RU2194782C1 - Method of integrated processing of polymetallic production wastes and rendering them harmless - Google Patents

Abstract

FIELD: metallurgy and chemical technology of inorganic substances. SUBSTANCE: method includes chlorination in melt of alkali metal chlorides with obtaining of spent melts and vapor-gas mixture, separation, purification and utilization of titanium tetrachloride, alkali decomposition of vanadium oxytrichloride, precipitation of ammonium metavanadate, separation of its mother liquor, washing and calcination to produce vanadium pentoxide, hydraulic washing of spent melts in reusable solutions, neutralization of pulp with magnesium suspension, separation of sediments of metal hydroxides from solution. In this case, polymetallic vanadium-containing wastes prior to chlorination are preliminarily subjected to reducing melting at 1600-2000 C together with titanium-containing concentrates. Spent chlorate melts are discharged into mortar liquors, and washing waters of ammonium metavanadate are neutralized. After neutralization successively introduced, first, are hyprochloride pulp, then solution of high-molecular flocculant. Hydroxide pulp is held for some time, and clarified part is discharged, thickened part is filtered out, hydroxide sediment is washed, filtrate and washing waters are combined and directed for production of synthetic carnallite. Hydroxide sediment is mixed, first, with insoluble residue formed in hydraulic washing of spent melts and dust trapped in ore melting of titanium-containing concentrates and polymetallic wastes, then, with ground materials containing chlorides and oxides of magnesium, and obtained paste composition is heated and formed into blocks. Titanium-containing concentrates are used in the form of ilmenite and/or rutile, and/or ilmenorutile. Method is used at metallurgical and chemical-metallurgical plants, for example, at titanium-magnesium plants for recovery of vanadium. EFFECT: increased productivity and provision of rendering harmless of sewage waters. 5 cl, 1 ex

Description

 The invention relates to the field of metallurgy and chemical technology of inorganic substances and can be used at metallurgical and chemical-metallurgical enterprises, for example, during complex processing and disposal of polymetallic production wastes at titanium-magnesium enterprises with the extraction of valuable components, production of marketable products, and neutralization of radioactive production wastes.

The present invention can be used, in particular, for processing various production wastes containing 1-10% V ₅ O ₅ , 10-60% Fe ₂ O ₃ and oxides and / or hydroxides of Mn, Ti, Cr, Al, Si, Mg , Ca, namely:
- waste sludge - oxyhydrate sediments formed during the neutralization of drain (waste) water from vanadium;
- dump slag, cake, sludge and waste from various industries;
- angry at some CHP plants.

Known (Hydrometallurgical processing of vanadium-containing waste // Non-ferrous metallurgy, 2000, 1, pp. 25-29) a method of processing waste from JSC "Chusovskoy Metallurgical Plant" containing 1-6% V ₂ O ₅ and oxides of Fe, Ti, Si, Mn, Cr, Ca, Mg, etc.

According to the known method, polymetallic vanadium-containing wastes are subjected to two-stage leaching, the leaching being carried out with a NaOH solution (10-40 g / dm ³ ) in the first stage and with HCl solution (10-40 g / dm ³ ) in the second, the resulting solutions are then combined, add acid and / or alkali and again return to leaching operations. To obtain relatively concentrated solutions of vanadium (more than 15-20 g / dm ³ ), the circulation is 5-10 times. The insoluble residue is separated from the solution and sent to the dump. NH ₄ Cl is added to the sodium metavanadate (NaVO ₃ ) solution, the ammonium metavanadate released is filtered off, washed and calcined to obtain a marketable V ₂ O ₅ that meets the requirements of TU for V ₂ O ₅ qualifications VNO-1 and / or VNO-2.

The reasons that impede the achievement of the following technical result include:
- the complexity and multi-stage process;
- unsatisfactory degree of extraction of vanadium in commercial products;
- the formation of a large amount of difficult to recycle secondary production waste: insoluble residue, wastewater.

Of the known analogues, the closest in technical essence and the achieved result is the well-known (Chlorine technology for processing vanadium-containing wastes to produce marketable products // Non-ferrous metallurgy, 2000, 8-9, pp. 24-26) a method for complex processing of polymetallic vanadium-containing wastes containing 1-6 % V ₂ O ₅ , oxides of Fe, Ti, Mn, Cr, Si, Al, Ca, Mg, etc., adopted as a prototype.

According to the prototype method, the polymetallic vanadium-containing wastes are calcined at 500-700 ^{o C.} , mixed with NaCl and / or KCl, petroleum or pitch coke and chlorinated at 600-700 ^o C. Waste melts are poured into water and / or working solutions in a salt ratio waste: water phase = 1: (8 ÷ 10). The pulp is circulated to obtain solutions with a density of 1.21 ÷ 1.23 kg / dm ³ concentrated by the sum of metal chlorides, then neutralized with milk of lime or magnesia, filtered, the precipitate of metal oxyhydrates is separated from the solution of alkali and alkaline earth metal chlorides. The gas-vapor mixture is subjected to salt cleaning in a KCl / NaCl melt, the obtained technical vanadium oxytrichloride (VOCl ₃ + TiCl ₄ ) is either used as a commercial product as an organic synthesis catalyst, or sent to produce commercial V ₂ O ₅ and inorganic sorbents based on titanium oxyhydrates, or sent to distillation-chemical separation to obtain purified TiCl ₄ and VOCl ₃ (99.0 ÷ 99.9%). To obtain commercial V ₂ O _5, vanadium oxytrichloride is poured into a NaOH solution, then NH ₄ Cl is introduced into the resulting sodium metavanadate solution, the released NH ₄ VO _{3 is} separated from the mother liquor, washed, dried and calcined to obtain commercial vanadium pentoxide.

The chlorine method (prototype) in comparison with the hydrochemical method (analogue method) provides higher technological indicators of vanadium extraction. Comparative tests showed that the best results are observed during the chlorine processing of various polymetallic vanadium industrial products - technogenic raw materials containing from 10 to 80% V ₂ O ₅ . However, in the case of using chlorine technology to extract vanadium from production wastes containing 1-10% V ₂ O ₅ , technical, economic and technological indicators drop sharply.

The reasons that impede the achievement of the technical result indicated below include the high consumption of gaseous chlorine for the chlorination of related metals (Fe, Cr, Mn, Al, etc.) and the formation of a large amount of secondary production waste in the form of spent melt containing metal chlorides in addition to KCl / NaCl -impurities (Fe, Cr, Mn, etc.), which, in turn, is associated with their high content in the initial polymetallic vanadium-containing (1-10% V ₂ O ₅ ) production waste; in addition, the specific composition of the initial vanadium-containing wastes and the lack of selectivity of the chlorination process itself (at 600-800 ^o С almost all metal compounds present in vanadium-containing wastes are chlorinated) lead to a decrease in the useful capacity of the chlorinator and a decrease in its productivity with respect to the main valuable components: VOCl ₃ and TiCl ₄ . Another reason that impedes the achievement of the technical result indicated below is that the prototype method does not provide for the neutralization of highly toxic vanadium-containing wastewater - mother liquors and the promotion of ammonium metavanadate. The possibility of disposing of oxyhydrate polymetallic sludge and transferring it into an environmentally friendly form suitable for long-term storage is also not provided.

The claimed invention is aimed at solving the problem of providing selective extraction of vanadium from a relatively low V ₂ O ₅ rare metal man-made material containing 1-10% V ₂ O ₅ , recycling and decontamination of secondary production waste.

 The technical result that can be obtained by implementing the claimed invention is to reduce the formation ("yield") of secondary production waste (in the form of spent melt and sublimators of chlorinators); increasing the degree of beneficial use of chlorine, increasing the productivity of the process as a whole and ensuring the neutralization of wastewater and the conversion of polymetallic sludge, radioactive dust and insoluble residue into a stored safe form.

The specified technical result in the implementation of the claimed invention is achieved by the fact that in the known method of processing polymetallic production wastes, including calcining, chlorinating in a melt of alkali metal chlorides to produce spent melts and gas mixture, separation, purification and utilization of titanium tetrachloride, decomposition of vanadium oxytrichloride, precipitation ammonium metavanadate, separating it from the mother liquor, washing and calcining to obtain vanadium pentoxide, discharging spent p alloys into working solutions, neutralization and neutralization of pulp by treatment with a magnesia suspension based on magnesium-containing oxide and chloride substances, filtering the pulp and separating the oxyhydrate precipitate from the chloride solution, the peculiarity is that the vanadium-containing wastes (WO) are subjected to reduction smelting at 1600 before chlorination -2000 ^o C ore-smelting furnaces (RTP) together with titaniferous concentrates (TC) at a weight ratio of BO: TC = 1: (10-20) waste melts cl vayut vanadium in the mother liquors and promvody ammonium metavanadate, neutralized to a pH of 7-10, preferably 8-9 magnesia slurry with a concentration of MgO 50-150 g / dm ^3, neutralization is carried out at continuous gassing with air, and then into the slurry after neutralization sequentially administered initially hypochlorite a pulp containing 40-100 g / dm ³ Ca (ClO) ₂ in an amount of 3-10% (vol.), then a solution of a high molecular weight flocculant, filtered, the wet paste, the amount of metal oxyhydrates is washed with 1-3 volumes of the initial magnesia suspension per 1 volume o xhydrate precipitate, mixed with magnesium-containing mineral oxide and chloride materials at a ratio of 1: (0.1-1.0) with inert fillers and molded into blocks.

 It is preferable to use ilmenite and / or rutile and / or ilmenorutil as titanium-containing concentrates.

Moreover, as the magnesium-containing oxide and chloride materials, crushed sludges of carnallite chlorinators of magnesium production are used, containing, wt.%: MgO 30-50; MgCl ₂ 30-50; the rest is chlorides K, Na, etc.

 At the same time, an insoluble residue from the hydraulic removal of the spent melt is used as an inert filler.

 Ceteris paribus, the proposed method, characterized by new methods of performing actions and a new order of actions, using certain substances, without which it is impossible to implement the method itself, new modes and parameters of the process, provides a technical result in the implementation of the claimed invention.

 Checking the patentability of the claimed invention shows that it corresponds to the inventive step, as it should not be obvious to specialists.

The analysis of the prior art indicates that in the book, magazine, patent literature there is no information about the above set of essential features of the claimed method for the integrated processing and disposal of polymetallic waste products containing 1-10% V ₂ O ₅ . At the same time, analysis of the totality of the features of the claimed invention and the result achieved at the same time shows that there is a well-defined causal relationship between them, expressed in the fact that the implementation of the process of extracting vanadium from wastes under the strictly defined conditions and conditions above ensures, on the one hand, a high degree of vanadium extraction of waste into marketable products - VOCl ₃ and / or V ₂ O _5, and on the other hand provides highly defusing secondary waste production and transfer x in a form suitable for long-term safe storage.

 It is especially necessary to emphasize that in violation of the established optimal process conditions and a strictly defined sequence of actions and operations, the above technical result is not achieved.

 It should also be noted that the established causal relationship does not explicitly follow for specialists and does not follow from the literature data on metallurgy and on the chemistry and technology of vanadium and its compounds and is expressed in the following.

It has been experimentally established that preliminary reduction smelting in a ore-thermal furnace of vanadium-containing waste (1-10% V ₂ O ₅ ) together with titanium-containing concentrates before chlorination provides a reduction in the formation ("yield") of secondary production waste (in the form of spent melt and sublimators of chlorinators) , increasing the degree of beneficial use of chlorine and increasing the productivity of the process as a whole.

 It has been experimentally established that it is most expedient to conduct the reduction melting of vanadium-containing wastes (WO) in the presence of titanium-containing concentrates (TK) with a mass ratio of BO: TK = 1: (10-20). When the ratio is less than (1:20), for example, at VO: TK = 1: 40, the costs of installation and maintenance of the unit for the preparation and supply of vanadium-containing polymetallic waste to the RTP do not pay off. With a ratio greater than 1:10, for example 1: 5, the resulting titanium slag is enriched in iron oxide, which leads to the irrational use of chlorine in the subsequent chlorination stage and the formation of a significant amount of secondary production waste - spent melt and sublimates of titanium chlorinators.

The use of ilmenite and / or rutile and / or ilmenorutil as titanium-containing concentrates does not require any additional changes in the hardware and technological design of the titanium production process as a whole: all operations according to the invention successfully fit into the existing technology of ore-thermal reduction smelting concentrates , chlorination of slag and distillation-chemical separation of TiCl ₄ and VOCl ₃ .

It was experimentally established that the reduction melting in the RTP of vanadium-containing waste together with titanium concentrate is carried out at 1600-2000 ^o С. At a temperature below 1600 ^o С, the process is unreasonably extended in time, while the degree of enrichment of the concentrate in titanium and vanadium is significantly lower, and at a temperature above 2000 ^o With the need to use an expensive lining of the furnace, significantly increases the formation of radioactive dust RTP.

 It was experimentally established that the most rationally worked out melt (OR) should not be drained into water, but into vanadium-containing wastewater (CB) with the ratio OR: CB = 1: (8-12), while the resulting pulp should be circulated 4-6 times and further neutralize. When the ratio is less than 1: 8, “pops” are observed when the melt is drained from the chlorinator, and when the ratio is greater than 1:12, the volume of the processed solutions unreasonably increases. The discharge of spent melts into vanadium-containing wastewater provides favorable conditions for the mutual neutralization of two different types of waste and makes it possible to increase the degree of purification of solutions (wastewater) from vanadium (V), iron (II), and manganese (II).

It is advisable to neutralize the pulp with a magnesian suspension obtained on the basis of magnesian magnesium-containing oxide minerals selected from the series: brucite, magnesite, serpentinite, since in this case it is possible to dispose of the formed filtrates - solutions (MgCl ₂ + KCl and impurities NaCl and CaCl ₂ ) to obtain synthetic carnallite, which is then used to produce magnesium metal.

The choice of the optimal concentration of magnesian suspension (MgO 50-150 g / dm ³ ) is due to the fact that a large volume of tank equipment is required below 50 g / dm ³ , and at a MgO concentration above 150 g / dm ³ the neutralization process is complicated due to an increase in the viscosity of the suspension and due to the deposition of the solid phase of the suspension in the volume of equipment. Neutralization of the pulp with a magnesian suspension at pH 7-10 (mainly 8-9), while bubbling air and then supplying 3-10% (vol.) Of hypochlorite pulp (40-100 g / dm ³ Ca (ClO) ₂ provides almost complete cleaning of solutions from impurities of II-V valence metals. At pH <7, incomplete precipitation of oxyhydrates occurs, and at pH> 10 there is an unproductive consumption of reagents. Air sparging and treatment with a small amount of hypochlorite pulp as applied to recyclable waste is the easiest way to re-precipitate the compound . Fe and Mn at high doses (over 10.3%) hypochlorite pulp occurs a reverse process - the transition manganese, vanadium, chromium from the solid phase into solution.

It has been experimentally established that the most rational way of processing pulp after neutralizing and re-precipitating Fe and Mn is the following sequence of operations: treatment with a high molecular weight flocculant (Navy), holding without stirring for 0.5-2 hours (settling), filtering, mixing the resulting wet paste with the amount of oxyhydrates metals from insoluble residue by hydroremoval, fine dust from RTP, then crushed materials containing MgCl ₂ and Mg at a ratio of 1: (0.5-2), heating the resulting composition (150-300 ^o C) and after blowing formation provides translation of highly toxic waste containing chromium, manganese, vanadium, thorium, its breakdown products, iron et al., non-dusting and insoluble precipitation, groundwater and subsurface waters form suitable for transportation and long term storage. Under other conditions and with other ratios of solidification of the waste does not occur, that is, one of the main important technical results is not achieved.

 In addition, the wet paste of metal oxyhydrates obtained in the process of neutralizing the pulp is mixed with magnesium-containing mineral oxide substances (materials) and an inert filler at a ratio of 1: (1-0.1). This ratio is optimal for ensuring the strength properties of the resulting blocks and it has been established experimentally.

 It was also established that it is most rational to use crushed slurries of carnallite chlorinators as magnesium-containing oxide and chloride material, since this allows, ceteris paribus, to utilize magnesium production waste and use it for solidification of other types of waste.

 Information confirming the possibility of implementing the present invention to obtain the above result is shown in the example.

Example
Comparative tests of various methods for the complex processing and disposal of polymetallic industrial wastes, studies to find optimal conditions (temperature, time, ratio of starting components, concentration of reagents, sequence of operations, etc.) were carried out with polymetallic vanadium-containing wastes of the ferrovanadium workshop of Chusovskaya Metallurgical Plant OJSC .

These wastes contained, wt. %: V ₂ O ₅ - 5.0; Fe ₂ O ₃ - 50; TiO ₂ - 8.5; MnO ₂ - 8.0; Cr ₂ O ₃ - 6.0; Al ₂ O ₃ - 2.5; CaO - 2.0; MgO - 1.0, etc.

In the first series of experiments, the waste of the above composition was processed according to the prototype method: it was chlorinated in a salt chlorinator in the spent electrolyte of the process of electrolytic production of magnesium from carnallite, composition, wt. %: KCl - 75, NaCI - 5, MgCl ₂ - 6, CaCl ₂ - 3, etc. Chlorination was carried out at 750 ± 50 ^o С. In the process of chlorination of TiCl ₄ and VOCl ₃ from titanium slag passes into the vapor-gas mixture, which was purified from impurities FeCl ₃ , AlCl ₃ and others in a salt (KCl) filter were condensed, a mixture of chlorides (VOCl ₃ + TiCl ₄ ) was separated by distillation to obtain purified products: TiCl ₄ and VOCl ₃ . From the obtained vanadium oxytrichloride, vanadium pentoxide was obtained according to the current technology — by alkaline decomposition followed by addition of ammonium chloride NH ₄ Cl into the solution, crystallization of ammonium metavanadate NH ₄ VO ₃ , filtration, washing, drying and calcination to obtain a commodity V ₂ O ₅ corresponding to as shown by the results of chemical analysis, the requirements of technical specifications for V ₂ O ₅ qualifications VNO-1.

Waste melts (KCl, NaCl, MgCl ₂ , CaCl ₂ , FeCl ₂ , MnCl ₃ , CrCl ₃ , etc.) and sublimates (KCl, NaCl, FeCl ₃ , AlCl ₃ , impurities VOCl ₃ , TiCl ₄ , ZrCl ₄ , etc. ) was poured into water at a melt: water ratio of 1:10, the solution was circulated 5 times to obtain solutions saturated with the total amount of metal chlorides, then neutralized to pH 7 with a magnesia suspension, the oxyhydrate precipitate was separated from the chloride solution (KCl, NaCl, MgCl ₂ , CaCl ₂ , impurities MnCl ₂ , FeCl ₂ ), as unsuitable for the content of metal impurities, was discharged into the sewer.

It is established that in the above conditions, when carried out according to the prototype method:
the "output" of secondary salt waste - spent melt and sublimates amounted to 1.9 tons per 1 ton of the initial polymetallic vanadium-containing waste;
the “yield” of wet oxyhydrate cake (humidity ≈60%) and insoluble residue was 1.6 tons per 1 ton of initial calcined waste;
the volume of wastewater - filtrates after separation of the oxyhydrate sludge 3 m ³ per 1 ton of source waste.

the volume of non-utilizable vanadium-containing wastewater (mother liquors and NH ₄ VO ₃ promo-vate) is 80 m ³ per 1 t V ₂ O _{5 the} concentration of vanadium in these effluents ranged from 0.1 g / dm ³ (last portions NH ₄ VO ₃ promo-v) 1.5-2 g / dm ³ - mother liquors after separation of NH ₄ VO ₃ (In accordance with current standards and MPC requirements for vanadium 0.1 mg / dm ³ ).

In the second series of experiments, the processing and disposal of polymetallic waste products was carried out according to the claimed method. To do this, the polymetallic vanadium-containing wastes were preliminarily subjected to reduction melting in an electric arc furnace at a temperature of 1800 ± 50 ^° С together with a titanium concentrate (ilmeno-rutile) containing 64% TiO ₂ , 32% FeO and up to 4% impurities of oxides Cr, Mn, before chlorination. Al, Zr and others. For this, waste having a composition similar to the above was calcined at 500 ^o C for 2 hours, mixed (1:15) with ilmeno-rutile (≈TiO ₂ • 2FeTiO ₃ ) and pitch coke, this the mixture was loaded into an electric arc furnace and reductive melting was carried out according to the regime, respectively the current melting mode in the RTP furnace upon receipt of titanium slag. The resulting melts of slag and cast iron were poured into the molds. At the same time, the melt discharge was organized in such a way that they received slag and associated metal (cast iron) in various molds. The ratio of cast iron: titanium slag = 0.6: 1. It was found that the slag contained 1.0 ± 0.2% V ₂ O ₅ .

The resulting slag enriched in TiO ₂ was grinded and mixed according to the existing technology with the spent electrolyte of the process for the electrolytic production of magnesium from carnallite composition, wt.%: KCl-75, NaCl - 5, MgCl ₂ - 6, CaCl ₂ - 3 and petroleum coke. Chlorination was carried out in a titanium chlorinator at 750 ± 50 ^o С without changing the mode of operation of the chlorinator, that is, according to the established technology. During chlorination, VOCl ₃ and TiCl ₄ from titanium slag were transferred to a gas-vapor mixture, which was purified from FeCl ₃ , AlCl _3, and other impurities in a salt (KCl) filter, condensed, and the chloride mixture (VOCl ₃ + TiCl ₄ ) was separated by distillation-chemical by the method (according to the adopted technological scheme) to obtain purified products: TiCl ₄ and VOCl ₃ .

From the obtained vanadium oxytrichloride, vanadium pentoxide was obtained according to the current technology — by alkaline decomposition followed by addition of ammonium chloride NH ₄ Cl into the solution, crystallization of ammonium metavanadate NH ₄ VO ₃ , filtration, washing, drying and calcination to obtain a commodity V ₂ O ₅ corresponding to as shown by the results of chemical analysis, the requirements of technical specifications for V ₂ O ₅ qualifications VNO-1.

The spent melts from the chlorinator were periodically (2-3 times per shift) poured into vanadium-containing wastewater (0.2 - 2 g / dm ³ V ₂ O ₅ ) - mother liquors and promoters NH ₄ VO ₃ . Drainage was carried out at the melt: effluent ratio = 1: (10 ± 1), the resulting pulp (55 ± 5 ^o ) was cooled to 30-35 ^o C and circulated 5 times in the hydraulic removal bath-circulation tank-hydraulic sump system. Under these conditions, coarse particles of the water-insoluble part of the spent melt were deposited in the hydraulic settler (up to 45-55% of the total mass of the water-insoluble part of the melt. The total mass of the water-insoluble residue (representing the non-chlorinated part of titanium slag, carbon reducing agent: TiO ₂ , FeTiO ₃ , Fe ₂ , Fe _{2 3} , SiO ₂ , Al ₂ O ₃ ZrO ₂ , ThO2 and partially polyvalent metal oxyhydrates) amounted to 250 ± 25 kg per 1 ton of spent melt discharged from the chlorinator. Density of the resulting pulp: 1.18-1.20 kg / dm ³ . Pulp output in specified s conditions was 2.2-2.5 m ³ per 1 ton of melt the waste. The aqueous slurry phase is a substantially saturated (or nearly saturated) solution of chlorides K, Na, Mg, Ca, chlorides and oxychlorides Fe (II, III) , Cr (III), V (IV and V), Mn (II), Ti (IV), Th, Zr, Al, Sc, etc. Metals. To neutralize this pulp from toxic metals, the pulp was pumped from the circulation tank to the tank. the drive or directly into the reactor for precipitation and neutralization, which was fed with continuous stirring (by sparging with air) magnesia suspension containing MgO 100 ± 10 g / dm ³ . In various experiments, the preparation of magnesia milk (suspension) used pre-crushed (less than 100 microns) magnesium-containing oxide minerals: brucite or magnesite, or serpentinite or mixtures thereof. (In some experiments, the above-mentioned mineral magnesium-containing oxide materials — magnesite, serpentinite — were subjected to thermal activation before calcining them by preparation of magnesia milk (suspension) by calcining at 500–800 ^° C). Neutralization of the pulp (supply of magnesia milk) was carried out to a pH of 8.5 ± 0.5, after which the hypochlorite pulp containing 80 ± 20 g / dm ³ Ca (OSl) ₂ and 15 ± 5 g / dm was first sequentially introduced into the pulp with stirring ³ CaO (a waste product generated at various stages of titanium-magnesium redistribution during the purification of exhaust gases from chlorine with lime milk containing 100 ± 20 g / dm ³ CaO). The introduction into the oxyhydrate pulp of a small amount (3–5 no more than 10 vol.%) Of hypochlorite pulp provides, as shown by the test results, ceteris paribus, a higher degree of purification of solutions from iron (II) and manganese (II) due to their oxidation to iron (III) and manganese (IV). At a high dosage of hypochlorite pulp, a negative effect is observed - the transition to the aqueous phase of compounds of manganese (VII), chromium (VI) and vanadium (V). After processing the initial pulp with a magnesia suspension and hypochlorite pulp, diluted (from 0.01 to 0.2%) solutions of high molecular weight flocculants (Navy) in an amount of from 2 to 10 vol. Were introduced into the formed oxyhydrate pulp. %, which were used polyacrylamide (PAA) and / or hydrolyzed polyacrylamide (GPAA) and / or praestol. After processing the Navy, the pulp was kept (without stirring) in the reactor for 1 ± 0.5 h, the clarified part was drained, and the thickened pulp was fed to a filter press. The oxyhydrate precipitate was separated from the mother liquor (KCl + MgCl ₂ , CaCl ₂ impurities, NaCl) and washed on the filter with the initial magnesia suspension (100 ± 10 g / dm ³ MgO) in an amount of (2 ± 0.5) volumes per 1 volume of oxyhydrate precipitate Promotions were combined with the mother liquor. The combined chloride solution was evaporated, then sent to obtain synthetic carnallite - according to known existing technology - by two-stage dehydration: first in fluidized bed furnaces, then for final dehydration in carnallite chlorinators to obtain a commercial product - dehydrated synthetic carnallite, which, as shown by the results of chemical analysis , for all normalized impurities (in the content of Fe, Mn, V, Ti, Zr, etc.) fully complies with the requirements of the current technical specifications for carnallite for lektroliticheskogo magnesium production. As production waste, at the second stage of the dehydration process, carnallite chlorine sludge is formed, containing, wt.%: MgO - 40 ± 5, MgCl ₂ - 35 ± 5, the rest - chlorides K, Na and Ca.

Wet (60 ± 5%) washed oxyhydrate precipitate (OO) - the sum of the oxyhydrates of Fe, Cr, Mn, Ti, Zr, Th, V, Al, Sc, etc., was mixed with the washed insoluble residue formed in the water settling tank upon receipt initial concentrated (after 4-5-fold recirculation) pulp and dust trapped during ore-smelting, then, with continuous stirring, crushed (less than 100 microns) slurry of carnallite chlorinators (MgCl ₂ - 30, MgO - 35, NaCl - 28, KCl, CaCl ₂ and others) in an amount of 1.0 wt. hours for 1 wt. h. mixtures of TO and BUT. Thus obtained thoroughly mixed paste-like composition was heated and subjected to molding at elevated temperature (250 ± 50 ^o C) in blocks.

 The combination of the above operations with production waste: discharge of the spent melt into vanadium-containing wastewater, pulp circulation and its neutralization, mixing the amount of metal oxyhydrates with an insoluble residue, dust of the heat transfer agent and sludge from carnallite chlorinators with subsequent molding ensures, as the test results show, the disposal of secondary waste from highly toxic metals (Cr, V, Mn, Fe, Ti, Zr, Th and its decomposition products, etc.). It should be emphasized that the conversion of oxyhydrate polymetallic sediments into solid blocks ensures the prevention of environmental pollution by highly toxic vanadium-containing wastewater and containing toxic metals, including Th, Po, Bi, Pb, secondary production waste due to dust removal, erosion of sludge - oxyhydrate cakes by precipitation, etc. At the same time, the transfer of toxic wastes - oxyhydrate precipitates, insoluble residues and RTP dust into the rejected state - into solid blocks facilitates their transportation and makes it possible to compactly place them at landfills and organize their long-term and safe storage for the population and the environment.

Thus, in comparison with the previously known, the developed method for the complex processing of polymetallic production wastes makes it possible to increase the degree of extraction of valuable components from non-utilized technogenic raw materials into commercial products (cast iron, TiCl ₄ , VOCl ₃ and / or V ₂ O ₅ ), while preventing environmental pollution by compounds of highly toxic metals.

Claims (5)

1. A method for the complex processing and disposal of polymetallic waste products, including their chlorination in a melt of alkali metal chlorides to produce spent melts and a gas mixture, separation, purification and utilization of titanium tetrachloride, alkaline decomposition of vanadium oxytrichloride, precipitation of ammonium metavanadate, its separation from the mother liquor, washing and calcining to obtain vanadium pentoxide, hydraulic washing of spent melts in working solutions, neutralization of pulp of magnesian suspension s based on the magnesium oxide material, separating the precipitate from solutions of metal oxyhydrates, characterized in that the vanadium base metal waste (IN) before pre-chlorination was subjected to reduction melting at 1600-2000 ^o C in an ore-smelting furnace together with titaniferous concentrates (TC) at a weight ratio VO : TC = 1: (10-20), spent chlorinator melts are poured into mother liquors and promoters of ammonium metavanadate, neutralized to pH 7-10, mainly 8-9 with a magnesian suspension, soda rzhaschey 50-150 g / dm ^3, MgO, after neutralization sequentially administered first 3-10 vol. % hypochlorite pulp containing 40-100 g / m ³ Ca (ClO) ₂ , then a solution of high molecular weight flocculant in an amount of 1-10 vol. %, after which the oxyhydrate pulp is kept without stirring for 0.5-2 hours, the clarified part is drained, the thickened part is filtered off, the oxyhydrate precipitate on the filter is washed with 1-3 volumes of the initial magnesia suspension per volume of precipitate, the filtrate and the promoters are combined and sent to obtain a synthetic carnallite, an oxyhydrate precipitate is first mixed with the insoluble residue of the spent melts formed during hydraulic erosion and dust captured during ore-thermal smelting of titanium-containing concentrates and polymetallic Sgiach waste then crushed materials containing magnesium chlorides and oxides, taken in an amount of 0.5-2 wt. hours for 1 wt. including oxyhydrate precipitate, the resulting pasty composition is heated and molded into blocks.  2. The method according to p. 1, characterized in that as titanium-containing concentrates use ilmenite and / or rutile, and / or ilmenorutil.  3. The method according to p. 1, characterized in that the spent melts (OR) of the chlorinators are poured into the mother liquors and promvod (SV) with a mass ratio of 1: (8-12), after which the pulp is circulated 4-5 times, coarse part the undissolved residue is isolated in a sump, and the pulp after concentration is neutralized with a magnesian suspension.  4. The method according to p. 1, characterized in that as the magnesium-containing oxide materials for the preparation of magnesia suspension using mineral magnesium-containing oxide substances selected from the series: brucite, magnesite, serpentinite. 5. The method according to p. 1, characterized in that as the crushed materials containing chloride and magnesium oxide mixed with oxyhydrate sludge, carnallite chlorine sludge is used - waste from the second stage of carnallite dehydration containing, wt. %: 30-50 MgCl ₂ , 30-50 MgO, chlorides K, Na, etc. the rest.