CN1033018C - Rutile-type titanium dioxide powder prepared by plasma chlorination process - Google Patents

Abstract

The present invention relates to a process and a technology for preparing rutile type titanium dioxide. Fluidizing chlorination is carried out by high titanium slag, petroleum coke and chlorine gas; then, refined titanium tetrachloride reacts with high temperature plasma oxygen to carry out oxidation; rutile type TiO2 is prepared by the processes and technologies of fractionation, capsule, drying, etc. The present invention has the advantages of automatic technological process, stable product performance and wide application.

Description

Rutile-type titanium dioxide powder prepared by plasma chlorination process

The present invention relates to prepare the technology and the technology of Rutile type Titanium Dioxide.

Produce at present titanium dioxide and mainly contain sulfuric acid process and chlorination process, and sulfuric acid process is because of long flow path, " three wastes " are seriously polluted, and poor product quality and the method that progressively is chlorinated replaces adopts chlorination process production titanium dioxide in technology with technically have more following subject matters:

One. common chlorination furnace can not adapt to the higher raw materials of impurity such as calcic, magnesium, silicon, otherwise the phenomenon that can result in blockage.

Two. in the oxygen heating process, the general combustion method (as by means of dimethylbenzene tighter on carbon monoxide or the market) that adopts, because this class combustionmaterial directly contacts with oxygen, product meeting polluted product after the burning, and having diluted the chlorine that the titanium tetrachloride oxidizing reaction produces, the chlorine of low concentration can cause chlorination reaction unfavorable.

Three. the compound modifying agent aluminum chloride adds method in oxidizing reaction, adopts the technology of dissolving, filtration, evaporation, preheating usually, not only long flow path, seriously corroded, easily stop up process pipeline, and cause the severe contamination of environment.

Four. adopt usual method, the titanium tetrachloride preheating temperature is less than 400～450 ℃, and is unfavorable with oxygen mixing initial reaction.

Five. the titanium tetrachloride oxidizing reaction obtains titanium dioxide and chlorine, titanium dioxide makes finished product through aftertreatment, chlorine returns chlorination furnace and utilizes, returns the fluctuation of the normal oxidated furnace operating of chlorine in the general technology and fluctuates, and the more conference of fluctuating directly influences the reaction of chlorination furnace as the start-stop car; And the fluctuation of chlorination furnace makes that more the oxidized still reaction is not steady, even rarer chlorine can make consumption rising, the chlorine of oxidation in common technology that hence one can see that return the direct quality that influence the reaction of two big operations (chlorination and oxidation) of quality meeting of situation.

The object of the present invention is to provide a kind of plasma chlorination process to prepare rutile TiO ₂Novel process and technology.

Concrete technical solution of the present invention is as follows:

One). adopt the major diameter sieve plate (1～1.2m) and the fluidizing chlorination of no sieve plate chlorination furnace solution titanium slag (or artificial rutile), can make contain, the higher raw materials of impurity such as magnesium, silicon carry out than complete reaction.

Two). the employing precipitator method (natural sedimentation) are removed the insoluble impurities in the crude titanic chloride, adopt fractionating technology (use separation column) to remove high boiling material silicon, adopt reduction or extraction process to remove the impurity vanadium, obtain the refining titanic chloride of purity more than 99.9% by adopting above-mentioned purification isolation technique.

Three). titanium and scandium obtain reclaiming and purify through technology such as flotation, chemical reaction, extractions in chlorinated furnace slag and the mud, and titanium dioxide is selected to content more than 85.

Four). oxygen adds the thermal recovery plasma technology, can obtain 2000 °～3000 ° K high temperature ion-oxygens, and installed capacity can satisfy 30～400KW scope and select arbitrarily.

Can satisfy evaporation, the preheating large scale industry device of titanium tetrachloride, preheating temperature can make titanium tetrachloride gases reach 450～800 ℃.

Five). take compound modifying agent aluminum chloride vapor phase process adding technology and the technology supporting, add the corrosion that a spot of aluminum chloride can overcome system, help operating environment and improve and titanium dioxide crystal formation transformation efficiency (reaching more than 98%) with oxidized still.

Six). it is oxidized still that the extremely crucial nucleus equipment of titanium dioxide is produced in the titanium tetrachloride oxidation, and the major technique of oxidized still is the uniform mixing of raw material; Initial reaction to termination reaction must be finished between instantaneous (0.1～1 second, even still less); Reaction at high temperature (1300 to 1500 ℃) is carried out; Reactant must be with the air-flow reaction zone that speeds away, otherwise can form melting charge and the obstruction reaction zone that scabs, and makes the undesired very fast obstruction burner hearth of reaction, until being forced to stopped reaction or forging and ruin burner hearth; Must make reacts completely carries out titanium tetrachloride transformation efficiency＞99%; The titanium dioxide that produces is rutile-type, reaches more than 98%; Oxidation reaction heat is removed rapidly; Reacted titanium dioxide granule degree occupies more than 70% below reaching 0.2～0.3 μ m, the way that solves is can adopt low gas velocity scraper stove reactor (at three kilotons/below year) on than dingus in scale, and larger device can adopt no scraper stove reactor.

Seven). normally drive for guaranteeing chlorination and oxidation two big operations, the present invention has adopted low concentration chlorine solvent absorbing and analytic technique to obtain high purity (＞92%) chlorine, keeps chlorination reaction normally to carry out; When chlorination hinders temporary transient parking for some reason, the chlorine TiCl that oxidation produced ₄Absorb preheating TiCl ₄Parse Cl then ₂, can keep oxidation operation normally to move, waste gas Ca (OH) ₂Absorb.

Eight). in the titanium dioxide postprocessing working procedures, select binary or ternary (Si, Al, Ti) film-coating technique, it is excellent to obtain product performance; Product can obtain product and be better than Japanese R-820 through sorting, secondary filtration, drying, comminution by gas stream again behind the coating.

Nine). the oxidized still structure can be selected scraper (structure and material) or not have scraper (adopting air curtain, air-blowing, grit blast technology) stove according to device character, partly is made up of burner, mixing, reaction, interruption reaction etc., and each one all gets according to reaction kinetics fluidised form length of schooling.

The key technical indexes of the present invention:

One. raw material:

1. titanium slag: TiO ₂＞90%

Granularity: 60～100 orders account for 70%

Build by 40 orders

∑Fe＜2.0％

SiO ₂＜6.0％

∑Ca.Mg＜1％

2. refinery coke: should meet 1 ^#The refinery coke standard

3. chlorine: Cl ₂＞85% (V/V)

4. oxygen: O ₂＞99% (V/V)

5. aluminium: meet the Aoo standard

Or aluminum chloride: AlCl ₃〉=99%

Two. middle product:

1. crude titanic chloride: TiCl ₄＞99%

2. smart titanium tetrachloride: V＜0.002%

Si＜0.002％

Outward appearance: colourless liquid

3. work in-process titanium dioxide: TiO ₂＞99%

R type＞99%

Granularity: 0.2～0.3 μ m accounts for 70%

Three. product: Tianjin Chemical Plant titanium dioxide company standard.

Principal reaction equipment and technology reference mark among the present invention:

1. chlorination furnace: ratio of components titanium slag: coke=100: 30～35

Conversion zone temperature: 800～900 ℃

Slag:＜7%

Furnace roof tail gas: Cl ₂＜1%

CO: CO ₂Be 2～3: l

2. oxidized still: ratio of components: TiCl ₄: O ₂=1: 1.05～1.1 (mol ratios)

Temperature of reaction: 1300～1500 ℃

Heater outlet temperature:＜700 ℃

TiCl ₄Transformation efficiency＞99%

RTiO ₂＞98％

Granularity (TiO ₂) 0.3 μ m to be to assign more than 70%

Reach continuous steady running more than 120 hours

3. return purity of chlorine gas feeding＞85%

4. coating: 50～70 ℃ of temperature (optional on request)

PH value 7～8

5. dehydration: two sections are filtered filter and H ₂O≤45%

6. dry: H ₂O≤0.5%

7. pulverize: granularity 0.3 μ m is to assign 70%

8. product: meet the Tianjin Chemical Plant company standard

Specific embodiments of the invention are as described in the following technical process:

Fig. 1 is the rutile-type titanium dioxide powder prepared by plasma chlorination process process flow sheet.

As shown in Figure 1, (1) is chlorination, and (2) are refining, and (3) are vaporizers, and (4) are preheaters, (5) Gas-phase reactor, and (6) are plasma generators, and (7) are oxidation reactors, and (8) are to collect.(9) be Cl ₂Extract, (10) are making beating, and (11) are classifications, (12) aftertreatment, and (13) are to filter, and (14) are second dehydrations, and (15) are dry, and (16) are to pulverize, (17) are finished products.

Above-mentioned process flow sheet can be described below:

1. titanium slag and refinery coke enter chlorination furnace (1) on demand behind the proportioning uniform mixing and generate thick TiCl with the chlorine reaction that returns from oxidation reactor (7) ₄, the recycling of exhaust gas evacuation waste sludge discharge.

2. thick TiCl ₄Need refining the purification to remove impurity and obtain smart TiCl more than 99.9% ₄

3. smart TiCl ₄Through vaporizer (3) liquid-phase conversion be gas phase then again through preheater (4) heat temperature to 450～800 ℃ of arbitrary scopes, simultaneously, compound modifying agent AlCl in the gas phase producer (5) ₃With TiCl ₄By a certain percentage and TiCl ₄Steam enters oxidation reactor (7) after mixing

4. oxygen is heated to 2000 ° through ion generator (6) and enters oxidation reactor (7) and TiCl more than the K ₄Steam rapid reaction at high temperature generates TiO ₂(solid phase)

5. the TiO that generates of oxidation ₂Through collecting (8) gas solid separation, chlorine returns chlorination, TiO ₂Water making beating (10) back becomes liquid, and classified (11), the two-stage sorting, the one-level vibratory screening apparatus, the one-level spinning liquid separates, and fine particle is sent to aftertreatment (12) less than 1 micron, classification again after coarse particles grinds.

6. adding binary or multiple-addition agent make its modification satisfy coating level titanium white needs in aftertreatment (12) process.50～70 ℃ of treatment temps, promoter addition is pressed TiO ₂Weight is calculated, and adds by 0.5%～3% prescription

7. the intact slurries of aftertreatment second dehydration (14) again behind two-stage filtration (13), dry (15) then, 120～160 ℃ of temperature, charging is moisture less than 45%, and discharging is moisture less than 1%

8. dry (15) back material carries out micronizing (16), and mean particle size accounts for 70% below 0.3 μ m, and packing is finished product (17).

The advanced operation of technology of the present invention serialization, product performance are stable, and the quality height is of many uses, and extremely the user welcomes.

Claims (1)

1. the technology of a rutile-type titanium dioxide powder prepared by plasma chlorination process, mainly through comprising the fluidizing chlorination in chlorination furnace with titanium slag and refinery coke (coke), separation is removed impurity and is obtained pure titanium tetrachloride liquid for it, and the vaporization back feeds in the oxidized still, high temperature oxidation in the presence of compound modifying agent, reaction product titanium dioxide grinds through the making beating sorting, passes through coating again, filter, drying, micronizing is characterized in that

(1). with titanium slag (TiO ₂)＞90%) with coke (proportioning is 100: 30-50) uniform mixing, in the chlorination furnace of major diameter sieve plate (1-1.2M), feed chlorine (＞92%), under 800～900 ℃ of temperature, carry out fluidizing chlorination;

(2). insoluble impurities is removed in natural sedimentation, and fractionating process is removed high boiling material silicon, and removes the impurity vanadium with reduction or extraction process, obtains 99.9% refining four titanium oxide;

(3). the compound modifying agent aluminum chloride becomes gas phase through the gas phase producer and enters low gas velocity scraper oxidizing reaction stove or do not have scraper grit blast oxidizing reaction stove again with after 450-800 ℃ of the gas phase titanium tetrachloride mixing preheating, feeding is by the high temperature ion-oxygen of 2000-3000 ° of K of 40-400KW plasma generator generation, in less than 0.1 second, carry out oxidizing reaction and generate solid phase titanium dioxide, remove reaction product and reaction heat rapidly;

(4). the water making beating, the two-stage sorting, the one-level vibratory screening apparatus, the one-level spinning liquid separates, and collects the fine particle less than micron;

(5). used additives (titanium, aluminium or silicon) coating, PH=7-8, wherein auxiliary agent and titanium dioxide proportioning are 0.5-3%, filter, discharging is moisture less than 1%, and is dry down at 120～160 ℃.Packing is the rutile titanium dioxide product.