The present disclosure provides a method for isolation and purification of sodium sulfide (Na2S) formed during desulfurization of petroleum residue. The process involves treating a sludge containing Na2S obtained during desulfurization of petroleum residue with a mixture of at least one organic solvent and water.

Regeneration of sodium sulfite digestion waste liquor

A process for separation and purification of sodium sulfide

A process for producing surface modified carbon black is disclosed. The process comprises the step of treating carbon black with a sulfur compound in an amount in the range of 0.005%-1% of the carbon black to effect in situ formation of surface groups to produce the surface modified carbon black which when combined with a polymer composition alters the carbon black-polymer interaction to decrease the hysteresis of the polymer composition. The curing time required for polymer composition comprising the surface modified carbon black is also decreased. The preferred sulfur compounds are sulfite or sulfate salts.

Process for the production of carbon black

PURPOSE: To obtain an amplifier which has a wide band, a small distortion, high power efficiency and a high effective utility in correspondence with a use state by feeding back a component which compensates a non-linear distortion component to the input side of the amplifier with a wide band and the small distortion. CONSTITUTION: Multifrequency signals S (S 1 ∼S n ) are supplied to the amplifier with wide band and small distortion 24 through an (n) synthesizer 22 and a distortion compensation part 23, and a multifrequency signals being outputs are outputted through a coupler 26 and are inputted to a distortion detection part 28. When the number of input signals and a frequency arrangement change in the multifrequency simultaneous amplifier 20, the distortion detection part 28 detects a spurious component which can be detected under the control of a control part 30, and the distortion component is fed back to the distortion compensation part 23 at a high speed so that the amount of distortion becomes minimum. Consequently, the amplifier which can freely change and use the number of the signals that can be amplified and the frequency arrangement. COPYRIGHT: (C)1989,JPO&Japio

Regeneration of sodium sulfite digestion waste liquor

Citations

A process for separation and purification of sodium sulfide

Process for the production of carbon black

Distortion compensation circuit in multifrequency simultaneous amplifier