Low flotation recovery, high pulp temperature, and large dosage of reagents are the typical disadvantages when using mixed fatty acids (MFA) prepared from hogwash oil for flotation directly. To determine the type of fatty acid that yields poor flotation performance, flotation performance and adsorption characteristics of saturated fatty acids (SFA) and unsaturated fatty acids (UFA) separated from the MFA were studied in our work. GC-MS, FT-IR, iodine value detection and melting point measurement showed that UFA contained –(CH=CH–CH₂)_n- groups and had much lower melting point. Quartz flotation tests were used to compare the flotation performance of UFA and SFA, which showed that UFA had excellent low-temperature floatability, and the flotation recovery of UFA was 35 percentage points higher than that of SFA at 20 °C and pH = 11.5. Zeta potential, FT-IR and XPS analysis indicated that UFA and SFA could adsorb onto the surface of activated quartz through chemisorption and hydrogen bonding. However, the adsorption of UFA was much stronger and more favorable; thus, the reason MFA have poor flotation performance was the presence of SFA.

中文翻译：

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从猪油中分离出饱和脂肪酸和不饱和脂肪酸浮选性能的比较研究

浮选回收率低，纸浆温度高以及试剂用量大是直接使用由猪油制得的混合脂肪酸（MFA）进行浮选的典型缺点。为了确定浮选性能差的脂肪酸的类型，在我们的工作中对浮选性能和从MFA分离出的饱和脂肪酸（SFA）和不饱和脂肪酸（UFA）的吸附特性进行了研究。GC-MS，FT-IR，碘值检测和熔点测量表明，UFA含–（CH = CH–CH ₂）_n-基团并且具有低得多的熔点。用石英浮选法比较了UFA和SFA的浮选性能，表明UFA具有优良的低温浮选性，在20℃和pH = 11.5的条件下，UFA的浮选回收率比SFA高35个百分点。Zeta电位，FT-IR和XPS分析表明，UFA和SFA可以通过化学吸附和氢键吸附到活化石英表面。但是，UFA的吸附作用更强，更有利。因此，MFA浮选性能差的原因是SFA的存在。