TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The step (a) is carried out in: an aqueous phase; a basic medium, preferably in the presence of an alkali metal or alkaline earth metal hydroxide; and the presence of a surfactant, preferably a nonionic surfactant. The step (b) is carried out under the action of an acid, preferably sulfuric acid. The step (c) is carried out by addition of an oxidizing agent to the reaction medium, where the oxidizing agent is peroxides, such as hydrogen peroxide, organic or inorganic peracids, preferably peracetic acid, and their mixture or mixture with strong acids, for e.g. hydrogen peroxide/strong acids mixtures, the strong acid is sulfuric acid or hydrochloric acid, and the oxidizing agent preferably being hydrogen peroxide. The processing aid is added to the reaction medium during the step (d), where the processing aid is an oil, preferably naphthenic or paraffinic oil type. The bis-DMTD recovered in the solid form is washed with water and then dried at 50-150 degrees C, preferably 70-90 degrees C. The amount of organic matter dissolved in the reaction effluents is very low and results in a chemical oxygen demand (COD) value of less than 10 g/l, preferably less than 2 g/l. Preferred Components: The CS2/N2H4 molar ratio is 1.8-4, preferably 2.2-2.4. The base/hydrazine molar ratio is 0.8-1.5, preferably 1-1.2. The oxidizing agent/DMTD molar ratio is 0.35:1-0.65:1, preferably 0.45:1-0.55:1 EXAMPLE - Water (4000 l), hydrazine monohydrate (800 kg) and 50 wt.% of aqueous sodium hydroxide solution (1300 kg) were added to enameled reactor (16 m3) or a reactor made of stainless steel. The temperature of the reactor was raised to 30 degrees C. Carbon disulfide (2900 kg) were subsequently added over 10 hours at 36-40 degrees C. The hydrogen sulfide released during the reaction was trapped by absorption/reaction in an aqueous sodium hydroxide solution. The reaction medium was heated to 98 degrees C and stripping with nitrogen was carried out for 5 hours. The reaction medium was subsequently cooled to 20 degrees C and then water (2000 l) was added. 42% Sulfuric acid (2200 kg) was added at 20 degrees C with stirring. 35% Aqueous hydrogen peroxide (770 kg) was added at 50-55 degrees C, and then stirring was maintained at 50 degrees C for 2 hours. 85% Neutral solvent oil (36 kg) was added and worked up to give the bis-(dimercaptothiadiazole) (yield 92%).