Ca3(PO4)2 + 3SiO2 + 5C = 3CaSiO3 + 5CO + 2P
v (P) = m / M = 93000 / 31 = 3000 моль
v (Ca3(PO4)2) = 0,5 v (P) = 1500 моль
m (Ca3(PO4)2) = v * M = 1500 * (3 * 40 + 2(31 + 4 * 16)) = 465000 г
ω (Ca3(PO4)2) = m / m (фосф-тов) * 100% = 465000 / 620000 * 100% = 75%
Ответ: ω = 75 %