METHOD OF DETERMINING CONCENTRATION OF SULFUR TRIOXIDE IN BRAWN COAL ASHES (OPTIONS) Russian patent published in 2003 - IPC

FIELD: analytical methods. SUBSTANCE: invention relates to building material area and may be used in manufacture of ash-containing building materials. In the first option, sulfur trioxide is determined involving assaying ash sample for sulfur trioxide and using preliminarily obtained dependence between SO₃ and following indirect characteristics: content of total free lime in ashes [CaO(free,tot)], ash hardening temperature difference (Δt), screening residue of ashes with particle size at least 80 mcm (res. 80). Following two-parameter dependences are used: SO₃ = 0.10+0.54 CaO(free, tot) + 0.13Δt (with correlation factor r=0.76) or SO₃ = 1.01+0.76 CaO(free, tot)-0,23 res. 80 (r=0.91). In the second option, open free lime [CaO(free, open)] is taken into account and following two-parameter dependences are used: SO₃ = 3.23+0.64*CaO(free,open)-0.31 res.80 (r=0.83) or SO₃ = 3.77+0.16 Δt-0.15 res. 80 (r=0.72). In the third option, following two- or four-parameter dependences are used: SO₃ =1.01+0.04 Δt+0.7 CaO(free.tot)-2.1 res.80 (r=0.92) or SO₃=4.7+0.04 Δt+0.95 CaO(free,tot)-0.26 res.80-0.23 CaO(bor.ac), where CaO(bor.ac) denotes concentration of lime in ashes contained in boric acid extract. EFFECT: increased analytical accuracy. 9 cl, 3 tbl, 3 ex