定义Definition
索尔维制碱法（氨碱法）以食盐、石灰石和氨为原料生产纯碱（碳酸钠）：向氨盐水中通入 CO₂ 析出溶解度较小的 NaHCO₃，煅烧得 Na₂CO₃；母液中的 NH₄Cl 用石灰乳处理回收氨循环使用。
The Solvay (ammonia–soda) process makes soda ash (sodium carbonate) from salt, limestone and ammonia: CO₂ is passed into ammoniated brine to precipitate the less soluble NaHCO₃, which is calcined to Na₂CO₃; the NH₄Cl in the mother liquor is treated with lime to recover ammonia for reuse.
化学原理Chemistry
NaCl + NH₃ + CO₂ + H₂O → NaHCO₃↓ + NH₄Cl；2NaHCO₃ → Na₂CO₃ + CO₂ + H₂O；CaCO₃ → CaO + CO₂；CaO + H₂O → Ca(OH)₂；2NH₄Cl + Ca(OH)₂ → CaCl₂ + 2NH₃ + 2H₂O。总反应 2NaCl + CaCO₃ → Na₂CO₃ + CaCl₂。氨先使溶液呈碱性，从而能吸收大量 CO₂。
NaCl + NH₃ + CO₂ + H₂O → NaHCO₃↓ + NH₄Cl; NaHCO₃ is calcined to Na₂CO₃; limestone gives CO₂ and lime; lime liberates NH₃ from NH₄Cl. Overall 2NaCl + CaCO₃ → Na₂CO₃ + CaCl₂. Ammonia makes the brine alkaline so it absorbs plenty of CO₂.
由来Origin
比利时化学家欧内斯特·索尔维于 1861 年前后开发，1864 年起建厂，取代了污染严重的吕布兰法。
Developed by the Belgian chemist Ernest Solvay around 1861, with plants from 1864, replacing the polluting Leblanc process.
优缺点Pros and cons
原料便宜、氨循环、产品纯度高；缺点是食盐利用率只有约 70%，并产生大量难以利用的 CaCl₂ 废液。侯德榜的联合制碱法改进了这两点。
Cheap raw materials, recycled ammonia and pure product; but only about 70 % of the salt is used and large volumes of hard-to-use CaCl₂ waste result. Hou Debang's combined process addressed both.
反应Reactions
饱和食盐水吸氨后碳酸化，约 30–40 °C 析出 NaHCO₃；160–230 °C 煅烧
Ammoniated saturated brine carbonated at about 30–40 °C; NaHCO₃ calcined at 160–230 °C
饱和食盐水吸收氨。
Saturated brine absorbs ammonia.
通入 CO₂ 析出碳酸氢钠。
CO₂ is passed in and NaHCO₃ precipitates.
煅烧碳酸氢钠得纯碱，CO₂ 回用。
NaHCO₃ is calcined to soda ash; CO₂ is recycled.
母液加石灰乳蒸出氨循环。
Lime liberates ammonia from the mother liquor for recycling.
关键的碳酸化步骤。
The key carbonation step.
年表Timeline
- 1791
吕布兰法问世
The Leblanc process appears
- 1861
索尔维开发氨碱法
Solvay develops the ammonia–soda process
- 1864
首家索尔维工厂建立
First Solvay plant is built