Showing papers on "Sodium sulfite published in 2010"

Hydrogen production via photolytic oxidation of aqueous sodium sulfite solutions.

Abstract: Sulfur dioxide (SO(2)) emission from coal-burning power plants and refinery operations has been implicated as a cause of acid rain and other air pollution related problems. The conventional treatment of SO(2)-contaminated air consists of two steps: SO(2) absorption using an aqueous sodium hydroxide solution, forming aqueous sodium sulfite (Na(2)SO(3)), and Na(2)SO(3) oxidation via air purging to produce sodium sulfate (Na(2)SO(4)). In this process, the potential energy of SO(2) is lost. This paper presents a novel ultraviolet (UV) photolytic process for production of hydrogen from aqueous Na(2)SO(3) solutions. The results show that the quantum efficiency of hydrogen production can reach 14.4% under illumination from a low pressure mercury lamp. The mechanism occurs via two competing reaction pathways that involve oxidation of SO(3)(2-) to SO(4)(2-) directly and through the dithionate (S(2)O(6)(2-)) ion intermediate. The first route becomes dominant once a photostationary state for S(2)O(6)(2-) is established. The initial pH of Na(2)SO(3) solution plays an important role in determining both the hydrogen production rate and the final products of the photolytic oxidation. At initial solution pH of 9.80 Na(2)SO(3) photo-oxidation generates Na(2)SO(4) as the final reaction product, while Na(2)S(2)O(6) is merely a reaction intermediate. The highest hydrogen production rate occurs when the initial solution pH is 7.55. Reduction in the initial solution pH to 5.93 results in disproportionation of HSO(3)(-) to elemental sulfur and SO(4)(2-) but no hydrogen production.

Photometric determination of ammonium nitrogen with the nessler reagent in drinking water after its chlorination

Abstract: The photometric procedure for determining ammonium nitrogen in the drinking water containing inorganic chloramines has been refined. The preliminary reduction of chloramines at pH 4–9 was performed by using sodium sulfite at the fixed concentration in the interval 0.1–0.2 mM. Thereafter the mixture of solutions K2HgI4 (1–2 mM) and NaOH (80–100 mM) was added and the optical density of the resultant colored solution was measured at 440 and 600 nm.

Mechanism and kinetics of sulfite-thiosulfate dissolution of gold

Abstract: Dissolution mechanisms of noble metals in aqueous solutions of sodium thiosulfate, sodium sulfite, and their mixture under standard conditions (without heating the medium) in alkali and acidic media are described. The conditions of intensifying the dissolution process are evaluated. The reaction rates are investigated. Based on the obtained data, it is concluded that it is rational to apply the sulfite-thiosulfate solvents of noble metals to recover them from concentrates under the usual conditions.

Application of alkaline sulfite pulping on corn stalks

Abstract: Alkaline sulfite pulping of corn stalks was investigated to produce supplementary pulp for corrugating board manufacture. Three pulping temperatures (125, 145, and 165°C) and five active alkali charges (10, 12, 14, 16, and 18%) were used. Cooking time at 30 minutes, Na2SO3/ NaOH ratio at 50:50, and liquor to residue ratio of 8:1 were kept constant. The highest total yield (61.9%) was reached applying the treatment combination of 125°C and 10% active alkali, and the lowest total yield (42.5%) was related to 165°C and 16% chemical. The influence of sodium sulfite/sodium hydroxide ratios was studied applying different ratios (30:70, 40:60, 50:50, 60:40, and 70:30) at constant time and temperature of 30 minutes and 145°C respectively and 14 and 16% active alkali. Pulping condition; 16% active alkali, 30 minutes time, 145°C pulping temperature and varying ratios of sodium sulfite/sodium hydroxide were selected for pulp strength evaluation. The results of handsheet evaluation indicated that 16% active alkali, 30 minutes pulping at 145oC and sodium sulfite/sodium hydroxide ratio of 50:50 is the optimum pulping condition for corn stalks. Tear, tensile, and burst indices and breaking length of this pulp were measured as 10.53 mN.m2g-1, 62.4 N.mg-1, 3.80 kPa.m2g-1, and 6.07 km, respectively.

Method for treating tail gas of thionyl chloride chlorination

Abstract: The present invention discloses a disposal method of a tail gas, which is produced from a thionyl chloride used in a chlorination reaction. The cost of the prior traditional tail gas disposal method is high because of large consumption of alkali, and a high environmental protection pressure is resulted from a plurality of finally produced waste water which contains heteroions. Firstly, the present invention uses water to absorb the hydrogenchloride of the tail gas by controlling the water consumption, and a first grade absorption obtains a concentrated hydrochloric acid, the a hydrogenchloride content of which is approximately saturated and little sulfur dioxide is contained; a second grade absorption is that water is used to process the tail gas after the first grad absorption for the second grade absorption, which is that the added water is not discharged to obtain a diluted hydrochloric acid which contains little hydrogenchloride and little sulfur dioxide, and the diluted hydrochloric acid is used as a liquid of raw material used for the first grade absorption; then the alkali or alkaline water is used to process the tail gas after the second grade absorption for a third grade absorption to absorb the sulfur dioxide in the tail gas and obtain a quite pure sodium sulfite aqueous solution. The disposal efficiency of the present invention is high, and the tail gas absorption is complete, which reduces the environmental protection pressure.

Removal of impurities in the production of crystalline sodium carbonate, bicarbonate, or sulfite

Abstract: A magnesium treatment for removing water-soluble impurities in a process for making crystalline sodium carbonate, bicarbonate, or sulfite. A waste comprising such impurities is treated with a magnesium compound to form water-insoluble matter which is removed to form a purified solution. The treatment may be performed on a solution which contains the waste and optionally dissolved calcined trona. The purified solution may be used as a feedstock to form crystalline soda ash, and/or used as a reactant to produce crystalline sodium sulfite or bicarbonate via reaction with SO2 or CO2. In preferred embodiments, the waste may comprise a purge or weak liquor, a reclaimed solid, or combinations thereof. The water-soluble impurities may be silicates and/or foam-causing organics, and the waste may contain sodium bicarbonate, sodium sesquicarbonate, and/or one or more sodium carbonate hydrates, such as decahydrate.

Thermodynamics of interaction between sulfite-thiosulfate solutions and noble metals

Abstract: The thermodynamic probability of dissolution of noble metals in aqueous solutions of sodium thiosulfate, sodium sulfite, and their mixture under standard conditions (without heating of the solution) is considered. The influence of impurities and catalysts (divalent copper, elemental sulfur, oxygen access into the solution, and ammonia) is evaluated. Theoretical calculations of reaction rates are performed. As a result of theoretical investigations, a conclusion about the usefulness of applying sulfite-thiosulfate solvents of noble metals from ores and concentrates is made.

Aliphatic series high-efficiency water reducing agent and preparation method thereof

Abstract: The invention relates to an aliphatic series high-efficiency water reducing agent and a preparation method thereof, belonging to the technical field of water reducing agent for concrete The aliphatic series high-efficiency water reducing agent is characterized in that the structure of the aliphatic series high-efficiency water reducing agent is shown as the upper formula, wherein a, b, c and d are positive integers and larger than or equal to 80, but less than or equal to 200; water and sodium sulfite are added into a reaction container, acetone is added into the reaction container to be stirred and reflowed for 30-60 minutes under the temperature below 20-40 DEG C, a formaldehyde solution with the mass concentration of 37 percent is dripped into the reaction container in the first step, the contrary dripping speed is controlled to complete dripping within1-2 hours, and then the mixture is heated to increase the temperature to 80-120 DEG C and reacted under constant temperature for 3-6 hours so as to obtain a brownish red liquid finished product with the mass concentration of 30-40 percent, namely, the aliphatic series high-efficiency water reducing agent The invention solves the problems of long reaction period and the nonuniform molecular weight distribution of reaction products in the preparation process of the prior sodium sulfite

Preparation method of cyanide-free gold sodium sulfite complex for gold plating

Abstract: The invention discloses a preparation method of a cyanide-free gold sodium sulfite complex for gold plating and belongs to the technical field of chemistry. The preparation method comprises: dissolving gold in the solution of nitric acid and hydrochloric acid prepared in a certain proportion, condensing and crystallizing at a temperature less than 100 DEG C, adding water to dissolve a crystal to prepare a chloroauric acid solution, adding a neutralizing agent water solution to the chloroauric acid solution while agitating, adjusting pH value, adding the prepared sodium sulfite water solution to the solution, agitating and mixing, preserving heat at 50-65 DEG C, continuously reacting until the color of the solution becomes colorless or yellowish, obtaining a mother liquid, filtering the mother liquid, evaporating and condensing the filtrate at 50-65 DEG C while agitating until crystalline precipitate does not appear anymore, filtering the precipitate, drying at a certain temperature, and crushing to obtain products. The invention has the advantages that the plating solution is innocuous and harmless, product purity is high and the preparation method is simple.

Chromatographic Behavior of Food Additives on Thin Layers of Titanium(IV) Silicate Ion-Exchanger

Abstract: The chromatographic behavior of acetaldehyde, o -anisidine, ascorbic acid, benzoic acid, butylated hydroxyanisole, butylated hydroxytoluene, butyraldehyde, butyric acid, cinnamaldehyde, fumaric acid, furfural, lactic acid, lauric acid, maleic acid, DL -malic acid, 1- octanol, oleic acid, propionic acid, propyl gallate, salicylic acid, sodium benzoate, sodium nitrate, sodium nitrite, sodium sulfite, sodium tartrate, sodium thiocyanate, sodium thiosulfate, sorbic acid, tartaric acid, and vitamin E has been studied on thin layers of titanium(IV) silicate ion-exchanger using several aqueous, organic, and mixed mobile phases. Rapid separations of one food additive from many other food additives, and quaternary and ternary separations are reported. The term SR F has been introduced to quantify the separating power of the adsorbent. The effect of salt concentration on R F has been studied and is discussed.

Effect of antibrowning agents on browning and intermediate formation in the glucose-glutamic acid model.

Abstract: In this study, the inhibitory effects of antibrowning agents on browning and the formation of intermediates such as 3-deoxyglucosone (3-DG) and hydroxymethylfurfural (HMF) were evaluated with a glucose-glutamic acid model for soybean paste. The initial antibrowning capacity was measured in the following order: pentasodium tripolyphosphate < citric acid and oxalic acid < cysteine and glutathione < sodium sulfite. Our data showed that antibrowning agents, such as pentasodium tripolyphosphate, citric acid, and oxalic acid, were maintained antibrowning capacities during storage at both 4 and 30 °C, respectively. However, both cysteine and glutathione was reduced with storage time, especially in the air. A marked effect of nitrogen treatment was noted for 3 of the antibrowning agents after storage in air at 30 °C in the following order: sodium sulfite < cysteine < glutathione. The formation ratio of 3-DG and HMF was higher after storage at 30 °C than at 4 °C. These compounds were produced most abundantly in the presence of sodium sulfite, and the yields were not related significantly to the degree of browning. Citric acid and oxalic acid were identified as the most effective in inhibitors of browning and intermediates, even during storage in air at 30 °C.

Method for producing sodium thiosulfate

Abstract: The invention relates to an improved process for producing sodium thiosulfate in the field of the chemical industry. The improved process uses alkali waste water deoxidized by an aromatic nitro compound sodium sulfide as a raw material and comprises the process steps of sulfur oxidization, introduction of sulfur dioxide into the alkali waste water, heat filtration, sulfur treatment, concentration,active carbon decoloration, filtration, crystallization and separation. The improved process is characterized in that the technological processes of the sulfur oxidization and the introduction of sulfur dioxide into the alkali waste water comprise the following steps: crushing solid sulfurs and then inputting the crushed sulfur into a combustion furnace; introducing air into the furnace so as toensure that the sulfur powder is oxidized into a sulfur dioxide gas; imputing the sulfur dioxide gas into a reaction kettle to react with sodium hydrate and sodium sulfide in the alkali waste water soas to generate sodium sulfite; and then obtaining the finished product of the sodium thiosulfate through the process steps of the heat filtration, the sulfur treatment, the concentration, the decoloration, the filtration, the crystallization and the separation. The process saves energy resources and reduces the cost.

Reduction treatment method for ballast water

Abstract: The present invention relates to a method for reduce treating ballast water which has been subjected to a biocidal treatment with a chlorine-based oxidizing agent or an oxygen-based oxidizing agent, by using a tablet or pellet of sodium sulfite.

Evaluation of autoclave oxidation of sulfide concentrates as applied to the subsequent sulfite-thiosulfate leaching of noble metals

Abstract: The results of investigations into the completeness of the sulfite-thiosulfate dissolution of noble metals depending on the conditions of the autoclave opening (AO) of flotation concentrates under various leaching conditions (the reagent concentration and the influence of various additions) are described. The necessity of carrying out the AO process with the complete maximum recovery using cyanidation is shown allowing for the factors that increase the content of elemental sulfur in the AO cake.

A 4-Methylumbelliferone-based Fluorescent Probe for Sodium New Houttuyfonate

Abstract: A new fluorogenic probe for sodium new houttuyfonate (SNH) was proposed. 4-Methylumbelliferyl-2,4-dinitrobenzenesulfonate (4-MUDNBS) was a nonfluorescent compound and was synthesized via the one-step reaction of 4-methylumbelliferone (4-MU) with 2,4-dinitrobenzenesulfonyl chloride. In basic media, SNH was decomposed to produce sodium sulfite, which then reacted with 4-MUDNBS to yield highly fluorescent 4-MU, hence leading to the fluorescence increase of the reaction solution. A linear correlation existed between the emission intensity and the concentration of SNH within the range from 0.5 to 15 μg·mL−1 with a detection limit of 0.15 μg· mL−1 (3δ). The effect of substituents on the benzenesulfonyl moiety of the probe is discussed, and the presence of electronegative groups is favorable for the proposed cleavage reaction.

Pantoprazole sodium freeze-drying medicinal composition for injection and preparation method thereof

Abstract: The invention relates to a pantoprazole sodium freeze-drying medicinal composition for injection and a preparation method thereof. The pantoprazole sodium freeze-drying medicinal composition for injection comprises the following components in part by weight: 1 part of pantoprazole sodium, 0.01 to 0.1 part of mannitol, 0.02 to 0.03 part of natrium adetate, 0.07 to 0.10 part of sodium sulfite and 0 to 0.1 part of sodium citrate. In the method, the stability of the solution of the pantoprazole sodium is improved, related matters of the solution of the pantoprazole sodium in the process of preparation, packaging or freeze-drying during preparation are not increased obviously, the content of the related matters is not reduced obviously; the prepared pantoprazole sodium freeze-drying powder injection is good in stability in the process of transportation and storage; solution mixed with the injection during clinical use can be placed for a long time, so that the clinical use is more convenient; and simultaneously, hidden troubles of the medication safety of patients due to the increase of impurities (related matters) and the problem of the curative effect on the patients due to content reduction are reduced greatly.

Preparation method of analytically pure sodium thiosulfate

Abstract: The invention relates to a preparation method of analytically pure sodium thiosulfate, comprising the following steps: (1) placing distilled water and sodium sulfite into a stainless steel reactor, heating for dissolving, heating the mixed solution until boiling, slowly adding sulphur powder to the stainless steel reactor, enabling the reacted mixture to boil for 2-3 hours until the solution does not show alkalinity, stopping heating, standing for 5-6 hours, and filtering to obtain solution A; and (2) heating and concentrating the solution A into 22-33 degree Be, cooling to obtain crystals, moving the crystals into a vacuum drier to dry at 30-35 DEG C, and taking out to obtain the finished product. In the method, the analytically pure sodium thiosulfate is obtained by synthetic reaction of the sodium sulfite and the sulphur powder, thus having simple process steps, easily controlled operation and high production efficiency; and the obtained sodium thiosulfate has low impurity content, thus the product can be widely applied to the market.

Double circulation double alkali method flue gas desulfurization device

Abstract: The utility model discloses a double circulation double alkali method flue gas desulfurization device which comprises an absorption circulating system and a regeneration circulating system. The absorption tower of the double circulation double alkali method flue gas desulfurization device adopts an empty tower spraying structure to reduce the parts inside the tower and reduce the possibility of scaling in the tower, which greatly improves the running safety and stability of the desulfurization device; meanwhile, the double circulation double alkali method flue gas desulfurization device adopts a circulating pump outside the tower to spray and increase the gas-liquid contact area, which has high desulfurization efficiency, reduces the smoke gas resistance, and reduces the liquid discharge and circulating liquid of slurry outside the absorption tower, saves energies, reduces running cost, and simultaneously reduces the investments on the accessory equipment like regeneration and dewatering; during the circulating process, when the concentration of sulfur dioxide in the smoke gas is changed, the volume of barren liquor (sodium hydroxide) is added into the absorption tower through adjustment to adjust the proportion of sodium sulfite, sodium hydrogensulfite and sodium hydroxide in the slurry. The double circulation double alkali method flue gas desulfurization device has stronger adaptability to the change of sulfur dioxide parameters.

Method for synthesizing drospirenone

Abstract: The invention relates to a method for synthesizing drospirenone and belongs to the field of pharmaceutical chemicals, which comprises: reacting a 3beta,5beta-dyhydroxy-6beta,7beta,15beta,16beta-imethylene-17alpha-(3'-hydroxypropyl)-androstene-17ol compound serving as a raw material in dichloromethane in the presence of dichlorodimethylhydantoin, potassium bicarbonate and crown ether, which serve as catalysts, to obtain an 3-oxo-5beta-hydroxy-6beta, 7beta,15beta,16beta-dimethylene-17alpha(spiro)butyrolactone intermediate; removing excessive oxidant by using a small amount of sodium sulfite, filtering the solution, adding a certain amount of phosphorus pentoxide into solution of dichloromethane for dehydration, adding water for washing the reaction product for one time at the end ( detected by thin-layer chromatography) of the reaction and washing the reaction product for one time with saturated solution of sodium bicarbonate; drying the reaction product with anhydrous sodium sulfate, filtering the reaction product, distilling and recovering solvent and crystallizing the solid with water solution (in a volume ratio of 3:1) of methanol; and finally, recrystallizing the obtained solid with isopropylacetate to obtain a qualified drospirenone product. The synthesis yield of the method is about 67 percent. The reaction is mild and easy to operate and consumes a small amount of organic solvent.

Preparation of 2-aminoethylsulfonic acid

Abstract: Preparation process of 2-aminoethylsulfonic acid (taurine) from ethanolamine, sulfuric acid and sodium sulfite has been studied. The process involves two steps of reactions, the first was esterification of ethanolamine (H2N-CH2-CH2-OH) with sulfuric acid to produce the intermediate product of 2-aminoethyl ester (H2N-CH2-CH2-OSO3H) which then was extended to the second step by sulfonation with sodium sulfite to produce 2-aminoethylsulfonic acid (H2N-CH2-CH2SO3H). These two process conditions were observed by varying mole ratio of reactants, temperature and time period of reactions. Taurine product was qualitatively analyzed using 1 H-NMR and LC-MS. Physical-chemical analysis were done by observing its melting point and determining its water, chloride and sulfate contents. Its melting point, water content, and sulfate content were 290 o C, 0.303%, and 3 ppm, respectively, while its chloride content was undetected. After purification, the yield of process was 25.57%.

Synthesizing process of 4-methyl sodium benzene sulphinate

Abstract: The invention relates to a synthesizing process of 4-methyl sodium benzene sulphinate, comprising the following steps of: (1) dissolving 4-methyl benzene sulfonyl chloride in methylene dichloride; (2) dropwise adding a methylene dichloride solution containing the 4-methyl benzene sulfonyl chloride, obtained in the step 1, into the aqueous solution of sodium sulfite, meanwhile dropping 10 percent of sodium hydroxide solution and controlling a system to be alkaline; (3) distilling to recover the methylene dichloride of the solvent in reaction liquid obtained in the step 2 to obtain the aqueous solution of 4-methyl sodium benzene sulphinate; and (4) cooling, filtering, washing and baking the aqueous solution of the 4-methyl benzene sulfinic acid sodium to obtain the 4-methyl sodium benzene sulphinate. In the method, the methylene dichloride solution containing the 4-methyl benzene sulfonyl chloride is directly dropwise added into the aqueous solution of the sodium sulfite, which preventsthe hydrolysis of the 4-methyl benzene sulfonyl chloride; an acid binding agent is changed into sodium hydroxide, a buffer pair formed by a reducing agent reaches the balance under alkali regulation,and the recovery rate of the solvent is improved, thereby ensuring that the production environment is cleaner and also avoiding gas emission.

Method for detecting sulfur dioxide content in shitake mushrooms

Abstract: The invention discloses a method for detecting sulfur dioxide content in shitake mushrooms, which comprises the following steps of: 1) preparing standard solution, namely preparing standard stock solution from anhydrous sodium sulfite, formaldehyde solution, NaOH solution, and deionized water, preparing the standard stock solution into the standard solution at step concentration , filtering, injecting by adopting ion chromatography, and drawing a standard curve according to the concentration and peak appearance area; 2) treating samples, namely taking dried shitake mushrooms as samples, injecting the obtained supernatant by adopting ion chromatography, substituting the peak appearance area obtained under the same peak appearance time in the step 1) into the standard curve obtained in the step 1), and obtaining sulfur dioxide content c of the injected solution; and 3) obtaining the sulfur dioxide content in the shitake mushrooms. The method for detecting the sulfur dioxide content in the shitake mushrooms has the characteristics of accurate result and convenient use.

Method of separating pyrite from copper-containing material

Abstract: PROBLEM TO BE SOLVED: To provide a method of obtaining a copper refined ore having high copper grade easily carried out by applying ore floatation without using a specific chemical or a high hazardous chemical and separating pyrite from a copper ore containing a large amount of pyrite or the copper refined ore. SOLUTION: The pyrite is separated by pulverizing the copper-containing material containing pyrite to prepare slurry, adding an inhibitor, a foaming agent and a collector and blowing air into the slurry to apply the ore floatation. In such a case, a compound containing a sulfite such as sodium sulfite or sodium disulfite is used as the inhibitor. The pH of the slurry is preferably 8-12. COPYRIGHT: (C)2011,JPO&INPIT

Fenton and fenton-like system hardening agent and usage thereof

Abstract: Fenton and Fenton-like system enhancing agent and the usage thereof are provided. It relates to a water treatment enhancer (enhancing agent) and the usage thereof. It widens water pH range of Fenton and Fenton-like system reaction. It reduces amount of Fe 2+ required for Fenton reaction. It increases rate of Fenton-like reaction. The enhancing agent is selected from sodium sulfite, lithium sulfite, potassium sulfite, magnesium sulfite, calcium sulfite, hydroxylamine hydrochloride, hydroxylamine perchlorate, hydroxylamine sulfate, hydrazine, N,N-diethylhydroxylamine, amino ethanolamine, hydroxylamine solution or N,N,N′,N′-tetrasubstituted p-phenylenediamine. The method of use of enhancing agent comprises the steps of: adding Fenton or Fenton-like system enhancing agent, an agent for enhancement and hydrogen peroxide into water subject to treatment; and mixing and allowing reaction. The enhancing agent can increase the rate of reaction for the water treatment and reduce the dosage of the agent for enhancement.

Method for preparing glyphosate by catalytic oxidation method

Abstract: This invention discloses a method for oxidizing N-(carboxymethyl)-N-(phosphonomethyl)-glycine into glyphosate by using carbon nanotubes or modified nanotubes as a novel catalyst. The method has such advantages as high reaction selectivity, no need for reductant such as ferrous sulfate or sodium sulfite, repeated use of the catalyst, high product yield, high product quality, and little mother liquor. The method can avoid the problems of low solid glyphosate yield, low quality and large wastewater discharge faced by sodium tungstate-ferrous sulfate method.

Copper-separating process of high-sulfur copper ore containing higher silicate minerals of speckstone and like

Abstract: The invention relates to a copper-separating process of high-sulfur copper ore containing higher silicate minerals of speckstone and the like. The process comprises the following steps of: using solvent naphtha No. 200 and aerofloat sodium as a collector, oil No. 2 as a foaming agent and sodium sulfite as an inhibitor; carrying out bulk floatation on chalcopyrite and easily-floating silicate minerals; adding aluminum sulfate and ferrous sulfate for inhibiting the obtained copper-silicon mixed concentrate ; and re-separating and recovering the chalcopyrite by using a shaker. By the provided copper-separating process, copper ore in ore can be effectively recovered, the easily-floating silicate minerals are floated in the copper-separating process, and the influence of the silicate minerals of speckstone and the like on the subsequent floatation and recovery of sulfurous iron ore is eliminated.

Solid oil-well cement filtrate reducer

Abstract: The invention discloses a solid oil-well cement filtrate reducer, which comprises the following components: 20 parts of 2-acrylamide-2-methylpropene sulfonic acid, 3 parts of acrylic acid, 10 parts of acrylamide, 3 parts of alkene-mixed sodium sulfonate, 4 parts of sodium hydroxide, and 60 parts of deionized water. The method for preparing the solid oil-well cement filtrate reducer comprises the following steps of: (1) adding the 60 parts of deionized water, 20 parts of 2-acrylamide-2-methylpropene sulfonic acid, 3 parts of acrylic acid, 10 parts of acrylamide, and 3 parts of alkene-mixed sodium sulfonate into a reaction kettle for dissolving; (2) adding the 4 parts of sodium hydroxide into the kettle to neutralize the pH value of the solution to 7, and maintaining the temperature below 40 DEG C; (3) raising the temperature of the mixed solution in the reaction kettle to the temperature of 45 DEG C, and adding 0.2 part of hydrogen peroxide and 0.15 part of sodium sulfite for reaction, and reacting for 4 hours at the constant temperature; and (4) performing drying, crushing and sieving with a 20-mesh sieve on the materials after the reaction, and forming white solid powder or granules, namely the solid oil-well cement filtrate reducer. The solid oil-well cement filtrate reducer has the excellent effects of resisting high temperature and salt, and has the advantages of convenient use, storage and transportation.

Method for preparing sodium sulfite by sulfur dioxide in tail gas generated by calcining molybdenum concentrate

Abstract: The invention relates to a method for preparing sodium sulfite by sulfur dioxide in the tail gas generated by calcining molybdenum concentrate; when the molybdenum concentrate is calcined by a rotary kiln, the generated tail gas is filter by a bag type dust collector, and larger granular dust is filtered out; after that, the tail gas is sent into a water scrubber by a main fan and an auxiliary fan to further purify the dust and colored substance in the tail gas; then, the tail gas is sent into a multi-stage purification tower, and the sulfur dioxide in the tail gas and alkaline liquor inside the multi-stage purification tower have chemical reaction to generate sodium sulfite solution; after being precipitated and purified, the sodium sulfite solution is treated by evaporative crystallization and centrifuge dripping; and finally, anhydrous sodium sulfite can be obtained after being dried by a drier. After the tail gas is purified, no waste liquid is generated, the water body is avoided being polluted, byproduct can be obtained, and the sulfur dioxide is fully utilized. The method has simple technique and the tail gas purification rate reaching up to 99.8%, is good in purifying effect, and changes waste into valuable, thus leading enterprises to obtain considerable economic benefit.