CN105132936B - One kind prepares CaTiO with fused salt electrolysis process from ilmenite3The method of powder - Google Patents

Abstract

The invention relates to a method for preparing _CaTiO3 powder from ilmenite by molten salt electrolysis, belonging to the technical field of nonferrous metallurgy. Under an inert atmosphere, mix CaO, _NaCl and CaCl uniformly and heat up to obtain a completely molten molten salt, add ilmenite accounting for 1% to 15.2% of the mass fraction of molten salt to the molten salt and mix uniformly to obtain an electrolytic molten salt; Place the electrolytic molten salt in the electrolytic cell, use the molybdenum rod as the cathode, control the molybdenum rod not to touch the ilmenite at the bottom of the electrolytic cell, and use the graphite rod as the anode to electrolyze for 6-8 hours, take out the product at the bottom of the electrolytic cell, and pass through 1wt.% HCl solution After steps such as filtering out impurities in the product, rinsing with deionized water and drying, the _CaTiO3 powder was obtained. The method aims to solve the problems of high reaction temperature, long process flow, high energy consumption and the like in the production process of the prior art of CaTiO ₃ .

Description

A method for preparing CaTiO3 powder from ilmenite by molten salt electrolysis

technical field

The invention relates to a method for preparing _CaTiO3 powder from ilmenite by molten salt electrolysis, belonging to the technical field of nonferrous metallurgy.

Background technique

Calcium titanate (CaTiO ₃ ), as a new type of inorganic non-metallic material of perovskite composite oxide ABO ₃ , has a stable crystal structure, unique electromagnetic properties and high redox, photocatalytic and electrocatalytic activities. , It has a wide range of applications in microwave dielectric ceramics, photocatalytic reduction and other fields.

At present, the production methods of CaTiO ₃ mainly include solid phase sintering method, mechanochemical synthesis method, soft chemical method and so on. Among them, the solid-phase sintering method uses _TiO2 and corresponding metal carbonates or oxides as raw materials, and crystallizes through pre-sintering, re-sintering, cooling and other steps to obtain titanate powder, but the grain size synthesized by this method is It is greatly affected by the sintering temperature, has high requirements for raw materials, and consumes a lot of energy, so it is not suitable for wide application. The mechanochemical synthesis method is to obtain the precursor after passing the raw material through high-energy ball milling for a certain period of time, and then obtain it after high-temperature sintering. However, this method is significantly affected by the milling time and is not widely used. Soft chemical methods mainly include sol-gel (sol-gel) method, molten salt (solvent) method, etc. These methods can prepare ultrafine composite oxide powder with uniform composition, but the reaction cycle is long and the process conditions are not easy. Control, yield less.

The preparation of metals and alloys by molten salt electrolysis has a long history, the most typical representative of which is the production of aluminum by Bayer method electrolysis of cryolite-alumina as raw material. Since the 20th century, the emergence of a new generation of molten salt electrolysis method represented by FFC method and a new type of molten salt method represented by SOM method has injected new vitality into the research of molten salt electrolysis, especially in the preparation of refractory metals. In the process, the production process is greatly shortened, the cost is downgraded, and the requirements for the preparation of raw materials are lowered.

Chinese Patent Publication No. CN 102874866 A reports the preparation of flaky micron-sized calcium titanate crystals by using molten salt method combined with topological chemistry method. This method goes through two steps of precursor preparation and chemical synthesis in molten salt, which increases the reaction speed and shortens the preparation cycle, but the reaction temperature is high and impurities are easy to form.

Chinese Patent Publication No. CN 101792304 B reports the preparation of a composite perovskite structure ceramic material with good electrical conductivity and excellent corrosion resistance by a solid-state sintering method, but the reaction cycle of this method is long and the composition cannot be controlled.

Chinese Patent Publication No. CN 103159473 A provides a method for preparing microwave dielectric ceramic materials with dielectric constant, high Q, and adjustable frequency temperature coefficient. The main disadvantages of this method are long process flow and uneven grain size.

Contents of the invention

Aiming at the problems and deficiencies in the above-mentioned prior art, the present invention provides a method for preparing _CaTiO3 powder from ilmenite by molten salt electrolysis. The purpose of the method is to solve the problems of high reaction temperature, long process flow and high energy consumption in the production process of the prior art of CaTiO ₃ , and the present invention is realized through the following technical solutions.

_A method of preparing CaTiO powder from ilmenite by molten salt electrolysis, its concrete steps are as follows:

Step 1. Under an inert atmosphere, mix CaO, NaCl and CaCl ₂ according to the molar ratio (0.8-1): (8-12): (10-20) evenly and heat up to 650-850°C to obtain a completely molten molten salt , adding ilmenite accounting for 1% to 15.2% of the mass fraction of the molten salt to the molten salt and mixing evenly to obtain an electrolytic molten salt;

Step 2. Place the electrolytic molten salt in step 1 in the electrolytic cell, use the molybdenum rod as the cathode, control the molybdenum rod not to touch the ilmenite at the bottom of the electrolytic cell, and use the graphite rod as the anode, and then control the voltage of the cell at 2.8-3.2V, The electrolysis temperature is 650-850°C for 6-8 hours, the product at the bottom of the electrolytic cell is taken out, the impurities in the product are filtered through 1wt.% HCl solution, rinsed with deionized water and dried to obtain CaTiO ₃ powder.

The inert atmosphere is argon inert gas, wherein the purity of argon is >99.9%.

The ilmenite includes the following components in mass percentage: 31.6% titanium and 36.8% iron.

The beneficial effect of the present invention is: this method provides a kind of effective way that _CaTiO3 powder is prepared from ilmenite by molten salt electrolysis, and the obtained _CaTiO3 powder has high purity, and compared with existing solid phase method, greatly reduces The temperature of the reaction is reduced, the production cycle and process flow are shortened, and the source of ilmenite is abundant and the price is low. The energy consumption in the process of preparing CaTiO ₃ powder by electrolysis of ilmenite is low, and it is economical and environmentally friendly.

detailed description

The present invention will be further described below in combination with specific embodiments.

Example 1

This prepares _CaTiO3 powder method from ilmenite by molten salt electrolysis, and its concrete steps are as follows:

Step 1. Under an inert atmosphere, mix CaO, NaCl and _CaCl2 uniformly according to the molar ratio of 0.8:8:20 and raise the temperature to 650°C to obtain a completely molten molten salt. Add titanium with a mass fraction of molten salt of 1% to the molten salt Iron ore is mixed evenly to obtain electrolytic molten salt; the inert atmosphere is argon, with a purity >99.9%; ilmenite includes the following mass percentage components: titanium 31.6%, iron 36.8%;

Step 2. Put the electrolytic molten salt in step 1 in the electrolytic cell, use the molybdenum rod (purity ≥ 99.95%) as the cathode, control the molybdenum rod not to touch the ilmenite at the bottom of the electrolytic cell, use the graphite rod as the anode, and then control the voltage of the cell Electrolyze at 2.8V and electrolysis temperature of 650°C for 8 hours, take out the product at the bottom of the electrolytic cell, filter through 1wt.% HCl solution to remove impurities in the product, rinse with deionized water and dry to obtain CaTiO ₃ powder.

Example 2

This prepares _CaTiO3 powder method from ilmenite by molten salt electrolysis, and its concrete steps are as follows:

Step 1. Under an inert atmosphere, mix CaO, NaCl and _CaCl2 uniformly according to the molar ratio of 1:12:10 and raise the temperature to 850°C to obtain a completely molten molten salt. Add titanium with a mass fraction of molten salt of 15.2% to the molten salt Iron ore is mixed evenly to obtain electrolytic molten salt; the inert atmosphere is argon, with a purity >99.9%; ilmenite includes the following mass percentage components: titanium 31.6%, iron 36.8%

Step 2. Put the electrolytic molten salt in step 1 in the electrolytic cell, use the molybdenum rod (purity ≥ 99.95%) as the cathode, control the molybdenum rod not to touch the ilmenite at the bottom of the electrolytic cell, use the graphite rod as the anode, and then control the voltage of the cell Electrolyze at 3.2V and electrolysis temperature of 850°C for 6h, take out the product at the bottom of the electrolytic cell, filter through 1wt.% HCl solution to remove impurities in the product, rinse with deionized water and dry to obtain CaTiO ₃ powder.

Example 3

This prepares _CaTiO3 powder method from ilmenite by molten salt electrolysis, and its concrete steps are as follows:

Step 1. Under an inert atmosphere, mix CaO, NaCl and _CaCl2 uniformly according to the molar ratio of 1:10:15 and raise the temperature to 700°C to obtain a completely molten molten salt. Add titanium with a mass fraction of molten salt of 10% to the molten salt Iron ore is mixed evenly to obtain electrolytic molten salt; the inert atmosphere is argon, with a purity >99.9%; ilmenite includes the following mass percentage components: titanium 31.6%, iron 36.8%

Step 2. Put the electrolytic molten salt in step 1 in the electrolytic cell, use the molybdenum rod (purity ≥ 99.95%) as the cathode, control the molybdenum rod not to touch the ilmenite at the bottom of the electrolytic cell, use the graphite rod as the anode, and then control the voltage of the cell Electrolyze at 3.2V and electrolysis temperature of 700°C for 7h, take out the product at the bottom of the electrolytic cell, filter through 1wt.% HCl solution to remove impurities in the product, rinse with deionized water and dry to obtain CaTiO ₃ powder.

Example 4

This prepares _CaTiO3 powder method from ilmenite by molten salt electrolysis, and its concrete steps are as follows:

Step 1. Under an inert atmosphere, mix CaO, NaCl and _CaCl2 uniformly according to the molar ratio of 1:8:20 and raise the temperature to 700°C to obtain a completely molten molten salt. Add titanium with a mass fraction of molten salt of 15.2% to the molten salt Iron ore is mixed evenly to obtain electrolytic molten salt; the inert atmosphere is argon, with a purity >99.9%; ilmenite includes the following mass percentage components: titanium 31.6%, iron 36.8%;

Step 2. Put the electrolytic molten salt in step 1 in the electrolytic cell, use the molybdenum rod (purity ≥ 99.95%) as the cathode, control the molybdenum rod not to touch the ilmenite at the bottom of the electrolytic cell, use the graphite rod as the anode, and then control the voltage of the cell Electrolyze at 3.2V and electrolysis temperature of 700°C for 8 hours, take out the product at the bottom of the electrolytic cell, filter through 1wt.% HCl solution to remove impurities in the product, rinse with deionized water and dry to obtain CaTiO ₃ powder.

Example 5

This prepares _CaTiO3 powder method from ilmenite by molten salt electrolysis, and its concrete steps are as follows:

Step 1. Under an inert atmosphere, mix CaO, NaCl and _CaCl2 uniformly according to the molar ratio of 0.8:12:20 and raise the temperature to 750°C to obtain a completely molten molten salt. Add titanium with a mass fraction of molten salt of 10% to the molten salt Iron ore is mixed evenly to obtain electrolytic molten salt; the inert atmosphere is argon, with a purity >99.9%; ilmenite includes the following mass percentage components: titanium 31.6%, iron 36.8%;

Step 2. Put the electrolytic molten salt in step 1 in the electrolytic cell, use the molybdenum rod (purity ≥ 99.95%) as the cathode, control the molybdenum rod not to touch the ilmenite at the bottom of the electrolytic cell, use the graphite rod as the anode, and then control the voltage of the cell Electrolyze at 3.0V and electrolysis temperature of 750°C for 6h, take out the product at the bottom of the electrolytic cell, filter through 1wt.% HCl solution to remove impurities in the product, rinse with deionized water and dry to obtain CaTiO ₃ powder.

The specific embodiments of the present invention have been described in detail above, but the present invention is not limited to the above embodiments, and various changes can be made without departing from the gist of the present invention within the scope of knowledge possessed by those of ordinary skill in the art .

Claims (3)

_1. a method of preparing CaTiO powder from ilmenite by molten salt electrolysis, is characterized in that concrete steps are as follows: Step 1. Under an inert atmosphere, mix CaO, NaCl and CaCl ₂ according to the molar ratio (0.8-1): (8-12): (10-20) evenly and heat up to 650-850°C to obtain a completely molten molten salt , adding ilmenite accounting for 1% to 15.2% of the mass fraction of the molten salt to the molten salt and mixing evenly to obtain an electrolytic molten salt; Step 2. Place the electrolytic molten salt in step 1 in the electrolytic cell, use the molybdenum rod as the cathode, control the molybdenum rod not to touch the ilmenite at the bottom of the electrolytic cell, and use the graphite rod as the anode, and then control the voltage of the cell at 2.8-3.2V, The electrolysis temperature is 650-850°C for 6-8 hours, the bottom product of the electrolytic cell is taken out, the impurities in the product are filtered out through 1wt.% HCl solution, and the CaTiO ₃ powder is obtained after deionized water washing and drying steps. 2. The method for preparing _CaTiO3 powder from ilmenite by molten salt electrolysis according to claim 1, characterized in that: the inert atmosphere is argon inert gas, wherein the purity of argon is >99.9%. 3. The method for preparing _CaTiO3 powder from ilmenite by molten salt electrolysis according to claim 1, characterized in that: the ilmenite comprises the following components in mass percentage: 31.6% titanium and 36.8% iron.