Method for treating ferric trichloride etching waste liquor

Abstract

The invention relates to a method for treating ferric trichloride etching waste liquor, in particular to a method for treating the ferric trichloride etching waste liquor containing nickel, which mainly adopts a two-stage extraction method to remove iron so as to achieve the complete separation of the nickel and the iron, wherein a first stage extraction organic phase combination comprises 15 to 40 percent of extractant, 10 to 20 percent of synergist and 40 to 75 percent of diluent agent according to the volume ratio; a second stage extraction organic phase combination comprises 20 to 50 percent of extractant, 5 to 10 percent of synergist and 40 to 75 percent of diluent agent according to the volume ratio; the extractants and the synergists used in the two stages have various selections; and under the condition that the technological parameters are controlled strictly, with the two stages of extractions, the iron contained in the etching waste liquor is regenerated into a liquid state ferric trichloride product, and the nickel is regenerated into a nickel chloride product. The method overcomes various defects of the prior art, has good iron and nickel separation effect, high efficiency and low cost, achieves the resource recycling of valuable metals to the utmost extent while achieving the decontamination of the ferric trichloride etching waste liquor, and has board technique application prospect.

Description

technical field [0001] The invention relates to a method for processing ferric chloride etching waste liquid, in particular to a method for processing nickel-containing ferric chloride etching waste liquid. technical background [0002] In the production process of printed circuit boards, high concentration liquid FeCl is usually used 3 To etch shadow masks composed of iron group metals and refractory metals such as nickel. Using high-concentration ferric chloride as etching solution can make the whole etching reaction proceed gently without generating bubbles, thus producing a shadow mask with dense surface and good quality. However, as the etching process continues, during the etching process, ferric chloride will be reduced to ferric chloride by the etched metal iron and nickel, and the produced nickel chloride will also enter the etching solution. In this way, the concentration of ferric chloride in the etching solution decreases, and the etching efficiency and effect ...

AI Technical Summary

Problems solved by technology

[0009] (1) Diaphragm electrolysis method: the equipment is complicated, the membrane material depends on imports, the processing cost is high, and the separation effect of nickel and iron is poor

[0010] (2) Evaporation and concentration crystallization method: the iron trichloride or nickel chloride purity of this method crystallization gained is low, often occurs that nickel chloride is arranged in the ferric chloride product, and iron trichloride phenomenon is arranged in the nickel chloride product, has limited Application of recycled products

[0011] (3) Alkali neutralization step-by-step precipitation method: high production cost, incomplete separation of ferronickel

[0014] ①The iron powder used is expensive and the processing cost is high

In this process, when iron is used to replace nickel, there will still be Fe with a content of more than 15% in the discharged etching waste liquid. 3+ reduced to Fe 2+ , after the replacement is completed, it is necessary to use chlorine gas to remove the Fe in the solution 2+ reoxidized to Fe 3+ , this process of first reduction and then oxidation wastes a lot of iron powder, and also increases the amount of chlorine gas, resulting in higher processing costs

[0015] ②There is often a large amount of iron in the nickel slag produced by this method, resulting in low nickel grade, and the production cost of nickel recovery in the next step is higher

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