Autoclave Metal Powder Dissolution for High-Purity Sulfate Solutions
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Solution Overview
Problem
Existing methods for producing metal sulphates such as nickel sulphate are impractically slow, unsafe, and inefficient, often requiring aggressive oxidizing agents, oxygen or nitrogen gases, and are not scalable for commercial operations.
Innovation Solution
A process involving the reaction of an aqueous slurry of metal powder with sulphuric acid in an autoclave reactor at controlled temperatures (100°C to 250°C) with a molar ratio below 1.0, followed by separation of the metal sulphate solution from residual powder, operates under reducing conditions without oxygen, and allows for continuous or batch processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If elemental nickel is dissolved in sulfuric acid at room temperature, then the process is safe, but the reaction rate is impractically slow
Solution Approach 1:
The patent applies parameter changes by increasing the temperature from room temperature to 100-250°C and adjusting the molar ratio of sulfuric acid to metal to below 1.0, thereby achieving both rapid dissolution and process safety through controlled parameter optimization
2Productivity
If the pH is lowered to increase reaction rate, then the dissolution speed improves, but the final product pH becomes too low for battery applications
Solution Approach 1:
The patent applies preliminary action by conducting the dissolution at elevated temperature (100-250°C) with controlled acid-to-metal ratio below 1.0, which pre-optimizes the reaction conditions to achieve both high dissolution rate and appropriate final pH (3.5-5.0) suitable for battery applications without requiring additional pH adjustment steps
3Productivity
If oxidizing agents are added to accelerate dissolution, then the reaction rate increases, but the process complexity and safety requirements increase
Solution Approach 1:
The patent applies the taking out principle by removing oxidizing agents from the process entirely, achieving rapid dissolution through thermal energy input (100-250°C) and optimized acid-to-metal ratio instead, thereby simplifying the process and eliminating safety concerns associated with oxidizing agents
4Device complexity
If atmospheric pressure is used for dissolution, then the equipment complexity is reduced, but hydrogen gas accumulation creates safety hazards
Solution Approach 1:
The patent applies parameter changes by operating at elevated temperatures (100-250°C) which increase the solubility of hydrogen gas in the aqueous solution and accelerate its evolution, allowing safe hydrogen management through temperature control rather than complex pressure management systems
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 process ensures safe, efficient, and scalable production of high-purity metal sulphate solutions with minimal reagent use, high circuit utilization, and flexibility in operation modes, promoting rapid dissolution and high nickel sulphate concentrations.
Implementation Method 1
reacting an aqueous slurry of metal powder with sulfuric acid in an autoclave reactor at a temperature between 100°C and 250°C
Implementation Method 2
reacting an aqueous slurry of metal powder with sulfuric acid in an autoclave reactor at a temperature between 100°C and 250°C
Implementation Method 3
reacting an aqueous slurry of metal powder with sulfuric acid... thereby forming a metal sulphate solution
Data Source
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AI summary
The present invention provides a controlled autoclave dissolution of metal powders for producing high-purity metal sulphate solutions, comprising the steps of: a. reacting an aqueous slurry comprising a metal powder with sulphuric acid in an autoclave section comprising one or more autoclave reactors at a temperature between 100°C and 250°C, thereby forming a metal sulphate solution having a residual amount of metal powder, whereby the molar ratio of sulphuric acid and metal in said autoclave section is lower than 1.0; and b. separating said metal sulphate solution from said residual metal powder.