| 摘要 |
The invention relates to a process for producing leather from animal skins. In a first step, the animal skins are treated with milk of lime and optionally sodium sulphide to produce leather preproducts. The leather preproducts are then delimed in a vessel (1) containing an aqueous treatment liquid by addition of carbon dioxide to the treatment liquid. Owing to the resulting shift in the pH, the sulphidic compounds still present in the protein structure of the leather preproducts are converted into mercaptans and hydrogen sulphide. To prevent any escape of these volatile, toxic, aggressive and malodorous compounds, it is proposed that the treatment liquid have added to it an oxidising agent, especially technically pure oxygen. For this the treatment liquid is withdrawn from the vessel (1) and transferred into a reactor (6). Carbon dioxide and oxygen are passed into the reactor via lines (14, 11). The treatment liquid loaded with the carbon dioxide and the oxygen is finally returned into the vessel (1) via line (15). |
