High-pressure acid leach (HPAL) is a hydrometallurgical method for extracting nickel and cobalt from laterite ores. It involves finely ground ore being treated under high temperature and high pressure with sulfuric acid, resulting in the dissolution of nickel and cobalt into solution, while impurities such as iron and magnesium are separated as solid residues. The main stages include:
-
Ore preparation: Crushing, grinding, and classification to achieve the required particle size.
-
Slurry preparation: Mixing ore with water to form a uniform slurry.
-
High-pressure leaching: The slurry is reacted with concentrated sulfuric acid in autoclaves at high temperature and pressure, typically 250–270°C and 4–5 MPa, to dissolve nickel and cobalt.
-
Solid-liquid separation: The leach residue is separated from the nickel-cobalt rich solution using thickening and filtration equipment.
-
Solution purification and metal recovery: Impurities are removed through precipitation or solvent extraction, followed by recovery of nickel and cobalt through crystallization or electrowinning.
Designed for the HPAL process and highly corrosive slurry environments, this product series utilizes highly corrosion-resistant titanium materials. It is widely applied in nickel-cobalt, chromite, and rare earth element (scandium) production processes. By enhancing corrosion resistance, mechanical strength, and electrochemical performance, it provides long-term, stable solutions for high-pressure, high-temperature acidic systems.
Main Products and Applications
Titanium Anodes
Application Scenarios: Electrolytic oxidation, chlorination reactions, and auxiliary precipitation treatment
Technical Advantages:
-
Surface coated with platinum, iridium, ruthenium, or other noble metal catalytic layers to improve anode efficiency and selectivity
-
High uniformity of current distribution, reducing local overpotential and extending service life
-
Resistant to high temperatures (≤270 °C) and concentrated sulfuric acid corrosion
Typical Process Applications:
-
In HPAL leach tanks, titanium anodes assist in electrolytic oxidation of nickel-cobalt leach solutions, keeping iron and sulfur impurities within precipitable limits
-
Promote uniform oxidation of nickel-cobalt mixed sulfide (MS) precursors, enhancing subsequent precipitation and drying efficiency
-
Applied in chlorination or oxidizer-generating auxiliary reactions to maintain stable composition of intermediate products
Titanium Tubes / Heat Exchangers
Application Scenarios: Heat exchange and circulation of high-temperature, high-pressure acidic solutions
Technical Advantages:
-
Resistant to sulfuric acid and chloride corrosion
-
High-strength design capable of withstanding 4–6 MPa leach pressure
-
Long service life, low maintenance, and high thermal efficiency
Typical Process Applications:
-
During HPAL leaching, circulate low-grade nickel slurry to high-pressure reactors while maintaining temperatures of 250–270 °C for efficient nickel-cobalt extraction
-
Recover leach heat to preheat feed slurry, optimizing overall energy consumption
-
Connect to intermediate product precipitation systems to ensure fluid stability and reduce the risk of pipeline blockage
Titanium Reactors & Filters
Application Scenarios: Slurry processing, intermediate product separation, and purification
Technical Advantages:
-
High acid and temperature resistance
-
Anti-clogging design for continuous and stable operation
-
Easy integration into automated processing systems
Typical Process Applications:
-
Post-HPAL leach slurry passes through titanium filter units to remove unreacted ore residue and impurities, ensuring the purity of nickel-cobalt mixed sulfide solutions
-
In scandium or chromite production, titanium reactors handle acidic solutions for precipitation, washing, and concentration operations
-
Combined with titanium heat exchangers to control liquid temperature, enhancing reaction rate and product yield
Product Value:
-
Extend equipment lifespan and reduce maintenance and replacement costs in highly corrosive environments
-
Ensure stability of leaching and precipitation processes, improving quality of nickel-cobalt intermediate products
-
Support commercialization of HPAL technology and efficient utilization of low-grade ores