CN108892177A - The method of laser-induced self-propagating reaction high―temperature nuclei cu ferrite material - Google Patents

Abstract

The invention discloses a method for laser-induced self-propagating high-temperature synthesis of copper ferrite materials. The method uses a laser to output laser light to induce the material, and the self-propagating reaction is regulated by the laser, which can effectively adjust the laser sintering power, sintering area and sintering time to inductively control the formation of the desired ferrite material at high temperature. The preparation method of the present invention is simple, and the reaction conditions and the original state can be adjusted in time to meet the product demand, the raw material utilization rate is high, there is no process waste, the product preparation cycle is short, and the product is controllable.

Description

Laser-induced self-propagating high-temperature synthesis of copper ferrite materials

technical field

The invention relates to a method for producing a copper ferrite material, in particular to a method for synthesizing a copper ferrite material by laser-induced self-propagation at high temperature.

Background technique

Copper ferrite belongs to a class of metal oxides in ferrite, and has the unique ferromagnetism of ferrite compounds. Copper ferrite is a semiconductor material with a spinel structure, and its structure and performance are stable. It has attracted much attention because of its good gas-sensing properties, electromagnetic properties, adsorption properties, and catalytic properties. In particular, spinel-type copper ferrite has good photocatalytic properties, such as narrow band gap, wide light absorption band and many other excellent characteristics, and has ferromagnetism that is easy to recycle. It has been often studied and applied in recent years. In the application field of wastewater treatment.

Since modern times, the demand for the treatment of a large amount of organic wastewater discharged in industrial production and life has become increasingly urgent. Among the emerging advanced oxidation technologies, photocatalytic oxidation is degradable, non-selective, normal temperature and pressure, non-toxic, and stable in chemical properties. , reusability, and the prospect of large-scale utilization of solar energy have attracted much attention. As a typical photocatalyst material, copper ferrite compound with spinel structure has many advantages such as small forbidden band width, no photocorrosion, and active catalytic performance.

The commonly used preparation methods of copper ferrite compounds are as follows: gas-phase chemical reaction method, sol-gel method, chemical co-precipitation method and solid-phase method. The general gas-phase chemical reaction method is suitable for experimental research, but its limited synthesis amount and high cost make it difficult for industrial production. The ferrite powder prepared by the sol-gel method is easy to form hard agglomeration phenomenon after drying, shrinks greatly during drying, is easy to crack, and the preparation steps are complicated. In the chemical co-precipitation method, colloidal precipitation often occurs during the precipitation process, which is difficult to filter and wash, and the precipitation is uneven. The solid-phase method has the characteristics of simple equipment and process, low cost, and large output, and the prepared powder particles have no agglomeration, but it also has disadvantages such as high energy consumption, difficult control, insufficient powder fineness, and easy mixing of impurities.

In summary, the preparation of copper ferrite materials is a major obstacle to the current research progress of copper ferrite, and people urgently need a simple, energy-saving, high-efficiency, controllable, and pollution-free formation of ferrite compounds. method.

Contents of the invention

The purpose of the present invention is to provide a method for laser-induced self-propagating high-temperature synthesis of copper ferrite materials. The method quickly and efficiently synthesizes copper ferrite products. The process is simple, energy-saving, and efficient, and the products are controllable and waste-free. pollutants are produced.

The concrete technical scheme that realizes the object of the invention is:

A method for laser-induced self-propagating high-temperature synthesis of copper ferrite materials, characterized in that copper, copper oxides, iron and iron oxides are used as raw materials, and laser-induced self-propagating reactions occur to make the raw materials react to form Cu ₂ O , the carrying out of catalytic synthesis process; Concretely comprise the following steps:

Step 1: Select the required raw material powder, and mix the raw material fully and evenly to obtain the mixed raw material;

Step 2: placing the mixed raw materials in a reaction vessel;

Step 3: Use laser light to irradiate the mixed raw materials, adjust the laser, and the laser induces a self-propagating reaction to generate the primary product of copper ferrite material;

Step 4: Grinding the initial product of the copper ferrite material to obtain a copper ferrite material with small particles and good uniformity; wherein:

The raw material powder described in step 1 is copper, copper oxide, iron and iron oxide, and the type and ratio of the raw material powder are selected according to actual product requirements; the fully uniform mixing is obtained by grinding and stirring. Granular powder, or compress uniformly mixed small particle powder;

The laser-induced self-propagating reaction described in step 3 controls the process speed, temperature, conversion rate, and product composition and structure by changing the heat release and transmission speed.

The laser is a continuous laser or a pulsed laser, and the output laser band is an infrared band; the spectral band of the laser is an infrared band, a visible light band or a mixed band of infrared and visible light.

The laser is irradiated on the mixed raw materials, and the irradiated area, power, and time are controlled by feedback adjustment, and the target product is generated according to the demand, and the process of preparing the generated product is localized and real-time controllable.

The adjustment laser refers to the laser control response output by the laser, which can focus the laser and control the spatial distribution of the sintering area, including laser space lattice and laser space scanning.

The gas control is carried out in the preparation environment, and the gas is N ₂ .

The invention adopts high-power laser to irradiate the surface of the raw material to control the self-propagating reaction induced by the laser. Using a high-power laser to output laser, the laser wavelength is the wavelength of the reactant absorption band, which is conducive to the heat absorption of the reactant to speed up the reaction process, realizes the laser-induced self-propagating reaction, and prepares copper ferrite materials in an energy-saving and efficient manner; through feedback adjustment to control the laser effect on The area, power, and time on the reactant can generate the target product according to the demand, and realize the real-time controllable localization of the process of preparing the product; use the Cu ₂ O generated in the reaction process to realize the catalysis of the reaction process and efficiently prepare the product.

The invention is applicable to the controllable preparation of copper ferrite materials by mixing various copper and iron oxide powders, and is applicable to the preparation of various raw materials and products with different requirements. The whole production process has simple steps, the self-spreading process is controllable, the preparation rate is high, and no waste is generated.

Description of drawings

Fig. 1 is a flowchart of the present invention;

Fig. 2 is the schematic diagram of the self-propagating combustion process of preparing copper ferrite material in the present invention;

Fig. 3 is an XRD pattern of the copper ferrite material prepared in the embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments and accompanying drawings.

The self-propagating combustion reaction induced by laser is used in the process of synthesizing copper ferrite material in the present invention, which is a technique for synthesizing materials by exothermic chemical reaction itself, also known as combustion synthesis, to prepare copper ferrite compounds The schematic diagram of the self-propagating combustion process is shown in Fig. 1. This synthetic process utilizes chemical reaction to release heat, which reduces the external heat source required in the process; the self-sustaining reaction of fast automatic wave combustion can obtain the desired composition and structure of the product, and the synthetic impurity content is low; The release and transmission speed are used to control the speed, temperature, conversion rate and product composition and structure of the process to achieve regulation and controllability.

Among the selected reactant raw materials, CuO can be decomposed into Cu ₂ O and O ₂ in a small amount at high temperature, expressed as Cu ₂ O has the function of catalytic combustion and can promote the reaction at high temperature.

Preferably, the raw materials of the reactants are selected from common compounds such as Cu, _CuO , _Fe2O3 , etc., all of which are solid powders.

Preferably, the selected laser is a continuous laser, and the output laser mode power is stable.

Preferably, a laser with an output wavelength of 980nm is used instead of a common heat source.

Preferably, the output spot of the laser is used, and the irradiation position of the laser spot is selected to realize the localization of the reaction area and realize the localized material generation.

Preferably, the laser power adjustment control is adopted, which can effectively control the local temperature of the reaction area in real time, and realize stable and reasonable heating and annealing temperature control.

Preferably, the comprehensive control of the power, sintering area and sintering time of the high-power laser can realize local high-temperature control with a predetermined effect and comprehensive regulation of the product generation process.

Preferably, gas control can be performed on the preparation environment, and the ambient gas is _N2 to ensure that the reaction synthesis process has no environmental gas influence.

Preparation of the laser-induced self-propagating high-temperature synthetic copper ferrite material:

The raw material powder is selected, and the type and ratio of the reactants can be changed according to the actual product requirements.

The prepared raw material powder is pretreated, and a uniformly mixed small particle powder is obtained by grinding and stirring. The powder can also be compressed into tablets upon request.

The self-propagating process is induced by laser irradiation, and the desired copper-ferrite material is synthesized at high temperature. The laser power of the high-power laser used can be adjusted according to the actual situation; the coverage area of the laser spot output by the laser can be adjusted according to the demand, and a part of the powder area can be selected to be covered, and the generation process is self-propagating and growing; according to the required purity and composition of the product, The laser power can be adjusted in real time, the sintering time can be changed, and the self-propagating reaction rate can be controlled; the laser can control the reaction intensity, and the reaction can be controlled in real time. This process can synthesize the target initial product.

The laser-induced primary product is processed. The initial product can be ground to obtain a product powder with uniform particles. Initial products can be screened according to product requirements.

A copper ferrite product whose particle size, uniformity and other properties meet requirements is obtained.

The self-propagating combustion process for the preparation of copper ferrite compounds is shown in Figure 2.

Example 1

According to the molar ratio of copper oxide: ferric oxide is 1:1, 3 grams of the two compound powders are weighed, wherein copper oxide is 1.000 g, and ferric oxide is 2.000 g. The weighed powders were placed in a mortar, mixed and thoroughly ground with a pestle, so that the powders of each compound were mixed evenly.

Spread the obtained mixed powder into a high temperature resistant container. The laser used is a continuous light semiconductor laser with a wavelength of 980nm and an output power adjusted to 61W. The output laser is irradiated on the surface of the powder, and the size of the spot is consistent with the size of the flat powder plane. After 60s, the laser was turned off, and a black agglomerate with the same size as the laser spot was formed.

Use tweezers to take out the initially generated product, and use a magnet to preliminarily judge that the generated product can be attracted and is a ferromagnetic substance. Put the primary product in a mortar and grind it thoroughly with a pestle. The product can be easily crushed and ground into small particles. After sufficient grinding, the product powder with uniform and fine particle size, that is, copper ferrite material, is obtained.

Example 2

According to the molar ratio of copper oxide: ferric oxide is 2:1, 3 grams of the two compound powders are weighed, wherein copper oxide is 1.500 g, and ferric oxide is 1.500 g. The weighed powders were placed in a mortar, mixed and thoroughly ground with a pestle, so that the powders of each compound were mixed evenly.

The product preparation conditions and steps are the same as in Example 1, forming a magnetic plate agglomerate with the same size as the laser spot, and fully grinding to obtain the product powder, that is, copper ferrite material.

Example 3

According to the molar ratio of copper oxide: ferric oxide is 5:2, 3 grams of the two compound powders were weighed, wherein copper oxide was 1.667 g, and ferric oxide was 1.333 g. The weighed powders were placed in a mortar, mixed and thoroughly ground with a pestle, so that the powders of each compound were mixed evenly.

The product preparation conditions and steps are the same as in Example 1, forming a magnetic plate agglomerate with the same size as the laser spot, and fully grinding to obtain the product powder, that is, copper ferrite material.

Example 4

According to the molar ratio copper oxide: ferric oxide is 4:1, weigh the two compound powders in total 3 grams, wherein the copper oxide is 2.0000g, and the ferric oxide is 1.0000g. The weighed powders were placed in a mortar, mixed and thoroughly ground with a pestle, so that the powders of each compound were mixed evenly.

The product preparation conditions and steps are the same as in Example 1, forming a magnetic plate agglomerate with the same size as the laser spot, and fully grinding to obtain the product powder, that is, copper ferrite material.

Example 5

According to the molar ratio copper: copper oxide: iron sesquioxide is 1:1:1 and weighs 3.8 grams of the three compound powders, wherein copper is 0.8000g, copper oxide is 1.0000g, and iron sesquioxide is 2.0000g. The weighed powders were placed in a mortar, mixed and thoroughly ground with a pestle, so that the powders of each compound were mixed evenly.

The product preparation conditions and steps are the same as in Example 1, forming a magnetic plate agglomerate with the same size as the laser spot, and fully grinding to obtain the product powder, that is, copper ferrite material.

The XRD pattern of the copper ferrite compound prepared in each embodiment is shown in FIG. 3 .

The specific embodiments described above have further described the technical problems, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit In the present invention, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (5)

1. A method for laser-induced self-propagating high-temperature synthesis of copper ferrite materials, characterized in that, using copper, copper oxides, iron and iron oxides as raw materials, adopting laser-induced self-propagating reactions to make raw materials react Generate Cu ₂ O to carry out the catalytic synthesis process; specifically include the following steps: Step 1: Select the required raw material powder, and mix the raw material fully and evenly to obtain the mixed raw material; Step 2: placing the mixed raw materials in a reaction vessel; Step 3: Use laser light to irradiate the mixed raw materials, adjust the laser, and the laser induces a self-propagating reaction to generate the primary product of copper ferrite material; Step 4: Grinding the initial product of the copper ferrite material to obtain a copper ferrite material with small particles and good uniformity; wherein: The raw material powder described in step 1 is copper, copper oxide, iron and iron oxide, and the type and ratio of the raw material powder are selected according to actual product requirements; the fully uniform mixing is obtained by grinding and stirring. Granular powder, or compress uniformly mixed small particle powder; The laser-induced self-propagating reaction described in step 3 controls the process speed, temperature, conversion rate, and product composition and structure by changing the heat release and transmission speed. 2. the method for a kind of laser-induced self-propagating high-temperature synthetic copper ferrite material according to claim 1 is characterized in that: the laser device described in step 3 is a continuous laser device or a pulsed laser device, and the output laser waveband is an infrared waveband; The spectral waveband of the laser is infrared waveband, visible light waveband or mixed waveband of infrared light and visible light. 3. a kind of method for laser-induced self-propagating high-temperature synthetic copper ferrite material according to claim 1, is characterized in that: the laser described in step 3 is irradiated on the mixed raw material, and the area of its irradiation, power, time pass through Feedback adjustment control generates the target product according to the demand, and realizes localized real-time controllability of the process of preparing the generated product. 4. A kind of method for laser-induced self-propagating high-temperature synthetic copper ferrite material according to claim 1, it is characterized in that: said adjustment laser refers to the laser control reaction of laser output, can carry out laser focusing, to sintering area Carry out spatial distribution control, including laser spatial lattice and laser spatial scanning. 5 . The method for laser-induced self-propagating high-temperature synthesis of copper ferrite material according to claim 1 , characterized in that: the preparation environment is controlled by gas, and the gas is N ₂ .