume of 14 ml of concentrated sulfuric acid H 2 SO 4 at 100 g / l is added to 100 ml of leaching solution of pH 11.8.
• the pH is raised from 11.8 to 7.
• the volume of the purified solution is 114 ml and the pH is 6.6.
• a precipitate is collected: its mass is 2 g.
• Table 4 shows the results obtained during the purification.
• a selective precipitation of vanadium and molybdenum is carried out.
• the selective precipitation of Mo and V contained in the purified leaching solution is carried out on 100 ml of purified solution at 90 ° C. with the addition of 38 ml of aqueous solution of ammonium chloride NH 4 CI concentrated to 100 g / l.
• the precipitation yields of molybdenum and vanadium are respectively 1, 5% and greater than 95%.
• the solution is filtered and clarified. Then, the solution thus clarified and freed from vanadium is mixed with 14 ml of aqueous solution of CaCl 2 concentrated to 100 g / l.
• the precipitation yield of the molybdenum is greater than 95%.
• the solution is filtered and clarified.
• the moisture content of the filtered calcium molybdate in filter press is 40 to 45%.
• the Mo content of calcium molybdate, on a dry basis, is between 35 and 45%.
• Calcium molybdate is powdery after drying.
• a calcination step between 500 and 700 0 C or granulation makes it possible to obtain respectively sintered blocks (diameter less than 100 mm) or granules (diameter less than 50 mm).
• the calcination makes it possible to bring the molybdenum content, on a dry basis, between 40 and 46% Mo.
• used catalysts are available from the hydrotreating of petroleum fractions, having the following composition:
• Table 6 Chemical Composition of Used Hydrotreating Catalyst of Petroleum Cuts (renormalization of the contents after removal of carbon and sulfur)
• these catalysts are roasted in excess of air at a temperature ranging from 700 to 1000 ° C. Used burnt catalysts and dust rich in molybdenum oxides are recovered.
• the used grilled catalysts obtained in the preceding step are leached with sodium hydroxide.
• the leaching yields of Mo and Al are respectively 80% and 9.9%.
• the leaching solution obtained in the preceding step is purified by treating this solution at neutral pH.
• the precipitation is carried out at 90 ° C. for 1 hour with stirring.
• a volume of 17 ml of sulfuric acid H 2 SO 4 at 98% purity is added to 450 ml of leaching solution of pH 13-14, in order to bring the pH to 7.
• the volume of the purified solution is 467 ml and the pH of 7.
• a precipitate is collected: its mass is 32.3 g.
• This precipitate mainly comprises arsenic (As), aluminum (Al) and a small proportion of molybdenum (Mo).
• Table 8 shows the results obtained during the purification.
• Table 8 Results of the purification of the leaching solution of hydroprocessing catalyst with sodium hydroxide The loss of molybdenum due to the precipitation of part of the molybdenum during the purification represents 5 to 15% of the molybdenum present in the leaching solution before purification.
• the precipitation yields of Al and As during the purification range from 40 to 60% and from 60 to 85%, respectively.
• CaCl 2 is then added, respecting a mass ratio of 1 between the amount of CaCl 2 and that of the theoretical Mo. After stirring, a precipitate is obtained.
• the molybdenum precipitation yield is greater than 60%.
• a washing with clear water of the formed precipitate can be carried out to eliminate the residual salts such as Cl, Na, ...
• the moisture content of the filter-filtered calcium molybdate is 30 to 50%.
• the Mo content of calcium molybdate, on a dry basis, is between 20 and 30%.
• Calcium molybdate is powdery after drying.
• a calcination step between 500 and 700 0 C or granulation makes it possible to obtain respectively sintered blocks (diameter less than 100 mm) or granules (diameter less than 50 mm).
• the calcination makes it possible to bring the molybdenum content, on a dry basis, between 25 and 45% Mo, according to the residual impurities.
• the calcium molybdate obtained by the process according to the invention is practically free of undesirable pollutants such as arsenic and phosphorus, the latter being present at levels strictly below 200 ppm.
• the pure or mixed molybdates, tungstates, calcium vanadates produced from used catalysts for the refining of petroleum fractions can be used in the production of ferroalloys of the FeMo, FeV, FeW, FeMoV, FeVW or FeMoW type, for example, or in the form of enrichment. ferrous or non-ferrous alloys.
• the vanadate, tungstate and calcium molybdate are advantageously charged as a material for the substitution of MoO 3 , WO 3 or WO 2 O 5 technical oxides or ferroalloys FeMo, FeV and FeW associated therewith.

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• 2005
  • 2005-08-16 FR FR0508556A patent/FR2889843B1/fr not_active Expired - Fee Related
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