Showing papers on "Sodium sulfite published in 2017"
TL;DR: In this research, degradation of P-Nitrophenol (PNP) as a model nitro-aromatic compound was carried out by photocatalytic process using magnetic Titania nano particles (MTNPs) using a second order reduced polynomial model.
54 citations
TL;DR: In this article, the potentials of S(IV) species were investigated on a renewable graphite electrode as the dependence on the concentration of these particles, electrode potential and pH of solution.
44 citations
TL;DR: Results of this study indicate that ammonium thiosulphate may be an optimal chelating ligand for phytoextraction due to its great potential to enhance Hg accumulation in plants while decreasing bioavailable Hg concentration in the soil.
43 citations
TL;DR: In this article, a novel process of recovering from high tellurium-bearing materials by alkaline sulfide leaching followed sodium sulfite precipitation is developed, where the influences of Na 2 S concentration, leaching temperature, liquid to solid ratio and leaching time were studied during the leaching process.
33 citations
TL;DR: The intention of this study was to evaluate the effect of the reactive additives sodium sulfite, sodium dodecyl sulfate (SDS), and urea on the oxygen barrier, water vapor barrier, and protein solubility of whey protein cast films.
Abstract: Whey protein coatings and cast films are promising for use as food packaging materials. Ongoing research is endeavoring to reduce their permeability. The intention of this study was to evaluate the effect of the reactive additives sodium sulfite, sodium dodecyl sulfate (SDS), and urea on the oxygen barrier, water vapor barrier, and protein solubility of whey protein cast films. The concentration of the reactive additives was 1 to 20 wt.-%. Dried whey protein cast films were used as substrate materials. The water vapor transmission rate, the oxygen permeability, and the protein solubility were measured. Effective diffusion coefficients and effective sorption coefficients were calculated from the results of the water vapor sorption experiments. The presence of sodium sulfite resulted in an increased number of hydrophobic interactions and hydrogen bonds and a slightly decreased number of disulfide bonds. The oxygen permeability decreased from 68 to 46 cm³ (STP / standard temperature and pressure) 100 µm (m² d bar)-1 for 1 wt.-% SDS in the whey protein cast film. The water vapor transmission rate decreased from 165 to 44 g 100 µm (m² d)-1 measured at 50 to 0 % r. h. for 20 wt.-% SDS in the whey protein cast film. The reduction in the water vapor transmission rate correlated with the lower effective diffusion coefficient.
33 citations
TL;DR: In this article, a renewable acidic resin which was prepared by one-step condensation/sulfation of sodium sulfite, cyclopentanone and formaldehyde followed by ion-exchanging was found to be a highly active and stable catalyst for the production of 5-hydroxymethylfurfural (HMF) by the dehydration of fructose and inulin.
32 citations
TL;DR: In this paper, the effect of two sacrificial agents (methanol and sodium sulfite) on the photocatalytic reduction of 4-nitrophenol employing a ZrO2-TiO2 photocatalyst is reported.
Abstract: The effect of two sacrificial agents (methanol and sodium sulfite) on the photocatalytic reduction of 4-nitrophenol employing a ZrO2–TiO2 photocatalyst is reported. The experimental results showed a decrease in the generation of OH˙ radicals and diminution in the charge transfer resistance that favor the electron transfer toward 4-nitrophenolate ions. Based on the results, it is possible to establish that methanol acts as a hole scavenger while sulfite ions act as radical scavengers, improving the reduction from 4-nitrophenol to 4-aminophenol. The synergistic effect has been corroborated by photoluminescence and photoelectrochemical measurements.
24 citations
TL;DR: HCA showed that both sunset yellow and sodium sulfite had synergistic effects on cell number, membrane permeability, mitochondrial membrane potential, intracellular calcium level, oxidative stress, and high dose group DNA damage.
24 citations
TL;DR: In this article, a new strategy for the efficient reduction of nitroarenes using sodium sulfide as reducing agent with MOF-derived Co 3 S 4 as catalyst in water and at room temperature was developed.
23 citations
TL;DR: In this paper, a two-chamber setup was used to synthesize DABCO·(SO2)2 (abbreviated as DABSO) in a closed system overcomes safety issues related to working with toxic SO2 gas.
20 citations
TL;DR: In this paper, the effect of sodium sulfate and sodium sulfite on the corrosion behavior of carbon steel in CO2 capture process with methyldiethanolamine (MDEA) solution has been studied under an absorber temperature condition (50 °C).
Abstract: The effect of sodium sulfate and sodium sulfite on the corrosion behavior of carbon steel in CO2 capture process with methyldiethanolamine (MDEA) solution has been studied under an absorber temperature condition (50 °C). The corrosion behavior was evaluated using electrochemical methods, weight loss measurements, and surface analytical techniques. Sodium sulfate increased the system corrosiveness and the rate of corrosion increased with concentration while sodium sulfite reduced the corrosion rate and the inhibition performance improved with concentration. Weight loss measurements showed an increase in corrosion rate with time for sodium sulfate while the inhibition performance for sodium sulfite was considerably low for the tested concentration.
TL;DR: In this paper, softwood kraft lignin was modified via sulfuric acid and sodium sulfite treatments in order to valorize its potential end-use applications, and the elemental compositions, molecular weights, and thermal and rheological properties of modified Lignin samples were characterized.
Abstract: Kraft lignin is produced in great quantities in many countries, but is mainly used as an energy source. To valorize its potential end-use applications, softwood kraft lignin was modified via sulfuric acid and sodium sulfite treatments in this study. The modification of kraft lignin through a sulfuric acid treatment resulted in a modified lignin (SA-lignin) with a charge density of 0.8 meq/g but with a limited water solubility. The sulfonation of the kraft lignin through a sodium sulfite treatment induced a soluble sulfonated lignin (SS-lignin) with a charge density of 1.4 meq/g, which was obtained under the conditions of 90 °C, 4 h, and 0.67 Na2SO3/lignin molar ratio. The elemental compositions, molecular weights, and thermal and rheological properties of modified lignin samples were characterized.
TL;DR: In this article, a neutral sulfite semichemical (NSSC) pulping process, wood chips are pretreated with sodium sulfite and sodium carbonate solution, and their thermal properties were determined.
TL;DR: In this paper, the authors used a quartz tube-hydrous pyrolysis at 360°C for thermal degradation of aromatic organic sulfur compounds and found that the extent of degradation of each compound showed good correlations with its aromatic stabilization and strongly depended on the added inorganic sulfur species, with DBT being the most stable and 2-OT the least stable.
TL;DR: In this article, a sulfite biosensor based on immobilization and bioelectrocatalysis of human sulfite oxidase (hSO) on indium tin oxide (ITO) was reported.
Abstract: In this paper we report a sulfite biosensor based on immobilization and bioelectrocatalysis of human sulfite oxidase (hSO) on indium tin oxide (ITO). Stable immobilization of catalytically active enzyme in a direct electron transfer configuration was achieved after modification of ITO with aminopropyltriethoxysilane (APTES). The electrochemical characteristics of the hSO modified electrode have been investigated by cyclic voltammetry for various pretreatment and binding conditions. Amperometry was utilized to demonstrate the current responses of the sulfite sensor toward sodium sulfite in an aqueous solution under the optimized conditions. The proposed sulfite sensor exhibits a fast response and high sulfite sensitivity with a linear range of 0.5 to 2 μM. An additional polyvinyl alcohol (PVA) cover membrane was applied to extend the linear working range. As a result, the upper concentration in the linear range for the sulfite sensor was extended from 2 μM to 20 μM for 5 % PVA. In addition, the sulfite sensor with PVA has improved storage stability when kept in 0.5 mM Tris-buffer, pH 7.0 at 4 °C.
TL;DR: In this article, an isophthalaldehyde bisulfite adduct (IBA) was synthesized using a reaction between sodium sulfite and isophalaldehyde, which was then used as the starting monomer for the synthesis of poly[2,2′-(m-phenylene)-5,5′-bisbenzimidazole] (PBI).
Abstract: An isophthalaldehyde bisulfite adduct (IBA) was synthesized using a reaction between sodium sulfite and isophthalaldehyde. Isophthalaldehyde monosulfite adduct (IMA) was inevitably synthesized during the reaction. Because IBA and IMA have similar solubility in water, it is difficult to separate them through a recrystallization process. In order to obtain pure IBA, an excess of sodium sulfite was used. Highly pure IBA was subsequently obtained without the need for recrystallization. The IBA was then used as the starting monomer for the synthesis of poly[2,2′-(m-phenylene)-5,5′-bisbenzimidazole] (PBI). Previous isolation methods for IBA hindered the synthesis of high molecular weight PBI. This new synthetic procedure produces high-purity IBA, which can be used to synthesize high molecular weight PBI. © 2017 Society of Chemical Industry
Patent•
24 May 2017
TL;DR: In this article, a double-layer coated slow-release nitrogen fertilizer for improving saline-alkali soil is presented, which is composed of the following raw materials in parts by weight: 55-70 parts of urea, 22-30 parts of ammonium phosphate, 35-50 parts of acrylic acid, 15-25 parts of wheat straw, a right amount of distilled water, 2-7 parts of potassium hydroxide, 05-2 parts of sodium borohydride, 10-16 parts of humic acid, 8-12 parts of anhydrous
Abstract: The invention discloses a double-layer coated slow-release nitrogen fertilizer for improving saline-alkali soil The nitrogen fertilizer is composed of the following raw materials in parts by weight: 55-70 parts of urea, 22-30 parts of ammonium phosphate, 35-50 parts of acrylic acid, 15-25 parts of wheat straw, a right amount of distilled water, 2-7 parts of potassium hydroxide, 05-2 parts of sodium borohydride, 10-16 parts of humic acid, 8-12 parts of anhydrous sodium sulfite, 5-9 parts of formaldehyde solution, 3-7 parts of ammonium persulfate, 1-3 parts of N,N'-methylenebisacrylamide, 9-16 parts of sodium alginate, a right amount of 5% calcium chloride water solution, 2-4 parts of paraffin, 2-4 parts of furfural residue, 4-10 parts of attapulgite clay, 2-5 parts of dilute sulfuric acid and a right amount of sodium hydroxide solution According to the invention, the humic acid is modified to enhance the water solubility, and the urea fertilizer effect and the nitrogen utilization ratio are increased, thereby improving the water absorption property, water retention property and salt tolerance of the slow-release fertilizer
Patent•
08 Mar 2017
TL;DR: In this article, a slow-crosslinked high-strength jelly profile control water-plugging agent is presented, which has excellent thermal stability, does not lose water after hot treatment at a temperature of 60-90 DEG C for 270 days and can satisfy the requirements on most of deep oil reservoir displacement.
Abstract: The invention discloses a slow-crosslinked high-strength jelly profile control water-plugging agent. The slow-crosslinked high-strength jelly profile control water-plugging agent comprises, by mass, 0.3% to 0.6% of a hydrophobic associating polymer, 0. 3% to 0.6% of a melamine resin crosslinking agent, 0.03% to 0.05% of a phenol crosslinking agent, 0.2% to 0.4% of an oxygen scavenger, 0.1% to 0.3% of a delayed crosslinking agent, 0.1% to 0.2% of a water loss inhibitor and the balance water. The phenol crosslinking agent comprises one or two of resorcinol and hydroquinone. The oxygen scavenger comprises one or more of thiourea, sodium sulfite and sodium bisulfate. The delayed crosslinking agent comprises one or two of ammonium chloride and sodium trimetaphosphate. The water loss inhibitor comprises one or two of sodium malonate and sodium salicylate. The gelatinization time of the jelly provided by the invention is adjustable and is 6 days or more. After gelatinization, the jelly strength at least reach to level H based on visual inspection. The water-plugging agent has excellent thermal stability, does not lose water after hot treatment at a temperature of 60-90 DEG C for 270 days and can satisfy the requirements on most of deep oil reservoir displacement.
Patent•
09 Jun 2017
TL;DR: In this article, a double-layer enveloped slow-release nitrogen fertilizer with high water retaining property is presented, which consists of the following raw materials in parts by weight: 55-70 parts of urea, 20-30 parts of ammonium phosphate, 35-50 parts of acrylic acid, 16-23 parts of wheat straw, appropriate distilled water, 2-7 parts of potassium hydroxide, 0.5-2 parts of sodium borohydride, 10-16 parts of humic acid, 6-12 parts of anhydrous sodium sulfite
Abstract: The invention discloses a double-layer enveloped slow-release nitrogen fertilizer with high water retaining property. The double-layer enveloped slow-release nitrogen fertilizer consists of the following raw materials in parts by weight: 55-70 parts of urea, 20-30 parts of ammonium phosphate, 35-50 parts of acrylic acid, 16-23 parts of wheat straw, appropriate distilled water, 2-7 parts of potassium hydroxide, 0.5-2 parts of sodium borohydride, 10-16 parts of humic acid, 6-12 parts of anhydrous sodium sulfite, 4-9 parts of formaldehyde solution, 3-7 parts of ammonium persulfate, 1-3 parts of N,N'-methylene bisacrylamide, 10-15 parts of sodium alginate, appropriate 5% calcium chloride aqueous solution, 2-4 parts of paraffin and appropriate 10% sodium hydroxide solution. In the invention, through modifying treatment on humic acid, the water solubility is improved; and then through copolymerization with pretreated straw and acrylic acid, wheat straw-g-polyacrylic acid/humic acid super absorbent resin with a macromolecular network structure is formed, the fertilizer efficiency of urea and the utilization rate of nitrogen are improved, and the water absorbing and retaining property and salt resistance of the slow-release fertilizer product are enhanced.
TL;DR: In this paper, the effect of time, pH, temperature, and pH on mercury desorption using sodium sulfite was studied with a series of batch experiments. And the results showed that desorization rate of mercury increased rapidly in the stage of 0 to 1h, after that, a much slower stage appeared.
Abstract: An effective reagent for mercury desorption from contaminated soil is a key condition for mercury remediation. Effects of time, pH, temperature on mercury desorption using sodium sulfite were studied with a series of batch experiments. Results showed that desorption rate of mercury increased rapidly in the stage of 0 to 1 h, after that, a much slower stage appeared. Desorption rate reached 92.05% with 0.7 mol/L sodium sulfite at 25°C in 24 h. Moreover, potential value increased rapidly from −162 to –31 mV in desorption of 1 h. It indicates that desorption process was a process of Hg(II) turning into Hg(I). A higher pH (10.5) or temperature (35°C) was helpful to increase mercury desorption rate. Furthermore, small fold and curves appeared in the surface of soil particles presented by scanning electron microscopy (SEM) show that soil particles may be destroyed in desorption process using sodium sulfite. The desorption of Hg from contaminated soil was accomplished within a reductive solution provided by sodium sulfite.
Patent•
21 Nov 2017
TL;DR: In this paper, a high-temperature-resisting filtration-loss reducer for drilling fluid is presented, which is prepared from the following raw materials, including acrylamide, acrylic acid, 2-acrylamido-2-methylpropane sulfonic acid and N-vinylpyrrolidone.
Abstract: The invention discloses a preparation method of a high-temperature-resisting filtration-loss reducer for drilling fluid. The high-temperature-resisting filtration-loss reducer is prepared from the following raw materials, including acrylamide, acrylic acid, 2-acrylamido-2-methylpropane sulfonic acid and N-vinylpyrrolidone; the optimum condition for synthesis is that the four monomers are used in parts by weight: 35-45 parts of acrylamide, 25-30 parts of acrylic acid, 25-35 parts of 2-acrylamido-2-methylpropane sulfonic acid and 5-8 parts of N-vinylpyrrolidone, which are subjected to aqueous solution polymerization to obtain the high-temperature-resisting filtration-loss reducer; the reducer also comprises 1-3 parts of an initiator assistant, namely chitosan Mn-bentonite; the reaction temperature is 30-40 DEG C, the reaction time is 8h, the ratio of oxidation/reduction initiator, namely n sodium persulfate to n sodium sulfite being 1.2 to 1, 0.3 part by weight of the initiator, is adopted, and the optimum pH value of a monomer solution is 7-8. The product can resist high temperature of 210 DEG C, and the filtration loss reducing effect is good.
Patent•
17 Nov 2017
TL;DR: In this article, a method for removing chlorine in waste zinc electrolyte was proposed, in which excessive sodium sulfite is added into the zinc electrolytes to enable the whole waste zinc ion electrolyte to be in a reducing state, and the reducibility of the zinc ion is guaranteed.
Abstract: The invention discloses a method for removing chlorine in waste zinc electrolyte. According to the method, excessive sodium sulfite is added into the waste zinc electrolyte to enable the whole waste zinc electrolyte to be in a reducing state; Cu2+ in the waste zinc electrolyte is fully reduced to Cu+, the reducibility of the waste zinc electrolyte is guaranteed, and Cu+ in the subsequent dechlorinated slag and dechlorinated slag treatment underflow is prevented from being oxidized; decoppered slag, a zinc leaching solution and the dechlorinated slag treatment underflow are added; an authigene product has a reduction reaction and a precipitation reaction in the solution through ingenious application of a zinc hydrometallurgy process, and chloride ions in a sulfuric acid containing zinc sulfate solution are removed. The content of chlorine returning to the chlorine in the leaching process is reduced. Accordingly, the requirement that the content of chlorine in the waste zinc electrolyte is lower than 300 mg/L home and abroad is met. The chlorine removal rate can reach up to 80% or above. Operation is easy. The practicality is high. At the same time, zinc is enriched in a decoppering solution, and the recovery rate of zinc is increased.
Patent•
24 May 2017
TL;DR: In this paper, a double-layered coated water-retention slow-released fertilizer capable of releasing negative ions is described. But the method is not suitable for use in agriculture.
Abstract: The invention discloses double-layered coated water-retention slow-released fertilizer capable of releasing negative ions. The double-layered coated water-retention slow-released fertilizer is prepared from the following raw materials in parts by weight: 55 to 70 parts of urea, 20 to 30 parts of ammonium phosphate, 30 to 40 parts of acrylic acid, 14 to 25 parts of wheat straw, a proper amount of distilled water, 2 to 7 parts of potassium hydroxide, 0.5 to 2 parts of sodium borohydride, 12 to 16 parts of humic acid, 5 to 10 parts of anhydrous sodium sulfite, 5 to 10 parts of a formaldehyde solution, 3 to 7 parts of ammonium persulfate, 1 to 3 parts of N,N'-methylene-bisacrylamide, 10 to 16 parts of sodium alginate, a proper amount of a 5 percent calcium chloride water solution, 2 to 4 parts of paraffin wax, 4 to 8 parts of tourmaline powder, 2 to 5 parts of inorganic clay, 2 to 4 parts of nano negative ion powder, 1 to 3 parts of red pine polyphenol and a proper amount of a 10 percent sodium hydroxide solution. According to the double-layered coated water-retention slow-released fertilizer, the humic acid is subjected to modification treatment so that the water solubility is improved; the fertilizer effect of the urea and the utilization rate of nitrogen are improved; the water absorption and water retention properties, and salt resistance of the slow-released fertilizer are improved.
Patent•
10 May 2017
TL;DR: In this article, a substitution reaction of a saturated aqueous solution of sodium sulfite and a chloro dihydroxy compound was carried out for the generation of a sodium dihydroxyl sulfonate compound.
Abstract: The invention relates to generation of a sodium dihydroxyl sulfonate compound by a substitution reaction of a saturated aqueous solution of sodium sulfite and a chloro dihydroxy compound; a dehydration reaction is carried out for the sodium dihydroxyl sulfonate compound obtained by the step and excess dehydrating agents, after the reaction, excess dehydrating agents are removed; residual sodium dihydroxyl sulfonate is removed by washing and extracting the reaction products; drying and purification are carried out in order to obtain a hydroxy substituted sultone compound; a fluorination reaction is carried out for the obtained hydroxy substituted sultone compound and a fluorating agent, underpressure distillation and purification are carried out, and the fluorosultone compound is obtained. The method has the advantages of cheap raw material, easy purchase, simple operation steps, mild reaction conditions, short reaction steps, easy purification, and high purity of produced products.
06 Jan 2017
TL;DR: In this paper, the decolorization of a series of azo dyes by sulfite aqua was studied under UV light irradiation and in the dark, respectively, and the decoloration efficiency reached up to 95.9% in 10min and 95.8% in 20min, using 1.0g/L sodium sulfite, respectively.
Abstract: In this paper, the decolorization of a series of azo dyes by sulfite aqua was studied under UV light irradiation and in the dark, respectively. Soluble azo dyes were easily decolorized with high decolorization efficiency under UV light irradiation, while their decolorization efficiency was much lower in the dark. The ultraviolet light is of the utmost importance for the rapid decolorization of azo dyes. As for the 10 mg/L Methyl Orange and Congo Red exposed to UV light, the decolorization efficiency reaches up to 95.9% in 10 min and 95.8% in 20 min, using 1.0 g/L and 8.0 g/L sodium sulfite, respectively. Whereas, for the same concentration of azo dyes and sodium sulfite, the decolorization efficiency of Methyl Orange and Congo Red is only 13.8% and 25.6%, respectively, even if they are laid in the dark with sodium sulfite for 48 h. The decolorization process of Methyl Orange and Congo Red follows the first order rate kinetics. The location of absorption peak in the visible region is blue-shifted in the co...
Patent•
26 Apr 2017
TL;DR: In this article, the authors provided a thickened oil thermal production channel blocking nano-composite gel, which is a mixture of partially hydrolyzed polyacrylamide and malonic acid chromium.
Abstract: The invention provides thickened oil thermal production channel blocking nano-composite gel The gel comprises, by weight, 04-05 part of a main agent, 01-03 part of an organic chromium cross-linking agent, 01-05 part of an inorganic chromium cross-linking agent, 1-15 parts of a reinforcer, 02-04 part of a stabilizer, 01-05 part of a dehydration inhibitor and the balance water, wherein the sum of the weight parts of the components is 100 The main agent refers to partially hydrolyzed polyacrylamide The organic chromium cross-linking agent refers to malonic acid chromium The inorganic chromium cross-linking agent is sodium bichromate, and the ratio of the sodium bichromate to sodium sulfite is 1:1-3 The reinforcer is silica soil nano particles, and the ratio of the silica soil nano particles to amino silane is 2-5:1 The stabilizer is thiourea The dehydration inhibitor is one or a combination of polyphosphates and phosphoro-amidate The ratio of the polyphosphates to the phosphoro-amidate is 1-4:1 during combination According to the thickened oil thermal production channel blocking nano-composite gel provided by the invention, the gel forming temperature can be selected to be 50-180 DEG C, the gel forming time is adjustable within the range of 12-60h, gel strength is high, viscoelasticity is good, temperature resistance water-holding power is high, no dehydration phenomenon happens after ageing for 3 months under the temperature condition of 180 DEG C, and steam channeling caused in the thickened oil thermal production process can be blocked selectively
Patent•
05 Sep 2017
TL;DR: In this article, a comprehensive utilization method of acid-making flue gas produced in a gold smelting plant is presented, which consists of the following steps: treating cyanide pulp with acid making waste gas; absorbing sulfur dioxide in lower-concentration acid-makings waste gas with a sodium hydroxide solution to produce a high-conscentration sodium sulfite solution.
Abstract: The invention provides a comprehensive utilization method of acid-making flue gas produced in a gold smelting plant. The comprehensive utilization method comprises the following steps: treating cyanide pulp with acid-making waste gas; absorbing sulfur dioxide in lower-concentration acid-making waste gas with a sodium hydroxide solution to produce a high-concentration sodium sulfite solution; removing cyanide from the cyanide pulp produced in the gold smelting plant under the synergistic effect of the sodium sulfite solution and the air; performing filter pressing on the treated pulp; recycling clear liquid produced by filter pressing into a production process flow of the gold smelting plant; piling and storing filter residues in a tailing pond after the filter residues reach a general industrial solid waste standard. The comprehensive utilization method has the advantages of simple process flow, stable treatment effect, high pollutant removing rate, low running cost and low building cost; meanwhile the aim of treating waste by waste is fulfilled.
Patent•
12 Dec 2017
TL;DR: In this paper, a method for preparing pure gold from silver anode mud through potential control is presented, which has the advantages of being high in gold direct recovery rate, stable in technological process and high in product purity, and the environmental pollution problem existing in a traditional aqua regia dissolution method.
Abstract: Provided is a method for preparing pure gold from silver anode mud through potential control. The silver anode mud is leached out in a nitric acid solution, after nitric acid leaching residue is immersed and digested in concentrated sulfuric acid, coarse gold powder is obtained, hydrogen peroxide is added into a hydrochloric acid solution containing the coarse gold powder to conduct potential controlling and gold leaching by chlorination, slurry is subjected to solid-liquid separation after being cooled, gold leaching liquid is added into sodium hydroxide and sodium sulfite to conduct potential controlling and reduction, and reduction gold powder is obtained, and after the reduction gold powder is subjected to concentrated sulfuric acid refining, pure gold powder is obtained. According to the method for preparing the pure gold from the silver anode mud through potential control, a potential control mode is adopted to achieve adjustment and controllability of the process for preparing the pure gold from the silver anode mud, the gold powder with the purity being 99.99% is prepared, the direct recovery rate of gold reaches to over 99.9%, the method has the advantages of being high in gold direct recovery rate, stable in technological process and high in product purity, and the environmental pollution problem existing in a traditional aqua regia dissolution method is solved.
Patent•
17 Oct 2017
TL;DR: In this paper, an absorption and post-treatment method for exhaust gas electrolysis is provided, in which skylight exhaust gas is absorbed and electrolyzed through a weak base solution, an economical and effective technical means is provided; and by effectively treating pollutants in exhaust gas, byproducts are obtained.
Abstract: Provided is an absorption and post-treatment method for exhaust gas electrolysis. The method comprises the following steps that (1) a sodium hydroxide solution is prepared as an absorption solution or seawater is adopted as the absorption solution; (2) the absorption solution is sprayed into a ventilator through a sprayer to be mixed with exhaust gas; (3) part of the saturated absorption solution is reserved, the rest of the absorption solution is filtered to separate solid impurities out, and filtrate is collected; (4) lime milk is injected into the filtrate to absorb sodium fluoride, filtering separation is conducted, and then solid-phase calcium fluoride and sulfur-containing filtrate are prepared; (5) lime milk is injected into the sulfur-containing filtrate to absorb sodium sulfite, filtering separation is conducted, and then solid-phase calcium sulfite and a solution rich in calcium ions are prepared; and (6) the reserved part of the saturated absorption solution is mixed with the solution rich in calcium ions, precipitate is generated, filtering separation is conducted, and then secondary solid-phase calcium fluoride and a non-calcium solution are prepared. By adoption of a novel technique that skylight exhaust gas is absorbed and electrolyzed through a weak base solution, an economical and effective technical means is provided; and by effectively treating pollutants in exhaust gas, by-products are obtained.
Patent•
14 Jul 2017
TL;DR: In this article, a method for treating SO2 in flue gas and producing anhydrous sodium sulfite, which relates to the field of environmental protection and product conversion, is presented.
Abstract: The invention provides a method for treating SO2 in flue gas and producing anhydrous sodium sulfite, and relates to the field of environmental protection and product conversion. The method comprises: washing and purifying flue gas, absorbing SO2 in the flue gas by using a sodium sulfite solution to generate a sodium hydrogen sulfite solution, adding a solid sodium carbonate, neutralizing to generate a sodium sulfite crystal, separating, and carrying out heating drying and packaging to obtain the anhydrous sodium sulfite product, wherein the mother liquor sodium sulfite solution returns so as to be absorbed and used. According to the present invention, with the method, the SO2 in the flue gas can be absorbed so as to make the emission gas meet the environmental protection requirement, the evaporation process is not required, and the absorbent can be converted into the valuable product having the value increment.