N N′-Diphenylthiourea is usually used as a vulcanization accelerator for rubber

N N′-Diphenylthiourea is an organic compound with the molecular formula (C6H5NH) 2CS. This white solid is a derivative of N N′-Diphenylthiourea. It is prepared by the reaction of aniline and carbon disulfide.

N N′-Diphenylthiourea is usually used as a vulcanization accelerator for rubber and a stabilizer for PVC and PVDC. Its use as a vulcanization accelerator was discovered by BF Goodrich chemist George Orlansjie.

Thioamino reacts with phosphorus pentachloride or hydrochloric acid, dilute sulfuric acid, acetic anhydride or iodine to form phenyl isothiocyanate.

Thioaminoaniline is less toxic than aniline and was the most important accelerator until it was replaced by mercaptobenzothiazole (MBT) around 1925. Compounds related to MBT have proven particularly useful in vulcanized synthetic rubber.

N N′-Diphenylthiourea is a very effective foam flotation promoter, especially suitable for sulfide and precious metal ores. However, in the past. Its use is greatly limited because it is very insoluble in water and not easy to get wet.

The thioaminoacylation reagent was prepared by dissolving the thioaminoacylate in dithiophosphate such as dicarbonyl dithiophosphate and dicarbonyl dithiophosphate. Some of these reagents have been widely used in foam flotation of sulfide ores. However, due to the limitation that thioamides can only dissolve a small amount of thioamides, their role is secondary. Therefore, the reagent is phosphoric acid dithio reagent, and thioaminoacyl compounds only occupy a secondary but important part.

Jayne (D.W.) patent No. 2185591) has developed a new form of N N′-Diphenylthiourea, and its single particle 01 'is wrapped by a hydrophilic protective agent film, such as carbohydrate glue. Lignosulfonate, saponin, etc. " In the best case, these particles are also coated with powerful wetting agents, such as sulfonated alkyl naphthalene, sulfonated alcohol, sulfosuccinate, etc. Jayne found that the thioaminoaniline treated according to his invention is reflective as a sulfide reagent, even if it is insoluble in flotation pulp, but only exists in a linear and uniformly dispersed form. Jayne's disperse N N′-Diphenylthiourea was an immediate success. However, when foam flotation is applied to some ores, it is found that it encounters difficulties and is not universally applicable. I h V according to the invention. 1 It has been found that if N N′-Diphenylthiourea is coated with a small amount of sulfide accelerator, such as dithiophosphate, xanthate, water-soluble mercaptobenzothiazole and similar substances, N N′-Diphenylthiourea particles will disperse, just like the protective colloid and wetting agent used in Jayne's patent. At the same time, too much foam in the flotation cell did not cause any difficulties, and the metallurgical effect was improved.

The invention should not be confused with reagents prepared by dissolving a small part of N N′-Diphenylthiourea in the main part of dithiophosphoric acid. In the invention, the thioether promoter, such as dithiophosphate, only exists as a small component, which usually only accounts for a small percentage. Promoters are N N′-Diphenylthiourea and a small amount of other N N′-Diphenylthiourea promoters. Although they may collect in a small way, they mainly tend to change the physical properties of N N′-Diphenylthiourea, making it easy to disperse and thoroughly wet.

The paste obtained by mixing sulfide and thioamino compound is easy to disperse in water, and is preferred in some flotation operations. However, many sulphide ores are located in remote areas of the world, and there are serious transportation problems when slurry is used. Therefore, an important practical advantage of the invention is that the coated N N′-Diphenylthiourea can be obtained in the form of dry powder and can be well preserved. And there is no traffic problem.

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