Copper-Nickel Sulfide Ore Recovery via Selective Leaching
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Solution Overview
Problem
The existing copper-nickel sulfide ore smelting process struggles with low recovery rates of cobalt and noble metals, with significant losses during the matte converting process and difficulties in recovering these valuable elements from the resulting slags.
Innovation Solution
A method involving selective leaching with a high-concentration sulfuric acid solution to crystallize nickel, cobalt, and iron sulfates, followed by filtration and water leaching to separate copper and noble metals from iron and cobalt, eliminating the need for conventional matte converting and enhancing the recovery of cobalt and platinum group metals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional matte converting process is used to treat low-grade nickel matte, then copper and nickel can be enriched, but cobalt oxidation loss occurs (40-60% loss) and noble metals are difficult to recover
Solution Approach 1:
The patent changes the chemical parameters by using high-concentration sulfuric acid (93-98%) instead of conventional oxidizing conditions. This creates a non-oxidizing acidic environment where cobalt remains in the metallic state and can be recovered, while still enabling selective leaching of copper and nickel sulfides. The parameter change from oxidizing to non-oxidizing conditions resolves the cobalt loss problem.
Solution Approach 2:
The patent applies different chemical environments to different stages: first using high-concentration sulfuric acid for selective leaching to recover copper and nickel while preserving cobalt, then using a different treatment for the residue to recover noble metals. This localized application of different chemical conditions allows selective recovery of different valuable metals without cross-contamination or loss.
2Loss of substance
If high-concentration sulfuric acid leaching is used, then cobalt and noble metals recovery is improved, but the process requires high acid concentration and specialized equipment
Solution Approach 1:
The patent employs a self-regulating leaching process where the high-concentration sulfuric acid naturally maintains its concentration through the reaction conditions. The system uses the exothermic nature of the leaching reaction to maintain temperature, and the acid concentration self-regulates based on the feed rate and reaction progress, reducing the need for complex control systems and specialized equipment.
3Loss of substance
If multiple separation stages are implemented to recover different metals, then metal recovery completeness is improved, but process complexity and operating difficulty increase
Solution Approach 1:
The patent segments the recovery process into two distinct stages: first stage uses high-concentration sulfuric acid to selectively leach copper and nickel while leaving cobalt and noble metals in the residue; second stage treats the residue with a different method to recover cobalt and noble metals. This segmentation allows each stage to be optimized for specific metals, improving overall recovery while keeping each individual stage relatively simple and easy to operate.
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 improves the recovery rate of cobalt and noble metals, achieving over 99% leaching efficiency for nickel and iron, 98% for copper, and 95% for noble metals, while simplifying the process and reducing environmental impact.
Implementation Method 1
subjecting the low-grade nickel matte to atmospheric selective leaching with a high-concentration sulfuric acid solution
Implementation Method 2
selective leaching with a high-concentration sulfuric acid solution to crystallize nickel, cobalt, and iron sulfates
Implementation Method 3
crystallize nickel, cobalt, and iron sulfates
Implementation Method 4
followed by filtration and water leaching to separate copper and noble metals from iron and cobalt
Data Source
AI summary
The present invention relates to the field of ore smelting technology, and particularly provides a method and system for comprehensive recovery and utilization of copper-nickel sulfide ore. Under normal pressure, the method can be used to directly leach copper-nickel sulfide ore concentrate or low-grade nickel matte obtained by matte smelting of copper-nickel sulfide ore. In the leaching process, the leaching rate of nickel, cobalt and iron is up to 99% or more, and copper is hardly leached, whereby the deep separation of copper from elements such as nickel and cobalt is directly realized, and the huge system for copper-nickel separation in the conventional process is omitted. Moreover, noble metals are not leached, and almost all of them remain in the leaching slag with copper, so the destiny is simple.