CN101016167A

CN101016167A - Process of preparing high-purity TiCl4 by preheating chlorine gas low-temperature chlorination method

Info

Publication number: CN101016167A
Application number: CN 200610041770
Authority: CN
Inventors: 朱作远
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-02-09
Filing date: 2006-02-09
Publication date: 2007-08-15

Abstract

The invention discloses a low-temperature chlorinating method to make high-purity TiCl4 through preheating chlorine, which comprises the following steps: 1. kneading rutile, coke powder, catalyst, foaming agent and adhesive into ball; drying into dry heat titanium ore ball; 2. adding dry heat ore ball into vertical typed low-temperature chlorinating furnace; preheating chlorine gas under 470+-50 deg.c; producing TiCl4 steam; dedusting; filtering; condensing; obtaining the rough liquid of TiCl4 and residual gas with Cl2 through BaS (or FeCl2) to produce BaCl2 and S deg (or FeCl3); sintering residual CO2+CO in the furnace; 3. Obtaining rough liquid of TiCl4; rectifying; obtaining high-purity TiCl4; 4. Preheating Cl2; 5. Entering into low-temperature chlorinating furnace.

Description

High-purity TiCl by low-temperature chlorination with preheated chlorine4Production technology

(I) technical field

The invention belongs to the production technology of inorganic chemicals, in particular to a method for preparing high-purity TiCl by low-temperature chlorination by preheating chlorine gas₄A production technology.

(II) technical background

TiCl₄In large-scale industrial production, rutile (or artificial rutile, titanium-rich slag) and Cl are used₂The gas directly reacts at thetemperature of 900 +/-50 ℃, and the reaction equipment is a fluidized bed furnace and an electric heat source and is mature; however, if the production is carried out in a small scale, the investment is too large, the cost is very high, and the method is not suitable. Takes IT industry as a representative of the rapid development of new technology, nano BaTiO₃、SrTiO₃Nano TiO called electronic ceramic column and its widely used₂Production of high purity TiCl is urgently needed₄As a titanium source. It is desirable to have batches of moderately high purity TiCl₄The production lines have small requirements on the tonnage in batches, have high requirements on the purity, are produced in China without goods and are expensive to import, the invention is produced by the future Su Union's book of inorganic salt technology' M.E wave, et al, Chinese edition in 1981, organization and translation of Tianjin chemical research and design institute, and 437-year 446 article, and the invention combines with the miniaturization requirement to make the focusing ratioCorrection, and also bulking agent, binder addition improvement, especially for Cl₂The corrosion resistance of the gas low-temperature preheating device is the most difficult problem of the technology, and TiCl is produced by chlorination₄Is an exothermic reaction, consumes little direct heat, and is Cl₂The air volume weight is nearly 2.5 times of that of air, the specific heat is less than half of that of air, the heat conductivity coefficient is very small, the corrosion is extremely strong, and the key of the invention is its conquer. The invention is put into production and is nano TiO produced in China₂、BaTiO₃、SrTiO₃Large-scale production and provides cheap high-purity TiCl₄The product becomes possible, and the industrial scale production is no precedent in theory.

Disclosure of the invention

The process of the invention is that ① contains TiO₂More than or equal to 90 percent of rutile (or artificial rutile, TiO)₂More than or equal to 70 percent of titanium-rich slag) is pulverized into less than or equal to 0.074mm as a Ti source; coke powder with C more than or equal to 80 percent, ash less than or equal to 10 percent and granularity less than or equal to 1mm is used as a reducing agent; containing MnO₂More than or equal to 70 percent of pyrolusite powder or artificial MnO₂Powder with the diameter less than or equal to 0.074mm is used as a catalyst; causticized starch is used as an adhesive; grass sawdust or pulp cake with the diameter less than or equal to 1mm is used as a loosening agent; 1000 kg of rutile powder, 250 kg of coke powder and MnO₂1.5-2 kg of starch, 30 kg of starch, 3kg of NaOH and 10-30 kg of Na₂CO₃As an auxiliary agent, 40 kg of a bulking agent is used as an optimal mixture ratio; adding starch into 140 liters of cold water, adding NaOH and Na under stirring₂CO₃Introducing steam, heating to boil, causticizing for 15 min, and making into adhesive. Rutile powder, coke powder and MnO at the same time₂Mixing powder and a loosening agent well, adding an adhesive, kneading and pressing into titanium ore pellets of-30-50 mm, adding wet titanium ore pellets into a drying preheater, controlling airflow to dry and dewater at 450 ℃ of 350-plus-material, carbonizing starch and the loosening agent, increasing specific surface area, preheating to 350 ℃ of 300-plus-material to obtain preheated titanium ore pellets, adding ② 300-plus-material preheated titanium ore pellets at 350 ℃ into a vertical chlorination furnace, introducing 470 +/-50 ℃ chlorine at the bottom of the furnace, performing low-temperature chlorination, and reacting: taking kcal as a main reaction; produce TiCl₄The gas is pumped out of the hearth from the upper part of the material column by negative pressure, filtered by a mineral wool layer through a cyclone dust collector, enters a condenser and is condensed into liquid coarse TiCl₄Recovering residual gas containing residual Cl₂、CO₂、N₂And CO gas is circulated by a hydraulic ejector to absorb Cl in two stages by BaS liquid₂Reaction of Cl₂+BaS→BaCl₂+ S ° residual Cl₂Gas with BaCl₂Is recycled to produce a byproduct of elemental sulfur S DEG, and can also be used as FeCl₂Recovering residual Cl from Al slurry₂By-product FeCl₃And AlCl₃Utilization, final discharge of CO₂Introducing the CO mixed gas into a furnace, burning and emptying, and ③ collecting TiCl₄Rectifying the crude liquid for 2-3 times, wherein H is added before the second rectification₂S changes the chemical valence of V into insoluble component, and after the rectified gas is passed through the active carbon adsorption and purification, it is condensed to obtain TiCl-containing gas₄Not less than 99.99 percent, does not reach the standard, can be rectified once again, and can be purified once again by the adsorption of the active carbon, so that the product can be ensured to contain TiCl₄High purity product of more than or equal to 99.99-99.999%, the equipment and process parameters are ready and detailed, ④ Cl₂Preheating gas: the coke with 600 deg.c temperature and heat capacity is filled into steel tank with clay refractory brick lining and heat insulating layer outside, coke block of 10-50mm in size and preheating layer of 1-1.3m in thickness, and the steel tank may be sealed and has temperature measuring device. Introduction of Cl₂Introducing Cl into the gas₂Drying air in a volume of 1/2, the air being dried over a layer of granular quicklime, Cl₂+ O in the air when the air is introduced into the preheated coke₂First reacts with hot carbon to generate CO₂And then CO₂Is reduced to CO, and heat, CO and Cl are released₂The mixture is preheated to about 500 ℃ and enters a chlorination furnace. At 3kmol/h TiCl₄Productivity meter, Cl₂Direct utilization rate of 70% is measured, and Cl is supplied₂Qi 600kg/h or 190Nm³/h Cl₂Air, at the same time, 95Nm of dry air should be inhaled³H, production of COThe discharged heat is enough to maintain the temperature of the preheated coke layer constant if the coke layer is preheated Cl₂The temperature of the gas is reduced to be less than 470 ℃, and oxygen can be enriched or added to increase the temperature. After the coke layer is consumed, the coke can be added and discharged at regular time, which is not described in detail. Preheated Cl₂The temperature of the gas is adjusted to 470 +/-50 ℃ before entering the chlorination furnace, the chlorination is too slow at the temperature of less than 420 ℃, and MnO is more than 520 DEG C₂The catalyst is greatly deactivated, the chlorination speed is greatly reduced along with the deactivation, the chlorination speed is not good, and rich O is introduced₂Or increasing and decreasing the air ventilation amount and adjusting the preheating temperature ⑤ vertical chlorination furnace is based on the productivity of 3kmol/h, the height of the furnace bottom is 0.8m, the distance from the inner 1m to the discharge port is 0.3m, a star valve is arranged to control a slag outlet, the slag outlet is immersed in water and sprayed with Cl₂The height from the air port to the top of the stock column is 2.5 meters, the height from the bottom of the stock column to the top of the stock column is 1m, the space from the bottom of the stock column to the top of the furnace is O.5m, the height from the bottom of the stock column to the top of the furnace is 1m, one side of the straight cylinder is provided with an exhaust pipe, and the exhaust pipe is used for dedusting and₄the hydraulic ejectors are connected in series, the height between the discharging bell and the upper water seal movable cover of the charging bell is 0.5m, the inner part is 0.6m, the water seal movable cover is opened when charging, the charging is closed, the hydraulic ejectors provide suction force to the whole furnace, and the furnace is in a negative pressure state, namely Cl₂Gas does not leak, and there are temperature, pressure, gas monitoring and sampling device and Cl₂Automatic Cl monitoring device for gas leakage sensitive element₂Contamination, automatic control of pressure vessel valves, if necessary spraying Ca (OH)₂+ NaOH mixed liquor for eliminating Cl leakage in workshop₂Gas harm, safe production can be guaranteed; pressing wet titanium ore pellet, drying and dehydrating by hot gas at 350-450 ℃, preheating, removing free water completely, carbonizing grass and wood chip starch, removing most of volatile components, maximizing the strength of the pellet at 350 ℃, reducing the volume weight from 1.5kg/L to 1.3kg/L, and carbonizing organic components to reduce the porosity and Cl in the pellet₂The specific surface area of the reaction is increased by tens of times, so that the reaction speed is greatly improved, and MnO is₂Under the catalysis, the reaction is particularly good, the reaction is sharply accelerated along with the temperature increase from 420 → 470 ℃, and when the temperature is higher than 520 ℃, due to MnO₂The catalyst deactivation is greatly reduced, and is characterized by low-temperature chlorination and hot Cl₂The reaction is accelerated by adding a small amount of CO gas into the furnace. The titanium ore mass stays in the effective chlorination layer for 6 to 7 hours under the hearth, and TiO₂The chlorination rate is generally more than 95 percent, and Na is added into the furnace charge₂CO₃Can reduce iron chlorination, and can reduce Na content in rutile₂CO₃Adding Na in addition to ilmenite₂CO₃After full chlorination, slag discharged from the furnace is only less than the weight of titanium ore 1/4, is loose, is mostly pressed into powder when passing through a slag discharge star valve, is directly filled with water, and is sealed by water and added with paraffin oil and airIsolated, water-cooled, non-combustible and non-chlorinated paraffin, slag-in water, MgCl₂、GaCl₂、NaCl₂Dissolving, treating, adhering clay refractory brick and steel shell with foam insulating brick, pearlite powder and water glass as insulating layer, and TiCl₄The recovery and rectification set is the same as the traditional process, is small and is more rectified once. Recovery of TiCl₄The liquid is stored in a water-cooled tank shell at the temperature of less than or equal to 15 ℃, and the description is omitted because the method is the same as the traditional method.

Claims

The process of the invention is as follows:

① containing TiO₂More than or equal to 90 percent of rutile (or artificial rutile, TiO)₂More than or equal to 70 percent of titanium-rich slag) is pulverized into less than or equal to 0.074mm as a Ti source; coke powder with C more than or equal to 80 percent, ash less than or equal to 10 percent and granularity less than or equal to 1mm is used as a reducing agent; containing MnO₂More than or equal to 70 percent of pyrolusite powder or artificial MnO₂Powder with the diameter less than or equal to 0.074mm is used as a catalyst; causticized starch as binder, Na₂CO₃As an auxiliary agent; grass sawdust or pulp cake with the diameter less than or equal to 1mm is used as a loosening agent; 1000 kg of rutile powder, 250 kg of coke powder and MnO₂1.5-2 kg of starch, 30 kg of starch, 3kg of NaOH and 10-30 kg of Na₂CO₃40 kilograms of bulking agent is used as the optimal mixture ratio; adding starch into 140 liters of cold water, adding NaOH and Na under stirring₂CO₃Introducing steam, heating to boil, causticizing for 15 min, and making into adhesive. Rutile powder, coke powder and MnO at the same time₂Mixing the powder and the loosening agent, adding an adhesive, kneading, and pressing into titanium ore pellets with the diameter of 30-50 mm; adding the wet titanium ore pellet into a drying preheater, controlling airflow to dry and dewater at the temperature of 350-;

② 300 preheating titanium ore pellets at 350 ℃, adding the titanium ore pellets into a vertical chlorination furnace, introducing chlorine gas at 470 +/-50 ℃ into the furnace bottom, and carrying out low-temperature chlorination reaction:taking kcal as a main reaction; produce TiCl₄The gas is pumped out of the hearth by negative pressure from the upper part of the material column,the dust is filtered by a mineral wool layer through a cyclone dust collector and then enters a condenser to be condensed into liquid coarse TiCl₄Recovering residual gas containing residual Cl₂、CO₂And CO gas is circulated by a hydraulic ejector to absorb Cl in two stages by BaS liquid₂Reaction of Cl₂+BaS→BaCl₂+ S ° residual Cl₂Gas withBaCl₂Is recycled to produce a byproduct of elemental sulfur S degrees (FeCl can also be used)₂Recovering residual Cl from Al slurry₂By-product FeCl₃And AlCl₃Utilization), and finally CO is discharged₂Feeding the CO mixed gas into a combustion furnace to burn out and exhaust;

③ collecting TiCl₄Rectifying the crude liquid for 2-3 times, wherein H is added before the second rectification₂S changes the chemical valence of V into insoluble component, and after the rectified gas is passed through the active carbon adsorption and purification, it is condensed to obtain TiCl-containing gas₄Not less than 99.99 percent, does not reach the standard, can be rectified once again, and can be purified once again by the adsorption of the active carbon, so that the product can be ensured to contain TiCl₄The product is a high-purity product with the purity of more than or equal to 99.99-99.999 percent, the equipment and process parameters are ready, and details are not repeated;

④Cl₂preheating gas: the coke with 600 deg.c temperature and heat capacity is filled into steel tank with clay refractory brick lining and heat insulating layer outside, coke block of 10-50mm in size and preheating layer of 1-1.3m in thickness, and the steel tank may be sealed and has temperature measuring device. Introduction of Cl₂Introducing Cl into the gas₂Drying air in a volume of 1/2, the air being dried over a layer of granular quicklime, Cl₂+ O in the air when the air is introduced into the preheated coke₂First reacts with hot carbon to generate CO₂And then CO₂Is reduced to CO, and heat, CO and Cl are released₂The mixture is preheated to about 500 ℃ and enters a chlorination furnace. At 3kmol/h TiCl₄Productivity meter, Cl₂Direct utilization rate of 70% is measured, and Cl is supplied₂Qi 600kg/h or 190Nm³/h Cl₂Air, at the same time, 95Nm of dry air should be inhaled³H, CO production and heat release are enough to maintain the temperature of the preheated coke layer constant, if the coke layer is preheated Cl₂The temperature of the gas is reduced to be less than 470 ℃, and oxygen can be enriched or added to increase the temperature. After the coke layer is consumed, the coke can be added and discharged at regular time, which is not described in detail. Preheated Cl₂The temperature of the gas is adjusted to 470 plus or minus 50 ℃ before entering the chlorination furnace, and the chlorination is carried out at the temperature of less than 420 DEG CToo slow, MnO>520 ℃₂The catalyst is greatly deactivated, the chlorination speed is greatly reduced along with the deactivation, the chlorination speed is not good, and rich O is introduced₂Or the amount of ventilation is increased or decreased, and the preheating temperature can be adjusted;

⑤ vertical chlorination furnace with the productivity of 3kmol/h and the bottom height of 0.8m_{Inner part}1m to a discharge port to be collected as_{Inner part}0.3m, star valve controlling the slag outlet, immersing the slag outlet in water, spraying Cl₂The gas port is arranged at the top of the stock column, the height is 2.5m, and the column is straight_{Inner part}1m, the space from the bottom of the charging column to the charging bell at the top of the furnace is 0.5m high, and the charging bell is straight_{Inner part}1m, one side of the dust collector is provided with an exhaust pipe, and dust removal and TiCl recovery are carried out₄The hydraulic ejector is connected in series, and the height between the blanking bell and the water seal movable cover on the blanking bell is 0.5m_{Inner part}0.8m, the movable cover is opened when water seal feeding is carried out, the feeding is closed, the whole furnace is provided with pumping force by a hydraulic ejector and is in a negative pressure state, Cl₂Gas does not leak, and has temperature, pressure, gas sampling device and Cl₂Automatic Cl monitoring device for gas leakage sensitive element₂Contamination, automatic control of pressure vessel valves, if necessary spraying Ca (OH)₂+ NaOH mixed liquor for eliminating Cl leakage in workshop₂Gas harm, safe production can be guaranteed; pressing wet titanium ore pellet, drying and dehydrating by hot gas at 350-450 ℃, preheating, removing free water completely, carbonizing grass and wood chip starch, removing most of volatile components, maximizing the strength of the pellet at 350 ℃, reducing the volume weight from 1.5kg/L to 1.3kg/L, and carbonizing organic components to reduce the porosity and Cl in the pellet₂Inverse directionThe specific surface area is increased by tens of times, so that the reaction speed is greatly improved, and MnO is₂The reaction is particularly good under the catalysis, the reaction is sharply accelerated along with the temperature increase from 420 → 470 ℃, and the hot Cl₂Little CO content, faster reaction, at a temperature of more than 520 ℃, due to MnO₂The catalyst is deactivated and greatly reduced, and is characterized by low-temperature chlorination. The titanium ore mass stays in the effective chlorination layer for 6 to 7 hours under the hearth, and TiO₂The chlorination rate is generally more than 95 percent, after full chlorination, the discharged slag is only not enough than 1/4 titanium ore volume weight, is loose, is mostly pressed into powder when passing through a slag discharge star valve, is directly put into water, water seal is isolated from air by adding paraffin oil, water cooling is carried out, paraffin is not combusted and is not chlorinated, and the material mass containsNa₂CO₃Can reduce iron chlorination product, ilmenite Na chloride₂CO₃Adding 30 kg/ton of the powder, adding water into the slag, and adding MgCl₂、CaCl₂、NaCl₂Dissolving, and optionally treating.

The process is superior to prior methods in which ①②④⑤ content, requesting intellectual property protection.