Gravity-Driven Multiple-Effect Magnesium Distillation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for magnesium production and recycling face challenges such as high production costs, environmental regulations, corrosion issues, and inefficient recycling of magnesium alloys, particularly in achieving low-iron, low-copper, low-nickel magnesium from post-consumer scrap, and in joining magnesium with other metals like steel or aluminum.
Innovation Solution
A gravity-driven multiple effect thermal distillation system that uses the heat released in condensation to facilitate evaporation, with a condenser operating at higher pressure than the evaporator, and incorporates features like counter-flow evaporators and condensers, and a molten salt electrolysis cell to separate and purify magnesium, reducing energy consumption and improving separation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional distillation methods are used for magnesium production, then magnesium can be produced, but energy consumption is high and production costs are elevated
Solution Approach 1:
The patent employs a multiple-effect distillation system that utilizes phase transitions of magnesium between liquid and vapor states. The system includes evaporators where magnesium liquid evaporates and condensers where magnesium vapor condenses, creating a continuous cycle that separates magnesium from impurities. This phase transition-based separation enables efficient purification and production with reduced energy consumption compared to conventional methods.
Solution Approach 2:
The distillation system is divided into multiple effects (evaporators and condensers arranged in series), where each effect handles a portion of the separation process. The first evaporator, first condenser, second evaporator, and second condenser work in sequence to progressively separate magnesium from impurities. This segmentation allows the system to achieve high purification efficiency while distributing the energy load across multiple stages, reducing overall energy consumption.
2Productivity
If post-consumer magnesium scrap is recycled, then magnesium can be recovered, but impurities such as iron, copper, and nickel remain at high concentrations
Solution Approach 1:
The multiple-effect distillation system utilizes vaporization and condensation of magnesium to separate it from impurities. In the evaporators, magnesium liquid evaporates preferentially over impurities due to differences in volatility. The magnesium vapor then condenses in the condensers, leaving impurities behind in the liquid residue. This phase transition-based separation enables the system to achieve high purity magnesium (reducing iron, copper, and nickel to trace levels) while maintaining efficient recycling of magnesium metal.
Solution Approach 2:
The system applies different thermal conditions and separation mechanisms to different stages of the distillation process. Each evaporator and condenser pair is optimized for specific separation tasks, with the first effect handling initial separation and subsequent effects achieving progressive purification. This localized optimization of separation conditions at each stage enables the system to achieve high final purity while maintaining overall recycling efficiency.
3Ease of manufacture
If a Hall-Héroult type cell with dense reactive liquid metal cathode is used for direct reduction of magnesium oxide, then magnesium alloy can be produced, but separation of pure magnesium from the alloy requires additional processing
Solution Approach 1:
The system uses vaporization and condensation of magnesium to separate pure magnesium from the magnesium alloy produced in the Hall-Héroult cell. The alloy is fed to the distillation system where magnesium evaporates from the liquid alloy, and the magnesium vapor is condensed to produce pure magnesium metal. This phase transition-based separation integrates well with the electrolysis process, enabling direct reduction of magnesium oxide with efficient separation of the produced magnesium from the alloy.
Solution Approach 2:
The patent combines the Hall-Héroult electrolysis cell with the multiple-effect distillation system into an integrated process. The dense reactive liquid metal cathode in the electrolysis cell produces magnesium alloy, which is then directly fed to the distillation system for separation. This merging of the production and separation processes into a single integrated system reduces overall complexity compared to separate processing steps, while maintaining high efficiency in both magnesium production and purification.
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 approach significantly reduces the energy required for magnesium production, enhances the purity and ductility of magnesium alloys, and enables efficient recycling, making magnesium production more cost-competitive with aluminum while improving corrosion resistance and joining capabilities.
Implementation Method 1
heat flows from the higher-temperature condenser to the lower-temperature evaporator
Implementation Method 2
the boiling point is higher in the condenser, and heat flows from the higher-temperature condenser to the lower-temperature evaporator
Implementation Method 3
the weight of a column of liquid metal raises the pressure in the evaporating chamber below it
Implementation Method 4
a heater configured to provide heat to the lowest evaporator of the plurality of evaporators
Implementation Method 5
a plurality of evaporators, for containing a liquid metal and a metal vapor in each of the evaporators
Implementation Method 6
a plurality of condensers, for containing a distillate metal liquid and metal vapor in each of the condensers
Data Source
AI summary
Method and apparatus are provided for efficient metal distillation, and for related primary product process. Vertically stacked and gravity-driven evaporators and condensers are employed to distill metals, such metals having different volatilities. A multiple-effect thermal system of magnesium and other volatile metals is used to efficiently distill and separate metals from multiple metal alloys.