Titanium sponge production process
1. Titanium sponge
It is a sponge-like metal titanium produced by metal thermal reduction and is the raw material for titanium processing materials. It is extracted from rutile ilmenite and turned into various titanium alloy materials after smelting and forging. According to different purity, sponge titanium can be divided into seven grades, one to five, as well as grade 0 and grade 0A. The titanium content ranges from 98.5 to 99.7. The smaller the number, the higher the titanium content.
The grade classification of titanium sponge is mainly classified according to its chemical composition, porosity and strength. The specific classification is as follows:
According to the chemical composition and Brinell hardness, titanium sponge products can be divided into 7 brands ( grades): MHT-95, MHT-100, MHT-110, MHT-125, MHT-140, MHT-160, MHT-200.
According to porosity and adsorption capacity, titanium sponge can be divided into two grades: low porosity and high porosity. Low-porosity titanium sponge has better breathability, while high-porosity titanium sponge has a larger surface area and better adsorption capacity.
According to the strength level, titanium sponge can be divided into different grades. Titanium sponge with higher strength can withstand greater force, has better durability and anti-deformation ability, and is suitable for some light load or low pressure application scenarios. Titanium sponge with lower strength is suitable for some light load or low pressure applications.
2. Titanium sponge is mainly divided into full process and semi-process processes:
The whole process process mainly includes three processes: chlorination refining, reduction distillation, and magnesium electrolysis. First, titanium-rich materials are chlorinated and refined to produce titanium tetrachloride, and then titanium tetrachloride is reduced with magnesium to obtain titanium sponge. Finally, electrolysis is used to reduce the magnesium chloride generated in the reduction step to chlorine gas and magnesium for recycling.
The semi-process process directly purchases refined titanium tetrachloride and produces titanium sponge after reduction, omitting the chloride refining and magnesium electrolysis processes. Since magnesium does not participate in the cycle, the cost of semi-process titanium sponge is generally higher.
3. Substances used in the production of titanium sponge:
Depending on the production process, different types and quantities of waste and products may be generated. Generally speaking, during the production of titanium sponge, both gaseous wastes, such as chlorine, hydrogen chloride and titanium tetrachloride, and solid wastes such as halides are generated. Most of these wastes need to be properly treated or recycled to ensure the safety and environmental protection of the production process.
In addition, a large amount of wastewater will be generated during the production process of titanium sponge. These wastewaters mainly contain substances such as hydrogen chloride and titanium tetrachloride, which need to be treated to meet discharge standards or recycling standards.
4. Secondary alkali washing treatment process
It is an improved alkali washing desulfurization method, which uses two continuous scrubbers for desulfurization. In the first-stage scrubber, the raw gas contacts the alkali solution, causing a gas-liquid reaction. The sulfur dioxide reacts with the hydroxide in the alkali solution to form thiosulfate. Commonly used alkali solutions include sodium hydroxide solution (NaOH) and sodium carbonate solution (Na2CO3). The chemical equation of this reaction is SO2 + NaOH → NaHSO3.
5. Working principle of caustic soda molten salt furnace
It utilizes the heat exchange between combustion gas and molten salt to conduct heat energy through hot salt flow circulation. Specifically, the salt material is heated to its melting point to form molten salt, and the thermal energy in it is stored in a thermal storage device. The thermal energy in the molten salt is then used to generate high-temperature and high-pressure steam, which is converted into electrical energy. Finally, the remaining hot and cold brine is returned to the molten salt furnace for heating to achieve recycling of heat energy. This working principle makes the caustic soda molten salt furnace an efficient and environmentally friendly energy conversion equipment that can be widely used in many fields, such as solar thermal power generation, industrial heating, etc.
6. Treatment method of industrial salt drying dust
Physical method: Make use of the solubility difference between industrial salt and sodium chloride to make a saturated solution of potassium nitrate. After cooling, most of it will become a crystalline precipitate, while sodium chloride will be in the mother liquor. , separate the filtered crystals from the mother liquor.
Chemical method: First dissolve industrial salt in water to make a solution, add excess silver nitrate solution, silver ions react with chloride ions to form silver chloride precipitate, then add excess hydrochloric acid to the solution to precipitate excess silver ions, and filter. Finally, the filtered solution is heated to remove excess hydrochloric acid.
Chlorination waste salt is the waste generated in the molten salt chlorination process, mainly salt-containing waste and salt residue. The generation of these wastes is an inevitable product of the chlorination process, and their components and composition are related to the chlorination raw materials and solvents used. The treatment methods of chlorinated waste salt include crushing, alkali reaction, filter press, precision filtration, ultrafiltration and other steps. The products obtained during the treatment process can be utilized as resources. For example, the iron-titanium slag obtained by press filtration can be utilized as resources or stacked as general waste. The sodium chloride brine obtained by ultrafiltration can be used as raw material for the process of preparing caustic soda by ion membrane electrolysis or Solid salt is obtained after evaporation and recovery.
The main differences between the sponge titanium chloride exhaust gas treatment system and the electrolytic magnesium exhaust gas treatment system are as follows:
The chlorination tail gas treatment system mainly treats the waste gas generated in the chlorination workshop, which mainly includes acidic gases such as chlorine and hydrogen chloride. In order to achieve the purification and discharge of waste gas, the system will perform alkali washing treatment, convert acidic gases into salt substances through chemical reactions, and realize the discharge of waste gas.
The electrolytic magnesium tail gas treatment system mainly treats the waste gas generated in the electrolytic magnesium workshop, which mainly includes chlorine gas and magnesium vapor. In order to purify and discharge exhaust gas, the system will perform dust removal, condense magnesium vapor into magnesium particles, and collect chlorine gas for reuse. At the same time, the system will also perform gas diffusion control to effectively control the magnesium vapor that has not been dust-removed in the exhaust gas inside the workshop and prevent it from spreading to the environment outside the workshop.
In general, the main difference between the sponge titanium chloride tail gas treatment system and the electrolytic magnesium tail gas treatment system lies in the different waste gas components and treatment methods.
7. Sponge titanium chloride tail gas treatment process and electrolytic magnesium tail gas treatment process :
The sponge titanium chloride tail gas treatment process mainly includes the following steps:
Wet purification treatment : First, the waste gas needs to be treated by wet purification. This step mainly involves sending the waste gas into the purification equipment and spraying it with water for washing. During this process, HCl and NaCl will dissolve in water, and TiCl4 will hydrolyze, washing solid dust particles into the water. Purification equipment can use washing towers, centrifugal scrubbers, spray absorption towers and foam dust collectors, etc.
Dechlorination: In order to further remove chlorine, different methods can be used depending on the concentration of chlorine. When the chlorine concentration in the exhaust gas is low, milk of lime (Ca(OH)2) is often sprayed, and the chlorine reacts with the milk of lime to generate Ca(ClO)2. If the chlorine concentration in the exhaust gas is low but the tail gas volume is large, NaOH or Na2CO3 is often used for spraying, and the chlorine will react with them to form NaClO, which can be used as bleaching powder. If the chlorine concentration in the exhaust gas is high but the tail gas volume is small, FeCl2 spray can be used to absorb the chlorine. In this process, the FeCl2 eluent is prepared by reacting iron filings with HCl in advance. After elution, FeCl3 is generated. FeCl3 is added with iron filings and reduced to FeCl2 for recycling.
The electrolytic magnesium tail gas treatment process mainly includes the following steps:
Magnesium electrolysis: The electrolysis workshop will electrolyze the magnesium chloride produced in the reduction workshop to produce magnesium and chlorine gas. The magnesium produced by electrolysis is sent to the reduction workshop as a reducing agent for the production of titanium sponge, while the chlorine gas is sent to the chlorination workshop for the production of titanium tetrachloride.
Electrolysis and re-steaming tail gas treatment : The electrolysis and re-steaming tail gas treatment system carries the functions of purifying and discharging acidic waste gases in the magnesium electrolysis system and the re-steaming workshop. These acidic waste gases are mainly composed of chlorine and hydrogen chloride.
8. Pollutants are produced during the chlorination process of titanium sponge:
Organic chlorides: such as titanium tetrachloride, chloroform, dichloromethane, etc. These organochlorides are often toxic and may cause environmental pollution.
Inorganic chlorides: such as chlorine, hydrogen chloride, etc. These inorganic chlorides are also toxic and may cause environmental and biological hazards.
Other pollutants: Some other pollutants may be produced during the chlorination process, such as phosgene (COCl2), which are also toxic substances.
9. Oxidation principle of sponge titanium chloride exhaust gas treatment system:
Mainly under certain temperature and pressure conditions, the oxygen in the air is used to oxidize titanium tetrachloride in the exhaust gas into titanium dioxide. Specifically, the oxidation reaction process can be divided into the following steps:
Chlorine reacts with oxygen to form chlorate ions: Cl2+O2=2ClO3
Chlorate ions react with titanium tetrachloride to form titanium dioxide and chlorine: TiCl4+2ClO3=TiO2+2Cl2+O2
This process is carried out at a certain temperature (such as 600-800 degrees) and pressure (normal pressure). At the same time, a catalyst (such as vanadium pentoxide, etc.) needs to be added to reduce the reaction activation energy and promote the reaction. The resulting titanium dioxide can be recycled as a by-product, while the chlorine can be reused in chlorination production.
It should be noted that the oxidation process is carried out under certain temperature and pressure conditions, so the reaction conditions need to be strictly controlled, and attention should be paid to the recycling of chlorine in the exhaust gas to reduce production costs and environmental pollution.
10. The relationship between high-end titanium and titanium alloys and titanium sponge:
First of all, high-end titanium and titanium alloys refer to titanium and titanium alloys with excellent properties and special uses, such as high strength, high toughness, corrosion resistance, high temperature performance , etc. Titanium sponge is a titanium alloy produced by the reaction of titanium tetrachloride and magnesium. It is usually used as a raw material for the production of high-end titanium and titanium alloys.
Specifically, the relationship between high-end titanium and titanium alloys and titanium sponge is mainly reflected in the following aspects:
Raw materials : Titanium sponge is one of the raw materials for the production of high-end titanium and titanium alloys. By further processing and alloying titanium sponge, high-end titanium and titanium alloys with excellent properties can be produced.
Production process: The production processes of high-end titanium and titanium alloys are similar to those of titanium sponge, which require a series of smelting, processing and heat treatment. However, the production process of high-end titanium and titanium alloys is more complex and sophisticated, requiring higher technical requirements and stricter quality control.
Application fields: High-end titanium and titanium alloys are mainly used in aerospace, military, petrochemical and other fields, and have a wide range of uses. Titanium sponge is mainly used to produce high-strength, corrosion-resistant titanium alloy parts required in aerospace, automobiles and other fields.
In general, there is a close relationship between high-end titanium and titanium alloys and titanium sponge. There are certain similarities between their production processes, raw materials and application fields, but in terms of production technology, product performance and application fields There are also certain differences.
11. The process flow of high-end titanium purification is as follows:
High-purity titanium dioxide is selected as the raw material, and a reducing agent is added for reduction treatment.
The reduced titanium dioxide is pickled to remove impurities.
After pickling, the titanium dioxide is washed with water and dried, and then a reducing agent is added for high-temperature reduction.
The reduced titanium sponge is crushed and ground to obtain fine particle titanium sponge.
Fine-grained sponge titanium is smelted at high temperatures and vacuum smelting technology is used to remove impurities and gases.
After refining, the titanium sponge is continuously cast and die-cast to obtain high-purity titanium ingots.
Using high-temperature forging technology, titanium ingots are forged at high temperatures to obtain high-purity titanium materials.
