Drug Name: Black Drug Alias: dialkyl thiophosphate mbth: Black Catcher Variety: Properties, characteristics and properties of black liquid. Black powder is widely used in sulfur ore flotation, second only to collector xanthate. 1925 began to be used, and its chemical name is dialkyl thiophosphate, which is divided into dialkyl dithiophosphate and dialkyl thiophosphate. There are many kinds of black drugs, but the varieties used in the early stage are mostly dark brown liquid, so China generally calls them black drugs. In fact, the pure alkyl dithiophosphate is not black, and the name of the foreign literature distributor is Aerofloat Flatt. Black drug can be regarded as a derivative in which two oxygen atoms in dialkyl phosphate are replaced by sulfur. Acid black drug is insoluble in water, but soluble in organic solvents such as aniline. Ammonium salt and sodium salt can be dissolved in water to form turbid liquid. Black medicine is more stable than yellow medicine and is not easy to decompose. After oxidation, similar to xanthate, it can also produce "black powder", which is also a collector of sulfide ore. Characteristics of No.25 black powder Compared with xanthate, the flotation performance of black powder has two main characteristics: (1) low collecting ability and high selectivity, especially for pyrite, so it can be used as a preferential flotation collector for the flotation of copper, lead and zinc sulfide ores with high iron sulfide content, and can obtain better concentrates, and many black powders also have better collecting performance for gold; (2) It has good stability, and can be used at a lower pH value without rapid decomposition.