translation.en: After some time, after setting it on fire, you seal it to restrict the oxygen that goes into the kiln, and then you end up with this carbonized material here.
translation.zh: 然后我们点燃甘蔗渣，让它烧一小会儿以后就把炉封好 不要让空气进去 最后就制成了这种炭化材料