Cov Khoom Siv Nyiaj Sib Txuas Thiab Cov Nyiaj Plating Cov Khoom Siv Siv Hluav Taws Xob: Ib txoj hauv kev los ntawm kev siv cov khoom siv rov ua dua tshiab kom siab dua -Vimage Regeneration

In electrical, electronic, and power control equipment, silver electrical contacts are widely used in key components such as relays, switches, and circuit breakers due to their excellent conductivity, resistance to arc erosion, and stable contact resistance. However, with the accelerated pace of equipment upgrades, a large amount of silver-containing waste-including scrapped Solid Silver Contacts, silver-plated copper parts, and silver alloy contacts-enters the recycling process. How to efficiently and environmentally extract high-purity silver from this waste is not only crucial for resource conservation but also directly impacts the sustainability of the precious metals supply chain. Currently, the wet silver extraction technology based on mixed acid dissolution-precipitation reduction has become one of the mainstream solutions in the industry due to its simple operation, high recovery rate (>95%), thiab haum rau me me - mus rau nruab nrab - nplai ua.

Cov nyiaj sib tiv tauj rau cov keyboards thiab cov nyiaj plating pov tseg feem ntau muaj cov nyiaj los yog cov nyiaj alloys (xws li AgCdO, AgNi) coated rau tooj liab, hlau, lossis tooj dag substrate. Lub hauv paus ntawm nws cov khoom siv rov ua dua yog nyob rau hauv kev xaiv stripping nyiaj txheej yam tsis muaj kev puas tsuaj rau lub substrate, tso cai rau rov qab siv cov substrate ncaj qha thaum ua tiav siab -purity nyiaj rov qab.

Cov txheej txheem no siv cov sulfuric acid-nitric acid tov kua qaub ua cov nyiaj stripping tov. Nitric acid (HNO₃) ua raws li lub zog oxidant, oxidizing hlau nyiaj rau hauv Ag⁺ ions soluble; sulfuric acid (H₂SO₄) muab qhov chaw siab - acidity ib puag ncig, inhibiting nitric acid decomposition, txo cov tshuaj volatility, thiab txhim kho cov tshuaj tiv thaiv stability. Qhov sib tov sib txawv me ntsis nyob ntawm cov khoom siv:

Silver contacts rau relay (khoom khov lossis tuab txheej): 80% H₂SO₄ + 20% HNO₃ raug pom zoo

Nyiaj-plated pov tseg (nyias txheej, xws li nyiaj-plated tooj liab terminals): 85% H₂SO₄ + 15% HNO₃ yog siv los qeeb corrosion ntawm tooj liab substrate.

Cov tshuaj tiv thaiv yog nqa tawm ntawm 70-80 degree. Cov nyiaj sib tiv tauj rau MCCB yuav tsum tau 10–30 feeb, thaum nyiaj-plated qhov chaw, vim lawv cov txheej nyiaj nyias nyias, tuaj yeem ua tiav hauv 5–10 feeb. Thaum lub sij hawm tus txheej txheem, nyiaj nkag mus rau hauv cov tshuaj nyob rau hauv daim ntawv ntawm Ag⁺. Cov tooj liab substrate yog passivated nyob rau hauv concentrated sulfuric acid thiab yog qhov tseem ceeb tsis cuam tshuam los ntawm corrosion. Tom qab yaug nrog dej huv, nws tuaj yeem raug muag raws li siv tooj liab.

Txawm hais tias lub hauv paus ntsiab lus ntawm cov txheej txheem no yog qhov yooj yim, nws yuav tsum muaj kev ua haujlwm siab heev hauv cov ntsiab lus ntawm kev ua haujlwm:

Tswj dej nruj: Tag nrho cov khoom siv yuav tsum qhuav, thiab dej yuav tsum tsis txhob tov rau hauv cov tshuaj tiv thaiv. Dej dilutes cov kua qaub concentration, ua rau nitric acid decompose hnyav thiab tsim NO₂ roj, uas kuj yuav ua rau txaws.

Precise Temperature Control: Hauv qab 70 degree, cov tshuaj tiv thaiv qeeb dhau; saum toj no 80 degree, acid volatilization intensifies, thiab txoj kev pheej hmoo ntawm tooj liab substrate corrosion nce. Nws raug nquahu kom siv lub da dej kub tas li los yog qhov kub thiab txias - tswj cov kua qaub- cov tshuaj tiv thaiv tank.

Silver Stripping Solution Recycling: Cov tshuaj tuaj yeem rov qab siv tau kom txog thaum cov nyiaj ions saturated lossis acidity txo, uas ua rau txo qis ntawm cov nyiaj stripping efficiency. Lub sijhawm no, kev daws teeb meem yuav yog xiav xiav (muaj Cu²⁺) lossis huab, qhia tias kev siv yuav tsum raug txiav.