Sodium sulfide

About: Sodium sulfide is a research topic. Over the lifetime, 2851 publications have been published within this topic receiving 27733 citations. The topic is also known as: disodium sulfide.

Hydrogen sulfide pretreatment of lignocellulosic materials in alkaline pulping processes

Abstract: DIRECTION OF THE SUPPORT TUBE (8) AND WHICH WHILE THE REACTOR IS IN OPERATION IS SUPPORTED ON THE LOCKING PLATE (5,6), AND WHILE THE REACTOR IS SHUT DOWN IS SUPPORTED ON THE SLEEVE TUBE (3) BY MEANS OF A PAWL DEVICE (14), THE LENGTH OF TRAVEL OF THE AUXILIARY TUBE (12) BEING SUCH THAT WHEN THE PAWL DEVICE IS IN OPERATION THE SUPPORT TUBE (8) IS AT LEAST PARTLY RELIEVE OF THE WEIGHT OF THE MODERATOR COLUMN. 1. IN AN ALKALINE PULPING PROCESS IN WHICH LIGNOCELLULOSIC MATERIAL IS PRE-TREATED WITH HYDROGEN SULFIDE, IN WHICH THE PRE-TREATED MATERIAL IS DIGESTED UNDER HEAT AND PRESSURE IN AN ALKALINE DIGESTING LIQUOR COMPRISING A SODIUM BASED DIGESTING AGENT TO FORM THE PULP, IN WHICH THE DIGESTED PULP IS SEPARATED FROM THE DIGESTING LIQUOR AFTER DIGESTION, AND IN WHICH THE DIGESTING LIQUOR IS PROCESSED FOR RECOVERY OF THE ALKALINE DIGESTING AGENT, THE IMPROVEMENT WHICH COMPRISES: PROVIDING FROM THE DIGESTING LIQUOR PROCESSED FOR RECOVERY OF THE ALKALINE DIGESTING AGENT, A HIGH SULFIDITY LIQUOR CONTAINING AT LEAST ONE MEMBER SELECTED FROM THE GROUP CONSISTING OF SODIUM SULFIDE AND SODIUM HYDROSULFIDE AND HAVING A SULFIDITY OF ABOUT 75% TO 200% AND A WEIGHT RATIO OF SULFUR TO SULFUR PLUS SODIUM OF FROM ABOUT 0.35-0.58; CONTACTING THE LIGNOCELLULOSIC MATERIAL WITH SAID HIGH SUFIDITY LIQUOR IN A PRE-TREATMENT VESSEL PRIOR TO ALKALINE DIGESTION; INTRODUCING CARBON DIOXIDE GAS INTO SAID HIGH SULFIDITY LIQUOR IN SAID VESSEL, IN AN AMOUNT IN EXCESS OF STOICHIOMETRIC TO GENERATE HYDROGEN SULFIDE FROM SAID HIGH SULFIDITY LIQUOR; MAINTAINING THE TEMPERATURE IN SAID PRE-TREATMENT VESSEL WITHIN THE RANGE OF ABOUT 120 TO 165*C. FOR ABOUT 20 TO 200 MINUTES AND UNDER A PARTIAL PRESSURE OF HYDROGEN SULFIDE GAS OF ABOUT 10 TO 80 P.S.I. TO EFFECT REACTION BETWEEN HYDROGEN SULFIDE AND THE LIGNOCELLULOSIC MATERIAL IN SAID PRE-TREATMENT VESSEL TO INCREASE PULP YIELD OVER THAT OBTAINED BY AN ALKALINE PULPING PROCESS IN WHICH THE LIGNOCELLULOSIC MATERIAL IS DIGESTED IN SAID ALKALINE DIGESTING LIQUOR; SEPARATING PRE-TREATED LIGNOCELLULOSIC MATERIAL FROM THE ACCORDING TO WHICH THE SUPPORT TUBES PASS THROUGH THE BOTTOM OF THE REACTOR VESSEL AND ARE PROVIDED AT THE OUTER END WITH AT LEAST ONE PLUG WHICH ACTS AS A RADIATION SHIELD AND A COOLING-GAS SEAL, IN WHICH THE SUPPORT TUBE (8) IS FIXED IN A SLEEVE TUBE (3) BY MEANS OF A LOCKING PLATE (5, 6) SUCH THAT BETWEEN THE SUPPORT TUBE (8) AND THE SLEEVE TUBE (3) THERE IS AN ANNULAR GAP (11) CONTAINING AN AUXILIARY TUBE (12) WHICH IS MOVABLE IN THE AXIAL

Treatment of waste water

Abstract: PURPOSE: To efficiently remove mercury contained in waste water, by a method wherein an oxidizing agent is added to a mercury-containing waste water to ionize mercury, thereafter mercury is brought into reaction with a sulfide to form mercury sulfide, and then mercury sulfide is precipitated by adding (a) flocculant CONSTITUTION: Treating steps are constituted by providing a sewage-receiving tank 1, a mixing tank 2 for sodium sulfide, a mixing tank 3 for a flocculant such as ferric chloride, a pH-adjusting tank 4, a mixing tank for a polymer flocculant and a precipirating tank 6 In this case, the treating efficiency can be enhanced by providing an adding tank 2A for an oxidizing agent on the upstream of the tank 2 and ionizing mercury contained in the waste water so that mercury can easily react with sodium sulfide or the like The oxidizing agent may be chlorine, ozone, a hypochlorite, a permanganate a peroxide such as hydrogen peroxide or the like Accordingly, the efficiency in removing mercury contained in waste water in a precipitating treatment can be enhanced COPYRIGHT: (C)1983,JPO&Japio

Heavy-metal-polluted soil remediation additive

Abstract: The invention provides a heavy-metal-polluted soil remediation additive which is prepared from the following components in parts by weight: 85-92 parts of kaolin, 1-15 parts of sodium sulfide, 2-6 parts of ferric sulfate, 1-6 parts of magnesium-containing preparation, 5-10 parts of apatite and 2-8 parts of calcium oxide. The invention also provides a soil remediation method by using the remediation additive, which is used for converting metal ions in the heavy-metal-polluted soil into water-insoluble compounds, such as sulfides and the like. The heavy metals lose activities and are fixed into the soil. By using the heavy-metal-polluted soil remediation additive and remediation method, the polluted soil can be effectively remediated within a short time.

Precipitating-hydrothermal preparation with high visible light catalytic activity nano CdxZn1-xS photocatalyst

Abstract: The invention discloses a deposition-hydrothermal method for producing a nano-sized CdxZn S photocatalyst with high visible-light photocatalytic activity The method includes the following steps: 1) adding dropwise a mixed solution of cadmium nitrate and zinc nitrate into a sodium sulfide solution, stirring at a medium rate for 05-3 hours, maintaining the temperature at 10-40 DEG C to obtain a nano-sized powdery precursor precipitate; 2) placing the nano-sized powdery precursor precipitate in a reaction vessel, raising the temperate at a rate of 1-5 DEG C/min up to 150-240 DEG C, maintaining the temperature, allowing hydrothermal reactions for 12-24 hours, stopping the hydrothermal reactions, naturally cooling down to room temperature, taking out the reaction products, washing with the deionized water and the anhydrous alcohol for 3-4 times, drying at 50-80 DEG C in a vacuum drying oven to obtain a solid solution of nano-sized CdxZn S photocatalyst The production method is carried out in water phase with easy operation and low cost The product has uniform distribution of particle size, the forbidden band width and optical properties thereof are controlled by changing components, and the product has high visible-light photocatalytic activity and good prospects in industrial application