Phosphorus Removal from Metal Smelting via Nitrogen Gas Reaction
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Solution Overview
Problem
Existing methods for removing phosphorus from phosphorus-containing substances in metal smelting and refining are energy-intensive, costly, and inefficient, with high treatment temperatures, wet treatment processes, and low phosphorus removal ratios, posing challenges for industrial-scale application and equipment safety.
Innovation Solution
A method involving the reaction of phosphorus-containing substances with a nitrogen-containing gas at controlled nitrogen and oxygen partial pressures, forming phosphorus nitride (PN) at temperatures below the melting point, which is then oxidized to remove phosphorus as P2O5, allowing for efficient phosphorus removal and reuse of by-products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high treatment temperature is used to remove phosphorus, then phosphorus removal efficiency is improved, but energy consumption increases and equipment safety deteriorates
Solution Approach 1:
The invention changes the temperature parameter from conventional high temperature (above melting point) to a specific temperature range (1000-1400°C) that is below the melting point of the phosphorus-containing substance. This parameter change achieves effective phosphorus removal while avoiding excessive energy consumption and equipment damage associated with melting the raw material.
Solution Approach 2:
The invention utilizes phase transition by maintaining the phosphorus-containing substance in a solid state (below melting point) during the phosphorus removal process. The phosphorus is removed as a gas phase product (phosphorus nitride or phosphorus oxynitride) while the bulk material remains solid, enabling efficient separation without requiring the entire system to reach melting temperature.
2Productivity
If conventional oxidation method is used to remove phosphorus, then phosphorus can be removed by forming P2O5, but iron is also oxidized increasing slag generation
Solution Approach 1:
The invention introduces nitrogen gas as an intermediary substance that mediates the phosphorus removal process. Nitrogen reacts with phosphorus to form phosphorus nitride or phosphorus oxynitride gases, selectively removing phosphorus without causing iron oxidation. This intermediary approach avoids the harmful side effect of iron oxidation that occurs with conventional oxygen-based oxidation methods.
Solution Approach 2:
The invention uses nitrogen gas (or nitrogen-rich atmosphere) as a selective reacting agent that accelerates phosphorus removal through formation of volatile phosphorus nitrides. This approach is more selective than conventional oxidation, as nitrogen preferentially reacts with phosphorus at the controlled temperature range while leaving iron largely unaffected.
3Ease of manufacture
If phosphorus-containing raw materials are used to reduce cost, then manufacturing cost decreases, but phosphorus content in steel product increases deteriorating quality
Solution Approach 1:
The invention applies preliminary action by removing phosphorus from the phosphorus-containing raw material (such as iron ore or manganese ore) before the actual steelmaking process. This pre-treatment eliminates the phosphorus contamination source, allowing the use of inexpensive phosphorus-rich raw materials while ensuring the final steel product meets quality requirements. The phosphorus is removed in advance as phosphorus nitride or phosphorus oxynitride gas.
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 reduces phosphorus content in metal smelting and refining processes, enabling the use of inexpensive raw materials, reducing dephosphorization treatment loads, and allowing for the recycling and reuse of phosphorus-rich by-products, while maintaining a stable and safe industrial process.
Implementation Method 1
the reaction of phosphorus-containing substances with a nitrogen-containing gas at controlled nitrogen and oxygen partial pressures, forming phosphorus nitride (PN)
Implementation Method 2
which is then oxidized to remove phosphorus as P2O5
Data Source
Figure 1~2
Figure 3~4
AI summary
Proposed is a method for removing phosphorus from a phosphorus-containing substance which is applicable in an industrial scale so as to effectively reduce phosphorus contained in the phosphorus-containing substance. In this method, the phosphorus-containing substance used as a raw material for metal smelting or metal refining is reacted with a nitrogen-containing gas at a treatment temperature T (°C) which is lower than a melting temperature (Tm) of the substance, so that phosphorus is removed preferably in the form of phosphorus nitride (PN). In this regard, a nitrogen partial pressure and an oxygen partial pressure in the nitrogen-containing gas are preferably controlled, thereby reducing a load of dephosphorization process, for example.