Water rinse

The solutions we offer are based on two main technologies electrolytic silver recovery from fixer solutions and cascade fixing. In what follows we will give more teclmical details about these teclmologies. We will clarify the key-factors to obtain reliable and more ecological solutions for the silver in the rinsing water. 

Depending on the boundary conditions, the optimal technology to decrease the silver in the rinsing water, may either be electrolytic desilvering or cascade fixation. 

To comply with existing and future legislation with respect to silver content in processor rinsing water, the approach developed by Agfa is threefold. 

First, we want to offer G335SF in combination with STRUCTURIX SILVERFIX as a viable solution to customers who want to upgrade their existing equipment (installed base processors) in order to decrease the silver content of their rinsing water. 

Thirdly, a NDT-S type cascade processor will be offered. By implementing a fixing cascade in the processor, large decreases of silver content in the rinsing water are possible, even for large customers. 

Operation nd Control. Control of chromium chromate conversion coating baths is accompHshed by controlling chromium concentration and pH. The quaHty of the conversion coating is sensitive to aluminum accumulations in the coating bath as well as to rinse water purity. Sulfate contamination is a particular problem. 

Following ultrafiltration of whey, the permeate passes over a reverse osmosis (qv) membrane to separate the lactose from other components of the permeate. Reverse osmosis can be used to remove water and concentrate soHds in a dairy plant, giving a product with 18% soHds and thus decreasing the difficulty of waste disposal. Concentration of rinse water gives a product with 4—5% total soHds. Proper maintenance of the membrane allows for use up to two years. Membranes are available for use up to 100°C with pH ranges from 1 to 14 the usual temperature range is 0—50°C. 

Cl recovery of CrO Cr plating rinse water Eltech Retec chrome recovery cell 131... 

FIG. 16"44 Multicomponent ion-exchange process for chromate recovery from plating rinse water. Adaptedfrom Rhom Haas with peimission.)... 

Fig. 6. Top Morphology of FPL surface following fluorine contamination. This is to be compared to the standard FTL morphology of Fig. 14. Middle Climbing drum peel (CDP) strength as a function of F surface concentration. Bottom F concentration on FPL surfaces following doping the FPL etch solution and the rinse water with NaF. The dotted line corresponds to the surface concentration with which the CDP strength began to decrease. Adapted from Ref. [37].

In the pickling process, use countercurrent flow of rinse water use indirect methods for heating and pickling baths. 

Counter-current rinsing and rinse-water reuse are useful tips for reducing usage. Counter-current contact systems are more efficient in promoting heat and mass exchanges, which are important to gas absorption, extraction, and many types of chemical reactions. 

The etched printed circuit boards are washed out with water to dilute the concentration of the contaminants on the board surface to an acceptable level. The extraction of copper from the effluent rinse water is essential for both environmental and economic reasons since decontaminated water is returned to the rinse vessel. 

A schematic representation of the etching process is demonstrated in Fig. 6.6. The proposed copiper recovery scheme is to feed both the spent etchant and the effluent rinse water... 

Spfilwaseer, n. rinsing water wash water flushing water dishwater. 

The disposal of the rinse water is dependent on local effluent restrictions. In some areas, mere dilution will be required before discharge, but in others, the water may have to be stored and the emulsion broken before discharge of the water layer and approved disposal of the organic material. 

The metallic substrate, clean and rinsed, is immersed wet in the plating cell. The base metals which are usually plated present an essentially metallic surface to the electrolyte, and the slight corrosive action of the rinse water in preventing the formation of any substantial oxide film is important. A critical balance of corrosion processes in the initial stages is vital to successful electroplating, and for this reason there is a severe restriction on the composition of the electroplating bath which may be used for a particular substrate. This will be discussed later. The substrate is made the cathode of the cell it may be immersed without applied potential ( dead entry) or may be already part of a circuit which is completed as soon as the substrate touches the electrolyte ( live entry). Live entry reduces the tendency for the plating electrolyte to corrode the substrate in the period before the surface... 

A patchy form of rust that attacks paint films from underneath, can be caused by sweaty hands, residues from fluxes, etc. Examples of the latter include residues from phosphating and soluble salts (including those from unsuitable rinsing water) and they can manifest themselves on steel in the form of a creeping filiform corrosion, i.e. as progressing threads of rust which loosen the coating. This can be followed visually through transparent films. It occurs, however, only when the relative humidity of the surround-... 

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