Bleaching Earths - The Complete Guide

As a potential source of material for salt/mineral licks

Bleaching earths and clays are vital for the edible oil industry. Oil producers use these crucial minerals to “bleach” or purify vegetable oils by allowing the bleaching clays to soak up impurities from the processed oil. Without them, our vegetable oils would simply not be fit for consumption. Yet, despite their immense significance, bleaching earths can be poorly understood within the edible oils industry beyond their basic purpose. That is not due to any failure on industry professionals’ part. Bleaching earth mining, processing, and distribution are complex topics, but knowing how these allimportant minerals make their way from the ground into the oil vat can help edible oil producers improve their processes. Multiple types of bleaching earth are utilised across various industries but the oils and fats sector is the largest user, and will continue to lead as population growth drives further consumption. The three basic types of bleaching earth – bentonite, attapulgite and sepiolite – can be used as natural products but they are more commonly refined further for specific industries and uses.

AOCS has experimented with a process to add salt to SBE to eliminate the risk of spontaneous combustion. A salt content as low as 35% can reduce the risk, but for optimal results, a salt content of 45% is recommended. The salt/SBE mixture can then be compressed into a salt-lick brick for cattle and other livestock.