42 results about "Dithionate" patented technology

The invention discloses a method for restraining the generation of manganous dithionate in the process of leaching sulfur dioxide gas out of pyrolusite, which comprises the following main technical measures: (1) pyrolusite pulp is prepared by stirring and mixing in the proportion that 100-500g of pyrolusite and 0.2-100g of granular active carbon are added into 1L of water; (2) in a synchronous reaction process of absorbing the sulfur dioxide gas by the pyrolusite pulp, desulphurizing and leaching manganese, the pH value of the pyrolusite pulp is controlled to be lower than 3.5 by blowing oxygen or air into the pyrolusite pulp. The method restraining the generation of the manganous dithionate does not need to extra consume sulphuric acid and guarantee an oxido-reduction potential by extra adjusting the concentration of Fe<3+>/Fe<2+>, is easy to meet the requirement of industrial process production and can guarantee the concentration of a manganese sulfate mother liquor.

The invention provides a method for producing manganese sulfate from manganese oxide ores. The method comprises the steps of mixing the manganese oxide ore powder with an appropriate amount of carbon reducing agent such as pulverized coal evenly, adding concentrated sulfuric acid without adding water and mixing evenly to obtain a mixture, controlling the initial concentration of the sulfuric acid in the mixture to be greater than or equal to 70%, curing the mixture by use of reaction heat via self-heating reduction and reducing the quadrivalent manganese in the manganese ores into bivalent manganese, mixing the cured material with water for stirring and leaching, and filtering the leached ore pulp to obtain a leachate, adding an appropriate amount of manganese oxide ores to the leachate to realize the oxidative decomposition of manganese dithionate, and performing neutralization, purification and impurity removal and crystallization on the solution obtained by filtering to produce the manganese sulfate. The method has the advantages that the low-cost easily available carbon reducing agent such as the pulverized coal is utilized to directly reduce the manganese oxide ores at a low temperature, and therefore, the energy consumption and the cost are low and the smoke pollution problem of reducing roasting is avoided; the manganese oxide ore powder is utilized to realize the oxidative decomposition of the manganese dithionate in the manganese sulfate solution and therefore, the quality of the manganese sulfate product is improved.

The process concerns hydrometallurgical processing of manganese sulphate and manganese dithionate containing liquors and recovery of water therefrom. Sodium sulphate and/or sodium dithionate containing liquors are derived from manganese sulphate and manganese dithionate containing liquids, which are then cooled to produce crystals of sodium sulphate decahydrate and sodium dithionate dehydrate. The sodium sulphate decahydrate and sodium dithionate dehydrate crystals are then heated to a temperature sufficient to decompose the sodium sulphate decahydrate crystals to form anhydrous sodium sulphate crystals, sodium dithionate hydrate crystals and water, after which water is removed from the sodium sulphate and sodium dithionate hydrate crystal. The sodium sulphate and sodium dithionate dehydrate crystals are then heated to form anhydrous sodium sulphate, sulfur dioxide and water or steam. The anhydrous sodium sulphate is then separated from the sulfur dioxide and water.

The invention relates to a preparation method of high-purity lithium sulfide, and belongs to the technical field of preparation of lithium sulfide. The technical problem to be solved by the invention is to provide the preparation method of the high-purity lithium sulfide. The method mainly comprises the following steps: reacting a lithium sulfide precursor (one or more of lithium sulfate, lithium sulfite, lithium bisulfate and lithium dithionate) with a related reducing agent at high temperature to prepare a lithium sulfide-containing substance, and leaching and purifying the lithium sulfide in the mixture; and finally, carrying out spray drying to obtain a lithium sulfide product with purity of 99.9% or above and controllable morphology. The method is simple and easy to operate, free of toxic organic solvents, safe and environmentally friendly, the purity of the obtained lithium sulfide is high and can reach 99.9% or above, the morphology is controllable, and the degree of sphericity is high.

The invention relates to a technology for producing electrolytic metal manganese from low-grade manganese mine. The technological flow comprises ore grinding, sulfuric acid pre-leach, combusting sulfur for preparing sulfur dioxide, sulfur dioxide reduction leaching, solid-liquid separation, purifying of a leaching liquid, separation of dithionate radical, production of electrolytic metal manganese, decomposition of dithionate radical, production of anhydrous sodium sulfate and recovery of production water. The technology is simple, resource is cycled for utilization, the reduction leaching rate of manganese is even up to 98%, and the recovery utilization efficiency is high.

The invention discloses a method for removing manganous dithionate in manganese ore desulfurizing liquid. Persulfate is added into the manganese oxide ore desulfurizing liquid, stirred and dissolved,ferrous sulfate is added, dithionate radical of the manganous dithionate in the manganese oxide ore desulfurizing liquid is oxidized into sulfate radical through sulfate radical and hydroxyl radical generated by high-order oxidation reaction between the persulfate and the ferrous iron, and thus the manganous dithionate in the manganese oxide ore desulfurizing liquid is removed. Through the method,purity of a manganese sulfate mother solution can be improved effectively, no energy needs to be consumed additionally to heat the manganese ore desulfurizing liquid, no acid or alkali needs to be consumed to adjust the pH of the desulfurizing liquid, technological conditions are simple and mild, operability is high, and industrialized application is easy to achieve.

The invention relates to a method for catalytic-degrading polyethylene glycol terephthalate (PET) by dithionate; the method is characterized in that: solid superacid S2O82-/ZnO is used as catalyst, ethylene glycol is used as solvent, and the using amount of the catalyst is 0.01-5.00 percent of the solvent mass, and under the conditions that the reaction temperature is 150-220 DEG C, the pressure is 1atm, and the reaction time is 1-8h, alcoholysis is carried out to the PET polyester. The solid acid catalyst is used in the method, and the method has the advantages of easy separation of products, high selectivity and recycling usage and the like.

The invention provides a passivator for cadmium in neutral soil and an application method thereof. The passivator is composed of calcium oxide with a weight accounting for 0.3-2.0% of the weight of neutral soil, calcium dithionate monohydrate with a weight accounting for 0.3-2.5% of the weight of the neutral soil, and charcoal with a weight accounting for 0.3-1.34% of the weight of the neutral soil. The passivator for cadmium in neutral soil provided by the invention reacts with effective cadmium in the neutral soil by using calcium oxide and calcined gypsum (calcium dithionate monohydrate) so as to generate small-activity cadmium sediments such as cadmium hydroxide and the like, and charcoal and the like in the passivator can selectively adsorb cadmium ions with large activity in the soil so as to reduce the transportability of the cadmium ions, therefore, an effect of reducing the quantity of effective-state cadmium in the neutral soil is achieved, the restoration of contaminated soil is implemented, and a situation that the pH value of the soil before and after the soil is treated is not changed can be ensured.

The invention belongs to the technical field of acid bright copper plating additives and relates to a PEG coupled heterocyclic compound and application thereof in acid bright copper plating. The PEG coupled heterocyclic compound can be used as a leveling agent and a grain refiner, more importantly, can increase the solubility of a slightly soluble component in a brightener in a water phase, effectively avoid the precipitation of the slightly soluble component, meanwhile, improve the compatibility of the slightly soluble component with other components in the brightener, maintain the balance among the components, and avoid the problem of proportional imbalance caused by overlarge consumption speed difference or partial precipitation of the components; the PEG coupled heterocyclic compound,a polyether surfactant and a dithionate compound are pre-prepared into the brightener to be applied to acid copper plating; and through the synergistic effect of the three compounds, the stability ofan MN type brightener system is improved, and meanwhile, the current density range is widened on the basis that good leveling performance is ensured.

This invention relates to solutions of dithionic acid and/or dithionate salts for use in metal finishing processes such as those used for the cleaning, activating, electroplating, electroless plating, conversion coating and/or other pre-treatment or post-treatment of a metallic surface. In particular the solutions are a useful electrolyte for the electroplating of metallic coatings, especially, Sn, Cu, Ni, Zn and precious metals, onto metal or plastic substrates and/or other surfaces.

The invention provides a cycling separation method for manganous dithionate in desulfurized liquid. The method comprises the following steps: (1) desulfurization: carrying out multi-stage countercurrent gas-liquid reaction between slurry containing manganese dioxide ore and ammonium sulfate with flue gas containing sulphur, and carrying out pressure filtration and separation; (2) sulfuration and acidification: introducing a filtrate obtained in step (1) into a hydrogen sulfide gas for sulfuration reaction, carrying out pressure filtration and separation, and acidifying a filter cake to obtain hydrogen sulfide and manganese sulfate products; (3) aftertreatment cycling working procedure: neutralizing the filtrate obtained in step (2) by sulfuration and acidification to reach pH of 7-7.0, carrying out pressure filtration and separation, returning the filtrate to prepare slurry by desulfurization for recycling, and using filter residue for preparing a building material. The method can separate 99.95%-99.96% of manganous dithionate in a manganese sulfate solution.

A process for water removal and/or recycling of sodium sulphate and/or sodium dithionate containing liquors derived from processing a cobalt resource derived from components of lithium ion batteries comprising steps of deriving from the cobalt resource a solution containing cobalt sulphate and cobalt dithionate, precipitation of cobalt as cobaltous carbonate or cobaltous hydroxide followed by removal thereof from the liquor, crystallization of sodium sulphate and sodium dithionate and removal of the resulting crystals, followed by heating of the crystals to anhydrous sodium sulphate, sulphur dioxide and water and then separating the anhydrous sodium sulphate.

A tire tread comprising a rubber composition based on at least one highly saturated elastomer, a reinforcing filler and a vulcanization system is provided. The highly saturated diene elastomer contains 1,3-diene units and more than 50 mol % of ethylene units, the vulcanization system comprises a dithiosulfate salt of formula MO₃S-S-A-S-SO₃M in which the symbol A represents an alkanediyl group or a group comprising two or more alkanediyl units, which units are connected in pairs by means of an oxygen or sulfur atom, of a group of formula —SO₂—, —NH—, —NH₂⁺—, —N(C₁—C₁₆ alkyl)- or —COO—, or of an arylene or cycloalkylene group and the symbol M represents a metal atom. An improved compromise between the bubbling of the tread at the exit of curing presses and its hysteresis can be achieved.

The invention discloses a method for preparing manganese sulfate from manganese-containing ore. The method comprises the following steps: pulverizing and calcining rhodochrosite, pulverizing by a pulverizer, screening, filling a fixed bed reactor with the pulverized rhodochrosite, introducing a gas mixture containing sulfur dioxide, oxygen and water vapor, reacting for 12 hours until the difference between the sulfur dioxide concentration at the reactor inlet and the sulfur dioxide concentration at the reactor outlet is small, stopping introducing the mixed gas, washing with deionized water, and carrying out rough filtration and fine filtration to obtain a filtrate; heating the filtrate, introducing air for 3 hours, adding sulfuric acid to adjust the pH value to 2-4, filtering to remove manganese dithionate, adding ammonia water into a neutralizing tank, clarifying and precipitating, and filtering to remove impurities, thereby obtaining a manganese sulfate clear solution; and further purifying, and preparing battery-grade manganese sulfate. According to the method for preparing manganese sulfate, no reducing substance needs to be added, the process is simple and easy to operate, and the extraction rate of manganese is high.

The invention relates to a method for synthesizing novel macrocyclic polydisulfide gymnorrhizol with an active constitutional formula as follows for resisting II-type diabetes. The method comprises: 3, 3'- disulfide group di (2- hydroxy propyl-1- thiosulfate) reacts with 2-hydroxide radical-1, 3- thioglycerin dibasic salt to obtain the gymnorrhizol, or the 3, 3'- disulfide group di (2- hydroxy propyl-1- thiosulfate) reacts with 2-hydroxide radical-1, 3-trimethylene thiosulfate to obtain the gymnorrhizol. The synthetic method of the gymnorrhizol provided by the invention has a new synthetic route, simple operation; compared with the prior art, the method has high yield and good reproduction quality.