Treatment for salty process water

Vibratory finishing is a surface finishing process and is often used for deburring and polishing large bulk quantities. The process water produced consists mainly of the aqueous solution (compound) used with the abrasives to treat the workpiece.

In addition to abrasion, the salty process water is also contaminated with oily ingredients from previous process steps. Centrifuges are often used to extend the bath life, which often do not achieve the desired success. The use of a KLC vacuum evaporator extends the service lifetime of bath decisively, the purified distillate is returned to the bath circuit and saves fresh water additionally.

Electroplating technology or electroplating is an electrochemical process in which surfaces are coated with a metallic layer.  

This method is used in the following industries:

• in the classical industries of metal working and processing
• in surface technology 
• in the automotive and aerospace industry 
• in microelectronics 

The resulting process water contains complexing agents and heavy metals. By using the KLC vacuum evaporators in combination with a complete solution of pre- and post-treatment, these ingredients can be removed from the salty process water.

The limit values for zinc and nickel are complied with, and cadmium and chromium VI are safely detoxified.

In surface technology, thorough cleaning is a prerequisite for an optimal result.

During the residue-free cleaning of the surface, salty process water is generated, such as from phosphating, passivation, pickling, anodizing/anodizing and electroplating.

The rinsing water quality is of decisive importance for the purity of the surface to be coated and subsequently for the quality of the subsequent surface coating.

Phosphating is a surface engineering process. The production of a conversion layer is used for corrosion/wear protection or to improve paint adhesion. The process water produced before and after the iron or zinc phosphating process can be treated with a KLC vacuum evaporator.

The rinsing water quality is of decisive importance for the purity of the surface to be coated and subsequently for the quality of the subsequent surface coating.

Passivation is a surface engineering process in which the metallic material is coated with a non-metallic protective layer, thus preventing oxygen corrosion. The rinsing water produced before and after the passivation process can be treated with a KLC vacuum evaporator.

The quality of the process water is of decisive importance for the quality of the surface and its subsequent coating.

Stainless steel pickling is a chemical surface engineering process. Pickling with hydrofluoric acid and nitric acid increases the corrosion resistance of the steel. Rinsing cycles are necessary before and after the pickling process. The resulting saline process water can be treated with a KLC vacuum evaporator.

Hardening is used to increase the mechanical resistance of ferrous materials. This is achieved by heat treatment and rapid cooling (quenching) of the workpiece.

Salt water baths are frequently used as cooling media. They contain, among other things, nitrite- or nitrate-containing AS hardening salts.

After hardening, the workpieces are cleaned for the subsequent process steps. The salty process water can be cleaned with the help of the KLC vacuum evaporator. The hardening salts contained in the concentrate are reused. The almost salt-free distillate is recycled for the rinsing processes.

Used and residually emptied containers and threads are generated in all industrial sectors. After a rinsing process, they can ideally be reused or disposed of cleaned. These include transport containers, drums, reusable packaging and KLTs (small load carriers).

In addition to cleaning agents, the process waters also contain small amounts of all kinds of transport ingredients.

Salty process water can be treated cost-effectively and efficiently by means of the KLC vacuum evaporators. After process water treatment, it is returned to the rinsing cycle. This reduces the amount of concentrate to be disposed of to a minimum. Significant amounts of fresh water can be saved via this distillate reuse.

In numerous sectors, washing and cleaning steps are necessary for the preparation of subsequent production steps.

These include the following industries:

• Automotive 
• Aerospace 
• Tool- and mechanical engineering 
• Hardening plants and foundries

A typical production step is the cleaning of parts after thermal or thermochemical heat treatment.

By using vacuum evaporator technology, washing and cleaning wastewater is treated safely and efficiently.

Reduced fresh water consumption via recirculation and distillate recycling and low energy costs of process water treatment have a positive effect on ongoing operating costs within the parts cleaning.

During the dismantling phase of a nuclear power plant, a large amount of weakly and moderately radioactively contaminated rinsing and cleaning water is generated. With the KLC vacuum evaporator, this contaminated process water can be reduced cost-effectively and efficiently.

The salt- and heavy metal-free, decontaminated distillate can be reused for rinsing and cleaning purposes. The small amount of radioactively contaminated concentrate is further conditioned for interim storage.

Process waters containing precious metals derive from recycling processes in mines, refineries and surface operations. They often contain platinum, palladium, osmium, rhodium and gold.

The electroplating of plastics also produces process waters containing copper and nickel. Here, it is also worthwhile to recover the metals.

Landfill leachate is generated by precipitation and groundwater that seeps and drains through landfills. In the process, chemical compounds from the landfill material are dissolved in the water.

This process water is characterized by high levels of organic pollution and by contamination with water-soluble nitrates, sulfates, chlorides, and heavy metals.

These pollutant loads depend on various factors:

• the type of waste
• the weather conditions
• the biochemical degradation processes (decomposition) in the landfill site

Mine water is formed by precipitation and groundwater seeping through various rock layers. In the process, the process water absorbs water-soluble mineral constituents.

Acid mine water is formed by the oxidation of pyrite, sulfur gravel, chalcopyrite and similar sulfides. Other constituents depend on the materials mined in the mine. In hard coal mining, for example, substances such as sodium chloride, nickel sulfate, iron oxides and manganese are produced.

Mine water is not only produced in active mines. It must also continue to be pumped out and treated in closed mines.