Nano metal powder preparing device and method based on supercritical hydro-thermal synthesis technology

Abstract

The invention discloses a nano metal powder preparing device and method based on a supercritical hydro-thermal synthesis technology, and belongs to the technical fields of chemical industry and environmental protection. According to the nano metal powder preparing device and method, disturbance to supercritical water is improved by arranging a static mixer, uniform jet flow and flow diversion of amaterial are achieved by designing an atomizing nozzle, accordingly, the mixing degree is increased, and heat transfer and mass transfer are improved. A plurality of parallel pipelines are designed by precisely calculating the flowing distance of fluid at a certain determined flow rate with certain time, and the reaction time is precisely controlled and can be flexibly changed. The fluid after reaction is directly cooled in a cold water spraying type quenching mode, thus, in the supercritical hydro-thermal synthesis reaction process, quick uniform mixing, precise timing reaction and quick sufficient cooling are achieved, and the quality of nano metal powder particle products is effectively ensured.

Description

technical field [0001] The invention belongs to the technical field of chemical industry and environmental protection, and in particular relates to a device and method for preparing nanometer metal powder based on supercritical hydrothermal synthesis technology. Background technique [0002] Nanotechnology has an important strategic position in the industrial revolution in the 21st century. Its rapid development has caused revolutionary changes in almost all industrial fields. It is the most important and most promising frontier technology in the 21st century. Compared with ordinary powders, nanomaterials have superior properties, such as large specific surface area, interface effects, quantum effects and quantum tunneling effects, etc., endowing them with unique properties and specific electrical, thermal, magnetic, optical and mechanical properties. , are widely used in various fields. Traditional methods for preparing nanopowders can be divided into two categories: physi...

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Problems solved by technology

[0004] However, during the popularization and application of supercritical hydrothermal synthesis technology, the following defects were found: since the metal inorganic salt solution completes the precipitation process instantly after reaching the supercritical state, generally speaking, the generation reaction of nanoscale metal / metal oxide particles is limited. The duration is between 5 seconds and 10 seconds. After the reaction, as time goes by, the crystallized particles will agglomerate and grow into submicron or even micron-sized particles, losing commercial value

Under the action of the above-mentioned many uncertain factors, it is difficult to ensure the precise control of the reaction time, which causes the actual reaction not to proceed according to the predetermined reaction time, thus making it impossible to produce the optimal product under the optimal parameters

In addition, for the cooling of the reacted fluid, the indirect heat exchange method is commonly used to cool the reacted fluid at present, which cannot achieve rapid cooling, and the cooling is uneven, and it is easy to cause some slow-cooling nano-metal particles to Reunion under high temperature environment

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