CN100418887C - Method of removing vanadium from titanium tetrachloride by aluminum powder as direct reducer - Google Patents

Abstract

The process of eliminating vanadium impurity from titanium tetrachloride (TiCl4) product with aluminum powder as direct reductant includes the following steps: feeding TiCl4 solution to be refined and surface activated aluminum powder into rectification tower, adding AlCl3 as catalyst and heating to boiling point to produce vanadium eliminating reaction; evaporating TiCl4 containing AlCl3 and high boiling point impurity inside the rectification tower to eliminate AlCl3 and high boiling point impurity, and condensing TiCl4 vapor escaping through the tower top to obtain refined TiCl4 product; and exhausting tower solution regularly or continuously to maintain the required AlCl3 concentration inside the tower. The said process can eliminate vanadium and high boiling point impurity simultaneously, and has continuous operation, low cost, high product quality and other advantages.

Description

A kind of is the method that direct reductive agent is removed vanadium impurity from titanic tetrachloride with aluminium powder

Technical field

The present invention relates to a kind of method of removing vanadium impurity from titanic tetrachloride, particularly a kind of is the method that direct reductive agent is removed vanadium oxydichloride impurity in the titanium tetrachloride with aluminium powder.

Background technology

Titanium tetrachloride is the raw material that gram Raul method is produced titanium sponge and chlorination process production titanium white.Have many detrimental impurity by titaniferous materials in the crude titanic chloride of chlorination manufacturing, these impurity directly influence the quality of titanium sponge and titanium white, therefore must with crude titanic chloride in addition purification just can be used to produce titanium sponge and titanium white.Adopt sedimentation filtration, distillation and the separable most of impurity removed in the crude titanic chloride of rectificating method, but the foreign matter of vanadium in the crude titanic chloride mainly is with vanadium oxydichloride (VOCl ₃) the form existence, its boiling point (127 ℃) is very close with titanium tetrachloride boiling point (136 ℃), adopt rectificating method little because of separation factor, and removes very difficult it is separated from titanium tetrachloride.So, in industrial production, adopt chemical process to remove vanadium.

Remove the method for vanadium impurity from titanic tetrachloride, studied tens of kinds, the relevant patent of delivering has reached hundreds of spare.But have only metallic copper (copper wire or copper powder), mineral oil (or other organism), hydrogen sulfide and the aluminium powder used in present industrial production remove the vanadium method for four kinds.

It is effective that copper removes vanadium, can obtain high-quality titanium tetrachloride, but adopt copper wire balls pack in the tower to remove the vanadium process be periodical operation, needed after copper wire balls lost efficacy from tower, draw off and wash, reinstall in the tower after the drying and reuse, the regenerative operation labour intensity of this copper wire is big, operating environment is poor, and washing process produces a large amount of copper-containing wastewaters to be needed to handle.In addition, when the aluminum chloride content in the titanium tetrachloride surpasses 0.01% (weight %) the copper surface is produced passivation, make copper remove vanadium and lost efficacy.Copper wire vanadium removal method in this tower, the utilization ratio of copper (promptly really being used for removing the copper of vanadium reaction) is very low, causes the copper loss amount big, removes vanadium cost height.So copper removes the vanadium method and only is fit to use in the small-scale production.

Mineral oil (or other organism) removes vanadium, though it is lower to remove the vanadium reagents price; But mineral oil adds removing in the vanadium process in the titanium tetrachloride, produce polymerizability, heavy-gravity, bulky residue liquid; Residue easily scabs on heated wall; A small amount of organism is not easily separated to be removed except that containing in the titanium tetrachloride behind the vanadium.This method is applicable to that chlorination process produces titanium white, if be used for titanium sponge production, because of the titanium tetrachloride that removes behind the vanadium contains a small amount of organism, makes the carbon content increase in the titanium sponge of production.

It is better that hydrogen sulfide removes the vanadium effect, but except that residual a small amount of sulfide in the titanium tetrachloride behind the vanadium, need carry out desulfurization and handle, and also can deposit sulfide in follow-up rectifying tower still otherwise not only influence quality product; Simultaneously, hydrogen sulfide is the hypertoxic gas with foul smell, has a strong impact on operating environment and labor condition.

Above-mentioned metallic copper, mineral oil and three kinds of shortcomings of removing the vanadium method of hydrogen sulfide are many; And aluminium powder is more except that vanadium method advantage, is particularly suitable for the vanadium that removes as the titanium tetrachloride of making the titanium sponge use.Aluminium powder removes the most outstanding advantage of vanadium method, is to remove the vanadium residue to separate with titanium tetrachloride easily, and helps reclaiming vanadium from residue.

USSR (Union of Soviet Socialist Republics) is studied successful aluminium powder and is removed the vanadium method, now uses in the titanium sponge of member country of the Commonwealth of Independent States (Ukraine, Russia, Kazakhstan) is produced, still belongs to restricted area so far but relevant aluminium powder removes the vanadium Processes and apparatus.Though applied for patent, in the patent of announcing, there is not word content, dated this patent will not disclose.

United States Patent (USP) 2,178,685 disclose a kind of employing TiCl ₃Remove the method for vanadium impurity from titanic tetrachloride, need be more than 2 hours but remove the vanadium reaction times.United States Patent (USP) 3,871,874 (1975, fritz Gerhard Winter disclosed a kind of employing TiCl in Krefeld) ₃.0.33AlCl ₃Remove the method for vanadium impurity from titanic tetrachloride, employed TiCl ₃.0.33AlCl ₃Be to adopt the method that is similar to the manufacturing polypropylene catalyst to make, just reaction is produced under high temperature (350 ℃) for aluminium powder and titanium tetrachloride.

It is the method that reductive agent is removed vanadium impurity from titanic tetrachloride that Deng state pearl in 2006 and Yuan Ji dimension contriver work out a kind of aluminium powder.

All aluminium powders of existing research both at home and abroad remove the vanadium method, all are two-step approachs, and the first step is made TiCl ₃Slurries (or TiCl ₃.0.33AlCl ₃), second step was used TiCl ₃Slurries (or TiCl ₃.0.33AlCl ₃) reduce thick TiCl ₄In VOCL ₃Be VOCL ₂Precipitation reaches except that the vanadium purpose.There are many shortcomings in this " two-step approach ": (1) makes TiCl ₃Slurries need add AlCl ₃Or generate AlCl with chlorine and aluminium powder reaction earlier ₃As catalyzer; (2) need be with the TiCl that makes ₃Slurries are transported to except that in the vanadium reactor, have TiCl ₃Trouble and difficulty that slurries are made, carried and measure; (3) can realize operate continuously, TiCl although remove the vanadium process ₃The slurries manufacturing is an intermittent process.

Summary of the invention

The purpose of this invention is to provide a kind of is the method (i.e. " step is removed the vanadium method ") that direct reductive agent is removed vanadium impurity from titanic tetrachloride with aluminium powder, it is simpler that this method has a processing unit, cost is lower, remove the vanadium process and realize operate continuously fully, the quality product height, rate of recovery height, advantage such as the disposal of three wastes is simple.

For achieving the above object the present invention by the following technical solutions: this is that the method that direct reductive agent is removed vanadium impurity from titanic tetrachloride comprises following step with aluminium powder:

(1), in rectifying Tata still, adds the TiCl that needs to remove vanadium ₄In still, add TiCl when solution, surface active aluminium powder, initial start-up operation ₄The AlCl of weight 0.01～2% ₃As catalyzer, be heated to boiling temperature and remove the vanadium reaction, the scope of boiling temperature is between 135 ℃～145 ℃; The surface active aluminium powder of described adding, be mineral oil, stearic acid, Palmiticacid or the oleic acid that in the aluminium powder that obtains with spray method, adds 1～10wt%, grind the flake aluminum of manufacturing under inert atmosphere nitrogen or argon gas, the aluminium powder median size is in 1～120 mu m range;

(2), remove vanadium after, contain AlCl ₃And the TiCl of high-boiling-point impurity ₄Evaporation enters rectifying Tata section, through refinery distillation isolated AlCl from titanium tetrachloride in the tower ₃Reach high-boiling-point impurity and return in the still downwards, and removed AlCl along tower ₃And the TiCl of high-boiling-point impurity ₄Steam is overflowed from cat head and is condensed into purified TiCl ₄Product;

(3), removing in the vanadium process of start-up operation generated AlCl ₃, make AlCl in the still ₃The concentration raising reaches after 2.5～4wt%, adds the TiCl that needs except that vanadium continuously in distillation Tata still ₄Solution and surface active aluminium powder carry out removing continuously vanadium;

(4), remove vanadium product VOCl for what get rid of to remove that the vanadium reaction generates ₂Solid and unnecessary AlCl ₃, regular or continuous blow-down goes out part still liquid.

The amount of added surface active aluminium powder is reduction TICl ₄Middle VOCl ₃Be VOCl ₂1～20 times of (adding mode and TICl of referring to the surface active aluminium powder of stoichiometry (chemical reaction theoretical amount) ₄Solution is for adding simultaneously); When the mode that adds the surface active aluminium powder is to adopt disposable adding or add fashionablely in batches, then press VOCl ₃Be reduced to VOCl ₂Total.

Need add the AlCl in the still kettle during initial start-up operation ₃Amount is TICl in the still kettle ₄The 0.01-2% of weight.

In still-process, AlCl in the still kettle ₃Concentration remains on respect to TICl ₄In 0.01～4wt% scope of weight.

Description of drawings

Fig. 1: process flow diagram of the present invention

Among Fig. 1,

The present invention adds mixed liquor in a tower bottom of rectifying tower 2; This mixed liquor comes from the raw material storage Groove 1 in the feed sump 1, needs the TiCl except vanadium₄Adding the surface active aluminium powder in the solution mixes; For the first time Also need during start-up operation in still, to add an amount of AlCl₃As catalyst: mixed liquor removes the vanadium reaction to boiling temperature (135 ℃～145 ℃) in the heating kettle, be removed vanadium but contain AlCl₃TICl₄Evaporation enters rectifying column section 3, has removed AICl through rectifying in the tower₃TICl₄Overflow from cat head, after condenser 4 condensations, a part refluxes, and another part becomes refining TICl₄Product is sent into product Product storage tank 5. AlCl in distillation still₃Regular or continuous blow-down still liquid makes AlCl in the distillation still after being enriched to a certain degree₃Concentration keeps in the prescribed limit. After start-up operation is finished, continuously in distillation still Add the TICl that needs except vanadium₄With surface active aluminium powder mixed liquor, carry out removing continuously vanadium, and do not need to add again AlCl₃Make catalyst.

Compare except the vanadium method with existing aluminium powder " two-step method ", " one-step method " of the present invention aluminium powder has many advantages except the vanadium method: (1) technological process and equipment are simpler: saved the TICl in " two-step method "₃Operation and the relevant devices such as slurries manufacturing, conveying and metering; (2) cost is lower: this When being preliminary start-up operation, bright method need add a small amount of AlCl₃, the AlCl that then utilizes reaction to generate after start-up operation is finished₃As catalysts, saved " two-step method " and will consume a large amount of AlCl₃Expense; (3) realize continued operation fully except the vanadium process, avoided " two-step method " to make TiCl₃Slurries The intermittently operated process.

A kind of aluminium powder direct-reduction of the present invention TiCl₄In VOCl₃Be VOCl₂The vanadium method of removing of precipitation, Be called " one-step method ". A this step aluminium powder except the vanadium method has overcome the shortcoming that has " two-step method " now is A kind of technological process and equipment are simpler, cost is lower, except the method for the complete serialization of vanadium process.

Embodiment

Embodiment 1

The ball aluminum powder of 5kg median size 80 μ m adds in the airtight surface activation process device, adds stearic acid 0.2kg, and mechanical mill is 6 hours under the argon gas atmosphere protection, obtains the flake aluminum of 5.2kg median size 40 μ m, wherein contains surfactant 3.6%

Embodiment 2

In a reactor that has a condensation reflux unit, add the titanium tetrachloride that contains foreign matter of vanadium (VOCl wherein ₃Be 0.10%) 500g, anhydrous AlCl ₃3g and 250mg surface active aluminium powder (median size 40 μ m) mix, and mixture heating up is boiling (137 ℃～138 ℃) extremely, and keep the boiling reflux state 30 minutes.Remove after the vanadium reaction finishes, the reaction mixture sedimentation also is cooled to 0 ℃, isolates limpid liquid 250ml and underflow and (contains AlCl ₃And VOCl ₂) 40ml, upper clear liquid V content is 3ppm by analysis

Embodiment 3

In a reactor that has a condensation reflux unit, add the titanium tetrachloride that contains foreign matter of vanadium (VOCl wherein ₃Being 0.10%) underflow 40ml and the 100mg surface active aluminium powder (median size 40 μ m) separated among 500g, the embodiment 2 mix, and mixture heating up is to boiling (137 ℃～139 ℃), and keeps the boiling reflux state 30 minutes.Remove after the vanadium reaction finishes, the reaction mixture sedimentation also is cooled to 0 ℃, isolates limpid liquid 280ml and underflow and (contains AlCl ₃And VOCl ₂) 50ml, upper clear liquid V content is 3.5ppm by analysis.

Embodiment 4

In a rectifying tower kettle device (seeing accompanying drawing), will contain the titanium tetrachloride solution (VOCl wherein of foreign matter of vanadium ₃For 0.12wt%, contain FeCl ₃0.05wt%) 4kg mixes with 3g (theoretical amount 0.2) surface active aluminium powder (median size 40 μ m), and mixed solution joins in 3 liters of still kettles, and adds AlCl in still ₃24g is heated to boiling (138 ℃～141 ℃), and the titanium tetrachloride that steams from the still 1h that refluxes in the packing tower of diameter 50mm, high 1.5m takes overhead out the TiCl through condensation ₄Contain V0.0003%, contain Fe 0.001%.After the overhead product content of vanadium is qualified, carry out continuous charging (mixed solution that contains 0.01% surface active aluminium powder of the titanium tetrachloride of foreign matter of vanadium and titanium tetrachloride weight), continuous still battery goes out product, remove the vanadium process and carry out continuously.AlCl in still kettle ₃Being enriched to concentration is TiCl in the still kettle ₄2.5% of weight, discharge still liquid 3kg, in still, replenish and add stock liquid (per kilogram contains the mixed solution that the vanadium titanium tetrachloride contains 750mg surface active aluminium powder) 3kg, and proceed continuous charging, continuous rectification goes out product, remove the vanadium process and carry out continuously once again, and do not need to add again AlCl ₃Make catalyzer.The 3kg still liquid of discharging carries out sedimentation, makes VOCl ₂Precipitate; And be cooled to 0 ℃, make AlCl ₃Crystallize out.Then, isolate clear liquid titanium tetrachloride 2.7kg and return use, underflow 300g contains AlCl ₃And VOCl ₂, and therefrom extract the vanadium product and reclaim titanium, aluminium product.

Embodiment 5

In a rectifying tower kettle device (seeing accompanying drawing), will contain the titanium tetrachloride (VOCl wherein of foreign matter of vanadium ₃Be 0.12%, contain FeCl ₃0.05%) 4kg mixes with 32g surface active aluminium powder (median size 40 μ m), and mixed solution joins in 3 liters of still kettles, and adds AlCl in still ₃20g is heated to boiling (138 ℃～141 ℃), and the titanium tetrachloride that steams from the still 1h that refluxes in the packing tower of diameter 50mm, high 1.5m takes overhead out the TiCl through condensation ₄Contain V 0.0003%, contain Fe0.001%.After the overhead product content of vanadium is qualified, adds the titanium tetrachloride, the continuous still battery that contain foreign matter of vanadium continuously and go out product, remove the vanadium process and carry out continuously.Aluminium powder or the TiCl that generates by its in still kettle ₃After exhausting, discharge still liquid 3kg, in still, replenish adding and contain vanadium titanium tetrachloride 3kg and surface active aluminium powder 32g, be heated to boiling (138 ℃～141 ℃), and proceed continuous charging, continuous rectification goes out product, remove the vanadium process and carry out continuously once again, and do not need to add again AlCl ₃Make catalyzer.The 3kg still liquid of discharging carries out sedimentation, makes VOCl ₂Precipitate; And be cooled to 0 ℃, make AlCl ₃Crystallize out.Then, isolate clear liquid titanium tetrachloride 2.7kg and return use, underflow 300g contains AlCl ₃And VOCl ₂, and therefrom extract the vanadium product and reclaim titanium, aluminium product.

Claims (1)

1. one kind is the method that direct reductive agent is removed vanadium impurity from titanic tetrachloride continuously with aluminium powder, it is characterized in that: it comprises following step:

(1), in rectifying Tata still, adds the TiCl that needs to remove vanadium ₄In still, add TiCl when solution, surface active aluminium powder, initial start-up operation ₄The AlCl of weight 0.01～2% ₃As catalyzer, be heated to boiling temperature and remove the vanadium reaction, the scope of boiling temperature is between 135 ℃～145 ℃; The surface active aluminium powder of described adding, be mineral oil, stearic acid, Palmiticacid or the oleic acid that in the aluminium powder that obtains with spray method, adds 1～10wt%, grind the flake aluminum of manufacturing under inert atmosphere nitrogen or argon gas, the aluminium powder median size is in 1～120 mu m range;

(2), remove vanadium after, contain AlCl ₃And the TiCl of high-boiling-point impurity ₄Evaporation enters rectifying Tata section, through refinery distillation isolated AlCl from titanium tetrachloride in the tower ₃Reach high-boiling-point impurity and return in the still downwards, and removed AlCl along tower ₃And the TiCl of high-boiling-point impurity ₄Steam is overflowed from cat head and is condensed into purified TiCl ₄Product;

(3), removing in the vanadium process of start-up operation generated AlCl ₃, make AlCl in the still ₃The concentration raising reaches after 2.5～4wt%, adds the TiCl that needs except that vanadium continuously in distillation Tata still ₄Solution and surface active aluminium powder carry out removing continuously vanadium;

(4), remove vanadium product VOCl for what get rid of to remove that the vanadium reaction generates ₂Solid and unnecessary AlCl ₃, regular or continuous blow-down goes out part still liquid.

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