Polyoxyethylene Monophenyl Ether Additive for Copper Refining

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Solution Overview

Problem

Conventional methods for producing high-purity copper through electrolysis are time-consuming, environmentally burdensome due to nitric acid use, and result in high sulfur and silver impurities, with additives like PEG and PVA causing slime formation and purity degradation.

Innovation Solution

A non-ionic surfactant additive with a hydrophobic aromatic ring and a hydrophilic polyoxyalkylene group is used in copper electrolysis, reducing slime generation and impurity concentrations by suppressing anode dissolution and electrodeposition, while maintaining a stable molecular chain for controlled bath conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If conventional additives (PVA, PEG) are used to smooth copper surface, then surface smoothness is improved, but sulfur concentration increases and purity degrades

Engineering Contradiction:

Improvesurface smoothnessVSAvoidpurity

Core Design Contradiction:

ShapeVSManufacturing precision

Solution Approach 1:

The patent changes the chemical parameters of the additive by specifying a polyoxyethylene monophenyl ether structure with controlled polyoxyethylene chain length (n=2-15). This structural parameter change allows the additive to provide surface smoothing effects while preventing sulfur incorporation into the copper deposit, thereby maintaining high purity

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite molecular structure combining phenyl groups (hydrophobic) with polyoxyethylene chains (hydrophilic). This composite structure provides both the surface-active properties needed for smoothing and the specific chemical characteristics that prevent sulfur contamination, resolving the contradiction between surface quality and purity

Inventive Principle:

Principle #40Composite materials

2Productivity

If current density is increased to improve productivity, then production efficiency is improved, but slime is blown up and adheres to cathode degrading purity

Engineering Contradiction:

Improvecurrent densityVSAvoidpurity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary anti-action by having the polyoxyethylene monophenyl ether additive pre-adhere to the cathode surface before slime can deposit. This preliminary occupation of surface sites prevents slime adhesion even under high current density conditions with vigorous stirring, allowing high productivity without purity loss

Inventive Principle:

Principle #9Preliminary anti-action

3Object-generated harmful factors

If additive strongly suppresses anode dissolution to reduce slime, then slime generation is reduced, but overvoltage increases and yield decreases

Engineering Contradiction:

Improveslime generationVSAvoidyield

Core Design Contradiction:

Object-generated harmful factorsVSProductivity

Solution Approach 1:

The patent optimizes the parameter of additive concentration (2-500 mg/L) and molecular structure (polyoxyethylene chain length n=2-15) to achieve balanced anode dissolution suppression. The phenyl group provides strong adsorption to reduce slime, while the controlled polyoxyethylene length prevents excessive suppression that would cause high overvoltage and reduced yield

Inventive Principle:

Principle #35Parameter changes

4Manufacturing precision

If two-stage electrolysis is performed to produce high-purity copper, then purity is improved, but time and effort increase significantly

Engineering Contradiction:

ImprovepurityVSAvoidelectrolysis time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent extracts and eliminates the need for the second electrolysis stage by using the polyoxyethylene monophenyl ether additive in the first stage. The additive enables single-stage production of copper with sulfur and silver concentrations of 1 ppm or less, removing the time-consuming second electrolysis step while maintaining high purity

Inventive Principle:

Principle #2Taking out (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

The additive significantly decreases sulfur and silver concentrations in electrolytic copper, improving yield and purity, with a slime generation rate lower than conventional additives, and allows for precise concentration control via HPLC analysis.

Implementation Method 1

a non-ionic surfactant that includes a hydrophobic group containing an aromatic ring and a hydrophilic group containing a polyoxyalkylene group

Methodology Applied

Scientific EffectSurfactant: Surfactant

Implementation Method 2

the additive strongly suppresses dissolution of an anode

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 3

a hydrophobic group containing an aromatic ring

Methodology Applied

Scientific EffectHydrophobic effect: Hydrophobe

Implementation Method 4

a hydrophilic group containing a polyoxyalkylene group

Methodology Applied

Scientific EffectHydrophilic effect: Hydrophile

Data Source

PatentUS10407785B2Additive for high-purity copper electrolytic refining and method of producing high-purity copper

Publication Date: 2019.09.10 MITSUBISHI MATERIALS CORP

AI summary

The additive for high-purity copper electrolytic refining of the present invention is an additive which is added to a copper electrolyte in electrolytic refining for high-purity copper and is formed of a non-ionic surfactant that includes a hydrophobic group containing an aromatic ring and a hydrophilic group containing a polyoxyalkylene group.