Mercury Removal from Crude Selenium via Vulcanization and Vacuum Distillation
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Solution Overview
Problem
Current methods for removing mercury from crude selenium, such as wet precipitation and fire distillation, are costly, energy-intensive, and complex, with low market appeal and inefficient mercury recovery rates, posing environmental and health risks due to mercury's toxicity.
Innovation Solution
A method involving crushing crude selenium slag to 200 mesh, mixing with a vulcanizing agent, briquetting, and subjecting it to vulcanization under an inert atmosphere followed by primary and secondary vacuum distillation to separate selenium and mercury based on their differing affinities and vapor pressures, resulting in a high-purity selenium product with minimal mercury content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If wet precipitation process is used to remove mercury from crude selenium, then mercury removal effectiveness is improved, but process complexity and cost increase
Solution Approach 1:
The patent extracts the harmful mercury component from crude selenium through vacuum distillation, separating it from the selenium matrix based on differences in volatility. This direct extraction approach simplifies the process compared to wet precipitation while effectively removing mercury impurities.
Solution Approach 2:
The patent changes the physical parameter of volatility by controlling temperature and pressure conditions during vacuum distillation. By adjusting these parameters, mercury is selectively vaporized and removed from selenium, achieving effective purification without complex chemical reagent systems.
2Object-affected harmful factors
If fire distillation process is used to remove mercury from crude selenium, then mercury removal effectiveness is improved, but energy consumption increases
Solution Approach 1:
The patent employs vacuum distillation in an inert or reduced-pressure environment, which lowers the boiling points of mercury and selenium. This reduces the energy input required compared to fire distillation, while still achieving effective mercury removal through selective volatility differences.
Solution Approach 2:
The patent utilizes phase transition of mercury from solid to vapor phase under vacuum conditions, enabling separation from selenium at lower temperatures than fire distillation. This phase change mechanism achieves mercury removal with reduced energy consumption.
3Manufacturing precision
If conventional distillation is used to separate selenium from mercury, then separation effectiveness is improved, but selenium loss increases
Solution Approach 1:
The patent conducts distillation under vacuum conditions that prevent selenium oxidation and loss. The controlled inert environment protects selenium from reacting with atmospheric oxygen, thereby minimizing selenium loss while maintaining effective separation from mercury.
Solution Approach 2:
The patent optimizes temperature and pressure parameters during distillation to exploit the volatility difference between mercury and selenium. By carefully controlling these parameters, mercury is selectively vaporized at temperatures that minimize selenium evaporation, achieving high separation purity with low selenium loss.
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 achieves a direct selenium recovery rate greater than 96% and a mercury removal rate of over 99.8%, meeting industry standards with a simple, safe, and controllable process, while minimizing environmental impact.
Implementation Method 1
mixing a vulcanizing agent with a crude selenium slag that is crushed to not more than 200 mesh uniformly, and performing briquetting to obtain a mixed material; adding the mixed material into a sealed furnace, and subjecting the mixed material to vulcanization by heating under an inert atmosphere to obtain a sulfurized selenium
Implementation Method 2
subjecting the sulfurized selenium to primary vacuum distillation, such that selenium is converted into a gas phase and collected in a form of a volatile, and generated mercury sulfide and valuable elements are enriched in a resulting residue
Implementation Method 3
subjecting the selenium to secondary distillation to further remove mercuryl
Data Source
AI summary
Disclosed is a method for removing impurity mercury from crude selenium. The method includes: mixing a vulcanizing agent with a crude selenium slag that is crushed to not more than 200 mesh uniformly, and performing briquetting to obtain a mixed material; adding the mixed material into a sealed furnace, and subjecting the mixed material to vulcanization by heating under an inert atmosphere to obtain a vulcanized selenium; subjecting the vulcanized selenium to primary vacuum distillation, such that selenium is converted into a gas phase and collected in a form of a volatile, and generated mercury sulfide and valuable elements are enriched in a resulting residue; and subjecting the selenium to secondary distillation to further remove mercury.