Dithiocarbamate Is By-product Research And Development,

Thionocarbamates are a kind of important sulphide minerals collectors. The properties, synthetic methods and application status of thionocarbamates are reviewed. Synthetic technics of thionocarbamates are emphatically studied. It is regarded the technics that xanthate esterified by organic halide and ammonolyzed by amine is very easy to be practised to produce thionocarbamates. But the by-pruduct therglycolic acid sodium is also made in the technics, which results high cost. So whether the thergiycolic acid sodium solution is treated reasonably will straightly affects the economic efficiency of the technics. By-product isooctyl mercaptoacetate was expoited, largely used to produce heat stabilization reagent of chloroethylene polymer plastic.Firstly, the synthetic technics of O-isopropyl-N-ethyl thionocarbamate was worked over. The optimal conditions determineded by experiments were as follow: chloracetic acid : sodium carbonate : isopropyl xanthate : ethylamine=l : 0.58 : 1 : 1.05(mol), water usage is 30 ml/O.lmol chloracetic acid, esterification temperature was 80癈, esterification time was 2h, ammonolysis temperature was 70 "C, ammonolysis time was Ih. In such conditions, the yield and purity of O- isopropyl-N-ethyl thionocarbamate reached above 96%.Secondly, the treatment to by-product therglycolic acid sodium solution was discussed. After acidified and third class countercurrent extracted by isooctanol, organic phase contended therglycolic acid(150g/L )was obtained. Under the catalysis of P-Toluene sulphonic acid, esterifying reaction took palce in the organic phase and isooctyl mercaptoacetate was made. The studied results showed the esterifiable conditions were that reaction temperature was 110癈, reaetion time was Ih, benzene usage was 30ml/50ml organic phase, P-Toluene sulphonic acid: therglycolic acid=l% : l(mass). Esterifiable yield got to 93%.The account results of material cost indicates that the ratio of gross material cost to production value was decreased 16.1% after exploitingisooctyl mercaptoacetate. Economic efficiency was notablely boosted.