Atomized Melt Droplet Phosphorus Recovery Process

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Solution Overview

Problem

The recovery of elemental phosphorus from waste materials containing iron oxides is hindered due to the formation of phosphorus iron at high temperatures, leading to a significant reduction in phosphorus yield, as elemental phosphorus dissolves in molten iron, making it difficult to obtain elemental phosphorus efficiently.

Innovation Solution

The process involves atomizing a melt containing iron oxide and phosphorus oxides and exposing the resulting droplets to carbon monoxide as a reducing agent, increasing the surface area for reaction, and using a separator to remove gaseous elemental phosphorus, thereby preventing phosphation of iron and maximizing phosphorus yield.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the melt is atomized and exposed to carbon monoxide for direct reduction, then the phosphorus yield is significantly improved, but the process complexity increases due to the need for atomization equipment and separator

Engineering Contradiction:
Improvephosphorus yieldVSAvoidprocess complexity
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The melt is atomized into fine droplets, dividing the bulk liquid into numerous small particles. This segmentation dramatically increases the surface area-to-volume ratio, enabling efficient contact with carbon monoxide for reduction and preventing phosphorus dissolution in iron by dispersing the phosphorus-containing phases throughout the droplet population

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The separator extracts gaseous elementary phosphorus from the melt droplets after reduction. By removing the phosphorus in gaseous form before the droplets cool and solidify, the process prevents phosphorus loss to the iron phase and achieves high recovery yields

Inventive Principle:
Principle #2Taking out (Extraction)

2Device complexity

If conventional reduction with carbon is used, then the process is simpler, but phosphorus yield is significantly reduced due to formation of phosphorus iron

Engineering Contradiction:
Improveprocess simplicityVSAvoidphosphorus yield
Core Design Contradiction:
Device complexityVSQuantity of substance

Solution Approach 1:

The reducing agent is changed from solid carbon to gaseous carbon monoxide, and the reaction conditions are changed from bulk melt treatment to atomized droplet treatment. This parameter change transforms the reduction mechanism, allowing phosphorus oxides to be reduced to gaseous phosphorus that can be immediately separated, preventing formation of phosphorus iron

Inventive Principle:
Principle #35Parameter changes

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 increases the yield of elemental phosphorus by enhancing the sublimation and reduction of phosphorus oxides to gaseous phosphorus, preventing phosphation of iron and allowing for efficient separation and collection of phosphorus, even in the presence of iron oxides.

Implementation Method 1

the melt is atomized and the resulting melt droplets come into contact with carbon monoxide

Methodology Applied
Scientific EffectAtomization:

Implementation Method 2

a considerable part of the P2O5 contained sublimates from the melt droplets into the gas phase

Methodology Applied
Scientific EffectSublimation: Sublimation

Implementation Method 3

the phosphorus oxides contained are at least partially reduced into gaseous elementary phosphorus

Methodology Applied
Scientific EffectReduction reaction: Reduction

Implementation Method 4

the reduction reaction can be described as follows: P2O5 + 5CO -> 5CO2 + P2

Methodology Applied
Scientific EffectRedox reaction: Redox Reactions

Implementation Method 5

the melt droplets are fed together with the gaseous elementary phosphorus to a separator, by means of which the gaseous elementary phosphorus is separated from the melt droplets

Methodology Applied
Scientific EffectPhase separation:

Implementation Method 6

At the same time, the already metallized iron is carburized

Methodology Applied
Scientific EffectCarburization: Carburizing

Data Source

PatentEP3541745B1Process and apparatus for workup of a melt containing iron oxide and phosphorus oxides
Publication Date: 2021.12.22 RADMAT AG
  • EP3541745B1 patent drawingFigure 1
  • EP3541745B1 patent drawingFigure 2
  • EP3541745B1 patent drawingFigure 3

AI summary

In a process for workup of a melt containing iron oxide and phosphorus oxides for recovering elemental phosphorus by direct carbothermic reduction of the phosphorus oxides the melt is atomized and the thus obtained melt droplets in contact with carbon monoxide as a reductant are passed through a direct reduction sector in which the phosphorus oxides present are at least partly reduced to afford gaseous elemental phosphorus and from which the melt droplets together with the gaseous elemental phosphorus are supplied to a separator by means of which the gaseous elemental phosphorus is separated from the melt droplets.