Animal fats and cold‐pressed vegetable oils hardly need bleaching but when vegetable oils started to be produced by solvent extraction, the resulting oils were too dark to sell as such. That also holds for palm oil. Bleaching these oils with bleaching clay solved their color problems but led to the problem of spent earth disposal. Many ways of treating spent earth and ways of disposal have been suggested and/or developed in the past. They will be reviewed in this paper. Given the recent observation that slurrying spent bleaching earth with crude oil inhibits the deterioration of the residual oil in the earth, leads to the conclusion that, for an integrated oil mill‐cum‐refinery, the best way of spent bleaching earth disposal is the recycling of the earth to the solvent extractor, whereas stand‐alone refineries are advised to sell their spent earth to chicken feed manufacturers. In future, a high‐temperature hydrolysis process that can treat all kinds of fatty waste may become an attractive means of disposal as well.

中文翻译：

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与花漂白地球怎么办？回顾

动物油脂和冷榨植物油几乎不需要漂白，但是当开始通过溶剂萃取生产植物油时，所得油太暗而无法出售。棕榈油也是如此。用漂白粘土漂白这些油解决了它们的颜色问题，但导致了废土处理的问题。过去已经提出和/或开发了许多处理废土的方法和处置方法。他们将在本文中进行审查。鉴于最近的观察结果，即用原油将用过的漂白土制浆，可以抑制地球上剩余油的变质，得出的结论是，对于综合性的炼油厂和精炼厂，用过的漂白土处置的最佳方法是回收利用大地到溶剂萃取器，建议独立炼油厂将废土卖给鸡肉饲料生产商。将来，可以处理各种脂肪废物的高温水解工艺也可能会成为有吸引力的处置方式。