? Processing method of alum

This product is potassium aluminum sulfate crystal, which is refined from ettringite or other aluminum ore.

job operation

First, purification: removing impurities (Pharmacopoeia 85).

Second, cut: mashed in time (Pharmacopoeia 85).

Third, roasting: dried alum.

(1) Take clean white powder, grind it into small pieces, put it on a smokeless place or in a suitable container, take it out when it is crisp, cool it and crush it (Pharmacopoeia 85).

(2) Take the alum and put it into the pot, and cook it until the alum turns into water, and then the water dries, and the body expands and the color turns white (fusion).

(3) Take pieces of alum, break them, put them into an iron pan, heat and melt them, calcine them until they are all loose and white-honeycomb, take them out and let them cool to get the finished product (Ningxia).

Modern research

1. The traditional method of calcining dried alum often leads to the phenomena of "dirty bottom", "grasping raw material" and "pulling top", so a drying furnace should be used to prepare dried alum. The temperature is controlled at about 14O degrees, and it can be taken out and cooled after 3 hours. The water loss rate is 40%. Compared with the traditional method, the quality of this method is obviously improved (Zhang Jing et al.: Science and Technology of Chinese Herbal Medicine, (67): 28, 1984).

2. The antibacterial effect of dried alum on Pseudomonas aeruginosa was observed by agar plate drilling method. The concentration is above 0.2-0.3g/ml, the diameter of bacteriostatic circle is above 20mm, and the sensitivity is high (Wu: Journal of Nanjing College of Traditional Chinese Medicine, (1): 46, 1985).

3. The weight loss rate, solubility and aluminum ion of calcined alum products under different conditions were measured and compared. The results show that alum loses most of its crystal water at about 200℃. At or above 600℃, part of potassium aluminum sulfate decomposes into alumina and releases sulfur oxide. Alum is calcined in charcoal fire, which takes about 4 minutes to cook thoroughly. There is 7.07 1% potassium aluminum sulfate decomposition, and it is speculated that the temperature is above 800 degrees.