COPPER ANODES

Copper Metal Anode

Copper Cu 99.99% min.

Analysis
Cu 99.997 % min. O 0.0005 %
Ag 0.0025 % P 0.0005 %
Al 0.0001 % Pb 0.0003 %
Mint 0.0003 % S 0.0010 %
Bi 0.0001 % Sb 0.0002 %
Cd 0.0001 % Se 0.0002 %
Fe 0.0005 % Si 0.0002 %
Hg 0.0001 % Sn 0.0001 %
Mn 0.0001 % Te 0.0002 %
Ni 0.0002 % Zn 0.0001 %

Copper anode – the best solution for metal processing to increase electrical conductivity.
Many manufacturers choose copper anodes for later use in microelectronics, electrotyping,
and copper coating projects.
Copper plating is one of the main areas where copper anodes are used as raw material.
During chemical electrolysis, when a copper coating is applied to a product surface, the anode helps form a protective copper layer on the treated surface.
The properties of copper plating include excellent electrical conductivity, good lubrication, and solderability.
If you have special requirements: contact us, and we will try to assist with any questions.
We work with suppliers both within and outside the European Union, offering multiple options in the field of metal anodes, including different metal forms, such as metal powders.

Properties of a good copper anode
Most often used for galvanization, a copper anode is essential for electrical conductivity. Since it is frequently used in electronic components, automotive parts, printed circuit boards, decorative galvanization, and other applications, poor quality can hinder the entire work. To find a good-quality anode, the following paragraphs compare bad and good-quality copper anodes.
Description of the copper anode
Generally, copper anodes can be classified into two types: pure and phosphorus copper. The main difference is that the latter contains a higher phosphorus content, whereas the first is pure and oxygen-free. They serve different functions; pure copper participates widely in the coating process, while the phosphorus type is mostly found in PCBs. Regardless of the type, a good copper anode should have smooth lubrication, solderability, and electrical conductivity.
Advantages of high-quality copper anodes
Once the anode participates in a project, a good anode will exhibit the following advantages:

• Sludge with low accumulation of impurities
• Purity
• Excellent solubility
• Predictable and measurable electrical conductivity
• Uniformly distributed quality
• Low or normal additive content
• Low likelihood of passivation

Causes of passivation:
The most common problem of poor-quality flake copper anodes is the tendency to passivate. Passivation refers to the reduction of ion transfer between the cathode and the anode. It generally appears as a layer formed on the anode. Additionally, these factors trigger anode passivation in acidic copper electrolytes.

• Excess chlorides: the clearest sign is a light gray-white layer accumulated on the anode. Solution analysis can be performed to confirm.
• Clogged anode slots: blocks the flow, causing the solution to become supersaturated.
• High-concentration solution: another cause, which can be confirmed by solution analysis, is excessively high impurities, such as sulfuric acid or copper sulfate.
• Excessive anode current density: the maximum anode current density is 2.5A/dm2.
• Poor quality or improper anode: check the copper anode content before use.

Phosphoric Acid Copper Anodes

Phosphoric acid copper anodes start from oxygen-free, high-purity copper that meets electronic industry standards.
Adding phosphorus to already oxygen-free and extremely low-impurity copper ensures an efficient, uniform phosphorus content and thus high yield. The copper anodes of phosphoric acid copper anodes are based on the same copper from which the CuOF 2000 grade copper is made.
The production of phosphoric acid copper anodes begins with electrolytic copper cathodes melted in an electric induction furnace in an oxygen-free atmosphere.
A controlled amount of phosphorus master alloy is then added to the molten copper, which is poured under a constant gaseous protective coating. This unique process prevents the formation of harmful oxides or the entry of other impurities.

Cast copper anode under a microscope

Rolled copper anode under a microscope

THE FOUR REASONS WHY PHOSPHORUS-COPPER ANODES PROVIDE MAXIMUM PERFORMANCE:
1. FEWER INSOLUBLE ELEMENTS MEAN SMOOTHER COPPER COATING. CONTROLLED PHOSPHORUS CONTENT PREVENTS ROUGHNESS.
With minimal sludge formation, the likelihood of roughness caused by sludge particle mixing is low.

2. LESS SLUDGE MEANS LESS TANK MAINTENANCE.
The anode’s purity and controlled phosphorus content together minimize the amount of sludge formed on the anode side. Less sludge means less maintenance for tanks, shorter downtime, and increased production.

3. UNIFORM DISSOLUTION
Phosphorus-copper anodes dissolve uniformly, both at the solution level and below the surface. Such uniform dissolution reduces anode wear until the end. In fact, more copper is used for the copper coating, resulting in less waste.

4. LESS POLISHING
Phosphorus-copper anodes allow for thinner copper deposition, as the coating is smooth, uniform, and dense. Non-homogeneous deposits, often reproduced with other anodes, require thicker and heavier copper coating and expensive polishing to achieve the same smooth surface achieved with phosphorus-copper anodes without polishing.

The bright acid copper coating – in the broader context of the corrosion protection system – enables excellent results at low cost, ensuring three requirements: shine, good ductility, and exceptionally smooth surfaces. To maximize the results of processes carried out with bright acid baths, however, high-activity phosphorus-copper anodes must be used.
In the galvanic bath, the copper anode is as important as the solution, the current, or the cathode itself. Therefore, the success of the copper coating also depends on the proper functioning of the anode. Acid copper baths require copper anodes with controlled phosphorus content, generally between 0.04 and 0.06%. Phosphorus actually allows achieving four interconnected goals.

1. Bright, smooth surface.
2. Elimination of copper enrichment in the bath.
3. Reduction of sludge formation in the tank.
4. Faster deposition.
Since the anode efficiency is higher than that of the cathode, phosphorus-free copper anodes dissolve faster in the acid bath than the cathode itself. This leads to accumulation of copper ions and consequently to solution imbalance. In addition, phosphorus-free copper anodes produce metal dust that settles as sludge at the bottom. This sludge problem worsens if the anodes contain insoluble impurities and copper oxides. The more impure the anode, the greater the sludge problem.

Sludge can play an important role in the formation of deposition roughness. Air entering the baths can further carry sludge particles, which migrate to the cathode along with copper ions, creating a rough and uneven coating. Furthermore, sludge causes additional costs for tank drainage, recovery, and maintenance operations.
The role of phosphorus
Phosphorus presence reduces electrical conductivity by dissolving more slowly. Therefore, a phosphorus anode dissolves with lower anode efficiency than a non-phosphorus anode, bringing it closer to the optimal 100% cathode efficiency.
The proper amount of phosphorus prevents the formation of cuprous ions, which may occur if phosphorus-free anodes are used in a sulfate bath.
Cuprous ions oxidize, forming copper ions and metallic copper, creating copper dust that forms the bulk of the sludge. Sludge from phosphorus-copper anodes is generally caused by insufficient phosphorus in the copper, insoluble impurities, or both.
Even and available phosphorus in the solution
Traditional phosphorus anodes are produced by adding phosphorus to electronically refined copper (ETP), which contains varying amounts of oxygen. Part of the phosphorus deoxidizes the copper, and therefore does not bind to it. Only a residual portion of added phosphorus is available. Thus, it is difficult to predict the available phosphorus, as it depends on the oxygen content in the refined copper, typically between 0.025% and 0.05%.
In addition, insoluble phosphorus pentoxides and other anode impurities contribute to roughness and sludge formation.
Low current density pores and points can create copper particles.
As the phosphorus content of deoxidized anodes with residual phosphorus varies randomly, so do porosity and impurities.

PACKAGING:
For PHOS 2000 anodes, the following shapes, sizes, and packaging are available:
SHAPES, SIZES, AND PACKAGING:

Oxygen-Free Alkaline Copper Anodes

USED FOR CYANIDE, PYROPHOSPHATE, AND ACID FLUOBORATE BRIGHT BATHS.
CuOF 2000 anodes are produced using an "oxygen-free" process and are designed to meet the sophisticated requirements of the electronics industry.
The production of CuOF 2000 anodes starts with the casting of the highest quality Class A copper cathodes.
The melting is done in induction furnaces under an oxygen-free atmosphere.
The molten metal is then cast into its final shape, again in a protected atmosphere.
This process prevents the formation of harmful oxides and the introduction of other impurities.

SEVEN REASONS TO USE OXYGEN-FREE ALKALINE COPPER ANODES:

1. THE LONG-GRAIN STRUCTURE HELPS PREVENT ROUGHNESS AND PROMOTES EVEN COVERAGE.
As with other metals, most oxides in copper form in the peripheral grains. These impurities are attacked by the plating bath solutions. Small particles or other impurities present in the peripheral grains can cause roughness in the deposit. The purity and structure of CuOF 2000 anodes provide a more uniform and smoother coverage.
2. THE ABSENCE OF ADDITIVES RESULTS IN SMOOTHER COVERAGE.
Since the lack of oxygen is achieved without adding additives, CuOF 2000 anodes contain no residual contaminants. This reduces the amount of insoluble particles in the bath.
3. LESS SLUDGE MEANS LESS MAINTENANCE FOR TANKS.
The purity of CuOF 2000 anodes helps reduce the amount of sludge in the baths. The absence of copper oxide particles and low levels of other impurities allow minimization of both sludge and film formed on the anode in cyanide baths. The amount of film formed can be controlled by changing the anode current density. CuOF 2000 copper anodes accept higher current density than other conventional anodes.
4. ELIMINATION OF BAGS REDUCES DOWNTIME.
In most cases, the use of contaminant-free CuOF 2000 anodes makes the use of bags unnecessary. This prevents metal accumulation in the bag, thereby reducing cleaning operations: all metal is available for the process without waste. However, using bags tends to slow deposition, and as a result, the number of anodes in the baths must be increased. Additionally, the bag tends to increase the amount of ionized copper in the solution, which increases anode polarization and reduces its efficiency. By eliminating the bag, CuOF 2000 anodes allow operation at higher current densities, enabling faster and more cost-effective deposition.
5. EVEN DISSOLUTION
CuOF 2000 copper anodes dissolve more uniformly than any other anode. In cyanide, fluoborate, and pyrophosphate baths, the anode dissolves completely, minimizing the quantity of anodes to be scrapped.
6. GUARANTEED DEPOSIT THICKNESS MEANS NO WASTE
Even a relatively thin deposit – when made with a CuOF 2000 anode – provides smooth, uniform coverage. To achieve the same result with electrolytic copper anodes, the deposit thickness must be increased.
7. DESIGNED FOR CYANIDE, PYROPHOSPHATE, AND FLUOBORATE ACID BATHS.
In these three baths, using CuOF 2000 anodes allows low-maintenance operation.

TECHNICAL DATA: OXYGEN-FREE ALKALINE COPPER ANODE PACKAGING
The following shapes, sizes, and packaging are available for CuOF 2000 anodes:

SHAPES, SIZES, AND PACKAGING:

TYPICAL IMPURITIES IN DIFFERENT COPPER TYPES:

Microscope image of the CuOF 2000 anode, highlighting the large, dense, inclusion-free grain structure

Copper Plate Anode

Chemical symbol: Cu

Purity: copper cathode purity > 99.99%

Dimensions: full-size copper cathodes: approx. 1000x1000 mm – cut copper cathodes: upon request.

Product description: the copper cathode is the first pure product extracted from the ore. After several weeks of copper sulfate electrolysis, the cathodes are removed and used as plating copper anodes.

The copper cathodes we offer are LME Class A registered. This is the purest quality, with copper content above 99.99%. They are generally 1000x1000 mm in size, with +/- 10 mm thickness.

Usage: These copper cathodes are cut to your size so that they can be used as anodes in alkaline copper baths. These baths can be copper-cyanide and sodium-cyanide or potassium-cyanide based.

Packaging: in bundles – the cut copper strips are delivered on pallets.