RU2192489C2 - Method of complex processing technogenious vanadium raw material - Google Patents

Abstract

FIELD: methods of complex processing of technogenious vanadium raw material. SUBSTANCE: proposed method consists in chlorination of metal chlorides in melt forming vapor-and-gas mixture and waste melt of salt chlorates, condensation of vanadium, titanium and silicon chlorides, rectifying and chemical separation of these chlorides, utilization of titanium and silicon tetrachlorides, hydrolysis of vanadium oxytrichloride at separation of sediments of ammonium metavanadate and/or vanadium pentaoxide, separation of sediments from mother liquor, flushing, drying and/or calcination for obtaining commercial vanadium compounds. Chlorination of vanadium raw material is performed together with titanium raw material at initial V₂O₅:TiO₂ mass ratio = (5-20); waste melt of chlorates is subjected to hydraulic washing by draining into mother liquor and intermediate water after processing and hydrolysis of vanadium oxytrichloride. Pulp thus obtained is cooled and is again directed for hydraulic washing of waste melt till saturated solutions are formed as considered by sum of metal chlorides, after which pulp is treated by alkaline reagent in presence of reductants to pH = 3.5 to 5.0 and then flocculant is introduced into pulp. After flocculation and settling, pulp is filtered and sediment is washed and dried and/or calcined, thus obtaining commercial concentrate of chromium and trace rare metals; filtrate and intermediate water are treated by alkaline reagent to pH = 8 to 10 accompanied by mixing with air, after which pulp is additionally treated with alkaline solution of oxidant. The pulp is settled and filtered, sediment is separated from mother liquor, washed, dried and calcined, thus obtaining commercial ferromanganese concentrate; used as titanium raw material is rutile and/or rutile concentrate, and/or ilmenite, and/or ilmenorutile , and/or titanium-containing slags; used as alkaline solution of oxidant is waste milk of lime of process of cleaning waste gases from chlorine. EFFECT: possibility of obtaining additional yield of commercial product; avoidance of discharge of high-toxic secondary waste. 3 cl, 1 ex

Description

The invention relates to the field of metallurgy and can be used at ferrous and non-ferrous metallurgy enterprises for the complex processing of various technogenic vanadium raw materials containing 10-80% V ₂ O ₅ , oxides of other elements: Fe, Cr, Mn, Al, Si, Ti, Zr , Mg, Ca, Na, K and others. The present invention can be used, in particular, in the complex processing of various vanadium-containing intermediate products, intermediate products and industrial waste: ash from thermal power plants, waste slag and waste sludge-oxyhydrate sludge formed, for example, in the treatment of effluents from vanadium.

There is a method of processing industrial products of vanadium production - technical V ₂ O ₅ containing impurities of oxides Fe, Cr, Mn, Si, Mg, Na and others (Non-ferrous metallurgy, 1995, 7-8, p. 33-37).

According to the known method, vanadium-containing intermediate products are treated, mainly at elevated temperature, with an alkaline reagent - a solution of sodium hydroxide or carbonate, insoluble precipitate (oxyhydrates and metal oxides of impurities) is separated from a solution of sodium metavanadate - NaVO ₃ , which is treated with an ammonium-containing inorganic compound (NH ₄ Cl, NH ₄ NO ₃ and others), the solid phase released from the solution — ammonium metavanadate (NH ₄ VO ₃ ) —separate, is filtered off from the mother liquor, washed, dried and calcined to obtain the marketable vanadium pentoxide V ₂ O ₅ corresponding in quality to the requirements of TU.

 The reasons that impede the achievement of the technical result indicated below include the formation of a large amount of non-utilizable secondary production waste containing a significant amount of vanadium, and in this regard, significant - up to 25-35% loss of vanadium with these waste.

Of the known analogues, the closest in technical essence and the achieved result to the proposed method is the method of complex processing of technogenic vanadium raw materials - from vanadium converter sludge containing V ₂ O ₅ , oxides Ti, Si, Fe, Al, Mn, Cr (Amirova S.A. ., Kutsenko S. A., Chizhov NN Processing of vanadium-containing sludge by chlorination method. Chemistry and technology of vanadium compounds. Materials of the I All-Union meeting on chemistry, technology and application of vanadium compounds (July 1972). - Perm: Perm book edition , 1974, p. 154-158).

According to the prototype method, vanadium containing (20% V ₂ O ₅ ) technogenic raw materials — converter slags is chlorinated in the melt of an equimolar mixture of sodium and potassium chlorides in the presence of a reducing agent, which uses pitch coke. As a result of chlorination receive:
- vapor-gas mixture of chlorides V, Ti, Si;
- sublimates of the condensation system (AlCl ₃ , FeCl ₃ , NaCl, KCl, impurities V, Ti);
- spent salt melt (NaCl, KCl, FeCl ₂ , FeCl ₃ , CrCl ₃ , MnCl ₂ and others).

Silicon tetrachloride SiCl ₄ is isolated from the vapor-gas mixture by fractional condensation, which is sent as feedstock for organosilicon synthesis, then VOCl ₃ and TiCl ₄ are separated by two-stage rectification. Titanium tetrachloride is sent to magnesium thermal production of sponge titanium, and vanadium oxychloride is VOCl ₃ , depending on market requirements;
- sold as a commercial product - for use as a catalyst in the production of synthetic rubber;
- VOCl _{3 is} chlorinated in the presence of coke -, VLC _{4 is} obtained, which is then decomposed to form vanadium trichloride VCl ₃ and chlorine gas; then VCl _{3 is} treated with metal magnesium, resulting in a commodity metallic vanadium and a magnesium chloride melt, which is sent to electrolysis, to obtain magnesium metal and chlorine gas;
- VOCl _{3 is} subjected to aqueous hydrolysis, the released V ₂ O _{5 is} separated from the mother liquor, dried, calcined to obtain marketable V ₂ O ₅ .

The reasons that impede the achievement of the following technical result include:
- the formation of a large amount of secondary solid and liquid waste products containing V, Ti, Fe, Cr, Mg, Na, etc. Processing, neutralization and / or disposal of secondary waste (spent melt, sublimates, mother liquors and wastewater - waste water after the allocation of V ₂ O ₅ , etc.) in the known method are not provided;
- difficulties associated with the technological design of the entire process of complex processing of vanadium man-made raw materials, which is due to sharp fluctuations in its composition, and, as a result, the need for changes and constant regulation of the input parameters and modes of individual stages of the technological scheme.

 For the above reasons, the known method over the past 25-30 years (from the date of research and publication of the work) has not been implemented either on a pilot scale or in industrial production.

 The claimed technical solution is aimed at solving problems consisting in ensuring the processing, utilization, neutralization of secondary production waste and the additional release of marketable products.

The technical result that can be obtained by implementing the claimed invention is to increase several times the output of marketable products - VOCl ₃ , NH ₄ VO ₃ , and / or V ₂ O ₅ from man-made raw materials on existing industrial equipment without significant reconstruction, additional release chromium concentrates and ferromanganese concentrates, while solving environmental problems - preventing the discharge of solid and liquid highly toxic polymetallic secondary waste generated during processing and Khodnev vanadium technogenic raw materials.

The technical result is achieved using the characteristics specified in the first claim that are common with the prototype, such as a method for complex processing of technogenic vanadium raw materials, including chlorination of alkali and alkaline earth metal chlorides with a vapor-gas mixture and spent molten salt chlorinators, condensation of vanadium chlorides, titanium and silicon, their distillation-chemical separation and purification, utilization of titanium and silicon tetrachlorides, hydrolysis of vanadium oxytrichloride with recovery sedimentation of ammonium metavanadate and / or vanadium pentoxide, separation of precipitation from the mother liquor, washing, drying and / or calcining to obtain commodity vanadium compounds and distinctive essential features, such as chlorination of vanadium raw materials, are carried out together with titanium raw materials, at the initial mass ratio V ₂ O ₅ / TiO ₂ 5-20, the waste is subjected to melt chlorinators gidrorazmyvu by draining in mother liquors and recycling promvody of vanadium oxytrichloride and hydrolysis, the resulting pulp is cooled and fed and the hydraulic washing of the spent melt to the formation of solutions saturated by the sum of metal chlorides, after which the pulp is treated with an alkaline reagent in the presence of reducing agents to a pH of 3.5-5.0, then a flocculant is introduced into the pulp, after flocculation and settling, the pulp is filtered, the precipitate is washed and dried and / or calcined to obtain commercial concentrate of chromium, rare and scattered metals, the filtrate and promoters are treated with an alkaline reagent to a pH of 8-10, with stirring with air, after which the pulp is additionally treated with an alkaline solution oxidizer rum, the pulp is defended, filtered, the precipitate is separated from the mother liquor, washed, dried and calcined to obtain salable ferromanganese concentrate.

 As the titanium raw material, rutile and / or rutile concentrate and / or ilmenite and / or ilmenorutil and / or titanium-containing slag are used.

Preferably, the spent milk of the chlorine waste gas purification process is used as an alkaline oxidizing solution
Thus, the first feature of the process is that the chlorination of technogenic vanadium raw materials (BC) is carried out in the presence of titanium raw materials (TC) at a mass ratio of V ₂ O ₅ : TiO ₂ = 1: 5-20. The second feature also consists in the fact that the initial vanadium raw materials are mixed beforehand with titanium raw materials, which are rutile (natural and / or synthetic), ilmenorutil, various ore titanium raw materials and / or concentrates, titanium slags. The third feature is that chlorination is carried out in salt titanium chlorinators.

 The fourth feature is that salt chloride production waste - spent chlorine melt is subjected to hydraulic washing by pouring into the mother liquors and wastewater from processing and hydraulic washing of vanadium oxytetrachloride, the resulting slurry is cooled and sent to the hydraulic washing of the spent melt until solutions are saturated in total metal chlorides, after whereupon the pulp is treated in the presence of a reducing agent with an alkaline reagent to a pH of 3.5: 5.0, then a flocculant is introduced into the pulp, after flocculation and settled I filter the pulp, the precipitate is washed and dried and / or calcined to obtain commercial concentrate of chromium, rare and scattered metals, the filtrate and wastes are treated with an alkaline reagent to pH 8-10 with stirring with air, after which the pulp is additionally treated with an oxidizing solution, which can hypochlorite pulp obtained by purification of waste gases from chlorine with milk of lime must be used, the pulp is settled, the precipitate (iron and manganese oxyhydrates) is washed, dried and calcined to obtain marketable lezomargantsevogo concentrate. The filtrate of chlorides of alkali and alkaline earth metals, purified from impurities of heavy metals, is sent to obtain synthetic carnallite and / or discharged into the general sewage system and sent to treatment facilities.

 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 is not obvious to specialists in the prior art.

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 processes of complex processing of vanadium man-made raw materials. At the same time, an 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 complex processing of vanadium man-made raw materials under the strictly defined above conditions and conditions ensures complex processing of the feedstock, neutralization and disposal of all secondary production wastes to produce various highly liquid products: vanadium compounds (VOCl ₃ , NH ₄ VO ₃ ; and / or V ₂ O ₅ , - deficient chromium concentrates and ferromanganese concentrates, it must be emphasized that if the optimal process conditions and sequence of actions are violated, 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 on the chemistry and technology of vanadium and its compounds. Information confirming the possibility of implementing the proposed technical solution is given in the example.

Example. For the complex processing of technogenic vanadium raw materials used industrial products containing, wt.%: 2-3 V ₂ O ₅ , 40-50 Fe ₂ O ₃ , 6-7 Cr ₂ O ₃ , 8-9 MnO ₂ , 8-9 TiO ₂ , 2-3 Al ₂ O ₃ , 16-19 SiO ₂ , impurities Mg, Ca, Na, K.

The chlorination of this vanadium feed was carried out in existing industrial salt chlorinators in a melt of sodium and potassium chlorides together with a titanium feed, which was taken as a titanium-containing slag, composition (by main components), wt.%: 0,055 V ₂ О ₅ , 5,0 Fe ₂ O ₃ , Cr ₂ O ₃ , MnO ₂ , 85 TiO ₂ and metal oxides of impurities Al, Sc, Th, Zr (Hf) Nb (Ta), etc. The ratio of titanium and vanadium raw materials in the initial charge fed to chlorination was taken based on the calculation of the mass ratio in the mixture V ₂ O ₅ : TiO ₂ = 1: 15. Chlorination was carried out at (760 ± 20) ^o With anodic chlorine gas of magnesium production in strict accordance with the current regulatory and technical documentation for the chlorination of titanium raw materials. The spent melt of chlorinators was periodically (2-3 times per shift) discharged from the chlorinator. From the gas-vapor mixture after the condensate, technical TiCl _{4 was} obtained containing an increased amount of vanadium, the concentration of vanadium increased in comparison with the traditional process of chlorination of titanium slags from 0.055-0.058% to 1.5-2%. After distillation-chemical separation and purification of technical TiCl ₄ from vanadium and impurities of other elements, according to the technology applicable at the enterprise, commercial TiCl ₄ was obtained by all indicators, including normalized ones (TU) for impurities to obtain sponge titanium. After purification of technical TiCl ₄ from vanadium impurities, first technical vanadium oxytrichloride (90-95% VOCl ₃ ) was obtained, which was sent for distillation purification from TiCl ₄ impurities to obtain marketable VOCl ₃ corresponding in terms of the ratio of impurities to TU requirements.

Research, testing and calculations based on the data obtained show that the implementation of the process of joint chlorination of vanadium and titanium raw materials allows to increase VOCl ₃ production from 1.7-1.8 to 65-70 kg per 1 ton within the existing hardware-technological scheme of the process TiCl ₄ .

It is important to note that an increase in the volume of produced chloride salt production wastes in the total mass of spent melt and sublimates of titanium production was practically not detected under the tests carried out by the proposed method (the estimated increase in chloride wastes is less than 2%). From the obtained vanadium oxytrichloride, vanadium pentoxide was obtained by hydrolysis of VOCl ₃ in an alkaline solution (120 g / dm ³ NaOH) containing 100 g / dm ³ NaCl. For this, VOCl ₃ (> 99%) purified from impurities was poured into an alkaline solution until a pH of 8 + 0.5 was reached. NH ₄ Cl was introduced into the resulting NaVO ₃ solution. The resulting pulp was cooled, the ammonium metavanadate released was separated from the mother liquor, washed, dried and calcined at 550 ^° C. to obtain marketable V ₂ O ₅ . The mother liquor and promotions of ammonium metavanadate were partially used directly in the processing of VOCl ₃ - by returning part of the mother liquor to the hydrolysis of VOCl ₃ and reusing the promvod. Most (more than 60-70%) were directed to the operation of hydraulic washing the spent melt. The spent melt (OR) was subjected to hydraulic washing by pouring into the vanadium-containing (0.1-1.0 g / dm ³ vanadium) mother liquors and promoters of ammonium metavanadate-wastewater (CB) with the ratio OR: CB = 1: (8-12) , the resulting pulp after cooling and partial sedimentation was used for hydraulic washing of the spent melt 4-5 times, i.e. concentrated to the formation of saturated in the amount of metal chloride solutions (with a density of 1.18-1.22 kg / DM ³ ). The solutions obtained in this way were sent for neutralization from heavy (Fe, Cr, Mn) and rare scattered metals V, Sc, Zr, etc., for which they were treated with alkaline reagents, which were used as: milk of lime (100 g / dm ³ CaO ), sodium hydroxide solution (120 g / dm ³ ), magnesia milk - aqueous suspensions of magnesite, or brucite, or serpentinite (100-150 g / dm ³ MgO). The neutralization, neutralization and deposition of metal oxyhydrates were carried out in two stages. At the first stage, the initial acidic chloride solution (and / or pulp) with a pH of 1.2-1.8 is saturated by the sum of metal chlorides: KCl, NaCl, MgCl ₂ , CaCl ₂ , FeCl ₂ , MnCl ₂ , CrCl ₂ , chloride V , Zr (Hf), Th, Si, Al, etc., were treated with an alkaline reagent to a pH of 4.0 ± 0.2, and the treatment was carried out in a reducing medium: sodium sulfite was introduced into the solution before treatment with alkali, and nitrogen gas was mixed with nitrogen - to prevent oxidation of Fe (II) to Fe (III). After this treatment, a 0.2% solution of hydrolyzed polyacrylamide (GPAA) was introduced into the pulp in an amount of 100 dm per 1 m of pulp. Under these conditions, hydroxides and basic salts of Cr (III), V (IV), Al, Sc, Ti, Zr, Th and small amounts of iron and manganese captured by the precipitate are separated from the solution into an oxyhydrate precipitate. It should be emphasized that this operation provides: neutralization of waste from chromium, concentrated rare and scattered metals, and most importantly, neutralization of wastewater (mother liquors and NH ₄ VO ₃ promo-vate) from vanadium:
It is especially necessary to note that neutralization from vanadium occurs only when two types of waste are combined: mother liquors and promo- -5.0.

The oxyhydrate precipitate was separated from the mother liquor in a frame filter press, washed, repulped, and filtered again. For washing and repulpation, a 0.02% HPAA solution was used to prevent sediment peptization. The washed precipitate was dried. (100 + 5 ^o C). Individual portions of precipitation were calcined at 300-500 ^o C using commercial concentrate of chromium and rare metals for the subsequent sale of these products as raw materials for the extraction of scandium and other metals. The first portions of the promvod (in volume approximately equal to the volume of wet (80% vl.) Sediment were combined with the mother liquor. The remainder of the promvod was directed to the operation of hydraulic washing of the spent melt, combining these promvods with wastewater - mother liquors and promvods formed during processing and hydrolysis with obtaining VOCl ₃ , NH ₄ VO ₃ and / or V ₂ O ₅ .

After separation of the drying of metal oxyhydrates, the chloride solutions were treated with an alkaline reagent - with stirring with air to a pH of 9.5 ± 0.5, after which an alkaline solution of an oxidizing agent was introduced into the pulp - spent lime milk from the process of purifying exhaust gases from chlorine. These two consecutive operations ensured, ceteris paribus, precipitation of iron and manganese oxyhydrates from the solution (presumably composition: 3FeOOH • MnO ₂ and / or Fe ₃ O ₄ • H ₂ O • MnO _{2. The} pulp was treated in a reactor with 0.2% HPAA solution with continuous stirring, kept for 1 hour without stirring, then fed to a filter press, the precipitate of Fe and Mn oxyhydrates was separated from the mother liquor, washed from K, Na, Mg and Ca chlorides, dried and calcined at 500 ^° C to obtain commercial ferromanganese concentrate (ratio Fe and Mn 3: 1). Analysis of the filtrates and promvod showed that the degree of neutralization of solutions from Fe, Cr, Mn, V, Ti, Zn, Th, Sc and other metals in all industrial and laboratory experiments was 99.0 99.9%.

Thus, the above method provides a complex processing of technogenic vanadium raw materials to produce commodity vanadium compounds: VOCl ₃ and / or NH ₄ VO ₃ ; and / or V ₂ O ₅ .

- processing of production waste, concentration of non-ferrous, rare and dispersed metals to produce marketable products - chromium concentrates, rare and dispersed metals and ferromanganese concentrates;
- mutual neutralization of secondary production effluents - wastewater (mother liquors and wastewater) NH ₄ O ₃ containing vanadium and melts of titanium chlorinators;
- Prevention of environmental pollution by highly toxic industrial wastes.

Claims (3)

1. A method for complex processing of technogenic vanadium raw materials, including chlorination of alkali and alkaline earth metal chlorides in a melt with the formation of a gas-vapor mixture and spent molten salt chlorine chlorides, condensation of vanadium, titanium and silicon chlorides, their distillation-chemical separation and purification, utilization of titanium and silicon tetrachlorides, hydrolysis of vanadium oxytrichloride with the release of precipitation of ammonium metavanadate and / or vanadium pentoxide, separation of precipitation from the mother liquor, washing, drying and / or etc. Kalka, to produce vanadium compounds, characterized in that the chlorination of raw materials of vanadium are together with the titanium raw material at an initial weight ratio of V ₂ O ₅ / TiO ₂ 5-20, the waste is subjected to melt chlorinators gidrorazmyvu by draining in mother liquors and recycling promvody by hydrolysis and vanadium oxytrichloride, the resulting slurry is cooled and sent to the hydraulic washing of the spent melt to form solutions saturated by the sum of metal chlorides, after which the pulp is treated in the presence of it with an alkaline reagent to a pH of 3.5-5.0, then a flocculant is introduced into the pulp, after flocculation and settling, the pulp is filtered, the precipitate is washed and dried and / or calcined to obtain commercial concentrate of chromium, rare and trace metals, the filtrate and wastes are treated with alkaline reagent to a pH of 8-10, with stirring with air, after which the pulp is additionally treated with an alkaline solution of an oxidizing agent, the pulp is settled, filtered, the precipitate is separated from the mother liquor, washed, dried and calcined to obtain marketable ferromanganese to ntsentrata.  2. The method according to p. 1, characterized in that rutile and / or rutile concentrate and / or ilmenite and / or ilmenorutil and / or titanium-containing slag are used as titanium raw materials.  3. The method according to p. 1, characterized in that the alkaline solution of the oxidizing agent is used spent milk of the process of purification of exhaust gases from chlorine.