依法取得危险化学品安全生产许可证、危险化学品安全使用许可证、危险化学品经营许可证的企业，凭相应的许可证件购买剧毒化学品、易制爆危险化学品。民用爆炸物品生产企业凭民用爆炸物品生产许可证购买易制爆危险化学品。前款规定以外的单位购买剧毒化学品的，应当向所在地县级人民政府公安机关申请取得剧毒化学品购买许可证

Gold smelting is the last process in gold production, and its product is finished gold. Smelting can be divided into roughing and refining. Refined and roughened products are alloys (commonly known as synthetic gold). Most of the gold in China's gold mines is synthetic gold, which is directly so

Activated carbon is one of the commonly used substances in organic synthesis experiments. It is mainly used to decolorize and remove impurities. According to the basic experiment book of chemistry, the standard use method of activated carbon is thermal filtration and decolorization before recrystall

(1) Pulverized coal configuration: lignite or bituminous coal and coking coal are crushed to ≤ 2mm respectively, then mixed according to the mass ratio of lignite or bituminous coal: coking coal = 1:0.2-0.5, and then ground to 74 μ M or less to obtain pulverized coal with uniform mixing;(2) Emulsi