Method for producing fine powder and the fine powder produced by the same
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Solution Overview
Problem
Conventional wet medium grinding methods face challenges such as bead abrasion, contamination of fine powders, increased process steps, and difficulty in collecting fine powders due to adherence to beads, leading to reduced recovery rates and contamination risks, especially when handling expensive materials like medicinal bulk powders.
Innovation Solution
An extreme cold grinding method using liquefied inert gases like liquid nitrogen and substituting granular dry ice for conventional beads to prevent bead abrasion and contamination, allowing for direct collection of fine powders without liquid-solid separation, maintaining crystal structure, and enhancing pulverization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional wet medium grinding method using beads is used, then pulverization and dispersion of raw materials can be achieved, but bead abrasion occurs and fine powders are contaminated
Solution Approach 1:
The patent extracts and removes the beads from the grinding system entirely, replacing them with a beadless wet medium grinding method that uses only liquid medium and mechanical agitation to achieve pulverization and dispersion without any solid grinding media that could cause contamination
Solution Approach 2:
The patent introduces a liquid medium as an intermediary substance that facilitates the grinding process without direct contact between solid beads and the material being ground, using the liquid medium to transmit mechanical energy and achieve size reduction while preventing contamination
2Productivity
If beads are used for pulverization, then grinding efficiency is improved, but fine powders adhere to beads making collection difficult and recovery rate reduced
Solution Approach 1:
The patent removes beads from the system entirely, eliminating the adhesion problem that causes fine powder loss, and achieves pulverization through direct mechanical agitation in liquid medium followed by simple filtration or decantation for powder recovery
Solution Approach 2:
The patent simplifies the recovery process by discarding the bead-based system and using direct liquid-solid separation methods that allow complete recovery of fine powders without the need to separate them from adhering beads
3Manufacturing precision
If conventional wet medium grinding is used, then pulverization can be achieved, but additional liquid-solid separation process steps are required
Solution Approach 1:
The patent merges the pulverization and separation functions into a single integrated process where mechanical agitation in liquid medium simultaneously achieves size reduction and maintains particles in suspension, allowing direct decantation or filtration without separate drying or complex separation steps
Solution Approach 2:
The patent maintains continuous suspension of pulverized particles in liquid medium throughout the grinding process, eliminating the need for intermittent separation steps and enabling continuous operation until the desired particle size is achieved
4Manufacturing precision
If beads are used for grinding, then material can be pulverized, but process time increases due to adhesion and separation requirements
Solution Approach 1:
The patent extracts beads from the process, eliminating the time-consuming steps of bead separation and fine powder recovery from bead surfaces, and achieves rapid pulverization through direct mechanical agitation followed by simple liquid-solid separation
Solution Approach 2:
The patent skips the intermediate steps of bead separation and extensive drying processes by using a beadless system where particles remain in liquid medium until final separation, rushing through the process to achieve quick recovery of fine powders
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method effectively produces submicron to nano-sized fine powders with improved resolvability, uniformity, and high collection rates, reducing contamination and process complexity, while maintaining the crystal structure of materials and enhancing the solubility of low-solubility substances.
Implementation Method 1
an extreme cold grinding method using liquefied inert gases like liquid nitrogen
Implementation Method 2
substituting granular dry ice for conventional beads to prevent bead abrasion and contamination
Implementation Method 3
allowing for direct collection of fine powders without liquid-solid separation
Data Source
AI summary
Disclosed is a method for producing a fine powder. Two or more kinds of original materials are suspended and liquefied inert gas to form two or more kinds of slurries wherein each slurry contains at least one or more different kinds of original materials. Granular dry ice grinding medium is put into the slurries. The slurries are individually stirred and the original materials are pulverized into submicron-sized or nano-sized particles in the liquefied inert gas. The slurries are thereafter mixed. The liquefied inert gas is vaporized and the granular dry ice is sublimated. A mixture of the particles of the two or more kinds of original materials is recovered.