Co-extraction of Vanadium, Titanium and Chromium from Slag
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Solution Overview
Problem
Current methods for extracting vanadium, titanium, and chromium from vanadium slag are inefficient, with low recovery rates and high environmental impact due to high-temperature processes, inability to co-extract titanium and chromium, and generation of industrial wastewater and waste gases.
Innovation Solution
A method involving low-temperature reduction of vanadium slag using ferric chloride followed by leaching with oxalic acid to break the spinel structure, allowing for simultaneous extraction of vanadium, titanium, and chromium, with specific conditions including temperature, pressure, and reagent concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-temperature roasting (850°C) is used for vanadium extraction, then vanadium can be extracted from the slag, but the process becomes energy-intensive and generates harmful emissions
Solution Approach 1:
The patent changes the temperature parameter from high-temperature roasting (850°C) to low-temperature leaching (room temperature to 100°C). It also changes the chemical environment from oxidative roasting conditions to reductive leaching conditions using oxalic acid, thereby eliminating the need for high-energy input and reducing harmful emissions while maintaining effective vanadium extraction
Solution Approach 2:
The patent replaces the thermal-mechanical roasting process with a chemical leaching process using oxalic acid. Instead of using high-temperature thermal energy to extract vanadium, the invention uses chemical reactions at low temperatures, substituting a less harmful process for the harmful high-temperature roasting
2Reliability
If conventional roasting methods are used, then vanadium extraction is achieved, but the process complexity increases and multiple separate steps are required
Solution Approach 1:
The patent merges multiple separate extraction steps into a single leaching operation. Instead of requiring separate roasting, leaching, and purification steps as in conventional methods, the invention combines vanadium, titanium, and chromium extraction into one oxalic acid leaching process, thereby simplifying the overall process flow and reducing equipment requirements
Solution Approach 2:
The patent makes the oxalic acid leaching solution multi-functional by enabling it to extract three different metals (vanadium, titanium, and chromium) simultaneously from the same slag material. This universal extraction capability eliminates the need for multiple specialized extraction processes
3Reliability
If direct leaching with high-concentration oxalic acid is used, then co-extraction of vanadium, titanium and chromium is achieved, but equipment requirements increase due to high temperature and pressure
Solution Approach 1:
The patent changes the concentration parameter of oxalic acid from high-concentration to low-concentration (5-20%), and changes the temperature parameter from high-temperature to low-temperature (room temperature to 100°C). It also changes the pressure parameter to atmospheric pressure, thereby enabling the use of simple equipment without special high-pressure or high-temperature requirements while maintaining effective co-extraction
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
Achieves vanadium, titanium, and chromium extraction rates greater than 99%, improving recovery rates and reducing environmental impact by avoiding high-temperature processes.
Implementation Method 1
leaching with oxalic acid to break the spinel structure
Implementation Method 2
conducting an iron removal reaction on the reduction material with a certain amount of a ferric chloride aqueous solution
Implementation Method 3
subjecting vanadium slag to a reduction reaction in a high-temperature reaction furnace
Data Source
AI summary
The present disclosure provides a method for co-extraction of vanadium, titanium and chromium from vanadium slag. The method selectively reduces pyroxene and fayalite wrapped on spinel through low-temperature hydrogen reduction, iron removal by ferric chloride, and low-temperature leaching of the vanadium slag by oxalic acid, thereby destroying a structure of the spinel, dissociating a spinel phase and a silicate phase, and fully exposing the spinel phase. The method also directly leaches the vanadium slag at a low temperature by acidity and strong complexation of the oxalic acid, and destroys the structure of the spinel, such that vanadium, titanium, chromium and oxalate are complexed into a solution to co-extract vanadium, titanium and chromium. The present disclosure extracts vanadium, titanium and chromium from the vanadium slag, with a leaching rate each being greater than 99%.