Lub Sulfur Crosslinking Challenge hauv Flotation Reagent Service
Sodium diethyldithiocarbamate (SDDC) ntawm 70℃yog siv los ua flotation reagent rau tooj liab thiab zinc ores. PFA encapsulation kev paub txog leej faj-induced crosslinking thaum raug cov ntsiab lus sulfur siab (10-30%) hauv cov tshuaj. Crosslinking nce polymer hardness thiab brittleness, ua rau tawg. Kev txheeb xyuas ntau los ntawm 9 cov chaw ua haujlwm ntxhia qhia tau hais tias PFA nrog cov ntsiab lus sulfur qis dua 15% hauv cov tshuaj qhia pom tias muaj kev sib txuas, thaum cov sulfur siab tshaj 25% ua rau ua tiav embrittlement hauv 6000 teev.
Sulfur Crosslinking Mechanism thiab Cov Khoom Hloov Hloov
Dithiocarbamate tso tawm cov sulfur radicals ntawm qhov kub siab, uas tawm tsam cov chaw tsis txaus ntseeg hauv PFA, tsim kev sib txuas ntawm cov saw hlau. Crosslinking nce hardness (Shore D) thiab txo elongation. Kev ntsuas ntawm 70℃hauv SDDC cov kev daws teeb meem nrog cov ntsiab lus sulfur sib txawv rau 6000 teev:
| Sulfur hauv SDDC Solution (%) | Shore D nce (cov ntsiab lus) | Elongation Retention (%) | Tensile Retention (%) | Crack Formation ntawm 6000h |
|---|---|---|---|---|
| 10% | +3 | 85% | 90% | Tsis muaj |
| 15% | +6 | 75% | 82% | Nto microcracks |
| 20% | +12 | 55% | 65% | Pom cov kab nrib pleb ntawm 100x |
| 25% | +20 | 35% | 45% | Los ntawm - phab ntsa tawg |
| 30% | +28 | 20% | 30% | Ua kom tiav embrittlement |
Crosslinking Kinetics thiab Phab Ntsa Thickness
Crosslinking pib ntawm qhov chaw thiab nce mus rau sab hauv. Rau 2.0mm phab ntsa, crosslinked qhov tob ntawm 6000 teev:
| Tshuaj sulfur | Crosslinked qhov tob (µm) | Phab ntsa Flexible (mm) | Kev nyab xeeb rau 2.0mm? |
|---|---|---|---|
| 15% | 80 | 1.84 | Yog lawm |
| 20% | 200 | 1.60 | Yog lawm |
| 25% | 400 | 1.20 (zeeg) | Ciam teb |
| 30% | 600 | 0.80 | Tsis yog (los ntawm -wall embrittlement) |
PFA Qib Resistance piv
PFA sib txawv formulations qhia txawv txawv rau sulfur crosslinking:
| PFA Qib | Initial Unsaturation | Crosslinking tus nqi ntawm 20% Sulfur | Sijhawm mus rau 10 Ntug Dej D nce (teev) | Kev pab lub neej ntawm 20% Sulfur |
|---|---|---|---|---|
| Standard (kev lag luam) | Siab | Ceev ceev | 2,000 | 4,000h |
| Siab -purity (tsawg unsaturation) | Nruab nrab | Nruab nrab | 3,500 | 7,000h |
| Tshaj tawm -fluorinated | Tsawg | qeeb | 5,500 | 11,000h |
| Stabilized (antioxidant) | Nruab nrab | qeeb | 6,000 | 12,000h |
| Crosslinked (ua ntej-crosslinked) | N/A | Tsis muaj | >10,000 | 20,000h+ |
Qhov kub thiab txias cuam tshuam
Ntawm 70 degree, crosslinking tus nqi raws li saum toj no. Ntawm 60 degree, tus nqi txo los ntawm 50% (20% sulfur: 10 Shore D nce ntawm 4,000h). Thaum 80 degree, tus nqi ob npaug. Sulfur concentration effect yog exponential: 20% sulfur ua 3x crosslinking ntau dua li 15% sulfur.
Core Material Compatibility
Crosslinking tsis cuam tshuam rau cov khoom tseem ceeb, tab sis tawg PFA nthuav tawm cov tub ntxhais rau SDDC:
| Core Hlau | Corrosion hauv SDDC ntawm 70℃(mm / xyoo) | Compatibility nrog Embritted PFA |
|---|---|---|
| Titanium Qib 2 | 0.01 | Zoo (txawm tias raug) |
| Hastelloy C-276 | 0.005 | Zoo heev |
| Stainless hlau 316L | 0.15 | pluag |
| lus 825 | 0.02 | Txais tau |
Specification Qhia rau SDDC Flotation
Rau SDDC cov kev daws teeb meem ntawm 70℃nrog sulfur cov ntsiab lus 15-25%, qhia post-fluorinated los yog ua ntej-crosslinked PFA nrog phab ntsa thickness 2.5mm rau 12,000+ teev kev pab cuam lub neej. Rau cov kev daws teeb meem tshaj 25% leej faj, qhia ua ntej-crosslinked PFA (e-beam, 10% gel) nrog 3.0mm phab ntsa. Yuav tsum tau muab ntawv pov thawj ntawm Shore D nce<10 points after 6000-hour immersion in the specific SDDC solution. For continuous mineral processing (8000 hours/year), select PFA grade with predicted service life >10,000h ntawm qhov tseeb sulfur concentration. Tus nqi them ua ntej -crosslinked PFA (30-50% dhau tus qauv) yog tsim nyog los ntawm kev tiv thaiv embrittlement tsis ua hauj lwm nyob rau hauv flotation reagent kev pab cuam uas unplanned shutdown nqi $10,000-30,000 ib hnub twg. Rau pilot nroj tsuag nrog sulfur<15%, standard PFA with 3.0mm walls and annual replacement may be acceptable.
