The invention relates to a method and a process for preparing metal powder by atomization
In the 1820s, air atomization was used to make Non-ferrous metal powders, and in the 1950s and 1960s, it was widely used to produce metal and alloy powders In the late 1970s and early 1980s, with the development of computer technology and modern control technology, atomization entered a period of vigorous development. At present, the conventional gas atomization scheme is to use liquid gas, such as liquid nitrogen, liquid argon, after heating gasification, using high-temperature high-pressure gas aimed at the liquid metal, metal atomization into particles. Now gas atomization is more use of inert gas, or high-pressure air, etc. , the disadvantage is from gas inert gas to liquid and then pressure, increase costs, and dangerous transportation.
The invention aims to provide a method for preparing metal powder by atomization, and solves the problem of high cost for preparing metal powder by atomization. In order to solve the technical problem, the invention provides a method for preparing metal powder by atomization, which comprises the following steps: a liquid atomizer is preheated and vaporized to obtain a gaseous atomizer, wherein, the atomizer is liquid at a atmosphere of 10 â ° c-30 â ° C, and a metal powder is obtained by passing the gaseous atomizer into the atomizer tray and performing a gas atomization of the metal liquid. The atomized substance is a substance with a boiling point in the range of 50 ° C to 200 ° C. Wherein, the nebulizer is ethanol or the nebulizer is a mixture of ethanol and water. The atomizer is water, and before the liquid atomizer is pressurized, heated and gasified in advance, the atomizer also comprises the following steps: distilling and removing oxygen, sterilizing and deionizing the raw water, to obtain purified liquid water. The raw water is any water in tap water, sea water or distilled water. The gas atomization of the metal liquid includes: At a pressure not less than 1.1 mpa and at a temperature not less than the boiling point of the atomizer, the metal liquid is atomized by the vaporized atomizer.
Wherein, after the metal liquid is gas atomized and the metal powder is obtained, the process of reducing the metal powder also comprises the following steps. Wherein, after the gas atomization of the metal liquid to obtain the metal powder, the gas atomization discharged from the atomization spray tray is recovered. The present invention provides a method for preparing metal powders by atomizing a substance that is liquid at a atmosphere of 10 â ° C to 30 â ° C, the aerosols present a liquid state. Compared with the inert gas and nitrogen which are gaseous at normal temperature and pressure, the invention does not need to liquefy the atomized material from the gaseous state, thereby reducing the cost of obtaining the liquid atomized material; At normal temperature and pressure, the atomizer is liquid, so high pressure transportation is not needed in the process of transportation, which reduces the transportation cost and danger of atomizer. To sum up, the method for preparing metal powder by atomization provided by the invention can greatly reduce the material cost of the atomized material, thereby reducing the preparation cost of the metal powder. To give a clearer picture of the technical scheme of the embodiment of the invention or of the prior art, a brief description of the drawings required to be used in the embodiment or the prior art description is given below, the attached drawings described below are only some embodiments of the present invention, and other attached drawings can be obtained without creative labor for ordinary technicians in this field. Fig.
1 shows the flow diagram of the method for preparing metal powder by atomization, and Fig. 2 shows the local structure diagram of an atomization tower.
In order to make people in the technical field better understand the scheme of the invention, the following is further explained in detail with the attached drawings and the specific embodiment. Obviously, the embodiments described are only part of the embodiments of the invention, not all of them. Based on the embodiments of the invention, all other embodiments obtained by ordinary technicians in the field without performing creative work fall within the scope of protection of the invention. As shown in Fig. 1, fig. 1 provides a flow diagram of a method for preparing a metal powder by atomization provided in an embodiment of the invention, which may include: Step S1: pre-vaporization of a liquid atomizer under pressure, to obtain a gaseous atomizer. The nebulizer in this embodiment refers to a substance that is liquid at normal temperature and pressure. Specifically, it could be a substance that is liquid at a atmosphere of 10 â ° C to 30 â ° C. Step S2: the gaseous atomizer is introduced into the atomizing spray tray, and the metal liquid is gas atomized to obtain the metal powder.
It should be noted that, since a gas is used to atomize a liquid metal, the gaseous state of the atomizer should be maintained when it is introduced into the spray tray; in addition, when the atomizer is used to atomize the liquid metal, the atomizer is used to spray the liquid metal at high pressure, which is similar to the conventional atomization to prepare the metal powder. As shown in fig. 2, fig. 2 provides a schematic diagram of the local structure of an atomizing spray tray of the embodiment of the invention. In the process of metal atomization, the metal liquid 2 flows down from the direction above the atomization spray plate 1; at the same time, the atomization gas is sprayed through the jet channel 3 on both sides of the metal liquid 2 flowing down, an impact is produced on the metal liquid 2, which in turn produces a powdered metal. Most of the atomized gases currently in use are nitrogen or other inert gases. But this gas in the industrial transport is often required to cool down first compressed into a liquid, in the low temperature and high pressure transport. First, it is relatively expensive to liquefy liquid nitrogen or liquid inert gas which is gaseous at normal temperature and pressure, and it is also costly to keep liquid nitrogen liquefied during transportation, the result is that the cost of the atomizer increases, which in turn leads to the higher cost of the metal powder. In the present invention, a substance which is liquid at normal temperature and pressure is directly used as atomizer, and is easier to obtain than a substance which is gaseous at normal temperature and pressure, and does not need to liquefy the substance, the invention reduces the purchase cost of the atomizer, and does not need to use high pressure and low temperature transportation in the transportation process. Therefore, the atomizer used in the invention can greatly reduce the cost of obtaining the atomizer, thereby reducing the cost of preparing metal powder by atomization.
Optionally, in a specific embodiment of the invention, the atomizer may be water, ethanol, or a mixture of water and ethanol, among others. Considering that the atomization of metal powder in the preparation, the final need to vaporize the atomization. Therefore, in order to reduce the cost of vaporizing liquid aerosols into gaseous aerosols, substances with a relatively low boiling point can be used as aerosols. Of course, it is understandable that its boiling point should not be too low, otherwise it is more volatile. Therefore, in another specific embodiment of the invention, the atomized material may further include a substance with a boiling point in the range of 50 ° C to 200 ° C. Of course, nebulizer with higher boiling point is not excluded in the invention, and the nebulizer with a boiling point of 50 ° C-200 ° C in the embodiment is a more preferred embodiment, the invention can reduce the cost of vaporizing the atomized liquid. In another specific embodiment of the invention, the atomizer may be water. It should be noted that the price of water is relatively low relative to other substances. The cost of the atomizer can be reduced to a great extent. Further, the water used as an atomizer in this embodiment may be readily available water such as seawater, tap water, or distilled water. Alternatively, in order to avoid impurities in the water, the water may also include:
The raw water is purified by distillation, sterilization and deionization to obtain the purified liquid water. The liquid water is used as atomizer to prepare metal powder by user atomization after gasification, which can effectively prevent impurity particles in water, oxygen and so on from oxidation to metal. Furthermore, in order to avoid the inevitable partial oxidation of the obtained metal powder during the preparation process, after obtaining the metal powder, it may further include the treatment of a metal powder by a reduction reaction. In particular, the metal powder can also be mixed with reducing gas to produce reduction reaction under certain reaction conditions, and finally obtain more pure metal powder. Based on the arbitrary embodiment, in another specific embodiment of the invention, the invention may further include: At a pressure not less than 1.1 mpa and not less than the boiling point temperature of the atomizer, the liquid metal is atomized by a vaporized atomizer. Specifically, when a gaseous atomizer vaporizes a liquid metal, it is ensured that the atomizer does not liquefy. Therefore, it is necessary to carry out metal atomization in high temperature and high pressure environment. In particular, atomization may be performed at a pressure higher than 1.1 mpa and at a temperature higher than the boiling point of the atomizer. It should be noted that a pressure of not less than 1.1 mpa may be applied in embodiments where the atomizer is water, but a pressure of 0.6 mpa or 0.7 mpa may also be applied for substances such as ethanol.
Optionally, in another specific embodiment of the invention, it may further include: following high-pressure gas atomization of a metal liquid, obtaining a metal powder, the gaseous aerosols discharged from the spray tray are recovered. Because the atomizer is liquid at normal temperature and pressure, when the gas atomizer is discharged from the high-temperature and high-pressure atomizer, the temperature and pressure drop, the atomizer can liquefy into liquid. It is easier to recycle than gaseous substances, thus further saving costs. The embodiments in this specification are described in a progressive manner. Each embodiment highlights differences from the other embodiments. The same or similar portions of each embodiment are referred to each other. For an embodiment-exposed device, the description is simple because it corresponds to the embodiment-exposed method, as described in the methods section. The method for preparing metal powder by atomization provided by the invention is introduced in detail. In this paper, the principle and implementation of the invention are described by specific examples, which are only used to help understand the method and its core idea. It should be pointed out that the invention can be improved and modified without being separated from the principle of the invention for the ordinary technical personnel in the technical field, these improvements and modifications also fall within the scope of protection of the claims of the invention.