Non-Cyanide Gold Stripping via Covalent Bonding and Electrochemical Control
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Solution Overview
Problem
Current gold stripping technologies using aqua regia or cyanide-based chemicals pose significant risks to human safety and the environment due to toxicity and corrosiveness, and they also damage electronic components, leading to inefficiencies in gold recovery and increased waste production.
Innovation Solution
A non-cyanide gold stripping method employing a compound that forms a covalent bond with gold, using stripping gold chemicals and conducting chemicals, which allows for controlled voltage electrochemical stripping without damaging substrates, and includes specific components like thiocarbamide, alkyl sulfate, and citrate, eliminating the need for cyanide and harmful acids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If aqua regia is used for gold stripping, then gold dissolution is achieved, but strong corrosiveness and high safety risk are produced
Solution Approach 1:
The patent changes the chemical parameters by replacing aqua regia with a non-cyanide stripping system that uses controlled electrochemical parameters (voltage 0.1-4.0V) and safe chemicals (sulfuric acid, sulfur trioxide, hydrogen peroxide) to achieve gold dissolution without the harmful corrosiveness of traditional methods
Solution Approach 2:
The patent substitutes the chemical corrosion mechanism of aqua regia with an electrochemical mechanism using controlled voltage application and safe chemical additives, replacing the harmful chemical attack with a controlled electrical process that dissolves gold without damaging the substrate
2Productivity
If cyanide is used for gold stripping, then gold dissolution is achieved, but toxic waste and safety hazards are produced
Solution Approach 1:
The patent converts the harmful cyanide-based system into a beneficial non-cyanide system by using sulfuric acid and sulfur trioxide as stripping agents, which produce no toxic waste and can be safely disposed of or recycled, eliminating the harmful effects of cyanide volatility and toxicity
Solution Approach 2:
The patent changes the chemical composition parameters by eliminating cyanide and using alternative chemicals (sulfuric acid, sulfur trioxide, hydrogen peroxide) that achieve the same gold dissolution function without generating toxic waste, thereby changing the environmental and safety parameters of the process
3Productivity
If aqua regia is used for gold stripping, then gold recovery is achieved, but substrate damage occurs
Solution Approach 1:
The patent substitutes the chemical corrosion mechanism of aqua regia with an electrochemical mechanism using controlled voltage application (0.1-4.0V), which selectively dissolves gold through electron transfer without the uncontrolled chemical attack that damages the substrate, thereby preserving substrate integrity while achieving gold recovery
Solution Approach 2:
The patent applies local quality by using selective electrochemical stripping that targets only the gold layer through controlled voltage application, while protecting the underlying substrate from damage, creating a localized effect that dissolves gold without affecting the substrate material
4Productivity
If cyanide-based chemicals are used for gold stripping, then gold dissolution is achieved, but operation cost increases due to waste treatment
Solution Approach 1:
The patent enables discarding and recovering by using a non-cyanide system where the stripping chemicals (sulfuric acid, sulfur trioxide, hydrogen peroxide) can be easily disposed of or recovered without requiring complex waste treatment facilities, thereby reducing operation costs compared to cyanide waste that requires specialized handling and treatment
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 enables efficient gold extraction with reduced environmental impact and operator safety, achieving high gold dissolution rates without substrate damage and minimizing waste, while avoiding the use of hazardous chemicals.
Implementation Method 1
the stripping gold compounds could form a covalent bond with Au and then bring the gold from the surface of substrate
Implementation Method 2
with the assistance of conducting chemical, the working voltage could be controlled as low as no damage to substrate
Data Source
AI summary
The invention provides a stripping gold component which could remove gold from substrate, comprising: a stripping gold chemical compound; and a assistant conductive compound wherein said stripping gold chemical compound bonds with gold to form covalent bond to strip gold from said substrate, said assistant conductive chemical compound helps the electric conduction and decreases the voltage, said substrate would not be damaged after stripping gold from said substrate, and the stripping gold component is cyanide free.