Acetic acid stage optional

A sandstone to be treated can be high in iron compounds such as siderite (iron carbonate), pyrite (iron sulfide), iron oxides, and iron chlorite clay. If this is the case, a separate acetic acid stage may be needed to reduce iron precipitation potential. The recommended acetic acid volume is 20-100 gal/ ft. Acetic acid reacts with carbonates and reduces reprecipitation of dissolved iron compounds through complexation. 

---

For the countercurrent extractor, select column then extract in the bottom menu bar. The acetic acid feed should be input at the top of the column and the pure solvent at the bottom of the column. For thermal option select specify tenperature profile and use 293 on the stages. Select acetic acid as the key component for the first liquid phase and triethylamine as the key component for the second liquid phase. 

Further Preparative Reactions. When pulps are to be used in the production of materials that do not retain the original fiber stmcture, such as rayon or ceUulose acetate film, the lignin, hemiceUulose, and other components must be reduced to the lowest possible concentrations. A surfactant (ionic or nonionic) is often added during a hot, weakly alkaline extraction step after chlorination. Another approach, sometimes used in addition to the surfactant step, is to treat the pulp with 6—10% NaOH after most of the oxidative bleaching is finished. This treatment removes most of the hemiceUulose. In most purification plants the final stage includes use of sulfuric acid chelators are optional. 

---