From: Composition, Respirable Fraction and Dissolution Rate of 24 Stone Wool MMVF with their Binder
screening at pH 4.5 | screening at pH 7.4 | pH4.5, (binder removed) | pH4.5 (milled) | pH4.5 respirable (milled + cyclone) | pH4.5 (1/5 lower SA/V) | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Ions (%) | S (%) | k | Ions (%) | S (%) | k | k | k | k | k | SEM morphology before and after after dissolution (full data in SEM Annex) | |
MMVF #17 (pre-1995) | 2 | 95 | 9 | Untreated – smooth surface | |||||||
pH4.5 - very limited change of fibre surface after treatment: minimal roughening, no significant gel formation, no leaching pits. | |||||||||||
MMVF #1 | 11 | 85 | 90 | 4 | 94 | 31 | 171 | Untreated - binder covers entire fibre, including 100 nm to 1 μm sized particles. | |||
pH4.5 - Very limited change of fibre surface after treatment: occasionally approx. 50 nm small leaching pits (pores). | |||||||||||
pH7.4 – significant change of fibre surface, approx. 200nm to 1 μm gel/deposit/crater structures | |||||||||||
MMVF #2 | 9 | 96 | 23 | Untreated - smooth surface, occasional lumps of 100 nm to 1 μm sized particles. | |||||||
MMVF #4 | 10 | 100 | 20 | 7 | 92 | 17 | 39 | Untreated – smooth surface | |||
pH4.5 – very significant change of fibre surface with pronounced gel; frequent occurence of approx. 400nm sized deep craters with sub-100-nm cracks at bottom. | |||||||||||
pH4.5 – without binder, change of fibre surface with limited gel, no cracks, no pits, but approx. 200nm sized shallow structures. Thermal removal more effectiove than plasma removal of binder. | |||||||||||
pH7.4 - very significant change of fibre surface with pronounced, inhomogenously structured gel and/or deposits, up to approx. 400nm large crater | |||||||||||
MMVF #5 | 10 | 85 | 87 | 4 | 97 | 35 | 104 | 122 | Untreated – smooth surface, occasional lumps of 100 nm to 1 μm sized particles. | ||
pH4.5 - significant change of fibre surface with extensive gel formation, leaching with sub-100-nm sized pits and cracks. pH4.5 on respirable-only fraction also induces gel formation, leaching with sub-100-nm sized pits | |||||||||||
pH7.4 - significant change of fibre surface, inhomogeneous leaching through gel with 1-μm-diameter honeycomb structures. | |||||||||||
MMVF #7 | 11 | 94 | 40 | 2 | 99 | 6 | 58 | Untreated – smooth surface, occasional 200 nm sized particles | |||
pH4.5 – significant change of fibre surface with extensive gel formation, up to 4 μm sized leaching pits, occasional micro-cracks and approx. 100 nm large pores. | |||||||||||
pH4.5 – binder removed thermally: no significant gel formation, occasional micro-cracks (intermediate gel formation if binder removed by plasma) | |||||||||||
pH7.4 – very significant change of fibre surface with gel formation and/or deposits of up to approx. 2 μm large crystalline particles | |||||||||||
MMVF #8 | 10 | 97 | 65 | Untreated – smooth surface. Binder covers entire fibre (see ruptured crossings). | |||||||
pH4.5 –significant change of fibre surface with gel formation, numerous up to approx. 100 nm sized leaching pits (pores). | |||||||||||
MMVF #11 | 13 | 85 | 58 | Untreated – smooth surface, occasional lumps of 200 nm to 1 μm sized particles | |||||||
pH4.5 – very significant change of fibre surface with gel formation and deep micro-cracks (3μm x 300nm). Pitting (approx. 1 μm large spots) and approximately 200nm visible pores | |||||||||||
MMVF #12 | 6 | 93 | 36 | 4 | 94 | 27 | 31 | 29 | Untreated – rough surface, lateral cracks | ||
pH4.5 – significant change of the fibre surface, increased smoothness. No significant gel formation, no leaching pits; pH 4.5 on respirable-only fraction: limited gel formation, no significant leaching pits. | |||||||||||
pH7.4 – significant change the fibre surface with pronounced gel formation, inhomogenous leaching, approx. 4μm x 0.5μm sized leaching pits | |||||||||||
MMVF #14 | 8 | 90 | 24 | 4 | 93 | 12 | Untreated – binder covers entire surface, frequent inclusion of approx. 100 nm sized particles | ||||
pH4.5- significant change of fibre surface with gel formation, inhomogenous leaching, up to approx. 500 nm large leaching pits, occasionally up to approx 200 nm wide pits/pores. | |||||||||||
pH7.4 – very significant change of fibre surface with fine grained deposits of approx. 100 to 500 nm sizes. | |||||||||||
MMVF #20 | 7 | 89 | 49 | Untreated – smooth surface, binder covers entire surface | |||||||
pH4.5 – significant change of fibre surface with gel formation and erosion by frequent approx. 50 nm sized leaching pits/pores | |||||||||||
MMVF #21 | 7 | 99 | 23 | Untreated – smooth surface, very rare inclusion of approx. 200 nm sized particles | |||||||
MMVF #22 | 5 | 91 | 17 | 5 | 95 | 15 | Untreated – smooth surface with inclusion of approx 250 nm sized particles. | ||||
pH4.5 – significant change of fibre surface with gel formation; up to 1.5 μm diameter plateaus that have an up to 1 μm long micro crack in their center. | |||||||||||
pH7.4 – significant change of fibre surface with gel formation, approx. 500nm diameter leaching crater | |||||||||||
MMVF #24 | 9 | 91 | 28 | Untreated – smooth surface with occasional inclusion of approx 500 nm particles | |||||||
pH4.5- very significant change of fibre surface with 2 μm diameter plateaus with several approx 50 nm leaching pits on the plateaus | |||||||||||
MMVF #26 | 4 | 93 | 18 | Untreated – structured surface with approx. 200 nm to 1μm diameter elevations. | |||||||
pH4.5 – significant change of fibre surface with gel formation, no leaching pits. |