Industrial Inorganic Chemistry, Glass Raw Materials & Soda Ash
Solvay Soda Ash Process Salt, Limestone & CaCl2 Yield Formula
Calculate Dense Soda Ash Na2CO3 Production (t/d), Quarried Limestone CaCO3 Kiln Feed (t/d), Byproduct Calcium Chloride CaCl2 (t/d), and Unreacted Brine NaCl Slip (t/d).
Aqueous NaHCO3 precipitation equilibrium caps Solvay NaCl utilization around ~74%—generating >1 ton CaCl2 per ton soda ash!
Synthetic Dense Soda Ash Na2CO3 (MW = 106.0 g/mol, essential for flat/container glass, lithium carbonate precipitation, and detergents) is manufactured globally from saturated salt brine NaCl (MW = 58.5 g/mol -> 2 moles = 117.0 g) and calcined limestone CaCO3 (MW = 100.0 g/mol) via an internal ammonia-recycle loop: overall net stoichiometry is 2NaCl + CaCO3 -> Na2CO3 + CaCl2 (MW = 111.0 g/mol)! Because sodium bicarbonate NaHCO3 precipitation in the Solvay carbonation tower reaches ionic solubility equilibrium near U_NaCl = 72%–76% single-pass brine conversion, every 117 tons of NaCl converted produces 106 tons of Na2CO3 alongside 111 tons of CaCl2 distiller waste + unreacted NaCl!
Verify on a 585.0 t/d Brine-Salt Solvay Plant (10,000 kmol/d NaCl = 5,000 stoichiometric Na2CO3 equivalents, B2) at Tower_Salt_Utilization U_NaCl = 0.74 (74.0%, B3) and Quarried_Limestone_Purity = 0.95 (95.0 wt% CaCO3, B4): Soda Ash Na2CO3 Produced hits (585 / 117) * 0.74 * 106 = 392.20 t/d (E2), Raw Limestone Kiln Feed equals ((585 / 117) * 0.74 * 100) / 0.95 = 389.47 t/d (E3), Byproduct CaCl2 Generated equals 410.70 t/d (E4), and Unconverted NaCl in Distiller Blowdown equals 585 * 0.26 = 152.10 t/d (E5)!
| Solvay Soda Ash KPI (585 t/d NaCl, 74% Utilization, 95% Pure Limestone) | Formula | Verified Output |
|---|---|---|
| Soda Ash Na2CO3 Output (t/d) | (NaCl_t_d / 117) * Salt_Util * 106 | 392.20 t/d (360.40 @ 68% util) |
| Raw Limestone Kiln Feed (t/d) | ((NaCl_t_d / 117) * Salt_Util * 100) / Purity | 389.47 t/d (357.89 @ 68% util) |
| Byproduct CaCl2 Formed (t/d) | (NaCl_t_d / 117) * Salt_Util * 111 | 410.70 t/d (377.40 @ 68% util) |
| Unreacted NaCl Blowdown (t/d) | NaCl_t_d * (1 - Salt_Util) | 152.10 t/d (187.20 @ 68% util) |
Solvay Carbonation-Tower Soda Ash & Limestone Stoichiometry Formula
Validate Salt_Feed > 0, Salt_Utilization in [0.50, 0.85] (thermodynamic solubility ceiling), and Limestone_Purity in [0.80, 1.0]!
=LET(nc_t, B2, ut_s, B3, lm_p, B4, IF(OR(nc_t <= 0, ut_s < 0.5, ut_s > 0.85, lm_p < 0.8, lm_p > 1), "Invalid Solvay Input", ROUND((nc_t / 117) * ut_s * 106, 2)))Warm Cooling-Water Tower Solubility Loss Check (Set Salt Utilization = 0.68)
Simulate warm summer cooling water raising NaHCO3 solubility in the carbonating tower so Salt_Utilization B3 drops from 0.74 to 0.68: Soda Ash Output E2 falls to 360.40 t/d while Unreacted NaCl Blowdown E5 climbs to 187.20 t/d!
=IF(ISTEXT(E2), E2, ROUND(B2 * (1 - B3), 2))Try the example
Use the original values or change them to test your understanding.