The production methods of lanolin mainly include the following:



1. Extracting lanolin from washing wastewater:
   - Add washing wastewater to aluminum chloride to obtain a slurry containing lanolin.
   - Remove water to obtain the slurry.
   - Mix the slurry with benzene and heat it, then stop stirring and allow it to settle.
   - After clarification, transfer the benzene solution to a distillation tower and distill to obtain crude lanolin.

2. Preparation of pharmaceutical-grade lanolin by neutralizing benzene:
   - Put the crude lanolin into a reaction vessel, heat it, and add hot sulfuric acid solution for stirring and precipitation.
   - After settling, add ethanol and water to the benzene layer, heat again, and stir to precipitate.
   - Repeat the above steps to obtain acid-treated benzene.
   - Add ethanol and sodium hydroxide solution to the acid-treated benzene, adjust the pH, add water, and stir.
   - After precipitation, obtain neutralized benzene.
   - Treat the neutralized benzene with hydrogen peroxide, precipitate, distill, and wash with ethanol to obtain pharmaceutical-grade lanolin.

3. Refining lanolin using inert gas hydration:
   - Use lanolin acid and lanolin alcohol as raw materials, add potassium hydroxide, and conduct a high-temperature reaction under continuous inert gas (such as nitrogen) flow.
   - After cooling, obtain lanolin in a solid, paste-like form.
   - Add sodium hypochlorite, methanol, and hydrochloric acid for bleaching.
   - Wash the bleached product with hot water, separate the oil phase, and repeat the washing.
   - After cooling, obtain a light yellow solid product, which is then vacuum-dried to obtain lanolin.

4. Preparation method for ultra-pure lanolin:
   - Mix crude lanolin with adsorbents and low-grade organic solvents, heat for adsorption, and filter to remove the adsorbents.
   - Slowly cool the filtrate to a low temperature range for cold crystallization, and filter again to remove high-melting point components.
   - Flow the filtrate into a packed silica gel chromatography column and use gradient elution with solvents of different polarities.
   - Collect the eluate, concentrate and recover the solvent under reduced pressure to obtain ultra-pure lanolin.

Note that the production methods of lanolin may vary due to different raw materials, equipment, and process conditions. In practical operations, suitable production methods and process parameters should be chosen based on specific circumstances. Additionally, the quality and safety of lanolin depend on control and management during the production process, so strict adherence to relevant standards and regulations is essential to ensure product quality and safety.