About acid purification

Luova Acid Purification (L-APU)

In the acid pickling of steel or chemical milling of Titanium, metals are continuously dissolved in the pickling solution. If the dissolved metals reach a critical level, problems in the process start to occur, such as metal salt precipitation which forms sludge.

The Luova Acid Purification Unit removes dissolved metals from the pickling acid. The dissolved metals are fed to waste or neutralization plant and the pickling acid is recovered to the pickling bath.


About acid purification

In most ion exchange operations, an ion in solution is replaced with an ion from the resin and the former solution ion remains with the resin.

In contrast, ion retardation chromatography uses the ion exchange resin as an adsorption or separation media, which provides an ionic environment, allowing two or more solutes in the feed stream to be separated.

In 1963 Melvin J. Hatch and John A. Dillon discovered and reported that Acid Retardation is a physical method for separation of strong acids from their salts. Acid retardation is defined by them, since this kind of separation is based on a preferential absorption of strong acids, which causes the movement of the acids on the bed to be retarded – i.e., slowed down – relative to the movement of the salt.

All APU systems from Luova is based upon this great principle.

Economically advantages

  • - Reduce consumption of raw acid
  • - Reduce chemicals used in the neutralization plant
  • - Reduce solid waste sludge to landfill


  • - Maintain consistent dissolved metal concentration
  • - Increase productivity due to less frequent dumping
  • - Less down time for sludge removal in the pickling tanks.

Surface quality

  • - Maintaining consistent pickling parameters produces a more consistent surface
  • - Reduce scrap and re-process due to poor surface quality

Environmental impact

  • - Reduce nitrates emission to environment
  • - Reduce purchase of raw acid
  • - Reduce chemicals used in the neutralization plant
  • - Reduce Hauling to landfill

Improved safety

  • - Avoiding the dangerous work of manually cleaning the pickling tanks

All systems delivered have the advantage of Luova's excellent maintenance program. All spare parts are kept in stock for immediate delivery.

Our Products

The Mini L-APU

Compact, affordable and efficient The compact Mini L-APU offers a capacity of 200-250 l/hr. The metal removal

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The expandable system The modular L-APU offers a capacity of 800 l/hr for each module. The modules

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Luova Automated Acid Filter The L-AAF is using the same FUNDABAC® technology as the PENTA. It is

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